2012 CT and MRI Pathology

 

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M R P THOLOGY POCKET

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Medicine is an e v e ~ h n g i n g science. s new research and clinical experience broaden our knowledge changes in treatment and drug therapy are required. The authors and the publisher of 17lis work have checked with sources believed t be reliable in their fforts t o provide information 17lat is complete and generally in accord with the standards accepted at the time o f publication. However in view of the possibility of human error o r changes in med medica icall scienc sciences es neither th the e authors nor no r th the e pub publis lishe herr nor any ot7ler party who has been involved in the preparation o r publication of this work warrants that 17le information contained herein is in every respect accurate o r complete and they disclaim all responsibility for any errors o r omissions o r for the results obtained from fr om us use e of the information containe contained d in this thi s work. work. Readers are encouraged t o confirm the informa-

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Second Edition

Michaell. lirey. PhD. RTIRI. ICTI. IMRI Associate Professor Radiologic Sciences MR IICT Specializations School Df Allied Health College o Applied Sciences and SoUitlem Illinois University Carbondale Illinois

rts

Jagan M. Ailinani M D FACR Clinical Professor o Radiology and Community Medicine SoUitlam Illinois University School o Medicine Medical Diractor of Imaging Herrin Hospital Herrin Illinois

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New York Chicago San Francisco Usbon London Madrid Mexico City Milan San Juan Seoul

Singapore

New Delhi

ydnay Toronto

 

 The McGraw·HIII Companies

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Grey Michael L. CT pathology gy : a pocke pockett atlas / Michael L. Grey Jagan M. MRI patholo

ed. Ailinani.-2nd p : em. CT and MRI pathology Includes bibliographical references and index. ISBN-13: 97B.Q..07-170319-2 [alk. paper) ISBN-10: 0.07-170319-5 [alk. paper) I. Ailinani, Jagan M . II. Title. Ill. Titl Title: e: CT and MRI pathology. [DNLM: [DN LM: 1 . Tom Tomogra ography phy,, X-Ray Computed-methods-Atlases. 2. Tomography, X-Ray Computed-methods-Handbooks. 3. Magnetic Magne tic Res eson onan ance ce Im Imag agin ingg-me meth thod odss-At Atla lase ses. s. 4. Magne Magnetic tic Resonance Imaging-methods-Handbooks. W N 171 616.075722-dc23

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CONTRIBUTING AUTHORS

.Ia

II.HII ck, MD

Department of Radiology Vanderbilt University Medical enter

A1•i llriq S.rtnri liD Department of Radiology Vanderbilt University Medical enter lim L lanlllar, MD Department of Radiology Vanderbilt University Medical enter M1tt111w D. Dallb1, MD

Department of Radiology Vanderbilt University Medical enter

 

CONTENTS

PREFACE

xvii

ACKNOWLEDGMENTS PART I

Princi

f Imaging

P thalagy

1

PRINCIPLES OF IMAGING IN COMPUTED TOMOGRAPHY AND

MAGNETIC RESONANCE IMAGING

PART II.

Cantral

a r ~ a u s

Sptam

5

BRAIN

Neapl m ACOUSTIC NEUROMA

6

ASTROCYTOMA

8

BRAIN METASTASIS

12

CRANIOPHARYNGIOMA

14

EPENDYMOMA

16

GLIOBLASTOMA MULTIFORME

18

LIPOMA

2

MEDULLOBLASTOMA

22

MENINGIOMA

24

OLIGODENDROGLIOMA

26

PITUITARY ADENOMA

28

Ca•aenihll AGENESIS OF Tl iE CORPUS CALLOSUM

3

ARACHNOID CYST

32

CRAINOSYNOSTOSIS

4

DANDY WALKER SYNDROME

36

ENCEPHALOCELE

38

 

liii

ontents

HYDROCEPHALUS

40

NEUROFIBROMAffiSIS NF1l

42

TUBEROUS SCLEROSIS

Ph1ku111ta1il STURGE-WEBER SYNDROME

46

VON HIPPEL-LINDAU DISEASE

48

IIICIIIIr

lil ll

ARTERIOVENOUS MALFORMATION

50

INTRACRANIAL ANEURYSM

52

INTRACEREBRAL HEMORRHAGE HEMORRHAGIC STROKE]

54

ISCHEMIC STROKE CEREBROVASCULAR ACCIDENn

56

SUPERIOR SAGITTAL SINUS THROMBOSIS

60

De1ener1tille Dise11e ALZHEIMER DISEASE

62

MULTI-INFARCT DEMENTIA

64

NORMAL-PRESSURE HYDROCEPHALUS

66

PARKINSON DISEASE

68

le11velin•tin1 MULTIPLE SCLEROSIS

70

lnfl ctian BRAIN ABSCESS

72

CYSTICERCOSIS

74

11 111111

BRAIN HERNIATION

7B

DIFFUSE AXONAL INJURY

80

EPIDURAL HEMATOMA

82

SUBARACHNOID HEMORRHAGE

84

SUBDURAL HEMATOMA

86

SPINE

Cang1nitll ARNOLD-CHIARI MALFORMATION

90

 

l

Contents SYRINGOMYELIM-IYDROMYELIA

92

TETHERED CORD

9

Dagananti• HERNIATED DISK

96

SPINAL STENOSIS

98 100

SPONDYLOLISTHESIS

Delltelinating 104

MULTIPLE SCLEROSIS SPINAL CORDl

lnfectiaa 106

VERTEBRAL OSTEOMYELITIS umor METASTATIC DISEASE TO Tl lE SPINE

108

SPINAL EPENDYMOMA

112

SPINAL HEMANGIOMA

114

SPINAL MENINGIOMA

116

Trau•a BURST FRACTURE

120

C-1 FRACTURE

122

VERTEBRAL COMPRESSION FRACTURE

124

SPINAL CORD HEMATOMA

126

FRACTURE/DISLOCATION IC6-C7J

128

ODONTOID FRACTURE

130

V.1cular Dill lll 132

SPINAL CORD ISCHEMIA/INFARCTION

PART Ill.

Head 1nd Neck

135

I:DIIII Rihll BRACHIAL CLEFT CYST

136

umor CAVERNOUS HEMANGIOMA IORBITALJ

138

CHOLESTEATOMA IACQUIREDJ

140

 

ontents

I

GLOMUS TUMOR PARAGANGLIOMA]

142

PAROTID GLAND TUMOR BENIGN ADENOMA]

146

TllYROID

14B

GOITER

lnflctian

PERITONSILLAR ABSCESS

15

SUBMANDIBULAR SALIVARY GLAND ABSCESS

152

Sinu

MUCOCELE

154

SINUSITIS

156

li IUIII

INTI=IAOCULAR FOREIGN BODY

158

TRIPOD FRACTURE

16

PART IV. Chast and Mallliastinum 1 6 C rdilc

CORONARY ARTERY DISEASE

164

PERICARDIAL EFFUSION

166

SITUS INVERSUS

168

SUPERIOR VENA CAVA SYNDROME

17

lnflctian

HISTOPLASMOSIS LUI

172

ll

ADULT RESPIRATORY DISTRESS SYNDROME

174

ASBESTOSIS

176

BRONCHOGENIC CARCINOMA

178

BULLOUS EMPHYSEMA

18

MESOTllELIOMA

182

PLEURAL EFFUSION

184

PULMONARY EMBOLI

186

PULMONARY FIBROSIS

188

PULMONARY METASTATIC DISEASE

19

SARCOIDOSIS

192

 

l

Contents Madiaatinu HODGKIN DISE SE

194

THYMOM

196

Aarta ORTIC CO RCT TION

2

ORTIC DISSECTION

2 2

Bra eat BRE ST C NCER

2 4

BRE ST IMPL NT LE K GE

2 8

Trau

21

ORTIC TE R

DI PHR GM TIC HERNI

212

LUNG CONTUSION

214

PNEUMOTHOR X

216

P RT V

Abdaman 219 lia truiate tinal C RCINOID

22

COLORECT L C NCER

222

CROHN DISE SE

226

FREE INTFI PERITDNE L

IR

23

G STRIC C RCINOM

232

INTUSSUSCEPTION

234

ISCHEMIC BOWEL

236

L RGE BOWEL OBSTRUCTION

238

MESENTERIC

DENITIS

24

MESENTERIC ISCHEMI

242

SM LL BOWEL OBSTRUCTION

246

VOLVULUS

25

He atalliliary C VERNOUS HEM NGIOM

252

 

 iii  i

ontents CHOLEDOCHAL CYSTS

254

CHOLEDOCHOLITHIASIS

256

FATIY INFILTRATION O F Tl lE LIVER

26

FOCAL NODULAR HYPERPLASIA

262

HEMOCHROMATOSIS

264

HEPATIC ADENOMA

266

HEPATIC CYSTS

27

HEPATIC METASTASES

272

HEPATOMA

274

PIRCI IIIII PANCREATIC ADENOCARCINOMA

278

PANCREATIC PSEUDOCYST

28

PANCREATITIS

282

G11ita1rinary AGENESIS OF THE KIDNEY

284

ANGIOMYOLIPOMA

286

HORSESHOE KIDNEY

288

PERINEPHRIC HEMATOMA

29

POLYCYSTIC KIDNEY DISEASE

292

PYELONEPHRITIS

294

RENAL ARTERY STENOSIS

296

RENAL CALCULUS

298

RENAL CELL CARCINOMA

3

RENAL INFARCT

3 2

WILM TUMOR

3 4

nfection APPENDICITIS

3 6

DIVERTICULITIS

3 8

PERINEPHRIC ABSCESS

31

RENAL ABSCESS

312

TI IIUIII LIVER LACERATION

314

RENAL LACERATION

316

SPLENIC LACERATION

318

 

iii

Contents Miacallanaoua

ADRENAL ADENOMA

32

ADRENAL METASTASES

322

AORTIC ANEURYSM ISTENT-GRAFTI

324

LYMPHOMA

326

SOFT TISSUE SARCOMA

328

SPLENOMEGALY

332

PART VI. Palvia 335 ADENOMYOSIS

336

BENIGN PROSTATIC HYPERPLASIA

338

OVARIAN CARCINOMA

34

OVARIAN CYST

342

PROSTATE CARCINOMA

344

UTERINE LEIOMYOMA FIBROID UTERUS]

346

PART VII. Muaculaakalatll 351 Shaulder

HILL -SACHS FRACTIJRE

IDEFECTJ

LABRAL TEAR ROT TOR

CUFF TEAR

352 356 36

Elbow TRICEPS TENDON TEAR

Hand

364

nd Wrist

CARPAL TUNNEL SYNDROME

366

GAMEKEEPER THUMB

368

GANGLION CYST

37

KIENBOCK DISEASE

374

TRIANGULAR FIBROCARTILAGE TEAR

376

AVASCULAR NECROSIS IOSTEONECROSISJ

378

Hip

 

  ii

ontents

FEMORAL NECK FRACTURE

382

HIP OISLOCAllON

384

ANTERIOR CRUCIATE LIGAMENT TEAR

386

BAKER CYST

388

BONE CONTUSION BRUISE]

39

LATERAL COLLATERAL LIGAMENT TEAR

392

MENISCAL TEAR

394

OSTEOARTHRITIS

396

OSTEOSARCOMA

398

PATELLAR FRACTURE

4 2

POSTERIOR CRUCIATE LIGAMENT TEAR

4 4

QUADRICEPS TEAR

4 6

RADIOGRAPHIC OCCULT FRACTIJRE

41

TIBIAL PLATEAU FRACTURE

414

UNICAMERAL [SIMPLEl BONE CYST

416

n

el d

ln

eet

ACHILLES TENDON TEAR

42

BRODIE ABSCESS

424

DIABETIC FOOT

428

PERONEAL TENDON TEAR

432

SINUS TARSI SYNDROME

434

c:

r

PERIPHERAL ARTERIAL DISEASE M i ~ e e l l

436

n e a u s

EWING SARCOMA

438

BIBLIOGRAPHY

443

INDEX

445

 

PREF CE

The second edition of the T MRI Pathology: A Pocket Atlas provides prov ides notabl no tablee additions. addition s. Imag I maging ing technolog technology, y, specif specifica ically lly com puted tomography CT) and magnetic resonance imaging (MRI), has continued contin ued to advance since since the publication of the firs firstt edition ed ition which has resulted i n improved image quality. For CT, advance ments made i n image quality include the development of multide multide tector systems with increased spatial resolution and increased temporal resolution. For MRI, increased magnetic field strength, stronger magnetic gradients, gradient s, and pul pulse se sequences have improved signal-to-n signal -to-noise oise ratios ra tios and increased temporal tem poral res resolut olution. ion. I n addition to the benefits this pocket atlas provides t o tech nologists and students, many others have also benefited from the fundamental approach presented. s with the first edition, this pocket atlas is not meant to replace standard textboo textbooks. ks. Instead, it it is designed to b e a n easy-to-use reference source for a concise review o f pathology pathology.. Pertinent Pert inent text and current technology images provide a basic overview for the pathology listed within this pocket atlas. I n this edition, the number of pathologies presented has increased from 110 cases to 180 cases. The increase in the number of pathologies pathologies indicates indicates the impact the advancements made i n CT and MRI have had on the imaging community. In addition to the number of pathology been added patho logy ca case ses, s, new images have reflec ref lectt curre cu rrent nt state-of state-of-the-ar -the-art t technology i n CT and MRI.

t

better

Michael L Grey, PhD, RT R) CT) MR) Jagan M. Ailinani, MD, FACR

 

  CKNOWLEDGMENTS

developing the second edition for the T M R I Pathology: A Pocket Atlas I was very impressed with m y students excitement, support, and encouragement i n completing this project. Though many students express expressed ed their desi desire re t o help, a couple of students stand out; they are M r Paul Magarity and M r Zachary Rich. I would also like t o again acknowledge all the various people behind the publication process a t McGraw-Hill especially M r Joe Morita. H e was very helpful, encouraging, and supportive through pocket ket atlas. I would like t o extend m y out the development o f this poc appreciation t o Dr. Ailinani and especially t o Drs. Heck, Sartawi, Sandler, and Dobbs for for their th eir contri contribution butions. s. I wou would ld like to express m y many thanks to m y wife Rebecca and our children Kayla, Emily, and Megan for allowing m e the time away from home t o n

work o n this project and complete this pocket atlas. Again, many thanks t o m y Lord and Savior Jesus Christ for continuing t o bless me with lif e now 25 years ye ars afte afterr cancer. cancer. ML

To

m y wife, Uma, and children children,, Vas Vasavi avi and Hary.

JM

 

P RT

Principles of maging Pathology

 

2

P RT I Principles of Imaging Pathology

PRINCIPLES O f IM GING IN COMPUTED TOMOGR PHY

ND

M GNETIC RESON NCE IM GING

Since the initial discovery o f x-ray b y Wllhelm Conrad Roentgen on Nov Novembe emberr 8, 1895, the field of radiology has experi experienced enced two major breakthroughs that have revolutionized how we look into the patient s body. The first, computed tomography CT) came i n the early 1970s. The second, magnetic resonance imaging MRI) initia tially lly introduced intro duced i n th thee ear e arly ly 19 1980 80s. s. was ini n CT, a finely collimated x-ray beam is directed upon the patient. As the x-ray tube travels around the patient, x-rays are emitted toward the patient. A s these xx-ray rayss interact with the vari ous tissues i n the patient s body, some of the x-ra x-rays ys are atten attenuate uated d b y the tissues while others are transmitted trans mitted through the tissues and interact with a very sensitive electronic detector. The purpose o f these detectors is t o measure the amount o f radiation that has been transmitted through the patient. patient. After After the amount of radiation has been measured, the detector converts the amount of radiation received into a n electronic signal that is sent to a computer. The computer then performs mathematical calculations o n the infor mation mati on rec receiv eived ed and reconstructs the desired des ired image. This informa tion is assigned a numerical value that represents the average density of the tissue i n that resp respecti ective ve pixel/vox pixel /voxel el o f tissue. These numericall values re numerica refl flec ectt the t he patient s tissue attenuation atten uation character character istics and may be referred t o a s Hounsfield numbers, Hounsfield units (HU), o r CT numbers that range from approximately -1000 (air) to +3000 (dense bone or tooth enamel). CT uses water as its standard value and i t is assigned a Houns Hounsfield field number of 0. diagnose se a disease process, the radiologist looks for changes change s To diagno i n the nonnal density (HU) o f a n organ, a n abnormal mass, or an altered o r loss o f norm normal al anato anatomy. my. The advantages advantage s o f CT include its ability t o image patients that 1) have experienced trauma 2) are suspect t o having had a stroke, 3) are acutely ill 4) have a contraindication t o MRI, o r 5) requi require re better bette r bone detail that can efficient cient manner. n addition, since be scanned i n CT i n a quick and effi the development o f helical (spiral) C T i n the early 1990s with single-slice technology and further tec technolo hnologica gicall advances in the mid-1990s t o multimulti-slice slice imaging imaging,, CT is able t o per perfor form m volumetri volumetricc imaging quic quickly kly and generate reformatted anatomic images i n any

 

  omputed Tomography and Magnetic Resonance Imaging

3

plane (eg, sagittal o r coronal). The disadvantages of CT include 1) exposure to the radiation dosag dosage, e, 2) possible reaction to the iodinated contrast agent, 3) lack of direct multiplanar imaging, and 4) loss of o f soft-ti soft-tissue ssue contrast wh when en compar co mpared ed to t o MR MRI. MRII incorporates MR incorporates the use of a strong magnetic field field and smaller conjunction on with wit h a radiofrequency radiofr equency RF) gradie gra dient nt magnetic fields i n conjuncti signal and RF coils specifically tuned to the Larmor frequency of the proton prot on being imaged. n image is acquired i n MRI by b y placing the patien pat ientt into a strong stro ng magnetic fiel field d and applyin applying g a radi radiofre ofre quency signal a t the Larmor frequency of the hydrogen proton 42.58 MHz/T). Gradient magnetic fields are used to assist with spatial localization localization of th thee RF signal signal.. The grad gradients ients are assigned t o the tasks of slice selection, phase encoding, and freque frequency ncy encoding enco ding or reado readout ut gradient. gradient. n the magnet, the patient s hydro hydrogen gen protons align either parallel (with) o r antiparallel (against) the magnetic field. The RF signal i s rapidly turned o n and off. When the RF signal i s turned on, the protons are llipped away from from the parallel axis of the magnetic field. Once the RF is turned off, the proton begins t o relax back into the parallel orientation of the magnetic fiel fi eld. d. Duri Du ring ng the relaxation time, time, a signal from the patie pa tient nt i s being received y th thee coi coils ls and sent to the computer for image recon struction. This process i s repeated several times until unti l the image i s acquired. There are several different different types of pul pulse se sequences sequences used i n MRI to acquire patient information. These can b e grouped into proton (spin) density, and Tl-weighted and 12-weighted pulse sequences. These pulse sequences demonstrate the anatomy differently and help differentiate between normal and abnormal structures. A combinati combi nation on of these pulse sequences may be used to assist with the diagnosis. A Tl-weigh Tl-w eighted ted pulse p ulse sequence uses a sho short rt TR (repetition time) and short TE (echo time) values t o produce a high o r bright signal i n substances such as fat, acute hemorrhage, and slow-flowing blood. Structures such suc h as as cerebrospinal fluid fluid an and d simple simpl e cysts cysts may appear with a low or dark signal. n many cases, the pathologic process pro cess will appear appe ar wit with h low signal i n Tl-we Tl-weighted ighted images. A proton-density-weighted proton-density-weighted image uses long TR and short TE values to produ produce ce images base based d o n the concentr concentration ation of hydrogen hyd rogen protons i n the tissue. tissue. The bri brighte ghterr th thee area, the greater the th e concen concen tration of hydrogen protons. The darker the area, the fewer the number of hydrogen protons. protons. A T2-weighte T2-weighted d puls p ulsee sequence uses use s long lo ng TR and long TE values to obtain a high signal i n substances such as cerebrospinal fluid, simple cys cysts, ts, edema, and tumors. Structures such as fat an and d muscle will appear with low signal. Many pathologic conditions present with high signal o n T2-weig T2-weighted hted puls pu lsee seque sequences. nces.

 

4

P RT

Principles of Imaging Pathology

MRI h s seve several ral advantages such as 1) i t acquir acquires es patie pat ient nt infor infor mation matio n withou wi thoutt the use of ionizin ionizing g radiation radiation;; 2) i t pro produc duces es excel excel lent le nt soft tissue contrast; 3) i t can acquire images i n the transverse (axial), sagittal, coronal, coronal, or o r oblique (orthogonal) planes; and 4) image quality is not affected b y bone. The disadvantages primarily asso asso ciated with MRI would include: 1) n y contraindication th t would present a detrimental effect t the patient or health care personnel; 2) long scan time when compared to CT; and 3) cost. The ef effe fect ctss of o f the magnetic field field,, var varying ying grad gradient ient magnetic magnet ic fi fiel elds ds,, or the RF energy used pose the greatest harmful effects to bio medical implants th t m y b e in the th e patient pat ient s body. body. Befor Beforee entrance into the th e strong magnetic fiel field d can c an b e obtained, everyone including patients, family members, health care professionals, n d mainte nance workers must be screened for any contraindications th t m y result i n injury t themselves o r others. These m y include any biomedica biomedicall implan imp lantt o r device that is electrically, magnetically, or mechanically activated such as pacemakers, pacemake rs, cochlear cochlear implant implants, s, and an d certain types of o f intracranial intracranial aneu aneurysm rysm cli clips ps n d orbit orbital al metal metal lic foreign bodies. The contraindi con traindication cationss focus focus o n dev device icess that th at may ma y move o r undergo a torque-effect i n the magnetic field, overheat, produce of n artifact o n the image image,, o r become damaged damag ed or func func tionally altered. Most magnets used i n MRI are superconductive and the magnetic field is always on. Any ferromagnetic material (eg, 0 2 tank, wheelchairs, stretchers, scissors, etc) m y become a projectile and potentially cause n injury or death when brought into int o the magnetic environment.

 

P RT II

Central Nervous System

 

P RT

 

Central Nervous System

BR IN NEOPL SM

COUSTIC

lescriptian:

URDM n acoustic neuroma, also known as a vestibular

schwannoma, is a benign fibrous tumor that arises from the Schwar Sch warm m cell cellss covering the vestibule portion port ion of th thee eighth crani cranial al nerve. These These tumors tu mors are well wel l encapsulated, compress compress but d o not invade the nerve. Acoustic neuromas account for approximately 80 to 85 of all cerebellopontine cerebellopontine angle a ngle (CPA) tumors and make u p 10 o f all intracranial tumors.

Etialagy: There is n o known cause for this tumor. Bilateral eighth cranial nerve schwannomas are pathognomonic for neurofibro matosis type IT Acoust ustic ic neuromas neuro mas account acco unt for approximately approximate ly 5 t Epillemialagy: Aco 10 of all intracr intracranial anial tumors. The They y are the most common tumors tumor s affect aff ecting ing the cerebellop cerebellopontine ontine angle. angle. Male Maless an and d females are ar e affected equally. he average age of onset is betw between een 40 and 60 years.

Signs nd Svmptams: Sensorineural hearing loss, tinnitus, and

vertigo vertig o are common i n patients.

Imaging Characteristic•: Note: MRI is the imaging modality of choice. T • Well Well-rou -rounded nded hypoden hypodense se to isodense isodense mass o n noncontrast study. • Hyperdense with contrast enhancement. MRI

• Tl-weigh. Tl-weigh.ted ted (TlW) imaging without witho ut contras contrastt is usual usually ly isoi isoin n tense t sligh slightly tly hypointense. • Tl-w Tl-weigh. eigh.ted ted pu puls lsee sequence with contrast enhancement dem onstrates the tumor wit with h a marked ma rked enhancement. enhancement. • 1 2.2.-wei weight ghted ed im imag ages es may demonstrate a n increase (hyperintense) i n signal. • Bas Baseli eline ne imagi imaging ng following sur surgery gery sh shou ould ld inc includ ludee a precon precon trast Tl-weighted and fat-suppression postcontrast pulse sequences.

 

J

  rain Neoplasm Aalustic Neuroma

DirfiNntial liag1a1i1: Include mainly meningioma, metasta metastasis, sis, nd

paraganglioma.

Treameat: Surgery intervention i s required. the size o the acoustic neuroma, prognosis i s encouraging n d usually i s curative. Pntnllil: Depending

on

FISIRl1

the

lclulti

N1u..-1. Noncontrast

-wei }l.ted axial image n d.emonstraling round

mass t the left cerebellopon.tine

isointe nse

CP)angle.

IIIURE I. AC 111ic

le1r1

Postcon.trast Tl-weighted axial image demonstrating n intense contrast enhancing extraaxi extr aaxial al mass at the left cerebellopontine angle l o < ~ e to the left internal auditory eanal

IAq consistent with

acoustic neuroma.

n

 

P RT

 

Central Nervous System

ASTROCYTOMA lescriptian: Astrocytomas are the most commo common n primary pr imary intracra intracra

niall neoplasm. They originate from nia from the astrocysts of the brain. The subdivi divided ded astrocytoma astrocytomass into four his histol tologi ogicc grades: grades: Grade I WHO sub (circumscribed astrocytoma); rade (diffuse astrocytoma); rade III (anaplastic astrocytoma); and Grade IV (glioblastoma multiforme).

Etialagv: Unknown.

Epillemiala11: Account for approxima appr oximately tely 10 10 gliomas i n adults.

t o 30

of cerebral

Signs anll Sym

m : Typically are associated with a n increase i n pressure within the skull. May include headaches, visual prob lems, change i n menta mentall status, seizu seizures, res, and vomiting.

lm1ging C hll ll:l ll:llristi lristics: cs: Approximately two-thirds of all low grad e astrocytomas grade astrocytomas are located above the tentoriu tentorium m (suprat (supratentori entorial), al), mainly i n the frontal, temporal, and parietal lobes o f the cerebrum. CT

• Helpful when M R is contraindicated. • Appea Appearr as poor poorly ly define defined, d, homogeneous, hypodense mass without V contrast. • Enhances with IV contrast contrast;; however, cyst cys t does not enhance. • Calcifica Calcification tion se seen en i n less than 10 . • Edema and mass effect may b e seen.

MAl • T1-weighted images appear hypointense. • T2-weighted images appear hyperintense. • Tl-weighted with V contrast shows sho ws enhancement. enhancement. • Fluid atte attenua nuated ted inversion recov recovery ery (FLAIR) images show hyper intense tumor. • Edema and mas masss effect may b e seen.

Traatmant: Surgery and radia radiation tion ther therapy. apy.

Pragnasis:

hen

detected detec ted early and rem remov oved ed compl complete etely, ly, a good go od

prognos prog nosis is (5(5-yea yearr sur surviv vival al ra rate te >90 ) i s possible.

 

  rain Neoplasm

9

s l r ~ I J T I B

Axial d shows a low

FISIRE 1.11ti IICJtl

NECT o f he he

attenuation m u s

n

the left

temporal tempo ral lobe with wrrounding

edema

RII E

2 Altroqtl

shows mild

enhanc:em ent o f the

m ss which contains

necrosis

xial CECT

areas o

 

P RT II Central Nervous System

 

HIU E

I Attraqtl• Sagittal

l W image

shows an isointense IIUI. i n the left temporal lobe lo be with wit h surrounding surr ounding low signa signall edema edema

 

Brain Neoplasm

s l r ~ I J T I B

Altraqt11111 Postcontrast axial l W image s ows enhancement enhancem ent of o f the mass i n the left nCURE 4

lobe There s mass effect temporalUITO\lrlding brain with

on the

effacement o cistern

FlllURE S

the

left ambient

lltn vt••· Axial T2W

~IrUI88 e ~ wit s t h surrounding e ~ f t t e m high ~ l signal

edema

 

 2

P RT

BRAIN

Central Nervous System

MET ST SIS

Description: Brain metastasis is the metastatic spread of cancer

from a distant dist ant site site or organ t o the brai brain. n.

Etialagv: Metastatic dissemination t o the br in primarily occurs through

hematogenous spread.

EpilllemialagJ: Metastases t o the brain acco accounts unts for approximately 15 to 25 o f l l intracranial tumors. Brain metastases m y involve the supratentorial or infratentoria infratentoriall parenchyma parenchyma meninges or calvarium. Most Mos t metastases metastases t o the brain parenchyma develop b y hematogenous sp sprea read d fr from om pr prim imar ary y lung breast gastr gastrointest ointestinal inal tract kidney n d melanoma tumors. Metastases t o the calvarium m y result from breast n d prostate cancers. Metastases t o the meninges m y result from bon bonee o r br brea east st cancer. cancer.

Signs anlll Symptoms: Depending o n th thee extent of involvemen involvementt the patient may present with seizures si ns of intracrania intracraniall pressure n d loss in sensory mot motor or fun functio ction. n.

Imaging Charuteristics: MRI is more sensitive than detection detect ion of brain br ain meta metastas stasis. is.

CT

for the

MRI nd CT • Sho Show w multipl multiplee discre discrete te lesio lesions ns wi with th variable densi density ty along the gray-white matter interface. • Show m rked peripheral edema ede ma surroun sur rounding ding larger l arger lesio lesions ns.. • Postcontrast sho show w ring ring-lik -likee enhan enhancement cement o n lar larger ger lesions. MRI

• Lesions r e hypointense t o isointense t o br in parenchyma o n Tl-weighted images. • TI-weighted images show the lesio lesions ns n d surroun surrounding ding edema as hi high gh signal inten intensit sity. y. • Postco Postcontrast ntrast Tl-weig Tl-weighted hted images demonstrate the lesion lesion as as hyperintense n d the ede edema ma as hypoint hypointense. ense.

Traatment: Usually patients with wit h mult multiple iple metastatic lesio lesions ns to the t he brain are treated with radiatio radiation n therapy while patients with a single metastatic lesion m y undergo surgical removal of th lesion lesi on followed followed b y radiation radia tion ther therapy. apy.

Pragna i : Depends o n the number n d extent of metastatic lesions i n the brain n d i the patient has n y evidenc evidencee of other oth er systemic syst emic canc cancer. er.

 

  rain Neoplasm

rain Metastasis

8

n URE 1. lr i

Mltlltnil

and high signal

n

Axial T2W

image shows the left parietal mass with high central signal likely due t o necrosis matter due

to

the surrouru.iin surrouru.iing g wh whit itee

vuogmic edema.

II URE 2. Br1i1 Mllllltl1it

Posttontrut

l W coronal MR. show multiple enhanc ing lesions with surrou surrounding nding lew-signal

edema involving the gray-white junction .

white mal:b r,. and cerebellum

 

 4

P RT

Central Nervous System

CRANIOPHARYNGIOMA lescriptian: Craniopharyngiomas are benign epithelial

alwayss located i n the suprasellar regio region n th t are almost alway sional i n the intrasellar region.

tumors n d occa

Craniopharyn pharyngiomas arise from squa s quamou mouss epithelial epit helial rests Etiology: along theCranio infundibulum infundi bulumgiomas of the hypophysis o r Rathke pouch.

Epilllamialagy: These tumors have a bimodal ge distribution. More th n half occur i n children nd young adults, while the second, smaller pe k occurs i n the fifth n d sixth decade o f life. Approximately 40 o f craniopharyngiomas occur in children between the ages o f 8 n d 12 years. Males n d females r e ffected equally.

Signl and SJ

plaml: Patients m y present with visual symptoms, obstructive hydrocephalus, n d endocrin endocrinee dysfunction.

Imaging Charuteristics: Small tumors are typically wel welll circumscribed, lobulated masses, while larger masses m y b e multicystic sellaa turci turcica. ca. Cran Cranioph iopharyn aryngiom giomas as i n appearance n d invading the sell m y present with calcificati calcification on (9 (90 0 ), con contr trast ast en enhan hance ce (90 ), n d cyst cy stic ic (8 (85 5 ), n d measure between 2 n d 6 e m i n si size ze (75 ). CT

• Lobulated solid n d cyst cystic ic suprasell supr asellar ar mass. • Calcifica Calcification tion se seen en i n approximately 90 o f pediatric tumors; adults 30 t 40 . • Contrast enhancement of solid portions n d periphery.

MR

• Appearance m y be extreme extremely ly varia variable, ble, with wit h most mos t showing low signal o n Tl-weight Tl-weighted ed images images n d bright o n T2-weighted images. • Solid portio portions ns of the tumor usually enhance with contrast. • Cystic areas m y b e hyperintense o n Tl-weigh Tl-weighted ted images. • FL FLAI AIR R ima image gess ppe r with high signal.

Traatment: Surgery is most commonly performed; however, the tumors m y become so large th t they are impossible t o excise. Radiation Radiat ion therapy m y also b e used. Recur Recurrenc rencee is common.

Pragnasis: Surgica Surgicall resection followed b y radiation supports a

10-yea 10yearr survival surviva l rate r ate o f 78 .

 

  rain Neoplasm Craniopharyngioma

FI URE 1

cr

llll

5

pgiaml.

Coronal TlW MR image shows a

low-signal suprasellar mass low-signal ma ss with small sma ll focus o f increased sign signal al wi W h enhances with contrast.

FIGURE 3

n ~ l i l l l l

FIGURE 2

Cl llillll

Postcontrast TlW coronal M R

pgiaml.

T W

xi l image shows high signal within

the cystic component o f the mass. The punctate punc tate areas o f low signal are due to calcification.

FIGURE 4

Cnniop lflnti•••·

NECI shows dense calc:ili c:ations within a suprasellar mass consistent with a cranio Axial

pharyngioma

paiaml.

 

P RT

1

Central Nervous System

EPENDYMOM Description n ependymoma is n intracranial glioma which arises from the ependymal cells which line the ventricle system n d central canal o f th thee spinal spi nal cord. cord. Etialagv Unknown. EpilllemialagJ Most commonly seen i n th thee fourth fou rth ven ventric tricle. le. This i s the thi third rd most common co mmon pediatric pediat ric tumor. Posterior fossa (infr (infraten aten toria tor ial) l) ependymomas make u p approximately 10 t o 15 of all pediatric tumors affecting the CNS n d about 3 t o 5 of all intracraniall tumors i n chil intracrania children dren 1 to 6 years of age. Signs anlll Symptams vertigo.

Headaches, nausea, vomiting, ataxia,

nd

Imaging Characteristics T

• Hydrocephalus i s seen o n mo most st ca case ses. s. • Hyperdens Hyperdensee enhancement with N contrast. • Calcification, cysts, n d edema m y b e seen o n approximately 50 of cases.

MRI

• Appear Appea r hypointense t o isointense o n Tl-w Tl-weight eighted ed images. images. • Appea Appearr hyperintense o n T2-weighted images. • Appears hyperintense hyperintense with gadolinium.

Surgical al intervention t o remove as much of the tumor Treatment Surgic as possi possible ble.. Conventional radi radiation ation ther t herapy apy n d stereotactic radio surgery m y also be helpful helpful..

Prognosis 5-year surviv survival al is approximat approximately ely 50 .

 

  rain Neoplasm Epeooymama

FI

IRE1. E

Axial NECT shows a large

mas s wi mass w i th calcificat calcifications ions rising from the fourth ventricle nd extending

posteriorly. 1 he:re s also hydroc:ephal us due t obstruction of CSF flow by the mass.

FISIRE I

E1 111

m1

Sagittal T2W image shows the large irregular mass arising

from the fourth ventricle compressing thee cerebellum th cerebellum nd herniating

own

the

spinal canal There s also severe hychoc:ephalus du duee t obstruction ofCSPflow.

FIIIRE I E1 111

m1

Postcontrast n w sagittal image shows irregular enhancement of the mas mass. s.

 

 8 GLIOBL STOM

P RT

Central Nervous System

MULTIFORME

lescriptian: According to the th e WHO WH O classific classification, ation, a glioblast g lioblastoma oma

multiforme is als also o known kno wn s n astr astrocyto ocytoma ma Grade G rade IV tumor. This rapid grow growing, ing, highly malignant tum tumor or is predo predomina minantly ntly located located in the intercerebral hemispheres, though similar lesions may by

occu occur r in iextension n the brainstem, cer cerebel ebellum, lum, spinal cord.hemisphere I t spreads to It direct nd c n cross fromorone cerebral the other through connecting white matter tracts such as the corpus callosu callosum. m. Etialagy: Unknown.

Epillemialagy: The glioblastoma multiforme is the most common primary intracranial tumor. I t typica typically lly appears a ppears betwe between en 45 n d 60 years of age. Males are slightly slig htly more mor e affected th n females.

Signs and Svmptams: Pati Patients ents may present wi with th nausea n d vomit ing, headaches, papilledema, change in mental status, seizures, and speech n d sensory disturbances. Imaging Characteri tics: These tumors are located in the white matter o f the cerebral cerebral hemisphere an and d will appea app earr heterogeneous, heterogeneous, with edema n d ma mass ss ef effe fect. ct. CT

• Nodular-rim enhancemen enhancementt with necrotic tissue tiss ue center. center. • Edema is general generally ly present.

IV

contrast demonstrates a

M l

• T1-weight T1-weighted ed images pres present ent as mixed sign l intensity. • T2-weighted images demonstr te n increased signal (hyperintense) (hyperi ntense) indicating a tum t umor or n d edema. • T1T1-wei weighte ghted d contrast enhan enhanced ced images will demonstrate demonst rate nodular-rim enhance enhancement, ment, the edema, n d necrotic tissue as hypointense. Traatmant: Surgical resection i f operable), radiation therapy, n d chemotherapy are currently the methods meth ods fo forr treating treatin g glioblastoma glioblastoma multiforme.

Pragnasis: Poor prognosis. he 1-year nd 2-yea 2-yearr survival surviv al rate is approximately 50 n d 15 , respect respectively. ively.

 

  rain

Neoplasm Gliablestcm MuMarme

9

B

Pre-- A) and postcontrast llll lllnt•• Multlann1 Pre (B) axial T images show a large peripherally eclwu:ing centrally necrotic mass n the right frontal. lobe which is extending acro across ss the white matter tracts of the anterior corp corpus us callosum callosum.. Note the t he UITOUI1ding edema and mass effect resulting n midline shift. n URE 1

FIGURE 2

li1bl111:1

MlllifiMI Same patient as i n

Figure 1). T l W axial MR A) shows a n isointerule mass with low signal central necrosis and surrounding edema. Post

c

contrast T I W image (B) shows peripheral peripher al irregular enhance enhance ment. FLAIR image (C) shows high signal edema.

 

P RT

2

Central Nervous System

liPOMA lescriptian: A beni benign gn fatty tumo tumor. r. Etialagv: Unknown. th n

1

Incidence ofag less of primary Epillemialagy: a t any tumors. May appear age. e. Are usuall us ually y located i n intracranial the midline (80 -95 ).

Signs and Svmptams: Asymptomatic, usually discovered as an

incidental finding. finding. Do not increase in size.

Imaging Charactaristics: CT

• Hyp Hypode odense nse appear appearance. ance.

o not enhance with wi th contrast.

MR

• Hyperintense o n Tl-we Tl-weight ighted ed ima image ges. s. • Hypointense o n T2-weighted images images.. • Hyperintense o n T2-weighted images indicate either fat o r subacute blood. • Fat suppress suppression ion images will diffe differen rentia tiate te bet between ween fat and blood.

Traatment: N o treatment may b e required.

Pragna i : Unless the lipoma i s positioned i n a life-threatening location, loca tion, th thee patient pati ent s prognosis is unaffected.

 

  rain Neoplasm UpiJTI

nGIIIE 1 Upiiii

Axial NECT shows a

small. very-low-attenwatian mass on i n the midli midline ne consisten consistentt with w ith a lipoma.

B

ill••· n w axial A)

sagittal B) images show small high-signal-intensity masses i n both cerebellopontine angles.

FI URE 2

nd

 

P RT

 

Central Nervous System

MEDULLOBLASTOMA lescriptian

Medulloblastomas Medulloblasto mas are rapid growing, highly malig malig medullar y velum. n nt tumors arising i n the posterior medullary

Etialagv

Arise from the embryonal cell rests i n the germinative

zone of the to posterior velum, acle. midline structure th t contributes t he roof medullary the of the fourth ventri ven tricle . Thesee tumors are the most mo st common commo n posterior fos fossa sa Epilllamialagy Thes neoplasm i n pediatric patients and account for approximately 20 of all prim ry br in tumors i n the pediatric population. There There i s a bimodal bimoda l inciden incidence, ce, showing a major peak pe ak i n children between 5 n d 8 years o f age n d a second smaller pe k between 20 n d 30 years of age. Seen more commonly i n males than female t a ratio rati o of 2:1.

Signs anlll SJ

plams: Patients m y experience hydrocephalus-like

signs n d sympto symptoms ms such su ch as increased intracr intracranial anial pressure pressur e (ICP (ICP), ), ataxia, n d nystagmus, and a herniation of the cerebellar tonsils can ca n cause neck stiffness stiffness..

Imaging Charutaristics CT

• Noncontrast Noncontrast stu study dy i s hyperdense, i n the midline, displacing the fourth four th vent ventricl ricle. e. • Enhances w i t N contrast. MR

• Tl-weigh. Tl-weigh.ted ted images range rang e from from hypointense to isointense to gray gra y matter. matter. • Hyperintense o n T2-weighte T2-weighted d images.

Traatmant Methods of treatme treatment nt m y include surgery resection, radiation radiatio n therapy, therapy, an and d multiagent chemother chemotherapy apy..

Pragnasis Good t o poor prognosis depending o n the patient's age, tumor location, n d amount of tumor resected. Favorable prognostic factors factors inc include lude n age greater than th an 2 years, undis undissemi semi n ted local disease, n d greater than 75 of the tu tumo morr resected resected..

 

  rain Neoplasm Medullablestxlme

8

A FI URE 1

M

ulllllllta•a Sagittal T l W image A) shows a large

low-signal low-sig nal fourth ventricular m u s with multiple cystic areas. he solid component enhances with gadolinium B). Also note th e hydrocephalus d u e t o obstruction o CSF flow.

RliRE 2

M

IDbiiiiiiM Axial T

W image

shows hyperint hyperintense ense cyme areas within the mass.

 

 4

P RT

Central Nervous System

MENINGIOMA Description Meningiomas are the most common benign intracra

nial neoplasms, and the second most common primary tumor

affecting the central nervous syst system. em. Meningiomas are characteris tically a hard slow-growing, usually highly vascular tumor occur superior longitudinal ring mainl mainly along the t he menin gealskull vessels vesse ls and Theyy invade dura and and lead to erosion and thinsinus. themeningeal ning o f the skull. n some cases, these tumors may also grow o n the

spine.

Etialagv Arise from the meninges. E idemialogv: Meningiomas are primarily adult tumors. They accountt for approx accoun approximatel imately y 20 of all prim ry brain tumors. The pe k incidence is between 40 nd 60 years o f age. Females are slightly more ffected th n males b y a ratio of 3:2. The majority of meningiomas (90 ) are intracr intracranial, anial, and 90 of these are supratentorial.

Signs and Symptoms

The signs and symptoms a patient may present depends o n the location and size o f the tumor; however,

headaches, seizures, nausea and vomiting and changes i n mental status may be seen.

Imaging Charutaristics CT

• Noncontrast study demonstrates a slightly slightly hyperdense hyperd ense extraaxial extraaxial mass. • N contrast study demonstrates marked enhancement. • Calcification is seen i n 20 t o 25 o f cases.

MR • Tl-weighted images demonstrate a n isointense t o slightly

hypointense mass. • Tl-weighted images greatly enhance following gadolinium administration. • TI-wei TI-weighted ghted images demonstr demonstrate ate a meningioma as isoin isointense tense t o sligh slightt hypointense. hypointense.

Traatmant Surgical resection is used t o remove this benign mass. Radiotherapy may b e useful when complete surgical removal is not possible o r the meningioma recurs.

Pragnosis Completely resected resected meningiomas mening iomas provide a n excellent

prognosis with 10-year survival rate of 80

to 90 .

 

  rain Neoplasm MeningiiJTla

FIGUR 1. M1111gl111 11.

Nonoontrast r shows round, high-density mass over the con vexity o the right r ight parieta pa rietall lobe. lobe.

5

M1ll1gl1nw Post contrast r mage shows a round, markedly contra contrast-en st-enhancin hancing g mass ma ss over the t he conv convexi exity ty of the right ri ght parieblllobe.

FIGUR

2.

M1n .gi . n-we n-weight ighted. ed. axial axial M R image shows an isofn tense leftparasag leftparasagitt31 itt31 meningioma A) and postco:ntrast Tl-weighted images i n the axial B), coronal C), nd sagittal D) planes.

R IRE 3.

 

PART

2

Central Nervous System

OLIGODENDROGLIOM

Description: Oligodendrogliomas are primary gli l br in tumors. They tend t o be slow-growing solid n d calcified tumors. They are primarily found n the supratentorial white whit e matter. matter. Etialagv: Unknown. EpilllemialagJ: The These se tumors represent represen t about 5 of all intracranial gliomas and 5 of all intracranial neoplasms. Males are affected ageii however the 2:1 t o females. These tumors m y occur t any age average aver age age whe when n diagnosed is between 40 40 and 50 years.

Signs and Svmptams: Seizures headaches ch nge weakness or para paralysi lysis. s.

n

behavior

MRII is the prefer pre ferred red imaging moda modalit lity. y. Imaging Chii ICIIrillil:l: MR • • • •

T

Mass appea appears rs hypodens hypodensee with mod moderate erate swe swelli lling. ng. Calcification is com common monly ly seen. Edemaa is typically no Edem nott se seen. en. Enhancement Enhance ment wi with th N contrast is i s var variab iable. le.

MR

• Appear Appea r hypointense o n Tl-w Tl-weight eighted ed images. images. • Appear hyperintense hyperintense on 12-weighted n d FL FLAI AIR R images image s except e xcept n areas o f calcification. • Low-grade oligodendroglioma typically do does es not enhance with N contrast while n anaplastic oligodendrogl oligodendroglioma ioma does enhance. Surger gery y rad radiat iation ion therapy an and d chemotherapy. Traatmant: Sur Five-yea -yearr survival is 50 Pragna1i1: Five

.

 

  rain Neoplasm Oligodendroglioma

FlllURE

1. Glt dlldratl••· Axial

NECT shows n ill defined partially cak:ified mass with sWTOUI\ding edema i n the left frontal lobe white

matter.

FlllURE

3. Glit dlldratli••·

PoetgadolirUum l W image shows minimal peripheral enharu:ement of the mass

7

n URE A xial

2. lligl

lglia

n w mage shows a n ill-

defined mass i n the left frontal klbe that is

so:intense to the Nl'l'OUJ\d-

ing gray matter.

FllliRE 4. Gliglillll.l ltlioml. Axial FLAIR shows a heteroge:n.eous, hyperintense mass i n the left frontal lobe which is fairly well ctrc wnsaibed with some mild surrounding edema.

 

P RT

 8

Central Nervous System

PITUITARY ADENOMA

Description: Pituitary adenomas are also classified a s either func

tioning o r hormones.

n o n f u n

he

t i o n i n ~

depending o n their ability t o secrete

u n kn o w n

exact cause is however, there is a predis Etialagv: that pituitary position tumors are inherited through a n autosomal dominant tra trait. it.

Epitllemialagy: Pituitary adenomas ade nomas constitute 10 o f all intracranial neoplasms and are the most common primary neoplasm found i n the sellar region. Occur i n both male and females equally during the third and fourth decades o life.

Signs and Svmptams: Patients may present with frontal headaches,

visual symptoms, increased intracranial pressure, personality changes, seizures, rhinorrhea, and pituitary apopl apoplexy exy seconda secondary ry t o hemorrhagic hemorr hagic infarction infarction o f the adenoma.

Imaging Characteristics: Adenomas that measure less than 1 rnm are defined a s microad microadenomas enomas,, while whi le those measuring meas uring greater than 10 rnm are defined a s macroadenomas. CT

• Fo Foca call region of hypodensity withi within n th gland. • Follo Following wing contrast enhanceme enhancement nt the tumor will b e isodense t o the normal pituitary pituitar y gland. MR

• Tl-weighted images appear a s a region o f hypointensity withi within n the gland. • Tl-w Tl-weight eighted ed contrast contrast-enhance -enhanced d images appear hyperintense. • T2-weighted image imagess appear with a variable signal that is unpredictable.

Trtatmant Methods may include transsphenoidal transsphenoidal pituitary pituitar y resec tion, cryoh cryohypop ypophyse hysectom ctomy, y, pituitar pitui tary y irradiation, o r bromocriptine.

Pragna i : The patient s prognosis is ranked from fair to good,

depending o n the extent the tumor spreads outside the sella

turcica.

 

Brain Neoplasm Pituitary deniJTla

nCIRE

1 llllu lry

29

11111

Axial

l W MR shows a sellar mass that is iso:intense to the sun:ounding gray

matter.

B FlliURE

2 Pillitlry Ade•••·

xial A) and coronal B) postmntrast

im ges show hete:rogeneO\IS enhancem.en.t pituibuy macroaden.oma.

o

nW

the :mass consist consistent ent with wi th a

 

P RT II Central Nervous System

 

BR IN CONGENIT L

GENESIS OF THE CORPUS C LLOSUM

Descripat: A partial o r complet completee absence absence of the coxpus callosum. the corpus callosum i s c used by n insult th t h s occurred embryologically prior to the lOth week o f

Etiologt: Agenesis o gestation.

E•i•alliDIIIIIf: Anomalies Anomalies age agenes nesis) is) of the cor corpus pus callosum occur between 10 n d 18 weeks o gestation. Males n d females are equally affected.

Sigal atd lp1pta111: Patients m

i n m ny cases there

y present asymptomatic; however,

are developmental dev elopmental abnormalities abnormalities present.

lllaging c•aracteriltil:l: c r

n d MRl demonstrate n elevated third ventricle, noticeable separation o f the lateral ventricles, p rti l o r complete absen absences ces o the corpus callosum, n d dysplasia o f the cerebellum.

Tl llltllant: There i s n o treat treatment ment for this condition; however, conditions such s hydrocephalus m y require treatment.

th t m y o n other extenuat Depends extenuating ing drrum.sbmces Pragao1i1: b e related t o other develo developmenta pmental l abnormalities. abnorma lities.

fi URE

1. At•n••il of th1 C p11

Coron.al12W image shows agenesis o f the corpus callosum with widely spaced lateral ventricle n d continuity o the dUrd ventricle with the intememispheric sw:e. hlll11•

 

  rain Ctwlgenitel/

A

g e n ~ i s

of the Corpus CaiiDSum

B

I 1tan11il f 11 1 CCI'IIH l:lllosu•. Aldal. c r A ) and. axial T W M R (B) sho show w enlarged and a nd parallel p arallel lateral ventri ventricle cless with. a 'race car config con figura uratio tion n an and d no n o oorpu callosum. FIIURE

FI IREI. IJIIRil f till 11'11• lalla11•

Sagiltal T1 W image shows congenital ab8enc:e o the corpus callosum with radially oriented gyri nd the absence o f the dngulate gyrus.

 

P RT

3

R CHNOID

Central Nervous System

YST

Description: Arachnoid cys cysts ts are benig be nign n cerebrospinal cerebrospinal fluid filled sacs sa cs which may ma y be located located in relationship to the arachnoid mem brane. They They do not commwti commwticate cate with wit h the t he ventric ventricular ular system system.. They matic are usually congenital; however, they m y result Etialagy: from a posttraumatic posttrau or post-sur post-surgical gical event. event. Epilllamialagy: They make u p about 1 of all intracranial masses. Approximately 50 to 60 occur in the middle fossa. Males are four times more likely likely than th an females females t hav havee an arachnoid cys cyst. t.

Signs and Symptoms: Depending o n the size and location of th cyst, they may go undetected. Large cysts m y cause headaches, impairment of vision, seizures, increased collection of CSF, increased intracranial pres pressure sure IC ICP) P),, delay i n mental n d physical development, n d altered behavi behavior. or. Imaging Charuteristics:

MAland CT • Extraaxia Extraaxiall beni benign-a gn-appea ppearing ring CS CSF-f F-fil ille led d cyst cystic ic mass. • Most com common mon supratentorial supraten torial locations inc include lude:: (1) middle crania cra niall fossa; fossa; (2) parase parasellar llar cis cister terns; ns; n d (3) subar subarachnoi achnoid d space space over ov er the th e convexiti convexities. es. use d to relie relieve ve symptoms. symptoms. A shunt shu nt may be Traatmant: Surgery is used th e peritoneum. perit oneum. used t o reduce the ICP b y draining the CSF into the cysts ts are benign beni gn n d treatable. Pragna i : Good, arachnoid cys

 

Brain Ctwlgenitel Araamoid Cyst

aa

1 lruh11ill Cpt Axial NECT shows a CSF density well circumsc::ribed extraaxial fluid FISIR

c:olledWn i n the left middle cranial fossa with posterior displacement o f the left temporal lobe.

A FlliUR

B

2 Anc•n•id Cpt

xial I2W (A) and

the signal c:haract£ristic:s o the CSF.

imagess follow l W C+ B) image

 

P RT

 4

Central Nervous System

CR INOSYNOSTDSIS Description: Crainosynostosis is a congenital condition i n which one o r more of the th e cranial cranial sutures sutur es fu fuse se prematurel prematurely. y. The three most common types are: 1) scaphocephaly (sagit (sagitta tal) l) the th e most mo st common typei 2) plagiocephalyi n d 3) trionocephaly. Etialagv: Unknown. births. s. Males are affected Epilllamialagy: ccurs i n 1 out of 2000 live birth twice mor moree often th n females.

Signs and Sym tDm :

absence o f th thee soft sp spot ot (font (fontanell anelle), e), a h rd ridge along the affected suture, unusual head shape, o r abnormal head size m y b e indicators for this condition. n increase in i n the th e intracranial intracra nial pressur pre ssuree (ICP (ICP)) may m ay occu occur. r. n

Imaging Characteristics: CT

• Three-dimensional Three-dimensional imagi imaging ng is bene benefici ficial al to see bony detail. • Bo Bone ne win window dowss sho show w fusion of of sutures.

MAl • Useful for long-te long-term rm follow follow-up. -up.

Treatment: Crani Craniofac ofacial ial sur surge gery ry m y b e required. Pragna i : Depends o n the degree of this congenital condition.

 

Brain

FISII

Coogenital

CrainoSIJ lostosis

1 CniiiiJIIIItiiiL

Axial NECI shows elongation of the calvarium i n the an ero-

premature complete

pO&terior dimension and narrowing i n the transverse

fusion o f the sagittal suture.

dimension.

A

B

FillI I CniiiiJIIIIhlliL LatEral D reconstructed image (A) and

above view B) image o f the skull shows complete fusion o f the sagittal wture and elongation o f the skull i n the P dimension.

 

3

PART

Central Nervous System

DANDY WALKER SYNDROME Description Dandy-Walker syndrome i s a noncommunicating type of hydrocephalus, results from a partial dysgenesis o the vermis and a remnant fourth ventricle ventricle tha t hatt communicat communicates es with a retrocerebellar cyst that i s als also o kn know own n as as a Bla Blake ke po pouc uch h se seee the section Hydrocephalus). n atresia of the foramen of Magendie and foramina of Etialagv Luschka o f the fourth fou rth ven ventri tricle cle..

EpillemialoiJ Represent Representss approximately a pproximately 2 of all cas cases es of hydro hydro  cephalus. ccurs i n 1 per 25,000 to 30,000 births and i s usually diagnosed b y 1 year of o f age. age. Male Maless and females are equall eq ually y affected. Associated with hydrocephalus i n 80 of cases and agenes agenesis is of o f the corpus callosum i n 20 o th thee cases. cases.

Signs and Symptoms Rela Related ted to hydrocephalus an and d other assoc associ i ated ate d anomalies. anomalies.

Imaging Characteristics Appears as a massively dilated fourth fossa demonstrating hydro ventricle vent ricle expanding into the posterior fossa cephalus. Both CT and MRI images demonstrate a massively dilated fourth ventri ventricle, cle, expand expa nded ed posterior posterio r fossa fossa with a n inferior hypoplasticc vermis. hypoplasti CT

• Hypo Hy pode dens nsee CSF CSF-fi -fill lled ed space locate located d i n the posterior fossa involving the fourth ventricle. M l

• Hypointense o n T1-weighte T1-weighted d images. • Hyperintense o n T2-weighte T2-weighted d images. intervention n and shun shunting ting the t he ex exces cesss CSF into Traatmant Surgical interventio right ght atriu a trium m or o r the peritoneal peritonea l cavi cavity ty.. the ri

Prognosis Depends o n other neurologic complications; however, surgical intervention and shunting the excess CSF into the right atrium o r into the peritone peritoneal al cavity will control control the Dandy-Wa Dandy-Walker lker syndrome.

 

Brain Ctwlgenitel Dandy Walker SyndriJTle

17

FISUAE 1

D111ft WIIbr

s n•nrne xial NECT shows a large poster posterior ior fossa with a CSF densit density y cyst, hypoplastic cerebellar hemisphere , and absence of thee vermis. th

FIIURE 1 . Da•lftWIIIIIer l p d . e .

Sagittal TlW image shows a massively dilated fourth ventricle, expanded posterior fossa,. high-riding tcm:u1a and hypoplastic cerebellum.

B FlliURE I

B)

D111ft WIIbr lll•nme

show absence o

xial T2 W A ) and c:o:mrud T thee cerebellar ver th vermis mis..

W

 

P RT

 8

Central Nervous System

ENCEPHALOCElE

lescriptian: Encephaloceles result from a herniation o f the brain

o r meninges, o r both, through a skull defect. The hernia may b e a small CSF-filled meningeal sac o r a large cyst-like structure that may exceed the size o f the head. t may b e covered with skin

and o r membr membrane ane of varying varyi ng thickness, thickness, and may contain the pons, midbrain, and vermis structures. The herniated portion o f the brain bra in is nonfunctioning. nonfunctioning.

Etialagv: Results from a congenital defect o r a trauma opening i n the skull.

Epidemialagy: Newborns are mostly affected. Encephaloceles account for 10 /o t o 20% o f craniospinal malformations. The inci dence rate is approximately 1 t o 3 per 10,000. The T he skul skulll defect def ect is commonly found i n the occipital region (71 ), parietal region (10 ), and throughout the skull base (18%).

Signs

and

Svmptams: Patients may present with hydrocephalus,

developmental delay, motor weakness a n d o r spasticity, ataxia, menta me ntall retardation, retar dation, microceph microcephaly, aly, seizures, and visual problems problems..

lctaristics: cs: Imaging Chal lctaristi T

• Osseous defect is best evaluated with CT. MR

• Provides Provide s exce excellent llent delineati delineation on o f th CSF and so soft ft tissue brain components of an encephalocele.

Traatmant:

cases involving hydrocephalus, shunt s hunting ing CS CSF fro from m the brain may be necessary. n

Pragnasis: The prognosis o f fetuses with a n encephalocele is vari

able depending o n the presence of brain i n the sac sac,, hydrocephalus, and microcephaly. With brain involvement the prognosis may be quite poor.

 

Brain Ctwlgenitel Encephalocele

9

baJI aale Axial NECl shows a small amount o f brai brain n proprofiGUR

1

truding posterio posteriorly rly Chrough a midline

defect

n

the occipital bone.

B EIIIJihlllale Axial TlW A) and T2.W (B) images sh.owing herniation o f lhe br in through a defect n the posterior skull. fiGUR

I

 

4

P RT

Central Nervous System

HYDROCEPH LUS Description: Hydrocephalus i s a n enlargement o f the ventricular

system o f the brain also known i n layman terms a s water o n the brain. There are two types of hydrocephalus: noncommunicating and communicating. Hydrocephalus may result from a n excessive amount of cerebral spinal fluid production, inadequate reabsorp tion o f CSF, o r a n obstruction o f the flow o f the CSF from one o r more o f the ventricles. n the noncommunicating type o f hydrocephalus, the flow o f the cerebral spinal fluid CSF) from the ventricular system into the subarachnoid space i s obstructed b y a mass-occupying lesion, con genital narrowing o f the aqueduct o f Sylvius, o r associated with a

meningomyelocele. The communicating type o f hydrocephalus may result from a n overp roduc roduction tion of o f CSF CSF i n the choroid plexus, o r inadequate reab sorption o f CSF b y the arachno id vil villi li.. late

Dandy-Walker syndrome, a n atresia of the foramen o f Magendie results i n a n enlarged fourth ventricle. 2. Normal-pressure hydrocephalus typically affects adults with progressive dementia. 1.

n the

Etialagv: Hydrocephalus may resul resultt from: 1) a n excessive amount of CSF production; 2) inadequate reabsorption o f CSF b y the arachn ara chnoid oid villi; villi; o r 3) a n obstruction of the outflow o f the CSF rom one o r more o f the ventricles.

Epilllemialalf: This congenital defect may also b e associated with a

history o f a meningomyelocele.

Sign1 anlll SJ

plaml: Patient may present with increase i n the cir cumference o f the head, behavioral changes such a s irritability and lethargy, letha rgy, seizures seizure s and vomiting, o r a change i n appetite.

Imaging Characteristics: MRI is the better modality for the evalu ation o f hydrocephalus.

T

• Noncontrast study demonstrates enl rged ventricles hypodense). MR

images demonstrate the enlarged CSF-filled • Tl-weighted ventricles as hypoin hypointense. tense. • Tl-weighted contrastcontrast-enhanced enhanced sequence should b e performed t o rule out intracranial mass i indicated. • T2-weighted images demonstrate the enlarged CSF-filled

ventricles a s hyperintense.  

 rain Coog oge eni nittal/ H yd ydrroce oceJile Jilelu luss IN 1 t11 1 1t 

S h u n tin g

th e

the p e r i t o n e a l c a v it y .  

e x c e s s   C S F i n t o  t h e  r i g h t

trium

or in to  

Pra Pr a  nDii : G o o d ,  f o l l o w i n g s h u n t i n g p r o c e d u r e .

lllll  1 

IIJII IIJII

uL 

n -w e :i :ig g h 1 e d   a x i a l M R I  s h o w s   m a r k e d l y c illai illaie e d l a t e r a l  v e n t r i c l e s w i t h  l o w - s i g n a l CSF

RIU IURIII RIII   .  

.

6 

•••llue. ••• ue.  

x ia l 

N E C I s h o w s m a r lc e d ly d il a t e d latm la tmt1 t1  ven enttricl riclees.

h • l l • .  

1 2 w e i g h te t e d a x i a l M R I sho hows ws  

h i g h - s ig ign n a l  C S F  o f  t h e m a z k e d l y  

d i l a t e d  l a t e r a l  v e n tric l e s .  

FIIU IIUIE IE  

F 

a   l n ~ a

H pi'IIC 'IICIJI IJIIIIII IIIII II.. T IW  

a x i a l im a g e s h ow owss h ig igh h - s ig n a l CSF SF   w i t h i n m   r k e d l y  d il t e d l a t e r a l   v e n t r i c l e s   u a   r e s u l t o f  a   s h u n t   m a l f u n c t i o n   ( f l u i d J e  ea1 a1d dng ng   r o u n d  

s h u n t  i l l r i g h t p a r i e t o - o c c i pita pitall s o f t  t i s s u e s ) .

 

42

NEUROFIBROM TOSIS

P RT

Central Nervous System

F1

Description:

Neurofibromatosis type 1 NF1) i s a multisystem genericc disorder which causes tumors neurofibromas) t o grow i n generi the nervous system.

Etialagv: Hereditary. Epidemialagv: The incidence o f NF1 i s 1 i n 2500 to 400l individuals.

Sign and Svmptam : The following are diagnostic findings for NFl. • Six o r more cafe-au-lait spots light brown spots) o n the skin measuring 5 m m i n diameter i n children o r more than 15 m m i n adolescents and adults. • Two o r more neurofibromas. • Freckling i n the area o f the armpit o r groin. • Familiai history o f NFl.

lm ging Chlrll:llri li : : MRI i s the imaging modality o f choice. CT

• • • •

Bony erosion may b e seen. Hydrocephalus may b e seen. Calcification, Calcificatio n, espe especiall cially y a t the vertex, may b e seen. Demonstrate solid fusifor fusiform m and plexiform neurofibromas with attenuation values o 3 0 t o 40 HU. • Good t o evaluate the chest, abdomen, nd pelvis o NF1 patients.

MRI • Intracranial nerve sheath tumors are isointense to brain tissue o n Tl weighted and hyperintense o n T2-weighted images. • Tumors appear with a smooth margin. • Enhance with gadolinium. • Opti Opticc gliomas, most common intracranial tumor for NH1; other gliomas may b e seen i n other parts of the brain. • Large tumor may be heterogeneous.

Treatment: Surgery as needed. Pragna i : Patient usually lives a healthy li life fe;; however, however , overall overal l life expectancy may be reduced b y a s much a s 15 years mostly due to malignant tumors.

 

Brain Ctwlgenitel/ Neurofibromatosis NF1)

41

FISIIE 1. flllurall.rlll lltllll CIIF1J Axial NECI' shows a soft tissue de.asity irlfiltrati ve UlSS

o f the right orbit with moderate

exophthalmos.

A

B

FISURE 2. f111urafi•l l•t.i1 liF1J. Coronal l W image (A) show low 19ignal-intensity mass within the right orbit which bright o n T2W

images (B) consistent with a plexiform neurofibroma.

 

44

P RT

Central Nervous System

TU EROUS SCLEROSIS

lescriptian: Tuberous scle sclerosis rosis is a rare multi-system genetic genetic

disease which causes benign tumors other organs organ s of the bo body dy..

Etialagv: About

50

grow i n the br in

t

are hereditary n d

50

nd

are sporadi sporadic. c.

EpilllemialagJ: Prevalence rate is 1 i n 6 000 to 15 000 population. Most cases cases are diagnosed between the ages of 2 nd 6 years.

Signs and Stm tams:

mentall retar menta retardation dation

Characteristic findings include seizures n d aden adenoma oma sebaceum.

Imaging Charactaristics: CT

• Used t o identify tumors of the br in n d abdomen. • • • •

Shows calc calcifie ified d cortical tu tuber berss nd subependymal nodul nodules. es. Cortical Corti cal tub tubers ers seen as low-att low-attenuatin enuating g perip peripheral heral lesi lesion. on. Subependymal nodu nodules les usually found along the lateral late ral ventricles. ventricles. Tubers usu usuall ally y d o not enhance.

M l

• Tl-weighted Tl-weig hted images m y appear hyper hyperinten intense se i n infants nd hypointense in adults. • TI-wei TI-weighted ghted images m y appear hypointense i n infants n d hyperintense i n adults. • FL FLAI AIR R imag images es are good for for seeing small smal l tube tubers. rs.

Treatment: Medical care is usu usuall ally y focused o n controlling seizures. Surgic Sur gical al intervention as needed.

Pragnasis: Depends o n the severity of the symptoms.

 

Brain Ctwlgenitel Tuberoos Sclerosis

5

B

PD axial A) a n d postcont:rut l W B) contrast shows a n enh ncing left suhependymal giant cell astrocytoma i n the foramen o f Monroe and a n enhancing subependymal nodule i n the trigone o f the left lateral ventricle. nlURE 1

T1b1r111 Scllrtli

2 T1b1nn Sd1n1iL Axial FL IR shows multipl multiplee hyperinlellse cortical a n d subco subcortic rtical al nodule no duless a n d small sma ll low-signa low-signal-intensi l-intensity ty cystic lesions. IIIUR

 

P RT

4

Central Nervous System

BRAIN PH KOM TOSIS

STURGE WEBER SYNDROME

lescriptian

Sturge-Weber syndrome encephalotrigeminal angiomatosis) s a congenital disorder characterized b y localized atrophy n d calcif calcificatio ication n of the th e cerebral corte cortex x with n ipsilateral port wine-colored facial nevus i n th area of the trigeminal nerve distribution.

Etialagv Hereditary disorder attributed to autosomal dominant and an d autosomal autoso mal recess recessive ive patterns.

Epidemialagv institutions.

Incidence is 1 per 1,000 p tients in ment l

Signs anll Svmptams

Patients m y present with port-wine stain, seizure disorder, hemiatrophy, hemianopsia, mental retardation, and an d glau glaucoma. coma.

Imaging Characteristics CT

• Cerebral Cerebral atrophy m y b e seen. app ear hype hyperdens rdense. e. • Calc Calcifie ified d areas of th thee br in will appear M l

• Cerebral Cerebral atrophy is best seen o n T1-weighted images. • Lower hypointense) hypointense) signal m y be present n calci calcified fied area areass of the brain. • FL FLAI AIR R ima images ges ar aree used to demonstrat demonstratee leptomeningeal pia mater n d arachnoid) abnormality as a hyper hyperintens intensee signal. signal.

Treatment Symptomatic treatment for the above-mentioned conditions.

Prognosis

Most cases are considered t o be mild and life expec tancy is usually normal. normal.

 

  rain Ph*omato Ph*omatosis sis Stll ge·Weber Syndrome

A FIGUR

7

B

1. Stu ...w.••r tvndram1. Noncontrast c r mages o

the brain

A) a n d bone window (B) demonstrate bilateral frontal and parietal

cortical cort ical calcifications. calcifications.

A

FIGUR

2. Stu ...W.•Ir tvndrantl. Postcontrast

coronal (B) images shaw cerebral atrophy.

lW

axial A) a n d

 

48

P RT

Central Nervous System

VON HIPPEL·LIND U DISE SE domi nantt (hereditary) (hereditary) conditi condition on char char Description: n autosomal dominan acterized b y angiomas of the retina n d cerebellum, visceral cysts and an d mal malign ignanci ancies, es, seizures seizures an and d mental retard retardation ation.. Hereditar itary y disorder. disorder. Etialagv: Hered

EpilllemialagJ: Prevalence i s estimated t 1 in i n 35,0 35,000 00 to t o 40,0 40,000 00 of o f the th e population. There i s n o predilection toward males o r females.

Signs 1nd Symi IDms: Patients typically become symptomatic i n

their third o r fourth decade of life. Characterized b y retinal angiomas, angiom as, hemangioblastomas of the cere cerebell bellum um and an d spinal cord, cystic disease of th thee ki kidn dne} e} panc pancreas reas,, n d liver, and a risk of malignancy involving the kidneys, adrenal glands, or pancreas. Patients m y exper experience ience seizures an and d mental ment al retardation.

lm1ging Charutari1tic1: MR

• Tumors Tumors with within in the CNS CNS app appear ear as isoi isointen ntense se t o hypointense o n Tl-weighted Tl-wei ghted images. • T2T2-wei weight ghted ed images prese present nt the tumors s hyperintense. • Tl-wei Tl-weighted ghted image imagess with contrast demonstrate th tumor as hyperintense (the most sensitive means of detecting the CNS tumor).

Treatment:

Symptomatic treatment for the above-mentioned

conditions intervention of tumors where whe re n d appropriate. n d surgical intervention

when

degree ee of symptoms sympt oms n d i f cancer Pl'lgiDiil: Varies depending o n degr

i s detected. There is n o known cure for t is hereditary disease.

De ath Deat h is usually usu ally associated associated with wi th complication complicationss of bra brain in tumors tumo rs or renal cancer.

 

Brain Ph omatosis Von Hippel l..indau Disease

A

9

B

Di1111e xial T W A) shows a small FlliURE 1 llln Hi11Jd·Li1 hypointense nodule n d:te medial aspect of the left cerebellar hemisphere which enhanced

with co.n.trast administration n W with gadolinium B).

FIGURE 2

llln Hiii

enhancing nodule

Lil

DilliN

s seen o n a

small

sagittal TlW image with gadol gadolinium. inium. These aze likely hemangioblastomas n this patient with Von Vo n Hipp Hippel-L el-Linda indau u VHL) disease.

 

P RT

5

Central Nervous System

BR IN V SCUL R DISE SE

RTERIOVENOUS M LFORM TION

lescrildian:

n arteriov arteriovenous enous malformation (AVM i s the mos mostt com com

mon type of vascular vascular malformation malformation and is characterized b y direct artery-toarter y-to-vein vein communica communication tion wi with thou outt a n interveni intervening ng capillary capillary bed.

Etialagv: n AVM is a congenital lesion, which i s the result o f abnormal fet fetal al developme dev elopment nt a t approximately 3 wee weeks' ks' gestation. gestation. Male less gene generall rally y present during duri ng middl mi ddlee age and are EpilllemialagJ: Ma slightly more affected than females. Between 80 and 90 are located i n the cerebr cerebrum, um, 10 and 20 located i n the posterior fossa.

Signs and Svmptams: Cli Clinic nical al presentation depend dep endss o n the location

and size o f the AVM with most present between the second to 90% are and third decade o f life. By the age of 50 years, 80 symptomatic. Hemorrhage will b e present i n about 50% o f the cases. Other sympto symptoms ms include seizures and headaches.

lm1ging Chii ICtlriltics: Appears a s a collection o f worms. CT

• Isodense t o sligh slightly tly hyperdense with w ithout out contrast enhancement. enhancement. • Calcification i n 25 to 30 . • Atrophy. • Hyperdense surpentine appearing vessels with contrast enhancement. MRI

• T l and T2-we T2-weighte ighted d images demonstrate demonstrat e serpentine-appearing serpentine-appear ing vessels with signal variations (fl (flow ow void) i n the vessels vessels..

Treatment: Depends o n the age and general health of the patient. Endova End ovascu scular lar embolizati embo lization on therapy. therapy . sur s urge gery ry inte interv rven enti tiOO OOtt stereotactic stereotactic radiotherapy, o r a combination o f the above is useful i n treating anAVM.

Pragna1i1: Th Thee mortality rate is approximately 10 orrhage orrha ge is is present.

when a hem

 

Brain Vascular Disease

A

Arteriovet1ous Malformation

rteriDn•••

B

1 M l l f l r w ~ t i a l and d pos postcon tcon-Axial TlW pre A ) an trast B) enh nced im ges s ow a left froot llobe mass wit with h surrounding edema minimal peripheral enhan enhancemen cementt and Hworm*-like flow voids.

FlliUR

Amrinen111 M11farm1ti11 T2W axial image shows hyperintEnse

FlliiRE 2

edema around the mass Hworm*-like flow voids

 

P RT

5

INTR CR NI L

Central Nervous System

NEURYSM

lescriptian:

A n intracranial aneurysm aneur ysm is a localized localized dilation of a cerebral artery. The most common form is the berry aneurysm, a sacl sa clike ike outpouching outpouch ing usually usu ally arising from at an arterial junction i n circ rcle le of Wi Will llis is.. Cerebral aneur ane urys ysms ms often ru rupt ptur uree and result i n the ci

a subarachnoid subarachnoi d hemorrhage.

Etialagv: Weakening o f the arterial wall may result from hemody namic stresses. A s a n example, hypertension and atherosclerosis may restrict blood bloo d flow thus increasi increasing ng blood pressure against ag ainst a n arterial wall, stretching i t like a n overblown balloon and making t likely t o rupture. There is a n increased incidence with: polycyst polycystic ic kidn ki dney ey disease, aortic coarctation, coarctation, and family history. Incidence nce rate is slightly higher high er in women than men. Epilllemiala : Incide The peak age o f occurrence is between 40 and 60 years. Anterior circulation is affected 90 o f the time, while the vertebrobasilar circulatio circu lation n is affected on only ly 10 .

Signs and SJ plaml: Intra Intracrani cranial al aneurys aneurysms ms may go undetected

until they rupture; however, a very large nonruptured aneurysm can mimic the signs and symptoms o f a tumor. f the aneurysm ruptures, they usually present as a subarachnoid hemorrhage. Signs and symptoms may vary depending o n the location and severity of th ruptured aneurysm. Other commo common n signs signs and symp toms may includ includee headaches, headaches, nausea naus ea and vomiting, hemiparesis o r moto mo torr deficit, deficit, nuchal nucha l rigidity, rigidity, loss of consciousness, consciousness, and coma.

Imaging dChlrlcleristics: standar standard for the diagnosis Conventional of aneurysms. angiography is the gold CT

• I n patients with ruptured intracranial aneurysm, a noncontrast noncontras t study demonstrates a subarachnoid hemorrhage i n the basilar cisterns ciste rns as hype hyperden rdense se in approximately 95 of the cases. • Contrast-enhanced CT may show very large aneurysms. MR

• T l and T2-weighted images appear with variable intensities (flow void). • Magnetic resonance angi angiogra ography phy (MRA) can diagnose most largee aneurysms larg aneurys ms >5 mm).

Treatment

Surgical intervention is best accomplished b y a

small metal clip o r ligation around the neck of the aneurysm.

 

Brain Vascular Disease /Intracranial neurysm

5

Neuroradiologic interventio intervention n techniques also available available for treatment treatme nt o f intracranial aneurysms inc includ ludee Guglielmi detacha detachable ble GD GD)) coi coils. ls. PrDtnDiit: I n event that the aneurysm rupture ruptures, s, the prognosis may b e determined b y the severity o f he initial hemorrhage, rebleeding o f the aneurysm, and vasospasm.

llltn ruill Alnlll•· Computed tomographic angiography (CI A) D :reconstruction shows a large right M 1 middle cerebral artery MCA) aneurysm.

FI URE 1

A

B

xialTI W pre A) and postcontrast IIMrp• lntncrui l enhanced images show a n enhancing mass i n the region o f the B) rigbtMCA.

FIGURE 2

 

P RT I Central Nervous System

5

INTRACEREBRAL HEMORRHAGE

HEMORRHAGIC STROKE) hemorrhage rhagess IC ICH) H) occur when blood Description: Intracerebral hemor escapes esc apes from from a rup r uptu ture red d vessel vessel in the brain. from m a rupturing o f a blood vessel, usually a n Etialagv: Results fro artery, within the brain. Hemorrhagic infarcts are frequently associated with hypertension, arteriosclerosis, or a n aneurysm. Other factors may include trauma neoplasms primary o r metastases), or drug use such a s cocaine, amphetamine, and phenylpropanolamine.

Epilllemiala : Approximately 20

strokes es are a re hemorrh hemorrhagic. agic. o f ll strok

Signs and Svmptams: Patient may present with paralysis, motor

weakness, headaches, heada ches, or lo loss ss of con conscio sciousn usness ess..

moda lity of cho choice ice for the diag Imaging Characteristics: CT i s the modality nosis of a n intracranial hemorrhage. T

• • • • •

Hyperacute < 4 hours) hyperdense. Acute (24 t 72 hours) hyperdense. Early Earl y Subac Subacute ute 4 to 7 days hyperdense. Late Subacute (1 t 4 weeks) isodense. Chronic ~ 2 weeks) weeks) hypodense. hypodens e.

MR

• Acute (24

t

72 hours)

Tl-W eighted Tl-Weigh ted Imag Imagee Isointense t Hypointense Hyperintense

• Early Subacute 4 to days) • Late Subacute Hyperintense (1 to 4 weeks) • Chro Chronic nic Hypointense Hypointen se 2 weeks o r more)

T2-Weighte T2-Weig hted d Image Hypointense Hypointense Hyperintense Hypointense

Treatment: Directed at reduc reducing ing intracranial pre pressur ssuree IC ICP) P) and controlling controll ing recurrent bleeding. bleeding. Emergent surgery surge ry may be necessary remove hematoma.

t

Pragnalil: Depends on the th e location and severit severity y of o f the hemorrh hemorrhage. age.

 

Brain Vascular Disease /Intracerebral HemiJ rhage IHem IHemtn tn hagic hagic Strdc Strdcel el

llltrleal llllnl Hlmlll fllgl. Axial NBCI shows a large hyperdense region i n the right parietal lobe consistmt with acute nlURE 1

hem.o:nhage. his is sum:runded by low-attenuation cerebral edema Note the mas masss effect effect and midline

shift

C

D

•••whiJL Axial NECT image A ) shows a n acute hemorrhage i n the left posterior parietal par ietal lob lobe. e. Note the bltmting o f the left ventricle. n axial n W image B) shows this azea as isoinl ense to hypointense. TlW axial image FIGURE 2

lntnllliiPBbl ll

C) shows the blood. to b e mildly hyperintense. Gradient Echo axial M R D ) shows the blood products to b e hypoinrense.  

PART

5

Central Nervous System

ISCHEMIC STROKE ICEREBROVASCULAR ACCIDENT Description A cerebrovascular accident CVA) o r stroke occurs as a result o ischemia o r hemorrha hemorrhage. ge. Cerebral ischemia is a reduc tion i n the regional o r global blood bloo d flow t o the brain. Etialagv Thromboembolic disease, usually as a result o f athero sclerosis, is the primary cause o f ischemic cerebrovascular disease. The source o f emboli may vary and arise from arterial stenosis and occlusion occlu sion,, atherosclerotic debris debris,, o r rom cardiac sources. Emboli from fro m a cardiac source occur i n about 15 t o 20 percent o f ischemic strokes. E idemialagy: Approximately 80% t o 85% o f all strokes are ischemic. This is the third leading cause o f death among Americans following cardiovascular disease and cancer. Males are affected

approximately three times more th n female females. s. People over 65 65 ye year arss of age age are a t a great gr eater er risk. Black Black men are 1.5 1.5 times more mor e a t risk for having a stroke than white men.

Signs and Symptoms Depends o n the etiology, location o f the ischemia, and the extent of damage to the brain cells.

Imaging Chlrll tariltil l MRI i s more sensitive than

however, noncontrast CT is more efficient for the diagnosis of a n acute stroke, stro ke, to rule out hemorrhage. Ti

T

• Is useful i n establishing the presence o r absence of a hemor rhage and therefore prescribing a thrombolytic o r anticoagulant treatment. • Acute sta stage: ge: Noncont Noncontrast rast study demonstrates a hyperdense middle cerebral ar arte tel' l'JJ di disa sappe ppear aring ing basal ganglia, and loss o f insula ins ularr cortex. cortex. • Subacute stage: Demonstrates wedge shaped area o f low den sity involving both gray and whi white te matter. matter. MAl • May identify about 80% o f strokes during the initial24 hours.

• seen Acut ewithin Acute stage: sta ge: Vascul cular ar enhanc enh anceme ement nt (slow flo flow) w) sig sign n may b e with in 2 Vas after afte r ictus. hours • Subacute stage: Parenchymal enhancement may appear hyperintense o n 1'2-weighted images.

 

Brain Vascular Disease /Ischemic Stroke ICerelnvascuhr Accident

57

• Chronic Chroni c stage: Appears hypointense o n Tl weighted images and hyperintense o n 1 2-wei.ghted images. Chances o f malacia with brain volume loss. • Diffusion Diffusion-weighted -weighted ima imagin ging g DWl) i s mor moree sensitive sensitive i n showing a n infarct within a few hours, a s a n area o f increased signal. Trealllett: Depending o n the time of onset, thrombolytic therapy

may

b e helpful i f administered within the first 3 hours follow ing the initial onset o f a n ischemic stroke. Other methods of treat ment may include anticoagulant therapy such a s the use of heparin chann el blocking and warfarin o r the administration o f calcium channel

drugs. Pratnlllil: Depends o n the severity o f the stroke. There is a 50' mortality rate within the first 24 hours following a stroke. Strokes affecting the post posterior erior circulation circulation have a higher mortality rate, but usually make a better bet ter recovery than hemisp hemispheric heric strokes.

RIIAE 1

Axial n

l ~ e h • • i l l t r a b

w mage (A) shows a n

area o f low signal i n the white matter and increased signal o f the gray ma«er i n the right posterior parietal p arietal lo lobe be.. A n axial TIW mage (B) shows inaeased

signal i n this area oonsistent

with edema. FLAIR

q shows

increased signal i n the white and gray matter i n this region.

c  

P RT II Central

5

A

erwus System

B

ltchemil ltrDU The portions o f the u e r e bright o n diffusion-w diffus ion-weighkd eighkd imagi imaging ng A) A),, but this s also bright o n the apparent diffusion diffus ion coefficent AD ADC) C) m p B) consistent with wit h a subacute infarct. infarct.

FlliUR

A

2

B

a IIChl•lr: l t n b n an acute stroke the diffusion w ill b e bright A) n d th thee AD ADC C m p will b e dark B).

ncUR

 

Brain Vascular Disease /Ischemic Stroke ICerelnvascuhr Accident)

A

5

8

h e illie Str1lra Sam Samee patient patien t as i n Figure wi.lh the left MCA stroke. Shows deaeased cerebral perfusion t o this are areaa (bl (blue) ue) A). Mean Thmsit Thne is prolonged. (blue) B). I n image q Re Red d :rep :represe resents nts FlllUR

4

infarct; Green :rep :repres resent entss dte d te penumb penu mbra ra of o f threatened (at risk) ischemic brain that may potentia saved d with n intervention. potentially lly be save (see (s ee Color Insert).

A

B

5 l1dlemic Stnle NECT axial image A ) shows a hyperdense leftt MCA lef M CA There is cl ecreased attenuation i n the left MCA territory

nllUR

n

B) i n the same patient

i n the

n d lOS

...insular ribbon sign.

of the gray wi with th dlfferen.t dlfferen.tiati iation on resulting resul ting

 

P RT

 D

Central Nervous System

SUPERIOR S GITT L SINUS THROM OSIS

lescriptian: A thrombus is a blockage of the cerebral venous

sinus. The sup super erior ior sagit sagittal tal sinu sinuss 555) is most commonly affe affecte cted d followed b y the transverse n d sigmoid sinuses, cerebral vein, straight strai ght vein, n d cerebellar veins.

Etialagv: Risk factors for SSS thrombosis may be associated with trauma, tumor compression, infection, oral contraceptive use, pregnancy, n d idiopathic.

EpillemialagJ: A thrombosis is most commonly seen i n the SSS. Tendss to b e seen i n the second and third decade of life. Females are Tend slightly more m ore affe affecte cted d th n males.

Signs and Svmptams: Headaches, seizures, n d possible cerebral

infarct.

lm ging Ch ractaristics: T

• May show signs of n infarct. angiography aphy short delay fol follow lowing ing N contras contrastt injectio injection n of • c r angiogr about 60 seconds) m y b e helpful i n evaluating the cerebral venouss sinus system. venou system. • Shows ve venou nouss filling defec defect. t. MRI

• MR venogr venography aphy i s best to demonstrate a filling defect i n the • • •

555. Diffusion-weighted Diffusion-weigh ted good t o detect infar infarct. ct. Loss of signal o n T:une of Fligh Flightt TOF) images. Conventional angiography sho should uld be considered i MR i s not diagnostic.

Treatment: Anticoagulation thera therapy. py.

Pragna i : Depending o n the extent o f complications, there is a chance chan ce of dea death, th, espec especially ially i n individuals who experienced coma, change i n their men menta tall status, intracerebral hemorrhage, n d infec tion.. For the va tion vast st majority majority of patients who do not experie experience nce any an y of the above listed compli complications cations,, their the ir outlook outl ook is favorable favorable wit w ith ha full recovery.

 

Brain Vascular Disease Superior Sagittal Sinus Th IJTlbosis

A flliURE 1

1

B Su

xial (A) and sagittal the superior sagitta sagittall sinus to b e

eriar l ~ g i t l l l l i l l l l l l r l m b l l i l .

B) NECI s show the anterior aspect o

hyperde:nse.

A

B

xial (A) and sagittal B) CE CECT CT venogram venogr am shows a filling def defect ect i n the anterior superior Ngi.ttal sinus. The axial image dem01\8trate the Hempty delm sign. The sagit sagittal tal FlliURE 2

Su

eriar lltitlll

shows congestion imageior super sagittal sinus. sinus.

A IIIURE I

iln liiNm llil

o f the

cerebrall veins cerebra vein s that normally drain into

B Su

venography y shows riar l ~ g i t l l l l i l l l l i i N m b l l i l . MR venograph

lack o signal intensity i n the superior sagittal sinus o n the sagittal (A) a n d

coronal B) images.

 

P RT

 2

Central Nervous System

BR IN DEGENER TIVE DISE SE

LZHEIMER DISE SE

lescrildian: Alzheimer disease disease (A (AD) is the most mos t common dementing dement ing

disorder disor der affect affecting ing the elderly population.

Etialagv: Factors such as atrophying of th hippocampal area, genetics, brain infarcts, and traumatic head injury are associated with th thee likelihood of having AD. AD.

Epidemialagv: The prevalence for D is less than 1 before the age of 65; however, this quickly increases t o 10 of the populatio population n over the age o f 65 and between 30 t o 50 over the age of 85 years and older. There seems t o be a higher prevalence i n women than i n men.

Signs nd Svm

Patients with AD present with w ith a multif multifacete aceted d loss of intellectual abilities such a s memory, judgment, abstract thought and other higher cortical functions, and changes i n per sonality and behavior. ams:

lm ging Ch ncteristics: MRI nd

CT

• Primarily used to rule out other causes of dementia such as normal pressure pres sure hydrocephal hyd rocephalus us (NPH) (NPH).. • f used only when MRI i s contraindicated. • Dif Diffus fusee cor cortic tical al atro atrophy, phy, usuall usually y more pro promin minent ent i n the tempo ral lobe lobes. s. • Hippocampal atrophy may b e seen. • Increases i n ventricular size, sulcal size, sylvian size, and total CSF volume vol ume are seen. • MR spectroscopy (MRS) shows reduced levels of N-acetyl aspartate (NAA) and increased levels of myoinositol.

Treatment: There is n o treatment currently available to stop o r slow the deterioration o f brain cells. Pragna i : Poo Poor; r; with a n 8- t o 10-ye 10-year ar survival. survival .

 

Brain Degeoorative Disease

FIGUR

1

lzheimer Disease

I

llllll• ••r li11111 Axial

NECT NE CT shows sho ws dl.ff dl.ffus usee cerebral cerebra l atro at roph phy y wit compensatory ventricular dilatation more than expected for the patient s age. age.

A

B

nW

A) and axial FLAIR B) images shows tempo temporal-p ral-pariet arietal al atrophy a trophy n d ventricular enlugement. The inaeasecl signal i n the periventricular white matter o n the FLAIR image is due to chronic small vessel ischemic change.

FIGUR

2

A11111l••r

ill••· Coronal

 

P RT

 4

Central Nervous System

MULTI INFARCT DEMENTIA

lescriptian:

Multi-infarct dementia MID) i s the second most common form o f dem dement entia ia follo following wing Alzheimer dise disease) ase) i n people older th n 65 year yearss of age. age. MID m y lso be called vascular demen deme n tia.

Etialagv: Usually occurs s a result of a series of small strokes. strokes. Epilllamialagy: Affects approximately 40 per 100,000 population. Estimates o f 10 t 20 o f all forms of dementia are MID. Incidences o f MI MID D are higher highe r in males th n i n fem female ales. s. Individua Indi viduals ls with Africa African n descent descen t have a higher incidence th n white people.

Signs nd Symptoms: • • • • • •

Difficulty i n perfor performing ming simple tas tasks ks.. Langua Lan guage ge difficulty su such ch as recalling recalling familiar ob objec jects ts.. Confusion, Confusi on, forgetfulness forgetfulness.. Personality change. Depression, agitation, n d delusions. Withdrawa Withd rawall fro from m soc social ial cont contact. act.

Imaging Chancteristics: MR MRII is more mor e sensit sensitive ive th n CT n d is the imaging modali modality ty o f choice. CT

• Multiple cortica corticall n d subcortical lacunar lacun ar infa infarcts rcts.. MR

d subcortical lacunar •• Multiple cortical cortica l l nintensit lacun ar infarcts infa rcts. Decreased signal signa intensity y o f white matter o n. Tl-weighted images. • T2-weighted n d FLAIR images show multiple hyperintense ischemic foci i n the whi white te matter. matter.

Treatment: Treab Treabnent nent for for MID i s symptomatic.

Pragnasis: Poor.

 

  rain Degeoorative Disease

u ~ i

l n f u r c t

A RIURE 1

Dementia

5

B xial NECI' (A) and TlW

MuHi·lllflrct Dam111tia.

(B) images sho show w oonfluentperiventri oonfluentperiventricular cular low-atte low-attenuation nuation white white matter changes a nd a n old infarct involving the left subi nsular region.

A

B

Axial T W (A) a nd axial FLAIR extensive nsive c::ordluent perivenbicular white matter (B) iirulge9 show exte hyperint:ensity from prior infarcts as well as diffuse cen bral atrophy. R URE 2

M11ti•lllflrct lll•llti

RIURE

a.

Mulli·lnflrct Proton Density

(PD)-weighted axial image shows two tw o small area areass of of very low signal (SW Ceptibility

artifact)

n the pons

prior hemDl'lbage.

from

 

 

P RT

Central Nervous System

NORMAL PRESSURE HYDROCEPH LUS lescriptian: Normal-p Normal-pressure ressure hydrocephalus NPH)

i s a n idio

pathic type of communic communicating ating hydrocephal hydrocephalus. us.

Etialagv: Idiopathic. elderly ly >65 year yearss of age). age). Epillamialalf: Tends to occur i n the elder

Sign•

d Svmptaml: N P is described b y a triad of clinical characteri chara cteristic sticss which con consis sists ts of dementia, gait disturbance, and urinary incontinence. Imaging Charactaristics: T

• • • •

and MAl Dilation Dilati on of the ventricular syst system. em. Sulcal dilation. Dilation of th thee sylvian fis fissur sure. e. Diffusion Diffusi on tensor imagi imaging ng DTI) is helpful i n identifying sm ll changes i n periventricular white matter mat ter structures i n the corpus callosum and corticos corticospinal pinal motor moto r tract.

ventriculoperitoneal itoneal VP) shunting, patie patients nts Traatmant: Following ventriculoper experience ience an impr improvem ovement ent i n their gait, urinary urin ary con contro trol, l, and may exper cognitive ability.

Pragna i : f untreated, this condition w i l l worsen. Early diagnosis and an d treat tr eatmen mentt increases increases th thee chance of a good re reco cove very ry..

 

Brain Degeoorative Disease

o r m a ~ P r e s s u r e

Hydrocephalus

7

A

II URE

c Hpi ICIPIIIID. Axial NECT A), coronal T2W 1. fllll llll·l lrelluN

B), and axial T2W Q im ges show ventric:ulomegaly with rounding o the frontal horns which i s out o proportion to the sulcal enlargement.

 

P RT

 8

Central Nervous System

P RKINSON DISE SE lasc:riptian: Park Parkinso inson n disease (P (PD) D) i s a neurodegenerative disorder disorde r characterized b y progressive dementia, bradykinesia, shuffling involunt luntary ary tremors. tremors. gait, rigidity, and invo Etialagv: Unknown; however, genetic and environmental influ ences are susp suspected ected to b e involved. populati lation on ove overr 50 year yearss Epilllamialagy: Approximately 1 of the popu of age i s aff affect ected. ed. There is a genetic tenden tendency cy i n about 5 t o 10 of those thos e affected affected with PD.

Signs

Svmptams: Symptoms typic typically ally appear betwee between n 40 and 70 years of age. age. here are three thr ee characteristic signs: tremors, trem ors, rigidi rigidity, ty, m ovement ent (bradykines (bradykinesia) ia).. and slowness in movem anlll

Imaging Charac:teristic:s: CT

• Shows non nonspe specif cific ic atr atroph ophy y with enlarged venhicles and sulci. MR

• T2-weighted images show narrowing o f the substantia substan tia nigra. • MRS shows decrease i n N (N-acety (N-a cetyll aspartate) aspart ate) and a signifi cantt increase can increase i n the ratio o f lactate to NAA. • Ring-e Ring-enhancin nhancing g focu focuss with vasogenic edema is typically seen about 3 months post-radiosurgery. o n controlling the symptoms. Treatment isofocused Traatmant: New treatments focusing image-guide guided d stereo stereotacti tacticc appro approaches aches n imageinclude: (1) ablative procedu pr ocedures res (tha (thalamo lamotomy tomy,, pallidotomy, pallidotomy, and subthalamotomy); (2) deep brain stimulation (DBS); (3) restore degenerated tissue with brain grafting; and (4) gamma-knife radiosurgery.

Pragna i : Though PD is not fatal, i t does reduce the life span o f the patient.

 

Brain Degeoorative Disease Pari< Pari5 mm). • Conventional T l and T2-weight T2-weighted ed images imag es are not very useful. • Conventional angiogra angiography phy is the gold standar standard d for for the diagno sis of cerebral aneurysms. aneurysms .

Traatmant: Treat the underlying aneurysm b y placing a small metal clip o r ligation around the neck o f the aneurysm. Neuroradiologic intervention techniques available for treatment of intracranial aneurys aneu rysms ms also include GD coil coils. s. Prevent Pre vent complica complica tions o f a SAH ie, vaso vasospas spasms, ms, rebleeding, and hydrocephalus).

Prognosis: Varies depending o n the severity of the initial hemor

rhage and possibility of rebleedin rebleeding g and vasospasm.

 

  rain

rwma SJbar rwm SJbarac achnoid hnoid Hemo HemoiThag iThagee

15

FI81R l1 FI81R . lill lilll1 l1rrh111 rrh111 N a n  c  co o ntrast a x i a l r d e m o nstrate nstratess b l o o d n the b asil asilaa r c i s t e r n s s w e l l s Sy l v i an f is issure suress

F IIURE 1 .  l n t n i N II IIill

.

. 

Carotid  a rteriogr Carotid rteriograa m  de:mon  de:monstr strates ates a la r g e l o bulate d a n e u r y s m lar internal c a r o t i d arre arrerry n e catio n  

o the r its  bifur

FIGUR FIGU R

H••

3

u u n c •llli•

•· A x i a l N E 

Tshow s  

h y p e r d e n s e b l o o d  w i t h l n t h e   r i g h t  S y l v ia i a n fissure fissure  

 

8

P RT

Central Nervous System

SUBDUR L HEM TOM

lescriptian A su subd bdur ural al hemat he matoma oma (SDH (SDH)) is a coll collecti ection on of venous venou s

blood located between the dur mater and the arachnoid mem brane bra ne (subdural (subdu ral spac space) e).. A sub subdur dural al hematoma usually develops as a result of the he d hitting n immovable object. Though SDHs occur as a result of trauma, seldom are they occur th ey associated associated with a skull fracture.

Etialagv SDHs are usually the result of the he d striking n immovable objec ectt. High-speed accelera accelerationtion- or deceleratio deceleration-related n-related he d injuries could result i n the tearing of the veins betw between een th cerebral cortex and the dur l veins. May also result from birth trauma o r child abuse. havee experienced experienced blunt trauma t EpilllemialagJ Individuals who hav Howeve ever, r, symptoms sy mptoms m y no nott arise arise immedi the he d are t risk How ately. There are three time tim e intervals bet betwee ween n trau tr auma ma n d the onset of clinical symptoms. These time intervals vary from: 1) 24 to 48 hours hou rs after injury i s defined as acute; 2) between 48 48 hours hou rs n d 2 weeks s subacute; n d 3) 7 to 10 days as chronic.

Signs and Svmptams

Patients m y present with headaches, a change i n mental status, motor n d sensory deficits, increased intercranial pressure, an and d pos possibl siblee deterioration of the neur neurolo ologic gic status. for the t he diagnosis of Charactariltics CT is the preferred modality for acute SDH, whereas MRI is more sensitive for a subacute o r

chronic SDH SDH.. Subdur Subdural al hematoma hema tomass typically are cre cresce scenti nticc shaped, shape d, conforming to the contour of the cranium s inner ta tabl ble. e. They may extend exte nd into the interhemisph interhemispheric eric or o r tentorial tentorial subdu su bdural ral space. space. CT • Acute stage appe appears ars hyperdense. • Subacute stage app appear earss isodense. • Chro Chronic nic stage appear appearss hypodense. MR

• Acute stage appe appears ars hypointense t isointense o n Tl-weighted images n d hypointense o n T2-weighte T2-weighted d images. • Subacut Subacutee stage appea appears rs hyperintens hyperintensee o n Tl-weighted images n d hypointense o n T2-weighted images. • Chro Chronic nic stage app appear earss with a higher signal (intermediate) th n

CSF o n Tl-weighte Tl-weighted d images n d hyperintense o n T2-weighted

images.

 

Brain

Tr11 1mB

lbdural HematxlmB

87

A subdur l hematoma m y be dr ined through a burr hole o r require a craniotomy cran iotomy t o dr in the accumulated blood.

Tl lilll lllt:

The mortality r te for acute n d chronic subdur l hematomas r e greater th n 50 n d less th n 10 , respectively Most patients resu resume me preoperative :fund :fundio iona na1 1 status. Outcome s highly dependent o n the presurgical presu rgical neurologic neurologic status. PntnDiis

FISIRE 1

l••

• n l Ha•atl

Noncontra.st xi l c r demonstrate9 a crescentic high-density cute right sul>duzal hematoma n the right parietal n d occipital :region with m ss effect o n the right lateral ventricle n d midline shift left. t. There i s also a right frontal to the lef lobe hemato hema toma ma (intr (intracere acerebral) bral).. There ill also a fr cture o f the rig right ht fro frontal ntal bone s well s pneumocephalus.

 

P RT II Central Nervous System

 

bll Fnctlrt Bo Bone ne window windo w setting of n axial C T shows a skull fracture right frontal bone). There s air IISUR

2

pneumocephalus)

space

n the subdural

 

Brain

Tr11 1mB

89

lbdural HematxlmB

A

B

Noncontrast Tl-weighted axial A) and coronal B) MR image& delr delru)n u)n trate large bilateral, mostly high-signal, high-signal, II URE I

u

H1m1tam1

subacute subdural subdu ral hematcmas. hematcmas.

 

P RT

I

Central Nervous System

SPINE CONGENIT L

ARNOLD CHIARI MALFORMATION

lescriptian: Amold-Chiari malformation malformationss consist of a spectr spectrum um of

are characterized characterize d congenital anomalies that affect the hindbrain. They are brains instem tem medulla oblon oblongata), gata), b y a downward elongation of the bra cerebellum cerebellar tonsils tonsils), ), and the fourth ventricle into the cervical portion of the spinal cord. Amold-Chirai malformations are categorized int into o three types. n a n Arnold-Chiari Type I, the cerebellar tonsils alone are dis placed 5 to 6 mm or more below the foramen magnum. There i s no hydrocephalus involved and the fourth ventricle remains i n its no norm rmal alcord location. locatio n. A syri syringoh ngohydro ydromyeli myeliaa syri syrinx) nx)wiof cervical spinal may b e seen. This may be associated with th the Klippe Klippel-Fe l-Feil il syndrome. th e cereb cerebella ellarr tonsils and vermis of n a n Amold-Chiari JYpe ll, the fourth rth vent ventricl ricle, e, cerebellum, cerebellum, and medulla oblongata have her the fou niated down thro through ugh the foramen foramen magnum into the cervical cervical spinal canal. Obstruction of the ourth ventricle results i n hydrocephalus. This typ typee is associated with myelomeningocele and agenesis of the corpus cor pus call callosu osum. m. n Amold-Chiari Type i l l malformation is characterized by displacement of the cerebellum meninges, and sometimes the brainstem into a n encephalocele. Encephaloceles result from a herniation of the brain bra in or men mening inges, es, o r both, through a skull defect. Characteristics Characteris tics seen i n Ty Typ pe II Chirai malformations may ma y b e pres ent. t occurs i n approximately 1 i n 4000 to 5000 deliveries.

Etialagv: Though there are several theories of the cause of this malform mal formatio ation, n, the one tha thatt is generally accepted accepted is that th at the th e poste rior ri or fo foss ssaa i s too small, small, causing a herniation of the brain brai n stem and cerebellar tonsils through the foramen magnum into the upper cervical spinal spi nal can canal. al. malformationss are found more Epillemialagy: JYpe I Amold-Chirai malformation often i n adults incidentally b y MRI) than i n children children.. Ther Theree does not seem to be any gender gend er prefere preference nce..

Signl nd Svmptaml: Hydrocephalus and developmental defects

may be seen early o n i n infants. Young adults may be asymptom

atic until atic un til neurolog neurologic ic deficits deficits suc s uch h as craniocervi craniocervial al junction abnor malities mali ties eg eg,, prog progres ressive sive ataxia ataxia)) occ occur. ur.  

Spine

l l

l g e n ~ a l /

.Arnold.Chiari Malformation

8

lmagilg Chilractariltict: MRI i s the modality o choi choice ce for diagnos diagno s ing this disorder. Cl • he

effectiveness o f demonstrating this anomaly with limited due t o the bony sunoundings and axial imaging.

r

is

MRI

• T l and T2-weighted pulse sequences will demonstrate the downward herniation o the cerebellar cerebellar tonsils thro th roug ugh h the for fora a men magnum into the upper cervical canal • Associated findings m a y include syringomyelia and hydrocephalus.

Treatllelt: Surgery intervention may

decompress the posterior poste rior fos fossa. sa. Shunt placement i s used t o trea treatt hydroc hydrocephalu ephalus. s. e used t o

Pn nDiit: Depends o n the type, age o f the patient when diag

nosed, and extent o f other related developmental defects. The prognosis for infan infants ts may be worse than t han for adults.

FIIIAE 1

lrwal

: ni Mllfll llltilt. Tl-weighted. sagittal image demonstrates clownward herniation o f the cerebellar tonsil 11m1W) through the for men m gnum into the upper cervical spinal canal with compression o f the

medulla med ulla oblongata. oblongata.

 

P RT

9

Central Nervous System

SYRINGDMYELIAIIIYDRDMYELIA

lescriptian Syringomyelia refers to n y fluidfluid-filled filled cavity within

the spinal cord. A cavity i n the cord m y b e due to central canal

dilatation (hydromyelia) or a cavity eccentric t o the central canal canal (syrinx). t is diffi difficult cult to differ differentia entiate te between betwe en these two entities.

Etialagv Approximately 50 of syringomyelias are congenital (Chirai (Chi rai malforma malformation tion). ). Acquired cases cases are the result of intr intrame amedull dullary ary tumors, tumor s, trauma tr auma,, infarcti infarction, on, n d hemorrhage. n some cases there i s known wn cau cause. se. n o kno

Epilllemialalf Approximately 90 occur i n association with an Arnold-Chirai JYpe I malformation, but also m y include, myelom eningocele, basilar skull impression (platybasia), atresia o f th foramen o f Magendie, o r Dandy-Walker cysts.

Signs ilnd Symptoms

Depends o n the extent of the syrinx. The patient pati ent may m ay experience experience sens sensory ory loss loss (los (loss of pai p ain n and an d temperature), muscle atrophy (lower neck, shoulders, arms, n d hands), n d thoracic scoliosis.

Imaging Charuteristil s MRI is th diagnosis of syringomyelia.

modality of choice for the

CT

• Postmye Postmyelogram logram CT CT demon demonstrat strates es a cont contrast rast fill filled ed syrinx surrounded b y the hypodense spinal sp inal cord. cord. MR

• Signal intensity of a syrin syrinx x m y be isointense t o CSF o n Tl-weighted Tl-wei ghted ima image ges. s. • Signal intensity o f a syrinx would b e isointense to CSF o n 1 2-weighted images.

Treatment treatment.

Surgical drainage o f the syrinx i s the suggestive

Pragnasis Va Vari riab able le,, depen dep endi ding ng o n the extent of the syrinx. syrinx.

 

Spine

l l

l g e n ~ a l /

SyringtmyeliWHydromyelia

A FlliUR

9

B

1

l l r i i ~ G ~ Q e l i l

Sagittal

(A) shows TIW abnormal lowwithin the intramedullary signal signal an and d cord expi I18ion. The abnormal fluid spinal oord. i hyperintense o n the sagitta sagittall T lW image (B).

I llri1101Q11il Axial T.ZW o th cervical spin spinee shows hyperintense Buid n the spinal cord (llml'W) cOI'Isistmt with a syrinx. FlliUR

 

P RT

  14

TETHERED

Central Nervous System

ORD

lescriptian: A tethered cord is a condition

i n which the conus medullaris is prevented from from ascendin ascending g t its usual position a t the level of Ll-12. t i s tethered a t a n abnormally low position b y a

tight, short, thickened filum terminale, fibrous bands, intradural

lipoma, o r some other intrad i ntradural ural ab abno norm rmal ality ity..

Etialagv and Epidemialagy: This congenital congenital abnormality is seen see n i n neonates.

Signs 1nd Svmptams:

Patient presents with muscle weakness, abnormal lower limb reflexes, bowel and bladder dysfunction, back pain, and scoliosis.

lm1ging Chii ICIIristics: MRI i s the imaging modality o f choice for thee diagnosis of a tethered cord. th cord. MR

• Tip Tip of th thee conus medullaris is below the lev level el of o f 12. • Tl-weighted xi l sho shows ws a thicken thickened ed >2 m m i n diameter filum terminale. • he conus medullaris may b e tethered b y spi spina na bifida occ occulta ulta and/or int intradu radural ral lipo lipoma ma poster posteriorly iorly displaced b y fat), glial cells, and collagen.

Tr11lment: Surgery in infancy or early childhood is required t o preven pre ventt progressive neurol neurologic ogic defic deficit. it.

Pragnasis: Depends o n the extent of the tethered cord and the age of the you young ng child a t the time of diagnosis and treatment.

 

Spine

l l

l g e n ~ a l /

9

Tethered Cml

xial contrasted CT scan through pelvis shows ahnan:rull fat l spinal canal consistent density witrun the s with terminal lipoma.

FIGURE 1.

.dl1r1d Can1

B Sagittal T2W A)

n d oomnal oblique

n

W B) images through lumbar l umbar spine demonstrates thiclcened terminal .filum and a terminal lipoma. Note: extension of fat through spi spinal nal d.ysraphis d.ysraphism m into spinal canal. FIGURE 2.

lllnd

~

 

9

P RT I Central Nervous System

SPINE DEGENER TIVE

HERNI TED DISK

Description: herniated disk is also referred to as a ruptured o r protuded disk disk.. herniat hern iated ed disk occ occurs urs when p rt or the entire nucleus pul pulpos posus us (the soft, soft, gelatinous gelatinous,, central central portion porti on of n inter vertebral disk) is fo forc rced ed thro t hrough ugh the disk's weakened weakened or o r torn outer ring (an (annul nulus us fibrosus). fibrosus). his extruded herniated disk m y impinge upon spinal nerve roots roots as they exit from the spinal spi nal canal or o n the spinal spi nal cord itself. itself. Etialagv: Herniat Herniated ed disks m y result from severe tr um or strain, In

e related o r m y bwith to intervertebral joint degeneration. older patients degenerative degenerativ e disk disease, diseas e, min minor or trauma tr auma m y cause herniation.

Epillemialagy: About 90 of herniated disks occur i n the lum bosacral spine, with the majo majority rity of these occurring at 15-Sl, 15- Sl, n d the rest t eit either her IA-15 o r 1.3-IA. small percent of herniated disks involve the cervical spine, with the majority of these being t C5-C6 n d C6C6-C7. C7. On Only ly 1 to 2 of herniated disks occur i n the thoracic spine.

Signs and Symptoms: Pati Patients ents with wit h lumbosacral lumbosacral herniated disks w i l l present with low back pain, radiating radiat ing to the buttocks, buttocks, legs legs n d feet,, usua feet us uall lly y unilaterally. Sensory n d mot motor or loss, muscle weakness, n d atrophy of o f the leg l eg muscles muscles m y be experienced i f a lumbar spinal spi nal nerve nerv e root is compre compressed. ssed. Cervica Cervicall disk dis k herniations presen pre sentt with p in i n the neck n d upper extremities n d weakness, n d neurologic deficit deficits, s, such suc h as muscle spasms, spasm s, numbness, numbnes s, n d tingling are common symptoms.

Imaging Chilrilcteristics: s a result of excelle excellent nt soft tissue res resolu olu tion n d multiplanar imaging, MRI is the imaging modality of choicee for diagnosing choic diagno sing herniate her niated d di disc sc.. nd CT • Demon Demonstra strate te disc degeneration. • Hern Herniat iated ed dis discc usuall usually y laterized t o one side sid e compressing compressing the

MRI

thecal sac n d nerv nervee root. • Free disc fragments m y migrate super su perior iorly ly or o r inferi inferiorl orly. y.

 

Spine

egenerative Herniated isk

9

Conservative treatment consists o f bed rest heat exer cise and medication ranging from anti-inflammatory drugs t o muscle relaxants. Patients not responding t o conservative treat ment may require surgical intervention. INilll lllt:

PntnDiit: Prognosis i s very mixed dependent o n the severity of damage the quali quality ty and skill o f smgical intervent intervention ion the age size and weight of the patient and whether there i s a physically physica lly active

o r 5ed 5edenta entary ry lifestyle lifestyle..

niiRE 1. lllniltld llilc. TI-weighted sagittal MR image shows hemiawd disc a t the 15-Sllevel.

FI IRE 2. HIL'IIilt

Dilc.

TI-weighted axial MR image demonstrates right 11ided

FI IIE 3. H niltM Dill:. T2W sagittal MR of lS-Sl

herniated disk a t the 15-Sllevel compressing the right side o f the thecal sac nd nerve :root.

verify disc bulge. End-plate hyperintensity about this clliJc space was degenerative.

 

P RT

9

Central Nervous System

SPIN L STENOSIS lescriptian: Spinal stenosis

m y b e defined s the narrowing o f the spinal canal n d lateral recesses s a result of progressive degenerative disease of the disk, bone, n d ligament. Problems arise when the spinal can canal al n d cord is i s cons constrict tricted. ed. Mostly involves

the cervical n d lumba lumbarr spi spine. ne.

Etialagv: Spinal stenosis m y b e categorized s either congenital developmental) o r acquired. Congenital spinal stenosis m y be due to achondroplasia o r anomaly, o r m y b e idiopathic. Acquire Acquired d central spinal stenosis m y result from several manifestations including degenerative disk disease, ligamentum flavum hypertrophy, spondylolisthesis, spondylolisthesis, bulging bulgin g disk, n d trauma. Epilllemiala : Most commonly found i n the cervical n d lumbar spine.

nd Svmptaml: hen the cerv cervica icall porti p ortion on o f the spine is involved, the patient m y present with a radiculopathy, r adiculopathy, myelop myelopaathy, o r neck o r shoulder pain. f the lumbar spine s pine is af affe fect cted ed,, the patient m y present with a limping type of gait neuro neurogenic genic o r spinal claudication), low back pain, o r paresthesia of the lower extremities.

Sign

Imaging ChlractariltiCI: MRI is the modality o f cho choice ice for diagno d iagnossing spi spinal nal sten stenosis osis.. r follo following wing myelography myelograph y would b e the next bestt choice bes choice for imaging spinal s pinal stenosis.

MAland • • • • •

CT

Narr owing of th spi Narrowing spinal nal canaL canaL latera l aterall recess, recess, n d neur neural al foramen. foramen. Bulging Bulgi ng discs. Hyper Hyp ertr troph ophy y of face facett joints n d ligamentum flavum flavum.. Spondylolisthesis. Compression o f the thecal sac n d ner nerve ve roots.

Traatmant: Surg Surgical ical intervention interve ntion m y b e considered.

Pragnasis: This con condit dition ion is progressive. progressive.

 

Spine

egenerative Spinal Stenosis

A

99

B S iHIIte•lit. Sagittal c r A) and T2 MR

fi URE 1

B) images

cervical cal spine demonstrate multi-level disc bulge bulgess most through the cervi notable

t

C5-C7, causing moderate canal stenoel.s.

 

  DD

P RT

Central Nervous System

SPON YlOLISTHESIS lelc:ri tian: Spondy Spondylolisthes lolisthesis is is the th e displacement displacemen t o r slippage, either anteri anterior or o r poster posterior, ior, of a vertebra vert ebra over o ver a n inferi inferior or vertebra verteb ra (usually the fifth lumbar verteb vertebra ra over the sacrum, sacrum, or the fourth lumbar vertebra over the fifth), causing a misalignment of the vertebra vert ebrall column. Ty Type pe I involves a 25 vert vertebra ebrall disp displacem lacement ent over the vertebra that i s immediately inferior t o it it,, Type II a 50 vertebral displacement, and Type III a 75 percent vertebral displacement over the inferior vertebra Typ Typee IV involves involv es anything over a 75 percent vertebral displacement over the inferior vertebra

Etialagv: Spondylolisthesis may result from acute trauma, con genital or acquired fibrous defects i n the pars interarticularis (spondyl (spo ndylolys olysis), is), or as a resul r esultt of spinal spin al instability due t degenera tive changes involving involving th thee disk dis k and face facett joints. joint s. EpillamialagJ: Spondylolisthesis occurs i n 60 of patients with spondylolysis, which occurs i n approximately 5 of the population. The L5-Sl interspace accounts for 90 o f the cases of cases being anterior anterio r spondylolisthesis, with the majority o f those cases displacement displace ment of o f the L5 vertebra vertebra.. The L4-L5 inte interspac rspacee accounts accounts for approximately 10 o f spondylolisthesis cases, with most involv ing anterior slippage of L4 vertebra. Cervical spondylolisthesis comprises less than 1 of all al l cases.

Signl and Symptam : Patients may present with low back

pain

and/ o r stiffness and loss of functio function. n. Tig Tight ht hamst hamstrings rings may force

the patient t walk with th thee knees bent and a short stride, causing causing poor posture o r unusual gait.

Imaging Charac:tari tic : Plain films films are a re usual usu ally ly sufficient sufficient t make the diagnosis. CT • Sagittal Sagittal reformatted images demonstr demonstrate ate a shifting of a vertebra over a n inferior vertebra vertebra.. • Shows pa pars rs interart interarticularis icularis defe defects cts (spondyl (spondylolysis). olysis). MRI

• Shows forward slippage o f one vert vertebra ebra over ano anothe ther. r. Best seen o n a sagittal sagitt al image. • Shows ot othe herr associated finding findingss (eg, (eg, degenerative disk disease

and spi spinal nal sten stenosis osis). ).

 

Spine

egenerative Spondylolisthesis

101

Conservative treatment i s usually initia Conservative initiated ted to treat the patient's symptoms. Surgery m y b e indicated i n symptomatic patients who d o not respond t o conservative treatment. INilll lllt:

PntnDiis

findings.

May v ry depending o n the type n d othe otherr assoc associated iated

FI IAE 1. l••nllflliltllelil

111•1

I.

Sagit131 Tl-weighted MR. image o the lumb r spine demonstrate mild forward displacement o f the L4 vertebral body over LS. This s consistent with gr de I spondylolisthesis. spondylolis thesis. Degenerative change of L4 L5 and 1.5 Sl disc. noted.

 

P RT II/ Central Nervous System

n•RE 2 IJIDftQIIiltllllil 11 II Tl weig weighted hted sagi sagittal ttal image demonstrates a forward displacement o the L vertebral body over S l consistent with a grade grad e n spondylolisthesis. Note Note:: the degenerative ch nges o f the 1 5 S l disk.

 

Spine I egenerative I Spondylolisthesis

A IICURE I

1 1

B

Spalilllolilnllnil Sagittal C T (A (A)) demonstrates traumatic

( IYpe 4} anterolisthe.sis of C o n J wit bilateral jumped facets not shown). Sagittal T2W MR. (B) shows anterolisthesis and extensive ligamentous/soft tis Jile injury.

 

P RT

  D4

Central Nervous System

SPINE DEMYELINATING

MULTIPLE

S LEROSIS

SPINAL CORD)

lescriptian

Multiple sclerosis MS) is a demyelinating disease affecting affecti ng the th e spina spi nall co cord rd (s (see ee the th e section Brain, Multiple Multip le Scle Scleros rosis) is).. The areas o f demyelin demyelination ation are commonl commonly y referred to as plaques plaques.. Multiple sclerosis may go through periods o f exacerbation n d remission.

Etialagv The exa exact ct cause of multiple multi ple scl sclero erosis sis is unknow unk nowni ni how h ow ever, theories suggest a slow-acting viral infection n d n auto immune response. Other theories suggest environmental nd genetic factors.

Epilllemialalf Multiple sclerosis commonly involves the spinal cord. Rarely is M S seen i n children n d older adults. Females are slightly mor moree affected affected th n males. pre sents with wi th fo foca call neurol neurologic ogic attacks, attacks, Signs and Symptams Patient presents

progressive deterioration, n d ultimately permanent neurologic dysfunction. Other complications include sensory n d motor dysfunction.

Imaging Characteristics MRI is the imagi imaging ng modality o f choice for thee diagnosis of multiple scle th sclerosi rosiss in i n the spin s pinal al cord. cord. MRI • Tl-w Tl-weight eighted ed imag images es are useful useful to evaluate the spinal cord morphology. • 1'2-wei 1'2-weighted ghted images demo demonstr nstrate ate th thee M S plaque as high signal. • Postco Postcontrast ntrast Tl-wei Tl-weighted ghted images demonstr demonstrate ate enhancement of active M S plaques. • FL FLAI AIR R image imagess imp improv rovee M S plaque detection b y suppressing signall near nea r the spinal cord. cord. CSF signa There The re is n no specif cific ic treatm tre atment ent forr,MS. Traatment • Corticosteroids d spe other drugs, howeve however, are used t o treat the symptoms. • Physical ther py m y help to postpone o r prevent specific

disabilities.

 

Spine Demyelirlllting Multiple Sclerosis (Spinal CIJ dl

1 5

Pl ltnDiit: h e course of the multi multiple ple scle sclerosi rosiss disease process i s varied and unpredictable.

B

FlllURE 1. MllliJIII lcl1n1iL Sagittal T2. MR A) image through cmvicaJ. spin spine e demonstrates demonstr ates a well-delineated hyper-intense lesion i n this patien patientt lesion n sho shows ws n o with known MS. xial r scan B) a t the level o f the lesio identifiable abnormality at that level.

 

P RT

1D

Central Nervous System

SPIN INFE TION

VERTEBR L OST OMY LITIS inflammation ion of the bone caused Description: Osteomyelitis is a n inflammat localized ed or spread throu through gh the b y a n infecting organism. t may be localiz bonee to involve the marrow cor bon cortex tex periosteu periosteum m and soft tissue surrounding the ffected area. Vertebral Vertebral osteomyelitis usual us ually ly occur occurss as a result resu lt of dis disk k space infecti infection; on; however osteomyeliti osteomyelitiss may occur through hematogenous dissemination directly t o the vertebral body. bod y. Pyogenic Pyogenic infecti infections ons to the t he disk di sk space are usually caused caus ed b y a blood-bo bloo d-borne rne pathogen from the lung o r uri urinar nary y tract. tract. These These patho gens get lodged i n the region of the end-plate of the bone and destroy the disk di sk space and a nd the adjace adjacent nt vertebral bodies. and d joint infect infection ionss are ar e Etialagv: The majority (90 ) o f all bone an caused by the Staphylococcus aureus microorg microorganism anism and may occur following trauma or surgery. Other common microorganisms include Escherichia coli and Proteus

Epillemialagy: Osteo Osteomyelit myelitis is can c an occur i n any location and patients a t any age. Patients who are particularly vulnerable include diabetics diabeti cs steroid users who are immunosuppressed those o n hemodialysis and drug addicts particularl particularly y heroin.

Signs and Svmptams: Patient presents with fever malaise pain and an d swelling over ove r the affected affected area.

lm ging Chlr ctaristic : MRI is the preferred imaging modality.

A gallium scan o r indium 111111-label labeled ed leukocyte leukocyte scan sc an can c an also be helpful. MRI

• Tl-weighted imag images es sho show w low signal inten intensity sity.. • T2-wei T2-weighted ghted images sh show ow high sig signal nal intensity. • Postcontrast fat-suppressed Tl weighted images show i n bone due to abscess enhancement abscess formation an and d juxtacortical juxtacortical soft tissue enhancement.

Traatmant: Antibiotic treatmen treat mentt is is required. require d. Severe cases cases may also need surgery.

 

Spine /Infection Vertelnl steomyelitis Pl ltnDiit:

treatment.

Generally good, with early diagnosis and effective

FIIURE 1. r

1 7

lllrtlllnllltiDmpitil. Axial (bone window)

scm shows lytic ciestruct:ion o f the L4 vertebral body

enha ncement involving the adjacent p9 with abnormal enhancement muscles.

A IIIURE 2.

a9

B

lllmbnll .tiiii lllmbn .tiiii I JiitiL Postcootrast n W fat-saturated. axial

spin inee demons dem onstra trate te abno abnoll.  (A) and sagittal B) images through the lumbar sp m l enhancement o L3 and lA with extension into the pso s muscles bilaterally. Note: right p9 a9 mus muscle cle absc abscess. ess.

 

P RT

1 8

Central Nervous System

SPINE TUMOR

MET ST TIC DISE SE TO TH

SPINE

lascriptian

Metastatic tumors involving the bony vertebrae of These tum tumor orss are are com commonl monly y a devastating devastati ng complic complica a the spine. These tion tio n of dissemin d isseminated ated ca canc ncer er..

Etialagv Metastatic spread of a cancer from a primary tumor. Metastases to the spine occur primarily as the result of hemato genous spread.

Epillemialagy

Any malignant tumor can involve the vertebral

spinei however howe ver breast carc carcinom inoma a and an lung carcinoma carc inomapatients are the most common. Approximately to cancer may 20 35d lun o fgall develop symptoms associated with metastasis to the vertebral spine. About 5 of affec affecte ted d patients p atients develop symptom symptomss related to spinal cord compression due to the collapse of on onee o r more verte brae o r epidural tumor spread. The thoracic (70'Ya) n d lumbar (20 ) regio regions ns are most m ost commonly affected affected wi with th 10 involving the cervical regions. There is a propensity for colon carcinoma to spread t o the lumbosacral spine n d breast n d lu lung ng ca carci rcinom nomaa t o metastasis to the t he thora thoracic cic spine.

Signs and Symptams Patient with wit h known kno wn cancer cancer history presents presents with bac back k p in nd possible loss of sensory and motor function. Suspected Suspe cted spinal cord co rd compre compression ssion requires requires emergent neurosurgic evaluation.

Imaging Characteristics Plain x-rays n d nuclear medicine bone modalities. scan CT, and MRI are useful imaging modalities. T

r is good goo d for the evaluation of bone b one destr destructi uction. on. • Shows osteolytic o r osteobl osteoblastic astic bony bon y metastatic metastat ic lesion. lesion. MRI

• MRI is excell excellent ent for the evaluatio eval uation n of spinal cord compression. compression. • Tl-weig Tl-weighted hted images images app appear ear with wit h low-s low-signa ignall intensity in the affected affec ted bony vertebrae. vertebrae .

• T2-weig T2-weighte hted d image imagess appear with wit h varia variable ble signal intensity in the affected affec ted bony vertebrae. vertebrae .  

Spine ITliTlor Metastatic Disease to the Spine

1 9

• Shows extension o the tumor into the spinal canal and spinal cord cor d compr compressio ession. n.

Trut111nt: Radiation therapy o r surgery depending o n the type o tumor. Spinal cord compression requires emergent radiation pe rmanen nentt paraly paralysis sis.. therapy o r neurosurgery t o prevent perma PntnDiis

FlllURE

poor prognosis i s expecte expected d for metastat metastatic ic cance cancer. r.

1 Spi11l MetlltaiL

Tl-weighted Tl-weight ed sagittal image

shows a large low-signal-intensity low-signal-intensity le on involving the C5-C6 vertebral bodle with enc::roe.ch ment o f the anterior spinal canal and an d compressi compression on of the spinal cord (lm OI D).

FlllURE I

Spi11l MetlltaiL

Tl-weighted Tl-weight ed image shows

low-signal-intensity lesions (tli I Ot D) o multiple vertebrae. There i s mark marked ed compression compression of the spinal card a t the level o f T

(IUTOW).

 

P RT II Central Nervous System

 

niURE I l il l Mmun11it n -weighted. axial imag imagee shows a high-signal-intmsity m u s (tm OW) encroaching

~ e ~ m a l (arro lllhttld).

~

~

d

r

o

m

~

~

e

~

m

a

l

r

o

M

niUAE l l il l Mlllllllllit Whole body bone scan shows multiple areas o ncl eased upt ke involving

the thoracic and lumbar spine s

the left pelvis and right uppern bs. well s

 

Spine ITliTlor Metastatic isease to the Spine

FIIURE

5 Spi11l Mltlltllllia

T myelogram bone wind.ow)

shows a lytic lesion n the lower l ower thor thoracic acic vertebral body

metast atic omcer. Biopsy revealed metastatic

 

112

P RT

SPINAL

Central Nervous System

EPENDYMOMA

lescriptian: A spinal ependymoma is the most common tumor o f

the spinal cor cord. d. They are benign ben ign n d slow growing n d arise from the ependymal cells lining the central canal o r from ependymal

rests.

Etialagv: These tumors develop from ependymal cells lining central cana canall o r from ependym epen dymal al rests. rests.

the

Epitllemialagy: Males are slightly more affected th n females. The pe k incidence is i n the ourth n d fifth decade decad e of lif life. e. The majority majori ty of all spinal ependymom epend ymomas as occur i n th thee lumbosacral l umbosacral region. region.

Signs and

Patients most commonly present with pain. Some patients m y complain of leg weakness n d sphincter dysfunction. Svm

tams:

lm1ging C hll ll:l ll:llristics: lristics: MRI i s the imaging modality o f choice for the diagnosi diagnosiss of spinal ependymona. MR

• Hypointense Hypoi ntense to isointe isointense nse t o the spinal cord o n Tl-weighted images. • T2T2-wei weight ghted ed images images prod produce uce a brig bright ht signal i n the CSF n d obscure obscu re the hig high h signal of the tumor. • Postco Postcontrast ntrast Tl-weig Tl-weighted hted image shows a homogeneous well circumscribed high-signal tumor. resectio ction. n. Tre1tment: Complete surgical rese

Pragnasis: A complete resection of cure.

the tumor

usually usuall y results results i n a

 

S pil pilll IT liT liTlor lor

.

pinal nal  Epe Epenndy dym m om omaa

FIIUR IUR    1 . lpi pi111l pa paaa 

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FIIU IIUR R 

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S p illl illl  E p ii. _ D n l. l.  

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m a B 8  w i t h  

o fl2 . 

 

114

P RT

Central Nervous System

SPINAL HEMANGIOMA lescriptian: A vertebral vertebral hemangioma

the most common benig benign n lesion incidentally found. Hemangi Hemangiomas omas are slow-growing vasc vascular ular tumors that generally d o not cause symptoms. These lesi lesions ons rarely result i n compression o r expansion o f the vertebral body with subsequent cord comp compressi ression. on. s

Etialagv: Unknown. Epitllemialagv: Vertebral hemangiomas are the most common benign lesion o f the spine and are present i n more than 10 o f all patients. Females are more ffected than males b y a ratio of 2:1. These lesions lesions are most m ost commonly c ommonly located i n the thoracic spine.

Signs and SJ

found.

plams: Nonspecific; these lesions are incidentally

lm1ging Ch•ractaristics: CT

• Bony striations associated with course, thickened trabeculae giving a corduroy appearance. • App Appea earr as low-a low-attenu ttenuation ation (hypodens (hypodense) e) are area. a. MR

• Tl weighted images will appear hyperintense due t o the presences o f fat o r hemorrhage. • T2-weight T2-weighted ed ima images ges will appear hyperintense.

Treatment: Symptomatic treatment.

Pl lgnasis: Ex Exce cell llen ent; t; a hemangio heman gioma ma is a benign beni gn tumor.

 

Spine ITliTlor Spinal emangiiJTla

FI URE

1 Spiul

hows cl.as.sic

5

_llltia••· Axial CT bone window

triated pattern with thickened trabecula n a

thoracic vertebral body body..

FI URE 2

Spiul _1111ia

Sagittal T2W MR. im

ge demon-

strates hyperintense portion o f thoracic vertebra vertebrall body Lesion appeazed similarly hyperin hyperintense tense m a ~ s

o n T1hemangioma. also consis consistent tent with

 

P RT

11

SPINAL

Central Nervous System

MENINGIOMA

Description: Spinal meningiomas are benign n d account for approximately 25 of all all intradura intra durall tumors. They are characteristi characteristi cally hard slow growing n d usual usually ly highly hi ghly vascular. vascular. spinee are believed t o arise from the Etialagv: Meningiomas of the spin arachnoid cel cells ls located located near ne ar the t he dorsa dorsall nerve root ganglia ganglia.. Meningiomas mas of the spine occur muc m uch h less less frequently Epidamialogv: Meningio meningiomas. Spinal meningiomas usually pres pre s th n intracranial meningiomas. ent fter the fourth decade of life n d occur more commonly i n females th n mal males. es. They are fou found nd mos m ostt commonly i n th thee thoracic region (80 ), followed b y th thee cervical region (17 ), nd least often i n the lumbar region (3 ). Patientt presents with w ith pain associated associated with Sign• and Svmptaml: Patien o

compression the spinal cord andweakness adjacent nerve and an d motor dysfunctio dysfu nctions ns suc such h as bowelroots. bladder n d Sensory dysfunction n d parethesias m y be present.

Imaging Characterilti : : MRI i s the imaging modality o f choice for thee diagnosis of spinal meningioma. th CT

• Shows calci calcified fied menin meningioma giomas. s. • c r myelography may demonstrate a blockag blockagee b y n intradural/ extramedullay extram edullay mass. MR

• Tl-wei Tl- weight ghted ed images are typi typically cally isointense t o the spinal cord. cord. • T2T2-wei weigh. gh.ted ted im imag ages es m y present with either low-signal o r high-signall inten high-signa intensity sity.. • Contrast-en Contrast-enhanced hanced Tl-weig Tl-weigh.ted h.ted images show a homogeneous enhancing enhanci ng high-signa high-signal-intensity l-intensity mass. mass.

Complete te surgical removal. Trlltmant: Comple

Prognosis: Good

this is a benign ben ign tumor.

 

S pill ITl ITliTlo iTlorr Spinal Spinal  M eningimla eningimla  

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arrorD)

o i nten ntens se mu 

t t h e l v l o T 6 1 7.

sh o w s   a

 

 .

P RT II/ Ce Cenntral Nervou Nervouss Syst System em

HIUR

I

llliiiiMin llliiiiMi n illiDml

Postcon Postco n t rast TI w e i g h t e d sa s a g ittal image s ow s intense  homo neous  e nharu neous nharu:eme :emen n t o t h e m ass t  th e l v l  o   T 6 1 7 .

 

Spine TliTlor I Spinal Meningitnla

Spi l M iltil P09U P0 9U:On :Ontr trut ut Tl Tl-w -wei eigh ghte ted d shows ws a contrast-enhancing extramed extramedullary ullary xi l image sho mass i n the right side o f the spinal canal short arruw t T6 T7 with displacement o f the cord long arrow) t o the left.

FIGURE 4

9

 

  2D

P RT

Central Nervous System

SPINE TR UM

URST FR CTURE Description

A vertically oriented fracture o the vertebral body with lateral dispersion of the fracture fragments, usually with associated fractures i n the posterior elements o f the vertebra ver tebra (e (eg, g, spinous ous pro proces cess). s). lamina and or spin

Etialagv Usually the result o f a flexion o r axia axiall loading traumatic force,, causin force cau sing g a flexion-compression injury. injury.

Epillemialagy Most commonly com monly occurs between betwee n 16 and

5

years o f

age.. Males are mor age m oree affected than females.

Signs and SJ

pai n, possibly plams: Patient presents with low back pain, extending down the buttocks and backs o f legs. Neurologic defici def icits, ts, such suc h a s numbness a n d o r tingling i n the lo lowe werr extremities extremities,, leg weakness, o r paralysis may b e present.

Imaging Characteristics C T is the imaging modality t o demon strate bony anatom} while :MRI i s better for showing show ing soft tissue tissue structures. T

• Fractures o f verteb vertebral ral body. • Fractures of the pedicles and lamina. • Shows displaced fractur fracturee fragments that may compromise the spinal spin al canal. MRI

• Excell Excellent ent mod modali ality ty t o evaluate the status o the spinal cana canall and spinal spin al cord. • May show cord hemorrhage. • May show compromise of the spinal canal and compression o f the spinal cord cord.. • May show asso associat ciated ed ligamentous injury o r hernia herniated ted di disk sk..

Treatment Surgica Surgicall stabilization of the damaged bone o r vertebra

via fusing o r met metalli allicc bracin b racing g may b e required.

 

Spine Trauma Burst racwre

2

PragnDiil: Mixed and varied, dependent upon the degree o f damage and neurologic involvement o f spinal nerve roots and spinal spin al cord.

FIIURE 1

Axial c r shows a burst w:idt displacement o f the fracture fragment resulting

C •inlltld unt Fnct

fracture o f T I i n contpxomiae of the spinal (:8J Ul}. Note: fracture

o f the

bilateral

pedicles and 8.9.90dated small parasplnal hematoma (arrows).

A FISIRE 2

B

£e•milllllll B1nt

Jncblre Sagittal multi·

planar reconstruction (MPR) CI (A) and sagittal T

W

t he lumbar spine demonstrate demonstrate MR. (B) images through the a burst .frac:tw:e of L with :retro :retropulsion pulsion of o f fragments. Note:: associ Note associated ated epidura epid urall hematoma. hematoma.

 

P RT

122

C 1

Central Nervous System

FR CTURE

lescriptian: Thr Three ee primary p rimary types of o f fractu fractures res have hav e been identified

involving the l vertebrae: 1) the posterior rch frac fracture ture usually usuall y occurs a t the junction of the posterior rch and the lateral mass; 2) the lateral mass fracture usually occurs unilaterally with the fracture line passing either through the articular surface o r just anterior and posterior to the lateral mas masss o n one side; 3) the burst fracture fract ure Jef Jeffe ferso rson n fracture) is chara character cterized ized b y four fractures fractures,, two i n the anterior arch and two i n the posterior arch. This fracture may presen presentt as a stable nondisplaced nondisplaced fractur fracturee with w ith n o encroach ment on the spinal cord o r as a displaced fracture with varying degreess of degree o f encroachment o n the spinal cord. A displaced fracture with encroachment o n the spina spinall cord may cause mor morbid bidity ity ie ie,, paralysis) paralysi s) or o r death.

Etialagv: Fractures t o

l occur a s a resul r esultt of axial loading to the

and diving-related accidents). top the head eg,depends swimmingThe of degree o f injury o n the magnitude of the axia axiall load ing and whether the spine is i n flexion, neutral, o r a n extension

position.

Epilllemiala : Trauma to the spine spi ne occurs occurs more commonl commonly y in the cervicall region than i n any other area cervica area of o f the spine.

Signs

d Symptams: The patient may present with pain o r a varying degreee of paralysis. degre Imaging Characteristics: CT i s the modality modal ity of cho choice ice for the diag diag

nosis of a

l fracture.

CT

• Noncontrast study with bone window setting shows sho ws fractu fracture re of of the l vertebrae. • May demonstrate other relat related ed bony o r soft tissue injuries t o the upper cervical region. MAl

• Useful i n evalu evaluating ating the spinal cord and othe otherr soft tissue struc struc tures of the spine. spine.

Tr atmant: Most fractures fractures of o f the l vertebrae can b e treated with immobiliz immo bilization ation eg, rig rigid id cerv cervica icall orthosis o r a halo vest).

Pragnasis: Depends o n the degree of injury injury and oth other er asso associat ciated ed

injuries.  

Spine Trauma C 1 Fracb.lre

II URE 1

fracture

r ~ d u N

28

f C1.

o f the anterior

xial c r o

rch (arrows).

l dem Il9trate

 

P RT

  24

VERTEBR L

COMPRESSION

Central Nervous System

fR CTURE

Description Compre Compressio ssion n fracture fracturess of the lumb r spin spinee occur occur as a result res ult of a combinatio combination n of fle flexio xion n n d axial loa loadin ding g compre compression) ssion) of the vertebrae. fracture ure can ca n occur as a result of tra trauma uma,, metasta metastatic tic Etialagy This fract disease t o the spine, o r osteoporosis.

Epilllamialogy Compressi Compression on fracture fracturess are ar e common commo n i n the aging n d geriatric patients with osteoporosis. Signs and Symptoms Pati Patient ent presents wit with h back p in n d possible neurologic deficit.

Imaging Characteristics T is the th e imaging modality modality t o demon strate bony ana anatomr tomr-- whil whilee MR MRI i s better for showing soft tissue structures n d spinal cord. CT

• Fracture of verteb vertebral ral body body.. • Fracture Fracturess of th thee pedicles n d lamina. • Shows displaced fracture fragments tha thatt .ma may y compromise th spinal spi nal canal. • Thin Thin-sec -section tion mult multipla iplanar nar images are very ve ry use useful ful.. MAl

• Excelle Excellent nt mod modali ality ty t o evaluate the status of the spinal canal spinal spi nal cord.

nd

• May show cord hemor hemorrhag rhage. e. • May show compromis compromisee of the spinal canal n d compression of the spinal cord. cord. • May sho show w assoc associated iated ligamentous injury or herni herniated ated disk disk..

Traatmant These injurie injuriess are usually usuall y stable stable because th thee bony bo ny pos terior element elementss n d longitudinal ligaments are intact. intact. Prognosis Depends o n the extent of the injury n d status of the spinal canal n d cord.

 

  pine Trauma Vertebral tilmpressirJI Fractll e

25

8

1 CamJNIIIal Fnclln l 1 In• l4 Sagittal T2W MR A) and sagittal MPR B) images show compression fractures of L1 and L4, respectively. IISURE

r

 

12

P RT

Central Nervous System

SPIN L CORD HEM TOM Description A spinal cord hematoma hematom a i s a collection collection of bl bloo ood d i n the spinal cord, most mos t commonly due t o trauma. Etialagv Most spinal cord hematomas occur occur as a result o f trauma t o the spinal cord cord,, ligament ligamentous ous structures, a n d o r bony vertebra. Other assoc associated iated causes may include a n acute herniated disk o r hemorrhage hemorrh age from a n arteriovenous malforma malformation. tion. Epitllemialagy Tra Trauma uma to the th e spinal column col umn occurs occurs a t an incidence of approximately 2 t o 5 per 100,000 population. Many of these injuries are a result of motor vehicle accidents. Less frequent causes includ in cludee fal falls, ls, divi d iving ng accidents, accidents, and sports and recreational injuries. Adolescences and young adults, especially males, are more mo re commonl co mmonly y affecte affected. d. Depending on the and extent o f and Symptoms Signsinjury, the patient may present with level the motor and sensory

dysfunction.

Imaging Characteristics Plain x-ra x-rays ys of the spine shoul should d b e done first. CT is good for the evaluation of bony structures, whereas MRI i s exc excelle ellent nt for for the t he evaluation of soft tissue and spinal cord. Extrinsic changes include isk herniation and ligamentous injury. Intrinsic changes include edema and hemorrhage.

MRI 1. Acute stag stagee seve several ral ho hours urs to 3 days) • Slightly Slightly lo low w signal o n Tl-we Tl-weight ighted ed im imag ages es.. • Marked low signal with high signal o n surrounding edema o n T2-weighted image images. s. 2. Subacut Subacutee stage 3 days to 3 weeks) • Hi High gh signa signall o n Tl-we Tl-weight ighted ed images. images. • Hig High h sig signal nal wit with h low signal cl clot ot o n T2-weighte T2-weighted d images. 3. Chronic stag stagee 3 weeks t o months) • Hi High gh signa signall o n Tl-we Tl-weight ighted ed images. images. • Hi High gh signa signall wi with th low-sig low-signal nal rim o n T2-weighted images. • Gradie Gradient nt echo images appear with low signal intensity.

Treatment Presence o f a spinal cord hematoma indica indicates tes a poor p oor prognosis. Permane Per manent nt neurologic neurologic def defici icitt is mo moss t likely. likely.

Prognosis Depends o n th thee type, ty pe, level, level, and extent of the injury.

 

Spine Trauma Spinal Cml ematoma

27

FlliURE 1 Spi11IIC1N H e m ~ 1

Sagittal T2W MR image demonstrated slightly heterogeneous hyperintense cord signal abnormality abnormal ity consistent wit hematoma and edema.

A

B

FIGURE 2 Spi11IIC11 11 Hamm a Axial A) and sagittal CT B) image demonstrate te a the same patient a s i n Figure 1) through the cervical spin demonstra fracture through CS.

 

P RT

  28

FRACTUREIIIISLDCATIDN

Central Nervous System

[C -C7J

Description Spinal subluxation is the partial dislocation of the spinal vertebrae. Facet dislocations dislocations m y e either stable unilat unilateral) eral) or unstab unstable le bila bilatera teral) l) i n more severe cases. A subluxation of the spinal vertebrae is associated with either a partial or complete disruption o f th posterior longitudinal ligament n d the anteri anterior or longitudinal ligame ligament. nt. n ma many ny cas cases, es, this m y b e associated with a fracture of either facet t the level of o f the th e disl dislocat ocation ion.. Etialagv Traumatic conditions that result i n hyperextension o r hyperflexion and a nd rotation of the th e cervica cervicall spine. Cervical cal spine subluxation is associated associated with wi th hyper Epillemialagy Cervi extens ext ension ion-- and hype hyperflex rflexionion-relat related ed traumatic traumat ic inj injurie uriess to th cervi cal colum column. n. and Symptams Signs ogic neurol neurologic deficit. deficit.

Imaging Characteristics screening.

Patient presents with p in nd possible Plain films should b e done first for

CT

• Useful i n identifying bo bony ny injury fra fractu cture) re),, exte extent nt of fract fracture, ure, status of posterior elements elements and spinal canal. canal. • Spiral c r si sing ngle le or o r multidetector) multidetector) with wi th thin sections 1 t o 3 mm) sagittal n d coronal reformatted reformatted..

MRI • Excellent for the evaluation of the spinal cord n d other soft tissuee injuries. tissu injuries. Reductio ction n of the t he fra fractu cture/ re/ disl disloca ocatio tion. n. Traatmant Redu t rauma n d status of the Pragnasis Depends o n the extent of the trauma spinal cord. cord. The presence of cord hemorrhage hemorrha ge i s generally consid ered to b e a poor po or prognosis.

 

Spine Trauma FrEK WreiDislocatian )).C7l

A

129

B

1 Frutwdalacalilll Sagittal MPR c r bone window (A) and T2W sagittal MR. B) images reveal fracture.dislocatian injury o C5 C7 with antemlisthe.sis o C 6 o n C , a m i hemonbage and ligamentc us injury FISIR

 

  3D

P RT

Central Nervous System

ODONTOID FRACTURE lescriptian: Fractures of the odontoid process process or dens have been

classified classifi ed in into to three types. A Type Type I fract fracture ure rarely seen is n avulsion of th thee tip ti p of the dens. Type Type II th thee most common con consists sists of a fracture through the base of the dens. Type III fractures extend through th upper body o the C2 vertebrae.

Etialagv: Fra Fractu ctures res of the dens usually u sually result from extreme flex flexion ion of the head.

Epillemiala : Trauma to the spine spi ne occurs occurs more commonl commonly y in the cervicall region th n i n n y other area cervica area of o f the spine.

Signs anll SJ

ptams: Patient may present with p in o r a varying degree of o f neurologic def deficit icit..

CT i s th thee modalit modality y of cho choic icee for for the Imaging Characteristics: diagnosis of n odon odontoid toidSpiral fractu fra cture. re. CT

• Noncontrast study with sagittal n d coron coronal al reformatted bone bo ne wind wi ndow ow images sh show owss fractu fracture re of the dens. • May demonstrate other rela related ted bony o r soft tissue injuries t o the upper cervical spine.

MAl • Useful i n evaluating the spinal cord structures.

n d other soft tissue

Treatment: Depending o n the type of frac fracture ture immobilization wi with th a halo vest nd possib possible le bony bon y fusion m y b e successful.

Pragnasis: Depends o n th type of frac fracture ture n d status o f th spinal cord.

 

Spine Trauma

dontoid Fractll e

A

111

B

Fruture f t ll Ddeltai• o 1:2 r sagittal MPR A) bone window and T2.W sagittal MR. (B) im ges demonstrate a transverse odontoid IISURE 1

type

mractw:e.

 

132

P RT

Central Nervous System

SPIN V SCUL R DISE SE

SPINAL

CORD IS ISCHEM CHEM IA INFARCTION

Description: Ischemia and infarction of the spinal cord is the

decrease o r absence o f blood to the spina spinall cord.

Etialaav: ost res result ult fro from m athe atherosc roscleros lerosis is hyperte hypertension nsion thor thora a coabdornina coabdo rninall aortic aneurysm aneur ysm sick sickle le cell anemi anemiaa caisson disease diabetes meningitis and spinal trauma. EpilllemialagJ: The lower thoracic cord and conus are most com monly involved.

Signs and Svmptams: The patient presents with diminished bowel

and bladder function loss o f perineal sensation and reduced sensory and motor function o f the lower extremities.

Imaging Chal lcleristics: MRI i s the imaging modality o f choice for the diagnosis of spinal cord co rd ischemia ischemia o r infarction. MRI

• Tl-weighted images may show a n enlargement of the spinal cord. • TI-weight TI-weighted ed images show high signal intensity i n the cord. • FL FLAI AIR R ima images ges ar aree very helpful b y sup suppre pressi ssing ng the CSF CSF signal. signal.

Treatment: Treatmen Treatmentt is usually usual ly symptomatic.

Pragnasis: Depends o n the extent and sever severity ity of the infarct. infarct.

 

Spine Vascuhr Disease Spinal ord lschemiallnhn tion

FlllUAE 1

pl11l C11 11

llch1rriiiWin:t FLAIR

sagittal image of the thoracic

spine shows n enlargement with diffuse increa8ed signal intensity amno.s) of the istlill thoracic spinal cord

 

P RT

ll

ead and Neck

 

P RT Ill

13

Head and Neck

CONGENITAL BR CHI L

CLEn

YST

lascriptian

Brachial deft cysts BCC) are congenital anomalies and usually arise from the second brachial arch during embryo logical logi cal development. Durin Du ring g cl clin inic ical al presentation presentat ion the cy cyst stic ic mass appears in the anteriola anteriolatera terall portion of the th e neck neck aroun ar ound d the angle of the mandible.

Etialaav Congenital anomaly. Epillemialagy Bimodal age distribution. The first occurrence is t birth with the second peak seen n young adults. About 10 are bilateral n location. Signs and Symptoms This cystic cystic mass is usually painle painless. ss.

Imaging Charactaristics Shows well-defined round cystic mass posteriolateral to the submandibular gland. There is n o contrast enhancement. T

• Shows cyst

s

low density.

M l

• TlTl-weig weighted hted TlW) image is hypointense. • T2-weighted image is hyperi hyperintense. ntense. resecti ction. on. Traatmant Complete surgical rese

Prognosis Good.

 

Congenital/

rachial Cleft

Cyst

II URE 1

117

Bradl1l Clift Cpt. Axial

Contrast Bnhancecl

T sho shows ws a cystic

i n the right neck of a child located lesion anteromedial to the sternocleidomastoid

muscle, posterolateral to the subman-

dibular gland, and lateral t o the carotid space. I n a child, this i s a classic location and appearance for a second type BCC considerations ns wou ld ther cliffe:rential consideratio include suppura tive lymphadenitis lymphadenitis o r necrotic lymph node metastases i n a n adult .

FI IRE 2.

BNr:: ill

lift C

lt.

Axial CECT i n a child shows a cystic lesion i n the left posterior neck with overlying infiltration

o f the fat r:epreserlting a n inflamed second BCC

 

138

P RT Ill

Head and Neck

TUMOR CAVERNOUS HEMANGIOMA ORBITAL) lascriptian: Cavernous hemangiomas of the orbit are the most

common benign orbital orbital tumors i n adults.

Etialagv: These vascular malformations are composed o f large dilated endothelium-lined vascular ch nnels covered b y a fibrous capsule.

EpidamialaiJ: These slow, progressive tumors usually occur i n patients between the second n d fourth decades of life n d are slightly more common i n females. These tumors are usually located intraconal, but extraconal cavernous hemangiomas are possible.

Signs and Svmptams: bulging eyes).

Patients present with painless proptosis

Imaging Charactaristics: CT

• Appea App earr as well-d well-defined, efined, i g h d e n s i ~ smooth-margined, homo geneous, geneou s, rounded, ovoid egg shaped shaped), ), or lobulated mass with marked mar ked contrast contr ast enhancement enhancement.. MR

• Tl-weighted Tl-wei ghted images demonstra demonstrate te n isointense to hypointense well-circumscribed mass. • The tum tumor or appears hyperintense to fat o n T2-weighted images images.. • Postcontr Postcontrast ast Tl-weighte Tl-weighted d images show marke marked d enhancement enhancement..

encapsulated benign tumors Tr1alm1nt: Surgical resection o f these encapsulated i s the recommende recommended d treat treatment ment of cho choic ice. e. Surgical cal resection produ produces ces a high hi gh cure rate. Pl lgnalil: Surgi

 

T ITlor

CBVeiTI(JUS

Hemangioma

[ ( )

b ~ a l l

illlll. Noncontrast CI' showing smoothly marginat ed high-density round. cont:l'a t-enhancing intraconal t n a of the left orbit displacing thee left th le ft globe anteriorly anteriorly.. IIIUR

1. Cn.-na11 H•••

2. Cnern••• He••aiam•. Sagittal Tl-weighted postcontras postcontrastt MR FlliUR

shows round. rou nd. slightly hyperinten hyperintense se retrobular mass displac displacing ing optic nerve ner ve superiorly.

119

 

  4D

P RT Ill

Head and Neck

CHOLESTEATOMA (ACIUIREO) lescriptian:

acquir ed choleste acquired cholesteatoma atoma consists consists of a n accumula tion of squamous epithelium epithelium i n the middle ea ear. r. n

Vari ries es,, depen de pendin ding g o n th thee specific specific type of cholesteatoma. Etialagv: Va Unknown; own; however, a cholesteatoma is a relativ relatively ely Epillamialalf: Unkn

common com mon reason reaso n for for ear surgery surgery..

Signs and Sym tam : Most common sign is frequent recurrent pain less discharge from the ear. ear. Heari H earing ng loss may also b e common. Imaging Chal 'lcteristics: High-resolution CT HR.CT) is the preferred modality used t o evaluate the mass-like lesion i n the middle ear whic wh ich h erodes the th e ossi ossicl cles es and an d bone. CT •

hin section

axial and coro coronal nal images useful usef ul i n evaluating tem tem--

hin section

axial and coro coronal nal images useful usef ul i n evaluating tem tem--

pora l bone. poral • Useful i n pla planni nning ng su surg rgery ery.. • choleste esteatoma atoma and related structure structures. s. a n determine extent of chol • Acquired temporal bone cholesteatoma characterized b y a soft-tissue homogeneous mass with focal bone destruction erosion). MAl •

• • • •

pora l bone. poral Useful i n pla planni nning ng su surg rgery ery.. choleste esteatoma atoma and related structure structures. s. a n determine extent of chol Acquired temporal bone cholesteatoma soft tissue mass) appears hypointense o n Tl-weighted images, no enhancement is seen following following gadolinium. gadolinium . Cholesteatoma Cholest eatoma is hyperintense o n T2-weighted images.

Surgical al intervention. intervention . Traatmant: Surgic

Pragnasis: Good.