Radiology Review Manual (Dahnert, Radiology Review Manual)

Authors: Dahnert, Wolfgang

Title: Radiology Review Manual, 6th Edition

Copyright 2007 Lippincott Williams & Wilkins

> Table of Contents > Central Nervous System

Central Nervous System

Differential Diagnosis of Skull and Spine Disorders

Low back pain

Low Back Pain in Childhood

Lumbosacral Postsurgical Syndrome

Frequency: failure of improvement in 5 15%

Cauda Equina Syndrome

Cause:

Skull

Sutural Abnormalities

Wide Sutures

= >10 mm at birth, >3 mm at 2 years, >2 mm at 3 years of age; (sutures are splittable up to age 12 15; complete closure by age 30)

P.178

Craniosynostosis

= CRANIOSTENOSIS = premature closure of sutures (normally at about 30 years of age)

Age: often present at birth; M:F = 4:1

Etiology:

Types:

Sagittal suture most commonly affected followed by coronal suture

Wormian Bones

Increased Skull Thickness

Hair-on-end Skull

mnemonic: HI NEST

Leontiasis Ossea

= overgrowth of facial bones causing leonine (lionlike) facies

Abnormally Thin Skull

Inadequate Calvarial Calcification

P.179

Osteolytic Lesion of Skull

Solitary Lytic Lesion in Skull

mnemonic: HELP MFT HOLE

Multiple Lytic Lesions in Skull

mnemonic: BAMMAH

Lytic Area in Bone Flap

mnemonic: RATI

Button Sequestrum

mnemonic: TORE ME

Absent Greater Sphenoid Wing

mnemonic: M FOR MARINE

Absence of Innominate Line

= Oblique carotid line

= vertical line projecting into orbit (on PA skull film) produced by orbital process of sphenoid

Widened Superior Orbital Fissure

mnemonic: A FAN

Tumors of Central Skull Base

Craniofacial Syndromes

= developmental malformations of the face + skull associated with CNS malformations

Maxilla and mandible

Maxillary Hypoplasia

Mandibular Hypoplasia = Micrognathia

Destruction of Temporomandibular Joint

mnemonic: HIRT

Radiolucent Lesion of Mandible

Cystic Lesion of Jaw

Tooth Mass

Craniovertebral junction

Craniovertebral Junction Anomaly

Basilar Invagination

= primary developmental anomaly with abnormally high position of vertebral column prolapsing into skull base

Associated with: Chiari malformation, syringohydromyelia in 25 35%

Cause:

limitation in range of motion of CVJ

abnormal craniometry

C-spine + foramen magnum bulge into cranial cavity

elevation of posterior arch of C1

Basilar Impression

= acquired form of basilar invagination with bulging of C-spine and foramen magnum into cranial cavity

tip of odontoid process projects >5 mm above Chamberlain line (= line between hard palate + opisthion)

Cause: Paget disease, osteomalacia, rickets, fibrous dysplasia, hyperparathyroidism, Hurler syndrome, osteogenesis imperfecta, skull base infection

mnemonic: PF ROACH

Platybasia

Atlas and axis

Atlas Anomalies

Axis Anomalies

P.184

Odontoid Erosion

mnemonic: P LARD

Atlantoaxial Subluxation

= displacement of atlas with respect to axis

Causes of subluxation:

mnemonic: JAP LARD

Pseudosubluxation of Cervical Spine

= ligamentous laxity in infants allows for movement of the vertebral bodies on each other, esp. C2 on C3

Spinal dysraphism

= abnormal / incomplete fusion of midline embryologic mesenchymal, neurologic, bony structures

External signs (in 50%):

subcutaneous lipoma spastic gait disturbance
hypertrichosis foot deformities
pigmented nevi absent tendon reflexes
skin dimple sinus tract
bladder + bowel dysfunction  
pathologic plantar response  

Spina Bifida

= incomplete closure of bony elements of the spine (lamina + spinous processes) posteriorly

Spina Bifida Occulta

= OCCULT SPINAL DYSRAPHISM

= cleft / tethered cord WITH skin cover

Frequency: 15% of spinal dysraphism

rarely leads to neurologic deficit in itself

Associated with:

Spina Bifida Aperta

= SPINA BIFIDA CYSTICA

= posterior protrusion of all / parts of the contents of the spinal canal through a bony spinal defect

Frequency: 85% of spinal dysraphism

Associated with: hydrocephalus, Arnold-Chiari II malformation

Caudal Spinal Anomalies

= malformation of distal spine and cord in association with hindgut, renal, and genitourinary anomalies

P.185

Segmentation Anomalies of Vertebral Bodies

Clefts in Neural Arch

during 9 12th week of gestation two ossification centers form for the ventral + dorsal half of vertebral body

Vertebral body

Destruction of Vertebral Body

Gas in Vertebral Body

Small Vertebral Body

Vertebra Plana

mnemonic: FETISH

Signs of Acute Vertebral Collapse on MRI

P.186

Enlarged Vertebral Body

Enlarged Vertebral Foramen

Cervical Spine Fusion

mnemonic: SPAR BIT

Vertebral Border Abnormality

Straightening of Anterior Border

Anterior Scalloping of Vertebrae

Posterior Scalloping of Vertebrae

in conditions associated with dural ectasia

mnemonic: DAMN MALE SHAME

Bony Outgrowths from Vertebra

Spine Ossification

Vertebral Endplate Abnormality

Ring Epiphysis

= normal aspect of developing vertebra (between 6 and 12 years of age)

small steplike recess at corner of anterior edge of vertebral body

Bullet-shaped Vertebral Body

mnemonic: HAM

Bone-within-bone Vertebra

= ghost vertebra following stressful event during vertebral growth phase in childhood

P.188

Ivory Vertebra

mnemonic: LOST FROM CHOMP

Sclerotic Pedicle

Tumor of vertebra

Expansile Lesion of Vertebrae

Blowout Lesion of Posterior Elements

mnemonic: GO APE

Bone Tumors Favoring Vertebral Bodies

mnemonic: CALL HOME

Primary Vertebral Tumors in Children

[in order of frequency:]

Primary Tumor of Posterior Elements

mnemonic: A HOG

Sacrum

Destructive Sacral Lesion

mnemonic: SPACEMON

Sacral Tumor

Sacral Bone Tumor

Sacral Canal Tumor (less common)

Intervertebral disk

Loss of Disk Space

Spinal Vacuum Phenomena

nucleus pulposus Osteochondrosis
annulus fibrosus Spondylosis deformans
disk within vertebral body Cartilaginous node
disk within spinal canal Intraspinal disk herniation
apophyseal joint Osteoarthritis
vertebral body Ischemic necrosis

Vacuum Phenomenon in Intervertebral Disk Space

= liberation of nitrogen gas from surrounding tissues into clefts with an abnormal nucleus or annulus attachment

Prevalence: in up to 20% of plain radiographs / in up to 50% of spinal CT in patients > age 40

Cause:

Intervertebral Disk Calcification

mnemonic: A DISC SO WHITE

Intervertebral Disk Ossification

Associated with: fusion of vertebral bodies

Schmorl = Cartilaginous Node

= superior / inferior intravertebral herniation of disk material through weakened area of vertebral endplate

Pathogenesis: disruption of cartilaginous plate of vertebral body left during regression of chorda dorsalis, ossification gaps, previous vascular channels

P.190

Cause:

concave defects at upper and lower vertebral endplates with sharp margins

MR:

Mneumonic of DDx: SHOOT

Spinal cord

Most spinal cord neoplasms are malignant!

90 95% are classified as gliomas

Intramedullary Lesion

Prevalence: 4 10% of all CNS tumors; 20% of all intraspinal tumors in adults (35% in children)

Intramedullary Neoplastic Lesion

Intramedullary Nonneoplastic Mass

Intramedullary Nonneoplastic Lesion

Prevalence: 4%

no cord expansion

Cord Lesions

Intradural Extramedullary Mass

mnemonic: MAMA N

Epidural Extramedullary Lesion

= EXTRADURAL LESIONS OF SPINE

arise from bone, fat, vessels, lymph nodes, extramedullary neural elements

Prevalence: 30% of all spinal tumors

mnemonic: MANDELIN

Cord Atrophy

Delayed Uptake of Water-Soluble Contrast in Cord Lesion

Extraarachnoid Myelography

P.192

Musculoskeletal neurogenic tumors

Spinal fixation devices

Function:

Posterior Fixation Devices

using paired / unpaired rods attached with

Anterior Fixation Devices

Spinal Fixation Devices

P.193

Cotrel-Dubousset Rods and Pedicle Screws

P.194

Anatomy of Skull and Spine

Foramina of base of skull

on inner aspect of middle cranial fossa 3 foramina are oriented along an oblique line in the greater sphenoidal wing from anteromedial behind the superior orbital fissure to posterolateral

mnemonic: rotos

Foramen Rotundum

Contents:

best visualized by coronal CT

Foramen Ovale

Location: medial aspect of sphenoid body, situated posterolateral to foramen rotundum (endocranial aspect) + at base of lateral pterygoid plate (exocranial aspect)

Contents:

Foramen Spinosum

Location: on greater sphenoid wing posterolateral to foramen ovale (endocranial aspect) + lateral to eustachian tube (exocranial aspect)

Contents:

Foramen Lacerum

Fibrocartilage cover (occasionally), carotid artery rests on endocranial aspect of fibrocartilage

Location: at base of medial pterygoid plate

Contents: (inconstant)

Foramen Magnum

Pterygoid Canal

Location: at base of pterygoid plate below foramen rotundum

Contents:

Hypoglossal Canal

= ANTERIOR CONDYLAR CANAL

Location: in posterior cranial fossa anteriorly above condyle starting above anterolateral part of foramen magnum, continuing in an anterolateral direction + exiting medial to jugular foramen

Contents:

Jugular Foramen

Location: at the posterior end of petro-occipital suture directly posterior to carotid orifice

Craniovertebral junction

Craniometry:

Normal dimensions for adults:

Basion-dens interval (in 95%) <12 mm
Basion-posterior axial line interval (in 98%)

posterior to dens

 <12 mm
   anterior to dens <4 mm
Prevertebral soft tissues at C2 <6 mm
Anterior atlanto-dens interval <2 mm
Lateral atlanto-dens interval (side-to-side) <3 mm
Atlanto-occipital articulation <2 mm
Atlantoaxial articulation <3 mm

Normal Relationship of Craniovertebral Junction

(range of the two extreme normal positions of the basion is drawn in dashes)

P.196

Meninges of spinal cord

Meninges of Spinal Cord

Typical Cervical Vertebra

(cranial aspect)

Thoracic spine

Thoracolumbar spine (T11 L2)

Transitional vertebra

Normal position of conus medullaris

P.198

Joints and Ligaments of Occipito-Atlanto-Axial Region

P.199

Skull and Spine Disorders

Arachnoiditis

Etiology: trauma, back surgery, meningitis, subarachnoid hemorrhage, pantopaque myelography (inflammatory effect potentiated by blood), idiopathic
Associated with: syrinx

Arachnoid Cyst of Spine

Location: dorsal to cord in thoracic region

Site:

Arachnoid Diverticulum

= widening of root sheath with arachnoid space occupying >50% of total transverse diameter of root + sheath together

Cause: ? congenital / traumatic, arachnoiditis, infection
Pathogenesis: hydrostatic pressure of CSF scalloping of posterior margins of vertebral bodies myelographic contrast material fills diverticula

Arteriovenous Malformation of Spinal Cord

Classification:

Atlantoaxial Rotary Fixation

Brachial Plexus Injury

Caudal Regression Syndrome

Etiology: disturbance of caudal mesoderm <4th week of gestation from toxic / infectious / ischemic insult
Prevalence: 1:7,500 births; 0.005 0.01% of population; in 0.1 1% of pregnancies of women with diabetes
Predisposed: infants of diabetic mothers; risk increase by 200 400 times in women dependent on insulin 16 22% of children with sacral agenesis have mothers with diabetes mellitus

NOT associated with VATER syndrome!

Sirenomelia

= fused lower extremities resembling a mermaid (siren)

Cause: aberrant vessel that shunts blood from the high abdominal aorta to the umbilical cord (steal phenomenon) resulting in severe ischemia of caudal portion of fetus

Differences between Caudal Regression Syndrome (CRS) and Sirenomelia

  CRS Sirenomelia
umbilical artery two one
lower limb two hypoplastic single / fused
renal anomaly nonlethal renal agenesis / severe dysgenesis
anus imperforate / normal absent
amniotic fluid polyhydramnios / normal oligohydramnios

NOT associated with maternal diabetes mellitus!

Prognosis: incompatible with life

Chordoma

Chordoma is the most common primary malignant tumor of the spine in adults excluding lymphoproliferative neoplasms!

Prevalence: 1:2,000,000; 1 2 4% of all primary malignant neoplasms of bone; 1% of all intracranial tumors
Etiology: originates from embryonic remnants of notochord / ectopic cordal foci (notochord appears between 4th and 7th week of embryonic development, extends from Rathke pouch to coccyx and forms nucleus pulposus)
Age: 30 70 (mean, 50) years (peak age in 6th decade); M:F = 2:1; highly malignant in children
Path: lobulated tumor contained within pseudocapsule
Histo:

  1. typical chordoma: cords + clusters of large bubblelike vacuolated (physaliferous) cells containing intracytoplasmic mucous droplets; abundant extracellular mucus deposition + areas of hemorrhage

  2. chondroid chordoma: cartilage instead of mucinous extracellular matrix

  
Location:

  1. 50% in sacrum

  2. 35% in clivus

  3. 15% in vertebrae

  4. other sites (5%) in mandible, maxilla, scapula amorphous calcification (50 75%) heterogeneous enhancement

  
Metastases (in 5 43%) to: liver, lung, regional lymph node, peritoneum, skin (late), heart
Prognosis: almost 100% recurrence rate despite radical surgery

P.201

Sacrococcygeal Chordoma (50 70%)

Most common primary malignant sacral tumor;

2 4% of all malignant osseous neoplasms!

Peak age: 40 60 years; M:F = 2:1
Location: esp. in 4th + 5th sacral segment

presacral mass with average size of 10 cm extending

superiorly + inferiorly; rarely posterior location

displacement of rectum + bladder

solid tumor with cystic areas (in 50%)

osteolytic midline mass in sacrum + coccyx

amorphous peripheral calcifications (15 89%)

secondary bone sclerosis in tumor periphery (50%)

honeycomb pattern with trabeculations (10 15%)

may cross sacroiliac joint
Prognosis: 8 10 years average survival; 66% 5-year survival rate (adulthood)
DDx: Giant cell tumor, plasmacytoma, lymphoma, metastatic adenocarcinoma, aneurysmal bone cyst, atypical hemangioma, chondrosarcoma, osteomyelitis, ependymoma

Sphenooccipital Chordoma (15 35%)

Age: younger patient (peak age of 20 40 years); M:F - 1:1
Location: clivus, spheno-occipital synchondrosis

bone destruction (in 90%): clivus > sella > petrous bone > orbit > floor of middle cranial fossa > jugular fossa > atlas > foramen magnum

reactive bone sclerosis (rare)

calcifications / bone fragments (20 70%)

soft-tissue extension into nasopharynx (common), into sphenoid + ethmoid sinuses (occasionally), may reach nasal cavity + maxillary antrum

variable degree of enhancement

MR:

Prognosis: 4 5 years average survival
DDx: meningioma, metastasis, plasmacytoma, giant cell tumor, sphenoid sinus cyst, nasopharyngeal carcinoma, chondrosarcoma

Vertebral / Spinal Chordoma (15 20%)

More aggressive than sacral / cranial chordomas

Age: younger patient; M:F = 2:1

low back pain + radiculopathy

Location: cervical (8% particularly C2), thoracic spine (4%), lumbar spine (3%)
Site: midline centra sparing posterior elements; arising in perivertebral musculature (uncommon)

solitary midline spinal mass

tumor calcification in 30%

sclerosis / ivory vertebra in 43 62%

total destruction of vertebra, initially unaccompanied by collapse

expansile growth:

   violates disk space to involve adjacent bodies (10 14%) simulating infection

   variable extension into epidural space of spine

   exophytic anterior soft-tissue mass

   expansion into neural foramen mimicking nerve sheath tumor
Cx: complete spinal block
Prognosis: 4 5 years average survival
DDx: metastasis, primary bone tumor, primary soft-tissue tumor, neuroma, meningioma

CSF Fistula

Location: fractures through frontoethmoidal complex + middle cranial fossa (most commonly)

high-resolution thin-section CT in coronal plane followed by rescanning after low-dose intrathecal contrast material instilled into lumbar subarachnoid space
Cx: infection (in 25 50% of untreated cases)

Degenerative Disk Disease

Pathophysiology:

Plain film:

Myelography:

CT (accuracy >90%):

MR:

reduction in disk height (late):

endplate + marrow changes (Modic & DeRoos):

= linear signal alterations paralleling adjacent endplates

NUC:

Sequelae:

DDx: Idiopathic segmental sclerosis of vertebral body (middle-aged / young patient, hemispherical sclerosis in anteroinferior aspect of lower lumbar vertebrae with small osteolytic focus, only slight narrowing of intervertebral disk; unknown cause)

Modified Dallas Diskogram Classification

Grade Description
0 contrast confined within nucleus pulposus
1 contrast extends to inner third of annulus
2 contrast extends to middle third of annulus
3 outer third of annulus + <30 of circumference
4 outer third of annulus + >30 of circumference
5 extension of contrast beyond annulus

P.203

Bulging Disk = Disk Bulge

= concentric smooth expansion of softened disk material beyond the confines of endplates with disk extension outward involving >50% of disk circumference

Cause: weakened and lengthened but intact annulus fibrosus + posterior longitudinal ligament
Age: common finding in individuals >40 years of age
Location: L4-5, L5-S1, C5-6, C6-7

rounded symmetric defect localized to disk space level

smooth concave indentation of anterior thecal sac

encroachment on inferior portion of neuroforamen

accentuated by upright myelography

Herniation of Nucleus Pulposus

= HNP = protrusion of disk material >3 mm beyond margins of adjacent vertebral endplates involving <50% of disk circumference

Cause: rupture of annulus fibrosus with disk material confined within posterior longitudinal ligament 21% of asymptomatic population has disk herniation!

Broad-based Disk Protrusion

P.204

Focal Disk Protrusion

Disk Extrusion

Disk Sequestration

Free Fragment Migration

Lateral Disk Herniation

Nerve compression occurs posterolaterally (here at L4-5); therefore an atypical lateral compression (here of L4 root) directs surgery to the wrong more cephalad level (L3-4 disk)

Cervical Disk Herniation

Peak age: 3rd 4th decade
Sites: C6-7 (69%); C5-6 (19%); C7-T1 (10%); C4-5 (2%)

Thoracic Disk Herniation

Prevalence: 1% of all disk herniations
Sites: T11-12
calcification of disk fragments + parent disk (frequent)

Lumbar Disk Herniation

Sites: L4-5 (35%) > L5/S1 (27%) > L3-4 (19%) > L2-3 (14%) > L1-2 (5%)

Dermoid of Spine

Prevalence: 1% of spinal cord tumors
Age at presentation: <20 years; M:F = 1:1
May be associated with: dermal sinus (in 20%)
Location: lumbosacral (60%), cauda equina (20%)
Site: extramedullary (60%), intramedullary (40%)

   almost always complete spinal block on myelography

   intensity of fat

   occasionally hypointense on T1WI + hypodense on CT (secretions from sweat glands within tumor)

   NO contrast enhancement

   CT myelography facilitates detection

Diastematomyelia

Etiology: congenital malformation as a result of adhesions between ectoderm and endoderm; M:F = 1:3

P.205

Associated with: myelomeningocele
Location: lower thoracic / upper lumbar > upper thoracic > cervical spine
Cx: progressive spinal cord dysfunction

Diskitis

Most common pediatric spine problem!

Etiology:

Agents:

Pathogenesis: infection starts in disk (still vascularized in children) / in anterior inferior corner of vertebral body (in adults) with spread across disk to adjacent vertebral endplate

Age peak: 6 months to 4 years and 10 14 years; average age of 6 years at presentation

Location: L3-4, L4-5, unusual above T9; usually one disk space (occasionally 2) involved

Plain film (positive 2 4 weeks after onset of symptoms):

CT:

MR (preferred modality; 93% sensitive, 97% specific, 95% accurate):

NUC (41% sensitive, 93% specific, 68% accurate on Tc-99m MDP + Tc-99m WBC scans):

Cx: epidural / paravertebral abscess, kyphosis
Rx: immobilization in body cast for ~4 weeks
DDx: neoplastic disease (no breach of endplate, disk space often intact)

Postoperative Diskitis

Frequency: 0.75 2.8%
Organism: Staphylococcus aureus; many times no organism recovered

Dislocation of Spine

Atlantooccipital Dislocation

= ATLANTOOCCIPITAL DISTRACTION INJURY

= disruption of tectorial membrane + paired alar ligaments resulting in grossly unstable injury

Diagnosis difficult to make!

Cause: rapid deceleration with either hyperextension or hyperflexion
Age: childhood (due to larger size of head relative to body, increased laxity of ligaments, horizontally oriented occipito-atlanto-axial joint, hypoplastic occipital condyles)
May be associated with: occipital condyle fracture

CT:

MR:

Cx:

Prognosis: usually fatal

Atlantoaxial Distraction

May be associated with: type 1 dens fracture

   prevertebral soft-tissue swelling

   subluxation with enlargement of predental space to

   >5 mm in children <9 years of age

   >3 mm in adults

   widening of C1-C2 facets

Dorsal Dermal Sinus

Cause: focal point of incomplete separation of cutaneous ectoderm from neural ectoderm during neurulation
Age: encountered in early childhood 3rd decade; M:F = 1:1
Location: lumbosacral (60%), occipital (25%), thoracic (10%), cervical (2%), sacrococcygeal (1%), ventral (8%)
Course: in a craniad direction from skin level toward cord (due to ascension of cord relative to spinal canal during embryogenesis)

P.207

   50% of dorsal dermal sinuses end in dermoid / epidermoid cysts!

   20 30% of dermoid cysts / dermoid tumors are associated with dermal sinus tracts!

Cx:

DDx: pilonidal sinus / simple sacral dimple (no extension to neural structures)

Epidermoid of Spine

Prevalence: 1% of spinal cord tumors
Age at presentation: 3rd 5th decade; M > F
May be associated with: dermal sinus
Location: upper thoracic (17%), lower thoracic (26%), lumbosacral (22%), cauda equina (35%)
Site: extramedullary (60%), intramedullary (40%)

   almost always complete spinal block on myelography

   displacement of spinal cord / nerve roots

   small tumors isointense to CSF

   NO contrast enhancement

   CT myelography facilitates detection

Epidural Abscess of Spine

Cause: diskitis, osteomyelitis, idiopathic

MR:

Epidural Hematoma of Spine

Pathophysiology: tearing of epidural veins
Mean age: 41 52 years
Location: cervical > thoracic > lumbar spine
Site: anterior / posterior to cord

spinal cord compression

high attenuation lesion on CT
Rx: conservative management

Fractures of Skull

Linear fracture (most common type) deeply black sharply defined line

DDx:

Depressed fracture

Cx: infection, acute / delayed cranial nerve deficit, vascular laceration / dissection / occlusion / infarction

LeFort Fracture

[Ren LeFort (1869 1951), French surgeon]

All LeFort fractures involve the pterygoid process!

Sphenoid Bone Fracture

Prevalence: involved in 15% of skull-base fractures

Temporal Bone Fracture

Longitudinal Fracture of Temporal Bone (75%)

Plain film views: Stenvers / Owens projection

P.209

Transverse Fracture of Temporal Bone (25%)

Plain film views: posteroanterior (transorbital) + Towne projection

Zygomaticomaxillary Fracture

Cause: direct blow to malar eminence

Blowout Fracture

Cause: sudden direct blow to globe (ball or fist) with increase in intraorbital pressure transmitted to the weak orbital floor
Associated with: fracture of the thin lamina papyracea (= medial orbital wall) in 20 50%

soft-tissue mass extending into maxillary sinus (= herniation of orbital fat)

complete opacification of maxillary sinus (edema + hemorrhage)

depression of orbital floor (= orbital process of maxilla)

posttraumatic atrophy of orbital fat leads to enophthalmos

opacification of adjacent ethmoid air cells

disruption of lacrimal duct

Fractures of Cervical Spine

Factors associated with higher risk of fracture:

Indications for screening CT of cervical spine:

high-risk adult patients (= >5% pretest probability of injury) defined by:

Frequency: 1 3% of all trauma cases;

C2, C6 > C5, C7 > C3, C4 > C1

   Cervical spine trauma accounts for 2/3 of all spinal cord injuries!

neurologic / spinal cord damage (39 50%)

Location:

Site: vertebral arch (50%), vertebral body (30%), intervertebral disk (25%), posterior ligaments (16%), dens (14%), locked facets (12%), anterior ligament (2%)
Associated with injury to: head (70%), thoracic spine (15%), lumbar spine (10%), thorax (35%), pelvis (15%), upper extremity (10%), lower extremity (30%)
N.B.: 5 8% of patients with fractures may have normal radiographs!

   Most missed fractures involve C1 (8%), C2 (34%), C4 (12%), C6-7 (14%), occipital condyles

   C7 T1 space not visualized in at least 26% of all trauma patients
Cx: neurologic deterioration with delay in diagnosis

Significant Signs of Cervical Vertebral Trauma

Atlas Fracture

Prevalence: 4% of cervical spine injuries
Site: posterior arch, anterior arch, massa lateralis, Jefferson fracture
Associated with: fractures of C7 (25%), C2 pedicle (15%), extraspinal fractures (58%)

Axis Fracture

Prevalence: 6% of cervical spine injuries
Associated with: fractures of C1 in 8%
Type I = avulsion of tip of odontoid (5 8%) difficult to detect
Type II = fracture through base of dens (54 67%) Cx: nonunion

Axial CT alone misses >50%!
Type III = subdental fracture (30 33%)

Prognosis: good
DDx: os odontoideum, ossiculum terminale, hypoplasia of dens, aplasia of dens

Fractures of Thoracolumbar Spine

40% of all vertebral fractures that cause neurologic deficit; mostly complex (body + posterior elements involved)

Location: 2/3 at thoracolumbar junction

diastasis of apophyseal joints

disruption of interspinal ligament

retropulsion of body fragments into spinal canal

burst fragments at superior surface of body

Fracture of Upper Thoracic Spine (T1 to T10)

Frequency: in 3% of all blunt chest trauma

Types:

Signs of Spinal Instability

Fracture of Thoracolumbar Junction (T11 to L2)

Chance Fracture

Chance Equivalent

Holdsworth Fracture

Seatbelt Injury

P.213

Transverse Process Fracture of Lumbar Spine

Cause: direct trauma, violent lateral flexion-extension forces, avulsion of psoas muscle, Malgaigne fracture
Frequency: 7%
In 21 51% associated injury:

genitourinary injury, hepatic + splenic laceration
Location: L3 > L2 > L1 > L4 > L5; L:R = 2:1; multiple:single = 2:1; unilateral:bilateral = 20:1

vertical:horizontal (94%:6%) fractures

associated lumbar burst / compression fracture

Detection by conventional radiography in 40% only!
Prognosis: minor and stable injury; 10% mortality

Sacral Fracture

Zone 1 = fracture lateral to sacral foramina

    significant neurologic deficit (uncommon)
Zone 2 = fracture through 1 foramina

    unilateral lumbar / sacral radiculopathy (rare)
Zone 3 = fracture through central canal

    significant bilateral neurologic damage (frequent): bowel / bladder incontinence
Cx: chronic disability (in up to 50%)

Glioma of Spinal Cord

Astrocytoma of Spinal Cord

Frequency: 30% of spinal cord tumors; 2nd in prevalence to ependymoma in adults
Mean age: 29 years; M:F = 58:42
Path: ill-defined fusiform cord enlargement without cleavage plane / capsule
Histo: hypercellularity with infiltrative growth along the scaffold of normal astrocytes, oligodendrocytes and axons;

Grade I pilocytic astrocytoma (75%), usually most common in cerebellum

Grade II low-grade fibrillary type

Grade III anaplastic astrocytoma with necrosis (up to 25%)

Grade IV glioblastoma multiforme with endothelial proliferation (0.2 1.5%)
Location: thoracic cord (67%), cervical cord (49%), conus medullaris (3%); on average over 4 7 vertebral segments involved; holocord presentation (in up to 60% in children); often extending into lower brainstem
Site: eccentric within spinal cord (57%) over

  • pain + sensory deficit (54%)

  • motor dysfunction (41%)

  • gait abnormalities (27%)

  • torticollis (27%)
Radiographs:

   scoliosis (24%)

   widened interpedicular distance

   bone erosion

  
MR:

   usually homogeneous extensive ill-defined cord tumor with expansion of spinal cord:

      iso- to hypointense to cord on T1WI

      hyperintense on T2WI

      poorly defined margins

   dilated veins on surface of cord

   patchy irregular Gd-enhancement on MR

   eccentric irregular tumor cysts + polar cysts + syrinx (common):

      water-soluble myelographic contrast enters cystic space on delayed CT images

   leptomeningeal spread (in 60% of glioblastoma multiforme)

  
Rx: tumor debulking + radiation therapy
Prognosis: 95% 5-year survival in low-grade tumors; higher mortality rate than for ependymoma
DDx: ependymoma (cap sign, central location, well defined, hemorrhage common, focal intense enhancement, predilection for conus)

Ependymoma of Spinal Cord

Most common intramedullary spinal neoplasm in adults!

Frequency: 40 60% of primary spinal cord tumors; 90% of primary tumors in the filum terminale
Mean age: 39 years; M:F = 57:43
Origin: ependymal cells lining the central canal (62 76%)
Path: symmetric cord expansion with displacement of neural tissue yielding a cleavage plane
Histo: perivascular pseudorosettes; cystic degeneration (50%); hemorrhage at superior + inferior tumor margins
      Subtypes: cellular (most common), papillary, clear cell, tanycytic, myxopapillary (along filum terminale), melanotic
Location: cervical cord alone (44%) / with extension into thoracic cord (23%); thoracic cord alone (26%); conus medullaris (7%); extends over several vertebral segments (on average 3.6 segments involved)
      ectopic: sacrococcygeal region, broad ligament of ovary (associated with spina bifida occulta [33%])
Site: central within spinal cord

long antecedent history (mean duration of 37 months) due to slow tumor growth:

    back / neck pain (67%) = compression / interruption of central spinothalamic tracts first

    sensory deficits (52%), motor weakness (46%)

    bowel / bladder dysfunction (15%)
Metastases to: lung, retroperitoneum, lymph nodes well-demarcated / diffusely infiltrating cord tumor associated with at least one cyst (in 78 84%):

   polar cysts (62%) at cranial and caudal aspect of tumor, which do not contain malignant cells

   tumoral cysts (4 50%), which may contain tumor

   syringohydromyelia (9 50%)
Radiographs:

   scoliosis (16%)

   widening of spinal canal (11%):

      scalloping of vertebral body

      pedicle erosion, laminar thinning

  
Myelography:

   enlarged cord with complete / partial block to flow of contrast material

  
CT:

   iso- / slightly hyperattenuating cord mass

   intense enhancement

  
MR:

   iso- / hypointense (rarely hyperintense from hemorrhage) mass relative to spinal cord on T1WI

   hyper- / isointense on T2WI

    cap sign = extremely hypointense rim at the tumor poles on T2WI (in 20 33%) due to hemosiderin deposits from prior hemorrhage

   cord edema (60%)

   mostly intense homogeneous enhancement on Gd-enhanced MR (84%)

   well-defined margins on contrast-enhanced images (89%)

  
Prognosis: 82% 5-year survival rate
DDx: astrocytoma (pediatric tumor, eccentric location, ill defined, hemorrhage uncommon, patchy irregular enhancement)

P.214

Myxopapillary Ependymoma of Spinal Cord

= special variant of ependymoma of lower spinal cord

Prevalence: 13% of all spinal ependymomas; most common neoplasm of conus medullaris (83%)
Mean age: 35 years; M>F
Origin: ependymal glia of filum terminale
Path: heterogeneous tumor with generous mucin production
lower back / leg / sacral pain
weakness / sphincter dysfunction
Location: conus medullaris, filum terminale; occasionally multiple (14 43%)

   isointense on T1Wi + hyperintense on T2WI

   occasionally hyperintense on T1WI + T2WI due to mucin content / hemorrhage

   almost always contrast enhancing

   occasionally large lytic area of bone destruction

Subependymoma of Spinal Cord

= variant of CNS ependymoma

Origin: tanycytes [tanyos, Greek = stretch] that bridge pial + ependymal layers
Mean age: 42 years; M:F = 74:26
Histo: sparsely dispersed ependymal cells among predominant fibrillar astrocytes
52 months mean duration of symptoms:

    pain, sensory + motor dysfunction

    atrophy of one / both distal upper extremities (83%)
Location: ventricular system of brain, some in cervical cord

   fusiform dilatation of spinal cord:

      enhancing lesion with well-defined borders (50%)

      nonenhancing lesion with diffuse symmetric cord enlargement

   eccentrically located mass

    edema

Ganglioglioma of Spinal Cord

Prevalence: 0.4 6.2% of all CNS tumors; 1.1% of all spinal neoplasms
Mean age: 12 years; children > adults; M:F = 1:1
Histo: mixture of irregularly oriented neoplastic mature neuronal elements (neurons / ganglion cells) + glial elements (neoplastic astrocytes), arranged in clusters = grade I or II lesions
Location: cervical cord (48%), thoracic cord (22%), conus, holocord (average length of 8 vertebral segments); usually supratentorial (temporal lobe)
duration of symptoms between 1 month and 5 years

scoliosis (44%), spinal remodeling (93%) due to relatively slow growth (rare in astrocytoma / ependymoma)

eccentric

small tumoral cysts (in 46%)

calcifications (rare compared with intracranial tumor)

  
MR:

   mixed tumor signal intensities on T1WI (in 84%)

   tumor homogeneously hyperintense on T2WI

   surrounding edema (less common than in ependymoma / astrocytoma)

   patchy (65%) / no (15%) tumor enhancement

   enhancement of pial surface (58%)

  
Cx: malignant transformation (10%)
Prognosis: slow growth; 89% 5-year and 83% 10-year survival rate; 27% recurrence rate

Hemangioblastoma of spine

= ANGIOBLASTOMA = angioreticuloma

Prevalence: 1 7.2% of all spinal cord tumors; mostly sporadic
Associated with: von Hippel-Lindau disease (in 1/3)
Recommendation: screening MR imaging of brain + spine in patients with von Hippel-Lindau syndrome
Age: middle age; M:F = 1:1
Path: nonglial highly vascular discrete nodular masses abutting leptomeninges with prominent dilated + tortuous vessels on posterior cord surface
Histo: large pale stromal cells of unknown origin packed between blood vessels of varying sizes
Location: intramedullary (75%), radicular (20%), intradural extramedullary (5%); thoracic cord (50%), cervical cord (40%); solitary in >80%, multiple lesions indicate von Hippel-Lindau syndrome + require screening of entire spine
Site: subpial aspect of dorsal spine; may extend exophytically into subarachnoid / extradural space
mean duration of symptoms is 38 months:
    sensory changes (39%): impaired proprioception
    motor dysfunction (31%), pain (31%)
   increased interpediculate distance (mass effect)
Angio:

   highly vascular mass with dense prolonged blush

   large draining veins form sinuous mass along posterior aspect of cord

  
MR:

   iso- (50%) / hyperintense (25%) diffuse cord expansion on T1WI

   hyperintense lesion with intermixed focal flow voids on T2WI:

      curvilinear areas of signal voids

P.215

   cyst formation / syringohydromyelia (in up to 100%):

      intratumoral cystic component (50 60%)

      occasionally cystic mass with enhancing mural nodule (CLASSIC for cerebellar hemangioblastoma)

      densely staining tumor nodule

    surrounding edema and cap sign

   well-demarcated Gd-enhancing mass

  
Cx: intramedullary hemorrhage, hematomyelia, subarachnoid hemorrhage (rare)
DDx: arteriovenous fistula (not well circumscribed, heterogeneous signal intensity)

Klippel-Feil Syndrome

K mmell Disease

Cause: ischemic necrosis weeks to months following an acute fracture
Pathophysiology: intraosseous cleft forms due to a decrease in vertebral volume; low pressure within cleft allows accumulation of gas (principally nitrogen)
Age: >50 years
Location: most commonly at thoracolumbar junction

   collapsed vertebral body

   transverse linear / semilunar radiolucency located centrally within / adjacent to endplate

   gas collection increases with extension + traction, decreases with flexion

Leptomeningeal Cyst

Prevalence: 1% of all pediatric skull fractures
Pathogenesis: skull fracture with dural tear leads to arachnoid herniation into dural defect; CSF pulsations produce fracture diastasis + erosion of bone margins (apparent 2 3 months after injury)

skull defect with indistinct scalloped margins

CSF-density cyst adjacent to / in skull, may contain cerebral tissue

MR:

Lipoma of Spine

Intradural Lipoma

= subpial juxtamedullary mass totally enclosed in intact dural sac

Prevalence: <1% of primary intraspinal tumors
Etiology: abnormal embryonic neurulation
Age peaks: first 5 years of life (24%), 2nd + 3rd decade (55%), 5th decade (16%)
slow ascending mono- / paraparesis, spasticity, cutaneous sensory loss, defective deep sensation (with cervical + thoracic intradural lipoma)
flaccid paralysis of legs, sphincter dysfunction (with lumbosacral intradural lipoma)
overlying skin most often normal
elevation of protein in CSF (30%)
Location: thoracic (30%) / cervicothoracic (24%) / cervical (12%)
Site: dorsal aspect of cord (75%), lateral / anterolateral (25%)

   spinal cord open in midline dorsally

   lipoma in opening between lips of placode

   exophytic component at upper / lower pole of lipoma

   syringohydromyelia (2%)

   focal enlargement of spinal canal adjacent neural foramina

   narrow localized spina bifida

Lipomyelomeningocele

= lipoma tightly attached to exposed dorsal surface of neural placode blending with subcutaneous fat

P.216

Prevalence: 20% of skin-covered lumbosacral masses; up to 50% of occult spinal dysraphism
Age: typically <6 months of age; M < F
semifluctuant lumbosacral mass with overlying skin intact
sensory loss in sacral dermatomes, motor loss, bladder dysfunction
foot deformities, leg pain
Location: lumbosacral; longitudinal extension over entire length of spinal canal (in 7%)
Site:

    lipoma dorsally continuous with subcutaneous fat

    lipoma may extend upward within spinal canal external to dura (= epidural lipoma )

    lipoma may enter central canal and extend rostrally (= intradural intramedullary lipoma )

   deformed undulating spinal cord with dorsal cleft

   tethered cord

   ventral + dorsal nerve roots leave neural placode ventrally

   dilated subarachnoid space

Fibrolipoma of Filum Terminale

Prevalence: 6% of autopsies
asymptomatic
Location: intradural filum, extradural filum, involvement of both portions

thin linear fat-containing mass of filum terminale
Prognosis: potential for development of symptoms of tethered cord

L ckensch del

Age: present at birth
Associated with:

  1. meningocele / myelomeningocele / encephalocele

  2. spina bifida

  3. cleft palate

  4. Arnold-Chiari II malformation
normal intracranial pressure
Location: particularly upper parietal area

   honeycombed appearance about 2 cm in diameter (thinning of diploic space)

premature closure of sutures (turricephaly / scaphocephaly)
Prognosis: spontaneous regression within first 6 months of life
DDx: (1) Convolutional impressions = digital markings (visible at 2 years, maximally apparent at 4 years, disappear by 8 years of age)
  (2) Hammered silver appearance of increased intracranial pressure

Lymphoma of Spinal cord

Prevalence: 3.3% of CNS lymphoma, 1% of all lymphomas
Mean age: 47 years; M<F
Histo: monotonous collection of lymphocytes packed tightly into perivascular space; predominantly B-cell lymphocyte population; no necrosis
weakness, numbness, progressive difficulty in ambulation
Location: cervical > thoracic > lumbar cord
Site: in extradural compartment (most commonly)
MR:

   mostly solitary, rarely multicentric

   isointense relative to cord on T1WI

   hypointense with cord on T2WI (related to high nuclear-to-cytoplasmic ratio)

   extensive cord edema

   hetero- / robust homogeneous enhancement

   restricted diffusion (owing to high cellularity + reduced extracellular matrix)
Cx: compression of cord due to narrowing of spinal canal
Rx: initial response to steroids; radiation therapy results in rapid reduction in size + compressive effects

Meningeal Cyst

= abnormal dilatation of meninges within sacral canal / foramina

Prevalence: 5%

Perineural Sacral Cyst / Tarlov Cyst

Location: posterior rootlets (S2 + S3 most common)

Sacral Meningeal / Arachnoid Cyst (less common)

Meningioma of Spine

Prevalence: 25 45% of all spine tumors; 2 3% of pediatric spinal tumors; 12% of all meningiomas
Age: >40 years + female (80%)
Location: thoracic region (82%); cervical spine on anterior cord surface near foramen magnum (2nd most common location); 90% on lateral aspect
Site: intradural extramedullary (50%); entirely epidural; intradural + epidural
DDx: nerve sheath tumor

Metastasis to Vertebra

Source:

  1. Metastatic tumors: lung, breast, prostate, kidney, lymphoma, malignant melanoma

  2. Primary tumor: multiple myeloma
Pathogenesis: hematogenous spread to vertebral bodies (bones with greatest vascularity)
MR:

   patchy multifocal relatively well-defined lesions

   diminished signal on T1WI on background of high-signal appearance of marrow fat

   increased signal on T2WI (except for blastic metastases with diminished T1 + T2 signals)

   contrast enhancement on T1WI (majority)

   pathologic compression fracture:

      fracture only after all vertebral body fat replaced

      hyperintense on diffusion-weighted images (DDx: hypointense benign osteoporotic fracture)
DDx: (1) Infection (centered around disk space)
  (2) Primary vertebral tumor (rare in older patients, almost always benign in patients <21 years of age)

Metastases to Spinal Cord

Intramedullary Metastasis

Prevalence: 0.9 2.1% of CNS metastases (autoptic)
Origin: lung (40 85%), breast (11%), melanoma (5%), renal cell (4%), colorectal (3%), lymphoma (3%), cerebellar medulloblastoma; 5% of unknown origin
Location: cervical (45%), thoracic (35%), lumbar cord (8%)
Prognosis: 66% die within 6 months
Rx: radiation therapy, corticosteroids

Intradural Metastasis

Dx: CSF analysis (more sensitive than imaging)
DDx: moderate to severe meningitis, benign postoperative arachnoiditis, neurofibromatosis

Metastases from Outside CNS

Drop Metastases

= CSF Seeding of Intracranial Neoplasms

Age: occurs more frequently in pediatric age group than in adults
Location: lumbosacral + dorsal thoracic spine (due to CSF flow / gravitation)
Site: on spinal arachnoid / pia mater

CNS tumors causing drop metastases:

Less common: choroid plexus carcinoma, teratoma, angioblastic meningioma
mnemonic: MEGO TP

Myelocystocele

May be associated with: GI tract anomalies, GU tract anomalies
Location: lower spine > cervical > thoracic spine

   direct continuity of meningocele with subarachnoid space

   cyst communicating with widened central canal of spinal cord typically posteriorly + inferiorly to meningocele

   lordosis, scoliosis, partial sacral agenesis (common)

P.218

Myelomeningocele

Prevalence: 1:1,000 2,000 births (in Great Britain 1:200 births); twice as common in infants of mothers >35 years of age; Caucasians > Blacks > Orientals; most common congenital anomaly of CNS
Etiology: localized defect of closure of caudal neuropore (usually closed by 28 days); persistence of neural placode causes derangement in the development of mesenchymal + ectodermal structures
Recurrence rate: 3 7% chance of NTD with previously affected sibling / in fetus of affected parent
Associated with:

  1. Hydrocephalus (70 90%): requiring ventriculoperitoneal shunt in 90%

    25% of patients with hydrocephalus have spina bifida!

  2. Chiari II malformation (99%)

  3. Congenital / acquired kyphoscoliosis (90%)

  4. Vertebral anomalies (vertebral body fusion, hemivertebrae, cleft vertebrae, butterfly vertebrae)

  5. Diastematomyelia (20 46%): spinal cord split above (31%), below (25%), at the same level (22%) as the myelomeningocele

  6. Duplication of central canal (5%) cephalic to + at level of placode

  7. Hemimyelocele (10%) = two hemicords in separate dural tubes separated by fibrous / bony spur: one hemicord with myelomeningocele on one side of midline, one hemicord normal / with smaller myelomeningocele at a lower level

    impaired neurological function on side of hemimyelocele

  8. Hydromyelia (29 77%) cranial to placode as a result of disturbed CSF circulation

  9. Chromosomal anomalies (10 17%): trisomy 18, trisomy 13, triploidy, unbalanced translocation

       In 20% no detectable associated anomalies!

  10. Tethering of spinal cord (70 90%)

  11. Arachnoid cyst (2%) due to developmental deficiency during formation of arachnoid / dura mater with a subdural location
Distribution: thoracic (2%), thoracolumbar (32%), lumbar (22%), lumbosacral (44%)

Location:

OB-US:

P.219

Sonographic Cranial Signs of Myelomeningocele

Prevalence: in 96% of fetuses 24 weeks; in 91% of fetuses >24 weeks

nonvisualization of cerebellum

effaced cisterna magna (100% sensitivity)

BPD <5th percentile during 2nd trimester (65 79% sensitive)

HC <5th percentile (35% sensitivity)

ventriculomegaly (40 90%) with choroid plexus incompletely filling the ventricles (54 63% sensitivity) = dangling choroid on dependent side

Prevalence: in 44% of myelomeningoceles <24 weeks GA; in 94% of myelomeningo-celes during 3rd trimester

Plain films:

Rx: (1) Possibly elective cesarean section at 36 38 weeks GA (may decrease risk of contaminating / rupturing the meningomyelocele sac)

(2) Repair within 48 hours

Postoperative complications:

Prognosis:

Neurenteric Cyst

= incomplete separation of foregut and notochord with persistence of canal of Kovalevski between yolk sac + notochord; cyst connected to meninges through midline defect

Incidence: rarest of bronchopulmonary foregut malformations (pulmonary sequestration, bronchogenic cyst, enteric cyst)
Associated with: neurofibromatosis; meningocele; spinal malformation (stalk connects cyst and neural canal; usually no stalk between cyst and esophagus)
Location: anterior to spinal canal on mesenteric side of gut posterior mediastinal mass

   air-fluid level (if communicating with GI tract through diaphragmatic defect)

   spinal dysraphism at the same level:

      midline cleft in centra (accommodates stalk)

      anterior / posterior spina bifida

      vertebral body anomalies: absent vertebra, butterfly vertebra, hemivertebra, scoliosis

      diastematomyelia

      thoracic myelomeningocele

Ossifying Fibroma

Peak incidence: first 2 decades of life
Histo: areas of osseous tissue intermixed with a highly cellular fibrous tissue
Sites: maxilla > frontal > ethmoid bone > mandible (rarely seen elsewhere)

   areas of increased + decreased attenuation

   intact inner + outer table

   slow-growing expansile lesion

   usually unilateral + monostotic
DDx: may be impossible to differentiate from fibrous dysplasia

Osteomyelitis of Vertebra

Prevalence: 2 10% of all cases of osteomyelitis

Cause:

Pathophysiology: infection begins in low-flow end-vascular arcades adjacent to subchondral plate
Organism: Staphylococcus aureus, Salmonella
Peak age: 5th 7th decade

  • pain in back, neck, chest, abdomen, flank, hip

  • neurologic deficit

  • fever (most common presenting symptom), leukocytosis

  • increased erythrocyte sedimentation rate

  • positive blood / urine culture

       disk space narrowing (earliest radiographic sign)

       demineralization of adjacent vertebral endplates

       bulging of paraspinal lines

       tracer uptake in adjacent portions of two vertebral bodies decreased marrow signal on T1WI

       iso- / hyperintense marrow signal on T2WI
Cx: secondary infection of intervertebral disk is frequent
Rx: >4 weeks course of IV antibiotics
DDx: diskitis

P.220

Paraganglioma

Mean age: 46 years; M > F
Path: soft encapsulated (75%) slightly hemorrhagic mass supplied by numerous feeding arteries
Histo: chief cells + sustentacular cells surrounded by fibrovascular stroma; nests of chief cells in classic Zellballen configuration
Location: cauda equina, filum terminale
Site: intradural extramedullary compartment

CT:

MR:

Angio:

Peripheral Nerve Sheath Tumor

Benign Peripheral Nerve Sheath Tumor

= (Benign PNST) = BENIGN TUMOR OF NERVE SHEATH = NEURINOMA

Histo: contains cellular elements closely related to Schwann cell

Plain film:

Angio:

MR, CT:

Ga-67 scintigraphy:

Schwannoma = Neurilemmoma

= usually solitary well-encapsulated benign slowly growing neoplasm arising from Schwann cells resulting in eccentric displacement of nerve fibers

Nerve root NOT incorporated

Prevalence: 5 10% of all benign soft-tissue tumors
Age: 20 30 years
Path: fusiform mass entering + exiting the nerve surrounded by a true capsule of epineurium; mass exophytic to involved nerve with nerve fibers splayed about the neoplasm in large nerves
Histo: S-100 protein positive

Location:

MR:

DDx: may appear similar to meningioma
Rx: excision (affected nerve usually separable from neoplasm after incision of epineurium)

Neurofibroma

= usually multiple often infiltrative tumors of nerve sheath separating nerve fibers resulting in fusiform enlargement of nerve

Prevalence: 5% of all benign soft-tissue tumors
Histo: swirls of neuronal elements containing Schwann cells, nerve fibers, fibroblasts, collagen in a myxoid / mucinous matrix
Association: HALLMARK lesion of NF1 (= neurofibromatosis type 1)
Age: 20 30 years; M:F = 1:1

   Malignant transformation exceedingly rare!

   The spinal neurofibroma is rarely sporadic and usually a sign of type 1 neurofibromatosis!

   Only 10% of patients with neurofibromas have von Recklinghausen disease!
Location: skin, soft tissues, viscera; any level, but particularly cervical

MR:

DDx: conjoined nerve root sleeve
Rx: surgical resection with sacrifice of nerve (tumor not separable from normal nerve)

Localized Neurofibroma

Prevalence: 90% of all neurofibromas
Path: fusiform tumor, often remaining within epineurium as a true capsule
Histo: interlacing fascicles of wavy elongated cells containing abundant amounts of collagen
Location: affecting primarily superficial cutaneous nerves, occasionally deep-seated larger nerves

mostly solitary slow-growing lesion <5 cm in size

Diffuse Neurofibroma

Age: children + young adults
Path: poorly defined lesion within subcutaneous fat, infiltrating along connective tissue septa, inseparable from normal nerve tissue
Histo: very uniform prominent fibrillary collagen
Location: most frequently in subcutaneous tissues of head + neck

plaquelike elevation of skin with thickening of entire subcutis

Plexiform Neurofibroma

= involvement of a long segment of nerve + branches extending into adjacent muscle, fat, subcutaneous tissue

Location: nerve plexus / multiple fascicles in a medium- to large-sized nerve

= PATHOGNOMONIC of neurofibromatosis type 1

serpentine bag of worms appearance = tortuous tangles / fusiform enlargement of a branching peripheral nerve

ropelike mass involving nonbranching nerve

reticulated linear branching pattern within subcutaneous tissue

Cx: potential for malignant transformation to malignant peripheral nerve sheath tumor

Malignant Peripheral Nerve Sheath Tumor

= (MPNST) Malignant TUMOR OF Nerve Sheath = Neurofibrosarcoma = Malignant schwannoma = Neurogenic Spindle Cell Sarcoma

Prevalence: 5 10% of all soft-tissue sarcomas;

4 5% lifetime risk in NF1
Age: 20 50 years (mean, 26 years); M:F = 8:1
Associated with: neurofibromatosis type 1 (in 25 70%), radiation therapy (in 11% of all malignant PNSTs after a latent period of 10 20 years)
Histo: tumor cells arranged in fascicles resembling fibrosarcoma; additional heterotopic foci with mature cartilage and bone, rhabdomyosarcoma elements, glandular and epithelial components (in 10 15%)

P.222

Location: paraspinal region of abdomen (sciatic n., sacral plexus, brachial plexus)
Metastases: lung, bone, pleura, retroperitoneum (60%); regional lymph nodes (9%)

   fusiform mass with entering + exiting nerve

   frequently indistinct margins

   sudden increase in size of a previously stable neurofibroma

   frequently areas of hemorrhage + necrosis
Rx: resection + adjuvant chemo- and radiation therapy with local recurrence in 40%
Prognosis: highly aggressive tumor with a 44% 5-year survival rate

Primitive Neuroectodermal Tumor of Spinal Cord

Prevalence: 20 cases reported in literature
Location: spinal cord, intradural-extramedullary compartment, extradural compartment
Age: more common in adults than children; M:F = 6:4
Histo: small round blue cells with hyperchromatic nuclei + scanty cytoplasm, frequent mitoses
weakness, paresthesia, gait disturbance, pain
Spread: throughout CSF space into cranium, lung, bone, lymph node

T1 and T2 prolongation
Prognosis: in >50% death within 2 years

Sacrococcygeal Teratoma

Prevalence: 1:40,000 livebirths; type I + II (80%); most common congenital solid tumor in the newborn; M:F = 1:4

Pathogenesis:

Histo:

Metastases to: lung, bone, lymph nodes (inguinal, retroperitoneal), liver, brain
Age: 50 70% during first few days of life; 80% by 6 months of age; <10% >2 years of age; rare in adulthood; M:F = 1:4

Classification (Altman):

Associated with: other congenital anomalies (in 18%):

Plain film:

BE:

IVP:

Myelography:

Angio:

US / CT:

MR:

Prognosis: prevalence of malignant germ cell tumors increases with patient's age

   predominantly fatty tissue tumors are usually benign hemorrhage / necrosis is suggestive of malignancy cystic lesions are less likely malignant

   sacral destruction indicates malignancy

   patients >2 months of age have a malignant tumor with a 50 90% probability
Cx: (1) dystocia in 6 13%

(2) massive intratumoral hemorrhage

(3) fetal death in utero / stillbirth
Rx: 1. Complete tumor resection + coccygectomy + reconstruction of pelvic floor: up to 37% recurrence rate, esp. without coccygectomy

2. Multiagent chemotherapy (in malignancy) with long-term survival rate of 50%
DDx: (1) Myelomeningocele (superior to sacrococcygeal region, not septated, axial bone changes)

(2) Rectal duplication, anterior meningocele (purely cystic)

(3) Hemangioma, lymphangioma, lipomeningocele, lipoma, epidermal cyst, chordoma, sarcoma, ependymoma, neuroblastoma

Scheuermann Disease

= SPINAL OSTEOCHONDROSIS = KYPHOSIS DORSALIS juvenilis = VERTEBRAL EPIPHYSITIS

= disorder consisting of vertebral wedging + endplate irregularity + narrowing of intervertebral disk space

Prevalence: in 31% of male + 21% of female patients with back pain
Age: onset at puberty
Location: lower thoracic / upper lumbar vertebrae; in mild cases limited to 3 4 vertebral bodies

anterior wedging of vertebral body of >5

increased anteroposterior diameter of vertebral body

slight narrowing of disk space

kyphosis of >40 / loss of lordosis; scoliosis

Schmorl nodes (intravertebral herniation of nucleus pulposus into vertebral body) = depression in contour of endplate in posterior half of vertebral body; found in up to 30% of adolescents + young adults

flattened area in superior surface of epiphyseal ring anteriorly = avulsion fracture of ring apophysis due to migration of nucleus pulposus through weak point between ring apophysis + vertebral endplate (fusion of ring apophysis usually occurs at about 18 years of age)

detached epiphyseal ring anteriorly
DDx: (1) Developmental notching of anterior vertebrae (NO wedging or Schmorl nodes)

(2) Osteochondrodystrophy (earlier in life, extremities show same changes)

Seronegative Spondyloarthritis

= group of joint conditions not associated with rheumatoid factor / rheumatoid nodules

Prevalence: 0.5 1.9%

Subgroups:

Extraaxial involvement:

Prognosis: ankylosing spondylitis
Rx: NSAID, TNF (tumor necrosis factor) inhibitors, intensive physical therapy

Anterior and Posterior Spondylitis

Spondylodiskitis

Prevalence: 8% of patients with ankylosing spondylitis irregularities / erosions of central portion of vertebral endplates

Spinal Stenosis

= encroachment on central spinal canal, lateral recess, or neuroforamen by bone / soft tissue

Cause:

Age: middle-aged for congenital cause / elderly during 6th 8th decade for acquired cause; M > F
Location: generally involves lumbar spinal canal; cervical spinal canal may be similarly affected

obliteration of epidural fat

interpedicular distance <25 mm

Measurements are not a valid indicator of disease!

Cervical Spinal Stenosis

Location: multiple levels in mid- and lower cervical spine

Lumbar Spinal Stenosis

Cause:

Age: presentation between 30 and 50 years of age

Split Notochord Syndrome

= spectrum of anomalies with persistent connection between gut + dorsal ectoderm

Etiology: failure of complete separation of ectoderm from endoderm with subsequent splitting of notochord and mesoderm around the adhesion about 3rd week of gestation

fistula / isolated diverticula / duplication / cyst / fibrous cord / sinus along the tract

Types:

Spondylolisthesis

= displacement of one vertebra over another

Direction: anterolisthesis, retrolisthesis, lateral translation
Prevalence: 4% of general population
Cause: fracture, infection of anterior column, bone tumor, isthmic spondylolisthesis, scoliosis, degenerative disk disease
Grades I IV (Meyerding method): each grade equals 1/4 anterior subluxation of upper on lower vertebral body

Isthmic Spondylolisthesis = open-arch type

= separation of anterior part (vertebral body, pedicles, transverse processes, superior articular facet) slipping forward from posterior part (inferior facet, laminae, dorsal spinous process)

P.225

Spondylolysis

Cause: usually bilateral spondylolysis
Age: often <45 years
Location: L5-S1 or L4-5
symptomatic if intervertebral disk + posterosuperior aspect of vertebral body encroaches on superior portion of neuroforamen

elongation of spinal canal in anteroposterior diameter

bilobed configuration of neuroforamen

ratio of maximum anteroposterior diameter of spinal canal at any level divided by diameter at L1 >1.25

Degenerative Spondylolisthesis = closed-arch type

Cause: degenerative / inflammatory joint disease (eg, rheumatoid arthritis)
Pathophysiology: excess motion of facet joints allowing forward / posterior movement
Age: usually >60 years; M < F (at L4-5)
commonly symptomatic due to spinal stenosis + narrowing of neuroforamen

narrowing of spinal canal

hypertrophy of facet joints

ratio of maximum anteroposterior diameter of spinal canal at any level divided by diameter at L1 <1.25

Spondylolysis

= pars interarticularis defect between superior + inferior articulating processes as the weakest portion of spinal unit

Prevalence: 3 7% of population; in 30 70% other family members afflicted
Age: early childhood; M:F = 3:1; Whites:Blacks = 3:1

Cause:

symptomatic in 50% (if associated with degenerative disk disease / spondylolisthesis)

Location: L5 (67 95%); L4 (15 30%); L3 (1 2%); in 75% bilateral

Plain film:

Planar / SPECT bone scintigraphy may be useful!

CT:

Spondylolysis of Cervical Spine

Prevalence: 5 10% at age 20 30; >50% at age 45; >90% by age 60
spastic gait disorder
neck pain
Location: C4-5, C5-6, C6-7 (greater normal cervical motion at these levels)

Sequelae:

DDx of myelopathy:

Syringohydromyelia

Age: primarily childhood / early adult life
Cause: Chiari I malformation (41%), trauma (28%), neoplasm (15%), idiopathic (15%)
Location: predominantly lower end of cervical cord; extension into brainstem (= syringobulbia)
DDx: pseudosyrinx = truncation artifact consisting of linear abnormal signal within cord on sagittal images in phase-encoding direction (due to limited number of frequencies for fast Fourier transform)

Hydromyelia

Histo: lined by ependymal tissue
DDx: transient dilatation of the central canal (transient finding in newborns during the first weeks in life)

Syringomyelia

Histo: not lined by ependymal tissue
Pathophysiology: interrupted flow of CSF through the perivascular spaces of cord between subarachnoid space + central canal

Reactive Cyst

Teratoma of spine

= neoplasm containing tissue belonging to all 3 germinal layers at sites where these tissues do not normally occur

Prevalence: 0.15% (excluding sacrococcygeal teratoma)
Age: all ages; M:F = 1:1
Path: solid, thin- / thick-walled partially / wholly cystic with clear / milky / dark cyst fluid, uni- / multilocular, presence of bone / cartilage
Location: intra- / extramedullary

complete block at myelography

syringomyelia above level of tumor

spinal canal may be focally widened

Terminal Myelocystocele

= combination of posterior spina bifida + meningocele + tethered cord + hydromyelia + cystic dilatation of the distal central canal
Cause: disturbed CSF circulation resulting in dilatation of ventriculus terminalis + disruption of dorsal mesenchyme
Associated with: anorectal + genitourinary + vertebral anomalies (anal atresia, cloacal exstrophy, scoliosis, sacral agenesis)
skin-covered mass in lumbosacral region

spinal cord surrounded dorsally + ventrally by dilated subarachnoid space of the meningocele

nerve root exit ventrally

bifid spinal cord

hydromyelia

Tethered cord

P.227

RULE OF THREES: above L3 by age 3 months!

Etiology: incomplete involution of distal spinal cord with failure of ascent of conus
Pathophysiology: stretching of cord leads to vascular insufficiency at level of conus
Age at presentation: 5 15 years (in years of growth spurt); M:F = 2:3
Associated with: filar lipoma in 29 78%, filar cyst, diastematomyelia, imperforate anus

MR:

Rx: decompressive laminectomy / partial removal of lipoma freeing of cord
Dx: tip of conus medullaris below L2-3

Traumatic Neuroma

= nonneoplastic proliferation of the proximal end of a severed / partially transected injured nerve

Histo: nonencapsulated tangled multidirectional regenerating axonal masses + Schwann cells + endo- and perineural cells in dense collagenous matrix with surrounding fibroblasts

Types:

Time of onset: 1 12 months after injury

Location: lower extremity (after amputation), head and neck (after tooth extraction), radial nerve, brachial plexus

fusiform mass / focal enlargement with entering and exiting nerve (spindle type)

bulbous mass in continuity with normal nerve proximally (lateral / terminal type)

MR:

Rx: acupuncture, cortisone injection, transcutaneous / direct nerve stimulation, physical therapy, surgical resection

Ventriculus Terminalis

= small ependyma-lined oval cyst at the transition from the tip of the conus medullaris to the origin of the filum terminale

Origin: result of canalization and regressive differentiation of the caudal end of the developing spinal cord during embryogenesis
Size: 8 10 mm long, 2 4 mm in diameter

Regresses during the first weeks after birth

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P.229

Differential Diagnosis of Brain Disorders

Birth trauma

Increased intracranial pressure

Prolactin elevation

Normal level: up to 25 ng/mL

Cause:

Stroke

= generic term designating a heterogeneous group of cerebrovascular disorders

Incidence:

Age: >55 years (12% occur in young adults); M:F = 2:1

Risk factors: heredity, hypertension (50%), smoking, diabetes (15%), obesity, familial hypercholesterolemia, myocardial infarction, atrial fibrillation, congestive heart failure, alcoholic excess, substance abuse, oral contraceptives, pregnancy, high anxiety + stress

Etiology:

Prognosis:

Clinical diagnosis inaccurate in 13%!

Role of imaging:

Indications for cerebrovascular testing:

Temporal classification:

Prognosis: 6 11% recurrent stroke rate

Transient ischemic attack

= brief episode of transient focal neurological deficit owing to ischemia of <24 hours duration with return to pre-attack status

Incidence: 31 per 100,000 population per year; increasing with age up to 300; 105,000 new cases per year in United States; M > F

Cause:

Risk factors:

Prognosis: 5.3% stroke rate per year for 5 years after first TIA; per year 12% increase of stroke / myocardial infarction / death; complete stroke in 33% within 5 years; complete stroke in 5% in 1 month

Carotid Transitory Ischemic Attack (2/3)

Vertebrobasilar Transient Ischemic Attack (1/3)

Accelerating / crescendo TIA

= repeated periodic events of neurologic dysfunction with complete recovery to normal in interphase

Rx:

Dementia

Trigeminal Neuropathy

Classification of CNS anomalies

Absence of Septum Pellucidum

Phakomatoses

Degenerative diseases of cerebral hemispheres

= progressive fatal disease characterized by destruction / alteration of gray and white matter

Etiology: genetic; viral infection; nutritional disorders (eg, anorexia nervosa, Cushing syndrome); immune system disorders (eg, AIDS); exposure to toxins (eg, CO); exposure to drugs (eg, alcohol, methotrexate + radiation)

Leukodystrophy

Leukoencephalopathy

Myelinoclastic / Demyelinating Disease

Dysmyelinating Disease

Vascular disease of brain

Classification of Vascular CNS Anomalies

Occlusive Vascular Disease

Cause:

Multiple Infarctions

Location: usually bilateral + supratentorial (3/4); supra- and infratentorial (1/4)

Brain atrophy

Cerebral Atrophy

= irreversible loss of brain substance + subsequent enlargement of intra- and extracerebral CSF-containing spaces (hydrocephalus ex vacuo = ventriculomegaly)

Cerebellar Atrophy

Hippocampal Atrophy

Brain herniation

= shift of normal brain to another site due to mass effect by tumor, trauma or infection

Transtentorial Herniation

Subfalcine Herniation

Alar / Retroalar / Sphenoid Herniation

= herniation of frontal lobe posteriorly across edge of sphenoid ridge

Associated with: transtentorial + subfalcine herniation

Transforaminal Herniation

= herniation of inferior mesial portions of cerebellum downward through foramen magnum (= inferior tonsillar)

Cx: obtundation death

Displacement of vessels

Hypodense brain lesions

Diffusely Swollen Hemispheres

Brain Edema

= increase in brain volume due to increased tissue-water content (80% for gray matter + 68% for white matter is normal)

Etiology:

Types:

CT:

MR:

US:

Midline Cyst

Cyst with Mural Nodule

Multiple Tiny CNS Cysts

Cholesterol-containing CNS Lesions

Mesencephalic Low-density Lesion

P.237

Intracranial Pneumocephalus

Mechanism of dural laceration:

Time of onset: on initial presentation (25%), usually seen within 4 5 days, delay up to 6 months (33%)

Mortality: 15%

Cx:

Hyperdense intracranial lesions

Intracranial Calcifications

mnemonic: PINEEAL

Physiologic Intracranial Calcification

Increased Density of Falx

Intraparenchymal Hemorrhage

mnemonic: ITHACANS

Dense Cerebral Mass

Substrate: calcification / hemorrhage / dense protein

Brain masses

Classification of Primary CNS Tumors

Incidence: 9% of all primary neoplasms (5th most common primary neoplasm); 5 10 cases per 100,000 population per year; account for 1.2% of autopsied deaths

CNS Tumors Presenting at Birth

CNS Tumors in Pediatric Age Group

Incidence:

2.4:100,000 (<15 years of age); 2nd most common pediatric tumor (after leukemia); 15% of all pediatric neoplasms; 15 20% of all primary brain tumors; M > F

Supratentorial Tumor with Mural Nodule

Supratentorial Midline Tumors

Differences between Meningioma and Schwannoma

  Meningioma Schwannoma
Angle with dura obtuse acute
Dural tail frequent rare
Calcification 20% rare
Cystic/necrotic rare 10%
IAC involvement rare 80%
NECT hyperdense isodense
Enhancement uniform 32% nonuniform

Classification by Histology

Superficial Gliomas

= peripherally located cortical neoplasms serving as a seizure focus

Multifocal CNS Tumors

Multifocal Deep Hemispheric Masses

CNS Tumors Metastasizing Outside CNS

mnemonic: MEGO

Large Heterogeneous Intracerebral Mass

Mass with Large Tumor Vessels and Edema

Avascular Mass of Brain

mnemonic: TEACH

Calcified Intracranial Mass

mnemonic: Ca2+ COME

Enhancing brain lesions

Solitary Ring-enhancing Lesion of Brain

Pathogenesis:

Incidence of ring blush:

mnemonic: MAGICAL DR

P.241

Small Spherical Ring-enhancing Lesion at Corticomedullary Margin & Substantial Amount of Vasogenic Edema

Well-defined Superficial Enhancing Mass

Dense & Enhancing Lesions

Multifocal Enhancing Lesions

Innumerable Small Enhancing Cerebral Nodules

Enhancing Lesion in Internal Auditory Canal

Brain ventricles

Ventriculomegaly

Colpocephaly

= dilatation of trigones + occipital horns + posterior temporal horns of lateral ventricles

Enhancing Ventricular Margins

Intraventricular Tumor

Prevalence: 10% of all intracranial neoplasms

Supratentorial Intraventricular Tumors

Uniformly Enhancing Tumor in Trigone of Lateral Ventricle

Dense Lesion near Foramen of Monro

Tumor in 3rd Ventricle

Tumor in 4th Ventricle

Periventricular region

Periventricular Calcifications in Childhood

Periventricular Hypodensity

Periventricular T2-hyperintense Lesions

Multifocal Black Dots on T2 + T2* GRE

= chronic microbleeds, blooming on T2* GRE

Basal ganglia

Bilateral Basal Ganglia Lesions in Childhood

Acute Basal Ganglia Lesions in Childhood

Chronic Basal Ganglia Lesions in Childhood

Low-attenuation Lesion in Basal Ganglia

Basal Ganglia Calcification

Prevalence in children: 1.1 1.6%

mnemonic: BIRTH

Multiple Small Enhancing Lesions in Deep Nuclei

Linear Echogenic Foci in Thalamus + Basal Ganglia

Eye-of-the-Tiger Sign

= markedly hypointense globus pallidus on T2WI surrounding a higher-intensity center

Cause: excess iron accumulation + central gliosis

Associated with: Hallervorden-Spatz syndrome (Hallervorden-Spatz disease, dementia, tetraparesis, neurofibrillary tangles, retinitis pigmentosa, acanthocytosis, pallidal degeneration, X-linked disorders with mental retardation + Dandy-Walker malformation, disorders with Lewy bodies); extrapyramidal parkinsonian disorders

No Caption Available.

Meninges

Diffuse Dural Thickening

Dural Tail Sign

= curvilinear area of enhancement tapering off from the margin of the lesion along dural surface (due to dural tumor infiltration / reactive inflammatory hypervascularity)

Leptomeningeal Disease

Gyral Enhancement

Extraaxial lesions

Extraaxial Tumor

mnemonic: MABEL

Low-attenuation Extraaxial Lesion

Pericerebral Fluid Collection in Childhood

Subdural Fluid Collection

Jugular Foramen Mass

Dumbbell Mass Spanning Petrous Apex

Cerebellopontine Angle Tumor

= extraaxial tumor arising in CSF-filled space bound by pons + cerebellar hemisphere + petrous bone

Incidence: 5 10% of all intracranial tumors

Types:

Corpus Callosum Lesion

Ring-enhancing Lesion Crossing Corpus Callosum

mnemonic: GAL

Posterior fossa

Posterior Fossa Cystic Malformation

Cystic Mass in Cerebellar Hemisphere

Sella

Destruction of Sella

J-shaped Sella

mnemonic: CONMAN

Enlarged Sella

mnemonic: CHAMPS

Pituitary Gland Enlargement

Complex Sellar / Parasellar Cyst

Intrasellar Mass

Hypointense Lesion of Sella

Parasellar Mass

Suprasellar Mass

Suprasellar Mass in Adulthood

mnemonic: SATCHMO

Suprasellar Mass with Low Attenuation

Suprasellar Low-density Lesion with Hydrocephalus

N.B.: Cystic lesion may be inapparent within surrounding CSF; metrizamide cisternography is helpful in detection + to exclude aqueduct stenosis

Suprasellar Mass with Mixed Attenuation

Suprasellar Mass with Calcification

Suprasellar Mass with T1 Shortening (Hyperintensity)

Suprasellar Mass with Uniform Enhancement

Enhancing Supra- and Intrasellar Mass

Perisellar Vascular Lesion

Lesion Expanding Cavernous Sinus

Pineal gland

Classification of Pineal Gland Tumors

Incidence of pineal mass:

Metastasis: eg, lung carcinoma

DDx considerations:

female: likely NOT germ cell tumor

hypodense matrix: likely NOT pineal cell tumor

distinct tumor margins: probably pineocytoma / teratoma / germinoma

calcification: likely NOT teratocarcinoma, metastasis, germinoma

CSF seeding: NOT teratoma

intense enhancement: likely NOT teratoma

Serum markers:

choriocarcinoma -HCG

embryonal cell carcinoma -FP and -HCG

endodermal sinus tumor -FP

teratoma -HCG and -FP

germinoma placental alkaline phosphatase

Intensely Enhancing Mass in Pineal Region

P.251

Anatomy of Brain

Embryology

Neurulation

neural plate = CNS originates as a plate of thickened ectoderm on the dorsal aspect of the embryo

neural crest = elevation of the lateral margins of the neural plate; forms the peripheral nervous system

neural tube = invagination between the two neural crests; its wall forms the brain + spinal cord; its lumen forms the ventricles + spinal canal

4.6 weeks MA: formation of neural tube

5.6 weeks MA: rostral neuropore closes

5.9 weeks MA: caudal neuropore closes

6.0 weeks MA: 3 primary brain vesicles develop (prosencephalon, mesencephalon, rhombencephalon) development of cervical flexure

7.0 weeks MA: 2 additional primary brain vesicles form out of rhombencephalon (pontine flexure divides into myelencephalon, metencephalon)

15 weeks MA: dorsal portion of alar plates bulging into 4th ventricle have fused in midline to form cerebellar vermis

Brain Growth

Neuronal Migration

7th  week subependymal neuronal proliferation = germinal matrix

8th  week radial migration to cortex along radial glial fibers

Sagittal Section through Brain at 10 11 Weeks GA

Myelination

Progression:  caudal to cranial; posterior to anterior

MR:  T1WI if <7 months of age; T2WI if >7 months of age

Classification of brain anatomy

Scalp

The outer 3 layers are often torn off as a unit in accidents; wounds do not gape if epicranius not involved

Meninges of brain

Cerebrospinal fluid

Cerebral Aqueduct

Septum pellucidum

Basal nuclei

= BASAL GANGLIA (earlier incorrect designation)

Pituitary gland

=  hypophysis CEREBRI within hypophyseal fossa of sphenoid, covered superiorly by sellar diaphragm (= dura mater) which has an aperture for the infundibulum centrally

Cavernous Sinus

(coronal view)

P.253

Coronal Section through Anterior Commissure

Axial Section through Level of Third ventricle

Coronal Section through Ventral Part of Pons

Size:  

Shape:

Anterior Lobe of Pituitary Gland

Pars Intermedia of Pituitary Gland

Posterior Lobe of Pituitary Gland

Pituitary Stalk / Infundibulum

Pineal gland

Trigeminal nerve (V)

Facial nerve (VII)

Perihippocampal fissures

Cerebral vessels

Common Carotid Artery

Carotid Bifurcation

= physiologic stenosis due to inertial forces of blood flow diverting main-flow stream from midvessel to a path along vessel margin at flow divider

Coronal Section through Right Mesial Temporal Lobe

(CA1 through CA4 = hippocampus)

P.257

Location:  lateral to upper border of thyroid cartilage; at level of C3-4 intervertebral disk

Branches:  ECA arises anterior + medial to ICA (95%)

External Carotid Artery Branches

mnemonic:  All Summer Long Emily Ogled Peter's Sporty Isuzu

Internal Carotid Artery

Carotid Siphon

Flow direction:  C4 C1

(a) C4 segment = before origin of ophthalmic a.
(b) C3 segment = genu of ICA
(c) C2 segment = supraclinoid segment after origin of ophthalmic a.
(d) C1 segment = terminal segment of ICA between pCom + ACA

Anterior Cerebral Artery (ACA)

Middle Cerebral Artery

Posterior Cerebral Artery

originates from bifurcation of basilar artery within inter-peduncular cistern (in 15% as a direct continuation of posterior communicating artery); lies above oculomotor nerve and circles midbrain above the tentorium cerebelli

Arterial Anastomoses of the Brain

Anastomoses via Arteries at the Base of the Brain

Anastomoses via Surface Vessels

P.259

Rete Mirabile

Ophthalmic Artery

Cerebral Veins

Important vascular markers:

Anastomoses between ICA and ECA and Vertebral Artery

P.260

Cerebellar vessels

Vertebral Artery

originates from subclavian a. proximal to thyrocervical trunk; left vertebral a. usually greater than right cerebral a.; left vertebral a. may originate directly from aorta (5%)

Anterior Inferior Cerebellar Artery

Posterior Inferior Cerebellar Artery

Arterial Supply of the Cerebellum - Inferior View

P.261

Superior Cerebellar Artery

Posterior Inferior Cerebellar Artery

1,2 = lines to establish orthotopic choroid point (see text)

Vascular Territories of Cerebellum

Vascular Territories of Brainstem

P.262

P.263

Brain Disorders

Abscess of Brain

Pyogenic Abscess

Cause:

Predisposed: diabetes mellitus, patients on steroids / immunosuppressive drugs, congenital / acquired immunologic deficiency
Organism: anaerobic streptococcus (most common), bacteroides, staphylococcus; in 20% multiple organisms; in 25% sterile contents

Pathophysiology:

Stage I: vascular congestion, petechial hemorrhage, edema
Stage II: cerebral softening + necrosis
Stage III: (after 2 3 weeks) liquefaction, cavitation + capsule consisting of inner layer of granulation tissue, a middle collagenous layer and an outer astroglial layer; edema outside abscess capsule
Location: typically at corticomedullary junction; frontal + temporal lobes; supratentorial: infratentorial = 2:1

NCCT:

CECT:

MR: (most sensitive modality)
Cx:
  1. (1) Development of daughter abscesses toward white matter

  2. (2) Rupture into ventricular system / subarachnoid space (thinner abscess capsule formation on medial wall of abscess related to fewer blood vessels) producing ventriculitis meningitis

Dx helpful features:

DDx: primary / metastatic neoplasm, subacute infarction, resolving hematoma

Granulomatous Abscess

Predisposed: immunocompromised host
Cx: Communicating hydrocephalus (secondary to thick exudate blocking basal cisterns)

Acrania

Incidence: 25 cases reported
Cause: impaired migration of mesenchyme to its normal location under the calvarial ectoderm resulting in failure for development of dura mater + skull + musculature
Time: develops after closure of anterior neuropore during 4th week

May be associated with:

Prognosis: uniformly lethal; progression to anencephaly (brain destruction secondary to exposure to amniotic fluid + mechanical trauma)
DDx: encephalocele, anencephaly, osteogenesis imperfecta, hypophosphatasia

Adrenoleukodystrophy

P.264

Etiology: defective peroxisomal fatty acid oxidation due to impaired function of lignoceryl-coenzyme A ligase with accumulation of saturated very long chain fatty acids (cholesterol esters) in white matter + adrenal cortex + testes
Dx: assay of plasma, red cells, cultured skin fibroblasts for the presence of increased amounts of very long chain fatty acids

Mode of inheritance:

Histo: PAS cytoplasmic inclusions in brain, adrenals, other tissues
Age: 3 10 years (X-linked recessive)
Location: disease process usually starts in central occipital white matter, advances anteriorly through internal + external capsules + centrum semiovale, centripetal progression to involve subcortical white matter, interhemispheric spread via corpus callosum particularly splenium, involvement of optic radiation auditory system pyramidal tract

CT:

MR:

Prognosis: usually fatal within several years after onset of symptoms

Adrenomyeloneuropathy

Agenesis of Corpus Callosum

Incidence: 0.7 5.3%
Cause: congenital, acquired (infarction of ACA)
Histo: axons from cerebral hemispheres that would normally cross continue along medial walls of lateral ventricles as longitudinal callosal bundles of Probst that terminate randomly in occipital + temporal lobes

Associated with:

OB-US (>22 weeks GA):

Angio:

P.265

DDx:
  1. (1) Prominent cavum septi pellucidi + cavum vergae (should not be mistaken for 3rd ventricle)

  2. (2) Arachnoid cyst in midline (suprasellar, collicular plate) raising and deforming the 3rd ventricle and causing hydrocephalus

Partial Agenesis of Corpus Callosum

Aids

Incidence: 1% of population in United States is HIV-seropositive; 187,000 new cases in 1991
Histo: formation of microglial nodules instead of granulomas in 75 80% of autopsied brains

Alexander Disease

Age: as early as first few weeks of life
Location: frontal white matter gradually extending posteriorly into parietal region + internal capsule

CT:

MR:

Prognosis: death in infancy / early childhood

Alzheimer Disease

Incidence: 10% of people >65 years of age; 50% of people >85 years of age

Amyotrophic Lateral Sclerosis

Cause: free radical damage to neurons / autoimmune process / heavy metal toxicity
Age: middle late adulthood; M > F
Path: atrophy of precentral gyrus
Histo: loss of pyramidal + Betz cells in motor cortex; loss of anterior horn cells in spinal cord; swelling of proximal axons of neuronal cells

MR:

DDx: Friedreich ataxia, vitamin B12 deficiency (abnormal signal limited to internal capsule)

Anencephaly

Incidence: 1:1,000 births (3.5:1,000 in South Wales); M:F = 1:4; most common congenital defect of CNS; 50% of all neural tube defects
Recurrence rate: 3 4%
Etiology: multifactorial (genetic + environmental)
Path: absence of cerebral hemispheres + cranial vault; partial / complete absence of diencephalic + mesencephalic structures; hypophysis + rhombencephalic structures usually preserved
Risk factors: family history of neural tube defect; twin pregnancy

Associated anomalies:

Dx: in 100% >14 weeks GA
Prognosis: uniformly fatal within hours to days of life; in 53% premature birth; in 68% stillbirth
DDx: acrania, encephalocele, amniotic band syndrome

Aneurysm of CNS

Etiology:

Risk factors:

Pathogenesis: arterial wall deficient in tunica media + external elastic lamina (natural occurrence with advancing age)

Location of aneurysm:

Angio (all 4 cerebral vessels):

Prognosis:

Cx: subdural hematoma
Surgical mortality rate: 50% for ruptured, 1 3% for unruptured aneurysms

Cavernous Sinus Aneurysm

Age: 20 70 years, peak 5th 6th decade; F >> M
Cause: sinus thrombophlebitis
Site: extradural portion of cavernous sinus ICA
Rx: often inoperable; balloon embolization parent artery occlusion

Giant Aneurysm

Incidence: 25% of all aneurysms
Age: no age predilection; M:F = 2:1
Location: (arise from arteries at the base of the brain)

Skull film:

CECT:

MR:

Cx: subarachnoid hemorrhage in <30%

P.268

Ruptured Berry Aneurysm

Incidence: 28,000 cases/year = 10 cases/10,000 people/year
Age: 50 60 years of age; M:F = 1:2
Rupture size: 5 15 mm

Clues for which aneurysm is bleeding:

mnemonic: BISH

Location of blood suggesting accurately in 70% the site of the ruptured aneurysm:

CAVE: blood may have entered in retrograde manner from subarachnoid location

Multiple CNS Aneurysms

Cause: congenital in 20 30%, mycotic in 22%
mnemonic: FECAL P

Mycotic Aneurysm

Source: subacute bacterial endocarditis (65%), acute bacterial endocarditis (9%), meningitis (9%), septic thrombophlebitis (9%), myxoma
Location: peripheral to first bifurcation of major vessel (64%); often located near surface of brain especially over convexities

NCCT:

CECT:

Cx: develop recurrent bleeding more frequently than congenital aneurysms

Supraclinoid Carotid Aneurysm

Site: (a) at origin of pCom (65%)
  (b) at bifurcation of internal carotid artery (23%)
  (c) at origin of ophthalmic artery (12%) medial to anterior clinoid process; most likely to become giant aneurysm
Presentation: bitemporal hemianopia (extrinsic compression on chiasm)

Aqueductal Stenosis

Embryology:

Incidence: 0.5 1:1,000 births; most frequent cause of congenital hydrocephalus (20 43%); recurrence rate in siblings of 1 4.5%; M:F = 2:1

Etiology:

May be associated with: other congenital anomalies (16%): thumb deformities

P.269

Prognosis: 11 30% mortality

Arachnoid Cyst

Incidence: 1% of all intracranial masses

Origin:

Histo: cyst filled with clear fluid, thin wall composed of cleaved arachnoid membrane lined by ependymal / meningothelial cells
Age: presentation at any time during life
Location: (arise in CSF cisterns between brain + dura)

MR (best modality):

Cx: (1) hydrocephalus (30 60%)
  (2) concurrent subdural / intracystic hemorrhage
Prognosis: favorable if removed before onset of irreversible brain damage
Rx: fenestration / cyst-peritoneal shunting

CT-DDx:

US-DDx:

Arteriovenous Fistula

Cause:

Location:

Arteriovenous Malformation

Prevalence: 0.1%; Most common type of symptomatic vascular malformation!
Histo: affected arteries have thin walls (no elastica, small amount of muscularis); intervening gliotic brain parenchyma between vessels
Age: 80% by end of 4th decade; 20% <20 years of age; peak age 20 40 years
Associated with: aneurysm in feeding artery in 10%
Location: usually solitary (2% multiple)

Vascular supply:

P.270

Skull film:

NCCT:

CECT:

MR:

Pitfalls: (1) signal void in tortuous vessels; (2) nonvisualization of draining veins resulting from spin saturation; (3) difficulty differentiating blood flow from blood clot

Angio:

Cx: (1) Hemorrhage (common): bleeding on venous side due to increased pressure / ruptured aneurysm (5%)
(2) Infarction
Prognosis: 10% mortality; 30% morbidity; 2 3% yearly chance of bleeding increasing to 6% in year following 1st bleed + 25% in year following 2nd bleed

Wyburn-Mason Syndrome

May be associated with: AVMs of posterior fossa, neck, mandible / maxilla presenting in childhood

Astrocytoma

Incidence: 70 75% of all primary intracranial tumors; most common brain tumor in children (40 50% of all primary pediatric intracranial neoplasms)

Location:

Well-differentiated = Low-grade Astrocytoma

Incidence: 9% of all primary intracranial tumors;
  10 15% of gliomas
Age: 20 40 years; M > F
Path: benign nonmetastasizing; poorly defined borders with infiltration of white matter + basal ganglia + cortex; NO significant tumor vascularity / necrosis / hemorrhage; blood-brain barrier may remain intact
Histo: homogeneous relatively uniform appearance with proliferation of well-differentiated multipolar fibrillary / protoplasmic astrocytes; mild nuclear pleomorphism + mild hypercellularity; mitoses rare
Location: posterior fossa in children, supratentorial in adults (typically lobar); distribution proportional to amount of white matter

CT:

MR:

Angio:

Prognosis: 3 10 years postoperative survival; occasionally converting into more malignant form several years after presentation

Anaplastic Astrocytoma

Incidence: 11% of all primary intracranial neoplasms; 25% of gliomas
Path: frequently vasogenic edema; NO necrosis / hemorrhage
Histo: less well differentiated with greater degree of hypercellularity + pleomorphism, multipolar fibrillary / protoplasmic astrocytes; mitoses + vascular endothelial proliferation common
Location: typically frontal + temporal lobes
Distribution: proportional to amount of white matter

MR:

Prognosis: 2 years postoperative survival

Pilocytic Astrocytoma

Incidence: 0.6 5.1% of all intracranial neoplasms Most common pediatric glioma; 85% of all cerebellar + 10% of all cerebral astrocytomas in children
Age: predominantly in children + young adults; 75% in first 2 decades of life; peak age between birth and 9 years of age; M:F = 1:1
Histo: biphasic pattern of compact bipolar pilocytic (hairlike) astrocytes arranged mostly around vessels + loosely aggregated protoplasmic astrocytes undergoing microcystic degeneration
Associated with: neurofibromatosis type 1 (in 15 21% of NF1 patients as the most common tumor)

Location:

common: cerebellum, hypothalamus (around 3rd ventricle), optic nerve / chiasm
less common: cerebral hemispheres (adults), cerebral ventricles, velum interpositum, spinal cord
Site: near ventricles (82%)

Imaging patterns:

CT:

MR:

Prognosis: relatively benign clinical course, almost never recurs after surgical excision; 94% + 79% postsurgical 10-year + 20-year survival; NO malignant transformation to anaplastic form
DDx: metastasis, hemangioblastoma, atypical medulloblastoma

Cerebellar Pilocytic Astrocytoma

Location: cerebellar hemisphere (29 53%), brainstem (34%), vermis (16 71%),

Brainstem Pilocytic Astrocytoma

DDx: fibrillary astrocytoma (dismal prognosis)

Hypothalamic Pilocytic Astrocytoma

Prognosis: may regress spontaneously

Cerebral Pilocytic Astrocytoma

Location: temporal lobe

Optic Pathway Pilocytic Astrocytoma

Pleomorphic Xanthoastrocytoma

Prevalence: 1% of all brain neoplasms
Age: average age of 26 years (range, 5 82 years)
Path: circumscribed tumor attached to meninges with infiltration into surrounding brain
Histo: pleomorphic spindled tumor cells (reactive to glial fibrillary acidic protein) with intracytoplasmic lipid (xanthomatous) deposits in a dense intercellular reticulin network; giant cells; eosinophilic granular bodies; WHO grade II tumor

P.272

Location: supratentorial (98%): temporal (49%) / parietal (17%) / frontal (10%) / occipital (7%) lobe; thalamus; cerebellum; spinal cord
  Its peripheral location is the single most consistent imaging feature

CT:

MR:

Rx: surgical resection (unresponsive to chemotherapy + radiation therapy)
Prognosis: 81% 5-year survival rate; 70% 10-year survival rate; high rate of recurrence; malignant transformation in 20%
DDx: meningioma, glioblastoma multiforme, oligodendroglioma, metastatic disease, infection

Ataxia-Telangiectasia

Incidence: 1:40,000 livebirths
Path: neuronal degradation + atrophy of cerebellar cortex (? from vascular anomalies)
Cx: (1) Bronchiectasis + pulmonary failure (most common cause of death)
  (2) Malignancies (10 15%): lymphoma, leukemia, epithelial malignancies

Benign Macrocephaly of Infancy

Cause: defective reabsorption of CSF at arachnoid villi; commonly familial with autosomal dominant inheritance
Age: presentation between 3 and 12 months
Location: bilateral frontoparietal area + interhemispheric fissure + sylvian fissure + basal cisterns
Cx: subdural hematoma in response to minor impacts
Prognosis: self-limiting transient development that usually resolves by 2 3 years
DDx: (1) Cerebral atrophy (diffuse sulcal prominence not localized to frontoparietal area)
  (2) Spontaneous subdural hematoma (12%)

Binswanger Disease

Cause: arteriosclerosis affecting the poorly collateralized distal penetrating arteries (perforating medullary arteries, thalamoperforators, lenticulostriates, pontine perforators); positive correlation with hypertension + aging
Path: ischemic demyelination / infarction
Age: >60 years
Location: periventricular white matter, centrum semiovale, basal ganglia; subcortical white matter U fibers + corpus callosum are spared

MR:

DDx: leukodystrophy, progressive multifocal leukoencephalopathy, multiple sclerosis

Canavan Disease

Incidence: <100 reported cases
Cause: deficiency of aspartoacyclase leading to accumulation of N-acetylaspartic acid in brain, plasma, urine, CSF
Histo: spongy degeneration of white matter with astrocytic swelling + mitochondrial elongation
Age: 3 6 months

CT:

MR:

Prognosis: death in 2nd 5th year of life
Dx: (1) elevation of N-acetylaspartic acid in urine
  (2) deficiency of aspartoacyclase in cultured skin fibroblasts

Capillary Telangiectasia

May be associated with:

Age: typically in elderly
Location: mostly in pons / midbrain > cerebral cortex > spinal cord; usually multiple / may be solitary
Cx: punctate hemorrhage (uncommon), gliosis + calcifications (rare)
Prognosis: bleeding in pons usually fatal
DDx: cavernous angioma (identical on images)

Cavernous angioma of brain

Path: well-circumscribed nodule of honeycomblike dilated endothelial lined spaces separated by fibrous collagenous bands without intervening neural tissue
Age: 3rd 6th decade; M > F
Location: cerebrum (mainly subcortical) > pons > cerebellum; solitary > multiple

NCCT:

CECT:

MR:

Angio:

Cx: hemorrhage of varying ages
DDx: (1) Hemorrhagic neoplasm (edema, mass effect)
  (2) Small AVM (thrombosed / small feeding vessels, associated hemorrhage)
  (3) Capillary angioma (no difference)

Central Pontine Myelinolysis

Etiology:

Pathophysiology:

Location: (a) isolated pons lesion (most commonly)
  (b) combined type: central + extrapontine areas: basal ganglia, cerebellar white matter, thalamus, caudate nucleus, subcortical cerebral white matter, corona radiata, lateral geniculate body

CT:

MR (positive 1 2 weeks post-onset of symptoms):

Prognosis: 5 10% survival rate beyond 6 months
DDx: hypoxia, Leigh disease, Wilson disease

Cephalocele

CRANIAL MENINGOCELE = herniation of meninges + CSF only
ENCEPHALOCELE = herniation of meninges + CSF + neural tissue

Nomenclature:

Prevalence:

P.274

Cause:

In 60% associated with:

Prognosis: dependent on associated malformations + size and content of lesion; 21% liveborn; 50% survival in liveborns, 74% retarded
  Outcome poorer the larger the brain volume
Risk of recurrence: 3% (25% with Meckel syndrome)
DDx: teratoma, cystic hygroma, iniencephaly, scalp edema, hemangioma, branchial cleft cyst, cloverleaf skull

Occipital Encephalocele (75%)

Associated with:

Location: supra- and infratentorial structures involved with equal frequency
DDx: cystic hygroma

Sincipital Encephalocele (13 15%)

Location: midface about dorsum of nose, orbits, and forehead
Cause: failure of anterior neuropore located near optic recess to close normally at 4th week GA

Types:

Associated with: midline craniofacial dysraphism (dysgenesis of corpus callosum, interhemispheric lipoma, anomalies of neural migration, facial cleft, schizencephaly)

OB-US:

CT:

MR:

N.B.: biopsy is CONTRAINDICATED (due to potential for CSF leaks, seizures, meningitis)
Risk of recurrence: 6% of congenital CNS abnormalities for younger siblings
Rx: complete surgical resection with repair of dura mater (NO neurologic deficit due to abnormal function of herniated brain)
DDx: (1) Dacryocystocele / nasolacrimal mucocele
  (2) Nasal glioma (no subarachnoid connection on cisternography)

Sphenoidal Encephalocele (10%)

Age: present at end of first decade of life
Associated with: agenesis of corpus callosum (80%)

Types:

Parietal Encephalocele (10 12%)

Associated with: dysgenesis of corpus callosum, large interhemispheric cyst
DDx: (1) sonographic refraction artifact at skull edge
  (2) clover leaf skull (temporal bone may be partially absent)

Cerebellar Astrocytoma

Incidence: 10 20% of pediatric brain tumors
Histo: mostly grade I
Age: children > adults; no specific age peak; M:F = 1:1

Path:

Location: originating in midline with extension into cerebellar hemisphere (30%) > vermis > tonsils > brainstem

CT:

MR:

Angio:

Prognosis:

DDx of solid astrocytoma:

DDx of cystic astrocytoma:

Cerebritis

CT:

MR:

Cx: brain abscess

Chiari Malformation

Chiari I Malformationx (adulthood)

Proposed causes:

Associated with:

Chiari II Malformation (childhood)

Associated with:

Skull film:

OB-US:

Chiari III Malformation

Prognosis: survival usually not beyond infancy

Chiari IV Malformation

Choroid Plexus Cyst

Incidence: 0.9 3.6% in sonographic population;
  50% of autopsied brains
Histo: no epithelial lining, filled with clear fluid debris

P.277

May be associated with:

Location: frequently at level of atrium; uni- / bilateral single / multiple round anechoic cysts 3 mm in size (average 4.5 mm, up to 25 mm)
Cx: hydrocephalus (if cyst large)
Prognosis: 90% disappear by 28th week; may persist; in 95% of no significance

OB-management:

Risk of karyotype abnormality:

DDx: Choroid plexus pseudocyst in the inferolateral aspect of atrium (? corpus striatum) on oblique coronal plane, which elongates by turning transducer

Choroid Plexus Papilloma

Incidence: 0.5 0.6% of all primary intracranial tumors; 2 5% of brain tumors in childhood; 5% of all supratentorial tumors in children; 60 70% of tumors of the choroids
Age: 20 40% <1 year of age; 86% <5 years of age; in 75% <2 years of age; M >> F
Path: large aggregation of choroidal fronds producing great quantities of CSF; occasionally found incidentally on postmortem examination
Pathophysiology: abnormal rate of CSF production of 1.0 mL/min (normal rate = 0.2 mL/min)
May be associated with: von Hippel-Lindau syndrome (papillomas in unusual locations)

Location:

CT:

CECT:

MR:

US:

Angio:

Cx: (1) transformation into malignant choroid plexus papilloma = choroid plexus carcinoma (in 5%)
  (2) hydrocephalus (in children) secondary to increased intracranial pressure from CSF-overproduction
Rx: surgical removal (24% operative mortality) cures hydrocephalus
DDx: intraventricular meningioma, ependymoma, metastasis, cavernous angioma, xanthogranuloma, astrocytoma

Cockayne Syndrome

Age: beginning at age 1
DDx: Progeria

Colloid Cyst

Incidence: 2% of glial tumors of ependymal origin; 0.5 1% of CNS tumors
Histo: ciliated + columnar epithelium; mucin-secreting; squamous cells of ependymal origin; tough fibrous capsule
Age: young adults; M > F
Location: exclusively arising from inferior aspect of septum pellucidum protruding into anterior portion of 3rd ventricle between columns of fornix
DDx: meningioma, ependymoma of 3rd ventricle (rare) with enhancement

Cortical Contusion

Incidence: most common type of primary intraaxial lesion; in 21% of head trauma patients; children:adults = 2:1
Pathogenesis: capillary disruption leads to extravasation of whole blood, plasma (edema) and RBCs
Path: petechial hemorrhage (= admixture of blood with native tissue) followed by liquefaction + edema after 4 7 days, tissue necrosis
Mechanism: linear acceleration-deceleration forces / penetrating trauma
Associated with: fall
Location: multiple bilateral lesions;
Cx: (1) Progression to cerebral hematoma
  (2) Encephalomalacia (= scarred brain)
  (3) Porencephaly (= formation of cystic cavity lined with gliotic brain and communicating with ventricles / subarachnoid space)
  (4) Hydrocephalus as a result of adhesions caused by subarachnoid blood

Craniopharyngioma

Incidence: 3 4% of all intracranial neoplasms; 15% of supratentorial + 50% of suprasellar tumors in children; most common suprasellar mass
Origin: from epithelial rests along vestigial craniopharyngeal duct (Rathke cleft / pouch within intermediate lobe of pituitary gland)
Path: benign tumor originating from neuroepithelium in craniopharyngeal duct + primitive buccal epithelium
Histo: cystic (rich in liquid cholesterol) / complex / solid
Age: from birth 7th decade; bimodal age distribution: age peaks in 1st 2nd decade (75%) + in 5th decade (25%); M > F

Location:

DDx: (1) Epidermoid (no contrast enhancement)
  (2) Rathke cleft cyst (small intrasellar lesion)

Cysticercosis of Brain

Larva of pork tapeworm (Taenia solium) frequently involving CNS, eyes, muscle, heart, fat tissue, skin

Incidence: most common parasitic infection involving CNS in developing countries; CNS involvement in up to 90%
Endemic to: Mexico, South America, Africa, eastern Europe, Asia, Indonesia
Location: meninges (39%) esp. in basal cisterns, parenchyma (20%), intraventricular (17%), mixed (23%), intraspinal (1%)
  Seeding: through subarachnoid space
    + intraventricular system

Cytomegalovirus Infection

Dx: positive viral culture within first 2 weeks of life
Rx: no effective treatment for maternal infection
DDx: toxoplasmosis, teratoma, tuberous sclerosis, Sturge-Weber syndrome, venous sinus thrombosis

Dandy-Walker Malformation

= characterized by (1) enlarged posterior fossa with high position of tentorium (2) dys- / agenesis of cerebellar vermis (3) cystic dilatation of 4th ventricle filling nearly entire posterior fossa

Incidence: 12% of all congenital hydrocephaly
Path: defect in vermis connecting an ependyma-lined retrocerebellar cyst with 4th ventricle (PATHOGNOMONIC)
Cause: dysmorphogenesis of roof of 4th ventricle with failure to incorporate the area membranacea into developing choroid plexus; proposed originally as congenital atresia of foramina of Luschka (lateral) + Magendie (median) not likely since foramina are not patent until 4th month

Dandy-Walker Variant

Dandy-Walker Complex

Pseudo-Dandy-Walker Malformation

Dermoid of CNS

Diffuse Axonal Injury

Diffuse Sclerosis

sporadic, young adults, fulminant course

Dural Sinus Thrombosis

Dyke-Davidoff-Mason syndrome

Dysembryoplastic Neuroepithelial Tumor

Empty Sella Syndrome

Primary Empty Sella (anatomic spectrum)

Incidence: 10% of adult population; M:F = 1:4

Secondary Empty Sella

Empyema of Brain

Cause: paranasal sinusitis, otitis media, calvarial osteomyelitis, infection after craniotomy or ventricular shunt placement, penetrating wound, contamination of meningitis-induced subdural effusion

P.284

Subdural Empyema

Epidural Empyema

Encephalitis

Herpes Simplex Encephalitis (HSE)

Human Immunodeficiency Virus Encephalitis

Postinfectious Encephalitis

Acute Disseminated Encephalomyelitis (ADEM)

Acute Hemorrhagic Leukoencephalitis

Ependymoma

Epidermoid of CNS

P.286

Epidural Hematoma of Brain

Ganglion Cell Tumor

Gangliocytoma

Dysplastic Cerebellar Gangliocytoma

Ganglioglioma

P.288

Desmoplastic Infantile Ganglioglioma

Ganglioneuroma

Glioblastoma Multiforme

Multifocal GBM

Glioma

Brainstem Glioma

Hypothalamic / Chiasmatic Glioma

Globoid Cell Leukodystrophy

Hallervorden-Spatz disease

Hamartoma of CNS

Head Trauma

Extracerebral Hemorrhage

Intracerebral Hemorrhage

Other Posttraumatic Lesions

Hemangioblastoma of CNS

Hematoma of Brain

Stages of Cerebral Hematomas

Hyperacute Cerebral Hemorrhage

Acute Cerebral Hematoma

Early Subacute Cerebral Hematoma

Late Subacute Cerebral Hematoma

Chronic Cerebral Hematoma

Basal Ganglia Hematoma

Heterotopic Gray Matter

Holoprosencephaly

Alobar Holoprosencephaly

Semilobar Holoprosencephaly

Lobar Holoprosencephaly

Hydatid Disease of Brain

Hydranencephaly

Hydrocephalus

Compensated hydrocephalus

Obstructive Hydrocephalus

Communicating Hydrocephalus

Noncommunicating Hydrocephalus

P.298

Nonobstructive Hydrocephalus

Congenital Hydrocephalus

Infantile Hydrocephalus

Normal Pressure Hydrocephalus

Hypothalamic Hamartoma

Idiopathic Intracranial Hypertension

Infarction of Brain

Hyperacute Ischemic Infarction

Acute Ischemic Infarction

Early Acute Ischemic Infarction

Late Acute Ischemic Infarction

Subacute Ischemic Infarction

Chronic Ischemic Infarction

Hemorrhagic Infarction

Basal Ganglia Infarct

Laminar Necrosis

Lacunar Infarction

TIA and RIND

Infection in immunocompromised patients

Iniencephaly

Intracranial Hypotension

Intraventricular Neurocytoma

Jakob-Creutzfeldt Disease

Joubert Syndrome

Lipoma

Lipoma of Corpus Callosum

Lissencephaly

Lymphoid Hypophysitis

Lymphoma

Spinal Epidural Lymphoma

Leukemia

Medulloblastoma

Meningeal Carcinomatosis

Meningioma

Atypical Meningioma (15%)

Sphenoid Wing Meningioma

Suprasellar Meningioma

Meningitis

Purulent / Bacterial Meningitis

Granulomatous Meningitis

Mesial Temporal Sclerosis

P.309

Metachromatic Leukodystrophy

Metastases to Brain

Hemorrhagic Metastases to Brain (in 3 4%)

P.310

Cystic Metastasis to Brain

Calcified Metastasis to Brain

Malignant Melanoma Metastatic to Brain

Microcephaly

Mineralizing microangiopathy

Moyamoya Disease

Moyamoya Syndrome

Multiple Sclerosis

Myelinoclastic Diffuse Sclerosis

Neonatal Intracranial Hemorrhage

Germinal Matrix Bleed

Choroid Plexus Hemorrhage

Intracerebellar Hemorrhage

Intraventricular Hemorrhage

Periventricular Leukoencephalopathy

Periventricular Leukomalacia

Periventricular Hemorrhagic Infarction

Encephalomalacia

Neuroblastoma

Olfactory Neuroblastoma

Neurocutaneous Melanosis

Neurofibromatosis

Peripheral Neurofibromatosis (90%)

Neurofibromatosis with Bilateral Acoustic Neuromas

Neuroma

Vestibular Schwannoma

Trigeminal Neuroma

Oligodendroglioma

Paragonimiasis of Brain

Pelizaeus-Merzbacher Disease

Pick Disease

Pineal Cyst

Pineal Germinoma

Pineal Teratocarcinoma

Pineal Teratoma

Pineal Cell Tumors

Pineoblastoma

Pineocytoma

Pituitary Adenoma

Functioning Pituitary Adenoma

Nonfunctioning Pituitary Adenoma

Pituitary Macroadenoma

Pituitary Microadenoma

Pituitary Apoplexy

Porencephaly

Primitive Neuroectodermal Tumor

Progressive Multifocal Leukoencephalopathy

Rathke Cleft Cyst

Reye Syndrome

Reversible Posterior Leukoencephalopathy Syndrome

Sarcoidosis of CNS

P.326

Schizencephaly

Septo-Optic Dysplasia

Sinus Pericranii

Spongiform Leukoencephalopathy

Sturge-Weber-Dimitri Syndrome

Subarachnoid Hemorrhage

Subdural Hematoma of Brain

Acute Subdural Hematoma

Interhemispheric Subdural Hematoma

Subdural Hemorrhage in Newborn

Subacute Subdural Hematoma

Chronic Subdural Hematoma

Subdural Hygroma

Teratoma of CNS

P.330

Toxoplasmosis of Brain

Tuberculosis

Cranial Tuberculous Meningitis

Spinal Tuberculous Meningitis

Tuberculoma of Brain

Tuberous Sclerosis

Unilateral Megalencephaly

Vein of Galen Aneurysm

Venous Angioma

Ventriculitis

Ventriculoperitoneal Shunt Malfunction

Mechanical Shunt Failure

Obstruction of VP Shunt

Disconnection & Breaks of VP Shunt

Migration of VP Shunt

Leakage of VP Shunt

CSF Pseudocyst of VP Shunt

Infection of VP Shunt

Incidence: 1 5 38%
Time of onset: within 2 months of shunt placement

Abdominal Complications of VP Shunt

Subdural Hematoma / Hygroma of VP Shunt

Granulomatous Lesion of VP Shunt

Slit Ventricle Syndrome (0.9 3.3%)

Visceral Larva Migrans of Brain

Von Hippel-Lindau Disease

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