Congenital malformation of the cranium and brain

PART 1

summarizaition

1. definition: lesion has existed when born

2. age: children

3. incidence: 1%

4. clinical: (a) mental retardation

(b) epilepsy

一、 dysgenesis of corpus callosum

1. definition: complete or part absence2. pathology: (1) early injury: complete absence (2) late injury: part absence 3. clinical: (1) part absence: no (2) complete absence: (a) mental retardation (b) epilepsy (c) cerebral palsy4. imaging findings: (1) CT (2) MR: the best

CT: 1. corpus callosum: complete or part absence 2. lateral ventricle: (1) body: separation (2) anterior horn: narrow (3) posterior horn: enlargement 3. third ventricle: (1) enlargment (2) location rise (3) anterior communicating to interhemispheric cistern

MR:

1. corpus callosum: complete or part absence

2. lateral ventricle: (1) body: separation

(2) anterior horn: narrow

(3) posterior horn: enlargement

3. third ventricle: (1) enlargment

(2) location rise

(3) anterior communicating to

interhemispheric cistern

二、 lipoma

1. definition: mature fat tissue

2. location: (1) peripheral corpus callosum ： 30~50%

(2) midline: 50~70%

3. clinical: (1) usually no symptom

(2) dysgenesis of corpus callosum co-existent

4. imaging findings:

(1) CT

(2) MR

CT: 1. density: very low, CT value= -60~ -100HU

2. border: clear

3. calcification ： yes or no

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quadrigeminal cistern lipoma

CT value= -87HU

MR: 1. signal: (1) T1: high

(2) T2: slight high< T1

(3) fat saturation sequence: low

2. border: clear

3. calcification ： yes or no

fat saturation

三、 cephalocele1. definition: part of meninges, CSF and brain bulge out pass through skull defect2. types: (1) according to components of herniation: (a) : meningocele Ⅰ (b) : meningoencephaloceleⅡ (c) : ventricle (include )Ⅲ Ⅱ (d) : CSF (include and )Ⅳ Ⅱ Ⅲ (2) according to cause of disease (a) congenital (b) acquired (trauma, surgery)3. location: midline (1) occipital: 70% (2) parietal, frontal and skull base: 10%

4. clinical:

extracranial mass in corresponding site

5. imaging findings: (a) CT

(b) MR

CT: 1. density: similar to brain or meninges or CSF

2. border: connect with brain or meninges

MR: 1. signal: vary dependent on components of herniation

2. border: clear, connect with brain or meninges

四、 Dandy-Walker syndrome

1. definition: congenital atresia of lateral and median aperture of 4th ventricle

2. pathology: (1) cerebellum hemisphere hypoplasia and vermis absence

(2) opening of back of 4th ventricle and communicating

with cisterna magna, and forming vast cyst

(3) tentorium of cerebellum, transverse sinus and

confluence of sinuses move up

(4) supratentorial hydrocephalus

3. clinical: (1) head enlargement

(2) intracranial pressure increase

(3) cerebellar ataxia

(4) mental retardation

CT: 1. vast cyst in posterior fossa communicating with 4th ventricle

2. absence of complete or part of vermis

3. tentorium of cerebellum, transverse sinus and confluence

of sinuses move up

4. supratentorial hydrocephalus

MR: 1. vast cyst in posterior fossa communicating with 4th ventricle

2. absence of complete or part of vermis

3. tentorium of cerebellum, transverse sinus and confluence

of sinuses move up

4. supratentorial hydrocephalus

五、 schizencephaly

1. definition: cerebral hemisphere superficial sulcus or fissure are very deep and get to lateral ventricle and enveloped by gray matter

2. types: according to form of fissure

(1) open type: 70%

(2) closed type: 30%

3. location: region of pre- or postcentral gyrus

CT: 1. cerebral superficial sulcus or fissure get to lateral ventricle

2. sulcus or fissure enveloped by gray matter

3. lateral wall of ventricle has peak-like protuberance

Open type Closed type

MR: 1. cerebral superficial sulcus or fissure get to lateral ventricle

2. sulcus or fissure enveloped by gray matter

3. lateral wall of ventricle has peak-like protuberance

Open type Closed type

六、 gray matter heterotopia1. definition: neuron gathered outside the cortex

2. types: (1) according to distribution:

(a) focal

(b) diffuse

(2) according to form of gray matter:

(a) nodular type

(b) girdle type

CT: 1. nodular or girdle similar density to gray matter

2. without mass effect

3. degree of enhancement equal to gray matter

MR: 1. nodular or girdle similar signal to gray matter

2. without mass effect or edema

3. degree of enhancement equal to gray matter

4. T2WI is the best sequence

七、 congenital porencephalic cyst

1. definition: cerebral cyst containing CSF communicating

with ventricle and/or subarachnoid space

2. typical feature: white matter around the cyst

CT:1. cerebral cyst containing CSF communicating

with ventricle and/or subarachnoid space

2. white matter around the cyst

MR:1. cerebral cyst containing CSF communicating

with ventricle and/or subarachnoid space

2. white matter around the cyst

八、 arachnoid cyst

1. definition: cerebral cyst containing CSF

2. types: (1) according to cause:

(a) congenital

(b) acquired

(2) according to form of pathology:

(a) cyst in the arachnoid

(b) cyst under the arachnoid

3. clinical: (1) small cyst: usual no symptom

(2) huge cyst: headache

CT: 1. density: low CT value=0~20HU

2. shape: round or similar round or irregular

3. border: clear

4. nearby bone: absorption, thinness, or bulge

5. enhancement: no

MR: 1. signal: T1: low T2: high

2. shape: round or similar round or irregular

3. border: clear

4. nearby bone: absorption, thinness, or bulge

5. enhancement: no

九、 tuberous sclerosis

1. definition: autosomal dominant genetic disease

2. age: children

3. location: (1) usually involved skin and nervous system (2) also involved urinary, skeletal, respiratory, etc.

4. pathology: (1) cortical gray matter nodules

(2) subependymal glial nodules

(3) subependymal giant cell astrocytoma

5. clinical: (1) facial steatadenoma

(2) epilepsy

(3) mental retardation

Kidney hamartoma

十、 Sturge-Weber syndrome

1. definition: craniofacial angiomatosis

2. cause: congenital heteroplasia of nerve, skin and vessel

3. location: (1) superficial brain

(2) pia mater

4. pathology: pia mater vein tumor owing to incomplete

development of venous drainage

5. clinical: (1) facial angioma

(2) epilepsy

(3) mental retardation

CT: (1) wire-like or earthworm-like or gyrus-like calcification

(2) nearby cortex atrophy

(3) nearby skull thickening

(4) enhancement: slight

Un-enhancement

enhancement

MR:

local cortex atrophy

十一、 Chiari malformation1. definition: cerebellar tissue down into the spinal canal

2. Cause : un-definite

3. types: (1) : (a) cerebellar tonsil become long and sharp and down into theⅠ spinal canal pass through foramen magnum

(b) the most common

(c) syringomyelia

(2) : (a) tonsil, vermis, pons, medulla oblongta, 4Ⅱ th

ventricle elongate and down

(b) the second most common

(c) syringomyelia

(3) : Ⅲ type + cephaloceleⅡ (4) : Ⅳ type + cerebellum dysplasiaⅡ4. clinical: (1) motor and sensory barrier

(2) ataxia

CT: seldom to use

MR: 1. sagittal and coronal T1WI are the best

2. T2WI are sensitive to syringomyelia

3. standard of tonsil down: (beyond the line which connecting anterior edge with posterior edge of foramen magnum)

(1) <3mm: normal

(2) 3~5mm: suspicious

(3) >5mm: sure

Ⅰtype

Ⅰtype

Ⅱtype

I am very sleepy

PART 2

Lesions of spinal cord

一、 tumor

1. intramedullary tumors:

(1) ependymoma

(2) astrocytoma

(3) hemangioblastoma

2. extramedullary intradural tumors:

(1) neurogenic tumors

(2) meningioma

3. extramedullary extradural tumors: metastasis

1. intramedullary tumors

ependymoma1. origin: ependymal cells

2. incidence : the most common, 60%

3. calcification: rare

4. cystic change: common

5. hemorrhage: common

6. imaging: MR>>CT

MR: 1. signal: T1: iso- or hypo- or mixed

T2: iso- or hyper- or mixed

2. borer: clear

3. spinal cord: enlargement

4. enhancement: solid portion obviously

un-enhancement

enhancement

astrocytoma

1. origin: glial cells

2. incidence : (1) the second most common, 30%

(2) the most common in children

3. calcification: rare

4. cystic change: common

5. hemorrhage: common

6. imaging: MR>>CT

MR: 1. signal: T1: iso- or hypo- or mixed

T2: iso- or hyper- or mixed

2. borer: un-clear

3. spinal cord: enlargement, involved range extensive

4. enhancement: solid portion

hemangioblastoma

1. origin: endothelial cells

2. incidence : 3~5%

3. age: 20~40 years old

3. pathology: (1) cystic portion

(2) mural nodule: blood supply rich

4. imaging: MR>>CT

MR: 1. signal: (1) cystic portion: T1: low T2: high (2) mural nodule: (a) T1: iso- T2: iso- or slight high (b) single or multiple (c) spinal cord dorsal or surface (d) point or earthworm-like flow void vessel

2. borer: clear 3. edema: obvious 4. spinal cord: enlargement 5. enhancement: (1) cystic portion no (2) mural nodule obvious and homogeneous

Un-enhancement

enhancement

2. extramedullary intradural tumors

meningioma1. origin: spinal dura mater

2. incidence : female: the most common, 80%

3. age: adults

4. location: (1) thoracic spinal cord: the most common

(2) cervical spinal cord: the second

(c) lumbar spinal cord: seldom

5. calcification: common

6. imaging: MR>>CT

MR: 1. signal: T1: iso- T2: iso-

2. borer: clear

3. dural tail sign: yes

4. spinal cord: pressed

5. enhancement: obvious and homogeneous

neurogenic tumor

1. origin: nerve sheath or fiber

2. age: adults

3. cystic and necrosis: yes

4. calcification: no

5. typical feature: (1) grow outside spinal canal pass through

intervertebral foramen along the nerve root

(2) intervertebral foramen: enlargement or

destruction of nearby bones

6. imaging: MR>>CT

MR: 1. signal: T1: iso- or slight low

T2: iso- or slight high

2. borer: clear

3. transaxial: dumbbell-shaped sign

4. spinal cord: pressed

5. enhancement: obvious and un-homogeneous

3. extradural tumors

metastasis1. origin: lung cancer, breast cancer and so on.

2. age: >50 years old

3. cystic and necrosis: yes

4. imaging: MR>>CT

MR: 1. signal: T1: iso- or slight low

T2: iso- or slight high

2. borer: un-clear

3. spinal cord: pressed

4. enhancement: un-homogeneous

Case: a 62-year old man, lung cancer for 1 year, has waist pain recently

二、 vertebrae and spinal cord injury

1. types: (1) according to hemorrhage:

(a) hemorrhagic injury

(b) un- hemorrhagic injury

(2) according to extent of injury:

(a) part injury

(b) complete injury

2. imaging: (1) plain film

(2) CT

(3) MR

Plain film:

fracture

CT:

(1) fracture

(2) hemorrhage

(3) vertebral canal stenosis

MR:

(1) spinal cord injury: T1: low , T2: high

(2) hemorrhage

(3) fracture

(4) vertebral canal stenosis

Case: a 40-year-old male, post-trauma

三、 spinal cord vascular malformation

1. arteriovenous malformation: common

2. cavernous angioma: rare

3. venous malformation: rare

arteriovenous malformation

MR:

(1) T1 and T2: flow void vessel

(2) feeding artery and draining vein

cavernous angioma

MR: 1. signal: (a) mixed signal (b) hoop sign: center high signal and

peripheral low signal on T1 and T2 2. shape: similar round 3.calcification: common 4. hemorrhage: common 5. mass effect: no 6. enhancement: obviously

四、 syringomyelia1. definition: a chronic developing degeneration

2. cause: (1) congenital

(2) degenerative

(3) post-trauma

(4) tumor3. clinical: (1) separated sensory disturbance of damaged segments

(2) lower motor neuron disturbance

4. imaging: MR>>CT

MR:

T1: low T2: high

五、 demyelinating disease brain and spinal cord

1. definition: white matter demyelination and formation dysplasia

2. cause: (1) ischemic

(2) inflammation

(3) tumor

(4) poisoning

3. types: (1) congenital

(2) acquired

4. clinical: (1) sensory disturbance

(2) visual impairment

(3) quadriplegia

5. imaging: MR>>CT

multiple sclerosis1. definition: white matter demyelination2. incidence: the most common3. age: young women: 20~40 years old 4. pathology: (1) white matter demyelination around ventricle or spinal cord (2) axone integrity5. types: (1) acute stage (2) catabasis (3) advanced stage6. Clinical feature: (1) condition in-and-out (2) ingravescence (3) effective after hormone therapy (4) easy to relapse7. imaging: MR>>CT

stationary stage

CT: ( 一 ) acute stage:

(1) density: low

(2) border: clear or un-clear

(3) location: around the ventricle

(4) mass effect: slight or no

(5) enhancement: patchy or ring or semi-ring

( 二 ) catabasis:

(1) lesion reduced or disappear

(2) border become clear

( 三 ) advanced stage:

brain atrophy

MR: ( 一 ) acute stage:

(1) signal: T1: iso- or low T2: high

(2) border: clear or un-clear

(3) location: (a) around the ventricle

(b) cervical spinal cord

(4) mass effect: slight or no

(5) enhancement: patchy or ring or semi-ring

notes: long axis of lesion perpendicular to that of lateral ventricle

( 二 ) stationary stage:

enhancement: no

notes: no enhancement after hormone therapy, but this does not indicate that it is in stationary stage

1. spinal meninges, spinal cord and fat tissue eventration to outside

六、 congenital disease

2. diastematomyelia

3. low position of spinal cord

normal

七、 intervertebral disk degeneration

1. cause: (1) age (2) trauma (3) tired and cold2. incidence: high3. age: at any age, but the old is the most common4. location: lumbar and cervical vertebrae5. pathology: (1) anulus fibrosus: degeneration (2) nucleus pulposus: dehydration (3) cartilage endplate: thinness and hyalinization6. types: (1) bulge (2) herniation7. Clinical feature: waist or legs pain8. imaging: MR>>CT

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S1 n

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