Upload
dinmanrituraj1683
View
113
Download
1
Tags:
Embed Size (px)
Citation preview
Cerebrovascular disease
summarization1. definition: diseases come from cerebral vessels(stroke: rupture or occlusion of cerebral vessels lead to hemorrhage or infarction, at las
t cause cerebral local blood circulation and dysfunction )
2. pathology: (1) vascular wall disease (2) changes of blood components (3) hemodynamic changes3. Clinical: (1) incidence: high (2) stroke types: (a) ischemic (b) hemorrhagic (c) mixed4. imaging: (1) CT (2) MRI
一、 cerebral hemorrhage
1. definition: cerebral parenchymal hemorrhage
2. cause: high blood pressure, aneurysm, vascular malformation, and so on.
3. pathology: atherosclerosis
4. location: basal ganglia, brain lobule, thalamus, pons and cerebellum
5. stages: (1) according to evolution of pathology:
(a) acute stage: 1 days ~3 days
(b) absorption stage: 3 days ~1 month
(c) cystic change stage: >1 month
(2) according to time:
(a) hyperacute: <24 h
(b) acute: 1~2days
(c) subacute: 3days ~ 1 month
(d) chronic: > 1 month
6. imaging findings: CT and MRI
Imaging findings
CT:1. acute stage:
(1) density: high, CT value=60~90Hu
(2) shape: round or oval or irregular
(3) border: clear
(4) peripheral edema: yes or no
(5) mass effect: nearby sulcus or cistern or ventricle
become narrow
2. Absorption stage:
(1) density: slight low and mixed
(2) shape: round or oval or irregular
(3) border: indistinct
(4) peripheral hypodensity: extend
(5) mass effect: lighten
(melting ice sign: process of absorption of hematom is from periph
eral to center)
2. Cystic change stage:
(1) density: low
(2) shape: round or oval
(3) border: distinct capsule
(4) peripheral hypodensity: disappear
(5) negative mass effect: nearby ventricle, sulcus,
cistern enlarge
focus of malacia
Evolution of hematoma on MRI
oxyhemoglobin
deoxyhemoglobin
methemoglobin (red blood cell complete )
methemoglobin ( red blood cell lysis)
hemosiderin
oxyhemoglobin
Without effect on T1 and T2
deoxyhemoglobin
T1WI T2WI
iso- or slight hypo- hypointensity
(notes: deoxyhemoglobin can shorten time of T2, but cannot effect on T1)
T1WI T2WI
Methemoglobin(red blood cell complete)
T1WI T2WI
high low
(notes: methemoglobin can shorten T1 and T2 )
Methemoglobin(red blood cell lysis)
T1WI T2WI
high high
(notes: methemoglobin can shorten T1 and prolong T2 )
hemosiderin
T1WI T2WI
low low
(notes: methemoglobin can shorten T2, but cannot effect on T1 )
MR:1. hyperacute stage(<24 hours, oxyhemoglobin)
(1) signal: T1: iso- or slight high
T2: iso- or slight high or mixed
(2) shape: round or oval
(3) border: clear
(4) peripheral edema: yes or no
(5) mass effect: nearby sulcus or cistern or ventricle
become narrow
2. Acute stage: (1~2days , deoxyhemoglobin)
(1) signal: T1: iso- or slight low
T2: low
(2) shape: round or oval
(3) border: clear
(4) peripheral edema: yes or no
(5) mass effect: nearby sulcus or cistern or ventricle
become narrow
T1WI T2WI
3. subacute stage: (3 days~1month)
(1) early stage: (methemoglobin in cell, 3~5days, )
T1: high (from peripheral to center)
T2: low
(2) middle stage: (methemoglobin out cell, 6~10days, )
T1: high
T2: high (from peripheral to center)
(3) late stage: (methemoglobin out cell, 10days~1month )
T1: high
T2: high (low ring-- hemosiderin)
early stage
late stage
4. Chronic stage: (>1 month , hemosiderin )
(1) hemosiderin: T1: low
T2: low
(2) cyst: T1: low
T2: high
cyst
A lot of hematomas have no typical evolution
Cause:
1. individual differences
2. time of hematoma is un-definite
3. repeated bleeding
4. difference of size of hematoma
5. different field strength
二、 cerebral infarction
1. definition: necrosis of cerebral tissue owing to blood barrier
2. cause: (1) atherosclerosis: 90%
(2) embolic embolism
(3) blood disease
(4) vasculitis
3. location: basal ganglia, brain lobule, thalamus, brain stem,cerebellum
4. stages: according to time:
(a) hyperacute: <6 h
(b) acute: <3 days
(c) subacute: 4day ~ 2 weeks
(d) chronic: > 2 weeks
5. types: (1) ischemic
(2) hemorrhagic
(3) lacunar
6. clinical:
(1) age: >40 years old (2) symptom and sign: (dependent on size, location and time of infarction)
(a) headache, dizzy, vomit, coma
(b) damage of cerebral function: hemiplegia, aphasia, hemianopsia
7. imaging findings: CT and MRI
1. ischemic cerebral infarction
1. definition: cerebral necrosis owing to lack of blood
2. cause: artery stenosis, occlusion
3. imaging: (a) CT
(b) MR
CT:
1. hyperacute stage: (< 6h)
(1) some of cases: normal
(2) some of cases: dense artery sign
(3) some of cases: gray-white borer obscure
?
>24h
dense artery sign
< 12h
> 12h
2. Acute stage: (<3 days)
(1) density: low
(2) shape : patchy or irregular
(3) border: unclear
(4) mass effect: slight
3. subacute stage: (4 days ~ 2 weeks)
(1) density: low
(2) shape : patchy or irregular
(3) border: un-clear
(4) mass effect: peak within 2~5 days
4. chronic stage: (> 2 weeks) (1) density: low (2) shape : patchy or irregular (3) border: clear or unclear (4) mass effect: disappear gradually (5) fogging effect: (a) time: 2~3 weeks (b) cause: capillary proliferation, reperfusion, macrophage activity
(c) isodensity on CT
fogging effect
MR: 1. hyperacute stage: (< 6h) (1) T1WI: (a) gyrus slight swelling (b) sulcus obscure (c) gray-white border unclear (2) T2WI: normal (3) DWI: hyperintensity (within 30 minutes DWI can get diagnosis)
DWI
DWI
2. acute stage: (< 3 days) (1) T1WI: low
(2) T2WI: high
(3) DWI: high
flair
DWI
3. subacute stage: (4 days ~2 weeks ) (1) T1WI: low > acute
(2) T2WI: high> acute
(3) enhancement: gyrus-like
4. chronic stage: (>2 weeks ) (1) T1WI: low
(2) T2WI: high
focus of malacia
2. Hemorrhagic cerebral infarction
1. definition: secondary hemorrhage after infarction
2. cause: (a) embolus embolism: common
(b) thrombosis
3. incidence: 18~42%
4. age: (a) embolism: all ages
(b) thrombosis: > 40 years old
5. imaging: (a) CT
(b) MR
CT:
(1) density: mixed
(2) shape: irregular
(3) border: unclear
MR:
T1 and T2: mixed signal
3. lacunar cerebral infarction
1. definition: small infarction in deep brain, D<15~20mm
2. cause: small branch of the artery blockage
3. incidence: 20%
4. location: basal ganglia, internal capsule, thalamus, corona radiata, brain stem
5. imaging: (a) CT
(b) MR
CT:
(1) density: low
(2) shape: dot-like, similar round
(3) border: unclear
MR:
T1: low
T2: high
三、 aneurysm
1. cause: (1) atherosclerosis
(2) trauma
(3) congenital development
2. types: according to the shape:
(1) berry: the most common
(2) fusiform
(3) dissecting aneurysm
3. location: (1) berry: furcation of MCA
(2) fusiform: vertebral-basilar artery
(3) dissecting: vertebral-basilar artery
4. clinical: subarachnoid hemorrhage
middle cerebral artery
anterior communicating artery
posterior communicating artery
anterior cerebral artery
posterior cerebral arteryvertebral artery
basilar artery
CT: (1) un-enhancement: (a) shape: round or similar round mass (b) density: high, mixed when thrombosis (c) subarachnoid hemorrhage (2) enhancement: obvously (3) CTA
Aneurysm in cavernous portion of internal carotid
CTA
Aneurysm in MCA
MR: (1) un-enhancement:
(a) shape: round or similar round mass
(b) signal: T1: low T2: low, mixed when thrombosis
(c) subarachnoid hemorrhage
(2) enhancement: obvously
(3) MRA
Aneurysm in MCA
MRA
DSA:
(1) the golden standard
(2) filling contrast mass
SAH,
aneurysm in anterior communicating artery
Fusiform aneurysm in MCA
四、 cerebral vascular malformation
1. cause: congenital development
2. types: (a) arteriovenous malformation
(b) cerebral venous malformation
(c) cavernous angioma
(d) capillary malformation
(e) occult cerebral vascular malformation
summarization
1. Arteriovenous malformation
1. definition: consist of a mass of arteries and venouses, directly connected
2. age: 11~40 years old, 80%3. location: (a) system of MCA: the most common (b) system of PCA4. clinical: (a) cerebral hemorrhage (b) epilepsy5. imaging findings: (a) CT and CTA (b) MR and MRA>> CT (c) DSA
CT:
1. density: high or mixed
2. shape: irregular
3.calcification: common
4. hemorrhage: common
5. mass effect: no, but yes with hemorrhage
6. enhancement: obviously (feeding artery and draining vein)
AVM with hemorrhage
MR:
1. signal: low tortuous vessel mass
2. shape: irregular
3.calcification: common
4. hemorrhage: common
5. mass effect: no , but yes with hemorrhage
6. enhancement: obviously (feeding artery and draining vein)
AVM with hemorrhage
DSA:
(1) the golden standard
(2) filling contrast mass
2. Cavernous angioma1. definition: consist of a mass of cavernous vessel sinus without muscular layer and elastic layer2. age: 20~60 years old common3. location: (a) supratentorial: common, 75% (b) infratentorial: rare, 25%4. clinical: (a) cerebral hemorrhage (b) epilepsy (c) headache5. imaging findings: (a) CT and CTA (b) MR and MRA>> CT (c) DSA
CT:
1. density: high or mixed
2. shape: similar round
3.calcification: common
4. hemorrhage: common
5. mass effect: no, but yes with hemorrhage
6. enhancement: un-homogeneous
MR: 1. signal: (a) well-defined 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 , but yes with hemorrhage 6. enhancement: un-homogeneous
Un-enhancement
enhancement
DSA:
Most of cases show normal
Cause: 1. thrombosis
2. blood stasis
3. smaller lesion
4. hematoma or edema oppression
5. technology
Cerebral infectious diseases
1. pathogen: germ, virus, fungus, parasite, and so on
2. types: according to site
(1) meningitis
(2) ependymitis
(3) encephalitis
(4) empyema
3. clinical: fever, headache, vomit
1. Pyogenic meningitis1. definition: meningococcus or other germs cause the meninges2. type: (1) epidemic meningitis (2) non-epidemic meningitis3. pathology: (1) early: meninges congestive (2) late: thickening of meningies4. clinical: (1) symptom and sign: acute fever, headache, meningeal irritation (2) lumbar puncture: (a) increased pressure (b) WBC and protein content increased (c) pathogen5. imaging findings:(a) CT (b) MR
CT:1. early stage: normal
2. advanced stage: (a) hyperdensity: sulcus, cistern of bottom of brain, hemisphere fissure and choroid plexu
s
(b) ventricle: enlargement: circulation of CSF blocked① ② narrow: diffuse brain swelling
3. enhancement: thread-like, gyrus-like
Cisterna ambiens
Cisterna of lateral sulcus Suprasellar cistren
MR:1. early stage: normal
2. advanced stage: T1: low (higher than CSF)
T2: high
3. enhancement: obviously, thread-like, gyrus-like
2. encephalitis1. definition: inflammation of parenchama2. pathogen: (1) virus: the most common (2) others: germ, fungus, parasite, and so on.3. viral types: (1) herpes simplex virus : the most common (2) Japanese encephalitis virus4. herpes simplex encephalitis types:
(1) type: adolescent or adultsⅠ (2) type: newbornsⅡ5. clinical: fever, headache, vomit6. imaging findings:(a) CT (b) MR
CT: 1. density: low 2. shape: patchy 3. border: un-clear 4. mass effect: vary from mild to moderate dependent on size of lesions 5. enhancement: (a) no (b) thread-like or gyrus-like (dependent on severity and course of lesion)
MR: 1. signal: T1: low T2: high (no involved lentiform nucleus)
2. shape: patchy
3. border: un-clear
4. mass effect: vary from mild to moderate dependent on size
of lesions
5. enhancement: (a) no
(b) thread-like or gyrus-like
(dependent on severity and course of lesion)
3.Cerebral abscess1. definition: parenchama local pyogenic inflammation and vomica come into being2. pathogen: (1) pyogenic germ: staphylococcus aureus
(2) others: anaerobe, colon bacillus etc.3. infectious way: (1) direct spread: 65% , otogenic and nose-derived (2) blood-borne: 25% (3) direct infection: 10%, open head injury4. stages: (1) acute encephalitis stage (2) purulent stage (3) capsule formation stage5. clinical: (1) infectious symptoms: fever, WBC increased (2) increased intracranial pressure: headache, vomit (3) focal symptoms of brain location: hemiplegia, aphasia, hemianopsia6. imaging findings: (a) CT (b) MR
CT:
(1) acute encephalitis stage: 1. density: low
2. shape: patchy
3. border: un-clear
4. mass effect: obviously
5. enhancement: (a) no
(b) thread-like or gyrus-like
(2) Purulent and capsule formation stage:
1. density: low
2. shape: round or similar round
3. border: clear
4. mass effect: obviously
5. enhancement: ring
MR:
(1) acute encephalitis stage: 1. signal: T1: low T2: high
2. shape: patchy
3. border: un-clear
4. mass effect: obviously
5. enhancement: (a) no
(b) thread-like or gyrus-like
(2) Purulent and capsule formation stage:
1. signal: T1: low T2:high, wall: low
2. shape: round or similar round
3. border: clear
4. mass effect: obviously
5. enhancement: ring
4. Cysticercosis of brain1. definition: parasite infecton2. pathogen: cysticercus of pork tapeworm3. infectious way: digestive canal4. stages: (1) early stage (2) medium stage (3) late stage (degeneration or death phase )5. types: (1) parenchama type (2) ventricle type (3) meninges type (4) mixed type5. clinical: (1) epilepsy: usual the first or only symptom (2) headache6. imaging findings: (a) CT (b) MR
CT:
(1) early stage: 1. density: low
2. shape: patchy
3. border: un-clear
4. peripheral edema: no
5. mass effect: mild
6. enhancement: no
(2) Medium stage:
1. density: low
2. shape: round or similar round or lobulated
3. border: clear
4. peripheral edema: no or slight
5. mass effect: mild or moderate
6. enhancement: no
(3) late stage (degeneration or death phase )
1. density: low
2. shape: patchy
3. border: unclear
4. peripheral edema: obviously
5. mass effect: mild or moderate
6. enhancement: ring or nodular
At last calcification:
1. density: high
2. shape: nodular or pathcy
3. border: clear
4. peripheral edema: disappear
5. mass effect: disappear
6. enhancement: no
degeneration phase
enhancement
calcification
MR:
(1) early stage: 1. signal: T1: low T2: high
2. shape: patchy
3. border: un-clear
4. peripheral edema: no
5. mass effect: mild
6. enhancement: no
(2) Medium stage:
1. signal: T1: low T2: high
2. shape: round
3. border: clear
4. peripheral edema: no or slight
5. mass effect: mild or moderate
6. enhancement: no
notable feature: scolex
(a) location: side-wall
(b) size: 1~2mm
(c) signal: similar to parenchama
(3) late stage (degeneration or death phase )
1. signal: T1: low T2: high 2. shape: patchy
3. border: unclear 4. peripheral edema: obviously 5. mass effect: mild or moderate 6. enhancement: ring or nodular
At last calcification: 1. signal: T1: low T2: low 2. shape: nodular or pathcy
3. border: clear 4. peripheral edema: disappear 5. mass effect: disappear 6. enhancement: no
calcification