CNS Imaging Flashcards
Whats the cerebellum blood supply from
Basilar Artery
- Superior Cerebellar Artery
- Posterior Inferior Cerebellar Artery
Where are the watershed infracts of brain
2 Cortical Border Zone
- 1 anterior - between ACA and MCA
- 1 posterior - between MCA and PCA
1 Internal Border Zone
- Long Circumferential A and MCA
Signs of Acute MCA [4]
Hyperdense MCA Sign WHITE
- thrombi, emboli
Loss of Insular Ribbon Sign (following MCA occlusion)
- insular cortex is now hypodense, BLACK
- insular cortex is furthest from collateral flow;
- seen as loss of grey-white matter interface
- note is a cortical structure;
Lentiform Nu obscuration
Infract hence Hypodense Brain - BLACK
What the colors on MRI and why colors
- Abscess, Infract
- CSF
Hyper vs Hypointense
Acute infraction is diffusion restriction
- Hence WHITE on DWI – ADC DARK BLACK
- same w inflammation, abscess, tumors;
CSF - increased diffusion
- BLACK on DWI; WHITE on ADC
Areas supplied by MCA branches
- how 2 branches lead to different symptoms during strokes;
Superior branch
- frontal, broca (on left frontal lobe) + central gyrus
- Contralateral hemiplegia, hemisensory loss
- speech impairment - Broca’s Dysphagia
Inferior Branch
- temporal, parietal , Wernicke (left temporal)
- Contra Hemianopia !!!
optic radiation receives blood through deep branches of the middle cerebral artery and posterior cerebral artery.
- Wenicke’s Dysphagia
Infraction
- what appears hyperdense (white)
- what appears hypodense (black)
- Note CT refers to density
Hyperdense - BLOOD, thrombi, emboli;
- note as time passes, blood becomes black - hypodense;
Hypodense - infracted brain, blood after time; oedema;
Normal healthy adult CT
- what appears hyperdense
- what appears hypodense
White:
- calcification - bone
- Pineal Gland, Choroid Plexus (calcified in adults)
Dark
- Grey matter paler than White matter!!!
- CSF!!! , Air
CSF also black in MRI DWI but white in ADC;
Subdural vs Epidural CT presentation
Epidural is Convex
Subdural is Concave;
Just note posterior circulation strokes
- affects brainstem, cerebellum
- Contralateral BODY stuff - UMN
- Ipsilateral Cranial Nerve stuff - LMN of CN;
- including deafness and stuff
- Sensory loss
- Ataxia
- MLF loss - vertical gaze
- PPRF loss - horizontal gaze
- RF - breathing and consciousness
okie
Stroke treatment
IV tPA
- except hemorrhagic stroke, venous thrombosis, infraction; emboli leading to RED infraction
- lit
- hemorrhagic infracts secondary to ischemic strokes
- this caused by venous thrombosis and any emboli
Gimme the CVA types and causes
Ischemic Stroke
- thrombi/emboli
- atherosclerosis, hypercoagulability
- emboli: fat, tumor, septic
- hypertension - lacunar infractions @ BG
- global hypoperfusion
- from shocks, CVS stuff
Hemorrhagic Stroke
- hypertension
- AV malformation, aneurysm, Charcot-Bouchard aneurysm @ BG;
- Cerebral Amyloid Angiopathy - amyloid weakens wall;
Cx of ischemic stroke and pathogenesis
Infraction of tissue
- pale/bland
- caused by artery ischemia, thrombosis
- hemorrhagic
- caused by venous thrombosis
- caused by emboli
Stroke
- ischemic infract
- gross and histology timeline
Within 2 days
- pale, corticomedullary junction;
- red neurones; neutrophils
- RED NEURONES is within 2 days know that nerves v susceptible to hypoxic damage
- from basophilic blue to ACIDOPHILIC eosinophilic RED now;
2-10 Days
- friable
- macrophages
> 10 Days
- liquefactive necrosis
- alotta macrophages; reactive gliosis
Whats lacunar infracts
- 1 property
Small infracts secondary to Hypertension artery sclerosis;
- @ Basal ganglia
Gimme the extra-axial intracranial hemorrhages
Sub-arachnoid Hemorrhage
- berry aneurysm @ circle of Willis
- thunderclap headache
- – COUNTED AS INTRACEREBRAL
- associated w ADPCKD + Aortic Coarctation
- USUALLY not traumatic
Subdural Hemorrhage
- Bridging Veins
- Traumatic
- Acceleration-D injuries
- Concave on CT
Epidural Hemorrhage
- Middle Meningeal Artery
- Traumatic @ Temporal Bone
- Convex on CT
- can have lucid interval then LOC
