Neuroscience Week 6: Neuroradiology of vascular diseases Flashcards
CT displays images in gray-scale from whit to black, based on?
Materials density
Ischemic infarctions often cause brain edema resulting in what on CT?
increased water density which appears hypodense
Acute intracranial hemorrhage often appears what on CT?
Hyperdense
Identify
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Epidural hemorrhage radiology
4 listed
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Epidural hemorrhage common etiology
associated with trauma and calvarial fractures
Subdural hemorrhage radiology
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Epidural hemorrhage cross calvarial sutures?
No
Subdural hemorrhage cross calvarial sutures?
May cross calvarial sutures
Subdural hemorrhage cross falx cerebri and tentorium cerebelli?
Does not cross the falx cerebri and tentorium cerebelli
Does epidural Hemorrhage cross the falx cerebri and tentorium cerebelli?
May cross the falx cerebri and tentorium cerebelli
Subdural hemorrhage common causes
associated with trauma: tearing of the bridging veins
Subarachnoid hemorrhage radiology
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Subarachnoid hemorrhage common causes
associated with trauma and aneurysms
Aneurysmal Subarachnoid hemorrhage common locations
Most commonly Saccular and arise from/near the circle of Willis
- ACOM, PCOM and MCA bifurcation
Aneurysm definition
abnormal dilation or outpouching
Aneurysmal Subarachnoid hemorrhage pattern: Supracellar cistern
- IC
- PCOM
- ACOM
Aneurysmal Subarachnoid hemorrhage pattern: Sylvian fissure
MCA bifurcation
Aneurysmal Subarachnoid hemorrhage pattern: Prepontine cistern, cerebellopontine angle
- PICA
- Basilar tip
- Vertebral
Identify
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Aneurysmal subarachnoid hemorrhage
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Identify
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Aneurysmal subarachnoid hemorrhage
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Identify
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Aneurysmal subarachnoid hemorrhage
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Identify
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Identify
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Identify
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Identify
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Identify
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Intraparenchymal hemorrhage: Hypertensive
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Intraparenchymal hemorrhage: Peripheral lobar
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Intraparenchymal hemorrhage: Traumatic (blunt)
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Identify
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Intraparenchymal hemorrhage shearing injury
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Stroke definition
“clinical” acute nervous system injury/focal neurologic deficit with abrupt onset
Infarct definition
Pathologic/Radiologic
- Brain cell death attributable to ischemia based on neuropathological, neuroimaging and/or clinical evidence of permanent injury
Hemorrhagic infarct
popped vessel
Ischemic infarct
Blocked vessel
Venous infarct
blocked or popped vein
Transient ischemic attack
clinical diagnosis
temporary blocked vessel/temporary neurologic deficit (<1 hour)
Acute ischemia accounts for what % of all stroke?
~80%
Ischemic stroke scale
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How is imaging helpful in stroke?
CT, MRI: Bleed or no bleed
CT, MRI, cerebral perfusion imaging: How large is the infarction? is there salvageable brain?
CTA, MRA, catheter angiogram: is there a large vessel occlusion
The primary goal for imaging in stroke is to?
- Rapidly identify and triage patients for appropriate therapeutic intervention
- Time = brain
- Imaging approach dependent on resources and expertise
Recent imaging clinical trials
Recent clinical trials
- Endovascular thrombectomy in large vessel occlusions
- Expanded time window for therapy (role for cerebral perfusion imaging)
How is CT of head helpful?
bleed or no bleed
no large-volume infarction
No intracranial hemorrhage nor large volume infarction =
t-PA
How is CTA head and neck helpful?
- Cardiac embolus
- Atheromatous plaque
- Vascular injury
- Aneurysm
Proximal accessible large vessel occlusion =
endovascular thrombectomy
Aneurysm treatment
Surgical clipping or endovascular coiling
Ischemic infarct by CT features
4 listed
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Ischemic infarct by MRI features
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Ischemic infarct evolution: Ages
- Hyperacute
- Acute
- Subacute
- Chronic
Ischemic infarct evolution: CT features
Hyperdense artery sign is the earliest sign
Parenchymal hypodensity as early as 1 hour, up to 6 hours
- lentiform nucleus hypodensity
- Insular ribbon sign
Parenchymal swelling day 1-7
Volume loss and gliosis is the latest sign
Ischemic infarct evolution: MRI features
DWI: Bright from 0-14 days
ADC: Dark from 0 hrs to 10 days, normalizes 10-14 days
T2 Flair: bright from 2-6 hours up to 21 days
Cortical laminar necrosis: T1 bright after 14 days, as early as 3-5 days
Parenchymal enhancement: ~5-7 days to 8 months
Ischemic infarct evolution: Hemorrhagic transformation
2-5 days
Identify
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Left MCA infarct, insular ribbon sign 18 hours later
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Identify
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Left MCA infarct, hyperdense MCA sign, carotid bulb thrombus
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Identify
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Global hypoxic ischemic injury
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Identify
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Herpes Encephalitis
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Identify
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Identify
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Identify
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Identify
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Identify
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Identify
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Identify
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Identify
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Identify
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Identify
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Identify
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Identify
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Identify
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Identify
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Identify
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Identify
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Homunculus
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Identify motor strip
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right finger tapping
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Identify motor strip
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Identify area
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Broca’s Area
Identify area & function
- Broca’s Area
- Naming objects
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Identify Area & Function
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- Wernicke’s Area
- Language comprehension
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Where is the primary visual cortex?
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