022615 neurological dis imaging Flashcards
neuro CT exams are usually performed without contrast except in
CTs of head and neck soft tissues looking for infection or malignancy
CT angiograms of head and neck
CT venograms of head and neck
indications for IV gadolinium contrast in MRI imaging
infection
primary tumors or metastatic disease
demyelinating disease
contrast is not usually necessary on MRIs and CTs in evaluating what?
stroke
trauma
degenerative spine disease
MRA of head is usually done with or without contrast
WITHOUT
MRA neck and MRV are best done with or without contrast
WITH
crescent shaped
subdural hemorrhage
acute intracranial hemorrhage differential diagnosis
- trauma
- HTN (usually parenchymal)
- neoplasm (usually parenchymal)
- vascular maformation like arteriovenous malform (would see abnormal vessel on CT)
- aneurysm (usually causes subarachnoid hemorrhage but some associated w/ parenchymal hemorrhage)
- cerebral amyloid angiopathy (usually in elderly and demented. see peripheral lobar parenchymal hemorrhage)
- venous thrombosis (usually parenchymal)
- anticoagulation
- drug abuse (cocaine-often parenchymal)
- hemorrhagic conversion of infarct
acute hemorrhage appears how on CT?
hyperdense (bright)
chronic hemorrhage appears how on CT?
hypodense (dark)
locations of acute intracranial hemorrhage
subarachnoid subdural epidural parenchymal intraventricular
two most common cuases of subarachnoid hemorrhage
trauma
ruptured aneurysm
to look for aneurysm on CTA, is contrast needed?
yes
to look for aneurysm on MRA, is contrast needed?
no
acute onset right sided weakness and aphasia in elderly pt-differential?
cerebrovascular accident (stroke)
transient ischemic attack
seizure
encephalopathy
what do acute infarcts look like on CT?
hypodense (dark) areas of edema, though may not see in first few hours
loss of grey/white differentation
swelling/edema leads to sulcal effacement or asymmetrically smaller sulci
hyperdense (bright) vessel sign (sometimes, acute thrombus in a vessel can appear dense)
