Brain imaging Flashcards
what imaging is indicated for Simple nasal bone fractures without significant deformity?
none
when is an orbital xray indicated?
MRI screening for suspected metal
preferred test for orbital fractures?
facial CT w/o contrast
preferred test for orbital cellulitis
facial bones CT w/ contrast
preferred test for retro-orbital hematoma
orbital CT w/ contrast
preferred test for facial cellulitis
facial bones CT w/ contrast
imaging for suspected cranial hemorrhages
head CT w/o contrast
when is head CT w/ angiography ordered?
Acute cerebrovascular accident/TIA
With symptoms that are >6 hours and <24 hours in duration
best study to differentiate b/w white and gray matter
MRI
put these in order of what yoou should look for 1st to last: blood, bones, brain, cisterns, ventricles
BLOOD, CISTERNS, BRAIN, VENTRICLES, BONES
what does black blood on CT indicate
ischemia or old blood
MCA dot sign
Thromboembolic occlusion of the distal MCA branches in the Sylvian fissure
subdural hematoma: venous or arterial?
venous
describe a what a subdural hematoma looks like on CT
Crescent/banana shaped, dark hypodensity
epidural hematoma: venous or arterial?
arterial
what color is fresh blood on CT?
bright white
white spots on CT are usually what?
hemorrhage
what does bright white CSF in ventricles indicate on CT?
subarachnoid hemorrhage
what can cause a midline shift?
Tumor, hemorrhage, abscess
will old blood be hypo or hyperattenuated on CT?
hypo
brain tumor: hypo or hyperattenuated on CT w/o contrast? T1 MRI? T2 MRI?
Hypoattenuation on head CT wo contrast
Hypoattenuation on T1 MRI
Hyperattenuation on T2 MRI
will edema be hypo or hyper attenuated on T2MRI?
hyper
hydrocephalus classic triad
Gait instability, urinary incontinence, dementia
hydrocephalus best imaging. what will it look like?
Ventriculomegaly on CT imaging
MRI is superior imaging for this
Depressed fractures definition
Displaced more than width of bone
indications for head CT
Trauma
Severe headache, esp “worst HA of my life” or ASW neuro deficits
Stroke/CVA/TIA
ideal timeframe to CT a pt w/ suspected subarachnoid hemorrhage
<6 hours
gold standard test for diagnosing SAH after 6 hrs
lumbar puncture (abscense of RBCs will r/o)
Afib could cause what type of stroke?
embolic ischemic
causes of hemorrhagic stroke
Hypertensive vasculopathy
Cerebral amyloid angiopathy
Arteriovenous and other vascular malformations
cerebral venous thrombosis
risk factors for hemorrhagic stroke
Risk factors:
Hypertension
Increasing age
Anticoagulant use
test to rule out hemorrhage stroke
head CT w/o contrast
risk factors for ischemic stroke
Hypertension Atherosclerotic disease Carotid stenosis/occlusion Atrial fibrillation Cardiac tumors Congenital heart disease Cardiomyopathy Patent foramen ovale Valvular disease/mechanical heart valves Sickle cell disease Hypercoagulable states
will you see any signs of ischemic stroke on CT if b/w 0-4 hrs?
no, but might see MCA dot sign
what study to get for:
Vertigo
Occult CVA/TIA
Multiple sclerosis
Headache (esp chronic or migraines—want to rule out structural cause)
Dementia/memory loss (rule out structural cause)
Hydrocephalus (plus CSF flow study)
Brain MRI without contrast
what imaging to get for: Tumor/metastatic disease Seizures (new) Follow-up on confirmed CVA/TIA Infection/Abscess Cranial nerve neuropathy Pituitary gland dysfunction
brain MRI w/ and w/o contrast
what study to get for:
Aneurysm/Arteriovenous malformation
Acute CVA/TIA if patient thrombectomy candidate and CTA inconclusive
brain MRI w/ angiography
what imaging to get for:
Cavernous sinus thrombosis
Brain MRI with venography
4 categories x-ray is best for
bone trauma, osteoarthritis, skeletal malignancy, FBs
1st line imaging for injury to vertebrae
CT w/o contrast
preferred imaging for spinal cord or spine soft tissue injury
MRI
orthogonal views
images taken at 90 degree angle to each other
minimum # of views when ordering xray
2
