Neuro Radiology Basic Flashcards
CT
-basically an x-ray -Used to evaluate ACUTE head trauma -VERY sensitive to detection of subarachnoid hemorrhage (aka very good at picking up acute blood… which is often caused by ruptured aneurysms) -results in 2 minutes
T1 MRI
-good for brain morphology -contrast between gray and white matter -fat is bright and water is dark
T2 MRI
-good at picking up pathology -fat and water both bright -diseased tissue tends to look bright -combined with “FLAIR” to to null background “noise” (like CSF within ventricls) causing pathology to pop out at you
Diffusion weighted imaging in MRI
-VERY good at picking up ischemia/strokes (within minutes)
PET
Used to evaluate brain function; ie Alzheimers, movement disorders etc.
Epidural Hematoma presentation
*Biconvex* *does NOT cross suture lines, but may cross midline
Subdural Hematoma presentation
Crescent shaped *does not cross midline but MAY cross suture lines
4 hour rule of acute subdural hematoma
30% mortality if operated on in 4 hours
Cauda Equina Syndrome
-usually due to trauma, tumor, or herniated Lumbar disc -causes lower extremity weakness, bladder incontinence etc. -best assessed via MRI
Purpose of post-contrast gadollinuium
Makes tissues brighter on T1 MRI if they have increased vascularity or BBB disruption