Neuroradiology Flashcards
indications for brain imaging
Headaches Raised ICP Seizures Weakness/Stroke Trauma Loss of consciousness/neuro defect Post-operative
what is computed tomography
CT
positives of CT
good bony details and spatial resolution
fast
compatible with emergency/ICU equipment
3D reconstruction
negatives of CT
poor soft tissue detail
lots of radiation
3D reconstruction but no direct multiplayer acquisition
what shows as bright white on CT
more dense objects
what shows as dark on CT
lower density objects
positives of MRI
excellent contrast/soft tissue resolution
excellent depiction of anatomy
marrow and cord pathologies
multiplayer capability
negatives of MRI
less bony detail less spatial resolution not compatible with pacemakers and many implants not compatible with emergency equipment not as quick at CT
how does MRI create an image
correlation of multiple sequences all viewed together
what are the two main sequences for MRI
T1 hyperitense
- fat
- methemoglobin
- mineral deposition
- melanin
- ‘mush’
T2 hypotenuse
- water
- air
- bone
- high flow liquid - artery flow voids
what does white matter look like on CT
slightly darker than grey matter
what is bright on T1
water
common vascular brain pathologies
infarcts
haemorrhage
vascular abnormality?
what imaging is used for a stroke
CT
what is seen on CT in acute stroke
darker blob were fluid collects
white infarct
loss of grey/white matter differentiation
