Neuroradiology Flashcards
What is a FLAIR MRI?
Fluid attenuated T2
When is a CTP (perfusion) useful?
When normal CT doesn’t show obvious signs of stroke
Look for pernumbra that can be saved with clot retrival
How do you tell the difference between a low grade and high grade glioma on contrast MRI?
Only high grade gliomas enhance
How do you differentiate intra and extra-axial lesions?
Look for CSF cleft and displaced cortex in extra-axial
What is meant be intra and extra axial?
Intra - inside the brain parenchyma
Extra - outside the brain parenchyma
What do you look for on MRI for MS?
Hyperintense plaques on T2 and flair
Often paraventricular
How do old infarcts appear on CT?
Black
How might a stroke appear on CT?
Loss of grey-white matter differentiation
Clot
What is dark on T2?
Some blood products/flow (Aneurysms)
Air
Dense cortical bone or calcification
Haemosiderin
What is the difference between cytotoxic and vasogenic oedema?
Vasogenic - due to compromise of BBB, typically in inflammatory or malignant
- White matter oedema, spares the cortex
Cytotoxic - has co-extensive grey and white matter involvement
How does acute infarct appear on DWI?
Bright
What are the most common cancers to metastasize to brain?
Lung
Breast
Colon
Melanoma
Renal
What are some DDx for intrasellar masses?
Pituitary adenoma
Rathke’s cleft cyst
Craniopharyngioma
Aneurysm
Histiocytosis
Metastatic tumour
What is a clue that a brain lesion on MRI is a met?
Extensive oedema
