Radiology Flashcards
two modalities used to investigate the brain
- CT
2. MRI
what is CT best for?
bone detail
spatial resolution
fast and compatible with emergency/ ICU equipment
what are the disadvantages of CT?
poor soft tissue
gives a large dose of radiation
appearance of white matter on CT
darker as it is of lower density than the grey matter
what is MRI best for?
soft tissue
bone marrow
cord pathologies
what is MRI less good for?
bone detail
not compatible with pacemakers, implants or emergency equipment
not as fast
requires patient cooperation
types of MRI scans
T1 hyperintense
T2 hyperintense
what shows up on T1 hyperintense?
fat and 4 M’s (methemoglobin, mineral, melanin and mush)
contrast material used in T1
gadolinium
what shows up on T2 MRI
water is white
where are extra-axial pathologies located?
external to the brain parenchyma
what is a chiari malformation?
brain tissue extends into the spinal canal due to an abnormally shaped skull
what is cortical dysplasia?
possibility in those presenting with seizure e.g. polymicrogyria (too many small gyri)
what is schizencephaly?
abnormal slits in cerebral hemispheres
examples of developmental/ congenital pathologies in the brain
- chiari malformation
- cortical dysplasia
- schizencephaly
- arachnoid cyst
