Imaging Flashcards
What 2 pathologies are ARXs good at confirming?
Bowel obstruction
Renal tract calculi
What’s the difference between the small and large bowel markings?
SB - plicae circulares tranverse the whole diameter
LB - haustra extend only 1/3rd the way
What colour is blood on a CT scan and why?
White
It contains proteins making it dense with a high attenuation
When would a CT head with contrast be useful?
Its good at showing blood vessels/vascular areas
Aneurysms, tumours, abscess and areas of high cell turnover
What are the things that you should think about when looking at a CT head?
Ventricular size Blood (white patches) Ischaemia (darker patches) Normal differentiation between white/grey matter Sulci effaced or mass effect? Check bony skull Are the visualised orbits normal?
Describe what you would see on a CT head of an extradural haemorrhage
Bi-conves (lentiform) shape Hyperdense Heterogeneous Sharply demarcated May have mass effect (Midline shift, subflacine herniation, uncal herniation)
At what time frame does a SDH become classified as chronic?
3 weeks
It can become hypodense
SDH can be difficult to see - what indirect signs can be useful to helpful?
CSF-filled sulci that do not reach the skull but fade out into subdural
Mass effect - sulcal effacement and midline shift
Apparent thickening of the cortex
For what scans are MRI more superior than CT?
Its better for superior soft tissue - better for brain, spine, joints + soft tissues
How can you tell the difference between T 1 or T2 MRI?
T1 - CSF is dark, fat is bright and inflammation is dark
T2 - CSF is bright, fat is light and inflammation is bright
What are the CI to MRI?
Implanted metallic devices (pacemakers, cochlear implants)
Unstable patients
Pregnancy
Severe agitation or claustrophobia
