Brain Radiology

Question 1

cause of ischaemic stroke

Answer 1

cardiac embolism
paradoxical embolism
air embolus 
fat embolus 
atherosclerotic thrombus/embolus 
arterial dissection

Question 2

what area does ACA supply

Answer 2

inferior temporal lobe and central parasagittal strip

Question 3

what area does PCA supply

Answer 3

occipital lobe and posterior temporal lobe

Question 4

what area does MCA supply

Answer 4

large portion of frontal, temporal and parietal lobes

Question 5

true/false - loss of one ICA compromises brain blood flow

Answer 5

false - it shouldnt theoretically due to the circle of willis but there are exceptions

Question 6

how may CT immediately following stroke appear

Answer 6

generally will appear normal

may see hyperdense intravascular thrombus

Question 7

how may CT hours following stroke appear

Answer 7

hypoattentuation of affected area, lost grey/white matter contour, cortex involvement, swelling and loss of gyri/sulci
mass effect

Question 8

how may CT months following stroke appear

Answer 8

gliosis of affected area

Question 9

what colour is acute blood on unenhanced CT

Answer 9

white

Question 10

what is an intra-axial brain bleed

Answer 10

brain bleed within parenchyma of the brain

Question 11

what is an extra-axial brain bleed

Answer 11

brain bleed outside of brain parenchyma but inside skull

Question 12

where would a bleed from severe hypertension possibly ocvcur

Answer 12

thalamus

Question 13

cause of epidural haematoma, radiological features

Answer 13

trauma, skull fracture, often MM artery
biconvex lentiform shape limited by cranial sutures
can lead to mass effect or herniation
sulcal effacement

Question 14

cause of subdural haematoma, radiological features

Answer 14

NAI, falls in elderly or RTA in young
semilunar shape and crosses sutures
possible mass effect

Question 15

cause of subarachnoid haemorrhage, radiological features

Answer 15

usually berry aneurism, can be AVM or trauma

high attentuated blood in SA space, suprasellar cistern, sylvian fissures and sulcu

Question 16

complications of SAH

Answer 16

vasospasm
infarct
hydrocephalus

Question 17

what colour does blood appear on CT in a subacute brain haemorrhage

Answer 17

isodense with brain parenchyma

Question 18

what colour does blood appear on CT in a chronic bleed

Answer 18

hypodense to brain parenchyma

Question 19

following diagnosis of SAH, what test is indicated and why

Answer 19

CT cerebral angiography to look for berry aneurism or AVM

Question 20

majority of brain masses in adults are due to?

Answer 20

metastatic disease

Question 21

majority of brain masses in children are due to?

Answer 21

primary lesions

Question 22

most common sites of mets to brain

Answer 22

lung, breast, melanoma, renal cell, colorectal

Question 23

how may a metastatic tumour appear on imaging

Answer 23

lots of oedema, mass effect, well enhancing

Question 24

how may primary tumours appear on imaging

Answer 24

degree of oedema, mass effect and enhancement depends on grading

Question 25

how can a brain mass be differentiated radiologically from stroke

Answer 25

not wedge shaped, or affecting cortex often

Question 26

what is tonsilar herniation and why is it an emergency

Answer 26

descent of cerebellar tonsils below foramen magnum, coning | can compress pons and medulla against clivus leading to alteration of life sustaining functions

Question 27

how can SAH lead to hydrocephalus

Answer 27

blockage of resorption of CSF

Question 28

where is the conus medullaris generally located

Answer 28

L1

Question 29

causes of spinal cord compression

Answer 29

``` Disc protrusion/extrusion, discitis osteomyelitis trauma tumour epidural abscess/haematoma spinal meningioma nerve sheath tumour ```

Question 30

investigation of spinal cord compression

Answer 30

MRI

Question 31

red flags for spinal cord compression

Answer 31

hx cancer major trauma thoracic/radicular pain constant and progressive non mechanical pain systemic unwell loss power LL grossly abnormal neuro signs/symptoms loss of sensation and saddle anaesthesia urinary retention, faecal and urinary incontinence