11. The importance of windowing:
Common window settings used when
interpreting a normal CT Brain scan.
A: Brain window (WW 80, WL 40)
B: Bone window (WW 3000, WL 500)
C: Soft tissue window (WW 260, WL 80)
D: Stroke window (WW 40, WL 40).
12. Hydrocephalus results from an excess of CSF, due to an
imbalance between CSF production and absorption, resulting
in increased intraventricular pressure.
B - blood
C - cisterns
B - brain
V - ventricles
B - bones
Blood Can Be Very Bad is a mnemonic that can be used
when faced with interpreting a CT head scan:
14. Cisterns
There are four key cisterns that which should be assessed for effacement, the presence of
blood and asymmetry:
Ambient cistern: surrounding the midbrain.
Suprasellar cistern: superior to the sella turcica.
Quadrigeminal cistern: adjacent to the corpora quadrigemina.
Sylvian cistern: across the insular surface and within the Sylvian fissure.