Stroke Overview

(Left) Axial NECT scan shows a

hyperattenuating left middle

cerebral artery (MCA)

(hyperdense MCA sign) ſt in

this patient with acute onset

of right hemiparesis. Compare

to the normal right MCA ﬇.

(Right) More cephalad NECT in

the same case shows the

disappearing basal ganglia

sign caused by the occluded

MCA. The basal ganglia should

normally be hyperdense

compared with white matter.

In this case, they are

hypodense ſt and thus

"disappear" (compare to the

normal right side ﬇).

(Left) Axial DWI MR shows

diffusion restriction in the left

anterior cerebral artery (ACA)

distribution ﬇ within the

medial parafalcine frontal

lobe. (Right) Axial ADC map in

the same case shows

hypointensity in the

distribution of the left ACA

ſt, confirming the presence of

an acute infarct in this

territorial distribution.

(Left) Axial DWI MR shows

diffusion restriction

﬈ in the

occipital lobe related to

posterior cerebral artery (PCA)

ischemia. DWI is the most

sensitive MR sequence for

acute ischemia. (Right) Axial

NECT scan shows a

hyperattenuating basilar

artery ſt in this patient with

acute onset of ataxia and

multiple cranial nerve palsies.

Note bilateral cerebellar

infarcts ﬇.

Trauma, and Stroke

Brain: Pathology-Based Diagnoses: Malformations,

71