In the noncontrast CT a hyperdense artery sign can be observed, involving the terminal part of the right internal carotid artery and the M1 segment of the right medial cerebral artery. The insula, head of caudate, and the lentiform nucleus appear hypodense, and blurred ipsilaterally. The ASPECTS score based on the noncontrast scan is therefore: 7.
In the CT angiography the right ICA and the right MCA appear completely occluded.
The postcontrast, angiography source image scan the supply area of the right MCA appears almost completely hypodense, corresponding to a CTA-SI ASPECTS score of 0, indicating a bleak prognosis in sharp contrast to the ASPECTS based on the noncontrast acquisition.
In the affected hemisphere only a few vessels are visible in the subsequent multiphase scans in any phase, corresponding to a very poor mCTA collateral score of 0-1.