Right ICA stenosis with MCA distribution ischemia
Findings:
Hyperintensity on PDWI in right frontal lobe, frontal
operculum and insula, consistent with unilateral ischemic changes in the
right MCA distribution. MRA shows diminished to absent flow signal in right
ICA, with termination of flow signal in right carotid bulb. DSA shows high
grade stenosis of right ICA at its origin, with a "string sign" indicative
of greater than 95% stenosis. There is delayed opacification of right ICA
and right intracranial vessels from reconstitution by collaterals from
ECA and minimal flow through stenosis, with cross-filling via Circle of
Willis.