Brain scanning in unilateral and bilateral occlusion of the posterior cerebral arteries.

Nineteen patients with unequivocal angiographic evidence of unilateral or bilateral posterior cerebral artery occulsion were scanned during the acute phase of the stroke. In 12 of them an abnormal accumulation of radioactivity was apparent on the posterior view, but only 2 also exhibited abnormal uptake on the corresponding lateral view. The size, shape, and location of the uptake were rather constant and appeared to be almost independent of the site of occlusion and also of a collateral circulation by meningeal anastomoses. Pathological uptake was found with increasing frequency as occlusion occurred farther distally.