[Comparison of the results obtained using 99mTc HM-PAO tomoscintigraphy and computer tomography in ischemic lesions of the brain].

: Fifty patients suffering from cerebral ischemic attacks, transient or not, were studied with both 99mTc HM-PAO single photon emission computed tomography (SPECT) and computed tomography (CT). In 31 patients both SPECT and CT showed pathologic areas, the max diameters of which were measured on CT images and SPECT orbitomeatal reconstructed sections, and then compared. We observed that: only SPECT images are positive for pathologic conditions in transient ischemic attacks and in the very early phases of infarctions; in recent infarctions (less than 15 days earlier) both SPECT and CT scans are positive but SPECT lesion areas are greater than CT ones; pathologic areas, with clear-cut outlines, having the same dimensions on both CT and SPECT images, are supposed to result from old static infarctions. A persistent perilesional hypoactive area on SPECT images means, in our opinion, a hypoperfusional area liable to new vascular troubles; in which case, medical/surgical therapy seems necessary.