[133Xe-DSPECT (Dynamic Single Photon Emission CT). Results of a new noninvasive method for measuring regional cerebral blood flow (rCBF). Comparison with cranial angiography and transmission CT].

133Xenon-DSPECT provides measurement of regional cerebral blood flow (rCBF in ml/100 g/min) during and after inhalation of 133Xe gas. The result is displayed as a flow map of three transaxial slices. ROI divide a slice into 12 areas (SA) computing flow values (FSA). The results in 36 patients with cranial vascular disease are presented in comparison to 12 "normals". In all patients, FSA in the diseased hemisphere were found to be below the standard range of normals. Related to number of SA, this was true in completed stroke (bilateral) in 55% or (unilateral) in 14%, in PRIND in 5% of SA and in TIA in 7%. The absolute flow values did not decrease with the severeness of the disease, presumably depending on patient's age. There were more (p less than 0,005) SA found with decreased rCBF (21%) than areas with low density in T-CT (10%). Since unilateral cerebrovascular findings presented also bilateral reduced FSA, the validity of the method lies in the calculation of flow values, which significantly adds to the results of imaging.