COMPARATIVE QUANTITATION OF CEREBRAL BLOOD-VOLUME - SPECT VERSUS PET

Quantification of cerebral blood volume (CBV) measured by SPECT has be en used for evaluation of Cerebral hemodynamics in patients with cereb rovascular diseases. The accuracy of such quantification, however, has not been validated with PET. Methods: CBV was assessed using SPECT an d in vitro Tc-99m-labeled red blood cells and PET with the O-15 steady -state inhalation method and (CO)-O-15. In 23 patients with carotid ar tery disease, we measured hemispheric (including cortical and subcorti cal areas) CBV, and in 11. patients, we measured regional CBV in small cortical regions. We further evaluated the interhemispheric and inter -regional asymmetry of CBV with both methods. Results: Quantitative va lues of both hemispheric and regional CBV measured by SPECT were signi ficantly correlated with those measured by PET in the same patients. T here was a significant correlation between the side-to-side asymmetry of CBV for both methods. Conclusion: This study demonstrates usefulnes s and the accuracy of SPECT for quantitative CBV assessment in compari son with the less widely available PET procedures.