COMPARATIVE SPECT STUDY OF STROKE USING TC-99M ECD, I-123 IMP, AND TC-99M HMPAO

Brain perfusion SPECT imaging using Tc-99m ethyl cysteinate dimer (ECD ) was carried out in 12 patients with chronic cerebrovascular disease. The sensitivity of lesion detection and lesion-to-normal tissue contr ast was compared with those of I-123 IMP and Tc-99m HMPAO. Eight patie nts underwent all three studies and the remaining four patients had Tc -99m ECD and I-123 IMP scans. The sensitivity of lesion detection and lesion contrast was analyzed quantitatively using an asymmetric index determined by the equation: 100 x \right - left\ / (right + left). In the cerebral cortex, cerebellum, and white matter, I-123 IMP showed hi gher lesion sensitivity than Tc-99m ECD and Tc-99m HMPAO. In the stria tum and thalamus, Tc-99m ECD and I-123 IMP showed higher lesion sensit ivity than Tc-99gm HMPAO. I-123 IMP showed the highest lesion contrast in cerebral cortex and cerebellum, whereas Tc-99m ECD showed the high est contrast in thalamus and striatum. In all regions, Tc-99m ECD show ed higher lesion contrast than Tc-99m HMPAO. These results suggest reg ional variation in the sensitivity of lesion detection and lesion cont rast of Tc-99m ECD compared to I-123 IMP, and the superiority of Tc-99 m ECD to Tc-99m HMPAO.