중추신경계 질환에서 전신 스캔으로 본 Tc-99m ECD의 생체 내 분포

Abstract

We evaluated prospectively in vivo distribution of Tc-99m Ethyl cysteinate dimer (ECD) in patients with central nervous system (CNS) diseases, especially in brain, liver and lung. Whole body scans were performed in 150 patients with CNS diseases at one hour after the injection of 800 MBq Tc-99m ECD. The clinical comments were divided into six groups such as vertigo (n=64), seizure (n=30), psychiatric symptoms (n=9), post-traumatic symptoms (n=7), cerebrovascular accident (CVA, n=34) and others (n=6). Mean counts/pixel of brain (B), liver (H), lung (P) were calculated with same-sized region of interest (ROI)s in whole body scan, and H/B and P/B ratios were analyzed. The same kind of study with Tc-99m Hexamethylpropylene amine oxime (HMPAO) was done in twelve cases. Average H/B and P/B ratios in all patients studied with Tc-99m ECD were 0.99±0.35 and 0.50±0.26, respectively. Average H/B and P/B ratios in male (1.11±0.30 and 0.57±0.29) were significantly higher than those in female (0.86±0.35 and 0.42±0.20) (p < 0.05). The H/B ratio was not significantly different among six different clinical comment groups, but P/B ratio in CVA was significantly higher than those in other groups (p < 0.05). Average H/B and P/B ratios of Tc-99m ECD (0.99±0.35 and 0.50±0.26) were much lower than those of Tc-99m HMPAO (2.40±0.63 and 1.09±0.34)(p<0.05). The hepatic uptake of Tc-99m ECD was nearly same as the brain uptake, and lung uptake was lower than that of brain, similar to those in normal volunteers. Liver and lung uptakes of Tc-99m ECD in male were higher than those in female, and lung uptake in CVA was higher than those in other clinical comment groups. Tc-99m ECD was more safe than Tc-99m HMPAO in view of the radiation exposure to liver and lung.