目的　进一步探讨心肌对 99m Tc- Q3 的摄取特性。方法　制备离体兔心脏灌注模型 ,采用双核素法 ,用含兔自体血红细胞的改良灌注液进行离体兔心脏灌注 ,研究 99m Tc- Q3 和 2 0 1 Tl在不同流量 (每分钟 0 .5 2～3.75 m l/g湿心肌组织 )冠脉灌注离体兔心肌中的摄取特性。结果　心肌对 99m Tc- Q3 的平均瞬时高峰摄取值 ( 0 .6 5±0 .0 77)低于 2 0 1 Tl值 ( 0 .82± 0 .0 7,P<0 .0 0 1) ,且前者受灌注流量的影响比后者更明显 ( P<0 .0 5 )。结论　 99m Tc- Q3的心肌摄取值比 2 0 1 Tl低 ;改变灌注流量对 99m Tc- Q3 和 2 0 1 Tl的心肌摄取值都有显著影响 ;与 2 0 1 Tl相同 ,低灌注流量水平获得的心肌对 99m Tc- Q3 的摄取值可能会过高估计心脏血流量 ,而高灌注流量水平获得的心肌对 99m Tc- Q3 的摄取值可能会过低估计心脏血流量 Objective To investigate myocardial uptake of 99m Tc-Q3. Methods The isolated rabbit heart perfusion model was prepared. The isolated rabbit hearts were perfused with modified perfusate containing rabbit red blood cells using dual-nuclide method. The effects of 99m Tc-Q3 and 2 0 1 Tl at different flow rates 2 ~ 3.75 ml / g wet myocardium) intima in isolated rabbit myocardium. Results The mean peak instantaneous uptake of 99m Tc-Q3 in myocardium was lower than that of 2 0 1 Tl (0.82 ± 0.0 7, P <0. 001) The former was more affected by perfusion flow than the latter (P <0.05). CONCLUSION: The myocardial uptake of 99m Tc-Q3 is lower than that of 2 0 1 Tl. The changes of perfusion flow have significant effects on myocardial uptake of 99m Tc-Q3 and 2 0 1 Tl. Of the myocardial 99m Tc-Q3 intake may overestimate the cardiac blood flow, and myocardial perfusion of 99m Tc-Q3 may be too low to estimate the cardiac blood flow