^(99m)Tc-Q_3和^(201)Tl在不同流量冠脉灌注的离体兔心肌中摄取特性的对照研究

^(99m )Tc Q_3 Uptake Prope rty at Varying Coronary Flow Rates in Isolated Rabbit Heart: Comparison Between 99mTc Q_3 and ^(201)T_l

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

Objective This experiment was designed to explore myocardial 99m Tc Q 3 u ptake property.Methods 20 New Zealand White rabbit heart perfu sion models were prepared and the isolated rabbit hearts were perfused by double radionuclide method at v a rying coronary flow rates from 0.52 to 3.75 ml/g wet wt /min using developed per fusion liquid with autoblood in comparison with 201 Tl in the absence of t racers recirculation.Results Mean 99m Tc Q 3 peak instantan eous uptake was lower(0.65±0.077) an d more affected by low rates ( P <0.05) than 201 Tl peak instantaneous u ptake (0.82±0.07, P <0.01).Conclsuion These data were inte rpreted to indicate:① 99m Tc Q 3 is not as well extracted as 201 Tl; ② varying the coronary flow rate ha s significant effects on the uptake of 99m Tc Q 3 and 201 Tl; ③ s imilarly to 201 Tl, the coronary blood flow conditions may be overestimate d by the myocardial radioactive uptake acquired with low flow perfusion, but the coronary blood flow conditions may be underestimated by the myocardial radioact ive uptake acquired with high flow perfusion. Further studies on retention and c learance of 99m Tc Q 3 need to be conducted.