Beller G A
Circulation. 1983 Aug;68(2 Pt 2):I70-6.
Whereas coronary arteriography demonstrates success of reflow or recanalization after intracoronary thrombolysis, myocardial perfusion imaging with thallium-201 (201Tl) permits assessment of viability of reperfused myocytes. The initial distribution of 201Tl in the myocardium immediately after intravenous injection is the result of both blood flow delivery of the radionuclide to the heart and the extraction fraction for 201Tl. If 201Tl is administered during a period of coronary occlusion, a scintigraphic defect will be observed in the territory of the occluded vessel. If, subsequently, blood flow is restored, as with reperfusion, and cellular kinetics transport of 201Tl returns to normal, myocardial regions initially deprived of 201Tl will demonstrate delayed redistribution and the defect will tend to normalize within several hours. In a sustained coronary occlusion, the defect will persist after 201Tl injection. Specific imaging protocols that have been or can be used to assess thrombolytic therapy are reviewed. If intracoronary streptokinase infusion is associated with a substantial enhancement of perfusion and preservation of cellular integrity in the ischemic zone, delayed 201Tl images obtained several hours after intravenous injection of the radionuclide will demonstrate significantly more 201Tl activity than the images before reflow. Direct intracoronary injections of 201Tl down the infarct vessel have also been used to evaluate the benefit of thrombolytic therapy by the demonstration of increased 201Tl uptake after reperfusion in the ischemic zone. Finally, computer methods for subtracting serial images obtained after two separate intravenous 201Tl injections administered before and after streptokinase infusion might be used to derive a "functional image" of the ischemic region that would quantitatively be proportional to the amount of myocardial salvage achieved.
虽然冠状动脉造影可显示冠状动脉内溶栓后再灌注或再通是否成功，但用铊-201（201Tl）进行心肌灌注显像可评估再灌注心肌细胞的存活性。静脉注射后，201Tl在心肌内的初始分布是放射性核素向心脏的血流输送以及201Tl提取分数的结果。如果在冠状动脉闭塞期间给予201Tl，在闭塞血管的供血区域将观察到闪烁显像缺损。随后，如果血流恢复，如再灌注时那样，并且201Tl的细胞动力学转运恢复正常，最初缺乏201Tl的心肌区域将显示延迟再分布，缺损将在数小时内趋于正常化。在持续性冠状动脉闭塞时，注射201Tl后缺损将持续存在。本文综述了已被或可用于评估溶栓治疗的特定显像方案。如果冠状动脉内输注链激酶与缺血区灌注的显著增强和细胞完整性的保留相关，在静脉注射放射性核素数小时后获得的延迟201Tl图像将显示出比再灌注前的图像明显更多的201Tl活性。也已通过梗死血管直接冠状动脉内注射201Tl来评估溶栓治疗的益处，方法是显示再灌注后缺血区201Tl摄取增加。最后，在链激酶输注前后分别静脉注射201Tl后获得的系列图像相减的计算机方法，可能用于得出缺血区域的“功能图像”，该图像在定量上与实现的心肌挽救量成比例。
