Gil V M, Ferreira J, Ventosa A, Calqueiro J, Abreu P, Seabra-Gomes R
Serviço de Cardiologia Hospital de Santa Cruz, Carnaxide.
Rev Port Cardiol. 1994 Mar;13(3):209-19, 192.
To assess the relative capacity of thallium-201 reinjection (RI) and redistribution (RD) for detection of reversibility in patients after myocardial infarction.
We prospectively studied patients referred to myocardial scintigraphy for viability evaluation with stress, redistribution and reinjection images.
Patients were studied with thallium-201 SPECT using three imaging acquisitions--stress, redistribution three to four hours later and reinjection 30-60 minutes after a second injection of thallium under nitroglycerin effect. Thallium uptake was classified in a 0 to 4 intensity scale in each of 13 myocardial segments and a score obtained. Reversibility was classified as "definite" if the increase in thallium uptake was > or = 2 in a myocardial segment and as "possible" if the increase was one.
We studied 44 patients with previous myocardial infarction.
The perfusion score after stress was 37.3 +/- 6.0, improving to 39.8 +/- 6.7 after redistribution and to 43.6 +/- 7.6 after reinjection (p < 0.02 between RD and RI). RD identified reversibility in 38% and RI in 63% (p < 0.001) of the 232 segments with perfusion defects. RI showed reversibility in 39% (definite in 25% and possible in 14%) of the 137 fixed perfusion defects in RD. For the detection of reversibility RI was superior to RD in all sub-groups analyzed. We found a relationship the degree of collateral circulation in the infarct related artery and the amount of reversibility in the infarcted area.
These data suggest a clear superiority of reinjection over redistribution in thallium-201 scintigraphy for the detection of reversibility of perfusion defects after myocardial infarction, and must probably be considered as a routine procedure for myocardial viability assessment.
评估心肌梗死后患者中，铊-201再注射（RI）和再分布（RD）检测可逆性的相对能力。
我们前瞻性地研究了因心肌存活能力评估而接受心肌闪烁显像检查的患者，获取了负荷、再分布和再注射图像。
对患者进行铊-201单光子发射计算机断层扫描（SPECT）检查，采用三次成像采集——负荷成像、三到四小时后的再分布成像以及在硝酸甘油作用下第二次注射铊后30至60分钟的再注射成像。在13个心肌节段的每一个节段中，铊摄取情况按0至4强度等级分类并得出一个分数。如果心肌节段中铊摄取增加≥2，则可逆性分类为“确定”；如果增加为1，则分类为“可能”。
我们研究了44例既往有心肌梗死的患者。
负荷后灌注评分为37.3±6.0，再分布后改善至39.8±6.7，再注射后改善至43.6±7.6（再分布和再注射之间p<0.02）。在232个有灌注缺损的节段中，再分布检测到可逆性的节段占38%，再注射检测到可逆性的节段占63%（p<0.001）。在再分布中137个固定灌注缺损中，再注射显示39%有可逆性（25%为确定可逆，14%为可能可逆）。在所有分析的亚组中，对于检测可逆性，再注射优于再分布。我们发现梗死相关动脉的侧支循环程度与梗死区域的可逆性程度之间存在关联。
这些数据表明，在心肌梗死后灌注缺损可逆性的检测中，铊-201闪烁显像中再注射明显优于再分布，很可能应被视为心肌存活能力评估的常规程序。
