THE RELATIONSHIP BETWEEN MYOCARDIAL RETENTION OF TC-99M TEBOROXIME AND MYOCARDIAL BLOOD-FLOW
THE RELATIONSHIP BETWEEN MYOCARDIAL RETENTION OF TC-99M TEBOROXIME AND MYOCARDIAL BLOOD-FLOW
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DOI：
10.1016/0735-1097(92)90029-m
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发表时间：
1992-09-01
影响因子：
24
通讯作者：
SCHWAIGER, M
中科院分区：
文献类型：
--
作者：
BEANLANDS, R;MUZIK, O;SCHWAIGER, M
目标。本研究的目的是确定犬模型中锝-99m 替硼肟组织保留与心肌血流之间关系的时间变化。背景。 Technetium-99m替硼肟是一种新型中性亲脂性心肌灌注剂。已知它被心肌高度提取但具有快速的清除率。方法。每个实验中通过局部冠状动脉闭塞和双嘧达莫输注诱导大范围的心肌血流。注射示踪剂后 1、2 或 5 分钟通过体外组织计数测定锝-99m 替硼肟的心肌滞留情况。示踪剂保留与微球确定的血流量相关，并且数据适合非线性函数。结果。这些函数在 1 分钟、2 分钟和 5 分钟时的相关系数分别为 0.92、0.95 和 0.95。注射后 1 分钟，锝-99m 替硼肟保留与血流的关系在较宽的流量范围内呈线性关系，在流速 >4.5 ml/min/g 时变为非线性关系。 5 分钟后，保留-流量关系仅在每克 2.5 毫升/分钟时呈线性，高于此值，保留几乎没有变化。还计算了标准化心肌滞留，表示为每克 1 毫升/分钟的滞留百分比。在流速为 1、2、3、4 和 5 ml/min/g 时，注射后 1 分钟时的归一化保留率为 100、169、228、277 和 317%，5 分钟时的归一化保留率为 100、171、217、239 和 237%。结论。注射后1分钟，锝-99m替硼肟心肌滞留与血流的关系在较宽的流量范围内得到良好维持。然而，仅 5 分钟后，示踪剂保留就低估了中等和高流速下的流量变化。因此，为了充分利用这种有前景的新型示踪剂在心肌灌注评估中的潜力，需要快速采集协议。
Objectives. The aim of this study was to define the temporal changes in the relationship between technetium-99m teboroxime tissue retention and myocardial blood flow in a canine model.Background. Technetium-99m teboroxime is a new neutral lipophilic myocardial perfusion agent. It is known to be highly extracted by the myocardium but to have a rapid clearance rate.Methods. A wide range of myocardial blood flow was induced in each experiment by regional coronary occlusion and dipyridamole infusion. Myocardial retention of technetium-99m teboroxime was determined by in vitro tissue counting at 1, 2 or 5 min after injection of the tracer. Tracer retention was correlated with microsphere-determined blood flow and the data were fitted to nonlinear functions.Results. Correlation coefficients for these functions were 0.92, 0.95 and 0.95 at 1, 2, and 5 min, respectively. At 1 min after injection, the relationship of technetium-99m teboroxime retention to blood flow was linear over a wide flow range, becoming nonlinear at flow rates >4.5 ml/min per g. After 5 min the retention-flow relationship was linear only to 2.5 ml/min per g, above which little change in retention was noted. Normalized myocardial retention, expressed as a percent of the retention at 1 ml/min per g, was also calculated. At flow rates of 1, 2, 3, 4 and 5 ml/min per g, normalized retention was 100, 169, 228, 277 and 317% at 1 min and 100, 171, 217, 239 and 237% at 5 min after injection.Conclusions. At 1 min after injection, the relationship of technetium-99m teboroxime myocardial retention to blood flow is well maintained over a wide range of flow. However, after only 5 min, tracer retention underestimates flow changes at moderate and high flow rates. Thus, rapid acquisition protocols are necessary to fully exploit the potential of this promising new tracer in the evaluation of myocardial perfusion.