Johnson G, Glover D K, Hebert C B, Okada R D
Saint Francis Medical Research Institute, University of Oklahoma Health Sciences Center, Tulsa.
J Nucl Med. 1993 Apr;34(4):630-6.
Technetium-99m-teboroxime (CardioTec) is a promising new myocardial perfusion imaging agent. The purposes of this study were to define teboroxime clearance kinetics in normal and flow-restricted myocardium over a 1-hr period and to determine whether teboroxime kinetics are useful in detecting myocardial hyperperfusion. Accordingly, the circumflex arteries of 23 dogs were stenosed. By using miniature cadmium-telluride radiation detectors, myocardial teboroxime activities were continuously monitored in both the control and the stenosed zones. Myocardial clearance of teboroxime was modeled and found to be biexponential over 1 hr. A significant difference in myocardial clearance between the normal and stenosed zones (t1/2 = 4.5 +/- 0.9 min versus 10.2 +/- 2.6 min, respectively; p < 0.05) was observed for the first exponential phase (the first 5 min following initial uptake), but not for the second exponential phase (t1/2 = 160.7 +/- 35.9 min versus 140.4 +/- 27.4 min, respectively; p = ns). One hour fractional teboroxime blood clearance was 0.95 +/- 0.03, with most of the clearance occurring during the first 4 min. Gamma camera images of excellent quality demonstrated an initial defect with significant quantitative differential clearance over 1 hr. Thus, there are two phases of myocardial teboroxime clearance. During the early exponential clearance phase, teboroxime kinetics at rest may be able to differentiate between normal and hypoperfused myocardium.
锝-99m-特博罗肟（CardioTec）是一种很有前景的新型心肌灌注显像剂。本研究的目的是确定正常心肌和血流受限心肌在1小时内特博罗肟的清除动力学，并确定特博罗肟动力学是否有助于检测心肌血流灌注过度。因此，对23只犬的左旋支动脉进行了狭窄处理。通过使用微型碲化镉辐射探测器，对正常区和狭窄区的心肌特博罗肟活性进行了连续监测。对心肌特博罗肟清除进行建模，发现其在1小时内呈双指数形式。在第一个指数期（初始摄取后的前5分钟），观察到正常区和狭窄区心肌清除存在显著差异（半衰期分别为4.5±0.9分钟和10.2±2.6分钟；p<0.05），但在第二个指数期不存在显著差异（半衰期分别为160.7±35.9分钟和140.4±27.4分钟；p=无显著性差异）。1小时特博罗肟的血清除分数为0.95±0.03，大部分清除发生在最初4分钟内。高质量的γ相机图像显示出初始缺损，在1小时内有显著的定量差异清除。因此，心肌特博罗肟清除有两个阶段。在早期指数清除阶段，静息状态下特博罗肟的动力学可能能够区分正常心肌和灌注不足的心肌。
