Herrero P, Markham J, Shelton M E, Weinheimer C J, Bergmann S R
Cardiovascular Division, Washington University School of Medicine, St. Louis, Missouri 63110.
Circulation. 1990 Oct;82(4):1377-86. doi: 10.1161/01.cir.82.4.1377.
Positron emission tomography (PET) centers without cyclotrons use generator-produced rubidium-82 (82Rb) for assessment of myocardial perfusion. The aim of the present study was to determine whether myocardial blood flow could be assessed quantitatively with 82Rb and PET. Because the myocardial extraction fraction of 82Rb varies inversely and nonlinearly with flow and cannot be measured conveniently with PET, we used an experimentally derived mathematical function defining the relation between single-pass extraction fraction of 82Rb and flow to obviate the necessity of measuring the extraction fraction directly. Myocardial blood flow in absolute terms (ml/g/min) was estimated from dynamic PET scans after intravenous administration of 82Rb in intact dogs and compared with flows measured with radiolabeled microspheres. In 36 comparisons in 13 dogs studied at rest, or after coronary occlusion, reperfusion, or after coronary hyperemia induced with intravenous dipyridamole, over the flow range from 0.2 to 2.0 ml/g/min, estimates of perfusion with rubidium correlated well with flows measured concomitantly with microspheres, although there was a slight underestimation of flow with rubidium (flow by 82Rb = 0.92 x flow by microspheres-0.021, r = 0.83). In general, estimates of flow in ischemic regions were less reliable than estimates for regions with normal flow. Thus, although the relation between myocardial extraction and retention of 82Rb and flow can vary under a variety of physiological and pathophysiological conditions, this study demonstrates the ability to obtain quantitative estimates of myocardial blood flow with 82Rb and PET under carefully defined conditions without measuring the extraction fraction directly.
没有回旋加速器的正电子发射断层扫描（PET）中心使用发生器产生的铷-82（82Rb）来评估心肌灌注。本研究的目的是确定是否可以用82Rb和PET定量评估心肌血流。由于82Rb的心肌摄取分数与血流呈反比且非线性关系，并且不能用PET方便地测量，我们使用通过实验得出的数学函数来定义82Rb的单次通过摄取分数与血流之间的关系，从而避免直接测量摄取分数的必要性。在完整的狗静脉注射82Rb后，通过动态PET扫描估计绝对心肌血流（ml/g/min），并与用放射性标记微球测量的血流进行比较。在对13只狗进行的36次比较中，这些狗处于静息状态、冠状动脉闭塞后、再灌注后或静脉注射双嘧达莫诱导冠状动脉充血后，在血流范围为0.2至2.0 ml/g/min时，用铷估计的灌注与同时用微球测量的血流相关性良好，尽管用铷测量的血流略有低估（82Rb测量的血流 = 0.92×微球测量的血流 - 0.021，r = 0.83）。一般来说，缺血区域血流的估计不如正常血流区域的估计可靠。因此，尽管在各种生理和病理生理条件下，82Rb的心肌摄取和保留与血流之间的关系可能会有所不同，但本研究表明，在仔细定义的条件下，无需直接测量摄取分数，就能够用82Rb和PET获得心肌血流的定量估计。
