Simultaneous measurement of myocardial oxygen consumption and blood flow using [1-carbon-11]acetate.
Simultaneous measurement of myocardial oxygen consumption and blood flow using [1-carbon-11]acetate.
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发表时间：
1998-02
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通讯作者：
K. Sun;L. Yeatman;D. Buxton;Kewei Chen;J. Johnson;Sung-Cheng Huang;K. Kofoed;S. Weismueller;J. Czernin;M. Phelps;H. Schelbert
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作者：
K. Sun;L. Yeatman;D. Buxton;Kewei Chen;J. Johnson;Sung-Cheng Huang;K. Kofoed;S. Weismueller;J. Czernin;M. Phelps;H. Schelbert
未标记的[1-碳-11]醋酸酯已被用作PET氧化代谢的示踪剂。本研究的目的是验证先前提出的用PET无创测量心肌耗氧量（MVO2）和心肌血流量（MBF）的醋酸[1-11C]双室模型在人体中的应用。方法对12名健康志愿者进行[13N]氨、[1-11C]醋酸酯和PET的研究。心肌耗氧量采用菲克法有创测定动脉和冠状窦O2浓度以及[13N]氨PET测定MBF。结果直接测得MVO2范围为5.2 ~ 11.1 ml/100g/min， MBF范围为0.48 ~ 0.88 ml/g/min。通过三羧酸循环的氧化通量，由速率常数k2反映，其与测量的MVO2呈线性相关[k2 = 0.0071 + 0.0074(MVO2)]；R = 0.74， S.E.E. = 0.015]。根据这种相关性，MVO2可以由模型推导的k2值估计为MVO2 = 135(k2) - 0.96。这种关系的斜率与先前在大鼠中获得的斜率接近，这意味着三羧酸循环中间代谢物池的大小具有可比性。PET测定的[1-11C]醋酸盐从血液进入心肌的净提取率（K1）与MBF密切相关，K1 = 0.15 + 0.73(MBF) (r = 0.93, s.e.e = 0.033)，因此提供了无创的血流量测量。结论提出的[1-11C]醋酸盐的室室模型与测量的动力学很好地吻合，并且通过适当的校准，可以估计绝对MVO2，而不仅仅是氧化代谢指标。此外，[1-11C]醋酸盐对MBF的估计是可行的。
UNLABELLED [1-Carbon-11]acetate has been used as a tracer for oxidative metabolism with PET. The aim of this study was to validate, in humans, a previously proposed two-compartment model for [1-11C]acetate for the noninvasive measurement of myocardial oxygen consumption (MVO2) and myocardial blood flow (MBF) with PET. METHODS Twelve healthy volunteers were studied with [13N]ammonia, [1-11C]acetate and PET. Myocardial oxygen consumption was invasively determined by the Fick method from arterial and coronary sinus O2 concentrations and from MBF obtained by [13N]ammonia PET. RESULTS Directly measured MVO2 ranged from 5.2 to 11.1 ml/100g/min, and MBF ranged from 0.48 to 0.88 ml/g/min. Oxidative flux through the tricarboxylic acid cycle, reflected by the rate constant k2, which correlated linearly with measured MVO2 [k2 = 0.0071 + 0.0074(MVO2); r = 0.74, s.e.e. = 0.015]. With this correlation, MVO2 could be estimated from the model-derived k2 value by MVO2 = 135(k2) - 0.96. The slope of this relationship was close to that previously obtained in rats and implies that the tricarboxylic acid cycle intermediate metabolite pool sizes are comparable. The net extraction (K1) of [1-11C]acetate, measured by PET, from blood into myocardium correlated closely with MBF by K1 = 0.15 + 0.73(MBF) (r = 0.93, s.e.e. = 0.033) and, thus, provided noninvasively obtainable measures of blood flow. CONCLUSION The proposed compartment model for [1-11C]acetate fits the measured kinetics well and, with proper calibration, allows estimation of absolute MVO2 rather than only an index of oxidative metabolism. Furthermore, [1-11C]acetate-derived estimates of MBF are feasible.