使用[1-碳-11]乙酸盐同时测量心肌耗氧量和血流量。

Simultaneous measurement of myocardial oxygen consumption and blood flow using [1-carbon-11]acetate.

作者信息

Sun K T, Yeatman L A, Buxton D B, Chen K, Johnson J A, Huang S C, Kofoed K F, Weismueller S, Czernin J, Phelps M E, Schelbert H R

机构信息

Department of Molecular and Medical Pharmacology, School of Medicine, University of California, Los Angeles 90095-1735, USA.

出版信息

J Nucl Med. 1998 Feb;39(2):272-80.

PMID:9476935

Abstract

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.

摘要

未标注

[1-碳-11]乙酸盐已被用作正电子发射断层扫描（PET）中氧化代谢的示踪剂。本研究的目的是在人体中验证先前提出的用于[1-11C]乙酸盐的双室模型，以通过PET无创测量心肌耗氧量（MVO2）和心肌血流量（MBF）。

方法

对12名健康志愿者进行了[13N]氨、[1-11C]乙酸盐和PET研究。通过Fick法从动脉血和冠状窦的氧浓度以及通过[13N]氨PET获得的MBF来有创地测定心肌耗氧量。

结果

直接测量的MVO2范围为5.2至11.1毫升/100克/分钟，MBF范围为0.48至0.88毫升/克/分钟。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，标准误 = 0.015]。基于这种相关性，可通过MVO2 = 135（k2） - 0.96从模型推导的k2值估计MVO2。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相当。通过PET测量的[1-11C]乙酸盐从血液到心肌的净摄取（K1）与MBF密切相关，K1 = 0.15 + 0.73（MBF）（r = 0.93，标准误 = 0.033），因此提供了无创获得的血流量测量值。