BACKGROUND Measurement of myocardial blood flow (MBF) with single photon emission computed tomography (SPECT) is feasible using cardiac cameras with solid-state detectors. SPECT MBF has been shown to be accurate when compared with positron emission tomography MBF measured in the same patients. However, the value of a test result applied to an individual patient depends strongly on the precision or repeatability of the test. The purpose of our study is to measure the precision of SPECT MBF measurements using 99mTc-tetrofosmin and a solid-state cardiac camera. METHODS SPECT MBF was measured in 30 patients and repeated at a mean interval of 18 days. MBF was evaluated from images with and without attenuation correction based on a separately acquired CT scan. The dynamic images were processed independently by 2 operators using in-house kinetic analysis software that applied a 1-tissue-compartment model. The K1 rate constant was converted to MBF using previously determined extraction fraction corrections. Correction for patient body motion was applied manually. RESULTS The average coefficient of variation (COV) in the differences between the 2 MBF measurements was between 28% and 31%. The interobserver COV was between 11% and 15%. Myocardial flow reserve is the ratio of MBF measured at stress and rest, and the COV is correspondingly higher. The COV for the difference in repeated myocardial flow reserve was 33% to 38%, whereas the interobserver COV was 13% to 22%. CONCLUSIONS The COV for the difference in SPECT MBF measurements obtained on separate days is 28% to 31%. The corresponding COV for myocardial flow reserve is 33% to 38%.

中文翻译：

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使用99mTc-Tetrofosmin和固态检测器单光子发射计算机断层扫描技术测量心肌血流的重测精度。

背景技术使用具有固态检测器的心脏照相机，利用单光子发射计算机断层扫描（SPECT）测量心肌血流量（MBF）是可行的。与在同一患者中测量的正电子发射断层扫描MBF相比，SPECT MBF已被证明是准确的。但是，应用于单个患者的测试结果的值在很大程度上取决于测试的准确性或可重复性。我们研究的目的是使用99mTc-四氟膦和固态心脏照相机来测量SPECT MBF测量的精度。方法对30例患者进行SPECT MBF测量，平均间隔18天重复一次。根据单独获取的CT扫描从有无衰减校正的图像中评估MBF。动态图像由2位操作员使用内部动力学分析软件（应用了1个组织室模型）独立处理。使用先前确定的萃取分数校正将K1速率常数转换为MBF。手动应用患者身体运动校正。结果两次MBF测量值之间的差异的平均变异系数（COV）在28％至31％之间。观察者之间的COV在11％和15％之间。心肌血流储备是在压力和休息时测得的MBF的比值，COV相应较高。重复心肌血流储备差异的COV为33％至38％，而观察者间COV为13％至22％。结论在不同日期获得的SPECT MBF测量值差异的COV为28％至31％。