DePuey E G, Nichols K, Dobrinsky C
Department of Radiology, St. Luke's-Roosevelt Hospital Center, New York, NY 10025.
J Nucl Med. 1993 Nov;34(11):1871-6.
By means of ECG gating of tomographic (SPECT) 99mTc-sestamibi (MIBI) images, myocardial perfusion and wall thickening have been evaluated after a single tracer injection. To determine if left ventricular ejection fraction (LVEF) can also be measured from gated MIBI SPECT, 30 patients 1 wk to 6 mo after myocardial infarction (MI) received 22-30 mCi 99mTc-MIBI during treadmill exercise. Eight frame per cardiac cycle gated MIBI 180 degrees SPECT was performed 60 min thereafter. Using 6.4-mm thick mid-ventricular vertical and horizontal long-axis slices from R-wave triggered end-diastolic and end-systolic frames, two independent observers manually drew endocardial borders at a count level of 34% of the maximum. LVEF was computed by the Simpson's rule method, corrected for the average point spread function of the SPECT camera. Results were correlated with LVEF determined from planar gated 99mTc-blood-pool studies performed within 4 days. LVEFs calculated from gated MIBI SPECT ranged from 0.21 to 0.73 and correlated linearly with gated blood-pool values (correlation coefficients ranged from 0.79 to 0.88; interobserver variability r = 0.75; intraobserver reproducibility r = 0.75). We conclude that in patients with MI resting LVEF can be determined from gated MIBI SPECT, thereby considerably augmenting the technique's diagnostic and prognostic value.
通过断层扫描（SPECT）99mTc-司他米比（MIBI）图像的心电图门控技术，在单次注射示踪剂后评估了心肌灌注和室壁增厚情况。为了确定是否也能从门控MIBI SPECT测量左心室射血分数（LVEF），30例心肌梗死（MI）后1周至6个月的患者在跑步机运动期间接受了22 - 30 mCi的99mTc-MIBI。此后60分钟进行每心动周期8帧的门控MIBI 180度SPECT检查。使用来自R波触发的舒张末期和收缩末期帧的6.4毫米厚的心室中部垂直和水平长轴切片，两名独立观察者在最大计数水平的34%处手动绘制心内膜边界。LVEF通过Simpson规则法计算，并根据SPECT相机的平均点扩散函数进行校正。结果与4天内进行的平面门控99mTc血池研究确定的LVEF相关。从门控MIBI SPECT计算出的LVEF范围为0.21至0.73，与门控血池值呈线性相关（相关系数范围为0.79至0.88；观察者间变异性r = 0.75；观察者内再现性r = 0.75）。我们得出结论，在MI患者中，静息LVEF可通过门控MIBI SPECT确定，从而大大提高了该技术的诊断和预后价值。
