Quantitative SPECT enables absolute quantification of uptake in perfusion defects. The aim of this experimental study is to assess quantitative accuracy and precision of a novel iterative reconstruction technique (Evolution; GE Healthcare) for the potential application of response monitoring using 99mTc-tetrofosmin SPECT/CT in patients with coronary artery disease (CAD). Acquisitions of an anthropomorphic torso phantom with cardiac insert containing defects (with varying sizes), filled with 99mTc-pertechnetate, were performed on a SPECT/CT (Discovery 670 Pro, GE Healthcare). Subsequently, volumes of interest of the defects were manually drawn on CT to assess the recovery coefficient (RC). Bull’s eye plots were composed to evaluate the uptake per segment. Finally, 99mTc-tetrofosmin SPECT/CT scans of 10 CAD patients were used to illustrate clinical application. The phantom study indicated that Evolution showed convergence after 7 iterations and 10 subsets. The average repeatability deviation of all configurations was 2.91% and 3.15% (%SD mean) for filtered (Butterworth) and unfiltered data, respectively. The accuracy after post-filtering was lower compared to the unfiltered data with a mean (SD) RC of 0.63 (0.05) and 0.70 (0.07), respectively (p < 0.05). More artificial defects were found on Bull’s eye plots created with the unfiltered data compared to filtered data. Eight out of ten patients showed significant changes in uptake before and after treatment (p < 0.05). Quantification of 99mTc-tetrofosmin SPECT/CT seems feasible for CAD patients when 7 iterations (10 subsets), Butterworth post-filtering (cut off frequency 0.52 in cycles/cm, order of 5) and manual CT-delineation are applied. However, future prospective patient studies are required for clinical application.

中文翻译：

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用于冠心病患者反应监测的绝对 SPECT/CT 量化的实验验证

定量 SPECT 能够对灌注缺损中的摄取进行绝对量化。本实验研究的目的是评估一种新型迭代重建技术（Evolution；GE Healthcare）的定量准确性和精确度，该技术使用 99mTc-tetrofosmin SPECT/CT 在冠状动脉疾病 (CAD) 患者中进行反应监测的潜在应用。在 SPECT/CT（Discovery 670 Pro，GE Healthcare）上采集了一个带有心脏插入物的拟人躯干体模（具有不同尺寸），填充了 99mTc 高锝酸盐。随后，在 CT 上手动绘制感兴趣的缺陷体积以评估恢复系数 (RC)。组成牛眼图以评估每段的吸收。最后，10名CAD患者的99mTc-tetrofosmin SPECT/CT扫描用于说明临床应用。幻像研究表明，Evolution 在 7 次迭代和 10 个子集后表现出收敛。对于过滤 (Butterworth) 和未过滤数据，所有配置的平均重复性偏差分别为 2.91% 和 3.15%（%SD 平均值）。与未过滤的数据相比，后过滤后的准确度较低，平均 (SD) RC 分别为 0.63 (0.05) 和 0.70 (0.07) (p < 0.05)。与过滤数据相比，在使用未过滤数据创建的牛眼图上发现了更多人为缺陷。十分之八的患者在治疗前后表现出显着的摄取变化（p < 0.05）。当 7 次迭代（10 个子集）时，99mTc-tetrofosmin SPECT/CT 的量化对于 CAD 患者似乎是可行的，应用了巴特沃斯后滤波（截止频率 0.52 周期/厘米，5 阶）和手动 CT 描绘。然而，临床应用需要未来的前瞻性患者研究。