Due to spatial resolution limitations, conventional NaI-SPECT typically overestimates the left ventricular (LV) ejection fraction (EF) in patients with small LV volumes. The purpose of this study was to explore the clinical application value of the small heart (SH) reconstruction protocol embedded in the postprocessing procedure of D-SPECT. We retrospectively analyzed patients who undergo both D-SPECT and echocardiography (Echo) within one week. Patients with small LV volume were defined as those with a rest end-systolic volume (rESV) ≤ 25 mL and underwent reconstruction using the standard (SD) reconstruction protocol. The SH protocol was deemed successful in correcting the LVEF value if it decreased by 5% or more compared to the SD protocol. The ROC curve was used to calculate the optimal cutoff value of the SH protocol. LVEF, ESV and EDV were computed with SD and SH, respectively. Echo was performed as a reference, and Echo-LVEF, ESV, and EDV were calculated using the Teichholz formula. One-way ANOVA was used to compare these parameters among the three groups. The final study included 209 patients (73.21% female, age 67.34 ± 7.85 years). Compared with the SD protocol, the SH protocol significantly decreased LVEF (67.43 ± 7.38% vs. 71.30 ± 7.61%, p < 0.001). The optimal cutoff value for using the SH protocol was rESV > 17 mL (AUC = 0.651, sensitivity = 78.43%, specificity = 45.57%, p = 0.001). In the subgroup of rESV > 17 mL, there was no significant difference in LVEF (61.84 ± 4.67% vs. 62.83 ± 2.85%, p = 0.481) between the SH protocol and Echo, and no significant difference was observed in rESV (26.92 ± 3.25 mL vs. 27.94 ± 7.96 mL, p = 0.60) between the SH protocol and Echo. This pilot study demonstrated that the SH reconstruction protocol was able to effectively correct the overestimation of LVEF in patients with small LV volumes. Particularly, in the rESV > 17 mL subgroup, the time and computing power waste could be reduced while still ensuring the accuracy of the LVEF value and image quality.

中文翻译：

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D-SPECT SH 重建方案：改进小左心室体积的量化

由于空间分辨率的限制，传统的 NaI-SPECT 通常会高估左心室 (LV) 体积较小的患者的左心室 (LV) 射血分数 (EF)。本研究的目的是探讨嵌入 D-SPECT 后处理程序的小心脏（SH）重建方案的临床应用价值。我们回顾性分析了一周内接受 D-SPECT 和超声心动图 (Echo) 的患者。小左室容积患者被定义为静息收缩末容积 (rESV) ≤ 25 mL 并使用标准 (SD) 重建方案进行重建的患者。如果与 SD 方案相比 SH 方案降低 5% 或更多，则认为 LVEF 值校正成功。ROC曲线用于计算SH协议的最佳截止值。LVEF、ESV 和 EDV 分别用 SD 和 SH 计算。进行回波作为参考，并使用 Teichholz 公式计算回波 LVEF、ESV 和 EDV。使用单因素方差分析来比较三组之间的这些参数。最终研究包括 209 名患者（73.21% 女性，年龄 67.34 ± 7.85 岁）。与 SD 方案相比，SH 方案显着降低 LVEF（67.43 ± 7.38% vs. 71.30 ± 7.61%，p < 0.001）。使用 SH 方案的最佳截止值为 rESV > 17 mL（AUC = 0.651，敏感性 = 78.43%，特异性 = 45.57%，p = 0.001）。在 rESV > 17 mL 的亚组中，SH 方案和 Echo 之间的 LVEF 没有显着差异（61.84 ± 4.67% 与 62.83 ± 2.85%，p = 0.481），rESV 也没有观察到显着差异（26.92 ± 2.85%，p = 0.481）。 SH 协议和 Echo 之间为 3.25 mL 与 27.94 ± 7.96 mL，p = 0.60）。该试点研究表明，SH 重建方案能够有效纠正 LV 容量较小的患者对 LVEF 的高估。特别是在rESV > 17 mL子组中，可以减少时间和计算能力的浪费，同时仍然保证LVEF值和图像质量的准确性。