Lantheus Medical Imaging, North Billerica, Massachusetts; and.
Division of Cardiology, Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, California.
J Nucl Med. 2021 Jun 1;62(6):849-854. doi: 10.2967/jnumed.120.252007. Epub 2020 Nov 27.
The performance of SPECT myocardial perfusion imaging (MPI) may deteriorate in smaller hearts, primarily because of the lower resolution of conventional Anger cameras. F-flurpiridaz is a novel PET MPI agent with superior image and defect resolution. We sought to determine the diagnostic performance of Tc-labeled SPECT MPI compared with F-flurpiridaz PET MPI according to left ventricle (LV) size. We conducted a substudy of the phase III clinical trial of flurpiridaz ( = 750) and stratified diagnostic performance according to the median PET LV end-diastolic volume (LVEDV), with smaller LVs defined as having an LVEDV of less than 113 mL ( = 369) and larger LVs defined as having an LVEDV of at least 113 mL ( = 381). Images were interpreted by the majority rule of 3 independent masked readers. The reference standard was quantitative invasive angiography, with at least 50% stenosis in at least 1 coronary artery considered significant. SPECT performance decreased significantly from an area under the curve (AUC) of 0.75 in larger LVs to 0.67 in smaller LVs ( = 0.03), whereas PET performance was similar in larger and smaller LVs (AUC, 0.79 vs. 0.77, = 0.49). Accordingly, in smaller LVs, PET had a higher AUC (0.77) than the SPECT AUC (0.67) ( < 0.0001), a phenomenon driven by female patients ( < 0.0001). In smaller LVs, there was a degradation of SPECT sensitivity that was highly significant ( < 0.001), whereas there was no significant change in PET sensitivity according to LV size ( = 0.07). Overall, PET had significantly higher sensitivity than SPECT in both smaller LVs (67% vs. 43%, < 0.001) and larger LVs (76% vs. 61%, < 0.001). The specificities of PET and SPECT were similar in larger LVs (76% vs. 83%, = 0.11). Although SPECT specificity improved in smaller compared with larger LVs (90% vs. 83%, = 0.03), the PET specificity did not change with LV size (76% vs. 76%, = 0.9). The diagnostic performance of F-flurpiridaz PET MPI is not affected by LV size and is superior to SPECT MPI in patients with smaller LVs, highlighting the importance of appropriate test selection in these patients.
正电子发射断层扫描（PET）心肌灌注成像（MPI）的性能可能在较小的心脏中恶化，主要是因为传统的 Anger 相机的分辨率较低。F-氟比拉嗪是一种新型的正电子发射断层扫描（PET）MPI 造影剂，具有更好的图像和缺陷分辨率。我们试图根据左心室（LV）的大小，确定 Tc 标记的 SPECT MPI 与 F-氟比拉嗪 PET MPI 的诊断性能。我们对氟比拉嗪（ = 750）的 III 期临床试验进行了子研究，并根据 PET LV 舒张末期容积（LVEDV）中位数对诊断性能进行分层，较小的 LV 定义为 LVEDV 小于 113 毫升（ = 369），较大的 LV 定义为 LVEDV 至少为 113 毫升（ = 381）。图像由 3 位独立的盲法读者进行多数规则解释。参考标准是定量的有创血管造影术，至少有 1 个冠状动脉狭窄至少 50%被认为是显著的。SPECT 性能从较大 LV 的曲线下面积（AUC）0.75显著下降到较小 LV 的 0.67（ = 0.03），而较大和较小 LV 的 PET 性能相似（AUC，0.79 与 0.77， = 0.49）。因此，在较小的 LV 中，PET 的 AUC（0.77）高于 SPECT 的 AUC（0.67）（<0.0001），这种现象是由女性患者驱动的（<0.0001）。在较小的 LV 中，SPECT 的敏感性显著降低（<0.001），而根据 LV 大小，PET 的敏感性没有显著变化（ = 0.07）。总体而言，PET 在较小和较大的 LV 中均具有比 SPECT 更高的敏感性（分别为 67%和 76%）（<0.001）。较大 LV 中 PET 和 SPECT 的特异性相似（76%与 83%， = 0.11）。尽管 SPECT 的特异性在较小的 LV 中比在较大的 LV 中有所提高（90%与 83%， = 0.03），但 PET 的特异性没有随 LV 大小而改变（76%与 76%， = 0.9）。F-氟比拉嗪 PET MPI 的诊断性能不受 LV 大小的影响，在较小的 LV 患者中优于 SPECT MPI，突出了在这些患者中选择适当测试的重要性。
