Department of Medical Physics and Engineering, Course of Health Science, Osaka University Graduate School of Medicine, Osaka, Japan;
Department of Quantum Medical Technology, Institute of Medical, Pharmaceutical, and Health Sciences, Kanazawa University, Kanazawa, Japan; and.
J Nucl Med Technol. 2024 Sep 5;52(3):247-251. doi: 10.2967/jnmt.124.267826.
The lack of pediatrics-specific equipment for nuclear medicine imaging has resulted in insufficient diagnostic information for newborns, especially low-birth-weight infants. Although PET offers high spatial resolution and low radiation exposure, its use in newborns is limited. This study investigated the feasibility of cardiac PET imaging using the latest silicon photomultiplier (SiPM) PET technology in infants of extremely low birth weight (ELBW) using a phantom model. The study used a phantom model representing a 500-g ELBW infant with brain, cardiac, liver, and lung tissues. The cardiac tissue included a 3-mm-thick defect mimicking myocardial infarction. Organ tracer concentrations were calculated assuming F-FDG myocardial viability scans and F-flurpiridaz myocardial perfusion scans and were added to the phantom organs. Imaging was performed using an SiPM PET/CT scanner with a 5-min acquisition. The data acquired in list mode were reconstructed using 3-dimensional ordered-subsets expectation maximization with varying iterations. Image evaluation was based on the depiction of the myocardial defect compared with normal myocardial accumulation. Increasing the number of iterations improved the contrast of the myocardial defect for both tracers, with F-flurpiridaz showing higher contrast than F-FDG. However, even at 50 iterations, both tracers overestimated the defect accumulation. A bull's-eye image can display the flow metabolism mismatch using images from both tracers. SiPM PET enabled cardiac PET imaging in a 500-g ELBW phantom with a 1-g heart. However, there were limitations in adequately depicting these defects. Considering the image quality and defect contrast,F-flurpiridaz appears more desirable than F-FDG if only one of the two can be used.
核医学成像缺乏儿科专用设备，导致新生儿，尤其是极低出生体重儿（ELBW）的诊断信息不足。尽管 PET 具有高空间分辨率和低辐射暴露，但在新生儿中的应用有限。本研究使用最新的硅光电倍增管（SiPM）PET 技术，在 500g 的 ELBW 婴儿的体模模型中，探讨了心脏 PET 成像的可行性。该研究使用了一个代表 500g 的 ELBW 婴儿的脑、心、肝和肺组织的体模模型。心脏组织包括一个 3 毫米厚的模拟心肌梗死的缺陷。根据 F-FDG 心肌存活扫描和 F-flurpiridaz 心肌灌注扫描假设计算器官示踪剂浓度，并添加到体模器官中。使用具有 5 分钟采集的 SiPM PET/CT 扫描仪进行成像。以列表模式获取的数据使用 3 维有序子集期望最大化重建，具有不同的迭代次数。图像评估基于与正常心肌积聚相比心肌缺陷的描绘。增加迭代次数可提高两种示踪剂的心肌缺陷对比度，F-flurpiridaz 的对比度高于 F-FDG。然而，即使在 50 次迭代时，两种示踪剂都高估了缺陷的积聚。牛眼图像可以使用两种示踪剂的图像显示血流代谢不匹配。SiPM PET 使 500g 的 ELBW 体模中 1g 大小的心脏能够进行心脏 PET 成像。然而，在充分描绘这些缺陷方面存在局限性。考虑到图像质量和缺陷对比度，如果只能使用两种示踪剂中的一种，那么 F-flurpiridaz 似乎比 F-FDG 更可取。
