Department of Nuclear Medicine, Isala, PO Box 10400, 8000 GK, Zwolle, The Netherlands.
MIRA: Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands.
J Nucl Cardiol. 2021 Aug;28(4):1536-1544. doi: 10.1007/s12350-019-01875-w. Epub 2019 Sep 4.
Clinical practice shows degrading image quality in heavier patients who undergo myocardial perfusion imaging (MPI) with Rubidium-82 (Rb-82) PET when using a fixed tracer activity. Our aim was to derive and validate a patient-specific activity protocol resulting in a constant image quality in PET MPI.
We included 251 patients who underwent rest MPI with Rb-82 PET (Discovery 670, GE Healthcare). 132 patients were included retrospectively and were scanned using a fixed activity of 740 MBq. The total number of measured prompts was normalized to activity and correlated to body weight, mass per body length and body mass index to find the best predicting parameter. Next, a patient-specific activity was derived and subsequently validated in 119 additional patients. Image quality was scored by three experts on a four-point scale.
Both image quality and prompts decreased in heavier patients when using a fixed activity (p < .005). Body weight was used to derive a new activity formula: Activity = 8.3 MBq/kg. When applying this formula, both measured prompts and scored image quality became independent of body weight (p > .60).
Administrating a Rb-82 activity that linearly depends on body weight resulted in a constant image quality across all patients and is recommended.
临床实践表明，在使用固定示踪剂活度对较重患者进行铷-82（Rb-82）PET 心肌灌注成像（MPI）时，图像质量会降低。我们的目的是制定并验证一种患者特异性活度方案，以确保 PET MPI 中的图像质量始终保持一致。
我们纳入了 251 例接受 Rb-82 PET（通用电气医疗系统公司的 Discovery 670）静息 MPI 的患者。其中 132 例为回顾性纳入，采用 740 MBq 的固定活度进行扫描。将测量的提示数与活度归一化，并与体重、体质量/体长和体重指数相关联，以找到最佳预测参数。接下来，在 119 例额外患者中推导并验证了一种患者特异性活度。图像质量由三位专家进行四点评分。
当使用固定活度时，较重患者的图像质量和提示数均降低（p < 0.005）。体重用于推导出一个新的活动公式：Activity = 8.3 MBq/kg。当应用该公式时，测量的提示数和评分的图像质量均与体重无关（p > 0.60）。
推荐使用与体重线性相关的 Rb-82 活度，可使所有患者的图像质量保持一致。
