Changes in renal blood flow (RBF) may play a pathophysiological role in hypertension and kidney disease. However, RBF determination in humans has proven difficult. We aimed to confirm the feasibility of RBF estimation based on positron emission tomography/computed tomography (PET/CT) and rubidium-82 (82Rb) using the abdominal aorta as input function in a 1-tissue compartment model. Eighteen healthy subjects underwent two dynamic 82Rb PET/CT scans in two different fields of view (FOV). FOV-A included the left ventricular blood pool (LVBP), the abdominal aorta (AA) and the majority of the kidneys. FOV-B included AA and the kidneys in their entirety. In FOV-A, an input function was derived from LVBP and from AA, in FOV-B from AA. One-tissue compartmental modelling was performed using tissue time activity curves generated from volumes of interest (VOI) contouring the kidneys, where the renal clearance of 82Rb is represented by the K1 kinetic parameter. Total clearance for both kidneys was calculated by multiplying the K1 values with the volume of VOIs used for analysis. Intra-assay coefficients of variation and inter-observer variation were calculated. For both kidneys, K1 values derived from AA did not differ significantly from values obtained from LVBP, neither were significant differences seen between AA in FOV-A and AA in FOV-B, nor between the right and left kidneys. For both kidneys, the intra-assay coefficients of variation were low (~ 5%) for both input functions. The measured K1 of 2.80 ml/min/cm3 translates to a total clearance for both kidneys of 766 ml/min/1.73 m2. Measurement of renal perfusion based on PET/CT and 82Rb using AA as input function in a 1-tissue compartment model is feasible in a single FOV. Based on previous studies showing 82Rb to be primarily present in plasma, the measured K1 clearance values are most likely representative of effective renal plasma flow (ERPF) rather than estimated RBF values, but as the accurate calculation of total clearance/flow is very much dependent on the analysed volume, a standardised definition for the employed renal volumes is needed to allow for proper comparison with standard ERPF and RBF reference methods.

中文翻译：

---

基于健康受试者 PET/CT 扫描测量铷 82 清除率估计肾灌注

肾血流量 (RBF) 的变化可能在高血压和肾脏疾病中发挥病理生理作用。然而，人类的 RBF 测定已被证明是困难的。我们旨在确认基于正电子发射断层扫描/计算机断层扫描 (PET/CT) 和铷 82 (82Rb) 使用腹主动脉作为 1 组织隔室模型中的输入函数的 RBF 估计的可行性。十八名健康受试者在两个不同的视野 (FOV) 中接受了两次动态 82Rb PET/CT 扫描。FOV-A 包括左心室血池 (LVBP)、腹主动脉 (AA) 和大部分肾脏。FOV-B 包括 AA 和整个肾脏。在 FOV-A 中，输入函数来自 LVBP 和 AA，在 FOV-B 中来自 AA。使用由绘制肾脏轮廓的感兴趣体积 (VOI) 生成的组织时间活动曲线进行单组织区室建模，其中 82Rb 的肾脏清除率由 K1 动力学参数表示。通过将 K1 值乘以用于分析的 VOI 的体积来计算两个肾脏的总清除率。计算测定内变异系数和观察者间变异系数。对于两个肾脏，来自 AA 的 K1 值与从 LVBP 获得的值没有显着差异，在 FOV-A 中的 AA 和 FOV-B 中的 AA 之间以及左右肾脏之间也没有显着差异。对于两个肾脏，两种输入函数的测定内变异系数都很低 (~ 5%)。测得的 K1 为 2.80 ml/min/cm3，转化为两个肾脏的总清除率为 766 ml/min/1。73 平方米。在单个 FOV 中使用 AA 作为输入函数在 1 组织隔室模型中基于 PET/CT 和 82Rb 测量肾灌注是可行的。基于之前的研究表明 82Rb 主要存在于血浆中，测得的 K1 清除率值最有可能代表有效肾血浆流量 (ERPF)，而不是估计的 RBF 值，但由于总清除率/流量的准确计算非常依赖在分析的体积上，需要对使用的肾脏体积进行标准化定义，以便与标准 ERPF 和 RBF 参考方法进行适当比较。