Alpert Nathaniel M, Rabito Carlos A, Correia D John A, Babich John W, Littman Bruce H, Tompkins Ronald G, Rubin Nina T, Rubin Robert H, Fischman Alan J
Division of Nuclear Medicine, Department of Radiology, Massachusetts General Hospital, 32 Fruit Street, Boston, MA 02114, USA.
J Nucl Med. 2002 Apr;43(4):470-5.
We developed a noninvasive method for the mapping of regional renal blood flow in humans using PET and H(2)(15)O.
Fifteen subjects participated in the study, 5 with normal renal function and 10 with renal disease. The protocol used a whole-body PET scanner, intravenous bolus injection of 1,110-1,850 MBq H(2)(15)O and sequential imaging at 3 s per frame. (131)I-Iodohippuran was used to independently assess effective renal plasma flow in each subject. Hippuran clearance and renal blood flow (RBF) were measured twice, before and after treatment with probenecid, to verify that RBF is not affected. Flow analysis was based on the Kety model, according to the operational equation: C(t) = F integral C(a)(u)du - k integral C(u)du, where F is the RBF, k is the tissue-to-blood clearance rate, C is the PET concentration, and C(a) is the tracer concentration in the abdominal aorta. F and k were estimated by linear least squares on a pixel-by-pixel basis to produce quantitative maps (parametric images) of RBF. The flow maps were analyzed by regions of interest (largely excluding the medulla and collecting system) for each kidney on each slice and pooled to yield mean RBF.
In the 5 healthy subjects, mean RBF was 3.4 +/- 0.4 mL/min/g. There was no difference in flow between kidneys (t = -0.59; n = 11; P > 0.95). Before treatment with probenecid, RBF was linearly related to hippuran clearance (r(2) = 0.92). Probenecid treatment significantly reduced hippuran clearance (P < 0.003), but RBF was unchanged (P > 0.17). Compared with healthy control subjects, RBF was significantly decreased in patients with renal disease (P < 0.002). Flow maps were of good quality in all subjects, exhibiting characteristic patterns, with higher values in regions composed largely of renal cortex.
Parametric mapping of RBF with PET and H(2)(15)O provides a straightforward, noninvasive method for quantitative mapping of RBF, which may prove useful in research applications and in the management of patients whose therapy alters renal tubular transport.
我们开发了一种使用正电子发射断层扫描（PET）和H₂¹⁵O对人体局部肾血流进行成像的非侵入性方法。
15名受试者参与了该研究，其中5名肾功能正常，10名患有肾脏疾病。研究方案使用全身PET扫描仪，静脉推注1110 - 1850 MBq的H₂¹⁵O，并以每秒3帧的速度进行序列成像。使用¹³¹I - 碘马尿酸独立评估每名受试者的有效肾血浆流量。在丙磺舒治疗前后，对马尿酸清除率和肾血流量（RBF）进行了两次测量，以验证RBF不受影响。流量分析基于凯蒂模型，根据运算方程：C(t) = F∫C(a)(u)du - k∫C(u)du，其中F是RBF，k是组织与血液的清除率，C是PET浓度，C(a)是腹主动脉中的示踪剂浓度。通过逐像素线性最小二乘法估计F和k，以生成RBF的定量图（参数图像）。通过对每个切片上每个肾脏的感兴趣区域（主要排除髓质和集合系统）分析流量图，并汇总得出平均RBF。
在5名健康受试者中，平均RBF为3.4±0.4 mL/min/g。两肾之间的血流量无差异（t = -0.59；n = 11；P > 0.95）。在丙磺舒治疗前，RBF与马尿酸清除率呈线性相关（r² = 0.92）。丙磺舒治疗显著降低了马尿酸清除率（P < 0.003），但RBF未改变（P > 0.17）。与健康对照受试者相比，肾病患者的RBF显著降低（P < 0.002）。所有受试者的流量图质量良好，呈现出特征性模式，在主要由肾皮质组成的区域值较高。
用PET和H₂¹⁵O对RBF进行参数成像提供了一种直接的、非侵入性的RBF定量成像方法，这在研究应用以及治疗改变肾小管转运的患者管理中可能证明是有用的。
