Evaluation of Renal Blood Flow in Chronic Kidney Disease Using Arterial Spin Labeling Perfusion Magnetic Resonance Imaging

Introduction: Chronic kidney disease (CKD) is known to be associated with reduced renal blood flow. However, data in humans are limited to date. Methods: In this study, noninvasive arterial spin labeling magnetic resonance imaging data were acquired in 33 patients with diabetes and stage 3 CKD as well as in 30 healthy controls. Results: A significantly lower renal blood flow in both the cortex (108.4 +/- 36.4 vs. 207.3 +/- 41.8; P < 0.001, d = 2.52) and medulla (23.2 +/- 8.9 vs. 42.6 +/- 15.8; P < 0.001, d = 1.5) was observed. Both cortical (rho +/- 0.67, P < 0.001) and medullary (rho = 0.62, P < 0.001) blood flow were correlated with estimated glomerular filtration rate, and cortical blood flow was found to be confounded by age and body mass index. However, in a subset of subjects who were matched for age and body mass index (n = 6), the differences between CKD patients and control subjects remained significant in both the cortex (107.4 +/- 42.8 vs. 187.51 +/- 20.44; P = 0.002) and medulla (15.43 +/- 8.43 vs. 39.18 +/- 11.13; P = 0.002). A threshold value to separate healthy controls and CKD patients was estimated to be a cortical blood flow of 142.9 and a medullary blood flow of 24.1. Discussion: These results support the use of arterial spin labeling in the evaluation of renal blood flow in patients with a moderate level of CKD. Whether these measurements can identify patients at risk for progressive CKD requires further longitudinal follow-up.