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

IntroductionChronic kidney disease (CKD) is known to be associated with reduced renal blood flow. However, data in humans are limited to date.MethodsIn 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.ResultsA 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 (ρ = 0.67, P < 0.001) and medullary (ρ = 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.DiscussionThese 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