Reproducibility of MRI renal artery blood flow and BOLD measurements in patients with chronic kidney disease and healthy controls

Purpose Determine the reproducibility of renal artery blood flow (RABF) and blood‐oxygenation level dependent (R 2 *) in patients with chronic kidney disease (CKD) and healthy controls. Materials and Methods RABF and R 2 * were measured in 11 CKD patients and 9 controls twice with 1‐ to 2‐week interval. R 2 * in the cortex and medulla were determined after breathing atmospheric air and 100% oxygen. Reproducibility was evaluated by coefficients of variation (CV), limits of agreements and intra‐class coefficient calculated by variance components by maximum likelihood modeling. Results Single‐kidney RABF (mL/min) for patients was: 170 ± 130 and 186 ± 137, and for controls: 365 ± 119 and 361 ± 107 ( P < 0.05 versus patients), for first and second scans, respectively. RABF measurements were reproducible with a CV of 12.9% and 8.3% for patients and controls, respectively. Renal cortical R 2 * was: 13.6 ± 0.9 and 13.5 ± 1.2 in patients (CV = 8.0%), and 13.8 ± 1.6 and 14.0 ± 1.5 in controls (CV = 5.6%), while medullary R 2 *(s −1 ) was: 26.9 ± 2.0 and 27.0 ± 4.0 (CV = 8.0%) in patients, and 26.0 ± 2.4 and 26.1 ± 2.1 (CV = 3.6%) in controls, for first and second scans, respectively. In both groups R 2 * in medulla decreased after breathing 100% oxygen. Conclusion The reproducibility was high for both RABF and R 2 * in patients and controls, particularly in the cortex. Inhalation of 100% oxygen reduced medullary R 2 *. J. Magn. Reson. Imaging 2014;40:1091–1098 . © 2013 Wiley Periodicals, Inc .