The purpose of this study was to demonstrate the feasibility of an asymmetric spin echo (ASE) single-shot echo planar imaging (EPI) sequence for the noninvasive quantitative measurement of intrarenal R2′ in humans within 20 s. The reproducibility of R2′ measurements with the ASE-EPI sequence was assessed in nine healthy young subjects in repeated studies conducted over three consecutive days. Moreover, we also evaluated whether the ASE-EPI sequence-measured R2′ reflected the intrarenal oxygenation changes induced by furosemide in another group of normal human subjects (n = 10). Different flow attenuation gradients (b = 0, 40 and 80 s/mm2) were utilized to examine the impact of the intravascular signal contribution on the estimation of intrarenal R2′. In the absence of flow dephasing gradients (b = 0 s/mm2), the computed coefficient of variation (CV) of R2′ was 21.31 ± 4.52%, and the estimated R2′ value decreased slightly, but not statistically significantly (p > 0.05), after the administration of furosemide in the medullary region. However, CV of R2′ was much smaller in the presence of flow dephasing gradients (9.68 ± 3.58% with b = 40 s/mm2and 10.50 ± 3.62% with b = 80 s/mm2). Moreover, a significant reduction in R2′ in the renal medulla was obtained (p < 0.05 for both b = 40 s/mm2 and b = 80 s/mm2) after the administration of furosemide, reflecting an increase in oxygen tension in the medullary region. In addition, R2′ measurements did not differ between the b = 40 s/mm2 and b = 80 s/mm2 scans, suggesting that small diffusion gradients were sufficient to minimize the intravascular signal contribution. In summary, we have demonstrated that renal R2′ can be obtained rapidly using an ASE-EPI sequence. The measurement was highly reproducible and reflected the expected intrarenal oxygenation changes induced by furosemide. Copyright © 2012 John Wiley & Sons, Ltd.