BOLD T2* MRI is a surrogate marker of tissue pO2 alterations associated with renal disease, but is limited by perfusion. Hyperpolarized [13C,15N2]urea is an alternative marker of renal function that correlates with normal renal oxygenation. We investigated the correlation between BOLD T2* and 13C-urea T2 in an acute kidney injury (AKI) model. We found that hyperpolarized urea T2 correlates with renal BOLD T2* in the healthy but not in the AKI kidney, and that whole kidney T2 is modulated significantly by the blood volume in addition to oxygen availability. 13C-urea T2 mapping therefore has potential to assist the BOLD estimation.