High-temporal-resolution dynamic EPI at 9.4T for monitoring renal oxygenation in rats: Responses to hyperoxia and hypoxia

Motivation: Rapid and dynamic MRI is essential to capture changes in the renal blood oxygen system during stepwise oxygen stimulation. Goal(s): In order to monitor the renal oxygenation various with high-temporal-resolution dynamic imaging by echo planar imaging (EPI) readout. Approach: The dynamic EPI with a 1-second temporal resolution was used to monitor the T2*-weighted signal of the rat kidney under hypoxic and hyperoxic stimulation, applying a second-order system step response model to fit the T2*-weighted signal intensity-time curves. Results: Dynamic EPI has higher temporal resolution and higher model parameter maps quality at the same image resolution. Impact: Dynamic EPI can effectively monitor the changes of renal oxygenation and may be beneficial for renal injury detection.