Increased temporal resolution of dynamic oximetry with spiral acquisition scheme

Motivation: To attain higher temporal resolution in MR oximetry to monitor rapid changes in venous blood oxygen saturation (SvO2) from physiological challenges. Goal(s): To implement a fully sampled spiral acquisition scheme to improve dynamic oximetry, minimizing motion artifacts and phase wrapping compared to keyhole and BRISK methods, respectively. Approach: We compared spiral acquisition against keyhole and BRISK approaches by quantifying rapid changes in SvO2 in the superficial femoral vein and superior sagittal sinus in response to cuff-induced ischemia and volitional apnea, respectively. Results: Spiral yielded higher temporal resolution and reduced artifacts compared to view-sharing approaches of keyhole and BRISK. Impact: Because of high efficiency in k-space coverage, spiral sampling is well suited for high temporal resolution dynamic oximetry. Spiral readout showed reduced motion and pulsatile flow artifacts, and the absence of phase wrapping often observed in BRISK field maps.