Dynamic Mode Decomposition (DMD) for Low-Latency Real-Time Cardiac MRI

To demonstrate dynamic mode decomposition (DMD) for high spatiotemporal low-latency online reconstruction in 2D real-time cardiac MRI.

DMD was applied to 2D spiral balanced steady state free precession (bSSFP) real-time adult and fetal cardiac MRI at 0.55 T, with data from 10 healthy adult volunteers (3F/7M; age: 21-49; BMI: 20-34) and 6 pregnant females (maternal age: 30-41; maternal BMI: 22-47; gestational age: 23 weeks 6 days-37 weeks 5 days). DMD model appropriateness was assessed against off-line spatiotemporally constrained reconstruction (STCR) as the reference. We retrospectively evaluated DMD-based low-latency online reconstruction at two temporal resolutions (21 and 42 ms/frame). DMD modes were estimated from the most recently acquired frames and used to remove aliasing while preserving underlying physiological motion.

DMD represented cardiac dynamics with normalized root-mean-square error (NRMSE) less than 7% when all modes retained. Low-latency DMD-based online reconstruction performed de-aliasing while preserving the physiological motion, supporting framerates (21 and 42 ms/frame).

We have demonstrated that the DMD framework is applicable to 2D real-time cardiac MRI and for low-latency de-aliasing for better online reconstruction.