Real-time fetal cardiac MRI at 0.55T enables assessment of ventricular function and heart and great vessel anatomy

We demonstrate a real-time spiral balanced steady-state free precession (bSSFP) pulse sequence for fetal cardiac examinations on a 0.55T scanner. The real-time sequence provides easy adjustments of scan plan, automatic volumetric sweeping covering the whole heart, and flexible choice of reconstruction temporal resolution, without relying on any maternal breath-hold or cardiac gating. In 9 experiments involving 8 volunteers, we demonstrated high-temporal resolution (40ms/frame) real-time videos that capture fetal cardiac dynamics, and low-temporal resolution (320ms/frame) volumetric images that capture cardiac anatomy. This approach provides both functional and structural evaluations of the fetal heart.