Spiral Real-time Phase Contrast MR on a 0.55T MRI System

Motivation: Free-breathing (FB) real-time phase contrast (RT-PC) MR is very useful to resolve the beat-by-beat variations and for patients for whom breath-holding poses a challenge; however its feasibility remains to be tested at low-field. Goal(s): To develop a FB RT-PC MR technique on a clinical wide-bore 0.55T MR scanner with reduced gradient performance. Approach: FB RT-PC was developed using a dual-density spiral readout with a modified golden-angle rotation strategy and compressed sensing reconstruction. Flow quantifications were compared with the conventional BH segmented PC approach. Results: Our proposed method yielded flow measurements of comparable accuracy and effectively captured the peak flow dynamics at low-field. Impact: The proposed RT PC MR technique for low-field systems could enable flow imaging for patients with arrhythmias, critical illnesses, or claustrophobia, potentially making cardiac MRI more accessible and patient-friendly in a variety of clinical settings.