Non-contrast assessment of pulmonary perfusion using pulsed arterial spin labeling on a 0.55T scanner

Motivation: Pulmonary perfusion imaging requires ionizing radiation (CT) or gadolinium-based contrast agents (MR) and therefore cannot be used on all patients.Goal(s): We propose an easy-to-prescribe non-contrast pulmonary perfusion imaging method to improve the diagnosis and monitoring of pulmonary hypertension.Approach: We designed a free-breathing arterial spin labeling imaging sequence that is compatible with whole-lung coverage at 0.55T. We demonstrate this method in healthy volunteers and a swine model. Results: We measured 11.55±4.09% and 7.76±2.62% ASL signals using inversion and saturation labeling which was comparable between breath-held and free-breathing scans. Perfusion defects were clearly visualized in the swine model. Impact: Our method should enable qualitative assessment of non-contrast pulmonary perfusion in patients who are contraindicated for gadolinium-based contrasts or who need frequent monitoring of pulmonary perfusion. Our method would contribute to enabling contrast-free comprehensive pulmonary exams at 0.55T.