Detectability of Pulmonary Embolism by contrast-free MR Angiography at 0.55T

Motivation: CT Pulmonary Angiography (CTPA) is the gold standard for rapid PE diagnosis, yet an alternative is needed for patients unsuitable for CTPA. Whole-body 0.55T MR scanners may improve MRI accessibility in high-volume settings and, with reduced B0 inhomogeneity, are promising for lung imaging. Goal(s): Investigate the detectability of PE by non-contrast MR Angiography at 0.55T Approach: 3D non-contrast free-breathing T2-weighted Turbo Spin Echo sequence imaged one patient. Two cardiothoracic radiologists evaluated the MRA and CTPA modalities, reporting diagnostic confidence. Results: High diagnostic confidence and image quality in MRA, rating it comparable to CTPA, with good visualization of pulmonary arteries to the segmental level. Impact: Whole-body 0.55T MR scanners, with reduced air-tissue interface susceptibility, offer a preliminary promising alternative to CTPA for detecting pulmonary embolism (PE) in patients for whom CTPA is unsuitable, potentially enabling non-contrast PE detection in high-volume clinical settings.