T2-weighted Lung Imaging Using a 0.55-T MRI System

Purpose: To assess a 0.55-T MRI system for imaging lung disease and to compare image quality with clinical CT scans. Materials and Methods: In this prospective study conducted between November 2018 and December 2019, respiratory-triggered T2weighted turbo spin-echo MRI at 0.55 T was compared with clinical CT scans in 24 participants (mean age, 59 years 6 16 [standard deviation]; 18 women) with common lung abnormalities. MR images were reviewed and scored by experienced readers. Abnormal findings identified with MRI and CT were compared using the Cohen k statistic. Results: High-quality structural pulmonary MR images were attained with an average acquisition time of 11 minutes 6 3. MRI generated sufficient image quality to robustly detect bronchiectasis (k = 0.61), consolidative opacities (k = 1.00), cavitary lesions (k = 1.00), effusion (k = 0.64), mucus plug (k = 0.68), and solid scattered nodularity (k = 0.82). Diffuse disease, including ground-glass opacities (k = 0.57) and tree-in-bud nodules (k = 0.48), were the findings that were most difficult to discern using MRI, with false readings in four of 18 patients for each feature. Nodule size, which was measured independently at CT and MRI, was strongly correlated (R-2 = 0.99) for nodules with a measurement of 10 mm +/- 5 (range, 5-23 mm). Conclusion: This initial study indicates that high-performance 0.55-T MRI holds promise in the evaluation of common lung disease.