Contemporary 0.55 T MRI to visualize interstitial lung disease – An exploratory study

Purpose: To evaluate the feasibility of contemporary 0.55 T MRI for visualizing interstitial lung disease (ILD) compared to high-resolution computed tomography (HRCT) in an exploratory first-experience study. Materials and methods: Thirty participants (mean age 60 ± 13 years; 13 females) with rheumatologic ILD underwent HRCT and 0.55 T MRI within 31 days. MRI protocols included proton-density-weighted turbo-spin-echo sequences (transverse) and T2-weighted short-tau inversion recovery sequences (coronal). Three blinded radiologists independently assessed overall disease extent, ground-glass opacity (GGO), reticulation, and emphysema using a semi-quantitative scoring system. Differences between modalities were tested using Wilcoxon signed-rank tests, and Bland-Altman analysis evaluated systematic bias. Results: Overall disease extent showed no statistically significant difference between low-field MRI and HRCT (median 22.5 % vs. 24.5 %), with excellent interobserver agreement (MRI ICC = 0.94; HRCT ICC = 0.97). MRI significantly overestimated GGO (13.1 % vs. 9.7 %) and underestimated reticulation (8.1 % vs. 11.4 %) compared to HRCT. Bland-Altman analysis confirmed no systematic bias for overall disease extent but consistent overestimation of GGO and underestimation of reticulation on MRI. Conclusions: Contemporary 0.55 T MRI showed no statistically significant difference in overall ILD extent compared to HRCT but tended to overestimate GGO and underestimate reticulation. Despite these limitations, 0.55 T MRI represents a promising candidate for future development as a radiation-free alternative for gross disease burden assessment in ILD, warranting further technical refinement before routine clinical use.