Contemporary 0.55 T MRI for Lung Disease Assessment in Children and Young Adults with Cystic Fibrosis: A Proof-of-Concept Study

Background: Lung surveillance in cystic fibrosis (CF) relies on chest radiography (CR) despite cumulative radiation. Low-field MRI may be a radiation-free alternative for children and young adults. Methods: We prospectively compared 0.55 T MRI and CR in 28 same-day examinations of 22 people with CF (mean age 13 ± 5 years). Three raters scored the disease with the MRI CF score and a modified Chrispin–Norman score, expanded from two to three zones per hemithorax to match the six MRI lobes. Analyses used per-examination values averaged across the raters (Wilcoxon tests, intraclass correlation coefficients, ICC). Results: MRI yielded higher global scores (median 8.2 vs. 6.7, p = 0.002) and higher centrilobular opacity scores (p = 0.005, adjusted p = 0.03). Air trapping was also higher on MRI (p = 0.025) but not after correction for multiple comparisons (adjusted p = 0.12). The other categories did not differ. Both correlated inversely with FEV1 (p < 0.001), without a significant modality-by-FEV1 interaction (p = 0.08). Interobserver agreement was higher for MRI (ICC = 0.93) than CR (0.82), difference 0.12 (95% bootstrap CI 0.06 to 0.18). The findings held in a per-participant sensitivity analysis. Conclusions: 0.55 T MRI is a feasible, radiation-free alternative to CR in CF, yielding higher modality-specific scores and more consistent interobserver agreement. Because the instruments were only category-mapped and no CT reference was available, higher scores do not establish superior lesion detection.