Comparing three-dimensional zero echo time (3D-ZTE) lung MRI and chest CT in the evaluation of systemic sclerosis-related interstitial lung disease.

OBJECTIVE

Systemic sclerosis (SSc) is a chronic disease that can cause interstitial lung disease (ILD), a poor prognostic factor in SSc patients. Given the concerns over radiation exposure from repeated CT scans, there is a growing interest in exploring radiation-free imaging alternatives like MRI for ILD evaluation. The aim of this study is to assess the efficacy of three-dimensional zero echo time (3D-ZTE) MRI in assessing SSc-related ILD compared to the thin-slice chest CT.

METHODS

This prospective single-center study investigated 65 SSc patients. SSc patients underwent CT, 3D-ZTE lung MRI, and pulmonary function tests (PFTs) within a week. Three independent reviews visually quantified ILD extent on ZTE and CT imaging and the correlation of ILD extent with PFTs was analyzed. Statistical analyses were performed, including the intraclass correlation coefficient (ICC), Kruskal-Wallis tests, Bland-Altmann analysis, and correlation analyses between imaging results and PFTs.

RESULTS

ILD was detected in 45 patients via CT. 3D-ZTE MRI identified ILD in 41 (91.1%) of these cases, demonstrating a strong correlation with CT in assessing ILD severity (r = 0.986, p < 0.001). The median ILD extent scores were 5% for CT and 6% for 3D-ZTE MRI. Interobserver reliability for 3D-ZTE MRI was excellent, with ICC values ranging from 0.853 to 0.969. The analysis also revealed significant negative correlations between ILD extent on ZTE MRI and lung function, particularly FVC.

CONCLUSION

3D-ZTE lung MRI is a reliable and radiation-free alternative to chest CT for evaluating SSc-related ILD, with a strong correlation in assessing total fibrosis and ground-glass opacities, though limitations remain in detecting fine reticulations and coarseness.

KEY POINTS: Question Can 3D-ZTE MRI replace thin-slice chest CT as a radiation-free method for assessing SSc-related ILD? Findings 3D-ZTE lung MRI showed an excellent agreement with thin-slice CT in evaluating ILD extent in SSc patients (r = 0.986, p < 0.001). Clinical relevance 3D-ZTE lung MRI provides a reliable, radiation-free alternative to CT for assessing ILD extent in SSc patients, ensuring safer longitudinal monitoring and management.