Characterization of Pulmonary Functional Abnormalities in Systemic Sclerosis Using Xenon MRI

Area of Science:

• Medical Imaging
• Pulmonary Medicine
• Radiology

Background:

• Systemic sclerosis (SSc) frequently involves lung complications like interstitial lung disease (ILD) and pulmonary hypertension (PH).
• Xenon MRI (Xe-MRI) is a developing tool for assessing lung function, particularly relevant for SSc-related pulmonary issues.

Purpose of the Study:

• To identify characteristic Xe-MRI findings in SSc patients.
• To assess Xe-MRI's potential for understanding regional lung function impairment mechanisms in SSc.

Main Methods:

• A prospective study involving 21 SSc patients and 16 healthy volunteers.
• Utilized 3T, 1-point Dixon imaging with Xe-MRI to measure ventilation defect percent, membrane uptake, RBC transfer, RBC defect percent, and RBC oscillation amplitude.
• Statistical analyses included Wilcoxon, t-tests, Fisher's exact tests, and Pearson's correlation, with significance set at p < 0.05.

Main Results:

• SSc patients showed significantly lower RBC/Membrane ratio (0.25 vs. 0.34) and RBC transfer (0.22 vs. 0.28) compared to controls.
• SSc patients also exhibited a significantly greater RBC defect percent (22.8% vs. 11.9%).
• These differences were observed despite a relatively mild pulmonary disease burden in the SSc cohort.

Conclusions:

• Xe-MRI measures, specifically RBC transfer, RBC/Membrane ratio, and RBC defect percent, differed significantly between female SSc patients and healthy volunteers.
• These findings suggest Xe-MRI is a promising method for evaluating regional pulmonary gas exchange impairments in SSc.