High-Resolution Computed Tomographic Findings in Systemic Sclerosis-Associated Interstitial Lung Disease Comparison Between Diffuse and Limited Systemic Sclerosis

Objective: This study aimed to compare the high-resolution computed tomographic (HRCT) findings between patients with diffuse cutaneous systemic sclerosis (DcSSc) and limited cutaneous systemic sclerosis (LcSSc) as well as to correlate the HRCT scores and the other variables. Methods: The medical records of all patients with SSc who presented at the Rheumatology Clinic, Chiang Mai University Hospital, from March 2005 to 2010 and underwent HRCT of the chest for the presence of interstitial lung disease were retrospectively reviewed. The extent of ground glass, lung fibrosis, and honeycombing was scored. All scores were aggregated to produce a total CT perfusion score. The widest coronal esophageal diameter (WED), the maximum diameter of the main pulmonary artery (MPAD), and ascending aortic diameter (AD) were measured. The ratio of MPAD to AD (MPAD/AD) was calculated. Results: Of the 71 patients with SSc, mean (SD) age and disease duration were 54.8 (11.8) and 3.9 (4.2) years, respectively. Of them, 69.0% were female and 67.6% were classified as having DcSSc. There were no significant differences between patients with DcSSc and LcSSc with respect to age, disease duration, New York Heart Association Functional Classification, the calculated HRCT scores, WED, and MPAD. The lung fibrosis and total CT perfusion score correlated inversely with the Spo(2) (r = -0.47, P < 0.01). The honeycombing correlated positively with the New York Heart Association Functional Classification and the WED (r = 0.29 and r = 0.32, respectively, P < 0.05). Conclusions: The HRCT scores of these patients were comparable in both subtypes of SSc. Careful evaluation of lungs and esophageal involvement should be performed irrespective of SSc subtypes. The calculated HRCT scores may be useful to assess the severity of the interstitial lung disease in SSc.