Quantitative volumetric assessment of pulmonary involvement in patients with systemic sclerosis

Computed tomography (CT) is the gold standard for assessing interstitial lung disease (ILD) in patients with systemic sclerosis (SSc). In this study, we performed a quantitative calculation of ILD severity by examining the lung volume of SSc patients. The present study was performed retrospectively on 38 patients with SSc who were referred to our clinic. Patients were divided into two groups based on high-resolution computed tomography (HRCT): patients with ILD and patients without ILD.The percentage of lower lobe volume (PLLV) was calculated using HRCT. In addition, we evaluated the PLLV in all patients according to age, diffusing capacity of the lung for carbon monoxide (DLCO) and spirometric findings, and assessed the relationships among these factors. PLLV of the right lung in patients with ILD was reduced when compared with patients without ILD (P=0.041). The PLLV of the right lung in patients with ILD was negatively correlated with age and forced vital capacity (FVC; P=0.01 and P=0.012, respectively). The PLLV of the right lung may decrease in SSc patients with ILD. In these patients, the PLLV may be a quantitative parameter indicating damage in the lung.