Rheumatology (Oxford). 2022 Jun 16:keac311. doi: 10.1093/rheumatology/keac311. Online ahead of print.
OBJECTIVES: Lung vascular and parenchymal changes can be recently assessed quantitatively in thoracic computed tomography (CT) images using automated software tools. We investigated the vessel parameters of patients with Systemic Sclerosis (SSc), quantified by CT imaging, and correlated them with the interstitial lung disease (ILD) features.
METHODS: SSc patients undergoing standard of care pulmonary function testing and CT evaluation were retrospectively evaluated. CT images were analyzed for ILD patterns and total pulmonary vascular volume (PVV) extents with Imbio LTA. Vascular analysis (volumes, numbers, and densities of vessels, separating arteries and veins) was performed with an in-house developed software. A threshold of 5% ILD extent was chosen to define the presence of ILD, and commonly used cut-offs of lung function were adopted.
RESULTS: 79 patients (52 women, 40 ILD, age 56.2 ± 14.2 years, total ILD extent 9.5 ± 10.7%, PVV/LV% 2.8%) were enrolled. Vascular parameters for total and separated PVV significantly correlated with functional parameters and ILD pattern extents. SSc-ILD patients presented with an increased number and volume of arterial vessels, in particular those between 2-4 mm of diameter, and with a higher density of arteries and veins of < 8 mm in diameter. Considering radiological and functional criteria concomitantly, as well as the descriptive trends from the longitudinal evaluations, the normalized PVVs, vessel numbers and densities increased progressively with the increase/worsening of ILD extent and functional impairment.
CONCLUSION: In SSc patients CT vessel parameters increase in parallel with ILD extent and functional impairment and may represent a biomarker of SSc-ILD severity.