Quantitative high-resolution computed tomography features of pulmonary vessel related structures in prediction of rapid progression of idiopathic inflammatory myopathies-related interstitial lung disease

<bold>Background:</bold> Pulmonary vessel related structures (VRS) have been identified as an independent risk factor for adverse outcomes in patients with interstitial lung disease (ILD). <bold>Objectives:</bold> The study aims to investigate the correlation between quantitative high-resolution computed tomography (HRCT) features of pulmonary VRS and prognosis, lung lesions, and pulmonary function tests (PFT) in patients with IIM-ILD. <bold>Material and Methods:</bold> Patients diagnosed with ASS or MDA-5 were retrospectively included. A convolutional neural network were employed to quantify the HRCT features. Logistic regression and Spearman's correlation were used to analyze. <bold>Results:</bold> A total of 514 patients with IIM-ILD (367 females, median age 54 years) were included in this study, out of which 249 cases were identified as RP-ILD. The mean pulmonary vessels diameter (mPVD) at distances of 6mm, 9mm, and 12mm from the pleura was statistically different between the groups (p < 0.05), The area under the ROC curve between above indexes and RP-ILD occurrence were 0.641, 0.611 and 0.572 respectively. The correlation coefficients for mPVD at a distance of 6mm from the pleura with ILD%, RE%, GGO%, consolidation% and honeycomb% were 0.64, 0.61, 0.46, 0.31 and 0.18 respectively. The correlation coefficients with VC%, FVC%, FEV1%, TLC% and DLCO SB% were -0.57, -0.57, -0.54, -0.56 and -0.5 respectively. <bold>Conclusion:</bold> The presence of RP-ILD in patients with IIM-ILD is correlated with increased mPVD and reduced vascular-pleural distance. There is a significant association between mPVD and the presence of imaging lesions as well as PFT.