Assessing pulmonary vascular remodeling in connective tissue disease-associated interstitial lung disease: a CT-based quantitative analysis.

BACKGROUND

It has recently become possible to quantitatively assess changes in the pulmonary arteries and veins on chest computed tomography (CT) images using automated software tools. The aim of this study was to assess the morphological characteristics of CT-based pulmonary arteries and veins to investigate pulmonary vascular remodeling in connective tissue disease-associated interstitial lung disease (CTD-ILD).

METHODS

This retrospective study recruited 168 CTD-ILD patients (80 males; mean age, 62±10 years) who underwent standard of care pulmonary function testing (PFT) and CT evaluations. Gender-Age-Physiology (GAP) 1-3 staging was performed on the basis of gender, age, and PFT results. Arterial and venous analyses (volumes, densities, fractions, and tortuosity) were performed using artificial intelligence.

RESULTS

Among the 168 subjects with GAP stage 1 (n=106), stage 2 (n=50), and stage 3 (n=12) who were enrolled, differences in arterial and venous BV5 [volume of pulmonary blood vessels with the cross-sectional area (CSA) less than 5 mm] volume, BV5+ (volume of pulmonary blood vessels with a CSA greater than 5 mm) volume, density and fraction of BV5a/v (BV5 in the pulmonary artery or pulmonary vein) and vascular tortuosity were statistically significant (all P<0.05). The 12 included patients were followed longitudinally for 3-43 months, and the BV5a/v parameters decreased progressively with the worsening of ILD extent and functional impairment. Arterial and venous BV5 volumes, densities, and fractions showed a positive correlation with PFT results (γ=0.179 to 0.608, P<0.05).

CONCLUSIONS

Patients with CTD-ILD exhibit pulmonary vascular remodeling, which is related to the disease's progress.