[Computed tomography lung density and small vessel quantification in pulmonary hypertension associated with progressive fibrosing interstitial lung disease (PF-ILD)]

Introduction: The main objective of this work was to investigate a possible link between lung density, small pulmonary vessels, and pulmonary hypertension (PH) in patients with progressive fibrosing interstitial lung disease (PF-ILD).

Methods: The study focused on patients with PF-ILD, all of whom underwent right cardiac catheterization and chest computed tomography prior to lung transplantation. Computed tomography scans were analyzed quantitatively for density and pulmonary vascularity. The relationship between computed tomography features and PH was investigated.

Results: Fifty-one patients with usual interstitial pneumonia (UIP) damage on lung explant were included. mPAP was positively correlated with lung mass (r=0.36, P=0.03) and lung volume (r=0.43, P=0.007). Patients with severe PH had more voxels lower than -856 Hounsfield Units (HU) (+16%, P=0.02), fewer voxels greater than -700 HU (-20%, P=0.03), and a higher lung volume (+1.57L, P=0.007) compared to patients without PH. No correlation was found between vascularization and HTP.

Conclusions: Patients with PF-ILD and severe PH have lower lung density than patients with moderate or without PH.