Pulmonary Vascular Volume is Associated With DLCO and Fibrotic Score in Idiopathic Pulmonary Fibrosis: An Observational Study
Abstract Background: Idiopathic pulmonary fibrosis (IPF) is primarily a disease of old age. However, it is difficult to diagnose and has a complex disease course. High-resolution computed tomography (HRCT) and lung function test are crucial for its diagnosis and follow-up. However, the correlation of HRCT findings to lung function test results was not extensively investigated.Methods: This study retrospectively analysed the medical records and images of patients with IPF. Patients with evident emphysema and lung cancer were excluded. All included cases would be investigated through a multidiscipline discussion to confirm the diagnosis. The correlation of CT findings including fibrotic score, CT lung volume, pulmonary artery trunk (PA) diameter and pulmonary vascular volume (PVV) to the lung function test such as forced vital capacity (FVC) and diffusing capacity for carbon monoxide (DLCO) was analysed.Results: A total of 32 patients were included. The fibrotic score and PVV were significantly correlated with DLCO (r = 0.59, p = 0.01; r = −0.43, p = 0.03, respectively) but not with FVC. The PVV was significantly correlated with fibrotic score (r = 0.59, p<0.01) and PA diameter (r = 0.47, p = 0.006).Conclusion: Our study shows the structural and functional correlation of IPF. The extent of lung fibrosis (fibrotic score) and PVV were associated with DLCO but not with FVC, especially for patients with IPF without significant FVC deficiency. The PA diameter, which reflects the pulmonary artery pressure, was associated with PVV.