The Effect of Diffuse Pulmonary Fibrosis on the Reliability of CT Signs of Pulmonary Hypertension

Anand Devaraj, MBBS, MRCP, FRCR Athol U. Wells, MD, FRACP Mark G. Meister, MBCHB, MRCP, FRCR Tamera J. Corte.MBBS, FRACP David M. Hansell, MD, FRCP

Purpose: To determine whether pulmonary artery (PA) dilatation is a reliable indicator of pulmonary hypertension (PH) in patients with pulmonary fibrosis.

Materials and Methods: This study had institutional review board approval. Patient consent was not required. Seventy-seven patients (39 men, 38 women) who underwent right heart catheteriza�tion were studied. The study population was divided into 30 patients with pulmonary fibrosis (group A), and 47 without (group B). The main PA diameter (dPA) and as�cending aorta diameter (dAA) were measured by using computed tomography (CT), and the extent of fibrosis was recorded in group A. The dPA and the dPA/dAA ratio were correlated (Spearman rank) with mean PA pressure (mPAP) and pulmonary vascular resistance index (PVRi). The relationship between dPA and pulmonary fibrosis ex�tent and total lung capacity (TLC) was examined by using multivariate linear regression.

Results: There were strong correlations between dPA and both mPAP (r = 0.67, P

Conclusion: PA dilatation occurs in the absence of PH in patients with pulmonary fibrosis and is therefore an unreliable sign of PH in these patients.