Evaluation of the relationship between chest radiography findings and pulmonary artery pressure during right heart catheterization

Pulmonary artery hypertension is difficult to diagnose because of its nonspecific symptoms. Although echocardiography and more accurately catheterization can recognize the pulmonary artery pressure, chest X ray is widely used because of its availability. The objective of this study was to evaluate the accuracy of Chest radiography parameters for estimation of pulmonary artery pressure.

Methods & Materials: 

This cross-sectional study included 81 subjects with a definite diagnosis of pulmonary artery hypertension. Mean pulmonary artery pressure (mPAP) was determined by Catheterization. Hilar widening, projection of the right side of the heart border (PRHB), hilar widening+PRHB and the ratio of these parameters to the thoracic diameter were compared to mPAP to evaluate correlations.

Average mPAP was 74.7±21 (ranging from 28 to 120 mmHg). Spearman's test revealed significant correlation between mPAP and hilar widening (r=0.489, P=0.000), hilar/thoracic ratio (r=0.482, P=0.001<) , hilar widening + PRHB (r= 0.517, P=0.001<) and hilar+PRHB/thoracic ratio(r:463, P=0.001<).

Hilar widening and hilar/thoracic ratio on the chest radiography is a proper parameter for estimation of the pulmonary artery pressure.