Cardiovascular parameters of chest CT scan in estimating pulmonary arterial pressure in patients with pulmonary hypertension.

OBJECTIVE: To develop a formula to compute mean pulmonary arterial pressure (MPAP) by chest computerized tomography (CT), and to verify its accuracy and reliability.

METHODS: Eighty-five patients who had taken chest CT and right heart catheterization (RHC) were recruited. The pulmonary arterial systolic pressure (PASP), pulmonary arterial diastolic pressure (PADP), and MPAP of each subject were measured and recorded by RHC. The diameters of the ascending aorta (dAA), descending aorta (dDA) and main pulmonary artery (dMPA), Cobb angle, diameters of right ventricle (dRV), diameters of left ventricle (dLV) were measured by means of chest CT scans. Systolic blood pressure (SBP) was measured by using electronic sphygmomanometer. A linear regression equation was generated in 56 patients to estimate PAP based on chest CT values, 29 patients were used to test the accuracy of the formula.

RESULTS: The computed equation for analyzing MPAP is: MPAP = 9.011 + 34.195 × dMPA/dAA - 0.319 × SBP + 0.402 × Cobb angle. AUC of equation with three variables (dMPA/dAA, SBP, and Cobb angle) was 0.923 with 95% CI (0.863-0.982). The mean ± SD of predicted values and RHC values had no statistical difference.

CONCLUSIONS: Ratio of dMAP/dAA, Cobb angle, and SBP can be reliably used to estimate MPAP and predict severity of PH.