Pulmonary Hypertension Parameters Assessment by Electrocardiographically Gated Computed Tomography: Normal Limits by Age, Sex, and Body Surface Area in a Chinese Population.

Abstract

Pulmonary hypertension (PH) parameters such as pulmonary artery or right ventricular size can be measured easily on computed tomography (CT). However, there are limited data on electrocardiographically (ECG) gated CT. We sought to determine age-specific and sex-specific normal reference values for PH parameters normalized by body surface area (BSA) using ECG-gated cardiac CT in a Chinese population. In total, we enrolled 519 non-PH patients undergoing ECG-gated CT coronary angiography and measured PH parameters, including main pulmonary artery (MPA) and right pulmonary artery (RPA) diameters and distension, the ratio of MPA to ascending aorta (AAO) diameter (MPA/AAO), and the ratio of right ventricular to left ventricular diameter (RV/LV). Maximum MPA and RPA diameters were also normalized to BSA (nMPA, nRPA). Age, sex, BSA, and body mass index (BMI) were variably associated with PH parameters. Age was an independent predictor of all PH parameters. The maximum MPA diameter (26.5±2.7 mm), maximum RPA diameter (20.9±3.0 mm), nMPA (15.8±2.0 mm/m), nRPA (12.4±2.0 mm/m), and RV/LV (0.85±0.11) increased with age. MPA/AAO (0.80±0.10), MPA, and RPA distension (25.4%±7.1%; 23.3%±6.7%) correlated negatively with age. Although absolute MPA and RPA diameters were slightly larger in men, women had significantly larger nMPA and nRPA values. MPA and RPA sizes and RV/LV were correlated positively with BSA and BMI. Using ECG-gated cardiac CT, we determined the normal reference values of PH parameters for non-PH adult Chinese patients, and these values were variably influenced by age, sex, BSA, and BMI.