To evaluate quantitative differences in central pulmonary artery (PA) and pulmonary global and regional enhancement in patients with and without pulmonary hypertension (PH) using dual-energy computed tomography (DECT).We retrospectively studied 391 thoracic DECT studies and identified 89 patients with PA pressure (PAP) data and a pulmonary angiogram. PH was defined as a mean PAP of ≥25 mm Hg on right heart catheterization (RHC) (n=19) or a systolic PAP of ≥40 mm Hg on echocardiography (n=20). PH absence was defined by entirely normal echocardiography or RHC (n=50). PA enhancement (PAenh) was calculated from DECT iodine images. Volumetric enhancement of each whole lung (WLenh), 6 standard lung regions (RLenh), and 24 two-dimensional standardized regions of interest (ROIenh) was performed in each patient using pulmonary blood volume analysis.Mean PAenh was greater in PH patients compared with controls (272 vs. 252 HU, P0.05), with a reciprocal reduction in mean WLenh (27 vs. 32 HU, P0.01). Mean ROIenh (n=2058) confirmed lower parenchymal enhancement in PH (27 vs. 32 HU, P0.001), with greater mean ROIenh standard deviation (10.5 vs. 9.3, P0.001). Mean intrapatient pulmonary enhancement variability was greater in PH patients than in controls for 6 RLenh (variance 37 vs. 22, P=0.02) and 24 ROIenh measures (variance 188 vs. 130, P=0.04). RLenh and ROIenh variance correlated with RHC pulmonary vascular resistance (PVR) (r=0.44, 0.48; P=0.04, 0.03, respectively). A ratio of PAenh/WLenh distinguished PH from non-PH patients (10.9 vs. 8.4, P0.001) and correlated best with PVR (r=0.59, P=0.004).PH patients demonstrate increased PAenh with a reciprocal reduction and greater variation in parenchymal enhancement; a DECT ratio of central to parenchymal enhancement correlates with PVR and may help identify PH.
