Heterogeneity In Lung 18f-Fdg Uptake In Precapillary Pulmonary Hypertension

Introduction: Proliferative changes in vessels may contribute to the development of pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). Previous studies using [18F]-fluoro-D-glucose positron emission tomography (PET-FDG) imaging in PAH have shown increased cellular metabolism in right ventricle (RV), while the results of uptake in pulmonary artery (PA) and lung parenchyma (LP) are contradictory. Methods: Four groups were evaluated: Healthy controls, n=20; idiopathic PAH (iPAH), n=20; proximal CTEPH (CTEPH-p), n=15; and distal CTEPH (CTEPH-d), n=10. The mean values of standardized 18F-FDG uptake of predefined regions of interest in LP, main pulmonary arteries (MPA), lobar pulmonary arteries (LPA) and right ventricle were. SUV ratios in patients were related to functional class (FC), exercise tolerance, hemodynamic parameters, and serum BNP. Results: The results are shown in Table 1. The RV/LV ratio and AP uptake were significantly correlated with the BNP. AP uptake was correlated with the walking test. Conclusions: We conclude that patients with precapillary pulmonary hypertension show increased FDG uptake in the right ventricle, particularly those with iPAH. The FDG uptake in both parenchyma and pulmonary arteries were significantly higher in the group with distal CTEPH. Funded by grants from Fondo de Investigación Sanitaria (PI15/00582) and Fundación Contra la Hipertensión Pulmonar (FCHP).