Abstract： Objective:To investigate the value of 18F-fluorodeoxyglucose (FDG) PET imaging in evaluating the 18F-FDG influx rate of lungs and its relationship with parameters of pulmonary hemodynamics in patients with pulmonary arterial hypertension related to congenital heart disease (PAH-CHD). Methods:From January 2018 to June 2019, a total of 16 PAH-CHD patients (6 males, 10 females, age (29.2±10.6) years) and 22 health controls who received physical examinations (8 males, 14 females, age (45.4±3.8) years) in Fuwai Hospital were respectively enrolled. All cases underwent dynamic 18F-FDG PET imaging for whole lung 18F-FDG influx rate (presented as Ki). Right heart catheterization was performed to evaluate pulmonary hemodynamic parameters such as pulmonary vascular resistance (PVR), mean pulmonary vascular pressure (mPAP) in PAH-CHD patients after imaging within one week. Independent-sample t test was used to compare Ki of 2 groups, and Pearson correlation analysis was used to analyze the relationship between Ki and PVR, mPAP in PAH-CHD patients. Results:Ki of the lungs was significantly higher in PAH-CHD patients than that in controls ((0.000 6±0.000 3) vs (0.000 4±0.000 3) ml·g -1·min -1; t=2.15, P=0.038). Ki was not correlated with PVR ((10.86±4.45) Wood units) or mPAP ((69.75±18.93) mmHg; 1 mmHg=0.133 kPa) in PAH-CHD patients ( r values: 0.202 and 0.006, both P>0.05). Conclusions:Pulmonary vascular remodeling can lead the increasing lung 18F-FDG uptake in patients with PAH-CHD. 18F-FDG PET may have the ability in monitoring and evaluating pulmonary vascular remodeling in PAH-CHD.