Chronic thromboembolic pulmonary hypertension: Evaluation of 2D-perfusion angiography in patients who undergo balloon pulmonary angioplasty

Objective To evaluate the feasibility of 2D-perfusion angiography (2D-PA) in order to quantify perfusion changes of the lung parenchyma pre- and post-balloon pulmonary angioplasty (BPA). Methods Thirty consecutive interventions in 16 patients with 99 treated pulmonary artery segments were included. To quantify changes in pulmonary blood flow using 2D-PA, the acquired digital subtraction angiographies (DSA) pre- and post-BPA were post-processed. A reference ROI in the treated pulmonary artery and a distal target ROI in the lung parenchyma were placed in corresponding areas on DSA pre- and post-BPA. Time to peak (TTP), peak density (PD) and area under the curve (AUC) were assessed. The ratios reference ROI to target ROI (TTP parenchyma /TTP inflow ; PD parenchyma /PD inflow ; AUC parenchyma /AUC inflow ) were calculated. Relative differences of the 2D-PA parameters were correlated to changes in the pulmonary-flow-grade-score. Results The pulmonary-flow-grade-score improved after BPA (p