The clinical value of dual-phase CT angiography (CTA) of the pulmonary artery and bronchial artery in diagnosing bronchial artery-pulmonary artery fistula.

To evaluate the diagnostic efficacy of dual-phase computed tomography angiography (CTA) in identifying bronchial artery-pulmonary artery fistulas (BPAF). A retrospective cohort study was conducted on 62 patients diagnosed with BPAF via dual-phase CTA at our institution between February 2022 and January 2025. Comprehensive analyses were performed to characterize vascular involvement patterns, ectopic vessel distribution, aberrant feeding vessels, and associated imaging features. Among the cohort, 26 patients (41.9%) presented with hemoptysis as the predominant symptom. Comorbid pulmonary conditions included bronchiectasis (54.8%, n = 34), atelectasis (16.1%, n = 10), chronic obstructive pulmonary disease (12.9%, n = 8), pulmonary embolism (6.4%, n = 4), pulmonary tuberculosis (3.2%, n = 2), fibrosing mediastinitis (3.2%, n = 2), and pneumoconiosis (3.2%, n = 2). Imaging revealed 82 BPAF lesions across 62 patients, with 12 cases (19.4%) demonstrating multi-vessel involvement. Anomalous vascular findings included non-bronchial systemic collaterals (n = 8, 12.9%) and ectopic bronchial artery origins (n = 6, 9.7%). Hallmark CTA features comprised tortuous bronchial artery dilation (100%), Phase-discordant opacification of pulmonary artery, delayed pulmonary artery opacification, and jet-like hypodense shadows within pulmonary arteries during the pulmonary phase. Dual-phase CT angiography (CTA) of the pulmonary artery and bronchial artery can better display the bronchial artery-pulmonary artery fistula and provide detailed and comprehensive treatment basis for clinical practice.