Prospective evaluation of time-resolved MRA in diagnosing and monitoring pulmonary arteriovenous malformations

Background Pulmonary arteriovenous malformations (PAVMs) are rare vascular anomalies that can lead to serious complications, and accurate imaging is essential for detection and post-embolization follow-up. Purpose To evaluate the diagnostic accuracy and clinical utility of time-resolved magnetic resonance angiography (TR-MRA) in detecting and monitoring PAVMs before and after embolization. Material and Methods In this prospective study, 29 patients were initially enrolled between January 2023 and December 2024. After exclusions and loss to follow-up, 27 patients (25 women; median age = 52 years; interquartile range [IQR] = 42–61 years) with 75 PAVMs confirmed on chest computed tomography (CT) were included in the final analysis. Pre-treatment TR-MRA was performed 1 day before embolization, and post-treatment TR-MRA and non-enhanced chest CT were conducted 6 months later. Conventional angiography and pre-procedure CT served as reference standards. TR-MRA was performed using a 3-T scanner with a temporal resolution of 1–1.2 s. Two independent readers evaluated TR-MRA findings. Results Among 75 PAVMs, 11 were previously treated lesions, including two cases of recanalization. Pre-treatment TR-MRA detected 98% (62/63) of naïve PAVMs confirmed on CT and angiography. Post-treatment TR-MRA detected 98% (60/61) of treated lesions. Inter-observer agreement was substantial to excellent (κ = 0.74 for pre-procedure diagnosis of PAVMs and 1.00 for post-procedure follow-up; P