17 - Time-Resolved MR Angiography for Pulmonary Arteriovenous Malformation Embolization: Evaluation of Efficacy and Follow-up Outcomes at a Korean Single Center

Purpose: This prospective study aimed to assess the efficacy of time-resolved magnetic resonance angiography (TR-MRA) in the pre- and post-embolization evaluation of pulmonary arteriovenous malformations (PAVMs) and to investigate its clinical utility in treatment planning.

Materials and Methods: A total of 25 patients (median age: 56 years, 23 females) with 59 PAVMs were enrolled in this institutional review board-approved study. All patients underwent recent chest computed tomography (CT) and TR-MRA imaging one day prior to embolization. Follow-up imaging with TR-MRA and unenhanced chest CT was performed six months post-embolization. TR-MRA images, with a time interval of 1.5 seconds, covered the entire PAVMs in the lungs. The study evaluated vessel diameter changes, embolic materials, and the diagnostic power of TR-MRA by comparing pre- and post-embolization images with CT.

Results: Among the 25 patients, 5 had hereditary hemorrhagic telangiectasia, while the rest were sporadic cases. Pre-embolization imaging identified 58 out of 59 PAVMs on TR-MRA. The median feeding artery diameter was 2.5mm (range, 0.5–7mm). At the six-month follow-up, 37 out of 41 treated PAVMs showed complete occlusion, with a median draining vein reduction rate of 67.7%. Only one case of recanalization (draining vein reduction rate: 19.1%) was noted.

Conclusion: Time-resolved MR angiography (TR-MRA) emerges as a useful diagnostic modality for the follow-up of PAVM embolization, demonstrating efficacy even in cases of small PAVMs. This technique not only aids in treatment planning but also offers valuable flow information for assessing treatment outcomes. The findings suggest that TR-MRA has the potential to enhance the management of PAVMs and improve patient care in clinical practice.