Feasibility of MR angiography and DSA fusion for visualization of brain arteriovenous malformations and dural arteriovenous fistulas

Surgery of brain arteriovenous malformations (bAVM) and dural arteriovenous fistulas (dAVF) can be challenging due to the complex angioarchitecture. Fusing DSA images with magnetic resonance angiography (MRA) images could improve understanding and enable intraoperative navigation of DSA images. This study investigated the technical feasibility, image quality and perceived usefulness of 2D DSA-MRA fusion. Patients with bAVM or dAVF were included retrospectively. 2D-DSA injections and a time-of-flight (TOF) MRA were fused using Brainlab Elements software. Feeding vessels, draining veins and fistulous points were segmented. A survey assessed perceived usefulness among Swiss and German neurosurgeons. 96 patients with 51 bAVM and 47 dAVF were included. 145 image pairs were fused, with a success rate of 92%. Median time required for the process was 17.5 min (IQR 12.4-26.3 min; median fusion time: 2.8 min, IQR 2.0-4.0 min; median segmentation time: 11.6 min, IQR 7.9-18.5 min). Image alignment was rated as precise in 82% of cases, with 85% inter-observer agreement. Co-registration of TOF MRA and 2D-DSA sequences is feasible with reasonable time expenditure, yielding well-aligned images suitable for intraoperative navigation. DSA-MRA fusion was met with interest, emphasizing the need to develop additional tools to improve the surgical workflow for bAVM and dAVF.