Non-enhanced MR imaging for preinterventional assessment of the angioarchitecture in vein of Galen malformations

Background and purpose Endovascular treatment of vein of Galen malformations (VGMs) requires sufficient preceding MR imaging. Standardized, preinterventional, non-invasive imaging has not been established. Our study is the first to examine the role of a dedicated, standardized, non-invasive imaging protocol in the evaluation of VGM angioarchitecture by non-contrast MRI/MR angiography. Materials and methods We retrospectively evaluated a consecutive series of VGM patients who underwent a 1.5 T MRI protocol, including standard T2 weighted images (T2WI), arterial time of flight (TOF), and thin T2WI without flow compensation (T2OffPh). The primary outcome was the proportion of patients in whom VGM subtypes and all arterial feeders (anterior (AChA) and posterior (PChA) choroidal arteries, pericallosal arteries, basilar tip, and leptomeningeal supply) could be accurately identified compared with a DSA gold standard. Results A total of 26 VGM patients who underwent 108 studies were used in the statistical analysis. VGM subtype was best seen in axial T2OffPh (92.1%) and TOF (89.8%). AChA feeders were best seen in TOF (86.5%) and axial T2OffPh (72.2%). PChA feeders were best seen in TOF (95.1%) and axial T2OffPh (88.1%). Pericallosal feeders were best seen in axial T2OffPh (95.4%) and TOF (95.1%). Basilar tip feeders were best seen in TOF (90.6%) and axial T2OffPh (88.4%). Conclusion VGM angioarchitecture is best seen in TOF and axial T2OffPh. It can be used as an alternative to global angiographic series.