Silent MRA nidus volume measurement is comparable with DSA and is practical, and can be used for nidus volume measurement and as a follow-up tool for evaluating nidus volume change after therapy.
Silent MRA showed higher nidus overlap volume compared to TOF-MRA when measured against 3D-DSA as reference standard.
TOF-MRA showed a significantly larger absolute volume difference from 3D-DSA compared to silent MRA.
Mean nidus volume measured by 3D-DSA, silent MRA, and TOF-MRA differed, with TOF-MRA yielding the lowest values.
Both silent MRA and TOF-MRA nidus volume measurements showed strong linear correlations with 3D-DSA measurements.
Previous embolization status significantly affected nidus volume measurement accuracy for both silent MRA and TOF-MRA.
A retrospective study design with 45 CAVM patients who received all three imaging modalities was used to compare nidus volume measurement accuracy.
This research suggests that a newer MRI technique called 'silent MRA' can measure the size of brain arteriovenous malformations (AVMs) — abnormal tangles of blood vessels in the brain — more accurately than the older standard MRI technique called time-of-flight MRA (TOF-MRA). The study compared both MRI methods against the gold-standard imaging technique, 3D digital subtraction angiography (DSA), in 45 patients. Silent MRA produced volume measurements much closer to DSA results, with better spatial overlap and smaller measurement errors than TOF-MRA, which tended to underestimate the size of the AVM. Accurate measurement of AVM size is important because it helps doctors decide on treatment strategies such as surgery, radiation, or a combination of approaches, and it helps predict patient outcomes. The fact that silent MRA performs comparably to DSA is clinically meaningful because DSA is invasive (requiring catheter insertion into blood vessels), while MRI is noninvasive and carries no radiation exposure. This research suggests silent MRA could serve as a practical, safer alternative for initial assessment and follow-up monitoring of AVMs after treatment. One important nuance found in this study is that prior embolization (a procedure used to block blood flow to the AVM before other treatment) affected the accuracy of both MRI methods. This means that for patients who have already undergone embolization, clinicians should be aware that MRI-based volume measurements may be less reliable. Overall, the findings support using silent MRA as a noninvasive tool to track changes in AVM size over time, potentially reducing the need for repeated invasive DSA procedures during follow-up care.
Dong M, Wu C, Hong T, Xiang S, Yu J, Yang K, et al.. (2026). Noninvasive Volume Measurement of Cerebral Arteriovenous Malformation Nidus: Silent MRA Compared with TOF-MRA.. AJNR. American journal of neuroradiology. https://doi.org/10.3174/ajnr.A9370