Background:To fabricate three-dimensional (3D) models of brain arteriovenous malformation (bAVM) and report our experience with customized 3D printed models of patients with bAVM as an educational and clinical tool for patients, doctors, and surgical residents.Methods:Using computerized tomography angiography (CTA) or digital subtraction angiography (DSA) images, the rapid prototyping process was completed with specialized software and “in-house” 3D printing service. Intraoperative validation of model fidelity was performed by comparing to DSA images of the same patient during the endovascular treatment process. 3D bAVM models were used for preoperative patient education and consultation, surgical planning, and resident training.Results:3D printed bAVM models were successful made. By neurosurgeons’ evaluation, the printed models precisely replicated the actual bAVM structure of the same patients (n = 7, 97% concordance, range 95%–99% with average of < 2 mm variation). The use of 3D models was associated shorter time for preoperative patient education and consultation, higher acceptable of the procedure for patients and relatives, shorter time between obtaining intraoperative DSA data and the start of endovascular treatment. Thirty surgical residents from residency programs tested the bAVM models and provided feedback on their resemblance to real bAVM structures and the usefulness of printed solid model as an educational tool.Conclusions:Patient-specific 3D printed models of bAVM can be constructed with high fidelity. 3D printed bAVM models were proven to be helpful in preoperative patient consultation, surgical planning, and resident training.

Objectives To evaluate whether the signal intensity ratio (rSI) of the draining vein on silent MR angiography is correlated with arteriovenous (A–V) transit time on digital subtraction angiography (DSA), thereby identifying high-flow A–V shunt in brain arteriovenous malformation (BAVM), and to analyze whether the rSI and the characteristic of draining veins on silent MRA are associated with hemorrhage presentation. Methods Eighty-one draining veins of 46 participants with BAVM (mean age 33.2 ± 16.9 years) who underwent silent MRA and DSA were evaluated retrospectively. The correlation between the rSI of the draining vein on silent MRA and A–V transit time on DSA was examined. The AUC-ROC was obtained to evaluate the performance of the rSI in determining the presence of high-flow A–V shunt. The characteristics of draining veins with the maximum rSI (rSImax) were further compared between the hemorrhagic and non-hemorrhagic untreated BAVM. Results The rSI of each draining vein on silent MRA was significantly correlated with A–V transit time from DSA (r = −0.81, p < .001). The AUC-ROC was 0.89 for using the rSI to determine the presence of high-flow A–V shunt. A cut-off rSI value of 1.09 yielded a sensitivity of 82.4% and a specificity of 82.8%. The draining vein with rSImax and no ectasia was significantly more observed in the hemorrhagic group (p = 0.045). Conclusions The rSI of the draining vein on silent MRA is significantly correlated with A–V transit time on DSA, and it can be used as an indicator of high-flow A–V shunt in BAVM. Key Points • The signal intensity ratio (rSI) of the draining vein on silent MRA significantly correlated with arteriovenous (A–V) transit time of brain arteriovenous malformation (BAVM) on digital subtraction angiography (DSA). • The area under the receiver operating characteristic curve (AUC) was 0.89 for using the rSI of draining veins to determine high-flow A–V shunt. • Draining veins with maximum rSI and no ectasia were significantly more observed in the hemorrhagic group of BAVM (p = 0.045).

Patient-specific 3D printed models of brain AVM can be constructed with high fidelity. 3D printed brain AVM models are proved to be helpful in preoperative patient consultation, surgical planning and resident training.