Three-dimensional printing of anatomically accurate, patient specific intracranial aneurysm models

Objective To develop and validate a method for creating realistic, patient specific replicas of cerebral aneurysms by means of fused deposition modeling. Methods The luminal boundaries of 10 cerebral aneurysms, together with adjacent proximal and distal sections of the parent artery, were segmented based on DSA images, and corresponding virtual three-dimensional (3D) surface reconstructions were created. From these, polylactic acid and MakerBot Flexible Filament replicas of each aneurysm were created by means of fused deposition modeling. The accuracy of the replicas was assessed by quantifying statistical significance in the variations of their inner dimensions relative to 3D DSA images. Feasibility for using these replicas as flow phantoms in combination with phase contrast MRI was demonstrated. Results 3D printed aneurysm models were created for all 10 subjects. Good agreement was seen between the models and the source anatomy. Aneurysm diameter measurements of the printed models and source images correlated well (r=0.999; p<0.001), with no statistically significant group difference (p=0.4) or observed bias. The SDs of the measurements were 0.5mm and 0.2mm for source images and 3D models, respectively. 3D printed models could be imaged with flow via MRI. Conclusions The 3D printed aneurysm models presented were accurate and were able to be produced inhouse. These models can be used for previously cited applications, but their anatomical accuracy also enables their use as MRI flow phantoms for comparison with ongoing studies of computational fluid dynamics. Proof of principle imaging experiments confirm MRI flow phantom utility.