2015 年 13 巻 1 号 p. 11-19
BACKGROUND: Neurosurgeons must perform surgeries with great care to avoid adverse sequelae. Before surgery, they must devise a precise surgical plan for removing brain stem tumors, and this plan should incorporate a variety of medical images based upon different imaging modalities. However, current medical imaging modalities cannot visualize cranial nerve tracts displaced by the tumors. Surgeons must thus rely upon their knowledge and experience to estimate the topology of displaced cranial nerve tracts. METHODS: A 3D visualizing system for estimating cranial nerve tracts displaced by brain stem tumors (CranialNvSim) was developed using a software development platform called UNITY (Unity Technologies, San Francisco, CA), and this was used to perform functional evaluations. A software application named AMIRA (FEI, Hillsboro, OR) was used to derive 3D models comprising brain stems, cranial arteries and brain stem tumors. The shapes of the cranial nerves were derived by a software application called Maya (Autodesk, San Rafael, CA) based upon a standard anatomical atlas. A patient-specific tumor shape was generated from the medical image segments. The algorithm used to define deformities of the cranial nerves, along with the position and shape of the tumor, was developed using a mass–spring–damper model. The system was evaluated by 9 neurosurgeons and 4 university students. RESULTS: The system successfully visualized the displaced structures of cranial nerves and was useful for surgical planning, enabling a more accurate estimation of the surgical problem. CONCLUSION: We here propose a 3D mobile visualizing simulation system for estimating cranial nerve tracts displaced by a brain stem tumor (CranialNvSim). The system was shown to be useful for surgical planning.
