Volumetric three-dimensional real-time image rendering for surgical planning and virtual simulation in intracranial procedures

With the advent of image guidance systems, the intraoperative localization of intracranial lesions has become safer and damage to healthy tissue can be minimized. However, surgical planning and the operative approach are still largely based on triaxial images that have to be reconstructed mentally by the surgeon. We investigated the possibility to plan and to simulate surgical approaches to intracranial lesions based on three-dimensional (3D) volumetric image rendering capabilities of a new navigation system (CBYON). Fifty-seven patients with intracranial lesions underwent a preoperative MRI (1.5 or 3 T) after placement of adhesive fiducial markers. The cortical surface was reconstructed three-dimensionally based on a volumetric rendering algorithm with the CBYON guidance system. By modulation of the opacity of overlying structures, tumors could be visualized simultaneously with the cortical surface. Before surgery, a “fly-through” video option was used to simulate the surgical approach to the lesion. Real-time 3D image rendering of the cortical surface was possible in all patients. During planning, several possible approaches and patient positions could be compared within seconds. The new guidance system allowed for fast-and-easy assessment of the complex anatomical structure of gyri and sulci and the course of hidden vessels. The possibility to visualize the cortical surface in real-time 3D images that match the surgical situs represents a new quality in surgical planning and virtual simulation. This feature by far surpasses triaxial scan rendering and allows for instantaneous familiarization of individual intraoperative anatomy. In combination with virtual fly-through options volumetric three-dimensional real-time image rendering may become indispensable in neurosurgical planning, teaching and intraoperative navigation in approaches to intracranial lesions.