A Dedicated Tool for Presurgical Mapping of Brain Tumors and Mixed-Reality Navigation During Neurosurgery

Abstract

Brain tumor surgery requires a delicate tradeoff between complete removal of neoplastic tissue while minimizing loss of brain function. Functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) have emerged as valuable tools for non-invasive assessment of human brain function and are now used to determine brain regions that should be spared to prevent functional impairment after surgery. However, image analysis requires different software packages, mainly developed for research purposes and often difficult to use in a clinical setting, preventing large-scale diffusion of presurgical mapping. We developed a specialized software able to implement an automatic analysis of multimodal MRI presurgical mapping in a single application and to transfer the results to the neuronavigator. Moreover, the imaging results are integrated in a commercially available wearable device using an optimized mixed-reality approach, automatically anchoring 3-dimensional holograms obtained from MRI with the physical head of the patient. This will allow the surgeon to virtually explore deeper tissue layers highlighting critical brain structures that need to be preserved, while retaining the natural oculo-manual coordination. The enhanced ergonomics of this procedure will significantly improve accuracy and safety of the surgery, with large expected benefits for health care systems and related industrial investors.

Evaluation Metrics for Augmented Reality in Neurosurgical Preoperative Planning, Surgical Navigation, and Surgical Treatment Guidance: A Systematic Review

“…In 30 studies (38%), the use of a head-mounted device for neurosurgery was evaluated ( Supplemental Digital Content 2, Table 1 , http://links.lww.com/ONS/B48). 10-86 In most of these studies, the HoloLens (Microsoft) was used for AR visualization. In 26 studies (32%), an image overlay, for either the microscopic or endoscopic field of view, was used.…”

“…Most of the studies reported on multiple evaluation metrics ( Supplemental Digital Content 3, Table 2 , http://links.lww.com/ONS/B49). 10-83,85-90 Based on the results of this review, the following evaluation categories have been defined: (1) registration accuracy, (2) clinical outcome, (3) time measurements, (4) task performance, (5) technical reliability, and (6) user perception (Table).…”

“…In four studies (5%), an AR application for preoperative visualization of imaging data was described ( Supplemental Digital Content 4, Table 3 , http://links.lww.com/ONS/B50). 10-83,85-90 Their most frequently described evaluation metrics were user perception metrics (Table). Clinical outcome was mentioned in one study.…”

Mixed Reality for Pediatric Brain Tumors: A Pilot Study from a Singapore Children’s Hospital

“…The former (i.e., VR) is able to immerse the users in a fully artificial digital environment, while the latter (i.e., AR) has the capability to overlay virtual objects in the real-world environment. In the AR approach, virtual information is "anchored" to the real object, and this combination is visualized via a head-mounted display (HMD) [9]. Here, the HoloLens (HoloLens; Microsoft Corporation, Redmond, Washington) is one such example that has been shown to be useful in the surgical innovations [7,10].…”

“…Although MR systems have been used as a teaching tool for simulation in adult neurosurgery, their use in children is comparatively unexplored [15]. Furthermore, our literature search reveals that most of the publications on neurosurgical MR applications stem from Europe and North America [9,16,17]. Overall, similar systems for pediatric neurosurgery from our part of the world in Southeast Asia remain underrepresented at this point in time.…”