Augmented reality for the virtual dissection of white matter pathways

Abstract

Background: The human white matter pathway network is complex and of critical importance for functionality. Thus, learning and understanding white matter tract anatomy is important for the training of neuroscientists and neurosurgeons. The study aims to test and evaluate a new method for fiber dissection using augmented reality (AR) in a group which is experienced in cadaver white matter dissection courses and in vivo tractography.

Methods: Fifteen neurosurgeons, neurolinguists, and neuroscientists participated in this questionnaire-based study. We presented five cases of patients with left-sided perisylvian gliomas who underwent awake craniotomy. Diffusion tensor imaging fiber tracking (DTI FT) was performed and the language-related networks were visualized separated in different tracts by color. Participants were able to virtually dissect the prepared DTI FTs using a spatial computer and AR goggles. The application was evaluated through a questionnaire with answers from 0 (minimum) to 10 (maximum).

Results: Participants rated the overall experience of AR fiber dissection with a median of 8 points (mean ± standard deviation 8.5 ± 1.4). Usefulness for fiber dissection courses and education in general was rated with 8 (8.3 ± 1.4) and 8 (8.1 ± 1.5) points, respectively. Educational value was expected to be high for several target audiences (student: median 9, 8.6 ± 1.4; resident: 9, 8.5 ± 1.8; surgeon: 9, 8.2 ± 2.4; scientist: 8.5, 8.0 ± 2.4). Even clinical application of AR fiber dissection was expected to be of value with a median of 7 points (7.0 ± 2.5).

Conclusion: The present evaluation of this first application of AR for fiber dissection shows a throughout positive evaluation for educational purposes.

Keywords: Augmented reality; Awake surgery; Glioma; Tractography.

Fig. 1

The figure shows the 3-D reconstructions of the prepared cases 1–5 (rows) as summarized in Table 1. Per row this figure shows the step by step reduction of anatomy until specific function-related fiber tracts are revealed. Case 1: a cerebral cortex and transparent skin including tumor and ventricles; b whole brain tractography; c specific fibers revealed, such as CST (yellow), FAT (blue), IFOF (green), and AF (pink). Case 2: d cerebral cortex and skin including tumor and ventricles; e cerebral cortex and transparent skin; f whole brain tractography; g IFOF (green), tumor, and ventricles; h SLF (pink), tumor, and ventricles. Case 3: i cerebral cortex and transparent skin including tumor and ventricles; j whole brain tractography; k specific fibers revealed for motor and language, such as CST (yellow) and SLF (pink). Case 4: l cerebral cortex and skin including tumor and ventricles; m whole brain tractography; n whole brain tractography without head; o specific language (pink) and motor (yellow)-related fibers revealed. Case 5: p whole brain tractography and skin including tumor and ventricles; q additional cortical location of motor (green) and language (pink) function; r specific fibers revealed, such as CST (yellow), FAT (blue), IFOF (green), SLF (pink), optic radiation (red), and tumor; s the skin, tumor, and ventricles plus MEP-positive sites of cortical motor function (green) with CST (yellow)

Fig. 2

The figure shows a screenshot visualizing the participant view during the application of AR for fiber dissection. The 3-D reconstruction is shown from left occipital. The green and red laser pointers can be used to describe structures or answer questions between participants or moderator. Additionally, the patient’s 2-D MRI scan slices can be visualized in the background and can be scrolled

Fig. 3

The figure shows another screenshot visualizing the participants view during the application of AR for fiber dissection. The different colors show different tracts. The tractography model is projected in the room