# Development and Validation of a Multimodal Optico-Radiological Image System for Neurosurgical Guidance: A Proof of Concept

## TL;DR

A new system called MORI combines optical and radiological imaging during brain surgery to improve precision and visualization.

## Contribution

The MORI platform is a novel proof-of-concept system for integrating intra-operative optical and radiological data in real-time.

## Key findings

- MORI achieved an average registration error of 2.2 mm across 10 cases.
- The system successfully overlaid DCS tags and 5-ALA fluorescence onto MRI images.
- MORI converted 2D surgical videos into a 4D surgical record for timeline-based integration.

## Abstract

Introduction

Advancements in neurosurgery have integrated imaging modalities like fluorescence imaging and neuronavigation to enhance tumor resection and functional preservation. However, aligning intra-operative optical data, such as 5-aminolaevulinic acid (5-ALA) fluorescence and direct cortical stimulation (DCS) tags, with radiological images remains challenging due to brain shift. To address this, we developed the Multimodal Optico-Radiological Image (MORI) platform, a proof-of-concept system integrating intra-operative optical imaging with MRI/CT for improved surgical visualization.

Methods

We evaluated MORI in 19 brain tumor surgeries near eloquent or deep-seated areas. The system comprised (1) optical image capture, (2) 3D surface reconstruction from stereo optical images, (3) registration of optical and radiological images using the iterative closest point (ICP) algorithm, and (4) visualization. Accuracy was validated by measuring registration errors between anatomical landmarks.

Results

MORI reconstructed 3D brain surfaces, integrating fluorescence and functional mapping with MRI. The system achieved an average registration error of 2.2 mm across 10 cases. Case studies demonstrated precise overlay of DCS tags onto MRI for eloquent area localization and 5-ALA fluorescence for tumor margin delineation. Additionally, MORI converted conventional 2D surgical videos into a 4D surgical record for timeline-based integration.

Conclusion

MORI enhances neurosurgical precision by dynamically integrating optical and radiological imaging. Future advancements, such as automation and surgical microscope integration, could refine it into a robust navigation tool, improving intra-operative decision-making, surgical education, and patient outcomes while advancing neurosurgical research.