Towards intra-operative guidance in brain tumor surgery using real-time resting-state functional MRI

Summary Resting-state functional MRI (rsfMRI) is a rapidly developing task-free approach for presurgical mapping. It can complement task-based functional MRI (tfMRI) in patients who have difficulties performing tasks and efficiently map resting state networks (RSNs) in regions that are not typically mapped with tfMRI due to time constraints, such as frontal cortex. It has the potential to provide iterative intra-operative guidance during progressive resection, enables connectome mapping in anesthetized patients, and holds promise for intra-operative guidance of minimally invasive surgery where intra-operative electrocortical mapping may not be possible. To achieve clinical acceptance, rsfMRI analysis needs to be highly tolerant to head movement, physiological signal pulsation, lesion-related changes of functional neuro-anatomy and cerebrovascular uncoupling; and provide data quality control metrics during the ongoing scan. Intra-operative guidance additionally requires automated online mapping of RSNs and tolerance to intra-operative brain shifts. There are currently no FDA-approved rsfMRI tools available for presurgical mapping. Here, we propose a fully automated, highly sensitive and cost-effective real-time rsfMRI analysis technology on a high-performance workstation for presurgical and intraoperative mapping. The project builds on TurboFIRE, a powerful real-time tfMRI and rsfMRI analysis software tool for high-speed fMRI, the success of a prior Phase I STTR study in 12 brain tumor patients that showed clinically acceptable concordance of real-time high-speed multi-echo rsfMRI with tfMRI, and intra-operative electrocortical stimulation (ECS); and our experience with intra-operative rsfMRI in anesthetized brain tumor patients. This technology provides online rsfMRI mapping, eliminating time-consuming postprocessing, and seamless integration into presurgical planning and intra-operative MRI. This methodology will have significant clinical and commercial potential for a wide range of neurological and psychiatric applications beyond pre-surgical mapping in patients with brain tumors. It opens up functional brain mapping to patient populations that have been difficult to study in the past.