Portable intraoperative MRI for neurosurgery - magnetic resonance imaging (MRI) is the gold-standard method for the detection and diagnosis of brain disease and surgical planning

Neurosurgery is closely guided by preoperative neuroimaging with MRI which can accurately localize and delineate lesions, map functionally critical brain regions, or probe tissue metabolism to guide clinical management. While the preoperative images are regularly consulted in the or, the surgeon's ability to navigate with these maps is degraded by tissue deformation and brain shifts that occur during surgery. Dedicated intraoperative MRI suites have been constructed to address this but are relatively rare due to the cost of equipment and installation and the excessive time they add to the surgical procedure. The latter results from the need to either reposition the patient (with conventional scanners or even the latest generation of low-field portable brain scanners) or evacuate non-MR compatible equipment and then RE- establish them with a track-driven high-field scanner such as the imris system. To address this, we develop a portable, ultra-compact, low-field MRI scanner for intraoperative imaging. The scanner will be integrated with a commercially available low-profile stereotactic (mayfield-like) frame that is necessary for most neurological surgeries. The size, weight, power, and cooling requirements of the scanner allow its integration into a standard operating room without special facility modifications. IT is designed to rapidly engage and disengage from the patient to minimize time delays associated with imaging. The low-field and self-shielded nature of the "halbach dome" magnet eliminate the need to evacuate ferromagnetic equipment from the vicinity further minimizing delays. Rapid intraoperative imaging with this system could directly guide the procedure by providing images to neuro-navigation software that identify tissue distortion (brain-shift) relative to high-resolution pre-operative images to allow more accurate and complete surgical resections with decreased repeat surgeries (call-backs). To efficiently mate with the stereotactic frame, we develop optimized RF coils that incorporate gaps and notches for the frame which has itself been made RF compatible. We also integrate an advanced electromagnetic interference (EMI) mitigation solution that obviates the need for an RF-shielded room (used in typical MRI suites) to allow for in situ operating room imaging. We will develop the critical acquisition sequences for neurosurgical guidance, e.g., T2, flair, and DWI, and a user-friendly software solution for console control and AI-based image reconstruction. Finally, the new scanner will be validated with bench measurements and imaging tests in anthropomorphic phantoms and healthy subjects.