Rampable Intraoperative Magnetic Resonance Imaging

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MRI scanners generate exquisitely detailed images of brain and spinal cord anatomy and pathology. Althoughan engineering challenge, the placement of MRI systems in the operating room will revolutionize neurosurgicalcare. The first commercial iMRI systems were developed by GE based on a 0.5 Tesla magnet with Brighamand Women's hospital in Boston. In 1988 a group in Winnipeg (IMRIS) developed an iMRI system based on a1.5 Tesla magnet which overcame many of the difficult issues discovered with the GE system. The iMRItechnology enabled neurosurgeons to improve surgeries and outcomes. Intraoperative MRI has also identified asignificant number of patients who harboured unsuspected, residual tumour at the end of surgery, thus sparingthem the discomfort and expense of reoperation.The major problem with the IMRIS intraoperative system which is the market leader it was is too expensive.An even more serious problem was that the cost of renovation to the hospital was much more expensive andrequired operating suites to be closed for months during this renovation.Our new concept is to base the iMRI on a cryogen free magnet which can be ramped to 1 tesla and is stable atthis field in 10 minutes. The magnet will be made with Magnesium Diboride (MgB2) which is a hightemperature superconducting material. The magnet will be continually connected to a power supply and so willnot require to be persistent allowing for the rapid ramp rate.The objective of the new design is to have an intra-operative MRI that take 2 weeks to install in a standardhospital surgical suite which can provide images of the same quality as a 1.5 Tesla commercial MRI on 2012 inthe same time. The important research factor being developed in this proposal is to obtain image qualityequivalent or better to what was obtained with the 1.5 tesla IMRIS systems. It is well known that the signal tonoise ratio (SNR) increases linearly with field strength so a 1 Tesla magnet will have about 60% of the SNR tothat of 1.5 Tesla magnet. We will develop RF coils and AI techniques to improve image quality.