0.55T MR Scanner for Biomedical Imaging Research

The common field strengths of mainstream commercial MRI scanners are 1.5T and 3T. The world’s largest MRI scanner manufacturer recently introduced a low-cost, low-field (0.55T) scanner that could significantly expand the MRI scanner market. The scanner has a small footprint, and the main magnet is fully sealed, requiring only 0.7 liters of helium, and does not require a quench pipe or helium refills. This makes it much easier to site than conventional MRI scanners, so that the low-field scanner can be installed in new settings such as intensive care units and emergency departments. The scanner has a wide (80 cm) bore, and thus can accommodate patients who are too large to be scanned in conventional MRI scanners. The scanner is also much less expensive to purchase and install than 1.5T and 3T scanners, so it is likely to expand the use of MRI for low-resourced regions both in the USA and in developing countries. While the 0.55T scanner has some technical challenges, such as reduced signal-to-noise ratio (SNR) and increased concomitant gradient magnetic field effects, it also presents important opportunities including safer and better imaging near implanted devices, less patient heating, and much longer signal lifetime for some tissues, which reduces image distortion in some areas of the body and enables much improved lung imaging. Based on our initial experience with low-field scanning at NIH on a prototype 0.55T MRI scanner, we believe that our efficient MRI methods could become a core technology in this emerging class of MRI scanners. If we are awarded a shared instrumentation grant to purchase the Siemens Free.Max 0.55T MRI scanner, we will be able to translate our MRI methods to this 0.55T scanner and to pursue exciting clinical opportunities in lung, cardiac, and brain MRI. This scanner would enable significant physics-based technique development for a new type of instrument, being used by numerous NIH-funded investigators to pursue exciting new research opportunities. Overall, the proposed instrument will enable biomedical research and will lead to new advances in MR methods which have the potential for broad health impact.