Fast digitizer module for wideband and high dynamic range MRI receivers

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DESCRIPTION (provided by applicant): In collaboration with the Magnetic Resonance Research Center at Yale University, Hypres proposes to develop and produce a new high dynamic range MRI digitizing module, and conduct experiments to validate the performance claims contained in this proposal. The new module will feature high dynamic range up to 24 bits, thereby rendering images with very high fidelity. Results of preliminary experiments on a Yale 4T MRI form the basis of the planned effort and support the team's assertion that this work can be directly commercialized from the results of this project. The planned modifications to target MRI systems would not alter the basic function of the system nor violate the integrity or safety of the system. The new module will feature programmability, flexibility, and modularity for easy integration into a wide class of current and future MRI systems. The result will be higher resolution images in both single channel and multi-channel MRI systems. The digitizer module will feature Hypres patented Digital-RF analog-to-digital converter (ADC) technology, packaged in compact, cryogen-free, cooling systems compatible with other electronic equipment in the MRI equipment room. It focuses on developing a retrofit digitizer for conventional high-field MRIs, as opposed to ultra-low-field SQUID MRIs, which would require developing an entirely new system. Digital SQUID ADC technology is mature and proven in modules similar to the one proposed, in wireless communications and metrology. Hypres and Yale successfully demonstrated operation in a series of experiments with a 4T MRI system, collecting data and rendering images that established the compatibility and low risk of the optimization and integration planned in this project. The digitizing module will also find applications in multi-col systems where the combination of high bandwidth and high dynamic range of the digitizer enable simultaneous digitization of the encoded signals from all the coils. Such encoding paradigms are used in other imaging systems (e.g., infrared imaging systems) and can be readily developed by researchers familiar with multi-coil MRI systems. Another application of the new digitizing module is Simultaneous Multi-slice Acquisition (SMA), first proposed by Weaver in 1988, and heretofore not realized because of the dynamic range and bandwidth limitations of semiconductor ADCs. SMA leads, in a straightforward manner, to faster imaging and enhanced resolution. Phase I will use an existing ADC module, already tested in preliminary experiments, to further characterize performance and the RF environment in the Yale MRI systems. The results will be used to design the new digitizing module in Phase I. Phase II will develop and produce the new ADC design optimized for the target MRI systems. A compact and modular "turnkey" digitizer will be developed and packaged as near production ready. The digitizer module will be fully commercialized in collaboration with one or more MRI manufacturer(s). PUBLIC HEALTH RELEVANCE: Hypres proposes to develop an advanced digitizer module for MRI systems in collaboration with researchers at the Yale University Magnetic Resonance Research Center (MRRC) which enables better resolution and faster imaging times. A similar digitizer module has been proven in advanced wireless communications and, with the modularity developed in this program, this digitizer will become a tool for researchers and developers to introduce the next generation of advanced MRI systems. The module will be easily adaptable to all classes of MRI and compatible with single and multi-channel designs.