MRI SYSTEM WITH DUAL COMPRESSORS

An MRI system is provided with a refrigeration system that includes dual compressors that are coupled to a single coldhead that cools the liquid helium in the MRI system. Because the single coldhead receives the compressed refrigerant regardless of the compressor that is being used, the unacceptable cooling loss that would have occurred with redundant coldheads is avoided. By coupling two compressors to a single coldhead, continuous operation can be provided despite a failure of either compressor. The dual refrigeration system may comprise a water-cooled compressor and an air-cooled compressor to enhance MRI system reliability in the event of a failure of the primary compressor or the cooling water circulation system. Alternatively, two water-cooled compressors may be provided, each with its own independent water system. Check valves may be used to enable passive control of the refrigerant gas flow from either compressor to the coldhead, thereby further improving the reliability.