Device For Remotely Tuning and Matching MRI/NMR Coils

Technology #12303

Optimizes Performance Adjustments for Medical Systems and Very High Field Research Magnets

This device is for remotely tuning the frequency and matching the impedance of a radio frequency coil used in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI). The problems associated with tuning and matching NMR/MRI radio frequency (RF) coils have been addressed in many different ways. Typical methods include placing a lumped circuit of tuning and matching capacitors in close proximity to the RF coil. However these approaches suffer from stray capacitances and tuning/matching inefficiencies that lead to instability. Also, typical designs require manual manipulation to adjust frequency and impedance which is not always possible due to limited space. Our researchers have developed a technique and apparatus, using a matching and tuning circuit, which eliminates stray capacitances and allows remote frequency/impedance adjustments thus eliminating major tuning difficulties.


Device for optimizing performance adjustments made remotely to medical imaging systems, high field research magnets, and commercial MRI/NMR systems


  • Eliminates stray capacitances, decreasing the possibility of misleading results and providing a market advantage as most reliable MRI/NMR design
  • Enables remote adjustment frequency and impedance, simplifying operation and reducing costs that are associated with training
  • Decreases required setup time, reducing costs that are associated with implementation
  • Improves data quality, decreasing data acquisition time and increasing number of patient studies that can be conducted per day


This approach uses a combination of NMR coil reactance and cable impedance, all grounded to create a purely resistive match and eliminate stray capacitances. This circuit, called the matching tuning (M-T) box circuit, greatly improves tuning/matching efficiency, and is especially effective at high fields with varying sample loads, and where space considerations are paramount. It also allows for enhanced frequency and impedance adjustments to be made remotely when space for accessing the mechanical matching components is limited or not available.