Preamplifier Noise Figure Measurement and Radio Frequency Field Optimization in High Field Magnetic Resonance Imaging

  • Author / Creator
    Lagore, Russell Luke
  • High field magnetic resonance imaging (MRI) is an area of research interest due to the associated improvement in image quality possible. This improvement comes at a cost. Hardware design becomes more complex in order to overcome technical challenges at these higher field strengths. Signal-to-noise ratio is of paramount importance to MR image quality and this comes from carefully designed hardware and pulse sequences. This thesis focuses on the radiofrequency hardware of a high field MRI system. As frequency increases, the difficulties associated with radiofrequency hardware design increase. A noise figure and noise parameter measurement system was developed for measurement of the noise added by measurement electronics in MRI. Noise figure was found to increase for many transistor semiconductors as magnetic field increased. The radiofrequency transmit field was also studied. Radiofrequency hardware was modified to optimize the radiofrequency field to achieve proper contrast in MR images and improve transmit power efficiency.

  • Subjects / Keywords
  • Graduation date
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
  • Institution
    University of Alberta
  • Degree level
  • Department
    • Department of Biomedical Engineering
  • Supervisor / co-supervisor and their department(s)
    • Wilman, Alan (Biomedical Engineering)
    • De Zanche, Nicola (Oncology)
  • Examining committee members and their departments
    • Iyer, Ashwin (Electrical and Computer Engineering)
    • De Zanche, Nicola (Oncology)
    • Wilman, Alan (Biomedical Engineering)