Molecular Imaging Laboratory
University of L'Aquila Andrew Webb
C.J. Gorter Center for High Field MRI
Leiden University Medical Center
M. Alecci, N. Avdievich, A. Galante, J. Mispelter, A. Webb
Since participants will construct their own RF coil this course is limited to a maximum of 20 participants.
Goals of the course
The course on RF coils: Design and build your own coil provides an overview of the basic principles of designing, constructing and testing of RF coils for both animal and human scanners. Practical sessions will cover approximately 50% of the course, in which participants will learn to build surface and volume RF coils relevant to their particular interests. More advanced topics include double-tuned coils and coil arrays. Finally, components such as hybrids, couplers, shields, baluns and isolation circuits are discussed. The course is designed for basic scientists and engineers, but also has been attended in the past by clinicians, radiographers, applications specialists and other MR users interested in gaining a better insight into RF coil technology.
This course is intended for scientists and engineers who have a basic knowledge of mathematics and simple electrical circuits. Attendees should have a working knowledge of magnetic resonance basics.
This course is designed to provide a theoretical and practical guide to RF coil design for both animal and human systems.
Simple tools for electrical circuit analysis will be introduced, followed by practical design of simple geometries such as
surface RF coils.
The participants will then design and construct a surface RF coil with chosen dimensions and frequency of operation. In the second stage, the design of volume RF coils will be introduced from a theoretical basis, software for modelling these coils
discussed, and again the participants will be guided true the design, construction and workbench testing of a birdcage RF
volume coil during the practical sessions.
Finally, advanced topics such as transmit/receive phased arrays and multi-tuned coils will be introduced, designed and in selected cases tested on the workbench. Methods for RF coils decoupling will be analysed, implemented and tested on the workbench. A number of ready-to-use RF coils will be available during the course for additional testing, including TEM, RF shield, RF endcaps, etc.
In addition to the large degree of practical work, the course will also include a substantial amount of time that will be spent on exercises, which are intended to enhance the understanding of basic and advanced topics and will be performed in small
participant groups under guidance of the lecturers.
RF circuit design
• Characteristics and use of lumped elements
• Concepts of resonant circuits
• Impedance matching for maximum power transfer
• Baluns and cable traps
• Maximising experimental SNR by optimising the coil quality factor
• Concepts in RF coil decoupling
• Multiple-tuned circuits
Hardware for RF testing
• Network analyser operation
• Quality factor measurements
• Frequency generators
• Resistance bridges, inductance and capacitance meters
• Workbench characterisation of RF coil performance
• Principles of EM simulation software packages
• B1-homogeneity versus B1-effi ciency
• SAR considerations
• High frequency RF effects
Advanced RF coils
• Birdcage and TEM coils
• Phased arrays
• RF decoupling
• RF shields and eddy currents