Radiofrequency Field Calculations for High Field MRI

  • Christopher M. Collins
Part of the Biological Magnetic Resonance book series (BIMR, volume 26)


In MRI, increasing radiofrequency magnetic (B 1) field frequency is a consequence of employing higher static magnetic (B 0) field strengths in the drive to improve signal-to-noise ratio (SNR). Due to the direct proportionality between B 0 field strength and B 1 field frequency in MRI, B 1 field distributions become more complex at higher B 0 fields due in part to shorter wavelengths and penetration depths. Consequently, it becomes both more difficult to calculate RF field behavior and more important to do so accurately for high-field MRI. In this chapter the basics of electromagnetic properties of tissue, the method of radiofrequency field calculation currently most prevalent in high-field MRI (the FDTD method), and methods for relating calculation results to MRI are covered briefly before results from calculations are used to discuss current challenges in high-field MRI including central brightening, SNR, power absorption by tissue, and image homogeneity.


Perfectly Match Layer Finite Difference Time Domain Finite Difference Time Domain Method Birdcage Coil Dielectric Resonance 
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Copyright information

© Springer Science+Business Media, LLC 2006

Authors and Affiliations

  • Christopher M. Collins
    • 1
  1. 1.Department of RadiologyPennsylvania State UniversityHersheyUSA

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