RF fields induced during MRI in a heterogeneous human head model

Author

Collins, Christopher M. ; Smith, Michael B.

Author_Institution

Dept. of Radiol., Pennsylvania State Coll. of Med., Hershey, PA, USA

fYear

1998

fDate

9-10 Apr 1998

Firstpage

29

Lastpage

31

Abstract

Results from numerical calculations of the radiofrequency electromagnetic fields induced in the human head during magnetic resonance imaging (MRI) of the head at frequencies from 63 to 200 MHz are presented. Numerical values are given in a form that can easily be used to determine specific SAR levels for any MRI procedures at these frequencies. Maximum local SAR levels are lower at lower frequencies, in circularly- than in linearly-polarized fields, and in linearly-polarized fields polarized posterior-to-anterior than left-to-right in the head model. Magnetic field homogeneity and signal-to-noise ratio are greater at lower frequencies and in circularly-polarized fields

Keywords

biomedical MRI; electromagnetic fields; physiological models; 63 to 200 MHz; MRI; RF fields; circularly-polarized fields; heterogeneous human head model; linearly-polarized fields; magnetic field homogeneity; magnetic resonance imaging; numerical calculations; specific SAR levels; Coils; Educational institutions; Geometry; Humans; Magnetic heads; Magnetic noise; Magnetic resonance imaging; Polarization; Radio frequency; Signal to noise ratio;

fLanguage

English

Publisher

ieee

Conference_Titel

Bioengineering Conference, 1998. Proceedings of the IEEE 24th Annual Northeast

Conference_Location

Hershey, PA

Print_ISBN

0-7803-4544-4

Type

conf

DOI

10.1109/NEBC.1998.664867

Filename

664867