Title :
Numerical computation of specific absorption rate and induced current for workers exposed to static magnetic fields of MRI scanners
Author_Institution :
Biomed. Eng. Dept., Modern Univ. for Technol. & Inf., Cairo, Egypt
Abstract :
Currently-used Magnetic Resonance Imaging (MRI) scanners in Cairo City possess static magnetic field (SMF) that varies from 0.25 up to 3T. More than half of them possess SMF of 1.5T. Workers in MRI environments are exposed to static magnetic fields. This research paper presents a novel approach for numerical computation of induced current density and Specific Absorption Rate (SAR) values by estimation of fringe static magnetic fields. Iso-gauss line of MR was mapped and a polynomial function of the 7th degree was generated and tested. Induced current due to worker motion in the SMF and SAR values for organs and tissues have been calculated. Results illustrate that the computation tool used permits quick accurate MRI iso-gauss mapping and calculation of induced current and SAR values which can then be used for assessment of occupational exposure profile of MRI operators.
Keywords :
absorption; biological effects of fields; biomagnetism; biomedical MRI; employee welfare; health hazards; magnetic field effects; occupational health; occupational medicine; occupational safety; MR isogauss line mapping; MRI environments; MRI operator occupational exposure; MRI scanner SMF; MRI scanner magnetic field-exposed worker; MRI scanner static magnetic field; accurate MRI isogauss mapping; fringe static magnetic field estimation; induced current absorption rate; induced current calculation; magnetic flux density 0.25 tesla to 3.00 tesla; magnetic resonance image; magnetic resonance imaging; magnetic resonance isogauss line mapping; numerical absorption rate computation; occupational exposure profile assessment; organ SAR values; organ SMF values; polynomial function; quick MRI isogauss mapping; specific absorption rate; tissue SAR values; tissue SMF values; worker motion-caused induced current; Biological systems; Biomedical engineering; Current density; Legged locomotion; Magnetic fields; Magnetic resonance imaging; Specific absorption rate; MRI Occupational exposure; MRI safety; Specific Absorption Rate; Static magnetic fields; induced current density;
Conference_Titel :
Biomedical Engineering and Sciences (IECBES), 2014 IEEE Conference on
DOI :
10.1109/IECBES.2014.7047576