title: Bio-effects of high magnetic fields: a study using a simple animal model.
abstract: The desire to do clinical imaging and spectroscopy at magnetic field strengths greater than 2 Tesla (T) necessitates investigation of possible bioeffects at these high fields. A simple T-maze was utilized to evaluate the aversive effects of exposure to three levels of static magnetic field (0, 1.5, and 4 T). The right arm of the maze extended into the center of a 30-cm horizontal bore magnet, while the left arm extended into a mock magnet bore with the same dimensions. The self-shielded design of the magnet reduces the fringe field to zero within 1 m of the bore, placing the start box of the maze outside the 5-G line of the magnet. Each rat performed a total of ten trials at each level of magnetic field strength. A follow-up subset was run at 4 T with the maze reversed. At 0 T, the rats entered the magnet freely. No significant differences from the control were observed at 1.5 T. At 4 T, however, in 97% of the trials the rats would not enter the magnet. In the maze-reversed subset a majority of the rats turned toward the magnet, indicating that they had learned an aversive response from the previous trials at 4 T. However, in only 4 decisions out of 58 did the rats actually enter the magnet. Eighteen decisions to turn around were made at the edge of the magnet in a region of strong field gradients (up to 13 T/m) and a field strength up to 1.75 T.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Baylor College of Medicine, Magnetic Resonance Center, Woodlands, TX 77380.
authors.forename: J
authors.initials: J
authors.lastname: Weiss
authors.forename: R C
authors.initials: RC
authors.lastname: Herrick
authors.forename: K H
authors.initials: KH
authors.lastname: Taber
authors.forename: C
authors.initials: C
authors.lastname: Contant
authors.forename: G A
authors.initials: GA
authors.lastname: Plishker
mesh_terms: D000818:Animals; D004574:Electromagnetic Fields / Q000009:adverse effects*; D008279:Magnetic Resonance Imaging / Q000009:adverse effects*; D008297:Male; D008954:Models, Biological; D051381:Rats