Physiologic responses to an MR imaging procedure performed at a specific absorption rate of 6.0 W/kg.
OBJECTIVE
To assess the physiologic responses to a magnetic resonance (MR) procedure performed at a whole-body-averaged specific absorption rate (SAR) of 6.0 W/kg.


METHODS
Tympanic membrane temperature, skin temperature at seven sites, heart rate, blood pressure, oxygen saturation, and cutaneous blood flow in six volunteers were assessed before, for 16 minutes during, and immediately after MR imaging performed at 1.5 T, 64 MHz.


RESULTS
Statistically significant (P < .05) increases in temperature of the tympanic membrane and the skin of the chest, abdomen, upper arm, hand, and thigh and in heart rate and cutaneous blood flow were associated with exposure to high SAR. None of these physiologic changes, however, were considered deleterious to the study subjects.


CONCLUSIONS
MR imaging procedures performed at the high SAR studied can be tolerated by persons with normal thermoregulatory function.
Shellock
F G
FG
Department of Radiological Sciences, UCLA School of Medicine.
Schaefer
D J
DJ
Kanal
E
E
D000328:Adult; D001794:Blood Pressure; D001831:Body Temperature; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D012867:Skin / Q000098:blood supply*
D010100:Oxygen