The risk of exposure to diagnostic ultrasound in postnatal subjects: thermal effects.
This review evaluates the thermal mechanism for ultrasound-induced biological effects in postnatal subjects. The focus is the evaluation of damage versus temperature increase. A view of ultrasound-induced temperature increase is presented, based on thermodynamic Arrhenius analyses. The hyperthermia and other literature revealed data that allowed for an estimate of a temperature increase threshold of tissue damage for very short exposure times. This evaluation yielded an exposure time extension of the 1997 American Institute of Ultrasound in Medicine Conclusions Regarding Heat statement (American Institute of Ultrasound in Medicine, Laurel, MD) to 0.1 second for nonfetal tissue, where, at this exposure time, the temperature increase threshold of tissue damage was estimated to be about 18 degrees C. The output display standard was also evaluated for soft tissue and bone cases, and it was concluded that the current thermal indices could be improved to reduce the deviations and scatter of computed maximum temperature rises.
O'Brien
William D
WD
Bioacoustics Research Laboratory, Department of Electrical and Computer Engineering, University of Illinois, 405 N Mathews, Urbana, IL 61801 USA. wdo@uiuc.edu
Deng
Cheri X
CX
Harris
Gerald R
GR
Herman
Bruce A
BA
Merritt
Christopher R
CR
Sanghvi
Naren
N
Zachary
James F
JF
D001831:Body Temperature; D006358:Hot Temperature / Q000009:adverse effects*; D006801:Humans; D012449:Safety; D013997:Time Factors; D014463:Ultrasonography / Q000009:adverse effects* / Q000592:standards