Heating caused by selected pulsed Doppler and physiotherapy ultrasound beams measured using thermal test objects.
OBJECTIVE
To assess the heating caused by selected pulsed Doppler and physiotherapy ultrasound beams by measurements made using thermal test objects.


METHODS
Thermal test objects were used to measure temperature rises in selected ultrasound fields. These were compared with theoretical predictions based on standard exposure measurements. A separate thermocouple was used to measure heating at the transducer surface.


RESULTS
Temperature rises of up to 6 degrees C were measured for Doppler fields using a thermal test object. The attenuation-corrected temperature rises that were measured generally agreed with calculated Thermal Indices. Temperature rises of up to 2 degrees C were observed for physiotherapy ultrasound fields in pulsed operation.


CONCLUSIONS
Significant overlap between the measured temperature rises of selected pulsed Doppler and physiotherapy ultrasound fields was observed.
Atkins
T J
TJ
Medical Physics Department, Royal United Hospital, Combe Park, Bath BA1 3NG, UK. timothy.atkins@ruh-bath.swest.nhs.uk
Duck
F A
FA
D006358:Hot Temperature; D006801:Humans; D026741:Physical Therapy Modalities / Q000009:adverse effects*; D014159:Transducers; D014464:Ultrasonic Therapy / Q000009:adverse effects*; D018608:Ultrasonography, Doppler / Q000009:adverse effects*