Blisters on the anterior shin in 3 research subjects after a 1-MHz, 1.5-W/cm , continuous ultrasound treatment: a case series.
BACKGROUND
Clinicians should consider multiple factors when estimating tissue-heating rates.


OBJECTIVE
To report 3 separate occurrences of blisters during an ultrasound treatment experiment.


BACKGROUND
While we were conducting a research experiment comparing the measurement capabilities of 2 different intramuscular temperature devices, 3 female participants (age = 26.33 +/- 3.79 years, height = 169.34 +/- 3.89 cm, mass = 63.39 +/- 3.81 kg) out of 16 healthy volunteers (7 men: age = 22.83 +/- 1.17 years, height = 170.61 +/- 7.77 cm, mass = 74.62 +/- 19.24 kg; 9 women: age = 24.22 +/- 2.73 years, height = 171.88 +/- 6.35 cm, mass = 73.99 +/- 18.55 kg) developed blisters on the anterior shin after a 1-MHz, 1.5-W/cm (2) continuous ultrasound treatment delivered to the triceps surae muscle.


METHODS
Allergies; chemical reaction with cleaning agents; sunburn; negative interaction between the temperature measurement instruments and the ultrasound field; the ultrasound transducer not being calibrated properly, producing a nonuniform field and creating a hot spot or heating differently when compared with other ultrasound devices; the smaller anatomy of our female subjects; or a confounding interaction among these factors.


METHODS
Participants were given standard minor burn care by a physician.


RESULTS
(1) The development of blisters on the anterior aspect of the shin as a result of an ultrasound treatment to the posterior aspect of the triceps surae muscle and (2) muscle tissue heating rates ranging from 0.19 degrees C to 1.1 degrees C/min, when ultrasound researchers have suggested tissue heating in the range of 0.3 degrees C/min with these settings.


CONCLUSIONS
These adverse events raise important questions regarding treatment application and potential differences in heating and quality control among different ultrasound devices from different manufacturers.
University of Toledo, Toledo, OH, USA. freyjl@jmu.edu
Jamie L
JL
Frye
Lennart D
LD
Johns
James A
JA
Tom
Christopher D
CD
Ingersoll
D000328:Adult; D001768:Blister / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D005260:Female; D006801:Humans; D007866:Leg; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology; D013817:Thermography / Q000295:instrumentation / Q000379:methods; D014463:Ultrasonography / Q000009:adverse effects* / Q000379:methods