Ultrasonic therapy and the intrauterine device

Is there any evidence that therapeutic ultrasonic treatment to the lower back and abdominal areas is hazardous to a patient with a metal IUD?

I found no direct evidence that customary exposure to therapeutic levels of ultrasound is harmful to a patient with a metal IUD. As you are probably aware, diagnostic ultrasound is used routinely to locate displaced IUDs, and for this application the radiation is considered innocuous. Therapeutic radiation, on the other hand, may reach levels as high as 3 W/sq cm, with exposure intervals that are protracted by comparison. Present standards only ensure that the lebel on the device accurately represents its product or, according to the Food and Drug Administration, "will assure that sufficient information on beam characteristics is supplied to allow medical personnel to make informed judgments regarding the application of ultra-sound energy." Little if any factual information is available on a situation such as you describe. There is some supposition that a projected longitudinal wave will undergo mode conversion to a transverse wave at the interface of tissue and metal with the release of energy as localized heat. The extent of such heating cannot be predicted, because each physician will vary the manner of treatment to his best judgment. It has been presumed, however, that no structural damage to tissue will occur if the temperature change is less than 10 degrees C. In summary, I suggest caution in the use of therapeutic ultrasonic treatment to the lower back and abdominal areas of a patient with a metal IUD until there is evidence on which we can base the factor of risk.