Patient radiation dose during lithotripsy.

Measurements were made of the radiation dose to patients undergoing lithotripsy. Two groups were studied; patients undergoing ultrasound localization of calculi, and patients undergoing fluoroscopic localization. Dose area product (DAP) measurements were obtained using a Diamentor ionization chamber. Ultrasound localization produced a mean DAP of 137 cGy cm2 equivalent to a mean effective dose of 0.24 mSv. Fluoroscopy localization produced a mean DAP of 552 cGy cm2 equivalent to a mean effective dose of 1.2 mSv. There was no correlation between stone size and fluoroscopy time. We recommend the use of ultrasound localization as a first option whilst restricting the use of fluoroscopy (preferably pulsed) for ureteric and difficult renal calculi.