International recommendations and guidelines for the safe use of diagnostic ultrasound in medicine

Modern sophisticated ultrasonographic equipment is capable of delivering su bstantial levels of acoustic energy into the body when used at maximum outp uts. The risk of producing bioeffects has been studied by international exp ert groups during symposia supported by the World Federation for Ultrasound in Medicine and Biology (WFUMB), These have resulted in the publication of internationally accepted conclusions and recommendations, National ultraso und safety committees have published guidelines as well. These recommendati ons and safety guidelines offer valuable information to help users apply di agnostic ultrasound in a safe and effective manner. Acoustic output from ul trasound medical devices is directly regulated only in the USA and this is done by the Food and Drug Administration (FDA), However, there is also a mo dern trend towards self-regulation which has implications for the worldwide use of diagnostic ultrasound. It has resulted in a move away from the rela tively simple scheme of FDA-enforced, application-specific limits can acous tic output to a scheme whereby risk of adverse effects of ultrasound exposu re is assessed from information provided by the equipment in the form of a real-time display of safety indices. Under this option, the FDA allows a re laxation of some intensity Limits, specifically approving the use of medica l ultrasound devices that can expose the fetus or embryo to nearly eight ti mes the intensity that was previously allowed. The shift of responsibility for risk assessment from a regulatory authority to the user creates an urge nt need for awareness of risk and the development of knowledgeable and resp onsible attitudes to safety issues, To encourage this approach, it is encum bent on authorities, ultrasound societies and expert groups to provide rele vant information on biological effects that might result from ultrasonograp hic procedures. It is obvious from the continued stream of enquiries receiv ed by ultrasound societies that effective dissemination of such knowledge r equires sustained strenuous effort on the part of ultrasound safety committ ees. There is a strong need for continuing education to ensure that appropr iate risk/benefit assessments are made by users based on an appropriate kno wledge of the probability of biological effects occurring with each type of ultrasound procedure. The primary purpose of this paper is to draw attenti on to current safety guidelines and show the similarities and areas of gene ral agreement with those issued by the parent ultrasound organisation, the WFUMB. It is equally important to identify gaps in our knowledge, where app licable. (C) 2000 World Federation for Ultrasound in Medicine & Biology.