The potential risk of ultrasonography resulting in adverse biologic effects
is particularly important in neurosonographic applications of diagnostic u
ltrasound in medicine. Key issues relate to the likelihood of producing bio
effects from the level of acoustic output emitted from modern diagnosticall
y powerful ultrasound equipment. Important elements in the assessment of ri
sk include the sensitivity of the tissue structures under examination, the
standards of practice in clinical use and the presence of biologic effects
identified from laboratory experimentation or from human studies. The World
Federation for Ultrasound in Medicine and Biology continues to support act
ivities related to evaluating bioeffects and safety of ultrasound. This pap
er includes extracts of some of the presentations given during the latest s
afety meeting, a mini-symposium on "ultrasound and the developing fetal cen
tral nervous system" held in conjunction with the WFUMB Congress in May 200
0. The speakers covered topics ranging from physics of estimating heating f
rom ultrasound equipment in clinical use to actual measurement of ultrasoun
d-induced intracranial temperature increases in animal fetuses. Finally, so
me practical scanning strategies were proposed to minimise risk of adverse
outcome in various clinical neurosonographic practices.