Abstract
Given the publicity that sonographically induced biologic effects have received and the subsequent patient concern about potential hazards related to the use of diagnostic ultrasound, users of this modality must have a basic understanding of the physical principles, phenomena, and parameters associated with the production of biologic effects. An understanding of these concepts aids the user in putting reports of biologic effects into perspective, thereby enabling him/her to more effectively respond to patient inquiry and concern. This is the first of a series whose purpose is to introduce the user to the fundamental concepts and terminology associated with bioeffect production and reporting. This will provide a basis for discussing pertinent bioeffects literature and developing a scheme for putting reports of biologic effects into perspective.