The recent decision by the U.S. Food and Drug Administration (FDA) to approve one ultrasound imaging system for use in making breast biopsy decisions prompted considerable interest in the radiology community about the regulatory process and the associated implications for the practice of medicine. In this report, the concepts and statutory authority guiding the FDA in the regulation of medical devices are summarized and discussed, including the device classification scheme, premarket approval, premarket notification, and investigational device exemptions. Also, the critical concepts of safety and effectiveness for a given indication for use, the roles of advisory panels, and examples of imaging and interventional devices are described to shed light on the approval process.