Overview of Diagnostic Ultrasound Safety: Review for Research and Institutional Review Boards

Ultrasound is widely regarded as a safe imaging modality; however, emerging ultrasound-based techniques-such as shear wave elastography and contrast-enhanced ultrasound-operate with varying acoustic output parameters that may approach or exceed traditional diagnostic limits. As these technologies are increasingly integrated into human research studies, Institutional Review Boards (IRBs) face the challenge of assessing their safety profiles. This article provides a comprehensive, organ-, and modality-specific review of current guidelines for ultrasound exposure parameters, including the mechanical index (MI), thermal index (TI), and acoustic intensity. Special emphasis is placed on less conventional applications, such as elastography in the eye and fetal applications, and on understanding the thermal and mechanical bioeffects associated with emerging techniques. We clarify distinctions in safety oversight and provide practical guidance to IRB members tasked with evaluating diagnostic ultrasound research protocols. Our aim is to facilitate informed decision-making and ensure patient safety while enabling innovation in ultrasound-based clinical research.