What is the maximum temperature increase allowed without thermal-induced biological effects?

The correct answer is based on the understanding of the bioeffects associated with ultrasound exposure. The maximum temperature increase that is generally accepted without causing significant thermal-induced biological effects is 1°C (1 degree Celsius). This threshold is critical in clinical practice and is supported by guidelines provided by regulatory bodies and professional organizations, such as the American Institute of Ultrasound in Medicine (AIUM) and the Food and Drug Administration (FDA).

Research has demonstrated that temperature increases of greater than 1°C can potentially lead to adverse biological effects in tissues, particularly in sensitive areas such as the fetal environment. Consequently, ultrasound equipment is designed and operated in a way to minimize temperature rise during diagnostic applications, ensuring that the increase remains within safe limits to prevent potential harm.

Selecting 2°C, or higher values like 5°C, exceeds the widely accepted safety threshold, which could pose risks of damage to tissues, particularly when exposure is prolonged or in sensitive populations. Therefore, the focus on maintaining temperature increases at or below 1°C is essential to ensure patient safety during ultrasound examinations.