The Thermal Index (TI) is a crucial safety parameter in medical ultrasound, quantifying the potential for tissue heating due to the absorption of acoustic energy. Representing the ratio of acoustic power to the power required to raise tissue temperature by 1°C, TI helps sonographers and clinicians monitor and minimize thermal bioeffects, especially during prolonged or high-power examinations. Understanding TI is essential for ensuring patient safety and adhering to ALARA (As Low As Reasonably Achievable) principles in diagnostic ultrasound.
Different TI values exist, such as TIS (soft tissue), TIB (bone), and TIC (cranial bone), tailored to the specific tissue types being interrogated. Monitoring these indices allows medical professionals to adjust scan parameters, like output power and exposure time, to maintain thermal exposure within safe limits. This proactive management of thermal bioeffects is paramount for responsible ultrasound practice, ensuring diagnostic accuracy while prioritizing patient well-being in all physics and medical imaging applications.