The Mechanical Index (MI) in medical ultrasound physics quantifies the potential for mechanical bioeffects, such as cavitation, in tissues. It’s calculated as the peak negative pressure divided by the square root of the ultrasound frequency. A higher MI indicates a greater likelihood of these effects, crucial for patient safety. Sonographers closely monitor MI to ensure diagnostic benefits outweigh potential risks, especially when imaging sensitive tissues or using contrast agents.
Understanding MI is essential for optimizing ultrasound examinations while adhering to safety guidelines. It helps differentiate between various imaging modes and adjust settings to minimize mechanical bioeffects, ensuring safe and effective diagnostic procedures. This fundamental physics principle underpins responsible ultrasound practice, allowing for the precise visualization of internal structures without compromising patient well-being.