Definition of Mechanical index
Mechanical index (MI) is a unitless ultrasound metric originally developed by Robert Apfel and Christy Holland. It is defined as
{\displaystyle {\text{MI}}={\frac {P_{r}}{\sqrt {f_{c}}}},}
Pr is the peak rarefaction pressure of the ultrasound wave (MPa), derated by an attenuation factor to account for in-tissue acoustic attenuation
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Frequently asked questions
What is Mechanical index?
Mechanical index (MI) is a unitless ultrasound metric originally developed by Robert Apfel and Christy Holland. It is defined as