Ultrasound and Human Body Safety

Ultrasound is very safe when used at the diagnostic frequency and intensities. However, a temperature rise of 1.5 – 2.5 °C or more above the normal temperature of the human body exposed to ultrasound for longer than 1 hour may cause thermal induced effects. For most diagnostic ultrasounds, the Mechanical Index should not exceed 1.9. The Mechanical Index should not exceed 0.23 when performing an ultrasound on the eyes. Using diagnostic ultrasound with Mechanical Index above, these limits may cause cavitation in tissues. This chapter mostly covers the possible hazards and harms associated with ultrasound. For the benefits and uses of ultrasound in our lives, you may read chapter 13 of our previously published book: An introduction to Medical Physics, edited by Muhammad Maqbool.