Ultrasonography is a technique widely considered to be without adverse biological effects, which has lead to the perception of ultrasound as a completely innocuous technology^(1-3). However, different bioeffects exist which have been classified into “thermal effects” and “non-thermal effects”⁽⁴⁾. In order to minimize these bioeffects, the manufacturers must comply with the TRACK 3 standard⁽⁵⁾, and the equipment must present visual information on the Thermal Index (TI) and Mechanical Index (MI) values through the Output Display Standard (ODS). Although not perfect, these are accepted as sensitive risk estimation tools^(2,6,7) (figure 1). This information helps users follow the ALARA principle (As Low As Reasonably Achievable) (Table 1).