**8.5 Ultrasonography**

Ultrasonography (US) consists of the use of ultrasound (usually at a frequency greater than 20,000 hz) to form images of the inner regions of the organism. To do this, a probe emits waves and they bounce back at different speeds according to the type of tissue [87]. From this technique, we can count on two different outputs. One is an image (frame) where the structure of medical interest is located. The other is a complete video where we can visualize, for example, blood flow or muscle contraction. Within the research in AI computer vision applied to US, most of the works include the analysis of individual frames. In this way, frames can be produced directly from the device or they can be extracted from ultrasound videos. When extracting frames from videos, the regions of interest for the specific task is usually timely located and the rest are discarded [88]. Other less common and more integrative methodologies can use videos directly as input. They produce the division into frames,
