Although ultrasound is considered to be a very safe modality, there is a small potential risk of doing damage to tissues, referred to as bioeffects. Because of this risk, practitioners must make prudent use of ultrasound. In this module we integrate previously reviewed concepts to formalize our understanding of the two primary bioeffect risks, mechanical bioeffects, related to cavitation, and thermal bioeffects, related to temperature increase.

In the second part of this module, statistical test validation is covered. In this section, we learn the statistical parameters used to compare various aspects of a clinical test to be validated against a gold standard test. Once the statistical terms are discussed, the concept is further clarified by using a series of numerical calculations. This statistical information will also prove very useful for labs undergoing laboratory accreditation.