**3. Real-time two-dimensional ultrasound physical QC**

To carry out periodic physical quality control on ultrasound equipment, it is necessary to define a minimum set of significant and measurable parameters and compare them with parameters measured upon acceptance of the machine itself, or with appropriate levels of acceptability.

To do this it is necessary to proceed with the measurement starting from a known machine state that can be reproduced in subsequent measurements. The standard configuration set for the test is called the initial setup and consists of a series of settings and adjustments to be recorded on the test protocol [6–10].

The parameters tested are the following:

