Diagnostic medical sonography is an imaging technique in which high frequency acoustic energy is transmitted into the body using a transducer in contact with the skin. The ultrasound wave is reflected from tissue interfaces of different densities.

Ultrasound wave is produced by an ultrasound transducer. These transducers come in different shapes and frequencies for specific applications. Ultrasound waves are generated by applying an alternative current to piezzoelectric crystals in the transducer. These kinds of crystals contract and expand at the same frequency at which the current changes polarity and generate a vibration: the ultrasound beam.