Physical Principles and Equipment: IVUS

Images made from ultrasound are based on the transmission and reception of sound waves reflected from tissue. Ultrasound transducers use a piezoelectric crystal (usually a ceramic) to generate and receive ultrasound waves. The piezoelectric crystal material has the property of expanding its crystal size through electrical current. When an alternating electric current is applied, the crystal alternately compressed and expands, generating an ultrasound wave [1]. The frequency of sound wave depends on the nature and thickness of the piezoelectric material. When reflected ultrasound waves return to the transducer, an electric current is generated and converted into the image.