Abstract
A velocity gradient is created by acoustic pressure in an ultrasonic wave travelling through an object (medium), and this will cause distortions in its wave form, generating harmonics as a result. Tissue Harmonic Imaging is a method for producing ultrasound images from harmonics (mainly second harmonics) .
Because of the sensitivity and directivity characteristics of harmonics, it has become possible to reduce acoustic noise, and to enhance and improve contrast resolution at organ boundaries, which will eventually lead to improved image quality in patients where imaging is difficult.
To realize this aim, it is most feasible to use a wide-band digital ultrasound scanner, whose basic performance has been dramatically improved in comparison with conventional analog scanners.
