A demonstration of Tissue Harmonic Imaging

Tissue Harmonic Imaging is a relatively recent discovery that greatly improves image quality, primarily due to a great reduction in the amount of ultrasound artifacts (see Chapter 14 of Ultrasound for Canine Pregnancy Scanning). Put simply, it involves sending out ultrasound at one frequency, but only using higher returning frequencies (that we didn’t used to know were even generated!) to generate the image. These higher frequencies are created as the ultrasound waves pass through tissue, so are particularly helpful when scanning larger animals – less helpful when scanning shallow structures that are very close to the transducer. In the video below (of the heart), watch the dramatic difference in image quality as the scanner is switched from fundamental to harmonic imaging.