Tissue harmonic imaging is an advanced ultrasound technique that improves image quality by using harmonic frequencies — multiples of the transmitted fundamental frequency — that are generated within the body tissues as the original sound waves travel through them. Instead of imaging with the echoes at the transmitted frequency, the machine filters and uses these higher harmonic frequencies, which produce images with better contrast resolution, reduced noise, and fewer near-field artifacts. Tissue harmonic imaging is particularly beneficial in technically difficult patients, such as those with a larger body habitus, where conventional fundamental frequency imaging may produce suboptimal images. It is now a standard feature on virtually all modern ultrasound machines and is routinely used in abdominal, obstetric, and cardiac imaging.
Sonography Term