Clinical Benefits

In this module you will be given an opportunity to compare images that were processed using either conventional or harmonic processing techniques. These images will demonstrate how Tissue Harmonic Imaging affects image quality.

Tissue Harmonic Imaging reduces the overall noise level and improves endocardial visualization when conducting cardiology examinations. Ribs are often in the way when trying to visualize the heart. The ribs produce reverberation artifacts that appear deep in the image as noise or clutter.

Similar image problems occur in general imaging. Reverberation artifacts do occur as well as surface layer aberrations. Skin and fat distort the beam, sending the sound in random directions. The distortion energy is not strong enough to generate harmonics, but the artifacts are present in the fundamental frequencies. In addition to reducing noise, harmonic imaging improves contrast resolution and border delineation in general imaging applications.

It is important to understand that Tissue Harmonic Imaging will not improve penetration. Harmonic frequencies obey the laws of physics, as does all ultrasound. At deeper depths, harmonic energy undergoes attenuation like any sound wave. Harmonics attenuate less than they would if they had to travel two paths, but they do get attenuated. A good fundamental image is still important for penetration in the visualization of certain imaging targets.