How does tissue harmonic imaging improve image quality?

Tissue harmonic imaging enhances image quality by employing higher frequency harmonics generated as ultrasound waves travel through tissue. When ultrasound waves penetrate tissue, they not only transmit at their fundamental frequency but can also produce harmonic frequencies, which are typically higher frequencies that are multiples of the original frequency. As these harmonic waves are generated, they tend to carry less distortion and have improved resolution compared to the fundamental frequencies. This results in images with greater clarity and detail, particularly at deeper tissue levels where attenuation of lower frequency waves can degrade image quality.

The higher frequency harmonics are less affected by scattering and attenuation, leading to better contrast and improved visualization of fine details. This principle is vital in diagnostic ultrasound, as clearer images can aid in more accurate diagnoses and assessments of various conditions.