Ultrasound Imaging Artifacts

Abstract

Ultrasound is based on ideal physical beam assumptions. In clinical practice, the ultrasound beam deviates from these assumptions quite frequently, producing artifacts. Ultrasound artifacts can be seen with both B-mode gray-scale and Doppler imaging. Gray-scale artifacts are created secondary to the ultrasound beam characteristics, errors in velocity, errors in attenuation, and production of multiple echoes. Gray-scale artifacts include side-lobe, beamwidth, anisotropy, refraction, speed displacement, posterior acoustic enhancement and shadowing, posterior reverberation, ring-down, comet-tail, and mirror image artifacts. Doppler artifacts include transducer pressure, motion, blooming, mirror image, background noise, aliasing, and twinkling. If not understood, these artifacts in musculoskeletal ultrasound imaging can be mistaken for pathology. It is important to be able to identify these artifacts and to employ techniques that help avoid or minimize them.