Different sound velocities in tissue are causing refraction artifacts. With convex elastomer lens transducers, sound beam refraction at the skin interface can alter the transducer's focusing characteristics and beam profile, cause element to element nonuniformity, and cause phase changes in the acoustic wave. These cumulative refraction induced errors degrade the image quality through distortion and loss of resolution. Because the amount of refraction is proportional to the velocity mismatch, the greater the mismatch, the greater the refraction.

Retrolenticular afterglow could occur through diffraction and refraction on interfaces. A circular object may act as a lens to the ultrasound beam, showing an artifact region of increased echogenicity.

Reverberation artifacts are produced from the multiple reflections from an object if the acoustical impedances of tissue layers are too much different and the detected echo does not run the shortest sound path because it bounces back and forth between the object and the transducer. In a reverberation artifact, the sound wave is reflected back into the body from the transducer-skin interface.

Different sound velocities in tissue are causing run-time artifacts.

The dimension of the ultrasound beam and the transducer array are the origin of grating-lobe artifacts (also called side lobe artifact). Grating lobes as side lobes are off-axis secondary ultrasound beams projecting at predictable angles to the main lobe. Side lobes are too small to produce important artifacts.

See also Apodization, and Subdicing.

The dimension of the ultrasound beam and the transducer array are the origin of the slice thickness artifact. This artifact is also called partial volume artifact or volume averaging artifact.

See also Validation.

Triplication artifacts can occur through diffraction and refraction on intersections.