What type of artifact is characterized by parallel equally spaced lines?

Reverberation artifact is characterized by parallel equally spaced lines appearing on the ultrasound image. This occurs when sound waves reflect between two strong reflectors, such as highly echogenic structures like metal or calcifications, causing multiple echoes to return to the transducer at slightly different times. The result is a series of equally spaced lines that represent these echoes.

The nature of the reverberation is such that it creates an illusion of additional structures or tissues that are not actually present in the scanned area, leading to possible misinterpretation of the ultrasound findings. This artifact can be more pronounced in situations where the spacing between strong reflectors is consistent, leading to the characteristic appearance of these parallel lines.

Other artifacts, such as multipath, grating lobes, and range ambiguity, have different mechanisms and effects on the ultrasound image. They don’t produce the distinctive pattern of evenly spaced lines as seen with reverberation. Multipath occurs when the ultrasound beam reflects off different structures before returning to the transducer, leading to incorrect depth information and potential artifacts. Grating lobes refer to additional echoes generated by side lobes of the transducer, and range ambiguity occurs when echoes from deeper structures arrive at the transducer before those from shallower structures.