[Bow artefact in B-image sonography].

Bow-shaped artifacts can often be seen in B-mode-ultrasound examinations. In order to find out the origin of these artifacts, water tank experiments were carried out and compared with in vivo observations. The studies showed that bow-shaped artifacts are caused by beam breadth, and that their shape is influenced by the type of the B-mode-instrument, the adjustment of the machine, and by the shape of the reflector. In vitro and in vivo, bow-shaped artifacts arise at strong reflectors and are visible in regions of low echogeneity. In vivo bow-shaped artifacts may imitate pathological findings such as septa or sludge.