Biomedical subjects
Publications and source records attributed to B Bönhof.
In B-mode-sonography artifacts arise because the beam dimensions are reduced to a single line with limited depth. Real-time range ambiguities, bow-shaped artifacts, and slice-thickness artifacts are important in clinical ultrasound examinations.
Artifacts as disruptions and duplications of the diaphragm, gallbladder wall, posterior wall of the left ventricle, etc., are often seen in B-mode ultrasound examinations. To identify their cause, in vitro experiments were carried out. These investigations showed that these artifacts are caused by acoustic dispersing lenses. In vivo they are due to rib cartilage and in vitro they can be reproduced by introducing an acryl lens into the sound field.
In Real-time Sonography slice-thickness artifacts may lead to misinterpretation, mainly in cystic organs. With in vitro studies it was possible to show the mechanism of this artifact, which is based on beam thickness.
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.