[Ultrasound of foreign bodies in the head and neck. Cases compared with an in vitro model].

BACKGROUND: High resolution ultrasound is an accepted method in identification and classification of various head and neck alterations. Foreign bodies are a seldom encountered entity and are supposed to have a characteristic echogenicity. In literature there are numerous publications describing diagnosing foreign bodies in other specialities like gynaecology or surgery with ultrasound. The aim of the study was to examine these findings and to reproduce them in the head and neck area.

MATERIALS AND METHODS: The study includes the retrospective analysis of 6 cases. 3 cases have been reconstructed in a cadaver dissection model and a selfmade gel model. The findings were compared to the clinical cases and interpreted.

RESULTS: In ultrasound foreign bodies have characteristic reflexions and artefacts. The diagnosis foreign body could be made in every case. The foreign body could not only be identified but also precisely localized. The findings were reproducable in both the cadaver and gel model.

CONCLUSION: High resolution ultrasound is a dynamic, 3-dimentional, inexpensive, portable and readily available imaging method, facilitating the identification of lesions in the superficial soft tissues. In the hands of an experienced operator ultrasound may be the first imaging modality to be used for detection of radiolucent foreign bodies in head and neck area.