Detection of foreign bodies of the head with digital volume tomography

OBJECTIVES: Foreign bodies occur as a sequela of trauma or therapeutic interventions. If the risks are not too high, therapy of choice is the removal of the foreign body. This is only possible if the existence of a foreign body is detected and it is localized accurately. METHODS: The suitability of digital volume tomography (DVT) for the detection and localization of foreign bodies was investigated. Samples of various materials that are typically found as foreign bodies in the head and neck region were used. RESULTS: All materials investigated are principally detectable with DVT. Highly radiopaque material was detectable down to small sizes. The detectability of less radiopaque substances like wood and resins was poor when located in soft tissue. CONCLUSION: DVT is an appropriate tool for the detection of radiopaque foreign bodies. However, foreign bodies made of wood and resin, although detectable by DVT, can be missed when located in muscular tissue. The detectability decreases further when the foreign body is located adjacent to a highly radiopaque tissue like bone. This has to be taken into consideration when using DVT for foreign body detection.