Localization and guided removal of soft-tissue foreign bodies with sonography.

Abstract

Sonography was used to detect, localize, and guide removal of foreign bodies in the soft tissues of the extremities and neck. Twenty localization procedures were performed in 19 patients (12 children and seven adults) with 21 foreign bodies including wood, glass, stone, metal, and lead pencil. Localization was accomplished by using anatomic landmarks, ink marks on the skin, and needle and hemostat markers. Localization was facilitated by the use of small standoff pads that were cut for use on small surfaces. The foreign bodies were visualized as hyperechoic foci with acoustic shadows that were partial or complete depending on the angle of insonation and foreign body composition. Hyperechoic comet-tail artifacts (reverberation artifacts) were seen with six metallic foreign bodies and one glass fragment. Nine foreign bodies were surrounded by hypoechoic halos caused by edema, abscess, or granulation tissue. A slow meticulous scanning technique and high-frequency transducer helped in detection of small foreign bodies. Sonographically guided removal of the foreign body was successful in all four patients in whom it was attempted. Scanning with the ultrasound beam parallel to the long axis of the hemostat and the foreign body was the fastest way to guide the hemostat to the tip of a foreign body. The procedure was accomplished most easily and quickly when one physician performed sonography and hemostat removal of the foreign body simultaneously. Our experience with these cases indicates that sonography is a useful tool in the localization and removal of soft-tissue foreign bodies.