Metal detector and swallowed metal foreign bodies in children

To evaluate a metal detector to diagnose swallowed radio-opaque metal foreign bodies (MFBs) in children, and whether they can detect non-radio-opaque MFBs.

In a prospective study, 231 children, who presented to the accident and emergency department with a history of swallowing MFBs, were evaluated by the metal detector as well as radiography to confirm and locate the presence or absence of MFBs.

A definite history of swallowing a MFB by the child was given by 186 (81%) parents. The metal detector located MFBs in 183 children and radiographs confirmed radio-opaque MFBs in 181. In the remaining 45 (19%), when swallowing was suspected and not definite, both metal detector and radiography confirmed the presence of a MFB in only four.

A high detection rate of swallowed MFBs was observed in this study, using a metal detector. It is also of value to detect non-radio-opaque MFBs like aluminium. The detection of MFBs is high when the history of swallowing is definite.