Is ultrasound superior to plain radiography for detecting radiolucent soft tissue foreign bodies in the extremities?

A short systematic review was undertaken to assess whether ultrasound is superior to plain radiography for detecting radiolucent soft-tissue foreign bodies in the extremities. A structured search of MEDLINE, EMBASE, Cochrane and Google Scholar databases identified six relevant papers. The author, year, country, study type, patient characteristics, key results and study weaknesses were tabulated. The included studies demonstrated high sensitivity of ultrasound (90%-99%) for detecting radiolucent foreign bodies, whereas plain radiography detected none in the comparative studies. However, most studies were small, single-centre and involved experienced operators, which limited generalisability. Overall, ultrasound appears superior to plain radiography for radiolucent foreign bodies, although larger prospective comparative studies are needed to strengthen recommendations.