The role of ultrasound in the detection of non-radiopaque foreign bodies.

Fifty consecutive ultrasound examinations performed for suspected non-radiopaque foreign bodies in extremities were reviewed to establish the value of this procedure. Ultrasound detected 21 of 22 foreign bodies found at operation. There were three false positive examinations. The sensitivity was 95.4%, the specificity 89.2%, the positive predictive value 87.5% and the negative predictive value was 96.2%. This study demonstrates that ultrasound is a reliable method for detecting non-radiopaque foreign bodies and makes a significant contribution to patient management.