Do we really need plain and soft-tissue radiographies to detect radiolucent foreign bodies in the ED?

The objective of this study was to compare 3 imaging techniques-plain radiography, soft-tissue radiography, and ultrasonography-in detecting nonradiopaque foreign bodies in soft tissue.

In this randomized, blinded, and descriptive in vitro study, 40 chicken thighs with 2 types of nonradiopaque foreign bodies (wood and rubber) and 40 chicken thighs as part of a control group were evaluated to detect soft-tissue foreign bodies with plain radiography, soft-tissue radiography, and high-frequency ultrasonography.

The overall sensitivity, specificity, as well as positive predictive and negative predictive values of plain radiography for both nonradiopaque foreign bodies were 5%, 90%, 33%, and 48%, respectively; those of soft-tissue radiography for both nonradiopaque foreign bodies were 5%, 90%, 33%, and 48%, respectively; and those of ultrasonography for both nonradiopaque foreign bodies were 90%, 80%, 81%, and 89%, respectively.

In this experimental model, the results show that high-frequency ultrasonography is superior to plain and soft-tissue radiographies and that the latter 2 techniques are similarly poor at detecting nonradiopaque foreign bodies.