Non-opaque soft tissue foreign body: Sonographic findings

Soft tissue foreign bodies are a common cause of orthopedic consultation in emergency
departments. It is difficult to confirm their existence because conventional radiology only detects radio-opaque
foreign bodies. Sonography can be a useful diagnostic method. The aim of this study is to evaluate diagnostic
accuracy of sonography in detection and localization of non-opaque foreign bodies.
Methods: We evaluated 47 patients with suspected foreign body retention in soft tissues by 10 MHz linear array
transducer. A single radiologist performed all examinations with 6 years’ experience in musculoskeletal Sonography.
We detected and localized the presence of the foreign body in the soft tissue as guidance for facilitating the
surgery.
Results: We detected soft tissue foreign body in 45 cases as hyperechoic foci. Posterior acoustic shadowing was
seen in 36 cases and halo sign was seen in 5 cases due to abscess or granulation tissue formation. Surgery was
performed in 39 patients and 44 foreign bodies were removed.
Conclusion: Sonography is a useful modality in detection and localization of radiolucent foreign bodies in soft
tissue which can avoid misdiagnosis during primary emergency evaluation