Soft Tissue Foreign Body: Utility of High Resolution Ultrasonography

Minor percentage of wooden foreign bodies is radio-opaque. High Resolution Ultrasonography (HRUSG) though existing is sparsely used as a primary imaging modality for diagnosis and localization of retained foreign body.

To evaluate the diagnostic accuracy of High Resolution Ultrasonography (HRUSG) in diagnoses and localization of retained foreign body.

A prospective study with registered 46 patients with history of foreign body injury which were initially imaged with conventional radiography was enrolled. Later patients were subjected for high resolution USG of the diseased part with a linear transducer. Surface marking was done for all subjects to assist the surgical exploration. Ultrasound findings were correlated with surgical exploration and histopathological findings.

Out of 46 patients, forty one showed foreign body with foreign body inflammatory reaction in the form of abscess and/or granulation tissue on high resolution ultrasonography. No foreign body was detected in five patients but they showed focal hypoechogenicity which represented abscess and/or haematoma. On surgical exploration, two out of 41 patients did not reveal foreign body where as rest were found to have foreign body with foreign body inflammatory reaction. Sensitivity and negative predictive value of the current study is 100%.

High resolution USG is not only an efficient modality in diagnosing and localizing the foreign body in soft tissue, but can also be utilized for guiding the foreign body removal.