emDocs - June 22, 2016 - Author: Alerhand S - Edited by: Koyfman A
"How to Perform Ultrasound of Soft Tissue to Visualize A Retained Foreign Body
- Use linear transducer (7.5 to 10 MHz) to scan in both longitudinal and transverse orientations.
- Water bath can enhance visualization.
- The FB appears hyperechoic with surrounding hypoechoic rim (inflammatory reaction if retained for > 24 hours).
- Wood or plastic FB usually produce posterior shadowing.
- Metal FB usually produces reverberation or comet tail artifact.
- Visualization is more difficult if FB is adjacent to bone or deep to subcutaneous tissue
- False positives: calcification, scar tissue, fresh hematoma, air trapped in soft tissues. However, these can often be correlated clinically.
- Measure the depth of FB from skin surface.
- Mark the skin for FB removal if indicated, while noting surrounding vessels and nerves"
