Echinoderm Envenomation Workup

Updated: Jun 01, 2022
  • Author: Scott A Gallagher, MD, FACEP; Chief Editor: Joe Alcock, MD, MS  more...
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Imaging Studies

Soft tissue radiographs are indicated as the initial study modality when attempting to exclude retained foreign bodies. Most calcareous spines are visualized either directly or indirectly with the use of radiographs. Nonradiodense objects can be revealed as filling defects or outlined by air drawn into the wound during the injury.

If an object cannot be visualized by plain radiography or retrieved easily through direct visualization, ultrasound may be used. Ultrasound can detect nonradiodense foreign bodies as small as 1 X 2 mm and can be used to accurately localize foreign material and provide guidance during removal. Tendons, deep scar tissue, fresh hematoma, and tissue calcifications can produce false-positive ultrasound readings. Ultrasonography requires experience and skill to maximize its usefulness.

Computed tomography (CT) scans and magnetic resonance imaging (MRI) are expensive alternatives to ultrasound that can identify and precisely localize retained foreign material. Both require a high degree of patient cooperation and may be difficult to perform on pediatric patients.