Soft Tissue / Abscess

1. 1

   Use high-frequency linear probe (10–18 MHz). No special patient preparation needed.

2. 2

   Survey the affected area in two perpendicular planes. Compare to the contralateral side when possible.

3. 3

   Cellulitis pattern: diffuse hyperechogenicity of subcutaneous fat with cobblestone appearance (edematous fat lobules separated by fluid).

4. 4

   Abscess: look for a hypoechoic/anechoic collection. Apply the squish sign — gentle compression causes internal swirling of debris = abscess.

5. 5

   If collection found: measure in 3 planes. Note depth from skin, wall characteristics, internal echoes, and vascularity with color Doppler.

6. 6

   Foreign body: linear hyperechoic structure with posterior shadowing (wood) or reverberation artifact (metal/glass).

7. 7

   Document all findings. For abscess drainage guidance: confirm needle trajectory in real time.

• Affected region (transverse)
• Affected region (longitudinal)
• Surrounding tissue

• Fluid collection
• Internal echoes/debris
• Wall characteristics
• Vascularity (Doppler)
• Foreign body shadowing

• Cobblestone appearance = cellulitis (no drainable collection)
• Hypoechoic ≠ always abscess — compare to other side

Squish sign: gentle compression causes swirling internal debris = abscess. Absence = solid mass or hematoma.