Imaging Case of the Week 119

The following lateral soft tissue neck x-ray is from a 3 year old child with fever who is unable to move his neck. There is no history of trauma but the child has had coryzal symptoms two days prior to presentation. What can be seen?


Lateral soft tissue neck x-ray

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The glaring finding in the neck x-ray is significant soft tissue swelling anterior to the upper cervical vertebrae. This is concerning for the presence of a retropharyngeal abscess. There are no areas of lucency/air fluid level.The cervical vertebral alignment looks abnormal but this is most likely secondary to the marked prevertebral swelling.

The normal limit of soft tissue width in paediatric population should be less than 7mm in front of the C2 vertebra and less than 14mm in front of the C6 vertebra.

Retropharyngeal abscess

This child was admitted and responded well to intravenous broad spectrum intravenous antibiotics.

How sensitive is the lateral neck x-ray in cases of retropharyngeal abscess?

Lateral neck x-rays have a reported sensitivity of 80% for retropharyngeal abscess. CT neck is supposed to be 100% sensitive for soft tissue abnormalities associated with retropharyngeal cellulitis and abscesses. However, one problem with CT may be that it is less useful in differentiating a true abscess from soft tissue infections that may resolve without surgical intervention.