"Ultrasound is an appropriate initial imaging modality for children presenting with solitary or multiple neck masses, with or without fever 4. Benefits of ultrasound include a lack of ionising radiation and the ability to differentiate between solid and cystic lesions. The ultrasound appearance of a suppurative retropharyngeal lymph node includes:"
"retropharyngeal effusion: symmetric low attenuation non-purulent fluid filling the retropharyngeal space from side to side with no wall thickening or enhancement and usually only exerting mild mass effect; does not require surgical drainage"
"retropharyngeal abscess: symmetric low attenuation purulent fluid filling the retropharyngeal space side to side with thick enhancing walls and distension of the retropharyngeal space 2; requires surgical drainage"
"lymph node metastasis: usually not a consideration in children; however, any low attenuation retropharyngeal lymph node in young adults should be considered as metastatic disease until proven otherwise, particularly from an oropharyngeal or nasopharyngeal squamous cell carcinoma"