title: Hounsfield unit values of retropharyngeal abscess-like lesions seen in Kawasaki disease.
abstract: CONCLUSIONS
  Retropharyngeal abscess-like lesions are occasionally seen in computed tomography (CT) imaging of patients with Kawasaki disease (KD) and these patients often undergo unnecessary surgery. We could distinguish the lesions from true abscesses by measuring their Hounsfield unit values (HUs).
  
  
  OBJECTIVE
  To distinguish the retropharyngeal abscess-like lesions from true abscesses without any surgical procedure.
  
  
  METHODS
  We investigated six cases of KD showing such lesions on CTs, both with and without contrast enhancement (CE). We measured the HUs of those lesions and compared them with those of 10 true abscesses as controls.
  
  
  RESULTS
  Abscess-like lesions of KD were well enhanced by CE, whereas abscesses showed virtually no enhancement. The mean HU in the six KD cases was 20.0 ± 4.65 (mean ± SD) on plain CTs and 35.6 ± 4.49 on contrast CTs. In abscesses, it was 30.3 ± 4.42 on plain CTs and 30.3 ± 3.57 on contrast CTs. The difference in HU values [(HU on contrast CT) - (HU on plain CT)] was defined as ΔHU. The mean ΔHU was 15.6 ± 5.36 in the six KD lesions and 0.0 ± 2.93 in abscesses, with statistical significance of p < 0.0001 by Student's t test. Thus, ΔHU value may potentially be a useful parameter for their distinction.
authors: Departments of 1Otolaryngology.
authors: Toru
authors: T
authors: Sasaki
authors: Rie
authors: R
authors: Miyata
authors: Yoshiho
authors: Y
authors: Hatai
authors: Kohzoh
authors: K
authors: Makita
authors: Koichi
authors: K
authors: Tsunoda
mesh_terms: D002675:Child, Preschool; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009080:Mucocutaneous Lymph Node Syndrome / Q000000981:diagnostic imaging*; D017703:Retropharyngeal Abscess / Q000175:diagnosis*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D003287:Contrast Media