title: Metastatic retropharyngeal lymph nodes: comparison of CT and MR imaging for diagnostic accuracy.
abstract: OBJECTIVE
  The purpose of this study was to compare the diagnostic accuracies of CT and MR imaging for the detection of metastatic retropharyngeal lymph nodes (RLNs) in patients with nasopharyngeal and oropharyngeal squamous cell carcinoma (SCC).
  
  
  METHODS
  The study included 38 patients (28 men and 10 women; mean age, 65 years; age range, 48-82 years) with nasopharyngeal (n=15) and oropharyngeal (n=23) SCC who underwent both contrast-enhanced CT and MR imaging before chemoradiotherapy. RLNs were classified as malignant or benign on the basis of the results of follow-up MR imaging. Two radiologists independently evaluated the images for diagnosing metastatic RLNs.
  
  
  RESULTS
  Among a total of 68 RLNs (minimum diameter, ≥ 4 mm) that were detected on gadolinium-enhanced fat-suppressed T1-weighted images, 30 (44%) were malignant and 38 (56%) were benign. The sensitivities of CT versus MRI were 60% versus 97% for observer 1 (p<0.01) and 37% versus 90% for observer 2 (p<0.01). The specificities of CT versus MRI were 92% versus 97% for observer 1 (p=0.50) and 92% versus 100% for observer 2 (p=0.25). The areas under the receiver operating characteristic curve (AUC) for CT versus MRI were 0.788 versus 0.996 for observer 1 (p<0.01) and 0.693 versus 0.961 for observer 2 (p<0.01).
  
  
  CONCLUSIONS
  MR imaging was superior to CT for the detection of metastatic RLNs.
authors.affiliation: Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan(1). Electronic address: hkato@gifu-u.ac.jp.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kato
authors.affiliation: Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan(1); High-level Imaging Diagnosis Center, Gifu University Hospital, 1-1 Yanagido, Gifu 501-1194, Japan(2). Electronic address: masa_gif@yahoo.co.jp.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kanematsu
authors.affiliation: Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan(1). Electronic address: haruwow860@yahoo.co.jp.
authors.forename: Haruo
authors.initials: H
authors.lastname: Watanabe
authors.affiliation: Department of Otolaryngology, Gifu University School of Medicine, Gifu, Japan(1). Electronic address: kmizuta@gifu-u.ac.jp.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Mizuta
authors.affiliation: Department of Otolaryngology, Gifu University School of Medicine, Gifu, Japan(1). Electronic address: aoki@gifu-u.ac.jp.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Aoki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000556:secondary*; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis*; D009959:Oropharyngeal Neoplasms / Q000175:diagnosis*; D010614:Pharynx / Q000000981:diagnostic imaging / Q000473:pathology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000077195:Squamous Cell Carcinoma of Head and Neck; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: CT; MRI; Metastasis; Retropharyngeal lymph node