title: Magnetic resonance imaging for the detection of nasopharyngeal carcinoma.
abstract: BACKGROUND
  Endoscopic guided biopsy (EGB) is performed after an initial endoscopy for the investigation of patients with suspected nasopharyngeal carcinoma (NPC). The aim of the study was to determine whether MR imaging has the potential to replace invasive EGB in patients with a normal endoscopy.
  
  
  METHODS
  Data from 2 groups of patients was reviewed, group 1 with proved NPC for MR staging (n = 456) and group 2 with suspected NPC (n = 77). The sensitivity was calculated for group 1 and sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for group 2.
  
  
  RESULTS
  In group 1, which included 118 of 456 (26%) with stage 1 disease, cancer was detected in all patients, giving a sensitivity of 100%. In group 2, MR imaging was negative for NPC in 70 (91%) patients, and no cancer has been detected on follow-up (follow-up range, 1-90 months; mean, 36 months). MR imaging was positive for NPC in 7 (9%) patients and NPC was confirmed by biopsy in 3 (4%). Two of these 3 patients had undergone negative endoscopy and biopsy before the MR imaging. NPC was not present in the remaining 4 patients, 2 of whom were found to have lymphoid hyperplasia. MR imaging had a sensitivity of 100%, specificity of 95%, NPV of 100%, PPV of 43%, and accuracy of 95%.
  
  
  CONCLUSIONS
  MR imaging has the potential to screen healthy patients who do not require EGB and direct the site of biopsy in small cancers that may be missed by endoscopy. On the basis of these results, a prospective study is planned.
authors.affiliation: Department of Diagnostic Radiology and Organ Imaging, Faculty of Medicine, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong, China.
authors.forename: A D
authors.initials: AD
authors.lastname: King
authors.forename: A C
authors.initials: AC
authors.lastname: Vlantis
authors.forename: R K Y
authors.initials: RK
authors.lastname: Tsang
authors.forename: T M K
authors.initials: TM
authors.lastname: Gary
authors.forename: A K Y
authors.initials: AK
authors.lastname: Au
authors.forename: C Y
authors.initials: CY
authors.lastname: Chan
authors.forename: S Y
authors.initials: SY
authors.lastname: Kok
authors.forename: W T
authors.initials: WT
authors.lastname: Kwok
authors.forename: H K
authors.initials: HK
authors.lastname: Lui
authors.forename: A T
authors.initials: AT
authors.lastname: Ahuja
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D002277:Carcinoma / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis* / Q000473:pathology; D009305:Nasopharynx / Q000473:pathology; D012680:Sensitivity and Specificity