title: Diagnostic accuracy of parotid CT for identifying Sjögren's syndrome.
abstract: OBJECTIVE
  To evaluate the diagnostic accuracy of computed tomography (CT) of the parotid gland for Sjögren's syndrome in comparison with conventional X-ray sialography.
  
  
  METHODS
  CT scans and X-ray sialography were performed in 34 patients with confirmed Sjögren's syndrome and 22 symptomatic controls without the disease. CT data from 57 asymptomatic controls were included for quantitative analysis. The CT findings of heterogeneity, abnormal diffuse fat tissue deposition, diffuse punctate calcification, swelling or atrophy, nodularity or cystic changes of the parotid gland were analyzed by two independent blinded readers. The correlation between CT and X-ray sialography findings was evaluated. Diagnostic performance and receiver operating characteristics curves were calculated.
  
  
  RESULTS
  On CT, heterogeneity of the parotid gland was seen in 30/31 (reader 1/reader 2) Sjögren's syndrome patients by the two readers (sensitivity 88.2%/91.2%; specificity 100%/90.9%). Abnormal diffuse fat tissue deposition was seen in 28/28 SS patients by the readers (sensitivity 82.3%/82.3%; specificity 100%/90.9%). Diffuse punctate calcification was seen in 10/12 Sjögren's syndrome patients (sensitivity 29.4%/35.2%; specificity 100%/100%). Stagings of CT findings correlate positively with sialography. The areas under the receiver operating characteristics curves were 0.887 (P=0.000) and 0.908 (P=0.000) for the maximum and standard deviation (SD) of the CT value.
  
  
  CONCLUSIONS
  Parotid CT is accurate and reliable in the diagnosis of Sjögren's syndrome. Heterogeneity, abnormal diffuse fat tissue deposition, and diffuse punctate calcification are specific for Sjögren's syndrome. CT attenuation analysis is helpful in diagnosis.
authors.affiliation: Department of Oral and Maxillofacial Radiology, School and Hospital of Stomatology, Peking University, No.22, South Zhong Guan Cun Ave., Haidian District, Beijing 100081, China. sunzhipeng@bjmu.edu.cn
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Sun
authors.forename: Zuyan
authors.initials: Z
authors.lastname: Zhang
authors.forename: Kaiyuan
authors.initials: K
authors.lastname: Fu
authors.forename: Yanping
authors.initials: Y
authors.lastname: Zhao
authors.forename: Denggao
authors.initials: D
authors.lastname: Liu
authors.forename: Xuchen
authors.initials: X
authors.lastname: Ma
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010306:Parotid Gland / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012796:Sialography / Q000379:methods*; D012859:Sjogren's Syndrome / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*