title: [TW systems in estimation of carpal bone age and their potential applications in diagnosis of idiopathic precocious puberty in Chinese girls].
abstract: OBJECTIVE
  To compare three assessment methods (TW2, TW2CH, and TW3) for carpal bone age and their potential applications in diagnosis of idiopathic precocious puberty (IPP) in Chinese girls.
  
  
  METHODS
  Fifty-five (55) girls with IPP and 83 normal girls as control group were selected in this study. The X-ray films of the left hand-wrist taken at their first visit were analyzed retrospectively. Three assessment methods were used to estimate the carpal bone age with single-blinded method and percentiles were set at 5 different decision thresholds (1)>97th percentile, (2)>90 th percentile, (3)>75th percentile, (4)>50 th percentile, and (5)< or =50th percentile.
  
  
  RESULTS
  All of the three methods showed similar high sensitivity and specificity at the threshold above 90th percentile.
  
  
  CONCLUSIONS
  Our data indicate that all of the three methods for estimation of the carpal bone age are useful in diagnosis of IPP. TW2CH and TW3 methods appear to be superior to TW2 method.
authors.affiliation: The 2nd West China Hospital of Sichuan University, Chengdu 610041, China. ng6611@163.com
authors.forename: Gang
authors.initials: G
authors.lastname: Ning
authors.forename: Hai-Bo
authors.initials: HB
authors.lastname: Qu
authors.forename: Guan-Jian
authors.initials: GJ
authors.lastname: Liu
authors.forename: Kang-Min
authors.initials: KM
authors.lastname: Wu
authors.forename: Shu-Xiang
authors.initials: SX
authors.lastname: Xie
authors.forename: Xi-Jian
authors.initials: XJ
authors.lastname: Chen
mesh_terms: D000365:Age Determination by Skeleton / Q000379:methods* / Q000592:standards; D000465:Algorithms; D001846:Bone Development; D002348:Carpal Bones / Q000000981:diagnostic imaging* / Q000254:growth & development; D016022:Case-Control Studies; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D002681:China; D005260:Female; D006801:Humans; D011629:Puberty, Precocious / Q000175:diagnosis*; D012372:ROC Curve; D012189:Retrospective Studies