title: [Quantitative analysis by real-time elastosonography for the differential diagnosis of azoospermia: preliminary application].
abstract: OBJECTIVE
  To evaluate the quantitative analysis by real-time elastosonography in the differential diagnosis of obstructive azoospermia (OA) and non-obstructive azoospermia (NOA).
  
  
  METHODS
  We evaluated the elastosonographic images of 200 cases of OA, 300 cases of NOA and 100 normal healthy controls, calculated the strain ratio of the testis to the scrotal skin and the median strain ratio among the three groups, and analyzed the best cut-off point for differentiating OA and NOA by the receiver operation characteristic (ROC) curve.
  
  
  RESULTS
  The median strain ratio of NOA was 0.49 +/- 0.43, while that of OA was 0.35 +/- 0.31, with significant difference between the two groups (Z = - 19.173, P = 0.000 < 0.017). According to the results of ROC curve analysis, the area under the curve was 0.857 +/- 0.012 and the best cut-off point for differentiating OA and NOA was 0.395 (sensitivity = 84.5%, specificity = 74.5%, accuracy = 80.5%).
  
  
  CONCLUSIONS
  Quantitative analysis by real-time elastosonography is a new valuable technique for the differential diagnosis of azoospermia.
authors.affiliation: Department of Ultrasound, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200001, China. limin0442051@126.com
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Feng-hua
authors.initials: FH
authors.lastname: Li
authors.forename: Jing
authors.initials: J
authors.lastname: Du
authors.forename: Zhi-qian
authors.initials: ZQ
authors.lastname: Wang
authors.forename: Ju-fen
authors.initials: JF
authors.lastname: Zheng
authors.forename: Zheng
authors.initials: Z
authors.lastname: Li
authors.forename: Ping
authors.initials: P
authors.lastname: Ping
mesh_terms: D000328:Adult; D053713:Azoospermia / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D008875:Middle Aged; D013737:Testis / Q000000981:diagnostic imaging; D014463:Ultrasonography / Q000379:methods*; D055815:Young Adult