title: A novel parameter by EFOV US for the quantification and the distinction of physiological amount of scrotal fluid and hydrocele: ratio of testis volume/scrotum volume.
abstract: OBJECTIVE
  To determine the limits for the amount of tunical fluid enough to be termed as hydrocele by using extended-field of view US technology and to define hydrocele for the first time with standard numerical criteria.
  
  
  METHODS
  A total of 60 patients were evaluated in this prospective study. Group 1 consisted of 20 patients with unilateral clinical hydrocele. Group 2 included 20 patients referred for scrotal US for reasons other than hydrocele. Group 3 comprised 20 male controls with no scrotal complaints. Testis volume (V(t)), scrotum volume (V(s)) and V(t)/V(s) ratio were calculated for each subject by dimensions measured in longitudinal and tranverse planes.
  
  
  RESULTS
  Mean V(t)/V(s) ratio was 0.28 +/- 0.17 (range, 0.07-0.57), 0.69 +/- 0.08 (range, 0.53-0.80) and 0.71 +/- 0.07 (range, 0.61-0.85) for groups 1, 2 and 3, respectively. Mean V(t)/V(s) for group 1 was significantly lower than those for groups 2 and 3, respectively (p<0.001 for each). Based on the ROC curve analysis, 0.55 for V(t)/V(s) ratio was determined as the optimal cut-off point below which the US diagnosis of hydrocele could be made (sensitivity 95.0% and specificity 97.5%).
  
  
  CONCLUSIONS
  We propose a novel US parameter of V(t)/V(s) ratio below 0.55 for a standard distinction between hydrocele and physiological amount of scrotal fluid.
authors.affiliation: Department of Radiology, Ankara Training and Research Hospital, TR-06590 Ankara, Turkey. ahmettuncayturgut@yahoo.com
authors.forename: Ahmet Tuncay
authors.initials: AT
authors.lastname: Turgut
authors.forename: Eriz
authors.initials: E
authors.lastname: Ozden
authors.forename: Alparslan
authors.initials: A
authors.lastname: Unsal
authors.forename: Pinar
authors.initials: P
authors.lastname: Koşar
authors.forename: Zafer Unsal
authors.initials: ZU
authors.lastname: Coşkun
authors.forename: Uğur
authors.initials: U
authors.lastname: Koşar
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D012611:Scrotum / Q000000981:diagnostic imaging*; D006848:Testicular Hydrocele / Q000000981:diagnostic imaging*; D014463:Ultrasonography