title: Accuracy of ultrasonography and magnetic resonance imaging in the diagnosis of non-palpable testis.
abstract: BACKGROUND
  Studies were needed to evaluate the accuracy of ultrasonography (US) and magnetic resonance imaging (MRI) for diagnosing non-palpable testis, and to study the clinical usefulness of US and MRI before surgical exploration.
  
  
  METHODS
  Fifty-six patients with non-palpable testis aged 1--12 years were examined between 1993 and 2002. Forty-six patients (55 non-palpable testes) underwent US. Forty patients (47 non-palpable testes) were examined using MRI. Both US and MRI were used in 29 patients (34 non-palpable testes). We used Fisher's exact probability test to compare the results of these graphic examinations with the surgical or laparoscopic findings for the non-palpable testis.
  
  
  RESULTS
  Ultrasonography had a sensitivity of 76%, a specificity of 100%, and an accuracy of 84% in the diagnosis of non-palpable testis, whereas MRI had a sensitivity of 86%, a specificity of 79%, and an accuracy of 85%.
  
  
  CONCLUSIONS
  There were no statistically significant differences in the accuracy rates of US and MRI for diagnosing non-palpable testis. Laparoscopy or inguinal exploration should be performed even if these graphic examinations demonstrate the absence of a testis, because some patients with a non-palpable testis were found to be false negatives. We recommend US as the first step after clinical examination, and MRI could be performed when the US findings are negative preoperatively for a non-palpable testis.
authors.affiliation: Department of Nephro-urology and Quantum Radiology, Nagoya City University, Graduate School of Medical Sciences, Nagoya, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kanemoto
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kojima
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Maruyama
authors.forename: Masato
authors.initials: M
authors.lastname: Ito
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Kohri
mesh_terms: D002648:Child; D002675:Child, Preschool; D003456:Cryptorchidism / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D005188:False Negative Reactions; D005189:False Positive Reactions; D006801:Humans; D007223:Infant; D010535:Laparoscopy; D008279:Magnetic Resonance Imaging; D008297:Male; D010173:Palpation; D012680:Sensitivity and Specificity; D014463:Ultrasonography