title: The diagnostic utility of combined diffusion-weighted imaging and conventional magnetic resonance imaging for detection and localization of non palpable undescended testes.
abstract: BACKGROUND
  We aimed to evaluate the diagnostic performance of combined diffusion weighted imaging (DWI) and conventional magnetic resonance imaging (MRI), including fat-suppression T2WI for identification and localization of non palpable undescended testes (UDTs).
  
  
  METHODS
  This prospective study included 40 consecutive patients, with 47 non-palpable undescended testes (unilateral in 33 cases and bilateral in seven cases). Their age ranged from 5 months to 18 years, mean = 7.5 ± 5.9 years. MRI examinations included T1WI, T2WI, fat-suppression T2WI and DWI at b value of 50, 400 and 800 s/mm(2) . All patients underwent laparoscopic exploration.
  
  
  RESULTS
  According to the laparoscopy findings, the final diagnoses of the location of UDTs were: intra-canalicular (n = 18, 38%), low intra-abdominal (n = 6, 13%), high intra-abdominal (n = 5, 11%). Absent or vanishing testes were detected in 18 cases (38%). The diagnostic accuracy, sensitivity, specificity of combined DWI and conventional MRI were 95.7%, 93.5% and 100% respectively.
  
  
  CONCLUSIONS
  Combined DWI and MRI showed a greater performance compared to conventional MRI alone for identification of non-palpable UDTs. Based on our findings, we can obviate the need for diagnostic laparoscopy in patients who had preoperative detection of inguinal testes or nubbins. However, laparoscopy is still needed to confirm an absent rather than undetected non-viable abdominal testes.
authors.affiliation: Diagnostic and Intervention Radiology Department, Cairo University Hospitals, Cairo, Egypt.
authors.forename: Sally
authors.initials: S
authors.lastname: Emad-Eldin
authors.affiliation: Diagnostic and Intervention Radiology Department, Cairo University Hospitals, Cairo, Egypt.
authors.forename: Nashwa
authors.initials: N
authors.lastname: Abo-Elnagaa
authors.affiliation: Diagnostic and Intervention Radiology Department, Cairo University Hospitals, Cairo, Egypt.
authors.forename: Sameh Az
authors.identifier: http://orcid.org/0000-0002-1197-0489
authors.initials: SA
authors.lastname: Hanna
authors.affiliation: Pediatric Surgery Department, Cairo University Hospitals, Cairo, Egypt.
authors.forename: Ayman H
authors.initials: AH
authors.lastname: Abdel-Satar
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003456:Cryptorchidism / Q000000981:diagnostic imaging* / Q000601:surgery; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D007223:Infant; D010535:Laparoscopy; D008279:Magnetic Resonance Imaging; D008297:Male; D011446:Prospective Studies; D012680:Sensitivity and Specificity
keywords: diffusion; fat-suppression T2WI; magnetic resonance imaging; undescended testes