title: Evaluation of testicular viability by power Doppler ultrasonography in experimentally induced acute testicular torsion.
abstract: OBJECTIVE
  We sought to determine whether torsed testis viability can be evaluated by ultrasonography (US) including power Doppler US in an experimental model of acute testicular torsion.
  
  
  METHODS
  Eighteen rats underwent unilateral 540 degrees testicular torsion and contralateral orchiopexy. Gray-scale and power Doppler US were performed 24 hours later. We evaluated echogenicity, intratesticular vascular flow, and testis size. Echogenicity and intratesticular vascular flow were quantitatively analyzed by using a visual scale and computer-based analysis. After US, detorsion was performed in torsed testes, and 6 days after detorsion testes were excised to determine testicular viability, which was determined using gross and microscopic findings. US findings before detorsion were correlated with testicular viability.
  
  
  RESULTS
  At US performed 24 hours after testicular torsion, all viable testes (n = 7) were homogeneous and isoechoic versus contralateral testes. In nonviable testes (n = 11), lower (82%) and heterogeneous (73%) echogenicities were seen on gray-scale US. Intratesticular vascular flow was preserved in 86% of viable testes. In nonviable testes, no intratesticular vascularity was observed in 82%, and intermittent, peripheral blood flow was detected in the remaining 18%. Intratesticular focal lesions were observed in 45% of nonviable testis. Quantitative analysis showed a statistically significant difference between viable and nonviable testes in terms of testicular echogenicity and intratesticular vascular flow.
  
  
  CONCLUSIONS
  Preoperative US including power Doppler examination can predict testicular viability in testicular torsion. Echogenicity of nonviable testes was found to be hypoechoic and inhomogeneous. Power Doppler examination showed no or intermittent peripheral blood flow in nonviable testes.
authors.affiliation: Department of Radiology, Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Jong Won
authors.initials: JW
authors.lastname: Kwon
authors.forename: Woo Sun
authors.initials: WS
authors.lastname: Kim
authors.forename: Jung-Eun
authors.initials: JE
authors.lastname: Cheon
authors.forename: Chong Jai
authors.initials: CJ
authors.lastname: Kim
authors.forename: In-One
authors.initials: IO
authors.lastname: Kim
authors.forename: Kyung Mo
authors.initials: KM
authors.lastname: Yeon
mesh_terms: D000208:Acute Disease; D000818:Animals; D002470:Cell Survival; D004195:Disease Models, Animal; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012720:Severity of Illness Index; D013086:Spermatic Cord Torsion / Q000000981:diagnostic imaging* / Q000473:pathology*; D013737:Testis / Q000000981:diagnostic imaging* / Q000473:pathology*; D014022:Tissue Survival; D018608:Ultrasonography, Doppler / Q000379:methods*