title: Determining the efficacy of ultrasonography for the detection of ureteral stone.
abstract: OBJECTIVE
  To assess the efficacy of ultrasonography (US) for the detection of ureteral stone using non-contrast-enhanced computed tomography (NCCT) as a standard reference.
  
  
  METHODS
  From January 2009 to September 2011, 428 patients underwent both NCCT and US on the same day. The sensitivity and specificity of US to detect ureteral stone was evaluated. The detection rates using US imaging were examined according to location and stone size. The sizes of stones determined in the longest axis of NCCT and US were compared. We also performed group classification based on size to examine whether stone sizes measured by NCCT and US were similar. Moreover, the factors that may affect the detection of ureteral stone by US were analyzed.
  
  
  RESULTS
  Out of 856 ureters, NCCT could detect 171 stones in 169 patients, whereas US could detect 98 stones, yielding a sensitivity of 57.3% and a specificity of 97.5%. Expectedly, detection rate of US increased with stone size but was lower for distal ureter. With hydronephrosis, the sensitivity of US improved from 57.3% to 81.3%. Stone sizes measured by US correlated positively with those by computed tomography, and were concordant with those of NCCT in 68 of 98 patients (69.4%). Interestingly, stone size and the presence of hydronephrosis were factors that independently affected ureteral stone detection by US.
  
  
  CONCLUSIONS
  These results indicate that US may be useful as an initial imaging modality for detecting ureteral stone.
authors.affiliation: Department of Urology, Ijinkai Takeda General Hospital, Kyoto, Japan. Electronic address: t.kan@kuhp.kyoto-u.ac.jp.
authors.forename: Toru
authors.initials: T
authors.lastname: Kanno
authors.affiliation: Department of Urology, Ijinkai Takeda General Hospital, Kyoto, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Kubota
authors.affiliation: Department of Urology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Sakamoto
authors.affiliation: Department of Urology, Ijinkai Takeda General Hospital, Kyoto, Japan.
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Nishiyama
authors.affiliation: Department of Urology, Ijinkai Takeda General Hospital, Kyoto, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Okada
authors.affiliation: Department of Urology, Ijinkai Takeda General Hospital, Kyoto, Japan.
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Higashi
authors.affiliation: Department of Urology, Ijinkai Takeda General Hospital, Kyoto, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yamada
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000737:chemistry; D016208:Databases, Factual; D005260:Female; D006801:Humans; D006869:Hydronephrosis / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014463:Ultrasonography / Q000379:methods*; D014514:Ureteral Calculi / Q000000981:diagnostic imaging*; D014517:Ureteral Obstruction / Q000000981:diagnostic imaging
chemical_list: D003287:Contrast Media