title: Predictive Value of Preoperative Unenhanced Computed Tomography During Ureteroscopic Lithotripsy: A Single Institute's Experience.
abstract: OBJECTIVE
  Ureteroscopic stone removal is frequently used to remove ureteral stones. Mucosal edema and bleeding are the two most important obstacles to a successful operation. This study analyzed relationships between unenhanced computed tomography (UECT) findings and ureteroscopic findings to determine whether ureteroscopic results could be predicted preoperatively by using UECT imaging.
  
  
  METHODS
  From January 2009 to July 2011, 675 patients were diagnosed with ureteral stones through UECT. Among them, we retrospectively reviewed 92 cases of patients who underwent ureteroscopy (URS). We identified findings such as hydronephrosis, rim sign, periureteral fat stranding, and perinephric fat stranding on the UECT and then categorized these findings into four categories (none, mild, moderate, and severe) according to their severity. We also divided the URS findings of mucosal edema and bleeding into four categories (none, mild, moderate, and severe) and compared these findings with the UECT images.
  
  
  RESULTS
  A total of 92 study patients were included in this study: 59 were male and 33 were female patients. According to the location of the stone, 31 cases were classified as upper ureteral stones, 15 were midureteral stones, and 46 were lower ureteral stones. Hydronephrosis identified with UECT was correlated with the mucosal edema severity observed during URS (p=0.004). The rim signs identified with UECT were proportional to the grade of mucosal edema (p=0.010).
  
  
  CONCLUSIONS
  Hydronephrosis and rim signs observed during UECT can be used as a predictive factor for intraoperative mucosal edema in patients undergoing URS.
authors.affiliation: Department of Urology, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Sunchan
authors.initials: S
authors.lastname: Kim
authors.forename: Seung-Kwon
authors.initials: SK
authors.lastname: Choi
authors.forename: Sol Min
authors.initials: SM
authors.lastname: Lee
authors.forename: Taesoo
authors.initials: T
authors.lastname: Choi
authors.forename: Dong-Gi
authors.initials: DG
authors.lastname: Lee
authors.forename: Gyeong Eun
authors.initials: GE
authors.lastname: Min
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Jeon
authors.forename: Hyung-Lae
authors.initials: HL
authors.lastname: Lee
authors.forename: Jun-Young
authors.initials: JY
authors.lastname: Chung
authors.forename: Jin Hyun
authors.initials: JH
authors.lastname: Joh
authors.forename: Koo Han
authors.initials: KH
authors.lastname: Yoo
keywords: Ureteral calculi; Ureteroscopy; X-ray computed tomography