title: Prolonged CT urography in duplex kidney.
abstract: BACKGROUND
  Duplex kidney is a common anomaly that is frequently associated with multiple complications. Typical computed tomography urography (CTU) includes four phases (unenhanced, arterial, parenchymal and excretory) and has been suggested to considerably aid in the duplex kidney diagnosi. Unfortunately, regarding duplex kidney with prolonged dilatation, the affected parenchyma and tortuous ureters demonstrate a lack of or delayed excretory opacification. We used prolonged-delay CTU, which consists of another prolonged-delay phase (1- to 72-h delay; mean delay: 24 h) to opacify the duplicated ureters and affected parenchyma.
  
  
  METHODS
  Seventeen patients (9 males and 8 females; age range: 2.5-56 y; mean age: 40.4 y) with duplex kidney were included in this study. Unenhanced scans did not find typical characteristics of duplex kidney, except for irregular perirenal morphology. Duplex kidney could not be confirmed on typical four-phase CTU, whereas it could be easily diagnosed in axial and CT-3D reconstruction using prolonged CTU (prolonged-delay phase).
  
  
  RESULTS
  Between January 2005 and October 2010, in this review board-approved study (with waived informed consent), 17 patients (9 males and 8 females; age range: 2.5 ~ 56 y; mean age: 40.4 y) with suspicious duplex kidney underwent prolonged CTU to opacify the duplicated ureters and confirm the diagnosis.
  
  
  CONCLUSIONS
  Our results suggest the validity of prolonged CTU to aid in the evaluation of the function of the affected parenchyma and in the demonstration of urinary tract malformations.
authors.affiliation: Department of Radiology, the First Affiliated Hospital of Nanchang University, 17 Yongwai Zheng Street, Donghu District, Nanchang, Jiangxi, 330006, China. honghan_gong@sina.com.
authors.forename: Honghan
authors.initials: H
authors.lastname: Gong
authors.affiliation: Department of Radiology, the First Affiliated Hospital of Nanchang University, 17 Yongwai Zheng Street, Donghu District, Nanchang, Jiangxi, 330006, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Gao
authors.affiliation: Department of Radiology, the First Affiliated Hospital of Nanchang University, 17 Yongwai Zheng Street, Donghu District, Nanchang, Jiangxi, 330006, China.
authors.forename: Xi-Jian
authors.initials: XJ
authors.lastname: Dai
authors.affiliation: Department of Radiology, the First Affiliated Hospital of Nanchang University, 17 Yongwai Zheng Street, Donghu District, Nanchang, Jiangxi, 330006, China.
authors.forename: Fuqing
authors.initials: F
authors.lastname: Zhou
authors.affiliation: Department of Radiology, the First Affiliated Hospital of Nanchang University, 17 Yongwai Zheng Street, Donghu District, Nanchang, Jiangxi, 330006, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.affiliation: Department of Radiology, the First Affiliated Hospital of Nanchang University, 17 Yongwai Zheng Street, Donghu District, Nanchang, Jiangxi, 330006, China.
authors.forename: Xianjun
authors.initials: X
authors.lastname: Zeng
authors.affiliation: Department of Radiology, the First Affiliated Hospital of Nanchang University, 17 Yongwai Zheng Street, Donghu District, Nanchang, Jiangxi, 330006, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Department of Radiology, the First Affiliated Hospital of Nanchang University, 17 Yongwai Zheng Street, Donghu District, Nanchang, Jiangxi, 330006, China.
authors.forename: Laichang
authors.initials: L
authors.lastname: He
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D007668:Kidney / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D008297:Male; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014513:Ureter / Q000000981:diagnostic imaging*; D014567:Urography / Q000379:methods*; D055815:Young Adult
keywords: Duplex kidney; Duplicated ureters; Multi-slice spiral CT urography; Prolonged-delay contrast enhancement