title: [Clinical application of dual-source computed tomographic urography using dual-energy virtual non enhanced computed tomography].
abstract: OBJECTIVE
  To evaluate the clinical feasibility of dual-source computed tomographic urography using dual-energy virtual non-enhanced CT.
  
  
  METHODS
  Totally 240 patients received dual-source CT, which included true non-enhanced CT (TNCT) , nephrographic phase scanning with dual-energy mode (100kVp/230mAs and Sn140kVp/178mAs) , and excretory phase scanning. A contrast bolus injection of 100 ml (370 mgI/ml) contrast agent was applied (4.5ml/s) , followed by 100ml normal saline (4.5ml/s) . Virtual non-enhanced CT (VNCT) image sets were reformatted from 'Liver VNC ' software. The mean CT number, noise, signal to noise ratio (SNR) , image quality, and radiation dose were compared between TNCT and VNCT image sets.
  
  
  RESULTS
  There was no significant difference in mean CT numbers of all organs (P>0.05) . However, VNCT images had significantly lower noise and higher SNR than TNCT images (both P<0.05) . Image quality of VNCT was lower than that of TNCT without significant difference (P>0.05) . Radiation dose of nephrographic phase with dual-energy mode was significantly higher than that of TNCT and excretory phase scanning (P<0.05) .
  
  
  CONCLUSIONS
  Dual-energy VNCT requires less radiation dose and therefore has a potential to replace TNCT in the dual-source CT urography.
authors.affiliation: Department of Radiology, PUMC Hospital, Beijing 100730, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Sun
authors.forename: Hua-dan
authors.initials: HD
authors.lastname: Xue
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Bai-yan
authors.initials: BY
authors.lastname: Su
authors.forename: Xin
authors.initials: X
authors.lastname: Sui
authors.forename: Jie
authors.initials: J
authors.lastname: DE
authors.forename: Wei-di
authors.initials: WD
authors.lastname: Ming
authors.forename: Zheng-yu
authors.initials: ZY
authors.lastname: Jin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014567:Urography / Q000379:methods*; D055815:Young Adult