title: [The value of split-bolus 2-phase with virtual non-enhanced scan in CT urography].
abstract: OBJECTIVE
  To investigate the value of split-bolus 2-phase with virtual non-enhanced scan in CT urography.
  
  
  METHODS
  Eighty (80) patients with urinary obstruction were divided into two groups, group A was traditional CT urography scan, group B was split-bolus 2-phase with virtual non-enhanced scan. The scan sequence of group A included conventional scan first, then enhanced scan in arterial phase, parenchyma phase and excretion delayed phase after the injection of 100 mL contrast agent. The scan sequence of group B included conventional scan and enhanced scan following two bolus injection of contrast; the first injection of contrast was 40 mL, the second injection was 60 mL with 15-30 minutes delay, then enhanced scan was conducted in arterial and parenchymal phase, the parenchymal phase scan was performed with dual energy scanning sequence. The image quality of urinary collecting system, the detection of urinary obstructive lesion, and radiation dose were compared between the two groups.
  
  
  RESULTS
  Between the two imaging methods, the imaging quality of urinary system did not show significant difference, but radiation dose was statistically significant difference. The radiation dose of split-bolus 2-phase with virtual non-enhanced scan was only 55% of traditional CTU scan.
  
  
  CONCLUSIONS
  Split-bolus2 phase with virtual non-enhanced scan could obtain the same image quality as tranditional CTU, while reducing the approximately half the radiation dose.
authors.affiliation: Department of Radiology, West China Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Shuai
authors.forename: Zhen-Lin
authors.initials: ZL
authors.lastname: Li
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Deng
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yuan
authors.forename: Xue-Lin
authors.initials: XL
authors.lastname: Pan
authors.forename: Wei
authors.initials: W
authors.lastname: Cheng
authors.forename: Wan-Jiang
authors.initials: WJ
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods; D036542:Tomography, Spiral Computed / Q000379:methods*; D014517:Ureteral Obstruction / Q000000981:diagnostic imaging; D014545:Urinary Calculi / Q000000981:diagnostic imaging*; D014567:Urography / Q000379:methods*; D014570:Urologic Diseases / Q000000981:diagnostic imaging; D055815:Young Adult
chemical_list: D003287:Contrast Media