title: Low-radiation-dose dual-phase MDCT protocol with split contrast media dose and time optimization: protocol design for renal donors evaluation.
abstract: BACKGROUND
  A routine, multiphase, computed tomography (CT) protocol is associated with high radiation exposure to potential kidney donors. To reduce radiation exposure, several authors have suggested a reduction in the number of phases.
  
  
  OBJECTIVE
  To evaluate a low-radiation-dose, dual-phase protocol (i.e. a protocol with an unenhanced phase and combined vascular and excretory phase) for the preoperative evaluation of potential renal donors.
  
  
  METHODS
  Sixty-five potential renal donors were divided into two groups. The first group was scanned with a routine quadric-phase protocol (non-contrast, arterial, venous, and delayed), and the second group was scanned with a triple-phase protocol (dual phase protocol + venous phase). In the second group, we replaced CT angiography with a routine abdominal CT technique. In addition to the evaluation of renal arteries, veins, and excretory systems, the radiation dose of the suggested protocol was compared to that of the routine quadric-phase protocol.
  
  
  RESULTS
  The suggested protocol was efficient in the evaluation of renal arteries, veins, and excretory systems in all studied potential renal donors. Renal arteries were well visualized in the combined vascular excretory phase using the routine abdominal CT technique; no significant difference was noted when these results were compared to those obtained from the CT angiography used in the quadric-phase protocol. The mean effective radiation dose of our suggested dual-phase protocol was only 34% of the dose resulting from the routine quadric-phase protocol.
  
  
  CONCLUSIONS
  Use of a low-radiation, dual-phase, CT protocol, which relied on both an unenhanced phase and a combined vascular and excretory phase, significantly reduced radiation dose. Furthermore, the proposed protocol provides adequate visualization of renal arteries and veins, and affords sufficient opacification of the urinary tract using improved acquisition triggering.
authors.affiliation: Department of Diagnostic Radiology, Faculty of Medicine, Mansoura University, Egypt. bazeed@mans.eun.eg
authors.forename: Mohamed Fayez
authors.initials: MF
authors.lastname: Bazeed
authors.forename: Fawzy F
authors.initials: FF
authors.lastname: Fooshang
authors.forename: Magdy Aly
authors.initials: MA
authors.lastname: Ahmed
mesh_terms: D000293:Adolescent; D000328:Adult; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007472:Iohexol / Q000008:administration & dosage / Q000031:analogs & derivatives; D007668:Kidney / Q000098:blood supply* / Q000000981:diagnostic imaging*; D016030:Kidney Transplantation; D019520:Living Donors; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D012079:Renal Circulation; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide