title: Trauma whole-body MDCT: an assessment of image quality in conventional dual-phase and modified biphasic injection.
abstract: OBJECTIVE
  To compare the image quality of conventional arterial and portal venous (PV) phase multidetector CT (MDCT) with two biphasic injection protocols in polytrauma patients.
  
  
  METHODS
  60 consecutive patients with polytrauma underwent body 256-slice MDCT with a conventional protocol or 1 of 2 single-pass biphasic protocols: Group A, arterial (30 s) and PV (60 s) phase acquisitions; Group B, "biphasic" contrast injection with a single acquisition at 60 s; and Group C, "modified biphasic" injection with a single acquisition at a 70-s delay. Images were analyzed for arterial, venous and parenchymal attenuation profiles with regions of interest in the major arteries, veins and solid abdominal organs. A 5-point scoring system was used to assess the image quality, with 5 representing excellent arterial, venous and parenchymal opacification and <3 representing non-diagnostic opacification. In addition, the effective dose (millisieverts) was compared between the groups.
  
  
  RESULTS
  In 93% of patients, image quality was scored as good or excellent (≥4). All studies were of satisfactory diagnostic quality. Overall, venous and arterial attenuation profiles were comparable. Attenuation profiles in the solid abdominal viscera were significantly higher (p < 0.01) using both biphasic protocols than with arterial or PV phase of conventional protocols. Effective doses were higher in Group A.
  
  
  CONCLUSIONS
  Comparable image quality can be achieved using a biphasic i.v. contrast injection protocol with single MDCT acquisition with less radiation and reduction in acquisition time.
  
  
  CONCLUSIONS
  For these particular biphasic injection protocols, we have shown that image quality is comparable with a conventional protocol. This has been achieved by comparing enhanced densities of specific structures, as well as gestalt scoring by assessors, on a 256-slice MDCT.
authors.affiliation: 1 Department of Radiology, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK.
authors.forename: Wasim
authors.initials: W
authors.lastname: Hakim
authors.affiliation: 2 Royal Lancaster Infirmary, UHMB NHS Trust, Lancaster, UK.
authors.forename: Raghavendra
authors.initials: R
authors.lastname: Kamanahalli
authors.affiliation: 1 Department of Radiology, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK.|3 Faculty of Medicine, Department of Surgery and Cancer, Imperial College London, UK.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Dick
authors.affiliation: 1 Department of Radiology, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK.|3 Faculty of Medicine, Department of Surgery and Cancer, Imperial College London, UK.
authors.forename: Nishat
authors.initials: N
authors.lastname: Bharwani
authors.affiliation: 1 Department of Radiology, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK.
authors.forename: Shirley
authors.initials: S
authors.lastname: Fetherston
authors.affiliation: 1 Department of Radiology, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK.|3 Faculty of Medicine, Department of Surgery and Cancer, Imperial College London, UK.
authors.forename: Elika
authors.initials: E
authors.lastname: Kashef
mesh_terms: D000328:Adult; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D061330:Multidetector Computed Tomography / Q000379:methods*; D009104:Multiple Trauma / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement / Q000379:methods*; D012189:Retrospective Studies; D051598:Whole Body Imaging / Q000379:methods*
chemical_list: D003287:Contrast Media