title: [Spiral-CT of the liver: optimizing contrast medium administration and examination technique].
abstract: OBJECTIVE
  To analyze different protocols for spiral-CT with regard to the enhancement of liver parenchyma and vessels of the upper abdomen. To compare the achieved density values with those obtained by conventional CT.
  
  
  METHODS
  30 CT-examinations of the abdomen of different patients with normal findings of the liver were selected. In all examinations the upper abdomen was scanned before injection of contrast agent in conventional technique. In 10 patients spiral-CT of the liver was performed in the arterial phase at a delay of 15 sec and a flow of 4 ml/sec with 100 ml contrast agent, in 10 other patients in the portal-venous phase at a delay of 35 sec and a flow of 4 ml/sec with 100 ml contrast agent, followed by a spiral-CT of the upper abdomen in the arterial-venous phase at a delay of 70 sec and a flow of 1 ml/sec with 85 ml contrast agent. In 10 patients conventional CT of the upper abdomen was performed at a delay of 30 sec and a flow of 1 ml/sec with 200 ml contrast agent.
  
  
  RESULTS
  The highest density of the aorta was achieved by the arterial spiral-CT (p < 0.001). In the portal-venous spiral-CT the density of liver parenchyma was lower than in the arterial-venous spiral-CT and conventional CT (p < 0.001). Both arterial-venous spiral-CT and conventional CT achieved the same contrast in the aorta (216 +/- 10 vs. 217 +/- 23 HE) and in liver parenchyma (110 +/- 3 vs. 112 +/- 16 HE), but arterial-venous spiral-CT showed a lower density in the inferior vena cava than conventional CT (138 +/- 9 vs. 162 +/- 21 HE) (p < 0.002).
  
  
  CONCLUSIONS
  The spiral-CT-protocol for the examination of the liver in arterial and arterial-venous phase enables a reliable and adequate enhancement of liver parenchyma and all vessels of the upper abdomen with a lower dose of contrast agent than is possible with conventional CT. Together with unenhanced CT, this protocol promises a better detection of focal lesions of the liver with different enhancement modes in the arterial and venous phases.
authors.affiliation: Strahlenklinik und Poliklinik, Virchow-Klinikum der Humboldt-Universität zu Berlin.
authors.forename: T J
authors.initials: TJ
authors.lastname: Vogl
authors.forename: N
authors.initials: N
authors.lastname: Hidajat
authors.forename: R J
authors.initials: RJ
authors.lastname: Schröder
authors.forename: W
authors.initials: W
authors.lastname: Pegios
authors.forename: R
authors.initials: R
authors.lastname: Langer
authors.forename: P
authors.initials: P
authors.lastname: Neuhaus
authors.forename: R
authors.initials: R
authors.lastname: Felix
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging; D008107:Liver Diseases / Q000000981:diagnostic imaging*; D008113:Liver Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods; D012016:Reference Values; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media