title: Quadruple-phase MDCT of the liver in patients with suspected hepatocellular carcinoma: effect of contrast material flow rate.
abstract: OBJECTIVE
  The purposes of this study were to evaluate the effect of contrast material flow rate (3 mL/sec vs 5 mL/sec) on the detection and visualization of hepatocellular carcinoma (HCC) with MDCT and the safety profile of iodixanol at different injection rates.
  
  
  METHODS
  In a prospective, randomized multicenter trial, 97 patients (83 men and 14 women, with a mean age of 64 years) suspected of having HCC underwent quadruple-phase (double arterial, portal venous, delayed phase) 4-16-MDCT. Patients were randomized to receive iodixanol, 320 mg I/mL (1.5 mL/kg body weight), at a flow rate of 3 mL/sec (48 patients) or 5 mL/sec (49 patients). Qualitative (lesion detection, image quality) and quantitative (liver and aortic enhancement, tumor-liver contrast) analyses and safety assessment were performed.
  
  
  RESULTS
  Overall, 145 HCCs were detected in the 5 mL/sec group and 100 HCCs in the 3 mL/sec group (p < 0.05). More lesions equal to or less than 1 cm were detected at 5 mL/sec (33 vs 16 lesions). The late arterial phase showed significantly more lesions than the early, arterial phase (133 vs 100 and 96 vs 67 lesions, respectively, p < 0.0001). Hyperattenuating HCCs were better visualized in the late arterial phase at 5 mL/sec (excellent visualization: 54% vs 27%). Using a flow of 5 mL/sec did not increase the rate of patient discomfort or contrast media-related adverse events. Most discomfort in both groups was of mild intensity and there was no severe discomfort.
  
  
  CONCLUSIONS
  For detection of HCC with MDCT, a higher flow rate of 5 mL/sec is recommended. Visualization of hyperattenuating HCC is improved with no greater discomfort or adverse events.
authors.affiliation: Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schima
authors.forename: Renate
authors.initials: R
authors.lastname: Hammerstingl
authors.forename: Carlo
authors.initials: C
authors.lastname: Catalano
authors.forename: Luis
authors.initials: L
authors.lastname: Marti-Bonmati
authors.forename: Ernst J
authors.initials: EJ
authors.lastname: Rummeny
authors.forename: Francisco Tardáguila
authors.initials: FT
authors.lastname: Montero
authors.forename: Albert
authors.initials: A
authors.lastname: Dirisamer
authors.forename: Bernd
authors.initials: B
authors.lastname: Westermayer
authors.forename: Massimo
authors.initials: M
authors.lastname: Bellomi
authors.forename: Denis
authors.initials: D
authors.lastname: Brisbois
authors.forename: Patrick
authors.initials: P
authors.lastname: Chevallier
authors.forename: Martin
authors.initials: M
authors.lastname: Dobritz
authors.forename: Jacques
authors.initials: J
authors.lastname: Drouillard
authors.forename: Francesco
authors.initials: F
authors.lastname: Fraioli
authors.forename: Maria
authors.initials: M
authors.lastname: Jesus Martinez
authors.forename: Sandro
authors.initials: S
authors.lastname: Morassut
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Vogl
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging*; D003287:Contrast Media / Q000493:pharmacokinetics*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014283:Triiodobenzoic Acids / Q000493:pharmacokinetics*
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; C044834:iodixanol