title: CT of the abdomen: degree and quality of enhancement obtained with two concentrations of the same iodinated contrast medium with fixed iodine delivery rate and total iodine load.
abstract: OBJECTIVE
  to compare vascular and parenchymal enhancement in abdominal computed tomography (CT) using two iodine concentrations (370 vs 300mgI/mL) of the same contrast medium (CM) molecule (iopromide), using fixed iodine delivery rate (IDR, 1.2gI/s) and total iodine load (630mgI/kg).
  
  
  METHODS
  144 patients were randomized into two groups: group A receiving iopromide 370 and group B receiving iopromide 300. Attenuation values (AV) were measured in correspondence to key anatomical structures on different phases and compared between groups with parametrical tests. Qualitative analysis was also performed. Peak injection pressure and local discomfort at the site of injection (pain and warmth) were registered.
  
  
  RESULTS
  mean AV of abdominal aorta in late arterial phase were 300.32±59.76 for group A and 298.2±59.14 for group B (p=0.8); mean AV of portal vein in portal phase were 190.5±29.92 for group A and 192.91±24.12 for group B (p=0.6). Mean AV of liver parenchyma in portal phase were 124.73±18.22 for group A and 125.11±15.7 for group B (p=0.9); mean AV of liver at equilibrium were 85.11±7.75 for group A and 85.41±8.09 for group B (p=0.8). Qualitative analysis did not show significant differences between groups (p>0.05). Median peak injection pressure was lower in group B (93psi, 76-172) than in group A (115psi, 88-288, p<0.0001), while discomfort at injection site was not significantly different (p>0.05).
  
  
  CONCLUSIONS
  with fixed IDR and total iodine load, comparable quantitative and qualitative enhancement can be achieved with different concentrations of the same CM. Peak injection pressure increases using CM with higher iodine concentration.
authors.affiliation: Radiology Unit, Diagnostic Imaging Department, E.O. Ospedali Galliera, Genoa, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Paparo
authors.affiliation: Radiology Unit, Diagnostic Imaging Department, E.O. Ospedali Galliera, Genoa, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Garello
authors.affiliation: Radiology Unit, Diagnostic Imaging Department, E.O. Ospedali Galliera, Genoa, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Bacigalupo
authors.affiliation: Radiology Unit, Diagnostic Imaging Department, E.O. Ospedali Galliera, Genoa, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Marziano
authors.affiliation: Radiology Unit, Diagnostic Imaging Department, E.O. Ospedali Galliera, Genoa, Italy.
authors.forename: Athena
authors.initials: A
authors.lastname: Galletto Pregliasco
authors.affiliation: School of Medicine, University of Genoa, Genoa, Italy.
authors.forename: Ludovica
authors.initials: L
authors.lastname: Rollandi
authors.affiliation: Radiology Unit, Diagnostic Imaging Department, E.O. Ospedali Galliera, Genoa, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Puppo
authors.affiliation: Pharmacology and Toxicology Unit, Internal Medicine Department, University of Genoa, Genoa, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Mattioli
authors.affiliation: Biostatistics Unit, Office of the Scientific Director, Genoa, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Puntoni
authors.affiliation: Radiology Unit, Diagnostic Imaging Department, E.O. Ospedali Galliera, Genoa, Italy. Electronic address: rollandi@galliera.it.
authors.forename: Gian Andrea
authors.initials: GA
authors.lastname: Rollandi
mesh_terms: D000368:Aged; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging*; D003287:Contrast Media / Q000008:administration & dosage / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007455:Iodine / Q000008:administration & dosage* / Q000097:blood*; D007472:Iohexol / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000378:metabolism; D008099:Liver / Q000000981:diagnostic imaging*; D008297:Male; D011169:Portal Vein / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide; D007455:Iodine
keywords: Abdominal imaging; Computed tomography; Contrast enhancement; Iodinated contrast media; injection pressure