title: A comparison between two different concentration of contrast media with multidetector CT for the study of abdominal vascular system.
abstract: OBJECTIVE
  To evaluate two different concentrations of contrast medium (CM) and two different acquisition techniques to obtain vascular images with multislice spiral CT (msCT).
  
  
  METHODS
  Thirty patients referred for msCT examinations of the kidney or upper abdomen underwent evaluation of the abdominal aorta during the arterial phase, after giving their consent (GE Light Speed Plus). In the first part of the study (20 patients) the enhancement values measured at six different levels of the aortoiliac axis (celiac trunk, suprarenal aorta, subrenal aorta, aortal bifurcation, right iliac and left iliac) were compared after administering two different concentrations of iodinated contrast medium (300 and 370 mgI/ml) with two different acquisition techniques (HQ and HS). The flow rate was 3 ml/sec. In the second part of the study 10 patients were examined by changing the flow rate (2 and 4 ml/sec). Both quantity and quality assessments were conducted on axial images and on vascular reconstructions.
  
  
  RESULTS
  In the first part of the study the best results were obtained with the 370 mgI/ml concentration and with the HQ acquisition technique (pitch 3, table feed 7.5 mm/rotation, gantry rotation speed 0.5 s). The quality of reconstructions gradually improved before reaching 240 HU, above which image quality remained constant. The patients examined with a flow rate of 2 ml/sec showed a poor image quality, unlike those examined with a flow rate of 4 ml/sec where we observed the maximum threshold values and constant optimal vascular opacification, with no significant differences from the patients studied at 3 ml/sec.
  
  
  CONCLUSIONS
  Our results indicate that, albeit on a limited number of patients, a higher concentration of CM and the use of an HQ technique allow a high quality examination to be obtained. The HS technique yields results comparable to those obtained with higher concentrations.
authors.affiliation: Dipartimento di Diagnostica per Immagini e Radiologia Interventistica, Università di Roma Policlinico Tor Vergata, Rome, Italy. ettoresquillaci@tiscali.it
authors.forename: Ettore
authors.initials: E
authors.lastname: Squillaci
authors.forename: Ezio
authors.initials: E
authors.lastname: Fanucci
authors.forename: Salvatore
authors.initials: S
authors.lastname: Masala
authors.forename: Alberto
authors.initials: A
authors.lastname: Nisini
authors.forename: Marco
authors.initials: M
authors.lastname: Tomassini
authors.forename: Giovanni
authors.initials: G
authors.lastname: Simonetti
mesh_terms: D000005:Abdomen / Q000098:blood supply*; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging*; D002445:Celiac Artery / Q000000981:diagnostic imaging*; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media