title: Adequacy of an early arterial phase low-volume contrast protocol in 64-detector computed tomography angiography for aortoiliac aneurysms.
abstract: OBJECTIVE
  This retrospective study was conducted to determine whether a low-volume contrast medium protocol provides sufficient enhancement for 64-detector computed tomography angiography (CTA) in patients with aortoiliac aneurysms.
  
  
  METHODS
  Evaluated were 45 consecutive patients (6 women; mean age, 72 +/- 6 years) who were referred for aortoiliac computed tomography angiography between October 2005 and January 2007. Group A (22 patients; creatinine clearance, 64.2 +/- 8.1 mL/min) received 50 mL of the contrast agent. Group B (23 patients; creatinine clearance, 89.4 +/- 7.3 mL/min) received 100 mL of the contrast agent. The injection rate was 3.5 mL/s, followed by 30 mL of saline at 3.5 mL/s. Studies were performed on the same 64-detector computed tomography scanner using a real-time bolus-tracking technique. Quantitative analysis was performed by determination of mean vascular attenuation at 10 regions of interest from the suprarenal aorta to the common femoral artery by one reader blinded to type and amount of contrast agent and compared using the Student t test. Image quality according to a 4-point scale was assessed in consensus by two readers blinded to type and amount of contrast medium and compared using the Mann-Whitney test. Multivariable adjustments were performed using ordinal regression analysis.
  
  
  RESULTS
  Mean total attenuation did not differ significantly between both groups (196.5 +/- 33.0 Hounsfield unit [HU] in group A and 203.1 +/- 44.2 HU in group B; P = .57 by univariate and P > .05 by multivariable analysis). Accordingly, attenuation at each region of interest was not significantly different (P > .35). Image quality was excellent or good in all patients. No significant differences in visual assessment were found comparing both contrast medium protocols (P > .05 by univariate and by multivariable analysis).
  
  
  CONCLUSIONS
  Aortoiliac aneurysm imaging can be performed with substantially reduced amounts of contrast medium using 64-detector computed tomography angiography technology.
authors.affiliation: Department of Interventional Radiology, Baptist Cardiac and Vascular Institute, Baptist Health Systems, Miami, FL 33176, USA.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Diehm
authors.forename: Constantino
authors.initials: C
authors.lastname: Pena
authors.forename: James F
authors.initials: JF
authors.lastname: Benenati
authors.forename: Athanassios I
authors.initials: AI
authors.lastname: Tsoukas
authors.forename: Barry T
authors.initials: BT
authors.lastname: Katzen
mesh_terms: D000368:Aged; D001014:Aortic Aneurysm / Q000000981:diagnostic imaging*; D001027:Aortography / Q000379:methods*; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D017543:Iliac Aneurysm / Q000000981:diagnostic imaging*; D007275:Injections, Intravenous; D008297:Male; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014283:Triiodobenzoic Acids / Q000008:administration & dosage*
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; C044834:iodixanol; C054871:ioversol