title: Aortoiliac gadolinium-enhanced CT angiography: improved results with a 16-detector row scanner compared with a four-detector row scanner.
abstract: OBJECTIVE
  To assess the level of vascular enhancement of gadolinium-enhanced aortoiliac computed tomographic (CT) angiography with a 16-detector row CT scanner and to compare it with the results of previous similar studies that used four-detector row CT units.
  
  
  METHODS
  Eleven gadolinium-enhanced CT angiograms were obtained in 10 consecutive patients with contraindication to iodinated contrast medium with use of a 16-detector row CT scanner. In the region of interest, attenuation measurements (in HU) were obtained from the proximal abdominal aorta to the common femoral arteries during unenhanced, gadolinium-enhanced, and delayed acquisitions. The results were compared to those in the 15 consecutive patients who most recently had similar examinations performed on a four-detector row CT unit. Phantom studies with diluted gadolinium were conducted to compare attenuation between CT units.
  
  
  RESULTS
  On four-detector row CT, throughout the scan length, mean enhancement values were 53.8 HU +/- 5.3 and 15.0 HU +/- 2.6 for gadolinium-enhanced and delayed series, respectively. For the 16-detector row CT unit, they were 76.1 HU +/- 3.4 and 21.3 HU +/- 1.3, respectively. As a result of a shorter scan time and a more optimal start time, the 16-detector row CT unit provided significantly greater and more consistent enhancement throughout the scan length compared with the four-detector row CT unit (P =.0106). Similar structures had significantly greater enhancement when 120 kV was applied instead of 140 kV (P =.0495)
  
  
  CONCLUSIONS
  The 16-detector row CT scanner improved gadolinium-enhanced CT angiography results compared with the four-detector row CT unit.
authors.affiliation: Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA. swicky@partners.org
authors.forename: Stephan
authors.initials: S
authors.lastname: Wicky
authors.forename: Alan
authors.initials: A
authors.lastname: Greenfield
authors.forename: Chieh-Min
authors.initials: CM
authors.lastname: Fan
authors.forename: Stuart C
authors.initials: SC
authors.lastname: Geller
authors.forename: Leena M
authors.initials: LM
authors.lastname: Hamberg
authors.forename: Udo
authors.initials: U
authors.lastname: Hoffmann
authors.forename: Arthur C
authors.initials: AC
authors.lastname: Waltman
mesh_terms: D000368:Aged; D000792:Angiography / Q000295:instrumentation*; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging*; D001027:Aortography / Q000295:instrumentation; D004867:Equipment Design; D005260:Female; D005682:Gadolinium / Q000494:pharmacology*; D006801:Humans; D007083:Iliac Artery / Q000000981:diagnostic imaging*; D008297:Male; D019047:Phantoms, Imaging; D015898:Tomography Scanners, X-Ray Computed; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*
chemical_list: D005682:Gadolinium