title: 3D contrast-enhanced MR angiography of the abdominal aorta and its distal branches: Interobserver agreement of radiologists in a routine examination.
abstract: OBJECTIVE
  To evaluate the quality of images of the aorta and visceral arteries made at a high level of spatial resolution with thin slices and an optimized acquisition time by three-dimensional contrast-enhanced magnetic resonance angiography (3D CE-MRA).
  
  
  METHODS
  3D CE-MRA with a 1.4-mm slice thickness and 512-pixel base matrix was done on 62 consecutive patients with a 1.5-T magnetic resonance imaging MRI unit. A bolus test with a power injector was used to calculate the optimal scan delay time. For quantitative evaluation, the signal-to-noise ratio (SNR) was measured in 3 regions of interest. Qualitative image analysis was evaluated independently by two radiologists and graded on a scale of 0-3. Separate analyses were done for the aorta and distal visceral arterial branches.
  
  
  RESULTS
  The means SNR values were respectively 56.2 +/- 15.2 (mean +/- SD) for the aorta, 59.2 +/- 15.1 for the celiac trunk, and 57 +/- 15.2 for the superior mesenteric artery, with a homogeneous distribution (P = .99). Consistent enhancement was confirmed by the lack of statistically significant differences between the SNR values. The average score for vessel visualization on source images ranged from good to excellent for different segments. After post-processing of images, the average score for distal arterial segments was significantly improved. The overall agreement between the 2 reviewers in the visualization of definite artery segments was excellent (k = .91).
  
  
  CONCLUSIONS
  3D CE-MRA with a 512-pixel base matrix and thin slices can be applied in a reproducible way with excellent depiction and delineation of small vessels. Such a protocol could be used routinely.
authors.affiliation: Département de Radiologie Digestive, Hôpital Universitaire E. Herriot, Lyon, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Billaud
authors.forename: Olivier
authors.initials: O
authors.lastname: Beuf
authors.forename: Guillaume
authors.initials: G
authors.lastname: Desjeux
authors.forename: Pierre J
authors.initials: PJ
authors.lastname: Valette
authors.forename: Frank
authors.initials: F
authors.lastname: Pilleul
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001012:Aorta, Abdominal / Q000033:anatomy & histology*; D001018:Aortic Diseases / Q000175:diagnosis*; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D019786:Gadolinium DTPA; D006499:Hepatic Artery; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011871:Radiology / Q000706:statistics & numerical data*; D012077:Renal Artery; D013157:Splenic Artery
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA