title: Breath-hold single-dose gadolinium-enhanced three-dimensional MR aortography: usefulness of a timing examination and MR power injector.
abstract: OBJECTIVE
  To determine the usefulness of a timing examination performed with 1 mL gadopentetate dimeglumine administered with a magnetic resonance (MR) power injector at single-dose three-dimensional (3D) MR aortography.
  
  
  METHODS
  3D fast imaging with steady-state precession (repetition time [msec]/echo time [msec] = 5.0/2.0, with 50 degrees flip angle) was performed in 30 patients after administration of 0.1 mmol/kg gadopentetate dimeglumine. In 15 inpatients, a power injector was used and a timing examination was performed (experimental group). In 15 outpatients, manual injection was used and a timing examination was not performed (control group). In the timing examination, 1 mL gadopentetate dimeglumine was followed with 15 mL saline, both at 2 mL/sec, during axial turbo fast low-angle shot imaging (11/4.2/300 [inversion time ¿msec¿], with a 15 degrees flip angle); one image was obtained every 2 seconds for 60 seconds. Aortic signal-to-noise ratios (S/Ns) and contrast-to-noise ratios (C/Ns) were determined on images obtained in the two groups.
  
  
  RESULTS
  In the timing examinations, aortic S/N increased significantly (902% +/- 517 [P < .001]) and was sufficient to help determine the timing of arterial enhancement. Findings on experimental images were superior to those on control images (S/N, 29.8 vs 20.5 [P = .003]; C/N, 23.8 vs 12.8 [P < .001], respectively). The time to perform procedures and calculations at the timing examination added a mean of 4.5 minutes to each examination.
  
  
  CONCLUSIONS
  The combined use of a power injector and a timing examination improved S/Ns and C/Ns at breath-hold single-dose gadolinium-enhanced 3D MR aortography.
authors.affiliation: Department of Radiology, New York University Medical Center, NY 10016, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Earls
authors.forename: N M
authors.initials: NM
authors.lastname: Rofsky
authors.forename: D R
authors.initials: DR
authors.lastname: DeCorato
authors.forename: G A
authors.initials: GA
authors.lastname: Krinsky
authors.forename: J C
authors.initials: JC
authors.lastname: Weinreb
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta; D003287:Contrast Media; D004338:Drug Combinations; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D009942:Organometallic Compounds; D004369:Pentetic Acid / Q000031:analogs & derivatives*; D013997:Time Factors
chemical_list: D003287:Contrast Media; D004338:Drug Combinations; D009942:Organometallic Compounds; D008536:Meglumine; D004369:Pentetic Acid; D019786:Gadolinium DTPA