title: Intraarterial gadolinium-enhanced 2D and 3D MR angiography: a preliminary study.
abstract: OBJECTIVE
  To evaluate, in phantom and canine models, intraarterial gadolinium-enhanced two-dimensional (2D) and three-dimensional (3D) magnetic resonance angiography (MRA).
  
  
  METHODS
  The in vitro experiments examined gadodiamide solutions ranging in gadolinium (Gd) concentration from 0.1% to 100%. A spoiled gradient-recalled echo (SPGR) sequence was used with various repetition time/echo time (TR/TE) parameters. Signal was measured to determine which concentration yielded the highest signal. For in vivo experiments, pigtail catheters were placed in the abdominal aortae of two dogs. Intraarterial injections of 20-30 mL of 0.5%-25% Gd solutions were performed. We acquired images with use of 2D and 3D SPGR techniques. Depiction of the abdominal aortae and renal vessels was assessed qualitatively and quantitatively.
  
  
  RESULTS
  Phantom experiments demonstrated that a 2%-6% solution of Gd produced the highest MR signal, depending on the imaging parameters. In the canine model, a 2% Gd solution was best for 2D techniques, whereas 7%-14% Gd solutions were optimal for 3D techniques.
  
  
  CONCLUSIONS
  Intraarterial contrast material-enhanced 2D and 3D MRA can be successfully implemented with use of dilute Gd. Dilution permits the administration of more intraarterial injections per day, without exceeding the dose limit, compared with intravenous Gd-enhanced MRA. Intraarterial injections also limit scan synchronization and contrast material dispersion issues. This technique may have application in MR-guided endovascular procedures.
authors.affiliation: Department of Radiology, University of Wisconsin- Madison Medical School, 53792-3252, USA. raomary@facstaff.wisc.edu
authors.forename: R A
authors.initials: RA
authors.lastname: Omary
authors.forename: R
authors.initials: R
authors.lastname: Frayne
authors.forename: O
authors.initials: O
authors.lastname: Unal
authors.forename: T M
authors.initials: TM
authors.lastname: Grist
authors.forename: C M
authors.initials: CM
authors.lastname: Strother
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000033:anatomy & histology; D017536:Carotid Artery, Common / Q000033:anatomy & histology; D003287:Contrast Media; D004285:Dogs; D005240:Feasibility Studies; D019786:Gadolinium DTPA; D007089:Image Enhancement / Q000379:methods*; D007269:Injections, Intra-Arterial; D018810:Magnetic Resonance Angiography; D019047:Phantoms, Imaging; D012077:Renal Artery / Q000033:anatomy & histology
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA