title: Improved vessel delineation in keyhole time-resolved contrast-enhanced MR angiography using a gadolinium doped flush.
abstract: OBJECTIVE
  To prospectively assess the influence of a gadolinium doped saline flush compared with a pure saline flush on the image quality of the supra-aortic vessels using time-resolved contrast-enhanced MR angiography (4D CE-MRA) in a randomized double blind clinical trial.
  
  
  METHODS
  Twenty-two patients scheduled for contrast-enhanced craniocerebral MRI underwent a supplemental 4D CE-MRA covering the carotids to the superior sinus consisting of 30 dynamics of a T1-weighted 3D gradient-echo sequence (FFE) in sagittal direction. The temporal resolution of 1.1 s per dataset was achieved using the keyhole technique with the reference scan acquired at the end. Immediately after the intravenous (IV) injection of 0.1 mmol Gd/kg body weight of gadoterate, our patients received a 50-mL flush consisting either of a 0.9% saline solution (n = 11) or doped with 50 mM gadolinium (n = 11; total Gd: 0.11 mmol/kg) at a flow-rate of 2 mL/s. Vessel delineation, image quality, signal-to-noise- (SNR) and contrast-to-noise (CNR) ratios over time were compared.
  
  
  RESULTS
  Both vessel delineation (internal carotid artery [ICA]: slope(saline) = 308.5; slope(Gd) = 528.9; P = 0.006; superior sagittal sinus [SSS]: slope(saline) = 505.3; slope(Gd) = 674.9; P = 0.007) and CNR (ICA: CNR(saline) = 57.3; CNR(Gd) = 80.55; P = 0.0417; SSS: CNR(saline) = 74.15; CNR(Gd) = 117.4; P = 0.0331) of the ICA and SSS were significantly increased using the gadolinium doped flush.
  
  
  CONCLUSIONS
  A low concentrated gadolinium flush in comparison to a pure saline flush improves significantly vessel contrast and their delineation in time-resolved CE-MRA using the keyhole technique.
authors.affiliation: Cantonal Hospital, Department of Radiology, Winterthur, Switzerland.
authors.forename: Jan
authors.initials: J
authors.lastname: Beranek-Chiu
authors.forename: John M
authors.initials: JM
authors.lastname: Froehlich
authors.forename: Klaus U
authors.initials: KU
authors.lastname: Wentz
authors.forename: Alexis N
authors.initials: AN
authors.lastname: Doert
authors.forename: Christoph L
authors.initials: CL
authors.lastname: Zollikofer
authors.forename: Boris P
authors.initials: BP
authors.lastname: Eckhardt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D002339:Carotid Arteries / Q000473:pathology*; D002340:Carotid Artery Diseases / Q000473:pathology*; D003287:Contrast Media; D004311:Double-Blind Method; D005260:Female; D006571:Heterocyclic Compounds / Q000008:administration & dosage*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds / Q000008:administration & dosage*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C050823:gadolinium 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetate