title: Time-resolved contrast-enhanced carotid imaging using undersampled projection reconstruction acquisition.
abstract: OBJECTIVE
  To investigate the utility of nonuniform angular spacing of projections in a three-dimensional (3D) hybrid undersampled projection reconstruction (PR) acquisition for contrast-enhanced (CE) time-resolved carotid imaging.
  
  
  METHODS
  Carotid CE magnetic resonance angiography (CE-MRA) was performed on seven healthy volunteers using a time-resolved hybrid sequence that combined undersampled PR acquisition in-plane and Cartesian slice encoding through-plane. The undersampling streak artifact comes mainly from the superior-inferior (S/I) direction in carotid imaging and is suppressed by nonuniform distribution of the projections. Phantom and volunteer studies were performed to demonstrate its efficacy.
  
  
  RESULTS
  The undersampling streak artifact was significantly suppressed through a nonuniform distribution of the projection angles with more projections aligned along the S/I direction. The hybrid PR sequence combined with nonuniform distribution of the projection angles provided time-resolved images of the carotid arteries with high temporal resolution (two seconds per frame) and high spatial resolution (1.0 x 1.0 x 1.5 mm(3)) simultaneously.
  
  
  CONCLUSIONS
  High-resolution dynamic imaging of the carotid arteries is feasible with the use of a hybrid undersampled PR acquisition. Undersampling streak artifact can be suppressed significantly through nonuniform distribution of the projections.
authors.affiliation: Department of Medical Physics and Radiology, University of Wisconsin, Madison, WI, USA. jiangdu@ucsd.edu
authors.forename: Jiang
authors.initials: J
authors.lastname: Du
authors.forename: Sean B
authors.initials: SB
authors.lastname: Fain
authors.forename: Frank R
authors.initials: FR
authors.lastname: Korosec
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Grist
authors.forename: Charles A
authors.initials: CA
authors.lastname: Mistretta
mesh_terms: D000328:Adult; D016477:Artifacts; D002339:Carotid Arteries / Q000033:anatomy & histology*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography / Q000379:methods*; D019047:Phantoms, Imaging
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA