Time-resolved contrast-enhanced carotid imaging using undersampled projection reconstruction acquisition.
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.
Du
Jiang
J
Department of Medical Physics and Radiology, University of Wisconsin, Madison, WI, USA. jiangdu@ucsd.edu
Fain
Sean B
SB
Korosec
Frank R
FR
Grist
Thomas M
TM
Mistretta
Charles A
CA
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
D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA