title: Time resolved contrast enhanced intracranial MRA using a single dose delivered as sequential injections and highly constrained projection reconstruction (HYPR CE).
abstract: Time-resolved contrast-enhanced magnetic resonance angiography of the brain is challenging due to the need for rapid imaging and high spatial resolution. Moreover, the significant dispersion of the intravenous contrast bolus as it passes through the heart and lungs increases the overlap between arterial and venous structures, regardless of the acquisition speed and reconstruction window. An innovative technique is presented that divides a single dose contrast into two injections. Initially a small volume of contrast material (2-3 mL) is used to acquiring time-resolved weighting images with a high frame rate (2 frames/s) during the first pass of the contrast agent. The remaining contrast material is used to obtain a high resolution whole brain contrast-enhanced (CE) magnetic resonance angiography (0.57 × 0.57 × 1 mm(3) ) that is used as the spatial constraint for Local Highly Constrained Projection Reconstruction (HYPR LR) reconstruction. After HYPR reconstruction, the final dynamic images (HYPR CE) have both high temporal and spatial resolution. Furthermore, studies of contrast kinetics demonstrate that the shorter bolus length from the reduced contrast volume used for the first injection significantly improves the arterial and venous separation.
authors.affiliation: Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53705, USA. yijingwu@wisc.edu
authors.forename: Yijing
authors.initials: Y
authors.lastname: Wu
authors.forename: Kevin
authors.initials: K
authors.lastname: Johnson
authors.forename: Steven R
authors.initials: SR
authors.lastname: Kecskemeti
authors.forename: Kang
authors.initials: K
authors.lastname: Wang
authors.forename: Oliver
authors.initials: O
authors.lastname: Wieben
authors.forename: Beverly L
authors.initials: BL
authors.lastname: Aagaard-Kienitz
authors.forename: Howard
authors.initials: H
authors.lastname: Rowley
authors.forename: Frank R
authors.initials: FR
authors.lastname: Korosec
authors.forename: Charles
authors.initials: C
authors.lastname: Mistretta
authors.forename: Patrick
authors.initials: P
authors.lastname: Turski
mesh_terms: D000465:Algorithms; D002536:Cerebral Arteries / Q000033:anatomy & histology*; D002550:Cerebral Veins / Q000033:anatomy & histology*; D003287:Contrast Media / Q000008:administration & dosage*; D005682:Gadolinium / Q000008:administration & dosage*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007275:Injections, Intravenous; D018810:Magnetic Resonance Angiography / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D005682:Gadolinium