title: A complex-difference phase-contrast technique for measurement of volume flow rates.
abstract: Magnetic resonance (MR) phase-difference methods work well for measuring volumetric flow rates when the vessel diameter is large compared with the in-plane voxel dimensions. For small vessels (eg, coronary arteries), partial-volume effects introduce substantial errors in the measured volume flow rate. To correctly measure flow rates through a voxel, both the fraction of the voxel containing moving spins and the phase shift imparted to those spins must be known. The authors propose a flow measurement method that combines information obtained with both the complex-difference and phase-difference processing techniques and thereby provides the fractional volume occupied by the moving spins and the phase of those spins. The complex-difference flow map method proposed results in improved accuracy of MR phase-contrast flow measurements in the presence of partial-volume effects.
authors.affiliation: Department of Radiology, University of Wisconsin, Madison, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Polzin
authors.forename: M T
authors.initials: MT
authors.lastname: Alley
authors.forename: F R
authors.initials: FR
authors.lastname: Korosec
authors.forename: T M
authors.initials: TM
authors.lastname: Grist
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: C A
authors.initials: CA
authors.lastname: Mistretta
mesh_terms: D001783:Blood Flow Velocity; D003198:Computer Simulation; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008961:Models, Structural