A complex-difference phase-contrast technique for measurement of volume flow rates.
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.
Polzin
J A
JA
Department of Radiology, University of Wisconsin, Madison, USA.
Alley
M T
MT
Korosec
F R
FR
Grist
T M
TM
Wang
Y
Y
Mistretta
C A
CA
D001783:Blood Flow Velocity; D003198:Computer Simulation; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008961:Models, Structural