Twisting radial lines with application to robust magnetic resonance imaging of irregular flow.
A problem with magnetic resonance angiograms of vessels containing irregular flow is that flow-induced dephasing can result in voids in the image. These void regions are susceptible to misinterpretation as regions of stenosis or other vessel pathology. Flow-induced dephasing can be minimized by using radial lines to cover k space. However, radial lines provide a very nonuniform, and hence, inefficient, coverage of k space. By twisting the outer portions of the radial trajectories, undistorted images of very rapid and turbulent flow can be obtained with a reasonable number of RF excitations.
Jackson
J I
JI
Magnetic Resonance Systems Research Laboratory, Stanford University, California 94305.
Nishimura
D G
DG
Macovski
A
A
D001783:Blood Flow Velocity; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008433:Mathematics; D008961:Models, Structural