Joseph G. Woods1, Divya Bolar1, and Eric C. Wong1
1Department of Radiology, University of California San Diego, San Diego, CA, United States
1Department of Radiology, University of California San Diego, San Diego, CA, United States
We introduce an elliptical shells trajectory with spherically symmetrical sampling density for accelerated single shot FSE based whole brain ASL imaging. This trajectory is faster than a stack of spirals, and is demonstrated in a human subject.
Generation of elliptical shells trajectory. Each spiral is confined to the surface of an ellipsoid of revolution about the Z axis. Ellipsoid i is defined by axes Kzmaxi and Kxymaxi. The dimensions of the voronoi patch are dkr*dkθ, as shown. For a given set of Kzmax and Kxymax, dkr is determined by the local geometry of the elliptical shells, and the spiral pitch dkθ is adjusted to produce a voronoi patch of the desired area for the local sampling density (see text).
PCASL difference images from the two
trajectories shown in Figure 2, as well as a fully sampled segmented
stack of spiral acquisition.
