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- Title
Efficient k-space sampling by density-weighted phase-encoding.
- Authors
Andreas Greiser; Markus von Kienlin
- Abstract
Acquisition-weighting improves the localization of MRI experiments. An approach to acquisition-weighting in a purely phase-encoded experiment is presented that is based on a variation of the sampling density in k-space. In contrast to conventional imaging or to accumulation-weighting, where k-space is sampled with uniform increments, density-weighting varies the distance between neighboring sampling points Δk to approximate a given radial weighting function. A fast, noniterative algorithm has been developed to calculate the sampling matrix in one, two, and three dimensions from a radial weighting function w(k), the desired number of scans NAtot and the nominal spatial resolution Δxnom. Density-weighted phase-encoding combines the improved shape of the spatial response function and the high SNR of acquisition-weighting with an extended field of view. The artifact energy that results from aliasing due to a small field of view is substantially reduced. The properties of density-weighting are compared to uniform and to accumulation-weighted phase-encoding in simulations and experiments. Density-weighted 31P 3D chemical shift imaging of the human heart is shown which demonstrates the superior performance of density-weighted metabolic imaging. Magn Reson Med 50:12661275, 2003. © 2003 Wiley-Liss, Inc.
- Subjects
BRAIN physiology; HEART metabolism; MEDICAL imaging systems; MAGNETIC resonance imaging; METABOLISM
- Publication
Magnetic Resonance in Medicine, 2003, Vol 50, Issue 6, p1266
- ISSN
0740-3194
- Publication type
Article
- DOI
10.1002/mrm.10647