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Effect of windowing and zero‐filled reconstruction of MRI data on spatial resolution and acquisition strategy
Author(s) -
Bernstein Matt A.,
Fain Sean B.,
Riederer Stephen J.
Publication year - 2001
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.1183
Subject(s) - interpolation (computer graphics) , ellipse , image resolution , imaging phantom , data acquisition , sampling (signal processing) , physics , resolution (logic) , k space , zero (linguistics) , voxel , boundary (topology) , geometry , iterative reconstruction , algorithm , optics , mathematical analysis , computer science , computer vision , mathematics , artificial intelligence , fourier transform , motion (physics) , linguistics , philosophy , detector , operating system
Standard, MR spin‐warp sampling strategies acquire data on a rectangular k‐space grid. That method samples data from the “corners” of k‐space, i.e., data that lie in a region of k‐space outside of an ellipse just inscribed in the rectangular boundary. Illustrative calculations demonstrate that the data in the corners of k‐space contribute to the useful resolution only if an interpolation method such as a zero‐filled reconstruction is used. The consequences of this finding on data acquisition and data windowing strategies are discussed. A further implication of this result is that the spatial resolution of images reconstructed with zero‐filling (but without radial windowing) is expected to display angular dependence, even when the phase‐ and frequency‐encoded resolutions are identical. This hypothesis is experimentally verified with a slit geometry phantom. It is also observed that images reconstructed without zero‐filling do not display the angular dependence of spatial resolution predicted solely by the maximal k‐space extent of the raw data. The implications of these results for 3D contrast‐enhanced angiographic acquisitions with elliptical centric view ordering are explored with simulations. J. Magn. Reson. Imaging 2001;14:270–280. © 2001 Wiley‐Liss, Inc.