GRAPPA operator for wider radial bands (GROWL) with optimally regularized self-calibration
✍ Scribed by Wei Lin; Feng Huang; Yu Li; Arne Reykowski
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 778 KB
- Volume
- 64
- Category
- Article
- ISSN
- 0740-3194
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✦ Synopsis
Abstract
A self‐calibrated parallel imaging reconstruction method is proposed for azimuthally undersampled radial dataset. A generalized auto‐calibrating partially parallel acquisition (GRAPPA) operator is used to widen each radial view into a band consisting of several parallel lines, followed by a standard regridding procedure. Self‐calibration is achieved by regridding the central k‐space region, where Nyquist criterion is satisfied, to a rotated Cartesian grid. During the calibration process, an optimal Tikhonov regularization factor is introduced to reduce the error caused by the small k‐space area of the self‐calibration region. The method was applied to phantom and in vivo datasets acquired with an eight‐element coil array, using 32‐64 radial views with 256 readout samples. When compared with previous radial parallel imaging techniques, GRAPPA operator for wider radial bands (GROWL) provides a significant speed advantage since calibration is carried out using the fully sampled k‐space center. A further advantage of GROWL is its applicability to arbitrary‐view angle ordering schemes. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.