Abstract #2651

Quantitative G-Factor Calculation in K-T-GRAPPA Reconstructions

Rebecca Ramb¹, Christian Binter², Felix A. Breuer³, Gerrit Schultz¹, Maxim Zaitsev¹, Sebastian Kozerke²,⁴, Bernd Jung¹

¹Dept. of Radiology, Medical Physics, University Medical Center, Freiburg, Germany; ²Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland; ³MRB Research Center, Wrzburg, Germany; ⁴Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom

The goal of this work is the analytical quantification of the noise enhancement in k-t-GRAPPA reconstructions from time-resolved k-t-accelerated acquisitions. Image reconstruction in x-f-space by transforming the three-dimensional convolution kernel is explained, the g-factor with respect to temporal frequencies is introduced and the method is validated in in-vivo-data by statistical noise estimation using the pseudo-replica method. In k-t-reconstruction temporal filtering is observed. The g-factor quantification in x-f-space for k-t-GRAPPA further reflects this and thus constitutes a measure for noise enhancement as well as the amount of temporal filtering introduced in the reconstruction process.