Exact Noise Maps and g-Factor in GRAPPA using a k–space Analysis
This code allows to exactly characterize the noise noise in GRAPPA (GeneRalized Autocalibrating Partial Parallel Acquisition) acquisitions with non-uniform undersampling patterns by a noise propagation analysis that operates directly in k–space. We exploit the extensive symmetries and separability into independent blocks in the reconstruction steps to take into account the correlation between all the acquired k–space samples. The code includes a script to reproduce the figures in .
 Iñaki Rabanillo, Santiago Aja-Fernández, Carlos Alberola-López and Diego Hernando (2017), "Exact Calculation of Noise Maps and g-Factor in GRAPPA using a k-space Analysis". submitted toMagn Reson Med. arXiv:1610.07843