Optimizing the Net Acceleration of GRAPPA and PEAK-GRAPPA

Simon Bauer¹, Michael Markl¹, Bernd Andre Jung¹

Many parallel imaging methods measure additional phase encoding lines for autocalibration of the reconstruction parameters to the coil sensitivities. This leads to a reduction of the net acceleration of the measurement. The aim of this work was to systematically evaluate trade-offs between undersampling factor and number of calibration lines for a given net acceleration for GRAPPA and PEAK-GRAPPA. Analysis was performed for in-vivo cardiac imaging and using a specially designed moving phantom. Optimal results regarding RMSE and noise were provided by the reconstructions using the smallest possible undersampling factor and number of calibration lines.