Rapid, Self-calibrated Parallel Reconstruction for Variable Density Spiral with GROWL

Wei Lin¹, Peter Brnert², Feng Huang¹, George R. Duensing¹, Arne Reykowski¹

A rapid and self-calibrated parallel imaging reconstruction method is proposed for undersampled variable density spiral datasets. A set of Generalized GRAPPA for wider readout line (GROWL) operators are used to expand each acquired spiral line into a wider spiral band, therefore fulfilling Nyquist sampling criterion throughout the k-space. The calibration of GROWL operators is performed using the fully sampled central k-space region. In vivo brain scans demonstrate that the technique can be used either to achieve a significant acceleration and/or to reduce off-resonance artifacts due to shortened readout duration.