31P Spectroscopic Imaging with GRAPPA

¹School of Electrical & Computer Engineering, Purdue University, West Lafayette, IN, USA; ²School of Health Sciences, Purdue University, West Lafayette, IN, USA; ³CEA-NeuroSpin, Gif-sur-Yvette, France; ⁴Department of Radiology, Indiana University School of Medicine, Indianapolis, IN, USA; ⁵Siemens Healthcare, Erlangen, Germany; ⁶Center for Magnetic Resonance Research,, University of Minnesota, USA; ⁷Department of Radiology, Indiana University, USA

Using a novel 8-channel phased-array dual-tuned 31P/1H coil the feasibility of using GRAPPA for accelerating 31P MRSI was tested. Single-slice 31P MRSI with 24x24 phase-encoding steps was acquired on a phantom, artificially undersampled and reconstructed with different GRAPPA acceleration factors. The reconstructed metabolite maps and spectra show acceptable quality and no aliasing artifacts, this showing that 31P MRSI can in principle be combined with parallel imaging. Whether 3D MRSI with large matrix sizes might be a candidate yielding enough SNR in vivo to be acquired with a single average and may benefit from GRAPPA acceleration is currently under investigation.