CHEMICAL-SHIFT IMAGING OF HUMAN BRAIN - AXIAL, SAGITTAL, AND CORONAL P-31 METABOLITE IMAGES

Multivoxel magnetic resonance (MR) spectroscopy and novel data analysis techniques were developed to obtain high-quality phosphorus-31 metabolite images from the human brain and to overlay each metabolite distribution directly onto corresponding hydrogen-1 MR images. The P-31 MR spectroscopic data were acquired by means of three-dimensional chemical shift imaging (phase encoding in three spatial dimensions) on a 1.5-T clinical instrument equipped with a specially designed quadrature P-31 birdcage coil constructed in the authors' laboratory. Axial, sagittal, and coronal metabolite images based on the area for any one of five peak regions (phosphodiester; phosphocreatine; gamma, alpha, and beta adenosine triphosphate) were generated from 8 X 8 X 8 or 12 X 12 X 8 CSI arrays with voxel sizes of 27 cm3 and 12 cm3, respectively. The positions of these images were aligned with anatomic features by means of the voxel-shifting capability of the Fourier transform. Direct overlays of these metabolite images on corresponding proton images demonstrated excellent correlation with anatomy, factors indicating the utility of this technique for viewing P-31 metabolite levels in all areas of the brain simultaneously.