Chemical shift imaging with spectrum modeling

A new chemical shift imaging technique was developed to efficiently obtain separate images for multiple chemical shift peaks from a set of spin-echo acquisitions. Information from localized NMR spectroscopy was used to model the chemical shift spectrum as sharp peaks with known resonance frequencies but unknown amplitudes. Based on this model, a set of spin-echo images with shifted 180 degrees RF pulses were acquired, in which the magnetization vectors of different chemical components were put into different directions. The amplitudes of the chemical shift peaks were obtained by solving nonlinear equations in a region-growing process. Experimental results on an ethanol phantom as well as a subject with silicone breast implants are presented. Magn Reson Med 46:126-130, 2001.