Determination of the optimal imaging parameters of the RODEO pulse sequence by computer simulation

A computer program has been developed for evaluating the NMR signal response of various imaging parameters and its efficiency in fat suppression of the RODEO (ROtating Delivery of Excitation Off-resonance) pulse sequence. Both spoiled and refocused RODEO pulse sequences have been considered. By numerically solving the Bloch equation modified for a three-dimensional volume of spins, for realistic RF excitations and Lorentzian distribution of the frequency spectrum for both fat and water, the program permits the imaging contrast and fat suppression of the RODEO pulse sequences to be assessed quantitatively. We have found that excellent fat suppression can be achieved by choosing appropriate imaging parameters. Imaging contrast for different tissues can be enhanced by using longer repetition time (TR) in the spoiled scheme. The complex pattern of NMR signal response and imaging contrast has been observed in the refocused scheme.