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 re sponse of various imaging parameters and its efficiency in fat suppres sion of the RODEO (ROtating Delivery of Excitation Off-resonance) puls e 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 Lo rentzian 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 tha t excellent fat suppression can be achieved by choosing appropriate im aging parameters. Imaging contrast for different tissues can be enhanc ed by using longer repetition time (TR) in the spoiled scheme. The com plex pattern of the NMR signal response and imaging contrast has been observed in the refocused scheme.