MR fluoroscopy using projection reconstruction multi-gradient-echo (prMGE)MRI

A projection reconstruction multi-gradient-echo (prMGE) technique is presen ted. The introduced technique is an extension of a standard projection reco nstruction steady-state gradient-echo technique allowing for the acquisitio n of several gradient echoes after each excitation of the spin system. Each echo train is used for acquiring data of a certain angular segment of k-sp ace. By use of echo trains consisting of up to four echoes, the overall acq uisition time for a 128(2) image can be reduced to 150 ms without sacrifici ng image quality. Results are presented for cardiac fluoroscopy, for the vi sualization of swallowing, and for the visualization of joint motion. For a ll investigated applications promising results have been obtained. Especial ly in parts of the body where motion on an even shorter time scale than the acquisition process or significant in-plane or through-plane flow are with in the field of view, the introduced technique appears to be a promising te chnique for MR fluoroscopy. Magn Reson Med 42:324-334, 1999. (C) 1999 Wiley -Liss, Inc.