PURPOSE: The Dixon techniques provide uniform water-fat separation but require multiple image sets, which extend the overall acquisition time. Here, an alternative rapid single acquisition method, lipid elimination with an echo-shifting N/2-ghost acquisition (LEENA), was introduced. METHODS: The LEENA method utilized a fast imaging with steady-state free precession sequence to obtain a single k-space dataset in which successive k-space lines are acquired to allow the fat magnetization to precess 180°. The LEENA data were then unghosted using either image-domain (LEENA-S) or k-space domain (LEENA-G) parallel imaging techniques to reconstruct water-only and fat-only images. An off-resonance correction technique was incorporated to improve the uniformity of the water-fat separation. RESULTS: Uniform water-fat separation was achieved for both the LEENA-S and LEENA-G methods for phantom and human body and leg imaging applications at 1.5T and 3T. The resultant water and fat images were qualitatively similar to conventional 2-point Dixon and fat-suppressed images. CONCLUSION: The LEENA-S and LEENA-G methods provide uniform water and fat images from a single MRI acquisition. These straightforward methods can be adapted to 1.5T and 3T clinical MRI scanners and provide comparable fat/water separation with conventional 2-point Dixon and fat-suppression techniques.
PURPOSE: The Dixon techniques provide uniform water-fat separation but require multiple image sets, which extend the overall acquisition time. Here, an alternative rapid single acquisition method, lipid elimination with an echo-shifting N/2-ghost acquisition (LEENA), was introduced. METHODS: The LEENA method utilized a fast imaging with steady-state free precession sequence to obtain a single k-space dataset in which successive k-space lines are acquired to allow the fat magnetization to precess 180°. The LEENA data were then unghosted using either image-domain (LEENA-S) or k-space domain (LEENA-G) parallel imaging techniques to reconstruct water-only and fat-only images. An off-resonance correction technique was incorporated to improve the uniformity of the water-fat separation. RESULTS: Uniform water-fat separation was achieved for both the LEENA-S and LEENA-G methods for phantom and human body and leg imaging applications at 1.5T and 3T. The resultant water and fat images were qualitatively similar to conventional 2-point Dixon and fat-suppressed images. CONCLUSION: The LEENA-S and LEENA-G methods provide uniform water and fat images from a single MRI acquisition. These straightforward methods can be adapted to 1.5T and 3T clinical MRI scanners and provide comparable fat/water separation with conventional 2-point Dixon and fat-suppression techniques.
Authors: Jingfei Ma; Jong Bum Son; James A Bankson; R Jason Stafford; Haesun Choi; Dustin Ragan Journal: Magn Reson Imaging Date: 2005-11-28 Impact factor: 2.546
Authors: Scott B Reeder; Angel R Pineda; Zhifei Wen; Ann Shimakawa; Huanzhou Yu; Jean H Brittain; Garry E Gold; Christopher H Beaulieu; Norbert J Pelc Journal: Magn Reson Med Date: 2005-09 Impact factor: 4.668
Authors: Peter J Shin; Peder E Z Larson; Martin Uecker; Galen D Reed; Adam B Kerr; James Tropp; Michael A Ohliger; Sarah J Nelson; John M Pauly; Michael Lustig; Daniel B Vigneron Journal: Magn Reson Med Date: 2014-10-08 Impact factor: 4.668