Lipid elimination with an echo-shifting N/2-ghost acquisition (LEENA) MRI

Area of Science:

• Magnetic Resonance Imaging (MRI)
• Medical Imaging Physics

Background:

• Conventional Dixon techniques offer uniform water-fat separation but require extended acquisition times due to multiple image sets.
• There is a need for faster MRI methods that maintain high-quality water-fat separation.

Purpose of the Study:

• Introduce a novel, rapid single acquisition method called lipid elimination with an echo-shifting N/2-ghost acquisition (LEENA).
• Evaluate LEENA's ability to achieve uniform water-fat separation efficiently.

Main Methods:

• LEENA employs a fast imaging with steady-state free precession (FISP) sequence to acquire a single k-space dataset.
• Successive k-space lines are acquired with fat magnetization precessing 180°.
• Image reconstruction utilizes image-domain (LEENA-S) or k-space domain (LEENA-G) parallel imaging with off-resonance correction.

Main Results:

• Uniform water-fat separation was successfully demonstrated using both LEENA-S and LEENA-G.
• The method was validated in phantom, body, and leg imaging at 1.5T and 3T.
• Reconstructed water and fat images were qualitatively comparable to conventional 2-point Dixon and fat-suppressed images.

Conclusions:

• LEENA-S and LEENA-G enable uniform water and fat imaging from a single MRI acquisition.
• These methods are adaptable to 1.5T and 3T clinical scanners.
• LEENA offers comparable water-fat separation to established Dixon and fat-suppression techniques with reduced acquisition time.