Fat and water separation in balanced steady-state free precession using the Dixon method.
In this work the feasibility of separating fat and water signals using the balanced steady-state free precession (SSFP) technique is demonstrated. The technique is based on the observation (Scheffler and Hennig, Magnetic Resonance in Medicine 2003;49:395-397) that at the nominal values of TE = TR/2 in SSFP imaging, phase coherence can be achieved at essentially only two orientations (0 degrees and 180 degrees ) relative to the RF pulses in the rotating frame, under the assumption of TR << T2, and independently of the SSFP angle. This property allows in-phase and out-of-phase SSFP images to be obtained by proper choices of the center frequency offset, and thus allows the Dixon subtraction method to be utilized for effective fat-water separation. The TR and frequency offset for optimal fat-water separation are derived from theories. Experimental results from healthy subjects, using a 3.0 Tesla system, show that nearly complete fat suppression can be accomplished.
Huang
Teng-Yi
TY
Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan, ROC.
Chung
Hsiao-Wen
HW
Wang
Fu-Nien
FN
Ko
Cheng-Wen
CW
Chen
Cheng-Yu
CY
D000005:Abdomen / Q000033:anatomy & histology; D000273:Adipose Tissue / Q000033:anatomy & histology*; D000328:Adult; D001834:Body Water; D005240:Feasibility Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*