Changho Choi1, Deborah Douglas1, Aditya Patel1, Ivan Dimitrov1,2
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States; 2Philips Medical Systems, Dallas, OH, United States
A proton MRS strategy for detection of serine (Ser) in human brain at 3T is proposed. Spectral difference of multiplet at different subecho times of triple refocusing at a constant total echo time was utilized to measure Ser and cancel the overlapping creatine (Cr) 3.92-ppm singlet via subtraction. A 50-ms non-spatially selective 180 RF pulse was applied between the 180 pulses of a PRESS sequence. A pair of subecho time sets, (TE1, TE2, TE3) = (70, 50, 135) and (35, 135, 85) ms, was obtained from density-matrix simulations. An in vivo test of this difference editing was conducted on the occipital cortex of a healthy adult brain. From spectral fitting of sub- and difference-spectra by LCModel, the serine to N-acetylaspartate concentration ratio was estimated as 0.05.