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.