Increased Detectability of Alpha Brain Glutamate/Glutamine in Neonatal Hypoxic-Ischemic Encephalopathy
Yonglin Pu
,a,
Qing-Feng Lia,
Chao-Mei Zenga,
Jian Gaoa,
Jing Qia,
De-Xin Luoa,
Srikanth Mahankalia,
Peter T. Foxa and
Jia-Hong Gaoa
a From The People's Hospital of The Beijing Medical University, Beijing, The People's Republic of China (Y.P., Q-F.L., C-M.Z., J.G., J.Q., D-X.L.), and Research Imaging Center, University of Texas Health Science Center, San Antonio, TX (Y.P., S.M., P.T.F., J-H.G.).
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FIG 1. Axial T2-weighted fast spin-echo MR image (4400/96eff/1) shows spectral volume in the neonatal brain that was chosen for the study
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FIG 2. A and B, Brain proton MRS in a healthy neonate obtained at 4 days of age. Both PRESS (2000/135/250) (A) and STEAM (2000/24/250) (B) proton MRS studies show the peaks of NAA at 2.0 ppm, ß- and  -Glx at 2.0 to 2.5 ppm, Cho at 3.2 ppm, (Cr + PCr) at 3.02 and 3.90 ppm, and M-Ino at 3.5 ppm. There is a barely visible peak of  -Glx at 3.75 ppm. The peaks of Lac + Lipid at 0.75 to 1.75 ppm are visible on STEAM proton MRS study. NAA indicates N-acetylaspartate; ß- and -Glx, ß- and -CH2 protons of Glx; Cr + PCr, creatine and phosphocreatine; Cho, choline-containing compounds; M-Ino, myo-inositol; -Glx, -CH protons of Glx; Lac + Lipid, lactate and lipid
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FIG 3. Initial and follow-up brain proton MRS studies in a neonate with mild HIE performed at 3 and 13 days of age, respectively. The peaks of NAA, Cho, (Cr + PCr), and M-Ino are clearly visible in all the MRS studies.
A, Initial PRESS proton MRS study (2000/135/250) shows a barely visible peak of -Glx at 3.75 ppm.
B, Initial STEAM proton MRS study (2000/24/250) shows the apparent peak of -Glx at 3.75 ppm.
C, Follow-up PRESS proton MRS study (2000/135/250) shows no apparent changes as compared with the initial PRESS proton MRS study.
D, Follow-up STEAM proton MRS study (2000/24/250) shows the decrease in the heights of the peaks of -Glx at 3.75 ppm and M-Ino at 3.5 ppm as compared with those on the initial STEAM proton MRS. There are no apparent changes in the heights of the other peaks. For abbreviations, see figure 1.
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FIG 4. Initial and follow-up brain proton MRS studies in a neonate with moderate HIE performed at 4 and 15 days of age, respectively. The peaks of NAA, Cho, and (Cr + PCr) are clearly visible in all the MRS studies. M-Ino is clearly visible in both the initial and follow-up STEAM proton MRS studies, but is only barely seen on the PRESS proton MRS studies.
A, Initial PRESS proton MRS study (2000/135/250) shows an apparent -Glx peak at 3.75 ppm.
B, Initial STEAM proton MRS study (2000/24/250) shows a remarkable -Glx peak.
C and D, Follow-up PRESS (2000/135/250) (C) and STEAM (2000/24/250) (D) proton MRS studies show that the height of the -Glx peak at 3.75 ppm is decreased as compared with that obtained on the initial proton MRS studies with both the PRESS and STEAM proton MRS sequences. Other peaks are similar on both the initial and follow-up PRESS and STEAM proton MRS studies. For abbreviations, see figure 1.
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FIG 5. Initial and follow-up brain proton MRS studies in a neonate with severe HIE performed at 7 and 14 days of age, respectively. The peaks of Cho and (Cr + PCr) are clearly visible in all the MRS studies. The NAA peak is easily detected on PRESS proton MRS. However, in STEAM proton MRS studies, it is not well defined and is decreased in height. M-Ino is clearly visible on both the initial and follow-up STEAM proton MRS studies, but is only barely seen on the PRESS proton MRS studies.
A, Initial PRESS proton MRS study (2000/135/250) shows a high peak of -Glx at 3.75 ppm.
B, Initial STEAM proton MRS study (2000/24/250) shows a remarkable -Glx peak at 3.75 ppm.
C and D, Follow-up PRESS (2000/135/250) (C) and STEAM (2000/24/250) (D) proton MRS studies show that the height of the -Glx peak at 3.75 ppm is decreased compared with that obtained on the initial PRESS and STEAM proton MRS studies. Other peaks are similar on both the initial and follow-up PRESS and STEAM proton MRS studies. For abbreviations, see figure 1.
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