@misc{oai:repo.qst.go.jp:00077106,
 author = {Hirose, Ayana and Shibasaki, Jun and Tomiyasu, Moyoko and Kumaki, Tatsuro and Tsuyusaki, Yu and Goto, Tomohide and Aida, Noriko and Tomiyasu, Moyoko and Aida, Noriko},
 month = {May},
 note = {Introduction: In nonketotic hyperglycinemia (NKH), 1H-MRS shows a striking increase in brain glycine levels. However, the signal overlap of glycine with myo-inositol makes it difficult to quantify each metabolite separately. Our aim was to investigate glycine measurement with 1H-MRS using different echo times (TE) in a neonate with NKH. 
Methods: Serial single-voxel 1H-MRS in the centrum semiovale was performed with TE of 30 and 270ms in a neonate with NKH on 6, 19, 44 days of age, and the peak area ratios of glycine plus myo-inositol to creatine ((Gly+mIns)/Cr) was evaluated. Glycine levels of plasma and cerebral spinal fluid (CSF) were also measured on 5, 19, and 44 days of ages. 
Results: In both TEs, (Gly+mIns)/Cr showed higher values at first, then decreased subsequently; TE 30msec: 1.43, 1.19, and 1.11, TE 270 msec: 1.05, 0.55, and 0.49, respectively. Both glycine levels of plasma and CSF showed similar decreasing: plasma: 1803.9, 353.0, and 140.0 μmol/L, CSF: 321.6, 135.3, and 69.7 μmol/L, respectively. On 6 days, the patient was comatose, and had no spontaneous respiration. On 19 days, he was lethargic but had spontaneous respirations. On 44 days, his consciousness was almost clear.
Conclusion: The continuing reduction of (Gly+mIns)/Cr with long-TE corresponded more reliably with glycine levels of plasma and CSF than the change with short-TE. In addition to T2 relaxation time effect, myo-inositol also has J-coupling induced-dephasing effect, which results in small signal in long TE. Therefore myo-inositol signal may have a relatively less contribution to (Gly+mIns) in TE 270ms., The 20th Annual Meeting of Infantile Seizure Society (ISS)},
 title = {Glycine measurement using short and long echo time  proton magnetic resonance spectroscopy in a neonate with nonketotic hyperglycinemia},
 year = {2019}
}