Prior to patient measurements, phantom measurements were performed at 7 T. The “Braino”-phantom (General-Electric, USA) was used with the following metabolite concentrations: 5 mM NAA (N-Acetyl-l-aspartic acid), 10 mM of Cr (creatine), 3 mM of Cho (choline chloride), 7.5 mM of mI (Myo-inositol), 12.5 mM of Glu (l-glutamic acid; the ionic form known as glutamate), and 5 mM of Lac (l-Lactic acid). Spherical 2HG-phantom consisted of a pH-7 buffered solution of 7.8 mM of 2HG and 18 mM of glycine.