“…Later work suggested that other brain constituents having N-acetyl moieties (e.g., N-acetylaspartylglutamate), also contribute to signal intensity in this region of the spectrum (5,6). Published evidence also shows that glutamate, glutamine, and various macromolecular constituents contribute to this spectral region (4,(7)(8)(9)(10)(11)(12), although it is unlikely that these latter signals are present in long echo time spectra, of the sort we present here, due to T, and J-modulation losses (12). Despite the controversy, most investigators accept the notion that NAA is a major contributor to the 2.02 ppm signal.…”