Daniel Rigotti1, Jan Hovener1, Michael Amann2, Peter Bachert3, Achim Gass2, Oded Gonen1
1Radiology, NYU School of Medicine, New York, NY, USA; 2Neurology and Neuroradiology, University Hospital Basel, Basel, Switzerland; 3Division of Medical Physics, German Cancer Research Center, Heidelberg, Germany
Despite its prominent peak in 1H-MRS of the brain and its near exclusivity to neurons, the absolute amount of N-Acetylaspartate (NAA) is difficult to obtain due to signal contamination from skull lipids. Here we report the performance of two methods that overcome this problem to yield the whole-brain NAA signal (WBNAA). WBNAA was obtained from twelve volunteers with both a lipid- and NAA-nulling scheme. Despite being twofold quicker, the lipid-nulling technique had a higher intrinsic (5.8%vs8.6%) and longitudinal (10.6%vs19.7%) coefficient of variation when compared with NAA-nulling. Therefore, when time is critical, lipid-nulling is viable, otherwise, however NAA-nulling is more precise.