title: Reproducibility of Neurochemical Profile Quantification in Pregenual Cingulate, Anterior Midcingulate, and Bilateral Posterior Insular Subdivisions Measured at 3 Tesla.
abstract: The current report assessed measurement reproducibility of proton magnetic resonance spectroscopy at 3 Tesla in the left and right posterior insular, pregenual anterior cingulate, and anterior midcingulate cortices. Ten healthy male volunteers aged 21-30 years were tested at four different days, of which nine were included in the data analysis. Intra- and inter-subject variability of myo-inositol, creatine, glutamate, total-choline, total-N-acetylaspartate, and combined glutamine-glutamate were calculated considering the influence of movement parameters, age, daytime of measurements, and tissue composition. Overall mean intra-/inter-subject variability for all neurochemicals combined revealed small mean coefficients of variation across the four regions: 5.3/9.05% in anterior midcingulate, 6.6/8.84% in pregenual anterior cingulate, 7.3/10.00% in left posterior and 8.2/10.55% in right posterior insula. Head movement, tissue composition and day time revealed no significant explanatory variance contribution suggesting a negligible influence on the data. A strong correlation between Cramer-Rao Lower Bounds (a measure of fitting errors) and the mean intra-subject coefficients of variation (r = 0.799, p < 0.001) outlined the importance of low fitting errors in order to obtain robust and finally meaningful measurements. The present findings confirm proton magnetic resonance spectroscopy as a reliable tool to measure brain neurochemistry in small subregions of the human brain.
authors.affiliation: Center of Dental Medicine, University of ZurichZurich, Switzerland; Institute for Complementary and Integrative Medicine, University Hospital Zurich and University of ZurichZurich, Switzerland.
authors.forename: Nuno M P
authors.initials: NM
authors.lastname: de Matos
authors.affiliation: Seminar for Statistics, ETH Zurich Zurich, Switzerland.
authors.forename: Lukas
authors.initials: L
authors.lastname: Meier
authors.affiliation: Institute for Biomedical Engineering, University of Zurich and ETH Zurich Zurich, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Wyss
authors.affiliation: Institute for Biomedical Engineering, University of Zurich and ETH Zurich Zurich, Switzerland.
authors.forename: Dieter
authors.initials: D
authors.lastname: Meier
authors.affiliation: Institute of Radiology and Nuclear Medicine, Hirslanden Hospital St. Anna Lucerne, Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Gutzeit
authors.affiliation: Center of Dental Medicine, University of Zurich Zurich, Switzerland.
authors.forename: Dominik A
authors.initials: DA
authors.lastname: Ettlin
authors.affiliation: Center of Dental Medicine, University of ZurichZurich, Switzerland; Institute for Biomedical Engineering, University of Zurich and ETH ZurichZurich, Switzerland.
authors.forename: Mike
authors.initials: M
authors.lastname: Brügger
keywords: anterior midcingulate; functional homogeneity; posterior Insula; pregenual cingulate; proton magnetic resonance spectroscopy; region-specific neurochemistry; reproducibility; structural homogeneity