https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24868 Wed 11 Apr 2018 16:46:08 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:21275 in vivo brain magnetic resonance spectroscopy biomarkers is investigated with respect to parameter values for two key stages of post-acquisitional processing. Our effort is specifically motivated by the lack of consensus on approaches and parameter values for the two critical operations, water resonance removal, and baseline correction. The different stages of data processing also introduce varying levels of uncertainty and arbitrary selection of parameter values can significantly underutilize the intrinsic differences between two classes of signals. The sensitivity of biomarkers points to the need for a better understanding of how all stages of post-acquisitional processing affect biomarker discovery and ultimately, clinical translation. Our results also highlight the possibility of optimizing biomarker discovery by the careful selection of parameters that best reveal class differences. Using previously reported data and biomarkers, our results demonstrate that small changes in parameter values affect the statistical significance and corresponding effect size of biomarkers. Consequently, it is possible to increase the strength of biomarkers by selecting optimal parameter values in different spectral intervals. Our analyses with a previously reported data set demonstrate an increase in effect sizes for wavelet-based biomarkers of up to 36%, with increases in classification performance of up to 12%.]]> Wed 11 Apr 2018 12:19:42 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:27129 in-vivo measurement of brain biochemistry. The objective of this study was to explore the effects of a commercial energy drink (ED) on brain metabolites in adult males using MRS. Methods: Ten males (18 to 30 years), of mean body mass index 23.8±2.2 kg/m² [range 21.4-27.8 kg/m²] were recruited and randomized to either the intervention group (n=5) or control group (n=5). The intervention group were asked to consume two 250ml cans of Red Bull and the control group consumed no drink. One dimensional MRS on a 1.5T Achieva MRI scanner was obtained of bi-occipital gray matter. Subjects were placed in the scanner and a spectrum acquired every 5.75 minutes for 60 minutes. Linear mixed models were generated to determine the main effects due to differences between groups and times and the interaction. Results: There was a significant group by time effect for N-acetylaspartate (NAA) (P= .02, d= 0.7) and a statistical trend for macromolecule 20 (MM20) (P= .06 d= 0.1) with the control group having higher concentrations than that of the intervention. Mean differences from baseline to 45 minutes for NAA in the intervention group were -0.8 mM (-12%) compared with 0.15 mM (<1%) for control and for MM20 -0.12 mM (<1%) in the intervention group compared with 0.03 mM (<1%) for control. Conclusions: Consumption of two cans of ED was found to produce few changes in brain metabolites with moderate effect sizes. Changes detected in this study demonstrate the sensitivity of the MRS method to explore nutrition related variables with 1.5T clinical MRI unit. The study provides some insight into an understudied, topical area of research.]]> Wed 11 Apr 2018 12:09:41 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:41391 Tue 02 Aug 2022 17:47:20 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24016 Thu 04 Nov 2021 10:39:04 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:20840 Sat 24 Mar 2018 08:05:57 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:25640 Sat 24 Mar 2018 07:28:09 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34385 Mon 23 Sep 2019 12:19:25 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:42377 Mon 22 Aug 2022 14:29:24 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:40208 Mon 01 Aug 2022 09:10:25 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47224 Fri 16 Dec 2022 10:37:25 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47876 0.12). in vivo results showed statistically significant diurnal variations (P ≤ 0.05, F > 3.88) for 22 resonances. Bonferroni post-hoc testing showed there was statistically significant increases in metabolite ratios between 0700 and 1700 and these include different moieties of N-acetylaspartate, creatine, choline, myo-inositol, lipids, fucose, glutathione, and homocarnosine. Data Conclusion: 2D L-COSY can detect diurnal physiological variability in neuro-metabolite levels. Thus, time of the day should be considered when planning MRS studies to avoid confounding results. Level of Evidence: 1. Technical Efficacy Stage: 1.]]> Fri 03 Feb 2023 15:17:52 AEDT ]]>