The intra‐individual reliability of ¹H‐MRS measurement in the anterior cingulate cortex across 1 year

Abstract

Magnetic resonance spectroscopy (MRS) is the primary method that can measure the levels of metabolites in the brain in vivo. To achieve its potential in clinical usage, the reliability of the measurement requires further articulation. Although there are many studies that investigate the reliability of gamma‐aminobutyric acid (GABA), comparatively few studies have investigated the reliability of other brain metabolites, such as glutamate (Glu), N‐acetyl‐aspartate (NAA), creatine (Cr), phosphocreatine (PCr), or myo‐inositol (mI), which all play a significant role in brain development and functions. In addition, previous studies which predominately used only two measurements (two data points) failed to provide the details of the time effect (e.g., time‐of‐day) on MRS measurement within subjects. Therefore, in this study, MRS data located in the anterior cingulate cortex (ACC) were repeatedly recorded across 1 year leading to at least 25 sessions for each subject with the aim of exploring the variability of other metabolites by using the index coefficient of variability (CV); the smaller the CV, the more reliable the measurements. We found that the metabolites of NAA, tNAA, and tCr showed the smallest CVs (between 1.43% and 4.90%), and the metabolites of Glu, Glx, mI, and tCho showed modest CVs (between 4.26% and 7.89%). Furthermore, we found that the concentration reference of the ratio to water results in smaller CVs compared to the ratio to tCr. In addition, we did not find any time‐of‐day effect on the MRS measurements. Collectively, the results of this study indicate that the MRS measurement is reasonably reliable in quantifying the levels of metabolites.

A neurometabolic signature in the frontal cortex explains individual differences in effort-based decision-making

“…Of note, while metabolite levels in the brain, including those in the dmPFC/dACC, often exhibit remarkable stability over time [90][91][92] , indicating distinct neuro-metabolic phenotypes 93 , they are still susceptible to change. For example, external factors such as stress can dynamically alter glutamate levels in the prefrontal cortex 80,94 , thereby influencing decision-making processes 95,96 .…”

The within-subject stability of cortical thickness, surface area, and brain volumes across one year

“…Besides the time-of-day effect, the seasonal effect on functional brain organization has recently attracted some attention (M. Y. Wang, Korbmacher, Eikeland, & Specht, 2023b;Zhang, Shokri-Kojori, & Volkow, 2023). Specifically, daylight length comes out as a potential contributor (Di, Woelfer, Kühn, Zhang, & Biswal, 2022) to the functional brain organization (M. Y.…”

“…Specifically, daylight length comes out as a potential contributor (Di, Woelfer, Kühn, Zhang, & Biswal, 2022) to the functional brain organization (M. Y. Wang et al, 2023b). For example, the salience network, one of the resting-state brain networks, is larger when daylight length is short compared to when it is long (M. Y.…”

“…For example, the salience network, one of the resting-state brain networks, is larger when daylight length is short compared to when it is long (M. Y. Wang et al, 2023b). To the best of our knowledge, there is still no study investigating the daylight length effect on brain structure.…”

Editorial: Variability and reproducibility of brain imaging

“…Widely used in clinical settings (Oz et al, 2014 ), MRS has recently been applied to identify IDH-mutated gliomas (Branzoli and Marjanska, 2020 ) and explore the association between behavior and MRS-derived neurotransmitters (Li et al, 2022 ). It is suggested that the MRS-derived metabolite estimates are reliable within the participants (Wang et al, 2024 ). In large-scale clinical studies, a multi-site/vendor design is often favored to achieve the necessary statistical power.…”