Reproducibility of brain MRS in older healthy adults at 7T

• Published in: NMR in biomedicine Vol. 32; no. 2; pp. e4040 - n/a
• Main Authors: Wijtenburg, S. Andrea, Rowland, Laura M., Oeltzschner, Georg, Barker, Peter B., Workman, Clifford I., Smith, Gwenn S.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.02.2019
• Subjects: 7 T; Adults; Aged; Aged, 80 and over; anterior cingulate cortex; Biological products; Brain; Brain - diagnostic imaging; Coefficient of variation; Creatine - metabolism; Data acquisition; Disease control; Feasibility studies; Female; Gyrus Cinguli - metabolism; Humans; Localization; Magnetic Resonance Spectroscopy; Male; Mathematical analysis; Medical treatment; Metabolites; Metabolome; Middle Aged; MRS; older adults; Older people; posterior cingulate cortex; Reproducibility; Reproducibility of Results; Steam; γ-Aminobutyric acid; older adults; 7 T; posterior cingulate cortex; reproducibility; anterior cingulate cortex; MRS
• ISSN: 0952-3480; 1099-1492; 1099-1492
• DOI: 10.1002/nbm.4040

To date, the majority of MRS reproducibility studies have been conducted in healthy younger adults, with only a few conducted in older adults at 3 T. With the growing interest in applying MRS methods to study the longitudinal course and effects of treatments in neurodegenerative disease, it is important to establish reproducibility in age‐matched controls, especially in older individuals. In this study, spectroscopic data were acquired using a stimulated echo acquisition mode (STEAM) localization technique in two regions (anterior and posterior cingulate cortices—ACC, PCC, respectively) in 10 healthy, cognitively normal older adults (64 ± 8.1 years). Reproducibility was assessed via mean coefficients of variation (CVs) and relative differences (RDs) calculated across two visits performed 2–3 months apart. Metabolites with high signal‐to‐noise ratio (SNR) such as NAA, tCho, and Glu had mean CVs of 10% or less and mean RDs of 15% or less across both regions. Metabolites with lower SNR such as GABA and Gln had slightly higher mean CVs of 22% or less and mean RDs of 27% or less across both regions. These results demonstrate the feasibility of acquiring MRS data at 7 T in older subjects, and establish that the spectroscopic data are reproducible in both the ACC and PCC in older, healthy subjects to the same extent as in previous studies in young subjects. MRS data were acquired in the anterior and posterior cingulate cortices in 10 healthy older adults at 7T. Reproducibility was assessed across two visits via mean coefficients of variation (CVs) and relative differences (RDs). High signal to noise ratio (SNR) metabolites had mean CVs ≤ 10% and RDs ≤ 15% compared with low SNR metabolites, which had slightly higher mean CVs and RDs. These results demonstrate the feasibility of acquiring MRS data at 7T in older subjects