Magnetic resonance spectroscopy (MRS) and its application in Alzheimer's disease

Abstract

Magnetic resonance spectroscopy (MRS) is a noninvasive tool to measure the chemical composition of tissues (in vivo) and characterize functional metabolic processes in different parts of the human organs. It provides vital biological information at the molecular level. Combined with magnetic resonance imaging (MRI), an integrated MRI/MRS examination provides anatomical structure, pathological function, and biochemical information about a living system. MRS provides a link between the biochemical alterations and the pathophysiology of disease. This article provides a comprehensive description of the MRS technique and its application in Alzheimer's disease (AD) research. This review is a primer for students and researchers seeking a firm theoretical understanding of MRS physics as well as its application in clinical AD research.

The Emerging Role of Glutathione in Alzheimer's Disease

“…Up until recently, the absence of an in vivo quantitative measure of OS status within specific regions of the brain has been a major deterrent in the progress of both fundamental as well as clinical AD research. GSH can be detected by various measurement sequences in proton ( 1 H) MRS, such as double quantum coherence filtering [62], and MEscher-GArwood PRESS (MEGA-PRESS) pulse sequences ( [63,64]; for detailed review of GSH estimation through MRS, including comparison of various MRS techniques, please refer to [65]). …”

Recent Advances in Magnetic Resonance Neurospectroscopy

“…170 Here we summarize applications of proton MRS to AD, which have been reviewed recently by Mandal 171 and by Soher et al 172 Historically, the definitive diagnosis of AD was made by pathologists at autopsy. MRI studies have attempted to show specific patterns of cerebral atrophy (primarily in the temporal lobe) in patients with a clinical diagnosis of AD.…”

“…Their report has been followed by a host of other articles that have shown reproducible patterns of decreased NAA and increased mI in the occipital, temporal, parietal, and frontal regions of patients with AD, even at the early stages of the disease. 171,172 These patterns of spectral alterations can be used to differentiate patients with suspected AD from normal elderly controls, as well as patients with other kinds of dementias. 174 These patterns, adapted from Kantarci et al, 174 are summarized in TABLE 1.…”

The separation of Gln and Glu in STEAM: a comparison study using short and long TEs/TMs at 3 and 7 T

“…1b) for 3 T subjects. Manual shimming was used to improve the magnetic field homogeneity for voxel-specific regions at 3 T, and a vendor-provided double-gradient echo shim technique was implemented to shim all voxels at 7 T. STEAM and STEAM VERSE sequences with identical TR/TE/TM In addition, PRESS with short TE = 35 ms was employed in the 3 T measurements for further exploring the relationship between high SNR and accurate metabolite quantification, although it requires much higher RF peak power than STEAM with an identical TE and, thus, is not suitable for the application in ultra-high field 7 T [26]. The scan parameters were as follows: 128 averages, TR = 2,000 ms, TE = 35 ms, voxel size = 25 × 15 × 10 mm 3 = 3.75 ml, data size = 2,048 points, BW = 2,000 Hz.…”