Dynamic study of cerebral bioenergetics and brain function using in vivo multinuclear MRS approaches

Abstract

ABSTRACT:One of the greatest merits of nuclear magnetic resonance (NMR) methodology used in biomedical research and clinical settings is its capability of measuring various physiological parameters in vivo. Besides MR imaging (MRI), which has been routinely applied to obtain vital information in living organs at normal and diseased states, in vivo MR spectroscopy (MRS) provides an invaluable tool for determining metabolites, chemical reaction rates, bioenergetics, and their dynamic changes in the human and animals noninvasively. These MRS capabilities are further enhanced at high/ultrahigh magnetic fields because of significant gain in NMR detection sensitivity and improvement in the spectral resolution. Recent progress has shown that in vivo MRS holds great promise in many biomedical research areas-in particular, brain research. This article provides a broad review of (i) in vivo multinuclear MRS approaches, (ii) advanced MRS methodologies, and (iii) MRS applications for determining cerebral metabolism as well as bioenergetics at resting brain state and their dynamic changes in response to brain activation.

Simultaneous Measurement of Glucose Blood–Brain Transport Constants and Metabolic Rate in Rat Brain using in-vivo1H MRS

“…The kinetic parameters of glucose transport and CMR glc can be measured by two popular strategies incorporated with a glucose infusion (Chen and Zhu, 2005;Gruetter et al, 1996;Holden et al, 1991;Mason et al, 1992). One is the steady-state glucose infusion approach, i.e., measuring the brain glucose concentration change as a function of plasma glucose concentration under the steady-state condition (i.e., at constant G 0 and G i levels).…”

“…Another strategy is based on the dynamic glucose infusion approach, i.e., measuring the glucose time courses of incremental brain and plasma glucose concentration changes during a well-controlled glucose infusion; consequently the absolute values of T max , CMR glc , and K T can be obtained by analyzing the brain and plasma glucose time courses and solving the glucose transport differential equation (Chen and Zhu, 2005;Gruetter et al, 1996;Mason et al, 1992;Shestov et al, 2007;Van Zijl et al, 1997). However, the measurement of the brain glucose time course and its fitting results are sensitive to the glucose infusion protocol for raising the plasma glucose concentration continuously and smoothly, which is a challenging task practically.…”

Oxygen-17 NMR spectroscopy: Basic principles and applications (part II)

“…One significant advantage of in vivo 17 O NMR, compared with other established methods, for the determination of CMRO 2 is that the metabolic H 2 17 O is directly detectable. Chen et al [1009,1010] have provided excellent review articles on the subject and a synopsis will be given below. Fig.…”

Localized intermolecular zero‐quantum coherence spectroscopy in vivo

“…MRS is established as a non invasive tool for monitoring the metabolic response on novel drug molecules in animal models, and for characterization of pathologies by measuring concentration changes in metabolic profiles in tissue. Recent developments in MR instrumentation and optimization of acquisition methods enabled the detection of metabolites in living organisms at low concentrations (below 1 mM in the human brain) with high spatial specificity (1,2). However, living organisms provide ample sources of magnetic field distortions, leading to line broadening and loss of sensitivity.…”