Fast magnetic resonance spectroscopic imaging techniques in human brain- applications in multiple sclerosis

Abstract

Multi voxel magnetic resonance spectroscopic imaging (MRSI) is an important imaging tool that combines imaging and spectroscopic techniques. MRSI of the human brain has been beneficially applied to different clinical applications in neurology, particularly in neurooncology but also in multiple sclerosis, stroke and epilepsy. However, a major challenge in conventional MRSI is the longer acquisition time required for adequate signal to be collected. Fast MRSI of the brain in vivo is an alternative approach to reduce scanning time and make MRSI more clinically suitable.Fast MRSI can be categorised into spiral, echo-planar, parallel and turbo imaging techniques, each with its own strengths. After a brief introduction on the basics of non-invasive examination (1H-MRS) and localization techniques principles, different fast MRSI techniques will be discussed from their initial development to the recent innovations with particular emphasis on their capacity to record neurochemical changes in the brain in a variety of pathologies.The clinical applications of whole brain fast spectroscopic techniques, can assist in the assessment of neurochemical changes in the human brain and help in understanding the roles they play in disease. To give a good example of the utilities of these techniques in clinical context, MRSI application in multiple sclerosis was chosen. The available up to date and relevant literature is discussed and an outline of future research is presented.

Serum Health Biomarkers in African and Asian Elephants: Value Ranges and Clinical Values Indicative of the Immune Response

“…In this study, an Asian elephant with a systemic infection exhibited elevated IL-10, IFN-γ, and TNF-α compared to paired non-clinical sample concentrations in the same individual. This is similar to models of systemic inflammation where increased TNF-α, IFN-γ, IL-6, and IL-10 have all been reported [ 69 ]. Localized infections also elicit immune responses that can be measured in circulation.…”

Magnetic Resonance Spectroscopy as a Non-invasive Method to Quantify Muscle Carnosine in Humans: a Comprehensive Validity Assessment

“…Nonetheless, a large variation was observed between test and retest measurements, indicating that even small differences in voxel position have a large impact on the results. Such a large variation arising from voxel repositioning and re-shimming is somewhat expected for a metabolite with a broad signal and of low amplitude, such as carnosine, since similar levels of variation have been reported for other metabolites of much sharper and high amplitude signals 28 . In addition, the ~17% variation reported in this study is not too dissimilar to previous investigations 11,13,17 .…”

Current Methods of Magnetic Resonance for Noninvasive Assessment of Molecular Aspects of Pathoetiology in Multiple Sclerosis

“…The remaining challenge is the whole-brain coverage during one investigative procedure, which is highly desirable in most clinical applications. The use of SVS is possible to measure volumes within the 3–8 cm 3 voxel size [ 37 , 125 , 128 ], whereas CSI enables the minimalization of the individual voxel size to 0.5–1.5 cm 3 [ 128 , 129 , 130 ] in one or several slices (single-slice two-dimensional (2D) CSI; multi-slice three-dimensional (3D) CSI) [ 37 , 125 , 128 ]. Furthermore, whole-brain CSI sequences based on time-sufficient echo-planar CSI [ 37 , 129 , 131 ], parallel- or spiral-encoded CSI [ 37 , 129 ], or free induction decay CSI [ 131 ] have been achieved; however, these methods are also still limited.…”