Applications of NMR Spectroscopy: Volume 6

Atta-ur-Rahman, M. Iqbal Choudhary

• Publisher: Bentham Science Publishers
• Year: 2017
• ISBN:
  9781681084398
• Topic: Physical Sciences
• Subtopic: Analytic Chemistry

Applications of NMR Spectroscopy is a book series devoted to publishing the latest advances in the applications of nuclear magnetic resonance (NMR) spectroscopy in various fields of organic chemistry, biochemistry, health and agriculture.
The sixth volume of the series features reviews focusing on NMR spectroscopic techniques for studying tautomerism, applications in medical diagnosis, in food chemistry and identifying secondary metabolites.

NMR Spectroscopy in Medical Diagnosis – Recent Developments

Kannan Vaidyanathan^*

Department of Biochemistry, & Scientist, Pushpagiri Research Centre, Pushpagiri Institute of Medical Science & Research Centre, Tiruvalla, Kerala – 689 101, India

Abstract

In the field of diagnostic medicine, Nuclear Magnetic Resonance (NMR) spectroscopy has found wide applications. Simplicity of sample preparation, biological safety, non-invasiveness, and non-destructiveness are the advantages of NMR based metabolomic studies. One of the main drawbacks is lower sensitivity. This review summarises the current achievements of NMR spectroscopy in the diagnosis of human disorders. NMR spectroscopy has been useful in metabolomics-based diagnosis. NMR-based screening for inborn errors of metabolism is practised as more metabolites can be detected. Fast, simple and cost-effective screening is possible. Neuropsychiatric disorders like schizophrenia, panic disorders, major depression, bipolar disorders and autism-spectrum disorders have been investigated systematically using NMR spectroscopy. NMR metabolomics is used in the search for biomarkers of infectious diseases like tuberculosis, malaria and pneumonia, neurological disorders and Parkinson’s disease. NMR metabolomics has been used in the identification of biomarker for cardiovascular diseases and risk stratification. It has also been used in cancer diagnosis and therapy. NMR metabolomics has been used to investigate processes like transformation, progression, proliferation and metastasis in cancer cell lines. Other examples for applications of NMR metabolomics include gastro-intestinal disorders, endocrine and nutritional disorders, disorders of the nervous system and respiratory system disorders. In the coming years, it is expected that further developments to overcome the technical limitations will take place, making it one of the key diagnostic modalities of the future.

Keywords: Magnetic Resonance Spectroscopy, Magnetic Resonance Imaging, Metabolomics, ¹H MRS, ¹³C MRS, Inborn errors of metabolism, white matter disease, N-acetyl aspartate, Choline, Creatine, Citrate, Neurological disorders, Neuropsychiatric disorders, Cancer, Prostate cancer, Breast cancer, Skeletal muscle disorder, Cardiac MRS studies, Bowel disorders, Urinary biomarkers, Pediatric disorders.

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^* Corresponding author Kannan Vaidyanathan: Department of Biochemistry, & Scientist, Pushpagiri Research Centre, Pushpagiri Institute of Medical Science & Research Centre, Tiruvalla, Kerala – 689 101, India;
Tel: - [phone]; (Mobile); [phone] (Off); Fax: [phone]; E-mail: [email protected]

INTRODUCTION

Magnetic resonance is a technique that probes atoms and molecules based on its interactions with external magnetic fields. Though it was initially used for elucidation of chemical structures, the biological functions have been identified over time. Magnetic resonance imaging (MRI) is used to identify anatomical structures and pathologies. ³¹P NMR studies of RBC and muscle tissues were done in the early 1970s. Significant differences between normal and cancerous tissues were observed early on, which was the basis for the development of MRI diagnostic studies.

MR imaging is based primarily on the detection of tissue water signals, whereas MR spectroscopy is based on the detection of localized metabolite signals in tissue. They are variants of NMR technique, and whereas in the former, living tissue is visualized, in the latter, biochemical information is extracted. The technical difference between MRI and MRS is that in MRI, the signal is acquired in the presence of magnetic field gradient, while in MRS, there is a homogeneous magnetic field, and thus no gradient. Both are non-invasive and hence repetitive measurements are possible. Functional MRI (fMRI) provides high resolution, non-invasive report.

Nuclei in different electronic bonds produce resonance signals at different shifted frequencies and thus produce characteristic spectra. The signatures of MRS are the chemically-shifted peaks, split further by coupling constants between spins. For example, under conditions of high resolution, chemically shifted signals for metabolites may be split into multiplet of lines known as J-coupling or spin-spin splitting. The most characteristic signatures of an MR spectrum include such chemical shifts and spin-spin splittings.

Numerous techniques have been proposed for obtaining spectra, of which Stimulated Echo Acquisition Mode (STEAM) and Point Resolved Spectroscopy (PRESS), are the most commonly employed ones. Single-voxel and spectroscopic imaging play extensive roles in clinical diagnosis, and have their own advantages and disadvantages. Multi-voxel 2D and 3D techniques are particularly useful for brain disorders like AIDS, Alzheimer’s disease and multiple sclerosis. Whatever the method used, MRS results obtained and medical decision making must be independent of the actual technical approach.

in vivo MRS has been the subject of vigorous clinical and biomedical investigations over the past three decades. In several MRS investigations carried out in the clinical setting, routine and speedy protocols are available. MRS has the advantage that it can be scheduled on conventional clinical MRI scanners and in the same session as other diagnostic MRI procedures [1].

NMR Metabolomics

Metabolomics is the quantitative analysis of a large number of low molecular weight metabolites that are intermediate or final products of all the metabolic pathways in a living organism. Any metabolic profiles detectable in a human biological fluid are caused by the interaction between gene expression and the environment [2]. Genomics, transcriptomics and proteomics are well established technologies and are commonly used by many s...

Table of contents

• Welcome
• Table of Contents
• Title
• BENTHAM SCIENCE PUBLISHERS LTD.
• PREFACE
• List of Contributors
• NMR as a Tool for Studying Rapid Equilibria: Tautomerism
• Identification & Characterization of Secondary Metabolites in the Biological Soup by NMR Spectroscopy
• NMR Spectroscopy in Medical Diagnosis – Recent Developments
• NMR Relaxometry Applied to Food Samples
• Application of Nuclear Magnetic Resonance Spectroscopy in Molecular Structure Identification: A Microbial Biogeochemistry Perspective