What is MR spectroscopy?

Abstract

H-Magnetic Resonance Spectroscopy (MRS) is a novel advanced imaging technique used as an adjunct to MRI to reveal complementary non-invasive information about the biochemical composition of imaged tissue. Clinical uses in paediatrics include aiding diagnosis of brain tumours, neonatal disorders such as hypoxic-ischaemic encephalopathy, inherited metabolic diseases, traumatic brain injury, demyelinating conditions and infectious brain lesions. MRS has potential to improve diagnosis and treatment monitoring of childhood brain tumours and other CNS diseases, facilitate biopsy and surgical planning, and provide prognostic biomarkers. MRS is employed as a research tool outside the brain in liver disease and disorders of muscle metabolism. The range of clinical uses is likely to increase with growing evidence for added value. Multicentre trials are needed to definitively establish the benefits of MRS in specific clinical scenarios and integrate this promising new technique into routine practice to improve patient care. This article gives a brief overview of MRS and its potential clinical applications, and addresses challenges surrounding translation into practice.

A patient with novel MBOAT7 variant: The cerebellar atrophy is progressive and displays a peculiar neurometabolic profile

“…When she was 9, a brain H‐MRS examination was performed in the right cerebellar hemispheric region and showed an increase in myo‐inositol and a relative decrease of NAA. Such a metabolite profile indicates a neuronal degeneration (NAA is indicative of both neuronal cell number and viability) and an increase in gliosis (myo‐I is considered a gliosis marker) and it is present in few other neurodegenerative conditions (Manias & Peet, 2018; Oz et al, 2014; Viau & Boulanger, 2004). Moreover, H‐MRS not only correlates with clinical status in spinocerebellar ataxia type 1 (SCA‐1), but it also suggested to be more sensitive than MRI and the clinical Scale for the Assessment and Rating of Ataxia for SCA (SARA) in the early stage of the disease and in the prediction of the disease progression (Deelchand et al, 2019; Oz et al, 2010).…”

Emerging Utility of Applied Magnetic Resonance Imaging in the Management of Traumatic Brain Injury

“…This causes them to react differently to the presence of a magnetic field. By varying the frequencies of that magnetic field, it is possible to detect separate signals from different metabolites and therefore differentiate the metabolic composition of the tissue [64][65][66]. Specifically, most centers rely on 1H-MR spectroscopy, which uses the signal from protons (1H) to assess the composition of metabolites that are commonly found in brain tissue.…”

“…Specifically, most centers rely on 1H-MR spectroscopy, which uses the signal from protons (1H) to assess the composition of metabolites that are commonly found in brain tissue. Common biomarkers quantified in the brain include choline (a substrate for cellular membrane synthesis), N-acetylaspartate (NAA, a neuronal metabolite), myo-inositol (a glial metabolite), mobile lipids that originate from small isotopically tumbling microdomains embedded within the plasma membrane or stored in cytoplasmic intracellular lipid droplets (increased with higher levels of apoptosis and necrosis), neurotransmitters such as glutamate and GABA, antioxidants such as glutathione, biochemical byproducts such as lactate, and more [64,65,67]. Previously, 31P-MRS was commonly used because it allowed for labeling of substrates of the tricarboxylic acid cycle (TCA) cycle, including pyruvate and ATP [68].…”

Effects of 12-Week Methylphenidate Treatment on Neurometabolism in Adult Patients with ADHD: The First Double-Blind Placebo-Controlled MR Spectroscopy Study

“…Magnetic resonance spectroscopy (MRS) is a unique non-invasive and non-radiative method used for assessing the neurometabolism of the human brain in vivo [13,14]. In contrast to positron emission tomography (PET) and other approaches involving ionizing radiation, MRS is presumably free of side effects and, thus, is a suitable tool for longitudinal investigations.…”

“…Glu is the most important excitatory neurotransmitter and Glu + Gln are also markers for metabolism (since the transformation from Gln to Glu is an energy dependent process). Glu and Gln are often reported in combination as Glx [13,14]. Unfortunately, dopamine and norepinephrine-which are both thought to play key roles in ADHD pathogenesis-are not measurable via MRS due to their low concentrations.…”