scholarly journals Implantable NMR Microcoils in Rats: A New Tool for Exploring Tumor Metabolism at Sub-Microliter Scale?

Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 176
Author(s):  
Justine Deborne ◽  
Noël Pinaud ◽  
Yannick Crémillieux
Keyword(s):  
Magnetic Resonance ◽  
Tumor Model ◽  
Surface Coil ◽  
Regions Of Interest ◽  
7 Tesla ◽  
Resonance Spectroscopy ◽  
Volume Coil ◽  
Detection Volume ◽  
The Right

The aim of this study was to evaluate the potential of a miniaturized implantable nuclear magnetic resonance (NMR) coil to acquire in vivo proton NMR spectra in sub-microliter regions of interest and to obtain metabolic information using magnetic resonance spectroscopy (MRS) in these small volumes. For this purpose, the NMR microcoils were implanted in the right cortex of healthy rats and in C6 glioma-bearing rats. The dimensions of the microcoil were 450 micrometers wide and 3 mm long. The MRS acquisitions were performed at 7 Tesla using volume coil for RF excitation and microcoil for signal reception. The detection volume of the microcoil was measured equal to 450 nL. A gain in sensitivity equal to 76 was found in favor of implanted microcoil as compared to external surface coil. Nine resonances from metabolites were assigned in the spectra acquired in healthy rats (n = 5) and in glioma-bearing rat (n = 1). The differences in relative amplitude of choline, lactate and creatine resonances observed in glioma-bearing animal were in agreement with published findings on this tumor model. In conclusion, the designed implantable microcoil is suitable for in vivo MRS and can be used for probing the metabolism in localized and very small regions of interest in a tumor.

scholarly journals Alteration within the Hippocampal Volume in Patients with LHON Disease—7 Tesla MRI Study

2020 ◽  
Vol 10 (1) ◽  
pp. 14
Author(s):  
Cezary Grochowski ◽  
Kamil Jonak ◽  
Marcin Maciejewski ◽  
Andrzej Stępniewski ◽  
Mansur Rahnama-Hezavah
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Molecular Layer ◽  
Three Dimensional ◽  
Hippocampal Volume ◽  
7 Tesla ◽  
Diagnostic Process ◽  
Resonance Imaging ◽  
The Right

Purpose: The aim of this study was to assess the volumetry of the hippocampus in the Leber’s hereditary optic neuropathy (LHON) of blind patients. Methods: A total of 25 patients with LHON were randomly included into the study from the national health database. A total of 15 patients were selected according to the inclusion criteria. The submillimeter segmentation of the hippocampus was based on three-dimensional spoiled gradient recalled acquisition in steady state (3D-SPGR) BRAVO 7T magnetic resonance imaging (MRI) protocol. Results: Statistical analysis revealed that compared to healthy controls (HC), LHON subjects had multiple significant differences only in the right hippocampus, including a significantly higher volume of hippocampal tail (p = 0.009), subiculum body (p = 0.018), CA1 body (p = 0.002), hippocampal fissure (p = 0.046), molecular layer hippocampus (HP) body (p = 0.014), CA3 body (p = 0.006), Granule Cell (GC) and Molecular Layer (ML) of the Dentate Gyrus (DG)–GC ML DG body (p = 0.003), CA4 body (p = 0.001), whole hippocampal body (p = 0.018), and the whole hippocampus volume (p = 0.023). Discussion: The ultra-high-field magnetic resonance imaging allowed hippocampus quality visualization and analysis, serving as a powerful in vivo diagnostic tool in the diagnostic process and LHON disease course assessment. The study confirmed previous reports regarding volumetry of hippocampus in blind individuals.

Hypophosphataemic Osteomalacia and Myopathy: Studies with Nuclear Magnetic Resonance Spectroscopy

1984 ◽  
Vol 67 (5) ◽  
pp. 505-509 ◽  
Author(s):  
R. Smith ◽  
R. J. Newman ◽  
G. K. Radda ◽  
M. Stokes ◽  
A. Young
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Nuclear Magnetic Resonance Spectroscopy ◽  
Normal Subjects ◽  
Resonance Spectroscopy ◽  
Vitamin D Resistant Rickets ◽  
The Right ◽  
Nuclear Magnetic

1. A patient with familial adult-onset hypophosphataemia, whose myopathy was closely related to the plasma phosphate concentration, was investigated by phosphorus nuclear magnetic resonance spectroscopy (31P n.m.r.) in vivo of the right flexor digitorum superficialis muscle. 2. During hypophosphataemia induced by stopping oral phosphate a significant reduction in measured muscle strength occurred, but the ratios of the intramyocellular levels of phosphocreatine (PCr), adenosine triphosphate (ATP) and inorganic phosphate (Pi) remained unchanged at rest. During exercise these levels changed, as did the intramyocellular pH, but they did not differ from the pattern previously recorded in normal subjects. 3. In four adults with inherited infantile-onset hypophosphataemia (vitamin D-resistant rickets, VDRR) without myopathy, the n.m.r. measurements were normal at rest and during exercise. 4. In one patient with inherited hyperphosphataemia (tumoral calcinosis) the resting PCr: Pi ratio was significantly reduced.

scholarly journals Cerebral phosphoester signals measured by 31P magnetic resonance spectroscopy at 3 and 7 Tesla

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248632
Author(s):  
Shizhe Li ◽  
Jan Willem van der Veen ◽  
Li An ◽  
JoEllyn Stolinski ◽  
Christopher Johnson ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Cell Membrane ◽  
Magnetic Resonance Spectroscopy ◽  
Building Blocks ◽  
3 Tesla ◽  
7 Tesla ◽  
High Signal ◽  
Resonance Spectroscopy ◽  
Membrane Phospholipids

Abnormal cell membrane metabolism is associated with many neuropsychiatric disorders. Free phosphomonoesters and phosphodiesters, which can be detected by in vivo 31P magnetic resonance spectroscopy (MRS), are important cell membrane building blocks. However, the quantification of phosphoesters has been highly controversial even in healthy individuals due to overlapping signals from macromolecule membrane phospholipids (MP). In this study, high signal-to-noise ratio (SNR) cerebral 31P MRS spectra were acquired from healthy volunteers at both 3 and 7 Tesla. Our results indicated that, with minimal spectral interference from MP, the [phosphocreatine (PCr)]/[phosphocholine (PC) + glycerophosphocholine (GPC)] ratio measured at 7 Tesla agreed with its value expected from biochemical constraints. In contrast, the 3 Tesla [PCr]/[PC+GPC] ratio obtained using standard spectral fitting procedures was markedly smaller than the 7 Tesla ratio and than the expected value. The analysis suggests that the commonly used spectral model for MP may fail to capture its complex spectral features at 3 Tesla, and that additional prior knowledge is necessary to reliably quantify the phosphoester signals at low magnetic field strengths when spectral overlapping is significant.

The role of neurometabolites in emotional processing

2016 ◽  
Vol 33 (S1) ◽  
pp. S87-S87
Author(s):  
D. Denzel ◽  
L.R. Demenescu ◽  
L. Colic ◽  
F. von Düring ◽  
H. Nießen ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Facial Expression ◽  
Facial Expressions ◽  
Emotional Processing ◽  
Neural Response ◽  
7 Tesla ◽  
Matching Task ◽  
Resonance Spectroscopy ◽  
Excitatory Neurotransmitter ◽  
The Right

ObjectiveTo investigate how brain metabolites, especially glutamate and glutamate to glutamine ratio of pgACC modulate the neural response within these areas and how this affects their function during emotion facial expression matching task.MethodsSeventy healthy volunteers underwent magnetic resonance spectroscopy (MRS) and task functional magnetic resonance imaging (fMRI) in 7 Tesla scanner. PgACC MRS data were obtained using STEAM sequence and analyzed using LCModel.Angry, fearful, and happy facial expressions were presented in an affect-matching block where one of the two facial expressions presented matched the target facial expression. The control condition was form matching. Data were preprocessed and analyzed in SPM 8.ResultsGlutamate to Creatine ratio measured in pgACC positively correlated with BOLD response in the right DLPFC during negative emotional perception (FWE = 0.05) Glutamate to glutamine ratio indicating on-off mechanisms in pgACC positively correlated with BOLD responses in FFA extending to cerebellum cluster (FWE < 0.05).ConclusionThis study indicate that pgACC, baseline metabolism predicts neural response to emotional processing. We conclude that individuals with higher glutamate ratios, an excitatory neurotransmitter, in pgACC during rest might have a better coping mechanism to potential danger indicated by perception of angry or afraid faces.The higher glutamate to glutamine ratio in pgACC indicates a higher turnover of excitatory metabolite glutamate. This mechanism is associated with higher emotional response in fusiform area and cerebellum suggesting higher visual attention towards negative emotions.Disclosure of interestThe authors have not supplied their declaration of competing interest.

scholarly journals Feasibility of deuterium magnetic resonance spectroscopy of 3-O-Methylglucose at 7 Tesla

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252935
Author(s):  
Benedikt Hartmann ◽  
Max Müller ◽  
Lisa Seyler ◽  
Tobias Bäuerle ◽  
Tobias Wilferth ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Chemical Shift ◽  
Magnetic Resonance Spectroscopy ◽  
Time Course ◽  
Relaxation Times ◽  
Exponential Model ◽  
7 Tesla ◽  
Invasive Technique ◽  
Resonance Spectroscopy

Deuterium Magnetic Resonance Spectroscopy (DMRS) is a non-invasive technique that allows the detection of deuterated compounds in vivo. DMRS has a large potential to analyze uptake, perfusion, washout or metabolism, since deuterium is a stable isotope and therefore does not decay during biologic processing of a deuterium labelled substance. Moreover, DMRS allows the distinction between different deuterated substances. In this work, we performed DMRS of deuterated 3-O-Methylglucose (OMG). OMG is a non-metabolizable glucose analog which is transported similar to D-glucose. DMRS of OMG was performed in phantom and in vivo measurements using a preclinical 7 Tesla MRI system. The chemical shift (3.51 ± 0.1 ppm) and relaxation times were determined. OMG was injected intravenously and spectra were acquired over a period of one hour to monitor the time evolution of the deuterium signal in tumor-bearing rats. The increase and washout of OMG could be observed. Three different exponential functions were compared in terms of how well they describe the OMG washout. A mono-exponential model with offset seems to describe the observed time course best with a time constant of 1910 ± 770 s and an offset of 2.5 ± 1.2 mmol/l (mean ± std, N = 3). Chemical shift imaging could be performed with a voxel size of 7.1 mm x 7.1 mm x 7.9 mm. The feasibility of DMRS with deuterium labelled OMG could be demonstrated. These data might serve as basis for future studies that aim to characterize glucose transport using DMRS.

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