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MR spectroscopy

Chloé Najac, Sabrina M Ronen
Metabolic reprogramming is an important hallmark of cancer. Alterations in many metabolic pathways support the requirement for cellular building blocks that are essential for cancer cell proliferation. This metabolic reprogramming can be imaged using magnetic resonance spectroscopy (MRS). H MRS can inform on alterations in the steady-state levels of cellular metabolites, but the emergence of hyperpolarized C MRS has now also enabled imaging of metabolic fluxes in real-time, providing a new method for tumor detection and monitoring of therapeutic response...
October 2016: Topics in Magnetic Resonance Imaging: TMRI
Mohamed I F Shariff, Jin U Kim, Nimzing G Ladep, Mary M E Crossey, Larry K Koomson, Abigail Zabron, Helen Reeves, Matthew Cramp, Stephen Ryder, Shaun Greer, I Jane Cox, Roger Williams, Elaine Holmes, Kathryn Nash, Simon D Taylor-Robinson
BACKGROUND: Discriminatory metabolic profiles have been described in urinary (1)H nuclear magnetic resonance (NMR) spectroscopy studies of African patients with hepatocellular carcinoma (HCC). This study aimed to assess similarities in a UK cohort, where there is a greater etiological diversity. METHODS: Urine from cirrhosis and HCC patients was analyzed using a 600 MHz (1)H NMR system. Multivariate analysis and median group MR spectra comparison identified metabolite alterations between groups...
September 2016: Journal of Clinical and Experimental Hepatology
Tamar M van Veenendaal, Dominique M IJff, Albert P Aldenkamp, Richard H C Lazeron, Nicolaas A J Puts, Richard A E Edden, Paul A M Hofman, Anton J A de Louw, Walter H Backes, Jacobus F A Jansen
OBJECTIVE: Although antiepileptic drugs (AEDs) are effective in suppressing epileptic seizures, they also induce (cognitive) side effects, with mental slowing as a general effect. This study aimed to assess whether concentrations of MR detectable neurotransmitters, glutamate and GABA, are associated with mental slowing in patients with epilepsy taking AEDs. METHODS: Cross-sectional data were collected from patients with localization-related epilepsy using a variety of AEDs from three risk categories, i...
October 13, 2016: Epilepsy & Behavior: E&B
Lara A Brandão, Mauricio Castillo
Proton magnetic resonance spectroscopy (H-MRS) may be helpful in suggesting tumor histology and tumor grade and may better define tumor extension and the ideal site for biopsy compared with conventional magnetic resonance (MR) imaging. A multifunctional approach with diffusion-weighted imaging, perfusion-weighted imaging, and permeability maps, along with H-MRS, may enhance the accuracy of the diagnosis and characterization of brain tumors and estimation of therapeutic response. Integration of advanced imaging techniques with conventional MR imaging and the clinical history help to improve the accuracy, sensitivity, and specificity in differentiating tumors and nonneoplastic lesions...
November 2016: Magnetic Resonance Imaging Clinics of North America
Chang-Hoon Choi, YongHyun Ha, Pandichelvam Veeraiah, Jörg Felder, Klaus Möllenhoff, N Jon Shah
Non-proton MRI has recently garnered gathering interest with the increased availability of ultra high-field MRI system. Assuming the availability of a broadband RF amplifier, performing multinuclear MR experiments essentially requires additional hardware, such as an RF resonator and a T/R switch for each nucleus. A double- or triple-resonant RF probe is typically constructed using traps or PIN-diode circuits, but this approach degrades the signal-to-noise ratio (SNR) and image quality compared to a single-resonant coil and this is a limiting factor...
October 10, 2016: Journal of Magnetic Resonance
Christine Gonzales, Hikari A I Yoshihara, Nahzli Dilek, Julie Leignadier, Melita Irving, Pascal Mieville, Lothar Helm, Olivier Michielin, Juerg Schwitter
BACKGROUND: 19F-MRI and 19F-MRS can identify specific cell types after in-vitro or in-vivo 19F-labeling. Knowledge on the potential to track in-vitro 19F-labeled immune cells in tumor models by 19F-MRI/MRS is scarce. AIM: To study 19F-based MR techniques for in-vivo tracking of adoptively transferred immune cells after in-vitro 19F-labeling, i.e. to detect and monitor their migration non-invasively in melanoma-bearing mice. METHODS: Splenocytes (SP) were labeled in-vitro with a perfluorocarbon (PFC) and IV-injected into non-tumor bearing mice...
2016: PloS One
Jean-Michel Petit, Jean-Pierre Cercueil, Romaric Loffroy, Damien Denimal, Benjamin Bouillet, Coralie Fourmont, Olivier Chevallier, Laurence Duvillard, Bruno Vergès
BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is very frequent in type 2 diabetes with increased risk of further development of liver fibrosis. Animal studies have shown that GLP-1 receptor agonists may reduce liver lipogenesis. However, data in humans are scarce. OBJECTIVE: To study the effect of liraglutide 1.2 mg/d on liver fat content (LFC) in patients with uncontrolled type 2 diabetes and to evaluate the factors potentially associated with liraglutide-induced modification of LFC...
October 12, 2016: Journal of Clinical Endocrinology and Metabolism
Priya D Shanmugarajah, Nigel Hoggard, Stuart Currie, Daniel P Aeschlimann, Pascale C Aeschlimann, Dermot C Gleeson, Mohammed Karajeh, Nicola Woodroofe, Richard A Grünewald, Marios Hadjivassiliou
BACKGROUND: Alcohol-related cerebellar degeneration is one of the commonest acquired forms of cerebellar ataxia. The exact pathogenic mechanisms by which alcohol leads to cerebellar damage remain unknown. Possible autoreactive immune mediated mechanisms have not been explored previously. In this study, we aim to investigate the potential role of alcohol-induced immune mediated cerebellar degeneration. METHODS: Patients with ataxia and a history of alcohol misuse were recruited from the Ataxia and Hepatology tertiary clinics at Sheffield Teaching Hospitals NHS Trust...
2016: Cerebellum & Ataxias
Zenon Starčuk, Jana Starčuková
Current possibilities and limitations of the simulation of in vivo magnetic resonance spectroscopic signals are demonstrated from the point of view of a simulation software user as well as its programmer. A brief review of the quantum-mechanical background addresses the specific needs of simulation implementation and in vivo MR spectroscopy in general. Practical application examples demonstrate how flexible simulation software, such as NMRScopeB, can be utilized not only for the preparation of metabolite basis signals for quantification of metabolite concentrations, but also in pulse sequence development, assessment of artifacts and analyzing mechanism leading to unexpected signal phenomena...
October 8, 2016: Analytical Biochemistry
Xin Zhang, Chuan-Wang Yang, Han-Qing Yu, Guo-Ping Sheng
Microbial extracellular polymeric substances (EPS) widely exist in natural environments and affect the migration and transformation of pollutants in aquatic environments. Previous works report that EPS have some reducing functional groups and can reduce heavy metals. However, because of the weak reducing capability of EPS, the reduction of heavy metals by EPS without cells is extremely slow, and its effect on heavy metals species is insignificant. In this work, the accelerated reduction of silver ions (Ag(+)) by EPS from Shewanella oneidensis MR-1 under illumination was investigated...
October 5, 2016: Water Research
Alexander J Taylor, Josef Granwehr, Clémentine Lesbats, James L Krupa, Joseph S Six, Galina E Pavlovskaya, Neil R Thomas, Dorothee P Auer, Thomas Meersmann, Henryk M Faas
Due to low fluorine background signal in vivo, 19F is a good marker to study the fate of exogenous molecules by magnetic resonance imaging (MRI) using equilibrium nuclear spin polarization schemes. Since 19F MRI applications require high sensitivity, it can be important to assess experimental feasibility during the design stage already by estimating the minimum detectable fluorine concentration. Here we propose a simple method for the calibration of MRI hardware, providing sensitivity estimates for a given scanner and coil configuration...
2016: PloS One
Harald Kramer, Perry J Pickhardt, Mark A Kliewer, Diego Hernando, Guang-Hong Chen, James A Zagzebski, Scott B Reeder
OBJECTIVE: The purpose of this study was to prospectively evaluate the accuracy of proton-density fat-fraction, single- and dual-energy CT (SECT and DECT), gray-scale ultrasound (US), and US shear-wave elastography (US-SWE) in the quantification of hepatic steatosis with MR spectroscopy (MRS) as the reference standard. SUBJECTS AND METHODS: Fifty adults who did not have symptoms (23 men, 27 women; mean age, 57 ± 5 years; body mass index, 27 ± 5) underwent liver imaging with un-enhanced SECT, DECT, gray-scale US, US-SWE, proton-density fat-fraction MRI, and MRS for this prospective trial...
October 11, 2016: AJR. American Journal of Roentgenology
P Porcari, M E Hegi, H Lei, M-F Hamou, I Vassallo, S Capuani, R Gruetter, V Mlynarik
Glioma models have provided important insights into human brain cancers. Among the investigative tools, MRI has allowed their characterization and diagnosis. In this study, we investigated whether diffusion MRI might be a useful technique for early detection and characterization of slow-growing and diffuse infiltrative gliomas, such as the proposed new models, LN-2669GS and LN-2540GS glioma sphere xenografts. Tumours grown in these models are not visible in conventional T2 -weighted or contrast-enhanced T1 -weighted MRI at 14...
September 15, 2016: NMR in Biomedicine
Stefan Z Lutz, Andreas Peter, Fausto Machicao, Apostolia Lamprinou, Jürgen Machann, Fritz Schick, Ingmar Königsrainer, Alfred Königsrainer, Andreas Fritsche, Harald Staiger, Hans-Ulrich Häring, Norbert Stefan, Konstantinos Kantartzis
CONTEXT/OBJECTIVE: Acute pharmacological inhibition of 11β-hydroxysteroid-dehydrogenase 1 (11β-HSD1), which converts cortisone into the much more potent cortisol in peripheral tissues, results in reduction of total-, visceral- and liver fat, but not of insulin resistance. We now investigated whether lifelong alterations of 11β-HSD1 activity similarly affect these cardiometabolic risk parameters, by studying single nucleotide polymorphisms (SNPs) in the 11β-HSD1-coding gene (HSD11B1)...
October 7, 2016: Journal of Clinical Endocrinology and Metabolism
Marc C Mabray, Soonmee Cha
This article presents a summary of advanced MR imaging techniques and their use in the evaluation of patients with brain tumors. It reviews diffusion-weighted imaging, diffusion-tensor imaging, T2* susceptibility-sensitive imaging, MR spectroscopy, MR perfusion, and functional MR imaging, and discusses their current roles in the evaluation of patients with brain tumors.
November 2016: Neuroimaging Clinics of North America
Lara A Brandão, Mauricio Castillo
Primary central nervous system lymphomas are aggressive, high-cell-density tumors. There is recent increase in their incidence in immunocompetent patients. Knowledge of imaging findings on computed tomography and conventional MR imaging is important to suggest the diagnosis. Moreover, information obtained from advanced MR imaging techniques, such as diffusion-weighted imaging, diffusion tensor imaging, MR spectroscopy, perfusion-weighted imaging, and dynamic contrast-enhanced studies, increases diagnostic confidence and helps distinguish them from other aggressive intracranial tumors...
November 2016: Neuroimaging Clinics of North America
Iris Yuwen Zhou, Taylor L Fuss, Takahiro Igarashi, Weiping Jiang, Xin Zhou, Leo L Cheng, Phillip Zhe Sun
Chemical exchange saturation transfer (CEST) provides sensitive MR contrast for probing dilute compounds via exchangeable protons, serving as an emerging molecular imaging methodology. CEST Z-spectrum is often acquired by sweeping radiofrequency saturation around bulk water resonance, offset by offset, to detect CEST effects at characteristic chemical shift offsets, which requires prolonged acquisition time. Herein, combining high-resolution magic angle spinning (HRMAS) with concurrent application of gradient and RF saturation to achieve fast Z-spectral acquisition, we demonstrated the feasibility of fast quantitative HRMAS CEST Z-spectroscopy...
October 6, 2016: Analytical Chemistry
Lucas Lindeboom, Robin A de Graaf, Christine I Nabuurs, Petronella A van Ewijk, Matthijs K C Hesselink, Joachim E Wildberger, Patrick Schrauwen, Vera B Schrauwen-Hinderling
The prevalence of fatty liver reaches alarming proportions. Fatty liver increases the risk for insulin resistance, cardiovascular disease, and nonalcoholic steatohepatitis (NASH). Although extensively studied in a preclinical setting, the lack of noninvasive methodologies hampers our understanding of which pathways promote hepatic fat accumulation in humans. Dietary fat retention is one of the pathways that may lead to fatty liver. The low (1.1%) natural abundance (NA) of carbon-13 ((13)C) allows use of (13)C-enriched lipids for in vivo MR studies...
August 18, 2016: JCI Insight
Izabela Aleksanderek, Stuart M K McGregor, Todd K Stevens, Sandy Goncalves, Robert Bartha, Neil Duggal
Purpose To characterize longitudinal metabolite alterations in the motor cortex of patients with cervical spondylotic myelopathy (CSM) by using proton magnetic resonance (MR) spectroscopy and to evaluate white matter integrity with diffusion-tensor imaging in patients who are recovering neurologic function after decompression surgery. Materials and Methods Informed written consent was obtained for all procedures and the study was approved by Western University's Health Sciences Research Ethics Board. Twenty-eight patients with CSM and 10 healthy control subjects were prospectively recruited and underwent two separate 3-T MR imaging examinations 6 months apart...
September 30, 2016: Radiology
D Male, R Gromnicova, C McQuaid
Gold nanoparticles with a core size of 2nm covalently coated with glycans to maintain solubility, targeting molecules for brain endothelium, and cargo molecules hold great potential for delivery of therapies into the CNS. They have low toxicity, pass through brain endothelium in vitro and in vivo, and move rapidly through the brain parenchyma. Within minutes of infusion the nanoparticles can be detected in neurons and glia. These nanoparticles are relatively easy to synthesize in association with their surface ligands...
2016: International Review of Neurobiology
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