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https://www.readbyqxmd.com/read/27910860/dynamic-nuclear-magnetic-resonance-field-sensing-with-part-per-trillion-resolution
#1
Simon Gross, Christoph Barmet, Benjamin E Dietrich, David O Brunner, Thomas Schmid, Klaas P Pruessmann
High-field magnets of up to tens of teslas in strength advance applications in physics, chemistry and the life sciences. However, progress in generating such high fields has not been matched by corresponding advances in magnetic field measurement. Based mostly on nuclear magnetic resonance, dynamic high-field magnetometry is currently limited to resolutions in the nanotesla range. Here we report a concerted approach involving tailored materials, magnetostatics and detection electronics to enhance the resolution of nuclear magnetic resonance sensing by three orders of magnitude...
December 2, 2016: Nature Communications
https://www.readbyqxmd.com/read/27904982/magnetic-resonance-evaluation-of-cardiac-thrombi-and-masses-by-t1-and-t2-mapping-an-observational-study
#2
Thibault Caspar, Soraya El Ghannudi, Mickaël Ohana, Aïssam Labani, Aubrietia Lawson, Patrick Ohlmann, Olivier Morel, Michel De Mathelin, Catherine Roy, Afshin Gangi, Philippe Germain
The purpose of this work was to evaluate CMR T1 and T2 mapping sequences in patients with intracardiac thrombi and masses in order to assess T1 and T2 relaxometry usefulness and to allow better etiological diagnosis. This observational study of patients scheduled for routine CMR was performed from September 2014 to August 2015. All patients referred to our department for a 1.5 T CMR were screened to participate. T1 mapping were acquired before and after Gadolinium injection; T2 mapping images were obtained before injection...
December 1, 2016: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/27903016/predicting-tissue-breaking-strengths-in-the-epileptic-brain-with-t2-relaxometry-application-of-pulsed-water-jet-dissection-system-for-epilepsy-surgery
#3
Yoko Takahashi, Masaki Iwasaki, Atsuhiro Nakagawa, Shiho Sato, Nobukazu Nakasato, Teiji Tominaga
Background The piezo actuator-driven pulsed water jet (ADPJ) system is a novel surgical instrument that enables dissection of tissue without thermal damage. Using the ADPJ system in epilepsy surgery requires prediction of the tissue breaking strength of the epileptic brain. The aim of this study was to elucidate whether magnetic resonance imaging T2 relaxometry could predict the breaking strength. Methods A total of 12 patients with drug-resistant temporal lobe epilepsy who received surgical treatment were included in the study...
November 30, 2016: Journal of Neurological Surgery. Part A, Central European Neurosurgery
https://www.readbyqxmd.com/read/27893386/optimizing-mr-scan-design-for-model-based-t1-t2-estimation-from-steady-state-sequences
#4
Gopal Nataraj, Jon-Fredrick Nielsen, Jeffrey Fessler
Rapid, reliable quantification of MR relaxation parameters T1 and T2 is desirable for many clinical applications. Steady-state sequences such as Spoiled Gradient-Recalled Echo (SPGR) and Dual-Echo Steady-State (DESS) are fast and wellsuited for relaxometry because the signals they produce are quite sensitive to T1 and T2 variation. However, T1, T2 estimation with these sequences typically requires multiple scans with varied sets of acquisition parameters. This paper describes a systematic framework for selecting scan types (e...
October 4, 2016: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/27862590/hepatic-gadoxetic-acid-uptake-as-a-measure-of-diffuse-liver-disease-where-are-we
#5
REVIEW
Ahmed Ba-Ssalamah, Nina Bastati, Andreas Wibmer, Romana Fragner, Jacqueline C Hodge, Michael Trauner, Christian J Herold, Mustafa R Bashir, Bernard E Van Beers
: MRI has emerged as the most comprehensive noninvasive diagnostic tool for focal liver lesions and diffuse hepatobiliary disorders. The introduction of hepatobiliary contrast agents, most notably gadoxetic acid (GA), has expanded the role of MRI, particularly in the functional imaging of chronic liver diseases, such as nonalcoholic fatty liver disease (NAFLD). GA-enhanced MRI (GA-MRI) may help to distinguish between the two subgroups of NAFLD, simple steatosis and nonalcoholic steatohepatitis...
November 8, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27858703/chronic-liver-disease-quantitative-mri-vs%C3%A2-ceus-based-microperfusion
#6
M Haimerl, S Poelsterl, L P Beyer, I Wiesinger, C Nießen, C Stroszczynski, P Wiggermann, E-M Jung
PURPOSE: To compare the diagnostic performance of MRI-based T1 relaxometry with dynamic contrast-enhanced ultrasound (CEUS)-based liver microcirculation for evaluation of liver function. MATERIALS AND METHODS: 22 patients underwent Gd-EOB-DTPA-enhanced MRI with T1 relaxometry and previous or consecutive CEUS examinations. A transverse 3D VIBE sequence with an inline T1 calculation was acquired and the reduction rate of T1 relaxation time (rrT1) was evaluated. For CEUS measurements (1-6 MHz), a bolus injection of 1...
November 18, 2016: Clinical Hemorheology and Microcirculation
https://www.readbyqxmd.com/read/27853501/evaluation-of-iron-deposition-in-the-adrenal-glands-of-%C3%AE-thalassemia-major-patients-using-3-tesla-mri
#7
Tevfik Guzelbey, Bengi Gurses, Erman Ozturk, Olcay Ozveren, Aysegul Sarsilmaz, Ebru Karasu
BACKGROUND: Beta-thalassemia major (β-TM) patients need blood transfusions, which result in iron deposition. To regulate chelation therapy, iron load has to be measured. With MRI, the amount of signal loss and T2* decay time shortening are used for iron quantification. OBJECTIVES: The aim was to measure adrenal iron load with T2* relaxometry using MRI, and to compare it with liver and cardiac iron and serum ferritin, and to find out whether adrenal iron could be predicted from those parameters...
July 2016: Iranian Journal of Radiology: a Quarterly Journal Published By the Iranian Radiological Society
https://www.readbyqxmd.com/read/27843765/t2-relaxometry-predicts-outcome-of-dbs-in-idiopathic-parkinson-s-disease
#8
Tarja Lönnfors-Weitzel, Thilo Weitzel, Johannes Slotboom, Claus Kiefer, Claudio Pollo, Michael Schüpbach, Markus Oertel, Alain Kaelin, Roland Wiest
INTRODUCTION: Deep brain stimulation (DBS) nowadays is a well-established treatment of motor symptoms in Parkinson's disease. The subthalamic nucleus (STN) is a common target for DBS, because motor improvements have been shown to be superior to best medical therapy, if DBS electrodes have been appropriately positioned. DBS target identification can be assisted by MRI beyond structural imaging by spatially resolved measurement of T2-relaxation times (T2r). AIM: We pose the question, whether T2r of the STN is linked to the severity of the disease and whether outcome of DBS may be correlated to an asymmetric manifestation of the disease...
2016: NeuroImage: Clinical
https://www.readbyqxmd.com/read/27836800/sex-and-age-dependence-of-region-and-layer-specific-knee-cartilage-composition-spin-spin-relaxation-time-in-healthy-reference-subjects
#9
Wolfgang Wirth, Susanne Maschek, Felix Eckstein
Compositional measures of articular cartilage are accessible in vivo by magnetic resonance imaging (MRI) based relaxometry and cartilage spin-spin transverse relaxation time (T2) has been related to tissue hydration, collagen content and orientation, and mechanical (functional) properties of articular cartilage. The objective of the current study was therefore to evaluate subregional variation, and sex- and age-differences, in laminar (deep and superficial) femorotibial cartilage T2 relaxation time in healthy adults...
November 9, 2016: Annals of Anatomy, Anatomischer Anzeiger: Official Organ of the Anatomische Gesellschaft
https://www.readbyqxmd.com/read/27834545/advanced-neuroimaging-to-quantify-myelin-in-vivo-application-to-mild-tbi
#10
S M Jurick, K J Bangen, N D Evangelista, M Sanderson-Cimino, L Delano-Wood, A J Jak
BACKGROUND: Difficulty providing accurate diagnosis and prognosis, especially after mild forms of traumatic brain injury (TBI), has increased efforts to detect changes in white matter microstructure using advanced neuroimaging techniques. Although methods such as diffusion tensor imaging (DTI) have greatly increased knowledge of white matter changes resulting from TBI, several shortcomings limit the utility of these techniques particularly when applied to populations with mild TBI (mTBI) history...
2016: Brain Injury: [BI]
https://www.readbyqxmd.com/read/27833805/whole-brain-ex-vivo-quantitative-mri-of-the-cuprizone-mouse-model
#11
Tobias C Wood, Camilla Simmons, Samuel A Hurley, Anthony C Vernon, Joel Torres, Flavio Dell'Acqua, Steve C R Williams, Diana Cash
Myelin is a critical component of the nervous system and a major contributor to contrast in Magnetic Resonance (MR) images. However, the precise contribution of myelination to multiple MR modalities is still under debate. The cuprizone mouse is a well-established model of demyelination that has been used in several MR studies, but these have often imaged only a single slice and analysed a small region of interest in the corpus callosum. We imaged and analyzed the whole brain of the cuprizone mouse ex-vivo using high-resolution quantitative MR methods (multi-component relaxometry, Diffusion Tensor Imaging (DTI) and morphometry) and found changes in multiple regions, including the corpus callosum, cerebellum, thalamus and hippocampus...
2016: PeerJ
https://www.readbyqxmd.com/read/27816433/measurement-of-the-bending-elastic-modulus-in-unilamellar-vesicles-membranes-by-fast-field-cycling-nmr-relaxometry
#12
Gabriela A Dominguez, Josefina Perlo, Carla C Fraenza, Esteban Anoardo
The elastic properties of lipid membranes can be conveniently characterized through the bending elastic modulus κ. Elasticity directly affects the deformability of a membrane, morphological and shape transitions, fusion, lipid-protein interactions, etc. It is also a critical property for the formulation of ultradeformable liposomes, and of interest for the design of theranostic liposomes for efficient drug delivery systems and/or different imaging contrast agents. Measurements of κ in liposome membranes have been made using the fast field cycling nuclear magnetic relaxometry technique...
November 2, 2016: Chemistry and Physics of Lipids
https://www.readbyqxmd.com/read/27809381/stability-and-sensitivity-of-water-t2-obtained-with-ideal-cpmg-in-healthy-and-fat-infiltrated-skeletal-muscle
#13
Christopher D J Sinclair, Jasper M Morrow, Robert L Janiczek, Matthew R B Evans, Elham Rawah, Sachit Shah, Michael G Hanna, Mary M Reilly, Tarek A Yousry, John S Thornton
Quantifying muscle water T2 (T2 -water) independently of intramuscular fat content is essential in establishing T2 -water as an outcome measure for imminent new therapy trials in neuromuscular diseases. IDEAL-CPMG combines chemical shift fat-water separation with T2 relaxometry to obtain such a measure. Here we evaluate the reproducibility and B1 sensitivity of IDEAL-CPMG T2 -water and fat fraction (f.f.) values in healthy subjects, and demonstrate the potential of the method to quantify T2 -water variation in diseased muscle displaying varying degrees of fatty infiltration...
December 2016: NMR in Biomedicine
https://www.readbyqxmd.com/read/27802565/biomass-water-interactions-correlate-to-recalcitrance-and-are-intensified-by-pretreatment-an-investigation-of-water-constraint-and-retention-in-pretreated-spruce-using-low-field-nmr-and-water-retention-value-techniques
#14
Noah D Weiss, Lisbeth Garbrecht Thygesen, Christian Roslander, Keith Gourlay, Claus Felby
The underlying mechanisms of the recalcitrance of biomass to enzymatic deconstruction are still not fully understood, and this hampers the development of biomass based fuels and chemicals. With water being necessary for most biological processes, it is suggested that interactions between water and biomass may be key to understanding and controlling biomass recalcitrance. This study investigates the correlation between biomass recalcitrance and the constraint and retention of water by the biomass, using SO2 pretreated spruce, a common feedstock for lignocellulosic biofuel production, as a substrate to evaluate this relationship...
November 1, 2016: Biotechnology Progress
https://www.readbyqxmd.com/read/27797829/genome-wide-transcriptional-profiling-and-structural-magnetic-resonance-imaging-in-the-maternal-immune-activation-model-of-neurodevelopmental-disorders
#15
Juliet Richetto, Robert Chesters, Annamaria Cattaneo, Marie A Labouesse, Ana Maria Carrillo Gutierrez, Tobias C Wood, Alessia Luoni, Urs Meyer, Anthony Vernon, Marco A Riva
Prenatal exposure to maternal infection increases the risk of neurodevelopmental disorders, including schizophrenia and autism. The molecular processes underlying this pathological association, however, are only partially understood. Here, we combined unbiased genome-wide transcriptional profiling with follow-up epigenetic analyses and structural magnetic resonance imaging to explore convergent molecular and neuromorphological alterations in corticostriatal areas of adult offspring exposed to prenatal immune activation...
October 23, 2016: Cerebral Cortex
https://www.readbyqxmd.com/read/27787955/nanomaterials-based-biosensors-for-detection-of-microorganisms-and-microbial-toxins
#16
REVIEW
Laura Sutarlie, Sian Yang Ow, Xiaodi Su
Detection of microorganisms and microbial toxins is important for health and safety. Due to their unique physical and chemical properties, nanomaterials have been extensively used to develop biosensors for rapid detection of microorganisms with microbial cells and toxins as target analytes. In this paper, the design principles of nanomaterials-based biosensors for four selected analyte categories (bacteria cells, toxins, mycotoxins, and protozoa cells), closely associated with the target analytes' properties is reviewed...
October 27, 2016: Biotechnology Journal
https://www.readbyqxmd.com/read/27766757/in-vivo-quantification-of-magnetically-labelled-cells-by-mri-relaxometry
#17
Ulysse Gimenez, Hélène Lajous, Michèle El Atifi, Marie Bidart, Vincent Auboiroux, Pascal Henry Fries, François Berger, Hana Lahrech
Cellular MRI, which visualizes magnetically labelled cells (cells*), is an active research field for in vivo cell therapy and tracking. The simultaneous relaxation rate measurements (R2 *, R2 , R1 ) are the basis of a quantitative cellular MRI method proposed here. U937 cells were labelled with Molday ION Rhodamine B, a bi-functional superparamagnetic and fluorescent nanoparticle (U937*). U937* viability and proliferation were not affected in vitro. In vitro relaxometry was performed in a cell concentration range of [2...
October 21, 2016: Contrast Media & Molecular Imaging
https://www.readbyqxmd.com/read/27759935/pulmonary-relaxometry-with-inversion-recovery-ultra-fast-steady-state-free-precession-at-1-5t
#18
Grzegorz Bauman, Francesco Santini, Orso Pusterla, Oliver Bieri
PURPOSE: To present a technique for simultaneous mapping of T1 , T2 , and relative spin density (M0 ) in human lung using inversion recovery ultra-fast steady-state free precession (IR-ufSSFP) imaging. METHODS: Pulmonary relaxometry with IR-ufSSFP is based on an interleaved time series acquisition of 2D images acquired at 1.5T. The technique was tested in a phantom and in four healthy volunteers using breath-hold and electrocardiogram triggering. Typically, 30 transient state images were acquired in a single breath-hold within < 10 s...
October 19, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/27758135/development-and-validation-of-noninvasive-magnetic-resonance-relaxometry-for-the-in-vivo-assessment-of-tissue-engineered-graft-oxygenation
#19
Samuel A Einstein, Bradley P Weegman, Meri T Firpo, Klearchos K Papas, Michael Garwood
Techniques to monitor the oxygen partial pressure (pO2) within implanted tissue-engineered grafts (TEGs) are critically necessary for TEG development, but current methods are invasive and inaccurate. In this study, we developed an accurate and noninvasive technique to monitor TEG pO2 utilizing proton ((1)H) or fluorine ((19)F) magnetic resonance spectroscopy (MRS) relaxometry. The value of the spin-lattice relaxation rate constant (R1) of some biocompatible compounds is sensitive to dissolved oxygen (and temperature), while insensitive to other external factors...
November 2016: Tissue Engineering. Part C, Methods
https://www.readbyqxmd.com/read/27753154/synthetic-quantitative-mri-through-relaxometry-modelling
#20
Martina F Callaghan, Siawoosh Mohammadi, Nikolaus Weiskopf
Quantitative MRI (qMRI) provides standardized measures of specific physical parameters that are sensitive to the underlying tissue microstructure and are a first step towards achieving maps of biologically relevant metrics through in vivo histology using MRI. Recently proposed models have described the interdependence of qMRI parameters. Combining such models with the concept of image synthesis points towards a novel approach to synthetic qMRI, in which maps of fundamentally different physical properties are constructed through the use of biophysical models...
December 2016: NMR in Biomedicine
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