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"magnetization transfer"

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...
October 18, 2016: NMR in Biomedicine
P Goossens, C Martineau-Corcos, F Saïdi, J A Martens, F Taulelle
Nafion proton exchange membranes (PEMs) for fuel cell applications are extensively studied and commercially applied, but their unique proton conduction capabilities are still somewhat unexplained. For studying proton dynamics in situ, molecular level spectroscopic techniques have been of limited utility so far. By solid-state (1)H and (19)F double resonance nuclear magnetic resonance (NMR) spectroscopy using the recently revived multiple contact cross-polarization (MC-CP) pulse sequence along with double-quantum (1)H-(1)H filtering, high resolution proton populations distinct from the dominant water resonance were observed in Nafion for the first time...
October 7, 2016: Physical Chemistry Chemical Physics: PCCP
Tiago Teixeira, Tarik Hafyane, Nikola Stikov, Cansu Akdeniz, Andreas Greiser, Matthias G Friedrich
BACKGROUND: T1 mapping based on cardiovascular magnetic resonance (CMR) is a novel approach using the magnetic relaxation T1 time as a quantitative marker for myocardial tissue composition. Various T1 mapping sequences are being used, with different strengths and weaknesses. Data comparing different sequences head to head however are sparse. METHODS: We compared three T1 mapping sequences, ShMOLLI, MOLLI and SASHA in phantoms and in a mid-ventricular slice of 40 healthy individuals (mean age 59 ± 7 years, 45 % male) with low (68 %) or moderate cardiovascular risk...
October 4, 2016: Journal of Cardiovascular Magnetic Resonance
Gautam Srivastava, Adi Moseri, Naama Kessler, Sabine R Akabayov, Boris Arshava, Fred Naider, Jacob Anglister
Weak protein-protein and protein-ligand interactions play important roles in biological recognition. In many cases, simplification of structural studies of large protein complexes is achieved by investigation of the interaction between the protein and a weakly binding segment of its protein ligand. Detection of pairwise interactions in such complexes is a major challenge for both X-ray crystallography and NMR. We demonstrate that transferrednuclear Overhauser effect, TRNOE, in combination with asymmetric deuteration of a protein and a peptide ligand can be used to detect intermolecular interactions in large protein complexes with molecular weights up to ~100 kDa...
October 4, 2016: FEBS Journal
Daniel Ontaneda, Robert J Fox
Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system. Magnetic resonance imaging (MRI) is sensitive to lesion formation both in the brain and spinal cord. Imaging plays a prominent role in the diagnosis and monitoring of MS. Over a dozen anti-inflammatory therapies are approved for MS and the development of many of these medications was made possible through the use of contrast-enhancing lesions on MRI as a phase II outcome. A similar phase II outcome method for the neurodegeneration that underlies progressive courses of the disease is still unavailable...
October 3, 2016: Neurotherapeutics: the Journal of the American Society for Experimental NeuroTherapeutics
Kai Jiang, Christopher M Ferguson, Behzad Ebrahimi, Hui Tang, Timothy L Kline, Tyson A Burningham, Prassana K Mishra, Joseph P Grande, Slobodan I Macura, Lilach O Lerman
Purpose To test the utility of magnetization transfer imaging in detecting and monitoring the progression of renal fibrosis in mice with unilateral renal artery stenosis. Materials and Methods This prospective study was approved by the Institutional Animal Care and Use Committee. Renal artery stenosis surgery (n = 10) or sham surgery (n = 5) was performed, and the stenotic and contralateral kidneys were studied longitudinally in vivo at baseline and 2, 4, and 6 weeks after surgery. After a 16.4-T magnetic resonance imaging examination, magnetization transfer ratio was measured as an index of fibrosis (guided by parameters selected in preliminary phantom studies)...
October 3, 2016: Radiology
Randall B Stafford, Myung-Kyun Woo, Se-Hong Oh, Sudipto Dolui, Tiejun Zhao, Young-Bo Kim, John A Detre, Zang-Hee Cho, Jongho Lee
7 T arterial spin labeling (ASL) faces major challenges including the increased specific absorption rate (SAR) and increased B0 and B1 inhomogeneity. This work describes the design and implementation of a dual-coil system that allows for continuous ASL (CASL) at 7 T. This system consisted of an actively detunable eight-channel transceiver head coil, and a three-channel transceiver labeling coil. Four experiments were performed in 5 healthy subjects: (i) to demonstrate that active detuning during ASL labeling reduces magnetization transfer; (ii) to measure the B1 profile at the labeling plane; (iii) to quantify B0 off-resonance at the labeling plane; and (iv) to collect in vivo CASL data...
June 2016: International Journal of Imaging Systems and Technology
James M Elliott, Sudarshan Dayanidhi, Charles Hazle, Mark A Hoggarth, Jacob McPherson, Cheryl L Sparks, Kenneth A Weber
Synopsis It is generally accepted that up to 50% of those with a whiplash injury following a motor vehicle collision will fail to fully recover. Twenty-five percent of these patients will demonstrate a markedly complex clinical picture that includes severe pain-related disability, sensory and motor disturbances, and psychological distress. A number of psychosocial factors have shown prognostic value for recovery following whiplash from a motor vehicle collision. To date, no management approach (eg, physical therapies, education, psychological interventions, or interdisciplinary strategies) for acute whiplash has positively influenced recovery rates...
October 2016: Journal of Orthopaedic and Sports Physical Therapy
Giuseppe Muscogiuri, Wolfgang G Rehwald, U Joseph Schoepf, Pal Suranyi, Sheldon E Litwin, Carlo N De Cecco, Julian L Wichmann, Stefanie Mangold, Damiano Caruso, Stephen R Fuller, Richard R Bayer 2nd, Akos Varga-Szemes
PURPOSE: To evaluate a new dark-blood late gadolinium enhancement (LGE) technique called "T(Rho) And Magnetization transfer and INvErsion Recovery" (TRAMINER) for the ability to detect myocardial LGE versus standard "bright-blood" inversion recovery (SIR) imaging. MATERIALS AND METHODS: This Institutional Review Board (IRB)-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant prospective study included 40 patients (62 ± 14 years [mean ± standard deviation (SD)], 29 males) with suspected myocardial infarction (MI) referred for the assessment of myocardial viability...
September 30, 2016: Journal of Magnetic Resonance Imaging: JMRI
Paul Kyu Han, Seung Hong Choi, Sung-Hong Park
PURPOSE: To investigate the performance of control scans in pseudo-continuous ASL (pCASL) and propose strategies for improving sensitivity and reliability of pCASL. METHODS: The labeling efficiencies of pCASL with conventional control scan and distal control scan were investigated at various radiofrequency (RF) duration/spacing of 0.5/1-2/4 ms, mean slice-selection gradients (GSS ) of 1 and 0 mT/m, and total labeling durations of 1.5-3 s, through Bloch equation simulations and in vivo experiments...
September 30, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Kimberly L Desmond, Hatef Mehrabian, Sofia Chavez, Arjun Sahgal, Hany Soliman, Radoslaw Rola, Greg J Stanisz
PURPOSE: The purpose of this work was to determine the predictive value of chemical exchange saturation transfer (CEST) metrics in brain metastases treated with stereotactic radiosurgery (SRS). METHODS: CEST spectra at a radiofrequency power of 0.52 µT were collected on a 3 Tesla (T) magnetic resonance imaging from 25 patients at three time points: pretreatment, 1 week, and 1 month post-treatment. Amide proton transfer-weighted images and maps of the amplitude and width of Lorentzian-shaped CEST peaks and the relaxation-compensated AREX metric were constructed at the offset frequencies of amide, amine, and relayed nuclear Overhauser effect (NOE) from aliphatic groups as well as the broad magnetization transfer effect...
September 30, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Jason Langley, Daniel E Huddleston, Christine J Liu, Xiaoping Hu
OBJECTIVES: The purpose of this study was to assess the reproducibility of substantia nigra pars compacta (SNpc) and locus coeruleus (LC) delineation and measurement with neuromelanin-sensitive MRI. MATERIALS AND METHODS: Eleven subjects underwent two neuromelanin-sensitive MRI scans. SNpc and LC volumes were extracted for each scan. Reproducibility of volume and magnetization transfer contrast measurements in SNpc and LC was assessed using intraclass correlation coefficients (ICC) and dice similarity coefficients (DSC)...
September 29, 2016: Magma
Caroline Guglielmetti, Debbie Le Blon, Eva Santermans, Angelica Salas-Perdomo, Jasmijn Daans, Nathalie De Vocht, Disha Shah, Chloé Hoornaert, Jelle Praet, Jurgen Peerlings, Firat Kara, Christian Bigot, Zhenhua Mai, Herman Goossens, Niel Hens, Sven Hendrix, Marleen Verhoye, Anna M Planas, Zwi Berneman, Annemie van der Linden, Peter Ponsaerts
Detrimental inflammatory responses in the central nervous system are a hallmark of various brain injuries and diseases. With this study we provide evidence that lentiviral vector-mediated expression of the immune-modulating cytokine interleukin 13 (IL-13) induces an alternative activation program in both microglia and macrophages conferring protection against severe oligodendrocyte loss and demyelination in the cuprizone mouse model for multiple sclerosis (MS). First, IL-13 mediated modulation of cuprizone induced lesions was monitored using T2 -weighted magnetic resonance imaging and magnetization transfer imaging, and further correlated with quantitative histological analyses for inflammatory cell influx, oligodendrocyte death, and demyelination...
September 29, 2016: Glia
Yan Zhang, Wenwen Liang, Guijun Wu, Xuelin Zhang, Ge Wen
BACKGROUND: Glaucoma is a neurodegenerative disease that affects both the retina and central visual pathway. Magnetization transfer imaging (MTI) is a sensitive magnetic resonance imaging (MRI) technique that can detect degenerative changes in the brain. PURPOSE: To investigate the geniculocalcarine (GCT) and striate areas in primary glaucoma patients using region of interest (ROI) analysis of magnetization transfer ratio (MTR). MATERIAL AND METHODS: Twenty patients with primary glaucoma in both eyes were compared with 31 healthy control patients...
September 2016: Acta Radiologica Open
Anna V Naumova, Andrey E Akulov, Marina Yu Khodanovich, Vasily L Yarnykh
A well-known problem in ultra-high-field MRI is generation of high-resolution three-dimensional images for detailed characterization of white and gray matter anatomical structures. T1-weighted imaging traditionally used for this purpose suffers from the loss of contrast between white and gray matter with an increase of magnetic field strength. Macromolecular proton fraction (MPF) mapping is a new method potentially capable to mitigate this problem due to strong myelin-based contrast and independence of this parameter of field strength...
September 17, 2016: NeuroImage
Se-Hong Oh, Wanyong Shin, Jongho Lee, Mark J Lowe
As the use of ultra-high field (UHF; ≥ 7 T) magnetic resonance (MR) imaging expands, there is an increasing need to establish high-resolution MR imaging protocols for (R2.1)patients with neurological disease. (R2.3)Magnetization transfer (MT) imaging has been used to provide information about changes in the magnitude of the restricted protons that are caused by tissue damages. (R2.17)Several studies have found that MTR has a good sensitivity to measure changes in myelin concentration within the brain. Because of the much higher specific absorption rate (SAR) of tissue and longer acquisition time required for UHF, however, in-vivo studies using (R2...
September 12, 2016: NeuroImage
Zhengfeng Zhang, Yanke Chen, Jun Yang
We propose a robust band-selective heteronuclear (15)N-(13)C recoupling method using dual back-to-back (BABA) pulses (DBP). It contains four 90° pulses in each rotor period and corresponding phase cycling on each channel ((13)C and (15)N). DBP aims at rapid band-selective heteronuclear magnetization transfer between (15)N and (13)Cα/(13)C', whose efficiency is close to that of the well-known SPECIFIC CP in membrane proteins with relatively short relaxation time in rotating frame (T1ρ). Compared to SPECIFIC CP, DBP is very simple to set up and highly robust to RF variations...
September 6, 2016: Journal of Magnetic Resonance
Xiao-Yong Zhang, Feng Wang, Tao Jin, Junzhong Xu, Jingping Xie, Daniel F Gochberg, John C Gore, Zhongliang Zu
PURPOSE: To detect, map, and quantify a novel nuclear Overhauser enhancement (NOE)-mediated magnetization transfer (MT) with water at approximately -1.6 ppm [NOE(-1.6)] in rat brain using MRI. METHODS: Continuous wave MT sequences with a variety of radiofrequency irradiation powers were optimized to achieve the maximum contrast of this NOE(-1.6) effect at 9.4 T. The distribution of effect magnitudes, resonance frequency offsets, and line widths in healthy rat brains and the differences of the effect between tumors and contralateral normal brains were imaged and quantified using a multi-Lorentzian fitting method...
September 8, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Ya-Jun Ma, Hongda Shao, Jiang Du, Eric Y Chang
MRI biomarkers such as T2 , T2 * and T1rho have been widely used, but are confounded by the magic angle effect. The purpose of this study is to investigate the use of the two-dimensional ultrashort echo time magnetization transfer (UTE-MT) sequence for potential magic angle independent MR biomarkers. Magnetization transfer was investigated in cadaveric Achilles tendon samples using the UTE-MT sequence at five MT powers and five frequency offsets ranging from 2 to 50 kHz. The protocol was applied at five sample orientations ranging from 0 to 90° relative to the B0 field...
November 2016: NMR in Biomedicine
Young Han Lee, Jaemoon Yang, Ha-Kyu Jeong, Jin-Suck Suh
PURPOSE: Biochemical imaging of glycosaminoglycan chemical exchange saturation transfer (gagCEST) could predict the depletion of glycosaminoglycans (GAG) in early osteoarthritis. The purpose of this study was to evaluate the relationship between the magnetization transfer ratio asymmetry (MTRasym) of gagCEST images and visual analog scale (VAS) pain scores in the knee joint. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board...
August 28, 2016: Magnetic Resonance Imaging
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