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Sample records for quantitative proton magnetic

  1. Determination of scutellarin in breviscapine preparations using quantitative proton nuclear magnetic resonance spectroscopy

    Directory of Open Access Journals (Sweden)

    Zhenzuo Jiang

    2016-04-01

    Full Text Available The objective of the present study was to develop the selection criteria of proton signals for the determination of scutellarin using quantitative nuclear magnetic resonance (qNMR, which is the main bioactive compound in breviscapine preparations for the treatment of cerebrovascular disease. The methyl singlet signal of 3-(trimethylsilylpropionic-2,2,3,3-d4 acid sodium salt was selected as the internal standard for quantification. The molar concentration of scutellarin was determined by employing different proton signals. To obtain optimum proton signals for the quantification, different combinations of proton signals were investigated according to two selection criteria: the recovery rate of qNMR method and quantitative results compared with those obtained with ultra-performance liquid chromatography. As a result, the chemical shift of H-2′ and H-6′ at δ 7.88 was demonstrated as the most suitable signal with excellent linearity range, precision, and recovery for determining scutellarin in breviscapine preparations from different manufacturers, batch numbers, and dosage forms. Hierarchical cluster analysis was employed to evaluate the determination results. The results demonstrated that the selection criteria of proton signals established in this work were reliable for the qNMR study of scutellarin in breviscapine preparations.

  2. Absolute quantitative analysis for sorbic acid in processed foods using proton nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Ohtsuki, Takashi; Sato, Kyoko; Sugimoto, Naoki; Akiyama, Hiroshi; Kawamura, Yoko

    2012-01-01

    Highlights: ► A method using qHNMR was applied and validated to determine SA in processed foods. ► This method has good accuracy, precision, selectiveness, and linearity. ► The proposed method is more rapid and simple than the conventional method. ► We found that the proposed method is reliable for the accurate determination of SA. ► This method can be used for the monitoring of SA in processed foods. - Abstract: An analytical method using solvent extraction and quantitative proton nuclear magnetic resonance (qHNMR) spectroscopy was applied and validated for the absolute quantification of sorbic acid (SA) in processed foods. The proposed method showed good linearity. The recoveries for samples spiked at the maximum usage level specified for food in Japan and at 0.13 g kg −1 (beverage: 0.013 g kg −1 ) were larger than 80%, whereas those for samples spiked at 0.063 g kg −1 (beverage: 0.0063 g kg −1 ) were between 56.9 and 83.5%. The limit of quantification was 0.063 g kg −1 for foods (and 0.0063 g kg −1 for beverages containing Lactobacillus species). Analysis of the SA content of commercial processed foods revealed quantities equal to or greater than those measured using conventional steam-distillation extraction and high-performance liquid chromatography quantification. The proposed method was rapid, simple, accurate, and precise, and provided International System of Units traceability without the need for authentic analyte standards. It could therefore be used as an alternative to the quantification of SA in processed foods using conventional method.

  3. Absolute quantitative analysis for sorbic acid in processed foods using proton nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ohtsuki, Takashi, E-mail: ohtsuki@nihs.go.jp [National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 (Japan); Sato, Kyoko; Sugimoto, Naoki; Akiyama, Hiroshi; Kawamura, Yoko [National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 (Japan)

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer A method using qHNMR was applied and validated to determine SA in processed foods. Black-Right-Pointing-Pointer This method has good accuracy, precision, selectiveness, and linearity. Black-Right-Pointing-Pointer The proposed method is more rapid and simple than the conventional method. Black-Right-Pointing-Pointer We found that the proposed method is reliable for the accurate determination of SA. Black-Right-Pointing-Pointer This method can be used for the monitoring of SA in processed foods. - Abstract: An analytical method using solvent extraction and quantitative proton nuclear magnetic resonance (qHNMR) spectroscopy was applied and validated for the absolute quantification of sorbic acid (SA) in processed foods. The proposed method showed good linearity. The recoveries for samples spiked at the maximum usage level specified for food in Japan and at 0.13 g kg{sup -1} (beverage: 0.013 g kg{sup -1}) were larger than 80%, whereas those for samples spiked at 0.063 g kg{sup -1} (beverage: 0.0063 g kg{sup -1}) were between 56.9 and 83.5%. The limit of quantification was 0.063 g kg{sup -1} for foods (and 0.0063 g kg{sup -1} for beverages containing Lactobacillus species). Analysis of the SA content of commercial processed foods revealed quantities equal to or greater than those measured using conventional steam-distillation extraction and high-performance liquid chromatography quantification. The proposed method was rapid, simple, accurate, and precise, and provided International System of Units traceability without the need for authentic analyte standards. It could therefore be used as an alternative to the quantification of SA in processed foods using conventional method.

  4. The investigations on the use of proton magnetic resonance in the quantitative analysis of organis compounds. Part 1. Review of analytical methods

    International Nuclear Information System (INIS)

    Ciercierska-Stoklosa, D.

    1976-01-01

    The review of papers on the application of proton magnetic resonance in quantitative analyisis of organic compounds in multicomponent mixtures has been presented. The applied techniques have been described and unified way of presentation of formulas used in calculations has been propsed. The information about precision, accuracy and detectability of the method and the possibility of improving of determination has been given. (author)

  5. Short TE quantitative proton magnetic resonance spectroscopy in variant Creutzfeldt-Jakob disease

    International Nuclear Information System (INIS)

    Cordery, R.J.; Godbolt, A.; Rossor, M.N.; MacManus, D.; Waldman, A.D.

    2006-01-01

    Variant Creutzfeldt-Jakob disease (vCJD) is a fatal neurodegerative disorder. Clinical diagnosis is difficult in the early stages as the disease often presents with non-specific psychiatric and neurological symptoms. To investigate the diagnostic potential of quantitative short TE in vivo MRS, and the nature and anatomical distribution of biochemical abnormalities in vCJD, localised single-voxel spectra (TE/TR 30 ms/2,000 ms) were acquired from three brain regions: thalami, caudate nuclei and frontal white matter. Metabolite concentrations and ratios from three patients with definite or probable vCJD were compared with eight normal age-matched controls. Abnormal signal on T2-weighted MRI was apparent in the pulvinar region in all vCJD patients; this region also showed greatly increased myo-inositol [MI] (mean 2.5-fold, P=0.01) and decreased N-acetyl-aspartate (NAA; mean 2-fold, P=0.01). Two patients also showed increased [MI] (z=17, 11; one with decreased NAA, z=-12) in normal-appearing caudate nuclei. The magnitude of metabolite abnormalities in the thalami in moderately advanced vCJD suggests a potential role in earlier diagnosis. Short TE protocols allow the measurement of MI, which adds discriminant power to the MRS examination. (orig.)

  6. Short TE quantitative proton magnetic resonance spectroscopy in variant Creutzfeldt-Jakob disease

    Energy Technology Data Exchange (ETDEWEB)

    Cordery, R.J.; Godbolt, A.; Rossor, M.N. [University College London, Dementia Research Group, Institute of Neurology, London (United Kingdom); Imperial College of Science, Technology and Medicine, Division of Neuroscience and Psychological Medicine, Faculty of Medicine, London (United Kingdom); MacManus, D. [University College London, NMR Research Unit, Department of Clinical Neurology,Institute of Neurology, London (United Kingdom); Waldman, A.D. [University College London, Dementia Research Group, Institute of Neurology, London (United Kingdom); Imperial College of Science, Technology and Medicine, Division of Neuroscience and Psychological Medicine, Faculty of Medicine, London (United Kingdom); Charing Cross Hospital, Department of Imaging, London (United Kingdom); National Hospital for Neurology and Neurosurgery, Dementia Research Group, London (United Kingdom)

    2006-08-15

    Variant Creutzfeldt-Jakob disease (vCJD) is a fatal neurodegerative disorder. Clinical diagnosis is difficult in the early stages as the disease often presents with non-specific psychiatric and neurological symptoms. To investigate the diagnostic potential of quantitative short TE in vivo MRS, and the nature and anatomical distribution of biochemical abnormalities in vCJD, localised single-voxel spectra (TE/TR 30 ms/2,000 ms) were acquired from three brain regions: thalami, caudate nuclei and frontal white matter. Metabolite concentrations and ratios from three patients with definite or probable vCJD were compared with eight normal age-matched controls. Abnormal signal on T2-weighted MRI was apparent in the pulvinar region in all vCJD patients; this region also showed greatly increased myo-inositol [MI] (mean 2.5-fold, P=0.01) and decreased N-acetyl-aspartate (NAA; mean 2-fold, P=0.01). Two patients also showed increased [MI] (z=17, 11; one with decreased NAA, z=-12) in normal-appearing caudate nuclei. The magnitude of metabolite abnormalities in the thalami in moderately advanced vCJD suggests a potential role in earlier diagnosis. Short TE protocols allow the measurement of MI, which adds discriminant power to the MRS examination. (orig.)

  7. Quantitative proton magnetic resonance spectroscopy of the normal liver and malignant hepatic lesions at 3.0 Tesla

    International Nuclear Information System (INIS)

    Fischbach, F.; Thormann, M.; Ricke, J.; Schirmer, T.; Freund, T.; Bruhn, H.

    2008-01-01

    This comparative study of tumour patients and volunteers aimed at differentiating liver parenchyma from neoplastic lesions by using localised 1 H MRS at 3.0 T as an adjunct to MRI. In total 186 single-voxel proton spectra of the liver were acquired at 3.0 T using the body transmit receive coil. Consecutive stacks of breath-hold spectra were acquired in the PRESS technique at a short echo time of 35 ms and a repetition time of 2,000 ms. Processing of the spectra included spectral alignment with the software package SAGE and quantitative processing with LCModel. The resulting metabolite concentrations were presented in arbitrary units relative to the internal water. In general, the spectra showed four main groups of resonances originating from the methyl protons (0.8-1.1 ppm) and methylene protons of the lipids (1.1-1.5 ppm; 2.0-2.2 ppm) as well as the methyl protons of choline-containing compounds (CCC) at 3.2 ppm. Overall, the CCC and lipid values in malignant liver tumours showed no significant differences to liver parenchyma. On average, total lipid measurements in normal liver parenchyma increased with age, while those of the CCC did not show pertinent changes. Significant differences between the contents of CCC in malignant liver tumours and normal liver parenchyma were not observed, because in patients and volunteers normal liver tissue showed a large variability in the content of CCC. (orig.)

  8. Quantitative in vivo detection of brain cell death after hypoxia ischemia using the lipid peak at 1.3 ppm of proton magnetic resonance spectroscopy in neonatal rats.

    Science.gov (United States)

    Ahn, So Yoon; Yoo, Hye Soo; Lee, Jang Hoon; Sung, Dong Kyung; Jung, Yu Jin; Sung, Se In; Lim, Keun Ho; Chang, Yun Sil; Lee, Jung Hee; Kim, Ki Soo; Park, Won Soon

    2013-07-01

    This study was performed to determine the accuracy of proton magnetic spectroscopy ((1)H-MRS) lipid peak as a noninvasive tool for quantitative in vivo detection of brain cell death. Seven day-old Sprague Dawley rats were subjected to 8% oxygen following a unilateral carotid artery ligation. For treatment, cycloheximide was given immediately after hypoxic ischemia (HI). Lipid peak was measured using (1)H-MRS at 24 hr after HI, and then brains were harvested for fluorocytometric analyses with annexin V/propidium iodide (PI) and fluorescent probe JC-1, and for adenosine-5'-triphosphate (ATP) and lactate. Increased lipid peak at 1.3 ppm measured with (1)H-MRS, apoptotic and necrotic cells, and loss of mitochondrial membrane potential (ΔΨ) at 24 hr after HI were significantly improved with cycloheximide treatment. Significantly reduced brain ATP and increased lactate levels observed at 24 hr after HI showed a tendency to improve without statistical significance with cycloheximide treatment. Lipid peak at 1.3 ppm showed significant positive correlation with both apoptotic and necrotic cells and loss of ΔΨ, and negative correlation with normal live cells. Lipid peak at 1.3 ppm measured by (1)H-MRS might be a sensitive and reliable diagnostic tool for quantitative in vivo detection of brain cell death after HI.

  9. Region-specific effects on brain metabolites of hypoxia and hyperoxia overlaid on cerebral ischemia in young and old rats: a quantitative proton magnetic resonance spectroscopy study

    Directory of Open Access Journals (Sweden)

    Giuliani Patricia

    2010-02-01

    Full Text Available Abstract Background Both hypoxia and hyperoxia, deregulating the oxidative balance, may play a role in the pathology of neurodegenerative disorders underlain by cerebral ischemia. In the present study, quantitative proton magnetic resonance spectroscopy was used to evaluate regional metabolic alterations, following a 24-hour hypoxic or hyperoxic exposure on the background of ischemic brain insult, in two contrasting age-groups of rats: young - 3 months old and aged - 24 months old. Methods Cerebral ischemia was induced by ligation of the right common carotid artery. Concentrations of eight metabolites (alanine, choline-containing compounds, total creatine, γ-aminobutyric acid, glutamate, lactate, myo-inositol and N-acetylaspartate were quantified from extracts in three different brain regions (fronto-parietal and occipital cortices and the hippocampus from both hemispheres. Results In the control normoxic condition, there were significant increases in lactate and myo-inositol concentrations in the hippocampus of the aged rats, compared with the respective values in the young ones. In the ischemia-hypoxia condition, the most prevalent changes in the brain metabolites were found in the hippocampal regions of both young and aged rats; but the effects were more evident in the aged animals. The ischemia-hyperoxia procedure caused less dedicated changes in the brain metabolites, which may reflect more limited tissue damage. Conclusions We conclude that the hippocampus turns out to be particularly susceptible to hypoxia overlaid on cerebral ischemia and that old age further increases this susceptibility.

  10. Optically transmitted and inductively coupled electric reference to access in vivo concentrations for quantitative proton-decoupled ¹³C magnetic resonance spectroscopy.

    Science.gov (United States)

    Chen, Xing; Pavan, Matteo; Heinzer-Schweizer, Susanne; Boesiger, Peter; Henning, Anke

    2012-01-01

    This report describes our efforts on quantification of tissue metabolite concentrations in mM by nuclear Overhauser enhanced and proton decoupled (13) C magnetic resonance spectroscopy and the Electric Reference To access In vivo Concentrations (ERETIC) method. Previous work showed that a calibrated synthetic magnetic resonance spectroscopy-like signal transmitted through an optical fiber and inductively coupled into a transmit/receive coil represents a reliable reference standard for in vivo (1) H magnetic resonance spectroscopy quantification on a clinical platform. In this work, we introduce a related implementation that enables simultaneous proton decoupling and ERETIC-based metabolite quantification and hence extends the applicability of the ERETIC method to nuclear Overhauser enhanced and proton decoupled in vivo (13) C magnetic resonance spectroscopy. In addition, ERETIC signal stability under the influence of simultaneous proton decoupling is investigated. The proposed quantification method was cross-validated against internal and external reference standards on human skeletal muscle. The ERETIC signal intensity stability was 100.65 ± 4.18% over 3 months including measurements with and without proton decoupling. Glycogen and unsaturated fatty acid concentrations measured with the ERETIC method were in excellent agreement with internal creatine and external phantom reference methods, showing a difference of 1.85 ± 1.21% for glycogen and 1.84 ± 1.00% for unsaturated fatty acid between ERETIC and creatine-based quantification, whereas the deviations between external reference and creatine-based quantification are 6.95 ± 9.52% and 3.19 ± 2.60%, respectively. Copyright © 2011 Wiley Periodicals, Inc.

  11. Internal magnetic target of proton synchrotron

    International Nuclear Information System (INIS)

    Gachurin, V.V.; Kats, M.M.; Kondrat'ev, L.N.; Rogal', A.D.; Rusinov, V.Yu.

    1988-01-01

    Proton extraction from a synchrotron by means of an internal target of magnetized iron is described. The particles that are aimed at the target pass directly through it and are deflected by the internal magnetic field of the target in the extraction direction. The general properties of magnetic targets are examined theoretically and a specific devices and results of its testing are described

  12. Regional brain metabolite abnormalities in inherited prion disease and asymptomatic gene carriers demonstrated in vivo by quantitative proton magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Waldman, A.D.; Cordery, R.J.; Godbolt, A.; Rossor, M.N. [University College London, Dementia Research Group, Department of Neurodegenerative Disease, Institute of Neurology, London (United Kingdom); Imperial College of Science, Technology and Medicine, Division of Neuroscience and Psychological Medicine, Faculty of Medicine, London (United Kingdom); MacManus, D.G. [University College London, NMR Research Unit, Department of Clinical Neurology, Institute of Neurology, London (United Kingdom); Collinge, J. [University College London, MRC Prion Unit, Department of Neurodegenerative Disease, Institute of Neurology, London (United Kingdom)

    2006-06-15

    Inherited prion diseases are caused by mutations in the gene which codes for prion protein (PrP), leading to proliferation of abnormal PrP isomers in the brain and neurodegeneration; they include Gerstmann-Straeussler-Scheinker disease (GSS), fatal familial insomnia (FFI) and familial Creutzfeldt-Jakob disease (fCJD). We studied two patients with symptomatic inherited prion disease (P102L) and two pre-symptomatic P102L gene carriers using quantitative magnetic resonance spectroscopy (MRS). Short echo time spectra were acquired from the thalamus, caudate region and frontal white matter, metabolite levels and ratios were measured and z-scores calculated for individual patients relative to age-matched normal controls. MRS data were compared with structural magnetic resonance imaging. One fCJD case had generalised atrophy and showed increased levels of myo-inositol (MI) in the thalamus (z=3.7). The other had decreased levels of N-acetylaspartate (z=4) and diffuse signal abnormality in the frontal white matter. Both asymptomatic gene carriers had normal imaging, but increased frontal white matter MI (z=4.3, 4.1), and one also had increased MI in the caudate (z=5.3). Isolated MI abnormalities in asymptomatic gene carriers are a novel finding and may reflect early glial proliferation, prior to significant neuronal damage. MRS provides potential non-invasive surrogate markers of early disease and progression in inherited prion disease. (orig.)

  13. Regional brain metabolite abnormalities in inherited prion disease and asymptomatic gene carriers demonstrated in vivo by quantitative proton magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Waldman, A.D.; Cordery, R.J.; Godbolt, A.; Rossor, M.N.; MacManus, D.G.; Collinge, J.

    2006-01-01

    Inherited prion diseases are caused by mutations in the gene which codes for prion protein (PrP), leading to proliferation of abnormal PrP isomers in the brain and neurodegeneration; they include Gerstmann-Straeussler-Scheinker disease (GSS), fatal familial insomnia (FFI) and familial Creutzfeldt-Jakob disease (fCJD). We studied two patients with symptomatic inherited prion disease (P102L) and two pre-symptomatic P102L gene carriers using quantitative magnetic resonance spectroscopy (MRS). Short echo time spectra were acquired from the thalamus, caudate region and frontal white matter, metabolite levels and ratios were measured and z-scores calculated for individual patients relative to age-matched normal controls. MRS data were compared with structural magnetic resonance imaging. One fCJD case had generalised atrophy and showed increased levels of myo-inositol (MI) in the thalamus (z=3.7). The other had decreased levels of N-acetylaspartate (z=4) and diffuse signal abnormality in the frontal white matter. Both asymptomatic gene carriers had normal imaging, but increased frontal white matter MI (z=4.3, 4.1), and one also had increased MI in the caudate (z=5.3). Isolated MI abnormalities in asymptomatic gene carriers are a novel finding and may reflect early glial proliferation, prior to significant neuronal damage. MRS provides potential non-invasive surrogate markers of early disease and progression in inherited prion disease. (orig.)

  14. Focussing magnets for proton Linac of ADS

    International Nuclear Information System (INIS)

    Malhotra, Sanjay; Mahapatra, U.; Singh, Pitamber; Choudhury, R.K.; Goel, Priyanshu; Verma, Vishnu; Bhattacharya, S.; Srivastava, G.P.; Kailas, S.; Sahni, V.C.

    2009-01-01

    A linear accelerator comprising of Radio frequency quadruple (RFQ) and drift tube linac (DTL) is being developed by BARC. The Alvarez type post-coupled cw DTL accelerates protons from an energy of 3 MeV to 20 MeV. The drift tube linac is excited in TM010 mode, wherein the particles are accelerated by longitudinal electric fields at the gap crossings between drift tubes. The particles are subjected to transverse RF defocusing forces at the gap crossings due to the increasing electric fields in the gap. The transverse defocusing is corrected by housing magnetic quadrupole focussing lenses inside the drift tubes. The permanent magnet quadrupoles (PMQs) are placed inside the hermetically sealed drift tubes and provide a constant magnetic field gradient in the beam aperture. This paper discusses various aspects of magnetic design, selection of magnetic materials and the engineering development involved in the prototype development of these drift tubes for proton Linac. (author)

  15. Proton capture by magnetic monopoles

    International Nuclear Information System (INIS)

    Olaussen, K.; Olsen, H.A.; Oeverboe, I.; Osland, P.

    1983-09-01

    In the Kazama-Yang approximation, the lowest monopole-proton bound states have binding energies of 938 MeV, 263 keV, 105 eV, and 0.04 eV. The cross section for radiative capture to these states is for velocities β = 10 -5 - 10 -3 found to be of the order of 10 -28 - 10 -26 cm 2 . For the state that has a binding energy of 263 keV, the capture length in water is 171 x (β/10 -4 )sup(0.48) m. Observation of photons from the capture process would indicate the presence of monopoles. (orig.)

  16. Quantitative PIXE at low proton energy

    International Nuclear Information System (INIS)

    Oliver, Alicia

    1994-01-01

    The energy of the proton beam plays an important role in the type of analysis that is intended. The need to take into account energy loss of the particles beam inside the specimen, the energy variation of the ionisation cross section for K and L lines, secondary fluorescence, and the surface topography draws the line between thin and thick target analysis. We present here the difficulties, calibrations and calculations for the ionisation cross sections needed to quantify at proton energies below one MeV. As conclusion we show with an example the necessity of reliable standards. (author)

  17. Magnetic monopole catalysis of proton decay

    International Nuclear Information System (INIS)

    Marciano, W.J.; Salvino, D.

    1986-09-01

    Catalysis of proton decay by GUT magnetic monopoles (the Rubakov-Callan effect) is discussed. Combining a short-distance cross section calculation by Bernreuther and Craigie with the long-distance velocity dependent distortion factors of Arafune and Fukugita, catalysis rate predictions which can be compared with experiment are obtained. At present, hydrogen rich detectors such as water (H 2 O) and methane (CH 4 ) appear to be particularly well suited for observing catalysis by very slow monopoles. 17 refs., 1 fig

  18. Proton magnetic resonance spectroscopic imaging in neurodegenerative diseases

    International Nuclear Information System (INIS)

    Schuff, Norbert; Vermathen, Peter; Maudsley, Andrew A.; Weiner, Michael W.

    1999-01-01

    Proton magnetic resonance spectroscopic imaging ( 1 H MRSI) was used to investigate changes in brain metabolites in Alzheimer's disease, epilepsy, and amyotrophic lateral sclerosis. Examples of results from several ongoing clinical studies are provided. Multislice 1 H MRSI of the human brain, without volume pre selection offers considerable advantage over previously available techniques. Furthermore, MRI tissue segmentation and completely automated spectral curve fitting greatly facilitate quantitative data analysis. Future efforts will be devoted to obtain full volumetric brain coverage and data acquisition at short spin-echo times (TE<30 ms) for the detection of metabolites. (author)

  19. Proton magnetic resonance spectroscopy in schizophrenia

    International Nuclear Information System (INIS)

    Bertolino, Alessandro; Weinberger, Daniel R.

    1999-01-01

    Proton magnetic resonance spectroscopy (MRS) has become an important tool to study in vivo certain biochemical aspects of brain disorders. In the last decade this technique has been applied to the in vivo investigation of pathophysiological aspects of psychiatric disorders, extending knowledge of the related brain alterations. This review will focus on providing some background to clarify technical and biochemical issues and it will describe the studies that have been performed in schizophrenia. The results will be framed in a more general context to highlight what we have learned and what remains to be understood from the application of this technique to schizophrenia

  20. Porphyrin Protonation Studied by Magnetic Circular Dichroism

    Czech Academy of Sciences Publication Activity Database

    Štěpánek, Petr; Andrushchenko, Valery; Ruud, K.; Bouř, Petr

    2012-01-01

    Roč. 116, č. 1 (2012), s. 778-783 ISSN 1089-5639 R&D Projects: GA ČR GAP208/11/0105; GA ČR GA203/09/2037; GA ČR GAP208/10/0559; GA MŠk(CZ) LH11033 Institutional research plan: CEZ:AV0Z40550506 Keywords : magnetic circular dichroism ( MCD ) * TPPS * spectra simulations * porphyrin protonation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.771, year: 2012

  1. Proton magnetic resonance spectroscopy in the fetus.

    Science.gov (United States)

    Story, Lisa; Damodaram, Mellisa S; Allsop, Joanna M; McGuinness, Amy; Wylezinska, Marzena; Kumar, Sailesh; Rutherford, Mary A

    2011-09-01

    Magnetic Resonance Imaging (MRI) has become an established technique in fetal medicine, providing complementary information to ultrasound in studies of the brain. MRI can provide detailed structural information irrespective of the position of the fetal head or maternal habitus. Proton Magnetic Resonance Spectroscopy ((1)HMRS) is based on the same physical principles as MRI but data are collected as a spectrum, allowing the biochemical and metabolic status of in vivo tissue to be studied in a non-invasive manner. (1)HMRS has been used to assess metabolic function in the neonatal brain but fetal studies have been limited, primarily due to fetal motion. This review will assess the technique and findings from fetal studies to date. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  2. Proton Density Fat-Fraction of Rotator Cuff Muscles Is Associated With Isometric Strength 10 Years After Rotator Cuff Repair: A Quantitative Magnetic Resonance Imaging Study of the Shoulder.

    Science.gov (United States)

    Karampinos, Dimitrios C; Holwein, Christian; Buchmann, Stefan; Baum, Thomas; Ruschke, Stefan; Gersing, Alexandra S; Sutter, Reto; Imhoff, Andreas B; Rummeny, Ernst J; Jungmann, Pia M

    2017-07-01

    Quantitative muscle fat-fraction magnetic resonance (MR) imaging techniques correlate with semiquantitative Goutallier scores with failure after rotator cuff (RC) repair. To investigate the relationship of proton density fat fraction (PDFF) of the RC muscles with semiquantitative MR scores, cartilage T2 relaxation times, and clinical isometric strength measurements in patients 10 years after unilateral RC repair. Cross-sectional study; Level of evidence, 3. Bilateral shoulder MR imaging was performed in 13 patients (11 male, 2 female; age, 72 ± 8 years) 10.9 ± 0.4 years after unilateral autologous periosteal flap augmented RC repair (total shoulders assessed, N = 26). Goutallier classification, muscle atrophy, RC tendon integrity, and cartilage defects were determined based on morphological MR sequences. A paracoronal 2D multi-slice multi-echo sequence was used for quantitative cartilage T2 mapping. A chemical shift-encoding-based water-fat separation technique (based on a 6-echo 3D spoiled gradient echo sequence) was used for quantification of the PDFF of RC muscles. Isometric shoulder abduction strength was measured clinically. Mean and SD, Pearson correlation, and partial Spearman correlation were calculated. There were 6 RC full-thickness retears in ipsilateral shoulders and 6 RC full-thickness tears in contralateral shoulders. Isometric shoulder abduction strength was not significantly different between ipsilateral and contralateral shoulders (50 ± 24 N vs 54 ± 24 N; P = .159). The mean PDFF of RC muscles was 11.7% ± 10.4% (ipsilateral, 14.2% ± 8.5%; contralateral, 9.2% ± 7.8%; P = .002). High supraspinatus PDFF correlated significantly with higher Goutallier scores ( R = 0.75, P isometric muscle strength ( R = -0.49, P = .011). This correlation remained significant after adjustment for muscle area measurements and tendon rupture ( R = -0.41, P = .048). More severe cartilage defects at the humerus were significantly associated with higher supraspinatus

  3. Strange magnetism and the anapole structure of the proton

    International Nuclear Information System (INIS)

    Hasty, R.; Beck, D.H.; Danagoulian, A.; Blake, A.; Carr, R.; Covrig, S.; Filipoone, B.W.; Ito, T.M.; Gao, J.; Jones, C.E.; Lee, P.; McKeown, R.D.; Savu, V.; Beise, E.J.; Breuer, H.; Spayde, D.T.; Tieulent, R.; Herda, M.C.; Barkhuff, D.; Dodson, G.; Dow, K.; Farkhondeh, M.; Kowalski, S.; Tsentalovich, E.; Yang, B.; Zwart, T.; Hawthorne-Allen, A.M.; Pitt, M.; Ritter, J.; Korsch, W.; Mueller, B.; Wells, S.P.; Averett, T.; Roche, J.; Kramer, K.

    2000-01-01

    The violation of mirror symmetry in the weak force provides a powerful tool to study the internal structure of the proton. Experimental results have been obtained that address the role of strange quarks in generating nuclear magnetism. The measurement reported here provides an unambiguous constraint on strange quark contributions to the proton's magnetic moment through the electron-proton weak interaction. We also report evidence for the existence of a parity-violating electromagnetic effect known as the anapole moment of the proton. The proton's anapole moment is not yet well understood theoretically, but it could have important implications for precision weak interaction studies in atomic systems such as cesium.

  4. Design of magnetic analysis system for magnetic proton recoil spectrometer

    International Nuclear Information System (INIS)

    Qi Jianmin; Jiang Shilun; Zhou Lin; Peng Taiping

    2010-01-01

    Magnetic proton recoil (MPR) spectrometer is a novel diagnostic instrument with high performance for measurements of the neutron spectra from inertial confinement fusion (ICF) experiments and high power fusion devices. The design of the magnetic analysis system, which is a key part of the compact MPR-type spectrometer, has been completed through two-dimensional beam transport simulations and three-dimensional particle transport simulation. The analysis of the system's parameters and performances was performed, as well as system designs based on preferential principles of energy resolution, detection efficiency, and count rate, respectively. The results indicate that the magnetic analysis system can achieve a detection efficiency of 10 -5 ∼ 10 -4 level at the resolution range of 1.5% to 3.0% and fulfill the design goals of the compact MPR spectrometer. (authors)

  5. Quantitative Magnetization Transfer Imaging in Human Brain at 3 T via Selective Inversion Recovery

    OpenAIRE

    Dortch, Richard D.; Li, Ke; Gochberg, Daniel F.; Welch, E. Brian; Dula, Adrienne N.; Tamhane, Ashish A.; Gore, John C.; Smith, Seth A.

    2011-01-01

    Quantitative magnetization transfer imaging yields indices describing the interactions between free water protons and immobile, macromolecular protons—including the macromolecular to free pool size ratio (PSR) and the rate of magnetization transfer between pools kmf. This study describes the first implementation of the selective inversion recovery quantitative magnetization transfer method on a clinical 3.0-T scanner in human brain in vivo. Selective inversion recovery data were acquired at 1...

  6. Observational limits on the magnetic-monopole structure of protons

    International Nuclear Information System (INIS)

    Broderick, J.J.; Ficenec, J.R.; Teplitz, D.C.; Teplitz, V.L.

    1979-01-01

    We report the results of a search for absorption of 42-cm radiation in neutral galactic hydrogen. One explanation of a positive result would be the existence of a type of anomalous proton whose magnetic moment arises from a distribution of magnetic charge rather than from a distribution of circulating currents. No absorption of 42-cm radiation was seen; this implies an upper limit of 2.3 x 10 -4 for the abundance of this type of anomalous proton relative to protons which radiate at 21 cm. The observed absence of anomalous protons also implies an absence of primordial anomalous protons since they could not have been swept up by heavier elements during cosmic nucleosynthesis. The observation is sensitive only to anomalous protons with exactly the same value for their magnetic moment that conventional ones have

  7. Programmable Power Supply for AC Switching Magnet of Proton Accelerator

    CERN Document Server

    Jeong, Seong-Hun; Kang Heung Sik; Lee, Chi-Hwan; Lee, Hong-Gi; Park, Ki-Hyeon; Ryu, Chun-Kil; Sik Han, Hong; Suck Suh, Hyung

    2005-01-01

    The 100-MeV PEFP proton linac has two proton beam extraction lines for user' experiment. Each extraction line has 5 beamlines and has 5 Hz operating frequency. An AC switching magnet is used to distribute the proton beam to the 5 beamlines, An AC switching magnet is powered by PWM-controlled bipolar switching-mode converters. This converter is designed to operate at ±350A, 5 Hz programmable step output. The power supply is employed IGBT module and has controlled by a DSP (Digital Signal Process). This paper describes the design and test results of the power supply.

  8. Parity Violation in Elastic Electron-Proton Scattering and the Proton's Strange Magnetic Form Factor

    International Nuclear Information System (INIS)

    Spayde, D. T.; Averett, T.; Barkhuff, D.; Beck, D. H.; Beise, E. J.; Benson, C.; Breuer, H.; Carr, R.; Covrig, S.; DelCorso, J.

    2000-01-01

    We report a new measurement of the parity-violating asymmetry in elastic electron scattering from the proton at backward scattering angles. This asymmetry is sensitive to the strange magnetic form factor of the proton as well as electroweak axial radiative corrections. The new measurement of A=-4.92±0.61±0.73 ppm provides a significant constraint on these quantities. The implications for the strange magnetic form factor are discussed in the context of theoretical estimates for the axial corrections. (c) 2000 The American Physical Society

  9. Magnetic properties of point defects in proton irradiated diamond

    Energy Technology Data Exchange (ETDEWEB)

    Makgato, T.N., E-mail: Thuto.Makgato@students.wits.ac.za [School of Physics, University of the Witwatersrand, Johannesburg 2050 (South Africa); Sideras-Haddad, E. [School of Physics, University of the Witwatersrand, Johannesburg 2050 (South Africa); Center of Excellence in Strong Materials, Physics Building, University of the Witwatersrand, Johannesburg 2050 (South Africa); Ramos, M.A. [CMAM, Centro de Micro-Analisis de Materiales, Universidad Autónoma de Madrid, C/Faraday 3, Campus de Cantoblanco, E-28049 Madrid (Spain); Departamento de Fisica de la Materia Condensada, Condensed Matter Physics Center (IFIMAC) and Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid (Spain); García-Hernández, M. [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, E-28049 Madrid (Spain); Climent-Font, A.; Zucchiatti, A.; Muñoz-Martin, A. [CMAM, Centro de Micro-Analisis de Materiales, Universidad Autónoma de Madrid, C/Faraday 3, Campus de Cantoblanco, E-28049 Madrid (Spain); Shrivastava, S. [School of Physics, University of the Witwatersrand, Johannesburg 2050 (South Africa); Erasmus, R. [School of Physics, University of the Witwatersrand, Johannesburg 2050 (South Africa); Center of Excellence in Strong Materials, Physics Building, University of the Witwatersrand, Johannesburg 2050 (South Africa)

    2016-09-01

    We investigate the magnetic properties of ultra-pure type-IIa diamond following irradiation with proton beams of ≈1–2 MeV energy. SQUID magnetometry indicate the formation of Curie type paramagnetism according to the Curie law. Raman and Photoluminescence spectroscopy measurements show that the primary structural features created by proton irradiation are the centers: GR1, ND1, TR12 and 3H. The Stopping and Range of Ions in Matter (SRIM) Monte Carlo simulations together with SQUID observations show a strong correlation between vacancy production, proton fluence and the paramagnetic factor. At an average surface vacancy spacing of ≈1–1.6 nm and bulk (peak) vacancy spacing of ≈0.3-0.5 nm Curie paramagnetism is induced by formation of ND1 centres with an effective magnetic moment μ{sub eff}~(0.1–0.2)μ{sub B}. No evidence of long range magnetic ordering is observed in the temperature range 4.2-300 K. - Highlights: • Proton macro-irradiation of pure diamond creates fluence dependent paramagnetism. • The effective magnetic moment is found to be in the range μ{sub eff}~(0.1–0.2)μ{sub B}. • No evidence of long range magnetic ordering is observed.

  10. Magnetic properties of point defects in proton irradiated diamond

    International Nuclear Information System (INIS)

    Makgato, T.N.; Sideras-Haddad, E.; Ramos, M.A.; García-Hernández, M.; Climent-Font, A.; Zucchiatti, A.; Muñoz-Martin, A.; Shrivastava, S.; Erasmus, R.

    2016-01-01

    We investigate the magnetic properties of ultra-pure type-IIa diamond following irradiation with proton beams of ≈1–2 MeV energy. SQUID magnetometry indicate the formation of Curie type paramagnetism according to the Curie law. Raman and Photoluminescence spectroscopy measurements show that the primary structural features created by proton irradiation are the centers: GR1, ND1, TR12 and 3H. The Stopping and Range of Ions in Matter (SRIM) Monte Carlo simulations together with SQUID observations show a strong correlation between vacancy production, proton fluence and the paramagnetic factor. At an average surface vacancy spacing of ≈1–1.6 nm and bulk (peak) vacancy spacing of ≈0.3-0.5 nm Curie paramagnetism is induced by formation of ND1 centres with an effective magnetic moment μ eff ~(0.1–0.2)μ B . No evidence of long range magnetic ordering is observed in the temperature range 4.2-300 K. - Highlights: • Proton macro-irradiation of pure diamond creates fluence dependent paramagnetism. • The effective magnetic moment is found to be in the range μ eff ~(0.1–0.2)μ B . • No evidence of long range magnetic ordering is observed.

  11. Proton nuclear magnetic resonance studies on brain edema

    International Nuclear Information System (INIS)

    Naruse, S.; Horikawa, Y.; Tanaka, C.; Hirakawa, K.; Nishikawa, H.; Yoshizaki, K.

    1982-01-01

    The water in normal and edematous brain tissues of rats was studied by the pulse nuclear magnetic resonance (NMR) technique, measuring the longitudinal relaxation time (T1) and the transverse relaxation time (T2). In the normal brain, T1 and T2 were single components, both shorter than in pure water. Prolongation and separation of T2 into two components, one fast and one slow, were the characteristic findings in brain edema induced by both cold injury and triethyl tin (TET), although some differences between the two types of edema existed in the content of the lesion and in the degree of changes in T1 and T2 values. Quantitative analysis of T1 and T2 values in their time course relating to water content demonstrated that prolongation of T1 referred to the volume of increased water in tissues examined, and that two phases of T2 reflected the distribution and the content of the edema fluid. From the analysis of the slow component of T2 versus water content during edema formation, it was demonstrated that the increase in edema fluid was steady, and its content was constant during formation of TET-induced edema. On the contrary, during the formation of cold-injury edema, water-rich edema fluid increased during the initial few hours, and protein-rich edema fluid increased thereafter. It was concluded that proton NMR relaxation time measurements may provide new understanding in the field of brain edema research

  12. Proton magnetic resonance spectroscopy in disturbances of cortical development

    International Nuclear Information System (INIS)

    Kaminaga, T.; Kobayashi, M.; Abe, T.

    2001-01-01

    Proton magnetic resonance spectroscopy( 1 H-MRS) can be used for looking at cerebral metabolites in vivo. However, measurement of concentrations of cerebral metabolites in patients with disturbances of cerebral development have not been successful. Our purpose was to measure the concentrations of cerebral metabolites in such patients. We carried out quantitative 1 H-MRS in eight patients with cortical dysplasia, four with lissencephaly and three with heterotopic grey matter and six age-matched normal controls. Regions of interest for 1 H-MRS were set over the affected cortex in the patients and the occipital cortex in controls. The calculated concentration of N-acetylaspartate (NAA) was significantly lower in the affected cortex in patients with cortical dysplasia (P < 0.05), lissencephaly (P < 0.01), and heterotopia (P < 0.05) than in controls, idnicating a decreased number and/or immaturity or dysfunction of neurones in the affected cortex. The concentration of choline (Cho) was significantly lower in patients with lissencephaly (P < 0.01) than in controls, indicating glial proliferation and/or membrane abnormality. (orig.)

  13. Mercury's Surface Magnetic Field Determined from Proton-Reflection Magnetometry

    Science.gov (United States)

    Winslow, Reka M.; Johnson, Catherine L.; Anderson, Brian J.; Gershman, Daniel J.; Raines, Jim M.; Lillis, Robert J.; Korth, Haje; Slavin, James A.; Solomon, Sean C.; Zurbuchen, Thomas H.; hide

    2014-01-01

    Solar wind protons observed by the MESSENGER spacecraft in orbit about Mercury exhibit signatures of precipitation loss to Mercury's surface. We apply proton-reflection magnetometry to sense Mercury's surface magnetic field intensity in the planet's northern and southern hemispheres. The results are consistent with a dipole field offset to the north and show that the technique may be used to resolve regional-scale fields at the surface. The proton loss cones indicate persistent ion precipitation to the surface in the northern magnetospheric cusp region and in the southern hemisphere at low nightside latitudes. The latter observation implies that most of the surface in Mercury's southern hemisphere is continuously bombarded by plasma, in contrast with the premise that the global magnetic field largely protects the planetary surface from the solar wind.

  14. A magnetically switched kicker for proton extraction

    International Nuclear Information System (INIS)

    Dinkel, J.; Biggs, J.

    1989-03-01

    The application of magnetic current amplification and switching techniques to the generation of precise high current pulses for switching magnets is described. The square loop characteristic of Metglas tape wound cores at high excitation levels provides excellent switching characteristics for microsecond pulses. The rugged and passive nature of this type pulser makes it possible to locate the final stages of amplification at the load for maximum efficiency. 12 refs., 8 figs

  15. The magnetic moments of the proton and the antiproton

    CERN Document Server

    Ulmer, S.; Blaum, K.; Braeuninger, S.; Franke, K.; Kracke, H.; Leiteritz, C.; Matsuda, Y.; Nagahama, H.; Ospelkaus, C.; Rodegheri, C.C.; Quint, W.; Schneider, G.; Smorra, C.; Van Gorp, S.; Walz, J.; Yamazaki, Y.

    2014-01-01

    Recent exciting progress in the preparation and manipulation of the motional quantum states of a single trapped proton enabled the first direct detection of the particle's spin state. Based on this success the proton magnetic moment $\\mu_p$ was measured with ppm precision in a Penning trap with a superimposed magnetic field inhomogeneity. An improvement by an additional factor of 1000 in precision is possible by application of the so-called double Penning trap technique. In a recent paper we reported the first demonstration of this method with a single trapped proton, which is a major step towards the first direct high-precision measurement of $\\mu_p$. The techniques required for the proton can be directly applied to measure the antiproton magnetic moment $\\mu_{\\bar{p}}$. An improvement in precision of $\\mu_{\\bar{p}}$ by more than three orders of magnitude becomes possible, which will provide one of the most sensitive tests of CPT invariance. To achieve this research goal we are currently setting up the Baryo...

  16. Quantitative perfusion imaging in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Zoellner, F.G.; Gaa, T.; Zimmer, F.; Ong, M.M.; Riffel, P.; Hausmann, D.; Schoenberg, S.O.; Weis, M.

    2016-01-01

    Magnetic resonance imaging (MRI) is recognized for its superior tissue contrast while being non-invasive and free of ionizing radiation. Due to the development of new scanner hardware and fast imaging techniques during the last decades, access to tissue and organ functions became possible. One of these functional imaging techniques is perfusion imaging with which tissue perfusion and capillary permeability can be determined from dynamic imaging data. Perfusion imaging by MRI can be performed by two approaches, arterial spin labeling (ASL) and dynamic contrast-enhanced (DCE) MRI. While the first method uses magnetically labelled water protons in arterial blood as an endogenous tracer, the latter involves the injection of a contrast agent, usually gadolinium (Gd), as a tracer for calculating hemodynamic parameters. Studies have demonstrated the potential of perfusion MRI for diagnostics and also for therapy monitoring. The utilization and application of perfusion MRI are still restricted to specialized centers, such as university hospitals. A broad application of the technique has not yet been implemented. The MRI perfusion technique is a valuable tool that might come broadly available after implementation of standards on European and international levels. Such efforts are being promoted by the respective professional bodies. (orig.) [de

  17. Experimental validation of a Monte Carlo proton therapy nozzle model incorporating magnetically steered protons

    International Nuclear Information System (INIS)

    Peterson, S W; Polf, J; Archambault, L; Beddar, S; Bues, M; Ciangaru, G; Smith, A

    2009-01-01

    The purpose of this study is to validate the accuracy of a Monte Carlo calculation model of a proton magnetic beam scanning delivery nozzle developed using the Geant4 toolkit. The Monte Carlo model was used to produce depth dose and lateral profiles, which were compared to data measured in the clinical scanning treatment nozzle at several energies. Comparisons were also made between measured and simulated off-axis profiles to test the accuracy of the model's magnetic steering. Comparison of the 80% distal dose fall-off values for the measured and simulated depth dose profiles agreed to within 1 mm for the beam energies evaluated. Agreement of the full width at half maximum values for the measured and simulated lateral fluence profiles was within 1.3 mm for all energies. The position of measured and simulated spot positions for the magnetically steered beams agreed to within 0.7 mm of each other. Based on these results, we found that the Geant4 Monte Carlo model of the beam scanning nozzle has the ability to accurately predict depth dose profiles, lateral profiles perpendicular to the beam axis and magnetic steering of a proton beam during beam scanning proton therapy.

  18. Proton nuclear magnetic resonance imaging of regionally ischemic canine hearts: effects of paramagnetic proton signal enhancement

    International Nuclear Information System (INIS)

    Brady, T.J.; Goldman, M.R.; Pykett, I.L.; Buonanno, F.S.; Kistler, J.P.; Newhouse, J.H.; Burt, C.T.; Hinshaw, W.S.; Pohost, G.M.

    1982-01-01

    In a study to evaluate the potential of proton nuclear magnetic resonance (NMR) imaging with and without manganese contrast enhancement for detecting acute myocardial infarction, 12 dogs underwent 90-minute occlusion of the left circumflex coronary artery. Transverse-section NMR images of the excised, nonbeating heart were obtained at 1-cm intervals using the steady-state-free-precession (SSFP) technique. All NMR images revealed detailed structure of the heart. The three hearts without manganese showed no difference in intensity between the normal and the ischemic posterior regions, whereas those with manganese demonstrated a clearly demarcated zone of reduced signal intensity consistent with the ischemic zone. It is concluded that high-resolution tomograms of the excised canine myocardium can be obtained using proton NMR imaging. With the SSFP imaging technique, proton signal enhancement with manganese infusion is necessary to differentiate between ischemic and nonischemic myocardium after 90 minutes of coronary occlusion

  19. Quantitative analysis by nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wainai, T; Mashimo, K [Nihon Univ., Tokyo. Coll. of Science and Engineering

    1976-04-01

    Recent papers on the practical quantitative analysis by nuclear magnetic resonance spectroscopy (NMR) are reviewed. Specifically, the determination of moisture in liquid N/sub 2/O/sub 4/ as an oxidizing agent for rocket propulsion, the analysis of hydroperoxides, the quantitative analysis using a shift reagent, the analysis of aromatic sulfonates, and the determination of acids and bases are reviewed. Attention is paid to the accuracy. The sweeping velocity and RF level in addition to the other factors must be on the optimal condition to eliminate the errors, particularly when computation is made with a machine. Higher sweeping velocity is preferable in view of S/N ratio, but it may be limited to 30 Hz/s. The relative error in the measurement of area is generally 1%, but when those of dilute concentration and integrated, the error will become smaller by one digit. If impurities are treated carefully, the water content on N/sub 2/O/sub 4/ can be determined with accuracy of about 0.002%. The comparison method between peak heights is as accurate as that between areas, when the uniformity of magnetic field and T/sub 2/ are not questionable. In the case of chemical shift movable due to content, the substance can be determined by the position of the chemical shift. Oil and water contents in rape-seed, peanuts, and sunflower-seed are determined by measuring T/sub 1/ with 90 deg pulses.

  20. Effect of neutron and proton radiations on magnetization of biotite

    CERN Document Server

    Abdurakhimov, A U; Sharipov, S M; Yugaj, V P; Granovskij, A B; Radkovskaya, A A

    2002-01-01

    One analyzes curves of field dependence of magnetization of biotite measured in the initial state under 4.2 K temperature subsequent to irradiation of 14 MeV energy and 1.2 x 10 sup 1 sup 3 cm sup - sup 2 dose neutrons and by 3 MeV energy and 2.2 x 10 sup 1 sup 4 cm sup - sup 2 dose protons, as well as, subsequent to annealing under 1000 deg temperature during 15 min. Irradiation by neutrons and protons was determined to result in increase of magneto-ordered phase content in biotite and, thus, in increase of magnetization of specimen. It is accounted for by formation of oxides in melt radiation thermal peaks and by freezing of high-temperature phase states corresponding to magnetite or solid solution of magnetite and hematite there. Thermal treatment does not change content of magneto-ordered phase in specimens

  1. Superconducting Magnet Technology for Future High Energy Proton Colliders

    Science.gov (United States)

    Gourlay, Stephen

    2017-01-01

    Interest in high field dipoles has been given a boost by new proposals to build a high-energy proton-proton collider to follow the LHC and programs around the world are taking on the task to answer the need. Studies aiming toward future high-energy proton-proton colliders at the 100 TeV scale are now being organized. The LHC and current cost models are based on technology close to four decades old and point to a broad optimum of operation using dipoles with fields between 5 and 12T when site constraints, either geographical or political, are not a factor. Site geography constraints that limit the ring circumference can drive the required dipole field up to 20T, which is more than a factor of two beyond state-of-the-art. After a brief review of current progress, the talk will describe the challenges facing future development and present a roadmap for moving high field accelerator magnet technology forward. This work was supported by the Director, Office of Science, High Energy Physics, US Department of Energy, under contract No. DE-AC02-05CH11231.

  2. Clinical applications of proton magnetic resonance spectroscopy of the brain

    International Nuclear Information System (INIS)

    Laubenberger, J.; Bayer, S.; Thiel, T.; Hennig, J.; Langer, M.

    1998-01-01

    In spite of all the scientific advances of the past few years, proton magnetic resonance spectroscopy of the brain has not attained the status of a routine examination technique with clinically accepted indications. The method should be considered as an additional option to MR imaging for inherited and acquired encephalopathic changes as well as, in future, for localization diagnosis of epilepsies. A proton magnetic resonance spectroscopic investigation without a prior intensive clinical and imaging investigation is not useful. Above all, factors influencing metabolite distribution such as for example, serum osmolability must be known. Methodological prerequisites for the clinical application of proton resonance spectroscopy are, first of all, a high stability of the chosen technique as well as a sufficiently certain quantification of metabolites and the availability of a reference group. The use of short echo times is necessary for the quantification of glutamine and the osmolyte myo-inositol. Indications for individual cases in which clinical investigations and MR topography cannot provide sufficient certainty and spectroscopy can furnish additional information are, in addition to uses in neuropediatrics, the suspicion of Alzheimer's dementia, HIV encephalopathy in early manifestations, and unclarified depressions of consciousness accompanying liver cirrhosis. (orig.) [de

  3. Quantitative magnetic resonance techniques in the evaluation of intracranial tuberculomas

    International Nuclear Information System (INIS)

    Vasudev, M.K.; Jayakumar, P.N.; Srikanth, S.G.; Nagarajan, K.; Mohanty, A.

    2007-01-01

    Purpose: To evaluate intracranial tuberculomas using quantitative magnetic resonance (MR) techniques such as T2 relaxometry, magnetization transfer (MT), and diffusion-weighted imaging (DWI). Material and Methods: Thirty-three patients with intracranial tuberculomas (histologically confirmed in 22) were evaluated using proton density/T2-weighted, T1-weighted (with and without MT), and echo-planar diffusion-weighted imaging sequences. T2 relaxation times, MT ratios (MTR), and apparent diffusion coefficient (ADC) values were calculated from the center of the lesion, the periphery, perilesional edema, and contralateral normal white matter. The mean and standard deviation values of each variable were calculated and correlated using Pearson's test (P = 0.05). Results: The measured mean values of T2 relaxation time, MTR, and ADC in the center of lesions were 155.5 ms, 14.1, and 1.27x10-3 mm 2 /s, respectively, compared to 117 ms, 23.72, and 0.74x10-3 mm 2 /s in normal white matter, and a T2 relaxation time of 187.45 ms in normal gray matter. Significant inverse correlations were noted between T2 relaxation values and MTR (P<0.001) and between MTR and ADC (P = 0.046). Significant positive correlation was seen between T2 relaxation and ADC values (P = 0.03). Conclusion: Intracranial tuberculomas are characterized by relatively short T2 relaxation times (compared to normal gray matter), decreased MTR, and mostly no restriction of diffusion. A combination of these quantitative parameters could be of help in the noninvasive diagnosis of tuberculomas

  4. On the importance of exchangeable NH protons in creatine for the magnetic coupling of creatine methyl protons in skeletal muscle

    NARCIS (Netherlands)

    Kruiskamp, M.J.; Nicolaij, K.

    2001-01-01

    The methyl protons of creatine in skeletal muscle exhibit a strong off-resonance magnetization transfer effect. The mechanism of this process is unknown. We previously hypothesized that the exchangeable amide/amino protons of creatine might be involved. To test this the characteristics of the

  5. Evaluation of human thyroid tumors by proton nuclear magnetic resonance

    International Nuclear Information System (INIS)

    deCertaines, J.; Herry, J.Y.; Lancien, G.; Benoist, L.; Bernard, A.M.; LeClech, G.

    1982-01-01

    Proton nuclear magnetic resonance (NMR) was used in a study of 40 patients with thyroid tumors following partial or total thyroidectomy. Three patient groups were considered: those with nodules showing increased uptake, those with solitary nodules with decreased uptake, and those with multinodular goiters. Spin-lattice and spin-spin relaxation times (T 1 and T 2 ) were measured on samples of nodular and extranodular tissue from each patient. Increased T 1 and T 2 were observed for benign cold nodules, an increase in T 1 alone for nodules with increased uptake, and a wide fluctuation in T 1 and T 2 for multinodular goiters. The four cancers in the series did not show a distinctive proton NMR pattern in comparison with the other nodular structures studied. The results point to the feasibility of applying NMR techniques to the detection of thyroid disease

  6. Proton magnetic resonance spectroscopy and perfusion magnetic resonance imaging in the evaluation of musculoskeletal tumors

    International Nuclear Information System (INIS)

    Costa, Flavia Martins; Setti, Marcela; Vianna, Evandro Miguelote; Domingues, Romulo Cortes; Meohas, Walter; Rezende, Jose Francisco; Gasparetto, Emerson Leandro

    2009-01-01

    Objective: To assess the role of proton magnetic resonance spectroscopy and dynamic contrast-enhanced magnetic resonance imaging in the differentiation between malignant and benign musculoskeletal tumors. Materials And Methods: Fifty-five patients with musculoskeletal tumors (27 malignant and 28 benign) were studied. The examinations were performed in a 1.5 T magnetic resonance scanner with standard protocol, and single voxel proton magnetic resonance spectroscopy with 135 msec echo time. The dynamic contrast study was performed using T1-weighted gradient-echo sequence after intravenous gadolinium injection. Time signal intensity curves and slope values were calculated. The statistical analysis was performed with the Levene's test, followed by a Student's t-test, besides the Pearson's chi-squared and Fischer's exact tests. Results: Proton magnetic resonance spectroscopy sensitivity, specificity and accuracy were, respectively, 87.5%, 92.3% and 90.9% (p < 0.0001). Statistically significant difference was observed in the slope (%/min) between benign (mean, 27.5%/min) and malignant (mean, 110.9%/min) lesions (p < 0.0001). Conclusion: The time-intensity curve and slope values using dynamic-enhanced perfusion magnetic resonance imaging in association with the presence of choline peak demonstrated by single voxel magnetic resonance spectroscopy study are useful in the differentiation between malignant and benign musculoskeletal tumors. (author)

  7. Magnetic moment of extremely proton-rich nucleus 23Al

    International Nuclear Information System (INIS)

    Nagatomo, T; Matsuta, K; Ozawa, A; Nakashima, Y; Matsumiya, R; Mihara, M; Yasuno, T; Chiba, A; Yamada, K; Momota; Ohtsubo, T; Ohta, M; Shinojima, D; Izumikawa, T; Tanaka, H; Yamaguchi, T; Nakajima, S; Maemura, H; Muranaka, K; Kumashiro, S; Fujiwara, H; Yoshida, K; Sumikama, T; Tanaka, K; Ogura, M; Minamisono, K; Fukuda, M; Minamisono, T; Nojiri, Y; Suzuki, T; Tanihata, I; Alonso, J R; Krebs, G F; Symons, T J M

    2005-01-01

    The g-factor of the extremely proton-rich nucleus 23 Al (T 1/2 = 0.47 s) has been measured by means of the β-NMR method for the first time. The g-factor were determined as |g| = 1.557(88) from the obtained NMR spectra. From the comparison between the experimental value and the shell model calculation, the spin parity of the ground state of 23 Al was determined as I π = 5/2 + . Thus, the magnetic moment of 23 Al was determined as vertical bar μvertical bar = 3.89(22)μ N

  8. Magnetic force microscopy : Quantitative issues in biomaterials

    NARCIS (Netherlands)

    Passeri, D.; Dong, C.; Reggente, M.; Angeloni, L.; Barteri, M.; Scaramuzzo, F.A.; De Angelis, F.; Marinelli, F.; Antonelli, F.; Rinaldi, F.; Marianecci, C.; Carafa, M.; Sorbo, A.; Sordi, D.; Arends, I.W.C.E.; Rossi, M.

    2014-01-01

    Magnetic force microscopy (MFM) is an atomic force microscopy (AFM) based technique in which an AFM tip with a magnetic coating is used to probe local magnetic fields with the typical AFM spatial resolution, thus allowing one to acquire images reflecting the local magnetic properties of the samples

  9. Pion Production from Proton Synchrotron Radiation under Strong Magnetic Field in Relativistic Quantum Approach

    Directory of Open Access Journals (Sweden)

    Maruyama Tomoyuki

    2016-01-01

    Full Text Available We study pion production from proton synchrotron radiation in the presence of strong magnetic fields by using the exact proton propagator in a strong magnetic field and explicitly including the anomalous magnetic moment. Results in this exact quantum-field approach do not agree with those obtained in the semi-classical approach. Furthermore, we also find that the anomalous magnetic moment of the proton greatly enhances the production rate about by two orders of magnitude, and that the polar angle of an emitted pion is the same as that of an initial proton.

  10. Fabrication of miniature magnetic magnet pole for validate simulation of magnetic cyclotron proton 13 MeV

    International Nuclear Information System (INIS)

    Subroto; Sukiya; Tony R

    2013-01-01

    A fabrication of miniature magnetic pole field has been made to validate the simulation system 13 MeV magnet of proton cyclotron using mild steel material. This electromagnet of magnetic pole at the end of the magnetic pole is divided into 8 parts of the valley and the hill interval to produce different magnetic field. Pole magnetic field fabrication is meet to match the design of the system simulation results 13 MeV cyclotron magnet. This requires strong cyclotron magnetic field average at 1.275 T magnetic field strength of each piece was different. So that the ion beam passing through a magnetic field. Will be focused before mashing target. The surface of magnetic pole is circular with a diameter of 100 mm and 32 mm pole spacing. Miniature of electrical pole diameter is only one-tenth the diameter of 960 mm designed this requires current 10 A with voltage 30 V to produce field strength of 0.3 T. To measure the magnetic field strength tesla meter is used and to measure the relationship curve in pole position with a magnetic field strength magnets cylinder directions X and Y the used mini lathe. Field strength measurement results with a straight, oblique and circular position show nearly equal to curve simulation results using a 3D module TOSCA opera program. (author)

  11. Proton nuclear magnetic resonance spectroscopy of plasma lipoproteins in malignancy

    International Nuclear Information System (INIS)

    Nabholtz, J.M.; Rossignol, A.; Farnier, M.; Gambert, P.; Tremeaux, J.C.; Friedman, S.; Guerrin, J.

    1988-01-01

    A recent study described a method of detecting malignant tumors by water-supressed proton nuclear magnetic resonance (1 H NMR) study of plasma. We performed a similar study of the W 1/2, a mean of the full width at half height of the resonances of the methyl and methylene groups of the lipids of plasma lipoproteins which is inversely related to the spin-spin apparent relaxation time (T 2 * ). W 1/2 values were measured at a fixed baseline width of 310 Hz. The study was prospective and blinded and comprised 182 subjects consisting of 40 controls, 68 patients with untreated malignancies, 45 with malignant tumors undergoing therapy and 29 benign tumor patients. No differences were seen between any groups that could serve as a basis for a useful clinical test. The major difficulty in the determination of W 1/2 was due to interference of metabolite protons (particularly lactate) within the lipoprotein resonance signal. Triglyceride level was seen to correlate inversely with W 1/2 within malignant patient groups. These discrepant results may be related to differing triglyceride-rich very low density lipoprotein (VLDL) levels in the ;atient populations of each study. We conclude that the water-suppressed 1H NMR of plasma lipoproteins is not a valid measurement for assessing malignancy. (orig.)

  12. Calibration of a compact magnetic proton recoil neutron spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jianfu, E-mail: zhang_jianfu@163.com [School of Nuclear Science and Technology, Xi' an Jiaotong University, Xi' an 710049 (China); Northwest Institute of Nuclear Technology, Xi' an 710024 (China); Ouyang, Xiaoping; Zhang, Xianpeng [School of Nuclear Science and Technology, Xi' an Jiaotong University, Xi' an 710049 (China); Northwest Institute of Nuclear Technology, Xi' an 710024 (China); Ruan, Jinlu [Northwest Institute of Nuclear Technology, Xi' an 710024 (China); Zhang, Guoguang [Applied Institute of Nuclear Technology, China Institute of Atomic Energy, Beijing 102413 (China); Zhang, Xiaodong [Northwest Institute of Nuclear Technology, Xi' an 710024 (China); Qiu, Suizheng, E-mail: szqiu@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi' an Jiaotong University, Xi' an 710049 (China); Chen, Liang; Liu, Jinliang; Song, Jiwen; Liu, Linyue; Yang, Shaohua [Northwest Institute of Nuclear Technology, Xi' an 710024 (China)

    2016-04-21

    Magnetic proton recoil (MPR) neutron spectrometer is considered as a powerful instrument to measure deuterium–tritium (DT) neutron spectrum, as it is currently used in inertial confinement fusion facilities and large Tokamak devices. The energy resolution (ER) and neutron detection efficiency (NDE) are the two most important parameters to characterize a neutron spectrometer. In this work, the ER calibration for the MPR spectrometer was performed by using the HI-13 tandem accelerator at China Institute of Atomic Energy (CIAE), and the NDE calibration was performed by using the neutron generator at CIAE. The specific calibration techniques used in this work and the associated accuracies were discussed in details in this paper. The calibration results were presented along with Monte Carlo simulation results.

  13. Pion Production from Proton Synchrotron Radiation under Strong Magnetic Field in a Relativistic Quantum Approach

    Directory of Open Access Journals (Sweden)

    Maruyama Tomoyuki

    2016-01-01

    Full Text Available We study pion production from proton synchrotron radiation in the presence of strong magnetic fields by using the exact proton propagator in a strong magnetic field and explicitly including the anomalous magnetic moment. Results in this exact quantum approach do not agree with those obtained in the semi-classical approach. Then, we find that the anomalous magnetic moment of the proton greatly enhances the production rate by about two orders magnitude, and that the decay width satisfies a robust scaling law.

  14. Quantitative susceptibility mapping (QSM): Decoding MRI data for a tissue magnetic biomarker

    Science.gov (United States)

    Wang, Yi; Liu, Tian

    2015-01-01

    In MRI, the main magnetic field polarizes the electron cloud of a molecule, generating a chemical shift for observer protons within the molecule and a magnetic susceptibility inhomogeneity field for observer protons outside the molecule. The number of water protons surrounding a molecule for detecting its magnetic susceptibility is vastly greater than the number of protons within the molecule for detecting its chemical shift. However, the study of tissue magnetic susceptibility has been hindered by poor molecular specificities of hitherto used methods based on MRI signal phase and T2* contrast, which depend convolutedly on surrounding susceptibility sources. Deconvolution of the MRI signal phase can determine tissue susceptibility but is challenged by the lack of MRI signal in the background and by the zeroes in the dipole kernel. Recently, physically meaningful regularizations, including the Bayesian approach, have been developed to enable accurate quantitative susceptibility mapping (QSM) for studying iron distribution, metabolic oxygen consumption, blood degradation, calcification, demyelination, and other pathophysiological susceptibility changes, as well as contrast agent biodistribution in MRI. This paper attempts to summarize the basic physical concepts and essential algorithmic steps in QSM, to describe clinical and technical issues under active development, and to provide references, codes, and testing data for readers interested in QSM. Magn Reson Med 73:82–101, 2015. © 2014 The Authors. Magnetic Resonance in Medicine Published by Wiley Periodicals, Inc. on behalf of International Society of Medicine in Resonance. This is an open access article under the terms of the Creative commons Attribution License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited. PMID:25044035

  15. Electromagnetic radiation of protons in edge fields of synchrotron dipole magnets

    International Nuclear Information System (INIS)

    Smolyakov, N.V.

    1986-01-01

    Effect of the edge shape of magnetic field of a dipole on the short-wave part of electromagnetic radiation spectrum of a proton beam is investigated. In some cases short-wave photons are shown to be shaped in the ranges of largest edge curvature of the magnetic field. Universality of edge radiation spectrum is proved. Spectral characteristics of proton edge radiation in a superconducting magnetic dipole of the storage-accelerator complex are obtained

  16. Regional-Scale Surface Magnetic Fields and Proton Fluxes to Mercury's Surface from Proton-Reflection Magnetometry

    Science.gov (United States)

    Winslow, R. M.; Johnson, C. L.; Anderson, B. J.; Gershman, D. J.; Raines, J. M.; Lillis, R. J.; Korth, H.; Slavin, J. A.; Solomon, S. C.; Zurbuchen, T.

    2014-12-01

    The application of a recently developed proton-reflection magnetometry technique to MESSENGER spacecraft observations at Mercury has yielded two significant findings. First, loss-cone observations directly confirm particle precipitation to Mercury's surface and indicate that solar wind plasma persistently bombards the planet not only in the magnetic cusp regions but over a large fraction of the southern hemisphere. Second, the inferred surface field strengths independently confirm the north-south asymmetry in Mercury's global magnetic field structure first documented from observations of magnetic equator crossings. Here we extend this work with 1.5 additional years of observations (i.e., to 2.5 years in all) to further probe Mercury's surface magnetic field and better resolve proton flux precipitation to the planet's surface. We map regions where proton loss cones are observed; these maps indicate regions where protons precipitate directly onto the surface. The augmentation of our data set over that used in our original study allows us to examine the proton loss cones in cells of dimension 10° latitude by 20° longitude in Mercury body-fixed coordinates. We observe a transition from double-sided to single-sided loss cones in the pitch-angle distributions; this transition marks the boundary between open and closed field lines. At the surface this boundary lies between 60° and 70°N. Our observations allow the estimation of surface magnetic field strengths in the northern cusp region and the calculation of incident proton fluxes to both hemispheres. In the northern cusp, our regional-scale observations are consistent with an offset dipole field and a dipole moment of 190 nT RM3, where RM is Mercury's radius, implying that any regional-scale variations in surface magnetic field strengths are either weak relative to the dipole field or occur at length scales smaller than the resolution of our observations (~300 km). From the global proton flux map (north of 40° S

  17. Quantitative dosing by nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Solomon, I.

    1958-01-01

    The measurement of the absolute concentration of a heavy water reference containing approximately 99.8 per cent of D 2 O has been performed, by an original magnetic resonance method ('Adiabatic fast passage method') with a precision of 5.10 -5 on the D 2 O concentration. (author) [fr

  18. Sequential observations of brain edema with proton magnetic resonance imaging and spectroscopy

    International Nuclear Information System (INIS)

    Kamada, Kyousuke

    1996-01-01

    The purpose of this study was to assess the relationship between morphological and metabolic changes in brain edema using proton magnetic resonance systems. The serial changes during the first 24 hours in the cold-injury trauma rat brain model were investigated by proton magnetic resonance imaging ( 1 H MRI) and high-resolution proton MR spectroscopy ( 1 H MRS). We also analyzed the efficacy of AVS 1,2-bis (nicotinamide)-propane which can scavenge free radicals to the edema in this experiment. The edema was developing extensively via the corpus callosum in ipsi- and contralateral hemispheres as shown by gradually increased signal intensity on 1 H MRI. 1 H MRS initially showed accumulation of acetate and lactate, and transient increasing of glutamine. After 24 hours, the increased glutamine decreased below the control, alanine increased, and N-acetyl aspartate decreased with the edema development. AVS-treatment significantly suppressed edema development, increases of lactate and alanine and decreases of N-acetyl aspartate. We suggest that the cold-induced lesion contains anaerobic glycolysis deterioration and results in severe brain tissue breakdown. AVS is proved valuable for the treatment of this edema lesion. Clinical 1 H MRS showed prolonged lactate elevation and significant decreases of other metabolites in human ischemic stroke edema. In peritumoral edema, decreased N-acetyl aspartate gradually improved, and slightly elevated lactate disappeared after tumor removal. 1 H MRS feasibly characterizes the ischemic and peritumoral edema and makes a quantitative analysis in human brain metabolism. We believe the combined 1 H MRI and MRS study is a practical method to monitor the brain conditions and will make it easy and possible to find new therapeutic agents to some brain disorders. (author)

  19. Absolute choline concentration measured by quantitative proton MR spectroscopy correlates with cell density in meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Qiang [University of Tsukuba, Department of Neurosurgery, Institute of Clinical Medicine, Tsukuba Science City, Ibaraki (Japan)]|[West China Hospital of Sichuan University, Huaxi MR Research Center, Department of Radiology, Chengdu (China); Shibata, Yasushi; Kawamura, Hiraku; Matsumura, Akira [University of Tsukuba, Department of Neurosurgery, Institute of Clinical Medicine, Tsukuba Science City, Ibaraki (Japan); Isobe, Tomonori [Kitasato University, Department of Medical Technology, School of Allied Health Sciences, Minato, Tokyo (Japan); Anno, Izumi [University of Tsukuba, Department of Radiology, Institute of Clinical Medicine, Tsukuba, Ibaraki (Japan); Gong, Qi-Yong [West China Hospital of Sichuan University, Huaxi MR Research Center, Department of Radiology, Chengdu (China)]|[University of Liverpool, Division of Medical Imaging, Faculty of Medicine, Liverpool (United Kingdom)

    2009-01-15

    This study was aimed to investigate the relationship between quantitative proton magnetic resonance spectroscopy (1H-MRS) and pathological changes in meningioma. Twenty-two meningioma cases underwent single voxel 1H-MRS (point-resolved spectroscopy sequence, repetition time/echo time = 2,000 ms/68, 136, 272 ms). Absolute choline (Cho) concentration was calculated using tissue water as the internal reference and corrected according to intra-voxel cystic/necrotic parts. Pathological specimens were stained with MIB-1 antibody to measure cell density and proliferation index. Correlation analysis was performed between absolute Cho concentration and cell density and MIB-1 labeled proliferation index. Average Cho concentration of all meningiomas before correction was 2.95 {+-} 0.86 mmol/kg wet weight. It was increased to 3.23 {+-} 1.15 mmol/kg wet weight after correction. Average cell density of all meningiomas was 333 {+-} 119 cells/HPF, and average proliferation index was 2.93 {+-} 5.72%. A linear, positive correlation between cell density and Cho concentration was observed (r = 0.650, P = 0.001). After correction of Cho concentration, the correlation became more significant (r = 0.737, P < 0.001). However, no significant correlation between Cho concentration and proliferation index was found. There seemed to be a positive correlation trend after correction of Cho concentration but did not reach significant level. Absolute Cho concentration, especially Cho concentration corrected according to intra-voxel cystic/necrotic parts, reflects cell density of meningioma. (orig.)

  20. Multivoxel proton magnetic resonance spectroscopy in heat stroke

    International Nuclear Information System (INIS)

    Li, J.; Zhang, X.Y.; Wang, B.; Zou, Z.M.; Li, H.F.; Wang, P.Y.; Xia, J.K.

    2015-01-01

    Aim: To assess the role of proton MR spectroscopy (MRS) in the detection of changes in metabolite levels of the cerebellum after heat stroke (HS). Materials and methods: The study group consisted of eight patients after HS, with a Glasgow Coma Scale (GCS) score of 3–9. The MR studies were performed with a 1.5 T system. MR spectra were recorded from a normal-appearing cerebellum region. Spectra from patients were compared with a control group including seven age-matched healthy volunteers recorded with the same techniques. Metabolites ratios including N-acetyl aspartate/creatine (NAA/Cr), N-acetyl aspartate/creatine2 (NAA/Cr2), choline/creatine (Cho/Cr), choline/creatine2 (Cho/Cr2), and N-acetyl aspartate/choline (NAA/Cho) were calculated and the differences between the two groups were evaluated using the Mann–Whitney U-test. Pearson correlation analysis was used to analyse the relationship between NAA/Cr ratios and GCS scores for eight patients after HS. Results: In the cerebellum of the patients after HS, NAA/Cr ratios were found to be significantly decreased compared to normal controls (p = 0.004) and Cho/Cr ratios were found to be decreased compared to normal controls (p = 0.032). Significant positive correlation was found between NAA/Cr ratios and GCS scores for eight patients after HS (r = 0.748, p = 0.033). Conclusions: Metabolite abnormalities were seen in normal-appearing cerebellum structures in patients after HS. Proton MRS is a useful tool for evaluating major changes in metabolite levels of the cerebellum after HS and the severity of the disease can be effectively evaluated by NAA/Cr ratios. - Highlights: • Proton magnetic resonance spectroscopy offers important information in patients with heat stroke. • Significantly different NAA/Cr ratios were found between heat stroke and controls. • The severity of heat stroke can be effectively evaluated by NAA/Cr ratios

  1. Quantitative Evaluation of the Total Magnetic Moments of Colloidal Magnetic Nanoparticles: A Kinetics-based Method.

    Science.gov (United States)

    Liu, Haiyi; Sun, Jianfei; Wang, Haoyao; Wang, Peng; Song, Lina; Li, Yang; Chen, Bo; Zhang, Yu; Gu, Ning

    2015-06-08

    A kinetics-based method is proposed to quantitatively characterize the collective magnetization of colloidal magnetic nanoparticles. The method is based on the relationship between the magnetic force on a colloidal droplet and the movement of the droplet under a gradient magnetic field. Through computational analysis of the kinetic parameters, such as displacement, velocity, and acceleration, the magnetization of colloidal magnetic nanoparticles can be calculated. In our experiments, the values measured by using our method exhibited a better linear correlation with magnetothermal heating, than those obtained by using a vibrating sample magnetometer and magnetic balance. This finding indicates that this method may be more suitable to evaluate the collective magnetism of colloidal magnetic nanoparticles under low magnetic fields than the commonly used methods. Accurate evaluation of the magnetic properties of colloidal nanoparticles is of great importance for the standardization of magnetic nanomaterials and for their practical application in biomedicine. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. S.C. correction coils and magnets for the HERA proton ring

    International Nuclear Information System (INIS)

    Daum, C.; Geerinck, J.; Schmueser, P.

    1986-05-01

    The quadrupole and sextupole correction coils of the HERA proton ring are mounted on the cold beam pipe inside the main dipole magnets. Superferric dipole magnets for orbit correction are located adjacent to the main quadrupole magnets in a common cryostat which also contains the beam monitor. The design, manufacture and performance of both types of correction elements are described. (orig.)

  3. Rapid and quantitative chemical exchange saturation transfer (CEST) imaging with magnetic resonance fingerprinting (MRF).

    Science.gov (United States)

    Cohen, Ouri; Huang, Shuning; McMahon, Michael T; Rosen, Matthew S; Farrar, Christian T

    2018-05-13

    To develop a fast magnetic resonance fingerprinting (MRF) method for quantitative chemical exchange saturation transfer (CEST) imaging. We implemented a CEST-MRF method to quantify the chemical exchange rate and volume fraction of the N α -amine protons of L-arginine (L-Arg) phantoms and the amide and semi-solid exchangeable protons of in vivo rat brain tissue. L-Arg phantoms were made with different concentrations (25-100 mM) and pH (pH 4-6). The MRF acquisition schedule varied the saturation power randomly for 30 iterations (phantom: 0-6 μT; in vivo: 0-4 μT) with a total acquisition time of ≤2 min. The signal trajectories were pattern-matched to a large dictionary of signal trajectories simulated using the Bloch-McConnell equations for different combinations of exchange rate, exchangeable proton volume fraction, and water T 1 and T 2 relaxation times. The chemical exchange rates of the N α -amine protons of L-Arg were significantly (P exchange using saturation power method. Similarly, the L-Arg concentrations determined using MRF were significantly (P exchange rate was well fit (R 2  = 0.9186) by a base catalyzed exchange model. The amide proton exchange rate measured in rat brain cortex (34.8 ± 11.7 Hz) was in good agreement with that measured previously with the water exchange spectroscopy method (28.6 ± 7.4 Hz). The semi-solid proton volume fraction was elevated in white (12.2 ± 1.7%) compared to gray (8.1 ± 1.1%) matter brain regions in agreement with previous magnetization transfer studies. CEST-MRF provides a method for fast, quantitative CEST imaging. © 2018 International Society for Magnetic Resonance in Medicine.

  4. Magnetic quadrupoles lens for hot spot proton imaging in inertial confinement fusion

    Energy Technology Data Exchange (ETDEWEB)

    Teng, J. [Science and Technology on Plasma Physics Laboratory, Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900 (China); Gu, Y.Q., E-mail: yqgu@caep.cn [Science and Technology on Plasma Physics Laboratory, Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900 (China); Center for Applied Physics and Technology, HEDPS, Peking University, Beijing 100871 (China); Chen, J.; Zhu, B.; Zhang, B.; Zhang, T.K.; Tan, F.; Hong, W.; Zhang, B.H. [Science and Technology on Plasma Physics Laboratory, Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900 (China); Wang, X.Q. [Academy of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230026 (China)

    2016-08-01

    Imaging of DD-produced protons from an implosion hot spot region by miniature permanent magnetic quadrupole (PMQ) lens is proposed. Corresponding object-image relation is deduced and an adjust method for this imaging system is discussed. Ideal point-to-point imaging demands a monoenergetic proton source; nevertheless, we proved that the blur of image induced by proton energy spread is a second order effect therefore controllable. A proton imaging system based on miniature PMQ lens is designed for 2.8 MeV DD-protons and the adjust method in case of proton energy shift is proposed. The spatial resolution of this system is better than 10 μm when proton yield is above 10{sup 9} and the spectra width is within 10%.

  5. Proton magnetic resonance spectroscopy in ecstasy (MDMA) users.

    Science.gov (United States)

    Daumann, Jörg; Fischermann, Thomas; Pilatus, Ulrich; Thron, Armin; Moeller-Hartmann, Walter; Gouzoulis-Mayfrank, Euphrosyne

    2004-05-20

    The popular recreational drug 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) has well-recognized neurotoxic effects upon central serotonergic systems in animal studies. In humans, the use of MDMA has been linked to cognitive problems, particularly to deficits in long-term memory and learning. Recent studies with proton magnetic resonance spectroscopy (1H MRS) have reported relatively low levels of the neuronal marker N-acetylaspartate (NAA) in MDMA users, however, these results have been ambiguous. Moreover, the only available 1H MRS study of the hippocampus reported normal findings in a small sample of five MDMA users. In the present study, we compared 13 polyvalent ecstasy users with 13 matched controls. We found no differences between the NAA/creatine/phosphocreatine (Cr) ratios of users and controls in neocortical regions, and only a tendency towards lower NAA/Cr ratios in the left hippocampus of MDMA users. Thus, compared with cognitive deficits, 1H MRS appears to be a less sensitive marker of potential neurotoxic damage in ecstasy users. Copyright 2004 Elsevier Ireland Ltd.

  6. Thixotropic Phenomena in Water: Quantitative Indicators of Casimir-Magnetic Transformations from Vacuum Oscillations (Virtual Particles

    Directory of Open Access Journals (Sweden)

    Michael A. Persinger

    2015-09-01

    Full Text Available The ~1.5 × 10−20 J which is considered a universal quantity and is associated with the movement of protons in water also relates to the ratio of the magnetic moment of a proton divided by its unit charge, multiplied by viscosity and applied over the O-H distance. There is quantitative evidence that thixotropy, the “spontaneous” increased viscosity in water when undisturbed, originates from the transformation of virtual particles or vacuum oscillations to real states through conversion of Casimir-magnetic energies that involve the frequency of the neutral hydrogen line and the upper bound threshold value for intergalactic magnetic fields. The results indicate that ½ of a single electron orbit is real (particle and the other ½ is virtual (wave. The matter equivalent per s for virtual-to-real states for electrons in 1 mL of water with a neutral pH is consistent with the numbers of protons (H+ and the measured range of molecules in the coherent domains for both width and duration of growth and is similar to widths of intergalactic dust grains from which planets and stars may condense. The de Broglie momentum for the lower boundary of the width of coherent domains multiplied by the fine structure velocity of an electron is concurrent with the quantum when one proton is being removed from another and when the upper boundary of the rest mass of a photon is transformed by the product of velocities for putative “entanglement” and light. Theoretical and experimental results indicate that components of thixotropy, such as specific domains of intercalated water molecules, could display excess correlations over very large distances. Because the energies of the universal quantity and water converge it may be a special conduit for discrete transformations from virtual to real states.

  7. Effects of proton irradiation on electronic structure of NdFeB permanent magnets

    Energy Technology Data Exchange (ETDEWEB)

    Yang, L. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Zhen, L. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)], E-mail: lzhen@hit.edu.cn; Xu, C.Y.; Sun, X.Y.; Shao, W.Z. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2009-09-15

    Effects of proton irradiation on electronic structure and atomic local structure of N35EH-type NdFeB permanent magnet were investigated by soft X-ray absorption spectrometry and Moessbauer spectrometry. The local coordination environment of Fe atoms changes after proton irradiation, and the average hyperfine field H{sub in} of the magnets decreases from 288.4 to 286.9 kOe. The effects of irradiation on Fe atoms local environment at different lattice sites are different. The near edge structure of Fe L{sub 3} edge is changed, indicating the density of unoccupied state of Fe 3d electrons increases after proton irradiation.

  8. Feasibility of quantitative PET/CT dosimetry for proton therapy using polymer gels

    Energy Technology Data Exchange (ETDEWEB)

    Zeidan, O A; Hsi, W C; Lopatiuk-Tirpak, O; Sriprisan, S I; Meeks, S L; Kupelian, P A; Li, Z; Palta, J R, E-mail: lenatirpak@gmail.co

    2010-11-01

    A feasibility study of proton beam PET/CT off-line quantitative dosimetry using polymer gels is presented. A newly developed proton-sensitive polymer gel dosimeter (BANG( (registered)) 3-Pro2) is used as a dosimeter and a tissue-equivalent phantom medium for this study. We explore a new approach to correlating measured proton 3-dimensional (3D) dose distributions directly to measured positron emission from in the gel medium using PET/CT imaging. A large cylindrical volume (2.2 Litres) of the gel was irradiated with a clinical modulated proton beam using irregular-shaped aperture geometry. The gel was imaged in a nearby PET/CT unit immediately (<3 min) after irradiation. Dose distribution in the gel was generated using an optical tomography scanning system. Direct 3D spatial comparison of dose and positron emission distributions was then performed. Profiles along the beam path show that the distal fall-off of the dose is nearly 2 cm deeper than the activity profile which is comparable to previous studies with plastic phantoms and Monte Carlo simulations of activity distributions. Planar PET and dose distributions at depth and perpendicular to beam axis show a strong one-to-one spatial correlation. This phantom study demonstrates that the gel medium could be potentially useful for quantifying various physical factors that can influence the PET activity range verification method in patients.

  9. Proton nuclear magnetic resonance in paramagnetic CoCl2.6H2O

    International Nuclear Information System (INIS)

    Oravcova, J.; Murin, J.; Rakos, M.; Olcak, D.

    1978-01-01

    Nuclear magnetic resonance (NMR) is studied of protons of the crystal water of paramagnetic CoCl 2 .6H 2 O. The measurements were carried out on powdered samples at room temperature, for values of the external magnetic field ranging from 0.3 to 1.0 T. The NMR signals of protons of the crystal water exhibit asymmetric shape which changes with the applied external magnetic field. We found that the second moment of the resonance line shows a linear dependence on the square of the induction of the externally applied magnetic field. The cause of the asymmetry of the NMR line of protons of the crystal water and the dependence of the second moment of the resonance line on the induction of external magnetic field are interpreted. (author)

  10. Multi-component quantitative magnetic resonance imaging by phasor representation

    NARCIS (Netherlands)

    Vergeldt, Frank J.; Prusova, Alena; Fereidouni, Farzad; Amerongen, Van Herbert; As, Van Henk; Scheenen, Tom W.J.; Bader, Arjen N.

    2017-01-01

    Quantitative magnetic resonance imaging (qMRI) is a versatile, non-destructive and non-invasive tool in life, material, and medical sciences. When multiple components contribute to the signal in a single pixel, however, it is difficult to quantify their individual contributions and characteristic

  11. Multi-component quantitative magnetic resonance imaging by phasor representation

    NARCIS (Netherlands)

    Vergeldt, F.J.; Prusova, A.; Fereidouni, F.; Amerongen, H.V.; As, H. Van; Scheenen, T.W.J.; Bader, A.N.

    2017-01-01

    Quantitative magnetic resonance imaging (qMRI) is a versatile, non-destructive and non-invasive tool in life, material, and medical sciences. When multiple components contribute to the signal in a single pixel, however, it is difficult to quantify their individual contributions and characteristic

  12. Magnetically scanned proton therapy beams: rationales and techniques

    International Nuclear Information System (INIS)

    Jones, D.T.L.; Schreuder, A.N.

    2000-01-01

    Perhaps the most important advantages of beam scanning systems for proton therapy in comparison with conventional passive beam spreading systems are: (1) Intensity modulation and inverse planning are possible. (2) There is negligible reduction in the range of the beam. (3) Integral dose is reduced as dose conformation to the proximal edge of the lesion is possible. (4) In principle no field-specific modifying devices are required. (5) There is less activation of the surroundings. (6) Scanning systems axe almost infinitely flexible. The main disadvantages include: (1) Scanning systems are more complicated and therefore potentially less reliable and more dangerous. (2) The development of such systems is more demanding in terms of cost, time and manpower. (3) More stable beams are required. (4) Dose and beam position monitoring are more difficult. (5) The problems associated with patient and organ movement axe more severe. There are several techniques which can be used for scanning. For lateral beam spreading, circular scanning (wobbling) or linear scanning can be done. In the latter case the beam can be scanned continuously or in a discrete fashion (spot scanning). Another possibility is to undertake the fastest scan in one dimension (strip scanning) and translate the patient or the scanning magnet in the other dimension. Depth variation is achieved by interposing degraders in the beam (cyclotrons) or by changing the beam energy (synchrotrons). The aim of beam scanning is to deliver a predetermined dose at any point in the body. Special safety precautions must be taken because of the high instantaneous dose rates. The beam position and the dose delivered at each point must be accurately and redundantly determined. (author)

  13. Quantitative magnetic resonance micro-imaging methods for pharmaceutical research.

    Science.gov (United States)

    Mantle, M D

    2011-09-30

    The use of magnetic resonance imaging (MRI) as a tool in pharmaceutical research is now well established and the current literature covers a multitude of different pharmaceutically relevant research areas. This review focuses on the use of quantitative magnetic resonance micro-imaging techniques and how they have been exploited to extract information that is of direct relevance to the pharmaceutical industry. The article is divided into two main areas. The first half outlines the theoretical aspects of magnetic resonance and deals with basic magnetic resonance theory, the effects of nuclear spin-lattice (T(1)), spin-spin (T(2)) relaxation and molecular diffusion upon image quantitation, and discusses the applications of rapid magnetic resonance imaging techniques. In addition to the theory, the review aims to provide some practical guidelines for the pharmaceutical researcher with an interest in MRI as to which MRI pulse sequences/protocols should be used and when. The second half of the article reviews the recent advances and developments that have appeared in the literature concerning the use of quantitative micro-imaging methods to pharmaceutically relevant research. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. Chiral discrimination of sibutramine enantiomers by capillary electrophoresis and proton nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Lee, Yong-Jae; Choi, Seungho; Lee, Jinhoo; Nguyen, NgocVan Thi; Lee, Kyungran; Kang, Jong Seong; Mar, Woongchon; Kim, Kyeong Ho

    2012-03-01

    Capillary electrophoresis (CE) and proton nuclear magnetic resonance spectroscopy ((1)H-NMR) have been used to discriminate the enantiomers of sibutramine using cyclodextrin derivatives. Possible correlation between CE and (1)H-NMR was examined. Good correlation between the (1)H-NMR shift non-equivalence data for sibutramine and the degree of enantioseparation in CE was observed. In CE study, a method of enantiomeric separation and quantitation of sibutramine was developed using enantiomeric standards. The method was based on the use of 50 mM of phosphate buffer of pH 3.0 with 10 mM of methyl-beta-cyclodextrin (M-β-CD). 0.05% of LOD, 0.2% of LOQ for S-sibutramine enantiomer was achieved, and the method was validated and applied to the quantitative determination of sibutramine enantiomers in commercial drugs. On a 600 MHz (1)H-NMR analysis, enantiomer signal separation of sibutramine was obtained by fast diastereomeric interaction with a chiral selector M-β-CD. For chiral separation and quantification, N-methyl proton peaks (at 2.18 ppm) were selected because of its being singlet and simple for understanding of diastereomeric interaction. Effects of temperature and concentration of chiral selector on enantiomer signal separation were investigated. The optimum condition was 0.5 mg/mL of sibutramine and 10 mg/mL of M-β-CD at 10°C. Distinguishment of 0.5% of S-sibutramine in R-sibutramine was found to be possible by (1)H-NMR with M-β-CD as chiral selector. Host-guest interaction between sibutramine and M-β-CD was confirmed by (1)H-NMR studies and CE studies. A Structure of the inclusion complex was proposed considering (1)H-NMR and 2D ROESY studies.

  15. Proton ring trapping in a gated magnetic mirror

    International Nuclear Information System (INIS)

    Pedrow, P.D.; Greenly, J.B.; Hammer, D.A.; Sudan, R.N.

    1985-01-01

    An axis-encircling proton ring has been trapped for times (roughly-equal4 μs) much longer than the ion cyclotron period (roughly-equal80 ns). The rings, with mean radius 10 cm and with particle energies 15 protons during the first pass and 2 x 10 13 protons during the eighth and final pass. With a central solenoidal field of 0.8 T, the peak diamagnetism and azimuthal current density of the injected ring were typically 10 mT (100 G) and 10 A/cm 2 , respectively

  16. Proton nuclear magnetic resonance study on the barrier function of pig corneal epithelium and endothelium

    International Nuclear Information System (INIS)

    Yokoi, Norihiko; Kinoshita, Shigeru; Morimoto, Taketoshi; Yoshizaki, Kazuo.

    1995-01-01

    Using gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) as a tracer, the barrier function of the corneal epithelium and endothelium was evaluated by proton nuclear magnetic resonance. Whole pig eyes and cornea excised with scleral rim, which had been incubated in dextran-added Gd-DTPA solution, were subjected to T 1 relaxation measurement and magnetic resonance imaging (MRI). After incubation, the T 1 relaxation rate (1/T 1 ) of the excised cornea increased to a steady value, whereas that of the cornea from the whole eye increased only slightly. These results indicated that the increase in the T 1 relaxation rate of the excised cornea was attributable to Gd-DTPA penetration from the corneal endothelium and that the corneal epithelium exhibited a strong barrier function against Gd-DTPA entry. The MRI study also confirmed the strong barrier, enhanced signals being detected within the aqueous fluid in the T 1 -weighted image only when the corneal epithelium was abraded. Since Gd-DTPA scarcely penetrates the intact corneal epithelium, Gd-DTPA-enhanced MRI shows potential as a quantitative tracer in evaluating epithelial barrier disruption. (author)

  17. High energy proton induced radiation damage of rare earth permanent magnet quadrupoles

    Science.gov (United States)

    Schanz, M.; Endres, M.; Löwe, K.; Lienig, T.; Deppert, O.; Lang, P. M.; Varentsov, D.; Hoffmann, D. H. H.; Gutfleisch, O.

    2017-12-01

    Permanent magnet quadrupoles (PMQs) are an alternative to common electromagnetic quadrupoles especially for fixed rigidity beam transport scenarios at particle accelerators. Using those magnets for experimental setups can result in certain scenarios, in which a PMQ itself may be exposed to a large amount of primary and secondary particles with a broad energy spectrum, interacting with the magnetic material and affecting its magnetic properties. One specific scenario is proton microscopy, where a proton beam traverses an object and a collimator in which a part of the beam is scattered and deflected into PMQs used as part of a diagnostic system. During the commissioning of the PRIOR (Proton Microscope for Facility for Antiproton and Ion Research) high energy proton microscope facility prototype at Gesellschaft für Schwerionenforschung in 2014, a significant reduction of the image quality was observed which was partially attributed to the demagnetization of the used PMQ lenses and the corresponding decrease of the field quality. In order to study this phenomenon, Monte Carlo simulations were carried out and spare units manufactured from the same magnetic material—single wedges and a fully assembled PMQ module—were deliberately irradiated by a 3.6 GeV intense proton beam. The performed investigations have shown that in proton radiography applications the above described scattering may result in a high irradiation dose in the PMQ magnets. This did not only decrease the overall magnetic strength of the PMQs but also caused a significant degradation of the field quality of an assembled PMQ module by increasing the parasitic multipole field harmonics which effectively makes PMQs impractical for proton radiography applications or similar scenarios.

  18. Proton magnetic resonance spectroscopy (1H-MRS) for the evaluation of treatment of brain tumours

    International Nuclear Information System (INIS)

    Houkin, K.; Kamada, K.; Sawamura, Y.; Iwasaki, Y.; Abe, H.; Kashiwaba, T.

    1995-01-01

    We investigated metabolic changes in brain tumours following treatment, using proton magnetic resonance spectroscopy. In meningiomas, effective therapeutic embolisation led to an acute increase in lactate. In radiosensitive tumours such as malignant lymphoma, a decrease in lactate and in increase in N-acetyl-aspartate occurred after radiotherapy, which preceded changes observed on magnetic resonance imaging. On the other hand, no significant changes in spectral patterns were observed in malignant gliomas resistant to therapy. Tissue characterisation of brain tumours by spectral patterns on proton magnetic resonance spectroscopy remains controversial. However, we have shown it to be sensitive to metabolic changes following treatment, which may reflect the efficacy of the therapy. (orig.)

  19. Characterization of human breast disease using phosphorus magnetic resonance spectroscopy and proton magnetic resonance imaging

    International Nuclear Information System (INIS)

    Merchant, T.E.

    1992-01-01

    This thesis provides the fundamental characterization and differentiation of breast tissues using in vivo and ex vivo MR techniques in the hope that these techniques and experimental findings will be used on a larger scale and in a predictive manner in order to improve the specificity of diagnosis and treatment of breast cancer. In this dissertation, clinical studies were performed using proton magnetic resonance imaging and phosphorus magnetic resonance spectro-scopy ( 31 P MRS) to characterize and differentiate malignant breast tumors, benign breast tumors and normal breast tissues in vivo. These studies were carried out following the methodical characterization of chemical extracts of malignant breast tumor, benign breast tumor and normal breast parenchymal surgical tissue specimens using high resolution 31 P MRS. Alterations in breast tissue metabolism, as a result of pathological processes, were postulated to be responsible for measurable differences between malignant breast tumors, benign breast tumors and normal breast tissues using magnetic resonance techniques. (author). 365 refs.; 37 figs.; 25 tabs

  20. Design of the proposed 250 MeV superconducting cyclotron magnet for proton therapy

    International Nuclear Information System (INIS)

    Dey, M.K.; Ahmed, M.; Murali, S.; Duttagupta, A.; Chaudhuri, J.; Mallik, C.; Bhandari, R.K.

    2006-01-01

    Here we describe the design calculations for the superconducting magnet of a 250 MeV proton cyclotron to be used for therapeutic purpose. Hard-edge approximation method has been adopted for finding the poletip geometry to meet the basic focusing requirements of the beam. Then the uniform-magnetization method has been applied to calculate the 3D magnetic field distribution due to saturated iron poletips, to verify the beam dynamical issues. (author)

  1. Proton radiography of magnetic field in laser produced plasma

    International Nuclear Information System (INIS)

    Le Pape, S.; Patel, P.; Chen, S.; Town, R.; Mackinnon, A.

    2009-01-01

    Electromagnetic fields generated by the interaction with plasmas of long-pulse laser beams relevant to inertial confinement fusion have been measure. A proton beam generated by the interaction of an ultra intense laser with a thin metallic foil is used to probe the B-fields. The proton beam then generated is temporally short (of the order of a ps), highly laminar and hence equivalent to a virtual point which makes it an ideal source for radiography. We have investigated, using face-on radiography, B fields at intensity around 10 14 W/cm 2 due to the non co-linearity of temperature and density gradients. (authors)

  2. Calculation of fusion gain in fast ignition with magnetic target by relativistic electrons and protons

    International Nuclear Information System (INIS)

    Parvazian, A.; Javani, A.

    2010-01-01

    Fast ignition is a new method for inertial confinement fusion in which the compression and ignition steps are separated. In the first stage, fuel is compressed by laser or ion beams. In the second phase, relativistic electrons are generated by pettawat laser in the fuel. Also, in the second phase 5-35 MeV protons can be generated in the fuel. Electrons or protons can penetrate in to the ultra-dense fuel and deposit their energy in the fuel. More recently, cylindrical rather than spherical fuel chambers with magnetic control in the plasma domain have been also considered. This is called magnetized target fusion. Magnetic field has effects on relativistic electrons energy deposition rate in fuel. In this work, fast ignition method in cylindrical fuel chambers is investigated and transportation of the relativistic electrons and protons is calculated using MCNPX and FLUKA codes with 0.25 and 0.5 tesla magnetic field in single and dual hot spot. Furthermore, the transfer rate of relativistic electrons and high energy protons to the fuel and fusion gain are calculated. The results show that the presence of external magnetic field guarantees higher fusion gain, and relativistic electrons are much more appropriate objects for ignition. Magnetized target fusion in dual hot spot can be considered as an appropriate substitution for the current inertial confinement fusion techniques.

  3. WE-D-17A-04: Magnetically Focused Proton Irradiation of Small Volume Targets

    Energy Technology Data Exchange (ETDEWEB)

    McAuley, G; Slater, J [Loma Linda University, Loma Linda, CA (United States); Wroe, A [Loma Linda University Medical Center, Loma Linda, CA (United States)

    2014-06-15

    Purpose: To explore the advantages of magnetic focusing for small volume proton irradiations and the potential clinical benefits for radiosurgery targets. The primary goal is to create narrow elongated proton beams of elliptical cross section with superior dose delivery characteristics compared to current delivery modalities (eg, collimated beams). In addition, more general beam shapes are also under investigation. Methods: Two prototype magnets consisting of 24 segments of samarium-cobalt (Sm2Co17) permanent magnetic material adhered into hollow cylinders were manufactured for testing. A single focusing magnet was placed on a positioning track on our Gantry 1 treatment table and 15 mm diameter proton beams with energies and modulation relevant to clinical radiosurgery applications (127 to 186 MeV, and 0 to 30 mm modulation) were delivered to a terminal water tank. Beam dose distributions were measured using a PTW diode detector and Gafchromic EBT2 film. Longitudinal and transverse dose profiles were analyzed and compared to data from Monte Carlo simulations analogous to the experimental setup. Results: The narrow elongated focused beam spots showed high elliptical symmetry indicating high magnet quality. In addition, when compared to unfocused beams, peak-to-entrance depth dose ratios were 11 to 14% larger (depending on presence or extent of modulation), and minor axis penumbras were 11 to 20% smaller (again depending on modulation) for focused beams. These results suggest that the use of rare earth magnet assemblies is practical and could improve dose-sparing of normal tissue and organs at risk while delivering enhanced dose to small proton radiosurgery targets. Conclusion: Quadrapole rare earth magnetic assemblies are a promising and inexpensive method to counteract particle out scatter that tends to degrade the peak to entrance performance of small field proton beams. Knowledge gained from current experiments will inform the design of a prototype treatment

  4. Account of magnetic field effects of polarized proton target on charged particle trajectories in experiments with magnetic spectrometers

    International Nuclear Information System (INIS)

    Telegin, Yu.N.; Ranyuk, Yu.N.; Karnaukhov, I.M.; Lukhanin, A.A.; Sporov, E.A.

    1980-01-01

    Some effects of the influence of magnetic field of a polarized proton target (PPT) on trajectories of secondary particles in experiments using magnetic spectrometers are considered. It is shown that these effects can be eliminated by the target shift relatively to the spectrometer rotation axis and variation of the spectrometer installation angle. Numerical calculations of the correction values were performed for emitted particle momenta of 100-800 MeB/s and working intensity of the H 0 magnetic field H 0 =27 kG. The influence of the PPT magnetic field on the functions of angular and energy resolution in the γp→π + n experiment is investigated. The results obtained can be used in experiments with a polarized proton target

  5. Quantitative interpretation of the magnetic susceptibility frequency dependence

    Science.gov (United States)

    Ustra, Andrea; Mendonça, Carlos A.; Leite, Aruã; Jovane, Luigi; Trindade, Ricardo I. F.

    2018-05-01

    Low-field mass-specific magnetic susceptibility (MS) measurements using multifrequency alternating fields are commonly used to evaluate concentration of ferrimagnetic particles in the transition of superparamagnetic (SP) to stable single domain (SSD). In classical palaeomagnetic analyses, this measurement serves as a preliminary assessment of rock samples providing rapid, non-destructive, economical and easy information of magnetic properties. The SP-SSD transition is relevant in environmental studies because it has been associated with several geological and biogeochemical processes affecting magnetic mineralogy. MS is a complex function of mineral-type and grain-size distribution, as well as measuring parameters such as external field magnitude and frequency. In this work, we propose a new technique to obtain quantitative information on grain-size variations of magnetic particles in the SP-SSD transition by inverting frequency-dependent susceptibility. We introduce a descriptive parameter named as `limiting frequency effect' that provides an accurate estimation of MS loss with frequency. Numerical simulations show the methodology capability in providing data fitting and model parameters in many practical situations. Real-data applications with magnetite nanoparticles and core samples from sediments of Poggio le Guaine section of Umbria-Marche Basin (Italy) provide additional information not clearly recognized when interpreting cruder MS data. Caution is needed when interpreting frequency dependence in terms of single relaxation processes, which are not universally applicable and depend upon the nature of magnetic mineral in the material. Nevertheless, the proposed technique is a promising tool for SP-SSD content analyses.

  6. Calculation of fusion gain in fast ignition with magnetic target by relativistic electrons and protons

    Directory of Open Access Journals (Sweden)

    A Parvazian

    2010-12-01

    Full Text Available Fast ignition is a new method for inertial confinement fusion (ICF in which the compression and ignition steps are separated. In the first stage, fuel is compressed by laser or ion beams. In the second phase, relativistic electrons are generated by pettawat laser in the fuel. Also, in the second phase 5-35 MeV protons can be generated in the fuel. Electrons or protons can penetrate in to the ultra-dense fuel and deposit their energy in the fuel . More recently, cylindrical rather than spherical fuel chambers with magnetic control in the plasma domain have been also considered. This is called magnetized target fusion (MTF. Magnetic field has effects on relativistic electrons energy deposition rate in fuel. In this work, fast ignition method in cylindrical fuel chambers is investigated and transportation of the relativistic electrons and protons is calculated using MCNPX and FLUKA codes with 0. 25 and 0. 5 tesla magnetic field in single and dual hot spot. Furthermore, the transfer rate of relativistic electrons and high energy protons to the fuel and fusion gain are calculated. The results show that the presence of external magnetic field guarantees higher fusion gain, and relativistic electrons are much more appropriate objects for ignition. MTF in dual hot spot can be considered as an appropriate substitution for the current ICF techniques.

  7. Magnetic Resonance Studies of Proton Loss from Carotenoid Radical Cations

    Energy Technology Data Exchange (ETDEWEB)

    Kispert, Lowell D [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Focsan, A Ligia [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Konovalova, Tatyana A [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lawrence, Jesse [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bowman, Michael K [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dixon, David A [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Molnar, Peter [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Deli, Jozsef [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2007-06-11

    Carotenoids, intrinsic components of reaction centers and pigment-protein complexes in photosynthetic membranes, play a photoprotective role and serve as a secondary electron donor. Before optimum use of carotenoids can be made in artificial photosynthetic systems, their robust nature in living materials requires extensive characterization of their electron transfer, radical trapping ability, stability, structure in and on various hosts, and photochemical behavior. Pulsed ENDOR and 2D-HYSCORE studies combined with DFT calculations reveal that photo-oxidation of natural zeaxanthin (I) and violaxanthin (II) on silica-alumina produces not only the carotenoid radical cations (Car•+) but also neutral radicals (#Car•) by proton loss from the methyl groups at positions 5 or 5', and possibly 9 or 9' and 13 or 13'. Notably, the proton loss favored in I at the 5 position by DFT calculations, is unfavorable in II due to the epoxide at the 5, 6 position. DFT calculations predict the isotropic methyl proton couplings of 8-10 MHz for Car•+ which agree with the ENDOR for carotenoid α-conjugated radical cations. Large α-proton hyperfine coupling constants (>10 MHz) determined from HYSCORE are assigned from the DFT calculations to neutral carotenoid radicals. Proton loss upon photolysis was also examined as a function of carotenoid polarity [Lycopene (III) versus 8'-apo-β-caroten-8'-al (IV)]; hydrogen bonding [Lutein (V) versus III]; host [silica-alumina versus MCM-41 molecular sieve]; and substituted metal in MCM-41. Loss of H+ from the 5(5'), 9(9') or 13(13') methyl positions has importance in photoprotection. Photoprotection involves nonphotochemical quenching (NPQ) in which 1Ch1* decays via energy transfer to the carotenoid which returns to the ground state by thermal dissipation; or via electron transfer to form a charge transfer state (I •+…Chl•-), lower in energy than 1Chl*. Formation of I •+ results in bond

  8. Magnetic Resonance Studies of Proton Loss from Carotenoid Radical Cations

    International Nuclear Information System (INIS)

    Kispert, Lowell D.; Focsan, A. Ligia; Konovalova, Tatyana A.; Lawrence, Jesse; Bowman, Michael K.; Dixon, David A.; Molnar, Peter; Deli, Jozsef

    2007-01-01

    Carotenoids, intrinsic components of reaction centers and pigment-protein complexes in photosynthetic membranes, play a photoprotective role and serve as a secondary electron donor. Before optimum use of carotenoids can be made in artificial photosynthetic systems, their robust nature in living materials requires extensive characterization of their electron transfer, radical trapping ability, stability, structure in and on various hosts, and photochemical behavior. Pulsed ENDOR and 2D-HYSCORE studies combined with DFT calculations reveal that photo-oxidation of natural zeaxanthin (I) and violaxanthin (II) on silica-alumina produces not only the carotenoid radical cations (Car ·+ ) but also neutral radicals ((number s ign)Car · ) by proton loss from the methyl groups at positions 5 or 5(prime), and possibly 9 or 9(prime) and 13 or 13(prime). Notably, the proton loss favored in I at the 5 position by DFT calculations, is unfavorable in II due to the epoxide at the 5, 6 position. DFT calculations predict the isotropic methyl proton couplings of 8-10 MHz for Car # center d ot# + which agree with the ENDOR for carotenoid π-conjugated radical cations. Large α-proton hyperfine coupling constants (>10 MHz) determined from HYSCORE are assigned from the DFT calculations to neutral carotenoid radicals. Proton loss upon photolysis was also examined as a function of carotenoid polarity (Lycopene (III) versus 8(prime)-apo-β-caroten-8(prime)-al (IV)); hydrogen bonding (Lutein (V) versus III); host (silica-alumina versus MCM-41 molecular sieve); and substituted metal in MCM-41. Loss of H + from the 5(5(prime)), 9(9(prime)) or 13(13(prime)) methyl positions has importance in photoprotection. Photoprotection involves nonphotochemical quenching (NPQ) in which 1 Ch1* decays via energy transfer to the carotenoid which returns to the ground state by thermal dissipation; or via electron transfer to form a charge transfer state (I # center d ot# + ...Chl # center d ot# - ), lower in

  9. Amide Proton Transfer (APT) MR imaging and Magnetization Transfer (MT) MR imaging of pediatric brain development

    International Nuclear Information System (INIS)

    Zhang, Hong; Kang, Huiying; Peng, Yun; Zhao, Xuna; Jiang, Shanshan; Zhang, Yi; Zhou, Jinyuan

    2016-01-01

    To quantify the brain maturation process during childhood using combined amide proton transfer (APT) and conventional magnetization transfer (MT) imaging at 3 Tesla. Eighty-two neurodevelopmentally normal children (44 males and 38 females; age range, 2-190 months) were imaged using an APT/MT imaging protocol with multiple saturation frequency offsets. The APT-weighted (APTW) and MT ratio (MTR) signals were quantitatively analyzed in multiple brain areas. Age-related changes in MTR and APTW were evaluated with a non-linear regression analysis. The APTW signals followed a decreasing exponential curve with age in all brain regions measured (R"2 = 0.7-0.8 for the corpus callosum, frontal and occipital white matter, and centrum semiovale). The most significant changes appeared within the first year. At maturation, larger decreases in APTW and lower APTW values were found in the white matter. On the contrary, the MTR signals followed an increasing exponential curve with age in the same brain regions measured, with the most significant changes appearing within the initial 2 years. There was an inverse correlation between the MTR and APTW signal intensities during brain maturation. Together with MT imaging, protein-based APT imaging can provide additional information in assessing brain myelination in the paediatric population. (orig.)

  10. Amide Proton Transfer (APT) MR imaging and Magnetization Transfer (MT) MR imaging of pediatric brain development

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hong; Kang, Huiying; Peng, Yun [Beijing Children' s Hospital, Capital Medical University, Imaging Center, Department of Radiology, Beijing (China); Zhao, Xuna [Philips Healthcare, Beijing (China); Jiang, Shanshan; Zhang, Yi; Zhou, Jinyuan [Johns Hopkins University, Division of MR Research, Department of Radiology, Baltimore, MD (United States)

    2016-10-15

    To quantify the brain maturation process during childhood using combined amide proton transfer (APT) and conventional magnetization transfer (MT) imaging at 3 Tesla. Eighty-two neurodevelopmentally normal children (44 males and 38 females; age range, 2-190 months) were imaged using an APT/MT imaging protocol with multiple saturation frequency offsets. The APT-weighted (APTW) and MT ratio (MTR) signals were quantitatively analyzed in multiple brain areas. Age-related changes in MTR and APTW were evaluated with a non-linear regression analysis. The APTW signals followed a decreasing exponential curve with age in all brain regions measured (R{sup 2} = 0.7-0.8 for the corpus callosum, frontal and occipital white matter, and centrum semiovale). The most significant changes appeared within the first year. At maturation, larger decreases in APTW and lower APTW values were found in the white matter. On the contrary, the MTR signals followed an increasing exponential curve with age in the same brain regions measured, with the most significant changes appearing within the initial 2 years. There was an inverse correlation between the MTR and APTW signal intensities during brain maturation. Together with MT imaging, protein-based APT imaging can provide additional information in assessing brain myelination in the paediatric population. (orig.)

  11. Quantitative metal magnetic memory reliability modeling for welded joints

    Science.gov (United States)

    Xing, Haiyan; Dang, Yongbin; Wang, Ben; Leng, Jiancheng

    2016-03-01

    Metal magnetic memory(MMM) testing has been widely used to detect welded joints. However, load levels, environmental magnetic field, and measurement noises make the MMM data dispersive and bring difficulty to quantitative evaluation. In order to promote the development of quantitative MMM reliability assessment, a new MMM model is presented for welded joints. Steel Q235 welded specimens are tested along the longitudinal and horizontal lines by TSC-2M-8 instrument in the tensile fatigue experiments. The X-ray testing is carried out synchronously to verify the MMM results. It is found that MMM testing can detect the hidden crack earlier than X-ray testing. Moreover, the MMM gradient vector sum K vs is sensitive to the damage degree, especially at early and hidden damage stages. Considering the dispersion of MMM data, the K vs statistical law is investigated, which shows that K vs obeys Gaussian distribution. So K vs is the suitable MMM parameter to establish reliability model of welded joints. At last, the original quantitative MMM reliability model is first presented based on the improved stress strength interference theory. It is shown that the reliability degree R gradually decreases with the decreasing of the residual life ratio T, and the maximal error between prediction reliability degree R 1 and verification reliability degree R 2 is 9.15%. This presented method provides a novel tool of reliability testing and evaluating in practical engineering for welded joints.

  12. Preclinical Magnetic Resonance Fingerprinting (MRF) at 7 T: Effective Quantitative Imaging for Rodent Disease Models

    Science.gov (United States)

    Gao, Ying; Chen, Yong; Ma, Dan; Jiang, Yun; Herrmann, Kelsey A.; Vincent, Jason A.; Dell, Katherine M.; Drumm, Mitchell L.; Brady-Kalnay, Susann M.; Griswold, Mark A.; Flask, Chris A.; Lu, Lan

    2015-01-01

    High field, preclinical magnetic resonance imaging (MRI) scanners are now commonly used to quantitatively assess disease status and efficacy of novel therapies in a wide variety of rodent models. Unfortunately, conventional MRI methods are highly susceptible to respiratory and cardiac motion artifacts resulting in potentially inaccurate and misleading data. We have developed an initial preclinical, 7.0 T MRI implementation of the highly novel Magnetic Resonance Fingerprinting (MRF) methodology that has been previously described for clinical imaging applications. The MRF technology combines a priori variation in the MRI acquisition parameters with dictionary-based matching of acquired signal evolution profiles to simultaneously generate quantitative maps of T1 and T2 relaxation times and proton density. This preclinical MRF acquisition was constructed from a Fast Imaging with Steady-state Free Precession (FISP) MRI pulse sequence to acquire 600 MRF images with both evolving T1 and T2 weighting in approximately 30 minutes. This initial high field preclinical MRF investigation demonstrated reproducible and differentiated estimates of in vitro phantoms with different relaxation times. In vivo preclinical MRF results in mouse kidneys and brain tumor models demonstrated an inherent resistance to respiratory motion artifacts as well as sensitivity to known pathology. These results suggest that MRF methodology may offer the opportunity for quantification of numerous MRI parameters for a wide variety of preclinical imaging applications. PMID:25639694

  13. Magnetic dipole moment of the doubly closed-shell plus one proton nucleus $^{49}$Sc

    CERN Multimedia

    Gaulard, C V; Walters, W; Nishimura, K; Muto, S; Bingham, C R

    It is proposed to measure the magnetic moment of $^{49}$Sc by the Nuclear Magnetic Resonance on Oriented Nuclei (NMR-ON) method using the NICOLE on-line nuclear orientation facility. $^{49}$Sc is the neutron rich, doubly closed-shell, nucleus $^{48}$Ca plus one proton. Results will be used to deduce the effective g-factors in the $^{48}$Ca region with reference to nuclear structure and meson exchange current effects.

  14. Prognostic Value of Quantitative Stress Perfusion Cardiac Magnetic Resonance.

    Science.gov (United States)

    Sammut, Eva C; Villa, Adriana D M; Di Giovine, Gabriella; Dancy, Luke; Bosio, Filippo; Gibbs, Thomas; Jeyabraba, Swarna; Schwenke, Susanne; Williams, Steven E; Marber, Michael; Alfakih, Khaled; Ismail, Tevfik F; Razavi, Reza; Chiribiri, Amedeo

    2018-05-01

    This study sought to evaluate the prognostic usefulness of visual and quantitative perfusion cardiac magnetic resonance (CMR) ischemic burden in an unselected group of patients and to assess the validity of consensus-based ischemic burden thresholds extrapolated from nuclear studies. There are limited data on the prognostic value of assessing myocardial ischemic burden by CMR, and there are none using quantitative perfusion analysis. Patients with suspected coronary artery disease referred for adenosine-stress perfusion CMR were included (n = 395; 70% male; age 58 ± 13 years). The primary endpoint was a composite of cardiovascular death, nonfatal myocardial infarction, aborted sudden death, and revascularization after 90 days. Perfusion scans were assessed visually and with quantitative analysis. Cross-validated Cox regression analysis and net reclassification improvement were used to assess the incremental prognostic value of visual or quantitative perfusion analysis over a baseline clinical model, initially as continuous covariates, then using accepted thresholds of ≥2 segments or ≥10% myocardium. After a median 460 days (interquartile range: 190 to 869 days) follow-up, 52 patients reached the primary endpoint. At 2 years, the addition of ischemic burden was found to increase prognostic value over a baseline model of age, sex, and late gadolinium enhancement (baseline model area under the curve [AUC]: 0.75; visual AUC: 0.84; quantitative AUC: 0.85). Dichotomized quantitative ischemic burden performed better than visual assessment (net reclassification improvement 0.043 vs. 0.003 against baseline model). This study was the first to address the prognostic benefit of quantitative analysis of perfusion CMR and to support the use of consensus-based ischemic burden thresholds by perfusion CMR for prognostic evaluation of patients with suspected coronary artery disease. Quantitative analysis provided incremental prognostic value to visual assessment and

  15. Quantitative Magnetic Separation of Particles and Cells Using Gradient Magnetic Ratcheting.

    Science.gov (United States)

    Murray, Coleman; Pao, Edward; Tseng, Peter; Aftab, Shayan; Kulkarni, Rajan; Rettig, Matthew; Di Carlo, Dino

    2016-04-13

    Extraction of rare target cells from biosamples is enabling for life science research. Traditional rare cell separation techniques, such as magnetic activated cell sorting, are robust but perform coarse, qualitative separations based on surface antigen expression. A quantitative magnetic separation technology is reported using high-force magnetic ratcheting over arrays of magnetically soft micropillars with gradient spacing, and the system is used to separate and concentrate magnetic beads based on iron oxide content (IOC) and cells based on surface expression. The system consists of a microchip of permalloy micropillar arrays with increasing lateral pitch and a mechatronic device to generate a cycling magnetic field. Particles with higher IOC separate and equilibrate along the miropillar array at larger pitches. A semi-analytical model is developed that predicts behavior for particles and cells. Using the system, LNCaP cells are separated based on the bound quantity of 1 μm anti-epithelial cell adhesion molecule (EpCAM) particles as a metric for expression. The ratcheting cytometry system is able to resolve a ±13 bound particle differential, successfully distinguishing LNCaP from PC3 populations based on EpCAM expression, correlating with flow cytometry analysis. As a proof-of-concept, EpCAM-labeled cells from patient blood are isolated with 74% purity, demonstrating potential toward a quantitative magnetic separation instrument. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Preliminary analysis of proton magnetic resonance 1D spectra of cerebrospinal fluid and brain cancer extracts

    International Nuclear Information System (INIS)

    Toczylowska, B.; Jozwik, A.; Kierul, K.; Matysiak, Z.; Sidor, M.; Wojcik, J.

    1999-01-01

    In series of cerebrospinal fluid samples from 25 patients proton spectra of magnetic resonance were measured. The spectra were measured also for series of brain tumor tissue extracts received from another 25 patients. This paper presents an attempt to apply statistical methods of image recognition for spectra analysis of the two measured series

  17. Glutamatergic Effects of Divalproex in Adolescents with Mania: A Proton Magnetic Resonance Spectroscopy Study

    Science.gov (United States)

    Strawn, Jeffrey R.; Patel, Nick C.; Chu, Wen-Jang; Lee, Jing-Huei; Adler, Caleb M.; Kim, Mi Jung; Bryan, Holly S.; Alfieri, David C.; Welge, Jeffrey A.; Blom, Thomas J.; Nandagopal, Jayasree J.; Strakowski, Stephen M.; DelBello, Melissa P.

    2012-01-01

    Objectives: This study used proton magnetic resonance spectroscopy ([superscript 1]H MRS) to evaluate the in vivo effects of extended-release divalproex sodium on the glutamatergic system in adolescents with bipolar disorder, and to identify baseline neurochemical predictors of clinical remission. Method: Adolescents with bipolar disorder who were…

  18. Conceptual design of the superconducting magnet for the 250 MeV proton cyclotron.

    Science.gov (United States)

    Ren, Yong; Liu, Xiaogang; Gao, Xiang

    2016-01-01

    The superconducting cyclotron is of great importance to treat cancer parts of the body. To reduce the operation costs, a superconducting magnet system for the 250 MeV proton cyclotron was designed to confirm the feasibility of the superconducting cyclotron. The superconducting magnet system consists of a pair of split coils, the cryostat and a pair of binary high temperature superconductor current leads. The superconducting magnet can reach a central magnetic field of about 1.155 T at 160 A. The three GM cryocooler with cooling capacities of 1.5 W at 4.5 K and 35 W at 50 K and one GM cryocooler of 100 W at 50 K were adopted to cool the superconducting magnet system through the thermosiphon technology. The four GM cryocoolers were used to cool the superconducting magnet to realize zero evaporation of the liquid helium.

  19. Proton transport model in the ionosphere. 2. Influence of magnetic mirroring and collisions on the angular redistribution in a proton beam

    Directory of Open Access Journals (Sweden)

    M. Galand

    1998-10-01

    Full Text Available We investigate the influence of magnetic mirroring and elastic and inelastic scattering on the angular redistribution in a proton/hydrogen beam by using a transport code in comparison with observations. H-emission Doppler profiles viewed in the magnetic zenith exhibit a red-shifted component which is indicative of upward fluxes. In order to determine the origin of this red shift, we evaluate the influence of two angular redistribution sources which are included in our proton/hydrogen transport model. Even though it generates an upward flux, the redistribution due to magnetic mirroring effect is not sufficient to explain the red shift. On the other hand, the collisional angular scattering induces a much more significant red shift in the lower atmosphere. The red shift due to collisions is produced  by <1 -keV protons and is so small as to require an instrumental bandwidth <0.2 nm. This explains the absence of measured upward proton/hydrogen fluxes in the Proton I rocket data because no useable data concerning protons <1 keV are available. At the same time, our model agrees with measured ground-based H-emission Doppler profiles and suggests that previously reported red shift observations were due mostly to instrumental bandwidth broadening of the profile. Our results suggest that Doppler profile measurements with higher spectral resolution may enable us to quantify better the angular scattering in proton aurora.Key words. Auroral ionosphere · Particle precipitation

  20. Sunflower oil ozonation. Following of the reaction by proton Nuclear Magnetic Resonance

    International Nuclear Information System (INIS)

    Diaz Gomez, Maritza F.

    2005-01-01

    Previous studies have demonstrated that the technique of Proton Nuclear Magnetic Resonance can be used for the pursuit of the reaction between the ozone and the unsaturated fatty acids. It's carried out the sunflower oil ozonization to different applied dose of ozone and the index of peroxides and the concentration of aldehydes are determined. The main reaction products were identified by Proton Nuclear Magnetic Resonance Spectroscopy (NMR 1 H). The intensities of the signs were used to follow the advance of the reaction between the ozone and the sunflower oil. It is was carried out until obtaining an index of peroxides of 1 202 mmol-equiv/kg. The intensities of the signs of the olefinic protons diminish with a gradual increment in the dose of applied ozone, but without ending up disappearing completely. The ozonides of Criegee obtained to applied dose of ozone of 107,1 mg/g were approximately bigger 7,4 times that those obtained at the beginning from the reaction to applied dose of ozone of 15,3 mg/g. The aldehydes protons were observed as a sign of weak intensity in all the spectra. The signs belonging to the olenifics protons of the hydroperoxides in d = 5,55 ppm increases with the increment of the applied dose of ozone. You concludes that to higher applied dose of ozone, haggler is the advance of the ozonization reaction, what belongs together with a bigger formation of oxygenated compounds

  1. Proton magnetic resonance spectroscopy of tubercular breast abscess: report of a case.

    Science.gov (United States)

    Das, Chandan Jyoti; Medhi, Kunjahari

    2008-01-01

    In vivo proton magnetic resonance spectroscopy (H-MRS) is a functional imaging modality. When magnetic resonance imaging is coupled with H-MRS, it results in accurate metabolic characterization of various lesions. Proton magnetic resonance spectroscopy has an established role in evaluating malignant breast lesions, and the increasing number of published literature supports the role of H-MRS in patients with breast cancer. However, H-MRS can be of help in evaluating benign breast disease. We present a case of tubercular breast abscess, initial diagnosis of which was suggested based on characteristic lipid pick on H-MRS and was subsequently confirmed by fine needle aspiration biopsy of the breast lesion.

  2. Pulsed high field magnets. An efficient way of shaping laser accelerated proton beams for application

    Energy Technology Data Exchange (ETDEWEB)

    Kroll, Florian; Schramm, Ulrich [Helmholtz-Zentrum Dresden - Rossendorf, 01328 Dresden (Germany); Technische Universitaet Dresden, 01062 Dresden (Germany); Bagnoud, Vincent; Blazevic, Abel; Busold, Simon [GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Helmholtz Institut Jena, 07734 Jena (Germany); Brabetz, Christian; Schumacher, Dennis [GSI Helmholtzzentrum fuer Schwerionenforschung, 64291 Darmstadt (Germany); Deppert, Oliver; Jahn, Diana; Roth, Markus [Technische Universitaet Darmstadt, 64289 Darmstadt (Germany); Karsch, Leonhard; Masood, Umar [OncoRay-National Center for Radiation Research in Oncology, TU Dresden, 01307 Dresden (Germany); Kraft, Stephan [Helmholtz-Zentrum Dresden - Rossendorf, 01328 Dresden (Germany)

    2015-07-01

    Compact laser-driven proton accelerators are a potential alternative to complex, expensive conventional accelerators, enabling unique beam properties, like ultra-high pulse dose. Nevertheless, they still require substantial development in reliable beam generation and transport. We present experimental studies on capture, shape and transport of laser and conventionally accelerated protons via pulsed high-field magnets. These magnets, common research tools in the fields of solid state physics, have been adapted to meet the demands of laser acceleration experiments.Our work distinctively shows that pulsed magnet technology makes laser acceleration more suitable for application and can facilitate compact and efficient accelerators, e.g. for material research as well as medical and biological purposes.

  3. Proton probe measurement of fast advection of magnetic fields by hot electrons

    International Nuclear Information System (INIS)

    Willingale, L; Thomas, A G R; Nilson, P M; Kaluza, M C; Dangor, A E; Evans, R G; Fernandes, P; Haines, M G; Kamperidis, C; Kingham, R J; Ridgers, C P; Sherlock, M; Wei, M S; Najmudin, Z; Krushelnick, K; Bandyopadhyay, S; Notley, M; Minardi, S; Rozmus, W; Tatarakis, M

    2011-01-01

    A laser generated proton beam was used to measure the megagauss strength self-generated magnetic fields from a nanosecond laser interaction with an aluminum target. At intensities of 10 15 W cm −2 , the significant hot electron production and strong heat fluxes result in non-local transport becoming important to describe the magnetic field dynamics. Two-dimensional implicit Vlasov–Fokker–Planck modeling shows that fast advection of the magnetic field from the focal region occurs via the Nernst effect at significantly higher velocities than the sound speed, v N /c s ≈ 10.

  4. Role of proton magnetic resonance spectroscopy in diagnosis of ...

    African Journals Online (AJOL)

    Mohammed Mahmoud Donia

    2012-01-23

    Jan 23, 2012 ... Subjects and methods: This study included seven pediatric patients ... ton magnetic resonance spectroscopy was done using either single or multi-voxel technique. ... with increased NAA/Cr ratio (2.32 ± 1.1). ... Table 1 Summary of the spectroscopic MRI findings in the seven patients included in the study.

  5. Motor-Generator powering the PS (Proton Synchrotron) main magnets

    CERN Multimedia

    1983-01-01

    This motor-generator,30 MW peak, 1500 r.p.m.,pulsed power supply for the PS main magnet replaced in 1968 the initial 3000 r.p.m. motor-generator-flywheel set which had served from the PS start-up in 1959 until end 1967. See also photo 8302337 and its abstract.

  6. Role of proton magnetic resonance spectroscopy in diagnosis of ...

    African Journals Online (AJOL)

    Background: Pilocytic astrocytomas are the second overall most common pediatric brain tumor. Magnetic resonance (MR) imaging is widely used in the diagnosis and follow up of pediatric patients with pilocytic astrocytomas because of its ability to provide anatomical detail. However conventional MR imaging does not ...

  7. Alternating-gradient canted cosine theta superconducting magnets for future compact proton gantries

    Directory of Open Access Journals (Sweden)

    Weishi Wan

    2015-10-01

    Full Text Available We present a design of superconducting magnets, optimized for application in a gantry for proton therapy. We have introduced a new magnet design concept, called an alternating-gradient canted cosine theta (AG-CCT concept, which is compatible with an achromatic layout. This layout allows a large momentum acceptance. The 15 cm radius of the bore aperture enables the application of pencil beam scanning in front of the SC-magnet. The optical and dynamic performance of a gantry based on these magnets has been analyzed using the fields derived (via Biot-Savart law from the actual windings of the AG-CCT combined with the full equations of motion. The results show that with appropriate higher order correction, a large 3D volume can be rapidly scanned with little beam shape distortion. A very big advantage is that all this can be done while keeping the AG-CCT fields fixed. This reduces the need for fast field ramping of the superconducting magnets between the successive beam energies used for the scanning in depth and it is important for medical application since this reduces the technical risk (e.g., a quench associated with fast field changes in superconducting magnets. For proton gantries the corresponding superconducting magnet system holds promise of dramatic reduction in weight. For heavier ion gantries there may furthermore be a significant reduction in size.

  8. Effectiveness of revascularization surgery evaluated by proton magnetic resonance spectroscopy and single photon emission computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Uno, Masaaki; Ueda, Shin; Hondo, Hideki; Matsumoto, Keizo; Harada, Masafumi [Tokushima Univ. (Japan). School of Medicine

    1996-08-01

    Proton magnetic resonance spectroscopy (MRS) and single photon emission computed tomography (SPECT) were used to evaluate chronic ischemic regions in 26 stroke patients before and 1, 3, and 6 months after revascularization surgery. The volume of interest for proton MRS was placed in an area including part of the frontal and temporal opercula, insular cortex, and basal ganglia. Twenty healthy volunteers served as controls for proton MRS. Patients were divided into three groups according to the preoperative proton MRS. Group A (n=12) had significantly lower N-acetylaspartate/choline (NAA/Cho) and N-acetylaspartate/creatine (NAA/Cr) ratios on the operative side compared to those on the contralateral side, and also lower than those in normal subjects. In seven patients in Group A, postoperative serial proton MRS demonstrated no recovery of these ratios on the operative side. However, proton MRS of the other five patients indicated gradual improvement in these ratios on the operative side at 3 to 6 months after surgery, and SPECT indicated an increase in cerebral blood flow on the operative side in four of these five patients. In Group B (n=9), proton MRS and SPECT showed no laterality before revascularization and no remarkable change during the postoperative course. In Group C (n=5), NAA/Cho or NAA/Cr decreased on the contralateral side preoperatively. Two patients showed fluctuating values of NAA/Cho or NAA/Cr during the postoperative period. Serial proton MRS and SPECT Studies may be useful for the evaluation of revascularization surgery on ischemic regions. The efficacy of revascularization surgery on the metabolism may appear gradually within 3-6 months. (author)

  9. Quantitative Evaluation of Range Degradation According to the Gradient of the Compensator in Passive Scattering Proton Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Wook Geun; Min, Chul Hee [Radiation Convergence Engineering, Yonsei University, Seoul (Korea, Republic of); Kim, Chan Kyu; Kim, Hak Soo; Jeong, Jong Hwi; Lee, Se Byeong [Proton Therapy Center, National Center Center, Seoul (Korea, Republic of)

    2017-04-15

    The Bragg peak enables proton therapy to deliver a high conformal target dose without exit dose. The passive scattering proton therapy employees patient-specific aperture and range compensator to shape the lateral and distal beam, and to deliver conformal dose to the target volume. The inaccurate dose calculation could cause underdose in the target volume and overdose in the normal tissues. The purpose of this study is to quantitatively evaluate the range degradation due to the slope of the range compensator using TOPAS Monte Carlo (MC) tool. The current study quantitatively evaluates the scattering effect due to the compensator slope with MC method. Our results show that not only patient geometry but also range compensator significantly contributes to the dose degradation. The current study quantitatively evaluates the scattering effect due to the compensator slope with MC method. Our results show that not only patient geometry but also range compensator significantly contributes to the dose degradation.

  10. Conformational analysis by quantitative NOE measurements of the β-proton pairs across individual disulfide bonds in proteins

    International Nuclear Information System (INIS)

    Takeda, Mitsuhiro; Terauchi, Tsutomu; Kainosho, Masatsune

    2012-01-01

    NOEs between the β-protons of cysteine residues across disulfide bonds in proteins provide direct information on the connectivities and conformations of these important cross-links, which are otherwise difficult to investigate. With conventional [U- 13 C, 15 N]-proteins, however, fast spin diffusion processes mediated by strong dipolar interactions between geminal β-protons prohibit the quantitative measurements and thus the analyses of long-range NOEs across disulfide bonds. We describe a robust approach for alleviating such difficulties, by using proteins selectively labeled with an equimolar mixture of (2R, 3S)-[β- 13 C; α,β- 2 H 2 ] Cys and (2R, 3R)-[β- 13 C; α,β- 2 H 2 ] Cys, but otherwise fully deuterated. Since either one of the prochiral methylene protons, namely β2 (proS) or β3 (proR), is always replaced with a deuteron and no other protons remain in proteins prepared by this labeling scheme, all four of the expected NOEs for the β-protons across disulfide bonds could be measured without any spin diffusion interference, even with long mixing times. Therefore, the NOEs for the β2 and β3 pairs across each of the disulfide bonds could be observed at high sensitivity, even though they are 25% of the theoretical maximum for each pair. With the NOE information, the disulfide bond connectivities can be unambiguously established for proteins with multiple disulfide bonds. In addition, the conformations around disulfide bonds, namely χ 2 and χ 3 , can be determined based on the precise proton distances of the four β-proton pairs, by quantitative measurements of the NOEs across the disulfide bonds. The feasibility of this method is demonstrated for bovine pancreatic trypsin inhibitor, which has three disulfide bonds.

  11. Effects of High-Energy Proton-Beam Irradiation on the Magnetic Properties of ZnO Nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jun Kue; Kwon, Hyeok-Jung; Cho, Yong Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    There are still many problem for the application due to its unstable magnetism state and too small magnetization values. Here we investigate magnetic properties of ZnO nanorods after high-energy proton-beam irradiation. Electron spin resonance (ESR) measurement on temperature was made to identify intrinsic or extrinsic defects as well as to observe magnetic ordering after irradiation. Understanding the effects of proton beam irradiation on magnetic behavior may help to shed light on the mechanism responsible for the magnetic ordering in this material. We have investigated proton-beam irradiation effects on the magnetic properties of ZnO nanorods. After irradiation a broad ESR line is observed, indicating emergence of ferromagnetic ordering up to room temperature. In M-H curve, stronger coercive field is observed after irradiation.

  12. Quantitative description of proton exchange processes between water and endogenous and exogenous agents for WEX, CEST, and APT experiments.

    Science.gov (United States)

    Zhou, Jinyuan; Wilson, David A; Sun, Phillip Zhe; Klaus, Judith A; Van Zijl, Peter C M

    2004-05-01

    The proton exchange processes between water and solutes containing exchangeable protons have recently become of interest for monitoring pH effects, detecting cellular mobile proteins and peptides, and enhancing the detection sensitivity of various low-concentration endogenous and exogenous species. In this work, the analytic expressions for water exchange (WEX) filter spectroscopy, chemical exchange-dependent saturation transfer (CEST), and amide proton transfer (APT) experiments are derived by the use of Bloch equations with exchange terms. The effects of the initial states for the system, the difference between a steady state and a saturation state, and the relative contributions of the forward and backward exchange processes are discussed. The theory, in combination with numerical calculations, provides a useful tool for designing experimental schemes and assessing magnetization transfer (MT) processes between water protons and solvent-exchangeable protons. As an example, the case of endogenous amide proton exchange in the rat brain at 4.7 T is analyzed in detail. Copyright 2004 Wiley-Liss, Inc.

  13. SU-D-304-02: Magnetically Focused Proton Irradiation of Small Field Targets

    International Nuclear Information System (INIS)

    McAuley, GA; Slater, JM; Slater, JD; Wroe, AJ

    2015-01-01

    Purpose: To investigate the use of magnetic focusing for small field proton irradiations. It is hypothesized that magnetic focusing will provide significant dose distribution benefits over standard collimated beams for fields less than 10 mm diameter. Methods: Magnets consisting of 24 segments of radiation hard samarium-cobalt adhered into hollow cylinders were designed and manufactured. Two focusing magnets were placed on a positioning track on our Gantry 1 treatment table. Proton beams with energies of 127 and 157 MeV, 15 and 30 mm modulation, and 8 mm initial diameters were delivered to a water tank using single-stage scattering. Depth dose distributions were measured using a PTW PR60020 diode detector and transverse profiles were measured with Gafchromic EBT3 film. Monte Carlo simulations were also performed - both for comparison with experimental data and to further explore the potential of magnetic focusing in silica. For example, beam spot areas (based on the 90% dose contour) were matched at Bragg depth between simulated 100 MeV collimated beams and simulated beams focused by two 400 T/m gradient magnets. Results: Preliminary experimental results show 23% higher peak to entrance dose ratios and flatter spread out Bragg peak plateaus for 8 mm focused beams compared with uncollimated beams. Monte Carlo simulations showed 21% larger peak to entrance ratios and a ∼9 fold more efficient dose to target delivery compared to spot-sized matched collimated beams. Our latest results will be presented. Conclusion: Our results suggest that rare earth focusing magnet assemblies could reduce skin dose and beam number while delivering dose to nominally spherical radiosurgery targets over a much shorter time compared to unfocused beams. Immediate clinical applications include those associated with proton radiosurgery and functional radiosurgery of the brain and spine, however expanded treatment sites can be also envisaged

  14. SU-D-304-02: Magnetically Focused Proton Irradiation of Small Field Targets

    Energy Technology Data Exchange (ETDEWEB)

    McAuley, GA; Slater, JM [Loma Linda University, Loma Linda, CA (United States); Slater, JD; Wroe, AJ [Loma Linda University Medical Center, Loma Linda, CA (United States)

    2015-06-15

    Purpose: To investigate the use of magnetic focusing for small field proton irradiations. It is hypothesized that magnetic focusing will provide significant dose distribution benefits over standard collimated beams for fields less than 10 mm diameter. Methods: Magnets consisting of 24 segments of radiation hard samarium-cobalt adhered into hollow cylinders were designed and manufactured. Two focusing magnets were placed on a positioning track on our Gantry 1 treatment table. Proton beams with energies of 127 and 157 MeV, 15 and 30 mm modulation, and 8 mm initial diameters were delivered to a water tank using single-stage scattering. Depth dose distributions were measured using a PTW PR60020 diode detector and transverse profiles were measured with Gafchromic EBT3 film. Monte Carlo simulations were also performed - both for comparison with experimental data and to further explore the potential of magnetic focusing in silica. For example, beam spot areas (based on the 90% dose contour) were matched at Bragg depth between simulated 100 MeV collimated beams and simulated beams focused by two 400 T/m gradient magnets. Results: Preliminary experimental results show 23% higher peak to entrance dose ratios and flatter spread out Bragg peak plateaus for 8 mm focused beams compared with uncollimated beams. Monte Carlo simulations showed 21% larger peak to entrance ratios and a ∼9 fold more efficient dose to target delivery compared to spot-sized matched collimated beams. Our latest results will be presented. Conclusion: Our results suggest that rare earth focusing magnet assemblies could reduce skin dose and beam number while delivering dose to nominally spherical radiosurgery targets over a much shorter time compared to unfocused beams. Immediate clinical applications include those associated with proton radiosurgery and functional radiosurgery of the brain and spine, however expanded treatment sites can be also envisaged.

  15. Short- and long-term quantitation reproducibility of brain metabolites in the medial wall using proton echo planar spectroscopic imaging.

    Science.gov (United States)

    Tsai, Shang-Yueh; Lin, Yi-Ru; Wang, Woan-Chyi; Niddam, David M

    2012-11-15

    Proton echo planar spectroscopic imaging (PEPSI) is a fast magnetic resonance spectroscopic imaging (MRSI) technique that allows mapping spatial metabolite distributions in the brain. Although the medial wall of the cortex is involved in a wide range of pathological conditions, previous MRSI studies have not focused on this region. To decide the magnitude of metabolic changes to be considered significant in this region, the reproducibility of the method needs to be established. The study aims were to establish the short- and long-term reproducibility of metabolites in the right medial wall and to compare regional differences using a constant short-echo time (TE30) and TE averaging (TEavg) optimized to yield glutamatergic information. 2D sagittal PEPSI was implemented at 3T using a 32 channel head coil. Acquisitions were repeated immediately and after approximately 2 weeks to assess the coefficients of variation (COV). COVs were obtained from eight regions-of-interest (ROIs) of varying size and location. TE30 resulted in better spectral quality and similar or lower quantitation uncertainty for all metabolites except glutamate (Glu). When Glu and glutamine (Gln) were quantified together (Glx) reduced quantitation uncertainty and increased reproducibility was observed for TE30. TEavg resulted in lowered quantitation uncertainty for Glu but in less reliable quantification of several other metabolites. TEavg did not result in a systematically improved short- or long-term reproducibility for Glu. The ROI volume was a major factor influencing reproducibility. For both short- and long-term repetitions, the Glu COVs obtained with TEavg were 5-8% for the large ROIs, 12-17% for the medium sized ROIs and 16-26% for the smaller cingulate ROIs. COVs obtained with TE30 for the less specific Glx were 3-5%, 8-10% and 10-15%. COVs for N-acetyl aspartate, creatine and choline using TE30 with long-term repetition were between 2-10%. Our results show that the cost of more specific

  16. [Dementias: diagnostic contribution of imaging and proton magnetic resonance spectroscopy].

    Science.gov (United States)

    Arana, E; Martínez-Granados, B; Marti-Bonmati, L; Martínez-Bisbal, M C; Gil, A; Blasco, C; Celda, B

    2007-06-01

    The objective is analyze the complementarity between 1H magnetic resonance spectroscopy (MRS) and magnetic resonance (MR) imaging in the global diagnosis of Alzheimer's disease (AD) or vascular dementia (VD). We studied 168 patients with cognitive impairment from AD, VD, mild cognitive impairment (MCI) and major depression. All patients were evaluated by brain MR imaging and MRS using two sample volumes localized at right medial temporal gyrus and posterior parietal gyrus. Metabolites analyzed were N-acetylaspartate (NAA), myo-Inositol (mI), Choline (Cho) and creatine (Cr), as standard references for obtaining the Co/Cr, mI/Cr and NAA/Cr ratios. Imaging and spectroscopy alterations were graded from 0 to 4 and the average of both was used to draw ROC and SROC curves. Area under ROC curve (Az) was used as a measure of discriminative ability. Combination of MR imaging and MRS significantly improved AD diagnosis (Global Az: 0.722 vs. MR imaging Az: 0.624; p: 0.003). However, the combination of MR imaging and MRS did not improve VD diagnosis. SROC curve obtained for the diagnosis of global dementia was Az: 0.6658 with 0.67 sensitivity and 0.65 specificity. Combination of both MR techniques significantly improved AD diagnosis versus MR imaging alone. More studies are needed to enhance VD classification. Metabolic data found by MRS can be useful to differentiate cognitive impairment

  17. Quantitative Magnetization Transfer in Monitoring Glioblastoma (GBM) Response to Therapy.

    Science.gov (United States)

    Mehrabian, Hatef; Myrehaug, Sten; Soliman, Hany; Sahgal, Arjun; Stanisz, Greg J

    2018-02-06

    Quantitative magnetization transfer (qMT) was used as a biomarker to monitor glioblastoma (GBM) response to chemo-radiation and identify the earliest time-point qMT could differentiate progressors from non-progressors. Nineteen GBM patients were recruited and MRI-scanned before (Day 0 ), two weeks (Day 14 ), and four weeks (Day 28 ) into the treatment, and one month after the end of the treatment (Day 70 ). Comprehensive qMT data was acquired, and a two-pool MT model was fit to the data. Response was determined at 3-8 months following the end of chemo-radiation. The amount of magnetization transfer ([Formula: see text]) was significantly lower in GBM compared to normal appearing white matter (p GBM are more sensitive to treatment effects compared to clinically used metrics. qMT could assess tumor aggressiveness and identify early progressors even before the treatment. Changes in qMT parameters within the first 14 days of the treatment were capable of separating early progressors from non-progressors, making qMT a promising biomarker to guide adaptive radiotherapy for GBM.

  18. B1 -sensitivity analysis of quantitative magnetization transfer imaging.

    Science.gov (United States)

    Boudreau, Mathieu; Stikov, Nikola; Pike, G Bruce

    2018-01-01

    To evaluate the sensitivity of quantitative magnetization transfer (qMT) fitted parameters to B 1 inaccuracies, focusing on the difference between two categories of T 1 mapping techniques: B 1 -independent and B 1 -dependent. The B 1 -sensitivity of qMT was investigated and compared using two T 1 measurement methods: inversion recovery (IR) (B 1 -independent) and variable flip angle (VFA), B 1 -dependent). The study was separated into four stages: 1) numerical simulations, 2) sensitivity analysis of the Z-spectra, 3) healthy subjects at 3T, and 4) comparison using three different B 1 imaging techniques. For typical B 1 variations in the brain at 3T (±30%), the simulations resulted in errors of the pool-size ratio (F) ranging from -3% to 7% for VFA, and -40% to > 100% for IR, agreeing with the Z-spectra sensitivity analysis. In healthy subjects, pooled whole-brain Pearson correlation coefficients for F (comparing measured double angle and nominal flip angle B 1 maps) were ρ = 0.97/0.81 for VFA/IR. This work describes the B 1 -sensitivity characteristics of qMT, demonstrating that it varies substantially on the B 1 -dependency of the T 1 mapping method. Particularly, the pool-size ratio is more robust against B 1 inaccuracies if VFA T 1 mapping is used, so much so that B 1 mapping could be omitted without substantially biasing F. Magn Reson Med 79:276-285, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  19. Proton magnetic resonance studies in solutions of o- and p-hydroxy benzoic acids in dioxan

    International Nuclear Information System (INIS)

    Arulmozhi, V.; Srinivasa Rao, A.; Balasubramanian, V.

    1990-01-01

    High resolution proton(NMR) studies were carried out in solutions of o- and p-hydroxy benzoic acids(OHBA and PHBA) in dioxan (D) for several solute concentrations in the range of 0.01 to 0.10 mole fraction (mf). The spectra corresponding to OH and COOH protons could be distinguished in solutions of OHBA in D whereas solution of PHBA in D show only peak in the range of chemical shifts attributable to OH and COOH protons. In the solution of OHBA in dioxan the chemical shift of the proton of the hydroxyl group increases with increase of solute concentration and attains a maximum at a solute concentration of 0.04 mf and then decreases with further increase of solute concentration. For the carboxyl group, the chemical shift increase with increase of solute concentration and attians a maximum at 0.08 mf solute concentration. In solutions of PHBA in D the chemical shift of the single line observed increases with increase of solute concentration and attains a maximum at a solute concentration of 0.05 mf. The data are interpreted as due to formation of hydrogen bonds between the molecule of OHBA and PHBA and dioxan. The proton magnetic relaxation studies in the above solutions also confirm the above findings. (author). 6 refs., 5 figs

  20. Design of the dipole and quadrupole magnets of the dedicated proton synchrotron for hadron therapy

    International Nuclear Information System (INIS)

    Kukarnikov, S.I.; Makoveev, V.K.; Minashkin, V.F.; Molodozhentsev, A.Yu.; Shevtsov, V.F.; Sidorov, G.I.

    1998-01-01

    The 2D-calculation results of magnetic elements of the PRAMES (Prague Medical Synchrotron) are presented. This machine is a dedicated accelerator for cancer therapy. The output energy of the beam should be variable in the range 60-220 MeV. The maximum magnetic field of the dipole magnet should be 1.2 T, the maximum magnetic field ramp - less than 8 T/s. The focusing structure of the proton synchrotron consists of 8 dipole and 18 quadrupole magnets. All magnets are laminated to minimize leakage currents. The dipoles are parallel-edge, H-type magnets. The field uniformity should be of the order of ± 1 x 10 -4 in the working area (± 63 mm and ± 27 mm in the horizontal and vertical planes, respectively). The maximum magnetic field on the pole of the quadrupole lenses should be less than 1 T. The gradient uniformity of quadrupole magnets in the working region should be less than ± 3.5 x 10 -4

  1. NuMI proton kicker extraction magnet termination resistor system

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, S.R.; Jensen, C.C.; /Fermilab

    2005-05-01

    The temperature stability of the kicker magnet termination resistor assembly directly affects the field flatness and amplitude stability. Comprehensive thermal enhancements were made to the existing Main Injector resistor assembly design to satisfy NuMI performance specifications. Additionally, a fluid-processing system utilizing Fluorinert{reg_sign} FC-77 high-voltage dielectric was built to precisely control the setpoint temperature of the resistor assembly from 70 to 120F, required to maintain constant resistance during changing operational modes. The Fluorinert{reg_sign} must be continually processed to remove hazardous breakdown products caused by radiation exposure to prevent chemical attack of system components. Design details of the termination resistor assembly and Fluorinert{reg_sign} processing system are described. Early performance results will be presented.

  2. Quantitative mapping of total choline in healthy human breast using proton echo planar spectroscopic imaging (PEPSI) at 3 Tesla.

    Science.gov (United States)

    Zhao, Chenguang; Bolan, Patrick J; Royce, Melanie; Lakkadi, Navneeth; Eberhardt, Steven; Sillerud, Laurel; Lee, Sang-Joon; Posse, Stefan

    2012-11-01

    To quantitatively measure tCho levels in healthy breasts using Proton-Echo-Planar-Spectroscopic-Imaging (PEPSI). The two-dimensional mapping of tCho at 3 Tesla across an entire breast slice using PEPSI and a hybrid spectral quantification method based on LCModel fitting and integration of tCho using the fitted spectrum were developed. This method was validated in 19 healthy females and compared with single voxel spectroscopy (SVS) and with PRESS prelocalized conventional Magnetic Resonance Spectroscopic Imaging (MRSI) using identical voxel size (8 cc) and similar scan times (∼7 min). A tCho peak with a signal to noise ratio larger than 2 was detected in 10 subjects using both PEPSI and SVS. The average tCho concentration in these subjects was 0.45 ± 0.2 mmol/kg using PEPSI and 0.48 ± 0.3 mmol/kg using SVS. Comparable results were obtained in two subjects using conventional MRSI. High lipid content in the spectra of nine tCho negative subjects was associated with spectral line broadening of more than 26 Hz, which made tCho detection impossible. Conventional MRSI with PRESS prelocalization in glandular tissue in two of these subjects yielded tCho concentrations comparable to PEPSI. The detection sensitivity of PEPSI is comparable to SVS and conventional PRESS-MRSI. PEPSI can be potentially used in the evaluation of tCho in breast cancer. A tCho threshold concentration value of ∼0.7 mmol/kg might be used to differentiate between cancerous and healthy (or benign) breast tissues based on this work and previous studies. Copyright © 2012 Wiley Periodicals, Inc.

  3. Importance of Proton Magnetic Resonance Spectroscopy in Diagnosis of Brain Tumors

    International Nuclear Information System (INIS)

    Polacek, H.; Zelenak, K.; Bittsansky, M.; Cisarikova, V.; DeRiggo, J.; Tichterova, R.

    2011-01-01

    Most brain tumors are routinely examined by CT and magnetic resonance (MR). MR plays a crucial role in the preoperative diagnosis and postoperative monitoring. In some cases, proton MR spectroscopy (MRS) provides additional diagnostic information to standard MR results. MRS analyzes important cerebral biochemical substances containing choline, N-acetylaspartate and more. We present a case of 42-year old patient with high-grade glioblastoma examined using MRS in addition to MR imaging before and after surgery. (author)

  4. Design summary of the magnet support structures for the proton storage ring injection line upgrade

    International Nuclear Information System (INIS)

    Bernardin, J.D.; Ledford, J.E.; Smith, B.G.

    1997-05-01

    This report summarizes the technical engineering and design issues associated with the Proton Storage Ring (PSR) Injection Line upgrade of the Los Alamos Neutron Science Center (LANSCE). The main focus is on the engineering design calculations of several magnet support structures. The general procedure based upon a set number of design criteria is outlined, followed by a case-by-case summary of the engineering design analyses, reutilization or fabrication callouts and design safety factors

  5. Application of random numbers at computerized simulation of proton magnetic resonance signals

    International Nuclear Information System (INIS)

    Populyakh, S.N.; Sapiga, A.V.

    2006-01-01

    One calculated numerically spectra of proton magnetic resonance of water molecules diffusing along the regular positions in a natrolite. One reached adequate conformity of the experimental and the calculated spectra within wide temperature range including a transition region. To ensure calculations one used generators of the pseudorandom Markov sequences. The numerical analysis, in particular, has shown that at the binary Markov process the time period when physical value remains unchanged is described by the random value with exponential distribution [ru

  6. Medulloblastoma: correlation among findings of conventional magnetic resonance imaging, diffusion-weighted imaging and proton magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fonte, Mariana Vieira de Melo da; Otaduy, Maria Concepcion Garcia; Lucato, Leandro Tavares; Reed, Umbertina Conti; Leite, Claudia da Costa [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Inst. de Radiologia]. E-mail: mvmfonte@uol.com.br; Costa, Maria Olivia Rodrigues; Amaral, Raquel Portugal Guimaraes [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Dept. de Radiologia; Reed, Umbertina Conti [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Dept. de Neurologia; Rosemberg, Sergio [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Dept. de Patologia

    2008-11-15

    To correlate imaging findings of medulloblastomas at conventional magnetic resonance imaging, diffusion-weighted imaging and proton magnetic resonance spectroscopy, comparing them with data in the literature. Preoperative magnetic resonance imaging studies of nine pediatric patients with histologically confirmed medulloblastomas (eight desmoplastic medulloblastoma, and one giant cell medulloblastoma) were retrospectively reviewed, considering demographics as well as tumors characteristics such as localization, morphology, signal intensity, contrast-enhancement, dissemination, and diffusion-weighted imaging and spectroscopy findings. In most of cases the tumors were centered in the cerebellar vermis (77.8%), predominantly solid (88.9%), hypointense on T 1-weighted images and intermediate/hyperintense on T 2-FLAIR-weighted images, with heterogeneous enhancement (100%), tumor dissemination/extension (77.8%) and limited water molecule mobility (100%). Proton spectroscopy acquired with STEAM technique (n = 6) demonstrated decreased Na a / Cr ratio (83.3%) and increased Co/Cr (100%) and ml/Cr (66.7%) ratios; and with PRESS technique (n = 7) demonstrated lactate peak (57.1%). Macroscopic magnetic resonance imaging findings in association with biochemical features of medulloblastomas have been useful in the differentiation among the most frequent posterior fossa tumors. (author)

  7. Medulloblastoma: correlation among findings of conventional magnetic resonance imaging, diffusion-weighted imaging and proton magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Fonte, Mariana Vieira de Melo da; Otaduy, Maria Concepcion Garcia; Lucato, Leandro Tavares; Reed, Umbertina Conti; Leite, Claudia da Costa; Costa, Maria Olivia Rodrigues; Amaral, Raquel Portugal Guimaraes; Reed, Umbertina Conti; Rosemberg, Sergio

    2008-01-01

    To correlate imaging findings of medulloblastomas at conventional magnetic resonance imaging, diffusion-weighted imaging and proton magnetic resonance spectroscopy, comparing them with data in the literature. Preoperative magnetic resonance imaging studies of nine pediatric patients with histologically confirmed medulloblastomas (eight desmoplastic medulloblastoma, and one giant cell medulloblastoma) were retrospectively reviewed, considering demographics as well as tumors characteristics such as localization, morphology, signal intensity, contrast-enhancement, dissemination, and diffusion-weighted imaging and spectroscopy findings. In most of cases the tumors were centered in the cerebellar vermis (77.8%), predominantly solid (88.9%), hypointense on T 1-weighted images and intermediate/hyperintense on T 2-FLAIR-weighted images, with heterogeneous enhancement (100%), tumor dissemination/extension (77.8%) and limited water molecule mobility (100%). Proton spectroscopy acquired with STEAM technique (n = 6) demonstrated decreased Na a / Cr ratio (83.3%) and increased Co/Cr (100%) and ml/Cr (66.7%) ratios; and with PRESS technique (n = 7) demonstrated lactate peak (57.1%). Macroscopic magnetic resonance imaging findings in association with biochemical features of medulloblastomas have been useful in the differentiation among the most frequent posterior fossa tumors. (author)

  8. Study of resonant magnet exciting system for the 3 GeV proton synchrotron

    Energy Technology Data Exchange (ETDEWEB)

    Koseki, Shoichiro; Zhang, Fengqing; Watanabe, Yasuhiro; Tani, Norio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Adachi, Toshikazu; Someya, Hirohiko [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

    2001-07-01

    Exciting system for magnets of the 3 GeV Proton synchrotron is under consideration. A resonant exciting system is studied, and two type of power supply are compared. One is a parallel supply that is used generally. Another is a modified series supply. Either of them uses IGBT sinusoidal converters. Capacity of the power converter of the series supply for bending magnets becomes 28.8 MVAp. This is lager more than twice compared with the parallel supply. In the other hand, the series supply has good control performance and flexibility. More study is necessary to decide finally. (author)

  9. Upgrade of the CERN Proton Synchrotron Booster bending magnets for 2 GeV Operation

    CERN Document Server

    Newborough, A; Chritin, R

    2013-01-01

    Since its first operation in 1972 at an energy of 800MeV the CERN Proton Synchrotron Booster, which consists of 4 super imposed synchrotrons, has seen two upgrades: once to 1.0 GeV in 1988 and then to 1.4 GeV in 1999. During this time the main magnets of the machine have remained largely unchanged with small differences (<1%) between the inner and outer gaps of the main bending magnet fields being compensated by trim power supplies. The future upgrade of the machine will demand to extract protons at an energy of 2.0 GeV and require almost double the original dipole field. At this field, due to saturation effects, the inner and outer gaps of the main dipole magnets will differ by up to 4%. This paper presents the design and implementation of a modification of the magnetic circuit strongly reducing these effects. We also discuss the results of experimental tests concerning the effects on field quality and eddy current transients, including the implications for the real-time magnetic field measurement system ...

  10. Validated ¹H and 13C Nuclear Magnetic Resonance Methods for the Quantitative Determination of Glycerol in Drug Injections.

    Science.gov (United States)

    Lu, Jiaxi; Wang, Pengli; Wang, Qiuying; Wang, Yanan; Jiang, Miaomiao

    2018-05-15

    In the current study, we employed high-resolution proton and carbon nuclear magnetic resonance spectroscopy (¹H and 13 C NMR) for quantitative analysis of glycerol in drug injections without any complex pre-treatment or derivatization on samples. The established methods were validated with good specificity, linearity, accuracy, precision, stability, and repeatability. Our results revealed that the contents of glycerol were convenient to calculate directly via the integration ratios of peak areas with an internal standard in ¹H NMR spectra, while the integration of peak heights were proper for 13 C NMR in combination with an external calibration of glycerol. The developed methods were both successfully applied in drug injections. Quantitative NMR methods showed an extensive prospect for glycerol determination in various liquid samples.

  11. Magnetic field perturbation in proton MR imaging - A study of a contrast agent and of distortions due to metallic implants

    International Nuclear Information System (INIS)

    Olsson, M.

    1992-01-01

    Perturbations of the static magnetic field in proton MR imaging (NMR imaging, MRI, MRT) result in image distortion and/or signal loss. An investigation of a superparamagnetic contrast agent for MR imaging has been performed. Magnetite particles were embedded in biodegradable starch spheres with a diameter of one micrometer. Animal experiments showed that the agent was quickly accumulated in the reticulo-endothelial system (RES), causing a decrease in signal intensity in this region. Diffusion within the locally generated magnetic field perturbation is responsible for signal loss in spin-echo images. Furthermore, the magnetic properties of various aneurysm clips were investigated to determine which clips could be used safely in a clinical MR investigation. MR artifacts caused by the metallic clips were studied using a geometric phantom. Non-ferromagnetic clips were concluded to be safe for examinations with medium field (0.3 tesla) MR imaging systems. A comparison study between MR and CT was performed on patients harbouring intracranial, nonferromagnetic aneurysm clips. The artifacts close to the clips were equally serve for MR and CT, but at some distance, the MR images were much less affected than the CT images. Finally, a computer program capable of simulating any realistic MR imaging situation has been developed. Raw data matrices are obtained by solving the Bloch equations. Corrections for intravascular spin behaviour have been implemented together with efficient algorithms. A quantitative investigation of signal displacement and signal loss, caused by small metallic implants, has been performed by computer simulation. An exact expression for the magnetic field outside a homogeneous ellipsoid in an external magnetic field has been derived. Distortions in MR images, caused by perturbing ellipsoids of different shapes and orientations, were studied. (30 refs.) (au)

  12. Proton-density fat fraction measurement: A viable quantitative biomarker for differentiating adrenal adenomas from nonadenomas

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Xiaoyan; Chen, Xiao; Shen, Yaqi; Hu, Xuemei; Tang, Hao; Hu, Daoyu [Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei (China); Li, Zhen, E-mail: zhenli@hust.edu.cn [Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei (China); Kamel, Ihab R. [Russell H. Morgan Department of Radiology and Radiological Science, the Johns Hopkins Medical Institutions, Baltimore, Maryland (United States)

    2017-01-15

    Highlights: • PDFF differentiated adenomas from nonadenomas with high sensitivity and specificity. • PDFF measurements are simple and can be readily applicable in clinical practice. • Oil-saline phantom study demonstarted good correlation between PDFF and SII. - Abstract: Purpose: This study aims to compare the accuracy of proton-density fat fraction (PDFF) measurements with chemical shift magnetic resonance imaging (CSI) for quantifying the fat content of adrenal nodules and for differentiating adenomas from nonadenomas. Materials and methods: Oil-saline phantom measurements was performed to compare the correlation between PDFF and CSI in detecting and quantifying fat content. 43 consecutive patients who had known adrenal nodules were imaged on a 3.0-T MR scanner. PDFF was measured, and the signal intensity (SI) index (SII), SI adrenal-to-liver ratio (ALR) and SI adrenal-to-spleen ratio (ASR) of the adrenal nodules were calculated. Results: In the phantom study, PDFF ranged from 12.6% to 99.1% and the SII was between 0.72 and 1.23. There was good correlation between these two methods (R square = 0.972, p < 0.0001). The PDFF of adrenal adenoma was significantly increased compared with that of nonadenoma (p < 0.001). PDFF was an effective tool for distinguishing adenoma from nonadenoma, with an area under the curve (AUC) of 0.98. In comparing SII, ALR and ASR the AUC was 0.94, 0.95 and 0.93, respectively. No significant difference was noted between these two methods (p > 0.05). Conclusion: PDFF measurements provide an accurate estimation of fat content in discriminating adenomas from nonadenomas compared with CSI, avoiding complicated data calculations and offering a simpler technique using 3T.

  13. Quantitative perfusion imaging in magnetic resonance imaging; Quantitative Perfusionsbildgebung in der Magnetresonanztomographie

    Energy Technology Data Exchange (ETDEWEB)

    Zoellner, F.G.; Gaa, T.; Zimmer, F. [Universitaet Heidelberg, Computerunterstuetzte Klinische Medizin, Medizinische Fakultaet Mannheim, Mannheim (Germany); Ong, M.M.; Riffel, P.; Hausmann, D.; Schoenberg, S.O.; Weis, M. [Universitaet Heidelberg, Institut fuer Klinische Radiologie und Nuklearmedizin, Universitaetsmedizin Mannheim, Medizinische Fakultaet Mannheim, Mannheim (Germany)

    2016-02-15

    Magnetic resonance imaging (MRI) is recognized for its superior tissue contrast while being non-invasive and free of ionizing radiation. Due to the development of new scanner hardware and fast imaging techniques during the last decades, access to tissue and organ functions became possible. One of these functional imaging techniques is perfusion imaging with which tissue perfusion and capillary permeability can be determined from dynamic imaging data. Perfusion imaging by MRI can be performed by two approaches, arterial spin labeling (ASL) and dynamic contrast-enhanced (DCE) MRI. While the first method uses magnetically labelled water protons in arterial blood as an endogenous tracer, the latter involves the injection of a contrast agent, usually gadolinium (Gd), as a tracer for calculating hemodynamic parameters. Studies have demonstrated the potential of perfusion MRI for diagnostics and also for therapy monitoring. The utilization and application of perfusion MRI are still restricted to specialized centers, such as university hospitals. A broad application of the technique has not yet been implemented. The MRI perfusion technique is a valuable tool that might come broadly available after implementation of standards on European and international levels. Such efforts are being promoted by the respective professional bodies. (orig.) [German] Die Magnetresonanztomographie (MRT) zeichnet sich durch einen ueberlegenen Gewebekontrast aus, waehrend sie nichtinvasiv und frei von ionisierender Strahlung ist. Sie bietet Zugang zu Gewebe- und Organfunktion. Eine dieser funktionellen bildgebenden Verfahren ist die Perfusionsbildgebung. Mit dieser Technik koennen u. a. Gewebeperfusion und Kapillarpermeabilitaet aus dynamischen Bilddaten bestimmt werden. Perfusionsbildgebung mithilfe der MRT kann durch 2 Ansaetze, naemlich ''arterial spin labeling'' (ASL) und dynamische kontrastverstaerkte (DCE-)MRT durchgefuehrt werden. Waehrend die erste Methode magnetisch

  14. Pathological Assessment of Brain White Matter in Relapsing-Remitting MS Patients using Quantitative Magnetization Transfer Imaging

    Directory of Open Access Journals (Sweden)

    Khodarahm Pahlevan

    2011-09-01

    Full Text Available Introduction: Multiple sclerosis (MS is characterized by lesions in the white matter (WM of the central nervous system. Magnetic resonance imaging is the most specific and sensitive method for diagnosis of multiple sclerosis. However, the ability of conventional MRI to show histopathologic heterogeneity of MS lesions is insufficient. Quantitative magnetization transfer imaging (qMTI is a relatively new method to investigate pathologic processes of the brain tissue occurring in MS patients. Material and Methods: Voxel-based analyses allow regional comparisons between groups to be made for the whole brain in a single analysis. This is done by coregistering data from all individual subjects to a reference brain, generally referred to as the "standard space", and then comparing them on a voxel-by-voxel basis. This study aimed to analyze whole-brain quantitative T1 maps, not to find global changes or changes in selected regions, but specifically to investigate the spatial distribution throughout the brain of T1 increases in MS WM with respect to control WM. In this study, 11 healthy controls, 10 relapsing-remitting (RR MS patients and 13 CIS patients were studied using MT-MRI imaging. MT parameters, including magnetization transfer ratio (MTR, magnetization transfer rate between free protons and restricted macromolecular protons, Ksat and longitudinal relaxation times (with and without MT saturation pulse, T1sat and T1free values were evaluated. Results: The results showed that, at a group level, there is widespread involvement of WM throughout the brain in CIS MS and especially in RRMS, where a significant T1 increase was found in 15.58% of WM voxels (normals < RR. Discussion and Conclusion: This study demonstrates that WM in large parts of the brain is susceptible to disease processes in RR and CIS MS

  15. Proton magnetic spectroscopy agreed better with magnetic resonance image to lateralization of epileptogenic zone than with surface electroencephalography

    Directory of Open Access Journals (Sweden)

    Ricardo Andre Amorim Leite

    2013-09-01

    Full Text Available Objective To analyze the agreement rate of proton magnetic spectroscopy with magnetic resonance image (MRI and surface electroence-phalography (EEG in extratemporal neocortical epilepsies. Methods A cross-sectional study, type series of cases included 33 patients, age range 13–59 years old, of both gender, presenting structural alteration identified by MRI (75.8% or by neurophysiologic techniques (72.7%. The variables were alterations of N-acetyl-aspartate/choline, N-acetyl-aspartate/creatine, choline/creatine, and N-acetyl-aspartate/cho-line+creatine coefficient of asymmetry. Results Agreement rates of lateralization by coefficient of asymmetry of NAA/Cho, NAA/Cr, Co/Cr, and NAA/Cho+Cr with MRI, independent of alteration of surface EEG, were equal to 93.3, 57.9, 15.4, and 93.3%, respectively, modifying to 100, 33.3, 0, and 100%, in 16 patients, with lateralization agreement of MRI and surface EEG. Conclusion Proton magnetic spectroscopy agreed better with MRI to lateralization of epileptogenic zone than with surface EEG.

  16. An experimentally derived magnetic moment for the f7/2 proton in trans-lead nuclei

    International Nuclear Information System (INIS)

    Stuchbery, A.E.; Byrne, A.P.; Dracoulis, G.D.

    1992-12-01

    An experimental value for the g-factor of the 1f 7/2 proton is derived from the measured magnetic moment of the 14 + 1 state in 214 Ra using the multiparticle octupole coupling model. The result, g(f 7/2 ) = 1.41(2), is smaller than anticipated by theories which assume first order core polarization corrections to the proton spin g-factor together with an anomalous orbital magnetism of about 0.12. The experimental value suggests the proton spin g-factor g s may be quenched, in this orbital, to about half the bare-nucleon value, similar to that found for the 0h 9/2 and 0i 13/2 protons, or, alternatively, that the anomalous orbital magnetism is much reduced for the 1f 7/2 orbital. 15 refs., 2 tabs

  17. Proton NMR for Measuring Quantum Level Crossing in the Magnetic Molecular Ring Fe10

    International Nuclear Information System (INIS)

    Julien, M.; Jang, Z.H.; Borsa, F.; Julien, M.; Lascialfari, A.; Borsa, F.; Horvatic, M.; Caneschi, A.; Gatteschi, D.

    1999-01-01

    The proton nuclear spin-lattice relaxation rate 1/T 1 has been measured as a function of temperature and magnetic field (up to 15thinspthinspT) in the molecular magnetic ring Fe 10 ( OCH 3 ) 20 (O 2 CCH 2 Cl) 10 (Fe10). Striking enhancement of 1/T 1 is observed around magnetic field values corresponding to a crossing between the ground state and the excited states of the molecule. We propose that this is due to a cross-relaxation effect between the nuclear Zeeman reservoir and the reservoir of the Zeeman levels of the molecule. This effect provides a powerful tool to investigate quantum dynamical phenomena at level crossing. copyright 1999 The American Physical Society

  18. Magnetic measurements on the ring dipoles and quadrupoles for the Los Alamos proton storage ring

    International Nuclear Information System (INIS)

    Schermer, R.I.; Blind, B.; Jason, A.J.; Sawyer, G.A.

    1985-01-01

    This paper discusses magnetic measurements and shimming performed on the ring dipoles and quadrupoles for the Los Alamos Proton Storage Ring (PSR). For the dipoles, point-by-point field maps were obtained using a search coil that could be scanned over a three-dimensional grid. By appropriate machining of removable end blocks, all magnet lengths were adjusted to within 0.01% of a nominal value and all integrated multipoles were set within tolerance. Integrated fields of 20 PSR quadrupoles were measured using a rotating ''Morgan Coil'' and a digital spectrum analyzer. The magnets were shimmed to specifications by adjusting steel bolts threaded through the field clamps. 3 refs., 5 figs., 4 tabs

  19. Uniform magnetic field in the bending magneto for the compact proton synchrotron

    CERN Document Server

    Tokura, S; Miyauchi, Y; Nakajima, S; Arakawa, M

    2003-01-01

    Radiation therapy using high-energy protons is a very effective method of cancer treatment. To attain the necessary beam energy for cancer therapy using a very compact synchrotron, the magnetic field of the normal-conductive bending magnet must be excited up to 3-5 T. However, increasing the field up to 4 T produces a sextupole component in the field. The sextupole component can be reduced by changing the geometry of the coil, but establishing the optimal geometry is very time-consuming. A new optimization method has been developed to establish the uniform field in the bending magnet. As a result, the optimal geometry is obtained with less calculation time. (author)

  20. Quantitative magnetic resonance imaging phantoms: A review and the need for a system phantom.

    Science.gov (United States)

    Keenan, Kathryn E; Ainslie, Maureen; Barker, Alex J; Boss, Michael A; Cecil, Kim M; Charles, Cecil; Chenevert, Thomas L; Clarke, Larry; Evelhoch, Jeffrey L; Finn, Paul; Gembris, Daniel; Gunter, Jeffrey L; Hill, Derek L G; Jack, Clifford R; Jackson, Edward F; Liu, Guoying; Russek, Stephen E; Sharma, Samir D; Steckner, Michael; Stupic, Karl F; Trzasko, Joshua D; Yuan, Chun; Zheng, Jie

    2018-01-01

    The MRI community is using quantitative mapping techniques to complement qualitative imaging. For quantitative imaging to reach its full potential, it is necessary to analyze measurements across systems and longitudinally. Clinical use of quantitative imaging can be facilitated through adoption and use of a standard system phantom, a calibration/standard reference object, to assess the performance of an MRI machine. The International Society of Magnetic Resonance in Medicine AdHoc Committee on Standards for Quantitative Magnetic Resonance was established in February 2007 to facilitate the expansion of MRI as a mainstream modality for multi-institutional measurements, including, among other things, multicenter trials. The goal of the Standards for Quantitative Magnetic Resonance committee was to provide a framework to ensure that quantitative measures derived from MR data are comparable over time, between subjects, between sites, and between vendors. This paper, written by members of the Standards for Quantitative Magnetic Resonance committee, reviews standardization attempts and then details the need, requirements, and implementation plan for a standard system phantom for quantitative MRI. In addition, application-specific phantoms and implementation of quantitative MRI are reviewed. Magn Reson Med 79:48-61, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  1. Influence of the interface on the magnetic properties of NiZn ferrite thin films treated by proton irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, X.D. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Guo, D.W. [Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Zhang, C.H., E-mail: c.h.zhang@impcas.ac.cn [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Fan, X.L.; Chai, G.Z. [Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Xue, D.S., E-mail: xueds@lzu.edu.cn [Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China)

    2015-09-01

    In order to systematically investigate the influence of the interface on the magnetic properties, polycrystalline NiZn ferrite thin films were irradiated with 60 keV proton in the dose range from 5 × 10{sup 12} to 5 × 10{sup 16} ions/cm{sup 2}. A non-destructive approach by proton irradiation was found to finely adjust the magnetic properties of polycrystalline NiZn ferrite thin films such as coercivity, perpendicular magnetic anisotropy as well as the effective g value. The coercivity is about 725 Oe for high proton dose ferrite, which is twice larger than the unirradiated one. The ferromagnetic resonance measurements indicated that perpendicular magnetic anisotropy and the effective g value increase with the irradiation dose. Our finding indicates that all modifications of these magnetic properties were associated with the change of interface due to the diffusion and the stress induced by proton irradiation. The change of the effective g value is a result of lattice expansion and the decrease of the magnetic dipole interaction between the columnar grains. This work provides a feasible way to tailor the magnetic properties of thin films by ion irradiation and promotes investigations for the stability of magnetic thin film devices in space or unclear radiation environments.

  2. A superconducting magnet mandrel with minimum symmetry laminations for proton therapy

    Science.gov (United States)

    Caspi, S.; Arbelaez, D.; Brouwer, L.; Dietderich, D. R.; Felice, H.; Hafalia, R.; Prestemon, S.; Robin, D.; Sun, C.; Wan, W.

    2013-08-01

    The size and weight of ion-beam cancer therapy gantries are frequently determined by a large aperture, curved, ninety degree, dipole magnet. The higher fields achievable with superconducting technology promise to greatly reduce the size and weight of this magnet and therefore also the gantry as a whole. This paper reports advances in the design of winding mandrels for curved, canted cosine-theta (CCT) magnets in the context of a preliminary magnet design for a proton gantry. The winding mandrel is integral to the CCT design and significantly affects the construction cost, stress management, winding feasibility, eddy current power losses, and field quality of the magnet. A laminated mandrel design using a minimum symmetry in the winding path is introduced and its feasibility demonstrated by a rapid prototype model. Piecewise construction of the mandrel using this laminated approach allows for increased manufacturing techniques and material choices. Sectioning the mandrel also reduces eddy currents produced during field changes accommodating the scan of beam energies during treatment. This symmetry concept can also greatly reduce the computational resources needed for 3D finite element calculations. It is shown that the small region of symmetry forming the laminations combined with periodic boundary conditions can model the entire magnet geometry disregarding the ends.

  3. Strange magnetic form factor of the proton at $Q^2 = 0.23$ GeV$^2$

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ping; Leinweber, Derek; Thomas, Anthony; Young, Ross

    2009-06-01

    We determine the $u$ and $d$ quark contributions to the proton magnetic form factor at finite momentum transfer by applying chiral corrections to quenched lattice data. Heavy baryon chiral perturbation theory is applied at next to leading order in the quenched, and full QCD cases for the valence sector using finite range regularization. Under the assumption of charge symmetry these values can be combined with the experimental values of the proton and neutron magnetic form factors to deduce a relatively accurate value for the strange magnetic form factor at $Q^2=0.23$ GeV$^2$, namely $G_M^s=-0.034 \\pm 0.021$ $\\mu_N$.

  4. 3D microscopy of hydrogen and magnetic force on proton implanted microstructures in graphite

    International Nuclear Information System (INIS)

    Reichart, P.; Cluitmans, J.F.J.; Pakes, C.; Orbons, S.; Jamieson, D.N.

    2005-01-01

    We investigated the depth dependence of magnetic signals in proton irradiated graphite using a tilted microspot implantation followed by combined AFM/MFM analysis. This study is motivated by the not yet independently reproduced discovery of ferromagnetism in carbon materials created by proton irradiation. We present results of 3D hydrogen analysis of pristine and irradiated highly oriented pyrolytic graphite (HOPG). These results, previously presented in collaboration with universities in Leipzig and Munich, are summarized here and reveal a hydrogen level in pristine HOPG less than 0.3 at-ppm and that 2.25 MeV implanted hydrogen is located within a peak confined to the end of range with no evidence of diffusion broadening. For implanted microspots, up to 40 at-% of the implanted hydrogen is not detected, providing support for lateral hydrogen diffusion. Up to 10 16 H-atoms/cm 2 are detected in the near-surface region on all samples, which has not yet been considered in possible mechanisms for creation of ferromagnetism. As theoretical models propose that hydrogen could play a major role in carbon ferromagnetism, this result raises the hypothesis for an effect restricted to the surface. Our preliminary data on magnetic force microscopy of tilted implants show a strong magnetic phase shift localized on the beam entrance point only. (author). 14 refs., 5 figs

  5. The effect of polymer coatings on proton transverse relaxivities of aqueous suspensions of magnetic nanoparticles

    International Nuclear Information System (INIS)

    Carroll, Matthew R J; House, Michael J; Woodward, Robert C; St Pierre, Timothy G; Huffstetler, Phillip P; Miles, William C; Goff, Jonathon D; Davis, Richey M; Riffle, Judy S

    2011-01-01

    Iron oxide magnetic nanoparticles are good candidates for magnetic resonance imaging (MRI) contrast agents due to their high magnetic susceptibilities. Here we investigate 19 polyether-coated magnetite nanoparticle systems comprising three series. All systems were synthesized from the same batch of magnetite nanoparticles. A different polyether was used for each series. Each series comprised systems with systematically varied polyether loadings per particle. A highly significant (p < 0.0001) linear correlation (r = 0.956) was found between the proton relaxivity and the intensity-weighted average diameter measured by dynamic light scattering in the 19 particle systems studied. The intensity-weighted average diameter measured by dynamic light scattering is sensitive to small number fractions of larger particles/aggregates. We conclude that the primary effect leading to differences in proton relaxivity between systems arises from the small degree of aggregation within the samples, which appears to be determined by the nature of the polymer and, for one system, the degree of polymer loading of the particles. For the polyether coatings used in this study, any changes in relaxivity from differences in water exclusion or diffusion rates caused by the polymer are minor in comparison with the changes in relaxivity resulting from variations in the degree of aggregation.

  6. The effect of polymer coatings on proton transverse relaxivities of aqueous suspensions of magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, Matthew R J; House, Michael J; Woodward, Robert C; St Pierre, Timothy G [School of Physics, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 (Australia); Huffstetler, Phillip P; Miles, William C; Goff, Jonathon D; Davis, Richey M; Riffle, Judy S, E-mail: stpierre@physics.uwa.edu.au [Macromolecules and Interfaces Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States)

    2011-08-12

    Iron oxide magnetic nanoparticles are good candidates for magnetic resonance imaging (MRI) contrast agents due to their high magnetic susceptibilities. Here we investigate 19 polyether-coated magnetite nanoparticle systems comprising three series. All systems were synthesized from the same batch of magnetite nanoparticles. A different polyether was used for each series. Each series comprised systems with systematically varied polyether loadings per particle. A highly significant (p < 0.0001) linear correlation (r = 0.956) was found between the proton relaxivity and the intensity-weighted average diameter measured by dynamic light scattering in the 19 particle systems studied. The intensity-weighted average diameter measured by dynamic light scattering is sensitive to small number fractions of larger particles/aggregates. We conclude that the primary effect leading to differences in proton relaxivity between systems arises from the small degree of aggregation within the samples, which appears to be determined by the nature of the polymer and, for one system, the degree of polymer loading of the particles. For the polyether coatings used in this study, any changes in relaxivity from differences in water exclusion or diffusion rates caused by the polymer are minor in comparison with the changes in relaxivity resulting from variations in the degree of aggregation.

  7. Characterization of the ELIMED Permanent Magnets Quadrupole system prototype with laser-driven proton beams

    Science.gov (United States)

    Schillaci, F.; Pommarel, L.; Romano, F.; Cuttone, G.; Costa, M.; Giove, D.; Maggiore, M.; Russo, A. D.; Scuderi, V.; Malka, V.; Vauzour, B.; Flacco, A.; Cirrone, G. A. P.

    2016-07-01

    Laser-based accelerators are gaining interest in recent years as an alternative to conventional machines [1]. In the actual ion acceleration scheme, energy and angular spread of the laser-driven beams are the main limiting factors for beam applications and different solutions for dedicated beam-transport lines have been proposed [2,3]. In this context a system of Permanent Magnet Quadrupoles (PMQs) has been realized [2] by INFN-LNS (Laboratori Nazionali del Sud of the Instituto Nazionale di Fisica Nucleare) researchers, in collaboration with SIGMAPHI company in France, to be used as a collection and pre-selection system for laser driven proton beams. This system is meant to be a prototype to a more performing one [3] to be installed at ELI-Beamlines for the collection of ions. The final system is designed for protons and carbons up to 60 MeV/u. In order to validate the design and the performances of this large bore, compact, high gradient magnetic system prototype an experimental campaign have been carried out, in collaboration with the group of the SAPHIR experimental facility at LOA (Laboratoire d'Optique Appliquée) in Paris using a 200 TW Ti:Sapphire laser system. During this campaign a deep study of the quadrupole system optics has been performed, comparing the results with the simulation codes used to determine the setup of the PMQ system and to track protons with realistic TNSA-like divergence and spectrum. Experimental and simulation results are good agreement, demonstrating the possibility to have a good control on the magnet optics. The procedure used during the experimental campaign and the most relevant results are reported here.

  8. Metabolic imaging of human kidney triglyceride content: reproducibility of proton magnetic resonance spectroscopy.

    Directory of Open Access Journals (Sweden)

    Sebastiaan Hammer

    Full Text Available OBJECTIVE: To assess the feasibility of renal proton magnetic resonance spectroscopy for quantification of triglyceride content and to compare spectral quality and reproducibility without and with respiratory motion compensation in vivo. MATERIALS AND METHODS: The Institutional Review Board of our institution approved the study protocol, and written informed consent was obtained. After technical optimization, a total of 20 healthy volunteers underwent renal proton magnetic resonance spectroscopy of the renal cortex both without and with respiratory motion compensation and volume tracking. After the first session the subjects were repositioned and the protocol was repeated to assess reproducibility. Spectral quality (linewidth of the water signal and triglyceride content were quantified. Bland-Altman analyses and a test by Pitman were performed. RESULTS: Linewidth changed from 11.5±0.4 Hz to 10.7±0.4 Hz (all data pooled, p<0.05, without and with respiratory motion compensation respectively. Mean % triglyceride content in the first and second session without respiratory motion compensation were respectively 0.58±0.12% and 0.51±0.14% (P = NS. Mean % triglyceride content in the first and second session with respiratory motion compensation were respectively 0.44±0.10% and 0.43±0.10% (P = NS between sessions and P = NS compared to measurements with respiratory motion compensation. Bland-Altman analyses showed narrower limits of agreement and a significant difference in the correlated variances (correlation of -0.59, P<0.05. CONCLUSION: Metabolic imaging of the human kidney using renal proton magnetic resonance spectroscopy is a feasible tool to assess cortical triglyceride content in humans in vivo and the use of respiratory motion compensation significantly improves spectral quality and reproducibility. Therefore, respiratory motion compensation seems a necessity for metabolic imaging of renal triglyceride content in vivo.

  9. Application of magnetic carriers to two examples of quantitative cell analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Chen; Qian, Zhixi; Choi, Young Suk; David, Allan E. [Department of Chemical Engineering, 212 Ross Hall, Auburn University, Auburn, AL 36849 (United States); Todd, Paul, E-mail: pwtodd@hotmail.com [Techshot, Inc., 7200 Highway 150, Greenville, IN 47124 (United States); Hanley, Thomas R. [Department of Chemical Engineering, 212 Ross Hall, Auburn University, Auburn, AL 36849 (United States)

    2017-04-01

    The use of magnetophoretic mobility as a surrogate for fluorescence intensity in quantitative cell analysis was investigated. The objectives of quantitative fluorescence flow cytometry include establishing a level of labeling for the setting of parameters in fluorescence activated cell sorters (FACS) and the determination of levels of uptake of fluorescently labeled substrates by living cells. Likewise, the objectives of quantitative magnetic cytometry include establishing a level of labeling for the setting of parameters in flowing magnetic cell sorters and the determination of levels of uptake of magnetically labeled substrates by living cells. The magnetic counterpart to fluorescence intensity is magnetophoretic mobility, defined as the velocity imparted to a suspended cell per unit of magnetic ponderomotive force. A commercial velocimeter available for making this measurement was used to demonstrate both applications. Cultured Gallus lymphoma cells were immunolabeled with commercial magnetic beads and shown to have adequate magnetophoretic mobility to be separated by a novel flowing magnetic separator. Phagocytosis of starch nanoparticles having magnetic cores by cultured Chinese hamster ovary cells, a CHO line, was quantified on the basis of magnetophoretic mobility. - Highlights: • Commercial particle tracking velocimetry measures magnetophoretic mobility of labeled cells. • Magnetically labeled tumor cells were shown to have adequate mobility for capture in a specific sorter. • The kinetics of nonspecific endocytosis of magnetic nanomaterials by CHO cells was characterized. • Magnetic labeling of cells can be used like fluorescence flow cytometry for quantitative cell analysis.

  10. Bragg peak prediction from quantitative proton computed tomography using different path estimates

    International Nuclear Information System (INIS)

    Wang Dongxu; Mackie, T Rockwell; Tome, Wolfgang A

    2011-01-01

    This paper characterizes the performance of the straight-line path (SLP) and cubic spline path (CSP) as path estimates used in reconstruction of proton computed tomography (pCT). The GEANT4 Monte Carlo simulation toolkit is employed to simulate the imaging phantom and proton projections. SLP, CSP and the most-probable path (MPP) are constructed based on the entrance and exit information of each proton. The physical deviations of SLP, CSP and MPP from the real path are calculated. Using a conditional proton path probability map, the relative probability of SLP, CSP and MPP are calculated and compared. The depth dose and Bragg peak are predicted on the pCT images reconstructed using SLP, CSP, and MPP and compared with the simulation result. The root-mean-square physical deviations and the cumulative distribution of the physical deviations show that the performance of CSP is comparable to MPP while SLP is slightly inferior. About 90% of the SLP pixels and 99% of the CSP pixels lie in the 99% relative probability envelope of the MPP. Even at an imaging dose of ∼0.1 mGy the proton Bragg peak for a given incoming energy can be predicted on the pCT image reconstructed using SLP, CSP, or MPP with 1 mm accuracy. This study shows that SLP and CSP, like MPP, are adequate path estimates for pCT reconstruction, and therefore can be chosen as the path estimation method for pCT reconstruction, which can aid the treatment planning and range prediction of proton radiation therapy.

  11. Bragg peak prediction from quantitative proton computed tomography using different path estimates

    Energy Technology Data Exchange (ETDEWEB)

    Wang Dongxu; Mackie, T Rockwell; Tome, Wolfgang A, E-mail: tome@humonc.wisc.edu [Department of Medical Physics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705 (United States)

    2011-02-07

    This paper characterizes the performance of the straight-line path (SLP) and cubic spline path (CSP) as path estimates used in reconstruction of proton computed tomography (pCT). The GEANT4 Monte Carlo simulation toolkit is employed to simulate the imaging phantom and proton projections. SLP, CSP and the most-probable path (MPP) are constructed based on the entrance and exit information of each proton. The physical deviations of SLP, CSP and MPP from the real path are calculated. Using a conditional proton path probability map, the relative probability of SLP, CSP and MPP are calculated and compared. The depth dose and Bragg peak are predicted on the pCT images reconstructed using SLP, CSP, and MPP and compared with the simulation result. The root-mean-square physical deviations and the cumulative distribution of the physical deviations show that the performance of CSP is comparable to MPP while SLP is slightly inferior. About 90% of the SLP pixels and 99% of the CSP pixels lie in the 99% relative probability envelope of the MPP. Even at an imaging dose of {approx}0.1 mGy the proton Bragg peak for a given incoming energy can be predicted on the pCT image reconstructed using SLP, CSP, or MPP with 1 mm accuracy. This study shows that SLP and CSP, like MPP, are adequate path estimates for pCT reconstruction, and therefore can be chosen as the path estimation method for pCT reconstruction, which can aid the treatment planning and range prediction of proton radiation therapy.

  12. Bragg peak prediction from quantitative proton computed tomography using different path estimates

    Science.gov (United States)

    Wang, Dongxu; Mackie, T Rockwell

    2015-01-01

    This paper characterizes the performance of the straight-line path (SLP) and cubic spline path (CSP) as path estimates used in reconstruction of proton computed tomography (pCT). The GEANT4 Monte Carlo simulation toolkit is employed to simulate the imaging phantom and proton projections. SLP, CSP and the most-probable path (MPP) are constructed based on the entrance and exit information of each proton. The physical deviations of SLP, CSP and MPP from the real path are calculated. Using a conditional proton path probability map, the relative probability of SLP, CSP and MPP are calculated and compared. The depth dose and Bragg peak are predicted on the pCT images reconstructed using SLP, CSP, and MPP and compared with the simulation result. The root-mean-square physical deviations and the cumulative distribution of the physical deviations show that the performance of CSP is comparable to MPP while SLP is slightly inferior. About 90% of the SLP pixels and 99% of the CSP pixels lie in the 99% relative probability envelope of the MPP. Even at an imaging dose of ~0.1 mGy the proton Bragg peak for a given incoming energy can be predicted on the pCT image reconstructed using SLP, CSP, or MPP with 1 mm accuracy. This study shows that SLP and CSP, like MPP, are adequate path estimates for pCT reconstruction, and therefore can be chosen as the path estimation method for pCT reconstruction, which can aid the treatment planning and range prediction of proton radiation therapy. PMID:21212472

  13. PMR spectra and proton magnetic relaxation in uranyl nitrate-hexamethylenetetramine-urea-water gel forming system

    International Nuclear Information System (INIS)

    Vashman, A.A.; Pronin, I.S.; Brylkina, T.V.; Makarov, V.M.

    1979-01-01

    PMR spectra and proton relaxation in the nitrate-hexamethylenetetramine (HMTA)-urea-water gelling system are studied. According to PMR spectra products of HMTA chemical decomposition, which are supposed to be formed in the gelling process, have not been detected. Effect of hydrogen exchange upon PMR spectra of urea and water in the presence of HMTA and uranyl nitrate is studied. Periods of spin-lattice and spin-spin relaxations of water and HMTA protons in gels on the base of uranyl nitrate are found. Data on relaxation permitted to make qualitative conclusions upon the gel structure and HMTA molecule distribution over ''phases''. Nonproducibility of the results of period measurements in gels is the result of nonproducibility of the gel structure in the course of transformation of liquid solution into gel. Temperature dependences of proton relaxation in the gels are impossible yet to interpret on the basis of temperature behaviour of one correlation period, controlling dipole-dipole nuclear magnetic relaxation, and obeying Arrhenius dependence on the temperature

  14. Measurements of beam current density and proton fraction of a permanent-magnet microwave ion source

    Energy Technology Data Exchange (ETDEWEB)

    Waldmann, Ole; Ludewigt, Bernhard [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)

    2011-11-15

    A permanent-magnet microwave ion source has been built for use in a high-yield, compact neutron generator. The source has been designed to produce up to 100 mA of deuterium and tritium ions. The electron-cyclotron resonance condition is met at a microwave frequency of 2.45 GHz and a magnetic field strength of 87.5 mT. The source operates at a low hydrogen gas pressure of about 0.15 Pa. Hydrogen beams with a current density of 40 mA/cm{sup 2} have been extracted at a microwave power of 450 W. The dependence of the extracted proton beam fraction on wall materials and operating parameters was measured and found to vary from 45% for steel to 95% for boron nitride as a wall liner material.

  15. Measurements of beam current density and proton fraction of a permanent-magnet microwave ion source.

    Science.gov (United States)

    Waldmann, Ole; Ludewigt, Bernhard

    2011-11-01

    A permanent-magnet microwave ion source has been built for use in a high-yield, compact neutron generator. The source has been designed to produce up to 100 mA of deuterium and tritium ions. The electron-cyclotron resonance condition is met at a microwave frequency of 2.45 GHz and a magnetic field strength of 87.5 mT. The source operates at a low hydrogen gas pressure of about 0.15 Pa. Hydrogen beams with a current density of 40 mA/cm(2) have been extracted at a microwave power of 450 W. The dependence of the extracted proton beam fraction on wall materials and operating parameters was measured and found to vary from 45% for steel to 95% for boron nitride as a wall liner material. © 2011 American Institute of Physics

  16. Monitoring temozolomide treatment of low-grade glioma with proton magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Murphy, P. S.; Viviers, L; Abson, C

    2004-01-01

    Assessment of low-grade glioma treatment response remains as much of a challenge as the treatment itself. Proton magnetic resonance spectroscopy ((1)H-MRS) and imaging were incorporated into a study of patients receiving temozolomide therapy for low-grade glioma in order to evaluate and monitor...... tumour metabolite and volume changes during treatment. Patients (n=12) received oral temozolomide (200 mg m(-2) day(-1)) over 5 days on a 28-day cycle for 12 cycles. Response assessment included baseline and three-monthly magnetic resonance imaging studies (pretreatment, 3, 6, 9 and 12 months) assessing...... months, a significant reduction in the mean choline signal was observed compared with the pretreatment (P=0.035) and 3-month scan (P=0.021). The reduction in the tumour choline/water signal paralleled tumour volume change and may reflect the therapeutic effect of temozolomide...

  17. Methylmalonic aciduria and propionic acidaemia studied by proton nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Iles, R A; Hind, A J; Chalmers, R A

    1986-12-15

    Proton nuclear magnetic resonance spectroscopy has been used to monitor changes in urinary metabolites in a patient with propionic acidaemia over a period of 10 months and in a patient with methylmalonic aciduria over a period of 11 days. Results could be obtained within 5-10 min of sample receipt. In the spectra on the patient with propionic acidaemia not only could fluctuations in 3-hydroxypropionate and propionylglycine excretion be followed, but also variations in creatine, glycine and betaine, which were often present at millimolar concentrations. The patient with methylmalonic aciduria had an acute episode of severe ketoacidosis during which the glycine excretion fell but creatine excretion rose and then fell on recovery from the episode. The changes in the creatine excretion may reflect disorders in intracellular energy supply. Nuclear magnetic resonance is a powerful technique for monitoring metabolic perturbations in the organic acidurias in 'real-time', allowing the planning and evaluation of therapy. (Auth.). 18 refs.; 4 figs.; 3 tabs.

  18. Methylmalonic aciduria and propionic acidaemia studied by proton nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Iles, R.A.; Hind, A.J.; Chalmers, R.A.

    1986-01-01

    Proton nuclear magnetic resonance spectroscopy has been used to monitor changes in urinary metabolites in a patient with propionic acidaemia over a period of 10 months and in a patient with methylmalonic aciduria over a period of 11 days. Results could be obtained within 5-10 min of sample receipt. In the spectra on the patient with propionic acidaemia not only could fluctuations in 3-hydroxypropionate and propionylglycine excretion be followed, but also variations in creatine, glycine and betaine, which were often present at millimolar concentrations. The patient with methylmalonic aciduria had an acute episode of severe ketoacidosis during which the glycine excretion fell but creatine excretion rose and then fell on recovery from the episode. The changes in the creatine excretion may reflect disorders in intracellular energy supply. Nuclear magnetic resonance is a powerful technique for monitoring metabolic perturbations in the organic acidurias in 'real-time', allowing the planning and evaluation of therapy. (Auth.)

  19. Magnetic sublevel population in 1s-2p excitation of helium by fast electrons and protons

    Energy Technology Data Exchange (ETDEWEB)

    Godunov, A.L.; McGuire, J.H. [Department of Physics, Tulane University, New Orleans, LA (United States); Merabet, H.; Bruch, R.; Hanni, J. [Department of Physics, University of Nevada Reno, Reno, NV (United States); Schipakov, V.S. [Troitsk Institute for Innovation and Fusion Research, Troitsk, (Russian Federation)

    2001-07-14

    We report experimental and theoretical results for the magnetic sublevel population of the helium atom in collisions with fast (v{sub i}=3-9 au) electrons and protons. Cross sections for excitation of magnetic sublevels with M=0 and {+-}1 have been obtained using polarization measurements of emitted radiation in combination with differential cross sections. Calculations have been carried out using the expansion of the transition amplitude in the Born series over the projectile-target interaction through the second order. Results of calculations are in agreement with experimental data. We find that the particle-antiparticle Z{sup {+-}} difference exceeds the statistical error of measurement up to collision velocities v{sub i}{approx}6 au for excitation of sublevels with M=0. (author)

  20. Optimization of metabolite basis sets prior to quantitation in magnetic resonance spectroscopy: an approach based on quantum mechanics

    International Nuclear Information System (INIS)

    Lazariev, A; Graveron-Demilly, D; Allouche, A-R; Aubert-Frécon, M; Fauvelle, F; Piotto, M; Elbayed, K; Namer, I-J; Van Ormondt, D

    2011-01-01

    High-resolution magic angle spinning (HRMAS) nuclear magnetic resonance (NMR) is playing an increasingly important role for diagnosis. This technique enables setting up metabolite profiles of ex vivo pathological and healthy tissue. The need to monitor diseases and pharmaceutical follow-up requires an automatic quantitation of HRMAS 1 H signals. However, for several metabolites, the values of chemical shifts of proton groups may slightly differ according to the micro-environment in the tissue or cells, in particular to its pH. This hampers the accurate estimation of the metabolite concentrations mainly when using quantitation algorithms based on a metabolite basis set: the metabolite fingerprints are not correct anymore. In this work, we propose an accurate method coupling quantum mechanical simulations and quantitation algorithms to handle basis-set changes. The proposed algorithm automatically corrects mismatches between the signals of the simulated basis set and the signal under analysis by maximizing the normalized cross-correlation between the mentioned signals. Optimized chemical shift values of the metabolites are obtained. This method, QM-QUEST, provides more robust fitting while limiting user involvement and respects the correct fingerprints of metabolites. Its efficiency is demonstrated by accurately quantitating 33 signals from tissue samples of human brains with oligodendroglioma, obtained at 11.7 tesla. The corresponding chemical shift changes of several metabolites within the series are also analyzed

  1. Optimization of metabolite basis sets prior to quantitation in magnetic resonance spectroscopy: an approach based on quantum mechanics

    Science.gov (United States)

    Lazariev, A.; Allouche, A.-R.; Aubert-Frécon, M.; Fauvelle, F.; Piotto, M.; Elbayed, K.; Namer, I.-J.; van Ormondt, D.; Graveron-Demilly, D.

    2011-11-01

    High-resolution magic angle spinning (HRMAS) nuclear magnetic resonance (NMR) is playing an increasingly important role for diagnosis. This technique enables setting up metabolite profiles of ex vivo pathological and healthy tissue. The need to monitor diseases and pharmaceutical follow-up requires an automatic quantitation of HRMAS 1H signals. However, for several metabolites, the values of chemical shifts of proton groups may slightly differ according to the micro-environment in the tissue or cells, in particular to its pH. This hampers the accurate estimation of the metabolite concentrations mainly when using quantitation algorithms based on a metabolite basis set: the metabolite fingerprints are not correct anymore. In this work, we propose an accurate method coupling quantum mechanical simulations and quantitation algorithms to handle basis-set changes. The proposed algorithm automatically corrects mismatches between the signals of the simulated basis set and the signal under analysis by maximizing the normalized cross-correlation between the mentioned signals. Optimized chemical shift values of the metabolites are obtained. This method, QM-QUEST, provides more robust fitting while limiting user involvement and respects the correct fingerprints of metabolites. Its efficiency is demonstrated by accurately quantitating 33 signals from tissue samples of human brains with oligodendroglioma, obtained at 11.7 tesla. The corresponding chemical shift changes of several metabolites within the series are also analyzed.

  2. Non-destructive ripeness sensing by using proton NMR [Nuclear Magnetic Resonance

    International Nuclear Information System (INIS)

    Cho, Seong In; Krutz, G.W.; Stroshine, R.L.

    1990-01-01

    More than 80 kinds of fruits and vegetables are available in the United States. But only about 6 of them have their quality standards (Dull, 1986). In the 1990 Fresh Trends survey (Zind, 1990), consumers were asked to rate 16 characteristics important to their decision to purchase fresh produce. The four top ranking factors were ripeness/freshness, taste/flavor, appearance/condition and nutritional value. Of these surveyed, 96% rated ripeness/freshness as extremely important or very important. Therefore, the development of reliable grading or sorting techniques for fresh commodities is essential. Determination of fruit quality often involves cutting and tasting. Non-destructive quality control in fruit and vegetables is a goal of growers and distributors, as well as the food processing industry. Many nondestructive techniques have been evaluated including soft x-ray, optical transmission, near infrared radiation, and machine vision. However, there are few reports of successful non-destructive measurement of sugar content directly in fruit. Higher quality fruit could be harvested and available to consumers if a nondestructive sensor that detects ripeness level directly by measuring sugar content were available. Using proton Nuclear Magnetic Resonance (NMR) principle is the possibility. A nondestructive ripeness (or sweetness) sensor for fruit quality control can be developed with the proton NMR principle (Cho, 1989). Several feasibility studies were necessary for the ripeness sensor development. Main objectives in this paper was to investigate the feasibilities (1) to detect ripeness (or sweetness level) of raw fruit tissue with an high resolution proton NMR spectroscopy (200 MHz) and (2) to measure sugar content of intact fruit with a low resolution proton NMR spectroscopy (10 MHz). 7 refs., 4 figs

  3. Non-destructive Ripeness Sensing by Using Proton NMR [Nuclear Magnetic Resonance

    Science.gov (United States)

    Cho, Seong In; Krutz, G. W.; Stroshine, R. L.; Bellon, V.

    1990-01-01

    More than 80 kinds of fruits and vegetables are available in the United States. But only about 6 of them have their quality standards (Dull, 1986). In the 1990 Fresh Trends survey (Zind, 1990), consumers were asked to rate 16 characteristics important to their decision to purchase fresh produce. The four top ranking factors were ripeness/freshness, taste/flavor, appearance/condition and nutritional value. Of these surveyed, 96% rated ripeness/freshness as extremely important or very important. Therefore, the development of reliable grading or sorting techniques for fresh commodities is essential. Determination of fruit quality often involves cutting and tasting. Non-destructive quality control in fruit and vegetables is a goal of growers and distributors, as well as the food processing industry. Many nondestructive techniques have been evaluated including soft x-ray, optical transmission, near infrared radiation, and machine vision. However, there are few reports of successful non-destructive measurement of sugar content directly in fruit. Higher quality fruit could be harvested and available to consumers if a nondestructive sensor that detects ripeness level directly by measuring sugar content were available. Using proton Nuclear Magnetic Resonance (NMR) principle is the possibility. A nondestructive ripeness (or sweetness) sensor for fruit quality control can be developed with the proton NMR principle (Cho, 1989). Several feasibility studies were necessary for the ripeness sensor development. Main objectives in this paper was to investigate the feasibilities (1) to detect ripeness (or sweetness level) of raw fruit tissue with an high resolution proton NMR spectroscopy (200 MHz) and (2) to measure sugar content of intact fruit with a low resolution proton NMR spectroscopy (10 MHz).

  4. Lactate quantification by proton magnetic resonance spectroscopy using a clinical MRI machine: a basic study

    International Nuclear Information System (INIS)

    Isobe, T.; Muraishi, H.; Matsumura, A.; Kawamura, H.; Shibata, Y.; Anno, I.; Minami, M.

    2007-01-01

    The purpose of this study was to establish quantification method of lactate concentration by proton magnetic resonance spectroscopy (MRS) carried out using a conventional 1.5-T MRI machine. We used a lactate phantom with known concentrations (1, 1.5, 3, 6, 12 and 14 mmol/L). As a clinical example, a patient with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) was evaluated. Proton MRS was carried out using a clinical 1.5-T super-conducting magnetic resonance whole-body system. Data were acquired by point resolved spectroscopy. A coupling constant of J = 7.35 Hz (2/7 = 272 ms) and two long in-phase echo time of 272 ms and 544 ms were used to calculate the T2 relaxation time. The tissue water signal was used as an internal standard to quantify lactate. The correlation coefficient R between the calculated lactate concentrations and the known concentration of lactate was 0.99 with a constant factor of 0.32 (1/3.14). In patients with MELAS, the lactate concentration measured by MRS was 6.2 mmol/kg wet weight, which is similar to the value obtained in previous studies. In the present study, we have established a reliable method for lactate quantification in a phantom study and have shown a sample of clinical case of MELAS

  5. Measurements of the deuteron and proton magnetic form factors at large momentum transfers

    International Nuclear Information System (INIS)

    Bosted, P.E.; Katramatou, A.T.; Arnold, R.G.; Benton, D.; Clogher, L.; DeChambrier, G.; Lambert, J.; Lung, A.; Petratos, G.G.; Rahbar, A.; Rock, S.E.; Szalata, Z.M.; Debebe, B.; Frodyma, M.; Hicks, R.S.; Hotta, A.; Peterson, G.A.; Gearhart, R.A.; Alster, J.; Lichtenstadt, J.; Dietrich, F.; van Bibber, K.

    1990-01-01

    Measurements of the deuteron elastic magnetic structure function B(Q 2 ) are reported at squared four-momentum transfer values 1.20≤Q 2 ≤2.77 (GeV/c) 2 . Also reported are values for the proton magnetic form factor G Mp (Q 2 ) at 11 Q 2 values between 0.49 and 1.75 (GeV/c) 2 . The data were obtained using an electron beam of 0.5 to 1.3 GeV. Electrons backscattered near 180 degree were detected in coincidence with deuterons or protons recoiling near 0 degree in a large solid-angle double-arm spectrometer system. The data for B(Q 2 ) are found to decrease rapidly from Q 2 =1.2 to 2 (GeV/c) 2 , and then rise to a secondary maximum around Q 2 =2.5 (GeV/c) 2 . Reasonable agreement is found with several different models, including those in the relativistic impulse approximation, nonrelativistic calculations that include meson-exchange currents, isobar configurations, and six-quark configurations, and one calculation based on the Skyrme model. All calculations are very sensitive to the choice of deuteron wave function and nucleon form factor parametrization. The data for G Mp (Q 2 ) are in good agreement with the empirical dipole fit

  6. Quantitative assessment of the physical potential of proton beam range verification with PET/CT

    NARCIS (Netherlands)

    Knopf, A; Parodi, K.; Paganetti, Harald; Lo Cascio, E; Bonab, A; Bortfeld, Thomas

    2008-01-01

    A recent clinical pilot study demonstrated the feasibility of offline PET/CT range verification for proton therapy treatments. In vivo PET measurements are challenged by blood perfusion, variations of tissue compositions, patient motion and image co-registration uncertainties. Besides these

  7. Water volume quantitation using nuclear magnetic resonance imaging: application to cerebrospinal fluid

    International Nuclear Information System (INIS)

    Lecouffe, P.; Huglo, D.; Dubois, P.; Rousseau, J.; Marchandise, X.

    1990-01-01

    Quantitation in proton NMR imaging is applied to cerebrospinal fluid (CSF). Total intracranial CSF volume was measured from Condon's method: CSF signal was compared with distilled water standard signal in a single sagittal thick slice. Brain signal was reduced to minimum using a 5000/360/400 sequence. Software constraints did not permit easy implementing on imager and uniformity correction was performed on a microcomputer. Accuracy was better than 4%. Total intracranial CSF was found between 91 and 164 ml in 5 healthy volunteers. Extraventricular CSF quantitation appears very improved by this method, but planimetric methods seem better in order to quantify ventricular CSF. This technique is compared to total lung water measurement from proton density according to Mac Lennan's method. Water volume quantitation confirms ability of NMR imaging to quantify biologic parameters but image defects have to be known by strict quality control [fr

  8. Measurement of the relaxation rate of the magnetization in Mn12O12-acetate using proton NMR echo

    Science.gov (United States)

    Jang; Lascialfari; Borsa; Gatteschi

    2000-03-27

    We present a novel method to measure the relaxation rate W of the magnetization of Mn 12O (12)-acetate (Mn12) magnetic molecular cluster in its S = 10 ground state at low T. It is based on the observation of an exponential growth in time of the proton NMR signal during the thermal equilibration of the magnetization of the molecules. We can explain the novel effect with a simple model which relates the intensity of the proton echo signal to the microscopic reversal of the magnetization of each individual Mn12 molecule during the equilibration process. The method should find wide application in the study of magnetic molecular clusters in off-equilibrium conditions.

  9. Measurement of the Relaxation Rate of the Magnetization in Mn12O12 -Acetate Using Proton NMR Echo

    International Nuclear Information System (INIS)

    Jang, Z. H.; Lascialfari, A.; Borsa, F.; Gatteschi, D.

    2000-01-01

    We present a novel method to measure the relaxation rate W of the magnetization of Mn 12 O 12 -acetate (Mn12) magnetic molecular cluster in its S=10 ground state at low T . It is based on the observation of an exponential growth in time of the proton NMR signal during the thermal equilibration of the magnetization of the molecules. We can explain the novel effect with a simple model which relates the intensity of the proton echo signal to the microscopic reversal of the magnetization of each individual Mn12 molecule during the equilibration process. The method should find wide application in the study of magnetic molecular clusters in off-equilibrium conditions. (c) 2000 The American Physical Society

  10. Neurodegenerative evidences during early onset of depression in CMS rats as detected by proton magnetic resonance spectroscopy at 7 T.

    Science.gov (United States)

    Hemanth Kumar, B S; Mishra, Sushanta Kumar; Rana, Poonam; Singh, Sadhana; Khushu, Subash

    2012-06-15

    Depression is a complex psychiatric disorder characterized by anhedonia and feeling of sadness and chronic mild stress (CMS) seems to be a valuable animal model of depression. CMS animal model was induced and validated using behavioral studies. In the present study we investigated the neuro-metabolite changes occurring in prefrontal cortex and hippocampus during the onset of depression, in CMS rat model using in vivo proton magnetic resonance spectroscopy ((1)H MRS) at field strength of 7 T. Results showed that CMS caused depression-like behavior in rats, as indicated by the decrease in sucrose consumption and locomotor activity. (1)H MRS was performed in both control and CMS rats (n=10, in each group) and the quantitative assessment of the neurometabolites was done using LC model. Relative concentrations of all the metabolites along with the macromolecules were calculated for analysis. The results revealed a significant decrease of glutamate (Glu), glutamine (Gln), NAA+NAAG, Glx and GABA levels in both hippocampus and prefrontal cortex of CMS animals and an elevated level of myo-ionisitol (mI) and taurine (Tau) was observed only in hippocampus. These metabolite fluctuations revealed by proton MRS indicate that there might be change in the neuronal integrity of the glial cells and neurons within prefrontal cortex and hippocampus in CMS model of depression. The present study also suggests that there may be a degenerative process concerning the brain morphology in the CMS rats. The overall finding using (1)H MRS suggests that, there might be a major role of the glia and neuron in the onset of depression. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Quantitative HRMAS proton total correlation spectroscopy applied to cultured melanoma cells treated by chloroethyl nitrosourea: demonstration of phospholipid metabolism alterations.

    Science.gov (United States)

    Morvan, Daniel; Demidem, Aicha; Papon, Janine; Madelmont, Jean Claude

    2003-02-01

    Recent NMR spectroscopy developments, such as high-resolution magic angle spinning (HRMAS) probes and correlation-enhanced 2D sequences, now allow improved investigations of phospholipid (Plp) metabolism. Using these modalities we previously demonstrated that a mouse-bearing melanoma tumor responded to chloroethyl nitrosourea (CENU) treatment in vivo by altering its Plp metabolism. The aims of the present study were to investigate whether HRMAS proton total correlation spectroscopy (TOCSY) could be used as a quantitative technique to probe Plp metabolism, and to determine the Plp metabolism response of cultured B16 melanoma cells to CENU treatment in vitro. The exploited TOCSY signals of Plp derivatives arose from scalar coupling among the protons of neighbor methylene groups within base headgroups (choline and ethanolamine). For strongly expressed Plp derivatives, TOCSY signals were compared to saturation recovery signals and demonstrated a linear relationship. HRMAS proton TOCSY was thus used to provide concentrations of Plp derivatives during long-term follow-up of CENU-treated cell cultures. Strong Plp metabolism alteration was observed in treated cultured cells in vitro involving a down-regulation of phosphocholine, and a dramatic and irreversible increase of phosphoethanolamine. These findings are discussed in relation to previous in vivo data, and to Plp metabolism enzymatic involvement. Copyright 2003 Wiley-Liss, Inc.

  12. Real-time and quantitative isotropic spatial resolution susceptibility imaging for magnetic nanoparticles

    Science.gov (United States)

    Pi, Shiqiang; Liu, Wenzhong; Jiang, Tao

    2018-03-01

    The magnetic transparency of biological tissue allows the magnetic nanoparticle (MNP) to be a promising functional sensor and contrast agent. The complex susceptibility of MNPs, strongly influenced by particle concentration, excitation magnetic field and their surrounding microenvironment, provides significant implications for biomedical applications. Therefore, magnetic susceptibility imaging of high spatial resolution will give more detailed information during the process of MNP-aided diagnosis and therapy. In this study, we present a novel spatial magnetic susceptibility extraction method for MNPs under a gradient magnetic field, a low-frequency drive magnetic field, and a weak strength high-frequency magnetic field. Based on this novel method, a magnetic particle susceptibility imaging (MPSI) of millimeter-level spatial resolution (<3 mm) was achieved using our homemade imaging system. Corroborated by the experimental results, the MPSI shows real-time (1 s per frame acquisition) and quantitative abilities, and isotropic high resolution.

  13. SU-F-T-211: Evaluation of a Dual Focusing Magnet System for the Treatment of Small Proton Targets

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, TT; McAuley, GA; Heczko, S; Slater, J [Loma Linda University, Loma Linda, CA (United States); Wroe, A [Loma Linda University, Loma Linda, CA (United States); Loma Linda University Medical Center, Loma Linda, CA (United States)

    2016-06-15

    Purpose: To investigate magnetic focusing for small volume proton targets using a doublet combination of quadrupole rare earth permanent magnet Halbach cylinder assemblies Methods: Monte Carlo computer simulations were performed using the Geant4 toolkit to compare dose depositions of proton beams transported through two focusing magnets or in their absence. Proton beams with energies of 127 MeV and initial diameters of 5, 8 and 10 mm were delivered through two identical focusing magnets similar to those currently in experimental use at Loma Linda University Medical Center. Analogous experiments used optimized configurations based on the simulation results. Dose was measured by a diode detector and Gafchromic EBT3 film and compared to simulation data. Based on results from the experimental data, an additional set of simulations was performed with an initial beam diameter of 18 mm and a two differing length magnets (40mm & 68mm). Results: Experimental data matched well with Monte Carlo simulations. However, under conditions necessary to produce circular beam spots at target depth, magnetically focused beams using two identical 40 mm length magnets did not meet all of our performance criteria of circular beam spots, improved peak to entrance (P/E) dose ratios and dose delivery efficiencies. The simulations using the longer 68 mm 2nd magnet yielded better results with 34% better P/E dose ratio and 20–50% better dose delivery efficiencies when compared to unfocused 10 mm beams. Conclusion: While magnetic focusing using two magnets with identical focusing power did not yield desired results, ongoing Monte Carlo simulations suggest that increasing the length of the 2nd magnet to 68 mm could improve P/E dose ratios and dose efficiencies. Future work includes additional experimental validation of the longer 2nd magnet setup as well as experiments with triplet magnet systems. This project was sponsored with funding from the Department of Defense (DOD# W81XWH-BAA-10-1).

  14. Tests of prototype magnets and study on a MCP based proton detector for the neutron lifetime experiment PENeLOPE

    International Nuclear Information System (INIS)

    Materne, Stefan

    2013-01-01

    The precision experiment PENeLOPE will store ultra-cold neutrons in a magnetic trap and determine the neutron lifetime via the time-resolved counting of the decay-protons. The thesis reports on training and performance tests of prototypes of the superconducting coils. Additionally, a magnetic field mapper for PENeLOPE was characterized. In the second part of the thesis, microchannel plates (MCPs) were studied with alpha particles and protons as a possible candidate for the decay particle detector in PENeLOPE.

  15. Advanced quantitative magnetic nondestructive evaluation methods - Theory and experiment

    Science.gov (United States)

    Barton, J. R.; Kusenberger, F. N.; Beissner, R. E.; Matzkanin, G. A.

    1979-01-01

    The paper reviews the scale of fatigue crack phenomena in relation to the size detection capabilities of nondestructive evaluation methods. An assessment of several features of fatigue in relation to the inspection of ball and roller bearings suggested the use of magnetic methods; magnetic domain phenomena including the interaction of domains and inclusions, and the influence of stress and magnetic field on domains are discussed. Experimental results indicate that simplified calculations can be used to predict many features of these results; the data predicted by analytic models which use finite element computer analysis predictions do not agree with respect to certain features. Experimental analyses obtained on rod-type fatigue specimens which show experimental magnetic measurements in relation to the crack opening displacement and volume and crack depth should provide methods for improved crack characterization in relation to fracture mechanics and life prediction.

  16. Quantitative analysis of skin reaction by reflectance spectrophotometer. Acute reaction following proton therapy

    International Nuclear Information System (INIS)

    Kawashima, Mitsuhiko; Okumura, Toshiyuki; Tatsuzaki, Hideo; Tsuji, Hiroshi; Tsujii, Hirohiko.

    1994-01-01

    Acute reactions induced by proton irradiation were measured using a reflectance spectrophotometer, which is commonly used in the printing and textile industries. In this method, the skin color was expressed by three parameters, lightness (L * ), chroma (C * ) and hue (h). At first, in order to evaluate the accuracy of this spectrophotometer, the skin color of a normal volunteer was measured 100 times. The values of the three parameters for normal skin were as follows (mean values and standard deviation), L * : 68.64±0.29, C * : 19.08±0.13, h: 69.41±0.76. The standard deviations with regard to L * and h, were considered to be sufficiently small when compared with the changes of these parameters (prefix: Δ) in the irradiated sites (ΔL * * and h values significantly decreased with time, and the L * values were highly correlated with elapsed treatment days. The h values had a relatively low linear correlation compared with L * . The C * values had no trends as the treatment period was extended. Among these parameters, the L * values were the most valuable for assessment of proton-induced skin reactions, and it was suggested that the L * values measured with this spectrophotometer were a useful index for showing biological effects induced by proton irradiation. Further experiments are needed to apply this method to quantify the biological effects induced by other forms of ionizing radiation. (author)

  17. Quantitative constraints on the gluon distribution function in the proton from collider isolated-photon data

    Energy Technology Data Exchange (ETDEWEB)

    D' Enterria, David, E-mail: dde@cern.ch [CERN, PH Department, CH-1211 Geneva 23 (Switzerland); ICREA and ICC-UB, Universitat de Barcelona, 08028 Barcelona, Catalonia (Spain); Rojo, Juan [CERN, PH Department, TH Unit, CH-1211 Geneva 23 (Switzerland)

    2012-07-21

    The impact of isolated-photon data from proton-(anti)proton collisions at RHIC, Spp{sup Macron }S, Tevatron and LHC energies, on the parton distribution functions of the proton is studied using a recently developed Bayesian reweighting method. The impact on the gluon density of the 35 existing isolated-{gamma} measurements is quantified using next-to-leading order (NLO) perturbative QCD calculations complemented with the NNPDF2.1 parton densities. The NLO predictions are found to describe well most of the datasets from 200 GeV up to 7 TeV centre-of-mass energies. The isolated-photon spectra recently measured at the LHC are precise enough to constrain the gluon distribution and lead to a moderate reduction (up to 20%) of its uncertainties around fractional momenta x Almost-Equal-To 0.02. As a particular case, we show that the improved gluon density reduces the PDF uncertainty for the Higgs boson production cross section in the gluon-fusion channel by more than 20% at the LHC. We conclude that present and future isolated-photon measurements constitute an interesting addition to coming global PDF analyses.

  18. Quantitative constraints on the gluon distribution function in the proton from collider isolated-photon data

    CERN Document Server

    d'Enterria, David

    2012-01-01

    The impact of isolated-photon data from proton-(anti)proton collisions at RHIC, SppbarS, Tevatron and LHC energies, on the parton distribution functions of the proton is studied using a recently developed Bayesian reweighting method. The impact on the gluon density of the 35 existing isolated-gamma measurements is quantified using next-to-leading order (NLO) perturbative QCD calculations complemented with the NNPDF2.1 parton densities. The NLO predictions are found to describe well most of the datasets from 200 GeV up to 7 TeV centre-of-mass energies. The isolated-photon spectra recently measured at the LHC are precise enough to constrain the gluon distribution and lead to a moderate reduction (up to 20%) of its uncertainties around fractional momenta x~0.02. As a particular case, we show that the improved gluon density reduces the PDF uncertainty for the Higgs boson production cross section in the gluon-fusion channel by more than 20% at the LHC. We conclude that present and future isolated-photon measuremen...

  19. Quantitative investigation of physical factors contributing to gold nanoparticle-mediated proton dose enhancement

    International Nuclear Information System (INIS)

    Cho, Jongmin; Manohar, Nivedh; Kerr, Matthew; Cho, Sang Hyun; Gonzalez-Lepera, Carlos; Krishnan, Sunil

    2016-01-01

    Some investigators have shown tumor cell killing enhancement in vitro and tumor regression in mice associated with the loading of gold nanoparticles (GNPs) before proton treatments. Several Monte Carlo (MC) investigations have also demonstrated GNP-mediated proton dose enhancement. However, further studies need to be done to quantify the individual physical factors that contribute to the dose enhancement or cell-kill enhancement (or radiosensitization). Thus, the current study investigated the contributions of particle-induced x-ray emission (PIXE), particle-induced gamma-ray emission (PIGE), Auger and secondary electrons, and activation products towards the total dose enhancement. Specifically, GNP-mediated dose enhancement was measured using strips of radiochromic film that were inserted into vials of cylindrical GNPs, i.e. gold nanorods (GNRs), dispersed in a saline solution (0.3 mg of GNRs/g or 0.03% of GNRs by weight), as well as vials containing water only, before proton irradiation. MC simulations were also performed with the tool for particle simulation code using the film measurement setup. Additionally, a high-purity germanium detector system was used to measure the photon spectrum originating from activation products created from the interaction of protons and spherical GNPs present in a saline solution (20 mg of GNPs/g or 2% of GNPs by weight). The dose enhancement due to PIXE/PIGE recorded on the films in the GNR-loaded saline solution was less than the experimental uncertainty of the film dosimetry (<2%). MC simulations showed highly localized dose enhancement (up to a factor 17) in the immediate vicinity (<100 nm) of GNRs, compared with hypothetical water nanorods (WNRs), mostly due to GNR-originated Auger/secondary electrons; however, the average dose enhancement over the entire GNR-loaded vial was found to be minimal (0.1%). The dose enhancement due to the activation products from GNPs was minimal (<0.1%) as well. In conclusion, under the

  20. Quantitative study of magnetic field distribution by electron holography and micromagnetic simulations

    International Nuclear Information System (INIS)

    Beleggia, M.; Schofield, M.A.; Zhu, Y.; Malac, M.; Liu, Z.; Freeman, M.

    2003-01-01

    The magnetic configuration of a submicrometer Ni 88 Fe 12 permalloy island has been quantitatively mapped by off-axis electron holography. The two main contributions to the electron-optical phase shift, namely the phase shifts induced by the electrostatic and magnetic potentials, including fringing fields, were separated by inverting the specimen of 180 deg. with respect to the electron beam and directly measuring the mean inner potential. A quantitative map of the projected magnetic induction in the sample was thereby retrieved and compared to results of micromagnetic and electromagnetic calculations, providing the minimum-energy configuration and the phase shift, respectively

  1. Quantification of Representative Ciguatoxins in the Pacific Using Quantitative Nuclear Magnetic Resonance Spectroscopy

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Kato

    2017-10-01

    Full Text Available The absolute quantification of five toxins involved in ciguatera fish poisoning (CFP in the Pacific was carried out by quantitative 1H-NMR. The targeted toxins were ciguatoxin-1B (CTX1B, 52-epi-54-deoxyciguatoxin-1B (epideoxyCTX1B, ciguatoxin-3C (CTX3C, 51-hydroxyciguatoxin-3C (51OHCTX3C, and ciguatoxin-4A (CTX4A. We first calibrated the residual protons of pyridine-d5 using certified reference material, 1,4-BTMSB-d4, prepared the toxin solutions with the calibrated pyridin-d5, measured the 1H-NMR spectra, and quantified the toxin using the calibrated residual protons as the internal standard. The absolute quantification was carried out by comparing the signal intensities between the selected protons of the target toxin and the residual protons of the calibrated pyridine-d5. The proton signals residing on the ciguatoxins (CTXs to be used for quantification were carefully selected for those that were well separated from adjacent signals including impurities and that exhibited an effective intensity. To quantify CTX1B and its congeners, the olefin protons in the side chain were judged appropriate for use. The quantification was achievable with nano-molar solutions. The probable errors for uncertainty, calculated on respective toxins, ranged between 3% and 16%. The contamination of the precious toxins with nonvolatile internal standards was thus avoided. After the evaporation of pyridine-d5, the calibrated CTXs were ready for use as the reference standard in the quantitative analysis of ciguatoxins by LC/MS.

  2. Quantification of Representative Ciguatoxins in the Pacific Using Quantitative Nuclear Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    Kato, Tsuyoshi; Yasumoto, Takeshi

    2017-10-12

    The absolute quantification of five toxins involved in ciguatera fish poisoning (CFP) in the Pacific was carried out by quantitative ¹H-NMR. The targeted toxins were ciguatoxin-1B (CTX1B), 52-epi-54-deoxyciguatoxin-1B (epideoxyCTX1B), ciguatoxin-3C (CTX3C), 51-hydroxyciguatoxin-3C (51OHCTX3C), and ciguatoxin-4A (CTX4A). We first calibrated the residual protons of pyridine- d ₅ using certified reference material, 1,4-BTMSB- d ₄, prepared the toxin solutions with the calibrated pyridin- d ₅, measured the ¹H-NMR spectra, and quantified the toxin using the calibrated residual protons as the internal standard. The absolute quantification was carried out by comparing the signal intensities between the selected protons of the target toxin and the residual protons of the calibrated pyridine- d ₅. The proton signals residing on the ciguatoxins (CTXs) to be used for quantification were carefully selected for those that were well separated from adjacent signals including impurities and that exhibited an effective intensity. To quantify CTX1B and its congeners, the olefin protons in the side chain were judged appropriate for use. The quantification was achievable with nano-molar solutions. The probable errors for uncertainty, calculated on respective toxins, ranged between 3% and 16%. The contamination of the precious toxins with nonvolatile internal standards was thus avoided. After the evaporation of pyridine- d ₅, the calibrated CTXs were ready for use as the reference standard in the quantitative analysis of ciguatoxins by LC/MS.

  3. Search for magnetic monopoles with the MoEDAL prototype trapping detector in 8 TeV proton-proton collisions at the LHC

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    The MoEDAL experiment is designed to search for magnetic monopoles and other highly-ionising particles produced in high-energy collisions at the LHC. The largely passive MoEDAL detector, deployed at Interaction Point 8 on the LHC ring, relies on two dedicated direct detection techniques. The first technique is based on stacks of nuclear-track detectors with surface area ∼18 m2, sensitive to particle ionisation exceeding a high threshold. These detectors are analysed offline by optical scanning microscopes. The second technique is based on the trapping of charged particles in an array of roughly 800 kg of aluminium samples. These samples are monitored offline for the presence of trapped magnetic charge at a remote superconducting magnetometer facility. We present here the results of a search for magnetic monopoles using a 160 kg prototype MoEDAL trapping detector exposed to 8 TeV proton-proton collisions at the LHC, for an integrated luminosity of 0.75 fb−1. No magnetic charge exceeding 0.5gD (where gD is ...

  4. Search for magnetic monopoles with the MoEDAL prototype trapping detector in 8 TeV proton-proton collisions at the LHC

    CERN Document Server

    Acharya, B.

    2016-08-10

    The MoEDAL experiment is designed to search for magnetic monopoles and other highly-ionising particles produced in high-energy collisions at the LHC. The largely passive MoEDAL detector, deployed at Interaction Point 8 on the LHC ring, relies on two dedicated direct detection techniques. The first technique is based on stacks of nuclear-track detectors with surface area $\\sim$18 m$^2$, sensitive to particle ionisation exceeding a high threshold. These detectors are analysed offline by optical scanning microscopes. The second technique is based on the trapping of charged particles in an array of roughly 800 kg of aluminium samples. These samples are monitored offline for the presence of trapped magnetic charge at a remote superconducting magnetometer facility. We present here the results of a search for magnetic monopoles using a 160 kg prototype MoEDAL trapping detector exposed to 8 TeV proton-proton collisions at the LHC, for an integrated luminosity of 0.75 fb$^{-1}$. No magnetic charge exceeding $0.5g_{\\rm...

  5. Clinical value of proton magnetic resonance spectroscopy for differentiating recurrent or residual brain tumor from delayed cerebral necrosis

    International Nuclear Information System (INIS)

    Taylor, June S.; Langston, James W.; Reddick, Wilburn E.; Kingsley, Peter B.; Ogg, Robert J.; Pui, Margaret H.; Kun, Larry E.; Jenkins, Jesse J.; Gang, Chen; Ochs, Judith J.; Sanford, Robert A.; Heideman, Richard L.

    1996-01-01

    Purpose: Delayed cerebral necrosis (DN) is a significant risk for brain tumor patients treated with high-dose irradiation. Although differentiating DN from tumor progression is an important clinical question, the distinction cannot be made reliably by conventional imaging techniques. We undertook a pilot study to assess the ability of proton magnetic resonance spectroscopy ( 1 H MRS) to differentiate prospectively between DN or recurrent/residual tumor in a series of children treated for primary brain tumors with high-dose irradiation. Methods and Materials: Twelve children (ages 3-16 years), who had clinical and MR imaging (MRI) changes that suggested a diagnosis of either DN or progressive/recurrent brain tumor, underwent localized 1 H MRS prior to planned biopsy, resection, or other confirmatory histological procedure. Prospective 1 H MRS interpretations were based on comparison of spectral peak patterns and quantitative peak area values from normalized spectra: a marked depression of the intracellular metabolite peaks from choline, creatine, and N-acetyl compounds was hypothesized to indicate DN, and median-to-high choline with easily visible creatine metabolite peaks was labeled progressive/recurrent tumor. Subsequent histological studies identified the brain lesion as DN or recurrent/residual tumor. Results: The patient series included five cases of DN and seven recurrent/residual tumor cases, based on histology. The MRS criteria prospectively identified five out of seven patients with active tumor, and four out of five patients with histologically proven DN correctly. Discriminant analysis suggested that the primary diagnostic information for differentiating DN from tumor lay in the normalized MRS peak areas for choline and creatine compounds. Conclusions: Magnetic resonance spectroscopy shows promising sensitivity and selectivity for differentiating DN from recurrent/progressive brain tumor. A novel diagnostic index based on peak areas for choline and

  6. Quantitative analysis of treatment process time and throughput capacity for spot scanning proton therapy

    International Nuclear Information System (INIS)

    Suzuki, Kazumichi; Sahoo, Narayan; Zhang, Xiaodong; Poenisch, Falk; Mackin, Dennis S.; Liu, Amy Y.; Wu, Richard; Zhu, X. Ronald; Gillin, Michael T.; Palmer, Matthew B.; Frank, Steven J.; Lee, Andrew K.

    2016-01-01

    Purpose: To determine the patient throughput and the overall efficiency of the spot scanning system by analyzing treatment time, equipment availability, and maximum daily capacity for the current spot scanning port at Proton Therapy Center Houston and to assess the daily throughput capacity for a hypothetical spot scanning proton therapy center. Methods: At their proton therapy center, the authors have been recording in an electronic medical record system all treatment data, including disease site, number of fields, number of fractions, delivered dose, energy, range, number of spots, and number of layers for every treatment field. The authors analyzed delivery system downtimes that had been recorded for every equipment failure and associated incidents. These data were used to evaluate the patient census, patient distribution as a function of the number of fields and total target volume, and equipment clinical availability. The duration of each treatment session from patient walk-in to patient walk-out of the spot scanning treatment room was measured for 64 patients with head and neck, central nervous system, thoracic, and genitourinary cancers. The authors retrieved data for total target volume and the numbers of layers and spots for all fields from treatment plans for a total of 271 patients (including the above 64 patients). A sensitivity analysis of daily throughput capacity was performed by varying seven parameters in a throughput capacity model. Results: The mean monthly equipment clinical availability for the spot scanning port in April 2012–March 2015 was 98.5%. Approximately 1500 patients had received spot scanning proton therapy as of March 2015. The major disease sites treated in September 2012–August 2014 were the genitourinary system (34%), head and neck (30%), central nervous system (21%), and thorax (14%), with other sites accounting for the remaining 1%. Spot scanning beam delivery time increased with total target volume and accounted for

  7. Effect of Intrafraction Prostate Motion on Proton Pencil Beam Scanning Delivery: A Quantitative Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Shikui, E-mail: TangS@uphs.upenn.edu [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Deville, Curtiland; McDonough, James; Tochner, Zelig [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Wang, Ken Kang-Hsin [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Department of Radiation Oncology and Molecular Radiation Sciences, The Johns Hopkins University, Baltimore, Maryland (United States); Vapiwala, Neha; Both, Stefan [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States)

    2013-10-01

    Purpose: To assess the dosimetric impact caused by the interplay between intrafraction prostate motion and the intermittent delivery of proton pencil beam scanning (PBS). Methods and Materials: A cohort of 10 prostate patients was treated with PBS using a bilateral single-field uniform dose (SFUD) modality. Bilateral intensity-modulated proton therapy (IMPT) plans were generated for comparison. Because beam-on time in PBS was intermittent, the actual beam-on time was determined from treatment logs. Prostate motion was generalized according to real-time Calypso tracking data from our previously reported prospective photon trial. We investigated potential dose deviations by considering the interplay effect resulting from the worst-case scenario motion and the PBS delivery sequence. Results: For both bilateral-field SFUD and IMPT plans, clinical target volume (CTV) D{sub 99}% coverage was degraded <2% owing to prostate intrafraction motion when averaged over the course of treatment, but was >10% for the worst fraction. The standard deviation of CTV D{sub 99}% distribution was approximately 1.2%. The CTV coverage of individual fields in SFUD plans degraded as time elapsed after the initial alignment, owing to prostate drift. Intensity-modulated proton therapy and SFUD demonstrated comparable results when bilateral opposed fields were used. Single-field SFUD plans that were repainted twice, which could reduce half of the treatment time, resulted in similar CTV coverage as bilateral-field plans. Conclusions: Intrafraction prostate motion affects the actual delivered dose to CTV; however, when averaged over the course of treatment, CTV D{sub 99}% coverage degraded only approximately 2% even for the worst-case scenario. The IMPT plan results are comparable to those of the SFUD plan, and similar coverage can be achieved if treated by SFUD 1 lateral field per day when rescanning the field twice to shorten the treatment time and mitigate intrafraction motion.

  8. WE-FG-202-03: Quantitative CT-Based Analysis to Assess Lung Injury Following Proton Radiotherapy

    International Nuclear Information System (INIS)

    Underwood, T; Grassberger, C; Willers, H; MacDonald, S; Jimenez, R; Paganetti, H

    2016-01-01

    Purpose: Relative to photon alternatives, the increased dose-conformity associated with proton therapy is expected to reduce the extent of radiation-induced lung toxicity. However, analysis of follow-up data is yet to be published in this area. In this study we retrospectively analyzed late-phase HU changes for proton therapy cohorts of chest wall and lung patients. Methods: From our institution’s register of patients treated using double-scattered protons, all chest wall and stereotactic lung cases (treated 2011–2012 and 2008–2014 respectively) were initially considered. Follow-up CT data were accessible for 10 chest wall cases (prescribed 50.4 GyRBE in 28 fractions) and 16 lung cases (prescribed 42–50 GyRBE in 3–4 fractions). CT time-points ranged from 0.5–3.5 years post-treatment. Planning doses were recalculated using TOPAS Monte Carlo simulations and mapped onto the follow-up images using deformable registration. Excluding internal target volumes, changes in HU between each patient’s planning and follow-up CT(s) were evaluated for dose bins of 2–30 GyRBE (2 GyRBE increments). Results: Linear increases in HU per unit dose, with correlations statistically significant at the 1% level (one-sided Spearman’s rank test), were evident for all 10 chest wall cases and 14/16 lung cases. The mean changes in HU/Gy were: 1.76 (SD=0.73) for the chest wall cohort, and 1.40 (SD=0.87) for the lung cohort. The median scan times post treatment were 21 and 12 months respectively. All 26 patients developed solid consolidation (scar-like radiographic opacities) within the exposed lung(s). Conclusion: Analysis of follow-up CTs revealed statistically significant correlations in HU-change/dose for two proton cohorts (lung and chest wall). Quantitatively, the late-phase changes we report broadly match published photon data. Further analysis of such radiographic changes, particularly via matched cohort studies drawing upon consistent imaging protocols, could play an

  9. WE-FG-202-03: Quantitative CT-Based Analysis to Assess Lung Injury Following Proton Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, T [Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); University College London, London (United Kingdom); Grassberger, C; Willers, H; MacDonald, S; Jimenez, R; Paganetti, H [Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States)

    2016-06-15

    Purpose: Relative to photon alternatives, the increased dose-conformity associated with proton therapy is expected to reduce the extent of radiation-induced lung toxicity. However, analysis of follow-up data is yet to be published in this area. In this study we retrospectively analyzed late-phase HU changes for proton therapy cohorts of chest wall and lung patients. Methods: From our institution’s register of patients treated using double-scattered protons, all chest wall and stereotactic lung cases (treated 2011–2012 and 2008–2014 respectively) were initially considered. Follow-up CT data were accessible for 10 chest wall cases (prescribed 50.4 GyRBE in 28 fractions) and 16 lung cases (prescribed 42–50 GyRBE in 3–4 fractions). CT time-points ranged from 0.5–3.5 years post-treatment. Planning doses were recalculated using TOPAS Monte Carlo simulations and mapped onto the follow-up images using deformable registration. Excluding internal target volumes, changes in HU between each patient’s planning and follow-up CT(s) were evaluated for dose bins of 2–30 GyRBE (2 GyRBE increments). Results: Linear increases in HU per unit dose, with correlations statistically significant at the 1% level (one-sided Spearman’s rank test), were evident for all 10 chest wall cases and 14/16 lung cases. The mean changes in HU/Gy were: 1.76 (SD=0.73) for the chest wall cohort, and 1.40 (SD=0.87) for the lung cohort. The median scan times post treatment were 21 and 12 months respectively. All 26 patients developed solid consolidation (scar-like radiographic opacities) within the exposed lung(s). Conclusion: Analysis of follow-up CTs revealed statistically significant correlations in HU-change/dose for two proton cohorts (lung and chest wall). Quantitatively, the late-phase changes we report broadly match published photon data. Further analysis of such radiographic changes, particularly via matched cohort studies drawing upon consistent imaging protocols, could play an

  10. Clinical perspectives of hybrid proton-fluorine magnetic resonance imaging and spectroscopy.

    Science.gov (United States)

    Wolters, Martijn; Mohades, Seyede G; Hackeng, Tilman M; Post, Mark J; Kooi, Marianne E; Backes, Walter H

    2013-05-01

    The number of applications of fluorine 19 (19F) magnetic resonance (MR) imaging and spectroscopy in biomedical and clinical research is steadily growing. The 100% natural abundance of fluorine and its relatively high sensitivity for MR (83% to that of protons) make it an interesting nucleus for a wide range of MR applications. Fluorinated contrast media have a number of advantages over the conventionally used gadolinium-based or iron-based contrast agents. The absence of an endogenous fluorine background intensity in the human body facilitates reliable quantification of fluorinated contrast medium or drugs. Anatomy can be visualized separately with proton MR imaging, creating the application of hybrid hydrogen 1 (1H)/19F MR imaging. The availability of 2 channels (ie, the 1H and 19F channels) enables dual-targeted molecular imaging. Recently, novel developments have emerged on fluorine-based contrast media in preclinical studies and imaging techniques. The developments in fluorine MR seem promising for clinical applications, with contributions in therapy monitoring, assessment of lung function, angiography, and molecular imaging. This review outlines the translation from recent advances in preclinical MR imaging and spectroscopy to future perspectives of clinical hybrid 1H/19/F MR imaging applications.

  11. Quantitative study of the transmission of axially channeled protons in thin silicon crystals

    International Nuclear Information System (INIS)

    Rosner, J.S.; Gibson, W.M.; Golovchenko, J.A.; Goland, A.N.; Wegner, H.E.

    1978-01-01

    The azimuthal distributions of protons transmitted through thin silicon single crystals near the axis were measured using a two-dimensional position-sensitive detector. The data are composed of ringlike distributions with strong azimuthal and transverse energy dependence. The azimuthal distributions are compared with theoretical predictions based on the random string approximation using different forms of the interatomic potential. ''Blocking'' in the transverse plane is also observed. In addition, from an analysis of the radial spreading of the distribution the effects of inelastic scattering in the transverse plane are clearly seen

  12. Quantitative magnetic resonance imaging of cortical multiple sclerosis pathology

    DEFF Research Database (Denmark)

    Tardif, Christine L; Bedell, Barry J; Eskildsen, Simon Fristed

    2012-01-01

    pathology. The objective of this study was to characterize the MRI signature of CLs to help interpret the changes seen in vivo and elucidate the factors limiting their visualization. A quantitative 3D high-resolution (350 μm isotropic) MRI study at 3 Tesla of a fixed post mortem cerebral hemisphere from...

  13. Spin flipping a stored polarized proton beam with an rf magnetic field

    International Nuclear Information System (INIS)

    Hu, S.Q.; Blinov, B.B.; Caussyn, D.D.

    1995-01-01

    The authors studied the spin flipping of a vertically polarized, stored 139 MeV proton beam with an rf solenoid magnetic field. By sweeping the rf frequency through an rf depolarizing resonance, they made the spin flip. The spin flipping was more efficient for slower ramp times, and the spin flip efficiency peaked at some optimum ramp time that is not yet fully understood. Since frequent spin flipping could significantly reduce the systematic errors in scattering experiments using a stored polarized beam, it is very important to minimize the depolarization after each spin flip. In this experiment, with multiple spin flips, the authors found a polarization loss of 0.0000 ± 0.0005 per spin flip under the best conditions; this loss increased significantly for small changes in the conditions

  14. Proton magnetic resonance spectroscopy reflects metabolic decompensation in maple syrup urine disease

    Energy Technology Data Exchange (ETDEWEB)

    Heindel, W. [Dept. of Diagnostic Radiology, Univ. Koeln (Germany); Kugel, H. [Dept. of Diagnostic Radiology, Univ. Koeln (Germany); Wendel, U. [Children`s Hospital, Univ. Duesseldorf (Germany); Roth, B. [Children`s Hospital, Univ. Koeln (Germany); Benz-Bohm, G. [Dept. of Diagnostic Radiology, Univ. Koeln (Germany)

    1995-06-01

    Using localized proton magnetic resonance spectroscopy ({sup 1}H-MRS), accumulation of branchedchain amino acids (BCAA) and their corresponding 2-oxo acids (BCOA) could be non-invasively demonstrated in the brain of a 9-year-old girl suffering from classical maple syrup urine disease. During acute metabolic decompensation, the compounds caused a signal at a chemical shift of 0.9 ppm which was assigned by in vitro experiments. The brain tissue concentration of the sum of BCAA and BCOA could be estimated as 0.9 mmol/l. Localized {sup 1}H-MRS of the brain appears to be suitable for examining patients suffering from maple syrup urine disease in different metabolic states. (orig.)

  15. Quantification of brain metabolites in amyotrophic lateral sclerosis by localized proton magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Gredal, O; Rosenbaum, S; Topp, S

    1997-01-01

    We performed proton magnetic resonance spectroscopy (1H-MRS) in patients with motor neuron disease (MND) to determine the absolute in vivo concentrations in the brain of the metabolites N-acetyl aspartate (NAA), choline (Cho), and creatine (Cr/PCr). We examined the spectra acquired from a 20 x 20 x...... subjects. We estimated the concentrations of the metabolites using the water signal as an internal standard. The concentrations of Cho and Cr/PCr in both brain regions, as well as the concentration of NAA in the cerebellum, were unaltered in the MND patients compared with the controls. Only MND patients...... with both upper and lower motor neuron signs had a significantly decreased concentration of NAA (9.13 +/- 0.28 mM, mean +/- SEM) in the primary motor cortex when compared with healthy controls (10.03 +/- 0.22 mM). In conclusion, the slightly decreased concentration of NAA in the primary motor cortex from...

  16. Second law analysis of the helium refrigerators for the HERA proton magnet ring

    International Nuclear Information System (INIS)

    Ziegler, B.O.

    1986-01-01

    Each of the three refrigerators for the HERA proton magnet ring must provide 6.775 kW of refrigeration at 4.3 0 K plus 20.5 g/s of helium at 2.5 bar and 4.5 0 K for leads cooling and 20 kW of refrigeration at 40-80 0 K for shield cooling. The capital cost of large refrigerators is small compared with operating costs. Therefore the refrigeration process was analysed on the basis of exergy. This means the irreversibility of each component is expressed as power input into the plant. The process realised consists of the turbine cycle, divided into two streams with 5 gas bearing turbines all together, and the Joule Thomson cycle. Special attention was paid to the cold end of the plant. The optimization resulted in a new configuration with two turboexpanders running in parallel on different temperature levels

  17. Cerebral metabolic abnormalities in congestive heart failure detected by proton magnetic resonance spectroscopy.

    Science.gov (United States)

    Lee, C W; Lee, J H; Kim, J J; Park, S W; Hong, M K; Kim, S T; Lim, T H; Park, S J

    1999-04-01

    Using proton magnetic resonance spectroscopy, we investigated cerebral metabolism and its determinants in congestive heart failure (CHF), and the effects of cardiac transplantation on these measurements. Few data are available about cerebral metabolism in CHF. Fifty patients with CHF (ejection fraction OGM) and parietal white matter (PWM). Absolute levels of the metabolites (N-acetylaspartate, creatine, choline, myo-inositol) were calculated. In PWM only creatine level was significantly lower in CHF than in control subjects, but in OGM all four metabolite levels were decreased in CHF. The creatine level was independently correlated with half-recovery time and duration of heart failure symptoms in PWM (r = -0.56, p OGM (r = 0.58, p < 0.05). Cerebral metabolic abnormalities were improved after successful cardiac transplantation. This study shows that cerebral metabolism is abnormally deranged in advanced CHF and it may serve as a potential marker of the disease severity.

  18. Proton magnetic resonance spectroscopy reflects metabolic decompensation in maple syrup urine disease

    International Nuclear Information System (INIS)

    Heindel, W.; Kugel, H.; Wendel, U.; Roth, B.; Benz-Bohm, G.

    1995-01-01

    Using localized proton magnetic resonance spectroscopy ( 1 H-MRS), accumulation of branchedchain amino acids (BCAA) and their corresponding 2-oxo acids (BCOA) could be non-invasively demonstrated in the brain of a 9-year-old girl suffering from classical maple syrup urine disease. During acute metabolic decompensation, the compounds caused a signal at a chemical shift of 0.9 ppm which was assigned by in vitro experiments. The brain tissue concentration of the sum of BCAA and BCOA could be estimated as 0.9 mmol/l. Localized 1 H-MRS of the brain appears to be suitable for examining patients suffering from maple syrup urine disease in different metabolic states. (orig.)

  19. Ultrasound imaging for quantitative evaluation of magnetic density separation

    NARCIS (Netherlands)

    Sanaee, S.A.

    2013-01-01

    This thesis is dedicated to an investigation of the potential and technological possibilities of an inline ultrasound system as a quality control system for wet recycling of solid waste. The main targeted recycling technology is magnetic density separation (MDS), a novel technique that was

  20. Proton Magnetic Resonance Spectroscopy and MRI Reveal No Evidence for Brain Mitochondrial Dysfunction in Children with Autism Spectrum Disorder

    Science.gov (United States)

    Corrigan, Neva M.; Shaw, Dennis. W. W.; Richards, Todd L.; Estes, Annette M.; Friedman, Seth D.; Petropoulos, Helen; Artru, Alan A.; Dager, Stephen R.

    2012-01-01

    Brain mitochondrial dysfunction has been proposed as an etiologic factor in autism spectrum disorder (ASD). Proton magnetic resonance spectroscopic imaging ([superscript 1]HMRS) and MRI were used to assess for evidence of brain mitochondrial dysfunction in longitudinal samples of children with ASD or developmental delay (DD), and cross-sectionally…

  1. Accurate classification of brain gliomas by discriminate dictionary learning based on projective dictionary pair learning of proton magnetic resonance spectra.

    Science.gov (United States)

    Adebileje, Sikiru Afolabi; Ghasemi, Keyvan; Aiyelabegan, Hammed Tanimowo; Saligheh Rad, Hamidreza

    2017-04-01

    Proton magnetic resonance spectroscopy is a powerful noninvasive technique that complements the structural images of cMRI, which aids biomedical and clinical researches, by identifying and visualizing the compositions of various metabolites within the tissues of interest. However, accurate classification of proton magnetic resonance spectroscopy is still a challenging issue in clinics due to low signal-to-noise ratio, overlapping peaks of metabolites, and the presence of background macromolecules. This paper evaluates the performance of a discriminate dictionary learning classifiers based on projective dictionary pair learning method for brain gliomas proton magnetic resonance spectroscopy spectra classification task, and the result were compared with the sub-dictionary learning methods. The proton magnetic resonance spectroscopy data contain a total of 150 spectra (74 healthy, 23 grade II, 23 grade III, and 30 grade IV) from two databases. The datasets from both databases were first coupled together, followed by column normalization. The Kennard-Stone algorithm was used to split the datasets into its training and test sets. Performance comparison based on the overall accuracy, sensitivity, specificity, and precision was conducted. Based on the overall accuracy of our classification scheme, the dictionary pair learning method was found to outperform the sub-dictionary learning methods 97.78% compared with 68.89%, respectively. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Three-dimensional proton magnetic resonance spectroscopic imaging with and without an endorectal coil: a prostate phantom study

    NARCIS (Netherlands)

    Ma, C.; Chen, L.; Scheenen, T.W.J.; Lu, J.; Wang, J

    2015-01-01

    Proton magnetic resonance spectroscopic imaging (MRSI) of the prostate has been used with only a combination of external surface coils. The quality of spectral fitting of the (choline + creatine)/citrate ([Cho + Cr]/Cit) ratio at different field strengths and different coils is important for

  3. [Possibilities in the differential diagnosis of brain neoplasms using the long and short time sequences of proton magnetic resonance spectroscopy

    NARCIS (Netherlands)

    Gajewicz, W.; Goraj, B.M.

    2004-01-01

    Currently to perform proton magnetic resonance spectroscopy (1H MRS) with single voxel spectroscopy (SVS) technique long and/or short echo time sequences are used in order to provide complementary information. PURPOSE: The aim of the study was to compare the usefulness of STEAM (time echo, TE, 20

  4. N-acetylated metabolites in urine: proton nuclear magnetic resonance spectroscopic study on patients with inborn errors of metabolism.

    NARCIS (Netherlands)

    Engelke, U.F.H.; Liebrand-van Sambeek, M.L.F.; Jong, J.G.N. de; Leroy, J.G.; Morava, E.; Smeitink, J.A.M.; Wevers, R.A.

    2004-01-01

    BACKGROUND: There is no comprehensive analytical technique to analyze N-acetylated metabolites in urine. Many of these compounds are involved in inborn errors of metabolism. In the present study, we examined the potential of proton nuclear magnetic resonance ((1)H-NMR) spectroscopy as a tool to

  5. Correction magnetic field in electromagnet of proton accelerator using CST software; Correcao do campo magnetico em um eletroima de um acelerador de protons usando o software CST

    Energy Technology Data Exchange (ETDEWEB)

    Rabelo, L.A.; Campos, T.P.R., E-mail: luisarabelo88@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Dept. de Engenharia Nuclear

    2016-07-01

    The aim of this paper is to present the study and simulation of uniform magnetic field electromagnets new circular accelerator model for protons with energy range between 15 MeV and 64 MeV. In addition, investigating materials and the changes induced by the presence of 'gaps' synchronism correction. The electromagnet simulations, predefined, were made in electromagnetic field simulation software CST EM Studio® 3D 2015. The results showed an even distribution of the magnetic field in the compact electromagnet with the same homogenization structures. The results showed regular distribution of the magnetic field in the compact electromagnet with homogenization structures. In conclusion, the electromagnetic model proposed shown to be feasible for a circular accelerator and comply the synchronization requirements. (author)

  6. Quantitative in situ magnetization reversal studies in Lorentz microscopy and electron holography.

    Science.gov (United States)

    Rodríguez, L A; Magén, C; Snoeck, E; Gatel, C; Marín, L; Serrano-Ramón, L; Prieto, J L; Muñoz, M; Algarabel, P A; Morellon, L; De Teresa, J M; Ibarra, M R

    2013-11-01

    A generalized procedure for the in situ application of magnetic fields by means of the excitation of the objective lens for magnetic imaging experiments in Lorentz microscopy and electron holography is quantitatively described. A protocol for applying magnetic fields with arbitrary in-plane magnitude and orientation is presented, and a freeware script for Digital Micrograph(™) is provided to assist the operation of the microscope. Moreover, a method to accurately reconstruct hysteresis loops is detailed. We show that the out-of-plane component of the magnetic field cannot be always neglected when performing quantitative measurements of the local magnetization. Several examples are shown to demonstrate the accuracy and functionality of the methods. © 2013 Elsevier B.V. All rights reserved.

  7. Proton nuclear magnetic resonance and spectrophotometric studies of nickel(II)-iron(II) hybrid hemoglobins

    International Nuclear Information System (INIS)

    Shibayama, N.; Inubushi, T.; Morimoto, H.; Yonetani, T.

    1987-01-01

    Ni(II)-Fe(II) hybrid hemoglobins, α(Fe) 2 β(Ni) 2 and α(Ni) 2 β(Fe) 2 , have been characterized by proton nuclear magnetic resonance with Ni(II) protoporphyrin IX (Ni-PP) incorporated in apoprotein, which serves as a permanent deoxyheme. α(Fe) 2 β(Ni) 2 , α(Ni) 2 β(Fe) 2 , and NiHb commonly show exchangeable proton resonances at 11 and 14 ppm, due to hydrogen-bonded protons in a deoxy-like structure. Upon binding of carbon monoxide (CO) to α(Fe) 2 β(Ni) 2 , these resonances disappear at pH 6.5 to pH 8.5. On the other hand, the complementary hybrid α(Ni) 2 β(Fe-CO) 2 showed the 11 and 14 ppm resonances at low pH. Upon raising pH, the intensities of both resonances are reduced, although these changes are not synchronized. Electronic absorption spectra and hyperfine-shifted proton resonances indicate that the ligation of CO in the β(Fe) subunits induced changes in the coordination and spin states of Ni-PP in the α subunits. In a deoxy-like structure, the coordination of Ni-PP in the α subunits is predominantly in a low-spin (S = 0) four-coordination state, whereas in an oxy-like structure the contribution of a high-spin (S = 1) five-coordination state markedly increased. Ni-PP in the β subunits always takes a high-spin five-coordination state regardless of solution conditions and the state of ligation in the partner α(Fe) subunits. In the β(Ni) subunits, a significant downfield shift of the proximal histidyl N/sub δ/H resonance and a change in the absorption spectrum of Ni-PP were detected, upon changing the quaternary structure of the hybrid. The chemical shifts were analyzed in terms of the E11-Val methyls vs. the porphyrin rings in hybrid Hbs

  8. An improved permanent magnet quadrupole design with larger good field region for high intensity proton linacs

    Energy Technology Data Exchange (ETDEWEB)

    Mathew, Jose V., E-mail: josev.mathew@gmail.com; Rao, S.V.L.S.; Krishnagopal, S.; Singh, P.

    2013-11-01

    The Low Energy High Intensity Proton Accelerator (LEHIPA), being developed at the Bhabha Atomic Research Centre (BARC) will produce a 20 MeV, 30 mA, continuous wave (CW) proton beam. At these low velocities, space-charge forces dominate, and could lead to larger beam sizes and beam halos. Hence in the design of the focusing lattice of the LEHIPA drift tube linac (DTL) using permanent magnet quadrupoles (PMQs), a larger good field region is preferred. Here we study, using the two dimensional (2D) and three dimensional (3D) simulation codes PANDIRA and RADIA, four different types of cylindrical PMQ designs: 16-segment trapezoidal Halbach configuration, bullet-nosed geometry and 8- and 16-segment rectangular geometries. The trapezoidal Halbach geometry is used in a variety of accelerators since it provides very high field gradients in small bores, while the bullet-nosed geometry, which is a combination of the trapezoidal and rectangular designs, is used in some DTLs. This study shows that a larger good field region is possible in the 16-segment rectangular design as compared to the Halbach and bullet-nosed designs, making it more attractive for high-intensity proton linacs. An improvement in good-field region by ∼16% over the Halbach design is obtained in the optimized 16-segment rectangular design, although the field gradient is lower by ∼20%. Tolerance studies show that the rectangular segment PMQ design is substantially less sensitive to the easy axis orientation errors and hence will be a better choice for DTLs. -- Highlights: • An improved permanent magnet quadrupole (PMQ) design with larger good field region is proposed. • We investigate four PMQ designs, including the widely used Halbach and bullet nosed designs. • Analytical calculations are backed by 2D as well as 3D numerical solvers, PANDIRA and RADIA. • The optimized 16 segment rectangular PMQ design is identified to exhibit the largest good field region. • The effect of easy axis orientation

  9. An improved permanent magnet quadrupole design with larger good field region for high intensity proton linacs

    International Nuclear Information System (INIS)

    Mathew, Jose V.; Rao, S.V.L.S.; Krishnagopal, S.; Singh, P.

    2013-01-01

    The Low Energy High Intensity Proton Accelerator (LEHIPA), being developed at the Bhabha Atomic Research Centre (BARC) will produce a 20 MeV, 30 mA, continuous wave (CW) proton beam. At these low velocities, space-charge forces dominate, and could lead to larger beam sizes and beam halos. Hence in the design of the focusing lattice of the LEHIPA drift tube linac (DTL) using permanent magnet quadrupoles (PMQs), a larger good field region is preferred. Here we study, using the two dimensional (2D) and three dimensional (3D) simulation codes PANDIRA and RADIA, four different types of cylindrical PMQ designs: 16-segment trapezoidal Halbach configuration, bullet-nosed geometry and 8- and 16-segment rectangular geometries. The trapezoidal Halbach geometry is used in a variety of accelerators since it provides very high field gradients in small bores, while the bullet-nosed geometry, which is a combination of the trapezoidal and rectangular designs, is used in some DTLs. This study shows that a larger good field region is possible in the 16-segment rectangular design as compared to the Halbach and bullet-nosed designs, making it more attractive for high-intensity proton linacs. An improvement in good-field region by ∼16% over the Halbach design is obtained in the optimized 16-segment rectangular design, although the field gradient is lower by ∼20%. Tolerance studies show that the rectangular segment PMQ design is substantially less sensitive to the easy axis orientation errors and hence will be a better choice for DTLs. -- Highlights: • An improved permanent magnet quadrupole (PMQ) design with larger good field region is proposed. • We investigate four PMQ designs, including the widely used Halbach and bullet nosed designs. • Analytical calculations are backed by 2D as well as 3D numerical solvers, PANDIRA and RADIA. • The optimized 16 segment rectangular PMQ design is identified to exhibit the largest good field region. • The effect of easy axis orientation

  10. Quantitative assessment of the physical potential of proton beam range verification with PET/CT

    Science.gov (United States)

    Knopf, A.; Parodi, K.; Paganetti, H.; Cascio, E.; Bonab, A.; Bortfeld, T.

    2008-08-01

    A recent clinical pilot study demonstrated the feasibility of offline PET/CT range verification for proton therapy treatments. In vivo PET measurements are challenged by blood perfusion, variations of tissue compositions, patient motion and image co-registration uncertainties. Besides these biological and treatment specific factors, the accuracy of the method is constrained by the underlying physical processes. This phantom study distinguishes physical factors from other factors, assessing the reproducibility, consistency and sensitivity of the PET/CT range verification method. A spread-out Bragg-peak (SOBP) proton field was delivered to a phantom consisting of poly-methyl methacrylate (PMMA), lung and bone equivalent material slabs. PET data were acquired in listmode at a commercial PET/CT scanner available within 10 min walking distance from the proton therapy unit. The measured PET activity distributions were compared to simulations of the PET signal based on Geant4 and FLUKA Monte Carlo (MC) codes. To test the reproducibility of the measured PET signal, data from two independent measurements at the same geometrical position in the phantom were compared. Furthermore, activation depth profiles within identical material arrangements but at different positions within the irradiation field were compared to test the consistency of the measured PET signal. Finally, activation depth profiles through air/lung, air/bone and lung/bone interfaces parallel as well as at 6° to the beam direction were studied to investigate the sensitivity of the PET/CT range verification method. The reproducibility and the consistency of the measured PET signal were found to be of the same order of magnitude. They determine the physical accuracy of the PET measurement to be about 1 mm. However, range discrepancies up to 2.6 mm between two measurements and range variations up to 2.6 mm within one measurement were found at the beam edge and at the edge of the field of view (FOV) of the PET

  11. Quantitative assessment of the physical potential of proton beam range verification with PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Knopf, A; Paganetti, H; Cascio, E; Bortfeld, T [Department of Radiation Oncology, MGH and Harvard Medical School, Boston, MA 02114 (United States); Parodi, K [Heidelberg Ion Therapy Center, Heidelberg (Germany); Bonab, A [Department of Radiology, MGH and Harvard Medical School, Boston, MA 02114 (United States)

    2008-08-07

    A recent clinical pilot study demonstrated the feasibility of offline PET/CT range verification for proton therapy treatments. In vivo PET measurements are challenged by blood perfusion, variations of tissue compositions, patient motion and image co-registration uncertainties. Besides these biological and treatment specific factors, the accuracy of the method is constrained by the underlying physical processes. This phantom study distinguishes physical factors from other factors, assessing the reproducibility, consistency and sensitivity of the PET/CT range verification method. A spread-out Bragg-peak (SOBP) proton field was delivered to a phantom consisting of poly-methyl methacrylate (PMMA), lung and bone equivalent material slabs. PET data were acquired in listmode at a commercial PET/CT scanner available within 10 min walking distance from the proton therapy unit. The measured PET activity distributions were compared to simulations of the PET signal based on Geant4 and FLUKA Monte Carlo (MC) codes. To test the reproducibility of the measured PET signal, data from two independent measurements at the same geometrical position in the phantom were compared. Furthermore, activation depth profiles within identical material arrangements but at different positions within the irradiation field were compared to test the consistency of the measured PET signal. Finally, activation depth profiles through air/lung, air/bone and lung/bone interfaces parallel as well as at 6{sup 0} to the beam direction were studied to investigate the sensitivity of the PET/CT range verification method. The reproducibility and the consistency of the measured PET signal were found to be of the same order of magnitude. They determine the physical accuracy of the PET measurement to be about 1 mm. However, range discrepancies up to 2.6 mm between two measurements and range variations up to 2.6 mm within one measurement were found at the beam edge and at the edge of the field of view (FOV) of the

  12. Quantitative assessment of the physical potential of proton beam range verification with PET/CT.

    Science.gov (United States)

    Knopf, A; Parodi, K; Paganetti, H; Cascio, E; Bonab, A; Bortfeld, T

    2008-08-07

    A recent clinical pilot study demonstrated the feasibility of offline PET/CT range verification for proton therapy treatments. In vivo PET measurements are challenged by blood perfusion, variations of tissue compositions, patient motion and image co-registration uncertainties. Besides these biological and treatment specific factors, the accuracy of the method is constrained by the underlying physical processes. This phantom study distinguishes physical factors from other factors, assessing the reproducibility, consistency and sensitivity of the PET/CT range verification method. A spread-out Bragg-peak (SOBP) proton field was delivered to a phantom consisting of poly-methyl methacrylate (PMMA), lung and bone equivalent material slabs. PET data were acquired in listmode at a commercial PET/CT scanner available within 10 min walking distance from the proton therapy unit. The measured PET activity distributions were compared to simulations of the PET signal based on Geant4 and FLUKA Monte Carlo (MC) codes. To test the reproducibility of the measured PET signal, data from two independent measurements at the same geometrical position in the phantom were compared. Furthermore, activation depth profiles within identical material arrangements but at different positions within the irradiation field were compared to test the consistency of the measured PET signal. Finally, activation depth profiles through air/lung, air/bone and lung/bone interfaces parallel as well as at 6 degrees to the beam direction were studied to investigate the sensitivity of the PET/CT range verification method. The reproducibility and the consistency of the measured PET signal were found to be of the same order of magnitude. They determine the physical accuracy of the PET measurement to be about 1 mm. However, range discrepancies up to 2.6 mm between two measurements and range variations up to 2.6 mm within one measurement were found at the beam edge and at the edge of the field of view (FOV) of the

  13. In vivo quantitation of metabolite concentrations in the brain by means of proton MRS

    DEFF Research Database (Denmark)

    Henriksen, O

    1995-01-01

    MRS offers unique possibilities for non-invasive studies of biochemistry in the human brain in vivo. A growing body of evidence suggests that proton MRS may contribute to the clinical evaluation of a number of pathologies including ischaemia, tumours, epilepsy, metabolic and neuropaediatric...... (kg wet weight)-1 range between 8.2 and 17.2 (mean 10.2), 5.9 and 11.6 (mean 7.2), 1.1 and 2.0 (mean 1.5) and 3.9 and 8.1 (mean 6.1), respectively. So far only a limited number of clinical studies has been published including studies of acute stroke, multiple sclerosis and Alzheimer's disease...

  14. A new method for true quantitative elemental imaging using PIXE and the proton microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, C G [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience; Jamieson, D N [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Churms, C L; Pilcher, J V [National Accelerator Centre, Faure (South Africa)

    1994-12-31

    Traditional methods for X-ray imaging using PIXE and the Proton Microprobe have used a simple gate set on an X-ray peak in a spectrum from a Si(Li) detector to provide an image of the distribution of an element. This method can produce artefacts in images, due to overlapping X-ray lines from interfering elements, charge collection tails on peaks, background variation, Si escape peaks and pileup, all of which can render images misleading or qualitative at best. To address this problem, a matrix transform method has been developed at the CSIRO which not only eliminates most artefacts, but can be implemented on-line. The method has been applied to study trace gold distribution in a complex gold bearing ore from Fiji , and more recently has been installed for direct on-line elemental imaging at the NAC in South Africa. 4 refs., 2 figs.

  15. A new method for true quantitative elemental imaging using PIXE and the proton microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, C.G. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience; Jamieson, D.N. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Churms, C.L.; Pilcher, J.V. [National Accelerator Centre, Faure (South Africa)

    1993-12-31

    Traditional methods for X-ray imaging using PIXE and the Proton Microprobe have used a simple gate set on an X-ray peak in a spectrum from a Si(Li) detector to provide an image of the distribution of an element. This method can produce artefacts in images, due to overlapping X-ray lines from interfering elements, charge collection tails on peaks, background variation, Si escape peaks and pileup, all of which can render images misleading or qualitative at best. To address this problem, a matrix transform method has been developed at the CSIRO which not only eliminates most artefacts, but can be implemented on-line. The method has been applied to study trace gold distribution in a complex gold bearing ore from Fiji , and more recently has been installed for direct on-line elemental imaging at the NAC in South Africa. 4 refs., 2 figs.

  16. Search for Magnetic Monopoles with the MoEDAL Forward Trapping Detector in 13 TeV Proton-Proton Collisions at the LHC

    Science.gov (United States)

    Acharya, B.; Alexandre, J.; Baines, S.; Benes, P.; Bergmann, B.; Bernabéu, J.; Branzas, H.; Campbell, M.; Caramete, L.; Cecchini, S.; de Montigny, M.; De Roeck, A.; Ellis, J. R.; Fairbairn, M.; Felea, D.; Flores, J.; Frank, M.; Frekers, D.; Garcia, C.; Hirt, A. M.; Janecek, J.; Kalliokoski, M.; Katre, A.; Kim, D.-W.; Kinoshita, K.; Korzenev, A.; Lacarrère, D. H.; Lee, S. C.; Leroy, C.; Lionti, A.; Mamuzic, J.; Margiotta, A.; Mauri, N.; Mavromatos, N. E.; Mermod, P.; Mitsou, V. A.; Orava, R.; Parker, B.; Pasqualini, L.; Patrizii, L.; Pǎvǎlaş, G. E.; Pinfold, J. L.; Popa, V.; Pozzato, M.; Pospisil, S.; Rajantie, A.; Ruiz de Austri, R.; Sahnoun, Z.; Sakellariadou, M.; Sarkar, S.; Semenoff, G.; Shaa, A.; Sirri, G.; Sliwa, K.; Soluk, R.; Spurio, M.; Srivastava, Y. N.; Suk, M.; Swain, J.; Tenti, M.; Togo, V.; Tuszyński, J. A.; Vento, V.; Vives, O.; Vykydal, Z.; Whyntie, T.; Widom, A.; Willems, G.; Yoon, J. H.; Zgura, I. S.; MoEDAL Collaboration

    2017-02-01

    MoEDAL is designed to identify new physics in the form of long-lived highly ionizing particles produced in high-energy LHC collisions. Its arrays of plastic nuclear-track detectors and aluminium trapping volumes provide two independent passive detection techniques. We present here the results of a first search for magnetic monopole production in 13 TeV proton-proton collisions using the trapping technique, extending a previous publication with 8 TeV data during LHC Run 1. A total of 222 kg of MoEDAL trapping detector samples was exposed in the forward region and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges exceeding half the Dirac charge are excluded in all samples and limits are placed for the first time on the production of magnetic monopoles in 13 TeV p p collisions. The search probes mass ranges previously inaccessible to collider experiments for up to five times the Dirac charge.

  17. Search for Magnetic Monopoles with the MoEDAL Forward Trapping Detector in 13 TeV Proton-Proton Collisions at the LHC.

    Science.gov (United States)

    Acharya, B; Alexandre, J; Baines, S; Benes, P; Bergmann, B; Bernabéu, J; Branzas, H; Campbell, M; Caramete, L; Cecchini, S; de Montigny, M; De Roeck, A; Ellis, J R; Fairbairn, M; Felea, D; Flores, J; Frank, M; Frekers, D; Garcia, C; Hirt, A M; Janecek, J; Kalliokoski, M; Katre, A; Kim, D-W; Kinoshita, K; Korzenev, A; Lacarrère, D H; Lee, S C; Leroy, C; Lionti, A; Mamuzic, J; Margiotta, A; Mauri, N; Mavromatos, N E; Mermod, P; Mitsou, V A; Orava, R; Parker, B; Pasqualini, L; Patrizii, L; Păvălaş, G E; Pinfold, J L; Popa, V; Pozzato, M; Pospisil, S; Rajantie, A; Ruiz de Austri, R; Sahnoun, Z; Sakellariadou, M; Sarkar, S; Semenoff, G; Shaa, A; Sirri, G; Sliwa, K; Soluk, R; Spurio, M; Srivastava, Y N; Suk, M; Swain, J; Tenti, M; Togo, V; Tuszyński, J A; Vento, V; Vives, O; Vykydal, Z; Whyntie, T; Widom, A; Willems, G; Yoon, J H; Zgura, I S

    2017-02-10

    MoEDAL is designed to identify new physics in the form of long-lived highly ionizing particles produced in high-energy LHC collisions. Its arrays of plastic nuclear-track detectors and aluminium trapping volumes provide two independent passive detection techniques. We present here the results of a first search for magnetic monopole production in 13 TeV proton-proton collisions using the trapping technique, extending a previous publication with 8 TeV data during LHC Run 1. A total of 222 kg of MoEDAL trapping detector samples was exposed in the forward region and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges exceeding half the Dirac charge are excluded in all samples and limits are placed for the first time on the production of magnetic monopoles in 13 TeV pp collisions. The search probes mass ranges previously inaccessible to collider experiments for up to five times the Dirac charge.

  18. Search for magnetic monopoles with the MoEDAL forward trapping detector in 13 TeV proton-proton collisions at the LHC

    CERN Document Server

    Acharya, B.; Baines, S.; Benes, P.; Bergmann, B.; Bernabéu, J.; Branzas, H.; Campbell, M.; Caramete, L.; Cecchini, S.; de Montigny, M.; De Roeck, A.; Ellis, J.R.; Fairbairn, M.; Felea, D.; Flores, J.; Frank, M.; Frekers, D.; Garcia, C.; Hirt, A.M.; Janecek, J.; Kalliokoski, M.; Katre, A.; Kim, D.-W.; Kinoshita, K.; Korzenev, A.; Lacarrère, D.H.; Lee, S.C.; Leroy, C.; Lionti, A.; Mamuzic, J.; Margiotta, A.; Mauri, N.; Mavromatos, N.E.; Mermod, P.; Mitsou, V.A.; Orava, R.; Parker, B.; Pasqualini, L.; Patrizii, L.; Păvălaş, G.E.; Pinfold, J.L.; Popa, V.; Pozzato, M.; Pospisil, S.; Rajantie, A.; Ruiz de Austri, R.; Sahnoun, Z.; Sakellariadou, M.; Sarkar, S.; Semenoff, G.; Shaa, A.; Sirri, G.; Sliwa, K.; Soluk, R.; Spurio, M.; Srivastava, Y.N.; Suk, M.; Swain, J.; Tenti, M.; Togo, V.; Tuszyński, J.A.; Vento, V.; Vives, O.; Vykydal, Z.; Whyntie, T.; Widom, A.; Willems, G.; Yoon, J.H.; Zgura, I.S.

    2017-02-10

    MoEDAL is designed to identify new physics in the form of long-lived highly-ionising particles produced in high-energy LHC collisions. Its arrays of plastic nuclear-track detectors and aluminium trapping volumes provide two independent passive detection techniques. We present here the results of a search for magnetic monopole production in 13 TeV proton-proton collisions using the trapping technique, extending a previous publication with 8~TeV data during LHC run-1. A total of 222~kg of MoEDAL trapping detector samples were exposed in the forward region and analysed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges exceeding half the Dirac charge are excluded in all samples and limits are placed for the first time on the production of magnetic monopoles in 13 TeV collisions. The search probes mass ranges previously inaccessible to collider experiments for up to five times the Dirac charge.

  19. Electron Cloud Generation and Trapping in a Quadrupole Magnet at the Los Alamos Proton Storage Ring

    International Nuclear Information System (INIS)

    Macek, Robert J.; Browman, Andrew A.; Ledford, John E.; TechSource, Santa Fe; Los Alamos; Borden, Michael J.; O'Hara, James F.; McCrady, Rodney C.; Rybarcyk, Lawrence J.; Spickermann, Thomas; Zaugg, Thomas J.; Pivi, Mauro T.F.

    2008-01-01

    Recent beam physics studies on the two-stream e-p instability at the LANL proton storage ring (PSR) have focused on the role of the electron cloud generated in quadrupole magnets where primary electrons, which seed beam-induced multipacting, are expected to be largest due to grazing angle losses from the beam halo. A new diagnostic to measure electron cloud formation and trapping in a quadrupole magnet has been developed, installed, and successfully tested at PSR. Beam studies using this diagnostic show that the 'prompt' electron flux striking the wall in a quadrupole is comparable to the prompt signal in the adjacent drift space. In addition, the 'swept' electron signal, obtained using the sweeping feature of the diagnostic after the beam was extracted from the ring, was larger than expected and decayed slowly with an exponential time constant of 50 to 100 (micro)s. Other measurements include the cumulative energy spectra of prompt electrons and the variation of both prompt and swept electron signals with beam intensity. Experimental results were also obtained which suggest that a good fraction of the electrons observed in the adjacent drift space for the typical beam conditions in the 2006 run cycle were seeded by electrons ejected from the quadrupole

  20. Electron cloud generation and trapping in a quadrupole magnet at the Los Alamos proton storage ring

    Directory of Open Access Journals (Sweden)

    Robert J. Macek

    2008-01-01

    Full Text Available Recent beam physics studies on the two-stream e-p instability at the LANL proton storage ring (PSR have focused on the role of the electron cloud generated in quadrupole magnets where primary electrons, which seed beam-induced multipacting, are expected to be largest due to grazing angle losses from the beam halo. A new diagnostic to measure electron cloud formation and trapping in a quadrupole magnet has been developed, installed, and successfully tested at PSR. Beam studies using this diagnostic show that the “prompt” electron flux striking the wall in a quadrupole is comparable to the prompt signal in the adjacent drift space. In addition, the “swept” electron signal, obtained using the sweeping feature of the diagnostic after the beam was extracted from the ring, was larger than expected and decayed slowly with an exponential time constant of 50 to 100  μs. Other measurements include the cumulative energy spectra of prompt electrons and the variation of both prompt and swept electron signals with beam intensity. Experimental results were also obtained which suggest that a good fraction of the electrons observed in the adjacent drift space for the typical beam conditions in the 2006 run cycle were seeded by electrons ejected from the quadrupole.

  1. Quantitative in situ magnetization reversal studies in Lorentz microscopy and electron holography

    International Nuclear Information System (INIS)

    Rodríguez, L.A.; Magén, C.; Snoeck, E.; Gatel, C.; Marín, L.; Serrano-Ramón, L.

    2013-01-01

    A generalized procedure for the in situ application of magnetic fields by means of the excitation of the objective lens for magnetic imaging experiments in Lorentz microscopy and electron holography is quantitatively described. A protocol for applying magnetic fields with arbitrary in-plane magnitude and orientation is presented, and a freeware script for Digital Micrograph ™ is provided to assist the operation of the microscope. Moreover, a method to accurately reconstruct hysteresis loops is detailed. We show that the out-of-plane component of the magnetic field cannot be always neglected when performing quantitative measurements of the local magnetization. Several examples are shown to demonstrate the accuracy and functionality of the methods. - Highlights: • Generalized procedure for application of magnetic fields with the TEM objective lens. • Arbitrary in-plane magnetic field magnitude and orientation can be applied. • Method to accurately reconstruct hysteresis loops by electron holography. • Out-of-plane field component should be considered in quantitative measurements. • Examples to illustrate the method in Lorentz microscopy and electron holography

  2. Quantitative magnetic resonance imaging of articular cartilage in osteoarthritis

    Directory of Open Access Journals (Sweden)

    G Blumenkrantz

    2007-05-01

    Full Text Available Magnetic resonance imaging of articular cartilage has recently been recognized as a tool for the characterization of cartilage morphology, biochemistry and function. In this paper advancements in cartilage imaging, computation of cartilage volume and thickness, and measurement of relaxation times (T2 and T1Ρ are presented. In addition, the delayed uptake of Gadolinium DTPA as a marker of proteoglycan depletion is also reviewed. The cross-sectional and longitudinal studies using these imaging techniques show promise for cartilage assessment and for the study of osteoarthritis.

  3. Quantitative magnetic-moment mapping of a permanent-magnet material by X-ray magnetic circular dichroism nano-spectroscopy

    Directory of Open Access Journals (Sweden)

    Tetsuro Ueno

    2017-05-01

    Full Text Available We demonstrate the quantitative mapping of magnetic moments in a permanent-magnet material by X-ray magnetic circular dichroism nano-spectroscopy. An SmCo5 specimen was prepared from the bulk material by using a micro-fabrication technique. Scanning transmission X-ray microscopy images were obtained around the Sm M4,5 absorption edges. By applying the magneto-optical sum rules to these images, we obtained quantitative maps of the orbital and spin magnetic moments as well as their ratio. We found that the magnitudes of the orbital and spin magnetic moments and their ratio do not depend on thickness of the specimen.

  4. Search for magnetic monopoles with the MoEDAL prototype trapping detector in 8 TeV proton-proton collisions at the LHC

    Science.gov (United States)

    Acharya, B.; Alexandre, J.; Bendtz, K.; Benes, P.; Bernabéu, J.; Campbell, M.; Cecchini, S.; Chwastowski, J.; Chatterjee, A.; de Montigny, M.; Derendarz, D.; De Roeck, A.; Ellis, J. R.; Fairbairn, M.; Felea, D.; Frank, M.; Frekers, D.; Garcia, C.; Giacomelli, G.; Hasegan, D.; Kalliokoski, M.; Katre, A.; Kim, D.-W.; King, M. G. L.; Kinoshita, K.; Lacarrère, D. H.; Lee, S. C.; Leroy, C.; Lionti, A.; Margiotta, A.; Mauri, N.; Mavromatos, N. E.; Mermod, P.; Milstead, D.; Mitsou, V. A.; Orava, R.; Parker, B.; Pasqualini, L.; Patrizii, L.; Păvălas, G. E.; Pinfold, J. L.; Platkevič, M.; Popa, V.; Pozzato, M.; Pospisil, S.; Rajantie, A.; Sahnoun, Z.; Sakellariadou, M.; Sarkar, S.; Semenoff, G.; Sirri, G.; Sliwa, K.; Soluk, R.; Spurio, M.; Srivastava, Y. N.; Staszewski, R.; Suk, M.; Swain, J.; Tenti, M.; Togo, V.; Trzebinski, M.; Tuszynski, J. A.; Vento, V.; Vives, O.; Vykydal, Z.; Whyntie, T.; Widom, A.; Willems, G.; Yoon, J. H.

    2016-08-01

    The MoEDAL experiment is designed to search for magnetic monopoles and other highly-ionising particles produced in high-energy collisions at the LHC. The largely passive MoEDAL detector, deployed at Interaction Point 8 on the LHC ring, relies on two dedicated direct detection techniques. The first technique is based on stacks of nucleartrack detectors with surface area ~18m2, sensitive to particle ionisation exceeding a high threshold. These detectors are analysed offline by optical scanning microscopes. The second technique is based on the trapping of charged particles in an array of roughly 800 kg of aluminium samples. These samples are monitored offline for the presence of trapped magnetic charge at a remote superconducting magnetometer facility. We present here the results of a search for magnetic monopoles using a 160 kg prototype MoEDAL trapping detector exposed to 8TeV proton-proton collisions at the LHC, for an integrated luminosity of 0.75 fb-1. No magnetic charge exceeding 0:5 g D (where g D is the Dirac magnetic charge) is measured in any of the exposed samples, allowing limits to be placed on monopole production in the mass range 100 GeV≤ m ≤ 3500 GeV. Model-independent cross-section limits are presented in fiducial regions of monopole energy and direction for 1 g D ≤ | g| ≤ 6 g D, and model-dependent cross-section limits are obtained for Drell-Yan pair production of spin-1/2 and spin-0 monopoles for 1 g D ≤ | g| ≤ 4 g D. Under the assumption of Drell-Yan cross sections, mass limits are derived for | g| = 2 g D and | g| = 3 g D for the first time at the LHC, surpassing the results from previous collider experiments.

  5. A free-jet Hg target operating in a high magnetic field intersecting a high-power proton beam

    Science.gov (United States)

    Van Graves; Spampinato, Philip; Gabriel, Tony; Kirk, Harold; Simos, Nicholas; Tsang, Thomas; McDonald, Kirk; Peter Titus; Fabich, Adrian; Haseroth, Helmut; Lettry, Jacques

    2006-06-01

    A proof-of-principal experiment to investigate the interaction of a proton beam, high magnetic field, and high- Z target is planned to take place at CERN in early 2007. This experiment is part of the Muon Collider Collaboration, with participants from Brookhaven National Laboratory, Princeton University, Massachusetts Institute Of Technology, European Organization for Nuclear Research-CERN, Rutherford Appleton Laboratory, and Oak Ridge National Laboratory. An unconstrained mercury jet target system that interacts with a high power (1 MW) proton beam in a high magnetic field (15 T) is being designed. The Hg jet diameter is 1-cm with a velocity up to 20 m/s. A laser optical diagnostic system will be incorporated into the target design to permit observation of the dispersal of the jet resulting from interaction with a 24 GeV proton beam with up to 20×10 12 ppp. The target system includes instruments for sensing mercury vapor, temperature, flow rate, and sump tank level, and the means to position the jet relative to the magnetic axis of a solenoid and the proton beam. The design considerations for the system include all issues dealing with safely handling approximately 23 l of Hg, transporting the target system and the mercury to CERN, decommissioning the experiment, and returning the mildly activated equipment and Hg to the US.

  6. Evaluation of recent quantitative magnetospheric magnetic field models

    International Nuclear Information System (INIS)

    Walker, R.J.

    1976-01-01

    Recent quantitative magnetospheric field models contain many features not found in earlier models. Magnetopause models which include the effects of the dipole tilt were presented. More realistic models of the tail field include tail currents which close on the magnetopause, cross-tail currents of finite thickness, and cross-tail current models which model the position of the neutral sheet as a function of tilt. Finally, models have attempted to calculate the field of currents distributed in the inner magnetosphere. As the purpose of a magnetospheric model is to provide a mathematical description of the field that reasonably reproduces the observed magnetospheric field, several recent models were compared with the observed ΔB(B/sub observed/--B/sub main field/) contours. Models containing only contributions from magnetopause and tail current systems are able to reproduce the observed quiet time field only in an extremely qualitative way. The best quantitative agreement between models and observations occurs when currents distributed in the inner magnetosphere are added to the magnetopause and tail current systems. However, the distributed current models are valid only for zero tilt. Even the models which reproduce the average observed field reasonably well may not give physically reasonable field gradients. Three of the models evaluated contain regions in the near tail in which the field gradient reverses direction. One region in which all the models fall short is that around the polar cusp, though most can be used to calculate the position of the last closed field line reasonably well

  7. Ground-state magnetization of the molecular cluster Mn12O12-acetate as seen by proton NMR

    International Nuclear Information System (INIS)

    Furukawa, Y.; Watanabe, K.; Kumagai, K.; Jang, Z. H.; Lascialfari, A.; Borsa, F.; Gatteschi, D.

    2000-01-01

    1 H nuclear magnetic resonance (NMR) measurements have been carried out in Mn 12 O 12 -acetate clusters at low temperature in order to investigate microscopically the static and dynamic magnetic properties of the molecule in its high-spin S=10 ground state. Below liquid helium temperature it is found that the local hyperfine fields at the proton sites are static as expected for the very slow superparamagnetic relaxation of Mn 12 O 12 at low temperature. The magnitude and distribution of the hyperfine fields can be reproduced to a good approximation by considering only the dipolar interaction of protons with the local Mn magnetic moments and by assigning the magnitude and orientation of the local moments of the different Mn 3+ and Mn 4+ ions according to an accepted coupling scheme for the total S=10 ground state. The relaxation time of the macroscopic magnetization of the cluster was measured by monitoring the change of the intensity of the 1 H-NMR shifted lines following inversion of the applied magnetic field. This is possible because the sudden change of the field orientation changes the sign of the shift of the NMR lines in the proton spectrum. Although important differences are noticed, the relaxation time of the magnetization as measured indirectly by the 1 H-NMR method is comparable to the one obtained directly with a superconducting quantum interference device magnetometer. In particular we could reproduce the minima in the relaxation time as a function of magnetic field at the fields for level crossing, minima which are considered to be a signature of the quantum tunneling of the magnetization

  8. TU-H-CAMPUS-TeP1-03: Magnetically Focused Proton Irradiation of Small Volume Radiosurgery Targets

    Energy Technology Data Exchange (ETDEWEB)

    McAuley, GA; Slater, JM [Loma Linda University, Loma Linda, CA (United States); Wroe, AJ [Loma Linda University, Loma Linda, CA (United States); Loma Linda University Medical Center, Loma Linda, CA (United States)

    2016-06-15

    Purpose: To investigate the use of magnetic focusing for small volume proton radiosurgery targets using a triplet combination of quadrupole rare earth permanent magnet Halbach cylinder assemblies Methods: Fourteen quadrupole magnets consisting of 24 segments of radiation hard samarium-cobalt adhered into k=3 Halbach cylinders with various field gradients (100 to 250 T/m) were designed and manufactured. Triplet combinations of the magnets were placed on a positioning track on our Gantry 1 treatment table. Unmodulated 127 MeV proton beams with initial diameters of 3 to 20 mm were delivered to a water tank using single-stage scattering. Depth and transverse dose distributions were measured using a PTW PR60020 diode detector and EBT3 film, respectively. This data was compared with unfocused passively collimated beams. Monte Carlo simulations were also performed - both for comparison with experimental data and to further investigate the potential of triplet magnetic focusing. Results: Experimental results using 150 T/m gradient magnets and 15 to 20 mm initial diameter beams show peak to entrance dose ratios that are ∼ 43 to 48 % larger compared with spot size matched 8 mm collimated beams (ie, transverse profile full-widths at 90% maximum dose match within 0.5 mm of focused beams). In addition, the focusing beams were ∼ 3 to 4.4 times more efficient per MU in dose to target delivery. Additional results using different magnet combinations will also be presented. Conclusion: Our results suggest that triplet magnetic focusing could reduce entrance dose and beam number while delivering dose to small (∼≤ 10 mm diameter) radiosurgery targets in less time compared to unfocused beams. Immediate clinical applications include those associated with proton radiosurgery and functional radiosurgery of the brain and spine, however other treatment sites can be also envisioned. This project was sponsored with funding from the Department of Defense (DOD# W81XWH-BAA-10-1).

  9. The hippocampus in patients treated with electroconvulsive therapy: a proton magnetic resonance spectroscopic imaging study.

    Science.gov (United States)

    Ende, G; Braus, D F; Walter, S; Weber-Fahr, W; Henn, F A

    2000-10-01

    We monitored the effect of electroconvulsive therapy (ECT) on the nuclear magnetic resonance-detectable metabolites N-acetylaspartate, creatine and phosphocreatine, and choline-containing compounds in the hippocampus by means of hydrogen 1 magnetic resonance spectroscopic imaging. We hypothesized that if ECT-induced memory deterioration was associated with neuronal loss in the hippocampus, the N-acetylaspartate signal would decrease after ECT and any increased membrane turnover would result in an increase in the signal from choline-containing compounds. Seventeen patients received complete courses of ECT, during which repeated proton magnetic resonance spectroscopic imaging studies of the hippocampal region were performed. Individual changes during the course of ECT were compared with values obtained in 24 healthy control subjects and 6 patients remitted from major depression without ECT. No changes in the hippocampal N-acetylaspartate signals were detected after ECT. A significant mean increase of 16% of the signal from choline-containing compounds after 5 or more ECT treatments was observed. Despite the mostly unilateral ECT application (14 of 17 patients), the increase in the choline-containing compound signal was observed bilaterally. Lactate or elevated lipid signals were not detected. All patients showed clinical amelioration of depression after ECT. Electroconvulsive therapy is not likely to induce hippocampal atrophy or cell death, which would be reflected by a decrease in the N-acetylaspartate signal. Compared with an age-matched control group, the choline-containing compounds signal in patients with a major depressive episode was significantly lower than normal, before ECT and normalized during ECT.

  10. A magneto-optical microscope for quantitative measurement of magnetic microstructures.

    Science.gov (United States)

    Patterson, W C; Garraud, N; Shorman, E E; Arnold, D P

    2015-09-01

    An optical system is presented to quantitatively map the stray magnetic fields of microscale magnetic structures, with field resolution down to 50 μT and spatial resolution down to 4 μm. The system uses a magneto-optical indicator film (MOIF) in conjunction with an upright reflective polarizing light microscope to generate optical images of the magnetic field perpendicular to the image plane. A novel single light path construction and discrete multi-image polarimetry processing method are used to extract quantitative areal field measurements from the optical images. The integrated system including the equipment, image analysis software, and experimental methods are described. MOIFs with three different magnetic field ranges are calibrated, and the entire system is validated by measurement of the field patterns from two calibration samples.

  11. Quantitative forecasting of the 27-day recurrent magnetic activity

    International Nuclear Information System (INIS)

    Akasofu, S.-I.; Olmsted, C.

    1988-01-01

    It is shown that forecasting of the recurrent geomagnetic activity is reduced to predicting the solar wind speed V and the magnitude B of the Interplanetary Magnetic Field IMF for a 27-day period. It is shown further that the prediction of V and B is reduced to inferring the geometry of the neutral line on the source surface which is an imaginary spherical surface of radius 2.5 solar radii. For this purpose, we note that it has recently been found that the neutral line on the source surface can be reproduced fairly accurately by a dipole at the center of the Sun and a few dipoles on the photosphere. This finding provides us with an opportunity to predict the geometry of the neutral line on the source surface by extrapolating time variations of the magnitude and orientation of the dipoles. We show that time variations of the dipoles are fairly systematic, making the extrapolation possible. (author)

  12. Iron filled carbon nanotubes as novel monopole-like sensors for quantitative magnetic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wolny, F; Muehl, T; Weissker, U; Lipert, K; Schumann, J; Leonhardt, A; Buechner, B, E-mail: f.wolny@ifw-dresden.de, E-mail: t.muehl@ifw-dresden.de [Leibniz Institute for Solid State and Materials Research (IFW) Dresden, Helmholtzstrasse 20, 01069 Dresden (Germany)

    2010-10-29

    We present a novel ultrahigh stability sensor for quantitative magnetic force microscopy (MFM) based on an iron filled carbon nanotube. In contrast to the complex magnetic structure of conventional MFM probes, this sensor constitutes a nanomagnet with defined properties. The long iron nanowire can be regarded as an extended dipole of which only the monopole close to the sample surface is involved in the imaging process. We demonstrate its potential for high resolution imaging. Moreover, we present an easy routine to determine its monopole moment and prove that this calibration, unlike other approaches, is universally applicable. For the first time this enables straightforward quantitative MFM measurements.

  13. Spin-polarized scanning tunneling microscopy with quantitative insights into magnetic probes.

    Science.gov (United States)

    Phark, Soo-Hyon; Sander, Dirk

    2017-01-01

    Spin-polarized scanning tunneling microscopy and spectroscopy (spin-STM/S) have been successfully applied to magnetic characterizations of individual nanostructures. Spin-STM/S is often performed in magnetic fields of up to some Tesla, which may strongly influence the tip state. In spite of the pivotal role of the tip in spin-STM/S, the contribution of the tip to the differential conductance d I /d V signal in an external field has rarely been investigated in detail. In this review, an advanced analysis of spin-STM/S data measured on magnetic nanoislands, which relies on a quantitative magnetic characterization of tips, is discussed. Taking advantage of the uniaxial out-of-plane magnetic anisotropy of Co bilayer nanoisland on Cu(111), in-field spin-STM on this system has enabled a quantitative determination, and thereby, a categorization of the magnetic states of the tips. The resulting in-depth and conclusive analysis of magnetic characterization of the tip opens new venues for a clear-cut sub-nanometer scale spin ordering and spin-dependent electronic structure of the non-collinear magnetic state in bilayer high Fe nanoislands on Cu(111).

  14. Investigation of the structure of isobutylene oligomers, used in the capacity of stock for succinimide additives, by the method of proton magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Iarmoliuk, V.M.; Garun, Ia.E.; Ostroverkhov, V.G.; Pustovit, V.E.; Tikhonov, V.P.

    1980-01-01

    By the method of proton magnetic resonance, investigation was made of the structure of hydrocarbon framework of isobutylene oligomers of the Salavatsk petrochemical plant, produced by the cation polymerization of the isobutane isobutylene fraction at a temperature from -10 to +20/sup 0/ with A1C1/sub 3/ and used in the production of succinide additives. Determination was made of the qualitative and quantitative compositions of the various structures in the oligomers. It is shown, that as a rule, oligobutenes are not pure oligomers of isobutylene, but represent, at least, fragments of four structures, which can be formed on the basis of isobutylene. The content of the given structures does not affect the reaction capacity of the oligomers in respect to the maleic anhydride. It was established, that the low molecular fraction, contained in oligomers up to 5%, are not isobutylene oligomers, but represent a low molecular polymer of butene-2 and its copolymer with isobutylene.

  15. Effects of proton irradiation on structure of NdFeB permanent magnets studied by X-ray diffraction and X-ray absorption fine structure

    International Nuclear Information System (INIS)

    Yang, L.; Zhen, L.; Xu, C.Y.; Sun, X.Y.; Shao, W.Z.

    2011-01-01

    The effects of proton irradiation on the structure of NdFeB permanent magnet were investigated by X-ray diffraction and X-ray absorption fine structure (XAFS). The results reveal that proton irradiation has no effect on the long-range structure, but significantly affects the atomic local structure of the NdFeB magnet. The alignment degree of the magnet decreases and the internal stress of the lattice increases after proton irradiation. XAFS results show that the coordination number of Fe-Nd in the first neighboring coordination shell of the Fe atoms decreases and the disorder degree increases.

  16. Effects of proton irradiation on structure of NdFeB permanent magnets studied by X-ray diffraction and X-ray absorption fine structure

    Energy Technology Data Exchange (ETDEWEB)

    Yang, L. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Zhen, L., E-mail: lzhen@hit.edu.c [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Xu, C.Y.; Sun, X.Y.; Shao, W.Z. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2011-01-15

    The effects of proton irradiation on the structure of NdFeB permanent magnet were investigated by X-ray diffraction and X-ray absorption fine structure (XAFS). The results reveal that proton irradiation has no effect on the long-range structure, but significantly affects the atomic local structure of the NdFeB magnet. The alignment degree of the magnet decreases and the internal stress of the lattice increases after proton irradiation. XAFS results show that the coordination number of Fe-Nd in the first neighboring coordination shell of the Fe atoms decreases and the disorder degree increases.

  17. Proton Nuclear Magnetic Resonance-Spectroscopic Discrimination of Wines Reflects Genetic Homology of Several Different Grape (V. vinifera L.) Cultivars

    Science.gov (United States)

    Zhu, Yong; Wen, Wen; Zhang, Fengmin; Hardie, Jim W.

    2015-01-01

    Background and Aims Proton nuclear magnetic resonance spectroscopy coupled multivariate analysis (1H NMR-PCA/PLS-DA) is an important tool for the discrimination of wine products. Although 1H NMR has been shown to discriminate wines of different cultivars, a grape genetic component of the discrimination has been inferred only from discrimination of cultivars of undefined genetic homology and in the presence of many confounding environmental factors. We aimed to confirm the influence of grape genotypes in the absence of those factors. Methods and Results We applied 1H NMR-PCA/PLS-DA and hierarchical cluster analysis (HCA) to wines from five, variously genetically-related grapevine (V. vinifera) cultivars; all grown similarly on the same site and vinified similarly. We also compared the semi-quantitative profiles of the discriminant metabolites of each cultivar with previously reported chemical analyses. The cultivars were clearly distinguishable and there was a general correlation between their grouping and their genetic homology as revealed by recent genomic studies. Between cultivars, the relative amounts of several of the cultivar-related discriminant metabolites conformed closely with reported chemical analyses. Conclusions Differences in grape-derived metabolites associated with genetic differences alone are a major source of 1H NMR-based discrimination of wines and 1H NMR has the capacity to discriminate between very closely related cultivars. Significance of the Study The study confirms that genetic variation among grape cultivars alone can account for the discrimination of wine by 1H NMR-PCA/PLS and indicates that 1H NMR spectra of wine of single grape cultivars may in future be used in tandem with hierarchical cluster analysis to elucidate genetic lineages and metabolomic relations of grapevine cultivars. In the absence of genetic information, for example, where predecessor varieties are no longer extant, this may be a particularly useful approach. PMID

  18. Status of intense permanent magnet proton source for China-accelerator driven sub-critical system Linac.

    Science.gov (United States)

    Wu, Q; Ma, H Y; Yang, Y; Sun, L T; Zhang, X Z; Zhang, Z M; Zhao, H Y; He, Y; Zhao, H W

    2016-02-01

    Two compact intense 2.45 GHz permanent magnet proton sources and their corresponding low energy beam transport (LEBT) system were developed successfully for China accelerator driven sub-critical system in 2014. Both the proton sources operate at 35 kV potential. The beams extracted from the ion source are transported by the LEBT, which is composed of two identical solenoids, to the 2.1 MeV Radio-Frequency Quadrupole (RFQ). In order to ensure the safety of the superconducting cavities during commissioning, an electrostatic-chopper has been designed and installed in the LEBT line that can chop the continuous wave beam into a pulsed one. The minimum width of the pulse is less than 10 μs and the fall/rise time of the chopper is about 20 ns. The performance of the proton source and the LEBT, such as beam current, beam profile, emittance and the impact to RFQ injection will be presented.

  19. Status of intense permanent magnet proton source for China-accelerator driven sub-critical system Linac

    Science.gov (United States)

    Wu, Q.; Ma, H. Y.; Yang, Y.; Sun, L. T.; Zhang, X. Z.; Zhang, Z. M.; Zhao, H. Y.; He, Y.; Zhao, H. W.

    2016-02-01

    Two compact intense 2.45 GHz permanent magnet proton sources and their corresponding low energy beam transport (LEBT) system were developed successfully for China accelerator driven sub-critical system in 2014. Both the proton sources operate at 35 kV potential. The beams extracted from the ion source are transported by the LEBT, which is composed of two identical solenoids, to the 2.1 MeV Radio-Frequency Quadrupole (RFQ). In order to ensure the safety of the superconducting cavities during commissioning, an electrostatic-chopper has been designed and installed in the LEBT line that can chop the continuous wave beam into a pulsed one. The minimum width of the pulse is less than 10 μs and the fall/rise time of the chopper is about 20 ns. The performance of the proton source and the LEBT, such as beam current, beam profile, emittance and the impact to RFQ injection will be presented.

  20. Status of intense permanent magnet proton source for China-accelerator driven sub-critical system Linac

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Q., E-mail: wuq@impcas.ac.cn; Ma, H. Y.; Yang, Y.; Sun, L. T.; Zhang, X. Z.; Zhang, Z. M.; Zhao, H. Y.; He, Y.; Zhao, H. W. [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China)

    2016-02-15

    Two compact intense 2.45 GHz permanent magnet proton sources and their corresponding low energy beam transport (LEBT) system were developed successfully for China accelerator driven sub-critical system in 2014. Both the proton sources operate at 35 kV potential. The beams extracted from the ion source are transported by the LEBT, which is composed of two identical solenoids, to the 2.1 MeV Radio-Frequency Quadrupole (RFQ). In order to ensure the safety of the superconducting cavities during commissioning, an electrostatic-chopper has been designed and installed in the LEBT line that can chop the continuous wave beam into a pulsed one. The minimum width of the pulse is less than 10 μs and the fall/rise time of the chopper is about 20 ns. The performance of the proton source and the LEBT, such as beam current, beam profile, emittance and the impact to RFQ injection will be presented.

  1. Direct measurement of kilo-tesla level magnetic field generated with laser-driven capacitor-coil target by proton deflectometry

    Science.gov (United States)

    Law, K. F. F.; Bailly-Grandvaux, M.; Morace, A.; Sakata, S.; Matsuo, K.; Kojima, S.; Lee, S.; Vaisseau, X.; Arikawa, Y.; Yogo, A.; Kondo, K.; Zhang, Z.; Bellei, C.; Santos, J. J.; Fujioka, S.; Azechi, H.

    2016-02-01

    A kilo-tesla level, quasi-static magnetic field (B-field), which is generated with an intense laser-driven capacitor-coil target, was measured by proton deflectometry with a proper plasma shielding. Proton deflectometry is a direct and reliable method to diagnose strong, mm3-scale laser-produced B-field; however, this was not successful in the previous experiment. A target-normal-sheath-accelerated proton beam is deflected by Lorentz force in the laser-produced magnetic field with the resulting deflection pattern recorded on a radiochromic film stack. A 610 ± 30 T of B-field amplitude was inferred by comparing the experimental proton pattern with Monte-Carlo calculations. The amplitude and temporal evolutions of the laser-generated B-field were also measured by a differential magnetic probe, independently confirming the proton deflectometry measurement results.

  2. Osteosarcoma subtypes: Magnetic resonance and quantitative diffusion weighted imaging criteria.

    Science.gov (United States)

    Zeitoun, Rania; Shokry, Ahmed M; Ahmed Khaleel, Sahar; Mogahed, Shaimaa M

    2018-03-01

    Osteosarcoma (OS) is a primary bone malignancy, characterized by spindle cells producing osteoid. The objective of this study is to describe the magnetic resonance imaging (MRI) features of different OS subtypes, record their attenuation diffusion coefficient (ADC) values and to point to the relation of their pathologic base and their corresponding ADC value. We performed a retrospective observational lesion-based analysis for 31 pathologically proven osteosarcoma subtypes: osteoblastic (n = 9), fibroblastic (n = 8), chondroblastic (n = 6), para-osteal (n = 3), periosteal (n = 1), telangiectatic (n = 2), small cell (n = 1) and extra-skeletal (n = 1). On conventional images we recorded: bone of origin, epicenter, intra-articular extension, and invasion of articulating bones, skip lesions, distant metastases, pathological fractures, ossified matrix, hemorrhage and necrosis. We measured the mean ADC value for each lesion. Among the included OS lesions, 51.6% originated at the femur, 29% showed intra-articular extension, 16% invaded neighboring bone, 9% were associated with pathological fracture and 25.8% were associated with distant metastases. On MRI, all lesions showed ossified matrix, 35.5% showed hemorrhage and 58% showed necrosis. The mean ADC values for OS lesions ranged from 0.74 × 10 -3  mm 2 /s (recorded for conventional osteoblastic OS) to 1.50 × 10 -3  mm 2 /s (recorded for telangiectatic OS) with an average value of 1.16 ± 0.18 × 10 -3  mm 2 /s. Conventional chondroblastic OS recorded higher values compared to the other two conventional subtypes. Osteosarcoma has different pathologic subtypes which correspondingly vary in their imaging criteria and their ADC values. Copyright © 2018. Production and hosting by Elsevier B.V.

  3. Quantitative analysis of beam delivery parameters and treatment process time for proton beam therapy

    International Nuclear Information System (INIS)

    Suzuki, Kazumichi; Gillin, Michael T.; Sahoo, Narayan; Zhu, X. Ronald; Lee, Andrew K.; Lippy, Denise

    2011-01-01

    Purpose: To evaluate patient census, equipment clinical availability, maximum daily treatment capacity, use factor for major beam delivery parameters, and treatment process time for actual treatments delivered by proton therapy systems. Methods: The authors have been recording all beam delivery parameters, including delivered dose, energy, range, spread-out Bragg peak widths, gantry angles, and couch angles for every treatment field in an electronic medical record system. We analyzed delivery system downtimes that had been recorded for every equipment failure and associated incidents. These data were used to evaluate the use factor of beam delivery parameters, the size of the patient census, and the equipment clinical availability of the facility. The duration of each treatment session from patient walk-in and to patient walk-out of the treatment room was measured for 82 patients with cancers at various sites. Results: The yearly average equipment clinical availability in the last 3 yrs (June 2007-August 2010) was 97%, which exceeded the target of 95%. Approximately 2200 patients had been treated as of August 2010. The major disease sites were genitourinary (49%), thoracic (25%), central nervous system (22%), and gastrointestinal (2%). Beams have been delivered in approximately 8300 treatment fields. The use factor for six beam delivery parameters was also evaluated. Analysis of the treatment process times indicated that approximately 80% of this time was spent for patient and equipment setup. The other 20% was spent waiting for beam delivery and beam on. The total treatment process time can be expressed by a quadratic polynomial of the number of fields per session. The maximum daily treatment capacity of our facility using the current treatment processes was estimated to be 133 ± 35 patients. Conclusions: This analysis shows that the facility has operated at a high performance level and has treated a large number of patients with a variety of diseases. The use

  4. Quantitative Study on Corrosion of Steel Strands Based on Self-Magnetic Flux Leakage

    Directory of Open Access Journals (Sweden)

    Runchuan Xia

    2018-05-01

    Full Text Available This paper proposed a new computing method to quantitatively and non-destructively determine the corrosion of steel strands by analyzing the self-magnetic flux leakage (SMFL signals from them. The magnetic dipole model and three growth models (Logistic model, Exponential model, and Linear model were proposed to theoretically analyze the characteristic value of SMFL. Then, the experimental study on the corrosion detection by the magnetic sensor was carried out. The setup of the magnetic scanning device and signal collection method were also introduced. The results show that the Logistic Growth model is verified as the optimal model for calculating the magnetic field with good fitting effects. Combined with the experimental data analysis, the amplitudes of the calculated values (BxL(x,z curves agree with the measured values in general. This method provides significant application prospects for the evaluation of the corrosion and the residual bearing capacity of steel strand.

  5. Noninvasive evaluation of adult onset myopathy from carnitine palmitoyl transferase II deficiency using proton magnetic resonance spectroscopy.

    Science.gov (United States)

    Videen, J S; Haseler, L J; Karpinski, N C; Terkeltaub, R A

    1999-08-01

    The adult onset metabolic myopathy of carnitine palmitoyl transferase II (CPT II) deficiency is under-recognized, in part due to variable degrees of enzyme deficiency and symptomatology, as well as limitations in means for noninvasive evaluation. We describe a proton magnetic resonance spectroscopy (MRS) technique, using a standard clinical magnetic resonance imaging scanner, to diagnose and help monitor the response to therapy in adult CPT II deficiency. A 53-year-old woman presented with a long standing history of diffuse aching and fatigue provoked by high fat intake, fasting, or prolonged exertion. Muscle biopsy revealed myopathic features and a deficiency (33% of control) of CPT II activity with elevated palmitoyl carnitine. Proton MRS of the soleus muscle was performed using a 1.5 Tesla scanner before and during dietary therapy. Proton MRS revealed shortening of the transverse relaxation time (T2), consistent with increased acetylation of the carnitine pool. The symptoms resolved completely by treatment with frequent feedings of a high carbohydrate diet low in long chain fatty acids supplemented with medium chain triglycerides and L-carnitine. Recovery of normal muscle MRS and carnitine T2 relaxation was documented by the third month of therapy. Proton MRS is a novel, potentially useful, and readily available adjunct in the diagnosis and therapeutic monitoring of muscle CPT II deficiency.

  6. Diffusion-weighted imaging and magnetic resonance proton spectroscopy following preterm birth

    International Nuclear Information System (INIS)

    Hart, A.R.; Smith, M.F.; Whitby, E.H.; Alladi, S.; Wilkinson, S.; Paley, M.N.; Griffiths, P.D.

    2014-01-01

    Aim: To study the associations between magnetic resonance proton spectroscopy (MRS) data and apparent diffusion coefficients (ADC) from the preterm brain with developmental outcome at 18 months corrected age and clinical variables. Materials and methods: A prospective observational cohort study of 67 infants born before 35 weeks gestational age who received both magnetic resonance imaging of the brain between 37 and 44 weeks corrected gestational age and developmental assessment around 18 months corrected age. Results: No relationships were found between ADC values and MRS results or outcome. MRS ratios involving N-acetyl aspartate (NAA) from the posterior white matter were associated with ''severe'' and ''moderate to severe'' difficulties, and fine motor scores were significantly lower in participants with a visible lactate doublet in the posterior white matter. The presence of a patent ductus arteriosus (PDA) was the only clinical factor related to NAA ratios. Conclusion: Altered NAA levels in the posterior white matter may reflect subtle white matter injury associated with neuro-developmental difficulties, which may be related to a PDA. Further work is needed to assess the longer-term neuro-developmental implications of these findings, and to study the effect of PDAs on developmental outcome in later childhood/adolescence. - Highlights: • ADC values around term corrected age from a wide area of the brain are not associated with developmental outcome. • NAA ratios from the posterior white matter are associated with adverse outcome. • No relationship between MRS data and ADC values exist when measured from the same region of the cerebral white matter. • The presence of a patent ductus arterious was associated with NAA ratios from the posterior white matter, but not outcome

  7. Analysis of the brain proton magnetic resonance spectroscopy - differences between normal grey and white matter

    International Nuclear Information System (INIS)

    Krukowski, P.; Podgorski, P.; Guzinski, M.; Szewczyk, P.; Sasiadek, M.

    2010-01-01

    Background: The proton magnetic resonance spectroscopy (HMRS) is a non-invasive diagnostic method that allows for an assessment of the metabolite concentration in tissues. The sources of the strongest resonance signals within the brain are N-acetylaspartate (NAA), creatine (Cr), choline (Cho), myoinositol (mI) and water. The aim of our study was to analyse the ratios of metabolite signals within the brain in HMRS in the healthy population, to define the differences between the grey and white matter spectra. Material/Methods: We studied prospectively 90 subjects aged from 8 to 80 years (mean 43.3 years, SD=17.9), without neurological symptoms or abnormalities in magnetic resonance imaging. In all patients, brain HMRS with Signa HDx 1.5 T MR unit (GE Healthcare) was performed with PRESS sequence, using a single voxel method, at TE of 35 ms and TR of 1500 ms. Spectroscopic evaluation involved voxels placed in the white matter of parietal lobe (PWM) and the grey matter of posterior cingulate gyrus (PGM). On the basis of the intensity of NAA, Cr, Cho, mI and water signals, the proportions of these signals were calculated, as well as the ratio of the analyzed metabolite signal to the sum of signals of NAA, Cho, Cr and mI (%Met) in the PGM and PWM voxels. We compared the proportions in the same patients in PGM and PWM voxels. Results: There has been a statistically significant difference between the proportions of a majority of the metabolite ratios evaluated in PGM and PWM, indicating the higher concentration of NAA, Cr and mI in grey matter, and higher concentration of Cho in white matter. Conclusions: HMRS spectra of the brain grey and white matter differ significantly. The concentrations of NAA, Cr and mI are higher in grey matter, while of choline - in the white matter. (authors)

  8. Double-trap measurement of the proton magnetic moment at 0.3 parts per billion precision.

    Science.gov (United States)

    Schneider, Georg; Mooser, Andreas; Bohman, Matthew; Schön, Natalie; Harrington, James; Higuchi, Takashi; Nagahama, Hiroki; Sellner, Stefan; Smorra, Christian; Blaum, Klaus; Matsuda, Yasuyuki; Quint, Wolfgang; Walz, Jochen; Ulmer, Stefan

    2017-11-24

    Precise knowledge of the fundamental properties of the proton is essential for our understanding of atomic structure as well as for precise tests of fundamental symmetries. We report on a direct high-precision measurement of the magnetic moment μ p of the proton in units of the nuclear magneton μ N The result, μ p = 2.79284734462 (±0.00000000082) μ N , has a fractional precision of 0.3 parts per billion, improves the previous best measurement by a factor of 11, and is consistent with the currently accepted value. This was achieved with the use of an optimized double-Penning trap technique. Provided a similar measurement of the antiproton magnetic moment can be performed, this result will enable a test of the fundamental symmetry between matter and antimatter in the baryonic sector at the 10 -10 level. Copyright © 2017, American Association for the Advancement of Science.

  9. Calibration Phantom for Quantitative Tomography Analysis of Biodistribution of Magnetic Nanoparticles

    Science.gov (United States)

    Rahn, Helen; Kettering, Melanie; Richter, Heike; Hilger, Ingrid; Trahms, Lutz; Odenbach, Stefan

    2010-12-01

    Ferrofluids are being investigated for cancer treatments such as magnetic drug targeting (MDT) and magnetic heating treatments with the aim of treating the cancer locally, since magnetic nanoparticles with attached drugs are concentrated within the target region. Thus, the side effects are considerably reduced. One of the crucial factors for the success of these therapies is the magnetic nanoparticle distribution. Microcomputed X-ray tomography (XμCT) has been introduced as adequate technique for non-destructive three-dimensional analysis of biological samples enriched with magnetic nanoparticles. The biological tissue specimens, in this case tumor bearing mice after intra-tumoral magnetic nanoparticle injection, have been analyzed by means of XμCT. Complementary measurements have been performed by magnetorelaxometry (MRX). This technique enables a sensitive quantification of magnetic nanoparticles down to few nanograms. For multi-phase samples, such as biological tissue enriched with magnetic nanoparticles the polychromasy and beam hardening artifacts occurring in XμCT with conventional X-ray tubes cause severe problems for quantitative density determination. This problem requires an appropriate calibration of the polychromatic tomography equipment enabling a semi-quantitative analysis of the data. For this purpose a phantom system has been implemented. These phantoms consist of a tissue substitute containing different amounts of magnetic nanoparticles. Since the attenuation of the beam also depends on the thickness i.e. the path length of the beam transmitting the object, the reference sample has been defined to a cone shape. Thus, with one phantom the information about the magnetic nanoparticle concentration as well as the attenuation in dependence of the path length can be determined. Two phantom systems will be presented, one based on agarose-gel and one based on soap.

  10. [Clinical application of proton magnetic resonance spectroscopy in children with idiopathic epilepsy].

    Science.gov (United States)

    Shao, Xiao-Li; Zhou, Zhong-Shu; Hong, Wen

    2010-06-01

    This study examined the biochemical metabolism by proton magnetic resonance spectroscopy ('H-MRS) in order to explore the value of 'H-MRS in idiopathic epilepsy in children. Thirty-three children with idiopathic epilepsy (14 cases with history of febrile seizures and 19 cases without) and six normal controls experienced MRI of the skull and brain and single-voxel 'H-MRS examinations of the hippocampi-temporal lobe. The signal intensities of N-acetylaspartate (NAA), eatine+phosphocreatine (Cr), choline-containing compounds (Cho) and lactate (Lac) and the ratios of NAA/ (Cho+Cr) and Lac/Cr were compared between the patients and normal controls. MRI examination showed that only one child with epilepsy had myelin dysplasia. 'H-MRS examination showed that the ratio of NAA/ (Cho+Cr) in the epilepsy group was lower than that in the control group (0.64+/-0.07 vs 0.73+/-0.05; Pepilepsy and the control groups. 'H-MRS may provide early information on brain injury sensitively and non-invasively in children with epilepsy. It may be used for diagnosis and prognosis evaluation of epilepsy.

  11. Determination of the Jet Neutron Rate and Fusion Power using the Magnetic Proton Recoil Neutron Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Sjoestrand, Henrik

    2003-01-01

    In this thesis a new independent method has been developed to enable precise measurements of neutron yields and rates from fusion plasmas and thereby determining the fusion power and fusion energy. The new method, together with the associated diagnostics, can provide information of great importance to present and future high fusion yield experiments, such as the Joint European Torus (JET) tokamak and the International Thermonuclear Experiment Reactor (ITER). The method has been applied to data from high fusion rate experiments from the tritium campaign at JET. By using the count-rate from the Magnetic Proton Recoil (MPR) neutron spectrometer the number of neutrons in the spectrometer's line of sight has been calculated. To be able to do this, all relevant factors between the plasma and the instrument have been evaluated. The number of neutrons in the MPR line of sight has been related to the total number of produced neutrons in the plasma by using information on the neutron emission profile. The achieved results have been compared with other JET neutron diagnostic data and the agreement is shown to be very good.

  12. Proton magnetic resonance with parahydrogen induced polarization. Imaging strategies and continuous generation

    Energy Technology Data Exchange (ETDEWEB)

    Dechent, Jan Falk Frederik

    2012-12-17

    A major challenge in imaging is the detection of small amounts of molecules of interest. In the case of magnetic resonance imaging (MRI) their signals are typically concealed by the large background signal of e.g. the tissue of the body. This problem can be tackled by hyperpolarization which increases the NMR signals up to several orders of magnitude. However, this strategy is limited for {sup 1}H, the most widely used nucleus in NMR and MRI, because the enormous number of protons in the body screen the small amount of hyperpolarized ones. Here, I describe a method giving rise to high {sup 1}H MRI contrast for hyperpolarized molecules against a large background signal. The contrast is based on the J-coupling induced rephasing of the NMR signal of molecules hyperpolarized via parahydrogen induce polarization (PHIP) and it can easily be implemented in common pulse sequences. Hyperpolarization methods typically require expensive technical equipment (e.g. lasers or microwaves) and most techniques work only in batch mode, thus the limited lifetime of the hyperpolarization is limiting its applications. Therefore, the second part of my thesis deals with the simple and efficient generation of an hyperpolarization. These two achievements open up alternative opportunities to use the standard MRI nucleus {sup 1}H for e.g. metabolic imaging in the future.

  13. Proton magnetic resonance spectroscopy in children with fetal alcohol spectrum disorders

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Rita de Cassia Ferreira; Vasconcelos, Marcio Moacyr; Faleiros, Leticia Oliveira; Brito, Adriana Rocha; Werner Junior, Jairo; Herdy, Gesmar Volga Haddad [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Faculdade de Medicina], e-mail: rcgonc@hotmail.com; Cruz Junior, Luiz Celso Hygino da; Domingues, Romeu Cortes [Multi-Imagem, Rio de Janeiro, RJ (Brazil)

    2009-06-15

    To analyze the metabolic constitution of brain areas through proton magnetic resonance spectroscopy in children affected with fetal alcohol spectrum disorder compared with normal children. Method: The sample of this case-control study included eight boys with epidemiologic history of in utero exposure to alcohol (median age 13.6{+-}3.8 years) who were diagnosed with fetal alcohol spectrum disorder, and eight controls (median age 12.1{+-}3,4 years). An 8 cm{sup 3} single voxel approach was used, with echo time 30 ms, repetition time 1500 ms, and 128 acquisitions in a 1.5T scanner, and four brain areas were analyzed: anterior cingulate, left frontal lobe, left striatum, and left cerebellar hemisphere. Peaks and ratios of metabolites N-acetylaspartate, choline, creatine, and myo-inositol were measured. Results: Children with fetal alcohol spectrum disorder showed a decrease in choline/creatine ratio (p=0.020) in left striatum and an increase in myo-inositol/creatine ratio (p=0.048) in left cerebellum compared with controls. There was no statistically significant difference in all peaks and ratios from the anterior cingulate and frontal lobe between the two groups. Conclusion: This study found evidence that the left striatum and left cerebellum are affected by intrauterine exposure to alcohol. Additional studies with larger samples are necessary to expand our knowledge of the effects of fetal exposure to alcohol. (author)

  14. Localised proton magnetic resonance spectroscopy of the brain after perinatal hypoxia: a preliminary report

    International Nuclear Information System (INIS)

    Chateil, J.F.; Quesson, B.; Thiaudiere, E.; Delalande, C.; Canioni, P.; Brun, M.; Diard, F.; Sarlangue, J.; Billeaud, C.

    1999-01-01

    Objectives. Perinatal hypoxic ischaemic injury is a significant cause of neurodevelopmental impairment. The aim of this study was to evaluate localised proton magnetic resonance spectroscopy ( 1 H-MRS) after birth asphyxia. Materials and methods. Thirty newborn infants suspected of having perinatal asphyxia (Apgar score 1 H-MRS was recorded in a single voxel, localised in white matter, using a STEAM sequence. Results. Image quality was good in 25 of 30 babies. 1 H-MRS was performed in 19 of 30 subjects, with adequate quality in 16. Choline, creatine/phosphocreatine and N-acetylaspartate peaks and peak-area ratios were analysed. Lactate was detected in four infants. The N-acetylaspartate/choline ratio was lower in infants with an impaired neurological outcome, but the difference was not statistically significant. Conclusions. This study suggests that 1 H-MRS may be useful for assessing cerebral metabolism in the neonate. A raised lactate level and decreased N-acetylaspartate/choline ratio may be predictive of a poor outcome. However, in our experience this method is limited by the difficulty in performing the examination during the first hours after birth in critically ill babies, the problems related to use of a monovoxel sequence, the dispersion of the ratios and the lack of determination of the absolute concentration of the metabolites. (orig.)

  15. Characterization of urban aerosol using aerosol mass spectrometry and proton nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Cleveland, M. J.; Ziemba, L. D.; Griffin, R. J.; Dibb, J. E.; Anderson, C. H.; Lefer, B.; Rappenglück, B.

    2012-07-01

    Particulate matter was measured during August and September of 2006 in Houston as part of the Texas Air Quality Study II Radical and Aerosol Measurement Project. Aerosol size and composition were determined using an Aerodyne quadrupole aerosol mass spectrometer. Aerosol was dominated by sulfate (4.1 ± 2.6 μg m-3) and organic material (5.5 ± 4.0 μg m-3), with contributions of organic material from both primary (˜32%) and secondary (˜68%) sources. Secondary organic aerosol appears to be formed locally. In addition, 29 aerosol filter samples were analyzed using proton nuclear magnetic resonance (1H NMR) spectroscopy to determine relative concentrations of organic functional groups. Houston aerosols are less oxidized than those observed elsewhere, with smaller relative contributions of carbon-oxygen double bonds. These particles do not fit 1H NMR source apportionment fingerprints for identification of secondary, marine, and biomass burning organic aerosol, suggesting that a new fingerprint for highly urbanized and industrially influenced locations be established.

  16. The thin-foil magnetic proton recoil neutron spectrometer MPRu at JET

    International Nuclear Information System (INIS)

    Andersson Sunden, E.; Sjoestrand, H.; Conroy, S.; Ericsson, G.; Gatu Johnson, M.; Giacomelli, L.; Hellesen, C.; Hjalmarsson, A.; Ronchi, E.; Weiszflog, M.; Kaellne, J.; Gorini, G.; Tardocchi, M.; Combo, A.; Cruz, N.; Batista, A.; Pereira, R.; Fortuna, R.; Sousa, J.; Popovichev, S.

    2009-01-01

    Neutrons are produced in fusion energy experiments with both deuterium (D) and deuterium-tritium (DT) plasmas. Neutron spectroscopy is a valuable tool in the study of the underlying fuel ion populations. The magnetic proton recoil neutron spectrometer, originally installed at JET in 1996 for 14-MeV neutron measurements, has been upgraded, with the main aim of improving its signal-to-background ratio (S/B), making measurements of the 2.5-MeV neutron emission in D plasmas possible. The upgrade includes a new focal-plane detector, based on the phoswich technique and consequently less sensitive to background, and a new custom-designed digital data acquisition system based on transient recorder cards. Results from JET show that the upgraded MPRu can measure 2.5-MeV neutrons with S/B=5, an improvement by a factor of 50 compared with the original MPR. S/B of 2.8x10 4 in future DT experiments is estimated. The performance of the MPRu is exemplified with results from recent D plasma operations at JET, concerning both measurements with Ohmic, ion cyclotron resonance (ICRH) and neutral beam injection (NBI) plasma heating, as well as measurements of tritium burn-up neutrons. The upgraded instrument allows for 2.5-MeV neutron emission and deuterium ion temperature measurements in plasmas with low levels of tritium, a feature necessary for the ITER experiment.

  17. Proton magnetic resonance with parahydrogen induced polarization. Imaging strategies and continuous generation

    International Nuclear Information System (INIS)

    Dechent, Jan Falk Frederik

    2012-01-01

    A major challenge in imaging is the detection of small amounts of molecules of interest. In the case of magnetic resonance imaging (MRI) their signals are typically concealed by the large background signal of e.g. the tissue of the body. This problem can be tackled by hyperpolarization which increases the NMR signals up to several orders of magnitude. However, this strategy is limited for 1 H, the most widely used nucleus in NMR and MRI, because the enormous number of protons in the body screen the small amount of hyperpolarized ones. Here, I describe a method giving rise to high 1 H MRI contrast for hyperpolarized molecules against a large background signal. The contrast is based on the J-coupling induced rephasing of the NMR signal of molecules hyperpolarized via parahydrogen induce polarization (PHIP) and it can easily be implemented in common pulse sequences. Hyperpolarization methods typically require expensive technical equipment (e.g. lasers or microwaves) and most techniques work only in batch mode, thus the limited lifetime of the hyperpolarization is limiting its applications. Therefore, the second part of my thesis deals with the simple and efficient generation of an hyperpolarization. These two achievements open up alternative opportunities to use the standard MRI nucleus 1 H for e.g. metabolic imaging in the future.

  18. Fragile X syndrome: a pilot proton magnetic resonance spectroscopy study in premutation carriers

    LENUS (Irish Health Repository)

    Hallahan, Brian P

    2012-08-30

    AbstractPurposeThere is increasing evidence that neurodevelopmental differences in people with Fragile X syndrome (FraX) may be explained by differences in glutamatergic metabolism. Premutation carriers of FraX were originally considered to be unaffected although several recent reports demonstrate neuroanatomical, cognitive, and emotional differences from controls. However there are few studies on brain metabolism in premutation carriers of FraX.MethodsWe used proton magnetic resonance spectroscopy to compare neuronal integrity of a number of brain metabolites including N-Acetyl Aspartate, Creatine + Phosphocreatinine, Choline, myoInositol, and Glutamate containing substances (Glx) in 17 male premutation carriers of FraX and 16 male healthy control individuals.ResultsThere was no significant between-group difference in the concentration of any measured brain metabolites. However there was a differential increase in N-acetyl aspartate with aging in premutation FraX individuals compared to controls.ConclusionsThis is the first 1 H-MRS study to examine premutation FraX individuals. Although we demonstrated no difference in the concentration of any of the metabolites examined between the groups, this may be due to the large age ranges included in the two samples. The differential increase in NAA levels with aging may reflect an abnormal synaptic pruning process.

  19. Proton magnetic resonance spectroscopy: normal findings in the cerebellar hemisphere in childhood

    International Nuclear Information System (INIS)

    Costa, Maria Olivia R.; Lacerda, Maria Teresa C.; Garcia Otaduy, Maria C.; Cerri, Giovanni Guido; Costa Leite, Claudia de

    2002-01-01

    The cerebellar hemispheres (CER) are different from the supratentorial white and gray matter embryologically, in cytoarchitecture, and probably in metabolic activity. Proton magnetic resonance spectroscopy ( 1 H MRS) can provide a noninvasive biochemical analysis of this region.Objective. To study, with 1 H MRS, metabolite concentrations in CER as a function of age and compare these metabolic data with those of parietoccipital white matter (PO WM) in healthy children.Materials and methods. Using single-voxel 1 H MRS, we studied 37 volunteers (3-18 years) with normal MRI scans of the brain. 1 H MRS was performed using the PRESS technique in CER and PO WM. The NAA/Cr, Cho/Cr, NAA/H 2 O, Cr/H 2 O, and Cho/H 2 O ratios were analyzed as a function of age. Metabolic data from these regions were compared.Results. The NAA/Cr ratio tended to increase with age in CER. Mean NAA/Cr and Cho/Cr ratios were found to be lower in CER than in PO WM. Mean NAA/H 2 O, Cr/H 2 O, and Cho/H 2 O ratios in CER were higher than in the PO WM.Conclusion. Our data confirm the regional variations between CER and PO WM metabolite ratios, and demonstrate a tendency of age-dependent change of the NAA/Cr ratio in CER. The creatine concentration was significantly higher in the cerebellum than in the PO WM. (orig.)

  20. Proton magnetic spectroscopic imaging of the child's brain: the response of tumors to treatment

    International Nuclear Information System (INIS)

    Tzika, A.A.; Young Poussaint, T.; Astrakas, L.G.; Barnes, P.D.; Goumnerova, L.; Scott, R.M.; Black, P.McL.; Anthony, D.C.; Billett, A.L.; Tarbell, N.J.

    2001-01-01

    Our aim was to determine and/or predict response to treatment of brain tumors in children using proton magnetic resonance spectroscopic imaging (MRSI). We studied 24 patients aged 10 months to 24 years, using MRI and point-resolved spectroscopy (PRESS; TR 2000 TE 65 ms) with volume preselection and phase-encoding in two dimensions on a 1.5 T imager. Multiple logistic regression was used to establish independent predictors of active tumor growth. Biologically vital cell metabolites, such as N-acetyl aspartate and choline-containing compounds (Cho), were significantly different between tumor and control tissues (P<0.001). The eight brain tumors which responded to radiation or chemotherapy, exhibited lower Cho (P=0.05), higher total creatine (tCr) (P=0.02) and lower lactate and lipid (L) (P=0.04) than16 tumors which were not treated (except by surgery) or did not respond to treatment. The only significant independent predictor of active tumor growth was tCr (P<0.01). We suggest that tCr is useful in assessing response of brain tumors to treatment. (orig.)

  1. Anterior insula GABA levels correlate with emotional aspects of empathy: a proton magnetic resonance spectroscopy study.

    Directory of Open Access Journals (Sweden)

    Qianfeng Wang

    Full Text Available Empathy is a multidimensional construct referring to the capacity to understand and share the emotional and affective states of another person. Cerebral γ-aminobutyric acid (GABA-ergic levels are associated with a variety of neurological and psychiatric disorders. However, the role of the GABA system in different dimensions of empathy has not been investigated.Thirty-two right-handed healthy volunteers took part in this study. We used proton magnetic resonance spectroscopy to determine GABA concentrations in the anterior insula (AI and the anterior cingulate cortex (ACC and to examine the relationship between the GABA concentrations and the subcomponents of empathy evaluated by the Interpersonal Reactivity Index (IRI.Pearson correlation analyses (two-tailed showed that AI GABA was significantly associated with the empathy concern score (r = 0.584, p<0.05 and the personal distress score (r = 0.538, p<0.05 but not significantly associated with other empathy subscales. No significant correlation was found between ACC GABA and empathy subscores.Left AI GABA was positively correlated with the emotional aspects of empathy. These preliminary findings call into question whether AI GABA alterations might predict empathy dysfunction in major psychiatric disorders such as autism and schizophrenia, which have been described as deficits in emotional empathic abilities.

  2. Absolute quantification of carnosine in human calf muscle by proton magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Oezdemir, Mahir S; Reyngoudt, Harmen; Deene, Yves de; Sazak, Hakan S; Fieremans, Els; Delputte, Steven; D'Asseler, Yves; Derave, Wim; Lemahieu, Ignace; Achten, Eric

    2007-01-01

    Carnosine has been shown to be present in the skeletal muscle and in the brain of a variety of animals and humans. Despite the various physiological functions assigned to this metabolite, its exact role remains unclear. It has been suggested that carnosine plays a role in buffering in the intracellular physiological pH i range in skeletal muscle as a result of accepting hydrogen ions released in the development of fatigue during intensive exercise. It is thus postulated that the concentration of carnosine is an indicator for the extent of the buffering capacity. However, the determination of the concentration of this metabolite has only been performed by means of muscle biopsy, which is an invasive procedure. In this paper, we utilized proton magnetic resonance spectroscopy ( 1 H MRS) in order to perform absolute quantification of carnosine in vivo non-invasively. The method was verified by phantom experiments and in vivo measurements in the calf muscles of athletes and untrained volunteers. The measured mean concentrations in the soleus and the gastrocnemius muscles were found to be 2.81 ± 0.57/4.8 ± 1.59 mM (mean ± SD) for athletes and 2.58 ± 0.65/3.3 ± 0.32 mM for untrained volunteers, respectively. These values are in agreement with previously reported biopsy-based results. Our results suggest that 1 H MRS can provide an alternative method for non-invasively determining carnosine concentration in human calf muscle in vivo

  3. Proton magnetic resonance spectroscopy in children with fetal alcohol spectrum disorders

    International Nuclear Information System (INIS)

    Goncalves, Rita de Cassia Ferreira; Vasconcelos, Marcio Moacyr; Faleiros, Leticia Oliveira; Brito, Adriana Rocha; Werner Junior, Jairo; Herdy, Gesmar Volga Haddad

    2009-01-01

    To analyze the metabolic constitution of brain areas through proton magnetic resonance spectroscopy in children affected with fetal alcohol spectrum disorder compared with normal children. Method: The sample of this case-control study included eight boys with epidemiologic history of in utero exposure to alcohol (median age 13.6±3.8 years) who were diagnosed with fetal alcohol spectrum disorder, and eight controls (median age 12.1±3,4 years). An 8 cm 3 single voxel approach was used, with echo time 30 ms, repetition time 1500 ms, and 128 acquisitions in a 1.5T scanner, and four brain areas were analyzed: anterior cingulate, left frontal lobe, left striatum, and left cerebellar hemisphere. Peaks and ratios of metabolites N-acetylaspartate, choline, creatine, and myo-inositol were measured. Results: Children with fetal alcohol spectrum disorder showed a decrease in choline/creatine ratio (p=0.020) in left striatum and an increase in myo-inositol/creatine ratio (p=0.048) in left cerebellum compared with controls. There was no statistically significant difference in all peaks and ratios from the anterior cingulate and frontal lobe between the two groups. Conclusion: This study found evidence that the left striatum and left cerebellum are affected by intrauterine exposure to alcohol. Additional studies with larger samples are necessary to expand our knowledge of the effects of fetal exposure to alcohol. (author)

  4. Antisickling activity evaluation of 4 aromatic aldehydes using proton magnetic relaxation

    International Nuclear Information System (INIS)

    Falcon Dieguez, J.E.; Grisel del Toro Garcia; Yamirka Alonso Geli; Lores Guevara, M.A.

    2006-12-01

    The formation of a Shiff base aduct hemoglobin-aromatic aldehyde, has been reported as inhibitor of the hemoglobin S polymerization. Using the Proton Magnetic Resonance methodology, the polymerization kinetics can be studied and the delay time can be determined. Our studies in vitro show the inhibitor effect of the isovanillin, o-vanillin, m-hydroxybenzaldehyde and the p-hydroxybenzaldehyde, using molar ratio (hemoglobin S/compound) 1:1, 1:4 and 1:8. The td increment (expressed in percents) obtained for each one of the molar ratio was the following: isovanillin: 34±6% (1:1), 68±16% (1:4), ovanillin: 26±10% (1:1), 63±20% (1:4), m-hydroxybelzaldehyde: 16±4% (1:1), 44±12% (1:4) and the phydroxybenzaldehyde: 10±3% (1:1), 32±8% (1:4). In the case of 1:8, the characteristic kinetics curve was not obtained. At the used concentrations, hemolytic activity was not found on the red blood cell. These results confirm the antisickling activity of these aromatic aldehydes, for a technique different to that reported in literature that also allows the quantification of concentration effect. The same ones will facilitate the study of the therapeutic usefulness of these compounds in the sickle cell anemia treatment. (author)

  5. Search for magnetic monopoles with the MoEDAL prototype trapping detector in 8 TeV proton-proton collisions at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Acharya, B. [Theoretical Particle Physics & Cosmology Group, Physics Dept., King’s College London (United Kingdom); International Centre for Theoretical Physics, Trieste (Italy); Alexandre, J. [Theoretical Particle Physics & Cosmology Group, Physics Dept., King’s College London (United Kingdom); Bendtz, K. [Physics Department, Stockholm University, Stockholm (Sweden); Benes, P. [IEAP, Czech Technical University in Prague (Czech Republic); Collaboration: The MoEDAL collaboration; and others

    2016-08-10

    The MoEDAL experiment is designed to search for magnetic monopoles and other highly-ionising particles produced in high-energy collisions at the LHC. The largely passive MoEDAL detector, deployed at Interaction Point 8 on the LHC ring, relies on two dedicated direct detection techniques. The first technique is based on stacks of nuclear-track detectors with surface area ∼18 m{sup 2}, sensitive to particle ionisation exceeding a high threshold. These detectors are analysed offline by optical scanning microscopes. The second technique is based on the trapping of charged particles in an array of roughly 800 kg of aluminium samples. These samples are monitored offline for the presence of trapped magnetic charge at a remote superconducting magnetometer facility. We present here the results of a search for magnetic monopoles using a 160 kg prototype MoEDAL trapping detector exposed to 8 TeV proton-proton collisions at the LHC, for an integrated luminosity of 0.75 fb{sup −1}. No magnetic charge exceeding 0.5g{sub D} (where g{sub D} is the Dirac magnetic charge) is measured in any of the exposed samples, allowing limits to be placed on monopole production in the mass range 100 GeV≤m≤ 3500 GeV. Model-independent cross-section limits are presented in fiducial regions of monopole energy and direction for 1g{sub D}≤|g|≤6g{sub D}, and model-dependent cross-section limits are obtained for Drell-Yan pair production of spin-1/2 and spin-0 monopoles for 1g{sub D}≤|g|≤4g{sub D}. Under the assumption of Drell-Yan cross sections, mass limits are derived for |g|=2g{sub D} and |g|=3g{sub D} for the first time at the LHC, surpassing the results from previous collider experiments.

  6. Alteration of the magnitude of the proton magnetic moment in nuclear magnetons in connection with the changes in the atomic mass values

    Energy Technology Data Exchange (ETDEWEB)

    Mamyrin, B.A.; Aruev, N.N.; Alekseenko, S.A.

    1983-06-01

    In connection with the revision of the table values of the atomic masses and the forthcoming coordination of the values of the fundamental physical constants, the result of measurement of the proton magnetic moment in nuclear Magnetons obtained in 1971 is re-examined by taking into account recent data. With the atomic masses recognized in 1982 the proton magnetic moment expressed in nuclear magnetons without a correction for diamagnetic screening of the proton in a water molecule is found to be ..mu..sub(p)'/..mu..sub(n)=2.7927729+-0.0000012 (4.3x10/sup -5/%).

  7. Quantitative imaging of magnetic nanoparticles by magneto-relaxometric tomography for biomedical applications

    International Nuclear Information System (INIS)

    Liebl, Maik

    2016-01-01

    Current biomedical research focuses on the development of novel biomedical applications based on magnetic nanoparticles (MNPs), e.g. for local cancer treatment. These therapy approaches employ MNPs as remotely controlled drug carriers or local heat generators. Since location and quantity of MNPs determine drug enrichment and heat production, quantitative knowledge of the MNP distribution inside a body is essential for the development and success of these therapies. Magnetorelaxometry (MRX) is capable to provide such quantitative information based on the specific response of the MNPs after switching-off an applied magnetic field. Applying a uniform (homogeneous) magnetic field to a MNP distribution and measuring the MNP response by multiple sensors at different locations allows for spatially resolved MNP quantification. However, to reconstruct the MNP distribution from this spatially resolved MRX data, an ill posed inverse problem has to be solved. So far, the solution of this problem was stabilized incorporating a-priori knowledge in the forward model, e.g. by setting priors on the vertical position of the distribution using a 2D reconstruction grid or setting priors on the number and geometry of the MNP sources inside the body. MRX tomography represents a novel approach for quantitative 3D imaging of MNPs, where the inverse solution is stabilized by a series of MRX measurements. In MRX tomography, only parts of the MNP distribution are sequentially magnetized by the use of inhomogeneous magnetic fields. Each magnetizing is followed by detection of the response of the corresponding part of the distribution by multiple sensors. The 3D reconstruction of the MNP distribution is then accomplished by a common evaluation of the distinct MRX measurement series. In this thesis the first experimental setup for MRX tomography was developed for quantitative 3D imaging of biomedical MNP distributions. It is based on a multi-channel magnetizing unit which has been engineered to

  8. An optimized framework for quantitative magnetization transfer imaging of the cervical spinal cord in vivo.

    Science.gov (United States)

    Battiston, Marco; Grussu, Francesco; Ianus, Andrada; Schneider, Torben; Prados, Ferran; Fairney, James; Ourselin, Sebastien; Alexander, Daniel C; Cercignani, Mara; Gandini Wheeler-Kingshott, Claudia A M; Samson, Rebecca S

    2018-05-01

    To develop a framework to fully characterize quantitative magnetization transfer indices in the human cervical cord in vivo within a clinically feasible time. A dedicated spinal cord imaging protocol for quantitative magnetization transfer was developed using a reduced field-of-view approach with echo planar imaging (EPI) readout. Sequence parameters were optimized based in the Cramer-Rao-lower bound. Quantitative model parameters (i.e., bound pool fraction, free and bound pool transverse relaxation times [ T2F, T2B], and forward exchange rate [k FB ]) were estimated implementing a numerical model capable of dealing with the novelties of the sequence adopted. The framework was tested on five healthy subjects. Cramer-Rao-lower bound minimization produces optimal sampling schemes without requiring the establishment of a steady-state MT effect. The proposed framework allows quantitative voxel-wise estimation of model parameters at the resolution typically used for spinal cord imaging (i.e. 0.75 × 0.75 × 5 mm 3 ), with a protocol duration of ∼35 min. Quantitative magnetization transfer parametric maps agree with literature values. Whole-cord mean values are: bound pool fraction = 0.11(±0.01), T2F = 46.5(±1.6) ms, T2B = 11.0(±0.2) µs, and k FB  = 1.95(±0.06) Hz. Protocol optimization has a beneficial effect on reproducibility, especially for T2B and k FB . The framework developed enables robust characterization of spinal cord microstructure in vivo using qMT. Magn Reson Med 79:2576-2588, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc

  9. Proton nuclear magnetic resonance study of water + t-butyl alcohol ...

    African Journals Online (AJOL)

    The water proton resonance initially shifts to higher frequencies (low fields) as the cosolvent is added to water, and the shift to higher frequency is strongly temperature dependent, the effect being greatly enhanced at lower temperatures. As the proportion of cosolvent increases the hydroxyl proton signals in the water + ...

  10. A proton nuclear magnetic resonance-based metabonomics study of metabolic profiling in immunoglobulin a nephropathy

    International Nuclear Information System (INIS)

    Sui, Weiguo; Che, Wenti; Guimai, Zuo; Chen, Jiejing; Li, Liping; Li, Wuxian; Dai, Yong

    2012-01-01

    Objectives: Immunoglobulin A nephropathy is the most common cause of chronic renal failure among primary glomerulonephritis patients. The ability to diagnose immunoglobulin A nephropathy remains poor. However, renal biopsy is an inconvenient, invasive, and painful examination, and no reliable biomarkers have been developed for use in routine patient evaluations. The aims of the present study were to identify immunoglobulin A nephropathy patients, to identify useful biomarkers of immunoglobulin A nephropathy and to establish a human immunoglobulin A nephropathy metabolic profile. Methods: Serum samples were collected from immunoglobulin A nephropathy patients who were not using immunosuppressants. A pilot study was undertaken to determine disease-specific metabolite biomarker profiles in three groups: healthy controls (N = 23), low-risk patients in whom immunoglobulin A nephropathy was confirmed as grades I-II by renal biopsy (N = 23), and high-risk patients with nephropathies of grades IV-V (N = 12). Serum samples were analyzed using proton nuclear magnetic resonance spectroscopy and by applying multivariate pattern recognition analysis for disease classification. Results: Compared with the healthy controls, both the low-risk and high-risk patients had higher levels of phenylalanine, myo-inositol, lactate, L6 lipids ( CH-CH 2 -CH = O), L5 lipids (-CH 2 -C = O), and L3 lipids (-CH 2 -CH 2 -C = O) as well as lower levels of β-glucose, α-glucose, valine, tyrosine, phosphocholine, lysine, isoleucine, glycerolphosphocholine, glycine, glutamine, glutamate, alanine, acetate, 3-hydroxybutyrate, and 1-methylhistidine. Conclusions: These metabolites investigated in this study may serve as potential biomarkers of immunoglobulin A nephropathy. Point scoring of pattern recognition analysis was able to distinguish immunoglobulin A nephropathy patients from healthy controls. However, there were no obvious differences between the low-risk and high-risk groups in our research

  11. Localised proton magnetic resonance spectroscopy of the brain after perinatal hypoxia: a preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Chateil, J.F. [Service de Radiologie A, Hopital Pellegrin, Bordeaux (France)]|[Unite de Radiopediatrie, Hopital Pellegrin, Bordeaux (France); Quesson, B.; Thiaudiere, E.; Delalande, C.; Canioni, P. [Resonance Magnetique des Systemes Biologiques, CNRS, Bordeaux (France); Brun, M.; Diard, F. [Service de Radiologie A, Hopital Pellegrin, Bordeaux (France); Sarlangue, J.; Billeaud, C. [Service de Neonatalogie, Hopital Pellegrin, Bordeaux (France)

    1999-03-01

    Objectives. Perinatal hypoxic ischaemic injury is a significant cause of neurodevelopmental impairment. The aim of this study was to evaluate localised proton magnetic resonance spectroscopy ({sup 1}H-MRS) after birth asphyxia. Materials and methods. Thirty newborn infants suspected of having perinatal asphyxia (Apgar score < 3) were studied. The mean gestational age was 37 weeks, mean age at the MR examination was 18 days and mean weight was 2.9 kg. A 1.5-T unit was used for imaging and spectroscopy. None of the babies had mechanically assisted ventilation. No sedation was used. Axial T1-weighted and T2-weighted images were obtained. {sup 1}H-MRS was recorded in a single voxel, localised in white matter, using a STEAM sequence. Results. Image quality was good in 25 of 30 babies. {sup 1}H-MRS was performed in 19 of 30 subjects, with adequate quality in 16. Choline, creatine/phosphocreatine and N-acetylaspartate peaks and peak-area ratios were analysed. Lactate was detected in four infants. The N-acetylaspartate/choline ratio was lower in infants with an impaired neurological outcome, but the difference was not statistically significant. Conclusions. This study suggests that {sup 1}H-MRS may be useful for assessing cerebral metabolism in the neonate. A raised lactate level and decreased N-acetylaspartate/choline ratio may be predictive of a poor outcome. However, in our experience this method is limited by the difficulty in performing the examination during the first hours after birth in critically ill babies, the problems related to use of a monovoxel sequence, the dispersion of the ratios and the lack of determination of the absolute concentration of the metabolites. (orig.) With 3 figs., 2 tabs., 20 refs.

  12. Proton magnetic resonance spectroscopy and single photon emission CT in patients with olivopontocerebellar atrophy

    International Nuclear Information System (INIS)

    Ikuta, Naomi

    1998-01-01

    Using proton magnetic resonance spectroscopy ( 1 H-MRS) and single photon emission CT (SPECT), the cerebellum of patients with olivopontocerebellar atrophy (OPCA) and of age-matched control subjects was studied. A spectrum was collected from a 27 cm 3 (3 x 3 x 3 cm) voxel in the cerebellum containing white and gray matters in order to measure the distribution and relative signal intensities of N-acetylaspartate (NAA), creatine (Cre) and choline (Cho). In the cerebellum of the patients with OPCA, mean NAA/Cre ratios for OPCA patients were significantly decreased compared with normal control subjects (OPCA, 1.01±0.247; controls, 1.526±0.144: p<0.001). Mean NAA/Cho ratios for OPCA patients were slightly decreased (OPCA, 1.285±0.228; controls 1.702±0.469: p<0.06). Cho/Cre ratios valued in the cerebellum of OPCA patients were not significantly different from those in normal controls (OPCA, 0.793±0.186; controls, 0.946±0.219). The ratio of RI count in the cerebellum to that in the occipital lobe was significantly decreased in OPCA patients (OPCA, 0.947±0.096; controls, 1.06±0.063: p<0.01). Cerebellar signs were assessed including gait ataxia, limb ataxia, dysarthria, saccadic pursuit, and nystagmus separately or in combination. In patients with more severe ataxic gait and dysarthria, MRS revealed slightly lowered NAA/Cre ratio. There was no significant correlation between NAA/Cre ratio and severity of other clinical signs. The MRS and SPECT findings give a confirmative evidence of hypofunction in cerebellum of patients with OPCA. (author)

  13. Proton magnetic resonance spectroscopy in patients with early stages of amyotrophic lateral sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Sivak, Stefan [Comenius University, Clinic of Neurology, Jessenius Faculty of Medicine, Martin (Slovakia); Jessenius Medical Faculty, Clinic of Neurology, Martin (Slovakia); Bittsansky, Michal; Dobrota, Dusan [Comenius University, Department of Medical Biochemistry, Jessenius Faculty of Medicine, Martin (Slovakia); Kurca, Egon; Turcanova-Koprusakova, Monika; Grofik, Milan; Nosal, Vladimir [Comenius University, Clinic of Neurology, Jessenius Faculty of Medicine, Martin (Slovakia); Polacek, Hubert [Comenius University, Clinic of Radiodiagnostics, Jessenius Faculty of Medicine, Martin (Slovakia)

    2010-12-15

    Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder primarily affecting upper and lower motor neurons. Due to relative fast progression of the disease, early diagnosis is essential. Proton magnetic resonance spectroscopy ({sup 1}H-MRS) is used for objectivization of upper motor neuron (UMN) lesions. The aim of this study was to assess the use of {sup 1}H-MRS in the early stages of ALS. Eleven patients with clinically definite (n = 2), probable (n = 7), and probable laboratory-supported (n = 2) diagnosis of ALS with disease duration of less than 14 months were studied. Control group consists of 11 sex- and age-matched healthy subjects. All subjects underwent assessment of functional disability using revised ALS Functional Rating Scale (ALSFRS-R) and single-voxel {sup 1}H-MRS examination of both precentral gyri, pons, medulla oblongata, and occipital lobe. Spectra were evaluated with LCModel software. The mean disease duration was 6.5 {+-} 3.5 months. The median ALSFRS-R was 42. Significant decrease between patient and control groups was found in the NAA/Cre ratio in the left and right precentral gyri (p = 0.008, p = 0.040). Other metabolite ratios in other areas did not show significant differences. Total ALSFRS-R score weakly positively correlated with NAA/Cre ratio in the left precentral gyrus (p = 0.047). {sup 1}H-MRS is sensitive to detect metabolic changes caused by neurodegeneration processes during ALS and can be used for detection of UMN dysfunction. These MRS changes in the early stages of ALS are most prominent in motor cortex. (orig.)

  14. Proton magnetic resonance spectroscopy in patients with early stages of amyotrophic lateral sclerosis

    International Nuclear Information System (INIS)

    Sivak, Stefan; Bittsansky, Michal; Dobrota, Dusan; Kurca, Egon; Turcanova-Koprusakova, Monika; Grofik, Milan; Nosal, Vladimir; Polacek, Hubert

    2010-01-01

    Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder primarily affecting upper and lower motor neurons. Due to relative fast progression of the disease, early diagnosis is essential. Proton magnetic resonance spectroscopy ( 1 H-MRS) is used for objectivization of upper motor neuron (UMN) lesions. The aim of this study was to assess the use of 1 H-MRS in the early stages of ALS. Eleven patients with clinically definite (n = 2), probable (n = 7), and probable laboratory-supported (n = 2) diagnosis of ALS with disease duration of less than 14 months were studied. Control group consists of 11 sex- and age-matched healthy subjects. All subjects underwent assessment of functional disability using revised ALS Functional Rating Scale (ALSFRS-R) and single-voxel 1 H-MRS examination of both precentral gyri, pons, medulla oblongata, and occipital lobe. Spectra were evaluated with LCModel software. The mean disease duration was 6.5 ± 3.5 months. The median ALSFRS-R was 42. Significant decrease between patient and control groups was found in the NAA/Cre ratio in the left and right precentral gyri (p = 0.008, p = 0.040). Other metabolite ratios in other areas did not show significant differences. Total ALSFRS-R score weakly positively correlated with NAA/Cre ratio in the left precentral gyrus (p = 0.047). 1 H-MRS is sensitive to detect metabolic changes caused by neurodegeneration processes during ALS and can be used for detection of UMN dysfunction. These MRS changes in the early stages of ALS are most prominent in motor cortex. (orig.)

  15. Phosphorus-31 and proton magnetic resonance spectroscopy of the medial temporal region in schizophrenic patients

    International Nuclear Information System (INIS)

    Yamada, Koichiro

    1996-01-01

    Phosphorus-31 magnetic resonance spectroscopy (MRS) was performed 22 schizophrenic patients and in 22 healthy volunteers. Psychiatric symptoms were estimated on the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Negative Symptoms (SANS) and the Scale for the Assessment of Positive Symptoms (SAPS). The spectra were quantified for phosphomonoesters (PME), inorganic orthophosphate (Pi), phosphodiesters (PDE), phosphocreatine (Pcr) and the γ, α and β phosphates of 5'-adenosine triphosphate (ATP) by peak area measurements. Proton MRS was performed in 15 schizophrenic patients and in 15 healthy volunteers. Psychiatric symptoms were estimated on the Positive and Negative Syndrome Scale (PANSS) and the SANS. The spectra of N-acetylates (NA), choline-containing compounds (Cho) and creatine-phosphocreatine (Cr) were quantified. The patients showed an increase in the % PDE and a decrease in the % β-ATP in the left temporal region. Positive correlations were found between the % PDE and the subscale of positive symptoms on the BPRS and the total score of SAPS. The % β-ATP correlated negatively with the total score on SAPS. The NA/Cho and NA/Cr ratios were significantly lower in patients than in normal subjects. The Cho/Cr ratio was higher in the patient group. The age at onset of illness correlated positively with the NA/Cho and NA/Cr ratios. No significant correlations were observed between the ratios of metabolites and the scores of PANSS and SANS. There were no significant associations between the mole percentages and the ratios and the daily doses of neuroleptics and anticholinergics. These findings suggest that the disturbed membrane phospholipid and high-energy phosphate metabolism in the left medial temporal region may be one of the pathophysiologies of neuroleptic-resistant positive symptoms in schizophrenia and these abnormalities may be related to neuronal loss and/or neuronal dysfunction in this region. (H.O.)

  16. A proton nuclear magnetic resonance-based metabonomics study of metabolic profiling in immunoglobulin a nephropathy

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Weiguo; Che, Wenti; Guimai, Zuo; Chen, Jiejing [181st Hospital Guangxi, Central Laboratory, Laboratory of Metabolic Diseases Research, Guangxi Province (China); Li, Liping [Guangxi Normal University, The Life Science College, Guangxi Province (China); Li, Wuxian [Key Laboratory of Laboratory Medical Diagnostics of Education Ministry, Chongqiong Medical University, Chongqing (China); Dai, Yong [Clinical Medical Research Center, the Second Clinical Medical College of Jinan University (Shenzhen People' s Hospital), Shenzhen, Guangdong Province (China)

    2012-07-01

    Objectives: Immunoglobulin A nephropathy is the most common cause of chronic renal failure among primary glomerulonephritis patients. The ability to diagnose immunoglobulin A nephropathy remains poor. However, renal biopsy is an inconvenient, invasive, and painful examination, and no reliable biomarkers have been developed for use in routine patient evaluations. The aims of the present study were to identify immunoglobulin A nephropathy patients, to identify useful biomarkers of immunoglobulin A nephropathy and to establish a human immunoglobulin A nephropathy metabolic profile. Methods: Serum samples were collected from immunoglobulin A nephropathy patients who were not using immunosuppressants. A pilot study was undertaken to determine disease-specific metabolite biomarker profiles in three groups: healthy controls (N = 23), low-risk patients in whom immunoglobulin A nephropathy was confirmed as grades I-II by renal biopsy (N = 23), and high-risk patients with nephropathies of grades IV-V (N = 12). Serum samples were analyzed using proton nuclear magnetic resonance spectroscopy and by applying multivariate pattern recognition analysis for disease classification. Results: Compared with the healthy controls, both the low-risk and high-risk patients had higher levels of phenylalanine, myo-inositol, lactate, L6 lipids ( CH-CH{sub 2}-CH = O), L5 lipids (-CH{sub 2}-C = O), and L3 lipids (-CH{sub 2}-CH{sub 2}-C = O) as well as lower levels of {beta}-glucose, {alpha}-glucose, valine, tyrosine, phosphocholine, lysine, isoleucine, glycerolphosphocholine, glycine, glutamine, glutamate, alanine, acetate, 3-hydroxybutyrate, and 1-methylhistidine. Conclusions: These metabolites investigated in this study may serve as potential biomarkers of immunoglobulin A nephropathy. Point scoring of pattern recognition analysis was able to distinguish immunoglobulin A nephropathy patients from healthy controls. However, there were no obvious differences between the low-risk and high

  17. Frontal lobe proton magnetic-resonance spectroscopy in Graves' disease: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Khushu, S.; Gupta, A.; Sankar, R.; Tripathi, R.P.; Bhatara, V.S. [NMR Research Center and Department of Endocrinology, Institute of Nuclear Medicine and Allied Sciences, Lucknow Marg, Delhi 110054 (India)

    1998-08-01

    Patients with hyperthyroidism may show impaired performance on several neuropsychological tests that require complex visual discrimination, conceptualization, mental flexibility or organization. These neurocognitive impairments appear to be consistent with prefrontal lobe dysfunction. This pilot study was undertaken to characterize the metabolite profile in the right prefrontal cortex in six patients with untreated Graves' disease by using in vivo proton magnetic-resonance spectroscopy ({sup 1}H-MRS). For comparison, {sup 1}H-MRS was also carried out inseven healthy controls. The choline/creatine (Cho/Cr) and N-acetyl aspartate/creatine (Naa/Cr) ratios were determined. Cho/Cr ratios of the hyperthyroid patients were significantly lower than that of controls (means{+-}SD=0.61{+-}0.09 vs. 0.90{+-}0.18, p=.05). The two groups did not differ in their Naa/Cr ratios. Follow-up data after antithyroid treatment were available in three patients: Cho/Cr ratios were higher after treatment (euthyroidism) than before treatment (1.06 vs. 0.55; 0.82 vs. 0.54; 1.15 vs. 0.76). Tentatively, these preliminary data are most consistent with reversible reductions in the concentrations of choline-containing compounds (especially glycerophosphocholine and phosphocholine) in the prefrontal area during hyperthyroidism. However, these findings await confirmation by a definitive study with a larger sample size. A possible explanation of the findings is an altered brain cholinergic-adrenergic balance in hyperthyroidism. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  18. The quantitative analysis of data for magnetization of ferromagnet. Extended thermodynamic approach

    International Nuclear Information System (INIS)

    Bodryakov, V.Yu.; Bashkatov, A.N.

    2005-01-01

    A quantitative analysis of M(H,T) data on magnetization of a gadolinium single crystal in the vicinity of Curie point is accomplished within the frameworks of extended thermodynamic approach. It is established that actually observed behavior of temperature dependences of thermodynamic coefficients for gadolinium even near Curie point is sharply different from that in Landau theory. A discrepancy revealed leads to conclusion that traditional concepts should be revised. The solution of extended equation of a ferromagnet magnetic state is found and criteria of its stability are shown [ru

  19. Cerebrospinal fluid metabolic profiles in multiple sclerosis and degenerative dementias obtained by high resolution proton magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Vion-Dury, J.; Confort-Gouny, S.; Maillet, S.; Cozzone, P.J.; Nicoli, F.; Gastaut, J.L.

    1996-01-01

    We have analyzed the cerebrospinal fluid (CSF) of 19 patients with multiple sclerosis (MS), 12 patients with degenerative dementia and 17 control patients using in vitro high resolution proton magnetic resonance spectroscopy (MRS) at 400 MHz. The CSF metabolic profile is slightly modified in MS patients (increased lactate and fructose concentrations, decreased creatinine and phenylalanine concentrations) and is not correlated with the intensity of the intrathecal inflammation. Proton MRS of CSF does not differentiate relapsing-remitting MS and primary progressive MS. We have not detected any specific abnormal resonance in native or lyophilized CSF. The CSF metabolic profile of demented patients is much more altered (increased concentration of lactate, pyruvate, alanine, lysine, valine, leucine-isoleucine, tyrosine, glutamine) and is in agreement with a brain oxidative metabolism impairment as already described in Alzheimer's disease. Unassigned abnormal but non specific or constant resonances have been detected on MR spectra of demented patients. CSF inositol concentration is also increased in the CSF of patients with Alzheimer's disease. In vitro high resolution proton MRS of the CSF constitutes a new and original way to explore CSF for the differential and/or early diagnosis of dementias, as a complement to in vivo proton cerebral MRS. (authors). 22 refs., 4 figs., 2 tabs

  20. Cerebrospinal fluid metabolic profiles in multiple sclerosis and degenerative dementias obtained by high resolution proton magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Vion-Dury, J.; Confort-Gouny, S.; Maillet, S.; Cozzone, P.J. [Centre Hospitalier Universitaire de la Timone, 13 - Marseille (France); Nicoli, F. [Centre Hospitalier Universitaire de la Timone, 13 - Marseille (France)]|[Hopital Sainte-Marguerite, 13 - Marseille (France); Gastaut, J.L. [Hopital Sainte-Marguerite, 13 - Marseille (France)

    1996-07-01

    We have analyzed the cerebrospinal fluid (CSF) of 19 patients with multiple sclerosis (MS), 12 patients with degenerative dementia and 17 control patients using in vitro high resolution proton magnetic resonance spectroscopy (MRS) at 400 MHz. The CSF metabolic profile is slightly modified in MS patients (increased lactate and fructose concentrations, decreased creatinine and phenylalanine concentrations) and is not correlated with the intensity of the intrathecal inflammation. Proton MRS of CSF does not differentiate relapsing-remitting MS and primary progressive MS. We have not detected any specific abnormal resonance in native or lyophilized CSF. The CSF metabolic profile of demented patients is much more altered (increased concentration of lactate, pyruvate, alanine, lysine, valine, leucine-isoleucine, tyrosine, glutamine) and is in agreement with a brain oxidative metabolism impairment as already described in Alzheimer`s disease. Unassigned abnormal but non specific or constant resonances have been detected on MR spectra of demented patients. CSF inositol concentration is also increased in the CSF of patients with Alzheimer`s disease. In vitro high resolution proton MRS of the CSF constitutes a new and original way to explore CSF for the differential and/or early diagnosis of dementias, as a complement to in vivo proton cerebral MRS. (authors). 22 refs., 4 figs., 2 tabs.

  1. Quantitative chemical exchange saturation transfer (qCEST) MRI--RF spillover effect-corrected omega plot for simultaneous determination of labile proton fraction ratio and exchange rate.

    Science.gov (United States)

    Sun, Phillip Zhe; Wang, Yu; Dai, ZhuoZhi; Xiao, Gang; Wu, Renhua

    2014-01-01

    Chemical exchange saturation transfer (CEST) MRI is sensitive to dilute proteins and peptides as well as microenvironmental properties. However, the complexity of the CEST MRI effect, which varies with the labile proton content, exchange rate and experimental conditions, underscores the need for developing quantitative CEST (qCEST) analysis. Towards this goal, it has been shown that omega plot is capable of quantifying paramagnetic CEST MRI. However, the use of the omega plot is somewhat limited for diamagnetic CEST (DIACEST) MRI because it is more susceptible to direct radio frequency (RF) saturation (spillover) owing to the relatively small chemical shift. Recently, it has been found that, for dilute DIACEST agents that undergo slow to intermediate chemical exchange, the spillover effect varies little with the labile proton ratio and exchange rate. Therefore, we postulated that the omega plot analysis can be improved if RF spillover effect could be estimated and taken into account. Specifically, simulation showed that both labile proton ratio and exchange rate derived using the spillover effect-corrected omega plot were in good agreement with simulated values. In addition, the modified omega plot was confirmed experimentally, and we showed that the derived labile proton ratio increased linearly with creatine concentration (p plot for quantitative analysis of DIACEST MRI. Copyright © 2014 John Wiley & Sons, Ltd.

  2. [Quantitative magnetic resonance imaging of brain iron deposition: comparison between quantitative susceptibility mapping and transverse relaxation rate (R2*) mapping].

    Science.gov (United States)

    Guan, Ji-Jing; Feng, Yan-Qiu

    2018-03-20

    To evaluate the accuracy and sensitivity of quantitative susceptibility mapping (QSM) and transverse relaxation rate (R2*) mapping in the measurement of brain iron deposition. Super paramagnetic iron oxide (SPIO) phantoms and mouse models of Parkinson's disease (PD) related to iron deposition in the substantia nigra (SN) underwent 7.0 T magnetic resonance (MR) scans (Bruker, 70/16) with a multi-echo 3D gradient echo sequence, and the acquired data were processed to obtain QSM and R2*. Linear regression analysis was performed for susceptibility and R2* in the SPIO phantoms containing 5 SPIO concentrations (30, 15, 7.5, 3.75 and 1.875 µg/mL) to evaluate the accuracy of QSM and R2* in quantitative iron analysis. The sensitivities of QSM and R2* mapping in quantitative detection of brain iron deposition were assessed using mouse models of PD induced by 1-methyl-4-phenyl-1,2,3,6-tetrahy-dropyridine (MPTP) in comparison with the control mice. In SPIO phantoms, QSM provided a higher accuracy than R2* mapping and their goodness-of-fit coefficients (R 2 ) were 0.98 and 0.89, respectively. In the mouse models of PD and control mice, the susceptibility of the SN was significantly higher in the PD models (5.19∓1.58 vs 2.98∓0.88, n=5; Pbrain iron deposition than R2*, and the susceptibility derived by QSM can be a potentially useful biomarker for studying PD.

  3. MO-G-18C-07: Improving T2 Determination and Quantification of Lipid Methylene Protons in Proton Magnetic Resonance Spectroscopy at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Breitkreutz, D. [of Oncology, University of Alberta, Edmonton, AB (Canada); Fallone, B. G.; Yahya, A. [of Oncology, University of Alberta, Edmonton, AB (Canada); Department of Medical Physics, Cross Cancer Institute, Edmonton, AB (Canada)

    2014-06-15

    Purpose: To improve proton magnetic resonance spectroscopy (MRS) transverse relaxation (T{sub 2}) determination and quantification of lipid methylene chain (1.3 ppm) protons by rewinding their J-coupling evolution. Methods: MRS experiments were performed on four lipid phantoms, namely, almond, corn, sunflower and oleic acid, using a 3 T Philips MRI scanner with a transmit/receive birdcage head coil. Two PRESS (Point RESolved Spectroscopy) pulse sequences were used. The first PRESS sequence employed standard bandwidth (BW) (∼550 Hz) RF (radiofrequency) refocussing pulses, while the second used refocussing pulses of narrow BW (∼50 Hz) designed to rewind J-coupling evolution of the methylene protons in the voxel of interest. Signal was acquired with each sequence from a 5×5×5 mm{sup 3} voxel, with a repetition time (TR) of 3000 ms, and with echo times (TE) of 100 to 200 ms in steps of 20 ms. 2048 sample points were measured with a 2000 Hz sampling bandwidth. Additionally, 30 mm outer volume suppression slabs were used to suppress signal outside the voxel of interest. The frequency of the RF pulses was set to that of the methylene resonance. Methylene peak areas were calculated and fitted in MATLAB to a monexponentially decaying function of the form M{sub 0}exp(-TE/T{sub 2}), where M{sub 0} is the extrapolated area when TE = 0 ms and yields a measure of concentration. Results: The determined values of M{sub 0} and T{sub 2} increased for all fatty acids when using the PRESS sequence with narrow BW refocussing pulses. M{sub 0} and T{sub 2} values increased by an average amount (over all the phantoms) of 31% and 14%, respectively. Conclusion: This investigation has demonstrated that J-coupling interactions of lipid methylene protons causes non-negligible signal losses which, if not accounted for, Result in underestimations of their levels and T{sub 2} values when performing MRS measurements. Funded by the Natural Sciences and Engineering Research Council of Canada

  4. Study of the magnetic characteristics of ferrites with a view to their application in a proton synchrotron

    International Nuclear Information System (INIS)

    Nguyen, K.C.

    1966-10-01

    In this report magnetic properties of some Ni Zn ferrites available in France are investigated for the purpose of their use in accelerating cavities of proton synchrotron. An attempt is made to measure permeability and quality factor of ferrite versus various physical parameters such as frequency F, the induction B, the magnetic bias field Hp and the temperature, the investigation ranges being: F ≤ 40 Mc/s; B ≤ 10 -2 Tesla; Hp ≤ 5000 AT/m; T ≤ 100 C. The measurements were carried out with the one hand, conventional impedance bridge (Q-meter, RX-meter) and on the other hand, with resonating method using an inductive ferrite loaded cavity in parallel with an external capacity. The latter method is of particular interest for the measurements in function of induction and magnetic bias field. (author) [fr

  5. Learning geosciences from science fictions movies: A quantitative analysis of Pando-magnetism in Avatar.

    Science.gov (United States)

    Martin-Hernandez, F.; Negredo, A. M.; Salguero, J. M.

    2015-12-01

    Many storylines presenting a geoscientific background are portrayed in science fiction movies. However, this background is often discussed only in qualitative terms in outreach books and forums. Here we report a mentoring experience of an end of degree project carried out in the fourth year of the degree in Physics in the Complutense University of Madrid (Spain). The supervisors intended to take advantage of the students' passion for science fiction movies to foster learning by assessing a robust, quantitative and critical analysis of the main geoscientific phenomena appearing in Avatar movie by James Cameron (2009). The student was supposed to consult abundant scientific literature. Much interest was paid to analyze the conditions for the levitation of Hallelujah floating mountains in Pandora, the imaginary satellite where the movie action takes place. Pandora was assumed to be an Earth-like astronomical object where the same physical laws as in the Earth could be applied. Hallelujah Mountains are made of unobtanium, an electrical superconductor at room-temperature and therefore diamagnetic material and they are assumed to be located over a magnetic field pole. The numerical values of the magnetic susceptibility and the required field to make the material levitate at the Pandora's gravity conditions were estimated. For this purpose, the magnetic susceptibility of the superconductor with the highest critical temperature existing today on Earth, the cuprate YBa2Cu3O7 was estimated. Results were compared with the magnetic susceptibility of two diamagnetic and abundant materials in the Earth's crust, namely quartz and calcite, and with the water susceptibility. The magnetic field required to levitate cuprates was almost 9 T, about six orders of magnitude higher than the Earth's magnetic field. On the basis of the quantitative analysis of magnetic and gravity field in Pandora, the student provided a list of suggestions to improve the scientific basis for futures

  6. Duchenne muscular dystrophy carriers. Proton spin-lattice relaxation times of skeletal muscles on magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, K.; Nakano, I. (Shimoshizu National Hospital, Chiba (Japan). Dept. of Neurology); Fukuda, N.; Ikehira, H.; Tateno, Y. (National Inst. of Radiological Sciences, Chiba (Japan). Div. of Clinical Research); Aoki, Y. (National Inst. of Radiological Sciences, Chiba (Japan))

    1989-11-01

    By means of magnetic resonance imaging (MRI), the proton spin-lattice relaxation times (T1 values) of the skeletal muscles were measured in Duchenne muscular dystrophy (DMD) carriers and normal controls. The bound water fraction (BWF) was calculated from the T1 values obtained, according to the fast proton diffusion model. In the DMD carriers, T1 values of the gluteus maximus and quadriceps femoris muscles were significantly higher, and BWFs of these muscles were significantly lower than in normal control. Degenerative muscular changes accompanied by interstitial edema were presumed responsible for this abnormality. No correlation was observed between the muscle T1 and serum creatine kinase values. The present study showed that MRI could be a useful method for studying the dynamic state of water in both normal and pathological skeletal muscles. Its possible utility for DMD carrier detection was discussed briefly. (orig.).

  7. Model for bremsstrahlung emission accompanying interactions between protons and nuclei from low energies up to intermediate energies: Role of magnetic emission

    Science.gov (United States)

    Maydanyuk, Sergei P.

    2012-07-01

    A model of the bremsstrahlung emission which accompanies proton decay and collisions of protons off nuclei in the low- to intermediate-energy region has been developed. This model includes spin formalism, a potential approach for describing the interaction between protons and nuclei, and an emission that includes a component of the magnetic emission (defined on the basis of the Pauli equation). For the problem of bremsstrahlung during proton decay the role of magnetic emission is studied by using such a model. For the 146Tm nucleus the following has been studied: (1) How much does the magnetic emission change the full bremsstrahlung spectrum? (2) At which angle is the magnetic emission the most intensive relative to the electric emission? (3) Is there some spatial region where the magnetic emission increases strongly relative to the electric emission? (4) How intensive is the magnetic emission in the tunneling region? (5) Which is the maximal probability? Which value does it equal to at the zero-energy limit of the emitted photons? It is demonstrated that the model is able to describe well enough experimental data of bremsstrahlung emission which accompanies collisions of protons off 9C, 64Cu, and 107Ag nuclei at an incident energy of Tlab=72 MeV (at a photon energy up to 60 MeV) and off 9Be, 12C, and 208Pb nuclei at an incident energy of Tlab=140 MeV (at a photon energy up to 120 MeV).

  8. 3D quantitative interpretation of archaeo-magnetic data: Adaptation of aero-magnetic interpretation techniques for archaeological purposes

    Science.gov (United States)

    Cheyney, S.; Hill, I. A.; Linford, N.; Fishwick, S.; Leech, C.

    2011-12-01

    High-resolution total-field magnetic data can be collected rapidly and relatively cheaply over large archaeological sites due to recent advances in data collection. However, interpretation of these datasets still generally comprises a sequence of data correction and filtering operations prior to a 2D visual interpretation based on pattern recognition. In contrast, current developments in aero-magnetic interpretation have led to several tools for identifying location, shape and depth information of anomalous sources. These methods often fail when directly applied to archaeo-magnetic data, due to the particular noise content typical in very near-surface surveys. Here techniques are explored that allow these aero-magnetic interpretation tools to be applied to archaeological problems, without the need for extensive, often biased user input. It is shown that full 3D quantitative interpretation of the subsurface is possible from just the magnetic data alone. Inversion of magnetic data is increasingly being applied to aero-magnetic surveys to produce 3D models of the subsurface magnetisation. Typically, an objective function is minimised in order to create a smooth distribution of magnetisation away from a reference model (or halfspace if no a-priori information is available). Often, although a good fit to the observed values may be obtained, the final model will be non-unique and biased by the reference model. Testing of synthetic data shows that when archaeo-magnetic datasets are inverted without applying a-priori information, large discrepancies between the true and modelled depths can occur. Where no a-priori information is available, information regarding the horizontal location of sources can be obtained from derivative-based methods such as the absolute horizontal gradient, tilt-angle and theta-map. Using pseudogravity data with these techniques, overcomes the problem of noise amplification that has previously hampered archaeological uses of these techniques. Depth

  9. Proton beam transport experiments with pulsed high-field magnets at the Dresden laser acceleration source Draco

    Energy Technology Data Exchange (ETDEWEB)

    Kroll, Florian; Schramm, Ulrich [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Technische Universitaet Dresden, Dresden (Germany); Kraft, Stephan; Metzkes, Josefine; Schlenvoigt, Hans-Peter; Zeil, Karl [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany)

    2016-07-01

    Compact laser-driven ion accelerators are a potential alternative to large and expensive conventional accelerators. High-power short-pulse lasers, impinging on e.g. thin metal foils, enable multi-MeV ion acceleration on μm length and fs to ps time scale. The generated ion bunches (typically protons) show unique beam properties, like ultra-high pulse dose. Nevertheless, laser accelerators still require substantial development in reliable beam generation and transport. Recently developed pulsed magnets meet the demands of laser acceleration and open up new research opportunities: We present a pulsed solenoid for effective collection and focusing of laser-accelerated protons that acts as link between fundamental research and application. The solenoid is powered by a capacitor-based pulse generator and can reach a maximum magnetic field of 20 T. It was installed in the target chamber of the Draco laser at HZDR. The transported beam was detected by means of radiochromic film, scintillator and Thomson parabola spectrometer. We present the characterization of the solenoid with regard to future application in radiobiological irradiation studies. Furthermore, a detailed comparison to previous experiments with a similar magnet at the PHELIX laser at GSI, Darmstadt is provided.

  10. Nuclear Magnetic Resonance Spectroscopy Applications: Proton NMR In Biological Objects Subjected To Magic Angle Spinning

    International Nuclear Information System (INIS)

    Wind, Robert A.; Hu, Jian Zhi

    2005-01-01

    Proton NMR in Biological Objects Submitted to Magic Angle Spinning, In Encyclopedia of Analytical Science, Second Edition (Paul J. Worsfold, Alan Townshend and Colin F. Poole, eds.), Elsevier, Oxford 6:333-342. Published January 1, 2005. Proposal Number 10896

  11. Proton magnetic resonance imaging for assessment of lung function and respiratory dynamics

    International Nuclear Information System (INIS)

    Eichinger, Monika; Tetzlaff, Ralf; Puderbach, Michael; Woodhouse, Neil; Kauczor, H.-U.

    2007-01-01

    Since many pulmonary diseases present with a variable regional involvement, modalities for assessment of regional lung function gained increasing attention over the last years. Together with lung perfusion and gas exchange, ventilation, as a result of the interaction of the respiratory pump and the lungs, is an indispensable component of lung function. So far, this complex mechanism is still mainly assessed indirectly and globally. A differentiation between the individual determining factors of ventilation would be crucial for precise diagnostics and adequate treatment. By dynamic imaging of the respiratory pump, the mechanical components of ventilation can be assessed regionally. Amongst imaging modalities applicable to this topic, magnetic resonance imaging (MRI), as a tool not relying on ionising radiation, is the most attractive. Recent advances in MRI technology have made it possible to assess diaphragmatic and chest wall motion, static and dynamic lung volumes, as well as regional lung function. Even though existing studies show large heterogeneity in design and applied methods, it becomes evident that MRI is capable to visualise pulmonary function as well as diaphragmatic and thoracic wall movement, providing new insights into lung physiology. Partly contradictory results and conclusions are most likely caused by technical limitations, limited number of studies and small sample size. Existing studies mainly evaluate possible imaging techniques and concentrate on normal physiology. The few studies in patients with lung cancer and emphysema already give a promising outlook for these techniques from which an increasing impact on improved and quantitative disease characterization as well as better patient management can be expected

  12. Visual and quantitative assessment of lateral lumbar spinal canal stenosis with magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Sipola, Petri; Vanninen, Ritva; Manninen, Hannu (Univ. of Eastern Finland, Faculty of Health Sciences, School of Medicine, Inst. of Clinical Medicine, Dept. of Clinical Radiology, Kuopio (Finland); Kuopio Univ. Hospital, Clinical Imaging Centre, Dept. of Clinical Radiology, Kuopio (Finland)), email: petri.sipola@kuh.fi; Leinonen, Ville (Kuopio Univ. Hospital, Dept. of Neurosurgery, Kuopio (Finland)); Niemelaeinen, Riikka (Kuopio Univ. Hospital, Clinical Imaging Centre, Dept. of Clinical Radiology, Kuopio (Finland); Faculty of Rehabilitation Medicine, Univ. of Alberta, Edmonton, Alberta (Canada)); Aalto, Timo (Kyyhkylae Rehabilitation Center and Hospital, Mikkeli (Finland)); Airaksinen, Olavi (Kuopio Univ. Hospital, Dept. of Physical and Rehabilitation Medicine and Univ. of Eastern Finland, Faculty of Health Sciences, School of Medicine, Inst. of Clinical Medicine, Kuopio (Finland)); Battie, Michele C. (Faculty of Rehabilitation Medicine, Univ. of Alberta, Edmonton, Alberta (Canada))

    2011-11-15

    Background. Lateral lumbar spinal canal stenosis is a common etiology of lumbar radicular symptoms. Quantitative measurements have commonly demonstrated better repeatability than visual assessments. We are not aware of any studies examining the repeatability of quantitative assessment of the lateral canal. Purpose. To evaluate the repeatability of visual assessments and newly developed quantitative measurements of lateral lumbar spinal canal stenosis using magnetic resonance imaging (MRI). Material and Methods. Twenty-eight patients with lateral lumbar spinal canal stenosis or prior spinal surgery with recurrent symptoms were imaged with MRI. A radiologist, a neurosurgeon and a spine research trainee graded visually and quantitatively subarticular (n = 188) and foraminal zones (n = 260) of the lateral spinal canal. Quantitative measurements included the minimal subarticular width and the cross-sectional area of the foramen. Results. The repeatability of visual assessment at the subarticular zone and foraminal zones between raters varied from 0.45-0.59 and 0.42-0.53, respectively. Similarly, the intraclass correlation coefficients for the quantitative measurements varied from 0.67-0.71 and 0.66-0.76, respectively. The intra-rater repeatability for the visual assessments of the subarticular and foraminal zones was 0.70 and 0.62, respectively, while the corresponding intraclass correlation coefficients for quantitative measurements were 0.83 and 0.81, respectively. Conclusion. Inter-rater repeatability of visual assessments of lateral stenosis is moderate, whereas quantitative measurements of both subarticular width and the cross-sectional area of the foramen have substantial reproducibility and may be particularly useful for longitudinal studies and research purposes. The clinical value of these parameters requires further study

  13. Visual and quantitative assessment of lateral lumbar spinal canal stenosis with magnetic resonance imaging

    International Nuclear Information System (INIS)

    Sipola, Petri; Vanninen, Ritva; Manninen, Hannu; Leinonen, Ville; Niemelaeinen, Riikka; Aalto, Timo; Airaksinen, Olavi; Battie, Michele C.

    2011-01-01

    Background. Lateral lumbar spinal canal stenosis is a common etiology of lumbar radicular symptoms. Quantitative measurements have commonly demonstrated better repeatability than visual assessments. We are not aware of any studies examining the repeatability of quantitative assessment of the lateral canal. Purpose. To evaluate the repeatability of visual assessments and newly developed quantitative measurements of lateral lumbar spinal canal stenosis using magnetic resonance imaging (MRI). Material and Methods. Twenty-eight patients with lateral lumbar spinal canal stenosis or prior spinal surgery with recurrent symptoms were imaged with MRI. A radiologist, a neurosurgeon and a spine research trainee graded visually and quantitatively subarticular (n = 188) and foraminal zones (n = 260) of the lateral spinal canal. Quantitative measurements included the minimal subarticular width and the cross-sectional area of the foramen. Results. The repeatability of visual assessment at the subarticular zone and foraminal zones between raters varied from 0.45-0.59 and 0.42-0.53, respectively. Similarly, the intraclass correlation coefficients for the quantitative measurements varied from 0.67-0.71 and 0.66-0.76, respectively. The intra-rater repeatability for the visual assessments of the subarticular and foraminal zones was 0.70 and 0.62, respectively, while the corresponding intraclass correlation coefficients for quantitative measurements were 0.83 and 0.81, respectively. Conclusion. Inter-rater repeatability of visual assessments of lateral stenosis is moderate, whereas quantitative measurements of both subarticular width and the cross-sectional area of the foramen have substantial reproducibility and may be particularly useful for longitudinal studies and research purposes. The clinical value of these parameters requires further study

  14. Monitoring of organic contaminants in sediments using low field proton nuclear magnetic resonance

    Science.gov (United States)

    Zhang, Chi; Rupert, Yuri

    2016-04-01

    The effective monitoring of soils and groundwater contaminated with organic compounds is an important goal of many environmental restoration efforts. Recent geophysical methods such as electrical resistivity, complex conductivity, and ground penetrating radar have been successfully applied to characterize organic contaminants in the subsurface and to monitor remediation process both in laboratory and in field. Low field proton nuclear magnetic resonance (NMR) is a geophysical tool sensitive to the molecular-scale physical and chemical environment of hydrogen-bearing fluids in geological materials and shows promise as a novel method for monitoring contaminant remediation. This laboratory research focuses on measurements on synthetic samples to determine the sensitivity of NMR to the presence of organic contaminants and improve understanding of relationships between NMR observables, hydrological properties of the sediments, and amount and state of contaminants in porous media. Toluene, a light non-aqueous phase liquid (LNAPL) has been selected as a representative organic contaminant. Three types of porous media (pure silica sands, montmorillonite clay, and various sand-clay mixtures with different sand/clay ratios) were prepared as synthetic sediments. NMR relaxation time (T2) and diffusion-relaxation (D - T2) correlation measurements were performed in each sediment saturated with water and toluene mixed fluid at assorted concentrations (0% toluene and 100% water, 1% toluene and 99% water, 5% toluene and 95% water, 25% toluene and 75% water, and 100% toluene and 0% water) to 1) understand the effect of different porous media on the NMR responses in each fluid mixture, 2) investigate the role of clay content on T2 relaxation of each fluid, 3) quantify the amount hydrocarbons in the presence of water in each sediment, and 4) resolve hydrocarbons from water in D - T2 map. Relationships between the compositions of porous media, hydrocarbon concentration, and hydraulic

  15. Novel use of proton magnetic resonance spectroscopy (1HMRS to non-invasively assess placental metabolism.

    Directory of Open Access Journals (Sweden)

    Fiona C Denison

    Full Text Available Placental insufficiency is a major cause of antepartum stillbirth and fetal growth restriction (FGR. In affected pregnancies, delivery is expedited when the risks of ongoing pregnancy outweigh those of prematurity. Current tests are unable to assess placental function and determine optimal timing for delivery. An accurate, non-invasive test that clearly defines the failing placenta would address a major unmet clinical need. Proton magnetic resonance spectroscopy ((1H MRS can be used to assess the metabolic profile of tissue in-vivo. In FGR pregnancies, a reduction in N-acetylaspartate (NAA/choline ratio and detection of lactate methyl are emerging as biomarkers of impaired neuronal metabolism and fetal hypoxia, respectively. However, fetal brain hypoxia is a late and sometimes fatal event in placental compromise, limiting clinical utility of brain (1H MRS to prevent stillbirth. We hypothesised that abnormal placental (1H MRS may be an earlier biomarker of intrauterine hypoxia, affording the opportunity to optimise timing of delivery in at-risk fetuses.We recruited three women with severe placental insufficiency/FGR and three matched controls. Using a 3T MR system and a combination of phased-array coils, a 20×20×40 mm(1H MRS voxel was selected along the 'long-axis' of the placenta with saturation bands placed around the voxel to prevent contaminant signals. A significant choline peak (choline/lipid ratio 1.35-1.79 was detected in all healthy placentae. In contrast, in pregnancies complicated by FGR, the choline/lipid ratio was ≤0.02 in all placentae, despite preservation of the lipid peak (p<0.001.This novel proof-of-concept study suggests that in severe placental insufficiency/FGR, the observed 60-fold reduction in the choline/lipid ratio by (1H MRS may represent an early biomarker of critical placental insufficiency. Further studies will determine performance of this test and the potential role of 1H-MRS in the in-vivo assessment of

  16. Listing of 502 Times When the Ulysses Magnetic Fields Instrument Observed Waves Due to Newborn Interstellar Pickup Protons

    International Nuclear Information System (INIS)

    Cannon, Bradford E.; Smith, Charles W.; Isenberg, Philip A.; Vasquez, Bernard J.; Joyce, Colin J.; Murphy, Neil; Nuno, Raquel G.

    2017-01-01

    In two earlier publications we analyzed 502 intervals of magnetic waves excited by newborn interstellar pickup protons that were observed by the Ulysses spacecraft. Due to the considerable effort required in identifying these events, we provide a list of the times for the 502 wave event intervals previously identified. In the process, we provide a brief description of how the waves were found and what their properties are. We also remind the reader of the conditions that permit the waves to reach observable levels and explain why the waves are not seen more often.

  17. Listing of 502 Times When the Ulysses Magnetic Fields Instrument Observed Waves Due to Newborn Interstellar Pickup Protons

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, Bradford E. [Physics Department, Florida State University, Tallahassee, Florida (United States); Smith, Charles W.; Isenberg, Philip A.; Vasquez, Bernard J.; Joyce, Colin J. [Physics Department and Space Science Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, New Hampshire (United States); Murphy, Neil [Jet Propulsion Laboratory, Mail Stop 180-600, 4800 Oak Grove Drive, Pasadena, California (United States); Nuno, Raquel G., E-mail: bc13h@my.fsu.edu, E-mail: Charles.Smith@unh.edu, E-mail: Phil.Isenberg@unh.edu, E-mail: Bernie.Vasquez@unh.edu, E-mail: Colin.Joyce@unh.edu, E-mail: Neil.Murphy@jpl.nasa.gov, E-mail: rgnuno@ucla.edu [Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA (United States)

    2017-05-01

    In two earlier publications we analyzed 502 intervals of magnetic waves excited by newborn interstellar pickup protons that were observed by the Ulysses spacecraft. Due to the considerable effort required in identifying these events, we provide a list of the times for the 502 wave event intervals previously identified. In the process, we provide a brief description of how the waves were found and what their properties are. We also remind the reader of the conditions that permit the waves to reach observable levels and explain why the waves are not seen more often.

  18. Envelope model for passive magnetic focusing of an intense proton or ion beam propagating through thin foils

    Directory of Open Access Journals (Sweden)

    Steven M. Lund

    2013-04-01

    Full Text Available Ion beams (including protons with low emittance and high space-charge intensity can be propagated with normal incidence through a sequence of thin metallic foils separated by vacuum gaps of order the characteristic transverse beam extent to transport/collimate the beam or to focus it to a small transverse spot. Energetic ions have sufficient range to pass through a significant number of thin foils with little energy loss or scattering. The foils reduce the (defocusing radial electric self-field of the beam while not altering the (focusing azimuthal magnetic self-field of the beam, thereby allowing passive self-beam focusing if the magnetic field is sufficiently strong relative to the residual electric field. Here we present an envelope model developed to predict the strength of this passive (beam generated focusing effect under a number of simplifying assumptions including relatively long pulse duration. The envelope model provides a simple criterion for the necessary foil spacing for net focusing and clearly illustrates system focusing properties for either beam collimation (such as injecting a laser-produced proton beam into an accelerator or for magnetic pinch focusing to a small transverse spot (for beam driven heating of materials. An illustrative example is worked for an idealization of a recently performed laser-produced proton-beam experiment to provide guidance on possible beam focusing and collimation systems. It is found that foils spaced on the order of the characteristic transverse beam size desired can be employed and that envelope divergence of the initial beam entering the foil lens must be suppressed to limit the total number of foils required to practical values for pinch focusing. Relatively modest proton-beam current at 10 MeV kinetic energy can clearly demonstrate strong magnetic pinch focusing achieving a transverse rms extent similar to the foil spacing (20–50  μm gaps in beam propagation distances of tens of mm

  19. Magnetic resonance imaging and proton magnetic resonance spectroscopy of the brain in the diagnostic evaluation of developmental delay

    NARCIS (Netherlands)

    Verbruggen, Krijn T.; Meiners, Linda C.; Sijens, Paul E.; Lunsing, Roelineke J.; van Spronsen, Francjan J.; Brouwer, Oebele F.

    Aim: To assess the contribution of MRI and proton spectroscopy (1HMRS) in establishing an etiological diagnosis in children with developmental delay (DD) and to assess whether the chance of finding specific abnormalities correlates with the presence of neurological signs and/or abnormal head

  20. Quantitative Assessment of Liver Fat with Magnetic Resonance Imaging and Spectroscopy

    Science.gov (United States)

    Reeder, Scott B.; Cruite, Irene; Hamilton, Gavin; Sirlin, Claude B.

    2011-01-01

    Hepatic steatosis is characterized by abnormal and excessive accumulation of lipids within hepatocytes. It is an important feature of diffuse liver disease, and the histological hallmark of non-alcoholic fatty liver disease (NAFLD). Other conditions associated with steatosis include alcoholic liver disease, viral hepatitis, HIV and genetic lipodystrophies, cystic fibrosis liver disease, and hepatotoxicity from various therapeutic agents. Liver biopsy, the current clinical gold standard for assessment of liver fat, is invasive and has sampling errors, and is not optimal for screening, monitoring, clinical decision making, or well-suited for many types of research studies. Non-invasive methods that accurately and objectively quantify liver fat are needed. Ultrasound (US) and computed tomography (CT) can be used to assess liver fat but have limited accuracy as well as other limitations. Magnetic resonance (MR) techniques can decompose the liver signal into its fat and water signal components and therefore assess liver fat more directly than CT or US. Most magnetic resonance (MR) techniques measure the signal fat-fraction (the fraction of the liver MR signal attributable to liver fat), which may be confounded by numerous technical and biological factors and may not reliably reflect fat content. By addressing the factors that confound the signal fat-fraction, advanced MR techniques measure the proton density fat-fraction (the fraction of the liver proton density attributable to liver fat), which is a fundamental tissue property and a direct measure of liver fat content. These advanced techniques show promise for accurate fat quantification and are likely to be commercially available soon. PMID:22025886

  1. Proton nuclear magnetic resonance studies on bulge-containing DNA oligonucleotides from a mutational hot-spot sequence

    International Nuclear Information System (INIS)

    Woodson, S.A.; Crothers, D.M.

    1987-01-01

    A series of bulge-containing and normal double-helical synthetic oligodeoxyribonucleotides, of sequence corresponding to a frame-shift mutational hot spot in the λ C/sub I/ gene, are compared by proton magnetic resonance spectroscopy at 500 MHz. The imino proton resonances are assigned by one-dimensional nuclear Overhauser effect spectroscopy. Nonselective T 1 inversion-recovery experiments are used to determine exchangeable proton lifetimes and to compare helix stability and dynamics of the three duplexes. An extra adenosine flanking the internal G-C base pairs has a strongly localized effect on helix stability, but the destabilizing effect of an extra cytidine in a C tract is delocalized over the entire G-C run. These data lead to the conclusion that the position of the bulge migrates along the run in the fast-exchange limit on the NMR time scale. Rapid migration of the bulge defect in homopolymeric sequences may help rationalize both frame-shift mutagenesis and translational frame shifting. The authors estimate that the unfavorable free energy of a localized bulge defect is 2.9-3.2 kcal/mol, in good agreement with earlier estimates for RNA helices

  2. Effects of magnetic non-linearities on a stored proton beam and their implications for superconducting storage rings

    International Nuclear Information System (INIS)

    Cornacchia, M.; Evans, L.

    1985-06-01

    A nonlinear lens may be used to study the effect of high-order multipolar field imperfections on a stored proton beam. Such a nonlinear lens is particulary suitable to simulate field imperfections of the types encountered in coil dominated superconducting magnets. We have studied experimentally at the SPS the effect of high order (5th and 8th) single isolated resonances driven by the nonlinear lens. The width of these resonances is of the order one expects to be caused by field errors in superconducting magnets of the SSC type. The experiment shows that, in absence of tune modulation, these resonances are harmless. Slow crossings of the resonance, on the other hand, have destructive effects on the beam, much more so than fast crossings caused by synchrotron oscillations. In the design of future storage rings, sources of low-frequency tune modulation should be avoided as a way to reduce the harmful effects of high order multipolar field imperfection

  3. Study of the interactions of 13.8 GeV/c protons with the heavy nuclei of the emulsions exposed in magnetic fuel of 170 kgauss

    International Nuclear Information System (INIS)

    Gomez Aleixandre, J. L.

    1967-01-01

    145 stars with N h >8 produced by the interactions of 13.8 GeV/c protons with Ag and Br nuclei have been analysed. The emulsion stack was irradiated in a 170 K gauss magnetic field. Statistical results concerning the main characteristics of the different particles emitted are given and the energy balance is evaluated. The main features of both 24 GeV/c protons and 17 GeV/c π- interactions are compared with those we have found for 13.8 GeV/c protons interactions. (Author) 27 refs

  4. Measurement of the Relaxation Rate of the Magnetization in Mn{sub 12}O{sub 12} -Acetate Using Proton NMR Echo

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Z. H. [Department of Physics and Astronomy, Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States); Lascialfari, A. [Dipartimento di Fisica ' ' A. Volta' ' e Unita' , INFM di Pavia, Via Bassi 6, 27100 Pavia, (Italy); Borsa, F. [Department of Physics and Astronomy, Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States); Dipartimento di Fisica ' ' A. Volta' ' e Unita' , INFM di Pavia, Via Bassi 6, 27100 Pavia, (Italy); Gatteschi, D. [Department of Chemistry, University of Florence, Via Maragliano 77, 50144 Firenze, (Italy)

    2000-03-27

    We present a novel method to measure the relaxation rate W of the magnetization of Mn{sub 12}O {sub 12} -acetate (Mn12) magnetic molecular cluster in its S=10 ground state at low T . It is based on the observation of an exponential growth in time of the proton NMR signal during the thermal equilibration of the magnetization of the molecules. We can explain the novel effect with a simple model which relates the intensity of the proton echo signal to the microscopic reversal of the magnetization of each individual Mn12 molecule during the equilibration process. The method should find wide application in the study of magnetic molecular clusters in off-equilibrium conditions. (c) 2000 The American Physical Society.

  5. Quantitation of magnetic resonance spectroscopy signals: the jMRUI software package

    International Nuclear Information System (INIS)

    Stefan, D; Andrasescu, A; Cesare, F Di; Popa, E; Lazariev, A; Graveron-Demilly, D; Vescovo, E; Williams, S; Strbak, O; Starcuk, Z; Cabanas, M; Van Ormondt, D

    2009-01-01

    The software package jMRUI with Java-based graphical user interface enables user-friendly time-domain analysis of magnetic resonance spectroscopy (MRS) and spectroscopic imaging (MRSI) and HRMAS-NMR signals. Version 3.x has been distributed in more than 1200 groups or hospitals worldwide. The new version 4.x is a plug-in platform enabling the users to add their own algorithms. Moreover, it offers new functionalities compared to versions 3.x. The quantum-mechanical simulator based on NMR-SCOPE, the quantitation algorithm QUEST and the main MRSI functionalities are described. Quantitation results of signals obtained in vivo from a mouse and a human brain are given

  6. Association between preoperative magnetic resonance imaging, pain intensity and quantitative sensory testing in patients awaiting lumbar diskectomy.

    LENUS (Irish Health Repository)

    Hegarty, Dominic

    2011-02-01

    Magnetic resonance imaging (MRI) offers important information regarding the morphology, location and size of a herniated disc, which influences the decision to offer lumbar diskectomy (LD). This study aims to examine the association between clinical neurophysiologic indices including pain intensity and quantitative sensory testing (QST), and the degree of lumbar nerve root compromise depicted on magnetic resonance (MR) in patients awaiting LD.

  7. Assessment of acute myocarditis by cardiac magnetic resonance imaging: Comparison of qualitative and quantitative analysis methods.

    Science.gov (United States)

    Imbriaco, Massimo; Nappi, Carmela; Puglia, Marta; De Giorgi, Marco; Dell'Aversana, Serena; Cuocolo, Renato; Ponsiglione, Andrea; De Giorgi, Igino; Polito, Maria Vincenza; Klain, Michele; Piscione, Federico; Pace, Leonardo; Cuocolo, Alberto

    2017-10-26

    To compare cardiac magnetic resonance (CMR) qualitative and quantitative analysis methods for the noninvasive assessment of myocardial inflammation in patients with suspected acute myocarditis (AM). A total of 61 patients with suspected AM underwent coronary angiography and CMR. Qualitative analysis was performed applying Lake-Louise Criteria (LLC), followed by quantitative analysis based on the evaluation of edema ratio (ER) and global relative enhancement (RE). Diagnostic performance was assessed for each method by measuring the area under the curves (AUC) of the receiver operating characteristic analyses. The final diagnosis of AM was based on symptoms and signs suggestive of cardiac disease, evidence of myocardial injury as defined by electrocardiogram changes, elevated troponin I, exclusion of coronary artery disease by coronary angiography, and clinical and echocardiographic follow-up at 3 months after admission to the chest pain unit. In all patients, coronary angiography did not show significant coronary artery stenosis. Troponin I levels and creatine kinase were higher in patients with AM compared to those without (both P quantitative (ER 0.89 and global RE 0.80) analyses were also similar. Qualitative and quantitative CMR analysis methods show similar diagnostic accuracy for the diagnosis of AM. These findings suggest that a simplified approach using a shortened CMR protocol including only T2-weighted STIR sequences might be useful to rule out AM in patients with acute coronary syndrome and normal coronary angiography.

  8. Quantitative Determination on Ionic-Liquid-Gating Control of Interfacial Magnetism.

    Science.gov (United States)

    Zhao, Shishun; Zhou, Ziyao; Peng, Bin; Zhu, Mingmin; Feng, Mengmeng; Yang, Qu; Yan, Yuan; Ren, Wei; Ye, Zuo-Guang; Liu, Yaohua; Liu, Ming

    2017-05-01

    Ionic-liquid gating on a functional thin film with a low voltage has drawn a lot of attention due to rich chemical, electronic, and magnetic phenomena at the interface. Here, a key challenge in quantitative determination of voltage-controlled magnetic anisotropy (VCMA) in Au/[DEME] + [TFSI] - /Co field-effect transistor heterostructures is addressed. The magnetic anisotropy change as response to the gating voltage is precisely detected by in situ electron spin resonance measurements. A reversible change of magnetic anisotropy up to 219 Oe is achieved with a low gating voltage of 1.5 V at room temperature, corresponding to a record high VCMA coefficient of ≈146 Oe V -1 . Two gating effects, the electrostatic doping and electrochemical reaction, are distinguished at various gating voltage regions, as confirmed by X-ray photoelectron spectroscopy and atomic force microscopy experiments. This work shows a unique ionic-liquid-gating system for strong interfacial magnetoelectric coupling with many practical advantages, paving the way toward ion-liquid-gating spintronic/electronic devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Quantitative and multiplexed detection for blood typing based on quantum dot-magnetic bead assay.

    Science.gov (United States)

    Xu, Ting; Zhang, Qiang; Fan, Ya-Han; Li, Ru-Qing; Lu, Hua; Zhao, Shu-Ming; Jiang, Tian-Lun

    2017-01-01

    Accurate and reliable blood grouping is essential for safe blood transfusion. However, conventional methods are qualitative and use only single-antigen detection. We overcame these limitations by developing a simple, quantitative, and multiplexed detection method for blood grouping using quantum dots (QDs) and magnetic beads. In the QD fluorescence assay (QFA), blood group A and B antigens were quantified using QD labeling and magnetic beads, and the blood groups were identified according to the R value (the value was calculated with the fluorescence intensity from dual QD labeling) of A and B antigens. The optimized performance of QFA was established by blood typing 791 clinical samples. Quantitative and multiplexed detection for blood group antigens can be completed within 35 min with more than 10 5 red blood cells. When conditions are optimized, the assay performance is satisfactory for weak samples. The coefficients of variation between and within days were less than 10% and the reproducibility was good. The ABO blood groups of 791 clinical samples were identified by QFA, and the accuracy obtained was 100% compared with the tube test. Receiver-operating characteristic curves revealed that the QFA has high sensitivity and specificity toward clinical samples, and the cutoff points of the R value of A and B antigens were 1.483 and 1.576, respectively. In this study, we reported a novel quantitative and multiplexed method for the identification of ABO blood groups and presented an effective alternative for quantitative blood typing. This method can be used as an effective tool to improve blood typing and further guarantee clinical transfusion safety.

  10. Model-based approach for quantitative estimates of skin, heart, and lung toxicity risk for left-side photon and proton irradiation after breast-conserving surgery.

    Science.gov (United States)

    Tommasino, Francesco; Durante, Marco; D'Avino, Vittoria; Liuzzi, Raffaele; Conson, Manuel; Farace, Paolo; Palma, Giuseppe; Schwarz, Marco; Cella, Laura; Pacelli, Roberto

    2017-05-01

    Proton beam therapy represents a promising modality for left-side breast cancer (BC) treatment, but concerns have been raised about skin toxicity and poor cosmesis. The aim of this study is to apply skin normal tissue complication probability (NTCP) model for intensity modulated proton therapy (IMPT) optimization in left-side BC. Ten left-side BC patients undergoing photon irradiation after breast-conserving surgery were randomly selected from our clinical database. Intensity modulated photon (IMRT) and IMPT plans were calculated with iso-tumor-coverage criteria and according to RTOG 1005 guidelines. Proton plans were computed with and without skin optimization. Published NTCP models were employed to estimate the risk of different toxicity endpoints for skin, lung, heart and its substructures. Acute skin NTCP evaluation suggests a lower toxicity level with IMPT compared to IMRT when the skin is included in proton optimization strategy (0.1% versus 1.7%, p < 0.001). Dosimetric results show that, with the same level of tumor coverage, IMPT attains significant heart and lung dose sparing compared with IMRT. By NTCP model-based analysis, an overall reduction in the cardiopulmonary toxicity risk prediction can be observed for all IMPT compared to IMRT plans: the relative risk reduction from protons varies between 0.1 and 0.7 depending on the considered toxicity endpoint. Our analysis suggests that IMPT might be safely applied without increasing the risk of severe acute radiation induced skin toxicity. The quantitative risk estimates also support the potential clinical benefits of IMPT for left-side BC irradiation due to lower risk of cardiac and pulmonary morbidity. The applied approach might be relevant on the long term for the setup of cost-effectiveness evaluation strategies based on NTCP predictions.

  11. Development of Superconducting Combined Function Magnets for the Proton Transport Line for the J-PARC Neutrino Experiments

    CERN Document Server

    Nakamoto, Tatsushi; Anerella, Michael; Escallier, John; Fujii, T; Fukui, Yuji; Ganetis, George; Gupta, Ramesh C; Harrison, Michael; Hashiguchi, E; Higashi, Norio; Ichikawa, Atsuko; Iwamoto, Yosuke; Jain, Animesh K; Kanahara, T; Kimura, Nobuhiro; Kobayashi, Takashi; Makida, Yasuhiro; Muratore, Joseph F; Obana, Tetsuhiro; Ogitsu, T; Ohhata, Hirokatsu; Okamura, T; Orikasa, T; Parker, Brett; Sasaki, Ken Ichi; Takasaki, Minoru; Tanaka, Ken Ichi; Terashima, Akio; Tomaru, Takayuki; Wanderer, Peter; Yamamoto, Akira

    2005-01-01

    A second generation of long-baseline neutrino oscillation experiments has been proposed as one of the main projects at J-PARC jointly built by JAERI and KEK. Superconducting combined function magnets, SCFMs, will be utilized for the 50 GeV, 750 kW proton beam line for the neutrino experiment and an R&D program is in underway at KEK. The magnet is designed to provide a combined function of a dipole field of 2.6 T with a quadrupole field of 19 T/m in a coil aperture of 173.4 mm. A series of 28 magnets in the beam line will be operated DC in supercritical helium cooling below 5 K. A design feature of the SCFM is the left-right asymmetry of the coil cross section: current distributions for superimposed dipole- and quadrupole- fields are combined in a single layer coil. Another design feature is the adoption of glass-fiber reinforced phenolic plastic spacers to replace the conventional metallic collars. To evaluate this unique design, fabrication of full-scale prototype magnets is in progress at KEK and the fi...

  12. Preliminary study for differential diagnosis of intracranial tumors using in vivo quantitative proton MR spectroscopy with correction for T2 relaxation time

    International Nuclear Information System (INIS)

    Isobe, Tomonori; Yamamoto, Tetsuya; Akutsu, Hiroyoshi; Shiigai, Masanari; Shibata, Yasushi; Takada, Kenta; Masumoto, Tomohiko; Anno, Izumi; Matsumura, Akira

    2015-01-01

    Introduction: The intent of this study was to differentiate intracranial tumors using the metabolite concentrations obtained by quantification with correction for T2 relaxation time, and to analyze whether the spectrum peak was generated by the existence of metabolites in proton magnetic resonance spectroscopy (MRS). Methods: All proton MRS studies were performed on a clinical 1.5T MR system. 7 normal volunteers and 57 patients (gliomas, metastases, meningiomas, acoustic neuromas, and pituitary adenomas) underwent single voxel proton MRS with different echo times (TE: 68, 136, 272 ms) for T2 correction of signal derived from metabolites and tissue water. With tissue water employed as an internal reference, the concentrations of metabolite (i.e. N-acetylaspartate (NAA), total creatine (t-Cr) and choline-containing compounds (Cho)) were calculated. Moreover, proton MRS data of previously published typical literatures were critically reviewed and compared with our data. Results: Extramedullary tumors were characterized by absence of NAA compared with intramedullary tumors. High-grade glioma differed from low-grade glioma by lower t-Cr concentrations. Metastasis differed from cystic glioblastoma by higher Cho concentrations, lower t-Cr concentrations, an absence of NAA, and a prominent Lipids peak. Based on these results and review of previous reports, we suggest a clinical pathway for the differentiation of intracranial tumors. Conclusion: The metabolite concentrations obtained by quantification with correction for T2 relaxation time, and to analyze whether the spectrum peak was generated by the existence of metabolites in proton MRS is useful for the diagnosis of the intracranial tumors

  13. BNL alternating gradient synchrotron with four helical magnets to minimize the losses of the polarized proton beam

    Directory of Open Access Journals (Sweden)

    N. Tsoupas

    2013-04-01

    Full Text Available The principle of using multiple partial helical magnets to preserve the polarization of the proton beam during its acceleration was applied successfully to the alternating gradient synchrotron (AGS which currently operates with two partial helical magnets. In this paper we further explore this idea by using four partial helical magnets placed symmetrically in the AGS ring. This provides many advantages over the present setup of the AGS, which uses two partial helical magnets. First, the symmetric placement of the four helical magnets and their relatively lower field of operation allows for better control of the AGS optics with reduced values of the beta functions especially near beam injection and allows both the vertical and horizontal tunes to be placed within the “spin tune gap,” therefore eliminating the horizontal and vertical intrinsic spin resonances of the AGS during the acceleration cycle. Second, it provides a wider spin tune gap. Third, the vertical spin direction during beam injection and extraction is closer to vertical. Although the spin tune gap, which is created with four partial helices, can also be created with a single or two partial helices, the high field strength of a single helical magnet which is required to generate such a spin tune gap makes the use of the single helical magnet impractical, and that of the two helical magnets rather difficult. In this paper we will provide results on the spin tune and on the optics of the AGS with four partial helical magnets, and compare them with those from the present setup of the AGS that uses two partial helical magnets. Although in this paper we specifically discuss the effect of the four partial helices on the AGS, this method which can eliminate simultaneously the vertical and horizontal intrinsic spin resonances is a general method and can be applied to any medium energy synchrotron which operates in similar energy range like the AGS and provides the required space to

  14. arXiv Search for magnetic monopoles with the MoEDAL forward trapping detector in 2.11 fb$^{-1}$ of 13 TeV proton-proton collisions at the LHC

    CERN Document Server

    Acharya, B.; The MoEDAL collaboration; Baines, S.; Benes, P.; Bergmann, B.; Bernabéu, J.; Bevan, A.; Branzas, H.; Campbell, M.; Caramete, L.; Cecchini, S.; de Montigny, M.; De Roeck, A.; Ellis, J.R.; Fairbairn, M.; Felea, D.; Frank, M.; Frekers, D.; Garcia, C.; Hays, J.; Hirt, A.M.; Janecek, J.; Kim, D.-W; Kinoshita, K.; Korzenev, A.; Lacarrère, D.H.; Lee, S.C.; Leroy, C.; Levi, G.; Lionti, A.; Mamuzic, J.; Margiotta, A.; Mauri, N.; Mavromatos, N.E.; Mermod, P.; Mitsou, V.A.; Orava, R.; Ostrovskiy, I.; Parker, B.; Patrizii, L.; Păvălaş, G.E.; Pinfold, J.L.; Popa, V.; Pozzato, M.; Pospisil, S.; Rajantie, A.; Ruiz de Austri, R.; Sahnoun, Z.; Sakellariadou, M.; Santra, A.; Sarkar, S.; Semenoff, G.; Shaa, A.; Sirri, G.; Sliwa, K.; Soluk, R.; Spurio, M.; Srivastava, Y.N.; Suk, M.; Swain, J.; Tenti, M.; Togo, V.; Tuszyński, J.A.; Vento, V.; Vives, O.; Vykydal, Z.; Widom, A.; Willems, G.; Yoon, J.H.; Zgura, I.S.

    2018-07-10

    We update our previous search for trapped magnetic monopoles in LHC Run 2 using nearly six times more integrated luminosity and including additional models for the interpretation of the data. The MoEDAL forward trapping detector, comprising 222~kg of aluminium samples, was exposed to 2.11~fb$^{-1}$ of 13 TeV proton-proton collisions near the LHCb interaction point and analysed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges equal to the Dirac charge or above are excluded in all samples. The results are interpreted in Drell-Yan production models for monopoles with spins 0, 1/2 and 1: in addition to standard point-like couplings, we also consider couplings with momentum-dependent form factors. The search provides the best current laboratory constraints for monopoles with magnetic charges ranging from two to five times the Dirac charge.

  15. Implantation of the method of quantitative analysis by proton induced X-ray analysis and application to the analysis of aerosols

    International Nuclear Information System (INIS)

    Margulis, W.

    1977-09-01

    Fundamental aspects for the implementation of the method of quantitative analysis by proton induced X-ray spectroscopy are discussed. The calibration of the system was made by determining a response coefficient for selected elements, both by irradiating known amounts of these elements as well as by the use of theoretical and experimental parameters. The results obtained by these two methods agree within 5% for the analysed elements. A computer based technique of spectrum decomposition was developed to facilitate routine analysis. Finally, aerosol samples were measured as an example of a possible application of the method, and the results are discussed. (Author) [pt

  16. A Direct Search for Stable Magnetic Monopoles Produced in Positron-Proton Collisions at HERA

    CERN Document Server

    Aktas, A.; Anthonis, T.; Aplin, S.; Asmone, A.; Babaev, A.; Backovic, S.; Bahr, J.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Baumgartner, S.; Becker, J.; Beckingham, M.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, Ch.; Berger, N.; Bizot, J.C.; Boenig, M.-O.; Boudry, V.; Bracinik, J.; Brandt, G.; Brisson, V.; Brown, D.P.; Bruncko, D.; Busser, F.W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Caron, S.; Cassol-Brunner, F.; Cerny, K.; Chekelian, V.; Contreras, J.G.; Coughlan, J.A.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; Delcourt, B.; Demirchyan, R.; De Roeck, A.; Desch, K.; De Wolf, E.A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, Guenter; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Ellerbrock, M.; Elsen, E.; Erdmann, W.; Essenov, S.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Ferencei, J.; Finke, L.; Fleischer, M.; Fleischmann, P.; Fleming, Y.H.; Flucke, G.; Fomenko, A.; Foresti, I.; Formanek, J.; Franke, G.; Frising, G.; Frisson, T.; Gabathuler, E.; Garutti, E.; Gayler, J.; Gerhards, R.; Gerlich, C.; Ghazaryan, Samvel; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Goyon, C.; Grab, C.; Greenshaw, T.; Gregori, M.; Grindhammer, Guenter; Gwilliam, C.; Haidt, D.; Hajduk, L.; Haller, J.; Hansson, M.; Heinzelmann, G.; Henderson, R.C.W.; Henschel, H.; Henshaw, O.; Herrera, G.; Herynek, I.; Heuer, R.-D.; Hildebrandt, M.; Hiller, K.H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Ibbotson, M.; Ismail, M.; Jacquet, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jung, H.; Kapichine, M.; Karlsson, M.; Katzy, J.; Keller, N.; Kenyon, I.R.; Kiesling, Christian M.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knies, G.; Knutsson, A.; Korbel, V.; Kostka, P.; Koutouev, R.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Kruger, K.; Kuckens, J.; Landon, M.P.J.; Lange, W.; Lastovicka, T.; Laycock, P.; Lebedev, A.; Leiner, B.; Lendermann, V.; Levonian, S.; Lindfeld, L.; Lipka, K.; List, B.; Lobodzinska, E.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lueders, H.; Luke, D.; Lux, T.; Lytkin, L.; Makankine, A.; Malden, N.; Malinovski, E.; Mangano, S.; Marage, P.; Marshall, R.; Martisikova, M.; Martyn, H.-U.; Maxeld, S.J.; Meer, D.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Mikocki, S.; Milcewicz-Mika, I.; Milstead, D.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J.V.; Mozer, Matthias Ulrich; Muller, K.; Murin, P.; Nankov, K.; Naroska, B.; Naumann, J.; Naumann, Th.; Newman, Paul R.; Niebuhr, C.; Nikiforov, A.; Nikitin, D.; Nowak, G.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J.E.; Osman, S.; Ozerov, D.; Pascaud, C.; Patel, G.D.; Peez, M.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Pitzl, D.; Placakyte, R.; Poschl, R.; Portheault, B.; Povh, B.; Prideaux, P.; Raicevic, N.; Reimer, P.; Rimmer, A.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D.P.C.; Sauvan, E.; Schatzel, S.; Scheins, J.; Schilling, F.-P.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schoning, A.; Schroder, V.; Schultz-Coulon, H.-C.; Schwanenberger, C.; Sedlak, K.; Sefkow, F.; Sheviakov, I.; Shtarkov, L.N.; Sirois, Y.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Stella, B.; Stiewe, J.; Strauch, I.; Straumann, U.; Tchoulakov, V.; Thompson, Graham; Thompson, P.D.; Tomasz, F.; Traynor, D.; Truoel, Peter; Tsakov, I.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, Marcel; Usik, A.; Utkin, D.; Valkar, S.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Van Remortel, N.; Vargas Trevino, A.; Vazdik, Y.; Veelken, C.; Vest, A.; Vinokurova, S.; Volchinski, V.; Vujicic, B.; Wacker, K.; Wagner, J.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Werner, N.; Wessels, M.; Wessling, B.; Wigmore, C.; Winter, G.-G.; Wissing, Ch.; Wolf, R.; Wunsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zimmermann, J.; Zohrabyan, H.; Zomer, F.

    2005-01-01

    A direct search has been made for magnetic monopoles produced in e^+ p collisions at a centre of mass energy of 300 GeV at HERA. The beam pipe surrounding the interaction region in 1995-1997 was investigated using a SQUID magnetometer to look for stopped magnetic monopoles. During this time an integrated luminosity of 62 pb^{-1} was delivered. No magnetic monopoles were observed and charge and mass dependent upper limits on the e^+ p production cross section are set.

  17. Idiopathic Dilated Cardiomyopathy-proton magnetic resonance spectroscopy ( 1 H MRS ) in evaluation of myocardial metabolism. Preliminary study

    International Nuclear Information System (INIS)

    Michalak, M.; Walecki, J.; Michalak, E.; Bilinska, Z.; Ruzyllo, W.

    2002-01-01

    Primary dilated cardiomyopathy is a disease of unknown etiology and it leads to serious cardiac insufficiency. Abnormalities in cardiac metabolism can play an important role in clinical manifestation and prognosis in this group. The aim of this study was an attempt to assess cardiac metabolism using proton spectroscopy magnetic resonance method (1H MRS) and to find a relationship between cardiac metabolites and functional class NYHA and left ventricular function parameters obtained by echocardiography. Proton spectroscopy magnetic resonance was performed in 15 patients with angiographically documented idiopathic dilated cardiomyopathy and 12 healthy volunteers with voxel localized at interventricular septum area. The contents of total creatine (CR) e.g. creatine+phosphocreatine, lipids (LIP) lactates (LAC) and their ratios (CR1A, CR2A, CR1/H20, CR2/H20, CR2/CR1, LIPA, LIP/H20, LIP/CR1, LACA, LAC/H20, LAC/CR1) were examined. Patents with dilated cardiomyopathy had significantly lower level of creatine CR1A (5.04I0.88 vs. 5.94I1.15, p<0.02) and ratios LIP/H20 (4.34I2.3 vs. 15.46I20.39, p<0.04) and LIP/CR1 (24.49I21.26 vs. 34.08I13.36, p<0.05) compared to healthy volunteers. Significant correlations between NYHA functional class and ratios CR2/CR1, CR2/H20 (r=0.59 p<0.038, r=0.59 p<0.02) and between %EFLV and LIP/CR1 (r=0.64, p<0.036), as well as between the duration of the disease (CTCH) and LIP/CR1 (r=0.67, p<0.046) were found. Preliminary study with proton spectroscopy magnetic resonance (1H MRS) showed impairment cardiac metabolism in patients with idiopathic dilated cardiomyopathy. A tendency to lowered values of creatine, lipids and some ratios of these metabolites were observed in dilated cardiomyopathy group compared to healthy subjects. Our results needs further study. (author)

  18. In vivo proton magnetic resonance spectroscopy of intraventricular tumours of the brain

    International Nuclear Information System (INIS)

    Majos, Carles; Aguilera, Carles; Cos, Monica; Camins, Angels; Samitier, Alex; Castaner, Sara; Sanchez, Juan J.; Candiota, Ana P.; Delgado-Goni, Teresa; Mato, David; Acebes, Juan J.; Arus, Carles

    2009-01-01

    The aim of this study was to assess the usefulness of proton MR spectroscopy in the diagnosis of intraventricular tumours. Fifty-two intraventricular tumours pertaining to 16 different tumour types were derived from our database. All cases had single-voxel proton MR spectroscopy performed at TE at both 30 and 136 ms at 1.5 T. The Mann-Whitney U test was used to search for the most discriminative datapoints each tumour type. Characteristic trends were found for some groups: high Glx and Ala in meningiomas (p<0.001 and p<0.01, respectively), high mobile lipids in metastasis (p<0.001), high Cho in PNET (p<0.001), high mI+Gly in ependymoma (p<0.001), high NAC (p<0.01) in the absence of the normal brain parenchyma pattern in colloid cysts, and high mI/Gly and Ala in central neurocytoma. Proton MR spectroscopy provides additional metabolic information that could be useful in the diagnosis of intraventricular brain tumors. (orig.)

  19. In vivo proton magnetic resonance spectroscopy of intraventricular tumours of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Majos, Carles; Aguilera, Carles [Hospital Universitari de Bellvitge, Institut de Diagnostic per la Imatge (IDI). Centre Bellvitge, L' Hospitalet de Llobregat, Barcelona (Spain); Biomateriales y Nanomedicina (CIBER-BBN), Centro de Investigacion Biomedica en Red en Bioingenieria, Cerdanyola del Valles (Spain); Cos, Monica; Camins, Angels; Samitier, Alex; Castaner, Sara; Sanchez, Juan J. [Hospital Universitari de Bellvitge, Institut de Diagnostic per la Imatge (IDI). Centre Bellvitge, L' Hospitalet de Llobregat, Barcelona (Spain); Candiota, Ana P.; Delgado-Goni, Teresa [Biomateriales y Nanomedicina (CIBER-BBN), Centro de Investigacion Biomedica en Red en Bioingenieria, Cerdanyola del Valles (Spain); Unitat de Bioquimica de Biociencies, Department de Bioquimica i Biologia Molecular, Cerdanyola del Valles (Spain); Mato, David [Hospital Universitari de Bellvitge, Department of Neurosurgery, L' Hospitalet de Llobregat, Barcelona (Spain); Acebes, Juan J. [Hospital Universitari de Bellvitge, Department of Neurosurgery, L' Hospitalet de Llobregat, Barcelona (Spain); Biomateriales y Nanomedicina (CIBER-BBN), Centro de Investigacion Biomedica en Red en Bioingenieria, Cerdanyola del Valles (Spain); Arus, Carles [Unitat de Bioquimica de Biociencies, Department de Bioquimica i Biologia Molecular, Cerdanyola del Valles (Spain); Biomateriales y Nanomedicina (CIBER-BBN), Centro de Investigacion Biomedica en Red en Bioingenieria, Cerdanyola del Valles (Spain)

    2009-08-15

    The aim of this study was to assess the usefulness of proton MR spectroscopy in the diagnosis of intraventricular tumours. Fifty-two intraventricular tumours pertaining to 16 different tumour types were derived from our database. All cases had single-voxel proton MR spectroscopy performed at TE at both 30 and 136 ms at 1.5 T. The Mann-Whitney U test was used to search for the most discriminative datapoints each tumour type. Characteristic trends were found for some groups: high Glx and Ala in meningiomas (p<0.001 and p<0.01, respectively), high mobile lipids in metastasis (p<0.001), high Cho in PNET (p<0.001), high mI+Gly in ependymoma (p<0.001), high NAC (p<0.01) in the absence of the normal brain parenchyma pattern in colloid cysts, and high mI/Gly and Ala in central neurocytoma. Proton MR spectroscopy provides additional metabolic information that could be useful in the diagnosis of intraventricular brain tumors. (orig.)

  20. Temperature mapping using proton phase shift on a 0.3 T permanent magnet open MRI system

    International Nuclear Information System (INIS)

    Komura, Kazumi; Takahashi, Tetsuhiko; Dohi, Michiko; Harada, Junta

    2000-01-01

    Temperature mapping using proton phase shift (PPS) was evaluated for ex vivo objects. The evaluation was done on a 0.3 T permanent magnet open magnetic resonance imaging (MRI) machine, like those widely used for clinical diagnosis. Temperature maps were acquired using a gradient echo sequence (TR/TE =80/30 ms, flip angle =60 degrees, field of view =200 x 200 mm, slice thickness =8 mm, matrix size =128 x 128, data acquisition number =1, and imaging time =10.2 s). Specific first order data correction was performed to eliminate calculated temperature fluctuation due to magnetic field instability. A ham, 10 cm in diameter, was heated with a Nd: YAG laser with a wavelength of 1064 nm. The laser fiber was inserted into the ham to a depth of 3 cm. The laser power was 5, 8, or 10 W. Magnetic resonance images were taken continually during and after irradiation. Temperature maps were taken every 15 s. The maps taken during laser ablation showed color changes for the heated areas. Temperatures measured by the MRI and thermocouple had a linear relationship of r 2 =0.80. The inter-image standard deviation of the temperature maps of a non-heated object was 2.07 degrees for a 4.68 x 4.68 x 8 mm volume. This value is negligible for a monitored laser heating process since temperature rise is typically larger than 30 degrees. These results show that temperature mapping based on PPS is feasible for a 0.3 T permanent magnet open MRI system. (author)

  1. Quantitative morphologic evaluation of magnetic resonance imaging during and after treatment of childhood leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Reddick, Wilburn E.; Glass, John O. [St. Jude Children' s Research Hospital, Division of Translational Imaging Research (MS 210), Department of Radiological Sciences, Memphis, TN (United States); Laningham, Fred H. [St. Jude Children' s Research Hospital, Division of Diagnostic Imaging, Memphis, TN (United States); Pui, Ching-Hon [St. Jude Children' s Research Hospital, Department of Oncology, Memphis, TN (United States)

    2007-11-15

    Medical advances over the last several decades, including CNS prophylaxis, have greatly increased survival in children with leukemia. As survival rates have increased, clinicians and scientists have been afforded the opportunity to further develop treatments to improve the quality of life of survivors by minimizing the long-term adverse effects. When evaluating the effect of antileukemia therapy on the developing brain, magnetic resonance (MR) imaging has been the preferred modality because it quantifies morphologic changes objectively and noninvasively. Computer-aided detection of changes on neuroimages enables us to objectively differentiate leukoencephalopathy from normal maturation of the developing brain. Quantitative tissue segmentation algorithms and relaxometry measures have been used to determine the prevalence, extent, and intensity of white matter changes that occur during therapy. More recently, diffusion tensor imaging has been used to quantify microstructural changes in the integrity of the white matter fiber tracts. MR perfusion imaging can be used to noninvasively monitor vascular changes during therapy. Changes in quantitative MR measures have been associated, to some degree, with changes in neurocognitive function during and after treatment. In this review, we present recent advances in quantitative evaluation of MR imaging and discuss how these methods hold the promise to further elucidate the pathophysiologic effects of treatment for childhood leukemia. (orig.)

  2. Quantitative morphologic evaluation of magnetic resonance imaging during and after treatment of childhood leukemia

    International Nuclear Information System (INIS)

    Reddick, Wilburn E.; Glass, John O.; Laningham, Fred H.; Pui, Ching-Hon

    2007-01-01

    Medical advances over the last several decades, including CNS prophylaxis, have greatly increased survival in children with leukemia. As survival rates have increased, clinicians and scientists have been afforded the opportunity to further develop treatments to improve the quality of life of survivors by minimizing the long-term adverse effects. When evaluating the effect of antileukemia therapy on the developing brain, magnetic resonance (MR) imaging has been the preferred modality because it quantifies morphologic changes objectively and noninvasively. Computer-aided detection of changes on neuroimages enables us to objectively differentiate leukoencephalopathy from normal maturation of the developing brain. Quantitative tissue segmentation algorithms and relaxometry measures have been used to determine the prevalence, extent, and intensity of white matter changes that occur during therapy. More recently, diffusion tensor imaging has been used to quantify microstructural changes in the integrity of the white matter fiber tracts. MR perfusion imaging can be used to noninvasively monitor vascular changes during therapy. Changes in quantitative MR measures have been associated, to some degree, with changes in neurocognitive function during and after treatment. In this review, we present recent advances in quantitative evaluation of MR imaging and discuss how these methods hold the promise to further elucidate the pathophysiologic effects of treatment for childhood leukemia. (orig.)

  3. Magnetic particle separation technique: a reliable and simple tool for RIA/IRMA and quantitative PCR assay

    International Nuclear Information System (INIS)

    Shen Rongsen; Shen Decun

    1998-01-01

    Five types of magnetic particles without or with aldehyde, amino and carboxyl functional groups, respectively were used to immobilize first or second antibody by three models, i. e. physical adsorption, chemical coupling and immuno-affinity, forming four types of magnetic particle antibodies. The second antibody immobilized on polyacrolein magnetic particles through aldehyde functional groups and the first antibodies immobilized on carboxylic polystyrene magnetic particles through carboxyl functional groups were recommended to apply to RIAs and/or IRMAs. Streptavidin immobilized on commercial magnetic particles through amino functional groups was successfully applied to separating specific PCR product for quantification of human cytomegalovirus. In the paper typical data on reliability of these magnetic particle ligands were reported and simplicity of the magnetic particle separation technique was discussed. The results showed that the technique was a reliable and simple tool for RIA/IRMA and quantitative PCR assay. (author)

  4. Continuous monitoring of the zinc-phosphate acid-base cement setting reaction by proton nuclear magnetic relaxation

    International Nuclear Information System (INIS)

    Apih, T.; Lebar, A.; Pawlig, O.; Trettin, R.

    2001-01-01

    Proton nuclear magnetic relaxation is a well-established technique for continuous and non destructive monitoring of hydration of conventional Portland building cements. Here, we demonstrate the feasibility of nuclear magnetic resonance (NMR) monitoring of the setting reaction of zinc-phosphate acid-base dental cements, which harden in minutes as compared to days, as in the case of Portland cements. We compare the setting of cement powder (mainly, zinc oxide) prepared with clinically used aluminum-modified orthophosphoric acid solution with the setting of a model system where cement powder is mixed with pure orthophosphoric acid solution. In contrast to previously published NMR studies of setting Portland cements, where a decrease of spin-lattice relaxation time is attributed to enhanced relaxation at the growing internal surface, spin-lattice relaxation time T 1 increases during the set of clinically used zinc-phosphate cement. Comparison of these results with a detailed study of diffusion, viscosity, and magnetic-field dispersion of T 1 in pure and aluminum-modified orthophosphoric acid demonstrates that the increase of T 1 in the setting cement is connected with the increase of molecular mobility in the residual phosphoric acid solution. Although not taken into account so far, such effects may also significantly influence the relaxation times in setting Portland cements, particularly when admixtures with an effect on water viscosity are used. [copyright] 2001 American Institute of Physics

  5. Investigation of proton spin relaxation in water with dispersed silicon nanoparticles for potential magnetic resonance imaging applications

    Science.gov (United States)

    Kargina, Yu. V.; Gongalsky, M. B.; Perepukhov, A. M.; Gippius, A. A.; Minnekhanov, A. A.; Zvereva, E. A.; Maximychev, A. V.; Timoshenko, V. Yu.

    2018-03-01

    Porous and nonporous silicon (Si) nanoparticles (NPs) prepared by ball-milling of electrochemically etched porous Si layers and crystalline Si wafers were studied as potential agents for enhancement of the proton spin relaxation in aqueous media. While nonporous Si NPs did not significantly influence the spin relaxation, the porous ones resulted in strong shortening of the transverse relaxation times. In order to investigate an effect of the electron spin density in porous Si NPs on the proton spin relaxation, we use thermal annealing of the NPs in vacuum or in air. The transverse relaxation rate of about 0.5 l/(g s) was achieved for microporous Si NPs, which were thermally annealing in vacuum to obtain the electron spin density of the order of 1017 g-1. The transverse relaxation rate was found to be almost proportional to the concentration of porous Si NPs in the range from 0.1 to 20 g/l. The obtained results are discussed in view of possible biomedical applications of Si NPs as contrast agents for magnetic resonance imaging.

  6. Measurements of the Backstreaming Proton IONS in the Self-Magnetic Pinch (SMP) Diode Utilizing Copper Activation Technique

    Science.gov (United States)

    Mazarakis, Michael; Cuneo, Michael; Fournier, Sean; Johnston, Mark; Kiefer, Mark; Leckbee, Joshua; Simpson, Sean; Renk, Timothy; Webb, Timothy; Bennett, Nichelle

    2016-10-01

    The results presented here were obtained with an SMP diode mounted at the front high voltage end of the 8-10-MV RITS Self-Magnetically Insulated Transmission Line (MITL) voltage adder. Our experiments had two objectives: first, to measure the contribution of the back-streaming proton currents emitted from the anode target, and second, to evaluate the energy of those ions and hence the actual Anode-Cathode (A-K) gap voltage. The accelerating voltage quoted in the literature is estimated utilizing para-potential flow theories. Thus, it is interesting to have another independent measurement of the A-K voltage. We have measured the back-streaming protons emitted from the anode and propagating through a hollow cathode tip for various diode configurations and different techniques of target cleaning treatment, namely, heating at very high temperatures with DC and pulsed current, with RF plasma cleaning, and with both plasma cleaning and heating. We have also evaluated the A-K gap voltage by energy filtering techniques. Sandia is operated by Sandia Corporation, a subsidiary of Lockheed Martin Company, for the US DOE NNSA under Contract No. DE-AC04-94AL85000.

  7. Magnetization transfer from macromolecules to water protons in murine dental tissues as revealed by 500 MHz 1H-NMR

    International Nuclear Information System (INIS)

    Nakamura, Koji; Era, Seiichi; Nagai, Naoki; Sogami, Masaru; Takasaki, Akihiko; Kato, Kazuo.

    1997-01-01

    Although much is known about magnetization transfer phenomena in biological soft tissues, little is known about those in hard tissues. Using a 500 MHz 1 H-NMR spectrometer, we studied the spin-lattice relaxation time (T 1 (H 2 O)) and the intermolecular cross-relaxation times (T IS (H 2 O)) from irradiated macromolecular protons to observed water protons in murine lower incisors (hard tissue) and compared with those in murine lens tissue (soft tissue). Mean values for the water content (%) of murine lower incisors and lens tissue were 16.02±2.39 (n=14) and 67.20±4.60 (n=15), respectively. These findings were consistent with the large different in water content between soft tissues and hard tissues. T IS (H 2 O) values obtained by f 2 -irradiation at 7.13 or -4.00 ppm showed no significant difference between lower incisors and lens tissue. Plots of 1/T IS (H 2 O) values vs. tissue dry weight (W(%)) for lower incisor tissue approximated a straight line with slope approximately equal for that obtained for lens tissue. These results suggest that the state of water in hard tissue may be similar to that in soft tissues, in spite of the significant difference in water content. Thus, saturation transfer NMR techniques such as measurement of T IS (H 2 O) values may be applicable to the study of water-macromolecule interactions in both biological soft and hard tissues. (author)

  8. Characterization of proton and neutron irradiated low resistivity p-on-n magnetic Czochralski ministrip sensors and diodes

    International Nuclear Information System (INIS)

    Pacifico, Nicola; Dolenc Kittelmann, Irena; Fahrer, Manuel; Moll, Michael; Militaru, Otilia

    2011-01-01

    Transient Current Technique (TCT) and Charge Collection Efficiency (CCE) measurements were performed on low resistivity (280Ωcm) n-bulk, p-readout magnetic Czochralski ministrip sensors and diodes. The detectors were irradiated with neutrons and 24 GeV/c protons up to a total NIEL equivalent fluence of 8×10 15 /cm 2 . The study was addressed to assess the radiation tolerance of the detectors up to fluences expected in the next generations of High Energy Physics experiments. The charge collection efficiency after irradiation was found to be much higher than for standard FZ silicon p-in-n sensors. The underlying physics of this remarkable result was investigated by performing Edge-TCT measurements on one of the neutron irradiated ministrip sensors to extract detailed informations about the field and efficiency profiles of the detector.

  9. Characterization of proton and neutron irradiated low resistivity p-on-n magnetic Czochralski ministrip sensors and diodes

    Energy Technology Data Exchange (ETDEWEB)

    Pacifico, Nicola, E-mail: nicola.pacifico@cern.ch [CERN, Geneva (Switzerland); Dolenc Kittelmann, Irena; Fahrer, Manuel; Moll, Michael [CERN, Geneva (Switzerland); Militaru, Otilia [UCL, Louvain (Belgium)

    2011-12-01

    Transient Current Technique (TCT) and Charge Collection Efficiency (CCE) measurements were performed on low resistivity (280{Omega}cm) n-bulk, p-readout magnetic Czochralski ministrip sensors and diodes. The detectors were irradiated with neutrons and 24 GeV/c protons up to a total NIEL equivalent fluence of 8 Multiplication-Sign 10{sup 15}/cm{sup 2}. The study was addressed to assess the radiation tolerance of the detectors up to fluences expected in the next generations of High Energy Physics experiments. The charge collection efficiency after irradiation was found to be much higher than for standard FZ silicon p-in-n sensors. The underlying physics of this remarkable result was investigated by performing Edge-TCT measurements on one of the neutron irradiated ministrip sensors to extract detailed informations about the field and efficiency profiles of the detector.

  10. Proton radiography of dynamic electric and magnetic fields in laser-produced high-energy-density plasmas

    International Nuclear Information System (INIS)

    Li, C. K.; Seguin, F. H.; Frenje, J. A.; Manuel, M.; Casey, D.; Sinenian, N.; Petrasso, R. D.; Amendt, P. A.; Landen, O. L.; Rygg, J. R.; Town, R. P. J.; Betti, R.; Meyerhofer, D. D.; Delettrez, J.; Knauer, J. P.; Marshall, F.; Sangster, T. C.; Smalyuk, V. A.; Soures, J. M.; Shvarts, D.

    2009-01-01

    Time-gated, monoenergetic-proton radiography provides unique measurements of the electric (E) and magnetic (B) fields produced in laser-foil interactions and during the implosion of inertial-confinement-fusion capsules. These experiments resulted in the first observations of several new and important features: (1) observations of the generation, decay dynamics, and instabilities of megagauss B fields in laser-driven planar plastic foils, (2) the observation of radial E fields inside an imploding capsule, which are initially directed inward, reverse direction during deceleration, and are likely related to the evolution of the electron pressure gradient, and (3) the observation of many radial filaments with complex electromagnetic field striations in the expanding coronal plasmas surrounding the capsule. The physics behind and implications of such observed fields are discussed.

  11. Quantitative imaging of magnetic nanoparticles by magneto-relaxometric tomography for biomedical applications; Quantitative Bildgebung magnetischer Nanopartikel mittels magnetrelaxometrischer Tomographie fuer biomedizinische Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Liebl, Maik

    2016-11-18

    Current biomedical research focuses on the development of novel biomedical applications based on magnetic nanoparticles (MNPs), e.g. for local cancer treatment. These therapy approaches employ MNPs as remotely controlled drug carriers or local heat generators. Since location and quantity of MNPs determine drug enrichment and heat production, quantitative knowledge of the MNP distribution inside a body is essential for the development and success of these therapies. Magnetorelaxometry (MRX) is capable to provide such quantitative information based on the specific response of the MNPs after switching-off an applied magnetic field. Applying a uniform (homogeneous) magnetic field to a MNP distribution and measuring the MNP response by multiple sensors at different locations allows for spatially resolved MNP quantification. However, to reconstruct the MNP distribution from this spatially resolved MRX data, an ill posed inverse problem has to be solved. So far, the solution of this problem was stabilized incorporating a-priori knowledge in the forward model, e.g. by setting priors on the vertical position of the distribution using a 2D reconstruction grid or setting priors on the number and geometry of the MNP sources inside the body. MRX tomography represents a novel approach for quantitative 3D imaging of MNPs, where the inverse solution is stabilized by a series of MRX measurements. In MRX tomography, only parts of the MNP distribution are sequentially magnetized by the use of inhomogeneous magnetic fields. Each magnetizing is followed by detection of the response of the corresponding part of the distribution by multiple sensors. The 3D reconstruction of the MNP distribution is then accomplished by a common evaluation of the distinct MRX measurement series. In this thesis the first experimental setup for MRX tomography was developed for quantitative 3D imaging of biomedical MNP distributions. It is based on a multi-channel magnetizing unit which has been engineered to

  12. Pattern recognition analysis of proton nuclear magnetic resonance spectra of brain tissue extracts from rats anesthetized with propofol or isoflurane.

    Directory of Open Access Journals (Sweden)

    Hiroshi Kawaguchi

    Full Text Available BACKGROUND: General anesthesia is routinely used as a surgical procedure and its safety has been endorsed by clinical outcomes; however, its effects at the molecular level have not been elucidated. General anesthetics influence glucose metabolism in the brain. However, the effects of anesthetics on brain metabolites other than those related to glucose have not been well characterized. We used a pattern recognition analysis of proton nuclear magnetic resonance spectra to visualize the changes in holistic brain metabolic phenotypes in response to the widely used intravenous anesthetic propofol and the volatile anesthetic isoflurane. METHODOLOGY/PRINCIPAL FINDINGS: Rats were randomized into five groups (n = 7 each group. Propofol and isoflurane were administered to two groups each, for 2 or 6 h. The control group received no anesthesia. Brains were removed directly after anesthesia. Hydrophilic compounds were extracted from excised whole brains and measured by proton nuclear magnetic resonance spectroscopy. All spectral data were processed and analyzed by principal component analysis for comparison of the metabolite profiles. Data were visualized by plotting principal component (PC scores. In the plots, each point represents an individual sample. The propofol and isoflurane groups were clustered separately on the plots, and this separation was especially pronounced when comparing the 6-h groups. The PC scores of the propofol group were clearly distinct from those of the control group, particularly in the 6-h group, whereas the difference in PC scores was more subtle in the isoflurane group and control groups. CONCLUSIONS/SIGNIFICANCE: The results of the present study showed that propofol and isoflurane exerted differential effects on holistic brain metabolism under anesthesia.

  13. Noninvasive quantitation of human liver steatosis using magnetic resonance and bioassay methods

    Energy Technology Data Exchange (ETDEWEB)

    D' Assignies, Gaspard; Ruel, Martin; Khiat, Abdesslem; Lepanto, Luigi; Kauffmann, Claude; Tang, An [Centre Hospitalier de l' Universite de Montreal (CHUM), Departement de Radiologie, Montreal, Quebec (Canada); Chagnon, Miguel [Universite de Montreal (UDEM), Departement de Mathematiques et de Statistique, Montreal, Quebec (Canada); Gaboury, Louis [Centre Hospitalier de l' Universite de Montreal (CHUM), Departement d' Anatomo-Pathologie, Montreal, Quebec (Canada); Boulanger, Yvan [Centre Hospitalier de l' Universite de Montreal (CHUM), Departement de Radiologie, Montreal, Quebec (Canada); Hopital Saint-Luc du CHUM, Departement de Radiologie, Montreal, Quebec (Canada)

    2009-08-15

    The purpose was to evaluate the ability of three magnetic resonance (MR) techniques to detect liver steatosis and to determine which noninvasive technique (MR, bioassays) or combination of techniques is optimal for the quantification of hepatic fat using histopathology as a reference. Twenty patients with histopathologically proven steatosis and 24 control subjects underwent single-voxel proton MR spectroscopy (MRS; 3 voxels), dual-echo in phase/out of phase MR imaging (DEI) and diffusion-weighted MR imaging (DWI) examinations of the liver. Blood or urine bioassays were also performed for steatosis patients. Both MRS and DEI data allowed to detect steatosis with a high sensitivity (0.95 for MRS; 1 for DEI) and specificity (1 for MRS; 0.875 for DEI) but not DWI. Strong correlations were found between fat fraction (FF) measured by MRS, DEI and histopathology segmentation as well as with low density lipoprotein (LDL) and cholesterol concentrations. A Bland-Altman analysis showed a good agreement between the FF measured by MRS and DEI. Partial correlation analyses failed to improve the correlation with segmentation FF when MRS or DEI data were combined with bioassay results. Therefore, FF from MRS or DEI appear to be the best parameters to both detect steatosis and accurately quantify fat liver noninvasively. (orig.)

  14. Proton therapy device

    International Nuclear Information System (INIS)

    Tronc, D.

    1994-01-01

    The invention concerns a proton therapy device using a proton linear accelerator which produces a proton beam with high energies and intensities. The invention lies in actual fact that the proton beam which is produced by the linear accelerator is deflected from 270 deg in its plan by a deflecting magnetic device towards a patient support including a bed the longitudinal axis of which is parallel to the proton beam leaving the linear accelerator. The patient support and the deflecting device turn together around the proton beam axis while the bed stays in an horizontal position. The invention applies to radiotherapy. 6 refs., 5 figs

  15. Clinical applications of proton magnetic resonance spectroscopy of the brain; Klinische Anwendungen der Protonen-Magnetresonanzspektroskopie des Gehirns

    Energy Technology Data Exchange (ETDEWEB)

    Laubenberger, J.; Bayer, S.; Thiel, T.; Hennig, J.; Langer, M. [Radiologische Universitaetsklinik Freiburg (Germany). Abt. Roentgendiagnostik

    1998-06-01

    In spite of all the scientific advances of the past few years, proton magnetic resonance spectroscopy of the brain has not attained the status of a routine examination technique with clinically accepted indications. The method should be considered as an additional option to MR imaging for inherited and acquired encephalopathic changes as well as, in future, for localization diagnosis of epilepsies. A proton magnetic resonance spectroscopic investigation without a prior intensive clinical and imaging investigation is not useful. Above all, factors influencing metabolite distribution such as for example, serum osmolability must be known. Methodological prerequisites for the clinical application of proton resonance spectroscopy are, first of all, a high stability of the chosen technique as well as a sufficiently certain quantification of metabolites and the availability of a reference group. The use of short echo times is necessary for the quantification of glutamine and the osmolyte myo-inositol. Indications for individual cases in which clinical investigations and MR topography cannot provide sufficient certainty and spectroscopy can furnish additional information are, in addition to uses in neuropediatrics, the suspicion of Alzheimer`s dementia, HIV encephalopathy in early manifestations, and unclarified depressions of consciousness accompanying liver cirrhosis. (orig.) [Deutsch] Die Protonen-Magnetresonanzspektroskopie des Gehirns ist trotz aller wissenschaftlicher Fortschritte der letzten Jahre noch nicht zu einer Routineuntersuchung mit anerkannter klinischer Indikationsstellung geworden. Die Untersuchung muss bei angeborenen und erworbenen enzephalopathischen Veraenderungen sowie in Zukunft in der Lokalisationsdiagnostik von Epilepsien als Zusatzoption zur MR-Bildgebung erachtet werden. Eine protonenspektroskopische Untersuchung ohne ausgiebige klinische und bildgebende Basisuntersuchung ist nicht sinnvoll. Insbesondere muessen Einflussfaktoren, wie z

  16. 7 Tesla proton magnetic resonance spectroscopic imaging in adult X-linked adrenoleukodystrophy

    Science.gov (United States)

    Ratai, Eva; Kok, Trina; Wiggins, Christopher; Wiggins, Graham; Grant, Ellen; Gagoski, Borjan; O'Neill, Gilmore; Adalsteinsson, Elfar; Eichler, Florian

    2010-01-01

    Background Adult patients with X-linked adrenoleukodystrophy (X-ALD) remain at risk for progressive neurological deterioration. Phenotypes vary in their pathology, ranging from axonal degeneration to inflammatory demyelination. The severity of symptoms is poorly explained by conventional imaging. Objective To test the hypothesis that neurochemistry in normal appearing brain differs among adult phenotypes of X-ALD, and that neurochemical changes correlate with the severity of symptoms. Patients and Methods Using a 7 Tesla scanner we performed structural and proton MRSI in 13 adult patients with X-ALD, including 4 patients with adult cerebral ALD (ACALD), 5 with adrenomyeloneuropathy (AMN) and 4 female heterozygotes. Studies were also performed in nine healthy controls. Results Among adult X-ALD phenotypes, MI/Cr was 46% higher and Cho/Cr 21% higher in normal appearing white matter of ACALD compared to AMN (p Tesla proton MRSI reveals differences in the neurochemistry of ACALD but is unable to distinguish AMN from female heterozygotes. MI/Cr correlates with the severity of the symptoms and may be a meaningful biomarker in adult X-ALD. PMID:19001168

  17. Quantitative evaluations of left ventricular function obtained by electrocardiographically-gated magnetic resonance imaging

    International Nuclear Information System (INIS)

    Takeda, Tohru; Iida, Kaname; Sugishita, Yasuro; Anno, Izumi; Akisada, Masayoshi; Matsuda, Mitsuo; Akatsuka, Takao; Koseki, Susumu.

    1989-01-01

    Using electrocardiographically-gated magnetic resonance imaging, regional cardiac function was evaluated in 12 normal volunteers and in 10 cases of old myocardial infarction. The optimal short axis of the left ventricle was selected at the chordae tendineae level. The left ventricle was divided into 12 segments using a computer-aided system, and percentile shortening fraction (%SF) and percentile wall thickening (%WT) were calculated in each segment by the fixed coordinate method. In the normal volunteers, heterogeneity of both %FS and %WT was observed, ranging from 25±13% and 37±13%, respectively in the septal segment, to 49±13% and 60±21%, respectively in the posterior segment. In the cases of myocardial infarction, decreased %FS and %WT were detected at the affected regions. The abnormal regions revealed by %WT tended to be narrower than those revealed by %FS. Thus the MR technique at the optimal axis may be useful for quantitative evaluations of regional cardiac function. (author)

  18. Quantitative magnetic resonance imaging and studies of degenerative diseases of the developing human brain

    International Nuclear Information System (INIS)

    Caviness, V.S. Jr.; Phil, D.; Filipek, P.A.; Kennedy, D.N.

    1992-01-01

    The Rett syndrome is a progressive disorder which is associated with regression of psychomotor development and precipitous deceleration of brain growth during the first year of life. General histopathological surveys in postmortem specimens have identified degeneration of subpopulations of neurons of the nigrostriatal system but no other evidence of degenerative process. Magnetic resonance imaging-based morphometry may usefully guide application of rigorous but demanding quantitative histologic search for evidence of neuronal degeneration. The volumes of the principal set of cortical and nuclear structures of principal interest in the disorder may be measured by currently avaiable MRI-based methods. Opimized levels of precision now allow detection of volumetric changes over time in the same brain of approximately 10% at the 95% confidence level. (author)

  19. Development of Selective Excitation Methods in Nuclear Magnetic Resonance: Investigation of Hemoglobin Oxygenation in Erythrocytes Using Proton and Phosphorus -31 Nuclear Magnetic Resonance

    Science.gov (United States)

    Fetler, Bayard Keith

    1993-01-01

    Nuclear magnetic resonance (NMR) offers a potential method for making measurements of the percent oxygenation of hemoglobin (Hb) in living tissue non-invasively. As a demonstration of the feasibility of such measurements, we measured the percent oxygenation of Hb in red blood cells (erythrocytes) using resonances in the proton-NMR (^1H-NMR) spectrum which are characteristic of oxyhemoglobin (oxy-Hb) and deoxyhemoglobin (deoxy-Hb), and are due to the unique magnetic properties of these molecules. To perform these measurements, we developed a new NMR method of selectively exciting signals in a region of interest with uniform phase and amplitude, while suppressing the signal of the water resonance. With this method, we are able to make exact calculations distinguishing between uniform phase excitation produced at large flip-angles using the non-linear properties of the Bloch equations, and uniform phase excitation produced at small flip-angles using asymmetric pulse excitation functions. We measured the percent oxygenation of three characteristic ^1H-NMR resonances of Hb: two from deoxy-Hb, originating from the N_delta H protons of histidine residue F8, which occur at different frequencies for the alpha and beta chains of Hb; and one from oxy-Hb, originating from the gamma_2 -CH_3 protons of valine residue E11. We performed experiments both on fresh erythrocytes and on erythrocytes depleted of 2,3-diphosphoglycerate (2,3-DPG), and found that oxygen is more tightly bound to Hb in the former case. In both fresh and 2,3-DPG-depleted samples, we found that: (i) from the deoxy-Hb marker resonances, there is a small but significant difference in the oxygen saturation between the alpha and beta chains; (ii) the decrease in the areas of the deoxy-Hb marker resonances correlates well with the increase in the percent oxygenation of Hb as measured optically; (iii) the area of the oxy-Hb marker resonance may be up to ~15% less than the optically measured Hb saturation. We are

  20. Toward comparability of coronary magnetic resonance angiography: proposal for a standardized quantitative assessment

    International Nuclear Information System (INIS)

    Dirksen, Martijn S.; Lamb, Hildo J.; Geest, Rob van der; Roos, Albert de

    2003-01-01

    A method is proposed for the quantitative assessment of coronary magnetic resonance angiography (MRA) acquisitions. The method is based on four parameters: signal-to-noise ratio (SNR); contrast-to-noise ratio (CNR); vessel length; and vessel-edge definition. A pig model (n=7) was used to illustrate the proposed quantitative analysis method. Three-dimensional gradient-echo coronary MRA was performed with and without exogenous contrast enhancement using a gadolinium-based blood-pool contrast agent (Vistarem, Guerbet, Aulnay-Sous-Bois, France). The acquired images could be well differentiated based on the four parameters. The SNR was calculated as 9.0±1.4 vs 10.4±2.1, the CNR as 6.2±0.8 vs 8.2±0.9, the vessel length as 48.2±11.6 vs 86.5±13.8 mm, and the vessel-edge definition as 4.9±1.5 vs 7.7±3.4. Different coronary MRA techniques can be evaluated objectively with the combined use of SNR, CNR, vessel length, and vessel-edge parameters. (orig.)

  1. Quantitative Magnetic Resonance Imaging Volumetry of Facial Muscles in Healthy Patients with Facial Palsy

    Science.gov (United States)

    Volk, Gerd F.; Karamyan, Inna; Klingner, Carsten M.; Reichenbach, Jürgen R.

    2014-01-01

    Background: Magnetic resonance imaging (MRI) has not yet been established systematically to detect structural muscular changes after facial nerve lesion. The purpose of this pilot study was to investigate quantitative assessment of MRI muscle volume data for facial muscles. Methods: Ten healthy subjects and 5 patients with facial palsy were recruited. Using manual or semiautomatic segmentation of 3T MRI, volume measurements were performed for the frontal, procerus, risorius, corrugator supercilii, orbicularis oculi, nasalis, zygomaticus major, zygomaticus minor, levator labii superioris, orbicularis oris, depressor anguli oris, depressor labii inferioris, and mentalis, as well as for the masseter and temporalis as masticatory muscles for control. Results: All muscles except the frontal (identification in 4/10 volunteers), procerus (4/10), risorius (6/10), and zygomaticus minor (8/10) were identified in all volunteers. Sex or age effects were not seen (all P > 0.05). There was no facial asymmetry with exception of the zygomaticus major (larger on the left side; P = 0.012). The exploratory examination of 5 patients revealed considerably smaller muscle volumes on the palsy side 2 months after facial injury. One patient with chronic palsy showed substantial muscle volume decrease, which also occurred in another patient with incomplete chronic palsy restricted to the involved facial area. Facial nerve reconstruction led to mixed results of decreased but also increased muscle volumes on the palsy side compared with the healthy side. Conclusions: First systematic quantitative MRI volume measures of 5 different clinical presentations of facial paralysis are provided. PMID:25289366

  2. Proton magnetic resonance chemical shift imaging (1H CSI)-directed stereotactic biopsy

    International Nuclear Information System (INIS)

    Son, B.-C.; Kim, B.-C.; Kang, J.-K.; Choi, B.-G.; Kim, E.-N.; Baik, H.-M.; Choe, B.-Y.; Naruse, S.

    2001-01-01

    Introduction. To add metabolic information during stereotactic biopsy target selection, the authors adopted proton chemical shift imaging ( 1 H CSI)-directed stereotactic biopsy. Currently, proton single voxel spectroscopy (SVS) technique has been reported in stereotactic biopsy. We performed 1 H CSI in combination with a stereotactic headframe and selected targets according to local metabolic information, and evaluated the pathological results. Patients and Method. The 1 H CSI-directed stereotactic biopsy was performed in four patients. 1 H CSI and conventional Gd-enhancement stereotactic MRI were performed simultaneously after the fitting of a stereotactic frame. After reconstructing the metabolic maps of N-acetylaspartate (NAA)/phosphocreatine (Cr), phosphocholine (Cho)/Cr, and Lactate/Cr ratios, focal areas of increased Cho/Cr ratio and Lac/Cr ratios were selected as target sites in the stereotactic MR images. Result. 1 H CSI is possible with the stereotactic headframe in place. No difficulty was experienced performing 1 H CSI or making a diagnosis. Pathological samples taken from areas of increased Cho/Cr ratios and decreased NAA/Cr ratios provided information upon increased cellularity, mitoses and cellular atypism, and facilitated diagnosis. Pathological samples taken from areas of increased Lac/ Cr ratio snowed predominant feature of necrosis. Conclusion. 1 H CSI was feasible with the stereotactic headframe in place. The final pathological results obtained were concordant with the local metabolic information from 1 H CSI. We believe that 1 H CSI-directed stereotactic biopsy has the potential to significantly improve the accuracy of stereotactic biopsy targeting. (author)

  3. A direct search for stable magnetic monopoles produced in positron proton collisions at HERA

    Czech Academy of Sciences Publication Activity Database

    Aktas, A.; Andreev, V.; Anthonis, T.; Cvach, Jaroslav; Herynek, Ivan; Reimer, Petr; Sedlák, Kamil; Zálešák, Jaroslav

    2005-01-01

    Roč. 41, - (2005), s. 133-144 ISSN 1434-6044 Institutional research plan: CEZ:AV0Z10100502 Keywords : HI experiment * ep scattering * magnetic monopoles Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.209, year: 2005

  4. Noninvasive monitoring of radiation-induced treatment response using proton magnetic resonance spectroscopy and diffusion-weighted magnetic resonance imaging in a colorectal tumor model

    International Nuclear Information System (INIS)

    Seierstad, Therese; Roe, Kathrine; Olsen, Dag Rune

    2007-01-01

    Background and purpose: To examine whether in vivo proton magnetic resonance spectroscopy ( 1 H MRS) and diffusion-weighted magnetic resonance imaging (DW-MRI) can monitor radiation-induced changes in HT29 xenografts in mice. Materials and methods: HT29 xenografts in mice received a dose of 15 Gy. In vivo 1 H MRS and DW-MRI were acquired pretreatment and 1, 3, 6 and 10 days post-irradiation. After imaging, tumors were excised for histological analysis. The amounts of necrosis, fibrosis and viable cells in the cross sections were scored and compared to changes in apparent diffusion coefficient (ADC) and choline/water ratio. Results: Radiation-induced necrosis in the xenografts was observed as increased tumor ADC. In-growth of fibrosis three days post-irradiation restricting water mobility was accompanied by decreased tumor ADC. Choline/water ratio correlated with metabolic activity and tumor growth. Conclusions: ADC and choline/water ratio assessed by in vivo DW-MRI and 1 H MRS depicts radiation-induced changes in HT29 xenografts following irradiation

  5. Effects of acupuncture therapy on abdominal fat and hepatic fat content in obese children: a magnetic resonance imaging and proton magnetic resonance spectroscopy study.

    Science.gov (United States)

    Zhang, Hong; Peng, Yun; Liu, ZuXiang; Li, Shilian; Lv, Zhongli; Tian, LiFang; Zhu, Jie; Zhao, XuNa; Chen, Min

    2011-05-01

    The aim of this study was to use magnetic resonance imaging (MRI) together with proton magnetic resonance spectroscopy ((1)H-MRS) to study the influence of acupuncture therapy on abdominal fat and hepatic fat content in obese children. The design was a longitudinal, clinical intervention study of acupuncture therapy. SUBJECTS were 10 healthy, obese children (age: 11.4 ± 1.65 years, body-mass index [BMI]: 29.03 ± 4.81 kg/m(2)). Measurements included various anthropometric parameters, abdominal fat (assessed by MRI) and hepatic fat content (assessed by (1)H-MRS) at baseline and after 1 month of acupuncture therapy. One (1) month of acupuncture therapy significantly reduced the subjects' BMI by 3.5% (p = 0.005), abdominal visceral adipose tissue (VAT) volume by 16.04% (p  0.05). There was a significant correlation between the level of abdominal fat (SAT, VAT) and anthropometric parameters (weight, BMI, waist circumferences, hip circumferences). There was no statistically significant correlation between IHTG and anthropometric parameters or abdominal fat content. The first direct experimental evidence is provided demonstrating that acupuncture therapy significantly reduces BMI and abdominal adipose tissue by reducing abdominal VAT content without significant changes in body weight, waist circumference, hip circumference, WHR, abdominal SAT, or IHTG content. Thus, the use of acupuncture therapy to selectively target a reduction in abdominal VAT content should become more important and more popular in the future.

  6. Characterization of the ELIMED Permanent Magnets Quadrupole system prototype with laser-driven proton beams

    Czech Academy of Sciences Publication Activity Database

    Schillaci, F.; Pommarel, L.; Romano, F.; Cuttone, G.; Costa, M.; Giove, D.; Maggiore, M.; Russo, A.D.; Scuderi, Valentina; Malka, V.; Vauzour, B.; Flacco, A.; Cirrone, G.A.P.

    2016-01-01

    Roč. 11, Jul (2016), s. 1-16, č. článku T07005. ISSN 1748-0221 R&D Projects: GA MŠk EF15_008/0000162; GA MŠk LQ1606 Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 Keywords : cceleration cavities and magnets superconducting * beam dynamics * Accelerator modelling and simulations * Beam Optics Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.220, year: 2016

  7. Magnetic resonance imaging of stents. Quantitative in vitro examination at 3 Tesla

    International Nuclear Information System (INIS)

    Reinhardt, Julia; Fachhochschule Jena; Nguyen-Trong, Thien-Hoa; Haehnel, Stefan; Bellemann, Matthias E.; Heiland, Sabine; Neurologische Universitaetsklinik Heidelberg

    2009-01-01

    The aim of this study was to qualitatively and quantitatively study MR artifacts of various stents on the basis of in vitro experiments. We were particularly interested whether sequence type and orientation of the stent with respect to the static magnetic field influences the artifact. We examined 18 stents of different material (nitinol, stainless steel, cobalt alloy), different design of the stent meshes (AccuLink, OmniLink, DynaLink, Xact, Protoge, Wallstent Monorail), different diameter (5-10 mm) and different length (18-58 mm) with a turbo spin echo (TSE), a 2D-fast low angle shot (FLASH) and a 3D-FLASH sequence. The MR images were examined qualitatively with respect to possible artifacts. Furthermore we examined the MR data quantitatively: The contrast-noise-ratio (CNR) was determined both within the stent and outside (within the tube); based on these values we calculated the transparency factor P, furthermore we calculated the apparent vascular lumen within the tube and within the stent. The stents made of stainless steel and cobalt alloy displayed severe susceptibility artifacts. Therefore the vessel lumen within the stent could not be assessed. The nitinol stents showed different artifact patterns: The AccuLink and DynaLink stents showed less artifacts compared to the Xact and Protoge stents. Besides the susceptibility artifacts we found artifacts due to RF shielding by the stent mesh, particularly in TSE sequences. A MR control of patients after stenting is possible and may yield diagnostic information when using the AccuLink or DynaLink stents. However, it is important to make sure that the stent is MR safe for the field strength used for the examination. (orig.)

  8. Molecular Imaging of Tumors Using a Quantitative T1 Mapping Technique via Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Kelsey Herrmann

    2015-07-01

    Full Text Available Magnetic resonance imaging (MRI of glioblastoma multiforme (GBM with molecular imaging agents would allow for the specific localization of brain tumors. Prior studies using T1-weighted MR imaging demonstrated that the SBK2-Tris-(Gd-DOTA3 molecular imaging agent labeled heterotopic xenograft models of brain tumors more intensely than non-specific contrast agents using conventional T1-weighted imaging techniques. In this study, we used a dynamic quantitative T1 mapping strategy to more objectively compare intra-tumoral retention of the SBK2-Tris-(Gd-DOTA3 agent over time in comparison to non-targeted control agents. Our results demonstrate that the targeted SBK2-Tris-(Gd-DOTA3 agent, a scrambled-Tris-(Gd-DOTA3 control agent, and the non-specific clinical contrast agent Optimark™ all enhanced flank tumors of human glioma cells with similar maximal changes on T1 mapping. However, the retention of the agents differs. The non-specific agents show significant recovery within 20 min by an increase in T1 while the specific agent SBK2-Tris-(Gd-DOTA3 is retained in the tumors and shows little recovery over 60 min. The retention effect is demonstrated by percent change in T1 values and slope calculations as well as by calculations of gadolinium concentration in tumor compared to muscle. Quantitative T1 mapping demonstrates the superior binding and retention in tumors of the SBK2-Tris-(Gd-DOTA3 agent over time compared to the non-specific contrast agent currently in clinical use.

  9. Insula-specific responses induced by dental pain. A proton magnetic resonance spectroscopy study

    International Nuclear Information System (INIS)

    Gutzeit, A.; Weymarn, C. von; Froehlich, J.M.; Binkert, C.A.; Meier, D.; Meier, M.L.; Bruegger, M.; Ettlin, D.A.; Graf, N.

    2011-01-01

    To evaluate whether induced dental pain leads to quantitative changes in brain metabolites within the left insular cortex after stimulation of the right maxillary canine and to examine whether these metabolic changes and the subjective pain intensity perception correlate. Ten male volunteers were included in the pain group and compared with a control group of 10 other healthy volunteers. The pain group received a total of 87-92 electrically induced pain stimuli over 15 min to the right maxillary canine tooth. Contemporaneously, they evaluated the subjective pain intensity of every stimulus using an analogue scale. Neurotransmitter changes within the left insular cortex were evaluated by MR spectroscopy. Significant metabolic changes in glutamine (+55.1%), glutamine/glutamate (+16.4%) and myo-inositol (-9.7%) were documented during pain stimulation. Furthermore, there was a significant negative correlation between the subjective pain intensity perception and the metabolic levels of Glx, Gln, glutamate and N-acetyl aspartate. The insular cortex is a metabolically active region in the processing of acute dental pain. Induced dental pain leads to quantitative changes in brain metabolites within the left insular cortex resulting in significant alterations in metabolites. Negative correlation between subjective pain intensity rating and specific metabolites could be observed. (orig.)

  10. Insula-specific responses induced by dental pain. A proton magnetic resonance spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Gutzeit, A.; Weymarn, C. von; Froehlich, J.M.; Binkert, C.A. [Cantonal Hospital Winterthur, Department of Radiology, Winterthur (Switzerland); Meier, D. [University and ETH Zurich, Institute for Biomedical Engineering, Zurich (Switzerland); Meier, M.L.; Bruegger, M. [University of Zurich, Institute of Psychology, Division Neuropsychology, Zurich (Switzerland); Ettlin, D.A. [University of Zuerich, Center for Dental and Oral Medicine and Cranio-Maxillofacial Surgery, Clinic for Removable Prosthodontics, Masticatory Disorders and Special Care Dentistry, Zuerich (Switzerland); Graf, N. [University Hospital of Zurich, Clinical Trials Center, Center for Clinical Research, Zurich (Switzerland)

    2011-04-15

    To evaluate whether induced dental pain leads to quantitative changes in brain metabolites within the left insular cortex after stimulation of the right maxillary canine and to examine whether these metabolic changes and the subjective pain intensity perception correlate. Ten male volunteers were included in the pain group and compared with a control group of 10 other healthy volunteers. The pain group received a total of 87-92 electrically induced pain stimuli over 15 min to the right maxillary canine tooth. Contemporaneously, they evaluated the subjective pain intensity of every stimulus using an analogue scale. Neurotransmitter changes within the left insular cortex were evaluated by MR spectroscopy. Significant metabolic changes in glutamine (+55.1%), glutamine/glutamate (+16.4%) and myo-inositol (-9.7%) were documented during pain stimulation. Furthermore, there was a significant negative correlation between the subjective pain intensity perception and the metabolic levels of Glx, Gln, glutamate and N-acetyl aspartate. The insular cortex is a metabolically active region in the processing of acute dental pain. Induced dental pain leads to quantitative changes in brain metabolites within the left insular cortex resulting in significant alterations in metabolites. Negative correlation between subjective pain intensity rating and specific metabolites could be observed. (orig.)

  11. Glutamatergic system dysfunction in schizophrenia. A proton magnetic resonance spectroscopy (1H MRS) study

    International Nuclear Information System (INIS)

    Szulc, A.; Galinska, B.; Czernikiewicz, A.; Tarasow, E.; Kubas, B.; Dzienis, W.; Walecki, J.

    2004-01-01

    The present study was performed to determine whether there are any differences in metabolite levels as measured by 1 H MRS between chronic and first-episode schizophrenic patients. 17 patients with the diagnosis of chronic schizophrenia and 31 patients with first-episode schizophrenia (ICD-10) were included into the study. The patients were assessed by means of PANSS, CGI and Calgary scales.We also examined 13 healthy persons as control group. MRI and MRS procedures: Proton resonance spectroscopy was performed on a 1,5 MR scanner, PRESS sequence, TR=1500 ms, TE=35 ms, number of repetition=192 and included suppression of water by MOIST sequence. Each volume element (voxel) had dimension of 2x2x2 cm and was localised in the left frontal lobe, in the left temporal lobe and in left thalamus. Complex containing glutamine (Gln), glutamate (Glu) and gamma-aminobutyric acid (GABA) was measured. Ratios of metabolite to creatine and unsuppressed water signal were analysed. We didn't find any significant differences in Glx levels between chronic and first-episode patients and between chronic patients and controls in all studied regions.In the left temporal lobe Glx/Cr ratio was significantly higher in first-episode patients in comparison to controls.We observed significant positive correlation between Glx/Cr level in the left temporal lobe and CGI and PANSS-Negative scores, and negative correlation between Glx/H 2 0 level in the left temporal lobe and PANSS-Positive score. Increased Glx level in the left temporal lobe in first-episode patients suggest that altered glutamatergic activity in this region is present at the onset of disease and doesn't progress over time. (author)

  12. Nonlinear Alfvén waves, discontinuities, proton perpendicular acceleration, and magnetic holes/decreases in interplanetary space and the magnetosphere: intermediate shocks?

    Directory of Open Access Journals (Sweden)

    B. T. Tsurutani

    2005-01-01

    Full Text Available Alfvén waves, discontinuities, proton perpendicular acceleration and magnetic decreases (MDs in interplanetary space are shown to be interrelated. Discontinuities are the phase-steepened edges of Alfvén waves. Magnetic decreases are caused by a diamagnetic effect from perpendicularly accelerated (to the magnetic field protons. The ion acceleration is associated with the dissipation of phase-steepened Alfvén waves, presumably through the Ponderomotive Force. Proton perpendicular heating, through instabilities, lead to the generation of both proton cyclotron waves and mirror mode structures. Electromagnetic and electrostatic electron waves are detected as well. The Alfvén waves are thus found to be both dispersive and dissipative, conditions indicting that they may be intermediate shocks. The resultant 'turbulence' created by the Alfvén wave dissipation is quite complex. There are both propagating (waves and nonpropagating (mirror mode structures and MDs byproducts. Arguments are presented to indicate that similar processes associated with Alfvén waves are occurring in the magnetosphere. In the magnetosphere, the 'turbulence' is even further complicated by the damping of obliquely propagating proton cyclotron waves and the formation of electron holes, a form of solitary waves. Interplanetary Alfvén waves are shown to rapidly phase-steepen at a distance of 1AU from the Sun. A steepening rate of ~35 times per wavelength is indicated by Cluster-ACE measurements. Interplanetary (reverse shock compression of Alfvén waves is noted to cause the rapid formation of MDs on the sunward side of corotating interaction regions (CIRs. Although much has been learned about the Alfvén wave phase-steepening processfrom space plasma observations, many facets are still not understood. Several of these topics are discussed for the interested researcher. Computer simulations and theoretical developments will be particularly useful in making further progress in

  13. Quantitative and qualitative assessment of structural magnetic resonance imaging data in a two-center study

    International Nuclear Information System (INIS)

    Chalavi, Sima; Simmons, Andrew; Dijkstra, Hildebrand; Barker, Gareth J; Reinders, AAT Simone

    2012-01-01

    Multi-center magnetic resonance imaging (MRI) studies present an opportunity to advance research by pooling data. However, brain measurements derived from MR-images are susceptible to differences in MR-sequence parameters. It is therefore necessary to determine whether there is an interaction between the sequence parameters and the effect of interest, and to minimise any such interaction by careful choice of acquisition parameters. As an exemplar of the issues involved in multi-center studies, we present data from a study in which we aimed to optimize a set of volumetric MRI-protocols to define a protocol giving data that are consistent and reproducible across two centers and over time. Optimization was achieved based on data quality and quantitative measures, in our case using FreeSurfer and Voxel Based Morphometry approaches. Our approach consisted of a series of five comparisons. Firstly, a single-center dataset was collected, using a range of candidate pulse-sequences and parameters chosen on the basis of previous literature. Based on initial results, a number of minor changes were implemented to optimize the pulse-sequences, and a second single-center dataset was collected. FreeSurfer data quality measures were compared between datasets in order to determine the best performing sequence(s), which were taken forward to the next stage of testing. We subsequently acquired short-term and long-term two-center reproducibility data, and quantitative measures were again assessed to determine the protocol with the highest reproducibility across centers. Effects of a scanner software and hardware upgrade on the reproducibility of the protocols at one of the centers were also evaluated. Assessing the quality measures from the first two datasets allowed us to define artefact-free protocols, all with high image quality as assessed by FreeSurfer. Comparing the quantitative test and retest measures, we found high within-center reproducibility for all protocols, but lower

  14. GABA concentration in schizophrenia patients and the effects of antipsychotic medication: a proton magnetic resonance spectroscopy study.

    Science.gov (United States)

    Tayoshi, Shin'Ya; Nakataki, Masahito; Sumitani, Satsuki; Taniguchi, Kyoko; Shibuya-Tayoshi, Sumiko; Numata, Shusuke; Iga, Jun-ichi; Ueno, Shu-ichi; Harada, Masafumi; Ohmori, Tetsuro

    2010-03-01

    Gamma-amino butyric acid (GABA) is thought to play a role in the pathophysiology of schizophrenia. High magnetic field proton magnetic resonance spectroscopy ((1)H-MRS) provides a reliable measurement of GABA in specific regions of the brain. This study measured GABA concentration in the anterior cingulate cortex (ACC) and in the left basal ganglia (ltBG) in 38 patients with chronic schizophrenia and 29 healthy control subjects. There was no significant difference in GABA concentration between the schizophrenia patients and the healthy controls in either the ACC (1.36+/-0.45 mmol/l in schizophrenia patients and 1.52+/-0.54 mmol/l in control subjects) or the ltBG (1.13+/-0.26 mmol/l in schizophrenia patients and 1.18+/-0.20 mmol/l in control subjects). Among the right handed schizophrenia patients, the GABA concentration in the ltBG was significantly higher in patients taking typical antipsychotics (1.25+/-0.24 mmol/l) than in those taking atypical antipsychotics (1.03+/-0.24 mmol/l, p=0.026). In the ACC, the GABA concentration was negatively correlated with the dose of the antipsychotics (rs=-0.347, p=0.035). In the ltBG, the GABA concentration was positively correlated with the dose of the anticholinergics (rs=0.403, p=0.015). To the best of our knowledge, this is the first study to have directly measured GABA concentrations in schizophrenia patients using (1)H-MRS. Our results suggest that there are no differences in GABA concentrations in the ACC or the ltBG of schizophrenia patients compared to healthy controls. Antipsychotic medication may cause changes in GABA concentration, and atypical and typical antipsychotics may have differing effects. It is possible that medication effects conceal inherent differences in GABA concentrations between schizophrenia patients and healthy controls. (c) 2009 Elsevier B.V. All rights reserved.

  15. Thermal Fluctuations in the Magnetic Ground State of the Molecular Cluster Mn12O12 Acetate from μSR and Proton NMR Relaxation

    International Nuclear Information System (INIS)

    Lascialfari, A.; Borsa, F.; Carretta, P.; Jang, Z.H.; Borsa, F.; Gatteschi, D.

    1998-01-01

    Measurements of the spin-lattice relaxation rate are reported for muons and protons as a function of temperature for different values of the applied magnetic field in the Mn 12 O 12 molecular cluster. Strongly field dependent maxima in the relaxation rate versus temperature are observed below 50thinspthinspK. The results are explained in terms of thermal fluctuations of the total magnetization of the cluster among the different orientations with respect to the anisotropy axis. The lifetimes of the different m components of the total spin, S T =10 , of the molecule are obtained from the experiment and shown to be consistent with the ones expected from a spin-phonon coupling mechanism. No clear evidence for macroscopic quantum tunneling was observed in the field dependence of the proton relaxation rate at low T . copyright 1998 The American Physical Society

  16. 7T Proton Magnetic Resonance Spectroscopy of Gamma-Aminobutyric Acid, Glutamate, and Glutamine Reveals Altered Concentrations in Patients With Schizophrenia and Healthy Siblings

    DEFF Research Database (Denmark)

    Thakkar, Katharine N; Rösler, Lara; Wijnen, Jannie P

    2017-01-01

    BACKGROUND: The N-methyl-D-aspartate receptor hypofunction model of schizophrenia predicts dysfunction in both glutamatergic and gamma-aminobutyric acidergic (GABAergic) transmission. We addressed this hypothesis by measuring GABA, glutamate, glutamine, and the sum of glutamine plus glutamate...... concentrations in vivo in patients with schizophrenia using proton magnetic resonance spectroscopy at 7T, which allows separation of metabolites that would otherwise overlap at lower field strengths. In addition, we investigated whether altered levels of GABA, glutamate, glutamine, and the sum of glutamine plus...... glutamate reflect genetic vulnerability to schizophrenia by including healthy first-degree relatives. METHODS: Proton magnetic resonance spectroscopy at 7T was performed in 21 patients with chronic schizophrenia who were taking medication, 23 healthy first-degree relatives of patients with schizophrenia...

  17. A proton nuclear magnetic resonance investigation of proximal histidyl residues in human normal and abnormal hemoglobins: a probe for the heme pocket

    International Nuclear Information System (INIS)

    Takahashi, S.; Lin, A.K.L.; Ho, C.

    1982-01-01

    Proton nuclear magnetic resonance spectroscopy at 250 MHz has been used to investigate the conformations of proximal histidyl residues of human normal adult hemoglobin, hemoglobin Kempsey [K145(HC2) Tyr #betta# Asp], and hemoglobin McKees Rocks [K145(HC2) Tyr #betta# Term] around neutral pH in H 2 O at 27 0 C, all in the deoxy form. Two resonances that occur between 58 and 76 ppm downfield from the water proton signal have been assigned to the hyperfine shifted proximal histidyl NH-exchangeable protons of the J and K-chains of deoxyhemoglobin. These two resonances are sensitive to the quaternary state of hemoglobin, amino acid substitutions in the J 1 K 2 -subunit interface and in the carboxy-terminal region of the K-chain, and the addition of organic phosphates. The experimental results show that there are differences in the heme pockets among these four hemoglobins studied. The structural and dynamic information derived from the hyperfine shifted proximal histidyl NH-exchangeable proton resonances complement that obtained from the ferrous hyperfine shifted and exchangeable proton resonances of deoxyhemoglobin over the spectral region from 5 to 20 ppm downfield from H 2 O. The relationship between these findings and Perutz's stereochemical mechanism for the cooperative oxygenation of hemoglobin is discussed

  18. Freezing-thawing hysteresis phenomena of biological systems by the new method of proton magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Eiichiro; Nagashima, Nobuya (Ajinomoto Co. Inc., Kawasaki, Kanagawa (Japan))

    1982-09-01

    an automatic recording system was developed for unfrozen water content and spin-spin relaxation time measurements as continuous functions of temperature, by using a broad-line pulsed NMR spectrometer and a minicomputer. The advantages of this system are that the exact quantitative measurements can be done by calibrating the nonlinearity of the NMR sensitivity, and that for high sensitivity temperature measurement the thermocouple with special device is directly immersed in a sample. Three types of freezing-thawing hysteresis phenomena, (1) recrystallization of solute (hydroxy-L-proline, D-mannitol) and refreezing of released hydrated water molecules in frozen aqueous solutions, and (2) hysteresis as the characteristic feature of gels (gelatin, alpha sub(sl)-casein), and (3) supercooling of capillary water in water-insoluble materials (zein, yeast RNA, cellulose) were analysed. The usefulness of this system as an analytical instrument of hydration properties of biological materials is emphasized.

  19. Freezing-thawing hysteresis phenomena of biological systems by the new method of proton magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, E.; Nagashima, N.

    1982-01-01

    An automatic recording system was developed for unfrozen water content and spin-spin relaxation time measurements as continuous functions of temperature, by using a broad-line pulsed NMR spectrometer and a mini-computer. The advantages of this system are that the exact quantitative measurements can be done by calibrating the nonlinearity of the NMR sensitivity, and that for high sensitivity temperature measurement the thermocouple with special device is directly immersed in a sample. Three types of freezing-thawing hysteresis phenomena, (1) recrystallization of solute(hydroxy-L-proline, D-mannitol) and refreezing of released hydrated water molecules in frozen aqueous solutions, and (2) hysteresis as the characteristic feature of gels(gelatin, J/sub s1/-casein), and (3) supercooling of capillary water in water-insoluble materials(zein, yeast RNA, cellulose) were analysed. The usefulness of this system as an analytical instrument of hydration properties of biological materials is emphasized.

  20. Freezing-thawing hysteresis phenomena of biological systems by the new method of proton magnetic resonance

    International Nuclear Information System (INIS)

    Suzuki, Eiichiro; Nagashima, Nobuya

    1982-01-01

    an automatic recording system was developed for unfrozen water content and spin-spin relaxation time measurements as continuous functions of temperature, by using a broad-line pulsed NMR spectrometer and a minicomputer. The advantages of this system are that the exact quantitative measurements can be done by calibrating the nonlinearity of the NMR sensitivity, and that for high sensitivity temperature measurement the thermocouple with special device is directly immersed in a sample. Three types of freezing-thawing hysteresis phenomena, (1) recrystallization of solute (hydroxy-L-proline, D-mannitol) and refreezing of released hydrated water molecules in frozen aqueous solutions, and (2) hysteresis as the characteristic feature of gels(gelatin, alpha sub(sl)-casein), and (3) supercooling of capillary water in water-insoluble materials(zein, yeast RNA, cellulose) were analysed. The usefulness of this system as an analytical instrument of hydration properties of biological materials is emphasized. (author)

  1. Nuclear magnetic resonance provides a quantitative description of protein conformational flexibility on physiologically important time scales.

    Science.gov (United States)

    Salmon, Loïc; Bouvignies, Guillaume; Markwick, Phineus; Blackledge, Martin

    2011-04-12

    A complete description of biomolecular activity requires an understanding of the nature and the role of protein conformational dynamics. In recent years, novel nuclear magnetic resonance-based techniques that provide hitherto inaccessible detail concerning biomolecular motions occurring on physiologically important time scales have emerged. Residual dipolar couplings (RDCs) provide precise information about time- and ensemble-averaged structural and dynamic processes with correlation times up to the millisecond and thereby encode key information for understanding biological activity. In this review, we present the application of two very different approaches to the quantitative description of protein motion using RDCs. The first is purely analytical, describing backbone dynamics in terms of diffusive motions of each peptide plane, using extensive statistical analysis to validate the proposed dynamic modes. The second is based on restraint-free accelerated molecular dynamics simulation, providing statistically sampled free energy-weighted ensembles that describe conformational fluctuations occurring on time scales from pico- to milliseconds, at atomic resolution. Remarkably, the results from these two approaches converge closely in terms of distribution and absolute amplitude of motions, suggesting that this kind of combination of analytical and numerical models is now capable of providing a unified description of protein conformational dynamics in solution.

  2. A semi-quantitative study of transient ischemic attacks by diffusion weighted magnetic resonance imaging

    International Nuclear Information System (INIS)

    Wen Feng; Guo Liang

    2007-01-01

    Objective: To explore the incidence and morphological findings of transient ischemic attacks (TIA) related-focus by diffusion weighted magnetic resonance imaging(DWI), and the semi-quantitative characteristics of TIA related-focus on DWI manifestation were researched. Methods: A prospective analysis was performed on 39 TIA patients who were admitted to the Pudong New Area People Hospital and who had also undergone DWI scan 3 , and rADC ratio of the lesion was (-25.8 ± 9.01)%, and rAI ratio was(59.9 ± 12.9)% and compared with that of the contralateral side there was significant difference. Conclusion: The incidence of positivity rate of DWI is more than that obtained by conventional MR imaging. The related focus of TIA are very small and the ADC value of the lesion is decreased slightly, but averge intensity is increased highly. These data may be of value in identifying those TIA patients for whom MRI evaluation with DWI is of great clinical utility. (authors)

  3. Quantitative Investigation of Roasting-magnetic Separation for Hematite Oolitic-ores: Mechanisms and Industrial Application

    Directory of Open Access Journals (Sweden)

    Peng Tiefeng

    2017-12-01

    Full Text Available Natural high-quality iron can be directly applied to pyro-metallurgy process, however, the availability of these ores has become less and less due to exploitation. This research reports a systematic approach using reduction roasting and magnetic separation for oolitic iron ores from west Hubei Province. Firstly, a mineralogical study was performed and it was shown that the oolitic particles were mainly composed of hematite, with some silicon-quartz inside the oolitic particle. Then, the roasting temperature was examined and shown to have significant influence on both Fe recovery and the Fe content of the concentrate. Also the Fe content gradually increased as the temperature increased from 700 to 850 °C. The most important aspects are the quantitative investigation of change of mineral phases, and reduction area (with ratio during the reduction roasting process. The results showed that Fe2O3 decreased with temperature, and Fe3O4 (magnetite increased considerably from 600 to 800 °C. The reductive reaction was found to occur from the outside in, the original oolitic structure and embedding relationship among the minerals did not change after roasting. Finally, 5% surrounding rock was added to mimic real industrial iron beneficiation. This study could provides useful insight and practical support for the utilization of such iron ores.

  4. Soil magnetic susceptibility: A quantitative proxy of soil drainage for use in ecological restoration

    Science.gov (United States)

    Grimley, D.A.; Wang, J.-S.; Liebert, D.A.; Dawson, J.O.

    2008-01-01

    Flooded, saturated, or poorly drained soils are commonly anaerobic, leading to microbially induced magnetite/maghemite dissolution and decreased soil magnetic susceptibility (MS). Thus, MS is considerably higher in well-drained soils (MS typically 40-80 ?? 10-5 standard international [SI]) compared to poorly drained soils (MS typically 10-25 ?? 10-5 SI) in Illinois, other soil-forming factors being equal. Following calibration to standard soil probings, MS values can be used to rapidly and precisely delineate hydric from nonhydric soils in areas with relatively uniform parent material. Furthermore, soil MS has a moderate to strong association with individual tree species' distribution across soil moisture regimes, correlating inversely with independently reported rankings of a tree species' flood tolerance. Soil MS mapping can thus provide a simple, rapid, and quantitative means for precisely guiding reforestation with respect to plant species' adaptations to soil drainage classes. For instance, in native woodlands of east-central Illinois, Quercus alba , Prunus serotina, and Liriodendron tulipifera predominantly occur in moderately well-drained soils (MS 40-60 ?? 10-5 SI), whereas Acer saccharinum, Carya laciniosa, and Fraxinus pennsylvanica predominantly occur in poorly drained soils (MS Urbana, IL, U.S.A.). Through use of soil MS maps calibrated to soil drainage class and native vegetation occurrence, restoration efforts can be conducted more successfully and species distributions more accurately reconstructed at the microecosystem level. ?? 2008 Society for Ecological Restoration International.

  5. A quantitative assessment of the weakening of wire ropes based on the magnetic testing

    Energy Technology Data Exchange (ETDEWEB)

    Kwasniewski, J.; Lankosz, L.; Tytko, A.

    1985-01-01

    Discusses the use of magnetic defectoscopes and defectographs in the nondestructive testing of wire ropes. Emphasizes the need for laboratory pre-calibration where quantitave results are required. Individual system calibration is recommended where instruments with a 95% confidence level in reading are used, e.g. MD-8 defectograph and DLS unit, but improved tolerances achieved in sensor head manufacture have made possible a universal calibration characteristic for use with defectoscopes and a wide variety of heads. A chart is given covering all heads and induction sensors available in Poland. Describes methods of interpreting presented results to indicate degree of wear due to fatigue, abrasion and corrosion in ropes with constituent wires of differing profile. States that the form of rope wear can be deduced from the character of the defectograph pulse readings. Formulae relating the degree of rope weakening to these readings and also to the integrated output are given. Briefly describes a method for determining the loss of rope cross sectional area based on Hall effect chart records. Outlines the use of the MD-9 and MD-10 defectoscopes in assessing rope wear in discrete ranges. Suggests that regular measurements permit an accurate determination of the character of progressive wear and further that pulse analysis of MD-10 results can permit a quantitative determination of wear. 4 refs.

  6. Quantitative magnetic resonance imaging traits as endophenotypes for genetic mapping in epilepsy

    Directory of Open Access Journals (Sweden)

    Saud Alhusaini

    2016-01-01

    Full Text Available Over the last decade, the field of imaging genomics has combined high-throughput genotype data with quantitative magnetic resonance imaging (QMRI measures to identify genes associated with brain structure, cognition, and several brain-related disorders. Despite its successful application in different psychiatric and neurological disorders, the field has yet to be advanced in epilepsy. In this article we examine the relevance of imaging genomics for future genetic studies in epilepsy from three perspectives. First, we discuss prior genome-wide genetic mapping efforts in epilepsy, considering the possibility that some studies may have been constrained by inherent theoretical and methodological limitations of the genome-wide association study (GWAS method. Second, we offer a brief overview of the imaging genomics paradigm, from its original inception, to its role in the discovery of important risk genes in a number of brain-related disorders, and its successful application in large-scale multinational research networks. Third, we provide a comprehensive review of past studies that have explored the eligibility of brain QMRI traits as endophenotypes for epilepsy. While the breadth of studies exploring QMRI-derived endophenotypes in epilepsy remains narrow, robust syndrome-specific neuroanatomical QMRI traits have the potential to serve as accessible and relevant intermediate phenotypes for future genetic mapping efforts in epilepsy.

  7. Clinical application of proton magnetic resonance spectroscopy in differential diagnosis of intracranial lesions with ring-like enhancement

    International Nuclear Information System (INIS)

    Lai Ying; Cheng Kailiang; Zhang Mengchao; Liu Yunxia; Wang Wei

    2009-01-01

    Objective: To study the value of clinical application of 1 H proton magnetic resonance spectroscopy ( 1 H MRS) in the differential diagnosis of intracranial lesions with ring-like enhancement. Methods: 28 cases were diagnosed of intracranial lesions with ring-like enhancement by clinical examination and pathologic test. A total of 28 ratios cases included 6 cases high grade glioma, 10 cases of metastatic carcinoma (n=10) and 12 cases of brain abscess, after examined with 1HMRS, the ratios of various metabolites in focal center, enhancement ring,perifocal edema region and normal control group were detected and compared. Results: The ratios of NAA/Cho, Cho/Cr and NAA/Cr in focal center had no significantly differences between high grade glioma and metastatic carcinoma (P>0.05). The peak of NAA was significantly different between high grade glioma and metastatic carcinoma (P 0.05). The peak of AA was characteristic of brain abscess. The ratio of Cho/Cr 0 in brain abscess was significantly lower than those in high grade glioma and metastatic carcinoma (P 0 denoted the Cho content of contralateral normal brain region). These results accorded with the result of pathological examination. Conclusion: 1 HMRS can improve the diagnostic accuracy of intracranial lesions with ring-like enhancement. (authors)

  8. Proton magnetic resonance spectroscopy ((1H-MRS reveals geniculocalcarine and striate area degeneration in primary glaucoma.

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    Full Text Available BACKGROUND: Glaucoma is a collection of neurodegenerative diseases that affect both the retina and the central visual pathway. We investigated whether metabolites' concentrations changed in the geniculocalcarine (GCT and the striate area of occipital lobe by proton magnetic resonance spectroscopy ((1H-MRS, suggesting neurodegeneration of the central visual pathway in primary glaucoma. METHODOLOGY/PRINCIPAL FINDINGS: 20 patients with glaucoma in both eyes were paired with 20 healthy volunteers in same gender and an age difference less than 3 years. All the participants were examined by MR imaging including T1 Flair, T2 FSE and (1H-MRS. The T1 intensity and T2 intensity of their GCTs and striate areas were measured. The ratio of N-acetylaspartate (NAA/Creatine (Cr, Choline (Cho/Cr, glutamine and glutamate (Glx/Cr were derived by multi-voxels (1H-MRS in the GCT and the striate area of each brain hemisphere. The T1 intensity and T2 intensity had no difference between the groups. Significant decreases in NAA/Cr and Cho/Cr but no difference in Glx/Cr was found between the groups in both the GCT and the striate area. CONCLUSIONS/SIGNIFICANCE: Primary glaucoma affects metabolites' concentrations in the GCT and the striate area suggesting there is ongoing neurodegenerative process.

  9. Correlation between memory, proton magnetic resonance spectroscopy, and interictal epileptiform discharges in temporal lobe epilepsy related to mesial temporal sclerosis.

    Science.gov (United States)

    Mantoan, Marcele Araújo Silva; Caboclo, Luís Otávio Sales Ferreira; de Figueiredo Ferreira Guilhoto, Laura Maria; Lin, Katia; da Silva Noffs, Maria Helena; de Souza Silva Tudesco, Ivanda; Belzunces, Erich; Carrete, Henrique; Bussoletti, Renato Tavares; Centeno, Ricardo Silva; Sakamoto, Américo Ceiki; Yacubian, Elza Márcia Targas

    2009-11-01

    The aim of the study described here was to examine the relationship between memory function, proton magnetic resonance spectroscopy ((1)H-MRS) abnormalities, and interictal epileptiform discharge (IED) lateralization in patients with temporal lobe epilepsy (TLE) related to unilateral mesial temporal sclerosis. We assessed performance on tests of memory function and intelligence quotient (IQ) in 29 right-handed outpatients and 24 controls. IEDs were assessed on 30-minute-awake and 30-minute-sleep EEG samples. Patients had (1)H-MRS at 1.5 T. There was a negative correlation between IQ (P=0.031) and Rey Auditory Verbal Learning Test results (P=0.022) and epilepsy duration; between(1)H-MRS findings and epilepsy duration (P=0.027); and between N-acetylaspartate (NAA) levels and IEDs (P=0.006) in contralateral mesial temporal structures in the left MTS group. (1)H-MRS findings, IEDs, and verbal function were correlated. These findings suggest that IEDs and NAA/(Cho+Cr) ratios reflecting neural metabolism are closely related to verbal memory function in mesial temporal sclerosis. Higher interictal activity on the EEG was associated with a decline in total NAA in contralateral mesial temporal structures.

  10. In vivo proton magnetic resonance spectroscopy reveals region specific metabolic responses to SIV infection in the macaque brain

    Directory of Open Access Journals (Sweden)

    Joo Chan-Gyu

    2009-06-01

    Full Text Available Abstract Background In vivo proton magnetic resonance spectroscopy (1H-MRS studies of HIV-infected humans have demonstrated significant metabolic abnormalities that vary by brain region, but the causes are poorly understood. Metabolic changes in the frontal cortex, basal ganglia and white matter in 18 SIV-infected macaques were investigated using MRS during the first month of infection. Results Changes in the N-acetylaspartate (NAA, choline (Cho, myo-inositol (MI, creatine (Cr and glutamine/glutamate (Glx resonances were quantified both in absolute terms and relative to the creatine resonance. Most abnormalities were observed at the time of peak viremia, 2 weeks post infection (wpi. At that time point, significant decreases in NAA and NAA/Cr, reflecting neuronal injury, were observed only in the frontal cortex. Cr was significantly elevated only in the white matter. Changes in Cho and Cho/Cr were similar across the brain regions, increasing at 2 wpi, and falling below baseline levels at 4 wpi. MI and MI/Cr levels were increased across all brain regions. Conclusion These data best support the hypothesis that different brain regions have variable intrinsic vulnerabilities to neuronal injury caused by the AIDS virus.

  11. Use of chemical fractionation and proton nuclear magnetic resonance to probe the physical structure of the primary plant cell wall

    International Nuclear Information System (INIS)

    Taylor, I.E.P.; Wallace, J.C.; MacKay, A.L.; Volke, F.

    1990-01-01

    Proton magnetic resonance has been used to monitor the microscopic physical properties of etiolated hypocotyl cell walls from Phaseolus vulgaris L. at all stages in a series of chemical fractionations with ammonium oxalate and potassium hydroxide. Solid echo measurements indicate that 75% of the polymers in the intact cell wall, including the cellulose and most of the hemicelluloses, are arranged such that there is almost complete restraint of molecular motion. The chemical fractionations generally altered the physical structures of the remaining cell wall components. Digestion with 0.25% ammonium oxalate/oxalic acid solubilized the pectin and increased the mobility of the hemicellulose I component. Extraction with 4% potassium hydroxide removed the hemicellulose I component and loosened the hemicellulose II. Further extraction with 24% potassium hydroxide removed the hemicellulose II and loosened some of the cellulose. The cellulose crystallinity, as monitored by Jeener echo measurements decreased from 83% to 63% during these fractionations. We conclude that, while hemicellulose I is firmly attached to hemicellulose II, it is not in a closely packed structure. Hemicellulose II is strongly bound to cellulose and has a much more closely packed structure

  12. Proton magnetic resonance spectroscopy shows lower intramyocellular lipid accumulation in middle-aged subjects predisposed to familial longevity.

    Science.gov (United States)

    Wijsman, C A; van Opstal, A M; Kan, H E; Maier, A B; Westendorp, R G J; Slagboom, P E; Webb, A G; Mooijaart, S P; van Heemst, D

    2012-02-01

    Families predisposed to longevity show enhanced glucose tolerance and skeletal muscle insulin sensitivity compared with controls, independent of body composition and physical activity. Intramyocellular lipid (IMCL) accumulation in skeletal muscle has been associated with insulin resistance. Here, we assessed whether subjects enriched for familial longevity have lower IMCL levels. We determined IMCL levels in 48 subjects from the Leiden Longevity Study, comprising 24 offspring of nonagenarian siblings and 24 partners thereof as control subjects. IMCL levels were assessed noninvasively using short echo time proton magnetic resonance spectroscopy ((1)H-MRS) of the tibialis anterior muscle with a 7 Tesla human MR scanner. IMCL levels were calculated relative to the total creatine (tCr) CH3 signal. Physical activity was assessed using the International Physical Activity Questionnaire (IPAQ). After correction for age, sex, BMI, and physical activity, offspring of long-lived nonagenarian siblings tended to show lower IMCL levels compared with controls (IMCL/tCr: 3.1 ± 0.5 vs. 4.5 ± 0.5, respectively, P = 0.051). In a pairwise comparison, this difference reached statistical significance (P = 0.038). We conclude that offspring of nonagenarian siblings predisposed to longevity show lower IMCL levels compared with environmentally matched control subjects. Future research should focus on assessing what mechanisms may explain the lower IMCL levels in familial longevity.

  13. Detection of inflammatory bowel disease by proton magnetic resonance spectroscopy (1H MRS using an animal model

    Directory of Open Access Journals (Sweden)

    Dolenko Brion

    2007-11-01

    Full Text Available Abstract Background The aim of this study was to analyze the potential of proton magnetic resonance spectroscopy (1H MRS in diagnosing early inflammatory bowel disease (IBD. Methods Thirty male Sprague Dawley rats were fed 2% carrageenan in their diet for either 1 or 2 weeks. 1H MRS was performed ex-vivo on colonic mucosal samples (n = 123 and the spectra were analyzed by a multivariate method of analysis. The results of the multivariate analysis were correlated with histological analysis performed using H & E stain for the presence of inflammation in the samples from each group. Results Multivariate analysis classified the samples in their respective groups with an accuracy of 82%. Our region selection algorithm identified four regions in the spectra as being discriminatory. The metabolites assigned to these regions include creatine, phosphatidylcholine, the -CH2HC= group in fatty acyl chain, and the glycerol backbone of lipids. The differences in concentration of these metabolites in each group offer insight into the biochemical changes occurring during IBD and confer diagnostic potential to 1H MRS as a tool to study colonic inflammation in conjunction with biopsy. Conclusion 1H MRS is a sensitive tool to detect early colonic inflammation in an animal model of IBD.

  14. Proton Magnetic Resonance Spectroscopy Study on the Metabolism Changes of Cerebellum in Patients with Post-Stroke Depression.

    Science.gov (United States)

    Zhang, Lei; Sui, Ru-Bo

    2017-01-01

    To study the metabolic changes of cerebellum by proton magnetic resonance Spectroscopy (1H-MRS) and discuss the relationships between the cerebellar changes and depression severity in patients with post-stroke depression. Data of demographic characteristics, individual history and life style of all subjects were collected. 40 patients with stroke and 20 controls were enrolled. All groups received T1WI, T2WI, DWI and 1H-MRS examination. The cerebral infarction volume and the distribution and severity of leukoaraiosis were evaluated. The ratios of NAA/Cr, Cho/Cr and Cho/NAA in the cerebellum were calculated. There were no statistical significant difference in the NAA/Cr, Cho/Cr and Cho/NAA ratios in bilateral cerebellum between CONT group and NORM group. The Cho/Cr and Cho/NAA ratios in the cerebellum contralateral to the stroke region were higher in PSD group than those in NORM and CONT groups, and the Cho/Cr and Cho/NAA ratios in the cerebellum ipsilateral to the stroke region were similar with those in NORM and CONT groups. However, there were no statistical significant difference in the NAA/Cr ratios in bilateral cerebellum among three groups. The result shows preliminarily that the cerebellum involves in the development of post-stroke depression. © 2017 The Author(s). Published by S. Karger AG, Basel.

  15. Quality evaluation and species differentiation of Rhizoma coptidis by using proton nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Fan Gang; Zhang Mengying; Zhou Xiangdong; Lai Xianrong; Yue Qinghong; Tang Ce; Luo Weizao; Zhang Yi

    2012-01-01

    Highlights: ► We report a qNMR method for the determination of six alkaloids in Rhizoma coptidis. ► The results of the qNMR method are reliable by comparison with a HPLC method. ► The proposed method has good selectivity, precision, repeatability and accuracy. ► This method coupled with chemometrics can distinguish three Rhizoma coptidis species. - Abstract: Rhizoma coptidis, a broadly used traditional Chinese medicine, derives from the dried rhizomes of Coptis chinensis Franch, Coptis deltoidea C.Y. Cheng et Hsiao and Coptis teeta Wall. Quantitative determination of protoberberine alkaloids in R. coptidis is critical for controlling its quality. In this study, a rapid, simple and accurate quantitative 1 H NMR (qNMR) method was developed for simultaneous determination of berberine, jatrorrhizine, epiberberine, coptisine, palmatine and columbamine in R. coptidis from the three species. Method validation was performed in terms of selectivity, precision, repeatability, stability, accuracy, robustness and linearity. The average recoveries obtained were in the range of 96.9–102.4% for all the six alkaloids. In addition, the qNMR data were analyzed with analysis of variance (ANOVA), hierarchical clustering analysis (HCA) and principal component analysis (PCA), and the results showed that the contents of the active alkaloids have significant difference among the three species. Compared with the conventional HPLC approach, the proposed qNMR method was demonstrated to be a powerful tool for quantifying the six alkaloids due to its unique advantages of high robustness, rapid analysis time and no need of standard compounds for calibration curves preparation. These findings indicate that this method has potential as a reliable method for quality evaluation of herb medicines, especially for protoberberine alkaloid-containing ones.

  16. Quality evaluation and species differentiation of Rhizoma coptidis by using proton nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fan Gang [College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu 611137 (China); Zhang Mengying [China Agricultural University, Beijing 100094 (China); Zhou Xiangdong, E-mail: zhouxd88@yahoo.cn [Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, Chongqing 400038 (China); Lai Xianrong; Yue Qinghong; Tang Ce [College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu 611137 (China); Luo Weizao [Chongqing Academy of Chinese Materia Medica, Chongqing 400065 (China); Zhang Yi, E-mail: tcmzhangyi@yahoo.cn [College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu 611137 (China)

    2012-10-17

    Highlights: Black-Right-Pointing-Pointer We report a qNMR method for the determination of six alkaloids in Rhizoma coptidis. Black-Right-Pointing-Pointer The results of the qNMR method are reliable by comparison with a HPLC method. Black-Right-Pointing-Pointer The proposed method has good selectivity, precision, repeatability and accuracy. Black-Right-Pointing-Pointer This method coupled with chemometrics can distinguish three Rhizoma coptidis species. - Abstract: Rhizoma coptidis, a broadly used traditional Chinese medicine, derives from the dried rhizomes of Coptis chinensis Franch, Coptis deltoidea C.Y. Cheng et Hsiao and Coptis teeta Wall. Quantitative determination of protoberberine alkaloids in R. coptidis is critical for controlling its quality. In this study, a rapid, simple and accurate quantitative {sup 1}H NMR (qNMR) method was developed for simultaneous determination of berberine, jatrorrhizine, epiberberine, coptisine, palmatine and columbamine in R. coptidis from the three species. Method validation was performed in terms of selectivity, precision, repeatability, stability, accuracy, robustness and linearity. The average recoveries obtained were in the range of 96.9-102.4% for all the six alkaloids. In addition, the qNMR data were analyzed with analysis of variance (ANOVA), hierarchical clustering analysis (HCA) and principal component analysis (PCA), and the results showed that the contents of the active alkaloids have significant difference among the three species. Compared with the conventional HPLC approach, the proposed qNMR method was demonstrated to be a powerful tool for quantifying the six alkaloids due to its unique advantages of high robustness, rapid analysis time and no need of standard compounds for calibration curves preparation. These findings indicate that this method has potential as a reliable method for quality evaluation of herb medicines, especially for protoberberine alkaloid-containing ones.

  17. Analysis of metabolic changes of brain in HIV-1 seropositive patients with proton magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Koltowska, A.; Hendrich, B.; Sokolska, V.; Mis, M.; Lubkowska, K.; Szewczyk, P.; Sasiadek, M.; Furdal, M.; Knysz, B.; Gasiorowski, J.; Gladysz, A.

    2010-01-01

    Background: Asymptomatic central nervous system involvement may occur in the early stages of the HIV infection. The aim of the study was to evaluate early brain metabolic changes by means of proton MR spectroscopy (H1MRS) in the HIV-1 seropositive patients without neurological deficits or significant abnormalities in the plain MR study. Material/Methods: The H1MRS examinations were performed with the use of a MR GE Signa 1,5 T system. There were 39 subjects examined, aged 21 to 57 years (mean age 35 years) were examined, including 25 patients infected with HIV-1 and 14 healthy volunteers who constituted a control group. The examinations were performed using the Single Voxel Spectroscopy technique with the PRESS sequence, with following parameters: TR=1500 ms, TE=35 ms, number of acquisitions =128, time of acquisition =3 min. 43 sec. Voxels of 8 cm 3 (20 x 20 x 20 mm) in size were located in the following 5 regions: posterior cingulate gyrus, grey matter of the frontal area, left basal ganglia, white matter of the left parietal area and white matter of the frontal area. The NAA/Cr, Cho/Cr, mI/Cr ratios in the defined regions of interest were statistically analyzed. Results: There was a statistically significant decrease (p < 0.05) in the NAA/Cr ratios in the posterior cingulate area and white matter of the left parietal area in HIV-1 seropositive patients, as compared to the control group. Other metabolite ratios in all the above mentioned locations showed no statistically significant differences, as was also the case for NAA/Cr ratios in grey matter of the frontal area, left basal ganglia and white matter of the frontal area. Conclusions: The reduction of NAA/Cr values revealed in H1MRS studies suggests loss of neurons/neuronal activity in the posterior cingulate area and white matter of the left parietal area, in patients with HIV-1 at the stage before clinical manifestations of retroviral infection and structural changes in the plain MR study. This may reflect a

  18. Cerebral proton magnetic resonance spectroscopy demonstrates reversibility of N-acetylaspartate/creatine in gray matter after delayed encephalopathy due to carbon monoxide intoxication

    DEFF Research Database (Denmark)

    Hansen, Marco Bo; Kondziella, Daniel; Danielsen, Else Rubæk

    2014-01-01

    with cerebral proton magnetic resonance spectroscopy showed a dramatically decrease in N-acetylaspartate to total creatine ratios and elevated lactate levels in the gray matter. Subsequently, our patient received six additional sessions of hyperbaric oxygen therapy with only minimal recovery. At six...... reversal of N-acetylaspartate to total creatine ratios in gray matter has, to our knowledge, never been described before and shows that severe, initial measurements may not predict poor long-term patient outcome....

  19. Construction and test of a polarized proton target

    International Nuclear Information System (INIS)

    Aures, R.

    1983-12-01

    This work describes experiments in which for the first time a proton target has been constructed which is polarized by the ''brute-force'' method. This method requires very low temperatures and high magnetic fields. The low temperatures (down to 10 mK) are obtained by a 3 He/ 4 He dilution refrigerator, the magnetic field (up to 9 T) is produced by a superconducting split pair magnet. The proton target has a volume of about 18 cm 3 and consists of pressed titaniumhydride powder, which has a titanium/-hydrogen ratio of 1:1,96. The hydrogen content is 1,3 mol. Titaniumhydride has the advantage of sufficient heat conductivity at low temperatures and a very high proton density. The heat conductivity of the sample is measured, with and without the presence of a magnetic field. Thermodynamical measurements and adiabatic demagnetisation experiments proved quantitatively the polarization of the protons. The polarization of the proton has been measured in a transmission experiment using polarized neutrons of 1.2 MeV. The result shows a good agreement of theoretical and actual polarization. From the results it can be concluded, that this sample can be used successfully as a polarized proton target for neutron scattering experiments to measure spin-correlations. (orig.) [de

  20. Proton-proton bremsstrahlung

    International Nuclear Information System (INIS)

    Fearing, H.W.

    1990-01-01

    We summarize some of the information about the nucleon-nucleon force which has been obtained by comparing recent calculations of proton-proton bremsstrahlung with cross section and analyzing power data from the new TRIUMF bremsstrahlung experiment. Some comments are made as to how these results can be extended to neutron-proton bremsstrahlung. (Author) 17 refs., 6 figs

  1. Investigation of the biochemical state of paramagnetic ions in vivo using the magnetic field dependence of 1/T1 of tissue protons (NMRD profile): applications to contrast agents for magnetic resonance imaging

    International Nuclear Information System (INIS)

    Koenig, S.H.; Brown, R.D. III; Spiller, M.; Wolf, G.L.

    1988-01-01

    Nuclear magnetic relaxation dispersion (NMRD) profiles of protons are obtained in homogenous aqueous solutions of the paramagnetic ions, Mn 2+ and Gd 3+ and their chelate and macromolecular complexes in vitro, giving information regarding the biochemical state of these ions. Similarly NMRD profiles of protons of excised rabbit tissues containing Mn 2+ and Gd 3+ complexes are obtained. These NMRD profiles are shown to be very useful for determining the fate of potentially useful paramagnetic NMR imaging contrast agents in vivo. (U.K.)

  2. Quantitative analysis of magnetic resonance imaging susceptibility artifacts caused by neurosurgical biomaterials. Comparison of 0.5, 1.5, and 3.0 tesla magnetic fields

    International Nuclear Information System (INIS)

    Matsuura, Hideki; Inoue, Takashi; Ogasawara, Kuniaki; Sasaki, Makoto; Konno, Hiromu; Kuzu, Yasutaka; Nishimoto, Hideaki; Ogawa, Akira

    2005-01-01

    Magnetic resonance (MR) imaging is an important diagnostic tool for neurosurgical diseases but susceptibility artifacts caused by biomaterial instrumentation frequently causes difficulty in visualizing postoperative changes. The susceptibility artifacts caused by neurosurgical biomaterials were compared quantitatively by 0.5, 1.5, and 3.0 Tesla MR imaging. MR imaging of uniform size and shape of pieces ceramic (zirconia), pure titanium, titanium alloy, and cobalt-based alloy was performed at 0.5, 1.5, and 3.0 Tesla. A linear region of interest was defined across the center of the biomaterial in the transverse direction, and the susceptibility artifact diameter was calculated. Susceptibility artifacts developed around all biomaterials at all magnetic field strengths. The artifact diameters caused by pure titanium, titanium alloy, and cobalt-based alloy increased in the order of 0.5, 1.5, to 3.0 Tesla magnetic fields. The artifact diameter of ceramic was not influenced by magnetic field strength, and was the smallest of all biomaterials at all magnetic field strengths. The artifacts caused by biomaterials except ceramic increase with the magnetic field strength. Ceramic instrumentation will minimize artifacts in all magnetic fields. (author)

  3. A Proton Magnetic Resonance Spectroscopic Study in Autism Spectrum Disorder Using a 3-Tesla Clinical Magnetic Resonance Imaging (MRI) System: The Anterior Cingulate Cortex and the Left Cerebellum.

    Science.gov (United States)

    Ito, Hiromichi; Mori, Kenji; Harada, Masafumi; Hisaoka, Sonoka; Toda, Yoshihiro; Mori, Tatsuo; Goji, Aya; Abe, Yoko; Miyazaki, Masahito; Kagami, Shoji

    2017-07-01

    The pathophysiology of autism spectrum disorder (ASD) is not fully understood. We used proton magnetic resonance spectroscopy to investigate metabolite concentration ratios in the anterior cingulate cortex and left cerebellum in ASD. In the ACC and left cerebellum studies, the ASD group and intelligence quotient- and age-matched control group consisted of 112 and 114 subjects and 65 and 45 subjects, respectively. In the ASD group, γ-aminobutyric acid (GABA)+/ creatine/phosphocreatine (Cr) was significantly decreased in the anterior cingulate cortex, and glutamate (Glu)/Cr was significantly increased and GABA+/Cr was significantly decreased in the left cerebellum compared to those in the control group. In addition, both groups showed negative correlations between Glu/Cr and GABA+/Cr in the left cerebellum, and positive correlations between GABA+/Cr in the anterior cingulate cortex and left cerebellum. ASD subjects have hypoGABAergic alterations in the anterior cingulate cortex and hyperglutamatergic/hypoGABAergic alterations in the left cerebellum.

  4. Quantitative multivoxel proton MR spectroscopy study of brain metabolites in patients with amnestic mild cognitive impairment: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhong-Xian; Cheng, Xiao-Fang; Xu, Zhi-Feng; Cao, Zhen; Xiao, Ye-Yu; You, Ke-Zeng; Liu, Yan-Yan [Medical College of Shantou University, Department of Medical Imaging, The Second Affiliated Hospital, Shantou (China); Huo, Shan-Shan [Science College of Shantou University, Department of Physics, Shantou (China); Zeng, Jie-Xia; Chen, Wei [Medical College of Shantou University, Department of Neurology, The Second Affiliated Hospital, Shantou (China); Wu, Ren-Hua [Medical College of Shantou University, Department of Medical Imaging, The Second Affiliated Hospital, Shantou (China); Medical College of Shantou University, Provincial Key Laboratory of Medical Molecular Imaging, Guangdong, Shantou (China)

    2012-05-15

    The purpose of this study is to investigate brain metabolic changes in patients with amnestic mild cognitive impairment (aMCI) using multivoxel proton MR spectroscopy ({sup 1}H-MVS). Fourteen aMCI patients and fifteen healthy control subjects participated in this experiment. All MR measurements were acquired using a 1.5-T GE scanner. {sup 1}H-MVS point resolved spectroscopy (2D PROBE-CSI PRESS) pulse sequence (TE = 35 ms; TR = 1,500 ms; phase x frequency, 18 x 18) was used for acquiring MRS data. All data were post-processed using Spectroscopy Analysis by General Electric software and linear combination of model (LCModel). The absolute concentrations of N-acetylaspartate (NAA), choline (Cho), myoinositol (MI), creatine (Cr), and the metabolite ratios of NAA/Cr, Cho/Cr, MI/Cr, and NAA/MI were measured bilaterally in the posterior cingulate gyrus (PCG), inferior precuneus (Pr), paratrigonal white matter (PWM), dorsal thalamus (DT), and lentiform nucleus (LN). Patients with aMCI displayed significantly lower NAA levels in the bilateral PCG (p < 0.01), PWM (p < 0.05), and left inferior Pr (p < 0.05). The metabolite ratio of NAA/MI was decreased in the bilateral PCG (p < 0.01) and PWM (p < 0.05) and in the left DT (p < 0.01). NAA/Cr was decreased in the left PCG (p < 0.01), DT (p < 0.05), right PWM (p < 0.05), and LN (p < 0.05). However, MI/Cr was elevated in the right PCG (p < 0.01) and left PWM (p < 0.05). Significantly increased Cho level was also evident in the left PWM (p < 0.05). Our observations of decreased NAA, NAA/Cr, and NAA/MI, in parallel with increased Cho and MI/Cr might be characteristic of aMCI patients. (orig.)

  5. Characterization of proton exchange membrane materials for fuel cells by solid state nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Zueqian [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    Solid-state nuclear magnetic resonance (NMR) has been used to explore the nanometer-scale structure of Nafion, the widely used fuel cell membrane, and its composites. We have shown that solid-state NMR can characterize chemical structure and composition, domain size and morphology, internuclear distances, molecular dynamics, etc. The newly-developed water channel model of Nafion has been confirmed, and important characteristic length-scales established. Nafion-based organic and inorganic composites with special properties have also been characterized and their structures elucidated. The morphology of Nafion varies with hydration level, and is reflected in the changes in surface-to-volume (S/V) ratio of the polymer obtained by small-angle X-ray scattering (SAXS). The S/V ratios of different Nafion models have been evaluated numerically. It has been found that only the water channel model gives the measured S/V ratios in the normal hydration range of a working fuel cell, while dispersed water molecules and polymer ribbons account for the structures at low and high hydration levels, respectively.

  6. Proton magnetic resonance spectroscopy of periventricular white matter and hippocampus in obstructive sleep apnea patients

    International Nuclear Information System (INIS)

    Kızılgöz, Volkan; Aydın, Hasan; Tatar, İdil Güneş; Hekimoğlu, Baki; Ardıç, Sadık; Fırat, Hikmet; Dönmez, Cem

    2013-01-01

    The purpose of this study was to diagnose the hypoxic impairment by Magnetic resonance spectroscopy (MRS), an advanced MR imaging technique, which could not be visualised by routine imaging methods in patients with obstructive sleep apnea (OSA). 20 OSA patients and 5 controls were included in this prospective research. MRS was performed on these 25 subjects to examine cerebral hypoxemia in specific regions (periventricular white matter and both hippocampi). Polysomnography was assumed as the gold standard. Statistical analysis was assessed by Mann-Whitney U test and Receiver operating characteristics (ROC) curve for NAA/Cho, NAA/Cr and Cho/Cr ratios. In the periventricular white matter, NAA/Cho ratio in OSA patients was significantly lower than in the control group (p<0.05). There were no statistical differences between the OSA and the control group for NAA/Cho, NAA/Cr and Cho/Cr ratios for both hippocampal regions. Additionally, Cho/Cr ratio in the periventricular white matter region of OSA group was higher than in the control group (p<0.05). Hypoxic impairment induced by repeated episodes of apnea leads to significant neuronal damage in OSA patients. MRS provides valuable information in the assessment of hypoxic ischemic impairment by revealing important metabolite ratios for the specific areas of the brain

  7. Investigating the Dissolution Performance of Amorphous Solid Dispersions Using Magnetic Resonance Imaging and Proton NMR

    Directory of Open Access Journals (Sweden)

    Francesco Tres

    2015-09-01

    Full Text Available We have investigated the dissolution performance of amorphous solid dispersions of poorly water-soluble bicalutamide in a Kollidon VA64 polymeric matrix as a function of the drug loading (5% vs. 30% bicalutamide. A combined suite of state-of-the-art analytical techniques were employed to obtain a clear picture of the drug release, including an integrated magnetic resonance imaging UV-Vis flow cell system and 1H-NMR. Off-line 1H-NMR was used for the first time to simultaneously measure the dissolution profiles and rates of both the drug and the polymer from a solid dispersion. MRI and 1H-NMR data showed that the 5% drug loading compact erodes linearly, and that bicalutamide and Kollidon VA64 are released at approximately the same rate from the molecular dispersion. For the 30% extrudate, data indicated a slower water ingress into the compact which corresponds to a slower dissolution rate of both bicalutamide and Kollidon VA64.

  8. Classification of brain tumors by means of proton nuclear magnetic resonance (NMR) spectroscopy

    International Nuclear Information System (INIS)

    Sottile, V.S.; Zanchi, D.E.

    2017-01-01

    In the present work, at the request of health professionals, a computer application named “ViDa” was developed. The aim of this study is to differentiate brain lesions according to whether or not they are tumors, and their subsequent classification into different tumor types using magnetic resonance spectroscopy (SVS) with an echo time of 30 milliseconds. For this development, different areas of knowledge were integrated, among which are Artificial intelligence, physics, programming, physiopathology, images in medicine, among others. Biomedical imaging can be divided into two stages: the pre-processing, performed by the resonator, and post-processing software, performed by ViDa, for the interpretation of the data. This application is included within the Medical Informatics area, as it provides assistance for clinical decision making. The role of the biomedical engineer is fulfilled by developing a health technology in response to a manifested real-life problem. The tool developed shows promising results achieving a 100% Sensitivity, 73% Specificity, 77% Positive Predictive Value and 100% Negative Predictive Value reported in 21 cases tested. The correct classifications of the tumor’s origin reach 70%, the classification of non-astrocytic lesions achieves 67% of correct classifications in that the gradation of astrocytomas achieves a 57% of gradations that agree with biopsies and 43% of slight errors. It was possible to develop an application of assistance to the diagnosis, which together with others medical tests, will make it possible to sharpen the diagnoses of brain tumors. (authors) [es

  9. Measurement of vertebral bone marrow lipid profile at 1.5-T proton magnetic resonance spectroscopy and bone mineral density at dual-energy X-ray absorptiometry: correlation in a swine model

    Energy Technology Data Exchange (ETDEWEB)

    Di Leo, Giovanni; Fina, Laura [IRCCS Policlinico San Donato, Unita di Radiologia, San Donato Milanese (Italy); Bandirali, Michele; Messina, Carmelo [Universita degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Milan (Italy); Sardanelli, Francesco [IRCCS Policlinico San Donato, Unita di Radiologia, San Donato Milanese (Italy); Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, San Donato Milanese (Italy)

    2014-08-15

    Bone marrow is mainly composed of red (hematopoietic) and yellow (fatty) components. Soon after the birth there is a physiological conversion of the bone marrow from red to yellow, so that the percentage of hematopoietic cells and adipocytes changes with aging. Although bone marrow adipogenesis is a physiologic process involving all mammals, recent studies showed an accelerated marrow adipogenesis associated with several chronic conditions, including osteoporosis [4] and diabetes mellitus. Moreover, this increased marrow fat is accompanied by a decrease in bone density. Marrow fat is therefore increasingly believed to influence the bone microenvironment. Diagnostic tools for quantitative measurement of bone marrow fat and bone mineral density (BMD) include proton magnetic resonance spectroscopy (MRS) and dual-energy Xray absorptiometry (DXA), respectively. Using MRS, an inverse relationship between vertebral bone marrow fat content and lumbar BMD has been demonstrated in patients affected with osteoporosis or with diabetes mellitus. In most studies, a quite standard MRS sequence has been used, with short echo times (TE) for the measurement of the bulk methylene. In this study we sought to optimize the MRS sequence in order to try to measure other fat components of the vertebral bone marrow at 1.5 T. For this purpose, we used an animal model that allowed long acquisition times and repeated measures. Moreover, we aimed at estimating in this model the relationship between vertebral bone marrow fat content at proton MRS and BMD at DXA.

  10. Measurement of vertebral bone marrow lipid profile at 1.5-T proton magnetic resonance spectroscopy and bone mineral density at dual-energy X-ray absorptiometry: correlation in a swine model

    International Nuclear Information System (INIS)

    Di Leo, Giovanni; Fina, Laura; Bandirali, Michele; Messina, Carmelo; Sardanelli, Francesco

    2014-01-01

    Bone marrow is mainly composed of red (hematopoietic) and yellow (fatty) components. Soon after the birth there is a physiological conversion of the bone marrow from red to yellow, so that the percentage of hematopoietic cells and adipocytes changes with aging. Although bone marrow adipogenesis is a physiologic process involving all mammals, recent studies showed an accelerated marrow adipogenesis associated with several chronic conditions, including osteoporosis [4] and diabetes mellitus. Moreover, this increased marrow fat is accompanied by a decrease in bone density. Marrow fat is therefore increasingly believed to influence the bone microenvironment. Diagnostic tools for quantitative measurement of bone marrow fat and bone mineral density (BMD) include proton magnetic resonance spectroscopy (MRS) and dual-energy Xray absorptiometry (DXA), respectively. Using MRS, an inverse relationship between vertebral bone marrow fat content and lumbar BMD has been demonstrated in patients affected with osteoporosis or with diabetes mellitus. In most studies, a quite standard MRS sequence has been used, with short echo times (TE) for the measurement of the bulk methylene. In this study we sought to optimize the MRS sequence in order to try to measure other fat components of the vertebral bone marrow at 1.5 T. For this purpose, we used an animal model that allowed long acquisition times and repeated measures. Moreover, we aimed at estimating in this model the relationship between vertebral bone marrow fat content at proton MRS and BMD at DXA.

  11. Design of a mannequin for spectroscopy magnetic resonance of proton. Preliminary results of its application; Diseno de un maniqui para espectroscopia por resonancia magnetica de proton. resultados preliminares de su aplicacion

    Energy Technology Data Exchange (ETDEWEB)

    Parra Osoirio, V.; Galan Montenegro, P.; Moreno Saiz, C.; Garcia-Alvarez, R.; Arrabal Nunez, S.; Caudepon Moreno, F.; Navarro Guirado, F.; Asensjo Garcia, B.

    2013-07-01

    The proton magnetic resonance spectroscopy is a technique of metabolic Imaging allowing in vivo measurement of the levels of different metabolites. Is under increasing development and has shown an improvement of diagnostic indexes and therapeutic, since it allows: differential diagnosis between injuries, determination of tumor grade of Pre surgical form, determination of the presence of a lesion until it is clear, definition of progress and evaluation of the effects of a treatment. The aim in this work is to have a mannequin that allows analyze and adjust various parameters involved in the spectroscopic process, and establish a quantification of these parameters. (Author)

  12. Supersonic transient magnetic resonance elastography for quantitative assessment of tissue elasticity.

    Science.gov (United States)

    Liu, Yu; Liu, Jingfei; Fite, Brett Z; Foiret, Josquin; Ilovitsh, Asaf; Leach, J Kent; Dumont, Erik; Caskey, Charles F; Ferrara, Katherine W

    2017-05-21

    Non-invasive, quantitative methods to assess the properties of biological tissues are needed for many therapeutic and tissue engineering applications. Magnetic resonance elastography (MRE) has historically relied on external vibration to generate periodic shear waves. In order to focally assess a biomaterial or to monitor the response to ablative therapy, the interrogation of a specific region of interest by a focused beam is desirable and transient MRE (t-MRE) techniques have previously been developed to accomplish this goal. Also, strategies employing a series of discrete ultrasound pulses directed to increasing depths along a single line-of-sight have been designed to generate a quasi-planar shear wave. Such 'supersonic' excitations have been applied for ultrasound elasticity measurements. The resulting shear wave is higher in amplitude than that generated from a single excitation and the properties of the media are simply visualized and quantified due to the quasi-planar wave geometry and the opportunity to generate the wave at the site of interest. Here for the first time, we extend the application of supersonic methods by developing a protocol for supersonic transient magnetic resonance elastography (sst-MRE) using an MR-guided focused ultrasound system capable of therapeutic ablation. We apply the new protocol to quantify tissue elasticity in vitro using biologically-relevant inclusions and tissue-mimicking phantoms, compare the results with elasticity maps acquired with ultrasound shear wave elasticity imaging (US-SWEI), and validate both methods with mechanical testing. We found that a modified time-of-flight (TOF) method efficiently quantified shear modulus from sst-MRE data, and both the TOF and local inversion methods result in similar maps based on US-SWEI. With a three-pulse excitation, the proposed sst-MRE protocol was capable of visualizing quasi-planar shear waves propagating away from the excitation location and detecting differences in shear

  13. Supersonic transient magnetic resonance elastography for quantitative assessment of tissue elasticity

    Science.gov (United States)

    Liu, Yu; Liu, Jingfei; Fite, Brett Z.; Foiret, Josquin; Ilovitsh, Asaf; Leach, J. Kent; Dumont, Erik; Caskey, Charles F.; Ferrara, Katherine W.

    2017-05-01

    Non-invasive, quantitative methods to assess the properties of biological tissues are needed for many therapeutic and tissue engineering applications. Magnetic resonance elastography (MRE) has historically relied on external vibration to generate periodic shear waves. In order to focally assess a biomaterial or to monitor the response to ablative therapy, the interrogation of a specific region of interest by a focused beam is desirable and transient MRE (t-MRE) techniques have previously been developed to accomplish this goal. Also, strategies employing a series of discrete ultrasound pulses directed to increasing depths along a single line-of-sight have been designed to generate a quasi-planar shear wave. Such ‘supersonic’ excitations have been applied for ultrasound elasticity measurements. The resulting shear wave is higher in amplitude than that generated from a single excitation and the properties of the media are simply visualized and quantified due to the quasi-planar wave geometry and the opportunity to generate the wave at the site of interest. Here for the first time, we extend the application of supersonic methods by developing a protocol for supersonic transient magnetic resonance elastography (sst-MRE) using an MR-guided focused ultrasound system capable of therapeutic ablation. We apply the new protocol to quantify tissue elasticity in vitro using biologically-relevant inclusions and tissue-mimicking phantoms, compare the results with elasticity maps acquired with ultrasound shear wave elasticity imaging (US-SWEI), and validate both methods with mechanical testing. We found that a modified time-of-flight (TOF) method efficiently quantified shear modulus from sst-MRE data, and both the TOF and local inversion methods result in similar maps based on US-SWEI. With a three-pulse excitation, the proposed sst-MRE protocol was capable of visualizing quasi-planar shear waves propagating away from the excitation location and detecting differences in shear

  14. 7T Proton Magnetic Resonance Spectroscopy of the Anterior Cingulate Cortex in First-Episode Schizophrenia.

    Science.gov (United States)

    Reid, Meredith A; Salibi, Nouha; White, David M; Gawne, Timothy J; Denney, Thomas S; Lahti, Adrienne C

    2018-01-29

    Recent magnetic resonance spectroscopy (MRS) studies suggest that abnormalities of the glutamatergic system in schizophrenia may be dependent on illness stage, medication status, and symptomatology. Glutamatergic metabolites appear to be elevated in the prodromal and early stages of schizophrenia but unchanged or reduced below normal in chronic, medicated patients. However, few of these studies have measured metabolites with high-field 7T MR scanners, which offer higher signal-to-noise ratio and better spectral resolution than 3T scanners and facilitate separation of glutamate and glutamine into distinct signals. In this study, we examined glutamate and other metabolites in the dorsal anterior cingulate cortex (ACC) of first-episode schizophrenia patients. Glutamate and N-acetylaspartate (NAA) were significantly lower in schizophrenia patients vs controls. No differences were observed in levels of glutamine, GABA, or other metabolites. In schizophrenia patients but not controls, GABA was negatively correlated with the total score on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) as well as the immediate memory and language subscales. Our findings suggest that glutamate and NAA reductions in the ACC may be present early in the illness, but additional large-scale studies are needed to confirm these results as well as longitudinal studies to determine the effect of illness progression and treatment. The correlation between GABA and cognitive function suggests that MRS may be an important technique for investigating the neurobiology underlying cognitive deficits in schizophrenia. © The Author(s) 2018. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  15. Quantitative interpretation of magnetic properties as a way to characterize biogeophysical signatures of biodegraded contaminated sites

    Science.gov (United States)

    Ustra, A.; Kessouri, P.; Leite, A.; Mendonça, C. A.; Bandeira, N.

    2017-12-01

    Magnetic minerals in soils and rocks are one way to study biogechemical and paleoenvironmental processes. The ultrafine fraction of these minerals (superparmagnetic (SP) and stable single domain (SSD)) are usually investigated in environmental magnetism studies, since changes in mineralogy, concentration, size and morphology of the magnetic grains can be related to biogeochemical processes. In this study, we use low-field frequency dependent susceptibility (FDS) and isothermal remanent magnetization (IRM) to characterize the magnetic properties of materials in environmental magnetism. Magnetic susceptibility (MS) measurements are frequently used as a proxy of magnetic minerals present in soils and rocks. MS is a complex function of magnetic mineralogy and grain size, as well as magnitude and frequency of the applied field. This work presents a method for inverting low-field FDS data. The inverted parameters can be interpreted in terms of grain size variations of magnetic particles on the SP-SSD transition. This work also presents a method for inverting IRM demagnetization curves, to obtain the saturation magnetization, the individual magnetic moment for an assemblage of ultrafine SP minerals and estimate the concentration of magnetic carriers. IRM magnetization curves can be interpreted as resulting from distinct contributions of different mineral phases, which can be described by Cummulative Log-Gaussian (CLG) distributions. Each acquisition curve provides fundamental parameters that are characteristic of the respective mineral phase. The CLG decomposition is widely used in an interpretation procedure named mineral unmixing. In this work we present an inversion method for mineral unmixing, implementing the genetic algorithm to find the parameters of distinct components. These methodologies have been tested by synthetic models and applied to data from environmental magnetism studies. In this work we apply the proposed methodologies to characterize the magnetic

  16. Spherical proton emitters

    International Nuclear Information System (INIS)

    Berg, S.; Semmes, P.B.; Nazarewicz, W.

    1997-01-01

    Various theoretical approaches to proton emission from spherical nuclei are investigated, and it is found that all the methods employed give very similar results. The calculated decay widths are found to be qualitatively insensitive to the parameters of the proton-nucleus potential, i.e., changing the potential parameters over a fairly large range typically changes the decay width by no more than a factor of ∼3. Proton half-lives of observed heavy proton emitters are, in general, well reproduced by spherical calculations with the spectroscopic factors calculated in the independent quasiparticle approximation. The quantitative agreement with experimental data obtained in our study requires that the parameters of the proton-nucleus potential be chosen carefully. It also suggests that deformed proton emitters will provide invaluable spectroscopic information on the angular momentum decomposition of single-proton orbitals in deformed nuclei. copyright 1997 The American Physical Society

  17. Functional and quantitative magnetic resonance myelography of symptomatic stenoses of the lumbar spine

    Energy Technology Data Exchange (ETDEWEB)

    Eberhardt, Knut [District Hospital Castle of Werneck, MRI Center of Excellence, Werneck (Germany); Ganslandt, Oliver [University of Erlangen-Nuremberg, Department of Neurosurgery, Erlangen (Germany); Stadlbauer, Andreas [University of Erlangen-Nuremberg, Department of Neurosurgery, Erlangen (Germany); Medical University Vienna, Department of Radiology and Nuclear Medicine, Vienna (Austria)

    2014-12-15

    The objective of this study was to demonstrate that functional, quantitative magnetic resonance myelography (MRM) allows standardized diagnosis of symptomatic lumbar spinal stenoses which show at least equal detectability compared to functional myelography and postmyelographic CT (pmCT) based on intra- and postoperative findings. We investigated 43 volunteers and 47 patients with symptomatic lumbar spinal stenoses using MRM in normal position as well as in flexion and extension in a standard whole-body MR scanner. Twenty volunteers were additionally examined under axial loading. All patients were investigated by functional myelography and pmCT and 10 patients had a functional lumbar MRM postoperatively. Range of motion and cerebrospinal fluid (CSF) volumes in normal position, flexion, extension, and under axial loading (volunteers) were assessed for each segment. Detectability was determined by using intraoperative findings, and postoperative freedom of symptoms was correlated with CSF volume changes in MRM. The ranges of motion in a standard whole-body MR scanner provide adequate scope for investigations into function (flexion and extension) in both volunteers and patients. Axial loading was associated with a mechanism of extension, albeit to a far smaller extent. Detectability of lumbar stenoses was 100 % for MRM, 58 % for conventional myelography, and 68 % for pmCT. Postoperative changes in CSF volume of levels with stenoses in MRM strongly correlated with freedom of symptoms (R = 0.772). This MRM method allows for exact diagnosis and reproducible quantification of stenoses, motion-related changes, and spondylolistheses of the lumbar spine. It may be useful for early detection of alterations in order to avoid neuronal compression. (orig.)

  18. Quantitative magnetization transfer imaging of rodent glioma using selective inversion recovery.

    Science.gov (United States)

    Xu, Junzhong; Li, Ke; Zu, Zhongliang; Li, Xia; Gochberg, Daniel F; Gore, John C

    2014-03-01

    Magnetization transfer (MT) provides an indirect means to detect noninvasively variations in macromolecular contents in biological tissues, but, so far, there have been only a few quantitative MT (qMT) studies reported in cancer, all of which used off-resonance pulsed saturation methods. This article describes the first implementation of a different qMT approach, selective inversion recovery (SIR), for the characterization of tumor in vivo using a rodent glioma model. The SIR method is an on-resonance method capable of fitting qMT parameters and T1 relaxation time simultaneously without mapping B0 and B1 , which is very suitable for high-field qMT measurements because of the lower saturation absorption rate. The results show that the average pool size ratio (PSR, the macromolecular pool versus the free water pool) in rat 9 L glioma (5.7%) is significantly lower than that in normal rat gray matter (9.2%) and white matter (17.4%), which suggests that PSR is potentially a sensitive imaging biomarker for the assessment of brain tumor. Despite being less robust, the estimated MT exchange rates also show clear differences from normal tissues (19.7 Hz for tumors versus 14.8 and 10.2 Hz for gray and white mater, respectively). In addition, the influence of confounding effects, e.g. B1 inhomogeneity, on qMT parameter estimates is investigated with numerical simulations. These findings not only help to better understand the changes in the macromolecular contents of tumors, but are also important for the interpretation of other imaging contrasts, such as chemical exchange saturation transfer of tumors. Copyright © 2013 John Wiley & Sons, Ltd.

  19. A quantitative study of ramped radio frequency, magnetization transfer, and slab thickness in three-dimensional time-of-flight magnetic resonance angiography in a patient population.

    Science.gov (United States)

    Goodrich, K C; Blatter, D D; Parker, D L; Du, Y P; Meyer, K J; Bernstein, M A

    1996-06-01

    The authors compare the effectiveness of various magnetic resonance (MR) angiography acquisition strategies in enhancing the visibility of small intracranial vessels. Blood vessel contrast-to-noise ratio (CNR) in time-of-flight MR angiography was studied as a function of vessel size and several selectable imaging parameters. Contrast-to-noise measurements were made on 257 vessel segments ranging in size from 0.3 mm to 4.2 mm in patients who recently had undergone intraarterial cerebral angiography. Imaging parameters studied included magnetization transfer, spatially variable radio frequency (RF) pulse profile (ramped RF), and imaging slab thickness. The combination of thin slabs (16 slices/slab), ramped RF, and magnetization transfer resulted in the highest CNR for all but the smallest vessel sizes. The smallest vessels (slab (64 slices/slab) with ramped RF and magnetization transfer. Magnetization transfer always improved vessel CNR, but the improvement diminished as the slab thickness was reduced. The CNR increased with a decrease in slab thickness for all but the smallest vessel sizes. Overall, the results provide a quantitative demonstration that inflow enhancement of blood is reduced for small vessels. Thus, whereas magnetization transfer is important at all vessel sizes, it becomes the primary factor in improving the visibility of the smallest vessels.

  20. Proton magnetic resonance spectroscopy of a boron neutron capture therapy 10B-carrier, L-p-boronophenylalanine-fructose complex

    Energy Technology Data Exchange (ETDEWEB)

    Timonen, M.

    2010-07-01

    Boron neutron capture therapy (BNCT) is a radiotherapy that has mainly been used to treat malignant brain tumours, melanomas, and head and neck cancer. In BNCT, the patient receives an intravenous infusion of a 10B-carrier, which accumulates in the tumour area. The tumour is irradiated with epithermal or thermal neutrons, which result in a boron neutron capture reaction that generates heavy particles to damage tumour cells. In Finland, boronophenylalanine fructose (BPA-F) is used as the 10B-carrier. Currently, the drifting of boron from blood to tumour as well as the spatial and temporal accumulation of boron in the brain, are not precisely known. Proton magnetic resonance spectroscopy (1H MRS) could be used for selective BPA-F detection and quantification as aromatic protons of BPA resonate in the spectrum region, which is clear of brain metabolite signals. This study, which included both phantom and in vivo studies, examined the validity of 1H MRS as a tool for BPA detection. In the phantom study, BPA quantification was studied at 1.5 and 3.0 T with single voxel 1H MRS, and at 1.5 T with magnetic resonance imaging (MRSI). The detection limit of BPA was determined in phantom conditions at 1.5 T and 3.0 T using single voxel 1H MRS, and at 1.5 T using MRSI. In phantom conditions, BPA quantification accuracy of +- 5% and +- 15% were achieved with single voxel MRS using external or internal (internal water signal) concentration references, respectively. For MRSI, a quantification accuracy of <5% was obtained using an internal concentration reference (creatine). The detection limits of BPA in phantom conditions for the PRESS sequence were 0.7 (3.0 T) and 1.4 mM (1.5 T) mM with 20 x 20 single voxel MRS, and 1.0 mM with acquisition-weighted MRSI, respectively. In the in vivo study, an MRSI or single voxel MRS or both was performed for ten patients (patients 1-10) on the day of BNCT. Three patients had glioblastoma multiforme (GBM), and five patients had a recurrent or

  1. Proton: the particle.

    Science.gov (United States)

    Suit, Herman

    2013-11-01

    The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10(80). Protons were created at 10(-6) -1 second after the Big Bang at ≈1.37 × 10(10) years beforethe present. Proton life span has been experimentally determined to be ≥10(34) years; that is, the age of the universe is 10(-24)th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W(+), W(-), Z(0), and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter. Copyright © 2013 Elsevier Inc. All

  2. Proton: The Particle

    Energy Technology Data Exchange (ETDEWEB)

    Suit, Herman

    2013-11-01

    The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10{sup 80}. Protons were created at 10{sup −6} –1 second after the Big Bang at ≈1.37 × 10{sup 10} years beforethe present. Proton life span has been experimentally determined to be ≥10{sup 34} years; that is, the age of the universe is 10{sup −24}th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W{sup +}, W{sup −}, Z{sup 0}, and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter.

  3. Brain metabolite changes on proton magnetic resonance spectroscopy in children with poorly controlled type 1 diabetes mellitus

    International Nuclear Information System (INIS)

    Sarac, K.; Alkan, A.; Baysal, T.; Akinci, A.; Aslan, M.; Oezcan, C.

    2005-01-01

    The metabolite changes in the brains of children with poorly controlled type 1 diabetes mellitus (DM) were investigated by proton magnetic resonance spectroscopy (MRS). A total of 30 subjects and 14 age-matched healthy volunteers underwent single-voxel MRS (TE: 136). The duration of disease, medication, presence of hypoglycaemia episodes and the level of haemoglobin A1C (HbA1C) in the patients were noted. Voxels were placed in the pons, left basal ganglion (LBG) and left posterior parietal white matter (PPWM). N-acetylaspartate (NAA)/creatinine (Cr) and choline (Cho)/Cr ratios were calculated. The average HbA1c level was 11.9±3.4 (8.2-19.4). The average number of keto-acidosis episodes was 1.9±2.2 (0-9) and the average number of daily insulin injections was 2.8±0.97 (2-4). MRS revealed lower NAA/Cr and Cho/Cr ratios in the pons and lower NAA/Cr ratio in the PPWM of patients with DM than in control subjects. No significant correlation was observed between the number of hypoglycaemia episodes and metabolite ratios. Metabolic abnormalities have been observed by MRS in the brain of poorly controlled type 1 DM children. These metabolic changes, in particular in the pons region, include a decrease in NAA, indicating neuronal loss or functional impairment, and likely explanations for a decrease in Cho may be dynamic changes in membrane lipids and/or decreased membrane turnover. (orig.)

  4. Brain metabolite changes on proton magnetic resonance spectroscopy in children with poorly controlled type 1 diabetes mellitus

    Energy Technology Data Exchange (ETDEWEB)

    Sarac, K.; Alkan, A.; Baysal, T. [Inonu University School of Medicine, Department of Radiology, Malatya (Turkey); Akinci, A.; Aslan, M. [Inonu University School of Medicine, Department of Paediatric Endocrinology, Malatya (Turkey); Oezcan, C. [Inonu University School of Medicine, Department of Neurology, Malatya (Turkey)

    2005-07-01

    The metabolite changes in the brains of children with poorly controlled type 1 diabetes mellitus (DM) were investigated by proton magnetic resonance spectroscopy (MRS). A total of 30 subjects and 14 age-matched healthy volunteers underwent single-voxel MRS (TE: 136). The duration of disease, medication, presence of hypoglycaemia episodes and the level of haemoglobin A1C (HbA1C) in the patients were noted. Voxels were placed in the pons, left basal ganglion (LBG) and left posterior parietal white matter (PPWM). N-acetylaspartate (NAA)/creatinine (Cr) and choline (Cho)/Cr ratios were calculated. The average HbA1c level was 11.9{+-}3.4 (8.2-19.4). The average number of keto-acidosis episodes was 1.9{+-}2.2 (0-9) and the average number of daily insulin injections was 2.8{+-}0.97 (2-4). MRS revealed lower NAA/Cr and Cho/Cr ratios in the pons and lower NAA/Cr ratio in the PPWM of patients with DM than in control subjects. No significant correlation was observed between the number of hypoglycaemia episodes and metabolite ratios. Metabolic abnormalities have been observed by MRS in the brain of poorly controlled type 1 DM children. These metabolic changes, in particular in the pons region, include a decrease in NAA, indicating neuronal loss or functional impairment, and likely explanations for a decrease in Cho may be dynamic changes in membrane lipids and/or decreased membrane turnover. (orig.)

  5. Correlative study of proton magnetic resonance spectroscopy and histopathology in a neonatal piglet model of hypoxic-ischemic encephalopathy

    International Nuclear Information System (INIS)

    Wang Xiaoming; Guo Qiyong; Lin Nan; Ding Changwei; Wang Shuxuan; Chen Liying; Lv Qingjie; Jiang Weiguo

    2005-01-01

    Objective: To evaluate proton magnetic resonance spectroscopy ( 1 H-MRS) in the diagnosis of hypoxic ischemic brain damage (HIBD) in hyperacute period using an animal model. Methods: Twenty-five term piglets at the age of 3 to 7 days were subjected and divided into one control group (n=5) and two experimental groups. 1 H spectrum curve was measured continuously in all cases at 0-6, 20-24, 44-48, and 68-72 h after hypoxic ischemia in frontoparietal region, basal ganglia, and hippocampus. Lac/Cr was calculated. Histopathologic examination included hematoxylin and glial fibrillary acidic protein (GFAP) stain, teminal transferase mediated dUTP-biotin nick- end eosin (HE) stain, labeling (TUNEL) stain, and transmission electron microscope. Results: Lac/Cr in hippocampus region was 0.95 ± 0.88 in control group compared with 5.65 ± 1.93 in model group 1 and 8.93 ± 6.95 in model group 2. Model group 1 showed significantly glial cells swelling in hippocampus region on histopathologic examination. Model group 2 showed neurons and glial cells swelling significantly in hippocampus, and prominent apoptosis was seen in the peripheral neurons and glial cells. Further more Lac/Cr remained high within 72 h. Lac /Cr was 0.41 ± 0.03 in basal ganglia in control group compared with no significant elevation in model group 1 and 13.59 ± 10.23 in model group 2. Model group 1 did not show significant neuron and glial cell pathological changes in basal ganglia. Model group 2 showed obvious glial cell swelling, while neurons changed mildly. Lac/Cr was high within 48 h, and then declined. Lac/Cr in frontoparietal region also increased, but the value was lower than the former two regions. Conclusion: Neurons have an acute energy consumption after hypoxic ischemia, and Lac/Cr reflectes the extent of lesions correctly. (authors)

  6. Metabolic changes in the visual cortex of binocular blindness macaque monkeys: a proton magnetic resonance spectroscopy study.

    Directory of Open Access Journals (Sweden)

    Lingjie Wu

    Full Text Available PURPOSE: To evaluate proton magnetic resonance spectroscopy ((1H-MRS in a study of cross-modal plasticity in the visual cortex of binocular blindness macaque monkeys. MATERIALS AND METHODS: Four healthy neonatal macaque monkeys were randomly divided into 2 groups, with 2 in each group. Optic nerve transection was performed in both monkeys in the experimental group (group B to obtain binocular blindness. Two healthy macaque monkeys served as a control group (group A. After sixteen months post-procedure, (1H-MRS was performed in the visual cortex of all monkeys. We compared the peak areas of NAA, Cr, Cho, Glx and Ins and the ratios of NAA/Cr, Cho/Cr, Glx/Cr and Ins/Cr of each monkey in group B with group A. RESULTS: The peak area of NAA and the NAA/Cr ratio in the visual cortex of monkey 4 in group B were found to be dramatically decreased, the peak area of NAA slightly decreased and the NAA/Cr ratio clearly decreased in visual cortex of monkey 3 in group B than those in group A. The peak area of Ins and the Ins/Cr ratio in the visual cortex of monkey 4 in group B slightly increased. The peak area of Cho and the Cho/Cr ratio in the visual cortex of all monkeys in group B dramatically increased compared with group A. The peak area of Glx in the visual cortex of all monkeys in group B slightly increased compared with group A. CONCLUSIONS: (1H-MRS could detect biochemical and metabolic changes in the visual cortex and therefore this technique can be used to provide valuable information for investigating the mechanisms of cross-modal plasticity of binocular blindness in a macaque monkey model.

  7. Hemodynamic and metabolic characterization of orthotopic rat prostate carcinomas using dynamic MRI and proton magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Kiessling, F.; Lichy, M.; Kauczor, H.U.; Schlemmer, H.P.; Grobholz, R.; Heilmann, M.; Meding, J.; Huber, P.E.; Peschke, P.

    2003-01-01

    The aim of this study was the noninvasive characterization of prostate carcinoma orthotopically implanted in rats using Gd-DTPA-assisted dynamic MRI (dMRI) and proton magnetic resonance spectroscopy ( 1 H-MRS). After surgical exposure of the prostate, Dunning R3327 orthotopic prostate carcinoma was induced by injecting cells of the MAT-LyLu subline. Six rats were examined 5 and 14 days after tumor induction with dMRI and 1 H-MRS at 1.5 T. Six tumor-free rats served as controls. Using an open two-compartment model, the parameters A (amplitude) and k ep (exchange rate constants) were calculated from the signal time curves of the dMRI. The relative signal intensities (Cho/Cr) of the resonances of choline (Cho) and the creatine-phosphocreatine complex (Cr) were computed from the MR spectra. Already after 5 days, the tumors in the prostate could be clearly identified based on the decrease in signal intensity to T2w and increase of A and k ep . High Cho/Cr levels and resonances of two lipid fractions (Lip 1 at 0.8-1.5 ppm and Lip 2 at 2.0-2.2 ppm) were observed by MRS in the highly necrotic tumors. The orthotopic rat prostate carcinoma model resembles human prostate carcinoma in regard to MR morphology, dMRI, and 1 H-MRS. The noninvasive characterization of perfusion and metabolism makes a comparative examination of different treatment modalities possible. (orig.) [de

  8. Proton magnetic resonance spectroscopy reveals neuroprotection by oral minocycline in a nonhuman primate model of accelerated NeuroAIDS.

    Directory of Open Access Journals (Sweden)

    Eva-Maria Ratai

    2010-05-01

    Full Text Available Despite the advent of highly active anti-retroviral therapy (HAART, HIV-associated neurocognitive disorders continue to be a significant problem. In efforts to understand and alleviate neurocognitive deficits associated with HIV, we used an accelerated simian immunodeficiency virus (SIV macaque model of NeuroAIDS to test whether minocycline is neuroprotective against lentiviral-induced neuronal injury.Eleven rhesus macaques were infected with SIV, depleted of CD8+ lymphocytes, and studied until eight weeks post inoculation (wpi. Seven animals received daily minocycline orally beginning at 4 wpi. Neuronal integrity was monitored in vivo by proton magnetic resonance spectroscopy and post-mortem by immunohistochemistry for synaptophysin (SYN, microtubule-associated protein 2 (MAP2, and neuronal counts. Astrogliosis and microglial activation were quantified by measuring glial fibrillary acidic protein (GFAP and ionized calcium binding adaptor molecule 1 (IBA-1, respectively. SIV infection followed by CD8+ cell depletion induced a progressive decline in neuronal integrity evidenced by declining N-acetylaspartate/creatine (NAA/Cr, which was arrested with minocycline treatment. The recovery of this ratio was due to increases in NAA, indicating neuronal recovery, and decreases in Cr, likely reflecting downregulation of glial cell activation. SYN, MAP2, and neuronal counts were found to be higher in minocycline-treated animals compared to untreated animals while GFAP and IBA-1 expression were decreased compared to controls. CSF and plasma viral loads were lower in MN-treated animals.In conclusion, oral minocycline alleviates neuronal damage induced by the AIDS virus.

  9. Metabolomics by proton nuclear magnetic resonance spectroscopy of the response to chloroethylnitrosourea reveals drug efficacy and tumor adaptive metabolic pathways.

    Science.gov (United States)

    Morvan, Daniel; Demidem, Aicha

    2007-03-01

    Metabolomics of tumors may allow discovery of tumor biomarkers and metabolic therapeutic targets. Metabolomics by two-dimensional proton high-resolution magic angle spinning nuclear magnetic resonance spectroscopy was applied to investigate metabolite disorders following treatment by chloroethylnitrosourea of murine B16 melanoma (n = 33) and 3LL pulmonary carcinoma (n = 31) in vivo. Treated tumors of both types resumed growth after a delay. Nitrosoureas provoke DNA damage but the metabolic consequences of genotoxic stress are little known yet. Although some differences were observed in the metabolite profile of untreated tumor types, the prominent metabolic features of the response to nitrosourea were common to both. During the growth inhibition phase, there was an accumulation of glucose (more than x10; P < 0.05), glutamine (x3 to 4; P < 0.01), and aspartate (x2 to 5; P < 0.01). This response testified to nucleoside de novo synthesis down-regulation and drug efficacy. However, this phase also involved the increase in alanine (P < 0.001 in B16 melanoma), the decrease in succinate (P < 0.001), and the accumulation of serine-derived metabolites (glycine, phosphoethanolamine, and formate; P < 0.01). This response witnessed the activation of pathways implicated in energy production and resumption of nucleotide de novo synthesis, thus metabolic pathways of DNA repair and adaptation to treatment. During the growth recovery phase, it remained polyunsaturated fatty acid accumulation (x1.5 to 2; P < 0.05) and reduced utilization of glucose compared with glutamine (P < 0.05), a metabolic fingerprint of adaptation. Thus, this study provides the proof of principle that metabolomics of tumor response to an anticancer agent may help discover metabolic pathways of drug efficacy and adaptation to treatment.

  10. Binge Toluene Exposure Alters Glutamate, Glutamine and GABA in the Adolescent Rat Brain as Measured by Proton Magnetic Resonance Spectroscopy*

    Science.gov (United States)

    Perrine, Shane A.; O'Leary-Moore, Shonagh K.; Galloway, Matthew P.; Hannigan, John H.; Bowen, Scott E.

    2010-01-01

    Despite the high incidence of toluene abuse in adolescents, little is known regarding the effect of binge exposure on neurochemical profiles during this developmental stage. In the current study, the effects of binge toluene exposure during adolescence on neurotransmitter levels were determined using high-resolution proton magnetic resonance spectroscopy ex vivo at 11.7 T. Adolescent male Sprague-Dawley rats were exposed to toluene (0, 8,000 , or 12,000 ppm) for 15 min twice daily from postnatal day 28 (P28) through P34 and then euthanized either one or seven days later (on P35 or P42) to assess glutamate, glutamine, and GABA levels in intact tissue punches from the medial prefrontal cortex (mPFC), anterior striatum and hippocampus. In the mPFC, toluene reduced glutamate one day after exposure, with no effect on GABA, while after seven days, glutamate was no longer affected but there was an increase in GABA levels. In the hippocampus, neither GABA nor glutamate was altered one day after exposure, whereas seven days after exposure, increases were observed in GABA and glutamate. Striatal glutamate and GABA levels measured after either one or seven days were not altered after toluene exposure. These findings show that one week of binge toluene inhalation selectively alters these neurotransmitters in the mPFC and hippocampus in adolescent rats, and that some of these effects endure at least one week after the exposure. The results suggest that age-dependent, differential neurochemical responses to toluene may contribute to the unique behavioral patterns associated with drug abuse among older children and young teens. PMID:21126832

  11. Quantitative correlational study of microbubble-enhanced ultrasound imaging and magnetic resonance imaging of glioma and early response to radiotherapy in a rat model

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chen [Department of Ultrasound, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022 (China); Lee, Dong-Hoon; Zhang, Kai; Li, Wenxiao; Zhou, Jinyuan [Division of MR Research, Department of Radiology, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21287 (United States); Mangraviti, Antonella; Tyler, Betty [Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21287 (United States); Su, Lin; Zhang, Yin; Zhang, Bin; Wong, John; Wang, Ken Kang-Hsin; Velarde, Esteban; Ding, Kai, E-mail: kding1@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21231 (United States)

    2015-08-15

    Purpose: Radiotherapy remains a major treatment method for malignant tumors. Magnetic resonance imaging (MRI) is the standard modality for assessing glioma treatment response in the clinic. Compared to MRI, ultrasound imaging is low-cost and portable and can be used during intraoperative procedures. The purpose of this study was to quantitatively compare contrast-enhanced ultrasound (CEUS) imaging and MRI of irradiated gliomas in rats and to determine which quantitative ultrasound imaging parameters can be used for the assessment of early response to radiation in glioma. Methods: Thirteen nude rats with U87 glioma were used. A small thinned skull window preparation was performed to facilitate ultrasound imaging and mimic intraoperative procedures. Both CEUS and MRI with structural, functional, and molecular imaging parameters were performed at preradiation and at 1 day and 4 days postradiation. Statistical analysis was performed to determine the correlations between MRI and CEUS parameters and the changes between pre- and postradiation imaging. Results: Area under the curve (AUC) in CEUS showed significant difference between preradiation and 4 days postradiation, along with four MRI parameters, T{sub 2}, apparent diffusion coefficient, cerebral blood flow, and amide proton transfer-weighted (APTw) (all p < 0.05). The APTw signal was correlated with three CEUS parameters, rise time (r = − 0.527, p < 0.05), time to peak (r = − 0.501, p < 0.05), and perfusion index (r = 458, p < 0.05). Cerebral blood flow was correlated with rise time (r = − 0.589, p < 0.01) and time to peak (r = − 0.543, p < 0.05). Conclusions: MRI can be used for the assessment of radiotherapy treatment response and CEUS with AUC as a new technique and can also be one of the assessment methods for early response to radiation in glioma.

  12. Amide Proton Transfer Magnetic Resonance Imaging of Alzheimer′s Disease at 3.0 Tesla: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Rui Wang

    2015-01-01

    Full Text Available Background: Amide proton transfer (APT imaging has recently emerged as an important contrast mechanism for magnetic resonance imaging (MRI in the field of molecular and cellular imaging. The aim of this study was to evaluate the feasibility of APT imaging to detect cerebral abnormality in patients with Alzheimer′s disease (AD at 3.0 Tesla. Methods: Twenty AD patients (9 men and 11 women; age range, 67-83 years and 20 age-matched normal controls (11 men and 9 women; age range, 63-82 years underwent APT and traditional MRI examination on a 3.0 Tesla MRI system. The magnetic resonance ratio asymmetry (MTR asym values at 3.5 ppm of bilateral hippocampi (Hc, temporal white matter regions, occipital white matter regions, and cerebral peduncles were measured on oblique axial APT images. MTR asym (3.5 ppm values of the cerebral structures between AD patients and control subjects were compared with independent samples t-test. Controlling for age, partial correlation analysis was used to investigate the associations between mini-mental state examination (MMSE and the various MRI measures among AD patients. Results: Compared with normal controls, MTR asym (3.5 ppm values of bilateral Hc were significantly increased in AD patients (right 1.24% ± 0.21% vs. 0.83% ± 0.19%, left 1.18% ± 0.18% vs. 0.80%± 0.17%, t = 3.039, 3.328, P = 0.004, 0.002, respectively. MTR asym (3.5 ppm values of bilateral Hc were significantly negatively correlated with MMSE (right r = −0.559, P = 0.013; left r = −0.461, P = 0.047. Conclusions: Increased MTR asym (3.5 ppm values of bilateral Hc in AD patients and its strong correlations with MMSE suggest that APT imaging could potentially provide imaging biomarkers for the noninvasive molecular diagnosis of AD.

  13. Multimodality imaging using proton magnetic resonance spectroscopic imaging and 18F-fluorodeoxyglucose-positron emission tomography in local prostate cancer

    Science.gov (United States)

    Shukla-Dave, Amita; Wassberg, Cecilia; Pucar, Darko; Schöder, Heiko; Goldman, Debra A; Mazaheri, Yousef; Reuter, Victor E; Eastham, James; Scardino, Peter T; Hricak, Hedvig

    2017-01-01

    AIM To assess the relationship using multimodality imaging between intermediary citrate/choline metabolism as seen on proton magnetic resonance spectroscopic imaging (1H-MRSI) and glycolysis as observed on 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) in prostate cancer (PCa) patients. METHODS The study included 22 patients with local PCa who were referred for endorectal magnetic resonance imaging/1H-MRSI (April 2002 to July 2007) and 18F-FDG-PET/CT and then underwent prostatectomy as primary or salvage treatment. Whole-mount step-section pathology was used as the standard of reference. We assessed the relationships between PET parameters [standardized uptake value (SUVmax and SUVmean)] and MRSI parameters [choline + creatine/citrate (CC/Cmax and CC/Cmean) and total number of suspicious voxels] using spearman’s rank correlation, and the relationships of PET and 1H-MRSI index lesion parameters to surgical Gleason score. RESULTS Abnormal intermediary metabolism on 1H-MRSI was present in 21/22 patients, while abnormal glycolysis on 18F-FDG-PET/CT was detected in only 3/22 patients. Specifically, index tumor localization rates were 0.95 (95%CI: 0.77-1.00) for 1H-MRSI and 0.14 (95%CI: 0.03-0.35) for 18F-FDG-PET/CT. Spearman rank correlations indicated little relationship (ρ = -0.36-0.28) between 1H-MRSI parameters and 18F-FDG-PET/CT parameters. Both the total number of suspicious voxels (ρ = 0.55, P = 0.0099) and the SUVmax (ρ = 0.46, P = 0.0366) correlated weakly with the Gleason score. No significant relationship was found between the CC/Cmax, CC/Cmean or SUVmean and the Gleason score (P = 0.15-0.79). CONCLUSION The concentration of intermediary metabolites detected by 1H MRSI and glycolytic flux measured 18F-FDG PET show little correlation. Furthermore, only few tumors were FDG avid on PET, possibly because increased glycolysis represents a late and rather ominous event in the progression of PCa. PMID:28396727

  14. Alternative method for the quantitative determination of Rashba- and Dresselhaus spin–orbit interaction using the magnetization

    International Nuclear Information System (INIS)

    Wilde, M A; Grundler, D

    2013-01-01

    The quantum oscillatory magnetization M of a two-dimensional electron system in a magnetic field B is found to provide quantitative information on both the Rashba- and Dresselhaus spin–orbit interaction (SOI). This is shown by first numerically solving the model Hamiltonian including the linear Rashba- and Dresselhaus SOI and the Zeeman term in particular in a doubly tilted magnetic field and second evaluating the intrinsically anisotropic magnetization for different directions of the in-plane magnetic field component. The amplitude of specific magnetic quantum oscillations in M(B) is found to be a direct measure of the SOI strength at fields B where SOI-induced Landau level anticrossings occur. The anisotropic M allows one to quantify the magnitude of both contributions as well as their relative sign. The influence of cubic Dresselhaus SOI on the results is discussed. We use realistic sample parameters and show that recently reported experimental techniques provide a sensitivity which allows for the detection of the predicted phenomena. (paper)

  15. Serial changes in metabolism and histology in the cold-injury trauma rat brain model. Proton magnetic resonance imaging and spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Kamada, Kyousuke; Houkin, Kiyohiro; Hida, Kazutoshi; Iwasaki, Yoshinobu; Abe, Hiroshi [Hokkaido Univ., Sapporo (Japan). School of Medicine

    1995-01-01

    The serial changes in metabolism and histology during the first 24 hours in the cold-injury trauma rat brain model were investigated by proton magnetic resonance (MR) imaging and high-resolution proton MR spectroscopy. Edema developed extensively via the corpus callosum in the ipsi- and contralateral hemispheres during observation as shown by gradually increased signal intensity on proton MR images. Proton MR spectroscopy showed increased levels of acetate (Ace), lactate (Lac), and glutamine (Glmi) 1 hour after lesion formation. The elevated Glmi level slightly decreased, the level of alanine (Ala) increased substantially, and that of N-acetyl-aspartate (NAA) decreased markedly after 24 hours. Increased Lac, Ace, and Ala might reflect anaerobic glycolysis associated with mitochondrial dysfunction, while decreased Glmi and NAA reveal brain tissue breakdown. The relationship between brain edema and tissue viability can be analyzed in detail using this simple traumatic model and MR techniques which will be useful in the development of therapeutic agents for brain injury. (author).

  16. Deep Learning for Magnetic Resonance Fingerprinting: A New Approach for Predicting Quantitative Parameter Values from Time Series.

    Science.gov (United States)

    Hoppe, Elisabeth; Körzdörfer, Gregor; Würfl, Tobias; Wetzl, Jens; Lugauer, Felix; Pfeuffer, Josef; Maier, Andreas

    2017-01-01

    The purpose of this work is to evaluate methods from deep learning for application to Magnetic Resonance Fingerprinting (MRF). MRF is a recently proposed measurement technique for generating quantitative parameter maps. In MRF a non-steady state signal is generated by a pseudo-random excitation pattern. A comparison of the measured signal in each voxel with the physical model yields quantitative parameter maps. Currently, the comparison is done by matching a dictionary of simulated signals to the acquired signals. To accelerate the computation of quantitative maps we train a Convolutional Neural Network (CNN) on simulated dictionary data. As a proof of principle we show that the neural network implicitly encodes the dictionary and can replace the matching process.

  17. Graphene oxide-Fe{sub 3}O{sub 4} nanoparticle composite with high transverse proton relaxivity value for magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Venkatesha, N.; Srivastava, Chandan, E-mail: csrivastava@materials.iisc.ernet.in [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India); Poojar, Pavan; Geethanath, Sairam [Medical Imaging Research Centre, Dayananda Sagar Institutions, Bangalore 560078 (India); Qurishi, Yasrib [Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore 560012 (India)

    2015-04-21

    The potential of graphene oxide–Fe{sub 3}O{sub 4} nanoparticle (GO-Fe{sub 3}O{sub 4}) composite as an image contrast enhancing material in magnetic resonance imaging has been investigated. Proton relaxivity values were obtained in three different homogeneous dispersions of GO-Fe{sub 3}O{sub 4} composites synthesized by precipitating Fe{sub 3}O{sub 4} nanoparticles in three different reaction mixtures containing 0.01 g, 0.1 g, and 0.2 g of graphene oxide. A noticeable difference in proton relaxivity values was observed between the three cases. A comprehensive structural and magnetic characterization revealed discrete differences in the extent of reduction of the graphene oxide and spacing between the graphene oxide sheets in the three composites. The GO-Fe{sub 3}O{sub 4} composite framework that contained graphene oxide with least extent of reduction of the carboxyl groups and largest spacing between the graphene oxide sheets provided the optimum structure for yielding a very high transverse proton relaxivity value. It was found that the GO-Fe{sub 3}O{sub 4} composites possessed good biocompatibility with normal cell lines, whereas they exhibited considerable toxicity towards breast cancer cells.

  18. Mechanical-property changes of structural composite materials after low-temperature proton irradiation: Implications for use in SSC magnet systems

    International Nuclear Information System (INIS)

    Morena, J.; Snead, C.L. Jr.; Czajkowski, C.; Skaritka, J.

    1993-01-01

    Longterm physical, mechanical, electrical, and other properties of advanced composites, plastics, and other polymer materials are greatly affected by high-energy proton, neutron, electron, and gamma radiation. The effects of high-energy particles on materials is a critical design parameter to consider when choosing polymeric structural, nonstructural, and elastomeric matrix resin systems. Polymer materials used for filled resins, laminates, seals, gaskets, coatings, insulation and other nonmetallic components must be chosen carefully, and reference data viewed with caution. Most reference data collected in the high-energy physics community to date reflects material property degradation using other than proton irradiations. In most instances, the data were collected for room-temperature irradiations, not 4.2 K or other cryogenic temperatures, and at doses less than 10 8 --10 9 Rad. Energetic proton (and the accompanying spallation-product particles) provide good simulation fidelity to the expected radiation fields predicted for the cold-mass regions of the SSC magnets, especially the corrector magnets. The authors present here results for some structural composite materials which were part of a larger irradiation-characterization of polymeric materials for SSC applications

  19. Quantitative determination of Quarternary alicyclic carbon atoms in coal and oil using nuclear magnetic resonance /sup 13/C method

    Energy Technology Data Exchange (ETDEWEB)

    Afonina, T.V.; Kushnarev, D.F.; Randin, O.I.; Shishkov, V.F.; Kalabin, G.A.

    1986-09-01

    Possibility is indicated for utilizing nuclear magnetic resonance spectroscopy for quantitative determination of Quarternary aliphatic carbon atoms in heavy hydrocarbon fractions of oil and coal extracts. C/sub n/, CH, CH/sub 2/ and CH/sub 3/ content in coal and oil samples are determined and corresponding resonance lines are referred to individual structural fragments (on the basis of nuclear magnetic resonance /sup 13/C spectra) of known saturated hydrocarbons. Tests were carried out on chloroform extracts of Irsha-Borodinsk coal, Mungunsk coal and paraffin and cycloparaffin of Sivinsk oil (b.p. over 550 C) fractions. Nuclear magnetic resonance spectra were obtained using Burker WP 200 spectrometer (50.13 MHz frequency). Results of the tests are given. 11 references.

  20. Quantitative NMR proton spectroscopy in vivo at 1,5 Tesla and possible applications to investigations of brain metabolism of depressive patients

    International Nuclear Information System (INIS)

    Metzler, D.

    1997-12-01

    Using a clinical magnetic resonance imaging/spectroscopy system 22 patients suffering from bipolar disorders and 22 healthy volunteers were examined by localized in vivo proton spectroscopy. The measurements were performed on a 1.5 Tesla whole body scanner of Siemens AG, Magnetom SP 4000, using the standard head coil (CP). For localization a STEAM sequence was used with an echo times TE of 55 ms. A recovery time of 3500 ms was chosen. The number of acquisitions was 256. The spectra were acquired from voxel volumes of 20 x 30 x 20 mm 3 . Three Gaussian presaturation pulses (CHESS) with subsequent dephasing gradients were used for water suppression. After correction for eddy-current effects and Fast-Fourier transformation the intensities of myo-inositol, choline compounds, creatine together with phospho-creatine, and N-acetylaspartate were evaluated from the spectra. The spectra from the frontal brain of depressed patients and controls revealed mInos/Cr ratios of about 0,4 - 0,5. This lies within the range, which is presumed to be the mInos concentration in 1 H-Magnetic Resonance Spectroscopy studies in human brain in vivo. Concerning the total sample (N = 2 x 22) there were no intergroup differences in the present study. Concluding a subsample of subjects younger than 40 years (N = 2 x 10), depressives showed lower mInos levels than controls in the right frontal lobe. The patients showed a significant positive correlation between age and mInos/Cr in the right frontal lobe, while in the left frontal lobe this could be seen only as a trend. In contrast, NAA/Cr decreased with increasing age. There were neither significant differences between sex nor between hemispheres. (author)

  1. Two-processor automatized system to control fast measurements of the magnetic field index of the JINR 10 GeV proton synchrotron

    International Nuclear Information System (INIS)

    Chernykh, E.V.

    1981-01-01

    A two-processor system comprizing a hard-wired module and ES-1010 computer to control measurements of the magnetic field index of the JINR 10 GeV proton synchrotron is described. The system comprises the control module, a computer interface and a parallel branch driver residing in CAMAC system crate. The control module controls analogue multiplexer and analogue-to-digital converter through their front panels and writes down the information into a buffer memory module through the CAMAC highway. The computer controls the system, reads the information into core memory, writes down it on a magnetic tape, processes it and outputs n=f(r) plots on TV monitor and printer. The system provides the measurement up to 100 points during a magnetic field rise and minimal time of measurement 50 μs [ru

  2. Quantitative magnetic resonance imaging in limb-girdle muscular dystrophy 2I

    DEFF Research Database (Denmark)

    Willis, Tracey A; Hollingsworth, Kieren G; Coombs, Anna

    2014-01-01

    -related protein (FKRP) gene were recruited. In each patient, T1-weighted (T1w) imaging was assessed by qualitative grading for 15 individual lower limb muscles and quantitative Dixon imaging was analysed on 14 individual lower limb muscles by region of interest analysis. We described the pattern and appearance......) that the quantitative Dixon technique is an objective quantitative marker of disease and (ii) new observations of gender specific patterns of muscle involvement in LGMD2I....

  3. Analytical applications of a recycled flow nuclear magnetic resonance system: quantitative analysis of slowly relaxing nuclei

    International Nuclear Information System (INIS)

    Laude, D.A. Jr.; Lee, R.W.K.; Wilkins, C.L.

    1985-01-01

    The utility of a recycled flow system for the efficient quantitative analysis of NMR spectra is demonstrated. Requisite conditions are first established for the quantitative flow experiment and then applied to a variety of compounds. An application of the technique to determination of the average polymer chain length for a silicone polymer by quantitative flow 29 Si NMR is also presented. 10 references, 4 figures, 3 tables

  4. X-ray magnetic dichroism: from quantitative determination of magnetic moments to imaging of magnetization dynamics; Dichroisme magnetique des rayons X: de la determination quantitative des moments magnetiques a l'imagerie de la dynamique de l'aimantation

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, J

    2006-03-15

    In this document, I use some results of my research activities of the last ten years to show the power of x-ray magnetic dichroism for determining magnetic properties of thin layers, multilayers and nano-structures. The use of sum rules for x-ray dichroism allows a quantitative determination of the spin and orbital contributions to the magnetic moment, for each element of a heterogeneous material separately. Used in a qualitative way, x-ray dichroism allows monitoring the magnetization of the different layers in a multilayer material as a function of applied field. In combination with the temporal structure of synchrotron radiation, it is possible to study fast magnetization reversal with element selectivity, which is important for devices like spin valves and magnetic tunnel junctions. Adding the spatial resolution of a photoelectron emission microscope (PEEM), it becomes possible to study all the details of the fast magnetization reversal in complex magnetic systems. (author)

  5. Myocardial blood flow estimates from dynamic contrast-enhanced magnetic resonance imaging: three quantitative methods

    Science.gov (United States)

    Borrazzo, Cristian; Galea, Nicola; Pacilio, Massimiliano; Altabella, Luisa; Preziosi, Enrico; Carnì, Marco; Ciolina, Federica; Vullo, Francesco; Francone, Marco; Catalano, Carlo; Carbone, Iacopo

    2018-02-01

    Dynamic contrast-enhanced cardiovascular magnetic resonance imaging can be used to quantitatively assess the myocardial blood flow (MBF), recovering the tissue impulse response function for the transit of a gadolinium bolus through the myocardium. Several deconvolution techniques are available, using various models for the impulse response. The method of choice may influence the results, producing differences that have not been deeply investigated yet. Three methods for quantifying myocardial perfusion have been compared: Fermi function modelling (FFM), the Tofts model (TM) and the gamma function model (GF), with the latter traditionally used in brain perfusion MRI. Thirty human subjects were studied at rest as well as under cold pressor test stress (submerging hands in ice-cold water), and a single bolus of gadolinium weighing 0.1  ±  0.05 mmol kg-1 was injected. Perfusion estimate differences between the methods were analysed by paired comparisons with Student’s t-test, linear regression analysis, and Bland-Altman plots, as well as also using the two-way ANOVA, considering the MBF values of all patients grouped according to two categories: calculation method and rest/stress conditions. Perfusion estimates obtained by various methods in both rest and stress conditions were not significantly different, and were in good agreement with the literature. The results obtained during the first-pass transit time (20 s) yielded p-values in the range 0.20-0.28 for Student’s t-test, linear regression analysis slopes between 0.98-1.03, and R values between 0.92-1.01. From the Bland-Altman plots, the paired comparisons yielded a bias (and a 95% CI)—expressed as ml/min/g—for FFM versus TM, -0.01 (-0.20, 0.17) or 0.02 (-0.49, 0.52) at rest or under stress respectively, for FFM versus GF, -0.05 (-0.29, 0.20) or  -0.07 (-0.55, 0.41) at rest or under stress, and for TM versus GF, -0.03 (-0.30, 0.24) or  -0.09 (-0.43, 0.26) at rest or under stress. With the

  6. High-resolution morphologic and ultrashort time-to-echo quantitative magnetic resonance imaging of the temporomandibular joint

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Won C.; Chang, Eric Y.; Biswas, Reni; Statum, Sheronda; Chung, Christine B. [Veterans Administration San Diego Healthcare System, Department of Radiology, San Diego, CA (United States); University of California, San Diego, School of Medicine, Department of Radiology, San Diego, CA (United States); Tafur, Monica; Du, Jiang; Healey, Robert [University of California, San Diego, School of Medicine, Department of Radiology, San Diego, CA (United States); Kwack, Kyu-Sung [Ajou University Medical Center, Department of Radiology, Wonchon-dong, Yeongtong-gu, Gyeonggi-do, Suwon (Korea, Republic of)

    2016-03-15

    To implement high-resolution morphologic and quantitative magnetic resonance imaging (MRI) of the temporomandibular joint (TMJ) using ultrashort time-to-echo (UTE) techniques in cadavers and volunteers. This study was approved by the institutional review board. TMJs of cadavers and volunteers were imaged on a 3-T MR system. High-resolution morphologic and quantitative sequences using conventional and UTE techniques were performed in cadaveric TMJs. Morphologic and UTE quantitative sequences were performed in asymptomatic and symptomatic volunteers. Morphologic evaluation demonstrated the TMJ structures in open- and closed-mouth position. UTE techniques facilitated the visualization of the disc and fibrocartilage. Quantitative UTE MRI was successfully performed ex vivo and in vivo, reflecting the degree of degeneration. There was a difference in the mean UTE T2* values between asymptomatic and symptomatic volunteers. MRI evaluation of the TMJ using UTE techniques allows characterization of the internal structure and quantification of the MR properties of the disc. Quantitative UTE MRI can be performed in vivo with short scan times. (orig.)

  7. Study of the magnetic characteristics of ferrites with a view to their application in a proton synchrotron; Etudes des caracteristiques magnetiques des ferrites en vue de leur application dans un synchrotron a protons

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, K C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-10-01

    In this report magnetic properties of some Ni Zn ferrites available in France are investigated for the purpose of their use in accelerating cavities of proton synchrotron. An attempt is made to measure permeability and quality factor of ferrite versus various physical parameters such as frequency F, the induction B, the magnetic bias field Hp and the temperature, the investigation ranges being: F {<=} 40 Mc/s; B {<=} 10{sup -2} Tesla; Hp {<=} 5000 AT/m; T {<=} 100 C. The measurements were carried out with the one hand, conventional impedance bridge (Q-meter, RX-meter) and on the other hand, with resonating method using an inductive ferrite loaded cavity in parallel with an external capacity. The latter method is of particular interest for the measurements in function of induction and magnetic bias field. (author) [French] Ce travail consiste a etudier les proprietes magnetiques d'un certain nombre de ferrites de Ni Zn disponibles sur le marche francais en vue de leur utilisation dans les cavites acceleratrices d'un synchrotron a protons. On se propose de mesurer la permeabilite et le facteur de qualite du ferrite en fonction de divers parametres physiques tels que la frequence F, l'induction B, le champ magnetique de polarisation Hp et la temperature T, avec: F {<=} 40 Mc/s; B {<=} 10{sup -2} Tesla; Hp {<=} 5000 AT/m; T {<=} 100 C. On effectue les mesures d'une part a l'aide des ponts d'impedance classiques (Q-metre, RX-metre) et d'autre part par la methode du resonateur qui consiste a mettre en parallele une cavite inductive chargee de ferrite et une capacite exterieure. Cette derniere methode est particulierement interessante pour les mesures en fonction de l'induction et du champ magnetique polarisant. (auteur)

  8. Quantitative measurements of magnetic polaron binding on acceptors in CdMnTe alloys

    Science.gov (United States)

    Nhung, Tran Hong; Planel, R.

    1983-03-01

    The acceptor binding energy is measured as a function of Temperature and composition in Cd1-x Mnx Te alloys, by time resolved spectroscopy. The Bound magnetic polaron effect is measured and compared with a theory accouting for magnetic saturation and fluctuations.

  9. Disturbed Intracardiac Flow Organization After Atrioventricular Septal Defect Correction as Assessed With 4D Flow Magnetic Resonance Imaging and Quantitative Particle Tracing

    NARCIS (Netherlands)

    Calkoen, Emmeline E.; de Koning, Patrick J. H.; Blom, Nico A.; Kroft, Lucia J. M.; de Roos, Albert; Wolterbeek, Ron; Roest, Arno A. W.; Westenberg, Jos J. M.

    2015-01-01

    Objectives Four-dimensional (3 spatial directions and time) velocity-encoded flow magnetic resonance imaging with quantitative particle tracing analysis allows assessment of left ventricular (LV) blood flow organization. Corrected atrioventricular septal defect (AVSD) patients have an abnormal left

  10. Drift tube with an electro-quadrupole magnet made with a conventional enamel wire for the proton engineering frontier project drift tube linac

    Science.gov (United States)

    Kim, Y. H.; Kwon, H. J.; Cho, Y. S.

    2006-12-01

    The proton engineering frontier project (PEFP) drift tube linac (DTL) chose the new type of electro-quadrupole magnet (EQM) using an enameled wire for a drift tube. By using this kind of EQM, we could simplify the drift tube structure. We verified the structural stability and thermal stability of this drift tube structure through a computational analysis and a simple experiment. We also verified the stability of the enameled wire regarding corrosion through a long period test of about 1 year. It was concluded that the design and fabrication of the drift tube and the EQM were successful.

  11. Drift tube with an electro-quadrupole magnet made with a conventional enamel wire for the proton engineering frontier project drift tube linac

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y.H. [PEFP, KAERI, DaeJeon (Korea, Republic of)]. E-mail: yhkim72@kaeri.re.kr; Kwon, H.J. [PEFP, KAERI, DaeJeon (Korea, Republic of); Cho, Y.S. [PEFP, KAERI, DaeJeon (Korea, Republic of)

    2006-12-21

    The proton engineering frontier project (PEFP) drift tube linac (DTL) chose the new type of electro-quadrupole magnet (EQM) using an enameled wire for a drift tube. By using this kind of EQM, we could simplify the drift tube structure. We verified the structural stability and thermal stability of this drift tube structure through a computational analysis and a simple experiment. We also verified the stability of the enameled wire regarding corrosion through a long period test of about 1 year. It was concluded that the design and fabrication of the drift tube and the EQM were successful.

  12. Drift tube with an electro-quadrupole magnet made with a conventional enamel wire for the proton engineering frontier project drift tube linac

    International Nuclear Information System (INIS)

    Kim, Y.H.; Kwon, H.J.; Cho, Y.S.

    2006-01-01

    The proton engineering frontier project (PEFP) drift tube linac (DTL) chose the new type of electro-quadrupole magnet (EQM) using an enameled wire for a drift tube. By using this kind of EQM, we could simplify the drift tube structure. We verified the structural stability and thermal stability of this drift tube structure through a computational analysis and a simple experiment. We also verified the stability of the enameled wire regarding corrosion through a long period test of about 1 year. It was concluded that the design and fabrication of the drift tube and the EQM were successful

  13. Prognostic value of proton magnetic resonance spectroscopy findings in near drowning patients: reversibility of the early metabolite abnormalities relates with a good outcome

    Energy Technology Data Exchange (ETDEWEB)

    Aragao, Maria de Fatima Vasco; Law, Meng; Prola Netto, Joao; Naidich, Thomas [Mount Sinai School of Medicine, New York, NY (United States). Dept. of Radiology], e-mail: aragao@truenet.com; Valenca, Marcelo Moraes [Federal University of Pernambuco (UFPE), Recife, PE (Brazil). Dept. of Neuropsychiatry and Behavioral Studies

    2009-03-15

    In two children with near drowning hypoxic encephalopathy and normal-appearing structural MRI, acute proton magnetic resonance spectroscopy ({sup 1}H MRS) showed biochemical alterations that correctly indicated prognosis and helped to guide management decisions. Elevation of the lipid-lactate and glutamine-glutamate peaks, on the early (72 hour) {sup 1}H MRS, predicts a poor prognosis. Absence of lipid-lactate and glutamine-glutamate peaks on the early {sup 1}H MRS and reversibility of early mild metabolite abnormalities on follow up examination relates with good outcome. (author)

  14. Prognostic value of proton magnetic resonance spectroscopy findings in near drowning patients: reversibility of the early metabolite abnormalities relates with a good outcome

    International Nuclear Information System (INIS)

    Aragao, Maria de Fatima Vasco; Law, Meng; Prola Netto, Joao; Naidich, Thomas; Valenca, Marcelo Moraes

    2009-01-01

    In two children with near drowning hypoxic encephalopathy and normal-appearing structural MRI, acute proton magnetic resonance spectroscopy ( 1 H MRS) showed biochemical alterations that correctly indicated prognosis and helped to guide management decisions. Elevation of the lipid-lactate and glutamine-glutamate peaks, on the early (72 hour) 1 H MRS, predicts a poor prognosis. Absence of lipid-lactate and glutamine-glutamate peaks on the early 1 H MRS and reversibility of early mild metabolite abnormalities on follow up examination relates with good outcome. (author)

  15. Reorientations in [Mg(H2O)6](CLO4)2 studied by the proton magnetic resonance and the quasielastic neutron scattering methods

    International Nuclear Information System (INIS)

    Svare, I.; Fimland, B.O.; Janik, J.A.; Janik, J.M.; Mikuli, E.; Migdal-Mikuli, A.

    1980-01-01

    Proton magnetic relaxation measurements carried out for [Mg(H 2 O)XL6](CLO 4 ) 2 revealed two processes responsible for T 1 vs temperature dependence: one connected with H 2 O 180deg flips about the symmetry axes and second connected with a tumbling of the complex cation. Quasielastic neutron scattering measurements gave another evidence of H 2 O 180deg flips. The reorientational corelation times, which in the 273 K - 325 K region are of the order of picoseconds, as derived from NMR coincide perfectly well with those derived from QNS. (author)

  16. Early time course of N-acetylaspartate, creatine and phosphocreatine, and compounds containing choline in the brain after acute stroke. A proton magnetic resonance spectroscopy study

    DEFF Research Database (Denmark)

    Gideon, P; Henriksen, O; Sperling, B

    1992-01-01

    BACKGROUND AND PURPOSE: The early time course after acute stroke of cerebral N-acetylaspartate, creatine and phosphocreatine, and compounds containing choline was studied in vivo by means of localized water-suppressed proton magnetic resonance spectroscopy. METHODS: Eight patients with acute stroke......, with the loss appearing to occur between 6 and 24 hours after the stroke incident. The reduction in N-acetylaspartate content was greater in the central part than in the peripheral part of the infarcted area. Creatine and phosphocreatine were also reduced in the infarcted area, whereas no significant change...

  17. Magnetic Resonance-based Motion Correction for Quantitative PET in Simultaneous PET-MR Imaging.

    Science.gov (United States)

    Rakvongthai, Yothin; El Fakhri, Georges

    2017-07-01

    Motion degrades image quality and quantitation of PET images, and is an obstacle to quantitative PET imaging. Simultaneous PET-MR offers a tool that can be used for correcting the motion in PET images by using anatomic information from MR imaging acquired concurrently. Motion correction can be performed by transforming a set of reconstructed PET images into the same frame or by incorporating the transformation into the system model and reconstructing the motion-corrected image. Several phantom and patient studies have validated that MR-based motion correction strategies have great promise for quantitative PET imaging in simultaneous PET-MR. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Reproducibility and variability of quantitative magnetic resonance imaging markers in cerebral small vessel disease

    NARCIS (Netherlands)

    Guio, F. De; Jouvent, E.; Biessels, G.J.; Black, S.E.; Brayne, C.; Chen, C.; Cordonnier, C.; Leeuw, F.E. de; Dichgans, M.; Doubal, F.; Duering, M.; Dufouil, C.; Duzel, E.; Fazekas, F.; Hachinski, V.; Ikram, M.A.; Linn, J.; Matthews, P.M.; Mazoyer, B.; Mok, V.; Norrving, B.; O'Brien, J.T.; Pantoni, L.; Ropele, S.; Sachdev, P.; Schmidt, R.; Seshadri, S.; Smith, E.E.; Sposato, L.A.; Stephan, B.; Swartz, R.H.; Tzourio, C.; Buchem, M. van; Lugt, A. van der; Oostenbrugge, R.; Vernooij, M.W.; Viswanathan, A.; Werring, D.; Wollenweber, F.; Wardlaw, J.M.; Chabriat, H.

    2016-01-01

    Brain imaging is essential for the diagnosis and characterization of cerebral small vessel disease. Several magnetic resonance imaging markers have therefore emerged, providing new information on the diagnosis, progression, and mechanisms of small vessel disease. Yet, the reproducibility of these

  19. Reproducibility and variability of quantitative magnetic resonance imaging markers in cerebral small vessel disease

    NARCIS (Netherlands)

    De Guio, F. (François); Jouvent, E. (Eric); G.J. Biessels (Geert Jan); S.E. Black (Sandra); C. Brayne (Carol); C. Chen (Christopher); C. Cordonnier (Charlotte); H.F. de Leeuw (Frank); C. Kubisch (Christian); Doubal, F. (Fergus); Duering, M. (Marco); C. Dufouil (Carole); Duzel, E. (Emrah); F. Fazekas (Franz); V. Hachinski (Vladimir); M.K. Ikram (Kamran); J. Linn (Jennifer); P.M. Matthews (P.); B. Mazoyer (Bernard); Mok, V. (Vincent); B. Norrving (Bo); O'Brien, J.T. (John T.); Pantoni, L. (Leonardo); S. Ropele (Stefan); P.S. Sachdev (Perminder); R. Schmidt (Reinhold); S. Seshadri (Sudha); E.E. Smith (Eric); L.A. Sposato (Luciano A); B.C.M. Stephan; Swartz, R.H. (Richard H.); C. Tzourio (Christophe); M.A. van Buchem (Mark); A. van der Lugt (Aad); R.J. van Oostenbrugge (Robert); M.W. Vernooij (Meike); Viswanathan, A. (Anand); D.J. Werring (David); Wollenweber, F. (Frank); J.M. Wardlaw (J.); Chabriat, H. (Hugues)

    2016-01-01

    textabstractBrain imaging is essential for the diagnosis and characterization of cerebral small vessel disease. Several magnetic resonance imaging markers have therefore emerged, providing new information on the diagnosis, progression, and mechanisms of small vessel disease. Yet, the reproducibility

  20. Leucoencephalopathy with brainstem and spinal cord involvement and high lactate: quantitative magnetic resonance imaging

    NARCIS (Netherlands)

    Steenweg, M.E.; Pouwels, P.J.W.; Wolf, N.I.; van Wieringen, W.N.; Barkhof, F.; van der Knaap, M.S.

    2011-01-01

    Leucoencephalopathy with brainstem and spinal cord involvement and elevated lactate is a white matter disorder caused by DARS2 mutations. The pathology is unknown. We observed striking discrepancies between improvement on longitudinal conventional magnetic resonance images and clinical deterioration

  1. Proton magnetic resonance study of the influence of chemical modification, mutation, quaternary state, and ligation state on dynamic stability of the heme pocket in hemoglobin as reflected in the exchange of the proximal histidyl ring labile proton

    International Nuclear Information System (INIS)

    Han, K.H.; La Mar, G.N.; Nagai, K.

    1989-01-01

    Proton nuclear magnetic resonance spectroscopy has been utilized to investigate the rates of exchange with deuterium of the proximal histidyl ring protons in a series of chemically modified and mutated forms of Hb A. Differences in rates of exchange are related to differences in the stability of the deformed or partially unfolded intermediates from which exchange with bulk solvent takes place. Each modified/mutated Hb exhibited kinetic subunit heterogeneity in the reduced ferrous state, with the alpha subunit exhibiting faster exchange than the beta subunit. Modification or mutation resulted in significant increases in the His F8 ring NH exchange rates primarily for the affected subunit and only if the modification/mutation occurs at the allosterically important alpha 1 beta 2 subunit interface. Moreover, this enhancement in exchange rate is observed primarily in that quaternary state of the modified/mutated Hb in which the modified/substituted residue makes the intersubunit contact. This confirms the importance of allosteric constraints in determining the dynamic properties of the heme pocket. Using modified or mutated Hbs that can switch between the alternate quaternary states within a given ligation state or ligate within a given quaternary state, we show that the major portion of the enhanced exchange rate in R-state oxy Hb relative to T-state deoxy Hb originates from the quaternary switch rather than from ligation. However, solely ligation effects are not negligible. The exchange rates of the His F8 ring labile protons increase dramatically upon oxidizing the iron to the ferric state, and both the subunit kinetic heterogeneity and the allosteric sensitivity to the quaternary state are essentially abolished

  2. A quantitative magnetic resonance histology atlas of postnatal rat brain development with regional estimates of growth and variability.

    Science.gov (United States)

    Calabrese, Evan; Badea, Alexandra; Watson, Charles; Johnson, G Allan

    2013-05-01

    There has been growing interest in the role of postnatal brain development in the etiology of several neurologic diseases. The rat has long been recognized as a powerful model system for studying neuropathology and the safety of pharmacologic treatments. However, the complex spatiotemporal changes that occur during rat neurodevelopment remain to be elucidated. This work establishes the first magnetic resonance histology (MRH) atlas of the developing rat brain, with an emphasis on quantitation. The atlas comprises five specimens at each of nine time points, imaged with eight distinct MR contrasts and segmented into 26 developmentally defined brain regions. The atlas was used to establish a timeline of morphometric changes and variability throughout neurodevelopment and represents a quantitative database of rat neurodevelopment for characterizing rat models of human neurologic disease. Published by Elsevier Inc.

  3. The Assessment of Structural Changes in MS Plaques and Normal Appearing White Matter Using Quantitative Magnetization Transfer Imaging (MTI

    Directory of Open Access Journals (Sweden)

    Masoomeh Fooladi

    2007-12-01

    Full Text Available Introduction: Multiple sclerosis (MS is a demyelinating disease of the central nervous system (CNS, affecting mostly young people at a mean age of 30 years. Magnetic resonance imaging (MRI is one of the most specific and sensitive methods in diagnosing and detecting the evolution of multiple sclerosis disease. But it does not have the ability to differentiate between distinct histopathological heterogeneities that occur in MS lesions and brain tissue.Quantitative magnetization transfer imaging (qMTI is a relatively new MRI technique which can be used to examine the pathological processes of the brain parenchyma which occur in MS patients.This quantitative MRI technique can provide more complete information about the extent and nature of the brain tissue destruction in multiple sclerosis, which cannot be detected by conventional MRI. Material and Methods: In this study, twelve patients with relapsing-remitting MS and twelve healthy control subjects underwent conventional MR imaging including: T2-FSE, T1-SE and FLAIR sequences as well as quantitative magnetization transfer imaging. All the focal lesions were identified on T2-weighted images and were classified according to their signal hypointensity on T1-weighted scans. The white matter and MS lesions were segmented using a semi-automated system. MT ratio (MTR histogram analysis was performed for the brain white matter and the average MTR value was calculated for the classified MS lesions. Results: A significant reduction was found in MTR value of the normal appearing white matter (NAWM in patients with relapsing-remitting MS, suggesting that MS is a more diffuse disease, affecting the whole brain tissue. A wide range changes in MTR values can be observed in MS lesions. MTR reduction is correlated with the degree of lesion hypointensity on T1-weighted scans. The lower MTR values of lesions that appear progressively more hypointense on T1-weigted images reflect varying degrees of demyelination and

  4. Quantitative characterization of myocardial infarction by cardiovascular magnetic resonance predicts future cardiovascular events in patients with ischemic cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Pauly John M

    2008-04-01

    Full Text Available Abstract Background Cardiovascular magnetic resonance (CMR can provide quantitative data of the myocardial tissue utilizing high spatial and temporal resolution along with exquisite tissue contrast. Previous studies have correlated myocardial scar tissue with the occurrence of ventricular arrhythmia. This study was conducted to evaluate whether characterization of myocardial infarction by CMR can predict cardiovascular events in patients with ischemic cardiomyopathy (ICM. Results We consecutively studied 86 patients with ICM (LVEF Conclusion Quantification of the scar volume and scar percentage by CMR is superior to LVEDV, LVESV, and LVEF in prognosticating the future likelihood of the development of cardiovascular events in patients with ICM.

  5. An integrated device for magnetically-driven drug release and in situ quantitative measurements: Design, fabrication and testing

    Energy Technology Data Exchange (ETDEWEB)

    Bruvera, I.J. [Aragon Institute of Nanoscience (INA), University of Zaragoza, 50018 (Spain); Hernández, R.; Mijangos, C. [Instituto de Ciencia y Tecnología de Polímeros, CSIC, Juan Cierva 3, E-28006 Madrid (Spain); Goya, G.F., E-mail: goya@unizar.es [Aragon Institute of Nanoscience (INA), University of Zaragoza, 50018 (Spain); Condensed Matter Physics Department, Science Faculty, University of Zaragoza, 50009 (Spain)

    2015-03-01

    We have developed a device capable of remote triggering and in situ quantification of therapeutic drugs, based on magnetically-responsive hydrogels of poly (N-isopropylacrylamide) and alginate (PNiPAAm). The heating efficiency of these hydrogels measured by their specific power absorption (SPA) values showed that the values between 100 and 300 W/g of the material were high enough to reach the lower critical solution temperature (LCST) of the polymeric matrix within few minutes. The drug release through application of AC magnetic fields could be controlled by time-modulated field pulses in order to deliver the desired amount of drug. Using B12 vitamin as a concept drug, the device was calibrated to measure amounts of drug released as small as 25(2)×10{sup −9} g, demonstrating the potential of this device for very precise quantitative control of drug release. - Highlights: • A device for magnetically driven drug release was developed and constructed. • Thermally responsive PNiPAAm and Fe3O4 nanoparticles were usedas drug reservoir. • The device allowed repetitive, remote and precisely controlled drug release. • By in situ spectrometry we could detect released drug quantities as small as 25 ng. • Released drug was controlled through magnetic ac field parameters H, f and time.

  6. An integrated device for magnetically-driven drug release and in situ quantitative measurements: Design, fabrication and testing

    International Nuclear Information System (INIS)

    Bruvera, I.J.; Hernández, R.; Mijangos, C.; Goya, G.F.

    2015-01-01

    We have developed a device capable of remote triggering and in situ quantification of therapeutic drugs, based on magnetically-responsive hydrogels of poly (N-isopropylacrylamide) and alginate (PNiPAAm). The heating efficiency of these hydrogels measured by their specific power absorption (SPA) values showed that the values between 100 and 300 W/g of the material were high enough to reach the lower critical solution temperature (LCST) of the polymeric matrix within few minutes. The drug release through application of AC magnetic fields could be controlled by time-modulated field pulses in order to deliver the desired amount of drug. Using B12 vitamin as a concept drug, the device was calibrated to measure amounts of drug released as small as 25(2)×10 −9 g, demonstrating the potential of this device for very precise quantitative control of drug release. - Highlights: • A device for magnetically driven drug release was developed and constructed. • Thermally responsive PNiPAAm and Fe3O4 nanoparticles were usedas drug reservoir. • The device allowed repetitive, remote and precisely controlled drug release. • By in situ spectrometry we could detect released drug quantities as small as 25 ng. • Released drug was controlled through magnetic ac field parameters H, f and time

  7. Elevated prefrontal cortex γ-aminobutyric acid and glutamate-glutamine levels in schizophrenia measured in vivo with proton magnetic resonance spectroscopy.

    Science.gov (United States)

    Kegeles, Lawrence S; Mao, Xiangling; Stanford, Arielle D; Girgis, Ragy; Ojeil, Najate; Xu, Xiaoyan; Gil, Roberto; Slifstein, Mark; Abi-Dargham, Anissa; Lisanby, Sarah H; Shungu, Dikoma C

    2012-05-01

    Postmortem studies have found evidence of γ-aminobutyric acid (GABA) deficits in fast-spiking, parvalbumin-positive interneurons in the prefrontal cortex in schizophrenia. Magnetic resonance spectroscopy studies in unmedicated patients have reported glutamine or glutamate-glutamine (Glx) elevations in this region. Abnormalities in these transmitters are thought to play a role in cognitive impairments in the illness. To measure GABA and Glx levels in vivo in 2 prefrontal brain regions in unmedicated and medicated patients with schizophrenia and healthy controls. Case-control study. Inpatient psychiatric research unit and associated outpatient clinic. Sixteen unmedicated patients with schizophrenia, 16 medicated patients, and 22 healthy controls matched for age, sex, ethnicity, parental socioeconomic status, and cigarette smoking. Proton magnetic resonance spectroscopy with a 3-T system and the J-edited spin-echo difference method. The GABA and Glx levels were measured in the dorsolateral and medial prefrontal cortex and normalized to the simultaneously acquired water signal. Working memory performance was assessed in all subjects. The GABA and Glx concentrations determined by proton magnetic resonance spectroscopy. In the medial prefrontal cortex region, 30% elevations were found in GABA (P = .02) and Glx (P = .03) levels in unmedicated patients compared with controls. There were no alterations in the medicated patients or in either group in the dorsolateral prefrontal cortex. Both regions showed correlations between GABA and Glx levels in patients and controls. No correlations with working memory performance were found. To our knowledge, this study presents the first GABA concentration measurements in unmedicated patients with schizophrenia, who showed elevations in both GABA and Glx levels in the medial prefrontal cortex but not the dorsolateral prefrontal cortex. Medicated patients did not show these elevations, suggesting possible normalization of levels with

  8. Study of the interactions of 13.8 GeV/c protons with the heavy nuclei of the emulsions exposed in magnetic fuel of 170 kgauss; Estudio de las interacciones de protones de 13,8 geV/c con los nucleos pesados de emusiones

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Aleixandre, J L

    1967-07-01

    145 stars with N{sub h}>8 produced by the interactions of 13.8 GeV/c protons with Ag and Br nuclei have been analysed. The emulsion stack was irradiated in a 170 K gauss magnetic field. Statistical results concerning the main characteristics of the different particles emitted are given and the energy balance is evaluated. The main features of both 24 GeV/c protons and 17 GeV/c {pi}- interactions are compared with those we have found for 13.8 GeV/c protons interactions. (Author) 27 refs.

  9. Repeatability of two-dimensional chemical shift imaging multivoxel proton magnetic resonance spectroscopy for measuring human cerebral choline-containing compounds.

    Science.gov (United States)

    Puri, Basant K; Egan, Mary; Wallis, Fintan; Jakeman, Philip

    2018-03-22

    To investigate the repeatability of proton magnetic resonance spectroscopy in the in vivo measurement of human cerebral levels of choline-containing compounds (Cho). Two consecutive scans were carried out in six healthy resting subjects at a magnetic field strength of 1.5 T. On each occasion, neurospectroscopy data were collected from 64 voxels using the same 2D chemical shift imaging (CSI) sequence. The data were analyzed in the same way, using the same software, to obtain the values for each voxel of the ratio of Cho to creatine. The Wilcoxon related-samples signed-rank test, coefficient of variation (CV), repeatability coefficient (RC), and intraclass correlation coefficient (ICC) were used to assess the repeatability. The CV ranged from 2.75% to 33.99%, while the minimum RC was 5.68%. There was excellent reproducibility, as judged by significant ICC values, in 26 voxels. Just three voxels showed significant differences according to the Wilcoxon related-samples signed-rank test. It is therefore concluded that when CSI multivoxel proton neurospectroscopy is used to measure cerebral choline-containing compounds at 1.5 T, the reproducibility is highly acceptable.

  10. Spin tunneling in magnetic molecules: Quantitative estimates for Fe8 clusters

    Science.gov (United States)

    Galetti, D.; Silva, Evandro C.

    2007-12-01

    Spin tunneling in the particular case of the magnetic molecular cluster octanuclear iron(III), Fe8, is treated by an effective Hamiltonian that allows for an angle-based description of the process. The presence of an external magnetic field along the easy axis is also taken into account in this description. Analytic expressions for the energy levels and barriers are obtained from a harmonic approximation of the potential function which give results in good agreement with the experimental results. The energy splittings due to spin tunneling is treated in an adapted WKB approach and it is shown that the present description can give results to a reliable degree of accuracy.

  11. ZGS beam transport for transverse or longitudinally polarized protons

    International Nuclear Information System (INIS)

    Colton, E.; Auer, I.P.; Beretvas, A.

    1977-01-01

    A combination of dipole magnets and a superconducting solenoid is utilized to transform the spin direction of transversely polarized protons from the Argonne ZGS for use in proton-proton scattering experiments

  12. Quantitative magnetic resonance imaging for stroke research in the pharmaceutical industry

    International Nuclear Information System (INIS)

    Eis, M.; Neumaier, M.; Pschorn, U.

    1998-01-01

    In conclusion, quantitative NMR imaging is a valuable method for monitoring the volume and degree of severity of cerebral lesions and therapeutic effects over time. Thus, it is an important tool for evaluating the efficacy of cerebroprotective drugs in vivo. (orig.)

  13. Quantification of skeletal muscle mitochondrial function by 31P magnetic resonance spectroscopy techniques : A quantitative review

    NARCIS (Netherlands)

    Kemp, G.J.; Ahmad, R.E.; Nicolay, K.; Prompers, J.J.

    2015-01-01

    Magnetic resonance spectroscopy (MRS) can give information about cellular metabolism in vivo which is difficult to obtain in other ways. In skeletal muscle, non-invasive 31P MRS measurements of the post-exercise recovery kinetics of pH, [PCr], [Pi] and [ADP] contain valuable information about muscle

  14. Quantitative chemical exchange saturation transfer (qCEST) MRI - omega plot analysis of RF-spillover-corrected inverse CEST ratio asymmetry for simultaneous determination of labile proton ratio and exchange rate.

    Science.gov (United States)

    Wu, Renhua; Xiao, Gang; Zhou, Iris Yuwen; Ran, Chongzhao; Sun, Phillip Zhe

    2015-03-01

    Chemical exchange saturation transfer (CEST) MRI is sensitive to labile proton concentration and exchange rate, thus allowing measurement of dilute CEST agent and microenvironmental properties. However, CEST measurement depends not only on the CEST agent properties but also on the experimental conditions. Quantitative CEST (qCEST) analysis has been proposed to address the limitation of the commonly used simplistic CEST-weighted calculation. Recent research has shown that the concomitant direct RF saturation (spillover) effect can be corrected using an inverse CEST ratio calculation. We postulated that a simplified qCEST analysis is feasible with omega plot analysis of the inverse CEST asymmetry calculation. Specifically, simulations showed that the numerically derived labile proton ratio and exchange rate were in good agreement with input values. In addition, the qCEST analysis was confirmed experimentally in a phantom with concurrent variation in CEST agent concentration and pH. Also, we demonstrated that the derived labile proton ratio increased linearly with creatine concentration (P analysis can simultaneously determine labile proton ratio and exchange rate in a relatively complex in vitro CEST system. Copyright © 2015 John Wiley & Sons, Ltd.

  15. Dynamic and quantitative evaluation of degenerative mitral valve disease: a dedicated framework based on cardiac magnetic resonance imaging.

    Science.gov (United States)

    Sturla, Francesco; Onorati, Francesco; Puppini, Giovanni; Pappalardo, Omar A; Selmi, Matteo; Votta, Emiliano; Faggian, Giuseppe; Redaelli, Alberto

    2017-04-01

    Accurate quantification of mitral valve (MV) morphology and dynamic behavior over the cardiac cycle is crucial to understand the mechanisms of degenerative MV dysfunction and to guide the surgical intervention. Cardiac magnetic resonance (CMR) imaging has progressively been adopted to evaluate MV pathophysiology, although a dedicated framework is required to perform a quantitative assessment of the functional MV anatomy. We investigated MV dynamic behavior in subjects with normal MV anatomy (n=10) and patients referred to surgery due to degenerative MV prolapse, classified as fibro-elastic deficiency (FED, n=9) and Barlow's disease (BD, n=10). A CMR-dedicated framework was adopted to evaluate prolapse height and volume and quantitatively assess valvular morphology and papillary muscles (PAPs) function over the cardiac cycle. Multiple comparison was used to investigate the hallmarks associated to MV degenerative prolapse and evaluate the feasibility of anatomical and functional distinction between FED and BD phenotypes. On average, annular dimensions were significantly (Pframework allows for the quantitative and dynamic evaluation of MV apparatus, with quantifiable annular alterations representing the primary hallmark of severe MV degeneration. This may aid surgeons in the evaluation of the severity of MV dysfunction and the selection of the appropriate MV treatment.

  16. Quantitative magnetic resonance imaging in limb-girdle muscular dystrophy 2I: a multinational cross-sectional study.

    Directory of Open Access Journals (Sweden)

    Tracey A Willis

    Full Text Available We conducted a prospective multinational study of muscle pathology using magnetic resonance imaging (MRI in patients with limb-girdle muscular dystrophy 2I (LGMD2I. Thirty eight adult ambulant LGMD2I patients (19 male; 19 female with genetically identical mutations (c.826C>A in the fukutin-related protein (FKRP gene were recruited. In each patient, T1-weighted (T1w imaging was assessed by qualitative grading for 15 individual lower limb muscles and quantitative Dixon imaging was analysed on 14 individual lower limb muscles by region of interest analysis. We described the pattern and appearance of muscle pathology and gender differences, not previously reported for LGMD2I. Diffuse fat infiltration of the gastrocnemii muscles was demonstrated in females, whereas in males fat infiltration was more prominent in the medial than the lateral gastrocnemius (p = 0.05. In the anterior thigh of males, in contrast to females, median fat infiltration in the vastus medialis muscle (45.7% exceeded that in the vastus lateralis muscle (11.2% (p<0.005. MRI is non-invasive, objective and does not rely on patient effort compared to clinical and physical measures that are currently employed. We demonstrated (i that the quantitative Dixon technique is an objective quantitative marker of disease and (ii new observations of gender specific patterns of muscle involvement in LGMD2I.

  17. Manufacture and Testing of a High Field Gradient Magnetic Fractionation System for Quantitative Detection of Plasmodium falciparum Gametocytes

    Science.gov (United States)

    Karl, Stephan; Woodward, Robert C.; Davis, Timothy M. E.; St. Pierre, Tim G.

    2010-12-01

    Plasmodium falciparum is the most dangerous of the human malaria parasite species and accounts for millions of clinical episodes of malaria each year in tropical countries. The pathogenicity of Plasmodium falciparum is a result of its ability to infect erythrocytes where it multiplies asexually over 48 h or develops into sexual forms known as gametocytes. If sufficient male and female gametocytes are taken up by a mosquito vector, it becomes infectious. Therefore, the presence and density of gametocytes in human blood is an important indicator of human-to-mosquito transmission of malaria. Recently, we have shown that high field gradient magnetic fractionation improves gametocyte detection in human blood samples. Here we present two important new developments. Firstly we introduce a quantitative approach to replace the previous qualitative method and, secondly, we describe a novel method that enables cost-effective production of the magnetic fractionation equipment required to carry out gametocyte quantification. We show that our custom-made magnetic fractionation equipment can deliver results with similar sensitivity and convenience but for a small fraction of the cost.

  18. Quantitation of magnetic resonance spectroscopy signals: the jMRUI software package

    Czech Academy of Sciences Publication Activity Database

    Stefan, D.; Di Cesare, F.; Andrasescu, A.; Popa, E.; Lazariev, A.; Vescovo, E.; Štrbák, Oliver; Williams, S.; Starčuk jr., Zenon; Cabanas, M.; van Ormondt, D.; Graveron-Demilly, D.

    2009-01-01

    Roč. 20, č. 10 (2009), 104035:1-9 ISSN 0957-0233 Grant - others:EC 6FP(XE) MRTN-CT-2006-035801 Source of funding: R - rámcový projekt EK Keywords : MR spectroscopy * MRS * MRSI * HRMAS-NMR * jMRUI software package * Java * plug-ins * quantitation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.317, year: 2009

  19. Quantitative evaluation of tongue atrophy on midsagittal magnetic resonance images (MRIs)

    International Nuclear Information System (INIS)

    Ohnishi, Akio; Oishi, Tomonari; Murai, Yoshiyuki; Tsukamoto, Yoshiki; Ikeda, Masato

    1992-01-01

    This study was undertaken mainly to establish the quantitative parameter to evaluate the tongue atrophy on midsagittal MRIs and to show the clinical usefulness of such quantitative evaluation. Midsagittal MRIs of the tongue of consecutive 103 patients were analyzed. They were classified into 67 patients showing normal size (group without atrophy), 11 patients showing atrophy (group with atrophy) and 25 patients showing unsatifactory MRIs with artifacts based on the routine evaluation. The patients in the group without atrophy did not show any pathologic processes to produce tongue atrophy on clinical findings. The area and perimeter of tongue and oral cavity, and the ratio of tongue area to oral cavity area and the ratio of tongue perimeter to oral cavity perimeter on midsagittal MRIs were obtained in each patient of groups with and without atrophy by using quantitative image analysis system. In the group without atrophy, regression analysis of the data on age was made and the 95% confidence interval of the data for age was obtained. No evidence that the tongue becomes atrophic with aging was obtained in the group without atrophy. Patients in the group with atrophy were best separated from those in the group without atrophy statistically when the ratio of tongue area to oral cavity area was regressed on age. Among 11 patients in the group with atrophy, 6 patients were not regarded as having tongue atrophy on clinical neurological examinations. Therefore, the evaluation of midsagittal MRIs is clinically useful. (author)

  20. Quantitative and qualitative assessment of structural magnetic resonance imaging data in a two-center study

    OpenAIRE

    Chalavi Sima; Simmons Andrew; Dijkstra Hildebrand; Barker Gareth J; Reinders AAT Simone

    2012-01-01

    Abstract Background Multi-center magnetic resonance imaging (MRI) studies present an opportunity to advance research by pooling data. However, brain measurements derived from MR-images are susceptible to differences in MR-sequence parameters. It is therefore necessary to determine whether there is an interaction between the sequence parameters and the effect of interest, and to minimise any such interaction by careful choice of acquisition parameters. As an exemplar of the issues involved in ...

  1. Processing tracking in jMRUI software for magnetic resonance spectra quantitation reproducibility assurance

    Czech Academy of Sciences Publication Activity Database

    Jabłoński, Michal; Starčuková, Jana; Starčuk jr., Zenon

    2017-01-01

    Roč. 18, 23 JAN (2017), s. 1-11, č. článku 56. ISSN 1471-2105 R&D Projects: GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 EU Projects: European Commission(XE) 316679 Institutional support: RVO:68081731 Keywords : Magnetic Resonance Spectroscopy * Signal Processing * SQL database * jMRUI Subject RIV: FS - Medical Facilities ; Equipment OBOR OECD: Medical engineering Impact factor: 2.448, year: 2016

  2. A quantitative study of particle size effects in the magnetorelaxometry of magnetic nanoparticles using atomic magnetometry

    Energy Technology Data Exchange (ETDEWEB)

    Dolgovskiy, V. [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Lebedev, V., E-mail: victor.lebedev@unifr.ch [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Colombo, S.; Weis, A. [Physics Department, University of Fribourg, CH-1700 Fribourg (Switzerland); Michen, B.; Ackermann-Hirschi, L. [Adolphe Merkle Institute, University of Fribourg, CH-1700 Fribourg (Switzerland); Petri-Fink, A. [Adolphe Merkle Institute, University of Fribourg, CH-1700 Fribourg (Switzerland); Chemistry Department, University of Fribourg, CH-1700 Fribourg (Switzerland)

    2015-04-01

    The discrimination of immobilised superparamagnetic iron oxide nanoparticles (SPIONs) against SPIONs in fluid environments via their magnetic relaxation behaviour is a powerful tool for bio-medical imaging. Here we demonstrate that a gradiometer of laser-pumped atomic magnetometers can be used to record accurate time series of the relaxing magnetic field produced by pre-polarised SPIONs. We have investigated dry in vitro maghemite nanoparticle samples with different size distributions (average radii ranging from 14 to 21 nm) and analysed their relaxation using the Néel–Brown formalism. Fitting our model function to the magnetorelaxation (MRX) data allows us to extract the anisotropy constant K and the saturation magnetisation M{sub S} of each sample. While the latter was found not to depend on the particle size, we observe that K is inversely proportional to the (time- and size-) averaged volume of the magnetised particle fraction. We have identified the range of SPION sizes that are best suited for MRX detection considering our specific experimental conditions and sample preparation technique. - Highlights: • We studied magnetorelaxation of magnetic nanoparticles using atomic magnetometers. • We show that atomic magnetometers yield high precision MRX data. • The observed magnetorelaxation is well described by the moment superposition model. • Model fits allow extraction of nanoparticle material parameters of six samples. • All samples exhibit an unexpected size-dependent anisotropy constant.

  3. Proton storage rings

    International Nuclear Information System (INIS)

    Rau, R.R.

    1978-04-01

    A discussion is given of proton storage ring beam dynamic characteristics. Topics considered include: (1) beam energy; (2) beam luminosity; (3) limits on beam current; (4) beam site; (5) crossing angle; (6) beam--beam interaction; (7) longitudinal instability; (8) effects of scattering processes; (9) beam production; and (10) high magnetic fields. Much of the discussion is related to the design parameters of ISABELLE, a 400 x 400 GeV proton---proton intersecting storage accelerator to be built at Brookhaven National Laboratory

  4. Preliminary results of proton ring current observations in time of magnetic perturbations with the 'Molniya-1' satellite

    International Nuclear Information System (INIS)

    Grechin, A.N.; Kovrygina, L.M.; Kovtyukh, A.S.

    1975-01-01

    The experimental results of observation on the injection of the annular current protons (30< Esub(r)<380 KeV) into the radiation band during the storm on October 28, 1973 and three storms on January 1, 1974, July 12 and 21, 1974, with the maximum values of Dsup(st) of 65, 30, and 20γ, respectively, are described. During the main phases of the storms the assymetry of the annular current of protons relative to the mid-day-mid-night meridian was observed. The injection of the particles was being accompanied by variation of the shape of the spectrum on the internal edge of the annular current. The possible effect of the ion-cyclotron instability on the formation of the initial edge of the annular current has been analyzed. Immediately after the main phases of the storms