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Sample records for 31p magnetic resonance

  1. Metabolism of perfused pig intercostal muscles evaluated by 31P-magnetic resonance spectroscopy

    Pedersen, Brian Lindegaard; Arendrup, Henrik; Secher, Niels H;

    2006-01-01

    consumption and 31P-magnetic resonance spectroscopy (31P-MRS). When perfused at rest with Krebs-Ringer buffer, the preparation maintained physiological levels of phosphocreatine (PCr), inorganic phosphate (Pi), ATP and pH at a stable oxygen consumption of 0.51 +/- 0.01 micromol min(-1) g(-1) for more than 2 h...

  2. 31P magnetic resonance spectroscopy of skeletal muscle in patients with fibromyalgia

    Jacobsen, Søren; Jensen, K E; Thomsen, C;

    1992-01-01

    31Phosphorous nuclear magnetic resonance (31P NMR) spectroscopy of painful calf muscle was performed in 12 patients with fibromyalgia (FS) and 7 healthy subjects during rest, aerobic and anaerobic exercising conditions, and postexercise recovery. Ratios of inorganic phosphate and creatinine...... phosphate (Pi/PCr) and pH were calculated from the collected 31P NMR spectra. Resting values of Pi/PCr were normal in the patients. Patients delivered only 49% of the muscle power of the controls (p = 0.005). Patients and controls had similar rates of Pi/PCr and pH changes during work and recovery. The...

  3. Feasibility of Rapid-Sequence 31P Magnetic Resonance Spectroscopy in Cardiac Patients

    Purpose: To determine the clinical feasibility of rapid-sequence phosphorus-31 magnetic resonance spectroscopy (31P -MRS) of the heart with cardiac patients using a 5T clinical MR system. Material and Methods: Twenty cardiac patients, i.e. dilated cardiomyopathy (DCM)3 cases, hypertrophic cardiomyopathy (HCM) 3 cases, hypertensive heart diseases (HHD) 3 cases, and aortic regurgitation (AR) case were examined using rapid cardiac 31P-MRS. Complete three-dimensional localization was performed using a two-dimensional phosphorus chemical-shift imaging sequence in combination with 30-mm axial slice-selective excitation. The rapid-sequence 31P-MRS procedure was phase encoded in arrays of 8x8 steps with an average of 4 acquisitions. The total examination time, including proton imaging and shimming, for the rapid cardiac 31P-MRS procedure, ranged from 0 to 5 min, depending on the heart rate. Student's t test was used to compare creatine phosphate (PCr)/adenosine triphosphate (ATP) ratios from the cardiac patients with those of the control subjects (n≅13). Results: The myocardial PCr/ATP ratio obtained by rapid 31P-MRS was significantly lower (P 31P-MRS may be a valid diagnostic tool for patients with cardiac disease

  4. Monitoring of the insecticide trichlorfon by phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy

    Trichlorfon is an organophosphorus insecticide, which is extensively being used for protection of fruit crops. Trichlorfon is a thermal labile compound, which cannot be easily determined by gas chromatography (GC) and has no suitable group for sensitive detection by high performance liquid chromatography (HPLC). In this study, a 31P nuclear magnetic resonance (31P NMR) has been described for monitoring of trichlorfon without any separation step. The quantitative works of 31P NMR spectroscopy has been performed in the presence of an internal standard (hexamethylphosphoramide). Limit of detection (LOD) for this method has been found to be 55 mg L-1, without any sample preparation, and the linear working range was 150-5500 mg L-1. Relative standard deviation (R.S.D.%) of the method for three replicates within and between days was obtained ≤9%. The average recovery efficiency was approximately 99-112%. This method was applied for monitoring trichlorfon in a commercial insecticide sample and tomato sample

  5. 1H and 31P nuclear magnetic resonance spectroscopy of erythrocyte extracts in myotonic muscular dystrophy

    Extracts freshly prepared from erythrocytes of patients with myotonic muscular dystrophy, their unaffected siblings, and normal control subjects were examined with both 1H and 31P nuclear magnetic resonance spectroscopy. A moderate variability was found in the relative amounts of various nonphosphorylated compounds among patients and control subjects; however, no significant differences were found between the groups. As for the phosphorylated compounds, the sum of ADP+ATP was found significantly elevated in the myotonic muscular dystrophy patients

  6. In vivo magnetic resonance studies of human brain energy metabolism by 31P-spectroscopy

    Magnetic resonance (MR) spectroscopy is a very powerful tool for obtaining biochemical information from structurally and functionally intact biological tissues. Following the introduction of high field (1.5 Tesla) wholebody systems it is possible to perform spectroscopic studies on human beings. Thus, MR-spectroscopy may become a very important research tool in physiology, clinical diagnosis and treatment follow-up. So far the human studies have concentrated on the phosphorus (31P) and (1H) nuclei. (author)

  7. Bioenergetic Measurements in Children with Bipolar Disorder: A Pilot 31P Magnetic Resonance Spectroscopy Study

    Sikoglu, Elif M.; J. Eric Jensen; Gordana Vitaliano; Liso Navarro, Ana A; Renshaw, Perry F.; Jean A. Frazier; Moore, Constance M.

    2013-01-01

    Background: Research exploring Bipolar Disorder (BD) phenotypes and mitochondrial dysfunction, particularly in younger subjects, has been insufficient to date. Previous studies have found abnormal cerebral pH levels in adults with BD, which may be directly linked to abnormal mitochondrial activity. To date no such studies have been reported in children with BD. Methods: Phosphorus Magnetic Resonance Spectroscopy (\\(^{31}\\)P MRS) was used to determine pH, phopshocreatine (PCr) and inorganic ph...

  8. Advancement of 31P Magnetic Resonance Spectroscopy Using GRAPPA Reconstruction on a 3D Volume

    Clevenger, Tony

    The overall objective of this research is to improve currently available metabolic imaging techniques for clinical use in monitoring and predicting treatment response to radiation therapy in liver cancer. Liver metabolism correlates with inflammatory and neoplastic liver diseases, which alter the intracellular concentration of phosphorus- 31 (31P) metabolites [1]. It is assumed that such metabolic changes occur prior to physical changes of the tissue. Therefore, information on regional changes of 31P metabolites in the liver, obtained by Magnetic Resonance Spectroscopic Imaging (MRSI) [1,2], can help in diagnosis and follow-up of various liver diseases. Specifically, there appears to be an immediate need of this technology for both the assessment of tumor response in patients with Hepatocellular Carcinoma (HCC) treated with Stereotactic Body Radiation Therapy (SBRT) [3--5], as well as assessment of radiation toxicity, which can result in worsening liver dysfunction [6]. Pilot data from our lab has shown that 31P MRSI has the potential to identify treatment response five months sooner than conventional methods [7], and to assess the biological response of liver tissue to radiation 24 hours post radiation therapy [8]. While this data is very promising, commonly occurring drawbacks for 31P MRSI are patient discomfort due to long scan times and prone positioning within the scanner, as well as reduced data quality due to patient motion and respiration. To further advance the full potential of 31P MRSI as a clinical diagnostic tool in the management of liver cancer, this PhD research project had the following aims: I) Reduce the long acquisition time of 3D 31P MRS by formulating and imple- menting an appropriate GRAPPA undersampling scheme and reconstruction on a clinical MRI scanner II) Testing and quantitative validation of GRAPPA reconstruction on 3D 31P MRSI on developmental phantoms and healthy volunteers At completion, this work should considerably advance 31P MRSI

  9. Feasibility of Rapid-Sequence {sup 31}P Magnetic Resonance Spectroscopy in Cardiac Patients

    Chida, K.; Otani, H.; Saito, H.; Nagasaka, T.; Kagaya, Y.; Kohzuki, M.; Zuguchi, M.; Shirato, K. [Tohoku Univ., School of Health Sciences, Sendai (Japan). Dept. of Radiological Technology

    2005-07-01

    Purpose: To determine the clinical feasibility of rapid-sequence phosphorus-31 magnetic resonance spectroscopy ({sup 31}P -MRS) of the heart with cardiac patients using a 5T clinical MR system. Material and Methods: Twenty cardiac patients, i.e. dilated cardiomyopathy (DCM)3 cases, hypertrophic cardiomyopathy (HCM) 3 cases, hypertensive heart diseases (HHD) 3 cases, and aortic regurgitation (AR) case were examined using rapid cardiac {sup 31}P-MRS. Complete three-dimensional localization was performed using a two-dimensional phosphorus chemical-shift imaging sequence in combination with 30-mm axial slice-selective excitation. The rapid-sequence {sup 31}P-MRS procedure was phase encoded in arrays of 8x8 steps with an average of 4 acquisitions. The total examination time, including proton imaging and shimming, for the rapid cardiac {sup 31}P-MRS procedure, ranged from 0 to 5 min, depending on the heart rate. Student's t test was used to compare creatine phosphate (PCr)/adenosine triphosphate (ATP) ratios from the cardiac patients with those of the control subjects (n{approx_equal}13). Results: The myocardial PCr/ATP ratio obtained by rapid {sup 31}P-MRS was significantly lower (P <0.001) in DCM patients (1.82{+-}0.33, mean{+-}SD), and in patients with global myocardial dysfunction (combined data for 20 patients:.89{+-}0.32) than in normal volunteers (2.96{+-}0.59). These results are similar to previous studies. Conclusion: Rapid-sequence {sup 31}P-MRS may be a valid diagnostic tool for patients with cardiac disease.

  10. Erythrocytes in muscular dystrophy. Investigation with 31P nuclear magnetic resonance spectroscopy

    Phosphorus 31 nuclear magnetic resonance (31P NMR) signals were recorded from intact human erythrocytes for 16 hours. Total phosphate concentration, which was estimated as the sum of the individual 31P signals, was 25% lower in erythrocytes from men with myotonic dystrophy than in control erythrocytes. The inorganic-phosphate fraction contained the highest average phosphate concentration over the 16-hour period, and made the major contribution to the difference in total phosphate between the two groups. This result was not observed in erythrocytes from either women with myotonic dystrophy or patients with Duchenne's dystrophy and may be due to a change in cell membrane permeability to inorganic phosphate, which lead to lower steady-state concentrations of the intracellular phosphates

  11. Erythrocytes in muscular dystrophy. Investigation with 31P nuclear magnetic resonance spectroscopy

    Phosphorus 31 nuclear magnetic resonance (31P NMR) signals were recorded from intact human erythrocytes for 16 hours. Total phosphate concentration, which was estimated as the sum of the individual 31P signals, was 25% lower in erythrocytes from men with myotonic dystrophy than in control erythrocytes. The inorganic-phosphate fraction contained the highest average phosphate concentration over the 16-hour period, and made the major contribution to the difference in total phosphate between the two groups. This result was not observed in erythrocytes from either women with myotonic dystrophy or patients with Duchenne's dystrophy and may be due to a change in cell membrane permeability to inorganic phosphate, which leads to lower steady-state concentrations of the intracellular phosphates

  12. In vivo magnetic resonance imaging and 31P spectroscopy of large human brain tumours at 1.5 tesla

    Thomsen, C; Jensen, K E; Achten, E;

    1988-01-01

    31P MR spectroscopy of human brain tumours is one feature of magnetic resonance imaging. Eight patients with large superficial brain tumours and eight healthy volunteers were examined with 31P spectroscopy using an 8 cm surface coil for volume selection. Seven frequencies were resolved in our spe...

  13. Early effects of radiotherapy in small cell lung cancer xenografts monitored by 31P magnetic resonance spectroscopy and biochemical analysis

    Kristjansen, P E; Pedersen, E J; Quistorff, B;

    1990-01-01

    31P magnetic resonance spectroscopy (31P MRS) and biochemical analysis of extracts were applied to study the metabolic response to X-irradiation of small cell lung cancer in nude mice. Two small cell lung cancer xenografts, CPH SCCL 54A and 54B, with different radiosensitivity, although derived...

  14. 31P nuclear magnetic resonance measurements of intracellular pH in giant barnacle muscle

    The accuracy of intracellular pH (pH/sub i/) measurements by 31P nuclear magnetic resonance (NMR) spectroscopy was examined in single muscle fibers from the giant barnacle, Balanus nubilis. The pH/sub i/ was derived from the chemical shifts of 2-deoxy-D-glucose-6-phosphate and inorganic phosphate. In fibers superfused with sea water at pH 7.7, pH/sub i/ = 7.30 +/- 0.02 at 200C. Experimentally induced pH/sub i/ changes were followed with a time resolution of 3 min. Intracellular alkalinization was induced by exposure to NH3Cl and intracellular acidification followed when NH3 was removed. Then acid extrusion was stimulated by exposure to bicarbonate containing sea water. In single muscle fibers 31P NMR results were in excellent agreement with microelectrode studies over the pH range of 6.5 to 8.0. The initial acid extrusion rate was 1.7 +/- 0.3 mmol x 1-1 x min-1 at pH/sub i/ 6.75. The authors results showed that 31P NMR is a reliable in vivo pH probe

  15. Interleaved localized 1H/31P nuclear magnetic resonance spectroscopy of skeletal muscle

    Nuclear magnetic resonance (NMR) has been used as a spectroscopic method in physics and chemistry before it was developed to become a diagnostic imaging tool in medicine. When NMR spectroscopy is applied to human tissue, metabolism can be studied in normal physiological and pathological states in vivo. Metabolite concentrations and rates can be monitored dynamically and with localization of a defined region of interest. The 'window' which is opened for observation, i.e. which quantities are measured, depends on the nucleus used for RF excitation. Mechanisms of adenosine tri-phosphate (ATP) resynthesis, as a direct source of energy for muscle contraction, are phosphocreatine (PCr) splitting, glycolysis, beta-oxidation and, finally, oxidative phosphorylation. Whilst the dependency of these processes' fractional contribution to muscular energy supply on exercise type and duration is well known, quantitative models of the regulating mechanisms involved are still subject of current research. A large fraction of the established knowledge about metabolism is based on biochemical analysis of tissue acquired invasively (e.g. microdialysis and open-flow microperfusion) or representing averaged metabolic concentrations for the whole body (via serum metabolites or gas exchange analysis). Localized NMR spectroscopy, however, is capable of non-invasively acquiring time-resolved data from a defined volume of interest, in vivo. In contrast to the vast majority of MRS studies investigating metabolism, where spectra of a single nucleus (commonly 1H, 31P or 13C) were acquired or several MR spectra with different nuclei were measured in separate experiments, this work opens an additional 'window' on muscle metabolism by interleaved localized acquisition of 1H and 31P NMR spectra from human calf muscle in vivo, during rest, exercise and recovery, in a single experiment. Using this technique, the time courses of the concentrations of phosphocreatine, inorganic phosphate (Pi), ATP, total

  16. INVIVO 31P MAGNETIC-RESONANCE SPECTROSCOPY (MRS) OF TENDER POINTS IN PATIENTS WITH PRIMARY FIBROMYALGIA SYNDROME

    DEBLECOURT, AC; WOLF, RF; VANRIJSWIJK, MH; KAMMAN, RL; KNIPPING, AA; MOOYAART, EL

    1991-01-01

    31P Magnetic Resonance-Spectroscopy was performed at the site of tender points in the trapezius muscle of patients with primary fibromyalgia syndrome. Earlier, in vitro studies have reported changes in the high energy phosphate-metabolism in biopsies taken from tender points of fibromyalgia patients

  17. {sup 1}H and {sup 31}P-magnetic resonance spectroscopy of cerebral infarction in rats

    Yamamuro, Manabu; Katayama, Yasuo; Igarashi, Hironaka; Terashi, Akiro [Nippon Medical School, Tokyo (Japan)

    1997-04-01

    Magnetic resonance spectroscopy (MRS) allows the noninvasive study of metabolism in vivo. In order to further understand the time course of biochemical changes during cerebral infarction, we performed the MRS study with pathological analysis. The left middle cerebral artery (MCA) was occluded in spontaneously hypertensive male rats (SHR) by the method of Tamura et al. The spectra were obtained from the infarcted hemisphere by placing the surface coils over the left side of the calvarium. {sup 31}P and {sup 1}H-MRS were performed at 3 hours, 24 hours and 7 days after MCA occlusion. Ischemic lesions caused by the left MCA occlusion extended into the parietal lobe and caudate putamen. After 3 hours of ischemia, vacuolated neurophils and shrunken neurons were observed. At 24 hours, these changes were severe. After 7 days, infiltration of monocytes and capillary hyperplasia were seen, and neurons had disappeared. At the acute stage of ischemia the phosphocreatine/inorganic phosphate (PCr/Pi) peak ratio decreased. After 7 days of ischemia, these changes became obscure. The intracellular pH (pHi) decreased after 3 hours of ischemia and recovered almost to the control level at 24 hours post ischemia. Alkalosis was apparent 7 days after ischemia. This alkalosis might be due to increased permeability of the deteriorated blood brain barrier. Although the lactate level was high 24 hours post ischemia, the pHi was almost normal. The N-acetyl-aspartate/creatine ratio decreased significantly from the acute stage of stroke. This decrease correlated with pathological changes. The correlation of the magnetic resonance spectra with the histological results may open aspects for monitoring stroke therapy and a new approach to tissue characterization. (author)

  18. 31P-nuclear magnetic resonance studies of chronic myocardial ischemia in the Yucatan micropig.

    Rath, D P; Bailey, M; Zhang, H; Jiang, Z; Abduljalil, A M; Weisbrode, S; Hamlin, R L; Robitaille, P M

    1995-01-01

    In this work, an x-irradiation/high fat/high cholesterol diet-induced atherogenic model was invoked to examine the effects of severe diffuse atherosclerosis on myocardial metabolism in the in vivo porcine heart. This model was studied using spatially localized 31P-nuclear magnetic resonance (NMR) to monitor pH and the levels of inorganic phosphate, phosphomonoesters, creatine phosphate, and adenosine triphosphate as a function of workload transmurally in control swine and in animals suffering from chronic ischemic heart disease. These preliminary studies revealed that the development of severe atherosclerosis and the accompanying chronically diseased state produce changes in high energy phosphates and that increases in rate pressure products result in demonstrable signs of ischemia in the myocardium which span the entire left ventricular wall. Ischemic changes include a global increase in inorganic phosphate and corresponding decreases in creatine phosphate, ATP, and pH. Importantly, changes in intracellular pH are noted with even the slightest increase in workload suggesting that these diseased hearts display elevated glycolytic activity. By challenging these animals with increased cardiac workload, we directly visualize how the chronically compromised heart responds to severe oxygen challenges in a clinically relevant model of this situation. PMID:7814609

  19. 31P-nuclear magnetic resonance analysis of extracts of vascular smooth muscle

    31P-nuclear magnetic resonance spectroscopy was used to assess phosphate metabolites in perchloric acid extracts of rabbit aorta. In addition to the high energy phosphates, several other phosphorus compounds were detected and quantified. Most notable was the presence of a prominent phosphomonoester compound appearing at a chemical shift of 3.86 delta. This compound constituted 26% of the total extractable tissue phosphorus and is tentatively identified as ribose-5-phosphate, a pentose phosphate pathway intermediate. While ATP and phosphocreatine did not change during glucose and oxygen deprivation or during prolonged muscle contraction, the 3.86delta phosphate decreased significantly. Furthermore, theophylline, an agent that increases intracellular cAMP, also decreased the level of the 3.86 delta phosphate. These results are consistent with the concept that intermediate metabolism sustains high energy phosphate pools in vascular smooth muscle in the steady state under various conditions. The pentose phosphate pathway may play an important role in vascular smooth muscle metabolism. (author)

  20. The structure of phosphate glass biomaterials from neutron diffraction and 31P nuclear magnetic resonance data

    Neutron diffraction and 31P nuclear magnetic resonance spectroscopy were used to probe the structure of phosphate glass biomaterials of general composition (CaO)0.5-x(Na2O)x(P2O5)0.5 (x = 0, 0.1 and 0.5). The results suggest that all three glasses have structures based on chains of Q2 phosphate groups. Clear structural differences are observed between the glasses containing Na2O and CaO. The P-O bonds to bridging and non-bridging oxygens are less well resolved in the neutron data from the samples containing CaO, suggesting a change in the nature of the bonding as the field strength of the cation increases Na+ → Ca2+. In the (CaO)0.5(P2O5)0.5 glass most of the Ca2+ ions are present in isolated CaOx polyhedra whereas in the (Na2O)0.5(P2O5)0.5 glass the NaOx polyhedra share edges leading to a Na-Na correlation. The results of the structural study are related to the properties of the (CaO)0.4(Na2O)0.1(P2O5)0.5 biomaterial

  1. Bioenergetic measurements in children with bipolar disorder: a pilot 31P magnetic resonance spectroscopy study.

    Elif M Sikoglu

    Full Text Available BACKGROUND: Research exploring Bipolar Disorder (BD phenotypes and mitochondrial dysfunction, particularly in younger subjects, has been insufficient to date. Previous studies have found abnormal cerebral pH levels in adults with BD, which may be directly linked to abnormal mitochondrial activity. To date no such studies have been reported in children with BD. METHODS: Phosphorus Magnetic Resonance Spectroscopy ((31P MRS was used to determine pH, phopshocreatine (PCr and inorganic phosphate (Pi levels in 8 subjects with BD and 8 healthy comparison subjects (HCS ages 11 to 20 years old. RESULTS: There was no significant difference in pH between the patients and HCS. However, frontal pH values for patients with BD increased with age, contrary to studies of HCS and the pH values in the frontal lobe correlated negatively with the YMRS values. Global Pi was significantly lower in subjects with BD compared with HCS. There were no significant differences in PCr between the groups. Global PCr-to-Pi ratio (PCr/Pi was significantly higher in subjects with BD compared with HCS. CONCLUSIONS: The change in Pi levels for the patients with BD coupled with the no difference in PCr levels, suggest an altered mitochondrial phosphorylation. However, our findings require further investigation of the underlying mechanisms with the notion that a mitochondrial dysfunction may manifest itself differently in children than that in adults. LIMITATIONS: Further investigations with larger patient populations are necessary to draw further conclusions.

  2. 31P nuclear magnetic resonance studies of effects of some chlorophenols on Escherichia coli and a pentachlorophenol-degrading bacterium.

    Steiert, J G; Thoma, W J; Ugurbil, K; Crawford, R L

    1988-01-01

    A Flavobacterium sp. that mineralizes pentachlorophenol degrades some, but not all, of the other chlorinated phenols. Whole-cell 31P nuclear magnetic resonance was used to compare and observe transmembrane pH gradients and nucleotide pools in the Flavobacterium sp. and Escherichia coli after pentachlorophenol and 3,4,5-trichlorophenol were added to the cell suspensions. The data suggest that those chlorinated phenols which are not degraded by the Flavobacterium sp. may be resistant to degrada...

  3. Energetics of acute pressure overload of the porcine right ventricle. In vivo 31P nuclear magnetic resonance.

    Schwartz, G G; Steinman, S; Garcia, J.; Greyson, C; Massie, B; Weiner, M W

    1992-01-01

    In vivo 31P nuclear magnetic resonance (NMR) spectroscopy of the right ventricular (RV) free wall was employed to determine (a) whether phosphorus energy metabolites vary reciprocally with workload in the RV and (b) the mechanisms that limit RV contractile function in acute pressure overload. In 20 open-chest pigs, phosphocreatine (PCr)/ATP ratio (an index of energy metabolism inversely related to free ADP concentration), myocardial blood flow (microspheres), and segment shortening (sonomicro...

  4. Exertional muscle pain in familial Mediterranean fever patients evaluated by MRI and 31P magnetic resonance spectroscopy

    Aim: To evaluate the effect of physical activity on the structural, morphological, and metabolic characteristics of the gastrocnemius muscle in familial Mediterranean fever (FMF) patients, utilizing quantitative 31P magnetic resonance spectroscopy (MRS), in order to elucidate the mechanism of their exertional leg pain. Materials and methods: Eleven FMF patients suffering from exertional leg pain (eight male, three female; mean age 33 years) and six healthy individuals (three male, three female; mean age 39 years) constituted the control group. All of the participants underwent magnetic resonance imaging (MRI) and non-selective 31P MRS (3 T) of the leg muscles before and after graded exercise on a treadmill. Phosphocreatine (PCr):inorganic phosphate (Pi), PCr:adenosine triphosphate (ATP) ratios and the intracellular pH of the leg muscles were measured using 31P MRS. Results: For both groups, normal muscle mass with no signal alterations was observed on the MRI images after exercise. The normal range of pre- and post- exercise MRS muscle parameters was observed in both groups. However, the intracellular pH post-exercise, was significantly higher (less acidic) in the FMF group compared to the control group [pH (FMF) = 7.03 ± 0.02; pH (control) 7.00 ± 0.02; p < 0.0006]. Conclusions: The finding of a less prominent, post-exercise acidification of the gastrocnemius muscle in this FMF patient group suggests a forme fruste of glycogenosis. This preliminary observation should be further investigated in a future, larger-scale study

  5. Cardiac metabolism during exercise in healthy volunteers measured by 31P magnetic resonance spectroscopy.

    Conway, M A; Bristow, J D; Blackledge, M J; Rajagopalan, B; Radda, G K

    1991-01-01

    A technique was devised for individuals to exercise prone in a magnet during magnetic resonance spectroscopy of the heart and phosphorus-31 magnetic resonance spectra of the heart were obtained by the phase modulated rotating frame imaging technique in six healthy volunteers during steady state dynamic quadriceps exercise. During prone exercise heart rate, blood pressure, and total body oxygen consumption were measured at increasing loads and the results were compared with those during Bruce protocol treadmill exercise. During prone exercise with a 5 kg load the heart rate was similar and the systolic and diastolic blood pressures were higher than those during stage 1 of the Bruce protocol. The rate-pressure products were similar but the total body oxygen consumption was lower during prone exercise. There was no difference in the ratio of phosphocreatine to adenosine triphosphate during rest and exercise.Thus during exercise that produced a local cardiac stress equal to or greater than that during stage 1 of the Bruce protocol treadmill exercise, the energy requirements of the normal human myocardium were adequately supplied by oxidative phosphorylation. PMID:1993127

  6. 31P-magnetic resonance spectroscopy: Impaired energy metabolism in latent hyperthyroidism

    31Phosphorous magnetic resonance spectroscopy allows an in vivo examination of energy metabolism. The present study was designed to evaluate whether in patients with latent hyperthyroidism alterations of muscle energy metabolism could be found similar to those observed in patients with overt hyperthyroidism. In 10 patients with overt hyperthyroidism before therapy and 20 with latent hyperthyroidism (also without therapy) and in 24 healthy volunteers magnetic resonance spectroscopy of the calf muscle was performed within a 1.5-Tesla magnet. Muscle concentrations of phosphocreatine, inorganic phosphate, and ATP were quantified compared to an external standard solution of K2HPO4. In the patients with overt hyperthyroidism and with latent hyperthyroidism a significant decrease of phosphocreatine was found. Further, the ATP concentration in patients with latent and manifest hyperthyroidism tended towards lower values. There were no significant differences in the decrease of phosphocreatine and ATP between both patient groups. Therefore, this study for the first time shows that alterations of energy metabolism in latent hyperthyroidism can be measured and that they are similar to those observed in overt hyperthyroidism. (orig.)

  7. Simultaneous electromyography and 31P nuclear magnetic resonance spectroscopy--with application to muscle fatigue

    Vestergaard-Poulsen, P; Thomsen, C; Sinkjaer, T;

    1992-01-01

    changes in human muscle. The aim of this study was to develop a method by which EMG and NMR spectroscopy measurements could be performed simultaneously. All measurements were performed in a whole body 1.5 Tesla NMR scanner. A calf muscle ergometer, designed for use in a whole body NMR scanner, was used......The electromyogram (EMG) is often used to study human muscle fatigue, but the changes in the electromyographic signals during muscle contraction are not well understood in relation to muscle metabolism. The 31P NMR spectroscopy is a semi-quantitative non-invasive method for studying the metabolic....... The subject had the left foot strapped to the ergometer. The anterior tibial EMG was recorded by bipolar surface electrodes. A surface coil was strapped to the anterior tibial muscle next to the EMG electrodes. Simultaneous measurements of surface EMG and surface coil 31P NMR spectroscopy were...

  8. Cellular applications of 31P and 13C nuclear magnetic resonance

    High-resolution nuclear magnetic resonance (NMR) studies of cells and purified mitochondria are discussed to show the kind of information that can be obtained in vivo. In suspensions of Escherichia coli both phosphorus-31 and carbon-13 NMR studies of glycolysis of bioenergetics are presented. In rat liver cells the pathways of gluconeogenesis from carbon-13-labeled glycerol are followed by carbon-13 NMR. In the intact liver cells cytosolic and mitochondrial pH's were separately measured by phosphorus-31 NMR. In purified mitochondria the internal and external concentrations of inorganic phosphate, adenosine diphosphate, and adenosine triphosphate were determined by phosphorus-31 while the pH difference across the membrane was measured simultaneously

  9. Intracellular pH in Dictyostelium discoideum: a 31P nuclear magnetic resonance study

    We have used phosphorus-31 nuclear magnetic resonance to determine intracellular pH in the cellular slime mold Dictyostelium discoideum. We devised an air-lift circulator to maintain the dense cell suspensions in a well-oxygenated and well-stirred state while causing minimal perturbation to the sample flowing through the detector coils. Cells continued to develop normally in this set-up. Spectra acquired under these conditions typically show two peaks in the inorganic phosphate region corresponding to pH values of 7.16 +/- 0.03 and 6.48 +/- 0.02. These peaks are believed to represent the mitochondrial and cytosolic compartments respectively, based on a comparison of these values with published data and the collapse of the two compartments upon addition of the mitochondrial uncoupler carbonyl cyanide 4-(trifluoromethoxy)-phenylhydrazone. Dictyostelium cells show a remarkable degree of intracellular pH homeostasis. Both mitochondrial and cytosolic pH remained unchanged as extracellular pH was varied from 4.3 to 8.1. There was also no apparent change in the pH of either compartment after up to 13.5 hours' development in suspension

  10. 1H and 31P magnetic resonance spectroscopic imaging of white matter signal hyperintensity areas in elderly subjects

    White matter signal hyperintensities (WMSH) are commonly seen on MRI of elderly subjects. The purpose of this study was to characterize metabolic changes in the white matter of elderly subjects with extensive WMSH. We used water-suppressed proton (1H) magnetic resonance spectroscopic imaging (MRSI) to compare six subjects with extensive WMSH with eight age-matched elderly subjects with minimal or absent WMSH, and phosphorus (31P) MRSI to compare nine subjects with extensive WMSH and seven age-matched elderly subjects without extensive WMSH. Relative to region-matched tissue in elderly controls, extensive WMSH were associated with increased signal from choline-containing metabolites, no significant change of signal from N-acetylaspartate, and a trend to a decreased phosphomonoester (PME) resonance. These findings suggest that WMSH may be associated with an alteration of brain myelin phospholipids in the absence of axonal damage. There were no differences in energy phosphates, consistent with lack of ongoing brain ischemia. Within the group with extensive WMSH, PME resonance measures were significantly lower in WMSH than in contralateral normal-appearing white matter. These results provide information on pathophysiology of WMSH and a basis for comparison with WMSH in Alzheimer's disease, vascular dementia, multiple sclerosis, and other diseases. (orig.). With 4 figs., 4 tabs

  11. Characterization of phosphorus forms in lake macrophytes and algae by solution (31)P nuclear magnetic resonance spectroscopy.

    Feng, Weiying; Zhu, Yuanrong; Wu, Fengchang; Meng, Wei; Giesy, John P; He, Zhongqi; Song, Lirong; Fan, Mingle

    2016-04-01

    Debris from aquatic macrophytes and algae are important recycling sources of phosphorus (P), which can result in continuing blooms of algae by recycling bioavailable P in the eutrophic lakes. However, knowledge of forms of P in aquatic macrophytes and algae and their contribution to internal loads of P in lakes is limited. Without such knowledge, it is difficult to develop appropriate strategies to remediate and or restore aquatic ecosystems that have become eutrophic. Therefore, in this work, P was extracted from six types of aquatic macrophytes and algae collected from Tai Lake of China and characterized by use of solution (31)P-nuclear magnetic resonance (NMR) spectroscopy. When extracted by 0.5 M NaOH-25 mM EDTA, extraction recovery of total P(TP) and organic P(Po) exceeded 90 %. Concentrations of Po in algae and aquatic macrophytes were 5552 mg kg(-1) and 1005 mg kg(-1) and accounted for 56.0 and 47.2 % of TP, respectively. When Po, including condensed P, was characterized by solution (31)P-NMR Po in algae included orthophosphate monoesters (79.8 %), pyrophosphate (18.2 %), and orthophosphate diester (2.0 %), and Po in aquatic macrophytes included orthophosphate monoesters (90.3 %), pyrophosphate (4.2 %), and orthophosphate diester (5.5 %). Additionally, orthophosphate monoesters in algal debris mainly included β-glycerophosphate (44.1 %), α-glycerophosphate (13.5 %), and glucose 6-phosphate (13.5 %). Orthophosphate monoesters in aquatic macrophytes mainly included β-glycerophosphate (27.9 %), α-glycerophosphate (24.6 %), and adenosine 5' monophosphate (8.2 %). Results derived from this study will be useful in better understanding nutrient cycling, relevant eutrophication processes, and pollution control for freshwater lakes. PMID:26681323

  12. Biochemical metabolic changes assessed by 31P magnetic resonance spectroscopy after radiation-induced hepatic injury in rabbits

    Ri-Sheng Yu; Liang Hao; Fei Dong; Jian-Shan Mao; Jian-Zhong Sun; Ying Chen; Min Lin; Zhi-Kang Wang; Wen-Hong Ding

    2009-01-01

    AIM:To compare the features of biochemical metabolic changes detected by hepatic phosphorus-31 magnetic resonance spectroscopy (31P MRS) with the liver damage score (LDS) and pathologic changes in rabbits and to investigate the diagnostic value of 31P MRS in acute hepatic radiation injury.METHODS:A total of 30 rabbits received different radiation doses (ranging 5-20 Gy) to establish acute hepatic injury models.Blood biochemical tests,31P MRS and pathological examinations were carried out 24 h after irradiation.The degree of injury was evaluated according to LDS and pathology.Ten healthy rabbits served as controls.The MR examination was performed on a 1.5 T imager using a 1H/31P surface coil by the 2D chemical shift imaging technique.The relative quantities of phosphomonoesters (PME),phosphodiesters (PDE),inorganic phosphate (Pi) and adenosine triphosphate (ATP) were measured.The data were statistically analyzed.RESULTS:(1) Relative quantification of phosphorus metabolites:(a) ATP:there were significant differences (P<0.05) (LDS-groups:control group vs mild group vs moderate group vs severe group,1.83±0.33 vs 1.55±0.24 vs 1.27±0.09 vs 0.98±0.18;pathological groups:control group vs mild group vs moderate group vs severe group,1.83±0.33 vs 1.58±0.25 vs 1.32±0.07 vs 1.02 ± 0.18) of ATP relative quantification among control group,mild injured group,moderate injured group,and severe injured group according to both LDS grading and pathological grading,respectively,and it decreased progressively with the increased degree of injury (r=-0.723,P=0.000).(b) PME and Pi;the relative quantification of PME and Pi decreased significantly in the severe injured group,and the difference between the control group and severe injured group was significant (P<0.05) (PME:LDScontrol group vs LDS-severe group,0.86±0.23 vs 0.58±0.22,P=0.031;pathological control group vs pathological severe group,0.86±0.23 vs 0.60±0.21,P=0.037;Pi:LDS-control group vs LDS-severe group,0.74±0.18 vs

  13. Bevacizumab impairs oxidative energy metabolism and shows antitumoral effects in recurrent glioblastomas: a 31P/1H MRSI and quantitative magnetic resonance imaging study

    HATTINGEN, ELKE; Jurcoane, Alina; Bähr, Oliver; Rieger, Johannes; Magerkurth, Jörg; Anti, Sandra; Steinbach, Joachim P.; Pilatus, Ulrich

    2011-01-01

    Bevacizumab shows unprecedented rates of response in recurrent glioblastomas (GBM), but the detailed mechanisms are still unclear. We employed in vivo magnetic resonance spectroscopic imaging (MRSI) and quantitative magnetic resonance imaging to investigate whether bevacizumab alters oxygen and energy metabolism and whether this effect has antitumoral activity in recurrent GBM. 31P and 1H MRSI, apparent diffusion coefficient (ADC), and high-resolution T2 and T2′ mapping (indirect marker of ox...

  14. Spin-lattice relaxation time of inorganic phosphate in human tumor xenografts measured in vivo by 31P-magnetic resonance spectroscopy. Influence of oxygen tension

    Previous 31P-magnetic resonance spectroscopy (31P-MRS) studies have suggested that the spin-lattice relaxation time (T1) of the inorganic phosphate (Pi) resonance is shorter in well-oxygenated than in poorly oxygenated tumors. Amelanotic human melanoma xenografts were therefore subjected to 31P-MRS to investigate whether the T1 of the Pi resonance might be a useful parameter for assessment of tumor oxygenation status. It was searched for possible correlations between the T1 of the Pi resonance and oxygen tension or parameters closely related to oxygen tension, including 31P-MRS tumor energy status and blood supply per viable tumor cell. Oxygen tension, tumor energy status, and blood supply per viable tumor cell decreased with increasing tumor volume. In contrast to previous suggestions, the T1 of the Pi resonance decreased with increasing tumor volume and decreasing oxygen tension, tumor energy status, and blood supply per viable tumor cell, possibly because the tumors developed necrotic regions concomitantly with the decrease in oxygenation status, resulting in increased concentrations of freely dissolved para-magnetic ions in the tissue. Consequently, the T1 of the Pi resonance can probably not be utilized to estimate the oxygenation status of tumors, at least not in tumors with necrotic regions. (orig.)

  15. 31P nuclear magnetic resonance studies of the association of basic proteins with multilayers of diacyl phosphatidylserine.

    Smith, R; Cornell, B A; Keniry, M A; Separovic, F

    1983-08-10

    Lysozyme, cytochrome c, poly(L-lysine), myelin basic protein and ribonuclease were used to form multilayer dispersions containing about 50% protein (by weight) with bovine brain diacyl phosphatidylserine (PS). 31P nuclear magnetic resonance shift anisotropies, spin-spin (T2) and spin-lattice (T1) relaxation times for the lipid headgroup phosphorus were measured at 36.44 MHz. At pH 7.5, lysozyme, cytochrome c, poly(L-lysine) and ribonuclease were shown to increase the chemical shift anisotropy of PS by between 12-20%. Myelin basic protein altered the shape of the phosphate resonance, suggesting the presence of two lipid components, one of which had a modified headgroup conformation. The presence of cytochrome c led to the formation of a narrow spike at the isotropic shift position of the spectrum. Of the various proteins or peptides we have studied, only poly(L-lysine) and cytochrome c had any effect on the T1 of PS (1050 ms). Both caused a 20-30% decrease in T1 of the lamellar-phase phosphate peak. The narrow peak in the presence of cytochrome c had a very short T1 of 156 ms. The possibility is considered that the cytochrome Fe3+ contributes to the phosphate relaxation in this case. The effect of all proteins on the T2 of the phosphorus resonance was to cause an increase from the value for pure PS (1.6 ms) to between 2 and 5 ms. The results obtained with proteins are compared with the effects of small ions and intrinsic membrane proteins on the order and motion of the headgroups of lipids in bilayers. PMID:6191774

  16. Physiological effects of the form of nitrogen on corn root tips: a 31P nuclear magnetic resonance study

    Physiological effects of different N forms (NO−3, NH+4, or a combination of both) on corn (Zea mays L.) root tips and leaves were studied by following 31P signals with a nuclear magnetic resonance spectrometer. With root tips, both cytoplasmic and vacuolar pH could be measured, whereas with leaves, only vacuolar pH could be determined. The N treatments did not affect the cytoplasmic pH of corn root tips in contrast to proposals of previous workers. Leaf vacuolar pH was higher and root tip vacuolar pH lower with NO−3 than with NH+4. Under anaerobic conditions, cytoplasmic pH was reduced because of lactic acid fermentation. Nitrate, an electron acceptor, delayed the acidification of the cytoplasm compartment because it represents an alternative way to reoxidize NADH. In conclusion, for the conditions of these experiments, the pH of the cytoplasm of corn root tips was not modified by the form of N absorbed; however, the pH of this compartment was affected by the form of N presented during development anaerobiosi. (author)

  17. Characterization of the phosphoserine of pepsinogen using /sup 31/P nuclear magnetic resonance: corroboration of X-ray crystallographic results

    Williams, S.P.; Bridger, W.A.; James, M.N.G.

    1986-10-21

    The endogenous phosphoserine residue in porcine pepsinogen has been titrated with use of phosphorus-31 nuclear magnetic resonance (/sup 31/P NMR). It has an observed pK/sub a/sub 2// of 6.7 and a narrow line width (approx. =10 Hz). The phosphate can be readily removed by an acid phosphatase from potato; however, it is resistant to hydrolysis by several alkaline phosphatases. The X-ray crystal structure of porcine pepsinogen at 1.8-A resolution shows a rather weak and diffuse region of electron density in the vicinity of the phosphorylated serine residue. This suggests considerable dynamic mobility or conformational disorder of the phosphate. In order to define more fully this behavior the NMR data have been used to corroborate these crystallographic results. All these physical data are consistent with a highly mobile phosphoserine residue on the surface of the zymogen and freely exposed to solvent. In addition, certain properties of this phosphoserine moiety on pepsinogen are similar to those of one of the phosphorylated residues of ovalbumin. The possible significance of this is discussed.

  18. Characterization of the phosphoserine of pepsinogen using 31P nuclear magnetic resonance: corroboration of X-ray crystallographic results

    The endogenous phosphoserine residue in porcine pepsinogen has been titrated with use of phosphorus-31 nuclear magnetic resonance (31P NMR). It has an observed pK/sub a2/ of 6.7 and a narrow line width (≅10 Hz). The phosphate can be readily removed by an acid phosphatase from potato; however, it is resistant to hydrolysis by several alkaline phosphatases. The X-ray crystal structure of porcine pepsinogen at 1.8-A resolution shows a rather weak and diffuse region of electron density in the vicinity of the phosphorylated serine residue. This suggests considerable dynamic mobility or conformational disorder of the phosphate. In order to define more fully this behavior the NMR data have been used to corroborate these crystallographic results. All these physical data are consistent with a highly mobile phosphoserine residue on the surface of the zymogen and freely exposed to solvent. In addition, certain properties of this phosphoserine moiety on pepsinogen are similar to those of one of the phosphorylated residues of ovalbumin. The possible significance of this is discussed

  19. 31P nuclear magnetic resonance study of the metabolic pools of adenosine triphosphate in cultured bovine adrenal medullary chromaffin cells

    31P NMR was used to resolve and determine the relative quantity and mobility of ATP in the cytosolic and vesicular compartments of isolated adrenomedullary chromaffin cells. The cells were cultured on microcarrier beads and superfused with an oxygenated medium-thereby permitting dense suspensions of viable cells to be maintained in the NMR probe for extended time periods. Under these conditions, distinct 31P signals could be seen for ATP within the vesicular and the cytosolic pools. Comparison of the integrated areas of the β-phosphate resonances from the two ATP pools indicated 77% of the endogenous ATP was in the vesicular pool. From this observation and the assumption that the concentration of ATP in the vesicle is 87.5 mM, the concentration of ATP calculated to be in the cytoplasmic pool was ∼ 4 mM. The pH in the vesicle determined from the chemical shift of the γ-phosphate resonance of vesicular ATP was 5.84 ± 0.17, slightly higher than the intragranular pH measured in hypoxic cells. Spin-lattice relaxation times of ATP 31P resonances in the vesicular pool were from 12 to 14 times shorter than the ATP resonances in the cytosol, corresponding to a decrease in molecular mobility due to incorporation of ATP within a catecholamine-storage complex

  20. A retunable surface coil for high field 31P and 1H magnetic resonance evaluations of the living mouse leg

    This study presents a retunable surface coil that can be adjusted to at least two Larmor frequencies sequentially without the need to remove the coil from the magnet and while avoiding interference between channels. A prototype 1H/31P surface coil for the analysis of the in vivo mouse leg under electrical stimulation was designed for operation at 11.75 T. The coil has a high-quality factor of over 100 for both operational frequencies. To demonstrate the capabilities of this simple design, in vivo experiments were conducted to acquire high-resolution 1H images and 31P spectra of the C57BL/6 mouse leg, both with high temporal resolution. Proton diffusion tensor imaging was also performed to evaluate rodent skeletal muscle architecture. This design makes the acquisition of physiological data about both muscle structure and energetics (PCr, ATP and Pi) possible in a single experimental session

  1. Maintenance of high-energy brain phosphorous compounds during insulin-induced hypoglycemia in men. 31P nuclear magnetic resonance spectroscopy study

    Hilsted, Jannik; Jensen, K E; Thomsen, C;

    1988-01-01

    31P nuclear magnetic resonance (NMR) spectroscopy allows noninvasive studies of cerebral energy-rich phosphorous compounds in humans. In an attempt to characterize the relationship between peripheral blood glucose concentrations and whole-brain phosphate metabolism during insulin...... constant during the experiment. These results show that the integrated brain profile of energy-rich phosphorous compounds is unaffected by experimental insulin-induced hypoglycemia in humans....

  2. Silencing of the glycerophosphocholine phosphodiesterase GDPD5 alters the phospholipid metabolite profile in a breast cancer model in vivo as monitored by 31P Magnetic Resonance Spectroscopy

    Wijnen, J.P.; Jiang, L.; Greenwood, T.R.; Cheng, M; Döpkens, M.; Cao, M.D.; Bhujwalla, Z M; Krishnamachary, B; Klomp, D. W. J.; Glunde, K.

    2014-01-01

    Abnormal choline phospholipid metabolism is an emerging hallmark of cancer, which is implicated in carcinogenesis and tumor progression. The malignant metabolic phenotype is characterized by high levels of phosphocholine (PC) and relatively low levels of glycerophosphocholine (GPC) in aggressive breast cancer cells. Phosphorus Magnetic Resonance Spectroscopy (31P MRS) is able to noninvasively detect these water-soluble metabolites of choline as well as ethanolamine phospholipid metabolism. He...

  3. 31P magnetic resonance spectroscopy of the Sherpa heart: a phosphocreatine/adenosine triphosphate signature of metabolic defense against hypobaric hypoxia.

    Hochachka, P W; Clark, C M; Holden, J E; Stanley, C; Ugurbil, K; Menon, R S

    1996-01-01

    Of all humans thus far studied, Sherpas are considered by many high-altitude biomedical scientists as most exquisitely adapted for life under continuous hypobaric hypoxia. However, little is known about how the heart is protected in hypoxia. Hypoxia defense mechanisms in the Sherpa heart were explored by in vivo, noninvasive 31P magnetic resonance spectroscopy. Six Sherpas were examined under two experimental conditions [normoxic (21% FiO2) and hypoxic (11% FiO2) and in two adaptational state...

  4. Tumour oxygenation assessed by polarographic needle electrodes and bioenergetic status measured by 31P magnetic resonance spectroscopy im human soft tissue tumours

    The purpose of this study was to evaluate the feasibility of polarographic oxygen electrode measurements and phosphorus magnetic resonance spectroscopy (31P-MRS) in extravisceral soft tissue tumours, designated to receive preoperative radiotherapy. Pretreatment tumour oxygenation was determined in 41 cases and 31P-MRS was amenable to lesions in 34 patients. Biopsies were characterized histopathologically as 25 primary soft tissue sarcomas (STS), 2 recurrent STS, 9 benign and 5 other malignancies. Evaluation of phosphorus (31P) spectra was possible in 11 cases. The oxygenation status of normal tissue was higher than that of tumours, whereas no difference was found between oxygenation status of benign lesions and that of STS. There was substantial variation between tumours in the median pO2 and the bioenergetic status (β-NTP/Pi). No correlation was found between tumour pO2 and volume (n=25). Moreover, there was no correlation between β-NTP/Pi and the median tumour pO2, the fraction of pO2 values ≤2.5 mm Hg or tumour volume (n=10), respectively. In conclusion, oxygen electrode assessment was found to be a clinically applicable and feasible technique for measuring tumour oxygenation status, whereas the success of 31P-MRS in human neoplasms was limited by a very poor resolution in the phosphorus signal that allowed analysis of 31P spectra in 11 tumours out of 34 cases. (orig.)

  5. Effects of hypo- und hyperthyroidism on skeletal muscle metabolism. A sup 31 P magnetic resonance spectroscopy study. Einfluss von Hyper- und Hypothyreose auf den Energiestoffwechsel der Skelettmuskulatur. Eine Untersuchung mit sup 31 P-Kernspinspektroskopie

    Moka, D.; Theissen, P.; Linden, A.; Waters, W.; Schicha, H. (Koeln Univ. (Germany, F.R.). Klinik und Poliklinik fuer Nuklearmedizin)

    1991-06-01

    {sup 31}P magnetic resonance spectroscopy allows non-invasive evaluation of phosphorus metabolism in man. The purpose of the present study was to assess the influence of hyper- and hypothyroidism on the metabolism of resting human skeletal muscle. The present data show that quantitative measurement of phosphate metabolism by NMR is possible as also demonstrated by other studies. Using a quantitative evaluation method with an external standard, significant differences in the levels of phosphocreatine, adenosintriphosphate, and phosphodiesters were found. In hypothyroid patients a TSH-dependent increase in phosphodiesters and a decrease in adenosintriphosphate and phosphocreatine was observed. In hyperthyroidism a similar decrease in adenosintriphosphate but a considerably higher decrease in phosphocreatine occurred. In the light of the results of other studies of muscle matabolism, these changes appear to be non-specific so that further studies are required to assess the clinical value of such measurements. (orig.).

  6. Different early effect of irradiation in brain and small cell lung cancer examined by in vivo 31P-magnetic resonance spectroscopy

    Kristjansen, P E; Pedersen, A G; Quistorff, B;

    1992-01-01

    Early effects of irradiation were evaluated by non-invasive in vivo 31P-magnetic resonance spectroscopy (31P-MRS) of two small cell lung cancer (SCLC) tumor lines CPH SCCL 54A and 54B, in nude mice. The tumors were originally derived from the same patient and have similar morphology and growth...... characteristics, but a different radiosensitivity. The 54A tumors are twice as radiosensitive as the 54B's. In the present study the tumors were treated with 2.5, 10, and 40 Gy. For comparison, nude mice were given cranial irradiation at the same three doses, and the effect was evaluated by in vivo 31P-MRS. No...... effect was observed in brain at any dose level. In contrast, 40 Gy induced a statistically significant reduction in ATP/Pi ratio during the 12-h post-irradiation period. This effect was more pronounced in 54A than in 54B. Some reduction was observed following 10 Gy, whereas 2.5 Gy induced no changes in...

  7. 31P magnetic resonance spectroscopy study of influences of cranial irradiation on cerebral energy metabolism in children with acute lymphoblastic leukemia

    The effect of cranial irradiation on the cerebrum was studied. Energy metabolism in the brain was assessed before and after cranial irradiation using 31P magnetic resonance spectroscopy (31P-MRS). The subjects were 3 pediatric patients with initial acute lymphotic leukemia (ALL), who underwent induction chemotherapy and central nervous system (CNS) prophylaxis according to the ALL high risk 911 protocol of Children's Cancer and Leukemia Study Group. The patients underwent 31P-MRS within one week before and after prophylactic CNS irradiation with a total dose of 18 Gy (i.e., 0.5 Gy in two fractions, 1.0 Gy in two fractions, and 1.5 Gy in 10 fractions - 4 times a week in 3-4 weeks). All 3 patients showed a decrease in phosphocreatine and ATP levels, which are indicators of energy metabolism, and also in the intracellular pH level in the brain tissue. Cranial irradiation was thus suggested to induce hypoxia in the brain tissue. (S.Y.)

  8. Ex vivo identification of atherosclerotic plaque calcification by a 31P solid-state magnetic resonance imaging technique.

    Hallock, Kevin J; Hamilton, James A

    2006-12-01

    Calcified tissue is a common component of atherosclerotic plaques, and occurs most often in mature plaques. The process of calcification is a poorly understood risk factor that may contribute to a plaque's vulnerability to sudden rupture. In this study a solid-state imaging sequence, termed single-point imaging (SPI), was used to observe calcification directly in ex vivo atherosclerotic plaques. Standards were used to validate the ability of (31)P SPI to detect and differentiate calcification from crystalline cholesterol, phospholipids, and other plaque components. After suitable experimental parameters were found, human carotid specimens obtained by endarterectomy were imaged ex vivo by (31)P solid-state imaging and standard (1)H methods. In contrast to (1)H imaging methods, (31)P imaging detected only the calcification in the plaque. PMID:17089379

  9. 31P magnetic resonance spectroscopy to measure in vivo cardiac energetics in normal myocardium and hypertrophic cardiomyopathy: Experiences at 3 T

    Background: 31P magnetic resonance spectroscopy (MRS) allows measurement of in vivo high-energy phosphate kinetics in the myocardium. While traditionally 31P cardiac spectroscopy is performed at 1.5 T, cardiac MRS at higher field strength can theoretically increase signal to noise ratio (SNR) and spectral resolution therefore improving sensitivity and specificity of the cardiac spectra. The reproducibility and feasibility of performing cardiac spectroscopy at 3 T is presented here in this study in healthy volunteers and patients with hypertrophic cardiomyopathy. Methods: Cardiac spectroscopy was performed using a Phillips 3T Achieva scanner in 37 healthy volunteers and 26 patients with hypertrophic cardiomyopathy (HCM) to test the feasibility of the protocol. To test the reproducibility a single volunteer was scanned eight times on separate occasions. A single voxel 31P MRS was performed using Image Selected In vivo Spectroscopy (ISIS) volume localization. Results: The mean phosphocreatine/adenosine triphosphate (PCr/ATP) ratio of the eight measurements performed on one individual was 2.11 ± 0.25. Bland Altman plots showed a variance of 12% in the measurement of PCr/ATP ratios. The PCr/ATP ratio was significantly reduced in HCM patients compared to controls, 1.42 ± 0.51 and 2.11 ± 0.57, respectively, P 31P MRS at 3 T is a reliable method of measuring in vivo high-energy phosphate kinetics in the myocardium for clinical studies and diagnostics. Based on our data an impairment of cardiac energetic state in patients with hypertrophic cardiomyopathy is indisputable.

  10. Value of dynamic 31p magnetic resonance spectroscopy technique in in vivo assessment of the skeletal muscle mitochondrial function in type 2 diabetes

    WU Fei-yun; TU Hui-juan; QIN Bin; CHEN Ting; XU Hua-feng; QI Jing; WANG De-hang

    2012-01-01

    Background Phosphorous magnetic resonance spectroscopy (31p-MRS) has been successfully applied to study intracellular membrane compounds and high-energy phosphate metabolism.This study aimed to evaluate the capability of dynamic 31p-MRS for assessing energy metabolism and mitochondrial function in skeletal muscle from type 2 diabetic patients.Methods Dynamic 31p-MRS was performed on 22 patients with type 2 diabetes and 26 healthy volunteers.Spectra were acquired from quadriceps muscle while subjects were in a state of rest,at exercise and during recovery.The peak areas of inorganic phosphate (Pi),phosphocreatine (PCr),and adenosine triphosphate (ATP) were measured.The concentration of adenosine diphosphate (ADP) and the intracellular pH value were calculated from the biochemistry reaction equilibrium.The time constant and recovery rates of Pi,PCr,and ADP were analyzed using exponential curve fitting.Results As compared to healthy controls,type 2 diabetes patients had significantly lower skeletal muscle concentrations of Pi,PCr and β-ATP,and higher levels of ADP and Pi/PCr.During exercise,diabetics experienced a significant Pi peak increase and PCr peak decrease,and once the exercise was completed both Pi and PCr peaks returned to resting levels.Quantitatively,the mean recovery rates of Pi and PCr in diabetes patients were (10.74±1.26) mmol/s and (4.74±2.36) mmol/s,respectively,which was significantly higher than in controls.Conclusions Non-invasive quantitative 31P-MRS is able to detect energy metabolism inefficiency and mitochondrial function impairment in skeletal muscle of type 2 diabetics.

  11. Improved energy kinetics following high protein diet in McArdle's syndrome. A 31P magnetic resonance spectroscopy study

    Jensen, K E; Jakobsen, J; Thomsen, C;

    1990-01-01

    A patient with McArdle's syndrome was examined using bicycle ergometry and 31P NMR spectroscopy during exercise. The patients working capacity was approximately half the expected capacity of controls. Muscle energy kinetics improved significantly during intravenous glucose infusion and after 6...

  12. Analysis of metabolites in human brain tumors and cerebral infarctions using 31P- and 1H-magnetic resonance spectroscopy

    31P- and 1H-MRS with a 2.0 tesla MRI/S system was used to monitor the cerebral energy levels, phospholipid metabolism, intracellular pH, and lactate and amino acid levels in patients with brain tumors and cerebral infarctions. Studies of human brain tumors have suggested that the 31P-MRS of malignant brain tumors show low concentrations of phosphocreatine (PCr) and β-ATP, high levels of phosphomonoester (PME) and inorganic Pi, and an alkaline pH. The Pi, PME, and intracellular pH of malignant lymphoma were higher than those of other brain tumors. 1H-MRS showed an increase of lactate in malignant brain tumors and epidermoids. After ACNU administration, the tumor 31P-MRS showed transient reduction and elevation of Pi on five patients with malignant gliomas. Intracellular pH also showed a transient reduction during radiotherapy. 1H-MRS showed a reduction of lactate at the beginning of therapy and showed a marked re-elevation of lactate with tumor regrowth. After radiotherapy, the normal brain 31P-MRS showed transient elevation and reduction of Pi. Intracellular pH also showed a transient elevation during radiotherapy. To investigate the mechanism of hyperbaric oxygen therapy (HBO) in cerebral ischemia, changes of brain lactate level were estimated by 1H-MRS. Although the Lactate/Creatine ratio decreased consistently over time in all patients, it decreased more rapidly in the patients receiving HBO therapy than in those without such therapy. 1H-MRS demonstrated that HBO therapy may improve metabolism in the ischemic brain and reduces the lactate levels. 31P- and 1H-MRS are practical tools for the clinical analysis of cerebral disorders as well as for deciding on therapeutic procedures and evaluating the response. (K.H.)

  13. Analysis of energy metabolism of the rabbit liver in obstructive jaundice using 31P magnetic resonance spectroscopy

    Phosphorus-31 magnetic resonance spectroscopy was used to assess the changes in hepatic high-energy phosphate metabolites in rabbits with obstructive jaundice. The rabbits, which had undergone operative ligation of the common bile duct, were studied using a 2.0 Tesla whole-body magnetic resonance imager. Comparison of the peak phosphorus signal values relative to α-ATP showed that the peak phosphodiester and γ-ATP values in the livers of the one-day-after-ligation group were significantly lower than those in the control group, and the peak phosphomonoester and phosphodiester values in the five-days-after-ligation group were larger than those in the control group, but not significantly. Comparison of the peak T1 values in the one-day-after-ligation group with those of the control group revealed that the T1 value of phosphodiester was significantly larger than that in control group. It is suggested that dysfunction of phospholipid metabolism appears in the early phase of hepatic dysfunction due to obstructive jaundice. (author)

  14. Functional pools of oxidative and glycolytic fibers in human muscle observed by 31P magnetic resonance spectroscopy during exercise

    Quantitative probing of heterogeneous regions in muscle is feasible with phosphorus-31 magnetic resonance spectroscopy because of the differentiation of metabolic patterns of glycolytic and oxidative fibers. A differential recruitment of oxidative and glycolytic fibers during exercise was demonstrated in 4 of 10 untrained young men by following changes in phosphate metabolites. Concentrations of inorganic phosphate (P/sub i/), phosphocreatine, and ATP were estimated in the wrist flexor muscles of the forearm at rest, during two cycles of three grades of exercise, and in recovery. At high work levels (40% of maximum strength), two distinct P/sub i/ peaks were observed and identified with P/sub i/ pools at pH 6.9 and pH 5.9-6.4, respectively. These could be accounted for as follows. At the lowest level of work (using 20% of maximum strength), early recruitment primarily of oxidative (type I) and possibly some intermediate (type IIA) muscle fibers occurs with relatively little net lactate production and consequently little decrease in pH. At higher work loads, however, primarily glycolytic (type IIB) muscle fibers are recruited, which have relatively high net lactate production and therefore generate a second pool of P/sub i/ at low pH. These observations indicated exhaustion of glycolytic type IIB fibers, removal of lactate by high local blood flow, and sustained contractions largely by oxidative type I and IIA fibers. A functional differentiation of fiber types could also be demonstrated during recovery if exercise was stopped while two pools of P/sub i/ were still apparent. The potential of magnetic resonance spectroscopy to characterize oxidative and glycolytic fibers, predict capacity for aerobic performance, and signal the presence of muscle pathology is discussed

  15. In vivo 31P nuclear magnetic resonance saturation transfer measurements of phosphate exchange reactions in the yeast Saccharomyces cerevisiae

    31P saturation transfer techniques have been used to measure phosphate kinetics in the yeast Saccharomyces cerevisiae. The phosphate comsumption rate observed in acetate grown mid-log cells was combined with measurements of O2 consumption to yield P/O ratios of 2.2 and 2.9, for cells respiring on glucose and ethanol, respectively. However, no phosphate consumption activity was observed in saturation transfer experiments on anaerobic glucose fed cells. The phosphate consumption rates measured by saturation transfer in cells respiring on glucose and ethanol was attributed to the unidirectional rates of mitochondrial ATP synthesis. (Auth.)

  16. Localized Semi-LASER Dynamic 31P Magnetic Resonance Spectroscopy of the Soleus During and Following Exercise at 7 T

    Fiedler, Georg B; Schmid, Albrecht I; Goluch, Sigrun; Schewzow, Kiril; Laistler, Elmar; Mirzahosseini, Arash; Niess, Fabian; Unger, Ewald; Wolzt, Michael; Moser, Ewald

    2015-01-01

    Object This study demonstrates the applicability of semi-LASER localized dynamic $^{31}$P MRS to deeper lying areas of the exercising human soleus muscle (SOL). The effect of accurate localization and high temporal resolution on data specificity is investigated. Materials and Methods To achieve high signal-to-noise ratio (SNR) at a temporal resolution of 6 s, a custom-built calf coil array was used at 7T. The kinetics of phosphocreatine (PCr) and intracellular pH were quantified separately in SOL and gastrocnemius medialis (GM) muscle of 9 volunteers, during rest, plantar flexion exercise and recovery. Results The average SNR of PCr at rest was 64$\\pm$15 in SOL (83$\\pm$12 in GM). End exercise PCr depletion in SOL (19$\\pm$9%) was far lower than in GM (74$\\pm$14%). pH in SOL increased rapidly and, in contrast to GM, remained elevated until the end of exercise. Conclusion $^{31}$P MRS in single-shots every 6 s localized in the deeper lying SOL enabled quantification of PCr recovery times at low depletions and of...

  17. 31P nuclear magnetic resonance study of intracellular phosphate pools and polyphosphate metabolism in Heterosigma akashiwo (Hada) Hada (raphidophyceae)

    The effects of starvation and subsequent addition of phosphate-containing medium on the phosphate metabolic intermediates were studied by 31P-NMR spectroscopy of perchloric acid extracts and intact cells of Heterosigma akashiwo (Hada) Hada. When orthophosphate in the medium was completely depleted the medium was enriched with orthophosphate (4.5 μM). In the phosphate starved condition, the P cell quota was 76 fmol x cell-1 and the major components of phosphate intermediates were phosphodiester, sugar phosphate and orthophosphate (P/sub i/). After addition of P/sub i/, rapid uptake of P/sub i/ was observed and the P cell quota increased to 108 fmol x cell-1 in 2 h, 134 fmol x cell-1 in 5 h and 222 fmol x cell-1 in 1 day after addition of phosphate. The 31P-NMR spectrum indicated that a major portion of P was stored as polyphosphate, in which the average chain length of polyphosphate increased from 10 to 20 phosphate residues in one day after addition of P/sub i/

  18. Comparison of the clinical state and its changes in patients with Duchenne and Becker muscular dystrophy with results of in vivo 31P magnetic resonance spectroscopy

    A total of 14 boys with the Duchenne and Becker forms of muscular dystrophy (DMD, BMD) were examined using 31P magnetic resonance (MR) spectroscopy; 12 boys were examined repeatedly. The results were correlated with clinical findings (including those of genetic tests) and with data obtained from examinations of an age-matched control group. Evaluation of results using principal component analysis revealed maximum variability in the following ratios: phosphocreatine/inorganic phosphate (PCr/Pi), phosphocreatine/phosphodiesters (PCr/PDe) and phosphocreatine/phosphomonoesters (PCr/PMe). A decrease in PCr/Pi correlates with weakness of the hip girdle and of the lower part of the shoulder girdle in DMD/BMD patients. The values of all ratios in the group of patients with the DMD phenotype differ significantly from results obtained in the group with the BMD phenotype. Continuous follow-up of patients using 31P MR spectroscopy revealed a marked decrease in PCr/Pi in DMD/BMD patients at an age that could be expected in subjects with a typical clinical course of DMD/BMD. An attempt to manage a concomitant disease with prednisone and carnitene was followed by an increase in PCr/Pi in 3 cases. A rise in the PCr/Pi ratio signalled clinical improvement in the patients. A decrease in PCr/Pi was found after controlled physical training, a finding consistent with data obtained from clinical observations describing an adverse effect of physical stress on the dystrophic process. (orig.)

  19. 1H and 31P nuclear magnetic resonance investigation of the interaction between 2,3-diphosphoglycerate and human normal adult hemoglobin

    High-resolution 1H and 31P nuclear magnetic resonance spectroscopy has been used to investigate the binding of 2,3-diphosphoglycerate to human normal adult hemoglobin and the molecular interactions involved in the allosteric effect of the 2,3-diphosphoglycerate molecule on hemoglobin. Individual hydrogen ion NMR titration curves have been obtained for 22-26 histidyl residues of hemoglobin and for each phosphate group of 2,3-diphosphoglycerate with hemoglobin in both the deoxy and carbonmonoxy forms. The results indicate that 2,3-diphosphoglycerate binds to deoxyhemoglobin at the central cavity between the two β chains and the binding involves the β2-histidyl residues. Moreover, the results suggest that the binding site of 2,3-diphosphoglycerate to carbonmonoxyhemoglobin contains the same (or at least some of the same) amino acid residues responsible for binding in the deoxy form. As a result of the specific interactions with 2,3-diphosphoglycerate, the β2-histidyl residues make a significant contribution to the alkaline Bohr effect under these experimental conditions. These results give the first experimental demonstration that long-range electrostatic and/or conformation effects of the binding could play an important role in the allosteric effect of 2,3-diphosphoglycerate on hemoglobin. The 31P nuclear magnetic resonance titration data for each phosphate group of 2,3-diphosphoglycerate have been used to calculate the pK values of the phosphate groups in 2,3-diphosphoglycerate bound to deoxy- and carbon-monoxyhemoglobin and the proton uptake by 2,3-diphosphoglycerate upon ligand binding to hemoglobin

  20. Development of 31P nuclear magnetic resonance methods for the study of phosphate metabolisms in E. coli and B. subtilis

    31P NMR experiments were performed on escherichia coli and Bacillus subtilis at various temperatures under aerobic and anaerobic conditions. The total soluble intracellular phosphate concentration was estimated to be 2 x 10-17 mole/cell, while intracellular orthophosphate concentration was around 1 x 10-17 mole/cell. Addition of glucose resulted in a general decrease in intracellular pH and was accompanied by the formation of sugar monophosphates. The concentrations of soluble intracellular phosphates, both inorganic and organic phosphates, were estimated by integration versus methylene diphosphonic acid (MDPA) standard. Although intracellular and extracellular orthophosphate could be observed, these appear to exchange rapidly on the NMR time scale. (Author)

  1. Changes in energy metabolism in the quadriceps femoris after a single bout of acute exhaustive swimming in rats: a 31p-magnetic resonance spectroscopy study

    Sun Yingwei; Pan Shinong; Chen Zhian; Zhao Heng; Ma Ying; Zheng Liqiang; Li Qi

    2014-01-01

    Background Little is known about the value of 31P-magnetic resonance spectroscopy (31P-MRS) in in vivo assessment of exhaustive exercise-induced injury in skeletal muscle.We aimed to evaluate the value of a 31P-MRS study using the quadriceps femoris after a single bout of acute exhaustive swimming in rats,and the correlation between 31P-MRS and histological changes.Methods Sixty male Sprague-Dawley rats were randomly assigned to control,half-exhaustive,and exhaustive exercise groups.31P-MRS of the quadriceps femoris of the right lower limb was performed immediately after swimming exercise to detect Pi,PCr,and β-ATP.The Pi/PCr,Pi/β-ATP,PCr/β-ATP,and PCr/(PCr+Pi) were calculated and pH measured.Areas under the receiver operating characteristic curve (AUCs) were calculated to evaluate the diagnostic potential of 31P-MRS in identifying and distinguishing the three groups.HE staining,electron microscopy and desmin immunostaining after imaging of the muscle were used as a reference standard.The correlation between 31P-MRS and the mean absorbance (A value) of desmin staining were analyzed with the Pearson correlation test.Results Pi,PCr,Pi/PCr,and PCr/(PCr+Pi) showed statistically significant intergroup differences (P<0.05).AUCs of Pi,PCr,Pi/PCr,and PCr/(PCr+Pi) were 0.905,0.848,0.930,and 0.930 for the control and half-exhaustive groups,while sensitivity and specificity were 90%/85%,95%/55%,95%/80%,and 90%/85%,respectively.The AUCs of Pi,PCr,Pi/PCr and PCr/(PCr+Pi) were 0.995,0.980,1.000,and 1.000 for the control and exhaustive groups,while sensitivity and specificity were 95%/90%,100%/90%,100%/95%,and 100%/95%,respectively.The AUCs of Pi,PCr,Pi/PCr,and PCr/(PCr+Pi) were 0.735,0.865,0.903,and 0.903 for the half-exhaustive and exhaustive groups,while sensitivity and specificity were 80%/60%,90%/75%,95%/65%,and 95%/70%,respectively.In the half-exhaustive group,some muscle fibers exhibited edema in HE staining,and the

  2. Modeling sickle cell vasoocculsion in the rat leg: Quantification of trapped sickle cells and correlation with 31P metabolic and 1H magnetic resonance imaging changes

    The authors have developed an animal model to elucidate the acute effects of perfusion abnormalities on muscle metabolism induced by different density-defined classes of erythrocytes isolated from sickle cell anemia patients. Technetium-99m (99mTc)-labeled, saline-washed normal (AA), homozygous sickle (SS), or high-density SS (SS4) erythrocytes were injected into the femoral artery of the rat and quantitative 99mTc imaging, 31P magnetic resonance spectroscopy by surface coil at 2 teslas, and 1H magnetic resonance imaging at 0.15 tesla were performed. Between 5 and 25 μl of SS4 cells was trapped in the microcirculation of the thigh. In contrast, fewer SS discocytes (SS2) or AA cells were trapped. After injection of SS4 cells an initial increase in inorganic phosphate was observed in the region of the thigh served by the femoral artery, intracellular pH decreased, and subsequently the proton relaxation time T1 reached a broad maximum at 18-28 hr. When T1 obtained at this time was plotted against the volume of cells trapped, an increase of T1 over the control value of 411 ± 48 msec was found that was proportional to the number of cells trapped. They conclude that the densest SS cells are most effective at producing vasoocclusion. The extent of the change detected by 1H magnetic resonance imaging is dependent on the amount of cells trapped in the microcirculation and the magnitude of the initial increase of inorganic phosphate

  3. Effects of Coenzyme Q10 on Skeletal Muscle Oxidative Metabolism in Statin Users Assessed Using 31P Magnetic Resonance Spectroscopy: a Randomized Controlled Study

    Buettner, Catherine; Greenman, Robert L.; Ngo, Long H.; Wu, Jim S.

    2016-01-01

    Objectives Statins partially block the production of coenzyme Q10 (CoQ10), an essential component for mitochondrial function. Reduced skeletal muscle mitochondrial oxidative capacity has been proposed to be a cause of statin myalgia and can be measured using 31phosphorus magnetic resonance spectroscopy (31P-MRS). The purpose of this study is to assess the effect of CoQ10 oral supplementation on mitochondrial function in statin users using 31P-MRS. Design/Setting In this randomized, double-blind, placebo-controlled pilot study, 21 adults aged 47–73 were randomized to statin+placebo (n=9) or statin+CoQ10 (n=12). Phosphocreatine (PCr) recovery kinetics of calf muscles were assessed at baseline (off statin and CoQ10) and 4 weeks after randomization to either statin+CoQ10 or statin+placebo. Results Baseline and post-treatment PCr recovery kinetics were assessed for 19 participants. After 4 weeks of statin+ CoQ10 or statin+placebo, the overall relative percentage change (100*(baseline−follow up)/baseline) in PCr recovery time was −15.1% compared with baseline among all participants, (p-value=0.258). Participants randomized to statin+placebo (n=9) had a relative percentage change in PCr recovery time of −18.9%, compared to −7.7% among participants (n=10) receiving statin+CoQ10 (p-value=0.448). Conclusions In this pilot study, there was no significant change in mitochondrial function in patients receiving 4 weeks of statin+CoQ10 oral therapy when compared to patients on statin+placebo.

  4. High-energy phosphate metabolism during incremental calf exercise in humans measured by 31 phosphorus magnetic resonance spectroscopy (31P MRS).

    Schocke, Michael F H; Esterhammer, Regina; Kammerlander, Christian; Rass, Anton; Kremser, Christian; Fraedrich, Gustav; Jaschke, Werner R; Greiner, Andreas

    2004-01-01

    Several previous 31 phosphorus magnetic resonance spectroscopy ((31)P MRS) studies performing incremental or progressive muscle exercises have observed that a decrease in pH is accompanied with an acceleration in phosphocreatine (PCr) hydrolysis. The purpose of this study was to investigate the relationship between PCr breakdown and pH during isotonic, exhaustive, incremental plantar flexion exercises. We included eight healthy, male volunteers into this study. Using a 1.5 Tesla MR scanner and a self-built exercise bench, we performed serial free induction decay (FID) (31)P MRS measurements with a time resolution of 1 min at rest, isotonic calf muscle exercise, and recovery. The exercise protocol consisted of 5-min intervals with 4.5, 6, 7.5, and 9 W workload followed by 9-min recovery. Changes in PCr and inorganic phosphate (Pi) were determined as percent changes in comparison to the baseline. In addition, pH values were calculated. This study obtained significant decreases in PCr corresponding to the gradual increases in workload. In each workload level that was succeeded by all volunteers, PCr hydrolysis passed into a steady state. After an early biphasic response, we detected a significant decrease in pH from the first to the second minute of the 6-W workload level followed by a further continuous decrease in pH up to the second minute of the recovery phase. The decrease in pH was not accompanied by acceleration in PCr hydrolysis. In conclusion, this study shows that PCr hydrolysis during incremental plantar flexion exercises passes into a steady state at different workload levels. The observed decrease in pH does not result in acceleration of PCr hydrolysis. PMID:14972400

  5. The effect of gingko biloba extract on energy metabolic status in C3H mouse fibrosarcoma: evaluated by in vivo 31P magnetic resonance spectroscopy

    Gingko biloba extract (GBE), a natural product extracted from Gingko leaves, is known to increase the radiosensitivity of tumors. This radiosensitization probably arises from the increase in the peripheral blood flow by decreasing the blood viscosity and relaxing the vasospasm. The influence of a GBE on the metabolic status in fibrosarcoma II (FSall) of a C3H mouse was investigated using 31P magnetic resonance spectroscopy (MRS). Eighteen C3H mice with fibrosarcoma II (from 100 mm3 to 130 mm3) were prepared for this experiment. The mice were divided into 2 groups; one (9 mice) without a priming dose, and the other (9 mice) with a priming dose of GBE. The GBE priming dose (100 mg/kg) was administered by an intraperitoneal (i.p.) injection 24 hours prior to the measurement. First 31P MRS spectra were measured in the mice from each group as a baseline and test dose of GBE (100 mg/kg) was then administered to each group. One hour later, the 31P MRS spectra were measured again to evaluate the change in the energy metabolic status. In the group without the priming dose, the mean pH, PCr/Pi, PME/ATP, Pi/ATP, PCr/(Pi + PME) values 1 hour after the test dose were not changed significantly compared to the values at the baseline. However, in the group with the priming dose, the mean PCr/Pi, Pi/ATP, PCr/(Pi + PME) values 1 hour after the test dose changed from the baseline values of 0.49, 0.77, 0.17 to 0.74, 0.57, 0.28 respectively. According to the paired t-test, the differences were statistically significant. The above findings suggest that the metabolic status is significantly improved after administering GBE if the priming dose is given 24 hours earlier. This shows that the radiosensitizing effect of GBE is based on the increase of tumor blood flow and the improvement in the metabolic status

  6. The effect of gingko biloba extract on energy metabolic status in C3H mouse fibrosarcoma: evaluated by in vivo {sup 31}P magnetic resonance spectroscopy

    Ha, Sung Whan; Kim, Won Dong; Ahn, Yong Chan; Park, Charn Il [Seoul National University, College of Medicine, Seoul (Korea, Republic of); Lim, Tae Hwan; Lee, Tae Kuen [Ulsan University, Seoul (Korea, Republic of)

    2002-06-15

    Gingko biloba extract (GBE), a natural product extracted from Gingko leaves, is known to increase the radiosensitivity of tumors. This radiosensitization probably arises from the increase in the peripheral blood flow by decreasing the blood viscosity and relaxing the vasospasm. The influence of a GBE on the metabolic status in fibrosarcoma II (FSall) of a C3H mouse was investigated using {sup 31}P magnetic resonance spectroscopy (MRS). Eighteen C3H mice with fibrosarcoma II (from 100 mm{sup 3} to 130 mm{sup 3}) were prepared for this experiment. The mice were divided into 2 groups; one (9 mice) without a priming dose, and the other (9 mice) with a priming dose of GBE. The GBE priming dose (100 mg/kg) was administered by an intraperitoneal (i.p.) injection 24 hours prior to the measurement. First {sup 31}P MRS spectra were measured in the mice from each group as a baseline and test dose of GBE (100 mg/kg) was then administered to each group. One hour later, the {sup 31}P MRS spectra were measured again to evaluate the change in the energy metabolic status. In the group without the priming dose, the mean pH, PCr/Pi, PME/ATP, Pi/ATP, PCr/(Pi + PME) values 1 hour after the test dose were not changed significantly compared to the values at the baseline. However, in the group with the priming dose, the mean PCr/Pi, Pi/ATP, PCr/(Pi + PME) values 1 hour after the test dose changed from the baseline values of 0.49, 0.77, 0.17 to 0.74, 0.57, 0.28 respectively. According to the paired t-test, the differences were statistically significant. The above findings suggest that the metabolic status is significantly improved after administering GBE if the priming dose is given 24 hours earlier. This shows that the radiosensitizing effect of GBE is based on the increase of tumor blood flow and the improvement in the metabolic status.

  7. Analyzing Ph value, energy and phospholipid metabolism of various cerebral tumors and normal brain tissue with 31P magnetic resonance spectroscopy

    Wei Tan; Guangyao Wu; Junmo Sun

    2006-01-01

    BACKGROUND: 31P magnetic resonance spectroscopy (31P MRS) can be used to non-injuredly and dynamicly detect various metabolites including phosphorus in organis and reflect changes of phospholipid metabolism and energy metabolism in tissue and pH value in cells.OBJECTIVE: To observe changes of pH value, phospholipid metabolism and energy metabolism of various cerebral tumors and normal brain tissue with 31P MRS.DESIGN: Semi-quantitative contrast observation.PARTICIPANTS: A total of 44 patients with cerebral tumor diagnosed with surgery operation were selected from the Department of Magnetic Resonance, Central South Hospital, Wuhan University from September 2004 to June 2006. All the subjects had complete 31P MRS data before steroid and operation. Among them,16 patients had glioma of grade Ⅱ-Ⅲ, 12 spongioblastoma and 16 meningioma. The mean age was (45±6)years. Another 36 subjects without focus on cerebral MRI were regarded as normal group, including 19 males and 18 females, and the mean age was (41±4) years. Included subjects were consent.METHODS: Eclipse1.5T MRS (Philips Company) was used to collect wave spectrum; jMRUI(1.3) was used to analyze experimental data and calculate pH value in voxel and ratios of phosphocreatine (PCr)/inorganic phosphate (Pi), PCr/phosphodiesterase (PDE) and phosphomonoesterase (PME)/β-adenosine triphosphate (β-ATP) of various metabolites. 31P MRS results were compared with t test between tumor patients and normal subjects.MAIN OUTCOME MEASURES: Changes of phospholipid metabolism (PME/PDE), energy metabolism (PCr/ATP) and pH value of various cerebral tumors and normal brain tissues.RESULTS: A total of 44 cases with cerebral tumor and 36 normal subjects were involved in the final analysis. pH value and semi-quantitative measurements of normal brain tissues and various cerebral tumors: ① pH value at top occipital region and temple occipital region of normal brain tissue was 7.04±0.02;PCt/β-ATP was 1.51 ±0.03; PCt/Pi was 2.85

  8. Bevacizumab impairs oxidative energy metabolism and shows antitumoral effects in recurrent glioblastomas: a 31P/1H MRSI and quantitative magnetic resonance imaging study.

    Hattingen, Elke; Jurcoane, Alina; Bähr, Oliver; Rieger, Johannes; Magerkurth, Jörg; Anti, Sandra; Steinbach, Joachim P; Pilatus, Ulrich

    2011-12-01

    Bevacizumab shows unprecedented rates of response in recurrent glioblastomas (GBM), but the detailed mechanisms are still unclear. We employed in vivo magnetic resonance spectroscopic imaging (MRSI) and quantitative magnetic resonance imaging to investigate whether bevacizumab alters oxygen and energy metabolism and whether this effect has antitumoral activity in recurrent GBM. (31)P and (1)H MRSI, apparent diffusion coefficient (ADC), and high-resolution T2 and T2' mapping (indirect marker of oxygen extraction) were investigated in 16 patients with recurrent GBM at 3 Tesla before and 1.5-2 months after initiation of therapy with bevacizumab. Changes of metabolite concentrations and of the quantitative values in the tumor and normal appearing brain tissue were calculated. The Wilcoxon signed-ranks test was used to evaluate differences for tumor/edema versus control as well as changes before versus after commencement of therapy. Survival analyses were performed for significant parameters. Tumor T2', pH, ADC, and T2 decreased significantly in patients responding to bevacizumab therapy (n = 10). Patients with at least 25% T2' decrease during treatment showed longer progression-free and overall survival durations. Levels of high-energy metabolites were lower at baseline; these persisted under therapy. Glycerophosphoethanolamine as catabolic phospholipid metabolite increased in responders. The MRSI data support the hypothesis that bevacizumab induces relative tumor hypoxia (T2' decrease) and affects energy homeostasis in recurrent GBM, suggesting that bevacizumab impairs vascular function. The antiangiogenic effect of bevacizumab is predictive of better outcome and seems to induce antitumoral activity in the responding GBMs. PMID:21890539

  9. Changes in energy metabolism following roentgen irradiation of in vivo growing Ehrlich ascites tumour cells studied by 31P magnetic resonance spectroscopy

    The energy metabolism in Ehrlich ascites tumour cells following in vivo irradiation of a dose of 5.0 Gy was studied in vitro in their ascites fluid up to 48 hours using 31P magnetic resonance spectroscopy measuring ATP, ADP and inorganic phosphate (Psub(i)). The results are also related to radiation induced changes in cell cycle composition. ATP was reduced by more than 50 per cent 20 to 24 hours after irradiation but normalized at 48 hours. ADP was reduced to about half the normal level 24 to 48 hours after irradiation. When the ATP and ADP had reduced levels, the inorganic phosphate increased correspondingly. Addition of glucose to the ascites cell suspension at the time of minimum ATP level immediately raised the ATP:Psub(i) ratio. Since the glucose concentrations in blood and in ascites fluid following irradiation were also reduced, lack of glucose for energy production might have been a major contributing factor for the reduced ATP production. (orig.)

  10. Cooperation and competition between adenylate kinase, nucleoside diphosphokinase, electron transport, and ATP synthase in plant mitochondria studied by 31P-nuclear magnetic resonance

    Nucleotide metabolism in potato (Solanum tuberosum) mitochondria was studied using 31P-nuclear magnetic resonance spectroscopy and the O2 electrode. Immediately following the addition of ADP, ATP synthesis exceeded the rate of oxidative phosphorylation, fueled by succinate oxidation, due to mitochondrial adenylate kinase (AK) activity two to four times the maximum activity of ATP synthase. Only when the AK reaction approached equilibrium was oxidative phosphorylation the primary mechanism for net ATP synthesis. A pool of sequestered ATP in mitochondria enabled AK and ATP synthase to convert AMP to ATP in the presence of exogenous inorganic phosphate. During this conversion, AK activity can indirectly influence rates of oxidation of both succinate and NADH via changes in mitochondrial ATP. Mitochondrial nucleoside diphosphokinase, in cooperation with ATP synthase, was found to facilitate phosphorylation of nucleoside diphosphates other than ADP at rates similar to the maximum rate of oxidative phosphorylation. These results demonstrate that plant mitochondria contain all of the machinery necessary to rapidly regenerate nucleoside triphosphates from AMP and nucleoside diphosphates made during cellular biosynthesis and that AK activity can affect both the amount of ADP available to ATP synthase and the level of ATP regulating electron transport

  11. Therapeutic effect of 15-deoxyspergualin on acute graft rejection detected by 31P nuclear magnetic resonance spectrography, and its effect on rat heart transplantation

    We investigated the effect of 15-deoxyspergualin (DSG) on graft rejection, starting administration at the onset of rejection and on the induction of immunologic unresponsiveness. Hearts from WKAH rats were transplanted into the neck of ACI rats. The energy metabolism of the grafted hearts was followed by 31P nuclear magnetic resonance spectroscopy. The day that energy metabolism started to fall was defined as the onset of rejection, and intraperitoneal administration of DSG was initiated at 5 mg/kg/day for 15 days from this day. The grafted heart arrested in 2 of 10 rats 9 and 11 days after transplantation, respectively, but the remaining 8 recovered from rejection and 5 of them showed evidence of immunologic unresponsiveness. Of 10 rats treated with DSG from the day of transplantation, only 1 rat showed evidence of unresponsiveness. The initiation of DSG treatment from the onset of rejection resulted in a higher percentage of induction of unresponsiveness. Therefore, DSG was considered to specifically inhibit lymphocyte clone expansion at the onset of rejection. Spleen cells obtained from recipients 7-10 days after the end of DSG treatment were administered to syngeneic ACI rats grafted with WKAH hearts. Graft survival was significantly prolonged, but long-term unresponsiveness could not be transferred. However, immunologic unresponsiveness could be adoptively transferred in 3 of 5 rats receiving spleen cells from syngeneic rats that had recovered from rejection after DSG treatment and had acquired long-term unresponsiveness. These results suggest that suppressor cells are resistant to DSG and are spared and participate in the maintenance of immunologic unresponsiveness

  12. Quantitative nuclear magnetic resonance spectrometry II. Purity of phosphorus-based agrochemicals glyphosate (N-(phosphonomethyl)-glycine) and profenofos (O-(4-bromo-2-chlorophenyl) O-ethyl S-propyl phosphorothioate) measured by 1H and 31P QNMR spectrometry

    The purities of the widely-used herbicide glyphosate (N-(phosphonomethyl)glycine), and the insecticide profenofos (O-(4-bromo-2-chlorophenyl) O-ethyl S-propyl phosphorothioate) were determined by 1H and 31P quantitative nuclear magnetic resonance (QNMR) spectrometry using an internal standard. QNMR does not need a standard reference of the same target analyte, in contrast to chromatographic methods, but only a compound containing the nucleus of interest. Sodium acetate and sodium phosphate of known purity were chosen as internal standards for 1H NMR and 31P NMR), respectively for the water soluble glyphosate and a single internal standard, trimethyl phosphate for both 1H and 31P NMR quantitative analysis of the organic soluble profenofos. These standards have NMR peaks that do not interfere with those of the analyte, they are chemically inert and are soluble in the deuterated solvent. The average purity of glyphosate obtained by 1H NMR (97.07%, σ=0.68) agreed with that by 31P NMR (96.53%, σ=0.90; ANOVA, P=0.074) for the five batches provided by the manufacturer according to the procedures for chemical registration in Australia. The standard deviations of seven independent analyses of a single batch by 1H NMR and 31P NMR were σ=0.24% and σ=0.33%, respectively, values which confirm the exceptional precision of the method. The purity of profenofos by 1H NMR (94.63%, σ=0.14) also agreed with that by 31P NMR (94.62%, σ=0.59; ANOVA, P=0.97). Uncertainty budgets for the measured purities of glyphosate and profenofos show that the uncertainty in the purity of the internal standard is a major contributor to the uncertainty of the result. NMR was also used to establish the impurity profile of both compounds, and quantify the impurities present

  13. Metabolism of D-glucose in a wall-less mutant of Neurospora crassa examined by 13C and 31P nuclear magnetic resonances: effects of insulin

    13C NMR and 31P NMR have been used to investigate the metabolism of glucose by a wall-less strain of Neurospora crassa (slime), grown in a supplemented nutritionally defined medium and harvested in the early stationary stage of growth. With D-[1-13C]- or D-[6-13C]glucose as substrates, the major metabolic products identified from 13C NMR spectra were [2-13C]ethanol, [3-13C]alanine, and C1- and C6-labeled trehalose. Several observations suggested the existence of a substantial hexose monophosphate (HMP) shunt: (i) a 70% greater yield of ethanol from C6- than from C1-labeled glucose; (ii) C1-labeled glucose yielded 19% C6-labeled trehalose, while C6-labeled glucose yielded only 4% C1-labeled trehalose; (iii) a substantial transfer of 13C from C2-labeled glucose to the C2-position of ethanol. 31P NMR spectra showed millimolar levels of intracellular inorganic phosphate (Pi), phosphodiesters, and diphosphates including sugar diphosphates and polyphosphate. Addition of glucose resulted in a decrease in cytoplasmic Pi and an increase in sugar monophosphates, which continued for at least 30 min. Phosphate resonances corresponding to metabolic intermediates of both the glycolytic and HMP pathways were identified in cell extracts. Addition of insulin (100 nM) with the glucose had the following effects relative to glucose alone: (i) a 24% increase (P less than 0.01) in the rate of ethanol production; (ii) a 38% increase (P less than 0.05) in the rate of alanine production; (iii) a 27% increase (P less than 0.05) in the rate of glucose disappearance. Insulin thus increases the rates of production of ethanol and alanine in these cells, in addition to increasing production of CO2 and glycogen, as previously shown. (author)

  14. Analysis of metabolites in human brain tumors and cerebral infarctions using {sup 31}P- and {sup 1}H-magnetic resonance spectroscopy

    Hirakawa, Wataru [Kagoshima Univ. (Japan). Faculty of Medicine

    1996-08-01

    {sup 31}P- and {sup 1}H-MRS with a 2.0 tesla MRI/S system was used to monitor the cerebral energy levels, phospholipid metabolism, intracellular pH, and lactate and amino acid levels in patients with brain tumors and cerebral infarctions. Studies of human brain tumors have suggested that the {sup 31}P-MRS of malignant brain tumors show low concentrations of phosphocreatine (PCr) and {beta}-ATP, high levels of phosphomonoester (PME) and inorganic Pi, and an alkaline pH. The Pi, PME, and intracellular pH of malignant lymphoma were higher than those of other brain tumors. {sup 1}H-MRS showed an increase of lactate in malignant brain tumors and epidermoids. After ACNU administration, the tumor {sup 31}P-MRS showed transient reduction and elevation of Pi on five patients with malignant gliomas. Intracellular pH also showed a transient reduction during radiotherapy. {sup 1}H-MRS showed a reduction of lactate at the beginning of therapy and showed a marked re-elevation of lactate with tumor regrowth. After radiotherapy, the normal brain {sup 31}P-MRS showed transient elevation and reduction of Pi. Intracellular pH also showed a transient elevation during radiotherapy. To investigate the mechanism of hyperbaric oxygen therapy (HBO) in cerebral ischemia, changes of brain lactate level were estimated by {sup 1}H-MRS. Although the Lactate/Creatine ratio decreased consistently over time in all patients, it decreased more rapidly in the patients receiving HBO therapy than in those without such therapy. {sup 1}H-MRS demonstrated that HBO therapy may improve metabolism in the ischemic brain and reduces the lactate levels. {sup 31}P- and {sup 1}H-MRS are practical tools for the clinical analysis of cerebral disorders as well as for deciding on therapeutic procedures and evaluating the response. (K.H.)

  15. 糖尿病大鼠脑能量代谢改变的核磁共振磷谱研究%Studies on Changes of Brain Energy Metabolism in Diabetic Rats by 31 P Magnetic Resonance Spectroscopy

    王娜; 郑涌泉; 许翠翠; 苏永超; 赵良才; 叶信健; 高红昌

    2014-01-01

    Considerable attention has been directed toward studying the impact of diabetes on the central nervous system. The current study investigates the biochemical changes in the brain tissue of streptozotocin (STZ)-induced diabetic rat using 31P magnetic resonance spectroscopy (31P MRS). The 31P NMR spectra of the whole brain show no significant changes of phosphomonoesters and phosphodiesters levels one week after STZ induction, suggesting no apparent structural changes in cell membranes. The results identifies the increased level of adenosine diphosphate, negligible changes of phosphocreatine ( PCr ) and adenosine triphosphate ( ATP) , but the decreased ratio of PCr/ATP, indicating that PCr plays a role of balancing the energy. Moreover, the decreased pH value indicates the changes of the intracellular environment in STZ-diabetic brains in rats. After 15 weeks of STZ injection, the metabolism of phospholipid membrane and brain energy metabolism has been obviously disturbed. Our study successfully shows that 31 P MRS can not only study phospholipid and energy metabolism non-invasively, but also measure intracellular pH and other important biochemical information. All of these spectroscopic characterizations contribute significantly to the understanding of pathogenesis and evolution of diabetes, and provide theoretical basis for early diagnosis and clinical treatment in diabetes.%应用链脲佐菌素( Streptozocin, STZ)制备糖尿病( Diabetes mellitus, DM)大鼠模型,采用离体的核磁共振磷谱(31 P Magnetic resonance spectroscopy, MRS)方法检测糖尿病大鼠脑组织的生化改变。全脑的31 P MRS谱图结果显示,STZ诱导1周后,磷酸单酯和磷酸二酯的含量无明显改变,表明糖尿病大鼠脑中并没有发生膜性结构的改变。二磷酸腺苷峰增高,磷酸肌酸( Phosphocreatine, PCr)和三磷酸腺苷( Adenosine triphosphate, ATP)含量无明显改变,但是PCr/ATP降低,说明PCr作为能量缓冲底

  16. An overview of the metabolic differences between Bradyrhizobium japonicum 110 bacteria and differentiated bacteroids from soybean (Glycine max) root nodules: an in vitro 13C- and 31P-nuclear magnetic resonance spectroscopy study

    Bradyrhizobium japonicum is a symbiotic nitrogen-fixing soil bacteria that induce root nodules formation in legume soybean (Glycine max.). Using 13C- and 31P-nuclear magnetic resonance (NMR) spectroscopy, we have analysed the metabolite profiles of cultivated B. japonicum cells and bacteroids isolated from soybean nodules. Our results revealed some quantitative and qualitative differences between the metabolite profiles of bacteroids and their vegetative state. This includes in bacteroids a huge accumulation of soluble carbohydrates such as trehalose, glutamate, myo-inositol and homo-spermidine as well as Pi, nucleotide pools and intermediates of the primary carbon metabolism. Using this novel approach, these data show that most of the compounds detected in bacteroids reflect the metabolic adaptation of rhizobia to the surrounding microenvironment with its host plant cells. (authors)

  17. Effect of estrogen withdrawal on energy-rich phosphates and prediction of estrogen dependence monitored by in vivo 31P magnetic resonance spectroscopy of four human breast cancer xenografts

    Kristensen, C A; Kristjansen, P E; Brünner, N;

    1995-01-01

    The effect of estrogen withdrawal on energy metabolism was studied in four human breast cancer xenografts: the estrogen-dependent MCF-7 and ZR75-1 and the estrogen-independent ZR75/LCC-3 and MDA-MB-231. The tumors were grown in ovariectomized nude mice with a s.c. implanted estrogen pellet. After...... Gompertzian growth was verified, the estrogen pellet was removed from half of the animals. In vivo 31P magnetic resonance spectroscopy of the tumors was performed 1 day before and on days 2, 6, and 14 after estrogen removal. Estrogen withdrawal induced a significant increase in the nucleoside triphosphate......:Pi ratio in the two estrogen-dependent xenografts, whereas this ratio remained unchanged in the estrogen-independent tumors. In ZR75/LCC-3 tumors a slight decrease in nucleoside triphosphate:Pi was observed following onset of estrogen stimulation after initial growth without estrogen. Extracts of freeze...

  18. In vivo 31P magnetic resonance spectroscopy and 1H magnetic resonance imaging of human bladder carcinoma on nude mice: effects of tumour growth and treatment with cis-dichloro-diamine platinum

    De Certaines, J D; Albrectsen, J; Larsen, V A;

    1992-01-01

    phosphate and phosphomonoesters and a decrease of phosphocreatine. Fast growing tumours and early stage of regrowth after treatment presented a higher phosphocreatine/beta NTP ratio. Following CDDP treatment, 31P metabolite ratios and pH were significantly altered compared with age-matched controls, as...... early as 6 hours after treatment. Although necrotic area was clearly visible in MRI, no treatment effect could be detected on the images of treated tumours....

  19. In vivo 31P magnetic resonance spectroscopy and 1H magnetic resonance imaging of human bladder carcinoma on nude mice: effects of tumour growth and treatment with cis-dichloro-diamine platinum

    De Certaines, J D; Albrectsen, J; Larsen, V A;

    1993-01-01

    phosphate and phosphomonoesters and a decrease of phosphocreatine. Fast growing tumours and early stage of regrowth after treatment presented a higher phosphocreatine/beta NTP ratio. Following CDDP treatment, 31P metabolite ratios and pH were significantly altered compared with age-matched controls, as...... early as 6 hours after treatment. Although necrotic area was clearly visible in MRI, no treatment effect could be detected on the images of treated tumours....

  20. 31P magnetization transfer measurements of Pi→ATP flux in exercising human muscle

    Savage, David B.; Williams, Guy B.; Porter, David; Carpenter, T. Adrian; Brindle, Kevin M.; Kemp, Graham J.

    2016-01-01

    Fundamental criticisms have been made over the use of 31P magnetic resonance spectroscopy (MRS) magnetization transfer estimates of inorganic phosphate (Pi)→ATP flux (VPi-ATP) in human resting skeletal muscle for assessing mitochondrial function. Although the discrepancy in the magnitude of VPi-ATP is now acknowledged, little is known about its metabolic determinants. Here we use a novel protocol to measure VPi-ATP in human exercising muscle for the first time. Steady-state VPi-ATP was measured at rest and over a range of exercise intensities and compared with suprabasal oxidative ATP synthesis rates estimated from the initial rates of postexercise phosphocreatine resynthesis (VATP). We define a surplus Pi→ATP flux as the difference between VPi-ATP and VATP. The coupled reactions catalyzed by the glycolytic enzymes GAPDH and phosphoglycerate kinase (PGK) have been shown to catalyze measurable exchange between ATP and Pi in some systems and have been suggested to be responsible for this surplus flux. Surplus VPi-ATP did not change between rest and exercise, even though the concentrations of Pi and ADP, which are substrates for GAPDH and PGK, respectively, increased as expected. However, involvement of these enzymes is suggested by correlations between absolute and surplus Pi→ATP flux, both at rest and during exercise, and the intensity of the phosphomonoester peak in the 31P NMR spectrum. This peak includes contributions from sugar phosphates in the glycolytic pathway, and changes in its intensity may indicate changes in downstream glycolytic intermediates, including 3-phosphoglycerate, which has been shown to influence the exchange between ATP and Pi catalyzed by GAPDH and PGK. PMID:26744504

  1. The clinical value of 31p magnetic resonance spectroscopy in patients with lipid storage myopathy%脂质沉积性肌病骨骼肌磁共振31磷波谱的临床价值研究

    李银; 赖鸿; 丁卫江

    2012-01-01

    目的 探讨脂质沉积性肌病(LSM)患者骨骼肌磁共振31磷波谱(31P-MRS)改变特征,以及在LSM辅助诊断和疗效评价方面的临床价值.方法 对12例LSM患者在治疗前后和11例对照者分别进行31P-MRS扫描,获取波谱图像,计算谱线中无机磷酸盐(Pi)、磷酸肌酸(PCr)及三磷酸腺苷(ATP)的峰下面积,记录Pi/ATP、PC r/ATP和Pi/PCr的比值,计算Pi、PCr、细胞内pH(pHim)、二磷酸腺苷(ADP)和磷酸化潜能(PP)的值,并比较LSM患者治疗前和对照组、LSM患者治疗前后上述31p-MRS指标的差异.结果 LSM患者治疗前的PCr、PCr/ATP和PP较对照组明显降低(P<0.05),Pi/PCr和ADP较对照组明显升高(P<0.05),Pi、Pi/ATP和pHint与对照组比较无明显差异(P>0.05);LSM患者治疗后的PCr、PCr/ATP和PP较治疗前明显升高(P<0.05),ADP较治疗前明显降低(P<0.05),Pi、Pi/ATP、Pi/PCr和pHint与治疗前比较无明显差异(P>0.05).结论 31P-MRS可无创性检测LSM患者肌肉组织的能量代谢变化,有利于LSM的辅助诊断,并可运用于LSM患者的疗效评价.%Objective To investigate the 31P magnetic resonance spectroscopy (31P-MRS) manifestations of skeletal muscle in patients with lipid storage myopathy( LSM)and evaluate its clinical value in auxiliary diagnosis and therapeutic effect. Methods 31 P-MRS scanning was performed in 12 patients prior to and after treatment and 11 collators. The areas under resonance of inorganic phosphate(Pi) ,phosphocreatine(PCr)and adenosine triphosphate( ATP)were calculated from the 31P-MRS images,then the ratios of Pi/ATP,PCr/ATP and Pi/PCr and the values of Pi,PCr,intracellular pH(pHint) .adenosine diphosphate( ABP)and phosphorylation potential(PP) were calculated at last. The above-mentioned variables were compared among LSM patients prior to treatment and the control group,and variables were also compared in LSM patients prior to and after treatment. Results Compared with the control group,LSM patients prior to

  2. Solid-State Nuclear Magnetic Resonance Measurements of HIV Fusion Peptide 13CO to Lipid 31P Proximities Support Similar Partially Inserted Membrane Locations of the α Helical and β Sheet Peptide Structures

    Gabrys, Charles M.; Qiang, Wei; Sun, Yan; Xie, Li; Schmick, Scott D.; Weliky, David P.

    2013-10-01

    Fusion of the human immunodeficiency virus (HIV) membrane and the host cell membrane is an initial step of infection of the host cell. Fusion is catalyzed by gp41, which is an integral membrane protein of HIV. The fusion peptide (FP) is the -25 N-terminal residues of gp41 and is a domain of gp41 that plays a key role in fusion catalysis likely through interaction with the host cell membrane. Much of our understanding of the FP domain has been accomplished with studies of -HFP-, i.e., a -25-residue peptide composed of the FP sequence but lacking the rest of gp41. HFP catalyzes fusion between membrane vesicles and serves as a model system to understand fusion catalysis. HFP binds to membranes and the membrane location of HFP is likely a significant determinant of fusion catalysis perhaps because the consequent membrane perturbation reduces the fusion activation energy. In the present study, many HFPs were synthesized and differed in the residue position that was 13CO backbone labeled. Samples were then prepared that each contained a singly 13CO labeled HFP incorporated into membranes that lacked cholesterol. HFP had distinct molecular populations with either α helical or oligomeric - sheet structure. Proximity between the HFP 13CO nuclei and 31P nuclei in the membrane headgroups was probed by solid-state NMR (SSNMR) rotational-echo double-resonance (REDOR) measurements. For many samples, there were distinct 13CO shifts for the α helical and - sheet structures so that the proximities to 31P nuclei could be determined for each structure. Data from several differently labeled HFPs were then incorporated into a membrane location model for the particular structure. In addition to the 13CO labeled residue position, the HFPs also differed in sequence and/or chemical structure. -HFPmn- was a linear peptide that contained the 23 N-terminal residues of gp41. -HFPmn_V2E- contained the V2E mutation that for HIV leads to greatly reduced extent of fusion and infection. The

  3. Recommendations concerning magnetic resonance spectroscopy

    In medicine the technique of nuclear magnetic resonance (NMR) is applied in the form of in vivo nuclear magnetic resonance spectroscopy (MRS). In vivo MRS can be carried out non-invasively. The committee of the Dutch Health Council briefly discusses the qualities and potentialities of the nuclei that will probably be used in future clinical spectroscopy: 31P, 13C, 1H (and possibly 19F and 23Na). The committee discusses several possibilities of combining imaging and spectroscopy. The imaging of nuclei other than protons is also possible with MRS. Potential applications are considered in oncology, cardiology, neurology and hepatology. (Auth.)

  4. Phosphorus-doped thin silica films characterized by magic-angle spinning nuclear magnetic resonance spectroscopy

    Jacobsen, H.J.; Skibsted, J.; Kristensen, Martin;

    2001-01-01

    Magic-angle spinning nuclear magnetic resonance spectra of 31P and 29Si have been achieved for a thin silica film doped with only 1.8% 31P and deposited by plasma enhanced chemical vapor deposition on a pure silicon wafer. The observation of a symmetric 31P chemical shift tensor is consistent...

  5. Analysis of the bond-valence method for calculating (29) Si and (31) P magnetic shielding in covalent network solids.

    Holmes, Sean T; Alkan, Fahri; Iuliucci, Robbie J; Mueller, Karl T; Dybowski, Cecil

    2016-07-01

    (29) Si and (31) P magnetic-shielding tensors in covalent network solids have been evaluated using periodic and cluster-based calculations. The cluster-based computational methodology employs pseudoatoms to reduce the net charge (resulting from missing co-ordination on the terminal atoms) through valence modification of terminal atoms using bond-valence theory (VMTA/BV). The magnetic-shielding tensors computed with the VMTA/BV method are compared to magnetic-shielding tensors determined with the periodic GIPAW approach. The cluster-based all-electron calculations agree with experiment better than the GIPAW calculations, particularly for predicting absolute magnetic shielding and for predicting chemical shifts. The performance of the DFT functionals CA-PZ, PW91, PBE, rPBE, PBEsol, WC, and PBE0 are assessed for the prediction of (29) Si and (31) P magnetic-shielding constants. Calculations using the hybrid functional PBE0, in combination with the VMTA/BV approach, result in excellent agreement with experiment. © 2016 Wiley Periodicals, Inc. PMID:27117609

  6. Conformation and dynamics of melittin bound to magnetically oriented lipid bilayers by solid-state (31)P and (13)C NMR spectroscopy.

    Naito, A.; T. Nagao; Norisada, K; Mizuno, T; Tuzi, S.; Saitô, H.

    2000-01-01

    The conformation and dynamics of melittin bound to the dimyristoylphosphatidylcholine (DMPC) bilayer and the magnetic orientation in the lipid bilayer systems were investigated by solid-state (31)P and (13)C NMR spectroscopy. Using (31)P NMR, it was found that melittin-lipid bilayers form magnetically oriented elongated vesicles with the long axis parallel to the magnetic field above the liquid crystalline-gel phase transition temperature (T(m) = 24 degrees C). The conformation, orientation, ...

  7. MRI (Magnetic Resonance Imaging)

    ... Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options ... 8 MB) Also available in Other Language versions . Magnetic Resonance Imaging (MRI) is a medical imaging procedure for making ...

  8. 31P NMR study of magnetic phase transitions of MnP single crystal under 2 GPa pressure

    Fan, GuoZhi; Zhao, Bo; Wu, Wei; Zheng, Ping; Luo, JianLin

    2016-05-01

    Superconductivity on the border of the long-range magnetic order has been discovered in MnP under high pressures. In order to investigate the nature of the magnetic properties adjacent to the superconducting state, we performed zero-field 31P NMR for MnP single crystal under ambient and hydrostatic pressure of 2 GPa, respectively. Radio frequency power level was used to determine whether NMR signal originates from a helical state or not. When 2 GPa pressure was applied, the signal from helical state exists even above 160 K, while that from the ferromagnetic phase was not observed. Our NMR results indicate that the magnetic phase which is adjacent to the superconducting state is in a helical magnetic structure.

  9. Magnetic resonance angiography

    MRA; Angiography - magnetic resonance ... Kwong RY. Cardiovascular Magnetic Resonance Imaging. In: Bonow RO, Mann DL, Zipes DP, Libby P, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine . ...

  10. Magnetic Resonance Imaging (MRI)

    ... How Can I Help a Friend Who Cuts? Magnetic Resonance Imaging (MRI) KidsHealth > For Teens > Magnetic Resonance Imaging (MRI) Print A A A Text Size What's ... Exam Safety Getting Your Results What Is MRI? Magnetic resonance imaging (MRI) is a type of safe, painless testing ...

  11. Early detection of cerebral infarction by 31P spectroscopic imaging

    Recent advances in magnetic resonance spectroscopy permit noninvasive study of brain metabolism in vivo, 31P spectroscopic imaging being the method for evaluation of localized phosphorous metabolism. Experimentally, an ischemic-hypoxic brain insult is characterized by depletion of high energy metabolites. These changes are seen immediately after an ischemic insult. We had the opportunity of carrying out 31P spectroscopic imaging of hyperacute cerebral infarction, while MRI and CT were negative. Cerebral infarction of the middle cerebral artery territory was suggested by 31P spectroscopic imaging, which was closely consistent with a later-developing region of low density on CT. In cerebral infarction, early detection of the lesion is a useful pointer to the patient's prognosis, making 31P spectroscopic imaging a potential tool. (orig.)

  12. Magnetic Resonance Imaging (MRI)

    ... Resonance Imaging (MRI) What is an MRI? MRI stands for Magnetic Resonance Imaging. It is an important ... MRI is often used for diagnosis or for monitoring disease. For example, if someone is having severe ...

  13. Magnetic Resonance Imaging and Magnetic Resonance Spectroscopy in Dementias

    Hsu, Yuan-Yu; Du, An-Tao; Schuff, Norbert; Weiner, Michael W.

    2001-01-01

    This article reviews recent studies of magnetic resonance imaging and magnetic resonance spectroscopy in dementia, including Alzheimer's disease, frontotemporal dementia, dementia with Lewy bodies, idiopathic Parkinson's disease, Huntington's disease, and vascular dementia. Magnetic resonance imaging and magnetic resonance spectroscopy can detect structural alteration and biochemical abnormalities in the brain of demented subjects and may help in the differential diagnosis and early detection...

  14. Efficient isotropic magnetic resonators

    Martin, O. J. F.; Gay-Balmaz, P.

    2002-01-01

    We study experimentally and numerically a novel three-dimensional magnetic resonator structure with high isotropy. It is formed by crossed split-ring resonators and has a response independent of the illumination direction in a specific plane. The utilization of such elements to build a finite left-handed medium is discussed. (C) 2002 American Institute of Physics.

  15. SQUID-detected magnetic resonance imaging in microtesla magnetic fields

    We describe studies of nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) of liquid samples at room temperature in microtesla magnetic fields. The nuclear spins are prepolarized in a strong transient field. The magnetic signals generated by the precessing spins, which range in frequency from tens of Hz to several kHz, are detected by a low-transition temperature dc SQUID (Superconducting QUantum Interference Device) coupled to an untuned, superconducting flux transformer configured as an axial gradiometer. The combination of prepolarization and frequency-independent detector sensitivity results in a high signal-to-noise ratio and high spectral resolution (∼1 Hz) even in grossly inhomogeneous magnetic fields. In the NMR experiments, the high spectral resolution enables us to detect the 10-Hz splitting of the spectrum of protons due to their scalar coupling to a 31P nucleus. Furthermore, the broadband detection scheme combined with a non-resonant field-reversal spin echo allows the simultaneous observation of signals from protons and 31P nuclei, even though their NMR resonance frequencies differ by a factor of 2.5. We extend our methodology to MRI in microtesla fields, where the high spectral resolution translates into high spatial resolution. We demonstrate two-dimensional images of a mineral oil phantom and slices of peppers, with a spatial resolution of about 1 mm. We also image an intact pepper using slice selection, again with 1-mm resolution. In further experiments we demonstrate T1-contrast imaging of a water phantom, some parts of which were doped with a paramagnetic salt to reduce the longitudinal relaxation time T1. Possible applications of this MRI technique include screening for tumors and integration with existing multichannel SQUID systems for brain imaging

  16. Magnetic resonance spectroscopy: clinical application in neuroradiology

    Full text: Magnetic Resonance Spectroscopy (MRS) provides a non-invasive method of studying metabolism in vivo. Magnetic resonance spectroscopy (MRS) defines neuro chemistry on a regional basis by acquiring a radiofrequency signal with chemical shift from one or many voxels or volumes previously selected on MRI. The tissue's chemical environment determines the frequency of a metabolite peak in an MRS spectrum. Candidates for MRS include: 1H, 31P, 13C, 23Na, 7Li, 19F, 14N, 15N, 17O, 39K The most commonly studied nuclei are 1H and 31P. This lecture is focused on Proton (1H) Spectroscopy. Proton MRS can be added on to conventional MR imaging protocols. It can be used to serially monitor biochemical changes in tumors, stroke, epilepsy, metabolic disorders, infections, and neurodegenerative diseases.The MR spectra do not come labeled with diagnoses. They require interpretation and should always be correlated with the MR images before making a final diagnosis. As a general rule, the single voxel, short TE technique is used to make the initial diagnosis, because the signal-to-noise is high and all metabolites are represented. Multi-voxel, long TE techniques are used to further characterize different regions of a mass and to assess brain parenchyma around or adjacent to the mass. Multi-voxel, long TE techniques are also used to assess response to therapy and to search for tumor recurrence. Each metabolite appears at a specific ppm, and each one reflects specific cellular and biochemical processes

  17. Advances in magnetic resonance 10

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 10, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains three chapters that examine superoperators in magnetic resonance; ultrasonically modulated paramagnetic resonance; and the utility of electron paramagnetic resonance (EPR) and electron-nuclear double-resonance (ENDOR) techniques for studying low-frequency modes of atomic fluctuations and their significance for understanding the mechanism of structural phase transitions in solids.

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

    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 (31P 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 31P 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

  19. 13C and 31P NMR [Nuclear Magnetic Resonance] studies of prostate tumor metabolism

    The current research on prostate cancer by NMR spectroscopy and microscopy will most significantly contribute to tumor diagnosis and characterization only if sound biochemical models of tumor metabolism are established and tested. Prior searches focused on universal markers of malignancy, have to date, revealed no universal markers by any method. It is unlikely that NMRS will succeed where other methods have failed, however, NMR spectroscopy does provide a non-invasive means to analyze multiple compounds simultaneously in vivo. In order to fully evaluate the ability of NMRS to differentiate non-malignant from malignant tissues it is necessary to determine sufficient multiple parameters from specific, well-diagnosed, histological tumor types that, in comparison to normal tissue and non-neoplastic, non-normal pathologies from which the given neoplasm must be differentiated, one has enough degrees of freedom to make a mathematically and statistically significant determination. Confounding factors may consist of tumor heterogeneity arising from regional variations in differentiation, ischemia, necrosis, hemorrhage, inflammation and the presence of intermingled normal tissue. One related aspect of our work is the development of {13C}-1H metabolic imaging of 13C for metabolic characterization, with enhanced spatial localization (46). This should markedly extend the range of potential clinical NMR uses because the spatial variation in prostate metabolism may prove to be just as important in tumor diagnoses as bulk (volume-averaged) properties themselves. It is our hope that NMRS and spectroscopic imaging will reveal a sound correlation between prostate metabolism and tumor properties that will be clinically straightforward and useful for diagnosis

  20. Functional Magnetic Resonance Imaging

    Voos, Avery; Pelphrey, Kevin

    2013-01-01

    Functional magnetic resonance imaging (fMRI), with its excellent spatial resolution and ability to visualize networks of neuroanatomical structures involved in complex information processing, has become the dominant technique for the study of brain function and its development. The accessibility of in-vivo pediatric brain-imaging techniques…

  1. Resonant magnetic vortices

    By using the complex angular momentum method, we provide a semiclassical analysis of electron scattering by a magnetic vortex of Aharonov-Bohm type. Regge poles of the S matrix are associated with surface waves orbiting around the vortex and supported by a magnetic field discontinuity. Rapid variations of sharp characteristic shapes can be observed on scattering cross sections. They correspond to quasibound states which are Breit-Wigner-type resonances associated with surface waves and which can be considered as quantum analogues of acoustic whispering-gallery modes. Such a resonant magnetic vortex could provide a different kind of artificial atom while the semiclassical approach developed here could be profitably extended in various areas of the physics of vortices

  2. Magnetic Resonance Imaging (MRI) Safety

    ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) Safety What is MRI and how does ... What is MRI and how does it work? Magnetic resonance imaging, or MRI, is a way of obtaining very ...

  3. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... during MRI, but this is rarely a problem. Tooth fillings and braces usually are not affected by ... Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic Resonance Imaging ( ...

  4. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) ... conditions such as: brain tumors stroke infections developmental anomalies hydrocephalus — dilatation of fluid spaces within the brain ( ...

  5. Magnetic resonance of phase transitions

    Owens, Frank J; Farach, Horacio A

    1979-01-01

    Magnetic Resonance of Phase Transitions shows how the effects of phase transitions are manifested in the magnetic resonance data. The book discusses the basic concepts of structural phase and magnetic resonance; various types of magnetic resonances and their underlying principles; and the radiofrequency methods of nuclear magnetic resonance. The text also describes quadrupole methods; the microwave technique of electron spin resonance; and the Mössbauer effect. Phase transitions in various systems such as fluids, liquid crystals, and crystals, including paramagnets and ferroelectrics, are also

  6. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...

  7. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...

  8. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head ... limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is ...

  9. Parallel Magnetic Resonance Imaging

    Uecker, Martin

    2015-01-01

    The main disadvantage of Magnetic Resonance Imaging (MRI) are its long scan times and, in consequence, its sensitivity to motion. Exploiting the complementary information from multiple receive coils, parallel imaging is able to recover images from under-sampled k-space data and to accelerate the measurement. Because parallel magnetic resonance imaging can be used to accelerate basically any imaging sequence it has many important applications. Parallel imaging brought a fundamental shift in image reconstruction: Image reconstruction changed from a simple direct Fourier transform to the solution of an ill-conditioned inverse problem. This work gives an overview of image reconstruction from the perspective of inverse problems. After introducing basic concepts such as regularization, discretization, and iterative reconstruction, advanced topics are discussed including algorithms for auto-calibration, the connection to approximation theory, and the combination with compressed sensing.

  10. Cavity- and waveguide-resonators in electron paramagnetic resonance, nuclear magnetic resonance, and magnetic resonance imaging.

    Webb, Andrew

    2014-11-01

    Cavity resonators are widely used in electron paramagnetic resonance, very high field magnetic resonance microimaging and also in high field human imaging. The basic principles and designs of different forms of cavity resonators including rectangular, cylindrical, re-entrant, cavity magnetrons, toroidal cavities and dielectric resonators are reviewed. Applications in EPR and MRI are summarized, and finally the topic of traveling wave MRI using the magnet bore as a waveguide is discussed. PMID:25456314

  11. Magnetic Resonance Facility (Fact Sheet)

    2012-03-01

    This fact sheet provides information about Magnetic Resonance Facility capabilities and applications at NREL's National Bioenergy Center. Liquid and solid-state analysis capability for a variety of biomass, photovoltaic, and materials characterization applications across NREL. NREL scientists analyze solid and liquid samples on three nuclear magnetic resonance (NMR) spectrometers as well as an electron paramagnetic resonance (EPR) spectrometer.

  12. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... bear denotes child-specific content. Related Articles and Media MR Angiography (MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...

  13. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful magnetic ... that are clearer and more detailed than other imaging methods. This exam does not use ionizing radiation ...

  14. Cranial magnetic resonance imaging

    Cranial Magnetic Resonance Imaging is comprehensive, well structured, and well written. The material is current and well referenced. The illustrations are good and complement the text well. The overall quality of publication is above average. The greatest attribute of the book is its readability. The author demonstrates ample skill in making complex subjects, such as MR physics and imaging of cerebral hemorrhage, easy to understand. The book closes with a detailed atlas on the anatomic appearance of the brain on MR images in the axial, coronal, and sagittal planes

  15. Dental magnetic resonance imaging

    Growing distribution and utilization of digital volume tomography (DVT) extend the spectrum of clinical dental imaging. Additional diagnostic value, however, comes along with an increasing amount of radiation. In contrast, magnetic resonance imaging is a radiation free imaging technique. Furthermore, it offers a high soft tissue contrast. Morphological and numerical dental anomalies, differentiation of periapical lesions and exclusion of complications of dental diseases are field of applications for dental MRI. In addition, detection of caries and periodontal lesions and injury of inferior alveolar nerve are promising application areas in the future.

  16. Magnetic resonance imaging equipments

    Magnetic resonance imaging (MRI) is a new examination technique used in diagnostic medicine. Its use has increased notably during the last few years in Finland, too. The biological effects of electromagnetic fields used in MRI are quite different from the effects of x-rays. This report introduces the physics and the techniques of MRI; the biological effects of magnetic fields and the hazards associated with the use of MRI systems are briefly discussed. The major national and international recommendations are summarized, too. Furthermore, a description is given how safety aspects are considered in Finnish MRI units. Finally, recommendations are given to restrict the exposure caused by MRI and to ensure the safe use of MRI. Diagnostic applications and clinical or economic aspects fall outside the scope of this report. (orig.)

  17. Advances in magnetic resonance 11

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 11, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains three chapters and begins with a discussion of the principles and applications of dynamic nuclear polarization, with emphasis on molecular motions and collisions, intermolecular couplings, and chemical interactions. Subsequent chapters focus on the assessment of a proposed broadband decoupling method and studies of time-domain (or Fourier transform) multiple-quantum nuclear magnetic resonance.

  18. Advances in magnetic resonance 6

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 6 focuses on the theoretical and practical aspects of applying magnetic resonance methods to various problems in physical chemistry, emphasizing the different aspects of the exegesis of these problems. This book discusses the gas phase magnetic resonance of electronically excited molecules; techniques for observing excited electronic states; NMR studies in liquids at high pressure; and effect of pressure on self-diffusion in liquids. The nuclear magnetic resonance investigations of organic free radicals; measurement of proton coupling constants by NMR; an

  19. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... or cause problems during an MRI exam. Nephrogenic systemic fibrosis is currently a recognized, but rare, complication ... Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...

  20. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... the same effect. A very irregular heartbeat may affect the quality of images obtained using techniques that ... Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...

  1. Nuclear magnetic resonance spectroscopy in pancreatic disorders

    Ofer Kaplan

    1997-03-01

    Full Text Available Nuclear magnetic resonance spectroscopy (NMRS is a powerful technique that enables continuous monitoring of biochemical processes in tissues and organs in a non-invasive manner. A model of isolated perfused rat pancreas, suitable for NMRS studies, was developed. Acute pancreatitis was induced by injections of either 0.5 ml 5% sodium taurocholate (TC into the bile duets, or 1.0 ml 10% TC injections into the pancreatic parenchyma. Phosphorous (31P NMRS of experimental pancreatitis were characterized by a transient signal at -0.18±0.04 ppm which was assigned as solubilized lecithin, and can be used as an indicator of the early phases of the discase. Depletion of the high energy phosphorous compounds, phosphocreatine and ATP, were also found during acute pancreatitis, and paralleled the extension of the pathological damage. The role of NMRS in pancreatic cancer diagnosis and its treatment were assessed in three models of pancreatic neoplasms. Perfused MIA PaCa-2 human pancreatic cancer cells, subcutancously implanted pancreatic tumors in hamsters, and pancreatic tumors induced in-situ in rats by direct appiication of the carcinogen 7,12-dimethyl benzanthracene, were studied by phosphorous (31P, sodium (23Na and proton (¹H NMRS. 31P spectra of pancreatic cancer were qualitatively similar to those of intact organs. However, 31P NMRS was found to be useful for monitoring the effects of treatment. Total (infra- and extracellular sodium concentrations, measured in the solid tumors, were similar in both the normal pancreas and the pancreatic tumors (39-40 mmol/g wet weight. Proton spectra of perchloric acid extracts revealed several differences between tumors and control pancreases. The principal findings were elevated levels of the amino acid taurine, from I.17±O.39 mmol/g wet weight in healthy pancreases, to 2.79±0.71 mmol/g wet weight in pancreatic carcinoma in rats, and lactate levels which increased from 0.92±0.2 to 6.19±1.93 mmol/g wet weight

  2. Accurate calculation of (31)P NMR chemical shifts in polyoxometalates.

    Pascual-Borràs, Magda; López, Xavier; Poblet, Josep M

    2015-04-14

    We search for the best density functional theory strategy for the determination of (31)P nuclear magnetic resonance (NMR) chemical shifts, δ((31)P), in polyoxometalates. Among the variables governing the quality of the quantum modelling, we tackle herein the influence of the functional and the basis set. The spin-orbit and solvent effects were routinely included. To do so we analysed the family of structures α-[P2W18-xMxO62](n-) with M = Mo(VI), V(V) or Nb(V); [P2W17O62(M'R)](n-) with M' = Sn(IV), Ge(IV) and Ru(II) and [PW12-xMxO40](n-) with M = Pd(IV), Nb(V) and Ti(IV). The main results suggest that, to date, the best procedure for the accurate calculation of δ((31)P) in polyoxometalates is the combination of TZP/PBE//TZ2P/OPBE (for NMR//optimization step). The hybrid functionals (PBE0, B3LYP) tested herein were applied to the NMR step, besides being more CPU-consuming, do not outperform pure GGA functionals. Although previous studies on (183)W NMR suggested that the use of very large basis sets like QZ4P were needed for geometry optimization, the present results indicate that TZ2P suffices if the functional is optimal. Moreover, scaling corrections were applied to the results providing low mean absolute errors below 1 ppm for δ((31)P), which is a step forward in order to confirm or predict chemical shifts in polyoxometalates. Finally, via a simplified molecular model, we establish how the small variations in δ((31)P) arise from energy changes in the occupied and virtual orbitals of the PO4 group. PMID:25738630

  3. Phosphorus metabolites in the human placenta estimated in vivo by magnetic resonance spectroscopy.

    Weindling, A M; Griffiths, R. D.; Garden, A S; P. A. Martin; Edwards, R H

    1991-01-01

    Normal human placental metabolism has been studied in vivo by image localised 31P magnetic resonance spectroscopy in 13 women with anterior placentas; five, however, were too fat for useful spectral signals to be obtained. Magnetic resonance spectra of good quality which were considered to have arisen from the placenta were obtained from seven women with uncomplicated pregnancies (median gestational age 35 weeks, range 28-39). One other woman had a twin pregnancy in which one fetus had died a...

  4. High-field small animal magnetic resonance oncology studies

    Bokacheva, Louisa; Ackerstaff, Ellen; LeKaye, H. Carl; Zakian, Kristen; Koutcher, Jason A.

    2014-01-01

    This review focuses on the applications of high magnetic field magnetic resonance imaging (MRI) and spectroscopy (MRS) to cancer studies in small animals. High-field MRI can provide information about tumor physiology, the microenvironment, metabolism, vascularity and cellularity. Such studies are invaluable for understanding tumor growth and proliferation, response to treatment and drug development. The MR techniques reviewed here include 1H, 31P, chemical exchange saturation transfer imaging and hyperpolarized 13C MRS as well as diffusion-weighted, blood oxygen level dependent contrast imaging and dynamic contrast-enhanced MRI. These methods have been proven effective in animal studies and are highly relevant to human clinical studies.

  5. Magnetic resonance in neuroborreliosis

    Magnetic resonance (MR) is commonly used in diagnosing infections of the central nervous system. The aim of the study is to evaluate central nervous system changes in neuroborreliosis patients. MR examinations were performed in 44 patients with clinical symptoms, epidemiology and laboratory tests results of neuroborreliosis. Abnormalities were detected in 22 patients. Most of them presented cortico-subcortical atrophy (86%). In 9 cases foci of increased signal in T2-weighted and FLAIR images were observed in white matter. They were single or multiple, located subcorticaly and paraventriculary. In 2 subjects areas of increased signal were found in the brain stem. Central nervous system abnormalities detected with MR are not specific for Lyme disease. They can suggest demyelinating lesions and/or gliosis observed in many nervous system disorders (SM, ADEM, lacunar infarcts). (author)

  6. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a ...

  7. Advances in magnetic resonance 12

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 12, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains six chapters and begins with a discussion of diffusion and self-diffusion measurements by nuclear magnetic resonance. This is followed by separate chapters on spin-lattice relaxation time in hydrogen isotope mixtures; the principles of optical detection of nuclear spin alignment and nuclear quadropole resonance; and the spin-1 behavior, including the relaxation of the quasi-invariants of the motion of a system of pairs of dipolar coupled spin-1/2 nu

  8. Magnetic resonance imaging methodology

    Magnetic resonance (MR) methods are non-invasive techniques to provide detailed, multi-parametric information on human anatomy, function and metabolism. Sensitivity, specificity, spatial and temporal resolution may, however, vary depending on hardware (e.g., field strength, gradient strength and speed) and software (optimised measurement protocols and parameters for the various techniques). Furthermore, multi-modality imaging may enhance specificity to better characterise complex disease patterns. Positron emission tomography (PET) is an interesting, largely complementary modality, which might be combined with MR. Despite obvious advantages, combining these rather different physical methods may also pose challenging problems. At this early stage, it seems that PET quality may be preserved in the magnetic field and, if an adequate detector material is used for the PET, MR sensitivity should not be significantly degraded. Again, this may vary for the different MR techniques, whereby functional and metabolic MR is more susceptible than standard anatomical imaging. Here we provide a short introduction to MR basics and MR techniques, also discussing advantages, artefacts and problems when MR hardware and PET detectors are combined. In addition to references for more detailed descriptions of MR fundamentals and applications, we provide an early outlook on this novel and exciting multi-modality approach to PET/MR. (orig.)

  9. Magnetic Resonance angiography. Pt 1

    The objective of this paper is to describe the basic physical principles important in magnetic resonance angiography (MRA). The data used were obtained from recent articles on MRA and direct experience working with prototype MRA sequence. The information is presented in a manner suitable for those unfamiliar with the principles of MRA and magnetic resonance imaging (MRI). Magnetic resonance angiography is an important method that can be used to obtain angiograms without the injection of intravascular contrast medium. It is already proving to be of clinical use in the assessment of vascular disease. 11 refs., 5 figs

  10. Advances in magnetic resonance 1

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 1, discusses developments in various areas of magnetic resonance. The subject matter ranges from original theoretical contributions through syntheses of points of view toward series of phenomena to critical and painstaking tabulations of experimental data. The book contains six chapters and begins with a discussion of the theory of relaxation processes. This is followed by separate chapters on the development of magnetic resonance techniques for studying rate processes in chemistry and the application of these techniques to various problems; the geometri

  11. Advances in magnetic resonance 9

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 9 describes the magnetic resonance in split constants and dipolar relaxation. This book discusses the temperature-dependent splitting constants in the ESR spectra of organic free radicals; temperature-dependent splittings in ion pairs; and magnetic resonance induced by electrons. The electron impact excitation of atoms and molecules; intramolecular dipolar relaxation in multi-spin systems; and dipolar cross-correlation problem are also elaborated. This text likewise covers the NMR studies of molecules oriented in thermotropic liquid crystals and diffusion

  12. Functional magnetic resonance imaging.

    Buchbinder, Bradley R

    2016-01-01

    Functional magnetic resonance imaging (fMRI) maps the spatiotemporal distribution of neural activity in the brain under varying cognitive conditions. Since its inception in 1991, blood oxygen level-dependent (BOLD) fMRI has rapidly become a vital methodology in basic and applied neuroscience research. In the clinical realm, it has become an established tool for presurgical functional brain mapping. This chapter has three principal aims. First, we review key physiologic, biophysical, and methodologic principles that underlie BOLD fMRI, regardless of its particular area of application. These principles inform a nuanced interpretation of the BOLD fMRI signal, along with its neurophysiologic significance and pitfalls. Second, we illustrate the clinical application of task-based fMRI to presurgical motor, language, and memory mapping in patients with lesions near eloquent brain areas. Integration of BOLD fMRI and diffusion tensor white-matter tractography provides a road map for presurgical planning and intraoperative navigation that helps to maximize the extent of lesion resection while minimizing the risk of postoperative neurologic deficits. Finally, we highlight several basic principles of resting-state fMRI and its emerging translational clinical applications. Resting-state fMRI represents an important paradigm shift, focusing attention on functional connectivity within intrinsic cognitive networks. PMID:27432660

  13. Magnetic resonance energy and topological resonance energy.

    Aihara, Jun-Ichi

    2016-04-28

    Ring-current diamagnetism of a polycyclic π-system is closely associated with thermodynamic stability due to the individual circuits. Magnetic resonance energy (MRE), derived from the ring-current diamagnetic susceptibility, was explored in conjunction with graph-theoretically defined topological resonance energy (TRE). For many aromatic molecules, MRE is highly correlative with TRE with a correlation coefficient of 0.996. For all π-systems studied, MRE has the same sign as TRE. The only trouble with MRE may be that some antiaromatic and non-alternant species exhibit unusually large MRE-to-TRE ratios. This kind of difficulty can in principle be overcome by prior geometry-optimisation or by changing spin multiplicity. Apart from the semi-empirical resonance-theory resonance energy, MRE is considered as the first aromatic stabilisation energy (ASE) defined without referring to any hypothetical polyene reference. PMID:26878709

  14. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - ...

  15. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... Magnetic resonance imaging (MRI) is a noninvasive medical test that physicians use to diagnose and treat medical ... CD. Currently, MRI is the most sensitive imaging test of the head (particularly the brain) in routine ...

  16. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... is not harmful, but it may cause some medical devices to malfunction. Most orthopedic implants pose no ... Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that physicians use to diagnose and treat ...

  17. Magnetic resonance imaging the basics

    Constantinides, Christakis

    2014-01-01

    Magnetic resonance imaging (MRI) is a rapidly developing field in basic applied science and clinical practice. Research efforts in this area have already been recognized with five Nobel prizes awarded to seven Nobel laureates in the past 70 years. Based on courses taught at The Johns Hopkins University, Magnetic Resonance Imaging: The Basics provides a solid introduction to this powerful technology. The book begins with a general description of the phenomenon of magnetic resonance and a brief summary of Fourier transformations in two dimensions. It examines the fundamental principles of physics for nuclear magnetic resonance (NMR) signal formation and image construction and provides a detailed explanation of the mathematical formulation of MRI. Numerous image quantitative indices are discussed, including (among others) signal, noise, signal-to-noise, contrast, and resolution. The second part of the book examines the hardware and electronics of an MRI scanner and the typical measurements and simulations of m...

  18. Advances in magnetic resonance 2

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 2, features a mixture of experimental and theoretical contributions. The book contains four chapters and begins with an ambitious and general treatment of the problem of signal-to-noise ratio in magnetic resonance. This is followed by separate chapters on the interpretation of nuclear relaxation in fluids, with special reference to hydrogen; and various aspects of molecular theory of importance in NMR.

  19. Magnetic Resonance Connectome Automated Pipeline

    Gray, William R.; Bogovic, John A.; Vogelstein, Joshua T; Landman, Bennett A.; Prince, Jerry L.; Vogelstein, R. Jacob

    2011-01-01

    This manuscript presents a novel, tightly integrated pipeline for estimating a connectome, which is a comprehensive description of the neural circuits in the brain. The pipeline utilizes magnetic resonance imaging (MRI) data to produce a high-level estimate of the structural connectivity in the human brain. The Magnetic Resonance Connectome Automated Pipeline (MRCAP) is efficient and its modular construction allows researchers to modify algorithms to meet their specific requirements. The pipe...

  20. Advances in magnetic resonance 4

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 4 deals with the relaxation, irradiation, and other dynamical effects that is specific to systems having resolved structure in their magnetic resonance spectra. This book discusses the anisotropic rotation of molecules in liquids by NMR quadrupolar relaxation; rotational diffusion constants; alternating linewidth effect; and theoretical formulations of the problem. The line shapes in high-resolution NMR; matrix representations of the equations of motion; matrix representations of the equations of motion; and intramolecular hydrogen bonds are also delibera

  1. Nuclear magnetic gamma double resonance

    A number of problems corresponding to different variants of experiments using nuclear magnetic-gamma double resonance (NMGDR) are theoretically investigated. Calculation is carried out and its results are compared to experimental ones concerning NMGDR for tantalum. Time dynamics of the source or scatterer nucleus sublevel populations under double resonance conditions with non-uniform initial population of this nucleus sublevels is studied

  2. Magnetic resonance imaging; Imagerie par resonance magnetique

    Fontanel, F. [Centre Hospitalier, 40 - Mont-de -Marsan (France); Clerc, T. [Centre Hospitalier Universitaire, 76 - Rouen (France); Theolier, S. [Hospice Civils de Lyon, 69 - Lyon (France); Verdenet, J. [Centre Hospitalier Universitaire, 25 - Besancon (France)

    1997-04-01

    The last improvements in nuclear magnetic resonance imaging are detailed here, society by society with an expose of their different devices. In the future the different technological evolutions will be on a faster acquisition, allowing to reduce the examination time, on the development of a more acute cardiac imaging, of a functional neuro-imaging and an interactive imaging for intervention. With the contrast products, staying a longer time in the vascular area, the angiography will find its place. Finally, the studies on magnetic fields should allow to increase the volume to examine. (N.C.).

  3. Magnetic Resonance Imaging of Thoracic Aortic Dissections

    Sax, Steven L.

    1990-01-01

    Magnetic resonance imaging is an excellent noninvasive method for evaluating thoracic aortic dissections. A variety of magnetic resonance scans of aortic dissections are shown, documenting the ability of magnetic resonance to image the true lumen, the false channel, and the intimal septum. Detail is provided on magnetic resonance imaging techniques and findings. (Texas Heart Institute Journal 1990;17:262-70)

  4. Advances in magnetic resonance 5

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 5 deals with the interpretation of ESR spectra and provides descriptions of experimental apparatus. This book discusses the halogen hyperfine interactions; organic radicals in single crystals; pulsed-Fourier-transform nuclear magnetic resonance spectrometer; and inhomogenizer and decoupler. The spectrometers for multiple-pulse NMR; weak collision theory of relaxation in the rotating frame; and spin Hamiltonian for the electron spin resonance of irradiated organic single crystals are also deliberated. This text likewise covers the NMR in helium three and m

  5. 2006 Rose Site 31P

    US Fish and Wildlife Service, Department of the Interior — Underwater Site 31P was established off Rose Atoll, American Samoa by Dr. James Maragos, U.S. Fish & Wildlife Service, on August 22, 1999. The site was...

  6. 2012 Rose Site 31P

    US Fish and Wildlife Service, Department of the Interior — Underwater Site 31P was established off Rose Atoll, American Samoa by Dr. James Maragos, U.S. Fish & Wildlife Service, on August 22, 1999. The site was...

  7. 2004 Rose Site 31P

    US Fish and Wildlife Service, Department of the Interior — Underwater Site 31P was established off Rose Atoll, American Samoa by Dr. James Maragos, U.S. Fish & Wildlife Service, on August 22, 1999. The site was...

  8. 2005 Rose Site 31P

    US Fish and Wildlife Service, Department of the Interior — Underwater Site 31P was established off Rose Atoll, American Samoa by Dr. James Maragos, U.S. Fish (5) = between meters 4 and 5). Quantitative analysis of the...

  9. 1999 Rose Site 31P

    US Fish and Wildlife Service, Department of the Interior — Underwater Site 31P was established off Rose Atoll, American Samoa by Dr. James Maragos, U.S. Fish & Wildlife Service, on August 22, 1999. The site was...

  10. 31P-MRS of skeletal muscle is not a sensitive diagnostic test for mitochondrial myopathy

    Jeppesen, Tina Dysgaard; Quistorff, Bjørn; Wibrand, Flemming;

    2007-01-01

    Clinical phenotypes of persons with mitochondrial DNA (mtDNA) mutations vary considerably. Therefore, diagnosing mitochondrial myopathy (MM) patients can be challenging and warrants diagnostic guidelines. (31)phosphorous magnetic resonance spectroscopy ((31)P-MRS) have been included as a minor...... investigated for the following: 1) (31)P-MRS of lower arm and leg muscles before and after exercise, 2) resting and peak-exercise induced increases of plasma lactate, 3) muscle morphology and -mitochondrial enzyme activity, 4) maximal oxygen uptake (VO(2max)), 5) venous oxygen desaturation during handgrip...... impaired citrate synthase-corrected complex I activity. Resting PCr/P(i) ratio and leg P(i) recovery were lower in MM patients vs. healthy subjects. PCr and ATP production after exercise were similar in patients and healthy subjects. Although the specificity for MM of some (31)P-MRS variables was as high...

  11. A comparison of MR elastography and 31P MR spectroscopy with histological staging of liver fibrosis

    Conventional imaging techniques are insensitive to liver fibrosis. This study assesses the diagnostic accuracy of MR elastography (MRE) stiffness values and the ratio of phosphomonoesters (PME)/phosphodiesters (PDE) measured using 31P spectroscopy against histological fibrosis staging. The local research ethics committee approved this prospective, blinded study. A total of 77 consecutive patients (55 male, aged 49 ± 11.5 years) with a clinical suspicion of liver fibrosis underwent an MR examination with a liver biopsy later the same day. Patients underwent MRE and 31P spectroscopy on a 1.5 T whole body system. The liver biopsies were staged using an Ishak score for chronic hepatitis or a modified NAS fibrosis score for fatty liver disease. MRE increased with and was positively associated with fibrosis stage (Spearman's rank = 0.622, P 31P MR spectroscopy and fibrosis stage. circle Magnetic resonance elastography (MRE) and MR spectroscopy can both assess the liver. (orig.)

  12. Magnetic resonance and porous materials

    Mention the words magnetic resonance to your medical advisor and he or she will immediately think of a multi-million pound scanner that peers deep into the brain. A chemist, on the other hand, will imagine a machine that costs several hundred thousand pounds and produces high-resolution spectra for chemical analysis. Food technologists will probably think of a bench-top instrument for determining moisture content, while an oil prospector will envisage a device that can be operated several kilometres down an oil well. To a physicist the term is more likely to conjure up a mental picture of nuclear spins precessing in a magnetic field. These examples illustrate the diverse aspects of a phenomenon discovered by physicists over 50 years ago. Electron spin resonance was first discovered by Russian scientists, and nuclear magnetic resonance was discovered in the US shortly afterwards by Ed Purcell at Harvard University and Felix Bloch at Stanford University. Today, nuclear magnetic resonance (NMR) is the most widely used technique. Modern NMR machines are making it possible to probe microstructure and molecular movement in materials as diverse as polymers, cements, rocks, soil and foods. NMR allows the distribution of different components in a material to be determined with a resolution approaching 1μm, although the signal can be sensitive to even smaller lengthscales. In this article the authors describe how physicists are still developing magnetic resonance to exploit a range of new applications. (UK)

  13. GHz nuclear magnetic resonance

    Cross, T.A.; Drobny, G.; Trewhella, J.

    1994-12-01

    For the past dozen years, 500- and 600-MHz spectrometers have become available in many laboratories. The first 600-MHz NMR spectrometer (at Carnegie Mellon University) was commissioned more than 15 years ago and, until 1994, represented the highest field available for high-resolution NMR. This year, we have witnessed unprecedented progress in the development of very high field magnets for NMR spectroscopy, including the delivery of the first commercial 750-MHz NMR spectrometers. In addition, NMR signals have been obtained from 20-Tesla magnets (850 MHz for {sup 1}H`s) at both Los Alamos National Laboratory and Florida State University in the NHMFL (National High Magnetic Field Laboratory). These preliminary experiments have been performed in magnets with 100-ppm homogeneity, but a 20-Tesla magnet developed for the NHMFL will be brought to field this year with a projected homogeneity of 0.1 ppm over a 1-cm-diam spherical volume.

  14. Magnetic resonance spectroscopy in schizophrenia. Possibilities and limitations

    Magnetic resonance spectroscopy is a noninvasive investigative technique for in vivo detection of biochemical changes in neuropsychiatric disorders for which especially proton (1H-MRS) and phosphorus (31P-MRS) magnetic resonance spectroscopy have been used. In this review we explain the principles of MRS and summarize the studies in schizophrenia. A systematic literature review was carried out for 1H-MRS studies investigating schizophrenic patients compared to controls. The inconsistent results in the cited studies may be due to different study population, specific neuroimaging technique, and selected brain regions. Frequent findings are decreased PME and increased PDE concentrations (31P-MRS) linked to altered metabolism of membrane phospholipids and decreased N-acetylaspartate (NAA) or NAA/choline ratio (1H-MRS) linked to neuronal damage in frontal (DLPFC) or temporal regions in patients with schizophrenia. These results contribute to the disturbed frontotemporal-thalamic network assumed in schizophrenia and are supported by additional functional neuroimaging, MRI morphometry, and neuropsychological evaluation. The combination of the described investigative techniques with MRS in follow-up studies may provide more specific clues for understanding the pathogenesis and disease course in schizophrenia. (orig.)

  15. magnetic resonance imaging,etc.

    张福基

    1998-01-01

    magnetic resonance imaging n.[1984] a noninvasive diagnostic technique that produces computerized images of internal body tissues and is based on nuclear magnetic resonance of atoms within he body induced by the application of radio waves磁共振成像(指一种非侵害 性诊断技术,能生成内部身体组织的计算机化影像,其依据是应用无线电波 感生体内原子并使之产磁共振)

  16. Molecular neurodevelopment: An in vivo31P-1H MRSI study

    Goldstein, Gerald; Panchalingam, Kanagasabai; McClure, Richard J.; Stanley, Jeffrey A.; Calhoun, Vince D.; Pearlson, Godfrey D.; Pettegrew, Jay W.

    2009-01-01

    Synaptic development and elimination are normal neurodevelopmental processes which if altered could contribute to various neuropsychiatric disorders. 31P-1H magnetic resonance spectroscopic imaging and structural MRI exams were conducted on 106 healthy children ages 6–18 years in order to identify neuromolecular indices of synaptic development and elimination. Over the age range studied, age-related changes in high-energy phosphate (phosphocreatine), membrane phospholipid metabolism (precurso...

  17. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... structures of the brain and can also provide functional information (fMRI) in selected cases. MR images of ... Articles and Media MR Angiography (MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain ...

  18. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Magnetic Resonance ... allergic reaction than iodinated contrast material. Tell your doctor about any health problems, recent surgeries or allergies ...

  19. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - ... into the bloodstream. The radiologist , technologist or a nurse may ask if you have allergies of any ...

  20. Magnetometer of nuclear magnetic resonance

    We present a nuclear magnetic resonance magnetometer that measures magnetic fields, between 2,500 gauss and 5,000 gauss, with an accuracy of a few parts per million. The circuit of the magnetometer, based on a marginal oscillator, permits a continuous tunning in the frequency range comprised between 10.0 MHz, with a signal to noise ratio of about 20. The radiofrequency amplifier is of the cascode type in integrated circuit and it operates with two 9V batteries. The modulation is at 35 Hz and it is provided by an external oscillator. The instrument is compact, inexpensive and easy to operate; it can also be used for didactic purposes to show the phenomenon of magnetic nuclear resonance and its main characteristics. (author)

  1. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    ... produced by: Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot ... I’d like to talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. MRA ...

  2. Advances in magnetic and optical resonance

    Warren, Warren S

    1997-01-01

    Since 1965, Advances in Magnetic and Optical Resonance has provided researchers with timely expositions of fundamental new developments in the theory of, experimentation with, and application of magnetic and optical resonance.

  3. Optically detected magnetic resonance imaging

    Optically detected magnetic resonance provides ultrasensitive means to detect and image a small number of electron and nuclear spins, down to the single spin level with nanoscale resolution. Despite the significant recent progress in this field, it has never been combined with the power of pulsed magnetic resonance imaging techniques. Here, we demonstrate how these two methodologies can be integrated using short pulsed magnetic field gradients to spatially encode the sample. This result in what we denote as an 'optically detected magnetic resonance imaging' technique. It offers the advantage that the image is acquired in parallel from all parts of the sample, with well-defined three-dimensional point-spread function, and without any loss of spectroscopic information. In addition, this approach may be used in the future for parallel but yet spatially selective efficient addressing and manipulation of the spins in the sample. Such capabilities are of fundamental importance in the field of quantum spin-based devices and sensors

  4. Resonant magnetic fields from inflation

    We propose a novel scenario to generate primordial magnetic fields during inflation induced by an oscillating coupling of the electromagnetic field to the inflaton. This resonant mechanism has two key advantages over previous proposals. First of all, it generates a narrow band of magnetic fields at any required wavelength, thereby allaying the usual problem of a strongly blue spectrum and its associated backreaction. Secondly, it avoids the need for a strong coupling as the coupling is oscillating rather than growing or decaying exponentially. Despite these major advantages, we find that the backreaction is still far too large during inflation if the generated magnetic fields are required to have a strength of O(10−15 Gauss) today on observationally interesting scales. We provide a more general no-go argument, proving that this problem will apply to any model in which the magnetic fields are generated on subhorizon scales and freeze after horizon crossing

  5. Pediatric Body Magnetic Resonance Imaging.

    Kandasamy, Devasenathipathy; Goyal, Ankur; Sharma, Raju; Gupta, Arun Kumar

    2016-09-01

    Magnetic resonance imaging (MRI) is a radiation-free imaging modality with excellent contrast resolution and multiplanar capabilities. Since ionizing radiation is an important concern in the pediatric population, MRI serves as a useful alternative to computed tomography (CT) and also provides additional clues to diagnosis, not discernible on other investigations. Magnetic resonance cholangiopancreatography (MRCP), urography, angiography, enterography, dynamic multiphasic imaging and diffusion-weighted imaging provide wealth of information. The main limitations include, long scan time, need for sedation/anesthesia, cost and lack of widespread availability. With the emergence of newer sequences and variety of contrast agents, MRI has become a robust modality and may serve as a one-stop shop for both anatomical and functional information. PMID:26916887

  6. Characterization of phosphorus forms in lake macrophytes and algae by solution 31P nuclear magnetic resonance spectroscopy

    Aquatic macrophytes and algae are important sources of phosphorus (P) in the lake environment that cause blooms of algae under certain biogeochemical conditions. However, the knowledge of forms of P in these plants and algae and their contribution to internal loads of lake P is very limited. Witho...

  7. Evanescent Waves Nuclear Magnetic Resonance

    Halidi, El Mohamed; Nativel, Eric; Akel, Mohamad;

    2016-01-01

    Nuclear Magnetic Resonance spectroscopy and imaging can be classified as inductive techniques working in the near- to far-field regimes. We investigate an alternative capacitive detection with the use of micrometer sized probes positioned at sub wavelength distances of the sample in order to char...... a new road to a better understanding of the evanescent waves component in NMR with the opportunity to perform localized spectroscopy and imaging....

  8. Tomography by nuclear magnetic resonance

    Imaging methods based on nuclear magnetic resonance allow the production of sectional images of the human body without ionizing radiation. It is possible to measure the density and relaxation times of the water protons in body fluids or tissue. This allows not only to obtain morphological information but also to get some insight into the spatial distribution of physiological data. Starting with a review of the principles of nuclear magnetic resonance it is explained how the measured signal can be associated with an image point; it is also explained what type of apparatus is necessary and what the physical limitations are. Possible risks the patient may be exposed to in an examination using nuclear magnetic resonance are discussed. The present state of the technical development enables the production of whole-body sectional images of a living person within about one minute. By means of some typical examples the nature and properties of these images are explained. Although extensive clinical studies will be necessary before a more general assessment can be made of this method, an outlook is provided on expected further developments and possible future fields of application. (orig.)

  9. Magnetic Resonance Force Detection using a Membrane Resonator

    Scozzaro, Nicolas; Ruchotzke, Will; Belding, Amanda; Cardellino, Jeremy D.; Blomberg, Erick C.; McCullian, Brendan A.; Bhallamudi, Vidya P.; Pelekhov, Denis V.; Hammel, P. Chris

    2016-01-01

    The availability of compact, low-cost magnetic resonance imaging instruments would further broaden the substantial impact of this technology. We report highly sensitive detection of magnetic resonance using low-stress silicon nitride (SiN$_x$) membranes. We use these membranes as low-loss, high-frequency mechanical oscillators and find they are able to mechanically detect spin-dependent forces with high sensitivity enabling ultrasensitive magnetic resonance detection. The high force detection...

  10. Ultra-high frequency magnetic resonance imaging

    Magill, Arthur W.

    2007-01-01

    This thesis addresses the problem of radiofrequency probe design for Ultra High Frequency Magnetic Resonance Imaging (7T). The signal-to-noise ratio available in Magnetic Resonance Imaging (MRI) is determined by the static magnetic field strength, causing a continued drive toward higher fields to enable faster image acquisition at finer spatial resolution. The resonant frequency increases linearly with static field strength. At 7T the proton resonant frequency is 300MHz, with a wavelength...

  11. Phosphatidylcholine contributes to in vivo 31P MRS signal from the human liver

    To demonstrate the overlap of the hepatic and bile phosphorus (31P) magnetic resonance (MR) spectra and provide evidence of phosphatidylcholine (PtdC) contribution to the in vivo hepatic 31P MRS phosphodiester (PDE) signal, suggested in previous reports to be phosphoenolpyruvate (PEP). Phantom measurements to assess the chemical shifts of PEP and PtdC signals were performed at 7 T. A retrospective analysis of hepatic 3D 31P MR spectroscopic imaging (MRSI) data from 18 and five volunteers at 3 T and 7 T, respectively, was performed. Axial images were inspected for the presence of gallbladder, and PDE signals in representative spectra were quantified. Phantom experiments demonstrated the strong pH-dependence of the PEP chemical shift and proved the overlap of PtdC and PEP (∝2 ppm relative to phosphocreatine) at hepatic pH. Gallbladder was covered in seven of 23 in vivo 3D-MRSI datasets. The PDEgall/γ-ATPliver ratio was 4.8-fold higher (p = 0.001) in the gallbladder (PDEgall/γ-ATPliver = 3.61 ± 0.79) than in the liver (PDEliver/γ-ATPliver = 0.75 ± 0.15). In vivo 7 T 31P MRSI allowed good separation of PDE components. The gallbladder is a strong source of contamination in adjacent 31P MR hepatic spectra due to biliary phosphatidylcholine. In vivo 31P MR hepatic signal at 2.06 ppm may represent both phosphatidylcholine and phosphoenolpyruvate, with a higher phosphatidylcholine contribution due to its higher concentration. (orig.)

  12. Phosphatidylcholine contributes to in vivo {sup 31}P MRS signal from the human liver

    Chmelik, Marek; Bogner, Wolfgang; Gajdosik, Martin; Gruber, Stephan; Trattnig, Siegfried [Medical University of Vienna, MR Centre of Excellence, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Valkovic, Ladislav [Medical University of Vienna, MR Centre of Excellence, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Institute of Measurement Science, Slovak Academy of Sciences, Department of Imaging Methods, Bratislava (Slovakia); Wolf, Peter; Krebs, Michael [Medical University of Vienna, Division of Endocrinology and Metabolism, Department of Internal Medicine III, Vienna (Austria); Halilbasic, Emina; Trauner, Michael [Medical University of Vienna, Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Vienna (Austria); Krssak, Martin [Medical University of Vienna, MR Centre of Excellence, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Medical University of Vienna, Division of Endocrinology and Metabolism, Department of Internal Medicine III, Vienna (Austria)

    2015-07-15

    To demonstrate the overlap of the hepatic and bile phosphorus ({sup 31}P) magnetic resonance (MR) spectra and provide evidence of phosphatidylcholine (PtdC) contribution to the in vivo hepatic {sup 31}P MRS phosphodiester (PDE) signal, suggested in previous reports to be phosphoenolpyruvate (PEP). Phantom measurements to assess the chemical shifts of PEP and PtdC signals were performed at 7 T. A retrospective analysis of hepatic 3D {sup 31}P MR spectroscopic imaging (MRSI) data from 18 and five volunteers at 3 T and 7 T, respectively, was performed. Axial images were inspected for the presence of gallbladder, and PDE signals in representative spectra were quantified. Phantom experiments demonstrated the strong pH-dependence of the PEP chemical shift and proved the overlap of PtdC and PEP (∝2 ppm relative to phosphocreatine) at hepatic pH. Gallbladder was covered in seven of 23 in vivo 3D-MRSI datasets. The PDE{sub gall}/γ-ATP{sub liver} ratio was 4.8-fold higher (p = 0.001) in the gallbladder (PDE{sub gall}/γ-ATP{sub liver} = 3.61 ± 0.79) than in the liver (PDE{sub liver}/γ-ATP{sub liver} = 0.75 ± 0.15). In vivo 7 T {sup 31}P MRSI allowed good separation of PDE components. The gallbladder is a strong source of contamination in adjacent {sup 31}P MR hepatic spectra due to biliary phosphatidylcholine. In vivo {sup 31}P MR hepatic signal at 2.06 ppm may represent both phosphatidylcholine and phosphoenolpyruvate, with a higher phosphatidylcholine contribution due to its higher concentration. (orig.)

  13. Magnetic resonance imaging in oncology

    Nuclear magnetic resonance (NMR) employs radio-frequency radiation in the presence of a static magnetic field to produce signals from naturally occurring nuclei in biological tissue. The information in magnetic resonance imaging (MRI) can be derived from these signals in any orthogonal plane. Hydrogen is the most abundant of such nuclei, occurring naturally in water and lipid, and can be detected at relatively low magnetic field strength (0.04 tesla (T) upwards). The MR signal from hydrogen depends not only on the proton density and the T1 and T2 relaxation times of those protons following radio-frequency pulse disturbances, but also on the timing parameters of the radio-frequency pulse sequences employed. Image contrast depends on the interaction between all these factors; not simply as in X-ray computed tomography (CT) on the properties of the tissue itself. Therefore an understanding of both the imaging process and the pathology under investigation is essential in the proper use of MRI

  14. Clinical protocols for 31P MRS of the brain and their use in evaluating optic pathway gliomas in children

    Introduction: In vivo 31P Magnetic Resonance Spectroscopy (MRS) measures phosphorus-containing metabolites that play an essential role in many disease processes. An advantage over 1H MRS is that total choline can be separated into phosphocholine and glycerophosphocholine which have opposite associations with tumour grade. We demonstrate 31P MRS can provide robust metabolic information on an acceptable timescale to yield information of clinical importance. Methods: All MRI examinations were carried out on a 3T whole body scanner with all 31P MRS scans conducted using a dual-tuned 1H/31P head coil. Once optimised on phantoms, the protocol was tested in six healthy volunteers (four male and two female, mean age: 25 ± 2.7). 31P MRS was then implemented on three children with optic pathway gliomas. Results: 31P MRS on volunteers showed that a number of metabolite ratios varied significantly (p < 0.05 ANOVA) across different structures of the brain, whereas PC/GPC did not. Standard imaging showed the optic pathway gliomas were enhancing on T1-weighted imaging after contrast injection and have high tCho on 1H MRS, both of which are associated with high grade lesions. 31P MRS showed the phosphocholine/glycerophosphocholine ratio to be low (<0.6) which suggests low grade tumours in keeping with their clinical behaviour and the histology of most biopsied optic pathway gliomas. Conclusion: 31P MRS can be implemented in the brain as part of a clinical protocol to provide robust measurement of important metabolites, in particular providing a greater understanding of cases where tCho is raised on 1H MRS

  15. Organic matter and pH affect the analysis efficiency of (31)P-NMR.

    Zhang, Wenqiang; Jin, Xin; Rong, Nan; Li, Jie; Shan, Baoqing

    2016-05-01

    Solution (31)P nuclear magnetic resonance spectroscopy ((31)P-NMR) is a useful method to analyze organic phosphorus (Po), but a general procedure for the analysis method is lacking. The authors used solution (31)P-NMR, which was found to be an effective method for analysis of Po in Haihe River sediment, to analyze the Po in the surface sediment in Eastern China at the regional scale, and found that the NaOH-ethylenediaminetetraacetic acid (EDTA) extraction rate was affected by environmental factors. At the regional scale, the extraction rate showed a positive relationship with loss on ignition, when the extraction rate was lower than 60%. The extraction rate had no relationship with the loss on ignition when the extraction rate was higher than 60%. The extraction rate showed a negative relationship with pH, which means that the extraction rate was higher in acidic sediment and lower in alkaline sediment. The ratio of TC/TN (the ratio of total carbon to total nitrogen) was considered to represent the origin of organic matter in the sediment. The extraction rate was high when the TC/TN ratio was lower than 20, meanwhile the extraction rate decreased as the TC/TN ratio increased. The results show that the origin of organic matter in sediment significantly affects the NaOH-EDTA extraction rate. This study will give theoretical support for building an effective and general solution (31)P-NMR analysis method. PMID:27155430

  16. Synthesis and physical studies of thiophospholipids using nuclear magnetic resonance

    1,2-Dipalmitoyl-sn-glycero-3-thiophosphocholine, DPPsC, and 1,2-dipalmitoyl-sn-glycero-3-thiophospho-L-serine, DPPsS, were synthesized and used to probe bilayer structural properties and enzymatic stereoselectivity. Using resolved diastereomers of DPPsC, the effect of a chiral phosphorus center on the thermotropic properties of lipid dispersions was probed. 31P and 2H nuclear magnetic resonance, NMR, were utilized to confirm the thermotropic phase assignments for DPPsC diastereomers observed by differential scanning calorimetry. 31P NMR of the thiophosphate analogs revealed a more rigid subgel and Lβ' gel phase than DPPC, in regard to the phosphate rotational motion. In the Pβ' gel phase, the degree of motion of Sp and (Rp+Sp) was similar to DPPC. The tiophosphate analogs in the liquid crystalline phase experienced a freer rotational environment compared to DPPC. 2H NMR was performed on DPPsC diastereomers deuterated at the three choline carbons, α, β, γ. The liquid crystalline phase was used to detect differences between the diastereomers along the choline moiety. The diastereomeric mixture of DPPsS was used as a substrate for two stereoselective enzymes, phospholipases A2 and C. Phospholipase A2 hydrolyzed (Rp)-DPPsS, while no apparent reaction was detected for the hydrolysis of (Sp)-DPPsS with phospholipase C

  17. Fast magnetization reversal of nanoclusters in resonator

    Yukalov, V. I.; Yukalova, E. P.

    2012-01-01

    An effective method for ultrafast magnetization reversal of nanoclusters is suggested. The method is based on coupling a nanocluster to a resonant electric circuit. This coupling causes the appearance of a magnetic feedback field acting on the cluster, which drastically shortens the magnetization reversal time. The influence of the resonator properties, nanocluster parameters, and external fields on the magnetization dynamics and reversal time is analyzed. The magnetization reversal time can ...

  18. Wide-range nuclear magnetic resonance detector

    Sturman, J. C.; Jirberg, R. J.

    1972-01-01

    Compact and easy to use solid state nuclear magnetic resonance detector is designed for measuring field strength to 20 teslas in cryogenically cooled magnets. Extremely low noise and high sensitivity make detector applicable to nearly all types of analytical nuclear magnetic resonance measurements and can be used in high temperature and radiation environments.

  19. Hyperpolarized Renal Magnetic Resonance Imaging

    Laustsen, Christoffer

    2016-01-01

    The introduction of dissolution dynamic nuclear polarization (d-DNP) technology has enabled a new paradigm for renal imaging investigations. It allows standard magnetic resonance imaging complementary renal metabolic and functional fingerprints within seconds without the use of ionizing radiation....... Increasing evidence supports its utility in preclinical research in which the real-time interrogation of metabolic turnover can aid the physiological and pathophysiological metabolic and functional effects in ex vivo and in vivo models. The method has already been translated to humans, although the clinical...

  20. Advances in magnetic resonance 3

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 3, describes a number of important developments which are finding increasing application by chemists. The book contains five chapters and begins with a discussion of how the properties of random molecular rotations reflect themselves in NMR and how they show up, often differently, in other kinds of experiments. This is followed by separate chapters on the Kubo method, showing its equivalence to the Redfield approach in the cases of most general interest; the current state of dynamic nuclear polarization measurements in solutions and what they tell us abou

  1. Evanescent Waves Nuclear Magnetic Resonance.

    Halidi, El Mohamed; Nativel, Eric; Akel, Mohamad; Kenouche, Samir; Coillot, Christophe; Alibert, Eric; Jabakhanji, Bilal; Schimpf, Remy; Zanca, Michel; Stein, Paul; Goze-Bac, Christophe

    2016-01-01

    Nuclear Magnetic Resonance spectroscopy and imaging can be classified as inductive techniques working in the near- to far-field regimes. We investigate an alternative capacitive detection with the use of micrometer sized probes positioned at sub wavelength distances of the sample in order to characterize and model evanescent electromagnetic fields originating from NMR phenomenon. We report that in this experimental configuration the available NMR signal is one order of magnitude larger and follows an exponential decay inversely proportional to the size of the emitters. Those investigations open a new road to a better understanding of the evanescent waves component in NMR with the opportunity to perform localized spectroscopy and imaging. PMID:26751800

  2. Tunable Magnetic Resonance in Microwave Spintronics Devices

    Chen, Yunpeng; Fan, Xin; Xie, Yunsong; Zhou, Yang; Wang, Tao; Wilson, Jeffrey D.; Simons, Rainee N.; Chui, Sui-Tat; Xiao, John Q.

    2015-01-01

    Magnetic resonance is one of the key properties of magnetic materials for the application of microwave spintronics devices. The conventional method for tuning magnetic resonance is to use an electromagnet, which provides very limited tuning range. Hence, the quest for enhancing the magnetic resonance tuning range without using an electromagnet has attracted tremendous attention. In this paper, we exploit the huge exchange coupling field between magnetic interlayers, which is on the order of 4000 Oe and also the high frequency modes of coupled oscillators to enhance the tuning range. Furthermore, we demonstrate a new scheme to control the magnetic resonance frequency. Moreover, we report a shift in the magnetic resonance frequency as high as 20 GHz in CoFe based tunable microwave spintronics devices, which is 10X higher than conventional methods.

  3. Cerebellar hemangioblastoma: magnetic resonance findings

    To characterize the results of magnetic resonance imaging in cerebellar hemangioblastoma. This retrospective study deals with seven cases of histologically-confirmed cerebellar hemangioblastoma after surgery. Another patient, diagnosed as having Von Hippel-Lindau disease, also developed this lesions, but the finding was not histologically confirmed. In all, there were 2 women and 6 men. Three of these patients presented Von Hippel-Lindaus disease. All were studied on a 0.5 T imager with T1, T2 and PD-weighted spin-echo axial planes; T1-weighted sequences were repeated after intravenous gadolinium administration. According to their aspects, the lesions were divided into three groups as follows: cyst containing a mural nodule (n=3)solid tumor (n=3) and cavitated tumor (n=1). In one patient, the lesion was initially solid and was found to present cavitation two years later. Abnormal vascularization was observed in all the tumors except for two small solid tumors, and the findings were not clear in one of the cysts containing a mural nodule. In the differential diagnosis it may be difficult to rule out other tumors, such as cystic astrocytoma. However, magnetic resonance imaging, together with the clinical data, is of diagnostic value in the three morphological types of cerebellar hemangioblastoma. (Author) 15 refs

  4. Magnetic resonance imaging of hemochromatosis arthropathy

    This study was undertaken to compare plain film radiography and magnetic resonance imaging in the assessment of hemochromatosis arthropathy of the knees of ten patients with a biopsy-proven diagnosis. Both modalities enabled visualisation of bony degenerative changes; magnetic resonance imaging enabled additional visualization of deformity of both cartilage and menisci. Magnetic resonance imaging failed reliably to confirm the presence of intra-articular iron in the patients studied. No correlation was observed between synovial fluid magnetic resonance signal values, corresponding serum ferritin levels, or the severity of the observed degenerative changes. (orig.)

  5. Society for Cardiovascular Magnetic Resonance guidelines for reporting cardiovascular magnetic resonance examinations

    van Rossum Albert C; Raman Subha V; McConnell Michael V; Lawson Mark A; Higgins Charles B; Friedrich Matthias G; Bogaert Jan G; Bluemke David; Hundley W Gregory; Flamm Scott; Kramer Christopher M; Nagel Eike; Neubauer Stefan

    2009-01-01

    Abstract These reporting guidelines are recommended by the Society for Cardiovascular Magnetic Resonance (SCMR) to provide a framework for healthcare delivery systems to disseminate cardiac and vascular imaging findings related to the performance of cardiovascular magnetic resonance (CMR) examinations.

  6. In vivo measurement of intracellular pH in human brain during different tensions of carbon dioxide in arterial blood. A 31P-NMR study

    Jensen, K E; Thomsen, C; Henriksen, O

    1988-01-01

    The effect of changes in carbon dioxide tension in arterial blood upon intracellular pH in brain tissue was studied in seven healthy volunteers, aged 22-45 years. The pH changes were monitored by use of 31P nuclear magnetic resonance spectroscopy, performed on a whole-body 1.5 Tesla Siemens imaging...

  7. Brief Report: Approaches to [Superscript 31]P-MRS in Awake, Non-Sedated Children with and without Autism Spectrum Disorder

    Erickson, Laura C.; Scott-Van Zeeland, Ashley A.; Hamilton, Gavin; Lincoln, Alan; Golomb, Beatrice A.

    2012-01-01

    We piloted a suite of approaches aimed to facilitate a successful series of up to four brain and muscle [superscript 31]Phosphorus-Magnetic Resonance Spectroscopy ([superscript 31]P-MRS) scans performed in one session in 12 "awake", non-sedated subjects (ages 6-18), 6 with autism spectrum disorders (ASD) and 6 controls. We targeted advanced…

  8. {sup 31}P-MR spectroscopy in children and adolescents with a familial risk of schizophrenia

    Rzanny, R.; Reichenbach, J.R.; Pfleiderer, S.O.R.; Kaiser, W.A. [Institut fuer Diagnostische und Interventionelle Radiologie, Abteilung MT, Klinikum der Friedrich-Schiller-Universitaet Jena, Philosophenweg 3, 07741 Jena (Germany); Klemm, S.; Blanz, B. [Klinik fuer Kinder- und Jugendpsychiatrie, Klinikum der Friedrich-Schiller-Universitaet Jena, Bachstrasse 18, 07741 Jena (Germany); Schmidt, B.; Volz, H.-P. [Klinik fuer Psychiatrie, Klinikum der Friedrich-Schiller-Universitaet Jena, Bachstrasse 18, 07741 Jena (Germany)

    2003-04-01

    Based on a previous report [9] on alterations of membrane phosphorus metabolism in asymptomatic family members of schizophrenic patients, the aim of the present study was to extend and improve the evaluation and data processing of {sup 31}P spectroscopic data obtained from a larger study population by including an analysis of the broad spectral component (BC) of membrane phospholipids (PL). Eighteen children and siblings of patients with schizophrenia and a gender- and age-matched control group of 18 healthy subjects without familial schizophrenia were investigated with phosphorus magnetic resonance spectroscopy ({sup 31}P-MRS) by using image selected in vivo spectroscopy (ISIS) in the dorsolateral prefrontal regions (DLPFR) of the brain. Spectral analysis was performed by using both the full and truncated FID to estimate metabolic peak ratios of different {sup 31}P metabolites and the intensity and linewidth of the broad component. A significantly higher PDE level (p<0.01) and increased linewidth of the PDE components were observed for the high-risk group compared with the control group (p=0.02). No significant differences were observed for PME as well as for other {sup 31}P-metabolites. No differences were observed between the left and right hemispheres for different normalised {sup 31}P-metabolic levels. Decreased intensities (p=0.03) and smaller linewidths (p=0.01) were obtained for the broad component in the high-risk group. Impairments of membrane metabolism that are typical for schizophrenic patients are partially observed in adolescent asymptomatic family members of schizophrenics, including increased levels of low molecular PDE compounds indicating increased membrane degradation processes, no changes for PME, and decreased intensities and linewidths of the BC indicating changes in the composition and fluidity of membrane phospholipids. Despite limitations to completely suppress fast-relaxing components by dismissing initial FID data points, the

  9. 31P-MR spectroscopy in children and adolescents with a familial risk of schizophrenia

    Based on a previous report [9] on alterations of membrane phosphorus metabolism in asymptomatic family members of schizophrenic patients, the aim of the present study was to extend and improve the evaluation and data processing of 31P spectroscopic data obtained from a larger study population by including an analysis of the broad spectral component (BC) of membrane phospholipids (PL). Eighteen children and siblings of patients with schizophrenia and a gender- and age-matched control group of 18 healthy subjects without familial schizophrenia were investigated with phosphorus magnetic resonance spectroscopy (31P-MRS) by using image selected in vivo spectroscopy (ISIS) in the dorsolateral prefrontal regions (DLPFR) of the brain. Spectral analysis was performed by using both the full and truncated FID to estimate metabolic peak ratios of different 31P metabolites and the intensity and linewidth of the broad component. A significantly higher PDE level (p31P-metabolites. No differences were observed between the left and right hemispheres for different normalised 31P-metabolic levels. Decreased intensities (p=0.03) and smaller linewidths (p=0.01) were obtained for the broad component in the high-risk group. Impairments of membrane metabolism that are typical for schizophrenic patients are partially observed in adolescent asymptomatic family members of schizophrenics, including increased levels of low molecular PDE compounds indicating increased membrane degradation processes, no changes for PME, and decreased intensities and linewidths of the BC indicating changes in the composition and fluidity of membrane phospholipids. Despite limitations to completely suppress fast-relaxing components by dismissing initial FID data points, the spectroscopic results indicate additional changes in the membrane metabolism of high-risk subjects beyond changes of synthesis and degradation. (orig.)

  10. Magnetic Resonance Imaging of Electrolysis.

    Meir, Arie; Hjouj, Mohammad; Rubinsky, Liel; Rubinsky, Boris

    2015-02-01

    This study explores the hypothesis that Magnetic Resonance Imaging (MRI) can image the process of electrolysis by detecting pH fronts. The study has relevance to real time control of cell ablation with electrolysis. To investigate the hypothesis we compare the following MR imaging sequences: T1 weighted, T2 weighted and Proton Density (PD), with optical images acquired using pH-sensitive dyes embedded in a physiological saline agar solution phantom treated with electrolysis and discrete measurements with a pH microprobe. We further demonstrate the biological relevance of our work using a bacterial E. Coli model, grown on the phantom. The results demonstrate the ability of MRI to image electrolysis produced pH changes in a physiological saline phantom and show that these changes correlate with cell death in the E. Coli model grown on the phantom. The results are promising and invite further experimental research.

  11. Magnetic Resonance Imaging of Neurosarcoidosis

    Daniel T Ginat

    2011-01-01

    Full Text Available Neurosarcoidosis is an uncommon condition with protean manifestations. Magnetic resonance imaging (MRI is often used in the diagnostic evaluation and follow-up of patients with neurosarcoidosis. Therefore, familiarity with the variety of MRI appearances is important. In this pictorial essay, the range of possible patterns of involvement in neurosarcoidosis are depicted and discussed. These include intracranial and spine leptomeningeal involvement, cortical and cerebral white matter lesions, corpus callosum involvement, sellar and suprasellar involvement, periventricular involvement, cranial nerve involvement, cavernous sinus involvement, hydrocephalus, dural involvement, ischemic lesions, perivascular involvement, orbit lesions, osseous involvement, nerve root involvement, and spinal cord intramedullary involvement. Differential diagnoses for each pattern of involvement of neurosarcoidosis are also provided.

  12. Synovial pathology: Magnetic resonance study

    The synovial membrane lines the inner surface of the entire joint capsule of the so-called synovial, or diarthrosis, joints. It also constitutes the lining synovial bursa and tendon sheaths. It is lubricated at all these sites by the synovial fluid secreted by the membrane itself. The identification of this structure is bases on the correct knowledge of its anatomical locations. Synovial membrane pathology includes lesions produced by tumors, inflammation, degeneration and trauma. In this report, we classify them as benign (cysts, chondromatosis, pigmented villonodular synovitis, inflammatory synovitis and hemangioma) or malignant (synovial sarcoma and hemangiosarcoma). Magnetic resonance (MR) constitutes a useful and reliable method for diagnosis synovial lesions, providing a means of determining their origin and identifying distinctive features of some types. We present our experience in 12 cases of synovial pathology studied by MR over the past year, all of which were confirmed by histopathological study. 13 refs

  13. Fetal abdominal magnetic resonance imaging

    This review deals with the in vivo magnetic resonance imaging (MRI) appearance of the human fetal abdomen. Imaging findings are correlated with current knowledge of human fetal anatomy and physiology, which are crucial to understand and interpret fetal abdominal MRI scans. As fetal MRI covers a period of more than 20 weeks, which is characterized not only by organ growth, but also by changes and maturation of organ function, a different MR appearance of the fetal abdomen results. This not only applies to the fetal intestines, but also to the fetal liver, spleen, and adrenal glands. Choosing the appropriate sequences, various aspects of age-related and organ-specific function can be visualized with fetal MRI, as these are mirrored by changes in signal intensities. Knowledge of normal development is essential to delineate normal from pathological findings in the respective developmental stages

  14. Fetal abdominal magnetic resonance imaging

    Brugger, Peter C. [Center of Anatomy and Cell Biology, Integrative Morphology Group, Medical University of Vienna, Waehringerstrasse 13, 1090 Vienna (Austria)]. E-mail: peter.brugger@meduniwien.ac.at; Prayer, Daniela [Department of Radiology, Medical University of Vienna, Waehringerguertel 18-20, 1090 Vienna (Austria)

    2006-02-15

    This review deals with the in vivo magnetic resonance imaging (MRI) appearance of the human fetal abdomen. Imaging findings are correlated with current knowledge of human fetal anatomy and physiology, which are crucial to understand and interpret fetal abdominal MRI scans. As fetal MRI covers a period of more than 20 weeks, which is characterized not only by organ growth, but also by changes and maturation of organ function, a different MR appearance of the fetal abdomen results. This not only applies to the fetal intestines, but also to the fetal liver, spleen, and adrenal glands. Choosing the appropriate sequences, various aspects of age-related and organ-specific function can be visualized with fetal MRI, as these are mirrored by changes in signal intensities. Knowledge of normal development is essential to delineate normal from pathological findings in the respective developmental stages.

  15. Chemical Principles Revisited. Proton Magnetic Resonance Spectroscopy.

    McQuarrie, Donald A.

    1988-01-01

    Discusses how to interpret nuclear magnetic resonance (NMR) spectra and how to use them to determine molecular structures. This discussion is limited to spectra that are a result of observation of only the protons in a molecule. This type is called proton magnetic resonance (PMR) spectra. (CW)

  16. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Full Text Available ... produced by: Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot ... I’d like to talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. MRA ...

  17. Contrast agents in magnetic resonance imaging

    The origine of nuclear magnetic resonance signal is reminded and different ways for contrast enhancement in magnetic resonance imaging are presented, especially, modifications of tissus relaxation times. Investigations have focused on development of agents incorporating either paramagnetic ions or stable free radicals. Pharmacological and toxicological aspects are developed. The diagnostic potential of these substances is illustrated by the example of gadolinium complexes

  18. Pituitary tumors: Diagnosis by magnetic resonance imaging

    This paper presents a survey of the current status of the diagnosis of pituitary tumors by means of magnetic resonance imaging. It focuses on the clinical and practical aspects. The recommended procedure and the sequences and slice orientations for magnetic resonance imaging of the pituitary gland are presented, and the features that are essential for the diagnosis of pituitary tumors are discussed. (orig.)

  19. Magnetic resonance force microscopy: recent results

    Force detection of magnetic resonance has been demonstrated experimentally and used for imaging in EPR. This paper will review the basic principles of Magnetic Resonance Force Microscopy (MRFM) and will report some recent results in NMR imaging and the operation of a low-temperature MRFM. (author). 31 refs., 14 figs

  20. Magnetic resonance imaging of the prostate

    Iversen, P; Kjaer, L; Thomsen, C;

    1987-01-01

    Magnetic resonance imaging offers new possibilities in the investigation of the prostate. The current results of imaging and tissue discrimination in the evaluation of prostatic disease are reviewed. Magnetic resonance imaging may be of value in the staging of carcinoma of the prostate....

  1. Magnetic resonance imaging of the prostate

    Iversen, P; Kjaer, L; Thomsen, C;

    1988-01-01

    Magnetic resonance imaging offers new possibilities in investigation of the prostate gland. Current results of imaging and tissue discrimination in the evaluation of prostatic disease are reviewed. Magnetic resonance imaging may be useful in the staging of carcinoma of the prostate....

  2. Functional Magnetic Resonance Imaging and Pediatric Anxiety

    Pine, Daniel S.; Guyer, Amanda E.; Leibenluft, Ellen; Peterson, Bradley S.; Gerber, Andrew

    2008-01-01

    The use of functional magnetic resonance imaging in investigating pediatric anxiety disorders is studied. Functional magnetic resonance imaging can be utilized in demonstrating parallels between the neural architecture of difference in anxiety of humans and the neural architecture of attention-orienting behavior in nonhuman primates or rodents.…

  3. Nuclear magnetic resonance studies of erythrocyte membranes

    Chapman, D.; Kamat, V.B.; Gier, J. de; Penkett, S.A.

    1968-01-01

    The use of nuclear magnetic resonance spectroscopy for studying molecular interactions in biological membranes has been investigated using erythrocyte membrane fragments. Sonic dispersion of these fragments produces a sharp and well-defined high-resolution nuclear magnetic resonance spectrum. The sp

  4. Nuclear magnetic resonance studies of biological systems: Applications to liver preservation and metabolism in cultured pituitary tumor cells

    This study centers on applications of both 31P and 13C nuclear magnetic resonance spectroscopy to two different biological systems. The first application utilizes 31P NMR to study mobile phospholipids in the MMQ cell line, a pituitary tumor cell line. These measurements characterize membrane phospholipids thought to be part of a RNA-proteolipid complex unique to cellular transformation. The second application utilizes both 31P and 13C spectroscopy to study liver preservation and transplantation an a rat model. In this work, several questions were addressed: (1) to what extent do successful preservation solutions slow ATP breakdown? (2) can clinically successful preservation conditions ameliorate total nucleotide breakdown? (3) to what extent is energy reconstitution following cold storage correlated with transport success? and (4) can any spectroscopic parameter be used as a diagnostic indicator of tissue viability?

  5. Magnetic non-collinear neutron wave resonator

    Khaidukov, Yu N

    2009-01-01

    The expression are received for amplitude of neutron reflection from layered magnetic non-collinear structure (neutron wave resonator (NWR)). It is showed the magnetic non-collinear NWR is characterized by the system of pairs of resonances for the spin flipped neutrons. The conditions are defined at which amplifying of spin-flipped neutron flux in wave resonator is multiple increased in comparison with amplifying of neutron absorption.

  6. Magnetic Resonance of the Knee

    Magnetic Resonance Imaging (MRI) has been applied to muscoloskeletal pathoanatomy and has proved to be useful in the detection and characterization of knees and 8 normal knees were examined. The images were obtained in the Diagnostic Centre RMRC of Naples on a 0.5 T superconductive magnetic system, using a surface coil and a spin-echo pulse sequence (SE 600/28 ms). The examined limb was immobilized and bent at 8-10 grade, extrarotated for the examination of the anterior cruciate ligament (ACL) only. Images were obtained on a 256x256 matrix and had a 2 or 4-mm thickness. MRI cleary showed all the anatomical structures. The anterior and posterior cruciate ligaments (ACL and PAL) and tha patellar ligament were shown by sagittal SE images through the intercondylar notch; the tibial and fibular collateral ligaments (TCL and FCL) were evaluated on coronal SE images; the articular capsula and menisci on axial transverse SE images. Objective criteria for ACL and PCL tears were: lack of continuity of the signal and change in signal intensity; in meniscal pathology, menisci with small linear regions of increased signal or with grossly truncated shape were interpreted as tears. Preliminary results of this study indicate that MRI together with clinical evaluation may be an useful non-invasive procedure in the assessment of acute injuries of the knee

  7. 2D exchange 31P NMR spectroscopy of bacteriophage M13 and tobacco mosaic virus.

    Magusin, P.C.M.M.; Hemminga, M A

    1995-01-01

    Two-dimensional (2D) exchange 31P nuclear magnetic resonance spectroscopy is used to study the slow overall motion of the rod-shaped viruses M13 and tobacco mosaic virus in concentrated gels. Even for short mixing times, observed diagonal spectra differ remarkably from projection spectra and one-dimensional spectra. Our model readily explains this to be a consequence of the T2e anisotropy caused by slow overall rotation of the viruses about their length axis. 2D exchange spectra recorded for ...

  8. Stepped Impedance Resonators for High Field Magnetic Resonance Imaging

    Akgun, Can E.; DelaBarre, Lance; Yoo, Hyoungsuk; Sohn, Sung-Min; Snyder, Carl J.; Adriany, Gregor; Ugurbil, Kamil; Gopinath, Anand; Vaughan, J. Thomas

    2014-01-01

    Multi-element volume radio-frequency (RF) coils are an integral aspect of the growing field of high field magnetic resonance imaging (MRI). In these systems, a popular volume coil of choice has become the transverse electromagnetic (TEM) multi-element transceiver coil consisting of microstrip resonators. In this paper, to further advance this design approach, a new microstrip resonator strategy in which the transmission line is segmented into alternating impedance sections referred to as step...

  9. Magnetic Microparticle Aggregation For Viscosity Determination By Magnetic Resonance

    Hong, Rui; Cima, Michael J; Weissleder, Ralph; Josephson, Lee

    2008-01-01

    Micron-sized magnetic particles were induced to aggregate when placed in homogeneous magnetic fields, like those of magnetic resonance (MR) imagers and relaxometers, and then spontaneously returned to their dispersed state when removed from the field. Associated with the aggregation and dispersion of the magnetic particles were time dependent increases and decreases in the spin-spin relaxation time (T2) of the water. Magnetic nanoparticles, with far smaller magnetic moments per particle, did ...

  10. Nuclear Magnetic Resonance imaging; Resonance magnetique nucleaire

    Thibierge, M.; Sevestre, L.; Slupecki, P. [Centre Hospitalier de Charleville-Mezieres, 08 (France)

    1998-06-01

    After many years of low profile business in the USA, MRI is back. Improvements are focused on high field magnets and on low field magnets. The former, are dedicated to high quality imaging. The new scanners are more and more efficient because of the spreading use of real time imaging. They can do now, procedures that just could not be imagined some years ago. Vascular imaging is done routinely. Abdominal imaging in apnea of EPI, perfusion and diffusion imaging, and, last not least, all the field of functional imaging are on the verge of coming out. The new magnets unveiled in 1997 are lighter, smaller, more, user friendly, less impressive for patients subject to claustrophobia. They also need less helium to operate and less space to be sited. The latter, are dedicated to interventional procedures. The new magnets are wide opened and a lot of companies show off. Though Picker unveiled a new light superconductive 0.5 Tesla magnet, it seems that this kind of machines are about to disappear. No significant progress was noticed in the field of dedicated MRI devices. Some features can be highlighted: the new Siemens short bore and its table integrates the Panoramic Array Coil Concept. It will allow simultaneous scanning with up to four coils; the excellent homogeneity of the new Picker magnet that will allow spectroscopy at 1 Tesla; the twin gradients of the Elscint Prisma that will open the field of microscopy MRI; the Philips `floppy gradients` that could speed up 4 or 6 times, the time needed for imaging; some new sequences sensitive to temperature are studied as WIP; a lot of work is achieved on 3 or 4 Tesla scanners etc. (author)

  11. Nuclear-Overhauser-enhanced MR imaging of (31)P-containing metabolites: multipoint-Dixon vs. frequency-selective excitation.

    Rink, Kristian; Berger, Moritz C; Korzowski, Andreas; Breithaupt, Mathies; Biller, Armin; Bachert, Peter; Nagel, Armin M

    2015-12-01

    The purpose of this study is to develop nuclear-Overhauser-enhanced (NOE) [(1)H]-(31)P magnetic resonance imaging (MRI) based on 3D fully-balanced steady-state free precession (fbSSFP). Therefore, two implementations of a 3D fbSSFP sequence are compared using frequency-selective excitation (FreqSel) and multipoint-Dixon (MP-Dixon). (31)P-containing model solutions and four healthy volunteers were examined at field strengths of B0=3T and 7T. Maps of the distribution of phosphocreatine (PCr), inorganic phosphate (Pi), and adenosine 5´-triphosphate (ATP) in the human calf were obtained with an isotropic resolution of 1.5cm (1.0cm) in an acquisition time of 5min (10min). NOE-pulses had the highest impact on the PCr acquisitions enhancing the signal up to (82 ± 13) % at 3T and up to (37 ± 9) % at 7T. An estimation of the level of PCr in muscle tissue from [(1)H]-(31)P MRI data yielded a mean value of (33 ± 8) mM. In conclusion, direct [(1)H]-(31)P imaging using FreqSel as well as MP-Dixon is possible in clinically feasible acquisition times. FreqSel should be preferred for measurements where only a single metabolite resonance is considered. MP-Dixon performs better in terms of SNR if a larger spectral width is of interest. PMID:26248272

  12. Magnetic resonance imaging in mucopolysaccharidosis

    Nakajima, Seijun; Tanaka, Akemi; Kawawaki, Hisashi; Hattori, Hideji; Matsuoka, Osamu; Murata, Ryosuke; Isshiki, Gen; Inoue, Yuichi

    1988-11-01

    Magnetic resonance (MR) images in six patients with mucopolysaccharidosis (MPS), two with type I S, one with type II A, two with type III B, and one with type VI MPS, were reviewed and compared with reported pathological findings and with CT scans. We used a Picker International MR imager with a 0.5-tesla superconducting magnet. The pulse sequences involved the inversion recovery technique (TR, 2,100 msec ; TI, 600 msec ; TE, 40 msec) for the T/sub 1/-weighted images and spin echo technique (TR, 1,800 msec ; TE, 120 msec) for the T/sub 2/-weighted images. The TC scanner was a Somatom 2 or DR3. In the patients with type II A and type VI MPS, there were multi-focal lesions of various sizes that showed prolonged T/sub 1/ and T/sub 2/ in the white matter. These lesions, which were not detected by CT, seemed to be correlated with the pathological findings of cavitation and dilated periadventitial space with viscous fluid. In the patients with type II A and type III B MPS, the T/sub 2/-weighted images showed a reduced contrast between gray and white matters, which may be related to the deposition of glycolipids and mucopolysaccharides in the lysosomes of the neurons and astrocytes of the gray and white matters. These findings seemed to be correlated with the clinical finding of mental retardation. In the patient of type II A MPS, there were lesions that showed prolonged T/sub 2/ of the periventricular white matter, suggesting periventricular edema. But CT hardly detected these lesions. In the patients with type I S MPS, no abnormal findings were found in MR imaging. It was concluded that MR imaging was far more sensitive for the detection of MPS lesions than CT, and was a useful method for differential diagnosis in MPS.

  13. Magnetic resonance imaging in mucopolysaccharidosis

    Magnetic resonance (MR) images in six patients with mucopolysaccharidosis (MPS), two with type I S, one with type II A, two with type III B, and one with type VI MPS, were reviewed and compared with reported pathological findings and with CT scans. We used a Picker International MR imager with a 0.5-tesla superconducting magnet. The pulse sequences involved the inversion recovery technique (TR, 2,100 msec ; TI, 600 msec ; TE, 40 msec) for the T1-weighted images and spin echo technique (TR, 1,800 msec ; TE, 120 msec) for the T2-weighted images. The TC scanner was a Somatom 2 or DR3. In the patients with type II A and type VI MPS, there were multi-focal lesions of various sizes that showed prolonged T1 and T2 in the white matter. These lesions, which were not detected by CT, seemed to be correlated with the pathological findings of cavitation and dilated periadventitial space with viscous fluid. In the patients with type II A and type III B MPS, the T2-weighted images showed a reduced contrast between gray and white matters, which may be related to the deposition of glycolipids and mucopolysaccharides in the lysosomes of the neurons and astrocytes of the gray and white matters. These findings seemed to be correlated with the clinical finding of mental retardation. In the patient of type II A MPS, there were lesions that showed prolonged T2 of the periventricular white matter, suggesting periventricular edema. But CT hardly detected these lesions. In the patients with type I S MPS, no abnormal findings were found in MR imaging. It was concluded that MR imaging was far more sensitive for the detection of MPS lesions than CT, and was a useful method for differential diagnosis in MPS. (author)

  14. Artifacts in Magnetic Resonance Imaging

    Artifacts in magnetic resonance imaging and foreign bodies within the patient’s body may be confused with a pathology or may reduce the quality of examinations. Radiologists are frequently not informed about the medical history of patients and face postoperative/other images they are not familiar with. A gallery of such images was presented in this manuscript. A truncation artifact in the spinal cord could be misinterpreted as a syrinx. Motion artifacts caused by breathing, cardiac movement, CSF pulsation/blood flow create a ghost artifact which can be reduced by patient immobilization, or cardiac/respiratory gating. Aliasing artifacts can be eliminated by increasing the field of view. An artificially hyperintense signal on FLAIR images can result from magnetic susceptibility artifacts, CSF/vascular pulsation, motion, but can also be found in patients undergoing MRI examinations while receiving supplemental oxygen. Metallic and other foreign bodies which may be found on and in patients’ bodies are the main group of artifacts and these are the focus of this study: e.g. make-up, tattoos, hairbands, clothes, endovascular embolization, prostheses, surgical clips, intraorbital and other medical implants, etc. Knowledge of different types of artifacts and their origin, and of possible foreign bodies is necessary to eliminate them or to reduce their negative influence on MR images by adjusting acquisition parameters. It is also necessary to take them into consideration when interpreting the images. Some proposals of reducing artifacts have been mentioned. Describing in detail the procedures to avoid or limit the artifacts would go beyond the scope of this paper but technical ways to reduce them can be found in the cited literature

  15. Phosphorus-31 and carbon-13 nuclear magnetic resonance studies of glucose and xylose metabolism in Candida tropicalis cell suspensions.

    Lohmeier-Vogel, E M; Hahn-Hägerdal, B.; Vogel, H J

    1995-01-01

    The metabolism of glucose and xylose was studied as a function of oxygenation in suspensions of Candida tropicalis by 31P and 13C nuclear magnetic resonance spectroscopy. Both the rate of carbohydrate metabolism and the cytoplasmic pH were independent of the rate of oxygenation in cells metabolizing glucose. However, these two parameters were markedly dependent on the rate of oxygenation in C. tropicalis cells metabolizing xylose. For example, the cytoplasmic pH in fully oxygenated xylose-met...

  16. Interaction of magnetic resonators studied by the magnetic field enhancement

    Yumin Hou

    2013-01-01

    It is the first time that the magnetic field enhancement (MFE) is used to study the interaction of magnetic resonators (MRs), which is more sensitive than previous parameters–shift and damping of resonance frequency. To avoid the coherence of lattice and the effect of Bloch wave, the interaction is simulated between two MRs with same primary phase when the distance is changed in the range of several resonance wavelengths, which is also compared with periodic structure. The calculated MFE osci...

  17. Functional magnetic resonance imaging by visual stimulation

    We evaluated functional magnetic resonance images obtained in 8 healthy subjects in response to visual stimulation using a conventional clinical magnetic resonance imaging system with multi-slice spin-echo echo planar imaging. Activation in the visual cortex was clearly demonstrated by the multi-slice experiment with a task-related change in signal intensity. In addition to the primary visual cortex, other areas were also activated by a complicated visual task. Multi-slice spin-echo echo planar imaging offers high temporal resolution and allows the three-dimensional analysis of brain function. Functional magnetic resonance imaging provides a useful noninvasive method of mapping brain function. (author)

  18. Presurgical functional magnetic resonance imaging

    Functional magnetic resonance imaging (fMRI) is an important and novel neuroimaging modality for patients with brain tumors. By non-invasive measurement, localization and lateralization of brain activiation, most importantly of motor and speech function, fMRI facilitates the selection of the most appropriate and sparing treatment and function-preserving surgery. Prerequisites for the diagnostic use of fMRI are the application of dedicated clinical imaging protocols and standardization of the respective imaging procedures. The combination with diffusion tensor imaging (DTI) also enables tracking and visualization of important fiber bundles such as the pyramidal tract and the arcuate fascicle. These multimodal MR data can be implemented in computer systems for functional neuronavigation or radiation treatment. The practicability, accuracy and reliability of presurgical fMRI have been validated by large numbers of published data. However, fMRI cannot be considered as a fully established modality of diagnostic neuroimaging due to the lack of guidelines of the responsible medical associations as well as the lack of medical certification of important hardware and software components. This article reviews the current research in the field and provides practical information relevant for presurgical fMRI. (orig.)

  19. Magnetic resonance in multiple sclerosis

    Magnetic Resonance Imaging was performed in more than 200 patients with clinical suspicion or knowledge of Multiple Sclerosis. One hundred and forty-seven (60 males and 87 females) had MR evidence of multiple sclerosis lesions. The MR signal of demyelinating plaques characteristically has prolonged T1 and T2 relaxation times and the T2-weighted spin-echo sequences are generally superior to the T1-weighted images because the lesions are better visualized as areas of increased signal intensity. MR is also able to detect plaques in the brainstem, cerebellum and within the cervical spinal cord. MR appears to be an important, non-invasive method for the diagnosis of Multiple Sclerosis and has proven to be diagnostically superior to CT, evoked potentials (EP) and CSF examination. In a selected group of 30 patients, with the whole battery of the relevant MS studies, MR was positive in 100%, CT in 33,3%, EP in 56% and CSF examination in 60%. In patients clinically presenting only with signs of spinal cord involvement or optic neuritis or when the clinical presentation is uncertain MR has proven to be a very useful diagnostic tool for diagnosis of MS by demonstrating unsuspected lesions in the cerebral hemispheres. (orig.)

  20. A Magnetic Resonance Measurement Technique for Rapidly Switched Gradient Magnetic Fields in a Magnetic Resonance Tomograph

    K. Bartušek

    2003-01-01

    Full Text Available This paper describes a method for measuring of the gradient magnetic field in Nuclear Magnetic Resonance (NMR tomography, which is one of the modern medical diagnostic methods. A very important prerequisite for high quality imaging is a gradient magnetic field in the instrument with exactly defined properties. Nuclear magnetic resonance enables us to measure the pulse gradient magnetic field characteristics with high accuracy. These interesting precise methods were designed, realised, and tested at the Institute of Scientific Instruments (ISI of the Academy of Sciences of the Czech Republic. The first of them was the Instantaneous Frequency (IF method, which was developed into the Instantaneous Frequency of Spin Echo (IFSE and the Instantaneous Frequency of Spin Echo Series (IFSES methods. The above named methods are described in this paper and their a comparison is also presented.

  1. Enhancement of artificial magnetism via resonant bianisotropy

    Markovich, Dmitry; Baryshnikova, Kseniia; Shalin, Alexander; Samusev, Anton; Krasnok, Alexander; Belov, Pavel; Ginzburg, Pavel

    2016-03-01

    All-dielectric “magnetic light” nanophotonics based on high refractive index nanoparticles allows controlling magnetic component of light at nanoscale without having high dissipative losses. The artificial magnetic optical response of such nanoparticles originates from circular displacement currents excited inside those structures and strongly depends on geometry and dispersion of optical materials. Here an approach for enhancing of magnetic response via resonant bianisotropy effect is proposed and analyzed. The key mechanism of enhancement is based on electric-magnetic interaction between two electrically and magnetically resonant nanoparticles of all-dielectric dimer. It was shown that proper geometrical arrangement of the dimer in respect to the incident illumination direction allows flexible control over all vectorial components of the magnetic moment, tailoring the latter in the dynamical range of 100% and delivering enhancement up to 36% relative to performances of standalone spherical particles. The proposed approach provides pathways for designs of all-dielectric metamaterials and metasurfaces with strong magnetic responses.

  2. In vivo 31P-NMR spectroscopy of right ventricle in pigs.

    Schwartz, G G; Steinman, S K; Weiner, M W; Matson, G B

    1992-06-01

    The energy metabolism of the right ventricle (RV) in vivo has been largely unexplored. The goal of this study was to develop and implement techniques for in vivo 31P nuclear magnetic resonance (NMR) spectroscopy of the RV free wall. A two-turn, crossover-design elliptical surface coil was constructed to provide high sensitivity across the thin RV wall but minimal sensitivity in the blood-filled RV cavity. In 36 open-chest, anesthetized pigs, 31P spectroscopy of the RV free wall was performed with this coil at a field strength of 2 Tesla. Spectra were obtained from 800 acquisitions in 24 min with an average signal-to-noise ratio of 13.2 for phosphocreatine (PCr). The PCr-to-ATP (PCr/ATP) ratio of porcine RV was 1.42 +/- 0.05 (mean +/- SE), uncorrected for saturation at a repetition time of 1.8 s. With the use of literature values of the time constant of longitudinal relaxation (T1) to correct for partial saturation, the RV PCr/ATP was estimated to lie between 1.7 and 2.3. Decreased RV PCr/ATP was observed during RV ischemia and pressure overload. Thus in vivo 31P spectroscopy of the RV is readily accomplished with an appropriate surface coil and can provide new information about RV energy metabolism. PMID:1621852

  3. Phosphorus magnetic resonance spectroscopy in malformations of cortical development

    Celi Santos Andrade

    2013-07-01

    Full Text Available Introduction Malformations of cortical development (MCD result from disruptions in the dynamic process of cerebral corticogenesis and are important causes of epilepsy, motor deficits and cognitive impairment. Objectives The aim of this study was to evaluate phospholipids metabolism in vivo in a series of patients with epilepsy and MCD. Methods Thirty-seven patients with MCD and 31 control subjects were studied using three-dimensional phosphorus magnetic resonance spectroscopy (31P-MRS at a 3.0 T scanner. Quantification methods were applied to the following resonances: phosphoethanolamine (PE, phosphocholine (PC, glycerophosphoethanolamine (GPE, glycerophosphocholine (GPC, inorganic phosphate (Pi, phosphocreatine (PCr, and a-, b-, and g-adenosine triphosphate (ATP. The magnesium (Mg2+ levels and pH were calculated based on PCr, Pi and b-ATP chemical shifts. Results Compared to controls, the MCD lesions exhibited lower pH values and higher Mg2+ levels (p<0.05. The lesions also presented significant reduction of GPC and PDE, and an increased PME/PDE ratio. The otherwise normal appearing parenchyma also demonstrated lower pH values in the frontoparietal cortex and bilateral centrum semiovale. Conclusions Our data support the idea that metabolic impairments occur in the lesions of MCD, with propagation to remote normal appearing parenchyma. The results also suggest that there are membrane turnover disturbances in MCD lesions.

  4. Application of 31P MR spectroscopy to the brain tumors

    To evaluate the clinical feasibility and obtain useful parameters of 31P magnetic resonance spectroscopy (MRS) study for making the differential diagnosis of brain tumors. Twenty-eight patients with brain tumorous lesions (22 cases of brain tumor and 6 cases of abscess) and 11 normal volunteers were included. The patients were classified into the astrocytoma group, lymphoma group, metastasis group and the abscess group. We obtained the intracellular pH and the metabolite ratios of phosphomonoesters/phosophodiesters (PME/PDE), PME/inorganic phosphate (Pi), PDE/Pi, PME/adenosine triphosphate (ATP), PDE/ATP, PME/phosphocreatine (PCr), PDE/PCr, PCr/ATP, PCr/Pi, and ATP/Pi, and evaluated the statistical significances. The brain tumors had a tendency of alkalization (pH = 7.28 ± 0.27, p = 0.090), especially the pH of the lymphoma was significantly increased (pH = 7.45 ± 0.32, p = 0.013). The brain tumor group showed increased PME/PDE ratio compared with that in the normal control group (p 0.012). The ratios of PME/PDE, PDE/Pi, PME/PCr and PDE/PCr showed statistically significant differences between each brain lesion groups (p 1'P MRS, and the pH, PME/PDE, PDE/Pi, PME/PCr, and PDE/PCr ratios are helpful for differentiating among the different types of brain tumors.

  5. Reducing Field Distortion in Magnetic Resonance Imaging

    Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob

    2010-01-01

    A concept for a magnetic resonance imaging (MRI) system that would utilize a relatively weak magnetic field provides for several design features that differ significantly from the corresponding features of conventional MRI systems. Notable among these features are a magnetic-field configuration that reduces (relative to the conventional configuration) distortion and blurring of the image, the use of a superconducting quantum interference device (SQUID) magnetometer as the detector, and an imaging procedure suited for the unconventional field configuration and sensor. In a typical application of MRI, a radio-frequency pulse is used to excite precession of the magnetic moments of protons in an applied magnetic field, and the decaying precession is detected for a short time following the pulse. The precession occurs at a resonance frequency proportional to the strengths of the magnetic field and the proton magnetic moment. The magnetic field is configured to vary with position in a known way; hence, by virtue of the aforesaid proportionality, the resonance frequency varies with position in a known way. In other words, position is encoded as resonance frequency. MRI using magnetic fields weaker than those of conventional MRI offers several advantages, including cheaper and smaller equipment, greater compatibility with metallic objects, and higher image quality because of low susceptibility distortion and enhanced spin-lattice-relaxation- time contrast. SQUID MRI is being developed into a practical MRI method for applied magnetic flux densities of the order of only 100 T

  6. International Society for Magnetic Resonance in Medicine

    ... Join the ISMRM Journals History & Mission Central Office Society Award Winners Strategic Plan Policies Corporate Members Contact ... E-Library Virtual Meetings Connect With Us International Society for Magnetic Resonance in Medicine 2300 Clayton Road, ...

  7. Magnetic moment of the Roper resonance

    Bauer, T. [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany); Gegelia, J., E-mail: gegelia@kph.uni-mainz.de [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany); Institut fuer Theoretische Physik II, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); High Energy Physics Institute of TSU, 0186 Tbilisi, Georgia (United States); Scherer, S. [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany)

    2012-08-29

    The magnetic moment of the Roper resonance is calculated in the framework of a low-energy effective field theory of the strong interactions. A systematic power-counting procedure is implemented by applying the complex-mass scheme.

  8. Magnetic resonance imaging for uterus leiomyoma diagnosis

    The possibilities of a new technique, magnetic resonance imaging (MRI) in leiomyoma diagnosis was studied. MRI has clear advantages to differentiate adenomyosis from lysosomes and to reveal combination of these processes, which can considerably influence the tactics of the treatment

  9. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Full Text Available ... Pediatric Ultrasound Video: Angioplasty & vascular stenting Video: Arthrography Radiology and You About this Site RadiologyInfo.org is ... Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot org Hello, I’m Dr. Elliot ...

  10. Chronic liver disease: evaluation by magnetic resonance

    Magnetic resonance (MR) imaging distinguished hepatitis from fatty liver and cirrhosis in a woman with a history of alcohol abuse. Anatomic and physiologic manifestations of portal hypertension were also demonstrated by MR

  11. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Full Text Available ... Angioplasty & vascular stenting Video: Arthrography Video: Contrast Material Radiology and You Take our survey About this Site ... Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot org Hello, I’m Dr. Elliot ...

  12. Biliary Ascariasis on Magnetic Resonance Cholangiopancreatography

    Hashmi, Mohammad A; Jevan K De

    2009-01-01

    A 17-year-old girl presented with features of biliary obstruction. Magnetic resonance cholangi-pancreatography revealed typical linear signals in common bile duct, which appears like Ascaris lumbricoides. The diagnosis was confirmed by endoscopic removal of the worm.

  13. Magnetic moment of the Roper resonance

    Bauer, T.; Gegelia, J.; Scherer, S.

    2012-01-01

    The magnetic moment of the Roper resonance is calculated in the framework of a low-energy effective field theory of the strong interactions. A systematic power-counting procedure is implemented by applying the complex-mass scheme.

  14. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Full Text Available ... this Site RadiologyInfo.org is produced by: Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) ... Recently posted: Focused Ultrasound for Uterine Fibroids Dementia Video: General Ultrasound Video: Pediatric Nuclear Medicine Radiology and ...

  15. Contribution to nuclear magnetic resonance imager using permanent magnets

    After some recalls of nuclear magnetic resonance, ways to get a stable and homogeneous magnetic field are studied with permanent magnets. Development of correction coils on integrated circuits has been particularly stressed. Gradient coil specific systems have been studied taking in account ferromagnetic material presence. Antenna system has been improved and possibility of image obtention with the prototype realized has been shown

  16. Solid State Multinuclear Magnetic Resonance Investigation of Electrolyte Decomposition Products on Lithium Ion Electrodes

    DeSilva, J .H. S. R.; Udinwe, V.; Sideris, P. J.; Smart, M. C.; Krause, F. C.; Hwang, C.; Smith, K. A.; Greenbaum, S. G.

    2012-01-01

    Solid electrolyte interphase (SEI) formation in lithium ion cells prepared with advanced electrolytes is investigated by solid state multinuclear (7Li, 19F, 31P) magnetic resonance (NMR) measurements of electrode materials harvested from cycled cells subjected to an accelerated aging protocol. The electrolyte composition is varied to include the addition of fluorinated carbonates and triphenyl phosphate (TPP, a flame retardant). In addition to species associated with LiPF6 decomposition, cathode NMR spectra are characterized by the presence of compounds originating from the TPP additive. Substantial amounts of LiF are observed in the anodes as well as compounds originating from the fluorinated carbonates.

  17. Advanced magnetic resonance spectroscopy techniques and applications

    Cao, Peng; 曹鹏

    2013-01-01

    Magnetic resonance (MR) is a well-known non-invasive technique that provides spectra (by MR spectroscopy, MRS) and images (by magnetic resonance imaging, MRI) of the examined tissue with detailed metabolic, structural, and functional information. This doctoral work is focused on advanced methodologies and applications of MRS for probing cellular and molecular changes in vivo. A single-voxel diffusion-weighted (DW) MRS method was first developed for monitoring the size changes of intramyocellu...

  18. Concepts and indications of abdominal magnetic resonance

    A literature review and conceptualization was performed of the main indications of magnetic resonance studies of the abdomen and the characteristic findings for each sequence, according to organ and pathology. The radiologist has had in mind main indications for magnetic resonance studies of the abdomen, with the purpose to guide the clinician in the choice of imaging modality that works best for the patient at diagnosis

  19. Magnetic Resonance Imaging with a Dielectric Lens

    Vazquez, F.; Marrufo, O.; MARTIN,R; Rodriguez, A. O.

    2009-01-01

    Recently, metamaterials have been introduced to improve the signal-to-noise ratio (SNR) of magnetic resonance images with very promising results. However, the use polymers in the generation of high quality images in magnetic resonance imaging has not been fully been investigated. These investigations explored the use of a dielectric periodical array as a lens to improve the image SNR generated with single surface coils. Commercial polycarbonate glazing sheets were used together with a circula...

  20. Nuclear Magnetic Resonance Imaging: Current Capabilities

    Davis, Peter L.; Crooks, Lawrence E.; Margulis, Alexander R.; Kaufman, Leon

    1982-01-01

    Nuclear magnetic resonance imaging can produce tomographic images of the body without ionizing radiation. Images of the head, chest, abdomen, pelvis and extremities have been obtained and normal structures and pathology have been identified. Soft tissue contrast with this method is superior to that with x-ray computerized tomography and its spatial resolution is approaching that of x-ray computerized tomography. In addition, nuclear magnetic resonance imaging enables us to image along the sag...

  1. Cardiovascular magnetic resonance of the right ventricle

    Alpendurada, Francisco Diogo

    2013-01-01

    Introduction: Whilst most of the attention has been devoted to the left ventricle in cardiovascular disease, the right ventricle has been somewhat neglected. In the last decades, there has been a renewal of interest in the right ventricle, in part driven by advances in cardiovascular imaging. Methods: Cardiovascular magnetic resonance is arguably the best imaging modality for the study of the right ventricle. In this research thesis, cardiovascular magnetic resonance w...

  2. Can magnetic resonance imaging differentiate undifferentiated arthritis?

    Østergaard, Mikkel; Duer, Anne; Hørslev-Petersen, K

    2005-01-01

    A high sensitivity for the detection of inflammatory and destructive changes in inflammatory joint diseases makes magnetic resonance imaging potentially useful for assigning specific diagnoses, such as rheumatoid arthritis and psoriatic arthritis in arthritides, that remain undifferentiated after...... conventional clinical, biochemical and radiographic examinations. With recent data as the starting point, the present paper describes the current knowledge on magnetic resonance imaging in the differential diagnosis of undifferentiated arthritis....

  3. Cat scratch disease: magnetic resonance imaging findings

    Cat scratch disease is an infectious lymphadenitis frequently occurring in children and adolescents. We present the magnetic resonance imaging findings of two patients with this disease. In both cases, lymphadenopathy was characterized by extensive stranding of the surrounding soft tissues, consistent with the inflammatory nature of this condition. Magnetic resonance imaging can be diagnostic and may obviate the need for invasive means of evaluation in patients suspected of having cat scratch disease. (orig.)

  4. Proton magnetic resonance spectroscopy in depression

    Naren P Rao; Venkatasubramanian, Ganesan; Bangalore N Gangadhar

    2011-01-01

    Magnetic Resonance Spectroscopy (MRS) is a unique technique that can directly assess the concentration of various biochemical metabolites in the brain. Thus, it is used in the study of molecular pathophysiology of different neuropsychiatric disorders, such as, the major depressive disorder and has been an area of active research. We conducted a computer-based literature search using the Pubmed database with ‘magnetic resonance spectroscopy’, ‘MRS’, ‘depression’, and ‘major depressive disorder...

  5. Magnetic resonance urography in children

    The imaging methods play an important role in the diagnosing of the urinary tract diseases in children. The magnetic resonance urography (MRU) aids the morphological and functional assessment of the urinary tract as well as the increase of the accuracy of the diagnosing process. Objective: The aim of the study is to assess the capabilities of the MRU for the diagnosing of the urogenital tract in children. Material and methods: In 30 children, age between 20 days and 14 years, suspected for urinary tract pathology MRU is performed. The technique includes a native and contrast examination of the abdomen and the pelvis. The duration, depending on the pathology, is between 20 and 30 min. The axial scans and the 3-dimensional reconstructed images have been processed at different reconstruction angle. The findings have been compared to the other imaging methods applied and the postoperative results. Results: The MRU has allowed to diagnose different types of urogenital diseases in children - 3 with double pyelo-calyx system, 12 with obstructed mega ureter, 5 with obstruction of the pyelo-urinary segment, 5 with accompanying parenchyma anomalies, 6 with renal calculi, 5 with tumors, 1 with extrarenal tumor formation, 3 with bladder anomalies and 1 with kidney transplantation. Most of the children have combined pathology. Conclusions: MRU shows significant advantages in a number of pathological conditions as urinary tract obstruction, renal tumors, transplanted kidney and some congenital anomalies. The technique is safe, non-invasive and relatively fast for children examinations. These features of MRU presents a reason to assume that it will replace a number of conventional radiography techniques, giving more precise diagnostic information

  6. Complex Response Function of Magnetic Resonance Spectrometers

    Annino, G.; Cassettari, M.; Fittipaldi, M.; M. Martinelli

    2002-01-01

    A vectorial analysis of magnetic resonance spectrometers, based on traveling wave resonators and including the reference arm and the automatic control of frequency, has been developed. The proposed model, valid also for stationary wave resonators, gives the response function of the spectrometer for any working condition, including scalar detectors with arbitrary response law and arbitrary excitation frequency. The purely dispersive and purely absorptive linear responses are discussed in detai...

  7. Nuclear magnetic resonance studies of biological systems

    The difference between intracellular and extracellular proton relaxation rates provides the basis for the determination of the mean hemoglobin concentration (MHC) in red blood cells. The observed water T1 relaxation data from red blood cell samples under various conditions were fit to the complete equation for the time-dependent decay of magnetization for a two-compartment system including chemical exchange. The MHC for each sample was calculated from the hematocrit and the intracellular water fraction as determined by NMR. The binding of the phosphorylcholine (PC) analogue, 2-(trimethylphosphonio)-ethylphosphate (phosphoryl-phosphocholine, PPC) to the PC binding myeloma proteins TEPC-15, McPC 603, and MOPC 167 was studied by 31P NMR

  8. Enhancement of artificial magnetism via resonant bianisotropy

    Markovich, Dmitry; Shalin, Alexander; Samusev, Anton; Krasnok, Alexander; Belov, Pavel; Ginzburg, Pavel

    2015-01-01

    All-dielectric "magnetic light" nanophotonics based on high refractive index nanoparticles allows controlling magnetic component of light at nanoscale without having high dissipative losses. The artificial magnetic optical response of such nanoparticles originates from circular displacement currents excited inside those structures and strongly depends on geometry and dispersion of optical materials. Here a new approach for increasing magnetic response via resonant bianisotropy effect is proposed and analyzed. The key mechanism of enhancement is based on electric-magnetic interaction between two electrically and magnetically resonant nanoparticles of all-dielectric dimer nanoantenna. It was shown that proper geometrical arrangement of the dimer in respect to the incident illumination direction allows flexible control over all vectorial components of magnetic polarizability, tailoring the later in the dynamical range of 100 % and enhancement up to 36 % relative to performances of standalone spherical particles....

  9. Nanoscale magnetic resonance imaging: Progress and challenges

    Magnetic resonance imaging (MRI), based on the sensitive detection of nuclear spins, enables three dimensional imaging without radiation damage. Conventional MRI techniques achieve spatial resolution that is at best a few micrometers due to sensitivity limitations of conventional inductive detection. The advent of ultrasensitive nanoscale magnetic sensing opens the possibility of extending MRI to the nanometer scale. If this can be pushed far enough, one can envision taking 3D images of individual biomolecules and, perhaps, even solving molecular structures of proteins. In this talk we will discuss issues related to nanoscale magnetic resonance imaging, especially its implementation using magnetic resonance force microscopy (MRFM). MRFM is based on the detection of ultrasmall (attonewton) magnetic forces. While 3D spatial resolution below 5 nm has been demonstrated, further progress depends on overcoming poorly understood near-surface force noise effects. We also consider the future possibility of using NV centers in diamond for detection of nanoMRI.

  10. Wilson's disease: 31P and 1H MR spectroscopy and clinical correlation

    Proton (1H) magnetic resonance spectroscopy (MRS) changes are noted in Wilson's disease (WD). However, there are no studies regarding membrane phospholipid abnormality using 31P MRS in these patients. We aimed to analyze the striatal spectroscopic abnormalities using 31P and 1H MRS in WD. Forty patients of WD (treated, 29; untreated,11) and 30 controls underwent routine MR image sequences and in vivo 2-D 31P and 1H MRS of basal ganglia using an image-selected technique on a 1.5-T MRI scanner. Statistical analysis was done using Student's t test. The mean durations of illness and treatment were 6.2 ± 7.4 and 4.8 ± 5.9 years, respectively. MRI images were abnormal in all the patients. 1H MRS revealed statistically significant reduction of N-acetyl aspartate (NAA)/choline (Cho) and NAA/creatine ratios in striatum (1H MRS) of treated patients compared to controls. The mean values of phosphomonoesters (PME) (p 31P MRS study. The duration of illness correlated well with increased PME/PDE [p < 0.001], PME/TPh [p < 0.05], and PDE/TPh [p < 0.05] and decreased NAA/Cho [p < 0.05] ratios. There was correlation of MRI score and reduced NAA/Cho ratio with disease severity. The PME/PDE ratio (right) was elevated in the treated group [p < 0.001] compared to untreated group. There is reduced breakdown and/or increased synthesis of membrane phospholipids and increased neuronal damage in basal ganglia in patients with WD. (orig.)

  11. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... a powerful magnetic field, radio waves and a computer to produce detailed pictures of the brain and ... powerful magnetic field, radio frequency pulses and a computer to produce detailed pictures of organs, soft tissues, ...

  12. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... of the head uses a powerful magnetic field, radio waves and a computer to produce detailed pictures ... medical conditions. MRI uses a powerful magnetic field, radio frequency pulses and a computer to produce detailed ...

  13. Coherence of magnetic resonators in a metamaterial

    Yumin Hou

    2013-12-01

    Full Text Available The coherence of periodic magnetic resonators (MRs under oblique incidence is studied using simulations. The correlated phase of interaction including both the retardation effect and relative phase difference between two MRs is defined, and it plays a key role in the MR interaction. The correlated phase is anisotropic, as is the coherence condition. The coherence condition is the same as the Wood's anomaly and verified by the Fano resonance. This study shows that the applications of the Fano resonance of periodic MRs will become widespread owing to achieving the Fano resonance simply by tuning the incident angle.

  14. Intermolecular (119)Sn,(31)P Through-Space Spin-Spin Coupling in a Solid Bivalent Tin Phosphido Complex.

    Arras, Janet; Eichele, Klaus; Maryasin, Boris; Schubert, Hartmut; Ochsenfeld, Christian; Wesemann, Lars

    2016-05-01

    A bivalent tin complex [Sn(NP)2] (NP = [(2-Me2NC6H4)P(C6H5)](-)) was prepared and characterized by X-ray diffraction and solution and solid-state nuclear magnetic resonance (NMR) spectroscopy. In agreement with the X-ray structures of two polymorphs of the molecule, (31)P and (119)Sn CP/MAS NMR spectra revealed one crystallographic phosphorus and tin site with through-bond (1)J((117/119)Sn,(31)P) and through-space (TS)J((117/119)Sn,(31)P) spin-spin couplings. Density functional theory (DFT) calculations of the NMR parameters confirm the experimental data. The observation of through-space (TS)J((117/119)Sn,(31)P) couplings was unexpected, as the distances of the phosphorus atoms of one molecule and the tin atom of the neighboring molecule (>4.6 Å) are outside the sum of the van der Waals radii of the atoms P and Sn (4.32 Å). The intermolecular Sn···P separations are clearly too large for bonding interactions, as supported by a natural bond orbital (NBO) analysis. PMID:27071033

  15. Low-temperature magnetic resonance force microscopy

    Wago, Koichi

    Magnetic resonance force microscopy (MRFM) is a technique whose goal is to combine the three-dimensional, chemically specific imaging capability of magnetic resonance imaging with the atomic-scale spatial resolution of scanning force microscopy. MRFM relies on the detection of small oscillatory magnetic forces between spins in the sample and a magnetic tip, using a micromechanical cantilever. The force resolution is a key issue for successfully operating MRFM experiments. Operating at low temperature improves the force resolution because of the reduced thermal energy and increased mechanical Q of the cantilever. The spin polarization is also enhanced at low temperature, leading to the improved magnetic resonance sensitivity for ensemble spin samples. A low-temperature magnetic resonance force detection apparatus was built and used to demonstrate a force resolution of 8×10sp{-17}\\ N/sqrt{Hz} at 6 K with a commercial single-crystal silicon cantilever. Both nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) were detected in micron-size samples. Force-detection technique was also applied to a wide range of magnetic resonance measurements, including inversion recovery, nutation, and spin echoes. Force-detected EPR spectra of phosphorus-doped silicon revealed hyperfine splitting, illustrating the possibility of using the MRFM technique for spectroscopic purposes. An improved low-temperature magnetic resonance force microscope was also built, incorporating a magnetic tip mounted directly on the cantilever. This allows a much wider variety of samples to be investigated and greatly improves the convenience of the technique. Using the improved microscope, three-dimensional EPR imaging of diphenylpicrylhydrazil (DPPH) particles was accomplished by scanning the sample in two dimensions while stepping an external field. The EPR force map showed a broad response reflecting the size and shape of the sample, allowing a three-dimensional real

  16. 170 Nanometer Nuclear Magnetic Resonance Imaging using Magnetic Resonance Force Microscopy

    Thurber, K R; Smith, D D; Thurber, Kent R.; Harrell, Lee E.; Smith, Doran D.

    2003-01-01

    We demonstrate one-dimensional nuclear magnetic resonance imaging of the semiconductor GaAs with 170 nanometer slice separation and resolve two regions of reduced nuclear spin polarization density separated by only 500 nanometers. This is achieved by force detection of the magnetic resonance, Magnetic Resonance Force Microscopy (MRFM), in combination with optical pumping to increase the nuclear spin polarization. Optical pumping of the GaAs creates spin polarization up to 12 times larger than the thermal nuclear spin polarization at 5 K and 4 T. The experiment is sensitive to sample volumes containing $\\sim 4 \\times 10^{11}$ $^{71}$Ga$/\\sqrt{Hz}$. These results demonstrate the ability of force-detected magnetic resonance to apply magnetic resonance imaging to semiconductor devices and other nanostructures.

  17. 31P saturation transfer and phosphocreatine imaging in the monkey brain

    31P magnetic resonance imaging with chemical-shift discrimination by selective excitation has been employed to determine the phosphocreatine (PCr) distribution in the brains of three juvenile macaque monkeys. PCr images were also obtained while saturating the resonance of the γ-phosphate of ATP, which allowed the investigation of the chemical exchange between PCr and the γ-phosphate of ATP catalyzed by creatine kinase. Superposition of the PCr images over the proton image of the same monkey brain revealed topological variations in the distribution of PCr and creatine kinase activity. PCr images were also obtained with and without visual stimulation. In two out of four experiments, an apparently localized decrease in PCr concentration was noted in visual cortex upon visual stimulation. This result is interpreted in terms of a possible role for the local ADP concentration in stimulating the accompanying metabolic response

  18. Embroidered Coils for Magnetic Resonance Sensors

    Michael I. Newton

    2013-04-01

    Full Text Available Magnetic resonance imaging is a widely used technique for medical and materials imaging. Even though the objects being imaged are often irregularly shaped, suitable coils permitting the measurement of the radio-frequency signal in these systems are usually made of solid copper. One problem often encountered is how to ensure the coils are both in close proximity and conformal to the object being imaged. Whilst embroidered conductive threads have previously been used as antennae in mobile telecommunications applications, they have not previously been reported for use within magnetic resonance. In this paper we show that an embroidered single loop coil can be used in a commercial unilateral nuclear magnetic resonance system as an alternative to a solid copper. Data is presented showing the determination of both longitudinal (T1 and effective transverse (T2eff relaxation times for a flat fabric coil and the same coil conformed to an 8 cm diameter cylinder. We thereby demonstrate the principles required for the wider use of fabric based conformal coils within nuclear magnetic resonance and magnetic resonance imaging.

  19. Planar Magnetic Metamaterial Slabs for Magnetic Resonance Imaging Applications

    Li, Chun-Lai; Guo, Jie; Zhang, Peng; Yu, Quan-Qiang; Ma, Wei-Tao; Miao, Xi-Gen; Zhao, Zhi-Ya; Luan, Lin

    2014-07-01

    A type of planar magnetic metamaterial is proposed with a square winding microstructure as a superlens for magnetic resonance imaging (MRI) applications. A direct magnetic field mapping measurement demonstrates that the radio-frequency magnetic field passing through the superlens is increased by as high as 46.9% at the position of about 3 cm behind the superlens. The resonance frequency of the fabricated slabs is found to be in good agreement with the target frequency (63.6 MHz) for a 1.5T MRI system. MRI experiments with the magnetic superlens show that the intensity of the image and the SNR (signal-to-noise ratio) are both enhanced, implying promising MRI applications of our planar magnetic superlens.

  20. Generation of nuclear magnetic resonance images

    Two generation techniques of nuclear magnetic resonance images, the retro-projection and the direct transformation method are studied these techniques are based on the acquisition of NMR signals which phases and frequency components are codified in space by application of magnetic field gradients. The construction of magnet coils is discussed, in particular a suitable magnet geometry with polar pieces and air gap. The obtention of image contrast by T1 and T2 relaxation times reconstructed from generated signals using sequences such as spin-echo, inversion-recovery and stimulated echo, is discussed. The mathematical formalism of matrix solution for Bloch equations is also presented. (M.C.K.)

  1. Susceptibility effects in nuclear magnetic resonance imaging

    The properties of dephasing and the resulting relaxation of the magnetization are the basic principle on which all magnetic resonance imaging methods are based. The signal obtained from the gyrating spins is essentially determined by the properties of the considered tissue. Especially the susceptibility differences caused by magnetized materials (for example, deoxygenated blood, BOLD-effect) or magnetic nanoparticles are becoming more important for biomedical imaging. In the present work, the influence of such field inhomogeneities on the NMR-signal is analyzed. (orig.)

  2. Magnetic plasmonic Fano resonance at optical frequency.

    Bao, Yanjun; Hu, Zhijian; Li, Ziwei; Zhu, Xing; Fang, Zheyu

    2015-05-13

    Plasmonic Fano resonances are typically understood and investigated assuming electrical mode hybridization. Here we demonstrate that a purely magnetic plasmon Fano resonance can be realized at optical frequency with Au split ring hexamer nanostructure excited by an azimuthally polarized incident light. Collective magnetic plasmon modes induced by the circular electric field within the hexamer and each of the split ring can be controlled and effectively hybridized by designing the size and orientation of each ring unit. With simulated results reproducing the experiment, our suggested configuration with narrow line-shape magnetic Fano resonance has significant potential applications in low-loss sensing and may serves as suitable elementary building blocks for optical metamaterials. PMID:25594885

  3. Magnetic resonance imaging of the body

    Higgins, C.B.; Hricak, H.

    1987-01-01

    This text provides reference to magnetic resonance imaging (MRI) of the body. Beginning with explanatory chapters on the physics, instrumentation, and interpretation of MRI, it proceeds to the normal anatomy of the neck, thorax, abdomen, and pelvis. Other chapters cover magnetic resonance imaging of blood flow, the larynx, the lymph nodes, and the spine, as well as MRI in obstetrics. The text features detailed coverage of magnetic resonance imaging of numerous disorders and disease states, including neck disease, thoracic disease; breast disease; congenital and acquired heart disease; vascular disease; diseases of the liver, pancreas, and spleen; diseases of the kidney, adrenals, and retroperitoneum; diseases of the male and female pelvis; and musculoskeletal diseases. Chapters on the biological and environmental hazards of MRI, the current clinical status of MRI in comparison to other imaging modalities, and economic considerations are also included.

  4. Focal renal masses: magnetic resonance imaging

    Thirty patients with focal renal masses were evaluated on a .12-Tesla resistive magnetic resonance unit using partial saturation and spin echo pulse sequence. Fifteen patients had cystic lesions, nine patients had renal cell carcinoma, two had metastatic lesions, one had an angiomyolipoma, and three had focal bacterial infection. Renal cell carcinomas demonstrated areas of increased signal using a partial saturation sequence. Magnetic resonance imaging accurately detected perinephric extension and vascular invasion in all patients. Metastatic disease to the kidney was uniformly low in signal, in contrast to primary renal cell carcinoma; an angiomyolipoma demonstrated very high signal intensity. Two masses resulting from acute focal bacterial nephritis were uniformly low in signal. Magnetic resonance imaging appears to be an accurate way of detecting, identifying, and staging focal renal masses

  5. Tutte polynomial in functional magnetic resonance imaging

    García-Castillón, Marlly V.

    2015-09-01

    Methods of graph theory are applied to the processing of functional magnetic resonance images. Specifically the Tutte polynomial is used to analyze such kind of images. Functional Magnetic Resonance Imaging provide us connectivity networks in the brain which are represented by graphs and the Tutte polynomial will be applied. The problem of computing the Tutte polynomial for a given graph is #P-hard even for planar graphs. For a practical application the maple packages "GraphTheory" and "SpecialGraphs" will be used. We will consider certain diagram which is depicting functional connectivity, specifically between frontal and posterior areas, in autism during an inferential text comprehension task. The Tutte polynomial for the resulting neural networks will be computed and some numerical invariants for such network will be obtained. Our results show that the Tutte polynomial is a powerful tool to analyze and characterize the networks obtained from functional magnetic resonance imaging.

  6. Magnetic resonance signal moment determination using the Earth's magnetic field

    Fridjonsson, Einar Orn

    2015-03-01

    We demonstrate a method to manipulate magnetic resonance data such that the moments of the signal spatial distribution are readily accessible. Usually, magnetic resonance imaging relies on data acquired in so-called k-space which is subsequently Fourier transformed to render an image. Here, via analysis of the complex signal in the vicinity of the centre of k-space we are able to access the first three moments of the signal spatial distribution, ultimately in multiple directions. This is demonstrated for biofouling of a reverse osmosis (RO) membrane module, rendering unique information and an early warning of the onset of fouling. The analysis is particularly applicable for the use of mobile magnetic resonance spectrometers; here we demonstrate it using an Earth\\'s magnetic field system.

  7. Intracellular Phosphate Dynamics in Muscle Measured by Magnetic Resonance Spectroscopy during Hemodialysis.

    Lemoine, Sandrine; Fournier, Thomas; Kocevar, Gabriel; Belloi, Amélie; Normand, Gabrielle; Ibarrola, Danielle; Sappey-Marinier, Dominique; Juillard, Laurent

    2016-07-01

    Of the 600-700 mg inorganic phosphate (Pi) removed during a 4-hour hemodialysis session, a maximum of 10% may be extracted from the extracellular space. The origin of the other 90% of removed phosphate is unknown. This study tested the hypothesis that the main source of phosphate removed during hemodialysis is the intracellular compartment. Six binephrectomized pigs each underwent one 3-hour hemodialysis session, during which the extracorporeal circulation blood flow was maintained between 100 and 150 ml/min. To determine in vivo phosphate metabolism, we performed phosphorous ((31)P) magnetic resonance spectroscopy using a 1.5-Tesla system and a surface coil placed over the gluteal muscle region. (31)P magnetic resonance spectra (repetition time =10 s; echo time =0.35 ms) were acquired every 160 seconds before, during, and after dialysis. During the dialysis sessions, plasma phosphate concentrations decreased rapidly (-30.4 %; P=0.003) and then, plateaued before increasing approximately 30 minutes before the end of the sessions; 16 mmol phosphate was removed in each session. When extracellular phosphate levels plateaued, intracellular Pi content increased significantly (11%; P<0.001). Moreover, βATP decreased significantly (P<0.001); however, calcium levels remained balanced. Results of this study show that intracellular Pi is the source of Pi removed during dialysis. The intracellular Pi increase may reflect cellular stress induced by hemodialysis and/or strong intracellular phosphate regulation. PMID:26561642

  8. The examination of cardiac metabolism of patients with hypercholesterolemia by phosphorus-31 magnetic resonance spectroscopy

    Martinek, M

    2001-01-01

    Objectives: we decided to investigate weather alterations in high energy phosphates occur in the myocardium of persons with hypercholesterolemia. Background: myocardial high energy phosphates have been shown to be reduced in various diseases of the heart such as coronary artery disease, heart failure and dilated cardiomyopathy. The latest studies on hypercholesterolemia show direct effects of high serum cholesterol on heart muscle cells, so do studies on statins. Methods: in the present study 32 male patients (mean age 48) with hypercholesterolemia and 27 male healthy volunteers (mean age 44,5) as age matched controls were included. The patients were divided into a statin-treated (n = 17) and an untreated subgroup (n = 15). Using a 1,5 Tesla whole-body magnetic resonance scanner (Siemens, Germany) phosphor-31 magnetic resonance spectroscopic imaging (31P MRSI) of the heart was performed in all subjects. The 31P MRSI slab (slab thickness = 40 mm, field of view = 320 mm, matrix 32 x 32, TR = 323 ms, TE 3 ms) co...

  9. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... is not harmful, but it may cause some medical devices to malfunction. Most orthopedic implants pose no risk, ... magnetic field is not harmful in itself, implanted medical devices that contain metal may malfunction or cause problems ...

  10. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... material called gadolinium, which is less likely to cause an allergic reaction than iodinated contrast material. Tell ... magnetic field is not harmful, but it may cause some medical devices to malfunction. Most orthopedic implants ...

  11. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... MRI uses a powerful magnetic field, radio frequency pulses and a computer to produce detailed pictures of ... sounds when the coils that generate the radiofrequency pulses are activated. Some centers provide earplugs, while others ...

  12. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... look like? The traditional MRI unit is a large cylinder-shaped tube surrounded by a circular magnet. ... still during imaging. A person who is very large may not fit into the opening of certain ...

  13. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... also screened for safety in the magnetic environment. Children will be given appropriately sized earplugs or headphones ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media MR Angiography ( ...

  14. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... allergies and whether there’s a possibility you are pregnant. The magnetic field is not harmful, but it ... if there is any possibility that they are pregnant. MRI has been used for scanning patients since ...

  15. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... scanner. top of page How does the procedure work? Unlike conventional x-ray examinations and computed tomography ( ... also screened for safety in the magnetic environment. Children will be given appropriately sized earplugs or headphones ...

  16. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... x-ray contrast material, drugs, food, or the environment, or if you have asthma. The contrast material ... are also screened for safety in the magnetic environment. Children will be given appropriately sized earplugs or ...

  17. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  18. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... pregnant. The magnetic field is not harmful, but it may cause some medical devices to malfunction. Most ... number of abrupt onset or long-standing symptoms. It can help diagnose conditions such as: brain tumors ...

  19. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... MRI centers allow a friend or parent to stay in the room as long as they are also screened for safety in the magnetic environment. Children will be given appropriately sized earplugs or headphones ...

  20. Magnetic resonance neurography. Imaging of peripheral nerves

    Magnetic resonance neurography (MRN) is a non-invasive technique using magnetic resonance imaging (MRI) in order to diagnose peripheral nerve pathologies and their underlying etiologies. MRN is already in clinical use and is now mostly used to delineate the anatomy of nerves and to establish the continuity or discontinuity of nerves in patients with traumatic nerve injuries, as well as to monitor processes of peripheral nerve degeneration and regeneration. This article reviews established and evolving novel MRN technologies with regard to their potential to meet the requirements for non-invasive imaging of peripheral nerves in clinical settings. (orig.)

  1. Magnetic Resonance Imaging with a Dielectric Lens

    Vazquez, F; Martin, R; Rodriguez, A O

    2009-01-01

    Recently, metamaterials have been introduced to improve the signal-to-noise ratio (SNR) of magnetic resonance images with very promising results. However, the use polymers in the generation of high quality images in magnetic resonance imaging has not been fully been investigated. These investigations explored the use of a dielectric periodical array as a lens to improve the image SNR generated with single surface coils. Commercial polycarbonate glazing sheets were used together with a circular coil to generate phantom images at 3 Tesla on a clinical MR imager.

  2. The progress of coronary magnetic resonance imaging

    Coronary heart disease (CHD) is a kind of disease with high morbidity and mortality. The early detection and treatment has important significance to patient. With the features of noninvasive, no radiation, good soft tissue contrast and multi parameter, and displaying anatomy in arbitrary plane, magnetic resonance imaging (MRI) was gradually applied in coronary artery imaging. In this paper, the main sequence and scanning technology of coronary MRI were reviewed, factors that affecting the quality of coronary magnetic resonance imaging were summarized, and the main advantages and disadvantages were concluded. (authors)

  3. Nuclear magnetic resonance as a petrophysical measurement

    Nuclear magnetic resonance (NMR) of hydrogen nuclei in fluids which saturate porous rocks is important in oil exploration and production, since NMR logs can provide good estimates of permeability and fluid flow. This paper reviews developments which connect the NMR properties of rocks with petrophysical properties, and particularly those relating to fluid flow. The recent advances in the use of NMR in boreholes which have spurred these developments are also discussed. The relevance of other NMR measurements on geological samples, including magnetic resonance imaging, is briefly referred to. (author)

  4. Progress in nuclear magnetic resonance spectroscopy

    Emsley, J W; Sutcliffe, L H

    2013-01-01

    Progress in Nuclear Magnetic Resonance Spectroscopy, Part 1 is a two-chapter text that reviews significant developments in nuclear magnetic resonance (NMR) applications.The first chapter discusses NMR studies of molecules physisorbed on homogeneous surfaces. This chapter also describes the phase changes in the adsorbed layer detected by following the variation in the NMR parameters. The second chapter examines the process to obtain a plotted, data reduced Fourier transform NMR spectrum. This chapter highlights the pitfalls that can cause a decrease in information content in a NMR spectrum. The

  5. Magnetic resonance neurography of the brachial plexus

    Vaishali Upadhyaya

    2015-01-01

    Full Text Available Magnetic Resonance Imaging (MRI is being increasingly recognised all over the world as the imaging modality of choice for brachial plexus and peripheral nerve lesions. Recent refinements in MRI protocols have helped in imaging nerve tissue with greater clarity thereby helping in the identification, localisation and classification of nerve lesions with greater confidence than was possible till now. This article on Magnetic Resonance Neurography (MRN is based on the authors′ experience of imaging the brachial plexus and peripheral nerves using these protocols over the last several years.

  6. Complex Response Function of Magnetic Resonance Spectrometers

    Annino, G; Fittipaldi, M; Martinelli, M

    2002-01-01

    A vectorial analysis of magnetic resonance spectrometers, based on traveling wave resonators and including the reference arm and the automatic control of frequency, has been developed. The proposed modelization, valid also for stationary wave resonators, gives the response function of the spectrometer for any working condition, including scalar detectors with arbitrary responsivity law and arbitrary excitation frequency. The purely dispersive and purely absorptive linear responses are discussed in detail for different scalar detectors. The developed approach allows to optimize the performances of the spectrometer and to obtain the intrinsic lineshape of the sample in a very broad range of working conditions. More complex setups can be modelized following the proposed scheme.

  7. Magnetic force microscopy using tip magnetization modulated by ferromagnetic resonance

    In magnetic force microscopy (MFM), the tip–sample distance should be reduced to analyze the microscopic magnetic domain structure with high spatial resolution. However, achieving a small tip–sample distance has been difficult because of superimposition of interaction forces such as van der Waals and electrostatic forces induced by the sample surface. In this study, we propose a new method of MFM using ferromagnetic resonance (FMR) to extract only the magnetic field near the sample surface. In this method, the magnetization of a magnetic cantilever is modulated by FMR to separate the magnetic field and topographic structure. We demonstrate the modulation of the magnetization of the cantilever and the identification of the polarities of a perpendicular magnetic medium. (paper)

  8. Magnetic force microscopy using tip magnetization modulated by ferromagnetic resonance

    Arima, Eiji; Naitoh, Yoshitaka; Li, Yan Jun; Yoshimura, Satoru; Saito, Hitoshi; Nomura, Hikaru; Nakatani, Ryoichi; Sugawara, Yasuhiro

    2015-03-01

    In magnetic force microscopy (MFM), the tip-sample distance should be reduced to analyze the microscopic magnetic domain structure with high spatial resolution. However, achieving a small tip-sample distance has been difficult because of superimposition of interaction forces such as van der Waals and electrostatic forces induced by the sample surface. In this study, we propose a new method of MFM using ferromagnetic resonance (FMR) to extract only the magnetic field near the sample surface. In this method, the magnetization of a magnetic cantilever is modulated by FMR to separate the magnetic field and topographic structure. We demonstrate the modulation of the magnetization of the cantilever and the identification of the polarities of a perpendicular magnetic medium.

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

    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)

  10. Interaction Study of an Amorphous Solid Dispersion of Cyclosporin A in Poly-Alpha-Cyclodextrin with Model Membranes by 1H-, 2H-, 31P-NMR and Electron Spin Resonance

    Jean-Claude Debouzy

    2014-01-01

    Full Text Available The properties of an amorphous solid dispersion of cyclosporine A (ASD prepared with the copolymer alpha cyclodextrin (POLYA and cyclosporine A (CYSP were investigated by 1H-NMR in solution and its membrane interactions were studied by 1H-NMR in small unilamellar vesicles and by 31P 2H NMR in phospholipidic dispersions of DMPC (dimyristoylphosphatidylcholine in comparison with those of POLYA and CYSP alone. 1H-NMR chemical shift variations showed that CYSP really interacts with POLYA, with possible adduct formation, dispersion in the solid matrix of the POLYA, and also complex formation. A coarse approach to the latter mechanism was tested using the continuous variations method, indicating an apparent 1 : 1 stoichiometry. Calculations gave an apparent association constant of log Ka = 4.5. A study of the interactions with phospholipidic dispersions of DMPC showed that only limited interactions occurred at the polar head group level (31P. Conversely, by comparison with the expected chain rigidification induced by CYSP, POLYA induced an increase in the fluidity of the layer while ASD formation led to these effects almost being overcome at 298 K. At higher temperature, while the effect of CYSP seems to vanish, a resulting global increase in chain fluidity was found in the presence of ASD.

  11. Nuclear magnetic resonance of thermally oriented nuclei

    The more recent developments in the spectroscopy of Nuclear Magnetic Resonance on Oriented Nuclei (NMRON) are reviewed; both theoretical and experimental advances are summarised with applications to On-Line and Off-Line determination of magnetic dipole and electric quadrupole hyperfine parameters. Some emphasis is provided on solid state considerations with indications of where likely enhancements in technique will lead in conventional hyperfine studies. (orig.)

  12. Multi-dimensionally encoded magnetic resonance imaging

    Lin, Fa-Hsuan

    2012-01-01

    Magnetic resonance imaging typically achieves spatial encoding by measuring the projection of a q-dimensional object over q-dimensional spatial bases created by linear spatial encoding magnetic fields (SEMs). Recently, imaging strategies using nonlinear SEMs have demonstrated potential advantages for reconstructing images with higher spatiotemporal resolution and reducing peripheral nerve stimulation. In practice, nonlinear SEMs and linear SEMs can be used jointly to further improve the image...

  13. Multimodal neuroimaging provides a highly consistent picture of energy metabolism, validating 31P MRS for measuring brain ATP synthesis

    Neuroimaging methods have considerably developed over the last decades and offer various noninvasive approaches for measuring cerebral metabolic fluxes connected to energy metabolism, including PET and magnetic resonance spectroscopy (MRS). Among these methods, 31P MRS has the particularity and advantage to directly measure cerebral ATP synthesis without injection of labeled precursor. However, this approach is methodologically challenging, and further validation studies are required to establish 31P MRS as a robust method to measure brain energy synthesis. In the present study, we performed a multimodal imaging study based on the combination of 3 neuroimaging techniques, which allowed us to obtain an integrated picture of brain energy metabolism and, at the same time, to validate the saturation transfer 31P MRS method as a quantitative measurement of brain ATP synthesis. A total of 29 imaging sessions were conducted to measure glucose consumption (CMRglc), TCA cycle flux (VTCA), and the rate of ATP synthesis (VATP) in primate monkeys by using 18F-FDG PET scan, indirect 13C MRS, and saturation transfer 31P MRS, respectively. These 3 complementary measurements were performed within the exact same area of the brain under identical physiological conditions, leading to: CMRglc = 0.27 ± 0.07 μmol.g-1.min-1, VTCA = 0.63 ± 0.12 μmol.g-1.min-1, and VATP = 7.8 ± 2.3 μmol.g-1.min-1. The consistency of these 3 fluxes with literature and, more interestingly, one with each other, demonstrates the robustness of saturation transfer 31P MRS for directly evaluating ATP synthesis in the living brain. (authors)

  14. Magnetic resonance imaging in sudden deafness

    The etiology of sudden deafness can remain undetermined despite extensive investigation. This study addresses the value of magnetic resonance imaging in the analysis of sudden deafness patients.Study Design: transversal cohort.Material And Method: In a prospective study, 49 patients attended at otolaryngology emergency room of Federal University of Sao Paulo - Escola Paulista de Medicina, from April 2001 to May 2003, were submitted to magnetic resonance imaging.Results: Magnetic Resonance abnormalities were seen in 23 (46.9%) patients and revealed two tumors suggestive of meningioma, three vestibular schwannomas, thirteen microangiopathic changes of the brain and five (21.7%) pathological conditions of the labyrinth.Conclusion: Sudden deafness should be approached as a symptom common to different diseases. The presence of cerebellopontine angle tumors in 10.2% of our cases, among other treatable causes, justifies the recommendation of gadolinium-enhanced magnetic resonance use, not only to study the auditory peripheral pathway, but to study the whole auditory pathway including the brain. (author)

  15. Numerical methods in electron magnetic resonance

    The focal point of the thesis is the development and use of numerical methods in the analysis, simulation and interpretation of Electron Magnetic Resonance experiments on free radicals in solids to uncover the structure, the dynamics and the environment of the system

  16. Measurement of myocardial perfusion using magnetic resonance

    Fritz-Hansen, T.; Jensen, L.T.; Larsson, H.B.;

    2008-01-01

    Cardiac magnetic resonance imaging (MRI) has evolved rapidly. Recent developments have made non-invasive quantitative myocardial perfusion measurements possible. MRI is particularly attractive due to its high spatial resolution and because it does not involve ionising radiation. This paper reviews...

  17. Sports Health Magnetic Resonance Imaging Challenge

    Howell, Gary A.; Stadnick, Michael E.; Awh, Mark H.

    2010-01-01

    Injuries to the Lisfranc ligament complex are often suspected, particularly in the setting of midfoot pain without radiographic abnormality. Knowledge of the anatomy and magnetic resonance imaging findings of injuries to this region is helpful for the diagnosing and treating physicians.

  18. Sports Health Magnetic Resonance Imaging Challenge

    Howell, Gary A.; Stadnick, Michael E.; Awh, Mark H.

    2010-01-01

    Injuries to the Lisfranc ligament complex are often suspected, particularly in the setting of midfoot pain without radiographic abnormality. Knowledge of the anatomy and magnetic resonance imaging findings of injuries to this region is helpful for the diagnosing and treating physicians. PMID:23015984

  19. Evaluation of nuclear magnetic resonance spectroscopy variability

    Barreto, Felipe Rodrigues; Salmon, Carlos Ernesto Garrido, E-mail: garrido@ffclrp.usp.br [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Filisofia, Ciencias e Letras; Otaduy, Maria Concepcion Garcia [Universidade de Sao Paulo (FAMUS/USP), Sao Paulo, SP (Brazil). Fac. de Medicina. Departamento de Radiologia

    2014-11-01

    Introduction: the intrinsically high sensitivity of Magnetic Resonance Spectroscopy (MRS) causes considerable variability in metabolite quantification. In this study, we evaluated the variability of MRS in two research centers using the same model of magnetic resonance image scanner. Methods: two metabolic phantoms were created to simulate magnetic resonance spectra from in vivo hippocampus. The phantoms were filled with the same basic solution containing the following metabolites: N-acetyl-aspartate, creatine, choline, glutamate, glutamine and inositol. Spectra were acquired over 15 months on 26 acquisition dates, resulting in a total of 130 spectra per center. Results: the phantoms did not undergo any physical changes during the 15-month period. Temporal analysis from both centers showed mean metabolic variations of 3.7% in acquisitions on the same day and of 8.7% over the 15-month period. Conclusion: The low deviations demonstrated here, combined with the high specificity of Magnetic Resonance Spectroscopy, confirm that it is feasible to use this technique in multicenter studies in neuroscience research. (author)

  20. Imaging Intelligence with Proton Magnetic Resonance Spectroscopy

    Jung, Rex E.; Gasparovic, Charles; Chavez, Robert S.; Caprihan, Arvind; Barrow, Ranee; Yeo, Ronald A.

    2009-01-01

    Proton magnetic resonance spectroscopy ([to the first power]H-MRS) is a technique for the assay of brain neurochemistry "in vivo." N-acetylaspartate (NAA), the most prominent metabolite visible within the [to the first power]H-MRS spectrum, is found primarily within neurons. The current study was designed to further elucidate NAA-cognition…

  1. Magnetic resonance imaging in radiotherapy treatment planning

    Moerland, Marinus Adriaan

    2001-01-01

    From its inception in the early 1970's up to the present, magnetic resonance imaging (MRI) has evolved into a sophisticated technique, which has aroused considerable interest in var- ious subelds of medicine including radiotherapy. MRI is capable of imaging in any plane and does not use ionizing rad

  2. Evaluation of nuclear magnetic resonance spectroscopy variability

    Introduction: the intrinsically high sensitivity of Magnetic Resonance Spectroscopy (MRS) causes considerable variability in metabolite quantification. In this study, we evaluated the variability of MRS in two research centers using the same model of magnetic resonance image scanner. Methods: two metabolic phantoms were created to simulate magnetic resonance spectra from in vivo hippocampus. The phantoms were filled with the same basic solution containing the following metabolites: N-acetyl-aspartate, creatine, choline, glutamate, glutamine and inositol. Spectra were acquired over 15 months on 26 acquisition dates, resulting in a total of 130 spectra per center. Results: the phantoms did not undergo any physical changes during the 15-month period. Temporal analysis from both centers showed mean metabolic variations of 3.7% in acquisitions on the same day and of 8.7% over the 15-month period. Conclusion: The low deviations demonstrated here, combined with the high specificity of Magnetic Resonance Spectroscopy, confirm that it is feasible to use this technique in multicenter studies in neuroscience research. (author)

  3. Sensorineural hearing loss after magnetic resonance imaging

    Mollasadeghi, Abolfazl; Mehrparvar, Amir Houshang; Atighechi, Saeid;

    2013-01-01

    Magnetic resonance imaging (MRI) devices produce noise, which may affect patient's or operators' hearing. Some cases of hearing impairment after MRI procedure have been reported with different patterns (temporary or permanent, unilateral or bilateral, with or without other symptoms like tinnitus...

  4. Recent progress in magnetic resonance imaging

    Magnetic resonance imaging (MRI) has become a powerful tool in the life sciences and medical diagnosis, for which it was awarded the 2003 Nobel prize in physiology or medicine. The latest progress in MRI, including medical, brain-functional, in-vivo spectroscopic, and microscopic imaging are briefly reviewed

  5. 3D Reconstruction in Magnetic Resonance Imaging

    Mikulka, J.; Bartušek, Karel

    2010-01-01

    Roč. 6, č. 7 (2010), s. 617-620. ISSN 1931-7360 R&D Projects: GA ČR GA102/09/0314 Institutional research plan: CEZ:AV0Z20650511 Keywords : reconstruction methods * magnetic resonance imaging Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  6. 3D Reconstruction in Magnetic Resonance Imaging

    Mikulka, J.; Bartušek, Karel

    Cambridge : The Electromagnetics Academy, 2010, s. 1043-1046. ISBN 978-1-934142-14-1. [PIERS 2010 Cambridge. Cambridge (US), 05.07.2010-08.07.2010] R&D Projects: GA ČR GA102/09/0314 Institutional research plan: CEZ:AV0Z20650511 Keywords : 3D reconstruction * magnetic resonance imaging Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  7. Brain Magnetic Resonance Imaging in Tyrosinemia

    A 3.5-year-old girl with tyrosinemia is reported. A computed tomography scan of the abdomen revealed multiple hepatic nodules. Brain magnetic resonance imaging revealed bilateral high-signal changes confined to the globus pallidus on T2-weighted images. Globus pallidus lesions likely represented neuropathologic changes such as astocytosis, delayed myelination, and status spongiosus (myelin splitting and vacuolation)

  8. Cardiovascular magnetic resonance in systemic hypertension

    Maceira Alicia M; Mohiaddin Raad H

    2012-01-01

    Abstract Systemic hypertension is a highly prevalent potentially modifiable cardiovascular risk factor. Imaging plays an important role in the diagnosis of underlying causes for hypertension, in assessing cardiovascular complications of hypertension, and in understanding the pathophysiology of the disease process. Cardiovascular magnetic resonance (CMR) provides accurate and reproducible measures of ventricular volumes, mass, function and haemodynamics as well as uniquely allowing tissue char...

  9. Magnetic Resonance Lithography with Nanometer Resolution

    Fahad AlGhannam

    2016-04-01

    Full Text Available We propose an approach for super-resolution optical lithography which is based on the inverse of magnetic resonance imaging (MRI. The technique uses atomic coherence in an ensemble of spin systems whose final state population can be optically detected. In principle, our method is capable of producing arbitrary one and two dimensional high-resolution patterns with high contrast.

  10. Texture analysis methodologies for magnetic resonance imaging

    Materka, Andrzej

    2004-01-01

    Methods for the analysis of digital-image texture are reviewed. The functions of MaZda, a computer program for quantitative texture analysis developed within the framework of the European COST (Cooperation in the Field of Scientific and Technical Research) B11 program, are introduced. Examples of texture analysis in magnetic resonance images are discussed.

  11. Numerical methods in electron magnetic resonance

    Soernes, A.R

    1998-07-01

    The focal point of the thesis is the development and use of numerical methods in the analysis, simulation and interpretation of Electron Magnetic Resonance experiments on free radicals in solids to uncover the structure, the dynamics and the environment of the system.

  12. Brain Morphometry Using Anatomical Magnetic Resonance Imaging

    Bansal, Ravi; Gerber, Andrew J.; Peterson, Bradley S.

    2008-01-01

    The efficacy of anatomical magnetic resonance imaging (MRI) in studying the morphological features of various regions of the brain is described, also providing the steps used in the processing and studying of the images. The ability to correlate these features with several clinical and psychological measures can help in using anatomical MRI to…

  13. Automated Segmentation of Cardiac Magnetic Resonance Images

    Stegmann, Mikkel Bille; Nilsson, Jens Chr.; Grønning, Bjørn A.

    2001-01-01

    Magnetic resonance imaging (MRI) has been shown to be an accurate and precise technique to assess cardiac volumes and function in a non-invasive manner and is generally considered to be the current gold-standard for cardiac imaging [1]. Measurement of ventricular volumes, muscle mass and function...

  14. Modelling Strategies for Functional Magnetic Resonance Imaging

    Madsen, Kristoffer Hougaard

    2009-01-01

    This thesis collects research done on several models for the analysis of functional magnetic resonance neuroimaging (fMRI) data. Several extensions for unsupervised factor analysis type decompositions including explicit delay modelling as well as handling of spatial and temporal smoothness and...

  15. Quantitative dosing by nuclear magnetic resonance

    The measurement of the absolute concentration of a heavy water reference containing approximately 99.8 per cent of D2O has been performed, by an original magnetic resonance method ('Adiabatic fast passage method') with a precision of 5.10-5 on the D2O concentration. (author)

  16. Biliary ascariasis on magnetic resonance cholangiopancreatography

    Mohammad A Hashmi

    2009-01-01

    Full Text Available A 17-year-old girl presented with features of biliary obstruction. Magnetic resonance cholangi-pancreatography revealed typical linear signals in common bile duct, which appears like Ascaris lumbricoides. The diagnosis was confirmed by endoscopic removal of the worm.

  17. Magnetic resonance studies of solid polymers

    This paper is a review of the application of nuclear magnetic resonance (NMR) to solid polymers. In the first, theoretical part, the elements of the theory of NMR, which are necessary for the study of the properties of solid polymers are discussed: the moments method, nuclear relaxation and the distribution of correlation times. In the second part the experimental results are presented. (author)

  18. Magnetic resonance imaging in acute tendon ruptures

    Daffner, R.H.; Lupetin, A.R.; Dash, N.; Riemer, B.L.

    1986-11-01

    The diagnosis of acute tendon ruptures of the extensor mechanism of the knee or the Achilles tendon of the ankle may usually be made by clinical means. Massive soft tissue swelling accompanying these injuries often obscures the findings, however. Magnetic resonance imaging (MRI) can rapidly demonstrate these tendon ruptures. Examples of the use of MRI for quadriceps tendon, and Achilles tendon rupture are presented.

  19. Magnetic resonance angiography in meningovascular syphilis

    Meningovascular neurosyphilis (MN) is an unusual cause of stroke in young adults. The clinical manifestations include prodromal symptoms weeks or months before definitive stroke. The diagnosis is based on clinical findings and examination of the serum and cerebrospinal fluid. We report a case of MN with basilar artery irregularities demonstrated by magnetic resonance angiography. (orig.)

  20. Fractioning of sodium polyphosphate and characterization by {sup 31}P NMR: a experience to physical-chemistry lessons; Fracionamento de polifosfato de sodio e caracterizacao por RMN de 31P: um experimento para aulas de Fisico-Quimica

    Lima, Emilia Celma de Oliveira; Alcantara, Glaucia Braz Alcantara; Damasceno, Fernando Cruvinel, E-mail: elima@quimica.ufg.b [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Inst. de Quimica; Moita Neto, Jose Machado [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil). Dept. de Quimica; Galembeck, Fernando [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica

    2010-07-01

    This text describes an experiment on fractional precipitation of a polymer together with determination of average degree of polymerization by NMR. Commercial sodium polyphosphate was fractionated by precipitation from aqueous solution by adding increasing amounts of acetone. The polydisperse salt and nine fractions obtained from it were analyzed by {sup 31}P nuclear magnetic resonance and the degree of polymerization of the salts and of the fractions were calculated. Long-chain sodium polyphosphate was also synthesized and analyzed. This experiment was tested in a PChem lab course but it can be used also to illustrate topics of inorganic polymers and analytical chemistry. (author)

  1. Interaction of magnetic resonators studied by the magnetic field enhancement

    Yumin Hou

    2013-12-01

    Full Text Available It is the first time that the magnetic field enhancement (MFE is used to study the interaction of magnetic resonators (MRs, which is more sensitive than previous parameters–shift and damping of resonance frequency. To avoid the coherence of lattice and the effect of Bloch wave, the interaction is simulated between two MRs with same primary phase when the distance is changed in the range of several resonance wavelengths, which is also compared with periodic structure. The calculated MFE oscillating and decaying with distance with the period equal to resonance wavelength directly shows the retardation effect. Simulation also shows that the interaction at normal incidence is sensitive to the phase correlation which is related with retardation effect and is ultra-long-distance interaction when the two MRs are strongly localized. When the distance is very short, the amplitude of magnetic resonance is oppressed by the strong interaction and thus the MFE can be much lower than that of single MR. This study provides the design rules of metamaterials for engineering resonant properties of MRs.

  2. The working principle of magnetic resonance therapy

    Brizhik, Larissa; Fermi, Enrico

    2015-01-01

    In this paper we describe briefly the basic aspects of magnetic resonance therapy, registered as TMR therapy. Clinical studies have shown that application of this therapy significantly accelerates wound healing and, in particular, healing of the diabetic foot disease. To understand the working principle of this therapy, we analyze relevant to it biological effects produced by magnetic fields. Based on these data, we show that there is a hierarchy of the possible physical mechanisms, which can produce such effects. The mutual interplay between the mechanisms can lead to a synergetic outcome delayed in time, which can affect the physiological state of the organism. In particular, we show that soliton mediated charge transport during the redox processes in living organisms is sensitive to magnetic fields, so that such fields can facilitate redox processes in particular, and can stimulate the healing effect of the organism in general. This and other non-thermal resonant mechanisms of the biological effects of mag...

  3. Muscle metabolism of professional athletes using 31P-spectroscopy

    Purpose: The aim of the study was to examine muscle metabolism in athletes by 31P-spectroscopy (MRS) and to evaluate to what degree the respective resonance spectrum correlates with the kind of muscle exercise. Material and Methods: Twelve runners and 12 young ice skaters were studied by 31P-spectroscopy of the gastrocnemic medialis muscle and the vastus medialis muscle using a surface coil at 1.5 T. Results: Sprinters displayed a higher phosphocreatinine/inorganic phosphate (PCr/Pi) and PCr/β-ATP ratios than marathon runners. The respective parameters for middle distance runners were in between. Ice skaters could prospectively be divided into sprint- and long-distance runners by our results which correlated with the athletes' training performance. Conclusion: 31P-spectroscopy can evaluate the distribution of muscle fiber types. Thus, the athlete's potential for sprint- or long-distance running can be determined. Additional studies will have to demonstrate to what extent training may change muscle fiber distribution. (orig.)

  4. Magnetic resonance imaging by using nano-magnetic particles

    Shokrollahi, H., E-mail: Shokrollahi@sutech.ac.ir [Electroceramics Group, Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of); Khorramdin, A. [Electroceramics Group, Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of); Isapour, Gh. [Department of Materials and Engineering, Hakim Sabzevari University (Iran, Islamic Republic of)

    2014-11-15

    Magnetism and magnetic materials play a major role in various biological applications, such as magnetic bioseparation, magnetic resonance imaging (MRI), hyperthermia treatment of cancer and drug delivery. Among these techniques, MRI is a powerful method not only for diagnostic radiology but also for therapeutic medicine that utilizes a magnetic field and radio waves. Recently, this technique has contributed greatly to the promotion of the human quality life. Thus, this paper presents a short review of the physical principles and recent advances of MRI, as well as providing a summary of the synthesis methods and properties of contrast agents, like different core materials and surfactants. - Highlights: • This paper studies the physics of MRI as a powerful diagnostic technique. • MRI uses the differentiation between healthy and pathological tissues. • The relaxation times can be shortened by the use of a magnetic contrast agent. • The magnetic nanoparticles act as contrast agents, helping to increase the resolution. • Different synthesis methods can influence the magnetic resonance behavior.

  5. Nuclear magnetic resonance (NMR): principles and applications

    The basis for the phenomenon of nuclear magnetic resonance (NMR) is the ability of certain nuclei possessing both intrinsic angular momentum or ''spin'' I and magnetic moment to absorb electromagnetic energy in the radio frequency range. In principle, there are approximately 200 nuclei which may be investigated using the NMR technique. The NMR spectrum consists of intensity peaks along an axis calibrated in terms of the steady magnetic field or the frequency of the radiofrequency electromagnetic radiation. Analysis of the number, spacing, position and intensity of the lines in an NMR spectrum consists of intensity peaks along an axis calibrated in terms of the steady magnetic field or the frequency of the radiofrequency electromagnetic radiation. Analysis of the number, spacing, position and intensity of the lines in an NMR spectrum provides a variety of qualitative and quantitative analytical applications. The most obvious applications consist of the measurements of nuclear properties, such as spin number and nuclear magnetic moment. In liquids, the fine structure of resonance spectra provides a tool for chemical identification and molecular structure analysis. Other applications include the measurements of self-diffusion coefficients, magnetic fields and field homogeneity, inter-nuclear distances, and, in some cases, the water content of biological materials. (author)

  6. Physics of Magnetic Resonance. Chapter 14

    The discovery of nuclear magnetic resonance (NMR), a property of nuclei in a magnetic field where they are able to absorb applied radiofrequency (RF) energy and subsequently release it at a specific frequency, goes back many decades to the early 1900s. Physicist Isidor I. Rabi, fascinated by the work of Otto Stern and Walther Gerlach which demonstrated that particles have intrinsic quantum properties, delved into the magnetic properties of nuclei, and in 1938 Rabi discovered the phenomenon of NMR. Several years later, in 1946, Felix Bloch and Edward Purcell refined the methods and successfully measured the NMR signal from liquids and solids. For their discoveries, Rabi received the Nobel Prize for physics in 1944 and Bloch and Purcell in 1952. While Rabi, Bloch, Purcell and other physicists working in this field had laid the foundations, a major discovery that transformed the NMR phenomenon for imaging was not made until 1973, when Paul Lauterbur developed a method for spatially encoding the NMR signal by utilizing linear magnetic field gradients. About the same time, Peter Mansfield had also discovered a means of determining the spatial structure of solids by introducing a linear gradient across the object. The idea of applying magnetic field gradients to induce spatially varying resonance frequencies to resolve the spatial distribution of magnetization was a major milestone and the beginning of magnetic resonance imaging (MRI). For their work, Lauterbur and Mansfield were awarded the Nobel Prize for medicine in 2003. Since its discovery, MRI has quickly become one of the most important medical imaging devices available to physicians today. Unlike other imaging modalities, such as X ray and computed tomography, MRI does not involve ionizing radiation. MRI also offers superior soft tissue contrast that is not possible with other imaging modalities. Furthermore, in MRI, the desired level of image contrast among different tissues can often be precisely controlled

  7. 21 CFR 892.1000 - Magnetic resonance diagnostic device.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Magnetic resonance diagnostic device. 892.1000... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1000 Magnetic resonance diagnostic device. (a) Identification. A magnetic resonance diagnostic device is intended for general diagnostic...

  8. Study of myocardial metabolism in heterotopically transplanted rat hearts by 31P NMR

    This is a first study which investigated in vivo myocardial metabolism changes associated with acute graft rejection by 31P nuclear magnetic resonance (NMR). The donor hearts were heterotopically transplanted in the cervical portion of the recipient rats. Mean graft survival in the allogeneic transplantation group (Exp. G.) was 9.3 ± 2.6 days (n = 6), while all of the grafts (n = 5) in the syngeneic transplantation group (Cont. G.) have survived more than 21 days (the longest one : > 192) without any rejection episode. Six different kinds of signals were obtained in the spectrum by 31P NMR spectroscopy : phosphomonoester (PME), inorganic phosphate (Pi), phosphocreatine (PCr), as well as ATP-α, -β and -γ. The results obtained here showed : (1) After 24 hours of transplantation, increased Pi/PCr ratios (> 0.5) were observed both in the Exp. G. and in the Cont. G., which suggested the myocardial damage due to transplantation operation procedure. The ratios were gradually decreased and reached to less than 0.5 on the 3rd day after grafting. (2) Thereafter, in the Exp. G. Pi was gradually increased and PCr was gradually decreased because of the acute rejection; the Pi/PCr ratio was elevated beyond 0.5. However, no change of Pi/PCr ratio was observed in the Cont. G. 31P NMR spectroscopy employed in the experimental model of heterotopic heart transplantation at the cervical portion of rats was found to be useful and non-invasive for the study of myocardial metabolism after grafting. (author)

  9. Human in-vivo 31P MR spectroscopy of benign and malignant breast tumors

    To assess the potential clinical utility of in-vivo 31P magnetic resonance spectroscopy (MRS) in patients with various malignant and benign breast lesions. Seventeen patients with untreated primary malignant breast lesions (group I), eight patients with untreated benign breast lesions (group II) and seven normal breasts (group III) were included in this study. In-vivo 31P MRS was performed using a 1.5 Tesla MR scanner. Because of the characteristics of the coil, the volume of the tumor had to exceed 12 cc (3x2x2 cm), with a superoinferior diameter at least 3 cm. Mean and standard deviations of each metabolite were calculated and metabolite ratios, such as PME/PCr, PDE/PCr, T-ATP/PCr and PCr/T-ATP were calculated and statistically analyzed. Significant differences in PME were noted between groups I and III (p=0.0213), and between groups II and III (p=0.0213). The metabolite ratios which showed significant differences were PME/PCr (between groups II and III) (p=0.0201), PDE/PCr (between groups I and III, and between groups II and III) (p=0.0172), T-ATP/PCr (between groups II and III) (p=0.0287), and PCr/T-ATP (between groups II and III) (p=0.0287). There were no significant parameters between groups I and II. In-vivo 31P MRS is not helpful for establishing a differential diagnosis between benign and malignant breast lesions, at least with relatively large lesions greater than 3 cm in one or more dimensions

  10. Soft x-ray resonant magnetic diffraction.

    Wilkins, S. B.; Hatton, P. D.; Roper, M.D.; Prabhakaran, D.; Boothroyd, A. T.

    2003-01-01

    We have conducted the first soft x-ray diffraction experiments from a bulk single crystal, studying the bilayer manganite La22xSr12xMn2O7 with x 0:475 in which we were able to access the (002) Bragg reflection using soft x rays. The Bragg reflection displays a strong resonant enhancement at the LIII and LII manganese absorption edges. We demonstrate that the resonant enhancement of the magnetic diffraction of the (001) is extremely large, indeed so large that it exceeds that of t...

  11. Advances in magnetic and optical resonance

    Warren, Warren S

    2013-01-01

    Advances in Magnetic and Optical Resonance contains three articles which review quite fundamentally different aspects of coherent spectroscopy. An enormous variety of effects can be observed when optical and spin resonances are coupled, usually by a combination of radio frequency and laser irradiation. The first article reviews these effects and pays particular attention to developing a theoretical framework which is as similar as possible for the optical and spin cases. Subsequent articles examine deuterium relaxation in molecular solids, and the spatiotemporal growth of multiple spin coheren

  12. Magnetic resonance imaging of valvular heart disease

    Søndergaard, Lise; Ståhlberg, F; Thomsen, C

    1999-01-01

    The optimum management of patients with valvular heart diseases requires accurate and reproducible assessment of the valvular lesion and its hemodynamic consequences. Magnetic resonance imaging (MRI) techniques, such as volume measurements, signal-void phenomena, and velocity mapping, can be used...... and predicting the optimal timing for valvular surgery. This paper reviews the validation of these MRI techniques in assessing valvular heart disease and discusses some typical pitfalls of the techniques, including suggestions for solutions.J. Magn. Reson. Imaging 1999;10:627-638....

  13. 2H-nuclear magnetic resonance investigations on phospholipid acyl chain order and dynamics in the gramicidin-induced hexagonal HII phase.

    Chupin, V.; Killian, J A; Kruijff, B. de

    1987-01-01

    The following results are reported in this paper: The interaction of gramicidin with [11,11-2H2]dioleoylphosphatidylcholine (DOPC) and [11,11-2H2]dioleoylphosphatidylethanolamine (DOPE) at different stages of hydration was studied by 2H- and 31P-nuclear magnetic resonance. In the L alpha phase in excess water the acyl chains of phosphatidylethanolamine (PE) are more ordered than phosphatidylcholine (PC) most likely as the result of the lower headgroup hydration of the former lipid. In excess ...

  14. Magnetic resonance spectroscopy in schizophrenia. Possibilities and limitations; Magnetresonanzspektroskopie bei Schizophrenie. Moeglichkeiten und Grenzen

    Wobrock, T. [Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany). Klinik fuer Psychiatrie und Psychotherapie; Universitaetsklinikum des Saarlandes, Klinik fuer Psychiatrie und Psychotherapie, Homburg/Saar (Germany); Scherk, H.; Falkai, P. [Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany). Klinik fuer Psychiatrie und Psychotherapie

    2005-02-01

    Magnetic resonance spectroscopy is a noninvasive investigative technique for in vivo detection of biochemical changes in neuropsychiatric disorders for which especially proton ({sup 1}H-MRS) and phosphorus ({sup 31}P-MRS) magnetic resonance spectroscopy have been used. In this review we explain the principles of MRS and summarize the studies in schizophrenia. A systematic literature review was carried out for {sup 1}H-MRS studies investigating schizophrenic patients compared to controls. The inconsistent results in the cited studies may be due to different study population, specific neuroimaging technique, and selected brain regions. Frequent findings are decreased PME and increased PDE concentrations ({sup 31}P-MRS) linked to altered metabolism of membrane phospholipids and decreased N-acetylaspartate (NAA) or NAA/choline ratio ({sup 1}H-MRS) linked to neuronal damage in frontal (DLPFC) or temporal regions in patients with schizophrenia. These results contribute to the disturbed frontotemporal-thalamic network assumed in schizophrenia and are supported by additional functional neuroimaging, MRI morphometry, and neuropsychological evaluation. The combination of the described investigative techniques with MRS in follow-up studies may provide more specific clues for understanding the pathogenesis and disease course in schizophrenia. (orig.) [German] Die Magnetresonanzspektroskopie (MRS) stellt ein nichtinvasives Verfahren dar, mit dem in vivo biochemische Veraenderungen spezifischer Hirnregionen bei verschiedenen psychiatrischen Erkrankungen untersucht werden koennen. Dabei werden insbesondere die Protonenmagnetresonanzspektroskopie ({sup 1}H-MRS) sowie die Phosphormagnetresonanzspektroskopie ({sup 31}P-MRS) verwendet. In der vorliegenden Uebersichtsarbeit werden die methodischen Grundlagen erlaeutert sowie die Befundlage bei der Schizophrenie referiert. Fuer die Darstellung der Studien zur {sup 1}H-MRS bei schizophrenen Patienten im Vergleich zu einer Kontrollgruppe

  15. A hyperpolarized equilibrium for magnetic resonance

    Hövener, Jan-Bernd; Schwaderlapp, Niels; Lickert, Thomas; Duckett, Simon B.; Mewis, Ryan E.; Highton, Louise A. R.; Kenny, Stephen M.; Green, Gary G. R.; Leibfritz, Dieter; Korvink, Jan G.; Hennig, Jürgen; von Elverfeldt, Dominik

    2013-12-01

    Nuclear magnetic resonance spectroscopy and imaging (MRI) play an indispensable role in science and healthcare but use only a tiny fraction of their potential. No more than ≈10 p.p.m. of all 1H nuclei are effectively detected in a 3-Tesla clinical MRI system. Thus, a vast array of new applications lays dormant, awaiting improved sensitivity. Here we demonstrate the continuous polarization of small molecules in solution to a level that cannot be achieved in a viable magnet. The magnetization does not decay and is effectively reinitialized within seconds after being measured. This effect depends on the long-lived, entangled spin-order of parahydrogen and an exchange reaction in a low magnetic field of 10-3 Tesla. We demonstrate the potential of this method by fast MRI and envision the catalysis of new applications such as cancer screening or indeed low-field MRI for routine use and remote application.

  16. In vivo 31P-NMR spectroscopy of chronically stimulated canine skeletal muscle

    Chronic stimulation converts skeletal muscle of mixed fiber type to a uniform muscle made up of type I, fatigue-resistant fibers. Here, the bioenergetic correlates of fatigue resistance in conditioned canine latissimus dorsi are assessed with in vivo phosphorus-31 nuclear magnetic resonance (31P-NMR) spectroscopy. After chronic electrical stimulation, five dogs underwent 31P-NMR spectroscopic and isometric tension measurements on conditioned and contralateral control muscle during stimulation for 200, 300, 500, and 800 ms of an 1,100-ms duty cycle. With stimulation, phosphocreatine (PCr) fell proportional to the degree of stimulation in both conditioned and control muscle but fell significantly less in conditioned muscle at all the least intense stimulation period (200 ms). Isometric tension, expressed as a tension time index per gram muscle, was significantly greater in the conditioned muscle at the two longest stimulation periods. The overall small change in PCr and the lack of a plateau in tension observed in the conditioned muscle are similar to that seen in cardiac muscle during increased energy demand. This study indicates that the conditioned muscle's markedly enhanced resistance to fatigue is in part the result of its increased capacity for oxidative phosphorylation

  17. Animal manure phosphorus characterization by sequential chemical fractionation, release kinetics and 31P-NMR analysis

    Tales Tiecher

    2014-10-01

    Full Text Available Phosphate release kinetics from manures are of global interest because sustainable plant nutrition with phosphate will be a major concern in the future. Although information on the bioavailability and chemical composition of P present in manure used as fertilizer are important to understand its dynamics in the soil, such studies are still scarce. Therefore, P extraction was evaluated in this study by sequential chemical fractionation, desorption with anion-cation exchange resin and 31P nuclear magnetic resonance (31P-NMR spectroscopy to assess the P forms in three different dry manure types (i.e. poultry, cattle and swine manure. All three methods showed that the P forms in poultry, cattle and swine dry manures are mostly inorganic and highly bioavailable. The estimated P pools showed that organic and recalcitrant P forms were negligible and highly dependent on the Ca:P ratio in manures. The results obtained here showed that the extraction of P with these three different methods allows a better understanding and complete characterization of the P pools present in the manures.

  18. Rapid-sequence phosphorus-31 magnetic resonance spectroscopy of the human heart using a 1.5-T clinical system

    Chida, K.; Saito, H.; Nagasaka, T.; Otani, H.; Kohzuki, M.; Zuguchi, M. [Tohoku Univ., Sendai (Japan). Dept. of Radiological Technology

    2004-02-01

    To compare a 'standard' slow phosphorus-31 magnetic resonance spectroscopy (31P-MRS) sequence with two faster sequences in phantoms and healthy volunteers using a 1.5-T clinical system. Complete 3D localization was performed using a 2D phosphorus chemical-shift imaging sequence in combination with 30-mm axial slice-selective excitation. Two 31P-MRS rapid sequences (RS8-4: 8 x 8 phase-encoding, with an average of 4 acquisitions, and RS16-1: 16 x 16 phase-encoding, 1 acquisition) were compared with the standard sequence (StdP: 16 x 16 phase-encoding, with an average of 8 acquisitions) in phantom and healthy volunteers. Acquisition time for the 31P-MRS procedure with StdP, RS8-4, and RS16-1 in the healthy volunteer studies ranged from 30 to 45, 3 to 5, and 3 to 5 minutes, respectively. Metabolite measurements of healthy volunteers obtained from 31P-MRS using RS8-4 correlated with values obtained using StdP (PCr r2=0.63, P<0.001; ATP r=0.41, P<0.01 and PCr/ATP ratio r2=0.25, P<0.05). There was no correlation between StdP and RS16-1 for either ATP or the PCr/ATP ratio (r2=0.03, P=0.60, and r2=0.11, p=0.26, respectively). Reproducibility (intensity of phosphorus signal) with RS16-1 was worse than that of RS8-4 or StdP. 31P-MRS using RS8-4 may be a valid diagnostic tool for patients with cardiac diseases.

  19. Thin layer and nuclear magnetic resonance magnetometers

    In the first part of this text, magnetometers with sensitive elements in the form of thin cylindrical ferromagnetic layers are described. These layers are anisotropic, uniaxial, C orientated and single domains. In the second part of the text, the principles of the nuclear magnetic resonance magnetometer realized at the LETI are presented. This instrument is accurate, of high efficiency, and isotropic. Very small variations in magnetic field intensity (10-7 oersteds) can be detected with a 1Hz pass band at zero frequency

  20. High speed functional magnetic resonance imaging

    Gibson, A M

    2002-01-01

    The work in this thesis has been undertaken by the except where indicated by reference, within the Magnetic Resonance Centre at the University of Nottingham during the period from October 1998 to October 2001. This thesis documents the implementation and application of a novel high-speed imaging technique, the multi-slice, echo shifted, echo planar imaging technique. This was implemented on the Nottingham 3 T imaging system, for functional magnetic resonance imaging. The technique uses echo shifting over the slices in a multi-slice echo planar imaging acquisition scheme, making the echo time longer than the repetition time per slice. This allows for rapid volumar sampling of the blood oxygen level dependent effect in the human brain. The new high-speed technique was used to investigate the variability of measuring the timing differences between haemodynamic responses, at the same cortical location, to simple cued motor tasks. The technique was also used in an investigation into motor cortex functional connect...

  1. Magnetic resonance tomography of the penis

    The magnetic resonance tomogram visualises the corpus spongiosum, the corpora cavernosa, the fascia penis profunda, the septum and the dorsal vein of the penis. These structures can be separated from the skin and from the glans penis. Changes of shape are still the essential criteria of assessment. At present it does not seem possible to be able to differentiate between diseased and healthy area if the connective tissue structures of the penis (e.g. in induratio penis plastica) do not show any change of shape. Compared with other imaging methods, imaging on different levels offers advantages, and so does the simultaneous imaging of the structures of the penis, of its environment and of the adjacent organs. We can assume that the magnetic resonance tomogram will supply essential additional information for clinical diagnosis and practice in conditions like induratio penis plastica, intersexuality, tumours of the prostate gland, and in postoperative follow-up, for example after surgery for priapism. (orig.)

  2. Magnetic resonance imaging of tuberculous spinal infection

    The magnetic resonance imaging (MRI) characteristics of 15 cases of tuberculous (TB) spinal infection were reviewed. The commonest site was the lumbar spine (53.3%) often with three or more contiguous vertebrae involved (47%). Destruction of the vertebral body and the presence of paraspinal soft-tissue masses were noted in 73.3%. Posterior element abnormalities, which is a significant finding, were seen in 40%, a slightly lower incidence rate than in other reported series. Epidural disease (53.3%) and disc abnormalities (73%) were more frequent than was realized. The role of intravenous contrast is discussed. Intravenous gadolinium is useful because it increases diagnostic confidence by characterizing and delineating the disease process, detects reactivation in old and healed TB, helps in treatment management and may prove valuable in monitoring therapy. Magnetic resonance imaging should be considered to be the imaging modality of choice for patients with suspected tuberculous spinal infection. 17 refs., 1 tab., 8 figs

  3. Contribution of magnetic resonance imaging in rheumatology

    Lavieille, J.; Amalric, R.; Stanoyevitch, J.F.; Hopf, M.A.; Antipoff, G.M.; Roux, H.

    1986-11-01

    The authors report their experience with magnetic resonance imaging in rheumatology, established on more than 250 examinations. The method seems interesting for the study of discal and somatic spine diseases, and especially for the evaluation of tumor extension, the diagnosis of herniated disc, the diagnosis of spondylodiscitis, the exploration of the cervico-occipital joint. As compared to tomodensitometry, this method presents at the same time advantages and drawbacks. Peripherally, magnetic resonance imaging is useful for the exploration of bony tumors and evaluation of their extension. It gives excellent images of the knees and the hips where it seems to improve the results of tomodensitometry and bony scintigraphy in the diagnosis of osteonecrosis. It is likely that advances will broaden the scope of the indications and capabilities of this method.

  4. Quality assurance in magnetic resonance spectroscopy system

    Nuclear Magnetic Resonance Spectroscopic clinical evaluation of metabolic changes in the human body has distinct advantages over Magnetic Resonance Imaging (MRI), CT and Nuclear Medicine, as it allows early detection of disease and monitoring of therapeutic processes through repeated procedures. To ensure reliable and reproducible results for spectroscopic examinations, the quality of MRS system should be controlled. Apart from the instrumental contribution in spectroscopic examinations, there are number of other variables such as tissue state and patient motion, severely affecting the image quality. The subject and instrumental contributions to the spectrum are closely related in MRS than in rest of medical imaging. Instrumental contribution in the quality of spectrum has been measured and presented

  5. Caroli's disease: magnetic resonance imaging features

    Our objective was to describe the main aspects of MR imaging in Caroli's disease. Magnetic resonance cholangiography with a dynamic contrast-enhanced study was performed in nine patients with Caroli's disease. Bile duct abnormalities, lithiasis, dot signs, hepatic enhancement, renal abnormalities, and evidence of portal hypertension were evaluated. Three MR imaging patterns of Caroli's disease were found. In all but two patients, MR imaging findings were sufficient to confirm the diagnosis. Moreover, MR imaging provided information about the severity, location, and extent of liver involvement. This information was useful in planning the best therapeutic strategy. Magnetic resonance cholangiography with a dynamic contrast-enhanced study is a good screening tool for Caroli's disease. Direct cholangiography should be reserved for confirming doubtful cases. (orig.)

  6. Female pelvic anatomy: magnetic resonance study

    The potential of magnetic resonance imaging was evaluated in this study. Conventional imaging methods like sonography and X-ray computerised tomography generally provide accurate data. Magnetic resonance imaging appears to be very suitable for studying the pelvis because it has the capacity to produce direct multidirectional images. By recording alterations in T1 and T2 values, it provides a wide range of information. A 1.5 T imaging system was used. Pulse sequences used always included T1 and T2 weighted spin-echo scans. The T2 scan was performed in the best plane for the organ of interest. The comparison between these different acquisitions provides good tissue differentiation. Results of 73 studies are exposed

  7. Antiferromagnetic resonance excitation by terahertz magnetic field resonantly enhanced with split ring resonator

    Excitation of antiferromagnetic resonance (AFMR) in a HoFeO3 crystal combined with a split ring resonator (SRR) is studied using terahertz (THz) electromagnetic pulses. The magnetic field in the vicinity of the SRR is induced by the incident THz electric field component and excites spin oscillations that correspond to the AFMR, which are directly probed by the Faraday rotation of the polarization of a near-infrared probe pulse. The good agreement of the temperature-dependent magnetization dynamics with the calculation using the two-lattice Landau-Lifshitz-Gilbert equation confirms that the AFMR is excited by the THz magnetic field, which is enhanced at the SRR resonance frequency by a factor of 20 compared to the incident magnetic field.

  8. Nuclear magnetic resonance spectrometer and method

    A nuclear magnetic resonance techniis described that allows simultaneous temperature determination and spectral acquisition. The technique employs a modification of the lock circuit of a varian xl-100 spectrometer which permits accurate measurement of the difference in resonance frequency between a primary lock nucleus and another , secondary, nucleus. The field stabilization function of the main lock circuit is not compromised. A feedback signal having a frequency equal to the frequency difference is substituted for the normal power supply in the spectrometer's existing radio frequency transmitter to modulate that transmitter. Thus, the transmitter's radio frequency signal is enhanced in a frequency corresponding to the resonance peak of the secondary nucleus. Determination of the frequency difference allows the determination of temperature without interference with the observed spectrum. The feedback character of the circuit and the presence of noise make the circuit self-activating

  9. Magnetic resonance imaging for acute pancreatitis

    Xiao, Bo; Zhang, Xiao-Ming

    2010-01-01

    Acute pancreatitis is characterized by acute chemical injury of the pancreatic parenchyma and peripancreatic tissue. The increased frequency of death in acute pancreatitis is directly correlated with the degree and progress of pancreatic necrosis. Moreover, the occurrence of some local complications in acute pancreatitis, such as pancreatic hemorrhage, peripancreatic abscess or large pseudocyst, and pseudoaneurysm, could influence the choice of treatment for these patients. Magnetic resonance...

  10. Methods for interventional magnetic resonance imaging

    Vahala, Erkki

    2002-01-01

    This thesis has as its central aim to demonstrate, develop, discuss and promote new methods and technology for improving interventional low field magnetic resonance imaging. The work addresses problems related to accurate localization of minimally invasive surgical tools by describing novel devices and improvements to prior art techniques, such as optical tracking. In addition to instrument guidance, ablative treatment of liver tumours is discussed in connection with low field temperature mea...

  11. Modelling Strategies for Functional Magnetic Resonance Imaging

    Madsen, Kristoffer Hougaard; Sidaros, Karam; Hansen, Lars Kai

    2009-01-01

    This thesis collects research done on several models for the analysis of functional magnetic resonance neuroimaging (fMRI) data. Several extensions for unsupervised factor analysis type decompositions including explicit delay modelling as well as handling of spatial and temporal smoothness and generalisations to higher order arrays are considered. Additionally, an application of the natural conjugate prior for supervised learning in the general linear model to efficiently incorporate prior in...

  12. Magnetic resonance imaging of pancreatitis: An update

    Manikkavasakar, Sriluxayini; AlObaidy, Mamdoh; Busireddy, Kiran K; Ramalho, Miguel; Nilmini, Viragi; Alagiyawanna, Madhavi; Semelka, Richard C

    2014-01-01

    Magnetic resonance (MR) imaging plays an important role in the diagnosis and staging of acute and chronic pancreatitis and may represent the best imaging technique in the setting of pancreatitis due to its unmatched soft tissue contrast resolution as well as non-ionizing nature and higher safety profile of intravascular contrast media, making it particularly valuable in radiosensitive populations such as pregnant patients, and patients with recurrent pancreatitis requiring multiple follow-up ...

  13. Magnetic resonance in diagnosis of ureterocele

    Nascimento, Humberto do; Hachul, Mauricio; Macedo Junior, Antonio [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Div. de Urologia]. E-mail: humbertojr1@aol.com

    2003-05-15

    Ultrasonography is the main non-invasive technique for screening of ureterocele, but presents some difficulties for its diagnosis. Other supplementary diagnostic methods have the disadvantage of being invasive or using ionizing radiation. Magnetic resonance (MR) has a high sensitivity for diagnosing urinary tract malformations in adults and children. We report one case of ureterocele in a 1-year old child with the purpose of presenting its diagnosis through MR. (author)

  14. Magnetic resonance in diagnosis of ureterocele

    Ultrasonography is the main non-invasive technique for screening of ureterocele, but presents some difficulties for its diagnosis. Other supplementary diagnostic methods have the disadvantage of being invasive or using ionizing radiation. Magnetic resonance (MR) has a high sensitivity for diagnosing urinary tract malformations in adults and children. We report one case of ureterocele in a 1-year old child with the purpose of presenting its diagnosis through MR. (author)

  15. Fundamental physics of magnetic resonance imaging.

    Villafana, T

    1988-07-01

    Although similar to computerized tomography, in that cross-sectional images are produced, the physical principles underlying magnetic resonance are entirely different. The MRI process, as commonly implemented, involves the excitation of hydrogen nuclei and the analysis of how these nuclei recover to the original equilibrium steady states that they had prior to excitation. This article discusses that process, that is, preparatory alignment, RF excitation, relaxation and signal measurement, and spatial localization. PMID:3380941

  16. Nuclear magnetic resonance in Kondo lattice systems

    Curro, Nicholas J.

    2016-06-01

    Nuclear magnetic resonance has emerged as a vital tool to explore the fundamental physics of Kondo lattice systems. Because nuclear spins experience two different hyperfine couplings to the itinerant conduction electrons and to the local f moments, the Knight shift can probe multiple types of spin correlations that are not accessible via other techniques. The Knight shift provides direct information about the onset of heavy electron coherence and the emergence of the heavy electron fluid.

  17. Relaxation measurements by magnetic resonance force microscopy

    The spatial resolution of magnetic resonance imaging can be greatly enhanced by replacing the coil antenna (or cavity) with a scanning force microscope. We describe how this mechanical detection can be applied to the measurement of both the transverse and longitudinal relaxation inside a micron-size volume. The measurement procedure and analysis is detailed for the case of paramagnetic and ferromagnetic spin systems. (authors)

  18. Polyorchidism: Sonographic and Magnetic Resonance Image Findings

    Oner, A. Y.; Sahin, C.; Pocan, S.; Kizilkaya, E. [Gazi Univ. School of Medicine, Ankara (Turkey). Dept. of Radiology

    2005-11-01

    Polyorchidism is a rare congenital anomaly frequently associated with maldescent testis, hernia, and torsion. Reports in the literature show an increased risk of testicular malignancy in the presence of polyorchidism. This entity has characteristic sonographic features and the diagnosis is often made on the basis of sonography. Magnetic resonance imaging might also be used for the diagnosis, but is more helpful in cases associated with cryptorchism or neoplasia. A conservative approach is the treatment of choice in uncomplicated cases.

  19. Polyorchidism: Sonographic and Magnetic Resonance Image Findings

    Polyorchidism is a rare congenital anomaly frequently associated with maldescent testis, hernia, and torsion. Reports in the literature show an increased risk of testicular malignancy in the presence of polyorchidism. This entity has characteristic sonographic features and the diagnosis is often made on the basis of sonography. Magnetic resonance imaging might also be used for the diagnosis, but is more helpful in cases associated with cryptorchism or neoplasia. A conservative approach is the treatment of choice in uncomplicated cases

  20. Cardiovascular magnetic resonance in carotid atherosclerotic disease

    Chen Huijun; Wang Jinnan; Li Rui; Ferguson Marina S; Kerwin William S; Dong Li; Canton Gador; Hatsukami Thomas S; Yuan Chun

    2009-01-01

    Abstract Atherosclerosis is a chronic, progressive, inflammatory disease affecting many vascular beds. Disease progression leads to acute cardiovascular events such as myocardial infarction, stroke and death. The diseased carotid alone is responsible for one third of the 700,000 new or recurrent strokes occurring yearly in the United States. Imaging plays an important role in the management of atherosclerosis, and cardiovascular magnetic resonance (CMR) of the carotid vessel wall is one promi...

  1. Myocardial tissue tagging with cardiovascular magnetic resonance

    Bluemke David A; Osman Nael F; Cheng Susan; Shehata Monda L; Lima João AC

    2009-01-01

    Abstract Cardiovascular magnetic resonance (CMR) is currently the gold standard for assessing both global and regional myocardial function. New tools for quantifying regional function have been recently developed to characterize early myocardial dysfunction in order to improve the identification and management of individuals at risk for heart failure. Of particular interest is CMR myocardial tagging, a non-invasive technique for assessing regional function that provides a detailed and compreh...

  2. Cardiovascular magnetic resonance in pulmonary hypertension

    Bradlow William M; R Gibbs J Simon; Mohiaddin Raad H

    2012-01-01

    Abstract Pulmonary hypertension represents a group of conditions characterized by higher than normal pulmonary artery pressures. Despite improved treatments, outcomes in many instances remain poor. In recent years, there has been growing interest in the use of Cardiovascular Magnetic Resonance (CMR) in patients with pulmonary hypertension. This technique offers certain advantages over other imaging modalities since it is well suited to the assessment of the right ventricle and the proximal pu...

  3. Quantitative cardiovascular magnetic resonance for molecular imaging

    Lanza Gregory M; Caruthers Shelton D; Winter Patrick M; Wickline Samuel A

    2010-01-01

    Abstract Cardiovascular magnetic resonance (CMR) molecular imaging aims to identify and map the expression of important biomarkers on a cellular scale utilizing contrast agents that are specifically targeted to the biochemical signatures of disease and are capable of generating sufficient image contrast. In some cases, the contrast agents may be designed to carry a drug payload or to be sensitive to important physiological factors, such as pH, temperature or oxygenation. In this review, examp...

  4. Noise and filtration in magnetic resonance imaging

    McVeigh, E. R.; Henkelman, R.M.; Bronskill, M. J.

    1985-01-01

    Noise in two-dimensional Fourier transform magnetic resonance images has been investigated using noise power spectra and measurements of standard deviation. The measured effects of averaging, spatial filtering, temporal filtering, and sampling have been compared with theoretical calculations. The noise of unfiltered images is found to be white, as expected, and the choice of the temporal filter and sampling interval affects the noise in a manner predicted by sampling theory. The shapes of the...

  5. Perfusion magnetic resonance imaging of the liver

    Choon; Hua; Thng; Tong; San; Koh; David; J; Collins; Dow; Mu; Koh

    2010-01-01

    Perfusion magnetic resonance imaging (MRI) studies quantify the microcirculatory status of liver parenchyma and liver lesions, and can be used for the detection of liver metastases, assessing the effectiveness of antiangiogenic therapy, evaluating tumor viability after anticancer therapy or ablation, and diagnosis of liver cirrhosis and its severity. In this review, we discuss the basic concepts of perfusion MRI using tracer kinetic modeling, the common kinetic models applied for analyses, the MR scanning t...

  6. Magnetic Resonance Elastography: Inversions in Bounded Media

    Kolipaka, Arunark; McGee, Kiaran P.; Manduca, Armando; Romano, Anthony J; Glaser, Kevin J.; Araoz, Philip A; Ehman, Richard L.

    2009-01-01

    Magnetic resonance elastography (MRE) is a noninvasive imaging technique capable of quantifying and spatially resolving the shear stiffness of soft tissues by visualization of synchronized mechanical wave displacement fields. However, MRE inversions generally assume that the measured tissue motion consists primarily of shear waves propagating in a uniform, infinite medium. This assumption is not valid in organs such as the heart, eye, bladder, skin, fascia, bone and spinal cord in which the s...

  7. "PALPATION BY IMAGING": MAGNETIC RESONANCE ELASTOGRAPHY

    Lei Xu; Pei-yi Gao

    2006-01-01

    Elasticity is an important physical property of human tissues.There is a tremendous difference in elasticity between normal and pathological tissues.Noninvasive evaluation of the elasticity of human tissues would be valuable for clinical practice.Magnetic resonance elastography(MRE)is a recently developed noninvasive imaging technique that can directly visualize and quantitatively measure tissue elasticity.This article reviewed the MRE technique and its current status.

  8. Functional magnetic resonance imaging in schizophrenia

    Gur, Raquel E.; Gur, Ruben C.

    2010-01-01

    The integration of functional magnetic resonance imaging (fMRI) with cognitive and affective neuroscience paradigms enables examination of the brain systems underlying the behavioral deficits manifested in schizophrenia; there have been a remarkable increase in the number of studies that apply fMRI in neurobiological studies of this disease. This article summarizes features of fMRI methodology and highlights its application in neurobehavioral studies in schizophrenia. Such work has helped elu...

  9. Cardiovascular magnetic resonance imaging - a pictorial review

    Vijay Dahya; Spottiswoode, Bruce S.

    2010-01-01

    Cardiovascular magnetic resonance imaging (CMR) is a powerful problem-solving tool and arguably offers the most comprehensive assessment of cardiac morphology and function, as well as the opportunity of rebuilding the bridge between cardiologists and radiologists. The role of CMR-trained imaging physicists is also valuable, and many CMR centres harmoniously incorporate these three sub-specialty fields. This paper comprises an overview of several CMR techniques, outlining both the strengths...

  10. Cardiovascular magnetic resonance imaging - a pictorial review

    Vijay Dahya

    2010-12-01

    Full Text Available Cardiovascular magnetic resonance imaging (CMR is a powerful problem-solving tool and arguably offers the most comprehensive assessment of cardiac morphology and function, as well as the opportunity of rebuilding the bridge between cardiologists and radiologists. The role of CMR-trained imaging physicists is also valuable, and many CMR centres harmoniously incorporate these three sub-specialty fields. This paper comprises an overview of several CMR techniques, outlining both the strengths and limitations of the modality.

  11. A comparison of MR elastography and {sup 31}P MR spectroscopy with histological staging of liver fibrosis

    Godfrey, Edmund M. [St James' Hospital, Leeds (United Kingdom); St James' Hospital, Department of Radiology, Leeds (United Kingdom); Patterson, Andrew J.; Priest, Andrew N.; Davies, Susan E.; Joubert, Ilse; Krishnan, Anant S.; Shaw, Ashley S.; Alexander, Graeme J.; Allison, Michael E.; Griffiths, William J.H.; Gimson, Alexander E.S. [Addenbrooke' s Hospital, Cambridge (United Kingdom); Griffin, Nyree [St Thomas' s Hospital, London (United Kingdom); Lomas, David J. [University of Cambridge, Department of Radiology, Cambridge (United Kingdom)

    2012-12-15

    Conventional imaging techniques are insensitive to liver fibrosis. This study assesses the diagnostic accuracy of MR elastography (MRE) stiffness values and the ratio of phosphomonoesters (PME)/phosphodiesters (PDE) measured using {sup 31}P spectroscopy against histological fibrosis staging. The local research ethics committee approved this prospective, blinded study. A total of 77 consecutive patients (55 male, aged 49 {+-} 11.5 years) with a clinical suspicion of liver fibrosis underwent an MR examination with a liver biopsy later the same day. Patients underwent MRE and {sup 31}P spectroscopy on a 1.5 T whole body system. The liver biopsies were staged using an Ishak score for chronic hepatitis or a modified NAS fibrosis score for fatty liver disease. MRE increased with and was positively associated with fibrosis stage (Spearman's rank = 0.622, P < 0.001). PME/PDE was not associated with fibrosis stage (Spearman's rank = -0.041, p = 0.741). Area under receiver operating curves for MRE stiffness values were high (range 0.75-0.97). The diagnostic utility of PME/PDE was no better than chance (range 0.44-0.58). MRE-estimated liver stiffness increases with fibrosis stage and is able to dichotomise fibrosis stage groupings. We did not find a relationship between {sup 31}P MR spectroscopy and fibrosis stage. circle Magnetic resonance elastography (MRE) and MR spectroscopy can both assess the liver. (orig.)

  12. 31P and 13C-NMR studies of the phosphorus and carbon metabolites in the halotolerant alga, Dunaliella salina

    The intracellular phosphorus and carbon metabolites in the halotolerant alga Dunaliella salina adapted to different salinities were monitored in living cells by 31P- and 13C-nuclear magnetic resonance (NMR) spectroscopy. The 13C-NMR studies showed that the composition of the visible intracellular carbon metabolites other than glycerol is not significantly affected by the salinity of the growth medium. The T1 relaxation rates of the 13C-glycerol signals in intact cells were enhanced with increasing salinity of the growth medium, in parallel to the expected increase in the intracellular viscosity due to the increase in intracellular glycerol. The 31P-NMR studies showed that cells adapted to the various salinities contained inorganic phosphate, phosphomonoesters, high energy phosphate compounds, and long chain polyphosphates. In addition, cells grown in media containing up to 1 molar NaCl contained tripolyphosphates. The tripolyphosphate content was also controlled by the availability of inorganic phosphate during cell growth. Phosphate-depleted D. salina contained no detectable tripolyphosphate signal. Excess phosphate, however, did not result in the appearance of tripolyphosphate in 31P-NMR spectra of cells adapted to high (>1.5 molar NaCl) salinities

  13. Analysis of monoglycerides, diglycerides, sterols, and free fatty acids in coconut (Cocos nucifera L.) oil by 31P NMR spectroscopy.

    Dayrit, Fabian M; Buenafe, Olivia Erin M; Chainani, Edward T; de Vera, Ian Mitchelle S

    2008-07-23

    Phosphorus-31 nuclear magnetic resonance spectroscopy ( (31)P NMR) was used to differentiate virgin coconut oil (VCO) from refined, bleached, deodorized coconut oil (RCO). Monoglycerides (MGs), diglycerides (DGs), sterols, and free fatty acids (FFAs) in VCO and RCO were converted into dioxaphospholane derivatives and analyzed by (31)P NMR. On the average, 1-MG was found to be higher in VCO (0.027%) than RCO (0.019%). 2-MG was not detected in any of the samples down to a detection limit of 0.014%. On the average, total DGs were lower in VCO (1.55%) than RCO (4.10%). When plotted in terms of the ratio [1,2-DG/total DGs] versus total DGs, VCO and RCO samples grouped separately. Total sterols were higher in VCO (0.096%) compared with RCO (0.032%), and the FFA content was 8 times higher in VCO than RCO (0.127% vs 0.015%). FFA determination by (31)P NMR and titration gave comparable results. Principal components analysis shows that the 1,2-DG, 1,3-DG, and FFAs are the most important parameters for differentiating VCO from RCO. PMID:18576656

  14. Applications of Magnetic Resonance in Model Systems: Cancer Therapeutics1

    Evelhoch, Jeffrey L.; Gillies, Robert J; Karczmar, Gregory S.; Koutcher, Jason A; Maxwell, Ross J.; Nalcioglu, Orhan; Raghunand, Natarajan; Ronen, Sabrina M.; Ross, Brian D.; Swartz, Harold M.

    2000-01-01

    The lack of information regarding the metabolism and pathophysiology of individual tumors limits, in part, both the development of new anti-cancer therapies and the optimal implementation of currently available treatments. Magnetic resonance [MR, including magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and electron paramagnetic resonance (EPR)] provides a powerful tool to assess many aspects of tumor metabolism and pathophysiology. Moreover, since this information ca...

  15. Electro-mechanical resonant magnetic field sensor

    We describe a new type of magnetic field sensor, which is termed as an Electro-Mechanical Resonant Sensor (EMRS). The key part of this sensor is a small conductive elastic element with low damping rate and therefore, a high Q fundamental mode of frequency f1. An AC current is driven through the elastic element which, in the presence of a magnetic field, causes an AC force on the element. When the frequency of the AC current matches the resonant frequency of the element, maximum vibration of the element occurs and this can be measured precisely by optical means. We have built and tested a model sensor of this type by using for the elastic element, a length of copper wire of diameter 0.030 mm formed into a loop shape. The wire motion was measured using a light-emitting diode photo-transistor assembly. This sensor demonstrated a sensitivity better than 0.001 G for an applied magnetic field of ∼1 G and a good selectivity for the magnetic field direction. The sensitivity can be easily improved by a factor of ∼10-100 by a more sensitive measurement of the elastic element motion and by having the element in vacuum to reduce the drag force

  16. First national meeting of magnetic resonance and hyperfine interactions

    Works performed at CNEA's: Magnetic Resonance Division; Moessbauer Spectroscopy; Solid State Physics Division; Nuclear magnetic Resonance Laboratory and Theoretical Physics Group; Mossbauer Spectroscopy Group; Nuclear Quadrupole Resonance; Physics and Materials Group; Perturbed Angular Correlation and Moessbauer Spectroscopy and Physics Department. (M.E.L.)

  17. Nuclear magnetic resonance imaging in brain tumors

    Full text: Magnetic resonance imaging (MRI) is a non-invasive imaging method based on the detecting signal from hydrogen nuclei of water molecules and fat. Performances of MRI are continuously increasing, and its domains of investigation of the human body are growing in both morphological and functional study. MRI also allows It also performing advanced management of tumours especially in the brain, by combining anatomical information (morphological MRI), functional (diffusion, perfusion and BOLD contrast) and metabolic (tissue composition in magnetic resonance spectroscopy (MRS)). The MRI techniques have an important role in cancerology. These techniques allow essential information for the diagnosis and answering therapist's questions before, during or after the treatment. The MR allows clarifying the localization of expanding processes, the differential diagnosis between brain tumour and a lesion confined by another structural aspect, the diagnosis of the tumoral aspect of a lesion, the histological ranking in case of glial tumour and the extension of its localization as well as the therapeutic follow-up (pre-therapeutic and post-therapeutics assessments). A better combination between the morphological, functional and metabolic studies, as well as integrating new technical developments, especially while using a multichannel bird cage coils the 3T magnet and suitable computing software, would allow significant improvements of the exploration strategies and management of brain tumors.

  18. Magnetic resonance imaging. Handbook and atlas

    Magnetic resonance imaging (MRI) as a diagnostic imaging tool relies on the generation of magnetic fields, whereas the computerized tomography (CT) uses X-radiation. The fundamental principle of MRI is the magnetic resonance of paramagnetic atomic nuclei. These nuclei, as e.g. protons (= hydrogen nuclei), are aligned in required orientation by application of a strong magnetic field. Upon simultaneous application of an electromagnetic high-frequency field perpendicular to the axis of the basic magnetic field, and in response to periodical changing of the electromagnetic field at a given frequency, the originally aligned paramagnetic nuclei are forced into a movement similar to that of a ''whipping top''. When the resonance frequency is shut off, the nuclei return to their former, aligned positions, inducing a weak signal in a coil. The series of signals generated by multiple repetition of this process of excitation of nuclei and their return to aligned rest is used as input to a specific computer for computing the 3D image. Thus images can be generated of the target body area from different angles and in different planes by varying the magnetic fields applied. Other than with the CT method, imaging of the various selected planes with MRI must not be done consecutively but is done in one scanning run (for a set of images of about 20 planes). The signal that is received by the coil is determined by the proton density in the volume compartment scanned, and by the relaxation times T1 and T2, which are the times needed by the nuclei to return to aligned rest. The relaxation times in turn are determined by the bonding states of the molecules and thus yield the significant information describing the actual physical and chemical properties of the body tissues scanned. So MRI yields sectional or ''sliced'' images of the body region of interest, as well as information describing tissue type and properties. Today, almost exclusively protons are used for MRI, as hydrogen is a

  19. Nanodiamond graphitization: a magnetic resonance study

    We report on the first nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) study of the high-temperature nanodiamond-to-onion transformation. 1H, 13C NMR and EPR spectra of the initial nanodiamond samples and those annealed at 600, 700, 800 and 1800 ° C were measured. For the samples annealed at 600 to 800 ° C, our NMR data reveal the early stages of the surface modification, as well as a progressive increase in sp2 carbon content with increased annealing temperature. Such quantitative experimental data were recorded for the first time. These findings correlate with EPR data on the sensitivity of the dangling bond EPR line width to air content, progressing with rising annealing temperature, that evidences consequent graphitization of the external layers of the diamond core. The sample annealed at 1800 ° C shows complete conversion of nanodiamond particles into carbon onions. (paper)

  20. Nature versus nurture: functional assessment of restoration effects on wetland services using Nuclear Magnetic Resonance Spectroscopy

    Sundareshwar, P.V.; Richardson, C.J.; Gleason, R.A.; Pellechia, P.J.; Honomichl, S.

    2009-01-01

    Land-use change has altered the ability of wetlands to provide vital services such as nutrient retention. While compensatory practices attempt to restore degraded wetlands and their functions, it is difficult to evaluate the recovery of soil biogeochemical functions that are critical for restoration of ecosystem services. Using solution 31P Nuclear Magnetic Resonance Spectroscopy, we examined the chemical forms of phosphorus (P) in soils from wetlands located across a land-use gradient. We report that soil P diversity, a functional attribute, was lowest in farmland, and greatest in native wetlands. Soil P diversity increased with age of restoration, indicating restoration of biogeochemical function. The trend in soil P diversity was similar to documented trends in soil bacterial taxonomic composition but opposite that of soil bacterial diversity at our study sites. These findings provide insights into links between ecosystem structure and function and provide a tool for evaluating the success of ecosystem restoration efforts. Copyright 2009 by the American Geophysical Union.

  1. Dynamics of asymmetric binary glass formers. II. Results from nuclear magnetic resonance spectroscopy

    Bock, D.; Kahlau, R.; Pötzschner, B.; Körber, T.; Wagner, E.; Rössler, E. A., E-mail: ernst.roessler@uni-bayreuth.de [Experimentalphysik II, Universität Bayreuth, 95440 Bayreuth (Germany)

    2014-03-07

    Various {sup 2}H and {sup 31}P nuclear magnetic resonance (NMR) spectroscopy techniques are applied to probe the component dynamics of the binary glass former tripropyl phosphate (TPP)/polystyrene-d{sub 3} (PS) over the full concentration range. The results are quantitatively compared to those of a dielectric spectroscopy (DS) study on the same system previously published [R. Kahlau, D. Bock, B. Schmidtke, and E. A. Rössler, J. Chem. Phys. 140, 044509 (2014)]. While the PS dynamics does not significantly change in the mixtures compared to that of neat PS, two fractions of TPP molecules are identified, one joining the glass transition of PS in the mixture (α{sub 1}-process), the second reorienting isotropically (α{sub 2}-process) even in the rigid matrix of PS, although at low concentration resembling a secondary process regarding its manifestation in the DS spectra. Pronounced dynamical heterogeneities are found for the TPP α{sub 2}-process, showing up in extremely stretched, quasi-logarithmic stimulated echo decays. While the time window of NMR is insufficient for recording the full correlation functions, DS results, covering a larger dynamical range, provide a satisfactory interpolation of the NMR data. Two-dimensional {sup 31}P NMR spectra prove exchange within the broadly distributed α{sub 2}-process. As demonstrated by {sup 2}H NMR, the PS matrix reflects the faster α{sub 2}-process of TPP by performing a spatially highly hindered motion on the same timescale.

  2. Magnetic resonance force detection using a membrane resonator

    Scozzaro, Nicolas; Ruchotzke, William; Belding, Amanda; Cardellino, Jeremy; Blomberg, Erick; McCullian, Brendan; Bhallamudi, Vidya; Pelekhov, Denis; Hammel, P. Chris

    Silicon nitride (Si3N4) membranes are commercially-available, versatile structures that have a variety of applications. Although most commonly used as the support structure for transmission electron microscopy (TEM) studies, membranes are also ultrasensitive high-frequency mechanical oscillators. The sensitivity stems from the high quality factor Q 106 , which has led to applications in sensitive quantum optomechanical experiments. The high sensitivity also opens the door to ultrasensitive force detection applications. We report force detection of electron spin magnetic resonance at 300 K using a Si3N4 membrane with a force sensitivity of 4 fN/√{ Hz}, and a potential low temperature sensitivity of 25 aN/√{ Hz}. Given membranes' sensitivity, robust construction, large surface area and low cost, SiN membranes can potentially serve as the central component of a compact room-temperature ESR and NMR instrument that has superior spatial resolution to conventional NMR.

  3. Molecular structure and motion in zero field magnetic resonance

    Zero field magnetic resonance is well suited for the determination of molecular structure and the study of motion in disordered materials. Experiments performed in zero applied magnetic field avoid the anisotropic broadening in high field nuclear magnetic resonance (NMR) experiments. As a result, molecular structure and subtle effects of motion are more readily observed

  4. 76 FR 58281 - Magnetic Resonance Imaging Safety; Public Workshop

    2011-09-20

    ... HUMAN SERVICES Food and Drug Administration Magnetic Resonance Imaging Safety; Public Workshop AGENCY... the safe use of magnetic resonance imaging (MRI) and approaches to mitigate risks. The overall goal is...: The Food and Drug Administration (FDA) is announcing a public workshop entitled: ``Magnetic...

  5. Exploring new Routes for Identifying Phosphorus Species in Terrestrial and Aquatic Ecosystems with 31P NMR

    Vestergren, Johan; Persson, Per; Sundman, Annelie; Ilstedt, Ulrik; Giesler, Reiner; Schleucher, Jürgen; Gröbner, Gerhard

    2014-05-01

    Phosphorus (P) is the primary growth-limiting nutrient in some of the world's biomes. Rock phosphate is a non-renewable resource and the major source of agricultural fertilizers. Predictions of P consumption indicate that rock phosphate mining may peak within 35 years, with severe impacts on worldwide food production1. Organic P compounds constitute a major fraction of soil P, but little is known about the dynamics and bioavailability of organic P species. Our aim is to develop new liquid and solid state 31P-NMR (nuclear magnetic resonance) techniques to identify P-species in water and soils; information required for correlating P speciation with plant and soil processes2, and eventually to improve P use. Soil organic P is frequently extracted using NaOH/EDTA, followed by characterization of the extract by solution 31P-NMR. However, the obtained NMR spectra usually have poor resolution due to line broadening caused by the presence of paramagnetic ions. Therefore, we successfully developed an approach to avoid paramagnetic line broadening by precipitation of metal sulfides. Sulfide precipitation dramatically reduces NMR line widths for soil extracts, without affecting P-composition. The resulting highly improved resolution allowed us to apply for the first time 2D 1H,31P-NMR methods to identify different P monoesters in spectral regions which are extremely crowded in 1D NMR spectra.3 By exploiting 2D 1H-31P NMR spectra of soil extracts we were able to unambiguously identify individual organic P species by combining 31P and 1H chemical shifts and coupling constants. This approach is even suitable for a structural characterization of unknown P-components and for tracing degradation pathways between diesters and monoesters3,4.Currently we apply our approach on boreal4 and tropical soils with focus on Burkina Faso. In addition we also monitor P-species in aqueos ecosystems. For this purpose stream water from the Krycklan catchment in northern Sweden5 has been used to

  6. Liquid Chromatography with Dual Parallel Mass Spectrometry and 31P Nuclear Magnetic Resonance Spectroscopy for Analysis of Sphingomyelin and Dihydrosphingomyelin. II. Bovine Milk Sphingolipids

    Liquid chromatography coupled to atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) mass spectrometry (MS), in parallel, was used for simultaneous detection of bovine milk sphingolipids (BMS). APCI-MS mass spectra exhibited mostly ceramide-like fragment ions, [Cer-H2O...

  7. Gluconeogenesis, liver energy metabolism and weight loss in lung cancer : dynamic studies using stable isotope tracers and 31P magnetic resonance spectroscopy

    S. Leij-Halfwerk (Susanne)

    1999-01-01

    textabstractWeight loss is a major problem in many types of cancer and is associated with reduced quality of life and a poor prognosis. Weight loss can also interfere with potentially curable treatment [41,561. Many uncertainties remain about the mechanisms underlying weight loss in patients with ca

  8. Effects of oral D-tagatose, a stereoisomer of D-fructose, on liver metabolism in man as examined by 31P-magnetic resonance spectroscopy

    Buemann, B; Gesmar, H; Astrup, A;

    2000-01-01

    D-tagatose, which is a stereoisomer of D-fructose, is phosphorylated to D-tagatose-1-phosphate by fructokinase in the liver. Because of a slow degradation rate of D-tagatose-1-phosphate, this substance may accumulate, and ingested D-tagatose may therefore cause a longer lasting reduction in...... concentration were found after D-fructose. These results suggest that a moderate intake of D-tagatose may affect liver metabolism by phosphate trapping despite the fact that the sugar may only be incompletely absorbed in the gut...

  9. Multiparametric magnetic resonance imaging of prostate cancer

    Sandeep S Hedgire

    2012-01-01

    Full Text Available In India, prostate cancer has an incidence rate of 3.9 per 100,000 men and is responsible for 9% of cancer-related mortality. It is the only malignancy that is diagnosed with an apparently blind technique, i.e., transrectal sextant biopsy. With increasing numbers of high-Tesla magnetic resonance imaging (MRI equipment being installed in India, the radiologist needs to be cognizant about endorectal MRI and multiparametric imaging for prostate cancer. In this review article, we aim to highlight the utility of multiparamteric MRI in prostate cancer. It plays a crucial role, mainly in initial staging, restaging, and post-treatment follow-up.

  10. Nuclear magnetic resonance common laboratory, quadrennial report

    This quadrennial report of the nuclear magnetic resonance common laboratory gives an overview of the main activities. Among the different described activities, only one is interesting for the INIS database: it concerns the Solid NMR of cements used for radioactive wastes storage. In this case, the NMR is used to characterize the structure of the material and the composition, structure and kinetics of formation of the alteration layer which is formed at the surface of concrete during water leaching conditions. The NMR methodology is given. (O.M.)

  11. Magnetic resonance imaging of the pediatric airway

    Evaluation of the pediatric airway is often complex and may require multiple imaging techniques and invasive procedures. We performed magnetic resonance (MR) imaging of the airway in 34 children with clinical evidence of chronic airway obstruction and compared MR findings with those obtained by surgery and/or endoscopy. MR diagnoses included vascular compression in 15 patients, primary tracheomalacic states in 12 patients, and mediastinal masses in 4 patients. Findings were normal for 3 patients. The MR findings were in agreement with the endoscopic findings in 25 to 28 cases and in agreement with the surgical findings in 21 to 21 cases. (orig./GDG)

  12. Magnetic resonance spectroscopy studies in migraine

    Montagna, P.; Cortelli, P.; Barbiroli, B. (Inst. of Medical Pathology, Univ. of Bologna (Italy))

    1994-06-01

    The authors describe the method of [sup 31]phosphorus magnetic resonance spectroscopy and review the results when it is applied to the study of brain and muscle energy metabolism in migraine subjects. Brain energy metabolism appears to be abnormal in all major subtypes of migraine when measured both during and between attacks. Impaired energy metabolism is also documented in skeletal muscle. It is suggested that migraine is associated with a generalized disorder of mitochondrial oxidative phosphorylation and that this may constitute a threshold for the triggering of migraine attacks. 47 refs., 10 figs., 3 tabs.

  13. Proton magnetic resonance spectroscopy in schizophrenia

    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

  14. Cardiac magnetic resonance in clinical cardiology

    Andreas; Kumar; Rodrigo; Bagur

    2015-01-01

    Over the last decades, cardiac magnetic resonance(CMR) has transformed from a research tool to a widely used diagnostic method in clinical cardiology. This method can now make useful, unique contributions to the work-up of patients with ischemic and non-ischemic heart disease. Advantages of CMR, compared to other imaging methods, include very high resolution imaging with a spatial resolution up to 0.5 mm × 0.5 mm in plane, a large array of different imaging sequences to provide in vivo tissue characterization, and radiationfree imaging. The present manuscript highlights the relevance of CMR in the current clinical practice and new perspectives in cardiology.

  15. Functional Magnetic Resonance Imaging in Consumer Research

    Reimann, Martin; Schilke, Oliver; Weber, Bernd;

    2011-01-01

    Although the field of psychology is undergoing an immense shift toward the use of functional magnetic resonance imaging (fMRI), the application of this methodology to consumer research is relatively new. To assist consumer researchers in understanding fMRI, this paper elaborates on the findings o...... and selling a common product. Results reveal a significantly stronger activation in the amygdala while consumers estimate selling prices versus buying prices, suggesting that loss aversion is associated with the processing of negative emotion. © 2011 Wiley Periodicals, Inc....

  16. Magnetic resonance imaging (MRI) of cerebral infarction

    Fifty-five patients with cerebral infarction were studied with magnetic resonance imaging (MRI) and correlative CT scans. MRI was more sensitive than CT for detecting cerebral infarction, and T2-weighted spin-echo (SE) pulse sequence was most sensitive for detecting cerebral infarction except for some subcortical infarction. The size of infarcted areas on MRI was larger than that on CT in 29 of 51 infarcted areas, equal in 22. The pulse sequence using long repetition time (TR) and double echo delay time (TE), such as SE (2000/30, 90), improved the detectability of cerebral infarction. (author)

  17. Magnetic resonance aspects in ulnar styloid nonunion

    Ulnar syloid process nonunion fractures are common, although isolated fractures may not be recognized and become a persistent wrist pain. Most time the fractures are asymptomatic. It is important , in symptomatic patients, the characterization of the lesion and the commitment of other structures that compose distal radio-ulnar joint for proper treatment. The classification is based on radio-ulnar joint stability. We report wrist magnetic resonance images from two patients, each one with one type of nonunion classification, which is based in anatomic findings and treatment options. (author)

  18. Magnetic resonance spectroscopy studies in migraine

    The authors describe the method of 31phosphorus magnetic resonance spectroscopy and review the results when it is applied to the study of brain and muscle energy metabolism in migraine subjects. Brain energy metabolism appears to be abnormal in all major subtypes of migraine when measured both during and between attacks. Impaired energy metabolism is also documented in skeletal muscle. It is suggested that migraine is associated with a generalized disorder of mitochondrial oxidative phosphorylation and that this may constitute a threshold for the triggering of migraine attacks. 47 refs., 10 figs., 3 tabs

  19. Magnetic resonance imaging of acoustic neuroma

    Kashihara, Kengo; Murata, Hideaki; Ito, Haruhide; Onishi, Hiroaki; Kadoya, Masumi; Suzuki, Masayuki.

    1989-03-01

    Thirteen patients with acoustic neuroma were studied on a 1.5T superconductive magnetic resonance (MR) imager. Acoustic neuromas appeared as lower signal intensity than the surrounding brain stem on T1 weighted image (W.I.), and as higher signal intensity on T2 W.I.. Axial and coronal sections of T1 W.I. were very useful in observing the tumor in the auditory canal and in investigating the anatomical relations of the tumor and the surrounding structures. MR imaging is very excellent examination to make early diagnosis of the acoustic neuroma and preoperative anatomical evaluation.

  20. Magnetic resonance imaging of cystic ovarian tumors

    We studied 48 cases of cystic ovarian tumors by magnetic resonance imaging (MRI) with 0.15 T resistive system and examined the ability of qualitative diagnosis by means of signal intensities and caluculated T1 values. MRI supposed to discriminate among various kinds of cystic ovarian tumors in most cases, especially dermoid cysts, endometrial cysts and cystadenomas. MRI has lots of merits which other imaging methods cannot offer, though it takes a long scan time and high cost at the present time. It plays an important role in the diagnosis of cystic ovarian tumors. (author)

  1. Magnetic resonance imaging findings in Kimura's disease

    Although early diagnosis of Kimura's disease, a rare chronic inflammatory disorder most commonly presenting with asymmetric swelling in the head and neck region, is helpful in avoiding unnecessary diagnostic tests and starting prompt treatment, only a few reports emphasized radiological findings in detail. Magnetic resonance imaging findings showing the infiltrative nature of the disease and diffuse loss of fat tissue even in nonpalpable normally appearing regions of the head and neck in a young man with Kimura's disease are presented in this report. (orig.)

  2. Magnetic resonance imaging of cervical myelopathy

    Chosa, Hirofumi; Yamano, Kouichirou; Ihara, Fumitoshi; Ueda, Yoshiaki; Maekawa, Masayuki; Tokuhisa, Ginichirou; Kuwano, Tadashi; Kamo, Yoshi; Nomura, Shigeharu (Kyushu Rosai Hospital, Fukuoka (Japan))

    1990-03-01

    Forty-three patients operated for cervical myelopathy were examined with a 1.5 T magnetic resonance imaging. Cord compression was demonstrated directly on the sagittal image in cases of cervical disc herniation, cervical spondylosis and O.P. L.L. Herniated disc material was seen positive on axial image. But factors of cord compression in cases of cervical spondylosis and O.P. L.L. were not clearly confirmed, so additional examinations such as myelogram, tomogram and CT was needed. (author).

  3. Magnetic Resonance Signal Processing in Medical Applications

    Mikulka, J.; Gescheidtová, E.; Bartušek, Karel

    Saint Gilles: IARIA, 2012, s. 148-153. ISBN 978-1-61208-184-7. [GlobeNet 2012: ICN 2012, ICONS 2012, VisGra 2012, DBKDA 2012. Saint Gilles (RE), 29.02.2012-05.03.2012] R&D Projects: GA MŠk ED0017/01/01; GA ČR GAP102/11/0318 Institutional support: RVO:68081731 Keywords : magnetic resonance * biomedical image processing * image segmentation * level set * active countour * edge analysis * noise suppression * volumetry Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  4. Magnetic resonance images of chronic patellar tendinitis

    Chronic patellar tendinitis can be a frustrating diagnostic and therapeutic problem. This report evaluates seven tendons in five patients with chronic patellar tendinitis. The etiologies included 'jumper's knee' and Osgood-Schlatter disease. In all cases magnetic resonance images (MRI) showed thickening of the tendon. Some of the tendons had focal areas of thickening which helped establish the etiology. All cases had intratendinous areas of increased signal which, in four cases, proved to be chronic tendon tears. MRI is useful in evaluating chronic patellar tendinitis because it establishes the diagnosis, detects associated chronic tears, and may help determine appropriate rehabilitation. (orig.)

  5. Magnetic resonance imaging of pelvic endometriosis

    Twenty-five magnetic resonance imaging (MRI) studies were performed in 18 patients with proven endometriosis. MRI findings were analyzed and compared with laparoscopic or surgical findings; MRI accurately demonstrated ovarian endometrial cysts as well as ectopic foci of endometriosis. Adhesions may be also suggested. Contrary to laparoscopy, MRI easily depicts both deep lesions and endometrial implants under the peritoneum. Consequently, MRI appears as an useful adjunct to laparoscopy for initial diagnosis before starting a medical treatment and above all as the imaging modality of choice for evaluation of the answer to treatment, avoiding iterative and often adhesions limited laparoscopies. (author). 7 refs.; 9 figs

  6. Structural magnetic resonance imaging in epilepsy

    Deblaere, Karel [Ghent University Hospital, Department of Neuroradiology, Ghent (Belgium); Ghent University Hospital, MR Department - 1K12, Ghent (Belgium); Achten, Eric [Ghent University Hospital, Department of Neuroradiology, Ghent (Belgium)

    2008-01-15

    Because of its sensitivity and high tissue contrast, magnetic resonance imaging (MRI) is the technique of choice for structural imaging in epilepsy. In this review the effect of using optimised scanning protocols and the use of high field MR systems on detection sensitivity is discussed. Also, the clinical relevance of adequate imaging in patients with focal epilepsy is highlighted. The most frequently encountered MRI findings in epilepsy are reported and their imaging characteristics depicted. Imaging focus will be on the diagnosis of hippocampal sclerosis and malformations of cortical development, two major causes of medically intractable focal epilepsy. (orig.)

  7. Structural magnetic resonance imaging in epilepsy

    Because of its sensitivity and high tissue contrast, magnetic resonance imaging (MRI) is the technique of choice for structural imaging in epilepsy. In this review the effect of using optimised scanning protocols and the use of high field MR systems on detection sensitivity is discussed. Also, the clinical relevance of adequate imaging in patients with focal epilepsy is highlighted. The most frequently encountered MRI findings in epilepsy are reported and their imaging characteristics depicted. Imaging focus will be on the diagnosis of hippocampal sclerosis and malformations of cortical development, two major causes of medically intractable focal epilepsy. (orig.)

  8. Magnetic resonance images of chronic patellar tendinitis

    Bodne, D.; Quinn, S.F.; Murray, W.T.; Cochran, C.; Bolton, T.; Rudd, S.; Lewis, K.; Daines, P.; Bishop, J.

    1988-01-01

    Chronic patellar tendinitis can be a frustrating diagnostic and therapeutic problem. This report evaluates seven tendons in five patients with chronic patellar tendinitis. The etiologies included 'jumper's knee' and Osgood-Schlatter disease. In all cases magnetic resonance images (MRI) showed thickening of the tendon. Some of the tendons had focal areas of thickening which helped establish the etiology. All cases had intratendinous areas of increased signal which, in four cases, proved to be chronic tendon tears. MRI is useful in evaluating chronic patellar tendinitis because it establishes the diagnosis, detects associated chronic tears, and may help determine appropriate rehabilitation. (orig.)

  9. Interactive Real-time Magnetic Resonance Imaging

    Brix, Lau

    Real-time acquisition, reconstruction and interactively changing the slice position using magnetic resonance imaging (MRI) have been possible for years. However, the current clinical use of interactive real-time MRI is limited due to an inherent low spatial and temporal resolution. This PhD project...... regard to optimal sampling strategy for detecting motion in four different anatomies on two different MRI scanner brands. A fully implemented interactive real-time MRI system was exploited in a group of healthy fetuses and proved its eligibility as an alternative diagnostic tool for fetal imaging...

  10. Indications for fetal magnetic resonance imaging (MRI)

    Indications to perform fetal magnetic resonance imaging (MRI) are composed of common ones related to methodological problems of ultrasound (US) assessment (such as for instance hydramnios) and special ones. The latter are related to MR capability of high-resolution soft tissue contrast and an extended field of view that allows visualization of the whole fetus, even in later stages of pregnancy. The most important indications include confirmation of US findings, work-up of malformations with respect to individual prognosis and genetic background, differentiation between acquired conditions and malformations, visualization of pathologies that have to be treated surgically immediately after birth, and morphological changes of the placenta. (orig.)

  11. Fetal magnetic resonance imaging: methods and techniques

    Since the introduction of fetal magnetic resonance imaging (MRI) into prenatal diagnostics, advances in coil technology and development of ultrafast sequences have further enhanced this technique. At present numerous sequences are available to visualize the whole fetus with high resolution and image quality, even in late stages of pregnancy. Taking into consideration the special circumstances of examination and adjusting sequence parameters to gestational age, fetal anatomy can be accurately depicted. The variety of sequences also allows further characterization of fetal tissues and pathologies. Fetal MRI not only supplies additional information to routine ultrasound studies, but also reveals fetal morphology and pathology in a way hitherto not possible. (orig.)

  12. Developments in boron magnetic resonance imaging (MRI)

    Schweizer, M.

    1995-11-01

    This report summarizes progress during the past year on maturing Boron-11 magnetic resonance imaging (MRI) methodology for noninvasive determination of BNCT agents (BSH) spatially in time. Three major areas are excerpted: (1) Boron-11 MRI of BSH distributions in a canine intracranial tumor model and the first human glioblastoma patient, (2) whole body Boron-11 MRI of BSH pharmacokinetics in a rat flank tumor model, and (3) penetration of gadolinium salts through the BBB as a function of tumor growth in the canine brain.

  13. Nuclear Magnetic Resonance in Liquids and Solids

    The paper outlines the basic principles of nuclear magnetic resonance, trying wherever possible to compare and contrast the method with that of slow neutron scattering as a technique for studying the properties of condensed phases and especially of molecular and atomic motions. It is emphasized that this is not a review of nmr for an expert audience but has a pedagogical aim. It is hoped to give persons with a main interest in neutron scattering some appreciation of the scope and limitations of the nmr method. This is illustrated by recent results on one substance which covers many but by no means all of the important points. (author)

  14. Magnetic Field Gradient Calibration as an Experiment to Illustrate Magnetic Resonance Imaging

    Seedhouse, Steven J.; Hoffmann, Markus M.

    2008-01-01

    A nuclear magnetic resonance (NMR) spectroscopy experiment for the undergraduate physical chemistry laboratory is described that encompasses both qualitative and quantitative pedagogical goals. Qualitatively, the experiment illustrates how images are obtained in magnetic resonance imaging (MRI). Quantitatively, students experience the…

  15. The examination of cardiac metabolism of patients with hypercholesterolemia by phosphorus-31 magnetic resonance spectroscopy

    Objectives: we decided to investigate weather alterations in high energy phosphates occur in the myocardium of persons with hypercholesterolemia. Background: myocardial high energy phosphates have been shown to be reduced in various diseases of the heart such as coronary artery disease, heart failure and dilated cardiomyopathy. The latest studies on hypercholesterolemia show direct effects of high serum cholesterol on heart muscle cells, so do studies on statins. Methods: in the present study 32 male patients (mean age 48) with hypercholesterolemia and 27 male healthy volunteers (mean age 44,5) as age matched controls were included. The patients were divided into a statin-treated (n = 17) and an untreated subgroup (n = 15). Using a 1,5 Tesla whole-body magnetic resonance scanner (Siemens, Germany) phosphor-31 magnetic resonance spectroscopic imaging (31P MRSI) of the heart was performed in all subjects. The 31P MRSI slab (slab thickness = 40 mm, field of view = 320 mm, matrix 32 x 32, TR = 323 ms, TE 3 ms) contained the left anterior ventricular wall (region of interest = 32 ml). The measurement was triggered on electrocardiography. The ratios of phosphocreatinine (PCr) to β-adenosine-triphosphate (β-ATP) were calculated. Results: the myocardium of untreated patients with hypercholesterolemia shows significantly decreased ratios of PCr/β-ATP compared with patients treated with statins (2,09 vs. 2,45). When comparing the untreated group with healthy persons there was a trend to significance for a difference of the groups (2,09 vs. 2,34). Conclusion: with this study we demonstrate the first time alterations of high energy phosphates in the myocardium of persons with hypercholesterolemia and the beneficial effects of statins on these parameters. (author)

  16. Magnetism and homogenization of micro-resonators

    Kohn, Robert V

    2007-01-01

    Arrays of cylindrical metal micro-resonators embedded in a dielectric matrix were proposed by Pendry, et. al., in 1999 as a means of creating a microscopic structure that exhibits strong bulk magnetic behavior at frequencies not realized in nature. This behavior arises for H-polarized fields in the quasi-static regime, in which the scale of the micro-structure is much smaller than the free-space wavelength of the fields. We carry out both formal and rigorous two-scale homogenization analyses, paying special attention to the appropriate method of averaging, which does not involve the usual cell averages. We show that the effective magnetic and dielectric coefficients obtained by means of such averaging characterize a bulk medium that, to leading order, produces the same scattering data as the micro-structured composite.

  17. Contrast Agent in Magnetic Resonance Imaging

    Vu-Quang, Hieu

    2015-01-01

    Nanoparticles have been employed as contrast agent in magnetic resonance imaging (MRI) in order to improve sensitivity and accuracy in diagnosis. In addition, these contrast agents are potentially combined with other therapeutic compounds or near infrared bio-imaging (NIR) fluorophores to obtain...... theranostic or dual imaging purposes, respectively. There were two main types of MRI contrast agent that were synthesized during this PhD project including fluorine containing nanoparticles and magnetic nanoparticles. In regard of fluorine containing nanoparticles, there were two types contrast agent...... cancer cells for cancer diagnosis in MRI. F127-Folate coated SPION were stable in various types of suspension medium for over six months. They could specifically target folate receptor of cancer cells in vitro and in vivo thus enhancing the contrast in MRI T2/T2* weighted images. These are preliminary...

  18. Enhancement of magnetic resonance imaging with metasurfaces

    Slobozhanyuk, A P; Raaijmakers, A J E; Berg, C A T van den; Kozachenko, A V; Dubrovina, I A; Melchakova, I V; Kivshar, Yu S; Belov, P A

    2015-01-01

    Magnetic resonance imaging (MRI) is the cornerstone technique for diagnostic medicine, biology, and neuroscience. This imaging method is highly innovative, noninvasive and its impact continues to grow. It can be used for measuring changes in the brain after enhanced neural activity, detecting early cancerous cells in tissue, as well as for imaging nanoscale biological structures, and controlling fluid dynamics, and it can be beneficial for cardiovascular imaging. The MRI performance is characterized by a signal-to-noise ratio, however the spatial resolution and image contrast depend strongly on the scanner design. Here, we reveal how to exploit effectively the unique properties of metasurfaces for the substantial improvement of MRI efficiency. We employ a metasurface created by an array of wires placed inside the MRI scanner under an object, and demonstrate a giant enhancement of the magnetic field by means of subwavelength near-field manipulation with the metasurface, thus strongly increasing the scanner sen...

  19. 31 P and two-dimensional 31 P-1 H NMR analysis of brain extracts in animal models of multiple sclerosis

    We report here the study of the brain phospholipid content of normal and myelin deficient (md) rats, which develop a physiological impairment at about 15-20 days, and die at 20-25 days of age. The aim is to gain insights into the lipid composition of developing brain, and also to reveal of there exist some early event in the phospholipid metabolism that produces a pathological condition similar to the formation of demyelination plaques in multiple sclerosis. 31 P NMR allows one to detect phospholipids selectively out of a complex lipid mixture in crude extracts. Two-dimensional (2D) 31 P-1H NMR with isotropic proton mixing seems to be a superior technique for assignment of phospholipid 31 P resonances. (author)

  20. Plasmon coupling of magnetic resonances in an asymmetric gold semishell

    Ye, Jian; Kong, Yan; Liu, Cheng

    2016-05-01

    The generation of magnetic dipole resonances in metallic nanostructures is of great importance for constructing near-zero or even negative refractive index metamaterials. Commonly, planar two-dimensional (2D) split-ring resonators or relevant structures are basic elements of metamaterials. In this work, we introduce a three-dimensional (3D) asymmetric Au semishell composed of two nanocups with a face-to-face geometry and demonstrate two distinct magnetic resonances spontaneously in the visible–near infrared optical wavelength regime. These two magnetic resonances are from constructive and destructive hybridization of magnetic dipoles of individual nanocups in the asymmetric semishell. In contrast, complete cancellation of magnetic dipoles in the symmetric semishell leads to only a pronounced electric mode with near-zero magnetic dipole moment. These 3D asymmetric resonators provide new ways for engineering hybrid resonant modes and ultra-high near-field enhancement for the design of 3D metamaterials.

  1. Hybrid resonant phenomenon in a metamaterial structure with integrated resonant magnetic material

    Gollub, Jonah N.; Smith, David R.; Baena, Juan D.

    2008-01-01

    We explore the hybridization of fundamental material resonances with the artificial resonances of metamaterials. A hybrid structure is presented in the waveguide environment that consists of a resonant magnetic material with a characteristic tuneable gyromagnetic response that is integrated into a complementary split ring resonator (CSRR) metamaterial structure. The combined structure exhibits a distinct hybrid resonance in which each natural resonance of the CSRR is split into a lower and up...

  2. [31P-NMR analysis of high energy phosphorous compounds (ATP and phosphocreatine) in the living rat brain--effects of halothane anesthesia and a hypoxic condition].

    Yuasa, T; Miyatake, T; Kuwabara, T; Umeda, M; Eguchi, K

    1983-11-01

    31phosphorus nuclear magnetic resonance (31P-NMR) measurements have provided new and valuable insights for studying the metabolism of living systems. The aim of this paper is to introduce a technique of application of 31P-NMR measurements using a surface coil method, and to discuss the effects of halothane anesthesia and hypoxic hypoxia on the energetic metabolism of intact rat brains. All measurements were made using a JEOL FX 270 spectrometer with a super conducting magnet of 54-mm bore diameter. The magnetic field intensity of this machine is 6.3 tesla, and the resonance frequency used for 31P was 109.14 MHz. We remodelled an ordinary probe to take a live rat, and the animals were made to inhale anesthetic halothane or mixture of oxygen and nitrogen at various concentrations controlled by a flow regulator. The best conditions for measurements with our surface coil method were determined in this study as follows: (1) 90 degrees pulse width and selectivity, Fig. 1 shows signal selectivity in depthwise direction changed with 90 degrees pulse width, which was set to 20 microseconds. (2) Sensitivity and resolution; To obtain a spectrum of 31P-NMR from a rat brain 500 accumulations of free induction decays were considered suitable for both time and space resolution. Fig. 2 shows variations of signal intensity with pulse repetition time, which was set to 2 sec. It took about 17 min for averaging to get a spectrogram. (3) Quantitative accuracy and qualification; As shown in Fig. 3, a linear relationship was found between the signal intensity of beta-phosphate of ATP and the concentration of ATP solutions, thus proving the quantitative accuracy of our systems.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6661335

  3. Electron-photon angular correlations in electron-helium collisions for 31P excitations

    Electron-photon angular correlations have been measured by detecting, in delayed coincidence, electrons inelastically scattered from helium and photons emitted in decays from the 31P level. The measurements have been carried out using both the 31P-11S (53.7nm) line and the 31P-21S (501.6nm) line. Analysis of the data yields the ratio of differential cross sections for exciting 31P magnetic sublevels and the absolute value of the relative phase between the corresponding excitation amplitudes for electron scattering angles between 100 and 300 at incident electron energies in the range 50 eV to 150 eV. Data of the atomic orientation is also presented. The results are compared with the predictions of the first Born approximation and a recent multichannel eikonal calculation. (author)

  4. Magnetic resonance imaging of the central nervous system

    Brant-Zawadzki, M.; Norman, D.

    1987-01-01

    This book presents the papers on technological advancement and diagnostic uses g magnetic resonance imaging. A comparative evaluation with computerized tomography is presented. Topics covered are imaging principles g magnetic resonance;instrumentation of magnetic resonance (MR);pathophysiology;quality and limitations g images;NMR imaging of brain and spinal cord;MR spectroscopy and its applications;neuroanatomy;Congenital malformations of brain and MR imaging;planning g MR imaging of spine and head and neck imaging.

  5. Cardiac Magnetic Resonance In Adults With Congenital Heart Disease

    Partington, Sara L.; Valente, Anne Marie

    2013-01-01

    Increasing numbers of adults with congenital heart disease are referred for cardiac magnetic resonance imaging. Knowledge of the congenital heart anatomy, prior surgical interventions, and the development of an imaging focus for each individual patient plays a crucial role when performing a successful cardiac magnetic resonance imaging examination. The following manuscript focuses on cardiac magnetic resonance imaging considerations of three specific conotruncal congenital heart lesions: tetr...

  6. Magnetic resonance imaging of spinal injury.

    Tracy, P T; Wright, R M; Hanigan, W C

    1989-03-01

    Magnetic resonance imaging (MRI) was performed on 30 patients following spinal injury (SI). Spin-echo sequences and surface coils were used for all patients. Plain radiographs, high-resolution computed tomography (CT), and MRI were compared for the delineation of bone, disc, and ligament injury, measurement of sagittal spinal canal diameter and subluxation, epidural hematoma, and spinal cord structure. Myelography or intrathecal contrast-enhanced CT were not performed on any of these patients. Magnetic resonance imaging accurately delineated intraspinal pathology in two of four patients with acute penetrating SI, and was normal in the other two patients. In 16 patients with acute nonpenetrating SI, MRI was superior to CT for visualizing injuries to discs, ligaments, and the spinal cord, while CT was superior to MRI in characterizing bony injury. Computed tomography and MRI provided similar measurements of subluxation in six of six patients and of sagittal spinal canal diameter in three of four patients. In ten patients with chronic SI, MRI demonstrated post-traumatic cysts, myelomalacia, spinal cord edema, and the presence or absence of spinal cord compression. In patients with acute penetrating SI and chronic SI, MRI provided comprehensive clinical information. In patients with acute nonpenetrating SI, the information obtained by MRI complemented the data given by plain radiographs and CT, allowing clinical decisions to be made without the need of invasive imaging modalities. PMID:2711244

  7. Clinical application of functional magnetic resonance imaging

    Alwatban, A Z W

    2002-01-01

    The work described in this thesis was carried out at the Magnetic Resonance Centre of the University of Nottingham during the time from May 1998 to April 2001, and is the work of the except where indicated by reference. The main source of signal changes in functional magnetic resonance imaging (fMRJ) is the fluctuation of paramagnetic deoxyhaemoglobin in the venous blood during different states of functional performance. For the work of this thesis, fMRI studies were carried out using a 3 T MR system with an echo planar imaging (EPI) pulse sequence. Hearing research utilising fMRI has been previously reported in normal subjects. Hearing fMRI is normally performed by stimulating the auditory cortex via an acoustic task presentation such as music, tone, etc. However, performing the same research on deaf subjects requires special equipment to be designed to allow direct stimulation of the auditory nerve. In this thesis, a new method of direct electrical stimulation of the auditory nerve is described that uses a ...

  8. Magnetic resonance imaging of the bone marrow

    Baur-Melnyk, Andrea (ed.) [Klinikum der Univ. Muenchen (Germany). Inst. fuer Klinische Radiologie

    2013-08-01

    The first book devoted to MRI of the bone marrow. Describes the MRI appearances of normal bone marrows and the full range of bone marrow disorders. Discusses the role of advanced MRI techniques and contrast enhancement. On account of its unrivalled imaging capabilities and sensitivity, magnetic resonance imaging (MRI) is considered the modality of choice for the investigation of physiologic and pathologic processes affecting the bone marrow. This book describes the MRI appearances of both the normal bone marrow, including variants, and the full range of bone marrow disorders. Detailed discussion is devoted to malignancies, including multiple myeloma, lymphoma, chronic myeloproliferative disorders, leukemia, and bone metastases. Among the other conditions covered are benign and malignant compression fractures, osteonecrosis, hemolytic anemia, Gaucher's disease, bone marrow edema syndrome, trauma, and infective and non-infective inflammatory disease. Further chapters address the role of MRI in assessing treatment response, the use of contrast media, and advanced MRI techniques. Magnetic Resonance Imaging of the Bone Marrow represents an ideal reference for both novice and experienced practitioners.

  9. Magnetic resonance spectroscopy as an imaging method

    An experimental Magnetic Resonance (MR) system with 4 tesla flux density was set up. For that purpose a data acquisition system and RF coils for resonance frequencies up to 170 MHz were developed. Methods for image guided spectroscopy as well as spectroscopic imaging focussing on the nuclei 1H and 13C were developed and tested on volunteers and selected patients. The advantages of the high field strength with respect to spectroscopic studies were demonstrated. Developments of a new fast imaging technique for the acquisition of scout images as well as a method for mapping and displaying the magnetic field inhomogeneity in-vivo represent contributions to the optimisation of the experimental procedure in spectroscopic studies. Investigations on the interaction of RF radiation with the exposed tissue allowed conclusions regarding the applicability of MR methods at high field strengths. Methods for display and processing of multi-dimensional spectroscopic imaging data sets were developed and existing methods for real-time image synthesis were extended. Results achieved in the field of computer aided analysis of MR images comprised new techniques for image background detection, contour detection and automatic image interpretation as well as knowledge bases for textural representation of medical knowledge for diagnosis. (orig.) With 82 refs., 3 tabs., 75 figs

  10. Magnetic resonance imaging findings in adnexial torsion

    Trindade, Ronald Meira Castro; Quadros, Marianne Siquara de [Hospital Albert Einstein, Sao Paulo, SP (Brazil). Instituto de Ensino e Pesquisa], e-mail: rtrindade@einstein.br; Baroni, Ronaldo Hueb; Rosemberg, Michelle; Racy, Marcelo de Castro Jorge; Tachibana, Adriano [Hospital Albert Einstein, Sao Paulo, SP (Brazil); Funari, Marcelo Buarque de Gusmao [Hospital Albert Einstein, Sao Paulo, SP (Brazil). Imaging Service

    2010-01-15

    Adnexial torsion is an unusual event, but a major cause of abdominal pain in women. It is often associated with ovarian tumor or cyst, but can occur in normal ovaries, especially in children. The twisting of adnexial structures may involve the ovary or tube, but frequently affects both. In most cases, it is unilateral, with slight predilection for the right size. In imaging findings, increased ovarian volume and adnexial masses are observed, with reduced or absent vascularisation. In cases of undiagnosed or untreated complete twist, hemorrhagic necrosis may occur leading to complications; in that, peritonitis is the most frequent. Early diagnosis helps preventing irreversible damage with conservative treatment, thereby saving the ovary. Limitations in performing physical examination, possible inconclusive results in ultrasound and exposure to radiation in computed tomography makes magnetic resonance imaging a valuable tool in emergency assessment of gynecological diseases. The objective of this study was to report two confirmed cases of adnexial twist, emphasizing the contribution of magnetic resonance imaging in the diagnosis of this condition. (author)

  11. Magnetic resonance imaging of congenital cardiac abnormalities

    Magnetic resonance imaging will not replace echocardiography as the simplest and most definitive method of establishing a noninvasive diagnosis in young patients with congenital cardiac malformations, nor will it replace radionuclide angiography for relatively noninvasive detection and quantitation of cardiac shunts. Magnetic resonance imaging is a complementary noninvasive imaging procedure that can answer some questions left in doubt by echocardiography (mainly extracardiac artery and vein assessments) or radionuclide angiography and used as a preferred follow-up imaging method in certain clinical circumstances. In addition, MRI can be a first-line modality for cardiovascular imaging in older patients in whom adequate echo windows are not available. Angiocardiography remains necessary to provide vital physiological data, i.e., chamber pressures, shunt volumes, oxygen saturations, and pulmonary vascular resistance; however, MRI could negate some follow-up catheterizations in appropriate clinical circumstances. High-resolution proton MRI tomography should ultimately permit the accurate evaluation of ventricular volumes, myocardial mass, and the assessment of regional wall motion and ejection fractions. Paramagnetic substances such as manganese ion may ultimately provide a basis for myocardial perfusion imaging. The potential for MRI evaluation of tissue characterization, noninvasive blood-flow measurements, and myocardial metabolism assessment in intriguing and awaits clinical evaluation

  12. Magnetic resonance imaging of the bone marrow

    The first book devoted to MRI of the bone marrow. Describes the MRI appearances of normal bone marrows and the full range of bone marrow disorders. Discusses the role of advanced MRI techniques and contrast enhancement. On account of its unrivalled imaging capabilities and sensitivity, magnetic resonance imaging (MRI) is considered the modality of choice for the investigation of physiologic and pathologic processes affecting the bone marrow. This book describes the MRI appearances of both the normal bone marrow, including variants, and the full range of bone marrow disorders. Detailed discussion is devoted to malignancies, including multiple myeloma, lymphoma, chronic myeloproliferative disorders, leukemia, and bone metastases. Among the other conditions covered are benign and malignant compression fractures, osteonecrosis, hemolytic anemia, Gaucher's disease, bone marrow edema syndrome, trauma, and infective and non-infective inflammatory disease. Further chapters address the role of MRI in assessing treatment response, the use of contrast media, and advanced MRI techniques. Magnetic Resonance Imaging of the Bone Marrow represents an ideal reference for both novice and experienced practitioners.

  13. Nuclear magnetic resonance imaging and prostatic cancer

    The diagnosis of prostatic cancer is histological. Apart from rectal examination, only imaging techniques allow evaluation of the extension of the cancer. Magnetic Resonance imaging (MRI) was performed with a Magniscan 5000 (Thomson C.G.R., France) apparatus. Three types of sequences were used: a short RT sequence (30/500, a multi-echo sequence with a long RT (40/2500) and echo gradient sequences (12 scans in less than 3 minutes). The MRI study of the pelvis is favoured by the abundance of fat which gives good contrast, spontaneous visualization of the vessels and the presence of the bladder with a high signal for urine in T2. This provides a very good anatomical study in three planes. In prostatic cancer, the study of the long sequence signal reveals heterogeneity of the prostatic signal on the second echo, but this is a non-specific variation. The staging of prostatic cancer is facilitated by scans in three planes. Different examples are presented in relation to various stages of the disease. Three clinical cases demonstrate that Magnetic Resonance may become an important element in the choice of treatment

  14. Magnetic resonance imaging findings in adnexial torsion

    Adnexial torsion is an unusual event, but a major cause of abdominal pain in women. It is often associated with ovarian tumor or cyst, but can occur in normal ovaries, especially in children. The twisting of adnexial structures may involve the ovary or tube, but frequently affects both. In most cases, it is unilateral, with slight predilection for the right size. In imaging findings, increased ovarian volume and adnexial masses are observed, with reduced or absent vascularisation. In cases of undiagnosed or untreated complete twist, hemorrhagic necrosis may occur leading to complications; in that, peritonitis is the most frequent. Early diagnosis helps preventing irreversible damage with conservative treatment, thereby saving the ovary. Limitations in performing physical examination, possible inconclusive results in ultrasound and exposure to radiation in computed tomography makes magnetic resonance imaging a valuable tool in emergency assessment of gynecological diseases. The objective of this study was to report two confirmed cases of adnexial twist, emphasizing the contribution of magnetic resonance imaging in the diagnosis of this condition. (author)

  15. General review of magnetic resonance elastography.

    Low, Gavin; Kruse, Scott A; Lomas, David J

    2016-01-28

    Magnetic resonance elastography (MRE) is an innovative imaging technique for the non-invasive quantification of the biomechanical properties of soft tissues via the direct visualization of propagating shear waves in vivo using a modified phase-contrast magnetic resonance imaging (MRI) sequence. Fundamentally, MRE employs the same physical property that physicians utilize when performing manual palpation - that healthy and diseased tissues can be differentiated on the basis of widely differing mechanical stiffness. By performing "virtual palpation", MRE is able to provide information that is beyond the capabilities of conventional morphologic imaging modalities. In an era of increasing adoption of multi-parametric imaging approaches for solving complex problems, MRE can be seamlessly incorporated into a standard MRI examination to provide a rapid, reliable and comprehensive imaging evaluation at a single patient appointment. Originally described by the Mayo Clinic in 1995, the technique represents the most accurate non-invasive method for the detection and staging of liver fibrosis and is currently performed in more than 100 centers worldwide. In this general review, the mechanical properties of soft tissues, principles of MRE, clinical applications of MRE in the liver and beyond, and limitations and future directions of this discipline -are discussed. Selected diagrams and images are provided for illustration. PMID:26834944

  16. Magnetic resonance epidurography with gadolinium-DTPA

    The aim of this study was to evaluate and describe MRI epidurography as a new imaging tool. Five volunteers and one patient were investigated with MR epidurography after injection of 20 ml Gd-DPTA solution (1 : 250/1 ml Gd-DPTA/250 ml normal saline). Magnetic resonance epidurography is possible. With fat-suppression techniques, the contrast between Gd-DPTA solution in the epidural space and surrounding soft tissue proved adequate. Using the multiplanar capability of MRI with MR epidurography coronal and sagittal projections similar to conventional epidurography, axial slices comparable to CT epidurography can be obtained. Magnetic resonance epidurography is superior to conventional and CT epidurography. Presently, due to high costs as compared with conventional and CT epidurography, MRI is not suitable for the routine monitoring of peridural catheters, but it may have a place in the future with decreasing costs for MRI and for the evaluation of patients with spine pathology, especially in describing epidural processes. (orig.) (orig.)

  17. Effects of chloramphenicol on brain energy metabolism using 31P spectroscopy: influences on sleep-wake states in rat.

    Chahboune, Halima; Mahdjoub, Rachid; Desgoutte, Pierre; Rousset, Colette; Briguet, André; Cespuglio, Raymond

    2008-08-01

    Effects of chloramphenicol (antibiotic inhibiting complex-1 of respiratory chain) and thioamphenicol (TAP, a structural analog of CAP inactive on complex-1) were examined on cerebral energy metabolites and sleep-wake cycle architecture in rat. In the first group, animals were chronically equipped with a cranial surface resonator and (31)P spectroscopic measurements were performed using a 2 T magnetic resonance spectrometer (operating frequency 34.46 MHz). CAP administration (400 mg/kg, tail vein, light period) induced deficits in phosphocreatine (-30%, p electrodes for EEG and electromyogram recordings. CAP administered intraperitoneally at light-onset reduced rapid-eye movement (REM) sleep (-60% in the first 6 h of light period, p EEG were, respectively, increased and decreased (p EEG. Overall, these data indicate that REM sleep occurrence is linked to an aerobic production of ATP. PMID:18507739

  18. Phosphorus 31 nuclear magnetic resonance examination of female reproductive tissues

    Nuclear magnetic resonance spectroscopy is a powerful method of investigating the relationship between metabolism and function in living tissues. We present evidence that the phosphorus 31 spectra of myometrium and placenta are functions of physiologic state and gestational age. Specific spectroscopic abnormalities are observed in association with disorders of pregnancy and gynecologic diseases. Our results suggest that noninvasive nuclear magnetic resonance spectroscopy examinations may sometimes be a useful addition to magnetic resonance imaging examinations, and that nuclear magnetic resonance spectroscopy of biopsy specimens could become a cost-effective method of evaluating certain biochemical abnormalities

  19. Nuclear magnetic resonance study of the conformation and dynamics of beta-casein at the oil/water interface in emulsions.

    ter Beek, L C; Ketelaars, M; McCain, D C; Smulders, P E; Walstra, P.; Hemminga, M.A.

    1996-01-01

    A (13)C and (31)P nuclear magnetic resonance (NMR) study has been carried out on beta-casein adsorbed at the interface of a tetradecane/water emulsion. (13)C NMR spectra show signals from the carbonyl, carboxyl, aromatic, and C alpha carbons in beta-casein, well resolved from solvent resonances. Only a small fraction of all carbon atoms in beta-casein contribute to detectable signals; intensity measurements show that the observable spectrum is derived from about 30 to 40 amino acid residues.(...

  20. Secondary resonance magnetic force microscopy using an external magnetic field for characterization of magnetic thin films

    Liu, Dongzi; Mo, Kangxin; Ding, Xidong; Zhao, Liangbing; Lin, Guocong; Zhang, Yueli; Chen, Dihu

    2015-09-01

    A bimodal magnetic force microscopy (MFM) that uses an external magnetic field for the detection and imaging of magnetic thin films is developed. By applying the external modulation magnetic field, the vibration of a cantilever probe is excited by its magnetic tip at its higher eigenmode. Using magnetic nanoparticle samples, the capacity of the technique which allows single-pass imaging of topography and magnetic forces is demonstrated. For the detection of magnetic properties of thin film materials, its signal-to-noise ratio and sensitivity are demonstrated to be superior to conventional MFM in lift mode. The secondary resonance MFM technique provides a promising tool for the characterization of nanoscale magnetic properties of various materials, especially of magnetic thin films with weak magnetism.

  1. Purely electric and magnetic dipole resonances in metamaterial dielectric resonators through perturbation theory inspired geometries

    Campione, Salvatore; Warne, Larry K; Sinclair, Michael B

    2014-01-01

    In this paper we describe a methodology for tailoring the design of metamaterial dielectric resonators, which represent a promising path toward low-loss metamaterials at optical frequencies. We first describe a procedure to decompose the far field scattered by subwavelength resonators in terms of multipolar field components, providing explicit expressions for the multipolar far fields. We apply this formulation to confirm that an isolated high-permittivity cube resonator possesses frequency separated electric and magnetic dipole resonances, as well as a magnetic quadrupole resonance in close proximity to the electric dipole resonance. We then introduce multiple dielectric gaps to the resonator geometry in a manner suggested by perturbation theory, and demonstrate the ability to overlap the electric and magnetic dipole resonances, thereby enabling directional scattering by satisfying the first Kerker condition. We further demonstrate the ability to push the quadrupole resonance away from the degenerate dipole ...

  2. Ultra-high-field magnetic resonance: Why and when?

    Moser, Ewald

    2010-01-01

    This paper briefly summarizes the development of magnetic resonance imaging and spectroscopy in medicine. Aspects of magnetic resonancephysics and -technology relevant at ultra-high magnetic fields as well as current limitations are highlighted. Based on the first promising studies, potential clinical applications at 7 Tesla are suggested. Other aims are to stimulate awareness of the potential of ultra-high field magnetic resonance and to stimulate active participation in much needed basic or...

  3. Cardiac magnetic resonance spectroscopy: potential clinical applications

    MR spectroscopy is the only method for non-invasive detection of various aspects of cardiac metabolism in humans. While the 1H nucleus of water and fat molecules is the signal source for MR imaging, the MR spectroscopic technique allows for the study of a number of other nuclei, such as 13C, 19F, 23Na, 31P, 39K and 87Rb. Clinical applications presently are confined to the 31P nucleus. 31P-MR spectroscopy allows the non-invasive study of cardiac high-energy phosphate metabolites ATP and phosphocreatine. The phosphocreatine/ATP ratio is considered an index of the energetic state of the heart. Possible clinical indications include heart failure, valve disease and coronary artery disease. In heart failure, the phosphocreatine/ATP ratio is reduced and correlates with clinical severity, ejection fraction and prognosis. In mitral and aortic valve disease, a reduced phosphocreatine/ATP ratio may indicate the optimum timing for valve replacement. In coronary artery disease, a regional decrease of phosphocreatine during stress (''biochemical ergometry'') may indicate local ischemia. Furthermore, absolute quantification of high-energy phosphates may allow diagnosis of myocardial viability. Major technical developments, leading to improved spatial and temporal resolution will be necessary to establish MR spectroscopy as a routine clinical tool. (orig.)

  4. NMRES: an artificial intelligence expert system for quantification of cardiac metabolites from 31phosphorus nuclear magnetic resonance spectroscopy.

    Chow, J L; Levitt, K N; Kost, G J

    1993-01-01

    The application of high-resolution 31Phosphorus Nuclear Magnetic Resonance (31P NMR) Spectroscopy in biology and medicine has provided new insights into biochemical processes and also a unique assessment of metabolites. However, accurate quantification of biological NMR spectra is frequently complicated by: (a) non-Lorentzian form of peak lineshapes, (b) contamination of peak signals by neighboring peaks, (c) presence of broad resonances, (d) low signal-to-noise ratios, and (e) poorly defined sloping baselines. Our objectives were to develop an expert system that captures and formalizes 31P NMR spectroscopists' expert knowledge, and to provide a reliable, efficient, and automated system for the interpretation of biological spectra. The NMR Expert System (NMRES) was written in the C and OPS5 programming languages and implemented on a Unix-based (Ultrix) mainframe system with XWindows bit-map graphics display. Expert knowledge was acquired from NMR spectroscopists and represented as production rules in the knowledge base. A heuristic weights method was employed to determine the confidence levels of potential peaks. Statistical and numerical methods were used to facilitate processing decisions. NMR spectra obtained from studies of ischemic neonatal and immature hearts were used to assess the performance of the expert system. The expert system performed signal extraction, noise treatment, resonance assignment, intracellular pH determination, and metabolite intensity quantitation in about 10 s per 4 KB (kilobyte) spectrum. The peak identification success rate was 98.2%. Peak areas and pH estimated by the expert system compared favorably with those determined by human experts. We conclude that the expert system has provided a framework for reliable and efficient quantification of complex biological 31P NMR spectra. PMID:8328724

  5. Magnetic resonance tracking of fluorescent nanodiamond fabrication

    Magnetic resonance techniques (electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR)) are used for tracking the multi-stage process of the fabrication of fluorescent nanodiamonds (NDs) produced by high-energy electron irradiation, annealing, and subsequent nano-milling. Pristine commercial high pressure and high temperature microdiamonds (MDs) with mean size 150 μm contain ∼5  ×  1018 spins/g of singlet (S = 1/2) substitutional nitrogen defects P1, as well as sp3 C–C dangling bonds in the crystalline lattice. The half-field X-band EPR clearly shows (by the appearance of the intense ‘forbidden’ g = 4.26 line) that high-energy electron irradiation and annealing of MDs induce a large amount (∼5  ×  1017 spins/g) of triplet (S = 1) magnetic centers, which are identified as negatively charged nitrogen vacancy defects (NV−). This is supported by EPR observations of the ‘allowed’ transitions between Zeeman sublevels of the triplet state. After progressive milling of the fluorescent MDs down to an ultrasubmicron scale (≤100 nm), the relative abundance of EPR active NV− defects in the resulting fluorescent NDs (FND) substantially decreases and, vice versa, the content of C-inherited singlet defects correlatively increases. In the fraction of the finest FNDs (mean particle size <20 nm), which are contained in the dried supernatant of ultracentrifuged aqueous dispersion of FNDs, the NV− content is found to be reduced by one order of magnitude whereas the singlet defects content increases up to ∼2  ×  1019 spins/g. In addition, another triplet-type defect, which is characterized by the g = 4.00 ‘forbidden’ line, appears. On reduction of the particle size below the 20 nm limit, the ‘allowed’ EPR lines become practically unobservable, whereas the ‘forbidden’ lines remain as a reliable fingerprint of the presence of NV− centers in small ND systems. The same size reduction causes the

  6. Nuclear magnetic resonance in hexaferrite/maghemite composite nanoparticles

    Kříšťan, P.; Hondlík, O.; Štěpánková, H.; Chlan, V.; Kouřil, K.; Řezníček, R.; Pollert, Emil; Veverka, Pavel

    Warszawa: Polish Academy of Sciences, 2015, s. 514-516. ISSN 0587-4246. [The European Conference PHYSICS OF MAGNETISM 2014/PM'14/. Poznań (PL), 23.06.2014-27.06.2014] Institutional support: RVO:68378271 Keywords : nuclear magnetic resonance and relaxation * ferrimagnetics * fine-particle systems * nanocrystalline materials * magnetic oxides * inorganic compounds Subject RIV: BM - Solid Matter Physics ; Magnetism

  7. Magnetic resonance imaging of vertebral compression fractures

    Magnetic resonance (MR) imaging was performed on 112 patients with 210 vertebral compression fractures. Forty fractures were due to malignancy; 170 were caused by benign process. Pathological fractures showed low signal intensity (SI) on T1 weighted image (WI) and various SI on T2 WI. In 39 of the 40 fractures caused by malignancy, MRI showed complete replacement of normal bone marrow. Other findings of pathological fractures, such as involvement of posterior structures, paraspinal soft tissue masses, are useful for discrimination between benign and pathologic compression fractures. In 120 of the 157 fractures caused osteoporosis had complete preservation of normal bone marrow and isointense or high intense marrow SI on T1 WI and T2 WI. Compression fractures caused by trauma showed low SI on T1 WI and high SI on T2 WI with an irregular pattern. We suppose MRI may be a useful modality in differenciating benign and metastatic fractures. (author)

  8. Modern magnetic resonance imaging of the liver

    Magnetic resonance imaging (MRI) of the liver has become an essential tool in the radiological diagnostics of both focal and diffuse diseases of the liver and is subject to constant change due to technological progress. Recently, important improvements could be achieved by innovations regarding MR hardware, sequences and postprocessing methods. The diagnostic spectrum of MRI could be broadened particularly due to new examination sequences, while at the same time scanning time could be shortened and image quality has been improved. The aim of this article is to explain both the technological background and the clinical application of recent MR sequence developments and to present the scope of a modern MRI protocol for the liver. (orig.)

  9. Basic concepts from magnetic resonance imaging

    The use of magnetic resonance imaging (MRI) has grown exponentially, due in part to excellent anatomic and pathologic detail provided by the modality, as recent technological advances that have led to more rapid acquisition times. Radiology residents in different parts of the world now receive training in MR images from their first year of residence, included the pulse sequences training spin-echo, gradient-echo, inversion-recovery, echo-planar image and MR angiographic sequences, commonly used in medical imaging. However, to optimize the use of this type of study, it has been necessary to understand the basic concepts of physics, included the concepts of recovery T1, degradation T2* and T2, repetition time, echo time, and the effects of chemical shift. Additionally, it has been important to understand the contrast weighting for better representation of specific tissues and thus perform an appropriate differential diagnosis of various pathological processes. (author)

  10. Magnetic resonance imaging for postoperative maxillary cyst

    Magnetic resonance images of 47 patients with postoperative maxillary cyst were analyzed for size, location, and signal intensity. The smallest cyst was confirmed at surgery to be 1 cmx1 cmx1 cm and the largest 5 cmx5 cmx5 cm. The cysts were usually found in the superomedial and inferomedial parts of the maxillary sinus (44%). Many patients (60%) had multiple cysts or bilateral cysts (30%). In most the signal intensity was low in the T1-weighted SE (500/40) images and high in the T2-weighted SE (2000/80) images. Cysts with a hemorrhagic component, though rare, showed high signal intensity in both T1-and T2-weighted images. (author)

  11. Valuation for magnetic resonance of neuro tuberculosis

    The increased incidence of neuro tuberculosis (NTB), due to the world epidemic of resistant strains and AIDS, has made of magnetic resonance (MR) imaging the study of choice for the early detection of lesions that lead the clinicians to an effective treatment. We present our experience with six cases of NTB, with meningoencephalic (4 cases), spinal, (1 case) and epidural (1 case) involvement. We identified basal arachnoiditis that was also seen on CT. Two cases demonstrated non-classifying tuberculomas, the spinal lesion consisted of casseifying tuberculoma that responded to treatment and disappeared on a follow up MR study. Epidural involvement consisted of Pott's disease with displacement and edema of the spinal cord. The differential diagnosis of these lesions includes mycoses, cysticercosis, sarcoidosis and leptomeningeal metastases

  12. Magnetic resonance imaging of pancreatitis: an update.

    Manikkavasakar, Sriluxayini; AlObaidy, Mamdoh; Busireddy, Kiran K; Ramalho, Miguel; Nilmini, Viragi; Alagiyawanna, Madhavi; Semelka, Richard C

    2014-10-28

    Magnetic resonance (MR) imaging plays an important role in the diagnosis and staging of acute and chronic pancreatitis and may represent the best imaging technique in the setting of pancreatitis due to its unmatched soft tissue contrast resolution as well as non-ionizing nature and higher safety profile of intravascular contrast media, making it particularly valuable in radiosensitive populations such as pregnant patients, and patients with recurrent pancreatitis requiring multiple follow-up examinations. Additional advantages include the ability to detect early forms of chronic pancreatitis and to better differentiate adenocarcinoma from focal chronic pancreatitis. This review addresses new trends in clinical pancreatic MR imaging emphasizing its role in imaging all types of acute and chronic pancreatitis, pancreatitis complications and other important differential diagnoses that mimic pancreatitis. PMID:25356038

  13. Cardiovascular magnetic resonance in carotid atherosclerotic disease

    Chen Huijun

    2009-12-01

    Full Text Available Abstract Atherosclerosis is a chronic, progressive, inflammatory disease affecting many vascular beds. Disease progression leads to acute cardiovascular events such as myocardial infarction, stroke and death. The diseased carotid alone is responsible for one third of the 700,000 new or recurrent strokes occurring yearly in the United States. Imaging plays an important role in the management of atherosclerosis, and cardiovascular magnetic resonance (CMR of the carotid vessel wall is one promising modality in the evaluation of patients with carotid atherosclerotic disease. Advances in carotid vessel wall CMR allow comprehensive assessment of morphology inside the wall, contributing substantial disease-specific information beyond luminal stenosis. Although carotid vessel wall CMR has not been widely used to screen for carotid atherosclerotic disease, many trials support its potential for this indication. This review summarizes the current state of knowledge regarding carotid vessel wall CMR and its potential clinical application for management of carotid atherosclerotic disease.

  14. Magnetic resonance imaging in tuberous sclerosis

    Two patients with tuberous sclerosis, who had the typical computed tomographic (CT) sign (calcified subependymal nodules), underwent magnetic resonance imaging (MRI) using inversion-recovery (IR) and spin-echo (SE) techniques. Subependymal nodules were discriminated from parenchymal nodules on IR and SE images and on T1-weighted images in one patient. Subependymal nodules were visualized as well in another patient. However, either IR or SE images failed to show nodules in the frontal lobe or caudate nucleus. Nor was nodules in the cerebellar odontoid nucleus detected on IR images. These results suggest the difficulty in uniformity of MRI findings. On the contrary, pathological difference in nudules may reflect relaxation times, probably causing the differences in IR and SE images. (Namekawa, K.)

  15. Magnetic resonance imaging of intervertebral disc degeneration

    Maeda, Hiroshi; Noguchi, Masao (Kitakyushu City Yahata Hospital, Fukuoka (Japan)); Kira, Hideaki; Fujiki, Hiroshi; Shimokawa, Isao; Hinoue, Kaichi

    1993-02-01

    The aim of this study was to correlate the degree of lumbar intervertebral disc degeneration with findings of magnetic resonance imaging (MRI). Seventeen autopsied (from 7 patients) and 21 surgical (from 20 patients) intervertebral discs were used as specimens for histopathological examination. In addition, 21 intervertebral discs were examined on T2-weighted images. Histopathological findings from both autopsied and surgical specimens were well correlated with MRI findings. In particular, T2-weighted images reflected increased collagen fibers and rupture within the fibrous ring accurately. However, when severely degenerated intervertebral discs and hernia protruding the posterior longitudinal ligament existed, histological findings were not concordant well with T2-weighted images. Morphological appearances of autopsy specimens, divided into four on T2-weighted images, were well consistent with histological degeneration. This morphological classification, as shown on T2-weighted images, could also be used in the evaluation of intervertebral disc degeneration. (N.K.).

  16. Magnetic Resonance Imaging in occult spinal dysraphism

    A prospective study was carried out in 100 cases of suspected occult spinal dysraphic anomalies with Magnetic Resonance Imaging (MRI) in order to determine its diagnostic efficacy as the initial imaging modality. MR imaging provided accurate preoperative information in 91 out of 92 cases (98.9%). Some of the unusual and interesting findings in the series were: presence of intrinsic cord abnormality in 19 out of 21 cases (90.4%) with a normal plain radiography, 4 cases of diastematomyelia with a dermoid in the dorsal and lumbar region associated with syringohydromyelia, intradural fibrous/glial bands, syringo-hydromyelia/myelomalacia of the conus with tethered cord syndrome having a normally paced conus, and myelocystocele. It is concluded that MRI is an excellent primary diagnostic tool, together with a plain radiography, for complete preoperative evaluation of mid-line spinal anomalies. 14 refs., 3 tabs., 7 figs

  17. Safety of magnetic resonance contrast media.

    Runge, V M

    2001-08-01

    Intravenous contrast media, specifically the gadolinium chelates, are well accepted for use in the clinical practice of magnetic resonance imaging. The gadolinium chelates are considered to be very safe and lack (in intravenous use) the nephrotoxicity found with iodinated contrast media. Minor adverse reactions, including nausea and hives, occur in a low percentage of cases. The four agents currently available in the United States cannot be differentiated on the basis of these adverse reactions. Severe anaphylactoid reactions are also known to occur with all agents, although these are uncommon. This review discusses the safety issues involved with intravenous administration of the gadolinium chelates and off-label use. The latter is common in clinical practice and permits broader application of these agents. PMID:11687717

  18. Magnetic resonance imaging of ovarian cystic tumor

    Seventeen cases with cystic ovarian tumors were examined with both magnetic resonance imaging (MRI) and CT scanning. The contents of the cysts were analyzed as for protein, fat, and iron. The intensity patterns of the cystic lesion were not directly related to the amount of protein, fat, nor iron. But an for the cystadenomas, protein concentration are the most responsible for their intensities, and as for the dermoid cysts, fat are the most responsible for. And in endemetrial cysts, it seems that variable amount of protein, fat, and iron make the unique intensity patterns. MRI was superior to CT in characterizing cyts especially for cystadenoma and endmetorial cysts. And with much more case studies, relationship between protein concentration and intensities will be proved. (author)

  19. Magnetic resonance imaging of traumatic cervical injury

    To evaluate magnetic resonance imaging (MRI) findings of cevical injuries. MRI studies of 34 patients with cervical spinal injuries were analyzed retrospectively. All MRI scans were obtained with an 1.0T superconductive MRI scanner (Siemens Magnetom 42SPE) and their findings were analyzed regarding the spinal cord, bony spine, ligaments, and intervertebral disks. A variety of abnormal findings were detected: 25 cord abnormalities including cord compression (15 cases), cord edema (4 cases), syringomyelia (4 cases), myelomalacia (1 case), and hemorrhagic contusion (1 case), 18 ligamentous injuries, 22 disk herniations (9 post-traumatic, 13 chronic degenerative), 11 spine fractures, and 4 subluxations. MRI is useful in evaluating the spinal cord itself, in depicting ligamentous injuries, in establishing the presence of disc herniation, and in assessing the alignment of cervical spine

  20. Magnetic resonance imaging of traumatic cervical injury

    Juhng, S. K.; Lee, K. S.; Sohn, K. J.; Choi, S. S.; Won, J. J. [Wonkwang University School of Medicine, Iri (Korea, Republic of)

    1994-04-15

    To evaluate magnetic resonance imaging (MRI) findings of cevical injuries. MRI studies of 34 patients with cervical spinal injuries were analyzed retrospectively. All MRI scans were obtained with an 1.0T superconductive MRI scanner (Siemens Magnetom 42SPE) and their findings were analyzed regarding the spinal cord, bony spine, ligaments, and intervertebral disks. A variety of abnormal findings were detected: 25 cord abnormalities including cord compression (15 cases), cord edema (4 cases), syringomyelia (4 cases), myelomalacia (1 case), and hemorrhagic contusion (1 case), 18 ligamentous injuries, 22 disk herniations (9 post-traumatic, 13 chronic degenerative), 11 spine fractures, and 4 subluxations. MRI is useful in evaluating the spinal cord itself, in depicting ligamentous injuries, in establishing the presence of disc herniation, and in assessing the alignment of cervical spine.

  1. Monitoring angiogenesis using magnetic resonance methods

    Holm, David Alberg

    2008-01-01

    When a tumor reaches a certain size it can no longer rely on passive perfusion for nutrition. The tumor therefore emits signaling molecules which stimulating surrounding vessels to divide and grow towards the tumor, a process known as angiogenesis. Very little angiogenesis is present in healthy...... adults where it is primaily found in wound healing, pregnancy and during the menstrual cycle. This thesis focus on the negative consequences of angiogenesis in cancer. It consists of a an initial overview followed by four manuscripts. The overview gives a short introduction to the process of angiogenesis...... and the involved signaling molecules. Subsequently, a short review of contrast agents and perfusion measurements is given. Finally, methods for monitoring angiogenesis using magnetic resonance imaging are reviewed. A method for monitoring early stages of angiogenesis as well as the effect of anti...

  2. Magnetic resonance tomography and ultrasound in rheumatology

    Technical innovations and software improvements in magnetic resonance imaging (MRI) and high-resolution sonography (US) have definitely influenced the diagnostic imaging of rheumatic diseases. For MRI, improvements in surface coils, dedicated low-field systems (0.2 T), and software improvements (shorter acquisition times and refinements of fat suppressing techniques) must be mentioned. For sonography, the main innovations concern the development of higher transducer frequencies (7-15 Mhz) and power Doppler imaging. Clinical evaluations have shown that MRI and US are most useful in cases of suspected rheumatic disease with negative plain film radiographs and for documenting the course of the disease, diagnosing of early rheumatoid arthritis, making a differential diagnosis in clinically unclear rheumatic diseases, investigating vascularization, and quantifying pannus formation. In order to improve diagnostic efficacy the role of MRI and US in the management of patients with rheumatic disease should be reconsidered. (orig.)

  3. Multivoxel Magnetic Resonance Spectroscopy in Gliomatosis Cerebri

    Gliomatosis cerebri is a rare entity with non-specific clinical and conventional magnetic resonance imaging (MRI) findings; accurate diagnosis is a differential diagnostic challenge. MR spectroscopy has recently been introduced as a useful diagnostic tool for detection of this entity. We present a gliomatosis cerebri case in which we made the radiological diagnosis using the MR spectroscopy findings; the diagnosis was confirmed by subsequent biopsy and histopathologic evaluation. Multivoxel spectroscopy (CSI, PRESS, 1500/135) shows a marked increase in Cho/NAA (6.6), normal to mild increase in Cho/Cr (1.2), and marked decrease in NAA/Cr (0.2) compared with the normally appearing contralateral side (Cho/NAA: 0.8, Cho/Cr: 0.9, NAA/Cr: 1.2)

  4. Cardiovascular magnetic resonance in hypertrophic cardiomyopathy

    Shiozaki, Afonso Akio; Parga, Jose Rodrigues; Arteaga, Edmundo; Rochitte, Carlos Eduardo [Sao Paulo Univ. (USP), SP (Brazil). Instituto do Coracao. Setor de Tomografia Computarizada e Ressonancia Magnetica Cardiovascular]. E-mail: rochitte@incor.usp.br; Kim, Raymond J. [Duke Cardiovascular Magnetic Resonance Center, Durham, NC (United States); Tassi, Eduardo Marinho [Diagnosticos da America S.A., Rio de Janeiro, RJ (Brazil). Sector of Cardiovascular Magnetic Resonance and Computed Tomography

    2007-03-15

    Hypertrophic cardiomyopathy (HCM) is the most frequent genetic cardiac disease that causes sudden death in young people, with an incidence of 1:500 adults. The routinely used criteria for worst prognosis have limited sensitivity and specificity. Thus, the estimated risk of evolving to dilated cardiomyopathy or sudden death is somewhat inaccurate, leading to management uncertainty of HCM patients. Therefore, an accurate noninvasive method for the diagnosis of HCM with prognostic value is of great importance. In the last years, Cardiovascular Magnetic Resonance (CMR) emerged not only as a diagnostic tool, but also as a study with prognostic values, by characterizing myocardial fibrosis with great accuracy in HCM patients. Additionally, CMR identifies the types of hypertrophy, analyses the ventricular function, estimates the intraventricular gradient and allows the determination of differential diagnosis. Moreover, CMR can uniquely access myocardial fibrosis in HCM. (author)

  5. Magnetic resonance imaging of the small bowel

    Deeab, Dhafer A., E-mail: dhafer_ahmed@yahoo.co [Department of Radiology, St Mary' s Campus, Imperial College NHS Trust, London (United Kingdom); Dick, Elizabeth; Sergot, Antoni A.; Sundblon, Lauren; Gedroyc, Wady [Department of Radiology, St Mary' s Campus, Imperial College NHS Trust, London (United Kingdom)

    2011-02-15

    Magnetic Resonance Imaging of the Small Bowel (MR Enterography, or MRE) is becoming increasingly popular as the first imaging modality for the diagnosis and follow-up of small bowel diseases. The inherent advantages of MRI, including excellent soft tissue contrast, multiplanar capability and lack of ionising radiation are well known. In addition, the use of luminal contrast agents in MRE has the added advantage of demonstrating the lumen and the wall directly, something not possible to achieve with conventional small bowel barium follow-through imaging. This review will highlight recent technical advances to this low cost, simple technique which is easily achievable in all hospitals. It will also review normal and abnormal radiological findings and highlight the value of this technique to both the clinician and patient alike in the investigation of small bowel disease.

  6. Magnetic resonance imaging of the small bowel

    Magnetic Resonance Imaging of the Small Bowel (MR Enterography, or MRE) is becoming increasingly popular as the first imaging modality for the diagnosis and follow-up of small bowel diseases. The inherent advantages of MRI, including excellent soft tissue contrast, multiplanar capability and lack of ionising radiation are well known. In addition, the use of luminal contrast agents in MRE has the added advantage of demonstrating the lumen and the wall directly, something not possible to achieve with conventional small bowel barium follow-through imaging. This review will highlight recent technical advances to this low cost, simple technique which is easily achievable in all hospitals. It will also review normal and abnormal radiological findings and highlight the value of this technique to both the clinician and patient alike in the investigation of small bowel disease.

  7. Magnetic resonance imaging of intervertebral disc degeneration

    The aim of this study was to correlate the degree of lumbar intervertebral disc degeneration with findings of magnetic resonance imaging (MRI). Seventeen autopsied (from 7 patients) and 21 surgical (from 20 patients) intervertebral discs were used as specimens for histopathological examination. In addition, 21 intervertebral discs were examined on T2-weighted images. Histopathological findings from both autopsied and surgical specimens were well correlated with MRI findings. In particular, T2-weighted images reflected increased collagen fibers and rupture within the fibrous ring accurately. However, when severely degenerated intervertebral discs and hernia protruding the posterior longitudinal ligament existed, histological findings were not concordant well with T2-weighted images. Morphological appearances of autopsy specimens, divided into four on T2-weighted images, were well consistent with histological degeneration. This morphological classification, as shown on T2-weighted images, could also be used in the evaluation of intervertebral disc degeneration. (N.K.)

  8. [Prostate biopsy under magnetic resonance imaging guidance].

    Kuplevatskiy, V I; CherkashiN, M A; Roshchin, D A; Berezina, N A; Vorob'ev, N A

    2016-01-01

    Prostate cancer (PC) is one of the most important problems in modern oncology. According to statistical data, PC ranks second in the cancer morbidity structure in the Russian Federation and developed countries and its prevalence has been progressively increasing over the past decade. A need for early diagnosis and maximally accurate morphological verification of the diagnosis in difficult clinical cases (inconvenient tumor location for standard transrectal biopsy; gland scarring changes concurrent with prostatitis and hemorrhage; threshold values of prostate-specific antigen with unclear changes in its doubling per unit time; suspicion of biochemical recurrence or clinical tumor progression after special treatment) leads to revised diagnostic algorithms and clinically introduced new high-tech invasive diagnostic methods. This paper gives the first analysis of literature data on Russian practice using one of the new methods to verify prostate cancer (transrectal prostate cancer under magnetic resonance imaging (MRI) guidance). The have sought the 1995-2015 data in the MEDLINE and Pubmed. PMID:27192773

  9. Two-dimensional nuclear magnetic resonance petrophysics.

    Sun, Boqin; Dunn, Keh-Jim

    2005-02-01

    Two-dimensional nuclear magnetic resonance (2D NMR) opens a wide area for exploration in petrophysics and has significant impact to petroleum logging technology. When there are multiple fluids with different diffusion coefficients saturated in a porous medium, this information can be extracted and clearly delineated from CPMG measurements of such a system either using regular pulsing sequences or modified two window sequences. The 2D NMR plot with independent variables of T2 relaxation time and diffusion coefficient allows clear separation of oil and water signals in the rocks. This 2D concept can be extended to general studies of fluid-saturated porous media involving other combinations of two or more independent variables, such as chemical shift and T1/T2 relaxation time (reflecting pore size), proton population and diffusion contrast, etc. PMID:15833623

  10. Magnetic resonance imaging of facial muscles

    Farrugia, M.E. [Department of Clinical Neurology, University of Oxford, Radcliffe Infirmary, Oxford (United Kingdom)], E-mail: m.e.farrugia@doctors.org.uk; Bydder, G.M. [Department of Radiology, University of California, San Diego, CA 92103-8226 (United States); Francis, J.M.; Robson, M.D. [OCMR, Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford (United Kingdom)

    2007-11-15

    Facial and tongue muscles are commonly involved in patients with neuromuscular disorders. However, these muscles are not as easily accessible for biopsy and pathological examination as limb muscles. We have previously investigated myasthenia gravis patients with MuSK antibodies for facial and tongue muscle atrophy using different magnetic resonance imaging sequences, including ultrashort echo time techniques and image analysis tools that allowed us to obtain quantitative assessments of facial muscles. This imaging study had shown that facial muscle measurement is possible and that useful information can be obtained using a quantitative approach. In this paper we aim to review in detail the methods that we applied to our study, to enable clinicians to study these muscles within the domain of neuromuscular disease, oncological or head and neck specialties. Quantitative assessment of the facial musculature may be of value in improving the understanding of pathological processes occurring within facial muscles in certain neuromuscular disorders.

  11. Chest magnetic resonance imaging: a protocol suggestion

    Bruno Hochhegger

    2015-12-01

    Full Text Available Abstract In the recent years, with the development of ultrafast sequences, magnetic resonance imaging (MRI has been established as a valuable diagnostic modality in body imaging. Because of improvements in speed and image quality, MRI is now ready for routine clinical use also in the study of pulmonary diseases. The main advantage of MRI of the lungs is its unique combination of morphological and functional assessment in a single imaging session. In this article, the authors review most technical aspects and suggest a protocol for performing chest MRI. The authors also describe the three major clinical indications for MRI of the lungs: staging of lung tumors; evaluation of pulmonary vascular diseases; and investigation of pulmonary abnormalities in patients who should not be exposed to radiation.

  12. Magnetic resonance imaging after exposure to microgravity

    Leblanc, Adrian

    1993-01-01

    A number of physiological changes were demonstrated in bone, muscle, and blood from exposure of humans and animals to microgravity. Determining mechanisms and the development of effective countermeasures for long-duration space missions is an important NASA goal. Historically, NASA has had to rely on tape measures, x-ray, and metabolic balance studies with collection of excreta and blood specimens to obtain this information. The development of magnetic resonance imaging (MRI) offers the possibility of greatly extending these early studies in ways not previously possible; MRI is also non-invasive and safe; i.e., no radiation exposure. MRI provides both superb anatomical images for volume measurements of individual structures and quantification of chemical/physical changes induced in the examined tissues. This investigation will apply MRI technology to measure muscle, intervertebral disc, and bone marrow changes resulting from exposure to microgravity.

  13. Magnetic resonance imaging of the musculoskeletal system

    Ever since the advent of computed tomography reliable determinations of the extension of musculoskeletal tumours have been possible before surgical intervention. It is basically owing to this technique that limb-sparing partial resection can now be performed as an alternative to amputation of an extremity. Magnetic resonance imaging is even more suitable for preoperative tumour staging, as skip lesions and the intraosseous or extraosseous spread of the tumour are more clearly discernible here than on CT displays. For evaluations of the type and severity of bone tumours that have not yet been analysed histologically survey radiography still appears to be the obvious method. CT and MRT, on the other hand, provide information as to the texture of the tumour matrix (fatty, liquid or solid consistency, tinges of blood). Some types of tumour seem to be associated with a particular morphological appearance in MRT images. (orig.)

  14. Magnetic resonance imaging in joint diseases

    Magnetic resonance imaging has proven an invaluable method in the diagnosis of joint diseases associated with osteonecrotic, inflammatory, traumatic and degenerative processes. At the clinical level, it has an important role in decisions about the method of treatment and evaluations of the therapeutic success. When the merits of MRT are balanced against those of conventional radiography including tomography and CT, which both ensure better spatial resolution in the visualisation of cortical and spongy bone structures, it becomes quite evident that MRT must not be regarded as an alternative method of imaging but as one that can be used additionally to obtain the most information for the diagnosis of arthropathy. The question as to whether new pulse sequences (snap shots) or invasive techniques like intra-articular injection of paramagnetic substances (MR arthrography) are likely to become routine procedures in the detection of joint diseases using MRT remains to be examined in further studies. (orig.)

  15. Pulsed nuclear-electronic magnetic resonance

    Morley, Gavin W; Mohammady, M Hamed; Aeppli, Gabriel; Kay, Christopher W M; Jeschke, Gunnar; Monteiro, Tania S

    2011-01-01

    Pulsed magnetic resonance is a wide-reaching technology allowing the quantum state of electronic and nuclear spins to be controlled on the timescale of nanoseconds and microseconds respectively. The time required to flip either dilute electronic or nuclear spins is orders of magnitude shorter than their decoherence times, leading to several schemes for quantum information processing with spin qubits. We investigate instead the novel regime where the eigenstates approximate 50:50 superpositions of the electronic and nuclear spin states forming "nuclear-electronic" qubits. Here we demonstrate quantum control of these states, using bismuth-doped silicon, in just 32 ns: orders of magnitude shorter than previous experiments where pure nuclear states were used. The coherence times of our states are over four orders of magnitude longer, being 1 ms or more at 8 K, and are limited by the naturally-occurring 29Si nuclear spin impurities. There is quantitative agreement between our experiments and no-free-parameter anal...

  16. Magnetic resonance imaging of cerebrotendinous xanthomatosis

    Tai, K.S.; Brockwell, J.; Chan, F.L.; Janus, E.D.; Lam, K.S.L.

    1995-02-01

    Cerebrotendinous xanthomatosis (CTX) is a rare genetic disorder in which cholestanol and cholesterol accumulate in the nervous system and other tissues. It has an autosomal recessive mode of inheritance. Most patients are of low intelligence with poor school performance. Specific clinical manifestations include xanthomas of the tendons. Furthermore, patients develop cataracts and a slowly progressive cerebellar ataxia. There is slight mental deterioration. Death usually occurs in the sixth or seventh decade and is often due to unrelated causes. Plasma cholesterol levels are normal or only moderately elevated. The pattern of serum lipids is normal, and only serum cholestanol is significantly increased. Radiological features of the disease are infrequently described in the literature. We report a case of CTX in which magnetic resonance imaging (MRI) was used to image the brain, lumbar spine and the tendinous xanthomas of the lower limbs. 15 refs., 5 figs.

  17. [Magnetic resonance urography in pediatric urology].

    Schindele, D; Furth, C; Liehr, U B; Porsch, M; Baumunk, D; Janitzky, A; Wendler, J J; Genseke, P; Ricke, J; Schostak, M

    2012-12-01

    Magnetic resonance urography (MRU) provides high resolution imaging of the urogenital system and the use of paramagnetic contrast agents enables a functional depiction. This review summarizes existing data concerning this diagnostic procedure in pediatric urology. A systematic search and assessment of the literature was performed.A total of 12 studies were reviewed in detail. In mostly small study populations a great heterogeneity concerning methodology, use of comparative examinations and standards of reference was noted. Besides the quality of anatomical imaging, the functional study of renal excretory function and differential renal function was also assessed. Only a few studies performed statistical analyses.The authors' rating of MRU was mostly positive. Due to methodical weaknesses, lack of independent standards of reference and statistical analyses the overall level of evidence was low. Further high quality studies will be necessary to assess the value of MRU for the diagnostic workup in pediatric urology. PMID:23160606

  18. Magnetic resonance imaging in head injury

    Magnetic resonance imaging (MRI) and computed tomography (CT) scan were compared to define their roles in the evaluation of head injured patients. MRI was found to be equal or inferior to CT scan in detection of extraparenchymatous lesions due to a failure of CT scan to indentify ultra-early hemorrhage. While, MRI was far superior to CT scan in regard to the indentification of the intraparenchymatous lesions in the acute stage of head injury. The lesions in the central structure suggesting diffuse axonal injury (DAI) were commonly found in the patients showing lower Glasgow Coma Scale score, though the degree of central structure damage shown in MRI was not correlated with the neurological grading and outcome. We concluded that DAI may play a major role in the severe head injury, but the severity of DAI is not predictable by using MRI. (author)

  19. Contrast-enhanced magnetic resonance angiography

    Magnetic resonance angiography (MRA) protocols are based on standard sequence protocols like time of flight MRA, which evaluates inflowing spins. This technique is limited by a variety of artifacts like the saturation artifact via turbulent blood flow. Contrast media diminish these artifacts like extracellular agents and blood-pool contrast media. The clinical value of the contrast-enhanced MRA for cerebral pathologies is based on the use of the paramagnetic contrast agent Gd-DTPA. For extracerebral diseases this technique is restricted because of the simultaneous visualization of both arterial and venous vascular territorities. Occult venous sinus thrombosis or AV malformations are clinical essential indications for the use of C-MRA. Experimental data prove the excellent contrast abilities of blood-pool agents like Gd-DTPA-polylysin or Gd-DTPA-albumin, which demonstrate long intravascular persistence and retarded excretion. (orig.)

  20. Magnetic resonance imaging of intramuscular metastases

    The aim of the present study was to analyse magnetic resonance findings of intramuscular metastases (IM) in a relatively large series. From January 2000 to January 2010, 28 patients (207 metastases) were retrospectively identified in the radiological database of the Martin-Luther-University. Several different scanning protocols were used depending on the localisation of IM. In 12 patients diffusion-weighted (DW) images were obtained with a multi-shot SE-EPI sequence. Apparent diffusion coefficient (ADC) maps were also calculated. Furthermore, fusion images were manually generated between the DW and half-Fourier acquisition single-shot turbo spin echo (HASTE) images. On T2-weighted images, 97% of the recognised IM were hyperintense in comparison to unaffected musculature, and 3% were mixed iso- to hyperintense. On T1-weighted images most IM (91%) were homogeneously isointense in comparison to muscle tissue, whereas 4% were hypointense, and 5% lightly hyperintense. ADC maps were calculated for 91 metastases ranging from 0.99 to 4.00 mm2s-1 (mean value 1.99 ± 0.66). ADC values of low (3.0) in 6%. Of the IM that were investigated with contrast medium, 88.5% showed marked enhancement. It was homogeneous in 88% and heterogenous in 6%. Rim enhancement with central low attenuation was seen in 6%. There was no difference in enhancement characteristics with respect to ADC values or fusion patterns. Peritumoral enhancement was identified in 2.4%. Magnetic resonance features of muscle metastases are relatively typical and consist of round or oval intramuscular masses with well-defined margins, marked enhancement, low or moderate ADC values, and moderate to high signal intensity on fusion images. (orig.)

  1. Magnetic resonance imaging of intramuscular metastases

    Surov, Alexey; Spielmann, Rolf-Peter; Behrmann, Curd [Martin-Luther-University Halle-Wittenberg, Department of Radiology, Halle (Germany); Fiedler, Eckhard [Martin-Luther-University Halle-Wittenberg, Department of Dermatology and Venereology, Halle (Germany); Voigt, Wieland [Martin-Luther-University Halle-Wittenberg, Department of Oncology, Halle (Germany); Wienke, Andreas [Martin-Luther-University Halle-Wittenberg, Department of Biometry, Halle (Germany); Holzhausen, Hans-Juergen [Martin-Luther-University Halle-Wittenberg, Department of Pathology, Halle (Germany)

    2011-04-15

    The aim of the present study was to analyse magnetic resonance findings of intramuscular metastases (IM) in a relatively large series. From January 2000 to January 2010, 28 patients (207 metastases) were retrospectively identified in the radiological database of the Martin-Luther-University. Several different scanning protocols were used depending on the localisation of IM. In 12 patients diffusion-weighted (DW) images were obtained with a multi-shot SE-EPI sequence. Apparent diffusion coefficient (ADC) maps were also calculated. Furthermore, fusion images were manually generated between the DW and half-Fourier acquisition single-shot turbo spin echo (HASTE) images. On T2-weighted images, 97% of the recognised IM were hyperintense in comparison to unaffected musculature, and 3% were mixed iso- to hyperintense. On T1-weighted images most IM (91%) were homogeneously isointense in comparison to muscle tissue, whereas 4% were hypointense, and 5% lightly hyperintense. ADC maps were calculated for 91 metastases ranging from 0.99 to 4.00 mm{sup 2}s{sup -1} (mean value 1.99 {+-} 0.66). ADC values of low (<1.5) signal intensity (SI) were identified in 26%, moderate SI (from 1.5 to 3.0) in 68%, and high SI (>3.0) in 6%. Of the IM that were investigated with contrast medium, 88.5% showed marked enhancement. It was homogeneous in 88% and heterogenous in 6%. Rim enhancement with central low attenuation was seen in 6%. There was no difference in enhancement characteristics with respect to ADC values or fusion patterns. Peritumoral enhancement was identified in 2.4%. Magnetic resonance features of muscle metastases are relatively typical and consist of round or oval intramuscular masses with well-defined margins, marked enhancement, low or moderate ADC values, and moderate to high signal intensity on fusion images. (orig.)

  2. Magnetic Resonance Studies of Energy Storage Materials

    Vazquez Reina, Rafael

    In today's society there is high demand to have access to energy for portable devices in different forms. Capacitors with high performance in small package to achieve high charge/discharge rates, and batteries with their ability to store electricity and make energy mobile are part of this demand. The types of internal dielectric material strongly affect the characteristics of a capacitor, and its applications. In a battery, the choice of the electrolyte plays an important role in the Solid Electrolyte Interphase (SEI) formation, and the cathode material for high output voltage. Electron Paramagnetic Resonance (EPR) and Nuclear Magnetic Resonance (NMR) spectroscopy are research techniques that exploit the magnetic properties of the electron and certain atomic nuclei to determine physical and chemical properties of the atoms or molecules in which they are contained. Both EPR and NMR spectroscopy technique can yield meaningful structural and dynamic information. Three different projects are discussed in this dissertation. First, High energy density capacitors where EPR measurements described herein provide an insight into structural and chemical differences in the dielectric material of a capacitor. Next, as the second project, Electrolyte solutions where an oxygen-17 NMR study has been employed to assess the degree of preferential solvation of Li+ ions in binary mixtures of EC (ethylene carbonate) and DMC (dimethyl carbonate) containing LiPF6 (lithium hexafluo-rophosphate) which may be ultimately related to the SEI formation mechanism. The third project was to study Bismuth fluoride as cathode material for rechargeable batteries. The objective was to study 19F and 7Li MAS NMR of some nanocomposite cathode materials as a conversion reaction occurring during lithiation and delithation of the BiF3/C nanocomposite.

  3. Magnetic resonance imaging of cerebellar Schistosomiasis mansoni

    A 15-year-old boy was admitted to hospital with a history of headache, dizziness, vomiting and double vision that started two weeks before. His parents denied any previous disease. During clinical examination he presented diplopia on lateral gaze to the left and horizontal nystagmus. No major neurological dysfunction was detected. He was well built, mentally responsive and perceptive. Laboratory findings revealed a leukocyte count of 10,000/mL, a normal red blood cell count and no eosinophilia. The magnetic resonance images (MRI) of the brain showed a left cerebellar lesion with mass effect compressing the surrounding tissues. Contrast-enhanced images showed a mass like structure and punctate nodules (Figures A and B: axial and coronal contrast-enhanced T1-weighted MR images showed the nodular - yellow arrows - enhancement pattern of a left cerebellar intraxial lesion). The lesion extended to the vermis and brachium pons and compressed the medulla. There was no hydrocephalus. He was taken to the operating room with the presumptive diagnosis of a neuroglial tumor, and submitted to a lateral suboccipital craniectomy. A brown, brittle tumoral mass without a clearly defined margin with the cerebellar tissue was removed. Microscopic examination revealed schistosomal granulomas in the productive phase in the cerebellum (Figure C). After surgery, treatment with praziquantel (50 mg/kg/dia, single dose) and prednisone (1 mg/kg/day) was offered and the patient improved quickly. Thirty days later he was seen again at the outpatient clinic: he was asymptomatic and with no neurological impairment. This is the eighth case of cerebellar involvement in schistosomiasis mansoni and the second report of a tumoral form of cerebellar schistosomiasis documented by magnetic resonance images. (author)

  4. Magnetic resonance imaging of the saccular otolithic mass.

    Sbarbati, A; Leclercq, F; Antonakis, K; Osculati, F.

    1992-01-01

    The frog's inner ear was studied in vivo by high spatial resolution magnetic resonance imaging at 7 Tesla. The vestibule, the internal acoustic meatus, and the auditory tube have been identified. The large otolithic mass contained in the vestibule showed a virtual absence of magnetic resonance signal probably due to its composition of closely packed otoconia.

  5. Computed tomography and magnetic resonance findings in lipoid pneumonia.

    Bréchot, J M; Buy, J N; Laaban, J P; Rochemaure, J

    1991-01-01

    A case of exogenous lipoid pneumonia was documented by computed tomography and magnetic resonance imaging. Although strongly suggesting the presence of fat on T1 weighted images, magnetic resonance does not produce images specific for this condition. Computed tomography is the best imaging modality for its diagnosis.

  6. Categorization of aortic aneurysm thrombus morphology by magnetic resonance imaging

    de la Motte, Louise; Pedersen, Mads Møller; Thomsen, Carsten;

    2013-01-01

    Magnetic resonance imaging (MRI) has been proposed for qualitative categorization of intraluminal thrombus morphology. We aimed to correlate the qualitative MRI categorization previously described to quantitative measurements of signal intensity and to compare morphological characteristics of...... intraluminal thrombus specimens to the appearance on magnetic resonance imaging....

  7. Parametric resonance in vircator with applied magnetic field

    Grigoryev, V.P.; Koval, T.V. [Inst. of Nuclear Physics, Tomsk (Russian Federation)

    1995-11-01

    The investigation of electromagnetic oscillations excitation in the vircator with an external magnetic field is carried out. The conditions of producing of cyclotron wave parametric resonance with virtual cathode oscillations harmonics have been obtained where the radiation power resonance character depends on the magnetic field value.

  8. Resonances and dipole moments in dielectric, magnetic, and magnetodielectric cylinders

    Dirksen, A.; Arslanagic, Samel; Breinbjerg, Olav

    2011-01-01

    An eigenfunction solution to the problem of plane wave scattering by dielectric, magnetic, and magnetodielectric cylinders is used for a systematic investigation of their resonances. An overview of the resonances with electric and magnetic dipole moments, needed in, e.g., the synthesis of...

  9. Inhibition of serine proteases by oxygen, sulfur and selenium dialkyl phosphoryl derivatives: Biochemical and 31P NMR studies

    31P NMR spectroscopy was employed to investigate the interaction of chymotrypsin with various organophosphorus inhibitors. The 31P NMR spectrum of diethyl selenophosphoryl chymotrypsin revealed two resonances at approximately 71 ppm and a single resonance at 48 ppm attributed to the covalent and non-covalent enzyme-inhibitor complexes, respectively. The goal of this investigation was to elucidate the basis of the two peaks at ∼71 ppm in the 31P NMR spectrum of diethyl selenophosphosphoryl-α-chymotrypsin. The possibility that the selenium atom in the structure of the organophosphorus inhibitor might have been responsible for the two peaks was addressed by extending the 31P NMR studies to diethyl thiophosphoryl- and diethyl phosphoryl-α-chymotrypsin. The fact that the latter modified enzyme derivatives also yielded 31P NMR spectra that exhibited two resonances assigned to covalent species discounted this possibility. The effect of the alkyl group of the inhibitor on the 31P NMR spectrum of the enzyme-inhibitor complex was further investigated by examining diisopropyl phosphoryl-α-chymotrypsin by 31P NMR spectroscopy

  10. Compact electrically detected magnetic resonance setup

    Electrically detected magnetic resonance (EDMR) is a commonly used technique for the study of spin-dependent transport processes in semiconductor materials and electro-optical devices. Here, we present the design and implementation of a compact setup to measure EDMR, which is based on a commercially available benchtop electron paramagnetic resonance (EPR) spectrometer. The electrical detection part uses mostly off-the-shelf electrical components and is thus highly customizable. We present a characterization and calibration procedure for the instrument that allowed us to quantitatively reproduce results obtained on a silicon-based reference sample with a “large-scale” state-of-the-art instrument. This shows that EDMR can be used in novel contexts relevant for semiconductor device fabrication like clean room environments and even glove boxes. As an application example, we present data on a class of environment-sensitive objects new to EDMR, semiconducting organic microcrystals, and discuss similarities and differences to data obtained for thin-film devices of the same molecule

  11. Magnetic resonance characterization of silicon nanowires

    Fanciulli, Marco; Belli, Matteo; Vellei, Antonio; Canevali, Carmen; Rotta, Davide; Paleari, Stefano; Basini, Martina

    2012-02-01

    Silicon nanowires (SiNWs) have been extensively investigated in the last decades. The interest in these nanostructures stems from both fundamental and applied research motivations. The functional properties of one- and zero-dimensional silicon structures are significantly different, at least below a certain critical dimension, from those well known in the bulk. The key and peculiar functional properties of SiNWs find applications in nanoelectronics, classical and quantum information processing and storage, optoelectronics, photovoltaics, thermoelectric, battery technology, nano-biotechnology, and neuroelectronics. We report our work on the characterization by continuous wave (CW) and pulse electron spin resonance (CW, FT-EPR) and electrically detected magnetic resonance (EDMR) measurements of silicon nanowires (SiNWs) produced by different top-down processes. SiNWs were fabricated starting from SOI wafers using standard e-beam lithography and anisotropic wet etching or by metal-assisted chemical etching. Further oxidation was used to reduce the wire cross section. Different EDMR implementations were used to address the electronic wave function of donors (P, As) and to characterize point defects at the SiNWs/SiO2 interface.

  12. Selectivity in multiple quantum nuclear magnetic resonance

    The observation of multiple-quantum nuclear magnetic resonance transitions in isotropic or anisotropic liquids is shown to give readily interpretable information on molecular configurations, rates of motional processes, and intramolecular interactions. However, the observed intensity of high multiple-quantum transitions falls off dramatically as the number of coupled spins increases. The theory of multiple-quantum NMR is developed through the density matrix formalism, and exact intensities are derived for several cases (isotropic first-order systems and anisotropic systems with high symmetry) to shown that this intensity decrease is expected if standard multiple-quantum pulse sequences are used. New pulse sequences are developed which excite coherences and produce population inversions only between selected states, even though other transitions are simultaneously resonant. One type of selective excitation presented only allows molecules to absorb and emit photons in groups of n. Coherent averaging theory is extended to describe these selective sequences, and to design sequences which are selective to arbitrarily high order in the Magnus expansion. This theory and computer calculations both show that extremely good selectivity and large signal enhancements are possible

  13. Rotating-frame gradient fields for magnetic resonance imaging and nuclear magnetic resonance in low fields

    Bouchard, Louis-Serge; Pines, Alexander; Demas, Vasiliki

    2014-01-21

    A system and method for Fourier encoding a nuclear magnetic resonance (NMR) signal is disclosed. A static magnetic field B.sub.0 is provided along a first direction. An NMR signal from the sample is Fourier encoded by applying a rotating-frame gradient field B.sub.G superimposed on the B.sub.0, where the B.sub.G comprises a vector component rotating in a plane perpendicular to the first direction at an angular frequency .omega.in a laboratory frame. The Fourier-encoded NMR signal is detected.

  14. 31P NMR spectroscopy measurements of hum ovarian carcinoma xenografts

    /sup 31/P NMR spectroscopy was used to study lipid and energy metabolism as well as tumour pH in three human ovarian carcinoma xenograft lines with widely differing growth rate, necrotic fraction and differentiation status. Two of the liines showed decreasing PCr (phosphocreatine) and NTPbhta (nucleoside triphosphates bhta) resonances and an increasing P/sub i/ (inorganic phosphate) resonance with increasing tumour volume in the volume range 100-4000 mm/sup 3/. This decrease in bioenergetic status was accompanied by a decrease in tumour pH from about 7.15 to about 6.95. The volume-dependence of these spectral parametes probably reflected increased nutritional deprivation and development of hypoxia and necrosis during tumour growth. The third xenograft line did not show changes in the intensity of any of the resonances during tumour growth. The spectral parameters differed significantly among the xenograft lines at given tumour volumes, but no correlations with volume-doubling time, necrotic fraction of differentiation status were found

  15. 31P-MR spectroscopy of the human liver - spectral hints on hepatic lymphoma infiltration

    Purpose: To evaluate whether phosphorus magnetic resonance spectroscopy (31P-MRS) enables a non-invasive detection of liver involvement in systemic diseases like Hodgkin's lymphoma. Materials and methods: Using a clinical 1.5 Tesla whole-body MR system image-guided localised phosphorus MR spectra from the anatomically defined volumes of interests were measured. A combination of surface coil, adiabatic excitation pulse and modified impage-selected in vivo spectroscopy (ISIS)-sequence was applied. The spectroscopy data were evaluated quantiatively with a time-domain fit programme using non-linear optimisation algorithms to quantify peak areas. After establishment of the examination protocol, 22 healthy volunteers and 13 patients with suspected lymphoma infiltration of the liver were examined. Results: Liver spectra of patients suffering from lymphoma infiltration differed significantly from spectra of persons with normal liver: 1. The peak area ratio of phosphomonoesters (PME) to β-NTP was elevated in all patients with histologically confirmed liver lymphoma. 2. Patients suffering from Hodgkin's disease with specific or unspecific liver infiltration (n=7) could be differentiated from patients without liver involvement. In case of infiltrated liver, the peak area ratio PME to β-NTP was increased, and the pH value was shifted to lower values. Unambiguous differentiation between non-specific (n=3) and specific (n=4) infiltration of the liver was not possible. 3. In patients after cytostatic treatment (n=3), an increase of the peak area ratio of inorganic phosphate to β-NTP was observed. Conclusion: Our preliminary results indicate that 31P-MRS can yield pointers to liver involvement in patients with systemic diseases such as Hodgkin's disease, which may be hardly detected by imaging methods. (orig.)

  16. Altered energy metabolism after myocardial infarction assessed by 31P-MR-spectroscopy in humans

    The value of 31P-magnetic resonance spectroscopy (MRS) as a possible tool to distinguish viable from non-viable tissue after myocardial infarction was analysed in humans. Fifteen patients 3 weeks after anterior myocardial infarction were studied with breath-hold cine MRI and 3D-CSI MRS (1.5 T system). 31P-spectra were obtained from infarcted as well as non-infarcted myocardium (voxel size 25 cm3 each). Gold standard for viability was recovery of regional function, as determined by a control MRI 6 months after revascularization. Ten age-matched healthy volunteers served as control group. No significant difference was found between the phosphocreatine to adenosinetriphosphate (PCr/ATP) ratio of volunteers (SD 1.72±0.31) and non-infarcted septal myocardium of patients. Cine MRI demonstrated recovery of regional function in 10 patients, i. e. 10 patients showed viable and 5 non-viable myocardium. In viable myocardium, the PCr/ATP ratio was 1.47±0.38 (non-significant vs volunteers; p>0.05). In the 5 patients with akinetic myocardium, PCr peaks could not be detected. Therefore, calculation of PCr/ATP ratios was not possible. However, a significant reduction of the ATP signal-to-noise ratio (SNR) was observed (2.92±0.73 vs 6.68±0.80; patients vs volunteers; p<0.05). The SNR of ATP of akinetic regions may predict recovery of function after revascularization in patients with myocardial infarction. (orig.)

  17. Cardiac magnetic resonance imaging of a patient with an magnetic resonance imaging conditional permanent pacemaker

    Chris B. Pepper; Mohan Sivananthan; Artis, Nigel J.; Hogarth, Andrew J.

    2011-01-01

    Cardiac Magnetic Resonance Imaging (MRI) is increasingly used as the optimum modality for cardiac imaging. An aging population and rising numbers of patients with permanent pacemakers means many such individuals may require cardiac MRI scanning in the future. Whilst the presence of a permanent pacemaker is historically regarded as a contra-indication to MRI scanning, pacemaker systems have been developed to limit any associated risks. No reports have been published regarding the use of such d...

  18. Plasma-induced magnetic responses during nonlinear dynamics of magnetic islands due to resonant magnetic perturbations

    Resonant magnetic perturbations (RMPs) produce magnetic islands in toroidal plasmas. Self-healing (annihilation) of RMP-induced magnetic islands has been observed in helical systems, where a possible mechanism of the self-healing is shielding of RMP penetration by plasma flows, which is well known in tokamaks. Thus, fundamental physics of RMP shielding is commonly investigated in both tokamaks and helical systems. In order to check this mechanism, detailed informations of magnetic island phases are necessary. In experiments, measurement of radial magnetic responses is relatively easy. In this study, based on a theoretical model of rotating magnetic islands, behavior of radial magnetic fields during the self-healing is investigated. It is confirmed that flips of radial magnetic fields are typically observed during the self-healing. Such behavior of radial magnetic responses is also observed in LHD experiments

  19. Magnetic resonance spectroscopy as a diagnostic modality for carcinoma thyroid

    Gupta, Nikhil [Department of Surgery, Maulana Azad Medical College, Lok Nayak Hospital, New Delhi (India)], E-mail: nikhil_ms26@yahoo.co.in; Kakar, Arun K. [Department of Surgery, Maulana Azad Medical College, Lok Nayak Hospital, New Delhi (India); Chowdhury, Veena [Department of Radiodiagnosis, Maulana Azad Medical College, Lok Nayak Hospital, New Delhi (India); Gulati, Praveen [MR Centre, A-23 Green Park, New Delhi (India); Shankar, L. Ravi [Department of Radioiodine Uptake and Imaging, Institute of Nucler Medicine and Allied Sciences (INMAS), Timarpur, New Delhi (India); Vindal, Anubhav [Department of Surgery, Maulana Azad Medical College, Lok Nayak Hospital, New Delhi (India)

    2007-12-15

    Aim: The aim of this study was to observe the findings of magnetic resonance spectroscopy of solitary thyroid nodules and its correlation with histopathology. Materials and methods: In this study, magnetic resonance spectroscopy was carried out on 26 patients having solitary thyroid nodules. Magnetic resonance spectroscopy (MRS) was performed on a 1.5 T super conductive system with gradient strength of 33 mTs. Fine needle aspiration cytology was done after MRS. All 26 patients underwent surgery either because of cytopathologically proven malignancy or because of cosmetic reasons. Findings of magnetic resonance spectroscopy were compared with histopathology of thyroid specimens. Results and conclusion: It was seen that presence or absence of choline peak correlates very well with presence or absence of malignant foci with in the nodule (sensitivity = 100%; specificity = 88.88%). These results indicate that magnetic resonance spectroscopy may prove to be an useful diagnostic modality for carcinoma thyroid.

  20. Magnetic resonance imaging in clinically-definite multiple sclerosis

    Forty-two patients with clinically-definite multiple sclerosis were examined by magnetic resonance imaging using a 1.5-T instrument. Magnetic resonance imaging detected an abnormality in 90% of patients. In four patients, no lesions were demonstrated. The number, size and site of the lesions by magnetic resonance imaging were compared with the patients' clinical status and other variables. The Kurtzke disability status scale score increased in patients with corpus callosum atrophy, brainstem and basal ganglia lesions, and correlated with the total number of lesions. No correlation was shown between the findings of magnetic resonance imaging and disease duration, age, sex or pattern-reversal visual-evoked potentials. The variety of magnetic resonance images that could be obtained in patients with clinically-definite multiple sclerosis is highlighted. 24 refs., 8 figs., 1 tab