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Sample records for 3t intera magnetic

  1. Philips 3T Intera Magnetic Resonance Imaging System and Upgrade of existing MRI equipment

    Evanochko, William T

    2004-05-14

    The objective of this proposal was twofold. First, upgrade existing MRI equipment, specifically a research 4.1T whole-body system. Second, purchase a clinical, state-of-the-art 3T MRI system tailored specifically to cardiovascular and neurological applications. This project was within the guidelines of ''Medical Applications and Measurement Science''. The goals were: [1] to develop beneficial applications of magnetic resonance imaging; [2] discover new applications of MR strategies for medical research; and [2] apply them for clinical diagnosis. Much of this proposal searched for breakthroughs in this noninvasive and nondestructive imaging technology. Finally, this proposal's activities focused on research in the basic science of chemistry, biochemistry, physics, and engineering as applied to bioengineering. The centerpiece of this grant was our 4.1T ultra-high field whole-body nuclear magnetic resonance system and the newly acquired state-of-the-art, heart and head dedicated 3T clinical MRI system. We have successfully upgraded the equipment for the 4.1T system so that it is now state-of-the-art with new gradient and radio frequency amplifiers. We also purchase a unique In Vivo EKG monitoring unit that will permit tracking clinical quality EKG signals while the patient is in a high field MR scanner. Important upgrades of a peripheral vascular coil and a state-of-the-art clinical workstation for processing complex heart images were implemented. The most recent acquisition was the purchase of a state-of-the-art Philips 3T Intera clinical MRI system. This system is unique in that the magnet is only 5 1/2 feet long compare to over 12 feet long magnet of our 4.1T MRI system. The 3T MRI system is fully functional and its use and applications are already greatly benefiting the UAB with 200-300 micron resolution brain images and diagnostic quality MR angiography of coronary arteries in less than 5 minutes.

  2. Malformations of cortical development:3T magnetic resonance imaging features

    Bilal; Battal; Selami; Ince; Veysel; Akgun; Murat; Kocaoglu; Emrah; Ozcan; Mustafa; Tasar

    2015-01-01

    Malformation of cortical development(MCD) is a term representing an inhomogeneous group of central nervous system abnormalities, referring particularly to embriyological aspect as a consequence of any of the three developmental stages, i.e., cell proliferation, cell migration and cortical organization. These include cotical dysgenesis, microcephaly, polymicrogyria, schizencephaly, lissencephaly, hemimegalencephaly, heterotopia and focal cortical dysplasia. Since magnetic resonance imaging is the modality of choice that best identifies the structural anomalies of the brain cortex, we aimed to provide a mini review of MCD by using 3T magnetic resonance scanner images.

  3. 3 T magnetic resonance imaging of the musculoskeletal system.

    Guglielmi, G; Biccari, N; Mangano, F; Toffanin, R

    2010-06-01

    The increasing distribution of high-field (3 T) magnetic resonance (MR) systems for clinical use has been accompanied by the need to fully understand the advantages and disadvantages that the increase in signal quality confers. Continuous development of the coils is required to fully express the potential of these systems, especially given the synergy between parallel imaging and the recent multichannel phased-array coils, which are able to improve image quality, spatial resolution and diagnostic accuracy in musculoskeletal imaging. The increase in signal offered by the high field makes possible improved visualisation of bone, cartilage, tendons and ligaments. This advantage, together with increased spatial resolution, is particularly useful when studying joints or some of their components, the evaluation of which has produced suboptimal results in non arthrographic examinations such as the glenoid labrum of the shoulder and the articular cartilage of the knee. Thanks to the greater signal-to-noise ratio and improved spatial resolution, MR imaging at 3 T is able to notably increase diagnostic performance in the musculoskeletal setting, with a consequent improvement in patient treatment and management. PMID:20177987

  4. Hepatic Iron Quantification on 3 Tesla (3 T) Magnetic Resonance (MR): Technical Challenges and Solutions

    MR has become a reliable and noninvasive method of hepatic iron quantification. Currently, most of the hepatic iron quantification is performed on 1.5 T MR, and the biopsy measurements have been paired with R2 and R2* values for 1.5 T MR. As the use of 3 T MR scanners is steadily increasing in clinical practice, it has become important to evaluate the practicality of calculating iron burden at 3 T MR. Hepatic iron quantification on 3 T MR requires a better understanding of the process and more stringent technical considerations. The purpose of this work is to focus on the technical challenges in establishing a relationship between T2* values at 1.5 T MR and 3 T MR for hepatic iron concentration (HIC) and to develop an appropriately optimized MR protocol for the evaluation of T2* values in the liver at 3 T magnetic field strength. We studied 22 sickle cell patients using multiecho fast gradient-echo sequence (MFGRE) 3 T MR and compared the results with serum ferritin and liver biopsy results. Our study showed that the quantification of hepatic iron on 3 T MRI in sickle cell disease patients correlates well with clinical blood test results and biopsy results. 3 T MR liver iron quantification based on MFGRE can be used for hepatic iron quantification in transfused patients

  5. Hepatic Iron Quantification on 3 Tesla (3 T) Magnetic Resonance (MR): Technical Challenges and Solutions

    MR has become a reliable and noninvasive method of hepatic iron quantification. Currently, most of the hepatic iron quantification is performed on 1.5 T MR, and the biopsy measurements have been paired withR2 and R2∗ values for 1.5 T MR. As the use of 3 T MR scanners is steadily increasing in clinical practice, it has become important to evaluate the practicality of calculating iron burden at 3 T MR. Hepatic iron quantification on 3 T MR requires a better understanding of the process and more stringent technical considerations. The purpose of this work is to focus on the technical challenges in establishing a relationship between T2 ∗ values at 1.5 T MR and 3 T MR for hepatic iron concentration (HIC) and to develop an appropriately optimized MR protocol for the evaluation of T2 ∗ values in the liver at 3 T magnetic field strength. We studied 22 sickle cell patients using multiecho fast gradient-echo sequence (MFGRE) 3 T MR and compared the results with serum ferritin and liver biopsy results. Our study showed that the quantification of hepatic iron on 3 T MRI in sickle cell disease patients correlates well with clinical blood test results and biopsy results. 3 T MR liver iron quantification based on MFGRE can be used for hepatic iron quantification in transfused patients.

  6. Development of eddy-current-free MR imaging system with 0.3-T permanent magnet

    This paper reports on the eddy current induced by the magnetic gradient field which causes various problems associated with a permanent magnet, the permanent magnetic circuit with new pole pieces has been studied. The magnetic circuit was composed of a permanent magnet, a yoke, and pole pieces. The pole pieces were magnetically connected to the Nd-Fe-B permanent magnet. To study for eddy current, read-size magnetic circuits with pole pieces of various material, such as (a) steel, (b) divided steel, (c) toroidal-shaped silicon steel, and (d) composite material were assembled. The whole 0.3-T MR imaging system consists of only three units, Gantry with coach, MR unit, and operational console with image processor. We have evaluated the frequency characteristics, rise time, spatial homogeneity of magnetic field, and image quality with respect to real-size magnetic circuits with various pole pieces. We have obtained following order for frequency characteristics: (d), (c), (b), (a). We have also made an effort to adjust uniformity of magnetic field for magnetic circuits with toroidal-shaped silicon steel. We have obtained crisp and accurate images with use of the new pole pieces, without causing an eddy current. Especially, MR angio imaging, which is sensitive for eddy current, can be obtained with remarkable improvement

  7. Magnetic resonance imaging of congenital heart disease at 0.3 T

    Malmgren, N.

    1995-11-01

    The aim of this study was to systematically evaluate the potential of static MR imaging in congenital heart disease. The diagnosis of vascular rings, causing significant respiratory morbidity, previously required invasive methods for diagnosis. In aberrant left pulmonary artery, an uncommon anomaly, MR imaging at 0.3 T provided complete anatomic information. Complex congenital heart malformation is a diagnostic challenge. MR imaging at 0.3 T was efficient in defining most of the components of complex disease. It is especially valuable for imaging of extracardiac structures, which can be difficult to evaluate using echocardiography. MR imaging is an important complement to echocardiography. Improved equipment with sophisticated dynamic applications using high magnetic field strength is now available. The anatomical evaluation of congenital heart anomalies is however still based on static images, and low field magnets will certainly be used even in the future. 141 refs, 11 figs, 8 tabs.

  8. Magnetic resonance imaging of congenital heart disease at 0.3 T

    The aim of this study was to systematically evaluate the potential of static MR imaging in congenital heart disease. The diagnosis of vascular rings, causing significant respiratory morbidity, previously required invasive methods for diagnosis. In aberrant left pulmonary artery, an uncommon anomaly, MR imaging at 0.3 T provided complete anatomic information. Complex congenital heart malformation is a diagnostic challenge. MR imaging at 0.3 T was efficient in defining most of the components of complex disease. It is especially valuable for imaging of extracardiac structures, which can be difficult to evaluate using echocardiography. MR imaging is an important complement to echocardiography. Improved equipment with sophisticated dynamic applications using high magnetic field strength is now available. The anatomical evaluation of congenital heart anomalies is however still based on static images, and low field magnets will certainly be used even in the future. 141 refs, 11 figs, 8 tabs

  9. Functional Magnetic Resonance Imaging at 3T as a Clinical Tool in Patients with Intracranial Tumors

    Purpose: To investigate the potential of functional magnetic resonance imaging (fMRI) at 3T as a clinical tool in the preoperative evaluation of patients with intracranial tumors. High magnetic field strength such as 3T is of benefit for fMRI because signal-to-noise ratio and sensitivity to susceptibility changes are field-strength-dependent. Material and Methods: Twenty patients with tumors close to eloquent sensorimotor or language areas were studied. Motor, sensory, and two language paradigms (word generation, rhyming) were used; their effectiveness was determined as the percentage of patients in whom the functional area of interest was activated. Activation maps were calculated and their quality rated as high, adequate, or insufficient. The influence of fMRI on the neurosurgical decision regarding operability, surgical approach, and extent of the resection, was assessed. Results: Paradigm effectiveness was 90% for motor and 95% for sensory stimulation, and varied from 79% to 95% for word generation and rhyming in combination. Ninety percent of the activation maps held high or adequate quality. fMRI proved useful: in the decision to operate (9 patients), in the surgical approach (13 patients), and in extent of the resection (12 patients). Conclusion: fMRI at 3T is a clinically applicable tool in the work-up of patients with intracranial tumors

  10. Vacuum phenomenon: prevalence and appearance in the knee with 3 T magnetic resonance imaging

    To determine the prevalence of vacuum phenomenon (VP) in the knee on magnetic resonance (MR) images, describe the imaging features that characterize VP, and assess how often VP mimics pathological knee lesions. Consecutive knee MR studies performed on a 3 T MR system over a 9-month period were retrospectively reviewed by one radiologist who then selected studies with findings potentially indicating VP. Three experienced musculoskeletal radiologists reviewed these cases in consensus to confirm the presence of VP and to assess the shape, size, and signal of VP; the presence of magnetic susceptibility artifacts; and the ability of MR sequences to show VP. A total of 914 consecutive exams from 875 patients (524 men; mean age, 35 years) were reviewed. Vacuum phenomenon was found in 12 patients (prevalence 1.3%). In six (50%) patients, VP mimicked a meniscal tear, with four cases simulating a torn medial discoid meniscus. The VP signal was not easily differentiated from meniscal signal on most sequences in most cases (9/12). Gradient-recalled echo (GRE) localizer images proved most definitive, with 3D SPACE images the next most effective. Fast spin echo (FSE) images were only occasionally able to differentiate VP from meniscus. Rarely recognized on MR, VP can mimic meniscal pathology, potentially leading to inappropriate surgery. Because differentiation of VP from the meniscus is challenging on FSE at 3 T, radiologists should become familiar with the appearance of VP and review GRE localizer or 3D images carefully to avoid misinterpretation. (orig.)

  11. Contributed Review: Nuclear magnetic resonance core analysis at 0.3 T

    Mitchell, Jonathan, E-mail: JMitchell16@slb.com; Fordham, Edmund J. [Schlumberger Gould Research, High Cross, Madingley Road, Cambridge CB3 0EL (United Kingdom)

    2014-11-15

    Nuclear magnetic resonance (NMR) provides a powerful toolbox for petrophysical characterization of reservoir core plugs and fluids in the laboratory. Previously, there has been considerable focus on low field magnet technology for well log calibration. Now there is renewed interest in the study of reservoir samples using stronger magnets to complement these standard NMR measurements. Here, the capabilities of an imaging magnet with a field strength of 0.3 T (corresponding to 12.9 MHz for proton) are reviewed in the context of reservoir core analysis. Quantitative estimates of porosity (saturation) and pore size distributions are obtained under favorable conditions (e.g., in carbonates), with the added advantage of multidimensional imaging, detection of lower gyromagnetic ratio nuclei, and short probe recovery times that make the system suitable for shale studies. Intermediate field instruments provide quantitative porosity maps of rock plugs that cannot be obtained using high field medical scanners due to the field-dependent susceptibility contrast in the porous medium. Example data are presented that highlight the potential applications of an intermediate field imaging instrument as a complement to low field instruments in core analysis and for materials science studies in general.

  12. Contributed Review: Nuclear magnetic resonance core analysis at 0.3 T

    Nuclear magnetic resonance (NMR) provides a powerful toolbox for petrophysical characterization of reservoir core plugs and fluids in the laboratory. Previously, there has been considerable focus on low field magnet technology for well log calibration. Now there is renewed interest in the study of reservoir samples using stronger magnets to complement these standard NMR measurements. Here, the capabilities of an imaging magnet with a field strength of 0.3 T (corresponding to 12.9 MHz for proton) are reviewed in the context of reservoir core analysis. Quantitative estimates of porosity (saturation) and pore size distributions are obtained under favorable conditions (e.g., in carbonates), with the added advantage of multidimensional imaging, detection of lower gyromagnetic ratio nuclei, and short probe recovery times that make the system suitable for shale studies. Intermediate field instruments provide quantitative porosity maps of rock plugs that cannot be obtained using high field medical scanners due to the field-dependent susceptibility contrast in the porous medium. Example data are presented that highlight the potential applications of an intermediate field imaging instrument as a complement to low field instruments in core analysis and for materials science studies in general

  13. Study on hippocampal volume with quantitative 3T magnetic resonance imaging in Chinese patients with epilepsy

    GAO Mei-chun; LU Qin-chi; LI Yan-sheng; SHEN Jia-lin

    2012-01-01

    Background It was still rare for the quantitative magnetic resonance imaging (MRI) research of regional changes in hippocampus sclerosis (HS) in Chinese patients with epilepsy.This study aimed to study the hippocampal volumes (HVs)with quantitative MRI measurement in Chinese patients with epilepsy.Methods Forty-six Chinese patients with epilepsy (intractable epilepsy (IE),n=21; non-intractable epilepsy (NIE),n=25)and 25 normal controls were collected between July 2007 and March 2008.All of the subjects underwent a 3T high-resolution MRI with oblique coronal thin sections oriented perpendicular to the hippocampal long axis.Hippocampal structures were assessed by visual detection,and HVs were quantitatively studied with a Picture Archiving and Communication System (PACS).Results Our study suggested that there was no significant difference in gender (P >0.05) while the right hippocampal head volume (HHV),hippocampal body volume (HBV),and the whole hippocampal volume (HCV) were greater than the left one (P <0.05),but no significant difference was found in bilateral hippocampal tail volume (HTV) (P >0.05) in normal controls.That unilateral/diffuse (64%/21%) and bilateral/focal (86%/20%) hippocampal atrophy (HA)were significant in IE and NIE patients,respectively.Anterior hippocampus,especially HHV (26% in IE and 20% in NIE) and HBV (29% in IE and 12% in NIE),had more significant atrophy than the HTV (5% in IE and 0% in NIE) in patients with epilepsy.Conclusion By assessing the volumes of the regional hippocampus with 3T MRI,we could better define the range and distribution of HS,since regional or subtle changes in HVs could be detected earlier with 3T MRI.

  14. Numerical study of remote detection outside the magnet with travelling wave Magnetic Resonance Imaging at 3T

    The use of the travelling wave approach for high magnetic field magnetic resonance imaging has been used recently with very promising results. This approach offer images one with greater field-of-view and a reasonable signal-to-noise ratio using a circular waveguide. This scheme has been proved to be successful at 7 T and 9.4 T with whole-body imager. Images have also been acquired with clinical magnetic resonance imaging systems whose resonant frequencies were 64 MHz and 128 MHz. These results motivated the use of remote detection of the magnetic resonance signal using a parallel-plate waveguide together with 3 T clinical scanners, to acquired human leg images. The cut-off frequency of this waveguide is zero for the principal mode, allowing us to overcome the barrier of transmitting waves at lower frequency than 300 MHz or 7 T for protons. These motivated the study of remote detection outside the actual magnet. We performed electromagnetic field simulations of a parallel-plate waveguide and a phantom. The signal transmission was done at 128 MHz and using a circular surface coil located almost 200 cm away for the magnet isocentre. Numerical simulations demonstrated that the magnetic field of the principal mode propagate inside a waveguide outside the magnet. Numerical results were compared with previous experimental-acquired image data under similar conditions

  15. Orthodontic springs and auxiliary appliances: assessment of magnetic field interactions associated with 1.5 T and 3 T magnetic resonance systems

    Kemper, J.; Priest, A.N.; Adam, G. [University Medical Center of Hamburg-Eppendorf, Clinic of Diagnostic and Interventional Radiology, Hamburg (Germany); Schulze, D. [University Hospital of Freiburg, Department of Oral and Maxillofacial Surgery, Freiburg (Germany); Kahl-Nieke, B.; Klocke, A. [University Medical Center of Hamburg-Eppendorf, Department of Orthodontics, Hamburg (Germany)

    2007-02-15

    The objective of this paper is to evaluate magnetic field interactions at 1.5 and 3 T for 20 orthodontic devices used for fixed orthodontic therapy. Twenty springs and auxiliary parts made from varying ferromagnetic alloys were tested for magnetic field interactions in the static magnetic field at 1.5 and 3 T. Magnetic translational force F{sub z} (in millinewtons) was evaluated by determining the deflection angle {beta} [American Society for Testing and Materials (ASTM standard test method)]. Magnetic-field-induced rotational force F{sub rot} was qualitatively determined using a five-point scale. {beta} was found to be >45 in 13(15) devices at 1.5(3) T and translational force F{sub z} exceeded gravitational force F{sub g} on the particular object [F{sub z} 10.17-261.4 mN (10.72-566.4 mN) at 1.5(3) T]. F{sub z} was found to be up to 24.1(47.5)-fold higher than F{sub g} at 1.5(3) T. Corresponding to this, F{sub rot} on the objects was shown to be high at both field strengths ({>=} +3). Three objects (at 1.5 T) and one object (at 3 T) showed deflection angles <45 , but F{sub rot} was found to be {>=} +3 at both field strengths. For the remaining objects, {beta} was below 45 and torque measurements ranged from 0 to +2. Of 20 objects investigated for magnetic field interactions at 1.5(3) T, 13(15) were unsafe in magnetic resonance (MR), based on the ASTM criteria of F{sub z}. The implications of these results for orthodontic patients undergoing MRI are discussed. (orig.)

  16. Orthodontic springs and auxiliary appliances: assessment of magnetic field interactions associated with 1.5 T and 3 T magnetic resonance systems

    The objective of this paper is to evaluate magnetic field interactions at 1.5 and 3 T for 20 orthodontic devices used for fixed orthodontic therapy. Twenty springs and auxiliary parts made from varying ferromagnetic alloys were tested for magnetic field interactions in the static magnetic field at 1.5 and 3 T. Magnetic translational force Fz (in millinewtons) was evaluated by determining the deflection angle β [American Society for Testing and Materials (ASTM standard test method)]. Magnetic-field-induced rotational force Frot was qualitatively determined using a five-point scale. β was found to be >45 in 13(15) devices at 1.5(3) T and translational force Fz exceeded gravitational force Fg on the particular object [Fz 10.17-261.4 mN (10.72-566.4 mN) at 1.5(3) T]. Fz was found to be up to 24.1(47.5)-fold higher than Fg at 1.5(3) T. Corresponding to this, Frot on the objects was shown to be high at both field strengths (≥ +3). Three objects (at 1.5 T) and one object (at 3 T) showed deflection angles rot was found to be ≥ +3 at both field strengths. For the remaining objects, β was below 45 and torque measurements ranged from 0 to +2. Of 20 objects investigated for magnetic field interactions at 1.5(3) T, 13(15) were unsafe in magnetic resonance (MR), based on the ASTM criteria of Fz. The implications of these results for orthodontic patients undergoing MRI are discussed. (orig.)

  17. Structural and magnetic properties of UCo1/3T2/3Al solid solutions (T = Ru, Pt, Rh)

    We report on neutron diffraction studies of UCo1/3T2/3Al (T = Ru, Pt, Rh). All three solid solutions form in the hexagonal ZrNiAl structure. The Ru-containing compound is found to be chemically ordered, while the Pt-containing compound is nearly disordered and the Rh-containing compound is purely disordered. All three compounds exhibit long-range magnetic order with rather small U moments

  18. 3-T breast magnetic resonance imaging in patients with suspicious microcalcifications on mammography

    Stehouwer, B.L.; Merckel, L.G.; Verkooijen, H.M.; Peters, N.H.G.M.; Mali, W.P.T.M.; Veldhuis, W.B.; Bosch, M.A.A.J. van den [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Mann, R.M. [University Medical Center St Radboud, Departement of Radiology, Nijmegen (Netherlands); Duvivier, K.M. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); VU University Medical Center, Department of Radiology, Amsterdam (Netherlands); Peeters, P.H.M. [University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands)

    2014-03-15

    To investigate the diagnostic value of 3-Tesla (T) breast MRI in patients presenting with microcalcifications on mammography. Between January 2006 and May 2009, 123 patients with mammographically detected BI-RADS 3-5 microcalcifications underwent 3-T breast MRI before undergoing breast biopsy. All MRIs of the histopathologically confirmed index lesions were reviewed by two breast radiologists. The detection rate of invasive carcinoma and ductal carcinoma in situ (DCIS) was evaluated, as well as the added diagnostic value of MRI over mammography and breast ultrasound. At pathology, 40/123 (33 %) lesions proved malignant; 28 (70 %) DCIS and 12 (30 %) invasive carcinoma. Both observers detected all invasive malignancies at MRI, as well as 79 % (observer 1) and 86 % (observer 2) of in situ lesions. MRI in addition to conventional imaging led to a significant increase in area under the receiver operating characteristic (ROC) curve from 0.67 (95 % CI 0.56-0.79) to 0.79 (95 % CI 0.70-0.88, observer 1) and to 0.80 (95 % CI 0.71-0.89, observer 2), respectively. 3-T breast MRI was shown to add significant value to conventional imaging in patients presenting with suspicious microcalcifications on mammography. (orig.)

  19. Time-resolved phosphorous magnetization transfer of the human calf muscle at 3 T and 7 T: A feasibility study

    Valkovič, Ladislav, E-mail: siegfried.trattnig@meduniwien.ac.at [MR Center of Excellence, Department of Radiology, Medical University Vienna, A-1090 Wien, Lazarettgasse 14 (Austria); Institute of Measurement Science, Department of Imaging Methods, Slovak Academy of Sciences, 841 04 Bratislava, Dúbravska cesta 9 (Slovakia); Chmelík, Marek, E-mail: marek.chmelik@meduniwien.ac.at [MR Center of Excellence, Department of Radiology, Medical University Vienna, A-1090 Wien, Lazarettgasse 14 (Austria); Just Kukurova, Ivica, E-mail: ivica.kukurova@meduniwien.ac.at [MR Center of Excellence, Department of Radiology, Medical University Vienna, A-1090 Wien, Lazarettgasse 14 (Austria); Krššák, Martin, E-mail: martin.krssak@meduniwien.ac.at [Department of Internal Medicine III, Medical University Vienna, A-1090 Wien, Lazarettgasse 14 (Austria); Gruber, Stephan, E-mail: stephan@nmr.at [MR Center of Excellence, Department of Radiology, Medical University Vienna, A-1090 Wien, Lazarettgasse 14 (Austria); Frollo, Ivan, E-mail: umerollo@savba.sk [Institute of Measurement Science, Department of Imaging Methods, Slovak Academy of Sciences, 841 04 Bratislava, Dúbravska cesta 9 (Slovakia); Trattnig, Siegfried, E-mail: siegfried.trattnig@meduniwien.ac.at [MR Center of Excellence, Department of Radiology, Medical University Vienna, A-1090 Wien, Lazarettgasse 14 (Austria); Bogner, Wolfgang, E-mail: wolfgang@nmr.at [MR Center of Excellence, Department of Radiology, Medical University Vienna, A-1090 Wien, Lazarettgasse 14 (Austria)

    2013-05-15

    Phosphorous ({sup 31}P) magnetization transfer (MT) experiments enable the non-invasive investigation of human muscle metabolism in various physiological and pathological conditions. The purpose of our study was to investigate the feasibility of time-resolved MT, and to compare the results of MT experiments at 3 T and 7 T. Six healthy volunteers were examined on a 3 T and a 7 T MR scanner using the same setup and identical measurement protocols. In the calf muscle of all volunteers, four separate MT experiments (each ∼10 min duration) were performed in one session. The forward rate constant of the ATP synthesis reaction (k{sub ATP}) and creatine kinase reaction (k{sub CK}), as well as corresponding metabolic fluxes (F{sub ATP}, F{sub CK}), were estimated. A comparison of these exchange parameters, apparent T{sub 1}s, data quality, quantification precision, and reproducibility was performed. The data quality and reproducibility of the same MT experiments at 7 T was significantly higher (i.e., k{sub ATP} 2.7 times higher and k{sub CK} 3.4 times higher) than at 3 T (p < 0.05). The values for k{sub ATP} (p = 0.35) and k{sub CK} (p = 0.09) at both field strengths were indistinguishable. Even a single MT experiment at 7 T provided better data quality than did a 4 times-longer MT experiment at 3 T. The minimal time-resolution to reliably quantify both F{sub ATP} and F{sub CK} at 7 T was ∼6 min. Our results show that MT experiments at 7 T can be at least 4 times faster than 3 T MT experiments and still provide significantly better quantification. This enables time-resolved MT experiments for the observation of slow metabolic changes in the human calf muscle at 7 T.

  20. Time-resolved phosphorous magnetization transfer of the human calf muscle at 3 T and 7 T: A feasibility study

    Phosphorous (31P) magnetization transfer (MT) experiments enable the non-invasive investigation of human muscle metabolism in various physiological and pathological conditions. The purpose of our study was to investigate the feasibility of time-resolved MT, and to compare the results of MT experiments at 3 T and 7 T. Six healthy volunteers were examined on a 3 T and a 7 T MR scanner using the same setup and identical measurement protocols. In the calf muscle of all volunteers, four separate MT experiments (each ∼10 min duration) were performed in one session. The forward rate constant of the ATP synthesis reaction (kATP) and creatine kinase reaction (kCK), as well as corresponding metabolic fluxes (FATP, FCK), were estimated. A comparison of these exchange parameters, apparent T1s, data quality, quantification precision, and reproducibility was performed. The data quality and reproducibility of the same MT experiments at 7 T was significantly higher (i.e., kATP 2.7 times higher and kCK 3.4 times higher) than at 3 T (p < 0.05). The values for kATP (p = 0.35) and kCK (p = 0.09) at both field strengths were indistinguishable. Even a single MT experiment at 7 T provided better data quality than did a 4 times-longer MT experiment at 3 T. The minimal time-resolution to reliably quantify both FATP and FCK at 7 T was ∼6 min. Our results show that MT experiments at 7 T can be at least 4 times faster than 3 T MT experiments and still provide significantly better quantification. This enables time-resolved MT experiments for the observation of slow metabolic changes in the human calf muscle at 7 T

  1. Magnetism in some UCo1/3T2/3Al solid solutions (T=transition metal)

    We report on the magnetic properties of UCo1/3T2/3Al (T=Ru, Rh, Pt) solid solutions which form in the hexagonal ZrNiAl structure. We performed neutron diffraction and bulk magnetization studies. All three solid solutions exhibit long-range magnetic order at low temperatures. Bulk magnetization studies indicate a ferromagnetic ground state for UCo1/3Ru2/3Al, UCo1/3Rh2/3Al, and UCo1/3Pt2/3Al below 42, 41, and 27 K, respectively. At 4.2 K, the spontaneous moment ranges from ∼0.15 μB/U-atom (UCo1/3Ru2/3Al) to ∼0.49μB/U-atom (UCo1/3Pt2/3Al). Below TC, we find additional weak magnetic contributions in the neutron diffraction data, and our refinement is consistent with magnetic moments along the c axis. The magnitudes of the moments are in good agreement with the spontaneous moments determined from bulk studies. The results are discussed in terms of f-d hybridization, which is modified by changes in the d band occupation and preferential occupation of the transition metals within the lattice. (c) 2000 American Institute of Physics

  2. Cystic adventitial disease of the popliteal artery: features on 3T cardiovascular magnetic resonance

    Gelabert Hugh

    2008-08-01

    Full Text Available Abstract Cystic adventitial disease (CAD of the popliteal artery is a rare vascular disease of unknown etiology in which a mucin-containing cyst develops in the adventitial layer of the artery. We report the case of a 26-year-old male with CAD of the right popliteal artery diagnosed non-invasively with 3 Tesla cardiovascular magnetic resonance and confirmed on post-operative histopathology.

  3. Cystic adventitial disease of the popliteal artery: features on 3T cardiovascular magnetic resonance

    Gelabert Hugh; Finn J Paul; Lai Chi; Tomasian Anderanik; Krishnam Mayil S

    2008-01-01

    Abstract Cystic adventitial disease (CAD) of the popliteal artery is a rare vascular disease of unknown etiology in which a mucin-containing cyst develops in the adventitial layer of the artery. We report the case of a 26-year-old male with CAD of the right popliteal artery diagnosed non-invasively with 3 Tesla cardiovascular magnetic resonance and confirmed on post-operative histopathology.

  4. Dynamic contrast-enhanced 3-T magnetic resonance imaging: a method for quantifying disease activity in early polyarthritis

    Navalho, Marcio [Faculdade de Medicina da Universidade de Lisboa, Rheumatology Research Unit, Instituto de Medicina Molecular, Lisbon (Portugal); Hospital da Luz, Radiology Department, Lisbon (Portugal); Hospital da Luz, Centro de Imagiologia, Lisbon (Portugal); Resende, Catarina [Hospital da Luz, Rheumatology Department, Lisbon (Portugal); Hospital de Santa Maria, Rheumatology Department, Centro Hospitalar de Lisboa Norte, EPE, Lisbon (Portugal); Rodrigues, Ana Maria; Fonseca, Joao Eurico; Canhao, Helena [Faculdade de Medicina da Universidade de Lisboa, Rheumatology Research Unit, Instituto de Medicina Molecular, Lisbon (Portugal); Hospital de Santa Maria, Rheumatology Department, Centro Hospitalar de Lisboa Norte, EPE, Lisbon (Portugal); Gaspar, Augusto [Hospital da Luz, Radiology Department, Lisbon (Portugal); Campos, Jorge [Hospital de Santa Maria, Radiology Department, Centro Hospitalar de Lisboa Norte, EPE, Lisbon (Portugal)

    2012-01-15

    To determine whether measurement of synovial enhancement and thickness quantification parameters with 3.0-Tesla magnetic resonance imaging (3-T MRI) can reliably quantify disease activity in patients with early polyarthritis. Eighteen patients (16 women, 2 men; mean age 46 years) with early polyarthritis with less than 12 months of symptoms were included. MRI examination using 3-T device was performed by a new approach including both wrists and hands simultaneously in the examination field-of-view. MRI scoring of disease activity included quantification of synovial enhancement with simple measurements such as rate of early enhancement (REE; REE{sub 57} = S{sub 57}/S{sub 200}, where S{sub 57} and S{sub 200} are the signal intensities 57 s and 200 s after gadolinium injection) and rate of relative enhancement (RE; RE = S{sub 200} - S{sub 0}). Both wrists and hands were scored according to the Rheumatoid Arthritis MRI Scoring System (RAMRIS) for synovitis. Disease activity was clinically assessed by the 28-joint Disease Activity Score (DAS28). DAS28 score was strongly correlated with RE (r = 0.8331, p < 0.0001), REE (r = 0.8112, p < 0.0001), and RAMRIS score for synovitis (r = 0.7659, p < 0.0002). An REE score above 0.778 accurately identified patients with clinically active disease (sensitivity 92%; specificity 67%; p < 0.05). A statistically significant difference was observed in the RE, REE, and RAMRIS scores for synovitis between patients with active and inactive disease (p < 0.05). Our findings support the use of 3-T dynamic contrast-enhanced MRI for precise quantification of disease activity and for discriminating active disease from inactive disease in early polyarthritis. (orig.)

  5. Magnetic Resonance Spectroscopy of the Breast at 3T: Pre- and Post-Contrast Evaluation for Breast Lesion Characterization

    E. Kousi

    2012-01-01

    Full Text Available Purpose. To determine whether in vivo proton magnetic resonance spectroscopy at 3T can provide accurate breast lesion characterization, and to determine the effect of gadolinium on the resonance of tCho. Methods. Twenty-four positive-mammogram patients were examined on a 3T MR scanner. 1H-MRS was performed before and after gadolinium administration. tCho peak was qualitatively evaluated before and after contrast injection. Results. Fourteen out of 27 lesions proved to be malignant after histopathological diagnosis. Using 1H-MRS, before contrast injection, 6/14 confirmed malignancies and 11/13 benign lesions were correctly classified; while, after contrast injection, 11/14 confirmed malignancies and 12/13 benign processes were correctly classified. Post gadolinium 1H-MRS proved useful in picking up tCho signal, improving the overall accuracy, sensitivity, and specificity by 35%, 83%, and 9%, respectively. Conclusion. 1H-MRS overall accuracy, sensitivity, and specificity in detecting breast lesion’s malignancy were increased after gadolinium administration. It is prudent to perform 1H-MRS before contrast injection in large breast lesions to avoid choline underestimation. In cases of small or non-mass lesions, it is recommended to perform 1H-MRS after contrast injection for better voxel prescription to enable a reliable preoperative diagnosis.

  6. Quantifiable Imaging Biomarkers for Evaluation of the Posterior Cruciate Ligament Using 3-T Magnetic Resonance Imaging

    Wilson, Katharine J.; Surowiec, Rachel K.; Ho, Charles P.; Devitt, Brian M.; Fripp, Jurgen; Smith, W. Sean; Spiegl, Ulrich J.; Dornan, Grant J.; LaPrade, Robert F.

    2016-01-01

    Background: Quantitative magnetic resonance imaging (MRI) techniques, such as T2 and T2 star (T2*) mapping, have been used to evaluate ligamentous tissue in vitro and to identify significant changes in structural integrity of a healing ligament. These studies lay the foundation for a clinical study that uses quantitative mapping to evaluate ligaments in vivo, particularly the posterior cruciate ligament (PCL). To establish quantitative mapping as a clinical tool for identifying and evaluating chronic or acute PCL injuries, T2 and T2* values first must be determined for an asymptomatic population. Purpose: To quantify T2 and T2* mapping properties, including texture variables (entropy, variance, contrast, homogeneity), of the PCL in an asymptomatic population. It was hypothesized that biomarker values would be consistent throughout the ligament, as measured across 3 clinically relevant subregions (proximal, middle, and distal thirds) in the asymptomatic cohort. Study Design: Cross-sectional study; Level of evidence, 4. Methods: Unilateral knee MRI scans were acquired for 25 asymptomatic subjects with a 3.0-T MRI system using T2 and T2* mapping sequences in the sagittal plane. The PCL was manually segmented and divided into thirds (proximal, middle, and distal). Summary statistics for T2 and T2* values were calculated. Intra- and interrater reliability was assessed across 3 raters to 2 time points. Results: The asymptomatic PCL cohort had mean T2 values of 36.7, 29.2, and 29.6 ms in the distal, middle, and proximal regions, respectively. The distal PCL exhibited significantly higher mean, variance, and contrast and lower homogeneity of T2 values than the middle and proximal subregions (P mapping values, and their texture variables, for the asymptomatic PCL. The distal third of the PCL had significantly greater T2 values than the proximal or middle thirds. Clinical Relevance: T2 and T2* values of the asymptomatic PCL can provide a baseline for comparison with acute

  7. A 3 T magnetic field generator using melt-processed bulk superconductors as trapped field magnets and its applications

    An intense magnetic field generator yielding 3.15 T in the open space between the magnetic poles has been constructed by using a pair of melt-processed bulk superconductors as trapped field magnets. The field was measured in a 2 mm gap between the magnetic poles set face-to-face after the pulsed-field magnetization 'IMRA' method. This field generator is composed of Sm-based 123 compounds, vacuum pumps, pulsed-field coils and GM refrigerators with compressors. The system can be used in various applications. We investigated, for instance, the application to a high gradient magnetic separation system. It was found that the alpha hematite fine particles mixed in the flowing water was completely removed by this technique which was operated in the field of 1.7 T in the gap of 20 mm

  8. Effect of orthodontic brackets and different wires on radiofrequency heating and magnetic field interactions during 3-T MRI

    Görgülü, S; Ayyıldız, S; Gökçe, S; Ozen, T

    2014-01-01

    Objectives: To evaluate the heating and magnetic field interactions of fixed orthodontic appliances with different wires and ligaments in a 3-T MRI environment and to estimate the safety of these orthodontic materials. Methods: 40 non-carious extracted human maxillary teeth were embedded in polyvinyl chloride boxes, and orthodontic brackets were bonded. Nickel–titanium and stainless steel arch wires, and elastic and stainless steel ligaments were used to obtain four experimental groups in total. Specimens were evaluated at 3 T for radiofrequency heating and magnetic field interactions. Radiofrequency heating was evaluated by placing specimens in a cylindrical plastic container filled with isotonic solution and measuring changes in temperature after T1 weighted axial sequencing and after completion of all sequences. Translational attraction and torque values of specimens were also evaluated. One-way ANOVA test was used to compare continuous variables of temperature change. Significance was set at p < 0.05. Results: None of the groups exhibited excessive heating (highest temperature change: <3.04 °C), with the maximum increase in temperature observed at the end of the T1 weighted axial sequence. Magnetic field interactions changed depending on the material used. Although the brackets presented minor interactions that would not cause movement in situ, nickel–titanium and stainless steel wires presented great interactions that may pose a risk for the patient. Conclusions: The temperature changes of the specimens were considered to be within acceptable ranges. With regard to magnetic field interactions, brackets can be considered “MR safe”; however, it would be safe to replace the wires before MRI. PMID:24257741

  9. Deltoid Ligament and Tibiofibular Syndesmosis Injury in Chronic Lateral Ankle Instability: Magnetic Resonance Imaging Evaluation at 3T and Comparison with Arthroscopy

    Chun, Ka-Young; Choi, Yun Sun; Lee, Seok Hoon; Kim, Jin Su; Young, Ki Won; Jeong, Min-Sun; Kim, Dae-Jung

    2015-01-01

    Objective To evaluate the prevalence of deltoid ligament and distal tibiofibular syndesmosis injury on 3T magnetic resonance imaging (MRI) in patients with chronic lateral ankle instability (CLAI). Materials and Methods Fifty patients (mean age, 35 years) who had undergone preoperative 3T MRI and surgical treatment for CLAI were enrolled. The prevalence of deltoid ligament and syndesmosis injury were assessed. The complexity of lateral collateral ligament complex (LCLC) injury was correlated ...

  10. 7 Tesla (T) human cardiovascular magnetic resonance imaging using FLASH and SSFP to assess cardiac function: validation against 1.5 T and 3 T

    Suttie, J. J.; DelaBarre, L; Pitcher, A.; van de Moortele, P. F.; Dass, S; Snyder, C. J.; Francis, J M; Metzger, G. J.; Weale, P.; Ugurbil, K; Neubauer, S.; Robson, M; Vaughan, T

    2011-01-01

    We report the first comparison of cardiovascular magnetic resonance imaging (CMR) at 1.5 T, 3 T and 7 T field strengths using steady state free precession (SSFP) and fast low angle shot (FLASH) cine sequences. Cardiac volumes and mass measurements were assessed for feasibility, reproducibility and validity at each given field strength using FLASH and SSFP sequences. Ten healthy volunteers underwent retrospectively electrocardiogram (ECG) gated CMR at 1.5 T, 3 T and 7 T using FLASH and SSFP se...

  11. Heating induced near deep brain stimulation lead electrodes during magnetic resonance imaging with a 3 T transceive volume head coil

    Heating induced near deep brain stimulation (DBS) lead electrodes during magnetic resonance imaging with a 3 T transceive head coil was measured, modeled, and imaged in three cadaveric porcine heads (mean body weight = 85.47 ± 3.19 kg, mean head weight = 5.78 ± 0.32 kg). The effect of the placement of the extra-cranial portion of the DBS lead on the heating was investigated by looping the extra-cranial lead on the top, side, and back of the head, and placing it parallel to the coil's longitudinal axial direction. The heating was induced using a 641 s long turbo spin echo sequence with the mean whole head average specific absorption rate of 3.16 W kg−1. Temperatures were measured using fluoroptic probes at the scalp, first and second electrodes from the distal lead tip, and 6 mm distal from electrode 1 (T6mm). The heating was modeled using the maximum T6mm and imaged using a proton resonance frequency shift-based MR thermometry method. Results showed that the heating was significantly reduced when the extra-cranial lead was placed in the longitudinal direction compared to the other placements (peak temperature change = 1.5–3.2 °C versus 5.1–24.7 °C). Thermal modeling and MR thermometry may be used together to determine the heating and improve patient safety online. (paper)

  12. Preoperative 3T high field blood oxygen level dependent functional magnetic resonance imaging for glioma involving sensory cortical areas

    LI Shao-wu; WANG Jiang-fei; JIANG Tao; LI Shou-wei; ZHANG Wen-bo; LI Zi-xiao; ZHANG Zhong; DAI Jian-ping; WANG Zhong-cheng

    2010-01-01

    Background Localization of sensory cortical areas during the operation is essential to preserve the sensory function.Intraoperative direct electrostimulation under awake anesthesia is the golden standard but time-consuming. We applied 3T high field blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) to identify the relationship between glioma and cortical sensory areas preoperatively and to guide intraoperative direct electrostimulation for quick and precise localization.Methods Five glioma patients with sensory cortex involvement by or next to the lesion had preoperative BOLD fMRI to determine the spatial relationship of cortical sensory areas to the tumours. Bilateral hand opposite movement was performed by these patients for fMRI. Precentral and postcentral gyri were identified by electrical stimulation during the operation. Karnofsky Performance Status scores of the patients' pre- and postoperative and the role of BOLD fMRI were evaluated.Results The cortical sensory areas were all activated in five glioma patients involving postcentral gyrus areas by BOLDf MRI with bilateral hand opposite movement. The detected activation areas corresponded with the results from cortical electrical stimulation.Conclusions The relationship between cortical sensory areas and tumour can be accurately shown by BOLD fMRI before operation. And the information used to make the tumour resection could obtain good clinical results.

  13. Classification of histologically scored human knee osteochondral plugs by quantitative analysis of magnetic resonance images at 3T.

    Lukas, Vanessa A; Fishbein, Kenneth W; Lin, Ping-Chang; Schär, Michael; Schneider, Erika; Neu, Corey P; Spencer, Richard G; Reiter, David A

    2015-05-01

    This work evaluates the ability of quantitative MRI to discriminate between normal and pathological human osteochondral plugs characterized by the Osteoarthritis Research Society International (OARSI) histological system. Normal and osteoarthritic human osteochondral plugs were scored using the OARSI histological system and imaged at 3 T using MRI sequences producing T1 and T2 contrast and measuring T1, T2, and T2* relaxation times, magnetization transfer, and diffusion. The classification accuracies of quantitative MRI parameters and corresponding weighted image intensities were evaluated. Classification models based on the Mahalanobis distance metric for each MRI measurement were trained and validated using leave-one-out cross-validation with plugs grouped according to OARSI histological grade and score. MRI measurements used for classification were performed using a region-of-interest analysis which included superficial, deep, and full-thickness cartilage. The best classifiers based on OARSI grade and score were T1- and T2-weighted image intensities, which yielded accuracies of 0.68 and 0.75, respectively. Classification accuracies using OARSI score-based group membership were generally higher when compared with grade-based group membership. MRI-based classification--either using quantitative MRI parameters or weighted image intensities--is able to detect early osteoarthritic tissue changes as classified by the OARSI histological system. These findings suggest the benefit of incorporating quantitative MRI acquisitions in a comprehensive clinical evaluation of OA. PMID:25641500

  14. Osteogenic differentiation of MC3T3-E1 cells on poly(L-lactide)/Fe3O4 nanofibers with static magnetic field exposure

    Proliferation and differentiation of bone-related cells are modulated by many factors such as scaffold design, growth factor, dynamic culture system, and physical simulation. Nanofibrous structure and moderate-intensity (1 mT–1 T) static magnetic field (SMF) have been identified as capable of stimulating proliferation and differentiation of osteoblasts. Herein, magnetic nanofibers were prepared by electrospinning mixture solutions of poly(L-lactide) (PLLA) and ferromagnetic Fe3O4 nanoparticles (NPs). The PLLA/Fe3O4 composite nanofibers demonstrated homogeneous dispersion of Fe3O4 NPs, and their magnetism depended on the contents of Fe3O4 NPs. SMF of 100 mT was applied in the culture of MC3T3-E1 osteoblasts on pure PLLA and PLLA/Fe3O4 composite nanofibers for the purpose of studying the effect of SMF on osteogenic differentiation of osteoblastic cells on magnetic nanofibrous scaffolds. On non-magnetic PLLA nanofibers, the application of external SMF could enhance the proliferation and osteogenic differentiation of MC3T3-E1 cells. In comparison with pure PLLA nanofibers, the incorporation of Fe3O4 NPs could also promote the proliferation and osteogenic differentiation of MC3T3-E1 cells in the absence or presence of external SMF. The marriage of magnetic nanofibers and external SMF was found most effective in accelerating every aspect of biological behaviors of MC3T3-E1 osteoblasts. The findings demonstrated that the magnetic feature of substrate and microenvironment were applicable ways in regulating osteogenesis in bone tissue engineering. - Highlights: • Magnetic nanofibers containing well-dispersed Fe3O4 nanoparticles were produced. • Static magnetic field (SMF) was applied to perform the culture of osteoblasts. • Osteogenic differentiation was enhanced on magnetic substrate with exposure to SMF

  15. Magnetic properties of mixed valence La2/3Sr1/3Mn1−TO3 (T = Fe,Cr) manganites obtained by Pechini method

    I Betancourt; A Morales-Hernández

    2013-05-01

    Polycrystalline manganites of composition La2/3Sr1/3Mn1−TO3 (T = Cr3+ or Fe3+, x = 0.0-0.10) were obtained by the Pechini method. Their magnetic properties exhibited a marked dependence on Fe/Cr content, with significant reduction of the magnetic moment per formula unit and their Curie temperatures. In addition, the magnetocaloric effect, determined by isothermal magnetization measurements, displayed a decreasing tendency with increasing Fe/Cr concentration. Results were interpreted on the basis of a deleterious effect on the double exchange interaction provoked by the presence of Fe3+ and Cr3+ ions within the crystal structure.

  16. Osteogenic differentiation of MC3T3-E1 cells on poly(L-lactide)/Fe{sub 3}O{sub 4} nanofibers with static magnetic field exposure

    Cai, Qing [State Key Laboratory of Organic–inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029 (China); Shi, Yuzhou; Shan, Dingying; Jia, Wenkai; Duan, Shun [Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029 (China); Deng, Xuliang [Department of Geriatric Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081 (China); Yang, Xiaoping, E-mail: yangxp@mail.buct.edu.cn [State Key Laboratory of Organic–inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029 (China)

    2015-10-01

    Proliferation and differentiation of bone-related cells are modulated by many factors such as scaffold design, growth factor, dynamic culture system, and physical simulation. Nanofibrous structure and moderate-intensity (1 mT–1 T) static magnetic field (SMF) have been identified as capable of stimulating proliferation and differentiation of osteoblasts. Herein, magnetic nanofibers were prepared by electrospinning mixture solutions of poly(L-lactide) (PLLA) and ferromagnetic Fe{sub 3}O{sub 4} nanoparticles (NPs). The PLLA/Fe{sub 3}O{sub 4} composite nanofibers demonstrated homogeneous dispersion of Fe{sub 3}O{sub 4} NPs, and their magnetism depended on the contents of Fe{sub 3}O{sub 4} NPs. SMF of 100 mT was applied in the culture of MC3T3-E1 osteoblasts on pure PLLA and PLLA/Fe{sub 3}O{sub 4} composite nanofibers for the purpose of studying the effect of SMF on osteogenic differentiation of osteoblastic cells on magnetic nanofibrous scaffolds. On non-magnetic PLLA nanofibers, the application of external SMF could enhance the proliferation and osteogenic differentiation of MC3T3-E1 cells. In comparison with pure PLLA nanofibers, the incorporation of Fe{sub 3}O{sub 4} NPs could also promote the proliferation and osteogenic differentiation of MC3T3-E1 cells in the absence or presence of external SMF. The marriage of magnetic nanofibers and external SMF was found most effective in accelerating every aspect of biological behaviors of MC3T3-E1 osteoblasts. The findings demonstrated that the magnetic feature of substrate and microenvironment were applicable ways in regulating osteogenesis in bone tissue engineering. - Highlights: • Magnetic nanofibers containing well-dispersed Fe{sub 3}O{sub 4} nanoparticles were produced. • Static magnetic field (SMF) was applied to perform the culture of osteoblasts. • Osteogenic differentiation was enhanced on magnetic substrate with exposure to SMF.

  17. Deltoid ligament and tibiofibular syndesmosis injury in chronic lateral ankle instability: Magnetic resonance imaging evaluation at 3T and comparison with arthroscopy

    To evaluate the prevalence of deltoid ligament and distal tibiofibular syndesmosis injury on 3T magnetic resonance imaging (MRI) in patients with chronic lateral ankle instability (CLAI). Fifty patients (mean age, 35 years) who had undergone preoperative 3T MRI and surgical treatment for CLAI were enrolled. The prevalence of deltoid ligament and syndesmosis injury were assessed. The complexity of lateral collateral ligament complex (LCLC) injury was correlated with prevalence of deltoid or syndesmosis injuries. The diagnostic accuracy of ankle ligament imaging at 3T MRI was analyzed using arthroscopy as a reference standard. On MRI, deltoid ligament injury was identified in 18 (36%) patients as follows: superficial ligament alone, 9 (50%); deep ligament alone 2 (11%); and both ligaments 7 (39%). Syndesmosis abnormality was found in 21 (42%) patients as follows: anterior inferior tibiofibular ligament (AITFL) alone, 19 (90%); and AITFL and interosseous ligament, 2 (10%). There was no correlation between LCLC injury complexity and the prevalence of an accompanying deltoid or syndesmosis injury on both MRI and arthroscopic findings. MRI sensitivity and specificity for detection of deltoid ligament injury were 84% and 93.5%, and those for detection of syndesmosis injury were 91% and 100%, respectively. Deltoid ligament or syndesmosis injuries were common in patients undergoing surgery for CLAI, regardless of the LCLC injury complexity. 3T MRI is helpful for the detection of all types of ankle ligament injury. Therefore, careful interpretation of pre-operative MRI is essential

  18. Deltoid ligament and tibiofibular syndesmosis injury in chronic lateral ankle instability: Magnetic resonance imaging evaluation at 3T and comparison with arthroscopy

    Chun, Ka Young; Choi, Yun Sun; Lee, Seok Hoon; Kim, Jin Su; Young, Ki Won; Jeong, Min Sun; Kim, Dae Jung [Eulji Hospital, Eulji University, Seoul (Korea, Republic of)

    2015-10-15

    To evaluate the prevalence of deltoid ligament and distal tibiofibular syndesmosis injury on 3T magnetic resonance imaging (MRI) in patients with chronic lateral ankle instability (CLAI). Fifty patients (mean age, 35 years) who had undergone preoperative 3T MRI and surgical treatment for CLAI were enrolled. The prevalence of deltoid ligament and syndesmosis injury were assessed. The complexity of lateral collateral ligament complex (LCLC) injury was correlated with prevalence of deltoid or syndesmosis injuries. The diagnostic accuracy of ankle ligament imaging at 3T MRI was analyzed using arthroscopy as a reference standard. On MRI, deltoid ligament injury was identified in 18 (36%) patients as follows: superficial ligament alone, 9 (50%); deep ligament alone 2 (11%); and both ligaments 7 (39%). Syndesmosis abnormality was found in 21 (42%) patients as follows: anterior inferior tibiofibular ligament (AITFL) alone, 19 (90%); and AITFL and interosseous ligament, 2 (10%). There was no correlation between LCLC injury complexity and the prevalence of an accompanying deltoid or syndesmosis injury on both MRI and arthroscopic findings. MRI sensitivity and specificity for detection of deltoid ligament injury were 84% and 93.5%, and those for detection of syndesmosis injury were 91% and 100%, respectively. Deltoid ligament or syndesmosis injuries were common in patients undergoing surgery for CLAI, regardless of the LCLC injury complexity. 3T MRI is helpful for the detection of all types of ankle ligament injury. Therefore, careful interpretation of pre-operative MRI is essential.

  19. Efficacy of magnetic resonance imaging at 3 T compared with 1.5 T in small pituitary tumors for stereotactic radiosurgery planning

    The objective of this study was to determine the value of high-field magnetic resonance imaging and to clarify the characteristics of each image among three-dimensional gradient echo (3D-GRE), two-dimensional spin echo (2D-SE) and inversion recovery (2D-IR) sequences used as contrast-enhanced T1-weighted images for stereotactic irradiation treatment planning of sellar lesions. Pulse sequences of 2D-SE and 3D-spoiled gradient recalled acquisition in the steady state (3D-SPGR) using GRE at 1.5 T and 2D-IR and 3D-fast SPGR (3D-FSPGR) at 3 T after injection of contrast material were acquired for 14 small pituitary tumors. As quantitative methods, signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were evaluated using a region-of-interest analysis. There was no significant difference in SNR between 1.5-T SPGR and 3-T FSPGR, while 3-T IR was superior to 1.5-T SE. The 2D-SE and -IR provided significantly better CNR than 3D-GRE between tumor and normal structures. Three Tesla was found to be superior to 1.5 T in distinguishing tumors from the normal sellar structure. Optimal dose planning will utilize each advantage of imaging; 3D-GRE allows high-resolution acquisition and 2D-SE and -IR can offer better tissue contrast. (author)

  20. Repair of distal biceps brachii tendon assessed with 3-T magnetic resonance imaging and correlation with functional outcome

    Alemann, Guillaume; Dietsch, Emmanuel [University Hospital of Besancon, Department of Musculoskeletal Imaging, Besancon (France); Gallinet, David; Obert, Laurent [University Hospital of Besancon, Department of Orthopedic Surgery, Besancon (France); Kastler, Bruno; Aubry, Sebastien [University Hospital of Besancon, Department of Musculoskeletal Imaging, Besancon (France); Franche Comte University, I4S Laboratory-EA 4268-IFR 133, Besancon (France)

    2015-05-01

    Objectives were to study the MRI appearance of the repaired distal biceps tendon (DBT), anatomically reinserted, and to search for a correlation between tendon measurements and functional results. Twenty-five patients (mean age, 49 ± 4.9 years old) who benefited from 3-T MRI follow-up of the elbow after surgical reinsertion of the DBT were retrospectively included and compared to a control group (n = 25; mean age, 48 ± 10 years old). MRI was performed during the month of clinical follow-up and on average 22 months after surgery. Delayed complications (secondary avulsion, new rupture), intratendinous osteoma, tendinous signal on T1-weighted (T1{sub w}) and fat-suppressed proton density-weighted (FS-PD{sub w}) images as well as DBT measurements were recorded. The maximum isometric elbow flexion strength (MEFS) and range of motion of the elbow were assessed. Repaired DBT demonstrated a heterogeneous but normally fibrillar structure. Its low T1{sub w} signal was less pronounced than that of normal tendons, and the FS-PD{sub W} image signal was similar to that of T1{sub w} images. MRI detected seven osteomas (Se = 53 % vs. plain radiography), one textiloma and one secondary avulsion. Repaired DBT measurements were significantly correlated with MEFS (dominant arm R2: 0.38; nondominant arm R2: 0.54); this correlation involved the insertion surface (Δ = -75.7 mm{sup 2}, p = 0.046), transverse diameter (Δ = -2.6 mm, p = 0.018), anteroposterior diameter at the level of the radial head (Δ = -3.9 mm, p = 0.001) and DBT cross-sectional area (Δ = -50.2 mm{sup 2}, p = 0.003). The quality of functional outcome after anatomical elbow rehabilitation of DBT correlates with the extent of tendinous hypertrophy during the healing process. (orig.)

  1. Repair of distal biceps brachii tendon assessed with 3-T magnetic resonance imaging and correlation with functional outcome

    Objectives were to study the MRI appearance of the repaired distal biceps tendon (DBT), anatomically reinserted, and to search for a correlation between tendon measurements and functional results. Twenty-five patients (mean age, 49 ± 4.9 years old) who benefited from 3-T MRI follow-up of the elbow after surgical reinsertion of the DBT were retrospectively included and compared to a control group (n = 25; mean age, 48 ± 10 years old). MRI was performed during the month of clinical follow-up and on average 22 months after surgery. Delayed complications (secondary avulsion, new rupture), intratendinous osteoma, tendinous signal on T1-weighted (T1w) and fat-suppressed proton density-weighted (FS-PDw) images as well as DBT measurements were recorded. The maximum isometric elbow flexion strength (MEFS) and range of motion of the elbow were assessed. Repaired DBT demonstrated a heterogeneous but normally fibrillar structure. Its low T1w signal was less pronounced than that of normal tendons, and the FS-PDW image signal was similar to that of T1w images. MRI detected seven osteomas (Se = 53 % vs. plain radiography), one textiloma and one secondary avulsion. Repaired DBT measurements were significantly correlated with MEFS (dominant arm R2: 0.38; nondominant arm R2: 0.54); this correlation involved the insertion surface (Δ = -75.7 mm2, p = 0.046), transverse diameter (Δ = -2.6 mm, p = 0.018), anteroposterior diameter at the level of the radial head (Δ = -3.9 mm, p = 0.001) and DBT cross-sectional area (Δ = -50.2 mm2, p = 0.003). The quality of functional outcome after anatomical elbow rehabilitation of DBT correlates with the extent of tendinous hypertrophy during the healing process. (orig.)

  2. Measurement precision and biological variation of cranial arteries using automated analysis of 3 T magnetic resonance angiography

    Amin, Faisal Mohammad; Lundholm, Elisabet; Hougaard, Anders;

    2014-01-01

    BACKGROUND: Non-invasive magnetic resonance angiography (MRA) has facilitated repeated measurements of human cranial arteries in several headache and migraine studies. To ensure comparability across studies the same automated analysis software has been used, but the intra- and interobserver, day......-to-day and side-to-side variations have not yet been published. We hypothesised that the observer related, side-to-side, and day-to-day variations would be less than 10%. METHODS: Ten female participants were studied using high-resolution MRA on two study days separated by at least one week. Using the...... automated LKEB-MRA vessel wall analysis software arterial circumferences were measured by blinded observers. Each artery was analysed twice by each of the two different observers. The primary endpoints were to determine the intraclass correlation coefficient (ICC) and intra- an inter-observer, the day...

  3. 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.

  4. Magnetic resonance diffusion tensor imaging (MRDTI) of the optic nerve and optic radiations at 3T in children with neurofibromatosis type I (NF-1)

    Optic pathway glioma (OPG) is a characteristic hallmark of neurofibromatosis type I (NF-I). To evaluate the feasibility of magnetic resonance diffusion tensor imaging (MRDTI) at 3T to detect abnormalities of the optic nerves and optic radiations in children with NF-I. 3-T MRDTI was prospectively performed in 9 children with NF-I (7 boys, 2 girls, average age 7.8 years, range 3-17 years) and 44 controls (25 boys, 19 girls, average age 8.1 years, range 3-17 years). Fractional anisotropy (FA) and mean diffusivity were determined by region-of-interest analysis for the optic nerves and radiations. Statistical analysis compared controls to NF-I patients. Two NF-I patients had bilateral optic nerve gliomas, three had chiasmatic gliomas and four had unidentified neurofibromatosis objects (UNOs) along the optic nerve pathways. All NF-I patients had statistically significant decreases in FA and elevations in mean diffusivity in the optic nerves and radiations compared to age-matched controls. MRDTI can evaluate the optic pathways in children with NF-I. Statistically significant abnormalities were detected in the diffusion tensor metrics of the optic nerves and radiations in children with NF-I compared to age-matched controls. (orig.)

  5. Magnetic resonance diffusion tensor imaging (MRDTI) of the optic nerve and optic radiations at 3T in children with neurofibromatosis type I (NF-1)

    Filippi, Christopher G.; Nickerson, Joshua P. [University of Vermont School of Medicine-FAHC, Department of Radiology, Burlington, VT (United States); Bos, Aaron [University of Vermont School of Medicine, Burlington, VT (United States); Salmela, Michael B. [University of Minnesota School of Medicine, Department of Radiology, Minneapolis, MN (United States); Koski, Chris J. [James Madison University, Department of Political Sciences, Harrisonburg, VA (United States); Cauley, Keith A. [University of Massachusetts Memorial Medical Center, Department of Radiology, Worcester, MA (United States)

    2012-02-15

    Optic pathway glioma (OPG) is a characteristic hallmark of neurofibromatosis type I (NF-I). To evaluate the feasibility of magnetic resonance diffusion tensor imaging (MRDTI) at 3T to detect abnormalities of the optic nerves and optic radiations in children with NF-I. 3-T MRDTI was prospectively performed in 9 children with NF-I (7 boys, 2 girls, average age 7.8 years, range 3-17 years) and 44 controls (25 boys, 19 girls, average age 8.1 years, range 3-17 years). Fractional anisotropy (FA) and mean diffusivity were determined by region-of-interest analysis for the optic nerves and radiations. Statistical analysis compared controls to NF-I patients. Two NF-I patients had bilateral optic nerve gliomas, three had chiasmatic gliomas and four had unidentified neurofibromatosis objects (UNOs) along the optic nerve pathways. All NF-I patients had statistically significant decreases in FA and elevations in mean diffusivity in the optic nerves and radiations compared to age-matched controls. MRDTI can evaluate the optic pathways in children with NF-I. Statistically significant abnormalities were detected in the diffusion tensor metrics of the optic nerves and radiations in children with NF-I compared to age-matched controls. (orig.)

  6. Carotid plaque regression following 6-month statin therapy assessed by 3T cardiovascular magnetic resonance: comparison with ultrasound intima media thickness

    Migrino Raymond Q

    2011-08-01

    Full Text Available Abstract Background Cardiovascular magnetic resonance (CMR allows volumetric carotid plaque measurement that has advantage over 2-dimensional ultrasound (US intima-media thickness (IMT in evaluating treatment response. We tested the hypothesis that 6-month statin treatment in patients with carotid plaque will lead to plaque regression when measured by 3 Tesla CMR but not by IMT. Methods Twenty-six subjects (67 ± 2 years, 7 females with known carotid plaque (> 1.1 mm and coronary or cerebrovascular atherosclerotic disease underwent 3T CMR (T1, T2, proton density and time of flight sequences and US at baseline and following 6 months of statin therapy (6 had initiation, 7 had increase and 13 had maintenance of statin dosing. CMR plaque volume (PV was measured in the region 12 mm below and up to 12 mm above carotid flow divider using software. Mean posterior IMT in the same region was measured. Baseline and 6-month CMR PV and US IMT were compared. Change in lipid rich/necrotic core (LR/NC and calcification plaque components from CMR were related to change in PV. Results Low-density lipoprotein cholesterol decreased (86 ± 6 to 74 ± 4 mg/dL, p = 0.046. CMR PV decreased 5.8 ± 2% (1036 ± 59 to 976 ± 65 mm3, p = 0.018. Mean IMT was unchanged (1.12 ± 0.06 vs. 1.14 ± 0.06 mm, p = NS. Patients with initiation or increase of statins had -8.8 ± 2.8% PV change (p = 0.001 while patients with maintenance of statin dosing had -2.7 ± 3% change in PV (p = NS. There was circumferential heterogeneity in CMR plaque thickness with greatest thickness in the posterior carotid artery, in the region opposite the flow divider. Similarly there was circumferential regional difference in change of plaque thickness with significant plaque regression in the anterior carotid region in region of the flow divider. Change in LR/NC (R = 0.62, p = 0.006 and calcification (R = 0.45, p = 0.03 correlated with PV change. Conclusions Six month statin therapy in patients with

  7. Three-dimensional delayed gadolinium-enhanced magnetic resonance imaging of hip joint cartilage at 3 T: A prospective controlled study

    Zilkens, Christoph, E-mail: christoph.zilkens@med.uni-duesseldorf.de [Univ. Dusseldorf, Medical Faculty, Department of Orthopaedic Surgery, Moorenstrasse 5, D-40225 Dusseldorf (Germany); Miese, Falk, E-mail: falk.miese@med.uni-duesseldorf.de [Univ. Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstrasse 5, D-40225 Dusseldorf (Germany); Kim, Young-Jo, E-mail: young-jo.kim@childrens.harvard.edu [Department of Orthopaedic Surgery, The Children' s Hospital Boston, 300 Longwood Ave., Boston, MA 02115 (United States); Hosalkar, Harish, E-mail: hhosalkar@rchsd.org [Department of Orthopaedic Surgery, Rady Children' s Hospital San Diego, 3030 Childrens Way Ste 410, San Diego, CA 92123 (United States); Antoch, Gerald, E-mail: antoch@med.uni-duesseldorf.de [Univ. Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Moorenstrasse 5, D-40225 Dusseldorf (Germany); Krauspe, Ruediger, E-mail: krauspe@med.uni-duesseldorf.de [Univ. Dusseldorf, Medical Faculty, Department of Orthopaedic Surgery, Moorenstrasse 5, D-40225 Dusseldorf (Germany); Bittersohl, Bernd, E-mail: bbittersohl@partners.org [Univ. Dusseldorf, Medical Faculty, Department of Orthopaedic Surgery, Moorenstrasse 5, D-40225 Dusseldorf (Germany)

    2012-11-15

    Purpose: To assess acetabular and femoral hip joint cartilage with three-dimensional (3D) delayed gadolinium-enhanced magnetic resonance imaging (dGEMRIC) in patients with degeneration of hip joint cartilage and asymptomatic controls with morphologically normal appearing cartilage. Methods and materials: A total of 40 symptomatic patients (18 males, 22 females; mean age: 32.8 {+-} 10.2 years, range: 18-57 years) with different hip joint deformities including femoroacetabular impingement (n = 35), residual hip dysplasia (n = 3) and coxa magna due to Legg-Calve-Perthes disease in childhood (n = 2) underwent high-resolution 3D dGEMRIC for the evaluation of acetabular and femoral hip joint cartilage. Thirty-one asymptomatic healthy volunteers (12 males, 19 females; mean age: 24.5 {+-} 1.8 years, range: 21-29 years) without underlying hip deformities were included as control. MRI was performed at 3 T using a body matrix phased array coil. Region of interest (ROI) analyses for T1{sub Gd} assessment was performed in seven regions in the hip joint, including anterior to superior and posterior regions. Results: T1{sub Gd} mapping demonstrated the typical pattern of acetabular cartilage consistent with a higher glycosaminoglycan (GAG) content in the main weight-bearing area. T1{sub Gd} values were significantly higher in the control group than in the patient group whereas significant differences in T1{sub Gd} values corresponding to the amount of cartilage damage were noted both in the patient group and in the control group. Conclusions: Our study demonstrates the potential of high-resolution 3D dGEMRIC at 3 T for separate acetabular and femoral hip joint cartilage assessment in various forms of hip joint deformities.

  8. Three-dimensional delayed gadolinium-enhanced magnetic resonance imaging of hip joint cartilage at 3 T: A prospective controlled study

    Purpose: To assess acetabular and femoral hip joint cartilage with three-dimensional (3D) delayed gadolinium-enhanced magnetic resonance imaging (dGEMRIC) in patients with degeneration of hip joint cartilage and asymptomatic controls with morphologically normal appearing cartilage. Methods and materials: A total of 40 symptomatic patients (18 males, 22 females; mean age: 32.8 ± 10.2 years, range: 18–57 years) with different hip joint deformities including femoroacetabular impingement (n = 35), residual hip dysplasia (n = 3) and coxa magna due to Legg–Calve–Perthes disease in childhood (n = 2) underwent high-resolution 3D dGEMRIC for the evaluation of acetabular and femoral hip joint cartilage. Thirty-one asymptomatic healthy volunteers (12 males, 19 females; mean age: 24.5 ± 1.8 years, range: 21–29 years) without underlying hip deformities were included as control. MRI was performed at 3 T using a body matrix phased array coil. Region of interest (ROI) analyses for T1Gd assessment was performed in seven regions in the hip joint, including anterior to superior and posterior regions. Results: T1Gd mapping demonstrated the typical pattern of acetabular cartilage consistent with a higher glycosaminoglycan (GAG) content in the main weight-bearing area. T1Gd values were significantly higher in the control group than in the patient group whereas significant differences in T1Gd values corresponding to the amount of cartilage damage were noted both in the patient group and in the control group. Conclusions: Our study demonstrates the potential of high-resolution 3D dGEMRIC at 3 T for separate acetabular and femoral hip joint cartilage assessment in various forms of hip joint deformities.

  9. Neuromelanin-related contrast in the substantia nigra semiquantitatively evaluated by magnetic resonance imaging at 3T. Comparison between normal aging and Parkinson disease

    Fast spin-echo (FSE) T1-weighted magnetic resonance imaging (MRI) at 3T, which was optimized to detect neuromelanin-related contrast (NRC), was applied to quantitative estimation of signal alterations in the substantia nigra pars compacta (SNc) of 72 normal volunteers and 59 patients with Parkinson disease (PD). We examined relationship between NRC in SNc and clinical parameters. The NRC showed significant positive correlation with normal aging and was slightly but significantly higher in women than in men. Significant reduction in the NRC was found in PD as compared with 59 age- and sex-matched normal volunteers. The NRC in PD was negatively and significantly correlated with duration of illness and disease severity assessed by unified Parkinoson's disease rating scale (UPDRS) and Hoehn and Yahr stage. Significant reduction of the NRC was demonstrated in patients with visual hallucinations as compare with patients without the symptoms. Rapid eye movement (REM) sleep behavior disorder also contributed reduction of NRC although it did more mildly than visual hallucination. Anosmia or hyposmia had no statistical relationship with the amount of NRC in PD. The overall visual inspection indicated that the reduction of the NRC in PD should start at the ventrolateral portion of SNc and advance medially. Additionally, we studied dementia with Lewy body disease (DLB). The NRC was reduced more significantly in DLB patients with PD symptoms than in those without them who also showed a significant reduction compared with normal controls. Quantification and distribution of the NRC obtained by 3T MRI was well correlated with pathological findings reported previously and clinical parameters in this study. Visualization and quantification of the NRC provide some parts of clinical and diagnostic information about pathologic condition of SNc. (author)

  10. Preliminary observation of dynamic changes in alcohol concentration in the human brain with proton magnetic resonance spectroscopy on a 3T MR instrument

    Our purposes were to establish suitable conditions for proton magnetic resonance spectroscopy (MRS) to measure dynamic changes in alcohol concentration in the human brain, to evaluate these changes, and to compare the findings with data from analysis of breath vapor and blood samples. We evaluated 4 healthy volunteers (mean age 26.5 years; 3 males, one female) with no neurological findings. All studies were performed with 3-tesla clinical equipment using an 8-channel head coil. We applied our modified single-voxel point-resolved spectroscopy (PRESS) sequence. Continuous measurements of MRS, breath vapor, and blood samples were conducted before and after the subjects drank alcohol with a light meal. The obtained spectra were quantified by LCModel Ver. 6.1, and the accuracy of the MRS measurements was estimated using the estimated standard deviation expressed in percentage (% standard deviation (SD)) as a criterion. Alcohol peaks after drinking were clearly detected at 1.2 ppm for all durations of measurement. Good correlations between breath vapor or blood sample and MRS were found by sub-minute MRS measurement. The continuous measurement showed time-dependent changes in alcohol in the brain and various patterns that differed among subjects. The clinical 3 T equipment enables direct evaluation of sub-minute changes in alcohol metabolism in the human brain. (author)

  11. Magnetization transfer in human achilles tendon assessed by a 3D ultrashort echo time sequence. Quantitative examinations in healthy volunteers at 3T

    Syha, R.; Grosse, U.; Springer, F. [Tuebingen Univ. (Germany). Diagnostic and Interventional Radiology; Tuebingen Univ. (Germany). Section on Experimental Radiology; Martirosian, P.; Schick, F. [Tuebingen Univ. (Germany). Section on Experimental Radiology; Ketelsen, D.; Claussen, C.D. [Tuebingen Univ. (Germany). Diagnostic and Interventional Radiology

    2011-11-15

    Magnetization transfer contrast (MTC) imaging provides insight into interactions between free and bounded water. Newly developed ultrashort echo time (UTE) sequences implemented on whole-body magnetic resonance (MR) scanners allow MTC imaging in tissues with extremely fast signal decay such as tendons. The aim of this study was to develop a technique for the quantification of the MT effect in healthy Achilles tendons in-vivo at 3 Tesla. 16 normal tendons of volunteers with no history of tendinopathy were examined using a 3D-UTE sequence with a rectangular on-resonant excitation pulse and a Fermi-shaped off-resonant MT preparation pulse. The frequency of the MT pulse was varied from 1 to 5 kHz. MT effects were calculated in terms of the MT ratio (MTR) between measurements without and with MT preparation. Direct saturation effects of MT preparation on the signal intensity were evaluated using numerical simulation of Bloch equations. One patient with tendinopathy was examined to exemplarily show changes of MTR under pathologic conditions. Calculation of MTR data was feasible in all examined tendons and showed a decrease from 0.53 {+-} 0.05 to 0.25 {+-} 0.03 (1 kHz to 5 kHz) for healthy volunteers. Evaluation of variation with gender and dominance of ankle revealed no significant differences (p > 0.05). In contrast, the patient with confirmed tendinopathy showed MTR values between 0.36 (1 kHz) and 0.19 (5 kHz). MT effects in human Achilles tendons can be reliably assessed in-vivo using a 3D UTE sequence at 3 T. All healthy tendons showed similar MTR values (coefficient of variation 10.0 {+-} 1.2 %). The examined patient showed a clearly different MT effect revealing a changed microstructure in the case of tendinopathy. (orig.)

  12. Differential diagnosis of metastasis from non-metastatic lymph nodes in cervical cancers: pilot study of diffusion weighted imaging with background suppression at 3T magnetic resonance

    YU Shen-ping; HE Li; LIU Bo; ZHUANG Xiao-zhao; LIU Ming-juan; HU Xiao-shu

    2010-01-01

    Background Diffusion weighted imaging with background suppression (DWIBS) is potentially useful in detecting metastatic lymph nodes. This study aimed to evaluate the efficacy of DWIBS at 3T magnetic resonance (MR) for diagnosing metastatic lymph nodes in cervical cancer.Methods This retrospective study included 25 patients with cervical cancer who underwent MR examination and were treated by hysterectomy and lymphadenectomy. The metastatic and non-metastatic lymph nodes were histologically proven by operation. Apparent diffusion coefficient (ADC) values, long-axis diameters, short-axis diameters, ratio of short- to long-axis diameters of all the identifiable lymph nodes were measured and compared.Results Twenty-five primary tumor lesions, 17 metastatic lymph nodes and 140 non-metastatic lymph nodes were pathologically confirmed in 25 cases with cervical cancer. The difference of ADC values between primary tumor lesions,metastatic and non-metastatic lymph nodes were statistically significant (F=7.93, P=0.001). There was no statistically significant difference between primary tumor lesions of cervical cancer and metastatic lymph nodes (t=-0.75, P=-0.456),and the difference between primary tumor lesions and non-metastatic lymph nodes was statistically significant (t =4.68, P<0.001). The ADC values, long-axis diameters, short-axis diameters, ratio of short- to long-axis diameters of metastatic and non-metastatic lymph nodes were (0.86±0.36)×10-3 mm2/s vs. (1.12±0.34)×10-3 mm2/s, (1.51±0.41) cm vs.(1.19±0.36) cm, (1.16±0.35) cm vs. (0.77±0.22) cm, 0.78±0.17 vs. 0.68±0.19 respectively, and statistically significant difference existed between two groups.Conclusions DWIBS at 3T MR has the distinct advantages in detecting pelvic lymph nodes of cervical cancer.Quantitative measurement of ADC values could reflect the degree of restriction of diffusion of metastatic and non-metastatic lymph nodes. The combination of size and ADC value would be useful in the

  13. Quantitative circumferential strain analysis using adenosine triphosphate-stress/rest 3-T tagged magnetic resonance to evaluate regional contractile dysfunction in ischemic heart disease

    Highlights: • Infarcted segments could be differentiated from non-ischemic and ischemic segments with high sensitivity and specificity under at rest conditions. • The time-to-peak circumferential strain values in infarcted segments were more significantly delayed than those in non-ischemic and ischemic segments. • Both circumferential strain and circumferential systolic strain rate values under ATP-stress conditions were significantly lower in ischemic segments than in non-ischemic segments. • Subtracting stress and rest circumferential strain had a higher diagnostic capability for ischemia relative to only utilizing rest or ATP-stress circumferential strain values. • A circumferential strain analysis using tagged MR can quantitatively assess contractile dysfunction in ischemic and infarcted myocardium. - Abstract: Purpose: We evaluated whether a quantitative circumferential strain (CS) analysis using adenosine triphosphate (ATP)-stress/rest 3-T tagged magnetic resonance (MR) imaging can depict myocardial ischemia as contractile dysfunction during stress in patients with suspected coronary artery disease (CAD). We evaluated whether it can differentiate between non-ischemia, myocardial ischemia, and infarction. We assessed its diagnostic performance in comparison with ATP-stress myocardial perfusion MR and late gadolinium enhancement (LGE)-MR imaging. Methods: In 38 patients suspected of having CAD, myocardial segments were categorized as non-ischemic (n = 485), ischemic (n = 74), or infarcted (n = 49) from the results of perfusion MR and LGE-MR. The peak negative CS value, peak circumferential systolic strain rate (CSR), and time-to-peak CS were measured in 16 segments. Results: A cutoff value of −12.0% for CS at rest allowed differentiation between infarcted and other segments with a sensitivity of 79%, specificity of 76%, accuracy of 76%, and an area under the curve (AUC) of 0.81. Additionally, a cutoff value of 477.3 ms for time-to-peak CS at rest

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

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

    2014-06-15

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

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

    Purpose: To improve proton magnetic resonance spectroscopy (MRS) transverse relaxation (T2) determination and quantification of lipid methylene chain (1.3 ppm) protons by rewinding their J-coupling evolution. Methods: MRS experiments were performed on four lipid phantoms, namely, almond, corn, sunflower and oleic acid, using a 3 T Philips MRI scanner with a transmit/receive birdcage head coil. Two PRESS (Point RESolved Spectroscopy) pulse sequences were used. The first PRESS sequence employed standard bandwidth (BW) (∼550 Hz) RF (radiofrequency) refocussing pulses, while the second used refocussing pulses of narrow BW (∼50 Hz) designed to rewind J-coupling evolution of the methylene protons in the voxel of interest. Signal was acquired with each sequence from a 5×5×5 mm3 voxel, with a repetition time (TR) of 3000 ms, and with echo times (TE) of 100 to 200 ms in steps of 20 ms. 2048 sample points were measured with a 2000 Hz sampling bandwidth. Additionally, 30 mm outer volume suppression slabs were used to suppress signal outside the voxel of interest. The frequency of the RF pulses was set to that of the methylene resonance. Methylene peak areas were calculated and fitted in MATLAB to a monexponentially decaying function of the form M0exp(-TE/T2), where M0 is the extrapolated area when TE = 0 ms and yields a measure of concentration. Results: The determined values of M0 and T2 increased for all fatty acids when using the PRESS sequence with narrow BW refocussing pulses. M0 and T2 values increased by an average amount (over all the phantoms) of 31% and 14%, respectively. Conclusion: This investigation has demonstrated that J-coupling interactions of lipid methylene protons causes non-negligible signal losses which, if not accounted for, Result in underestimations of their levels and T2 values when performing MRS measurements. Funded by the Natural Sciences and Engineering Research Council of Canada and the Canadian Breast Cancer Foundation - Prairies.NWT

  16. Quantitative circumferential strain analysis using adenosine triphosphate-stress/rest 3-T tagged magnetic resonance to evaluate regional contractile dysfunction in ischemic heart disease

    Nakamura, Masashi, E-mail: m.nakamura1230@gmail.com [Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime 791-0295 (Japan); Kido, Tomoyuki [Department of Radiology, Saiseikai Matsuyama Hospital, Ehime 791-0295 (Japan); Kido, Teruhito; Tanabe, Yuki; Matsuda, Takuya; Nishiyama, Yoshiko; Miyagawa, Masao; Mochizuki, Teruhito [Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime 791-0295 (Japan)

    2015-08-15

    Highlights: • Infarcted segments could be differentiated from non-ischemic and ischemic segments with high sensitivity and specificity under at rest conditions. • The time-to-peak circumferential strain values in infarcted segments were more significantly delayed than those in non-ischemic and ischemic segments. • Both circumferential strain and circumferential systolic strain rate values under ATP-stress conditions were significantly lower in ischemic segments than in non-ischemic segments. • Subtracting stress and rest circumferential strain had a higher diagnostic capability for ischemia relative to only utilizing rest or ATP-stress circumferential strain values. • A circumferential strain analysis using tagged MR can quantitatively assess contractile dysfunction in ischemic and infarcted myocardium. - Abstract: Purpose: We evaluated whether a quantitative circumferential strain (CS) analysis using adenosine triphosphate (ATP)-stress/rest 3-T tagged magnetic resonance (MR) imaging can depict myocardial ischemia as contractile dysfunction during stress in patients with suspected coronary artery disease (CAD). We evaluated whether it can differentiate between non-ischemia, myocardial ischemia, and infarction. We assessed its diagnostic performance in comparison with ATP-stress myocardial perfusion MR and late gadolinium enhancement (LGE)-MR imaging. Methods: In 38 patients suspected of having CAD, myocardial segments were categorized as non-ischemic (n = 485), ischemic (n = 74), or infarcted (n = 49) from the results of perfusion MR and LGE-MR. The peak negative CS value, peak circumferential systolic strain rate (CSR), and time-to-peak CS were measured in 16 segments. Results: A cutoff value of −12.0% for CS at rest allowed differentiation between infarcted and other segments with a sensitivity of 79%, specificity of 76%, accuracy of 76%, and an area under the curve (AUC) of 0.81. Additionally, a cutoff value of 477.3 ms for time-to-peak CS at rest

  17. A 3 T event-related functional magnetic resonance imaging (fMRI) study of primary and secondary gustatory cortex localization using natural tastants

    It is known that taste is centrally represented in the insula, frontal and parietal operculum, as well as in the orbitofrontal cortex (secondary gustatory cortex). In functional MRI (fMRI) experiments activation in the insula has been confirmed, but activation in the orbitofrontal cortex is only infrequently found, especially at higher field strengths (3 T). Due to large susceptibility artefacts, the orbitofrontal cortex is a difficult region to examine with fMRI. Our aim was to localize taste in the human cortex at 3 T, specifically in the orbitofrontal cortex as well as in the primary gustatory cortex. Event-related fMRI was performed at 3 T in seven healthy volunteers. Taste stimuli consisted of lemon juice and chocolate. To visualize activation in the orbitofrontal cortex a dedicated 3D SENSE EPI fMRI sequence was used, in addition to a 2D SENSE EPI fMRI sequence for imaging the entire brain. Data were analyzed using a perception-based model. The dedicated 3D SENSE EPI sequence successfully reduced susceptibility artefacts in the orbitofrontal area. Significant taste-related activation was found in the orbitofrontal and insular cortices. fMRI of the orbitofrontal cortex is feasible at 3 T, using a dedicated sequence. Our results corroborate findings from previous studies. (orig.)

  18. A 3 T event-related functional magnetic resonance imaging (fMRI) study of primary and secondary gustatory cortex localization using natural tastants

    Smits, Marion [Erasmus MC, University Medical Center Rotterdam, Department of Radiology, P.O. Box 2040, CA Rotterdam (Netherlands); K.U.Leuven, Department of Radiology, University Hospitals, Leuven (Belgium); Peeters, Ronald R.; Hecke, Paul van; Sunaert, Stefan [K.U.Leuven, Department of Radiology, University Hospitals, Leuven (Belgium)

    2007-01-15

    It is known that taste is centrally represented in the insula, frontal and parietal operculum, as well as in the orbitofrontal cortex (secondary gustatory cortex). In functional MRI (fMRI) experiments activation in the insula has been confirmed, but activation in the orbitofrontal cortex is only infrequently found, especially at higher field strengths (3 T). Due to large susceptibility artefacts, the orbitofrontal cortex is a difficult region to examine with fMRI. Our aim was to localize taste in the human cortex at 3 T, specifically in the orbitofrontal cortex as well as in the primary gustatory cortex. Event-related fMRI was performed at 3 T in seven healthy volunteers. Taste stimuli consisted of lemon juice and chocolate. To visualize activation in the orbitofrontal cortex a dedicated 3D SENSE EPI fMRI sequence was used, in addition to a 2D SENSE EPI fMRI sequence for imaging the entire brain. Data were analyzed using a perception-based model. The dedicated 3D SENSE EPI sequence successfully reduced susceptibility artefacts in the orbitofrontal area. Significant taste-related activation was found in the orbitofrontal and insular cortices. fMRI of the orbitofrontal cortex is feasible at 3 T, using a dedicated sequence. Our results corroborate findings from previous studies. (orig.)

  19. Morphologic characterization of meniscal root ligaments in the human knee with magnetic resonance microscopy at 11.7 and 3 T

    Chang, Eric Y.; Chung, Christine B. [VA San Diego Healthcare System, Department of Radiology, San Diego, CA (United States); University of California, San Diego Medical Center, Department of Radiology, San Diego, CA (United States); Biswas, Reni; DiCamillo, Paul; Statum, Sheronda; Tafur, Monica; Bydder, Graeme M. [University of California, San Diego Medical Center, Department of Radiology, San Diego, CA (United States)

    2014-10-15

    To determine the feasibility of using MR microscopy to characterize the root ligaments of the human knee at both ultra-high-field (11.7 T) and high-field (3 T) strengths. Seven fresh cadaveric knees were used for this study. Six specimens were imaged at 11.7 T and one specimen at 3 T using isotropic or near-isotropic voxels. Histologic correlation was performed on the posteromedial root ligament of one specimen. Meniscal root ligament shape, signal intensity, and ultrastructure were characterized. High-resolution, high-contrast volumetric images were generated from both MR systems. Meniscal root ligaments were predominantly oval in shape. Increased signal intensity was most evident at the posteromedial and posterolateral root ligaments. On the specimen that underwent histologic preparation, increased signal intensity corresponded to regions of enthesis fibrocartilage. Collagen fascicles were continuous between the menisci and root ligaments. Predominantly horizontal meniscal radial tie fibers continued into the root ligaments as vertical endoligaments. MR microscopy can be used to characterize and delineate the distinct ultrastructure of the root ligaments on both ultra-high-field- and high-field-strength MR systems. (orig.)

  20. Event-related dynamics of glutamate and BOLD effects measured using functional magnetic resonance spectroscopy (fMRS) at 3T in a repetition suppression paradigm.

    Apšvalka, Dace; Gadie, Andrew; Clemence, Matthew; Mullins, Paul G

    2015-09-01

    Proton MR spectroscopy ((1)H-MRS) complements other brain research methods by providing measures of neurometabolites noninvasively in a localized brain area. Improvements in MR scanner technologies, and data acquisition and analysis methods should allow functional (1)H-MRS (fMRS) to measure neurometabolite concentration changes during task-induced brain activation. The aim of the current study was to further develop event-related fMRS at 3T to investigate glutamate dynamics in response to repetition suppression. A secondary aim was to investigate the relationship between blood-oxygen-level-dependent (BOLD) responses and glutamate dynamics in the same paradigm at the same time. A novel approach of interleaved water-suppressed (metabolite) and unsuppressed (water) fMRS was used to simultaneously detect the event-related dynamics of glutamate and BOLD signal to repetition suppression in the lateral occipital cortex of thirteen (N=13) volunteers. On average, (1)H-MRS-visible glutamate increased after novel visual stimuli presentations by 12% and decreased by 11-13% on repeated compared to novel presentations. The BOLD signal, as measured by water peak amplitude changes, showed significant difference between Task and Rest trials, and, on a GLM based analysis of the time series, demonstrated a significant difference between the novel and repeated trials, however appeared to be decoupled from the glutamate response as no correlation was found between the two. These results are the first demonstration that reductions in neuronal activity typical of repetition suppression effects are reflected by reduced glutamatergic and BOLD measures, that glutamate and BOLD responses may not be coupled as previously thought, and that these changes and relationships can be measured simultaneously using event-related fMRS at 3T. PMID:26072254

  1. Role of 3T multiparametric magnetic resonance imaging without endorectal coil in the detection of local recurrent prostate cancer after radical prostatectomy: the radiation oncology point of view

    Couñago, Felipe; Cerro, Elia del; Díaz, Ana Aurora; Marcos, Francisco José; Cerezo, Laura; Maldonado, Antonio; Thuissard Vasallo, Israel John; Rodríguez Martín, José Luis

    2015-01-01

    The aims of this study were to evaluate the role of 3 tesla multiparametric magnetic resonance imaging (3TmMRI) without endorectal coil in the detection of radiographic local recurrences (rLRs) in a contemporary cohort of patients with prostate cancer who presented with biochemical recurrence after radical prostatectomy (RP) with low prostate-specific antigen (PSA) levels, and to identify clinical parameters associated with the 3TmMRI findings.

  2. Magnetic resonance direct thrombus imaging at 3 T field strength in patients with lower limb deep vein thrombosis: a feasibility study

    AIM: To investigate the feasibility of imaging lower limb deep vein thrombosis using magnetic resonance imaging (MRI) at 3.0 T magnetic field strength with an optimized a T1 magnetization prepared rapid gradient echo technique (MP-RAGE) in patients with normal volunteers as controls. MATERIALS AND METHODS: Patients with deep vein thrombosis (n=4), thrombophlebitis (n=2) and healthy volunteers (n=9) were studied. MRI of the distal thigh and upper calf was performed at 3.0 T with MP-RAGE using two pre-pulses to suppress blood and fat (flip angle 15o, echo time 5 ms, and repetition time 10 ms). A qualitative analysis was performed for detection of thrombi and image quality. Contrast-to-noise ratios were determined in thrombosed and patent veins. RESULTS: Thrombi were clearly visible as high-signal intensity structures with good suppression of the anatomical background. A blinded reader accurately diagnosed 15 out of 16 cases. The contrast-to-noise ratio measurements showed a positive contrast of thrombus over background muscle 16.9 (SD 4.3, 95% CI: 12.5-21.3) and a negative contrast of the lumen to muscle in patent veins of normal volunteers -7.8 (SD 4.3, 95% CI: -11.1 to -4.5), with p=0.0015. CONCLUSION: Thrombi generate high signal intensity at 3.0 T allowing for their direct visualization if flowing blood, stationary blood and fat are sufficiently suppressed. This preliminary data supports the development of these techniques for other vascular applications

  3. [G3T]5/Tb(3+) based DNA biosensor with target DNA-triggered autocatalytic multi-cycle-amplification and magnetic nanoparticles assisted-background-lowered.

    Jiang, Hong; Zhang, Xiaojun; Wang, Guangfeng

    2015-12-15

    Due to terbium's unique photophysical properties, nucleic-acid-sensitized terbium (DNA/Tb(3+)) bioluminescent system becomes a potential candidate for the fabrication of DNA biosensors. However, the low sensitivity of DNA/Tb(3+) bioluminescent system limits its development. In this paper, a strategy combining autocatalytic multi-cycle-amplification (including exonuclease III (exo III)-aided and Zn(2+)-requiring DNAzyme-assisted target recycling amplifications) and magnetic nanoparticles assisted-background-lowering to improve the sensitivity of DNA/Tb(3+) bioluminescent system is presented for sensitive detection of target DNA (tDNA). The DNA/Tb(3+) bioluminescent system was investigated by ultraviolet-visible (UV-vis) absorption and luminescence spectra. The possible conjugation mechanism and mode of DNA with Tb(3+) were discussed. The autocatalytic multi-cycle-amplification effect was investigated by the comparison of the luminescence. The carboxylation-functionalized Fe3O4-magnetic nanoparticles (MNPs) were characterized and its role in background lowering was proved. As a result, with the designed protocol, the detection limit for the tDNA detection reached a low level to aM, which is especially exciting for the DNA/Tb(3+) bioluminescent system. In the process, due to the separation effect of MNPs, the assay solution was purified to avoid the nonspecific luminescence of DNA/Tb(3+), not only lowering the background signal greatly (about five times lower than that without the use of MNPs but also improving the reproducibility and stability. We hope that our attempt in this field will not only extend the application of DNA/Tb(3+) luminescent system in biosensing areas but also open the road to adaptation of the protocols to other related analytes. PMID:26257185

  4. Follow-up of coiled intracranial aneurysms: comparison of 3D time-of-flight and contrast-enhanced magnetic resonance angiography at 3T in a large, prospective series

    To compare 3D-TOF magnetic resonance angiography (MRA) and contrast-enhanced MRA (CE-MRA) sequences at 3T in the follow-up of coiled aneurysms with digital subtracted angiography (DSA) as the gold standard. DSA, 3D-TOF and CE-MRA were performed in a prospective series of 126 aneurysms in 96 patients (57 female, 39 male; age: 25-75 years, mean: 51.3 ± 11.3 years). The quality of aneurysm occlusion was assessed independently and anonymously by a core laboratory. Using DSA (gold standard technique), total occlusion was depicted in 57 aneurysms (45.2%), neck remnant in 34 aneurysms (27.0%) and aneurysm remnant in 35 aneurysms (27.8%). Sensitivity, specificity, positive predictive value and negative predictive value were very similar with 3D-TOF and CE-MRA. Visibility of coils was much better with 3D-TOF (95.2%) than with CE-MRA (23.0%) (P < 0.001). Also, substantial artefacts were less frequent with 3D-TOF (4.0%) than with CE-MRA (11.9%; P = 0.012). In this large prospective series of patients with coiled aneurysms, at 3T 3D-TOF MRA was equivalent to CE-MRA for the evaluation of aneurysm occlusion, but coil visibility was superior at 3D-TOF. Thus the use of 3D-TOF at 3T is recommended for the follow-up of coiled intracranial aneurysms. (orig.)

  5. Follow-up of coiled intracranial aneurysms: comparison of 3D time-of-flight and contrast-enhanced magnetic resonance angiography at 3T in a large, prospective series

    Pierot, Laurent [University of Reims, Department of Radiology, Maison Blanche Hospital, Reims (France); Hopital de la Maison Blanche - CHU, Service de radiologie, Reims (France); Portefaix, Christophe [University of Reims, Department of Radiology, Maison Blanche Hospital, Reims (France); University of Reims, CReSTIC SIC EA3804, Reims (France); Boulin, Anne [Foch Hospital, Department of Neuroradiology, Suresnes (France); Gauvrit, Jean-Yves [University of Rennes, Department of Radiology, CHU Rennes, Rennes (France)

    2012-10-15

    To compare 3D-TOF magnetic resonance angiography (MRA) and contrast-enhanced MRA (CE-MRA) sequences at 3T in the follow-up of coiled aneurysms with digital subtracted angiography (DSA) as the gold standard. DSA, 3D-TOF and CE-MRA were performed in a prospective series of 126 aneurysms in 96 patients (57 female, 39 male; age: 25-75 years, mean: 51.3 {+-} 11.3 years). The quality of aneurysm occlusion was assessed independently and anonymously by a core laboratory. Using DSA (gold standard technique), total occlusion was depicted in 57 aneurysms (45.2%), neck remnant in 34 aneurysms (27.0%) and aneurysm remnant in 35 aneurysms (27.8%). Sensitivity, specificity, positive predictive value and negative predictive value were very similar with 3D-TOF and CE-MRA. Visibility of coils was much better with 3D-TOF (95.2%) than with CE-MRA (23.0%) (P < 0.001). Also, substantial artefacts were less frequent with 3D-TOF (4.0%) than with CE-MRA (11.9%; P = 0.012). In this large prospective series of patients with coiled aneurysms, at 3T 3D-TOF MRA was equivalent to CE-MRA for the evaluation of aneurysm occlusion, but coil visibility was superior at 3D-TOF. Thus the use of 3D-TOF at 3T is recommended for the follow-up of coiled intracranial aneurysms. (orig.)

  6. Tumor Volume and Metabolism of Prostate Cancer Determined by Proton Magnetic Resonance Spectroscopic Imaging at 3T Without Endorectal Coil Reveal Potential Clinical Implications in the Context of Radiation Oncology

    Purpose: To determine whether a relationship exists between the tumor volume (TV) or relative choline content determined using magnetic resonance spectroscopy imaging (MRSI) at 3T and the clinical prognostic parameters for patients with localized prostate cancer (PCa). Methods and Materials: A total of 72 men (mean age, 67.8 ± 6.2 years) were stratified as having low-risk (n = 26), intermediate-risk (n = 24), or high-risk (n = 22) PCa. MRSI was performed at 3T using a phased-array coil. Spectra are expressed as the total choline/citrate, total choline plus creatine/citrate, and total choline plus polyamines plus creatine/citrate ratios. The mean ratio of the most pathologic voxels and the MRSI-based TV were also determined. Results: The mean values of the total choline/citrate, total choline plus creatine/citrate, and total choline plus polyamine plus creatine/citrate ratios were greater for Stage T2b or greater tumors vs. Stage T2a or less tumors: 7.53 ± 13.60 vs. 2.31 ± 5.65 (p = .018), 8.98 ± 14.58 vs. 2.56 ± 5.70 (p = .016), and 10.32 ± 15.47 vs. 3.55 ± 6.16 (p = .014), respectively. The mean MRSI-based TV for Stage T2b or greater and Stage T2a or less tumors was significantly different (2.23 ± 2.62 cm3 vs. 1.26 ± 2.06 cm3, respectively; p = .030). This TV correlated with increased prostate-specific antigen levels (odds ratio, 1.293; p = .012). Patients with high-risk PCa had a larger TV than did the patients with intermediate-risk PCa. A similar result was found for the intermediate-risk group compared with the low-risk group (odds ratio, 1.225; p = .041). Conclusion: Biomarkers expressing the relative choline content and TV were significant parameters for the localization of PCa and could be helpful for determining the prognosis more accurately.

  7. 3T MRI neurography: preliminary experience

    Purpose. Demonstrate the advantages of the Ideal (Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation) sequence in the evaluation of peripheral nerves, brachial plexus and lumbar plexus, for the diagnosis of compression or entrapment neuropathies, non-entrapment neuropathies, and the underlying conditions. The Ideal sequence provides 4 types of images from a single acquisition, allowing uniform fat or water suppression and in phase/out of phase images of water, fat or a combination of both. Materials and Methods. This is a retrospective study, from January 2011 to June 2011. Eleven neurographies were performed on 3T MRI (HDX 3T, GE Healthcare, USA), with 8-channel phased array coils on sagittal and coronal planes, with 1.2-0 mm slices with no gap, axial 3D spoiled gradient recalled (SPGR) T , with 1-0-mm slice thickness with and without gadolinium injection and variable field of view (FOV) according to the nerve or plexus to explore. Results. We found 2 schwannomas (brachial plexus and sciatic nerve), 1 neuritis (compression to median nerve), 2 cases of multiple neurofibromas (lumbosacral plexus, sciatic nerve, brachial plexus), 3 traumatic neuromas (peroneal nerve) and 1 pseudomeningocele avulsion (brachial plexus), and 2 with no structural alterations (lumbosacral plexus and peroneal nerve). Conclusion. In this preliminary experience, the use of highresolution sequences in magnetic resonance imaging neurography studies provided excellent signal homogeneity, improving the recognition of the nerve structure and signal, the identification of anatomical variations, and causes of neuropathy, as well as the characterization of denervation changes of the affected muscle groups. (authors)

  8. Feasibility study of 3-T MR imaging of the skin

    The purpose of this study was to assess the quality of 3-T magnetic resonance (MR) imaging of the skin, to describe skin anatomy at 3 T and to discuss future prospects of skin MRI. A 7-cm single-element surface receiver coil was developed for our 3-T MRI system. Thin sections were obtained with a three-dimensional FIESTA acquisition sequence and a spin-echo T1-weighted sequence (SET1). Prospective analysis was performed twice by two radiologists independently. Thirty-six healthy volunteers were included and underwent MRI on the face and the calf. Image quality was assessed regarding visibility of skin layers and quantification of artefacts. High field strength MR enables imaging of the skin with a high spatial in-plane resolution (87-180 μm), the total examination lasting 15-20 min. Image quality was excellent for the calf (mean SET1 quality = 96%) with a high intra- and interobserver correlation (SET1 kappa coefficient concerning visibility of epidermis, dermis and hypodermis ≥ 0.84). Motion artefacts resulted in a small loss of quality and reproducibility for the face. In conclusion, 3-T MR allows high spatial resolution imaging of the skin and can potentially provide an accurate noninvasive means of analysing the skin. (orig.)

  9. 3T MR imaging of the brain.

    DeLano, Mark C; Fisher, Charles

    2006-02-01

    The advent of very high field clinical scanners that operate at 3T is taking structural and functional imaging to new levels and is reinvigorating clinical spectroscopy, fMR imaging, and noncontrast-enhanced methods of MRA. Most of the challenges that are related to 3T imaging have been addressed to facilitate routine clinical imaging. An awareness of the complexities that underlie the solutions to these challenges is important to the continued improvements to the 3T platform so that its maximal potential can be reached. The development of the multichannel-head coils and the improvement in the design of body coils, concurrently with the development of multichannel capabilities that enable parallel imaging, have benefited all field platforms. Perhaps the added value of parallel imaging has been greatest at 3T where the additional signal can be exploited. The definition of very high field is a moving target, and may be well on its way to 7.0 T, although in terms of the current clinical state of the art, 3T is our current reference. PMID:16530636

  10. Plasma system of the GOL-3T facility

    Arzhannikov, A. V.; Burdakov, A. V.; Burmasov, V. S.; Ivanov, I. A. [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation); Kuznetsov, S. A. [Novosibirsk State University (Russian Federation); Kuklin, K. N.; Mekler, K. I.; Polosatkin, S. V.; Postupaev, V. V., E-mail: V.V.Postupaev@inp.nsk.su; Rovenskikh, A. F.; Sinitsky, S. L.; Sklyarov, V. F. [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation)

    2015-11-15

    The plasma system and diagnostics of the new facility GOL-3T are described. This facility is the final result of the first stage in the deep upgrade of the GOL-3 multiple-mirror system, which has operated at the Budker Institute of Nuclear Physics since 1988. The upgrade project supposes creation of two new independent facilities at the site of GOL-3. The GOL-3T facility is intended to study the physics of beam—plasma interaction and generation of subterahertz electromagnetic radiation during the collective relaxation of a high-power relativistic electron beam with a duration of 5–10 μs. Studies on the physics of multiple-mirror plasma confinement in axisymmetric magnetic systems will be continued in a new range of experiment parameters at the second facility, named GOL-NB.

  11. Shielding benchmark test for JENDL-3T

    Hasegawa, Akira (Japan Atomic Energy Research Inst., Tokai, Ibaraki. Tokai Research Establishment)

    1988-03-01

    The results of the shielding benchmark tests for JENDL-3T (testing stage version of JENDL-3), performed by JNDC Shielding Sub-working group, are summarized. Especially, problems of total cross-section in MeV range for O, Na, Fe, revealed from the analysis of the Broomstick's experiment, are discussed in details. For the deep penetration profiles of Fe, which is very important feature in shielding calculation, ASPIS benchmark experiment is analysed and discussed. From the study overall applicability of JENDL-3T data for the shielding calculation is confirmed. At the same time some problems still remained are also pointed out. By the reflection of this feedback information applicability of JENDL-3, forth coming official version, will be greatly improved.

  12. Vanadium ions stimulate DNA synthesis in Swiss mouse 3T3 and 3T6 cells.

    Smith, J. B.

    1983-01-01

    Vanadyl sulfate and sodium orthovanadate in the concentration range between 5 and 50 microM are shown to be mitogenic for quiescent cultures of Swiss mouse 3T3 and 3T6 cells. The compounds caused a striking shift in the dose-response for the effect of serum on [3H]thymidine incorporation and DNA synthesis. In the absence of serum the effect of vanadium was greatly potentiated by insulin. Vanadium ions produced no more than additive increases in [3H]thymidine incorporation when combined with e...

  13. 3T MR-Guided Brachytherapy for Gynecologic Malignancies

    Kapur, Tina; Damato, Antonio; Schmidt, Ehud J; Viswanathan, Akila N; 10.1016/j.mri.2012.06.003

    2013-01-01

    Gynecologic malignancies are a leading cause of death in women worldwide. Standard treatment for many primary and recurrent gynecologic cancer cases includes a combination of external beam radiation, followed by brachytherapy. Magnetic Resonance Imaging (MRI) is benefitial in diagnostic evaluation, in mapping the tumor location to tailor radiation dose, and in monitoring the tumor response to treatment. Initial studies of MR-guidance in gynecologic brachtherapy demonstrate the ability to optimize tumor coverage and reduce radiation dose to normal tissues, resulting in improved outcomes for patients. In this article we describe a methodology to aid applicator placement and treatment planning for 3 Tesla (3T) MR-guided brachytherapy that was developed specifically for gynecologic cancers. This has been used in 18 cases to date in the Advanced Multimodality Image Guided Operating suite at Brigham and Women's Hospital. It is comprised of state of the art methods for MR imaging, image analysis, and treatment plann...

  14. A incompletude como virtude: interação de bebês na creche

    Vasconcelos Cleido Roberto Franchi e

    2003-01-01

    Full Text Available Neste artigo, mostramos algumas características dos processos interativos de crianças fundamentalmente no 1º ano de vida, através do estudo de alguns episódios de interação, recortados através do registro em vídeo, durante pesquisa em uma creche universitária, com crianças (7 a 14 meses brincando livremente. Num primeiro momento, mostramos a importância da definição de um conceito de interação que consiga captar e traduzir as características das interações ocorridas nessa faixa de idade. Também, mostramos a importância dos procedimentos metodológicos, usados para recortar o material empírico, na definição desse conceito de interação. Nessa faixa etária, os episódios de interação encontrados são bastante rápidos e desordenados e estas características são resultantes, em grande parte, do desajeitamento motor dos bebês. Esta incompletude motora, por sua vez, pode ser um elemento capaz de prolongar um episódio de interação entre crianças pequenas e/ou mesmo propiciar o surgimento de novos episódios de interação.

  15. A novel RF resonator for human-body MRI at 3 T

    Son, Hyeok-Woo; Cho, Young-Ki; Yoo, Hyoungsuk

    2014-03-01

    A square-slot-loaded (SSL) radio-frequency (RF) resonator using a microstrip transmission line (MTL) is designed for human-body magnetic resonance imaging (MRI) at 3 T MRI. The SSL RF resonator shows improved RF magnetic fields resulting in more homogenous fields near the center of the phantom than traditional RF resonators using MTL. A multichannel body coil using the SSL RF resonators is also simulated and provides improved parallel excitation performance. In addition, RF shimming for homogenization can be effectively controlled by adjusting the inputs to the eight resonators. Numerical results are obtained by using a spherical phantom and a realistic human-body model at 3 T to calculate the B {1/+} fields.

  16. Phosphatidylcholine induces apoptosis of 3T3-L1 adipocytes

    Li Hailan

    2011-12-01

    Full Text Available Abstract Background Phosphatidylcholine (PPC formulation is used for lipolytic injection, even though its mechanism of action is not well understood. Methods The viability of 3T3-L1 pre-adipocytes and differentiated 3T3-L1 cells was measured after treatment of PPC alone, its vehicle sodium deoxycholate (SD, and a PPC formulation. Western blot analysis was performed to examine PPC-induced signaling pathways. Results PPC, SD, and PPC formulation significantly decreased 3T3-L1 cell viability in a concentration-dependent manner. PPC alone was not cytotoxic to CCD-25Sk human fibroblasts at concentrations Conclusions PPC results in apoptosis of 3T3-L1 cells.

  17. Brain 1-H-MR spectroscopy in clinical neuroimaging at 3T

    Full text: Introduction: After more than 10 years of use, clinical neuroimaging spectroscopy has proven to be invaluable in the MRI assessment of several brain diseases. Materials and methods: The study is including more than 150 scans at 3T (unpublished material), and emphasizes, for every indication, a practical approach to brain MRS to achieve the optimal clinical impact. Results: The metabolic characterization of diverse brain lesions and pathological conditions is well established by spectroscopy studies at 1.5T, but recently, an increase in the number of 3T magnets has noticeably improved routine neuroimaging in general. For brain proton spectroscopy, the use of higher magnetic fields has been promising in terms of increasing the signal/noise ratio across the spectrum and widening the frequency bandwidth to allow clearer separation of peaks that are otherwise too close to each other at 1.5T, especially glutamate, glutamine and gamma-aminobutyric acid (GABA). The individual detection and quantification of these metabolites will add more details to the characterization of brain diseases, and allow the inclusion of more brain pathologies. Moreover, the ongoing advances in dedicated hardware and integrated software have led to more accurate and automated postprocessing, offering neuroradiologists a more user-friendly interface. Conclusion: This is an up to date review of the main clinical applications of brain proton MR spectroscopy that are potentially improved at 3T, taking into account the peculiarities of higher magnetic fields. It is based on both the literature and our own clinical experience, starting from February 2006 till January 2009 in Al Sabah Hospital, Kuwait. The study is including more than 150 scans at 3T (unpublished material), and emphasizes, for every indication, a practical approach to brain MRS to achieve the optimal clinical impact

  18. Topiramate effects lipolysis in 3T3-L1 adipocytes

    MARTINS, GABRIELA POLTRONIERI CAMPAGNARO; de Souza, Camila Oliveira; MARQUES, SCHEROLIN; LUCIANO, THAIS FERNANDES; DA SILVA PIERI, BRUNO LUIZ; Rosa, José César; da Silva, Adelino Sanchez Ramos; PAULI, JOSÉ RODRIGO; Cintra, Dennys Esper; Ropelle, Eduardo Rochete; Rodrigues, Bruno; DE LIRA, FABIO SANTOS; Souza, Claudio Teodoro de

    2015-01-01

    Studies have shown that topiramate (TPM)-induced weight loss can be dependent on the central nervous system (CNS). However, the direct action of TPM on adipose tissue has not been tested previously. Thus, the present study aimed to examine whether TPM modulates lipolysis in 3T3-L1. The 3T3-L1 cells were incubated in 50 µM TPM for 30 min. The β-adrenergic stimulator, isoproterenol, was used as a positive control. The release of lactate dehydrogenase, non-esterified fatty acid, glycerol and inc...

  19. Whole-body MR angiography with body coil acquisition at 3 T in patients with peripheral arterial disease using the contrast agent gadofosveset trisodium

    Nielsen, Yousef W; Eiberg, Jonas P; Løgager, Vibeke Berg; Hansen, Marc A; Schroeder, Torben V; Thomsen, Henrik S

    2009-01-01

    Whole-body magnetic resonance angiography (WB-MRA) at 3 T with body coil acquisition has not previously been investigated. In this study, WB-MRA was performed in this manner using the blood pool contrast agent gadofosveset trisodium.......Whole-body magnetic resonance angiography (WB-MRA) at 3 T with body coil acquisition has not previously been investigated. In this study, WB-MRA was performed in this manner using the blood pool contrast agent gadofosveset trisodium....

  20. Quantitation of glutamate in the brain by using MR proton spectroscopy at 1.5 T and 3 T; Quantitative Bestimmung von Glutamat im Hirn mithilfe der MR-Protonenspektroskopie bei 1,5 T und 3 T

    Gussew, A.; Rzanny, R.; Reichenbach, J.R. [AG Medizinische Physik, Inst. fuer Diagnostische und Interventionelle Radiologie, Friedrich Schiller Univ. Jena (Germany); Scholle, H.C. [Funktionsbereich Motorik, Pathophysiologie und Biomechanik, Klinik fuer Unfall-, Hand- und Wiederherstellungschirurgie, Friedrich Schiller Univ. Jena (Germany); Kaiser, W.A. [Inst. fuer Diagnostische und Interventionelle Radiologie, Friedrich Schiller Univ Jena (Germany)

    2008-08-15

    Purpose: the influence of different magnetic field strengths on the quantification of glutamate was experimentally investigated by means of in vitro and in vivo {sup 1}H-MR spectroscopic measurements at 1.5 T and 3 T. Materials and methods: in vitro {sup 1}H-MR measurements of aqueous solutions of NAA, glutamate, glutamine and GABA were performed on two clinical MR scanners at 1.5 T and 3 T using a single voxel PRESS sequence (TR/TE = 10000/30 ms). In vitro brain measurements were also performed at both field strengths using a PRESS 2D-{sup 1}H-CSI-sequence (TR/TE = 5000/30 ms) in 6 volunteers. Spectra at 1.5 T and 3 T were compared with respect to the overlap of the single compound spectra and the deviations between estimated and nominally adjusted concentrations. In vivo spectra at both field strengths were compared with respect to SNR{sub Glu}, line width and Cramer-Rao values of the estimated glutamate intensities by using the LCModel. For the thalamus, insular and parietal cortex mean Glu/tCr ratios were estimated and compared between 1.5 T and 3 T as well as with corresponding values in the literature. Results: in general, an improved separation of signal maxima was observed in the in vitro spectra at 3 T. Except for GABA, all in vitro concentrations estimated at 3 T revealed lower deviations from their adjusted nominal concentration compared to 1.5 T: NAA (1.5 T: -5.5%, 3 T: 0.7%), glutamate (1.5 T: -18.1%, 3 T: 12.3%), glutamine (1.5 T: 44.8%, 3 T: 9.2%), GABA (1.5 T: -24.8%, 3 T: 33.8%). The SNR of in vivo spectra at 3 T was nearly doubled compared to 1.5 T. The mean number of voxels with %SD{sub Glu} < 20 was distinctly lower at 1.5 T (53%) than at 3 T (80%). Estimated Glu/tCr ratios for thalamus, insular and parietal cortex lay in the upper range of the literature values. (orig.)

  1. Quantitation of glutamate in the brain by using MR proton spectroscopy at 1.5 T and 3 T

    Purpose: the influence of different magnetic field strengths on the quantification of glutamate was experimentally investigated by means of in vitro and in vivo 1H-MR spectroscopic measurements at 1.5 T and 3 T. Materials and methods: in vitro 1H-MR measurements of aqueous solutions of NAA, glutamate, glutamine and GABA were performed on two clinical MR scanners at 1.5 T and 3 T using a single voxel PRESS sequence (TR/TE = 10000/30 ms). In vitro brain measurements were also performed at both field strengths using a PRESS 2D-1H-CSI-sequence (TR/TE = 5000/30 ms) in 6 volunteers. Spectra at 1.5 T and 3 T were compared with respect to the overlap of the single compound spectra and the deviations between estimated and nominally adjusted concentrations. In vivo spectra at both field strengths were compared with respect to SNRGlu, line width and Cramer-Rao values of the estimated glutamate intensities by using the LCModel. For the thalamus, insular and parietal cortex mean Glu/tCr ratios were estimated and compared between 1.5 T and 3 T as well as with corresponding values in the literature. Results: in general, an improved separation of signal maxima was observed in the in vitro spectra at 3 T. Except for GABA, all in vitro concentrations estimated at 3 T revealed lower deviations from their adjusted nominal concentration compared to 1.5 T: NAA (1.5 T: -5.5%, 3 T: 0.7%), glutamate (1.5 T: -18.1%, 3 T: 12.3%), glutamine (1.5 T: 44.8%, 3 T: 9.2%), GABA (1.5 T: -24.8%, 3 T: 33.8%). The SNR of in vivo spectra at 3 T was nearly doubled compared to 1.5 T. The mean number of voxels with %SDGlu < 20 was distinctly lower at 1.5 T (53%) than at 3 T (80%). Estimated Glu/tCr ratios for thalamus, insular and parietal cortex lay in the upper range of the literature values. (orig.)

  2. 3 T MRI in paediatrics: Challenges and clinical applications

    Dagia, Charuta [Department of Medical Imaging, Royal Children' s Hospital and Murdoch Childrens Research Institute, Flemington Road, Parkville 3052 (Australia); Ditchfield, Michael [Department of Medical Imaging, Royal Children' s Hospital and Murdoch Childrens Research Institute, Flemington Road, Parkville 3052 (Australia)], E-mail: michael.ditchfield@rch.org.au

    2008-11-15

    3 T MRI is being increasingly performed for clinical purposes in paediatrics, primarily because of the potential to improve spatial and temporal resolution - these can assist in overcoming the unique anatomic, physiologic and behavioural challenges of imaging children. The increased spatial resolution improves the capacity to image small patients; with particular reference to smaller structures such as the inner ear, brachial plexus, biliary system and the vascular system. The challenges inherent to imaging at high field strength remain pertinent especially, the altered T1 contrast, artefacts (susceptibility, chemical shift and B1 inhomogeneity) and safety issues, including specific absorption rate - several of these are circumvented due to software and hardware advances, or by trade off of some of the increased signal. The above mentioned challenges also create opportunities at 3 T, with improvement in MR angiography, arterial spin labelling, functional MRI, susceptibility weighted imaging, and MR spectroscopy - all of which have distinctive applications in paediatrics. Whole body imaging also becomes more practical because of the capacity for faster scans. 3 T MRI has the potential to image all the systems in paediatrics. However, neonatal brain and paediatric spine imaging have specific challenges at 3 T. Several factors also limit cardiac imaging at present. Further improvements in coil technology and newer sequences may help overcome the challenges that remain.

  3. 3 T MRI in paediatrics: Challenges and clinical applications

    3 T MRI is being increasingly performed for clinical purposes in paediatrics, primarily because of the potential to improve spatial and temporal resolution - these can assist in overcoming the unique anatomic, physiologic and behavioural challenges of imaging children. The increased spatial resolution improves the capacity to image small patients; with particular reference to smaller structures such as the inner ear, brachial plexus, biliary system and the vascular system. The challenges inherent to imaging at high field strength remain pertinent especially, the altered T1 contrast, artefacts (susceptibility, chemical shift and B1 inhomogeneity) and safety issues, including specific absorption rate - several of these are circumvented due to software and hardware advances, or by trade off of some of the increased signal. The above mentioned challenges also create opportunities at 3 T, with improvement in MR angiography, arterial spin labelling, functional MRI, susceptibility weighted imaging, and MR spectroscopy - all of which have distinctive applications in paediatrics. Whole body imaging also becomes more practical because of the capacity for faster scans. 3 T MRI has the potential to image all the systems in paediatrics. However, neonatal brain and paediatric spine imaging have specific challenges at 3 T. Several factors also limit cardiac imaging at present. Further improvements in coil technology and newer sequences may help overcome the challenges that remain

  4. Visual evoked potential (VEP) measured by simultaneous 64-channel EEG and 3T fMRI.

    Bonmassar, G; Anami, K; Ives, J; Belliveau, J W

    1999-06-23

    We present the first simultaneous measurements of evoked potentials (EPs) and fMRI hemodynamic responses to visual stimulation. Visual evoked potentials (VEPs) were recorded both inside and outside the static 3T magnetic field, and during fMRI examination. We designed, constructed, and tested a non-magnetic 64-channel EEG recording cap. By using a large number of EEG channels it is possible to design a spatial filter capable of removing the artifact noise present when recording EEG/EPs within a strong magnetic field. We show that the designed spatial filter is capable of recovering the ballistocardiogram-contaminated original EEG signal. Isopotential plots of the electrode array recordings at the peak of the VEP response (approximately 100ms) correspond well with simultaneous fMRI observed activated areas of primary and secondary visual cortices. PMID:10501528

  5. MAGNET

    B. Curé

    The first phase of the commissioning ended in August by a triggered fast dump at 3T. All parameters were nominal, and the temperature recovery down to 4.5K was carried out in two days by the cryogenics. In September, series of ramps were achieved up to 3 and finally 3.8T, while checking thoroughly the detectors in the forward region, measuring any movement of and around the HF. After the incident of the LHC accelerator on September 19th, corrective actions could be undertaken in the forward region. When all these displacements were fully characterized and repetitive, with no sign of increments in displacement at each field ramp, it was possible to start the CRAFT, Cosmic Run at Four Tesla (which was in fact at 3.8T). The magnet was ramped up to 18.16kA and the 3 week run went smoothly, with only 4 interruptions: due to the VIP visits on 21st October during the LHC inauguration day; a water leak on the cooling demineralized water circuit, about 1 l/min, that triggered a stop of the cooling pumps, and resulte...

  6. 3 T MR cholangiopancreatography appearances of biliary ascariasis

    Ding, Z.X., E-mail: hangzhoudzx73@126.co [Department of Radiology, Zhejiang Provincial People' s Hospital, Hangzhou (China); Yuan, J.H. [Department of Radiology, Zhejiang Provincial People' s Hospital, Hangzhou (China); Chong, V. [Department of Diagnostic Imaging, National University Health System, Yong Loo Lin School of Medicine, National University of Singapore (Singapore); Zhao, D.J. [Department of Hepatobiliary Surgery, Zhejiang Provincial People' s Hospital, Hangzhou (China); Chen, F.H.; Li, Y.M. [Department of Radiology, Zhejiang Provincial People' s Hospital, Hangzhou (China)

    2011-03-15

    Aim: To evaluate the 3 T MR cholangiopancreatography (MRCP) appearances of biliary ascariasis. Materials and methods: Nine patients with a MRCP diagnosis of biliary ascariasis were reviewed. All patients had endoscopic retrograde cholangiopancreatography (ERCP) or surgical confirmation of the disease. Results: On thin-slab MRCP imaging, Ascaris worms are clearly demarcated within the biliary tree. All the identified worms demonstrated a characteristic three-parallel-lines appearance. The middle high-signal intensity line is sandwiched between two low-signal intensity lines and they are in turn surrounded by high signal bile. On thick-slab MRCP the worms also show the three-line sign but with less clarity. However, thick-slab MRCP has the advantage of providing three-dimensional ERCP-like images of the pancreaticobiliary system. Conclusion: The 'three-line' sign appears to be a characteristic sign of biliary ascariasis on 3 T MRCP.

  7. 3 T MR cholangiopancreatography appearances of biliary ascariasis

    Aim: To evaluate the 3 T MR cholangiopancreatography (MRCP) appearances of biliary ascariasis. Materials and methods: Nine patients with a MRCP diagnosis of biliary ascariasis were reviewed. All patients had endoscopic retrograde cholangiopancreatography (ERCP) or surgical confirmation of the disease. Results: On thin-slab MRCP imaging, Ascaris worms are clearly demarcated within the biliary tree. All the identified worms demonstrated a characteristic three-parallel-lines appearance. The middle high-signal intensity line is sandwiched between two low-signal intensity lines and they are in turn surrounded by high signal bile. On thick-slab MRCP the worms also show the three-line sign but with less clarity. However, thick-slab MRCP has the advantage of providing three-dimensional ERCP-like images of the pancreaticobiliary system. Conclusion: The 'three-line' sign appears to be a characteristic sign of biliary ascariasis on 3 T MRCP.

  8. Verapamil inhibits 3T3-L1 preadipocyte differentiation

    Nan Gu; Shi Liu; Xirong Guo; Li Fei; Xiaoqin Pan; Mei Guo; Ronghua Chen

    2009-01-01

    Objective: To investigate the effect of the calcium channel blocker verapamil on adipocyte differentiation and its mechanism of action. Methods: Preadipocytes from 3T3-L1 strain mouse embryos were cultured and differentiated into matured adipocytes in vitro. Verapamil was added to the culture medium in the concentration of 30 μmol/L on Day 0. Cell differentiation was determined by Oil Red O staining and marker gene mRNA expression was evaluated and compared by RT-PCR. The fluo-3/AM probe and laser scanning confocal microscopy were used to measure intracellular calcium concentrations. Results: ①The differentiation rate of 3T3-L1 preadipocytes exposed to verapamil was lower than that of untreated cells. ②Verapamil promoted the retention of pref-1 gene expression. Lipoprotein lipase expression in the verapamil group was significantly lower than that in the control group on Day 4, Day 6 and Day 8 (P 0.05). Conclusion: In 3T3-L1 preadipocytes verapamil significantly reduced adipocyte differentiation, down-regulated the mRNA expression of three marker genes for adipocytes differentiation, and prolonged the mRNA expression of an inhibitor of differentiation. The inhibitory effect of verapamil on differentiation may involve its role as a blocker of calcium influx in adipocytes.

  9. Interação de glyphosate com carfentrazone-ethyl Glyphosate - carfentrazone-ethyl interaction

    R.C. Werlang; Silva, A. A.

    2002-01-01

    Foi conduzido um experimento em condições controladas para determinar a interação do carfentrazone-ethyl em mistura no tanque com o herbicida glyphosate, no controle de seis espécies de plantas daninhas. Glyphosate aplicado isoladamente na dose de 720 g ha-1 foi eficaz no controle de Amaranthus hybridus (100%), Desmodium tortuosum (100%), Bidens pilosa (99%), Eleusine indica (96%), Digitaria horizontalis (100%) e Commelina benghalensis (93%) aos 21 DAA. Carfentrazone-ethyl aplicado isoladamen...

  10. Eight-channel transmit/receive body MRI coil at 3T.

    Vernickel, P; Röschmann, P; Findeklee, C; Lüdeke, K-M; Leussler, Ch; Overweg, J; Katscher, U; Grässlin, I; Schünemann, K

    2007-08-01

    Multichannel transmit magnetic resonance imaging (MR) systems have the potential to compensate for signal-intensity variations occurring at higher field strengths due to wave propagation effects in tissue. Methods such as RF shimming and local excitation in combination with parallel transmission can be applied to compensate for these effects. Moreover, parallel transmission can be applied to ease the excitation of arbitrarily shaped magnetization patterns. The implementation of these methods adds new requirements in terms of MRI hardware. This article describes the design of a decoupled eight-element transmit/receive body coil for 3T. The setup of the coil is explained, starting with standard single-channel resonators. Special focus is placed on the decoupling of the elements to obtain independent RF resonators. After a brief discussion of the underlying theory, the properties and limitations of the coil are outlined. Finally, the functionality and capabilities of the coil are demonstrated using RF measurements as well as MRI sequences. PMID:17654592

  11. MR imaging of the brachial plexus: comparison between 1.5-T and 3-T MR imaging: preliminary experience

    Tagliafico, Alberto; Neumaier, Carlo Emanuele; Calabrese, Massimo [National Institute for Cancer Research, Department of Radiology, Genova (Italy); Succio, Giulia; Serafini, Giovanni; Ghidara, Matteo [Santa Corona Hospital, Radiology Department, Savona (Italy); Martinoli, Carlo [Universita di Genova, Radiology Department, Genova (Italy)

    2011-06-15

    To compare 1.5-T and 3-T magnetic resonance (MR) imaging of the brachial plexus. Institutional review board approval and informed consent were obtained from 30 healthy volunteers and 30 consecutive patients with brachial plexus disturbances. MR was prospectively performed with comparable sequence parameters and coils with a 1.5-T and a 3-T system. Imaging protocols at both field strengths included T1-weighted turbo spin-echo (tSE) sequences and T2-weighed turbo spin-echo (tSE) sequences with fat saturation. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) between muscle and nerve were calculated for both field strengths. The visibility of brachial plexus nerve at various anatomic levels (roots, interscalene area, costoclavicular space, and axillary level) was analyzed with a four-point grading scale by two radiologists. MR imaging diagnoses and pathological findings were also compared qualitatively. SNR and CNRs were significantly higher on 3-T MR images than on 1.5-T MR images (Friedman test) for all sequences. Nerve visibility was significantly better on 3-T MR images than on 1.5-T MR images (paired sign test). Pathological findings (n = 30/30) were seen equally well with both field strengths. MR imaging diagnoses did not differ for the 1.5- and 3-T protocols. High-quality MR images of the brachial plexus can be obtained with 3-T MR imaging by using sequences similar to those used at 1.5-T MR imaging. In patients and healthy volunteers, the visibility of nerve trunks and cords at 3-T MR imaging appears to be superior to that at 1.5-T MR imaging. (orig.)

  12. MR imaging of the brachial plexus: comparison between 1.5-T and 3-T MR imaging: preliminary experience

    To compare 1.5-T and 3-T magnetic resonance (MR) imaging of the brachial plexus. Institutional review board approval and informed consent were obtained from 30 healthy volunteers and 30 consecutive patients with brachial plexus disturbances. MR was prospectively performed with comparable sequence parameters and coils with a 1.5-T and a 3-T system. Imaging protocols at both field strengths included T1-weighted turbo spin-echo (tSE) sequences and T2-weighed turbo spin-echo (tSE) sequences with fat saturation. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) between muscle and nerve were calculated for both field strengths. The visibility of brachial plexus nerve at various anatomic levels (roots, interscalene area, costoclavicular space, and axillary level) was analyzed with a four-point grading scale by two radiologists. MR imaging diagnoses and pathological findings were also compared qualitatively. SNR and CNRs were significantly higher on 3-T MR images than on 1.5-T MR images (Friedman test) for all sequences. Nerve visibility was significantly better on 3-T MR images than on 1.5-T MR images (paired sign test). Pathological findings (n = 30/30) were seen equally well with both field strengths. MR imaging diagnoses did not differ for the 1.5- and 3-T protocols. High-quality MR images of the brachial plexus can be obtained with 3-T MR imaging by using sequences similar to those used at 1.5-T MR imaging. In patients and healthy volunteers, the visibility of nerve trunks and cords at 3-T MR imaging appears to be superior to that at 1.5-T MR imaging. (orig.)

  13. Incidental pineal cysts in children who undergo 3-T MRI

    Pineal cysts, both simple and complex, are commonly encountered in children. More cysts are being detected with MR technology; however, nearly all pineal cysts are benign and require no follow-up. To discover the prevalence of pineal cysts in children at our institution who have undergone high-resolution 3-T MRI. We retrospectively reviewed 100 consecutive 3-T brain MRIs in children ages 1 month to 17 years (mean 6.8 ± 5.1 years). We evaluated 3-D volumetric T1-W imaging, axial T2-W imaging, axial T2-W FLAIR (fluid attenuated inversion recovery) and coronal STIR (short tau inversion recovery) sequences. Pineal parenchymal and cyst volumes were measured in three planes. Cysts were analyzed for the presence and degree of complexity. Pineal cysts were present in 57% of children, with a mean maximum linear dimension of 4.2 mm (range 1.5-16 mm). Of these cysts, 24.6% showed thin septations or fluid levels reflecting complexity. None of the cysts demonstrated complete T2/FLAIR signal suppression. No cyst wall thickening or nodularity was present. There was no significant difference between the ages of children with and without cysts. Cysts were more commonly encountered in girls than boys (67% vs. 52%; P = 0.043). There was a slight trend toward increasing pineal gland volume with age. Pineal cysts are often present in children and can be incidentally detected by 3-T MRI. Characteristic-appearing pineal cysts in children are benign, incidental findings, for which follow-up is not required if there are no referable symptoms or excessive size. (orig.)

  14. Incidental pineal cysts in children who undergo 3-T MRI

    Whitehead, Matthew T. [University of Tennessee Health Science Center, Department of Radiology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); Le Bonheur Children' s Hospital, Department of Radiology, Memphis, TN (United States); Oh, Christopher C. [University of Tennessee Health Science Center, Department of Radiology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); Choudhri, Asim F. [University of Tennessee Health Science Center, Department of Radiology, Memphis, TN (United States); Le Bonheur Children' s Hospital, Le Bonheur Neuroscience Institute, Memphis, TN (United States); University of Tennessee Health Science Center, Department of Neurosurgery, Memphis, TN (United States)

    2013-12-15

    Pineal cysts, both simple and complex, are commonly encountered in children. More cysts are being detected with MR technology; however, nearly all pineal cysts are benign and require no follow-up. To discover the prevalence of pineal cysts in children at our institution who have undergone high-resolution 3-T MRI. We retrospectively reviewed 100 consecutive 3-T brain MRIs in children ages 1 month to 17 years (mean 6.8 {+-} 5.1 years). We evaluated 3-D volumetric T1-W imaging, axial T2-W imaging, axial T2-W FLAIR (fluid attenuated inversion recovery) and coronal STIR (short tau inversion recovery) sequences. Pineal parenchymal and cyst volumes were measured in three planes. Cysts were analyzed for the presence and degree of complexity. Pineal cysts were present in 57% of children, with a mean maximum linear dimension of 4.2 mm (range 1.5-16 mm). Of these cysts, 24.6% showed thin septations or fluid levels reflecting complexity. None of the cysts demonstrated complete T2/FLAIR signal suppression. No cyst wall thickening or nodularity was present. There was no significant difference between the ages of children with and without cysts. Cysts were more commonly encountered in girls than boys (67% vs. 52%; P = 0.043). There was a slight trend toward increasing pineal gland volume with age. Pineal cysts are often present in children and can be incidentally detected by 3-T MRI. Characteristic-appearing pineal cysts in children are benign, incidental findings, for which follow-up is not required if there are no referable symptoms or excessive size. (orig.)

  15. S3T working group. Report 1: group aims

    The work group S3T which is aimed to designing and developing devices using unconventional holographic optics is presented. These devices find applications that are classified here in four items high resolution spectrometers, high definition imaging, high flux devices, metrology and interferometry. The problems to solve and the aims of the group in each of these cases are presented. Three synthesis of lectures are in this report. The main one concerns stigmatism conditions of concave holographic gratings used in normal incidence. This new process of focusing is very interesting for hot plasma diagnostics

  16. 3T MRI in evaluation of asbestos-related thoracic diseases – preliminary results

    3T high-field magnetic resonance imaging (MRI) scanners have recently become available for the clinical use and are being increasingly applied in the field of whole-body imaging and chest imaging as well. The aim of this study was to evaluate the diagnostic potential of 3 T MRI as a complementary imaging modality to CT in detecting the pathological changes of asbestos-related thoracic diseases. Fifteen patients with the asbestos-related thoracic disease were scheduled for 3T MRI. Five had a benign form of the disease and 10 had malignant pleural mesothelioma (MPM). From the patients with a benign form of the disease their last CT examination in digital form was acquired and patients with MPM were scheduled for CT examination with contrast media. The protocol of MR imaging consists of T2-weighted cardiac-gated breath-hold turbo spin echo (TSE) sequences in coronal, sagittal and axial plane and T1-weighted cardiac-gated breath-hold TSE black blood in axial plane. In T2-weighted sequences in axial plane, fat saturation was also used. CT examinations were obtained with the administration of the contrast medium from lung apices to the lower end of the liver. Images of 5 mm (mediastinum window) and 3 mm (lung window) in axial plan were reconstructed. MRI signal intensity of lesions and adjacent muscles on Syngo MultiModality Work Place were measured. Compared to muscles pleural plaques appeared hypo-intense to iso-intense on T1 weighted images (in 100%) and also hypo-intense on T2 fs-weighted images (in 100%). MPM appeared inhomogeneous hypo-intense to iso-intense on T1-weighted and hyperintense on T2 fs-weighted images in all patients (100%). These preliminary results pointed out that MRI was equal or even better compared with CT examination for detecting possible malignant potential of pleural changes in the asbestos-related pleural disease, using signal intensity measurements of T2 fs-weighted images. The 3T MRI enabled the accurate determination of chest pathology

  17. Clinical study of T3/T4 laryngeal carcinoma

    A total of 72 consecutive laryngeal carcinoma patients at stage T3 or T4 were studied. The laryngeal cancer patients were treated first with concurrent chemoradiotherapy (40 Gy) in our department. Patients with residual disease subsequently underwent curative surgery, and chemoradiotherapy was continued to 70 Gy for those without residual disease. The three-year disease-specific-free survival (DSS) rates in patients with supraglottic, glottic and subglottic tumors were 58%, 71% and 100%, respectively. In patients at stage T3/T4, the DSS rates were 75%/46%, and in those with/without lymph node metastasis (N+/N-) the rates were 56%/78%. The three-year laryngeal preservation (LP) rates in patients with supraglottic/glottic/subglottic tumors, T3/T4 and N+/N- tumors were 12%/26%/50%, 28%/4% and 13%/29%, respectively. The recurrence rate was 29%, of which 75% have died, primarily of distant metastasis. These DSS and LP rates were not significantly different among the three subregions and N stages, although those in patients at stage T4 were significantly low, compared with T3 patients (p=0.01). These results suggest that additional treatment may be required for patients with T4 disease. Chemotherapy after surgery is now considered for T4 patients. (author)

  18. Cannabidiol promotes browning in 3T3-L1 adipocytes.

    Parray, Hilal Ahmad; Yun, Jong Won

    2016-05-01

    Recruitment of the brown-like phenotype in white adipocytes (browning) and activation of existing brown adipocytes are currently being investigated as a means to combat obesity. Thus, a wide variety of dietary agents that contribute to browning of white adipocytes have been identified. The present study was designed to investigate the effects of cannabidiol (CBD), a major nonpsychotropic phytocannabinoid of Cannabis sativa, on induction of browning in 3T3-L1 adipocytes. CBD enhanced expression of a core set of brown fat-specific marker genes (Ucp1, Cited1, Tmem26, Prdm16, Cidea, Tbx1, Fgf21, and Pgc-1α) and proteins (UCP1, PRDM16, and PGC-1α). Increased expression of UCP1 and other brown fat-specific markers contributed to the browning of 3T3-L1 adipocytes possibly via activation of PPARγ and PI3K. In addition, CBD increased protein expression levels of CPT1, ACSL, SIRT1, and PLIN while down-regulating JNK2, SREBP1, and LPL. These data suggest possible roles for CBD in browning of white adipocytes, augmentation of lipolysis, thermogenesis, and reduction of lipogenesis. In conclusion, the current data suggest that CBD plays dual modulatory roles in the form of inducing the brown-like phenotype as well as promoting lipid metabolism. Thus, CBD may be explored as a potentially promising therapeutic agent for the prevention of obesity. PMID:27067870

  19. Correlation between 3 T apparent diffusion coefficient values and grading of invasive breast carcinoma

    Highlights: • Apparent diffusion coefficient is a quantitative parameter which reflects molecular water movement. • Grading is an independent prognostic factor which correlates with other histopathological features. • Apparent diffusion coefficient values were significantly different between G1 and G3 classes. - Abstract: Purpose: The aim of this study was to evaluate whether the apparent diffusion coefficient (ADC) provided by 3.0 T (3 T) magnetic resonance diffusion-weighted imaging (DWI) varied according to the grading of invasive breast carcinoma. Materials and methods: A total of 92 patients with 96 invasive breast cancer lesions were enrolled; all had undergone 3 T magnetic resonance imaging (MRI) for local staging. All lesions were confirmed by histological analysis, and tumor grade was established according to the Nottingham Grading System (NGS). MRI included both dynamic contrast-enhanced and DWI sequences, and ADC value was calculated for each lesion. ADC values were compared with NGS classification using the Mann–Whitney U and the Kruskal–Wallis H tests. Grading was considered as a comprehensive prognostic factor, and Rho Spearman test was performed to determine correlation between grading and tumor size, hormonal receptor status, HER2 expression and Ki67 index. Pearson's Chi square test was carried out to compare grading with the other prognostic factors. Results: ADC values were significantly higher in G1 than in G3 tumors. No significant difference was observed when G1 and G3 were compared with G2. Tumor size, hormonal receptor status, HER2 expression and Ki67 index correlated significantly with grading but there was a significant difference only between G1 and G3 related to the ER and PR status, HER2 expression and Ki67 index. There was no statistically significant difference in lesion size between the two groups. Conclusion: ADC values obtained on 3 T DWI correlated with low-grade (G1) and high-grade (G3) invasive breast carcinoma. 3

  20. Correlation between 3 T apparent diffusion coefficient values and grading of invasive breast carcinoma

    Cipolla, Valentina, E-mail: valentina.cipolla@yahoo.it [Department of Radiological Sciences, University of Rome “Sapienza”, Viale del Policlinico 155, 00161 Rome (Italy); Santucci, Domiziana; Guerrieri, Daniele; Drudi, Francesco Maria [Department of Radiological Sciences, University of Rome “Sapienza”, Viale del Policlinico 155, 00161 Rome (Italy); Meggiorini, Maria Letizia [Department of Gynaecological Sciences, University of Rome “Sapienza”, Viale del Policlinico 155, 00161 Rome (Italy); Felice, Carlo de [Department of Radiological Sciences, University of Rome “Sapienza”, Viale del Policlinico 155, 00161 Rome (Italy)

    2014-12-15

    Highlights: • Apparent diffusion coefficient is a quantitative parameter which reflects molecular water movement. • Grading is an independent prognostic factor which correlates with other histopathological features. • Apparent diffusion coefficient values were significantly different between G1 and G3 classes. - Abstract: Purpose: The aim of this study was to evaluate whether the apparent diffusion coefficient (ADC) provided by 3.0 T (3 T) magnetic resonance diffusion-weighted imaging (DWI) varied according to the grading of invasive breast carcinoma. Materials and methods: A total of 92 patients with 96 invasive breast cancer lesions were enrolled; all had undergone 3 T magnetic resonance imaging (MRI) for local staging. All lesions were confirmed by histological analysis, and tumor grade was established according to the Nottingham Grading System (NGS). MRI included both dynamic contrast-enhanced and DWI sequences, and ADC value was calculated for each lesion. ADC values were compared with NGS classification using the Mann–Whitney U and the Kruskal–Wallis H tests. Grading was considered as a comprehensive prognostic factor, and Rho Spearman test was performed to determine correlation between grading and tumor size, hormonal receptor status, HER2 expression and Ki67 index. Pearson's Chi square test was carried out to compare grading with the other prognostic factors. Results: ADC values were significantly higher in G1 than in G3 tumors. No significant difference was observed when G1 and G3 were compared with G2. Tumor size, hormonal receptor status, HER2 expression and Ki67 index correlated significantly with grading but there was a significant difference only between G1 and G3 related to the ER and PR status, HER2 expression and Ki67 index. There was no statistically significant difference in lesion size between the two groups. Conclusion: ADC values obtained on 3 T DWI correlated with low-grade (G1) and high-grade (G3) invasive breast carcinoma. 3

  1. Interações entre Antiparasitários e Alimentos

    Carina Duarte Venturini

    2014-01-01

    Full Text Available O uso, por vezes indiscriminado, de antiparasitários pode levar a consequências importantes na saúde do indivíduo, principalmente relacionadas a alterações no sistema gastrointestinal. As interações entre fármacos e nutrientes podem ocorrer quando um alimento ou nutriente altera a resposta esperada de um medicamento ou quando este interfere sobre o estado nutricional do indivíduo. Essa alteração da eficácia pode resultar em falha no tratamento ou até mesmo na toxicidade do fármaco. A fim de conhecer, identificar e prevenir interações indesejáveis entre antiparasitários e alimentos, o presente artigo de revisão aborda os principais fármacos e alimentos ou nutrientes envolvidos, bem como as consequências que tais interações podem acarretar ao indivíduo. O estado nutricional é de suma importância nas infecções parasitárias, pois é o determinante entre uma maior carga de parasitos ou a resistência total contra a infecção. De forma geral, indivíduos parasitados são inapetentes e emagrecidos, o que em crianças pode comprometer o desenvolvimento físico e intelectual. Portanto, o conhecimento e uma correta orientação médica, farmacêutica e nutricional levam a um tratamento bem sucedido.

  2. Clinical evaluation of single-shot and readout-segmented diffusion-weighted imaging in stroke patients at 3 T

    Morelli, John [Scott and White Memorial Hospital/Texas AandM Health Sciences Center, Radiology, Temple (United States); Porter, David [Siemens AG, Erlangen (Germany); Ai, Fei [Cancer Center of SUN YAT-SEN Univ., Radiology, Guangzhou (China)], e-mail: aifei1021@163.com [and others

    2013-04-15

    Background: Diffusion-weighted imaging (DWI) magnetic resonance imaging (MRI) is most commonly performed utilizing a single-shot echo-planar imaging technique (ss-EPI). Susceptibility artifact and image blur are severe when this sequence is utilized at 3 T. Purpose: To evaluate a readout-segmented approach to DWI MR in comparison with single-shot echo planar imaging for brain MRI. Material and Methods: Eleven healthy volunteers and 14 patients with acute and early subacute infarctions underwent DWI MR examinations at 1.5 and 3T with ss-EPI and readout-segmented echo-planar (rs-EPI) DWI at equal nominal spatial resolutions. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) calculations were made, and two blinded readers ranked the scans in terms of high signal intensity bulk susceptibility artifact, spatial distortions, image blur, overall preference, and motion artifact. Results: SNR and CNR were greatest with rs-EPI (8.1 {+-} 0.2 SNR vs. 6.0 {+-} 0.2; P <10{sup -4} at 3T). Spatial distortions were greater with single-shot (0.23 {+-} 0.03 at 3T; P <0.001) than with rs-EPI (0.12 {+-} 0.02 at 3T). Combined with blur and artifact reduction, this resulted in a qualitative preference for the readout-segmented scans overall. Conclusion: Substantial image quality improvements are possible with readout-segmented vs. single-shot EPI - the current clinical standard for DWI - regardless of field strength (1.5 or 3 T). This results in improved image quality secondary to greater real spatial resolution and reduced artifacts from susceptibility in MR imaging of the brain.

  3. Uma arquitetura para coordenar a interação de agentes na Internet

    Cazella, Silvio César; Alvares, Luis Otávio Campos

    1997-01-01

    O grande salto tecnológico ocorrido nos últimos decênios em áreas como a informática e as telecomunicações já começa a causar uma verdadeira revolução social. Com o advento da Internet, a possibilidade de substituir a presença física de pessoas por assistentes inteligentes ou agentes é uma realidade que começa a tomar forma. O objetivo principal deste trabalho é apresentar como deve ser feita a interação entre agentes, nas sociedades de agentes dentro da Internet. Para tanto, é apresentada...

  4. Interações entre Antiparasitários e Alimentos

    Carina Duarte Venturini; Paula Engroff; Luísa Scheer Ely; Tiana Tasca; Geraldo Attilio De Carli

    2014-01-01

    O uso, por vezes indiscriminado, de antiparasitários pode levar a consequências importantes na saúde do indivíduo, principalmente relacionadas a alterações no sistema gastrointestinal. As interações entre fármacos e nutrientes podem ocorrer quando um alimento ou nutriente altera a resposta esperada de um medicamento ou quando este interfere sobre o estado nutricional do indivíduo. Essa alteração da eficácia pode resultar em falha no tratamento ou até mesmo na toxici...

  5. Interação social entre agentes em ambientes de recursos limitados

    Bastos, Hélder Filipe de Oliveira

    2015-01-01

    O estudo da interação social entre agentes inteligentes é cada vez mais um tema central da investigação em inteligência artificial. Atualmente inseridos numa realidade onde veículos navegam autonomamente, não é difícil imaginar cenários onde estas máquinas poderão trabalhar em conjunto, maximizando as suas capacidades e tornando-se mais eficientes na utilização de recursos e na concretização dos respetivos objetivos. Devido à elevada complexidade computacional dos seus processos internos, ...

  6. Magnetizing of permanent magnets using HTS bulk magnets

    Oka, Tetsuo; Muraya, Tomoki; Kawasaki, Nobutaka; Fukui, Satoshi; Ogawa, Jun; Sato, Takao; Terasawa, Toshihisa

    2012-01-01

    A demagnetized Nd-Fe-B permanent magnet was scanned just above the magnetic pole which contains the HTS bulk magnet generating a magnetic field of 3.27 T. The magnet sample was subsequently found to be fully magnetized in the open space of the static magnetic fields. We examined the magnetic field distributions when the magnetic poles were scanned twice to activate the magnet plate inversely with various overlap distances between the tracks of the bulk magnet. The magnetic field of the "rewritten" magnet reached the values of the magnetically saturated region of the material, showing steep gradients at the border of each magnetic pole. As a replacement for conventional pulse field magnetizing methods, this technique is proposed to expand the degree of freedom in the design of electromagnetic devices, and is proposed as a novel practical method for magnetizing rare-earth magnets, which have excellent magnetic performance and require intense fields of more than 3 T to be activated.

  7. The value of high-field MRI (3 T) in the assessment of sellar lesions

    Pinker, K. [Department of Diagnostic Radiology, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Ba-Ssalamah, A. [Department of Diagnostic Radiology, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Wolfsberger, S. [Department of Neurosurgery, Medical University Vienna (Austria); Mlynarik, V. [Department of Diagnostic Radiology, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Knosp, E. [Department of Neurosurgery, Medical University Vienna (Austria); Trattnig, S. [Department of Diagnostic Radiology, Medical University Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria)]. E-mail: siegfried.trattnig@univie.ac.at

    2005-06-01

    The aim of this study was the evaluation of the normal sellar anatomy in vitro and in vivo with high-field MRI and its application in the diagnosis of sellar pathologies in comparison to standard MRI. All high-field MR images were obtained using a 3 T Bruker Medspec 30/80 Scanner with a head birdcage transmit/receive coil and an actively shielded gradient system with a maximum gradient strength of 45 mT/m. Firstly an in vitro study of the sella turcica was performed to depict normal pituitary and sellar anatomy at high field. After a pilot-study this sequence-protocol was established: A RARE sequence (TR/TE = 7790/19 ms; matrix size, 512 x 512; RARE factor = 8, FOV, 200 mm) was used for T2-weighted coronal, axial and sagittal images. A 3D gradient echo sequence with magnetization-preparation (MP-RAGE, TR/TE/TI 33.5/7.6/800 ms, matrix size, 512 x 512; FOV, 200 mm, effective slice thickness, 1.88 mm; 3 averages) was used for acquisition of T1-weighted pre- and post-contrast images. Between January 2002 and March 200458 patients were enrolled in this study. Seven patients were examined for suspected microadenoma and in 51 patients 3T MRI was used to obtain additional information about the sellar lesion already known to be present from standard MRI. In 21 cases the accuracy of the imaging findings was assessed afterwards by comparison with intraoperative findings. The infiltration of the medial cavernous sinus wall was suspected on standard MRI on 15 sides (47%), on high-field MRI on 9 sides (28%) and could be verified by intraoperative findings on 6 sides (19%). Accordingly, sensitivity to infiltration was 83% for 3 T and 67% for standard MRI. Specificity was 84% for 3 T and 58% for standard MRI. Moreover, high-field MRI revealed microadenomas in 7 patients with a median diameter of 4 mm (range 2-9 mm). The segments of the cranial nerves were seen as mean 4 hypointense spots (range 2-5 spots) on high-field MRI in contrast to 3 spots (range 0-4 spots) on standard MRI

  8. NMR scanning of the pelvis: initial experience with a 0.3 T system

    Pelvic NMR scans were obtained on 29 patients using a 0.3 T superconducting magnet system. Pathologies studied included four bladder carcinomas, four prostatic carcinomas, four ovarian dermoid cysts, three ovarian cysts, three endometrial carcinomas, two endometriomas, and one each of serous cystadenoma of the ovary, benign prostatic hypertrophy, pelvic hematoma, and undifferentiated sarcoma. NMR is a very promising method for characterizing pelvic masses and in staging pelvic malignancies. It can show primary tumors of the prostate, bladder, and uterus and reveals tumor extension into pelvic fat. The pelvis is particularly well suited to NMR scanning because of the abundant natural contrast provided by pelvic fat and by urine in the bladder and gas in the bowel. There is also less motion blurring than in the upper abdomen and chest because there is relatively little respiratory motion of pelvic organs. Various pulse sequences were used in scanning the pelvis; their relative merits are discussed

  9. Application of stereological methods to estimate post-mortem brain surface area using 3T MRI

    Furlong, Carolyn; García-Fiñana, Marta; Puddephat, Michael;

    2013-01-01

    The Cavalieri and Vertical Sections methods of design based stereology were applied in combination with 3 tesla (i.e. 3T) Magnetic Resonance Imaging (MRI) to estimate cortical and subcortical volume, area of the pial surface, area of the grey-white matter boundary, and thickness of the cerebral...... cortex. The material comprises eight human cadaveric cerebri which had been separated into sixteen cerebral hemisphere specimens prior to embedding in agar gel. The results from MRI were compared with corresponding 'gold standard' values subsequently obtained by application of the same methodology using...... physical sectioning of the specimens. 95% agreement intervals revealed poor agreement between MR imaging and physical sectioning, specially for pial surface and thickness, as well as cerebral cortex and subcortex volumes. On average, pial surface area was estimated to be almost half the extent using MRI...

  10. Apparent diffusion coefficients of normal uterus in premenopausal women with 3 T MRI

    Aim: To investigate the apparent diffusion coefficient (ADC) values of the normal uterine cervical zonal structures (cervical epithelium, the junctional zone, and myometrium) during different phases of the menstrual cycle among premenopausal women in different age groups. Materials and methods: Seventy healthy women, who were divided into three age groups (group A, 24 women in their twenties; group B, 23 women in their thirties; group C, 23 women in their forties), underwent 3 T magnetic resonance imaging (MRI) with T2-weighted and diffusion-weighted imaging (DWI) during the mid-proliferative and the mid-secretory phases. Results: The ADC values of each cervical zonal structure were significantly different from one another (p 0.05). Conclusion: ADC values of normal cervical epithelium and the junctional zone change with different phases of the menstrual cycle, which should be taken into consideration when early cervical disease is detected, when monitoring treatment response, and differentiating early tumour recurrence

  11. Interação medicamentosa de venlafaxina com captopril Drug interaction of velanfaxine with captopril

    Douglas D Sucar

    2000-09-01

    Full Text Available O autor descreve um caso de interação medicamentosa, em uma senhora de 53 anos de idade, com diagnóstico de depressão e de hipertensão arterial. Com níveis pressóricos estáveis, em conseqüência de um regime dietético e de uso do captopril -anti-hipertensivo inibidor da enzima de conversão da angiotensina -, passou a apresentar constantes descompensações do seu quadro clínico, com elevações da tensão arterial (TA, logo após a introdução da venlafaxina no seu esquema terapêutico. Esse medicamento é um potente antidepressivo de última geração, que atua no sistema nervoso central (SNC, inibindo a recaptação de serotonina e noradrenalina. Demonstra a interação pelo monitoramento da TA e aplicação do instrumento de Naranjo. Descreve as condições clínicas gerais da paciente e sua evolução, e discute os mecanismos prováveis que conduziram a interação pela hipótese que envolve o aumento de noradrenalina nos terminais sinápticos, o sistema renina-angiotensina e a bradicinina, concluindo que a venlafaxina agiu como antagonista, de modo indireto, sobre os efeitos hipotensores do captopril.This is a case report of drug interaction in a 53 year-old woman diagnosed with depression and arterial hypertension. As a result of a low-salt diet and the use of the captopril (an antihypertensive that inhibites the angiotensine conversion enzyme, her pressoric levels had been stable till venlafaxine was introduced in her therapeutic regime. By then she started to show an unstableclinical condition, with elevations of her arterial blood pressure (ABP. Venlafaxine is a potent last generation antidepressant drug, acting in the central nervous system (CNS by inhibiting the reuptake of serotonine and noradrenaline. The drug interaction is demonstrated by monitoring the ABP and using the Naranjo's tool.The patient's general clinical conditions and herprogress are presented, and the hypothetical mechanisms to the interaction, such as

  12. Analysis of the reduced growth factor dependency of simian virus 40-transformed 3T3 cells.

    Powers, S; Fisher, P B; Pollack, R.

    1984-01-01

    We have measured in a defined serum-free medium the platelet-derived growth factor (PDGF) and insulin requirements of normal Swiss 3T3 cells, simian virus 40-transformed 3T3 cells, and partial revertants of simian virus 40-transformed 3T3 cells. Swiss 3T3 cells displayed strong requirements for both PDGF and insulin. Both of these requirements were significantly diminished in simian virus 40-transformed 3T3 cells. Analysis of the PDGF and insulin requirements of the revertants indicated that ...

  13. 3T磁共振氢质子波谱在骨与软组织肿瘤诊断中的应用价值%Application Value of 3T 1H-Magnetic Resonance Spectroscopy in Diagnosing Tumors of Bone and Soft Tissue

    齐滋华; 李传福; 马祥兴; 李振峰; 张凯; 于德新

    2011-01-01

    Objective To study benign and malignant bone and soft tissue tumors with H-magnetic resonance spectroscopy ( H-MRS) at 3 Tesla MR scanner and assess the value of H-MRS in diagnosing bone and soft tissue tumors and distinguishing benign from malignant tumors. Methods Totally 49 patients with clinically and pathologically confirmed bone and soft tissue tumors were enrolled in this study. H-MRS was performed before treatment with point-resolved spectroscopy sequence. The imaging characteristics of 'H-MRS for bone and soft tissue tumors were observed and the possible differences between benign and malignant tumors was compared. Since spectra were directly found under single-voxel proton MRS brain examination, the peak height of choline containing compounds ( Cho) opposite to the creatine ( Cr) and the Cho peak were observed, and then the malignancies of the tumors were judged. Cho/Cr value was calculated and used to distinguishing benign tumors from malignancies. Results 'H-MRS spectra of bone and soft tissue tumors were different from those of the normal muscles, and such difference also existed between benign and malignant tumors. The Cho\\peak disappeared or was extremely low among benign tumors. The Cho/Cr values of malignant tumors and benign tumors were 3. 13 ±0. 9 and 1. 34 ± 1. 02 , respectively ( P = 0. 02). Using 1.79 as the threshold value, the Cho/Cr value had sensitivity, specificity, and accuracy of 94% , 80% , and 90% , respectively, in diagnosing malignancies. Conclusions The increased Cho level, as measured by ' H-MRS, is related with the bone and soft tissue malignant tumor. Cho/Cr value is useful in distinguishing benign tumors from malignancies. H-MRS can be an important supplement to the conventional magnetic resonance imaging.%目的 应用超高场3T磁共振机对良、恶性骨与软组织肿瘤进行磁共振氢质子波谱(1 H-MRS)研究,探讨1 H-MRS对骨与软组织肿瘤的成像特点,及对良、恶性骨与软组织肿瘤鉴

  14. 3 T MRI uterine peristalsis: Comparison of symptomatic fibroid patients versus controls

    Aim: To compare uterine peristalsis between symptomatic fibroid patients and normal subjects and to determine the possible effect of fibroid characteristics on uterine peristalsis at high-field magnetic resonance imaging (MRI). Materials and methods: The present study included 20 symptomatic fibroid patients (age range 39–53 years) and 20 normal subjects (age range 19–46 years). MRI images were obtained during the peri-ovulatory phase using 3 T MRI using a sagittal T2 turbo spin-echo sequence and a half-Fourier acquisition single-shot turbo spin-echo sequence for display on cine mode. Two radiologists independently evaluated the images for the presence of uterine peristalsis by confidence level. In cases where peristalsis was present, the images were also evaluated for peristalsis frequency and direction. For fibroid patients, uterine and index fibroid volume, fibroid burden and index fibroid location were also recorded. Results: Uterine peristalsis was significantly decreased in symptomatic fibroid patients compared with normal controls (p < 0.01). Peristalsis frequency in fibroid patients was also lower than in normal subjects. Direction of peristalsis was cervix-to-fundus for the majority of fibroid patients and controls. There was no significant relationship between fibroid characteristics, such as uterine volume, index fibroid volume, index fibroid location, and fibroid number in fibroid patients with, and fibroid patients without peristalsis. Conclusion: In women with symptomatic fibroids, the presence of uterine peristalsis is significantly decreased compared to normal controls on 3 T cine MRI. The presence of fibroids appears to disturb the normal conduction of uterine peristalsis and may interfere with fluid (e.g., menses, sperm) transport

  15. In-bore setup and software for 3T MRI-guided transperineal prostate biopsy

    Tokuda, Junichi; Tuncali, Kemal; Iordachita, Iulian; Song, Sang-Eun; Fedorov, Andriy; Oguro, Sota; Lasso, Andras; Fennessy, Fiona M.; Tempany, Clare M.; Hata, Nobuhiko

    2012-09-01

    MRI-guided prostate biopsy in conventional closed-bore scanners requires transferring the patient outside the bore during needle insertion due to the constrained in-bore space, causing a safety hazard and limiting image feedback. To address this issue, we present our custom-made in-bore setup and software to support MRI-guided transperineal prostate biopsy in a wide-bore 3 T MRI scanner. The setup consists of a specially designed tabletop and a needle-guiding template with a Z-frame that gives a physician access to the perineum of the patient at the imaging position and allows the physician to perform MRI-guided transperineal biopsy without moving the patient out of the scanner. The software and Z-frame allow registration of the template, target planning and biopsy guidance. Initially, we performed phantom experiments to assess the accuracy of template registration and needle placement in a controlled environment. Subsequently, we embarked on our clinical trial (N = 10). The phantom experiments showed that the translational errors of the template registration along the right-left (RP) and anterior-posterior (AP) axes were 1.1 ± 0.8 and 1.4 ± 1.1 mm, respectively, while the rotational errors around the RL, AP and superior-inferior axes were (0.8 ± 1.0)°, (1.7 ± 1.6)° and (0.0 ± 0.0)°, respectively. The 2D root-mean-square (RMS) needle-placement error was 3 mm. The clinical biopsy procedures were safely carried out in all ten clinical cases with a needle-placement error of 5.4 mm (2D RMS). In conclusion, transperineal prostate biopsy in a wide-bore 3T scanner is feasible using our custom-made tabletop setup and software, which supports manual needle placement without moving the patient out of the magnet.

  16. In-bore setup and software for 3T MRI-guided transperineal prostate biopsy

    MRI-guided prostate biopsy in conventional closed-bore scanners requires transferring the patient outside the bore during needle insertion due to the constrained in-bore space, causing a safety hazard and limiting image feedback. To address this issue, we present our custom-made in-bore setup and software to support MRI-guided transperineal prostate biopsy in a wide-bore 3 T MRI scanner. The setup consists of a specially designed tabletop and a needle-guiding template with a Z-frame that gives a physician access to the perineum of the patient at the imaging position and allows the physician to perform MRI-guided transperineal biopsy without moving the patient out of the scanner. The software and Z-frame allow registration of the template, target planning and biopsy guidance. Initially, we performed phantom experiments to assess the accuracy of template registration and needle placement in a controlled environment. Subsequently, we embarked on our clinical trial (N = 10). The phantom experiments showed that the translational errors of the template registration along the right–left (RP) and anterior–posterior (AP) axes were 1.1 ± 0.8 and 1.4 ± 1.1 mm, respectively, while the rotational errors around the RL, AP and superior–inferior axes were (0.8 ± 1.0)°, (1.7 ± 1.6)° and (0.0 ± 0.0)°, respectively. The 2D root-mean-square (RMS) needle-placement error was 3 mm. The clinical biopsy procedures were safely carried out in all ten clinical cases with a needle-placement error of 5.4 mm (2D RMS). In conclusion, transperineal prostate biopsy in a wide-bore 3T scanner is feasible using our custom-made tabletop setup and software, which supports manual needle placement without moving the patient out of the magnet. (paper)

  17. Multiparametric 3T MRI in the evaluation of intraglandular prostate cancer: correlation with histopathology

    Prostate cancer is common and may be treated immediately or managed conservatively by observation. We sought to determine how reliable multiparametric MRI is in the detection of intraprostatic prostate cancer and what role it has in risk stratification. The histology from 38 whole mount prostate specimens was compared with preoperative multiparametric 3T MRI studies with an endorectal receiver coil in place. T1-weighted, T2-weighted, diffusion (b values 50 400 800), perfusion (Ve, Kep, Ktrans, area under the curve) and proton spectroscopic sequences were used. For cancers greater than 0.5cc, the detection rate for combined T2-weighted imaging and diffusion-weighted imaging (DWI) was 85%. For cancers 0.1cc - 0.5cc, the sensitivity was 52%. Per patient, false positive rate was 50% for combined T2-weighted imaging and DWI. Perfusion imaging had a sensitivity of 70% for tumours greater than 0.5cc but had a per patient false positive rate of 80% influenced by benign prostatic hypertrophy. In only 15 patients could a satisfactory spectroscopy study be obtained. Weak correlation was found between the Gleason score and tumour size (r=0.51), apparent diffusion coefficient (ADC) (r=-0.30) and (choline + creatine)/citrate ratio(r=0.41). T2-weighted imaging and DWI in combination were the best strategy for detecting prostate cancer and had a sensitivity of 85% for detecting lesions greater than 0.5cc. At 3T, an ADC threshold of between 1100 - 1200.106mm2/s was optimal for diagnosing prostate cancer. There are significant limitations in the use of perfusion and spectroscopy to detect prostate cancer. Magnetic resonance imaging-targeted or guided biopsy post-MRI imaging is likely to be needed in some patients to assist risk stratification.

  18. High-resolution 3-T MR neurography of peroneal neuropathy

    Chhabra, Avneesh; Faridian-Aragh, Neda; Chalian, Majid; Soldatos, Theodoros; Thawait, Shrey K. [Johns Hopkins Hospital, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Williams, Eric H. [Johns Hopkins Hospital, Department of Plastic Surgery, Baltimore, MD (United States); Dellon Institute for Peripheral Nerve Surgery, Baltimore, MD (United States); Andreisek, Gustav [University Hospital Zurich, Institute for Diagnostic Radiology, Department of Medical Radiology, Zurich (Switzerland)

    2012-03-15

    The common peroneal nerve (CPN), a major terminal branch of the sciatic nerve, can be subject to a variety of pathologies, which may affect the nerve at any level from the lumbar plexus to its distal branches. Although the diagnosis of peripheral neuropathy is traditionally based on a patient's clinical findings and electrodiagnostic tests, magnetic resonance neurography (MRN) is gaining an increasing role in the definition of the type, site, and extent of peripheral nerve disorders. Current high-field MR scanners enable high-resolution and excellent soft-tissue contrast imaging of peripheral nerves. In the lower extremities, MR neurography has been employed in the demonstration of the anatomy and pathology of the CPN, as well as in the detection of associated secondary muscle denervation changes. This article reviews the normal appearance of the CPN as well as typical pathologies and abnormal findings at 3.0-T MR neurography of the lower extremity. (orig.)

  19. High-resolution 3-T MR neurography of peroneal neuropathy

    The common peroneal nerve (CPN), a major terminal branch of the sciatic nerve, can be subject to a variety of pathologies, which may affect the nerve at any level from the lumbar plexus to its distal branches. Although the diagnosis of peripheral neuropathy is traditionally based on a patient's clinical findings and electrodiagnostic tests, magnetic resonance neurography (MRN) is gaining an increasing role in the definition of the type, site, and extent of peripheral nerve disorders. Current high-field MR scanners enable high-resolution and excellent soft-tissue contrast imaging of peripheral nerves. In the lower extremities, MR neurography has been employed in the demonstration of the anatomy and pathology of the CPN, as well as in the detection of associated secondary muscle denervation changes. This article reviews the normal appearance of the CPN as well as typical pathologies and abnormal findings at 3.0-T MR neurography of the lower extremity. (orig.)

  20. MR images of mouse brain using clinical 3T MR scanner and 4CH-Mouse coil

    Lim, Soo Mee; Park, Eun Mi; Lyoo, In Kyoon; Lee, Junghyun; Han, Bo Mi; Lee, Jeong Kyong; Lee, Su Bin

    2015-07-01

    Objectives: Although small-bore high-field magnets are useful for research in small rodent models,this technology, however, has not been easily accessible to most researchers. This current study, thus,tried to evaluate the usability of 4CH-Mouse coil (Philips Healthcare, Best, the Netherlands) forpreclinical investigations in clinical 3T MR scan environment. We evaluated the effects of ischemicpreconditioning (IP) in the mouse stroke model with clinical 3T MR scanner and 4CH-Mouse coil. Materials and Methods: Experiments were performed on male C57BL/6 mice that either received the IP or sham operation (control). Three different MR sequences including diffusion weighted images (DWI), T2-weighted images (T2WI), and fluid attenuated inversion recovery (FLAIR) were performed on the mouse brains following 24, 72 hours of middle cerebral artery occlusion (MCAO) and analyzed for infarct lesions. Results: The images showed that the IP-treated mouse brains had significantly smaller infarct volumes compared to the control group. Of the MR sequences employed, the T2WI showed the highest level of correlations with postmortem infarct volume measurements. Conclusions: The clinical 3T MR scanner turned out to have a solid potential as a practical tool for imaging small animal brains. MR sequences including DWI, T2WI, FLAIR were obtained with acceptable resolution and in a reasonable time constraint in evaluating a mouse stroke model brain.

  1. Neurografía por resonancia magnética en 3T: experiencia preliminar 3T MRI neurography: preliminary experience

    Martín Aguilar

    2012-12-01

    Asymmetry and Least-squares estimation sequence in the evaluation of peripheral nerves, brachial plexus and lumbar plexus, for the diagnosis of compression or entrapment neuropathies, non-entrapment neuropathies, and the underlying conditions. The IDEAL sequence provides 4 types of images from a single acquisition, allowing uniform fat or water suppression and in phase/out of phase images of water, fat or a combination of both. Materials and Methods. This is a retrospective study, from January 2011 to June 2011. Eleven neurographies were performed on 3T MRI (HDX 3T, GE Healthcare, USA, with 8-channel phased array coils on sagittal and coronal planes, with 1.2-0 mm slices with no gap, axial 3D spoiled gradient recalled (SPGR T , with 1-0-mm slice thickness with and without gadolinium injection and variable field of view (FOV according to the nerve or plexus to explore. Results. We found 2 schwannomas (brachial plexus and sciatic nerve, 1 neuritis (compression to median nerve, 2 cases of multiple neurofibromas (lumbosacral plexus, sciatic nerve, brachial plexus, 3 traumatic neuromas (peroneal nerve and 1 pseudomeningocele avulsion (brachial plexus, and 2 with no structural alterations (lumbosacral plexus and peroneal nerve. Conclusion. In this preliminary experience, the use of highresolution sequences in magnetic resonance imaging neurography studies provided excellent signal homogeneity, improving the recognition of the nerve structure and signal, the identification of anatomical variations, and causes of neuropathy, as well as the characterization of denervation changes of the affected muscle groups.

  2. Lysophosphatidic acid receptor-5 negatively regulates cellular responses in mouse fibroblast 3T3 cells

    Highlights: • LPA5 inhibits the cell growth and motile activities of 3T3 cells. • LPA5 suppresses the cell motile activities stimulated by hydrogen peroxide in 3T3 cells. • Enhancement of LPA5 on the cell motile activities inhibited by LPA1 in 3T3 cells. • The expression and activation of Mmp-9 were inhibited by LPA5 in 3T3 cells. • LPA signaling via LPA5 acts as a negative regulator of cellular responses in 3T3 cells. - Abstract: Lysophosphatidic acid (LPA) signaling via G protein-coupled LPA receptors (LPA1–LPA6) mediates a variety of biological functions, including cell migration. Recently, we have reported that LPA1 inhibited the cell motile activities of mouse fibroblast 3T3 cells. In the present study, to evaluate a role of LPA5 in cellular responses, Lpar5 knockdown (3T3-L5) cells were generated from 3T3 cells. In cell proliferation assays, LPA markedly stimulated the cell proliferation activities of 3T3-L5 cells, compared with control cells. In cell motility assays with Cell Culture Inserts, the cell motile activities of 3T3-L5 cells were significantly higher than those of control cells. The activity levels of matrix metalloproteinases (MMPs) were measured by gelatin zymography. 3T3-L5 cells stimulated the activation of Mmp-2, correlating with the expression levels of Mmp-2 gene. Moreover, to assess the co-effects of LPA1 and LPA5 on cell motile activities, Lpar5 knockdown (3T3a1-L5) cells were also established from Lpar1 over-expressing (3T3a1) cells. 3T3a1-L5 cells increased the cell motile activities of 3T3a1 cells, while the cell motile activities of 3T3a1 cells were significantly lower than those of control cells. These results suggest that LPA5 may act as a negative regulator of cellular responses in mouse fibroblast 3T3 cells, similar to the case for LPA1

  3. Lysophosphatidic acid receptor-5 negatively regulates cellular responses in mouse fibroblast 3T3 cells

    Dong, Yan; Hirane, Miku; Araki, Mutsumi [Division of Cancer Biology and Bioinformatics, Department of Life Science, Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Fukushima, Nobuyuki [Division of Molecular Neurobiology, Department of Life Science, Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Tsujiuchi, Toshifumi, E-mail: ttujiuch@life.kindai.ac.jp [Division of Cancer Biology and Bioinformatics, Department of Life Science, Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan)

    2014-04-04

    Highlights: • LPA{sub 5} inhibits the cell growth and motile activities of 3T3 cells. • LPA{sub 5} suppresses the cell motile activities stimulated by hydrogen peroxide in 3T3 cells. • Enhancement of LPA{sub 5} on the cell motile activities inhibited by LPA{sub 1} in 3T3 cells. • The expression and activation of Mmp-9 were inhibited by LPA{sub 5} in 3T3 cells. • LPA signaling via LPA{sub 5} acts as a negative regulator of cellular responses in 3T3 cells. - Abstract: Lysophosphatidic acid (LPA) signaling via G protein-coupled LPA receptors (LPA{sub 1}–LPA{sub 6}) mediates a variety of biological functions, including cell migration. Recently, we have reported that LPA{sub 1} inhibited the cell motile activities of mouse fibroblast 3T3 cells. In the present study, to evaluate a role of LPA{sub 5} in cellular responses, Lpar5 knockdown (3T3-L5) cells were generated from 3T3 cells. In cell proliferation assays, LPA markedly stimulated the cell proliferation activities of 3T3-L5 cells, compared with control cells. In cell motility assays with Cell Culture Inserts, the cell motile activities of 3T3-L5 cells were significantly higher than those of control cells. The activity levels of matrix metalloproteinases (MMPs) were measured by gelatin zymography. 3T3-L5 cells stimulated the activation of Mmp-2, correlating with the expression levels of Mmp-2 gene. Moreover, to assess the co-effects of LPA{sub 1} and LPA{sub 5} on cell motile activities, Lpar5 knockdown (3T3a1-L5) cells were also established from Lpar1 over-expressing (3T3a1) cells. 3T3a1-L5 cells increased the cell motile activities of 3T3a1 cells, while the cell motile activities of 3T3a1 cells were significantly lower than those of control cells. These results suggest that LPA{sub 5} may act as a negative regulator of cellular responses in mouse fibroblast 3T3 cells, similar to the case for LPA{sub 1}.

  4. Accuracy of 3 T versus 1.5 T breast MRI for pre-operative assessment of extent of disease in newly diagnosed DCIS

    Highlights: •We compared sizes of known ductal carcinoma in situ (DCIS) on pre-operative breast MRI at 3 T and 1.5 T with final pathology sizes. •DCIS sizes on 3 T MRI correlated better with pathologic sizes than 1.5 T MRI. •Imaging features of DCIS, including morphology and kinetics, were similar at 3 T and 1.5 T MRI. -- Abstract: Objectives: While 3 T breast magnetic resonance imaging has increased in use over the past decade, there is little data comparing its use for assessing ductal carcinoma in situ (DCIS) versus 1.5 T. We sought to compare the accuracies of DCIS extent of disease measures on pre-operative 3 T versus 1.5 T MRI. Methods: This institutional review board-approved prospective study included 20 patients with ductal carcinoma in situ diagnosed by core needle biopsy (CNB) who underwent pre-operative breast MRI at both 3 T (resolution = 0.5 mm × 0.5 mm × 1.3 mm) and 1.5 T (0.85 mm × 0.85 mm × 1.6 mm). All patients provided informed consent, and the study was HIPPA compliant. Lesion sizes and imaging characteristics (morphologic and kinetic enhancement) were recorded for the 3 T and 1.5 T examinations. Lesion size measures at both field strengths were correlated to final pathology, and imaging characteristics also were compared. Results: Of the initial cohort of 20 patients with CNB-diagnosed DCIS, 19 underwent definitive surgery. Median DCIS sizes of these 19 patients were 6 mm (range: 0–67 mm) on 3 T, 13 mm (0–60 mm) on 1.5 T, and 6 mm (0–55 mm) on surgical pathology. Size correlation between MRI and pathology was higher for 3 T (Spearman's ρ = 0.66, p = 0.002) than 1.5 T (ρ = 0.36, p = 0.13). In 10 women in which a residual area of suspicious enhancement was identified on both field strengths, there was agreement of morphologic description (NME vs. mass) in nine, and no significant difference in dynamic contrast enhanced kinetics at 3 T compared to 1.5 T. Conclusions: Pre-operative breast MRI at 3 T provided higher

  5. Accuracy of 3 T versus 1.5 T breast MRI for pre-operative assessment of extent of disease in newly diagnosed DCIS

    Rahbar, Habib, E-mail: hrahbar@uw.edu; DeMartini, Wendy B.; Lee, Amie Y.; Partridge, Savannah C.; Peacock, Sue; Lehman, Constance D.

    2015-04-15

    Highlights: •We compared sizes of known ductal carcinoma in situ (DCIS) on pre-operative breast MRI at 3 T and 1.5 T with final pathology sizes. •DCIS sizes on 3 T MRI correlated better with pathologic sizes than 1.5 T MRI. •Imaging features of DCIS, including morphology and kinetics, were similar at 3 T and 1.5 T MRI. -- Abstract: Objectives: While 3 T breast magnetic resonance imaging has increased in use over the past decade, there is little data comparing its use for assessing ductal carcinoma in situ (DCIS) versus 1.5 T. We sought to compare the accuracies of DCIS extent of disease measures on pre-operative 3 T versus 1.5 T MRI. Methods: This institutional review board-approved prospective study included 20 patients with ductal carcinoma in situ diagnosed by core needle biopsy (CNB) who underwent pre-operative breast MRI at both 3 T (resolution = 0.5 mm × 0.5 mm × 1.3 mm) and 1.5 T (0.85 mm × 0.85 mm × 1.6 mm). All patients provided informed consent, and the study was HIPPA compliant. Lesion sizes and imaging characteristics (morphologic and kinetic enhancement) were recorded for the 3 T and 1.5 T examinations. Lesion size measures at both field strengths were correlated to final pathology, and imaging characteristics also were compared. Results: Of the initial cohort of 20 patients with CNB-diagnosed DCIS, 19 underwent definitive surgery. Median DCIS sizes of these 19 patients were 6 mm (range: 0–67 mm) on 3 T, 13 mm (0–60 mm) on 1.5 T, and 6 mm (0–55 mm) on surgical pathology. Size correlation between MRI and pathology was higher for 3 T (Spearman's ρ = 0.66, p = 0.002) than 1.5 T (ρ = 0.36, p = 0.13). In 10 women in which a residual area of suspicious enhancement was identified on both field strengths, there was agreement of morphologic description (NME vs. mass) in nine, and no significant difference in dynamic contrast enhanced kinetics at 3 T compared to 1.5 T. Conclusions: Pre-operative breast MRI at 3 T provided higher

  6. Utility of multiparametric 3-T MRI for glioma characterization

    Accurate grading of cerebral glioma using conventional structural imaging techniques remains challenging due to the relatively poor sensitivity and specificity of these methods. The purpose of this study was to evaluate the relative sensitivity and specificity of structural magnetic resonance imaging and MR measurements of perfusion, diffusion, and whole-brain spectroscopic parameters for glioma grading. Fifty-six patients with radiologically suspected untreated glioma were studied with T1- and T2-weighted MR imaging, dynamic contrast-enhanced MR imaging, diffusion tensor imaging, and volumetric whole-brain MR spectroscopic imaging. Receiver-operating characteristic analysis was performed using the relative cerebral blood volume (rCBV), apparent diffusion coefficient, fractional anisotropy, and multiple spectroscopic parameters to determine optimum thresholds for tumor grading and to obtain the sensitivity, specificity, and positive and negative predictive values for identifying high-grade gliomas. Logistic regression was performed to analyze all the parameters together. The rCBV individually classified glioma as low and high grade with a sensitivity and specificity of 100 and 88 %, respectively, based on a threshold value of 3.34. On combining all parameters under consideration, the classification was achieved with 2 % error and sensitivity and specificity of 100 and 96 %, respectively. Individually, CBV measurement provides the greatest diagnostic performance for predicting glioma grade; however, the most accurate classification can be achieved by combining all of the imaging parameters. (orig.)

  7. Utility of multiparametric 3-T MRI for glioma characterization

    Roy, Bhaswati; Gupta, Rakesh K. [Fortis Memorial Research Institute, Department of Radiology and Imaging, Gurgaon, Haryana (India); Maudsley, Andrew A.; Sheriff, Sulaiman [University of Miami, Department of Radiology, Miami (United States); Awasthi, Rishi; Mohakud, Sudipta [Sanjay Gandhi Postgraduate Institute of Medical Sciences, Department of Radiodiagnosis, Lucknow (India); Gu, Meng; Spielman, Daniel M. [Stanford University, Department of Radiology, Standford (United States); Husain, Nuzhat [Ram Manohar Lohia Institute of Medical Sciences, Department of Pathology, Lucknow (India); Behari, Sanjay [Sanjay Gandhi Postgraduate Institute of Medical Sciences, Department of Neurosurgery, Lucknow (India); Pandey, Chandra M. [Sanjay Gandhi Postgraduate Institute of Medical Sciences, Department of Biostatistics and Health Informatics, Lucknow (India); Rathore, Ram K.S. [Indian Institute of Technology, Department of Mathematics and Statistics, Kanpur (India); Alger, Jeffry R. [UCLA School of Medicine, Department of Radiological Sciences, Los Angeles (United States)

    2013-05-15

    Accurate grading of cerebral glioma using conventional structural imaging techniques remains challenging due to the relatively poor sensitivity and specificity of these methods. The purpose of this study was to evaluate the relative sensitivity and specificity of structural magnetic resonance imaging and MR measurements of perfusion, diffusion, and whole-brain spectroscopic parameters for glioma grading. Fifty-six patients with radiologically suspected untreated glioma were studied with T1- and T2-weighted MR imaging, dynamic contrast-enhanced MR imaging, diffusion tensor imaging, and volumetric whole-brain MR spectroscopic imaging. Receiver-operating characteristic analysis was performed using the relative cerebral blood volume (rCBV), apparent diffusion coefficient, fractional anisotropy, and multiple spectroscopic parameters to determine optimum thresholds for tumor grading and to obtain the sensitivity, specificity, and positive and negative predictive values for identifying high-grade gliomas. Logistic regression was performed to analyze all the parameters together. The rCBV individually classified glioma as low and high grade with a sensitivity and specificity of 100 and 88 %, respectively, based on a threshold value of 3.34. On combining all parameters under consideration, the classification was achieved with 2 % error and sensitivity and specificity of 100 and 96 %, respectively. Individually, CBV measurement provides the greatest diagnostic performance for predicting glioma grade; however, the most accurate classification can be achieved by combining all of the imaging parameters. (orig.)

  8. Variations of the ulnar nerve in Guyon's canal: in vivo demonstration using ultrasound and 3 T MRI

    Niitsu, Mamoru; Kokubo, Naomi; Nojima, Shoko (Dept. of Radiology, Faculty of Health Sciences, Tokyo Metropolitan Univ., Tokyo (Japan)), e-mail: niitsu@hs.tmu.ac.jp

    2010-10-15

    Background: The clinical importance of Guyon's canal is emphasized due to the various branching patterns of the ulnar nerve. So far, the arborization pattern of the ulnar nerve in Guyon's canal has been investigated mostly by cadaveric studies. Purpose: To demonstrate anatomic variations of the ulnar nerve in Guyon's canal in vivo by using high definition ultrasound (United States) and 3 T magnetic resonance imaging (MRI). Material and Methods: US imaging and 3 T MRI with an 8-channel coil was applied to 30 hands of 15 volunteers. The main trunk and the branched superficial and deep ulnar nerves, including neural bifurcation or trifurcation, were recognized on US and confirmed by 3 T MR images. The ulnar artery and vein and its branches were traced on color Doppler US and also visualized by MRI. The branching pattern of the ulnar nerve was determined from the inlet to the outlet of Guyon's canal. Results: Of 30 hands, 21 (70%) revealed bifurcation and 9 (30%) had trifurcation branching pattern of the ulnar nerve. In 16 hands (54%), imaging demonstrated that a single nerve entered the canal and divided into two trunks, one superficial and one deep, then exited the canal. The bifurcation occurred predominantly just after entering the canal inlet. The typical trifurcation pattern indicated that a single trunk entered the canal and divided into two, then one of the two bifurcated, producing a trifurcated pattern with two superficial and one deep bundle. Of 15 participants, symmetrical branching of bilateral hands was identified in 4 cases (27%), whereas 11 (73%) had asymmetrical branching. Conclusion: US and 3 T MRI readily delineated the branching pattern of the ulnar nerve in Guyon's canal in vivo. Morphological understanding about this neural branching can be informative in presurgical planning and also in diagnosis . Keywords Skeletal-appendicular, nerve bifurcation, trifurcation

  9. Variations of the ulnar nerve in Guyon's canal: in vivo demonstration using ultrasound and 3 T MRI

    Background: The clinical importance of Guyon's canal is emphasized due to the various branching patterns of the ulnar nerve. So far, the arborization pattern of the ulnar nerve in Guyon's canal has been investigated mostly by cadaveric studies. Purpose: To demonstrate anatomic variations of the ulnar nerve in Guyon's canal in vivo by using high definition ultrasound (US) and 3 T magnetic resonance imaging (MRI). Material and Methods: US imaging and 3 T MRI with an 8-channel coil was applied to 30 hands of 15 volunteers. The main trunk and the branched superficial and deep ulnar nerves, including neural bifurcation or trifurcation, were recognized on US and confirmed by 3 T MR images. The ulnar artery and vein and its branches were traced on color Doppler US and also visualized by MRI. The branching pattern of the ulnar nerve was determined from the inlet to the outlet of Guyon's canal. Results: Of 30 hands, 21 (70%) revealed bifurcation and 9 (30%) had trifurcation branching pattern of the ulnar nerve. In 16 hands (54%), imaging demonstrated that a single nerve entered the canal and divided into two trunks, one superficial and one deep, then exited the canal. The bifurcation occurred predominantly just after entering the canal inlet. The typical trifurcation pattern indicated that a single trunk entered the canal and divided into two, then one of the two bifurcated, producing a trifurcated pattern with two superficial and one deep bundle. Of 15 participants, symmetrical branching of bilateral hands was identified in 4 cases (27%), whereas 11 (73%) had asymmetrical branching. Conclusion: US and 3 T MRI readily delineated the branching pattern of the ulnar nerve in Guyon's canal in vivo. Morphological understanding about this neural branching can be informative in presurgical planning and also in diagnosis . Keywords Skeletal-appendicular, nerve bifurcation, trifurcation

  10. Interação Universidade-Empresa: o caso do setor sucroalcooleiro de Pernambuco

    Fagner Diego Spíndola

    2015-04-01

    Full Text Available O trabalho apresenta um panorama atual da inovação no setor sucroalcooleiro pernambucano, cujo objetivo foi melhor entender as interações das empresas com as universidades e institutos públicos de pesquisa que têm promovido alguma inovação no setor. Adicionalmente, testou-se a hipótese, através do estudo de caso, de que o segmento supracitado preservou traços de sua história que legaram uma postura de setor pouco inovativo e dependente de proteção governamental. Parte de pesquisa mais ampla, o presente trabalho resulta de estudo de caso em que foram entrevistados agentes envolvidos com a interação U-E em usinas de açúcar, na instituição patronal e em instituições de pesquisa em Pernambuco. O estudo permitiu verificar que a inovação nesse setor ocorre de forma distinta em cada um dos três diferentes segmentos em que está subdividido: agricultura, indústria e transporte e mecanização. Na área agrícola, as empresas introduzem inovações que, no entanto, são desenvolvidas por instituições públicas de pesquisa existentes no estado, como a Ridesa e o Cetene, para quem as usinas e os pequenos produtores transferem esforços em P&D. Na área industrial e na de transporte e mecanização, as inovações são introduzidas por intermédio do sindicato patronal e de empresas de consultoria técnica que as importam de outras regiões ou países, enquanto o desenvolvimento de novos produtos não foi observado na indústria sucroalcooleira pernambucana. O foco das usinas locais é o mercado externo de açúcar por possuírem uma vantagem comparativa logística e contarem internamente com grande concorrência de produtores do Centro-Sul. Essa exportação do açúcar tem sido feita a granel, levando a crer que os produtores têm passado adiante parte importante da agregação de valor ao produto, deixando os procedimentos mais específicos, como criação de produtos finais diferenciados, para o importador e, por isso

  11. Diffusion tensor imaging applications in multiple sclerosis patients using 3T magnetic resonance: a preliminary study

    Testaverde, Lorenzo; Caporali, Laura [University ' ' Sapienza' ' of Rome, Department of Radiological Sciences, Rome (Italy); Venditti, Eugenio; Grillea, Giovanni [U.O.C. Neuroradiologia, I.R.C.C.S. ' ' Neuromed' ' , Pozzilli (Italy); Colonnese, Claudio [University ' ' Sapienza' ' of Rome, Department of Radiological Sciences, Rome (Italy); U.O.C. Neuroradiologia, I.R.C.C.S. ' ' Neuromed' ' , Pozzilli (Italy)

    2012-05-15

    This study evaluated patients with multiple sclerosis using diffusion tensor imaging (DTI) to obtain fractional anisotropy (FA) and mean diffusivity (MD) values. We investigated the possible statistically significant variation of MD and FA in different MS patients, compared simultaneously, putting in comparison their normal appearing white matter (NAWM) and white matter affected by disease (plaques), both during activity and in remission, with normal white matter (NWM) of control subjects. Statistical analysis using Levene's test for comparison of variances revealed significant (P < 0.05) differences between FA values of the NWM of the controls and those of NAWM and active or inactive lesions, of the patients in the study. However, the differences between MD values of the NWM of the controls and those of NAWM and active or inactive lesions of the patients in the study were judged not significant (P > 0.05). Imaging of MS using MRI techniques is constantly searching for reproducible quantitative parameter. This study shows how these parameters can be identified in the MD and FA values, and thus suggests the implementation of MRI routine protocols for diagnosing MS with the DTI analysis, since it can provide valuable information otherwise unobtainable. (orig.)

  12. Motion-robust diffusion tensor acquisition at routine 3T magnetic resonance imaging

    We compared different acquisition and reconstruction methods in phantom and human studies in the clinical setting to validate our hypothesis that optimizing the k-space acquisition and reconstruction method could decrease motion artifacts. Diffusion tensor images of a water phantom were obtained with three table displacement magnitudes: 1 mm, 2 mm, and 3 mm. Images were reconstructed using homodyne and zero-fill reconstruction. Overscanning in 8- and 16-ky lines was tested. We performed visual assessment of the artifacts using reconstructed coronal images and analyzed them with Wilcoxon signed-ranks test both for phantom and human studies. Also, fractional anisotropy (FA) changes between acquisition methods were compared. Artifacts due to smaller displacement (1 and 2 mm) were significantly reduced in 16-ky overscan with zero filling. The Wilcoxon signed-ranks test showed significant differences (P<0.031 for reconstruction methods and P<0.016 for overscanning methods). FA changes were statistically significant (P<0.037; Student's t-test). The Wilcoxon signed-ranks test showed significant reductions (P<0.005) in the human study. Motion-induced artifacts can be reduced by optimizing acquisition and reconstruction methods. The techniques described in this study offer an effective method for robust estimation of diffusion tensor in the presence of motion-related artifactual data points. (author)

  13. Small solid renal masses: Characterization by diffusion-weighted MRI at 3 T

    Aim: To describe the appearance of small solid renal lesions (≤3 cm) on diffusion-weighted magnetic resonance imaging (MRI) and to determine whether ADC measurements may help to differentiate benign from malignant small solid renal masses. Methods and materials: Thirty-five patients with 47 small renal masses (23 malignant, 24 benign) who underwent 3 T MRI of the kidney using diffusion-weighted sequences (b values of 0 and 1000 s/mm2) were retrospectively evaluated. Qualitative and quantitative analysis of diffusion-weighted images was performed. Results: Most lesions were hyperintense to kidney on high b-value diffusion-weighted images and hypointense on apparent diffusion coefficient (ADC) map. The mean ADC of the lesions was significantly lower than that of kidney (1.22 ± 0.3 versus 1.85 ± 0.12 mm2/s; p 2/s), metastases (1.25 ± 0.04 mm2/s), angiomyolipoma (1.07 ± 0.3 mm2/s) and oncocytomas (1.56 ± 0.08 mm2/s; p 2/s; p 2/s). Conclusion: Small solid renal masses are hyperintense on high b value and have different ADC values

  14. Optimizing conventional cardiac MRI in the rabbit at 0.3 T

    The aim of this study was to define the most efficient way of performing cardiac MRI for anatomic information in small experimental animals, using a vertical magnetic field with a strength of 0.3 T (FONAR beta-3000M). This information may be used to improve cardiac MRI in infants and small children, since the size of a rabbit is considered comparable to that of a neonate. Experimental axial cardiac MRI studies were performed in a rabbit under general anesthesia in order to study the effects on image quality of changing various imaging parameters. These are ECG-gating, number of excitations (averages), number of warp levels, echo time (TE) and repetition time (TR). The effects of changing the size of the field of view (FOV), the slice thickness and the phase-encoding direction were also studied. We found that ECG-gating was crucial and that three excitations, TE 16 ms, and 257 vertical phase-encoding warp levels were adequate. Five-millimeter slice thickness and FOV 20 cm were preferred. (orig.)

  15. Monitoring fractional anisotropy in developing rabbit brain using MR diffusion tensor imaging at 3T

    Jao, Jo-Chi; Yang, Yu-Ting; Hsiao, Chia-Chi; Chen, Po-Chou

    2016-03-01

    The aim of this study was to investigate the factional anisotropy (FA) in various regions of developing rabbit brain using magnetic resonance diffusion tensor imaging (MR DTI) at 3 T. A whole-body clinical MR imaging (MRI) scanner with a 15-channel high resolution knee coil was used. An echo-planar-imaging (EPI)-DTI pulse sequence was performed. Five 5 week-old New Zealand white (NZW) rabbits underwent MRI once per week for 24 weeks. After scanning, FA maps were obtained. ROIs (regions of interests) in the frontal lobe, parietal & temporal lobe, and occipital lobe were measured. FA changes with time were evaluated with a linear regression analysis. The results show that the FA values in all lobes of the brain increased linearly with age. The ranking of FA values was FA(frontal lobe) FA(occipital lobe). There was significant difference (p rabbits to investigate the brain anatomy during development using clinical MRI. This technique can be further applied to the pre-clinical diagnosis, treatment, prognosis and follow-up of brain lesions.

  16. Using High Spatial Resolution to Improve BOLD fMRI Detection at 3T.

    Juliana Iranpour

    Full Text Available For different functional magnetic resonance imaging experiments using blood oxygenation level-dependent (BOLD contrast, the acquisition of T2*-weighted scans at a high spatial resolution may be advantageous in terms of time-course signal-to-noise ratio and of BOLD sensitivity when the regions are prone to susceptibility artifacts. In this study, we explore this solution by examining how spatial resolution influences activations elicited when appetizing food pictures are viewed. Twenty subjects were imaged at 3 T with two different voxel volumes, 3.4 μl and 27 μl. Despite the diminution of brain coverage, we found that high-resolution acquisition led to a better detection of activations. Though known to suffer to different degrees from susceptibility artifacts, the activations detected by high spatial resolution were notably consistent with those reported in published activation likelihood estimation meta-analyses, corresponding to taste-responsive regions. Furthermore, these regions were found activated bilaterally, in contrast with previous findings. Both the reduction of partial volume effect, which improves BOLD contrast, and the mitigation of susceptibility artifact, which boosts the signal to noise ratio in certain regions, explained the better detection noted with high resolution. The present study provides further evidences that high spatial resolution is a valuable solution for human BOLD fMRI, especially for studying food-related stimuli.

  17. Neural correlates of simple unimanual discrete and continuous movements: a functional imaging study at 3 T

    The cerebral and cerebellar network involved in unimanual continuous and discrete movements was studied in blood oxygenation level-dependent functional magnetic resonance imaging (fMRI) at 3 T. Seven healthy right-handed volunteers were scanned (1) while drawing a circle with the tip of the right index finger (continuous motor task), and (2) while drawing a triangle with the tip of the right index finger (discrete motor task). In both motor tasks, extensive activations were observed in the sensorimotor (M1/S1), parietal, prefrontal, insular, lateral occipital (LOC) and anterior cerebellar cortices. Subcortical activations within red, thalamic and lentiform nuclei were also detected. However, discrete movements were specifically followed by the recruitment of the left orbitofrontal cortex, right dentate nucleus and the second cerebellar homunculus (HVIII), and bilateral and stronger activation of the sensorimotor cortical areas, whereas continuous movements specifically activated the right prefrontal cortex and the lateral hemispherical part of the neocerebellum (crus 1). We confirm the findings of previous studies showing partly distinct neural networks involved in monitoring continuous and discrete movements, but we found new differential neural relays within the prefrontal, insular and neocerebellar cortices. (orig.)

  18. In vivo electrical conductivity imaging of a canine brain using a 3 T MREIT system

    Magnetic resonance electrical impedance tomography (MREIT) aims at producing high-resolution cross-sectional conductivity images of an electrically conducting object such as the human body. Following numerous phantom imaging experiments, the most recent study demonstrated successful conductivity image reconstructions of postmortem canine brains using a 3 T MREIT system with 40 mA imaging currents. Here, we report the results of in vivo animal imaging experiments using 5 mA imaging currents. To investigate any change of electrical conductivity due to brain ischemia, canine brains having a regional ischemic model were scanned along with separate scans of canine brains having no disease model. Reconstructed multi-slice conductivity images of in vivo canine brains with a pixel size of 1.4 mm showed a clear contrast between white and gray matter and also between normal and ischemic regions. We found that the conductivity value of an ischemic region decreased by about 10–14%. In a postmortem brain, conductivity values of white and gray matter decreased by about 4–8% compared to those in a live brain. Accumulating more experience of in vivo animal imaging experiments, we plan to move to human experiments. One of the important goals of our future work is the reduction of the imaging current to a level that a human subject can tolerate. The ability to acquire high-resolution conductivity images will find numerous clinical applications not supported by other medical imaging modalities. Potential applications in biology, chemistry and material science are also expected

  19. A interação de adolescentes marginalizados com a linguagem Logo

    Silva Paulo Vinicius Baptista da

    1998-01-01

    Full Text Available O estudo relata condutas de adolescentes frente a "erros" e "acertos" quando em interação com a linguagem Logo de programação. Os sujeitos foram cinco adolescentes de catorze a dezessete anos de idade, alunos de séries inicias de 1o Grau de uma instituição estadual de atendimento social de Curitiba. As sessões de programação foram individuais, acompanhadas pelo pesquisador, com dados gravados em disquete e vídeo. As verbalizações dos sujeitos após "erros" e "acertos" foram qualitativamente descritas em níveis sucessivos. As categorias obtidas revelaram um processo de modificação na avaliação das condutas frente aos "erros", passando os sujeitos pau-latinamente de uma perspectiva negativa à incorporação positiva do erro ao processo. As verbalizações frente aos acertos revelaram avaliações positivas dos sujeitos sobre si mesmos e sobre a produção própria.

  20. MAGNET

    by B. Curé

    2011-01-01

    The magnet operation was very satisfactory till the technical stop at the end of the year 2010. The field was ramped down on 5th December 2010, following the successful regeneration test of the turbine filters at full field on 3rd December 2010. This will limit in the future the quantity of magnet cycles, as it is no longer necessary to ramp down the magnet for this type of intervention. This is made possible by the use of the spare liquid Helium volume to cool the magnet while turbines 1 and 2 are stopped, leaving only the third turbine in operation. This obviously requires full availability of the operators to supervise the operation, as it is not automated. The cryogenics was stopped on 6th December 2010 and the magnet was left without cooling until 18th January 2011, when the cryoplant operation resumed. The magnet temperature reached 93 K. The maintenance of the vacuum pumping was done immediately after the magnet stop, when the magnet was still at very low temperature. Only the vacuum pumping of the ma...

  1. Interação educadora-criança em creches públicas: estilos linguísticos

    Deborah Dornellas Ramos

    2012-03-01

    Full Text Available O presente estudo teve o objetivo de analisar a interação educadora-criança em creches públicas, considerando os estilos linguísticos das educadoras e a comunicação infantil. O estudo dos estilos linguísticos destaca-se nas análises das interações entre adultos e crianças, especialmente em se tratando daquelas da faixa etária em torno dos 24 meses, devido à emergência das primeiras pequenas frases. Participaram do estudo seis educadoras e doze crianças com idade entre 23 e 25 meses, que frequentavam creches públicas de João Pessoa, Paraíba. As interações entre educadora e criança foram observadas sistematicamente em contextos diádicos e poliádicos de leitura. Categorias interacionais foram elaboradas a posteriori, para a análise dos dados. As educadoras utilizaram mais estilos associados à promoção do desenvolvimento linguístico nos contextos diádicos, enquanto os estilos relacionados à direção e ao controle dos comportamentos predominaram nos contextos poliádicos. As análises consideraram a influência mútua entre os estilos comunicativos e o nível de desenvolvimento linguístico infantil, além dos aspectos contextuais.

  2. MAGNET

    B. Curé

    2012-01-01

      The magnet was energised at the beginning of March 2012 at a low current to check all the MSS safety chains. Then the magnet was ramped up to 3.8 T on 6 March 2012. Unfortunately two days later an unintentional switch OFF of the power converter caused a slow dump. This was due to a misunderstanding of the CCC (CERN Control Centre) concerning the procedure to apply for the CMS converter control according to the beam-mode status at that time. Following this event, the third one since 2009, a discussion was initiated to define possible improvement, not only on software and procedures in the CCC, but also to evaluate the possibility to upgrade the CMS hardware to prevent such discharge from occurring because of incorrect procedure implementations. The magnet operation itself was smooth, and no power cuts took place. As a result, the number of magnetic cycles was reduced to the minimum, with only two full magnetic cycles from 0 T to 3.8 T. Nevertheless the magnet suffered four stops of the cryogeni...

  3. MAGNET

    Benoit Curé

    2010-01-01

    Operation of the magnet has gone quite smoothly during the first half of this year. The magnet has been at 4.5K for the full period since January. There was an unplanned short stop due to the CERN-wide power outage on May 28th, which caused a slow dump of the magnet. Since this occurred just before a planned technical stop of the LHC, during which access in the experimental cavern was authorized, it was decided to leave the magnet OFF until 2nd June, when magnet was ramped up again to 3.8T. The magnet system experienced a fault also resulting in a slow dump on April 14th. This was triggered by a thermostat on a filter choke in the 20kA DC power converter. The threshold of this thermostat is 65°C. However, no variation in the water-cooling flow rate or temperature was observed. Vibration may have been the root cause of the fault. All the thermostats have been checked, together with the cables, connectors and the read out card. The tightening of the inductance fixations has also been checked. More tem...

  4. MAGNET

    B. Curé

    2012-01-01

      Following the unexpected magnet stops last August due to sequences of unfortunate events on the services and cryogenics [see CMS internal report], a few more events and initiatives again disrupted the magnet operation. All the magnet parameters stayed at their nominal values during this period without any fault or alarm on the magnet control and safety systems. The magnet was stopped for the September technical stop to allow interventions in the experimental cavern on the detector services. On 1 October, to prepare the transfer of the liquid nitrogen tank on its new location, several control cables had to be removed. One cable was cut mistakenly, causing a digital input card to switch off, resulting in a cold-box (CB) stop. This tank is used for the pre-cooling of the magnet from room temperature down to 80 K, and for this reason it is controlled through the cryogenics control system. Since the connection of the CB was only allowed for a field below 2 T to avoid the risk of triggering a fast d...

  5. A escolha amorosa e interação conjugal na heterossexualidade e na homossexualidade

    Féres-Carneiro Terezinha

    1997-01-01

    Full Text Available Este estudo tem como objetivo investigar o processo de escolha amorosa em homens e mulheres hetero e homossexuais das camadas médias da população, de diferentes faixas etárias, em diversas situações amorosas - namoro, casamento (coabitação estável, separação e recasamento (segunda ou subsequente coabitação estável; as características das relações dos conflitos conjugais por eles estabelecidas; e o papel atribuído à terapia de casal na resolução dos conflitos conjugais. Foram estudados dois grupos: 240 heterossexuais (53 solteiros, 64 casados, 63 separados e 60 recasados e 116 homossexuais (49 solteiros, 36 casados, 19 separados e 12 recasados. Na avaliação da escolha amorosa foram utilizados 26 atributos dispostos em escalas de avaliação de 5 pontos, tal como proposto por Buss (1989, e entrevistas semi-estruturadas a partir de Féres-Carneiro (1987, contendo tópicos referentes a dimensões relevantes da interação conjugal. Os resultados mostraram algumas diferenças entre homens e mulheres de ambos os grupos e algumas semelhanças no processo de escolha amorosa dos sujeitos hetero e dos sujeitos homossexuais. Tais resultados são relevantes para a prática clínica da terapia de casal, possibilitando uma melhor compreensão das especificidades da relação amorosa em diferentes tipos de conjugalidade.

  6. Comparison of INTERA and WISAP consequence model application. Assessment of effectiveness of geologic isolation systems

    The Waste Isolation Safety Assessment Program (WISAP) is being conducted to develop, for the Office of Nuclear Waste Isolation (ONWI), the methodology necessary to perform long-term safety assessments of deep geologic repositories. The Waste Isolation Pilot Plant (WIPP) program is developing a nuclear waste storage facility and is performing assessments of that site. WISAP and WIPP have similar, though independent, methodologies for assessing the consequences of a repository breach subsequent to closure. Intera Environmental Consultants are under contract to Sandia Laboratories to conduct the hydrologic and transport modeling for the WIPP Site Release Consequence Analysis (WIPP EIS/ER 1978). To provide a mutual benchmark check of the radionuclide and ground-water transport models of these two programs, ONWI has requested WISAP to perform a release consequence analysis based on the WIPP site, utilizing the same data and conceptual model which the WIPP program used for its environmental assessments. Therefore, only a portion of the WISAP methodology was used; specifically, only WISAP geotransport models were exercised. The other important parts of WISAP assessment methodology were not used, so that WISAP did not develop the scenario nor did WISAP interpret the field data to develop the conceptual model of the geohydrology of the WIPP site. The results of the comparative assessment are presented. Although the different models required slightly different input parameters, the results of the hydrologic simulations show a very close correspondence between the WISAP and WIPP predictions. This was as expected, since the various hydrologic codes available essentially utilize and solve the same basic flow equations. In addition, this report presents the results of the WISAP radionuclide transport model simulations. These results will provide the basis for comparison with WIPP results when these become available

  7. Temperature induced modulation of lipid oxidation and lipid accumulation in palmitate-mediated 3T3-L1 adipocytes and 3T3-L1 adipocytes.

    Lin, Xiaofen; Li, Yi; Leung, Polly Hangmei; Li, Jiashen; Hu, Junyan; Liu, Xuan; Li, Zhi

    2016-05-01

    Human skin temperature can vary widely depending on anatomical location and ambient temperature. It is also known that local changes in skin and subcutaneous temperature can affect fat metabolism. This study aimed to explore the potential effects of surrounding thermal environment on fat by investigating cell viability, lipid oxidation, and lipid accumulation in 3T3-L1 adipocytes and palmitate-treated adipocytes after 4h incubation. No significant differences of viability in 3T3-L1 adipocytes were detected under different temperature conditions. Despite no significant increase being observed under warm temperature (39°C) conditions, a similarly significant suppression of intracellular reactive oxygen species (ROS) and lipid peroxidation were found in 3T3-L1 adipocytes and palmitate-treated adipocytes under 4h exposure to cooler temperatures of 31-33°C (Psize of lipid droplets in 3T3-L1 adipocytes (Padipocytes. In the palmitate-induced adiposity model, although excessive ROS and lipid peroxidation has been attenuated by temperature decrease (Psize (P>0.05) and remedy the palmitate damage induced cell death (Padipocytes. PMID:27157327

  8. A violência rompendo interações: as interações superando a violência Violence rupturing interaction: interaction overcomimg violence

    Elza Machado de Melo

    2007-03-01

    Full Text Available Trata-se de pesquisa qualitativa associada ao Projeto de Extensão e de Ensino "Frutos do Morro Programa Meninos do Rio", do Departamento de Medicina Preventiva e Social da Faculdade de Medicina da Universidade de Minas Gerais - que se desenvolve em Escolas Públicas do Aglomerado Urbano Morro das Pedras, Belo Horizonte, Minas Gerais, e aborda a percepção de adolescentes acerca da violência, os significados que dão a ela e as formas de enfrentamento geradas. Utilizamos como referencial teórico a tese da colonização do Mundo da Vida, de Jürgen Habermas, em que os imperativos sistêmicos, mediados pelo poder e pelo dinheiro, substituem os laços de sociabilidade e solidariedade próprios das interações coordenadas pela comunicação lingüística. MÉTODOS: foram selecionados, em 2005, 14 grupos focais de adolescentes das Escolas Públicas do Aglomerado, recrutados segundo idade, escola, turno. RESULTADOS: a violência assume papel de mediador das relações intersubjetivas, seja pela falta de opção, pela sedução ou pela presença cotidiana. Embora haja uma naturalização da violência há também um desejo explícito pela sua superação. A relação com o tráfico e o uso de drogas é constantemente mencionada. A violência simbólica - discriminação - é intensamente sentida e vista como causa da violência física. A violência policial é considerada a mais bruta e a mais irracional. Também presente é a violência familiar. CONCLUSÕES: os adolescentes do Morro convivem intimamente com a violência, não vêem muitas alternativas a ela, mas a capacidade de crítica e o desejo de mudança, ainda preservados, representam importantes elementos para a construção de intervenções apropriadas, corroborando a atuação do Projeto Frutos do Morro, fundada na criação de espaços de participação e restabelecimento de laços de solidariedade.This is a qualitative survey associated to the Extension and Education Project

  9. Synthesis, crystal structure and physical properties of EuTGe3 (T = Co, Ni, Rh, Pd, Ir, Pt) single crystals

    Highlights: • Single crystals of EuTGe3 (T = Co, Ni, Rh, Pd, Ir, Pt) compounds were prepared. • The crystal structures were refined from single-crystal X-ray diffraction data. • The physical properties of oriented single crystals were determined. • For each compound, an antiferromagnetic ordering was found at low temperatures. - Abstract: Single crystals of six EuTGe3 compounds with T = Co, Ni, Rh, Pd, Ir and Pt were prepared by high-temperature solution growth method. Their crystal structures of the BaNiSn3-type were refined from single-crystal X-ray diffraction data. The physical properties of oriented single-crystalline specimens were studied by means of magnetic susceptibility, heat capacity and electrical resistivity measurements. For each compound, an antiferromagnetic ordering was found to set in at low temperatures due to localized magnetic moments carried on divalent Eu ions. Despite the same crystal structure, the EuTGe3 compounds exhibit diverse magnetic structures with different directions of the ordered magnetic moments and a variety of dissimilar mutual arrangements of adjacent spins

  10. Optimization of Coronary Whole-Heart MRA Free Breathing Technique at 3T

    Gharib, Ahmed M.; Abd-Elmoniem, Khaled Z.; Herzka, Daniel A; Ho, Vincent B; Locklin, Julie; Tzatha, Efstathia; Stuber, Matthias; Pettigrew, Roderic I.

    2011-01-01

    Four different techniques for 3T whole-heart coronary MRA using free-breathing 3D segmented parallel imaging and adiabatic T2-Prep were assessed. Coronary MRA at 3T is improved by shortening the acquisition window more than employing the highest spatial resolution. Double oblique whole-heart acquisitions result in better overall image quality and allow for better delineation of the LAD. It is possible to attain shorter acquisition windows and a smaller voxel size at 3T than previously reporte...

  11. Targeting the Vasculature of Colorectal Carcinoma with a Fused Protein of (RGD)3-tTF

    Zheng-jie Huang; Yilin Zhao; Wei-yuan Luo; Jun You; Shui-wen Li; Wen-cheng Yi; Sheng-yu Wang; Jiang-hua Yan; Qi Luo

    2013-01-01

    Purpose. Truncated tissue factor (tTF) fusion protein targeting tumor vasculature can induce tumor vascular thrombosis and necrosis. Here, we generated (RGD)3-tTF in which three arginine-glycine-aspartic (RGD) targeting integrin α v β 3 and tTF induce blood coagulation in tumor vessels. Methods. The bioactivities of (RGD)3-tTF including coagulation activity, FX activation, and binding with integrin α v β 3 were performed. The fluorescent labeled (RGD)3-tTF was intravenously injected into tumo...

  12. Alteration of proteoglycan metabolism during the differentiation of 3T3- L1 fibroblasts into adipocytes

    1991-01-01

    3T3-L1 fibroblasts were induced to differentiate to 3T3-L1 adipocytes by dexamethasone, isobutyl-methylxanthine, and insulin. To study how differentiation affects extracellular matrix production, the accumulation of proteoglycans was studied by labeling the 3T3-L1 cells with [35S]sulphate for 24 h. The labeled proteoglycans were isolated from the medium and cell layer extracts by anion-exchange chromatography. They were then taken to gel filtration chromatography on Superose 6 before or after...

  13. Regulatory T Cells in Melanoma Revisited by a Computational Clustering of FOXP3+ T Cell Subpopulations

    Fujii, Hiroko; Josse, Julie; Tanioka, Miki; Miyachi, Yoshiki; Husson, François; Ono, Masahiro

    2016-01-01

    CD4+ T cells that express the transcription factor FOXP3 (FOXP3+ T cells) are commonly regarded as immunosuppressive regulatory T cells (Tregs). FOXP3+ T cells are reported to be increased in tumor-bearing patients or animals and are considered to suppress antitumor immunity, but the evidence is often contradictory. In addition, accumulating evidence indicates that FOXP3 is induced by antigenic stimulation and that some non-Treg FOXP3+ T cells, especially memory-phenotype FOXP3low cells, prod...

  14. Three dimensional first-pass myocardial perfusion imaging at 3T: feasibility study

    Pohost Gerald M

    2008-12-01

    Full Text Available Abstract Background In patients with ischemic heart disease, accurate assessment of the extent of myocardial perfusion deficit may be important in predicting prognosis of clinical cardiac outcomes. The aim of this study was to compare the ability of three dimensional (3D and of two dimensional (2D multi-slice myocardial perfusion imaging (MPI using cardiovascular magnetic resonance (CMR in determining the size of defects, and to demonstrate the feasibility of 3D MPI in healthy volunteers at 3 Tesla. Methods A heart phantom was used to compare the accuracy of 3D and 2D multi-slice MPI in estimating the volume fraction of seven rubber insets which simulated transmural myocardial perfusion defects. Three sets of cross-sectional planes were acquired for 2D multi-slice imaging, where each set was shifted along the partition encoding direction by ± 10 mm. 3D first-pass contrast-enhanced (0.1 mmol/kg Gd-DTPA MPI was performed in three volunteers with sensitivity encoding for six-fold acceleration. The upslope of the myocardial time-intensity-curve and peak SNR/CNR values were calculated. Results Mean/standard deviation of errors in estimating the volume fraction across the seven defects were -0.44/1.49%, 2.23/2.97%, and 2.59/3.18% in 3D, 2D 4-slice, and 2D 3-slice imaging, respectively. 3D MPI performed in healthy volunteers produced excellent quality images with whole left ventricular (LV coverage. Peak SNR/CNR was 57.6 ± 22.0/37.5 ± 19.7 over all segments in the first eight slices. Conclusion 3D performed better than 2D multi-slice MPI in estimating the size of perfusion defects in phantoms. Highly accelerated 3D MPI at 3T was feasible in volunteers, allowing whole LV coverage with excellent image quality and high SNR/CNR.

  15. Commissioning and quality control of a dedicated wide bore 3T MRI simulator for radiotherapy planning

    Aitang Xing

    2016-06-01

    Full Text Available Purpose: The purpose of this paper is to describe a practical approach to commissioning and quality assurance (QA of a dedicated wide-bore 3 Tesla (3T magnetic resonance imaging (MRI scanner for radiotherapy planning.Methods: A comprehensive commissioning protocol focusing on radiotherapy (RT specific requirements was developed and performed. RT specific tests included: uniformity characteristics of radio-frequency (RF coil, couch top attenuation, geometric distortion, laser and couch movement and an end-to-end radiotherapy treatment planning test. General tests for overall system performance and safety measurements were also performed.Results: The use of pre-scan based intensity correction increased the uniformity from 61.7% to 97% (body flexible coil, from 50% to 90% (large flexible coil and from 51% to 98% (small flexible coil. RT flat top couch decreased signal-to-noise ratio (SNR by an average of 42%. The mean and maximum geometric distortion was found to be 1.25 mm and 4.08 mm for three dimensional (3D corrected image acquisition, 2.07 mm and 7.88 mm for two dimensional (2D corrected image acquisition over 500 mm × 375 mm × 252 mm field of view (FOV. The accuracy of the laser and couch movement was less than ±1 mm. The standard deviation of registration parameters for the end-to-end test was less than 0.41 mm. An on-going QA program was developed to monitor the system’s performance.Conclusion: A number of RT specific tests have been described for commissioning and subsequent performance monitoring of a dedicated MRI simulator (MRI-Sim. These tests have been important in establishing and maintaining its operation for RT planning.

  16. Metabolic profiling of human brain metastases using in vivo proton MR spectroscopy at 3T

    Metastases to the central nervous system from different primary cancers are an oncologic challenge as the overall prognosis for these patients is generally poor. The incidence of brain metastases varies with type of primary cancer and is probably increasing due to improved therapies of extracranial metastases prolonging patient's overall survival and thereby time for brain metastases to develop. In addition, the greater access to improved neuroimaging techniques can provide earlier diagnosis. The aim of this study was to investigate the feasibility of using proton magnetic resonance spectroscopy (MRS) and multivariate analyses to characterize brain metastases originating from different primary cancers, to assess changes in spectra during radiation treatment and to correlate the spectra to clinical outcome after treatment. Patients (n = 26) with brain metastases were examined using single voxel MRS at a 3T clinical MR system. Five patients were excluded due to poor spectral quality. The spectra were obtained before start (n = 21 patients), immediately after (n = 6 patients) and two months after end of treatment (n = 4 patients). Principal component analysis (PCA) and partial least square regression analysis (PLS) were applied in order to identify clustering of spectra due to origin of metastases and to relate clinical outcome (survival) of the patients to spectral data from the first MR examination. The PCA results indicated that brain metastases from primary lung and breast cancer were separated into two clusters, while the metastases from malignant melanomas showed no uniformity. The PLS analysis showed a significant correlation between MR spectral data and survival five months after MRS before start of treatment. MRS determined metabolic profiles analysed by PCA and PLS might give valuable clinical information when planning and evaluating the treatment of brain metastases, and also when deciding to terminate further therapies

  17. MRI of the cervical spine with 3D gradient echo sequence at 3 T: initial experience

    Aim: The aim of this study was to compare three-dimensional (3D) high resolution T2*-weighted gradient echo (3D FFE) magnetic resonance (MR) sequence with conventional 2D T2-weighted turbo spin echo (TSE) MR sequence for imaging of the cervical spine, especially to assess the detectability of the internal anatomy of the cervical spinal cord, i.e. to distinguish the grey and white matter. Methods: Fifteen volunteers were examined at 3.0T MR unit. Signal-to-noise (SNR), contrast-to-noise (CNR) and image homogeneity were evaluated. In the visual analysis, the visibility of anatomical structures of the cervical spine and artifacts were assessed. The nonparametric method of paired sample t-test was adopted to evaluate the differences between the sequences. Results: The 3D FFE sequence provided better results for CNR, cerebrospinal fluid (CSF) versus white matter, grey matter, disk and bone. Moreover, it yielded good results for the CNR grey matter versus white matter. The butterfly-shaped “H” is clearly displayed in the 3D FFE sequence. The statistical analysis revealed the statistically significant difference between the 2D TSE and 3D FFE sequences for the contrast of CSF versus spinal cord (both grey matter and white matter). Conclusion: The 3D FFE sequence in MR imaging of the cervical spinal cord is superior in delineation of spinal cord anatomical structures compared to 2D TSE sequence. -- Highlights: •We investigate the potential of 3D FFE sequence to distinguish the grey-white of the cervical spinal cord at 3T MRI system. •We optimized The 3D FFE sequence was optimized to increase the grey-white contrast. •Utilizing medium TE for T2W and the shortest TR for reduction of susceptibility related artifacts and motion artefacts. •This technique may increase the confidence in the diagnosis of disease with the improved delineation of cord anatomy

  18. MAGNET

    B. Curé

    2011-01-01

    The CMS magnet has been running steadily and smoothly since the summer, with no detected flaw. The magnet instrumentation is entirely operational and all the parameters are at their nominal values. Three power cuts on the electrical network affected the magnet run in the past five months, with no impact on the data-taking as the accelerator was also affected at the same time. On 22nd June, a thunderstorm caused a power glitch on the service electrical network. The primary water cooling at Point 5 was stopped. Despite a quick restart of the water cooling, the inlet temperature of the demineralised water on the busbar cooling circuit increased by 5 °C, up to 23.3 °C. It was kept below the threshold of 27 °C by switching off other cooling circuits to avoid the trigger of a slow dump of the magnet. The cold box of the cryogenics also stopped. Part of the spare liquid helium volume was used to maintain the cooling of the magnet at 4.5 K. The operators of the cryogenics quickly restarted ...

  19. MAGNET

    Benoit Curé

    2010-01-01

    The magnet was successfully operated at the end of the year 2009 despite some technical problems on the cryogenics. The magnet was ramped up to 3.8 T at the end of November until December 16th when the shutdown started. The magnet operation met a few unexpected stops. The field was reduced to 3.5 T for about 5 hours on December 3rd due to a faulty pressure sensor on the helium compressor. The following day the CERN CCC stopped unintentionally the power converters of the LHC and the experiments, triggering a ramp down that was stopped at 2.7 T. The magnet was back at 3.8 T about 6 hours after CCC sent the CERN-wide command. Three days later, a slow dump was triggered due to a stop of the pump feeding the power converter water-cooling circuit, during an intervention on the water-cooling plant done after several disturbances on the electrical distribution network. The magnet was back at 3.8 T in the evening the same day. On December 10th a break occurred in one turbine of the cold box producing the liquid ...

  20. MAGNET

    B. Curé

    2013-01-01

      The magnet was operated without any problem until the end of the LHC run in February 2013, apart from a CERN-wide power glitch on 10 January 2013 that affected the CMS refrigerator, causing a ramp down to 2 T in order to reconnect the coldbox. Another CERN-wide power glitch on 15 January 2013 didn’t affect the magnet subsystems, the cryoplant or the power converter. At the end of the magnet run, the reconnection of the coldbox at 2.5 T was tested. The process will be updated, in particular the parameters of some PID valve controllers. The helium flow of the current leads was reduced but only for a few seconds. The exercise will be repeated with the revised parameters to validate the automatic reconnection process of the coldbox. During LS1, the water-cooling services will be reduced and many interventions are planned on the electrical services. Therefore, the magnet cryogenics and subsystems will be stopped for several months, and the magnet cannot be kept cold. In order to avoid unc...

  1. MAGNET

    B. Curé

    2012-01-01

      The magnet and its sub-systems were stopped at the beginning of the winter shutdown on 8th December 2011. The magnet was left without cooling during the cryogenics maintenance until 17th January 2012, when the cryoplant operation resumed. The magnet temperature reached 93 K. The vacuum pumping was maintained during this period. During this shutdown, the yearly maintenance was performed on the cryogenics, the vacuum pumps, the magnet control and safety systems, and the power converter and discharge lines. Several preventive actions led to the replacement of the electrovalve command coils, and the 20A DC power supplies of the magnet control system. The filters were cleaned on the demineralised water circuits. The oil of the diffusion pumps was changed. On the cryogenics, warm nitrogen at 343 K was circulated in the cold box to regenerate the filters and the heat exchangers. The coalescing filters have been replaced at the inlet of both the turbines and the lubricant trapping unit. The active cha...

  2. Final Gleason Score Prediction Using Discriminant Analysis and Support Vector Machine Based on Preoperative Multiparametric MR Imaging of Prostate Cancer at 3T

    Esen, Tarık; Çıtak-Er, Füsun; Vural, Metin; Onay, Aslıhan; Öztürk-Işık, Esin

    2014-01-01

    Objective. This study aimed at evaluating linear discriminant analysis (LDA) and support vector machine (SVM) classifiers for estimating final Gleason score preoperatively using multiparametric magnetic resonance imaging (mp-MRI) and clinical parameters. Materials and Methods. Thirty-three patients who underwent mp-MRI on a 3T clinical MR scanner and radical prostatectomy were enrolled in this study. The input features for classifiers were age, the presence of a palpable prostate abnormality,...

  3. The effects of Ganoderma lucidum herba pharmacopuncture on 3T3-L1 preadipocyte differentiation

    Chea-woo Lee

    2008-09-01

    Full Text Available Objective : The purpose of this study is to investigate the effects of Ganoderma lucidum herba pharmacopuncture (GHP on the adipogenesis in 3T3-L1 preadipocytes. Methods : 3T3- L1 preadipocytes were differentiated with adipogenic reagents by incubating for 2 days in the absence or presence of GHP ranging from 1 and 2%. The effect of GHP on cell proliferation of 3T3-L1 preadipocytes was investigated using MTT assay. The effect of GHP on adipogenesis was examined by Oil red O staining and measuring glycerol-3-phosphate dehydrogenase (GPDH and intracellular triglyceride (TG content. Results : Following results were obtained from the preadipocyte proliferation and adipocyte differentiation of 3T3-L1. We observed no effect of GHP on preadipocyte proliferation. GHP inhibited adipogenesis, the activity of GPDH and accumulation of intracellular TG content. Conclusions : These results suggest that GHP inhibit differentiation of preadipocyte.

  4. Exchange Splitting of 3T2g Band in Antiferromagnetic KNiF3

    Bandai, Toshio

    1981-05-01

    Absorption spectra of the 3T2g band in KNiF3, KMgF3: 1.5%Ni and K2NiF4 are measured at 2 K. In the antiferromagnetic KNiF3, splitting of the \\varGamma3 line in the 3T2g band is observed. Large linear dichroic spectra are obtained in the 3T2g band of KNiF3 under the and stress. This linear dichroism is induced by the movement of domain walls so as to align spins along the applied stress. The stress effect of the split \\varGamma3 lines is explained by the exchange interaction in the 3T2g state. The exchange constant J' is determined to be 7.5 cm-1 for spins aligned along the direction, and 8.7 cm-1 for spins aligned along the direction.

  5. Characterization of the hyperrecombination phenotype of the pol3-t mutation of Saccharomyces cerevisiae.

    Galli, Alvaro; Cervelli, Tiziana; Schiestl, Robert H.

    2003-01-01

    The DNA polymerase delta (Pol3p/Cdc2p) allele pol3-t of Saccharomyces cerevisiae has previously been shown to increase the frequency of deletions between short repeats (several base pairs), between homologous DNA sequences separated by long inverted repeats, and between distant short repeats, increasing the frequency of genomic deletions. We found that the pol3-t mutation increased intrachromosomal recombination events between direct DNA repeats up to 36-fold and interchromosomal recombinatio...

  6. Anti-adipogenic effect of mulberry leaf ethanol extract in 3T3-L1 adipocytes

    Yang, Soo Jin; Park, Na-Young; LIM, YUNSOOK

    2014-01-01

    BACKGROUND/OBJECTIVES Adipogenesis is part of the cell differentiation process in which undifferentiated fibroblasts (pre-adipocytes) become mature adipocytes with the accumulation of lipid droplets and subsequent cell morphological changes. Several transcription factors and food components have been suggested to be involved in adipogenesis. The aim of this study was to determine whether mulberry leaf ethanol extract (MLEE) affects adipogenesis in 3T3-L1 adipocytes. MATERIALS/METHODS The 3T3-...

  7. MAGNET

    B. Curé

    2011-01-01

    The magnet ran smoothly in the last few months until a fast dump occurred on 9th May 2011. Fortunately, this occurred in the afternoon of the first day of the technical stop. The fast dump was due to a valve position controller that caused the sudden closure of a valve. This valve is used to regulate the helium flow on one of the two current leads, which electrically connects the coil at 4.5 K to the busbars at room temperature. With no helium flow on the lead, the voltage drop and the temperatures across the leads increase up to the defined thresholds, triggering a fast dump through the Magnet Safety System (MSS). The automatic reaction triggered by the MSS worked properly. The helium release was limited as the pressure rise was just at the limit of the safety valve opening pressure. The average temperature of the magnet reached 72 K. It took four days to recover the temperature and refill the helium volumes. The faulty valve controller was replaced by a spare one before the magnet ramp-up resumed....

  8. Potenciais interações medicamentosas em pacientes com artrite reumatoide Potential drug interactions in patients with rheumatoid arthritis

    Fabíola Bagatini

    2011-02-01

    Full Text Available INTRODUÇÃO: O termo polifarmácia, ou seja, a utilização concomitante de múltiplos fármacos pelo mesmo indivíduo vem sendo amplamente associado a pacientes institucionalizados e idosos, no entanto pode ocorrer em grupos de pacientes portadores de doenças crônicas como artrite reumatoide (AR. OBJETIVO: Quantificar a polifarmácia em um grupo de pacientes com AR e realizar um levantamento sobre o risco de potenciais interações indesejáveis entre os medicamentos utilizados no manejo dessa doença e os fármacos utilizados em enfermidades não crônicas. MÉTODOS: Realizou-se um estudo de coorte com 103 pacientes portadores de AR, atendidos no Componente Especializado da Assistência Farmacêutica/MS, Florianópolis/SC. Os pacientes foram acompanhados mensalmente, por meio de fichas. As interações medicamentosas foram identificadas pelo Drugdex System - Thomson Micromedex® - Interactions. RESULTADOS: Observou-se a presença de polifarmácia em 95,1% dos pacientes e de 19 potenciais interações indesejáveis entre os medicamentos utilizados por 74 pacientes, em média 3,0 ± 1,2 interações/paciente. Todas as potenciais interações estavam relacionadas a metotrexato. Omeprazol foi o principal representante, correspondendo a 29,3% delas, seguido por diclofenaco sódico (17,6% e dipirona sódica (13,2%. CONCLUSÃO: Considerando que este estudo confirma que a polifarmácia é uma prática comum na terapêutica dos pacientes portadores de AR, deve haver maior vigilância acerca de efeitos adversos ou de redução da efetividade de determinados fármacos devido às suas interações farmacológicasINTRODUCTION: The term polypharmacy, meaning the concomitant use of multiple medications by one individual, has been widely reported in institutionalized or elderly patients. It can, however, occur in patients with chronic diseases, such as rheumatoid arthritis (RA. OBJECTIVE: To quantify polypharmacy in a group of RA patients and to assess the

  9. CERN Technical Training 2005: IT3T - IT Technical Training Tutorials (Summer 2005)

    Davide Vitè

    2005-01-01

    CERN Technical Training and the Internet Services group of the IT department (IT/IS) are jointly organizing a series of free tutorials, addressing some topics of common interest: the IT Technical Training Tutorials (IT3T). The first IT3T will be offered in June 2005, in English, with the following schedule: IT3T/1 - Read your mail and more with Outlook 2003: June 14 (Ruben Gaspar) IT3T/2 - Creating, managing and using distribution lists with Simba2: June 16 (Ruben Leivas) IT3T/3 - Working remotely with Windows XP: June 28 (Michel Christaller) IT3T/4 - Editing Websites with FrontPage 2003: June 30 (Andreas Wagner) All IT Technical Training Tutorials will take place in the Training Centre Auditorium (building 593, room 11), from 14h30 to 15h30. The tutorials are free of charge, but separate registration to each is required. Participation to any of the tutorials is open: attendance to any tutorial is not a prerequisite to attend subsequent ones. If you are interested in attending, please discuss with your sup...

  10. Optimization of diffusion-tensor MR imaging data acquisition parameters for brain fiber tracking using parallel imaging at 3 T

    Naganawa, Shinji; Koshikawa, Tokiko; Kawai, Hisashi; Fukatsu, Hiroshi; Ishigaki, Takeo [Department of Radiology, Nagoya University School of Medicine, 65 Tsurumai-cho, Shouwa-ku, 466-8550, Nagoya (Japan); Maruyama, Katsuya; Takizawa, Osamu [Siemens-Asahi Medical Technologies Ltd. (Japan)

    2004-02-01

    The purpose of this study was to optimize the parameters of diffusion-tensor magnetic resonance imaging (DT MRI) for brain fiber tracking using a slice thickness of 2 mm, a resolution advantage allowed by the high signal-to-noise ratio at 3 T, combined with an 8-channel phased-array head coil. The b-factor, number of motion probing gradient (MPG) directions, and number of averages were varied, and the results of brain fiber tracking for the pyramidal tract and trigeminal nerve were compared qualitatively and quantitatively. The DT MRI data sufficient for brain fiber tracking in healthy subjects can be obtained in <2 min with a 2-mm slice thickness, 700-s/mm{sup 2} b-factor, 6 MPG directions, and no averaging (number of averages=1). (orig.)

  11. Dynamic contrast-enhanced quantitative perfusion measurement of the brain using T-1-weighted MRI at 3T

    Larsson, H.B.W.; Hansen, A.E.; Berg, H.K.;

    2008-01-01

    Purpose: To develop a method for the measurement of brain perfusion based on dynamic contrast-enhanced T-1-weighted MR imaging. Materials and Methods: Dynamic imaging of the first pass of a bolus of a paramagnetic contrast agent was performed using a 3T whole-body magnet and a T-1-weighted fast...... field echo sequence. The input function was obtained from the internal carotid artery. An initial T-1 measurement was performed in order to convert the MR signal to concentration of the contrast agent. Pixelwise and region of interest (ROI)based calculation of cerebral perfusion (CBF) was performed...... using Tikhonov's procedure of deconvolution. Seven patients with acute optic neuritis and two patients with acute stroke were investigated. Results: The mean perfusion value for ROIs in gray matter was 62 mL/100g/min and 21 mL/100g/min in white matter in patients with acute optic neuritis. The perfusion...

  12. A trapped field of >3 T in bulk MgB2 fabricated by uniaxial hot pressing

    A trapped field of over 3 T has been measured at 17.5 K in a magnetized stack of two disc-shaped bulk MgB2 superconductors of diameter 25 mm and thickness 5.4 mm. The bulk MgB2 samples were fabricated by uniaxial hot pressing, which is a readily scalable, industrial technique, to 91% of their maximum theoretical density. The macroscopic critical current density derived from the trapped field data using the Biot–Savart law is consistent with the measured local critical current density. From this we conclude that critical current density, and therefore trapped field performance, is limited by the flux pinning available in MgB2, rather than by lack of connectivity. This suggests strongly that both increasing sample size and enhancing pinning through doping will allow further increases in trapped field performance of bulk MgB2. (rapid communication)

  13. Magnetic resonance imaging of spinal tumors. A study using a 0.3 T vertical magnetic field

    A total of 168 patients with spinal tumors were evaluated with MRI. The study shows that MRI is a sensitive method for demonstration of spinal tumors. MRI also provides a possibility to separate different histological types of tumors based on their morphology and signal characteristics. Intramedullary tumors (25 cases): Ependymomas (6 cases) and astrocytomas (7 cases) were most common. Ependymomas have a more irregular signal pattern than astrocytomas. Astrocytomas are more common in the upper spine and are more often completely cystic. Contrast enhancement is important for separation of cyst, edema and solid tumor. Intradural extramedullary tumors (31 cases): Neuromas (14 cases) and meningeomas (11 cases) were most common. Neuromas always had markedly increased signal intensity on T2-weighted images. Meningeomas were only hyperintense occasionally. Neuromas were more inhomogeneous than meningeomas on T1-weighted images. Contrast enhancement is valuable for delineation of small tumors. Extradural tumors (91 cases): 76 patients had metastases, 7 primary spinal tumors and 8 multiple myelomas. T1-weighted images are almost always superior to other sequences because tumor invasion in the fatty bone marrow is seen as a low signal area in contrast to the high signal from the fat. Spinal lymphomas (14 cases): May be divided into vertebral, paraspinal and epidural tumors. Most cases have all locations. Spinal neurofibromatosis (7 cases): Most patients had multiple, often bilateral neurofibromas. One patient had a meningeomas on one spinal dysplasia with meningoceles. MRI is superior to other modalities for evaluation of the full extent of the disease. The coronal view is often valuable because of the arrangement of the tumors. In addition to providing diagnosis, MRI is of great value in treatment follow-up

  14. A New Promising Technique of 3D Isovoxel Imaging Using 3T MRI in the Wrist: Comparison with 3T MR Arthrography

    Lee, Guen Young; Kim, Baek Hyun; Park, Jong Woong [Korea University Ansan Hospital, Korea University College of Medicine, Ansan (Korea, Republic of)

    2011-02-15

    We wanted to evaluate the usefulness of 3D isovoxel MR imaging using 3T MRI in the wrist joint, as compared with 3T MR arthrography. A total of 33 patients underwent both MR arthrography and 3D isovoxel imaging of the wrist joints using 3T MR, including 11 patients with arthroscopic confirmation. 3D isovoxel MR imaging was performed using an intermediateweighted fast spin echo coronal scan with a 0.4-mm slice thickness and the axial images were reconstructed with a 1-mm slice thickness. One radiologist evaluated for the presence of scapholunate or lunotriquetral ligament tear and she determined the grade of the triangular fibrocartilage complex tear and chondromalacia with its location. We compared the two examinations using kappa values. The rates of detecting wrist injury were similar for both exams with substantial to almost perfect inter-examination agreement (kappa value = 0.864 for scapholunate ligament tear, 0.835 for lunotriquetral ligament tear, 0.799 for TFCC tear and 0.940 for chondromalacia). For the eleven cases that underwent arthroscopy, their results of 3D isovoxel MRI were also similar to that of MR arthrography. 3D isovoxel MR imaging is useful for the evaluation of the wrist joint

  15. MAGNET

    B. Curé

    2013-01-01

    The magnet is fully stopped and at room temperature. The maintenance works and consolidation activities on the magnet sub-systems are progressing. To consolidate the cryogenic installation, two redundant helium compressors will be installed as ‘hot spares’, to avoid the risk of a magnet downtime in case of a major failure of a compressor unit during operation. The screw compressors, their motors, the mechanical couplings and the concrete blocks are already available and stored at P5. The metallic structure used to access the existing compressors in SH5 will be modified to allow the installation of the two redundant ones. The plan is to finish the installation and commissioning of the hot spare compressors before the summer 2014. In the meantime, a bypass on the high-pressure helium piping will be installed for the connection of a helium drier unit later during the Long Shutdown 1, keeping this installation out of the schedule critical path. A proposal is now being prepared for the con...

  16. MAGNET

    Benoit Curé

    2010-01-01

    The magnet worked very well at 3.8 T as expected, despite a technical issue that manifested twice in the cryogenics since June. All the other magnet sub-systems worked without flaw. The issue in the cryogenics was with the cold box: it could be observed that the cold box was getting progressively blocked, due to some residual humidity and air accumulating in the first thermal exchanger and in the adsorber at 65 K. This was later confirmed by the analysis during the regeneration phases. An increase in the temperature difference between the helium inlet and outlet across the heat exchanger and a pressure drop increase on the filter of the adsorber were observed. The consequence was a reduction of the helium flow, first compensated by the automatic opening of the regulation valves. But once they were fully opened, the flow and refrigeration power reduced as a consequence. In such a situation, the liquid helium level in the helium Dewar decreased, eventually causing a ramp down of the magnet current and a field...

  17. MAGNET

    Benoit Curé.

    The magnet operation restarted end of June this year. Quick routine checks of the magnet sub-systems were performed at low current before starting the ramps up to higher field. It appeared clearly that the end of the field ramp down to zero was too long to be compatible with the detector commissioning and operations plans. It was decided to perform an upgrade to keep the ramp down from 3.8T to zero within 4 hours. On July 10th, when a field of 1.5T was reached, small movements were observed in the forward region support table and it was decided to fix this problem before going to higher field. At the end of July the ramps could be resumed. On July 28th, the field was at 3.8T and the summer CRAFT exercise could start. This run in August went smoothly until a general CERN wide power cut took place on August 3rd, due to an insulation fault on the high voltage network outside point 5. It affected the magnet powering electrical circuit, as it caused the opening of the main circuit breakers, resulting in a fast du...

  18. MAGNET

    B. Curé

    MAGNET During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bough...

  19. Interação de glyphosate com carfentrazone-ethyl Glyphosate - carfentrazone-ethyl interaction

    R.C. Werlang

    2002-04-01

    Full Text Available Foi conduzido um experimento em condições controladas para determinar a interação do carfentrazone-ethyl em mistura no tanque com o herbicida glyphosate, no controle de seis espécies de plantas daninhas. Glyphosate aplicado isoladamente na dose de 720 g ha-1 foi eficaz no controle de Amaranthus hybridus (100%, Desmodium tortuosum (100%, Bidens pilosa (99%, Eleusine indica (96%, Digitaria horizontalis (100% e Commelina benghalensis (93% aos 21 DAA. Carfentrazone-ethyl aplicado isoladamente controlou eficazmente C. benghalensis. As misturas de glyphosate nas doses de 252 e 720 g ha-1 com carfentrazone-ethyl nas doses de 15 e 30 g ha¹ demonstraram efeito aditivo no controle de A. hybridus, D. tortuosum e Bidens pilosa, à exceção das misturas de glyphosate na dose de 252 g ha-1 com as doses de 15 e 30 g ha-1 de carfentrazone-ethyl, que proporcionam efeito sinergístico no controle de D. tortuosum. A adição das duas doses de carfentrazone-ethyl antagonizou o efeito de glyphosate na menor dose (252 g ha-1 no controle de E. indica, apresentando, no entanto, efeito aditivo com o glyphosate na maior dose (720 g ha-1. Já para D. horizontalis, as misturas de carfentrazone-ethyl com glyphosate na menor dose (252 g ha-1 apresentaram efeito sinergístico no controle dessa espécie, demonstrando, ainda, efeito aditivo na mistura com glyphosate na dose de 720 g ha-1. A mistura de carfentrazone-ethyl com glyphosate proporcionou efeito aditivo no controle de C. benghalensis, independentemente das combinações de doses avaliadas. Os resultados deste experimento indicam que carfentrazone-ethyl apresenta comportamento diferenciado quanto à interação com glyphosate, dependendo da espécie de planta daninha e da dose dos herbicidas utilizados na mistura em tanque, sendo complementar na mistura em tanque com glyphosate, pois demonstrou efeito antagônico em poucas das combinações estudadas, prevalecendo seu efeito aditivo na mistura com glyphosate, no

  20. Multimodal imaging: Simultaneous EEG in a 3T Hybrid MR-PET system

    Neuner, I.; Warbrick, T.; Tellmann, L.; Rota Kops, E.; Arrubla, J.; Boers, F.; Herzog, H.; Shah, N. J.

    2013-02-01

    The new generation of integrated MR-PET systems allows the simultaneous acquisition of MR and PET data. While MR delivers structural data with an excellent spatial resolution, the advantage of PET is its information on a molecular level. However, both modalities have a low temporal resolution. Thus, for pharmacological studies or patients who suffer from treatment resistant epilepsy the combination of yet another modality such as EEG could be desirable. We tested the feasibility of evoked visual potentials in a 3T Hybrid MR-PET system (Siemens Germany) in comparison to a standalone 3T Trio System (Siemens Germany). A T2*-weighted EPI sequence was used: TR: 2.2 s, TE: 30 ms, FOV: 200 mm, slice thickness 3, 36 slices in a healthy volunteer (male, 27 years old) using an MR-compatible 32-channel EEG system (Brainproducts, Munich, Germany). We applied 200 trials of visual stimulation from a white and black checkerboard. Visual evoked potentials were analyzed using Brain Vision Analyzer (Brainproducts, Munich, Germany). Gradient correction and cardioballistic artefact correction were performed as implemented in Vision Analyzer. Visual event related potentials were successfully recorded at the 3T Hybrid MR-PET system. Both curves differ slightly in shape and latency due to the following factors: the distance from the screen varies slightly and the size of the field of view of the subjects is smaller in the 3T MR-PET system in comparison to the 3T stand alone system. Extending the 3T MR-PET Hybrid system to 3T Hybrid MR-PET-EEG is feasible and adds another tool to clinical neuroimaging and research.

  1. Multimodal imaging: Simultaneous EEG in a 3T Hybrid MR–PET system

    The new generation of integrated MR–PET systems allows the simultaneous acquisition of MR and PET data. While MR delivers structural data with an excellent spatial resolution, the advantage of PET is its information on a molecular level. However, both modalities have a low temporal resolution. Thus, for pharmacological studies or patients who suffer from treatment resistant epilepsy the combination of yet another modality such as EEG could be desirable. We tested the feasibility of evoked visual potentials in a 3T Hybrid MR–PET system (Siemens Germany) in comparison to a standalone 3T Trio System (Siemens Germany). A T2⁎-weighted EPI sequence was used: TR: 2.2 s, TE: 30 ms, FOV: 200 mm, slice thickness 3, 36 slices in a healthy volunteer (male, 27 years old) using an MR-compatible 32-channel EEG system (Brainproducts, Munich, Germany). We applied 200 trials of visual stimulation from a white and black checkerboard. Visual evoked potentials were analyzed using Brain Vision Analyzer (Brainproducts, Munich, Germany). Gradient correction and cardioballistic artefact correction were performed as implemented in Vision Analyzer. Visual event related potentials were successfully recorded at the 3T Hybrid MR–PET system. Both curves differ slightly in shape and latency due to the following factors: the distance from the screen varies slightly and the size of the field of view of the subjects is smaller in the 3T MR–PET system in comparison to the 3T stand alone system. Extending the 3T MR–PET Hybrid system to 3T Hybrid MR–PET–EEG is feasible and adds another tool to clinical neuroimaging and research

  2. Multimodal imaging: Simultaneous EEG in a 3T Hybrid MR–PET system

    Neuner, I., E-mail: i.neuner@fz-juelich.de [Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich GmbH (Germany); Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University (Germany); JARA BRAIN—Translational Medicine (Germany); Warbrick, T.; Tellmann, L.; Rota Kops, E.; Arrubla, J.; Boers, F.; Herzog, H. [Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich GmbH (Germany); Shah, N.J. [Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich GmbH (Germany); Department of Neurology, RWTH Aachen University (Germany); JARA BRAIN—Translational Medicine (Germany)

    2013-02-21

    The new generation of integrated MR–PET systems allows the simultaneous acquisition of MR and PET data. While MR delivers structural data with an excellent spatial resolution, the advantage of PET is its information on a molecular level. However, both modalities have a low temporal resolution. Thus, for pharmacological studies or patients who suffer from treatment resistant epilepsy the combination of yet another modality such as EEG could be desirable. We tested the feasibility of evoked visual potentials in a 3T Hybrid MR–PET system (Siemens Germany) in comparison to a standalone 3T Trio System (Siemens Germany). A T2⁎-weighted EPI sequence was used: TR: 2.2 s, TE: 30 ms, FOV: 200 mm, slice thickness 3, 36 slices in a healthy volunteer (male, 27 years old) using an MR-compatible 32-channel EEG system (Brainproducts, Munich, Germany). We applied 200 trials of visual stimulation from a white and black checkerboard. Visual evoked potentials were analyzed using Brain Vision Analyzer (Brainproducts, Munich, Germany). Gradient correction and cardioballistic artefact correction were performed as implemented in Vision Analyzer. Visual event related potentials were successfully recorded at the 3T Hybrid MR–PET system. Both curves differ slightly in shape and latency due to the following factors: the distance from the screen varies slightly and the size of the field of view of the subjects is smaller in the 3T MR–PET system in comparison to the 3T stand alone system. Extending the 3T MR–PET Hybrid system to 3T Hybrid MR–PET–EEG is feasible and adds another tool to clinical neuroimaging and research.

  3. Potential Heating Effect in the Gravid Uterus by Using 3-T MR Imaging Protocols: Experimental Study in Miniature Pigs.

    Cannie, Mieke M; De Keyzer, Frederik; Van Laere, Sigrid; Leus, Astrid; de Mey, Johan; Fourneau, Catherine; De Ridder, Filip; Van Cauteren, Toon; Willekens, Inneke; Jani, Jacques C

    2016-06-01

    Purpose To determine the changes in temperature within the gravid miniature pig uterus during magnetic resonance (MR) imaging at 3 T. Materials and Methods The study received ethics committee approval for animal experimentation. Fiber-optic temperature sensors were inserted into the fetal brain, abdomen, bladder, and amniotic fluid of miniature pigs (second trimester, n = 2; third trimester, n = 2). In the first trimester (n = 2), the sensors were inserted only into the amniotic fluid (three sacs per miniature pig, for a total of six sacs). Imaging was performed with a 3-T MR imager by using different imaging protocols in a random order for animal, each lasting approximately 15 minutes. The first regimen consisted of common sequences used for human fetal MR examination, including normal specific absorption rate (SAR). The second regimen consisted of five low-SAR sequences, for which three gradient-echo sequences were interspersed with two diffusion-weighted imaging series. Finally, a high-SAR regimen maximized the radiofrequency energy deposition (constrained by the 2-W per kilogram of body weight SAR limitations) by using five single-shot turbo spin-echo sequences. Differences in temperature increases between the three regimens and between the three trimesters were evaluated by using one-way analysis of variance. The maximum cumulative temperature increase over 1 hour was also evaluated. Results Low-SAR regimens resulted in the lowest temperature increase (mean ± standard deviation, -0.03°C ± 0.20), normal regimens resulted in an intermediate increase (0.31°C ± 0.21), and high-SAR regimens resulted in the highest increase (0.56°C ± 0.20) (P pregnant miniature pigs, the use of 3-T magnets for diagnostic MR imaging with normal SAR regimens does not lead to temperature increases above 1°C if imaging time is kept below 30 minutes. Longer imaging time, especially with high-SAR regimens, can lead to an increase of 2.5°C. (©) RSNA, 2015 Online supplemental

  4. Effects of Ghrelin on the Proliferation and Differentiation of 3T3-L1 Preadipocytes

    Jing LIU; Hanhua LIN; Peixuan CHENG; Xiufen HU; Huiling LU

    2009-01-01

    The effects of ghrelin on the proliferation and differentiation of 3T3-L1 preadipocytes and the possible mechanisms were investigated in this study.3T3-L1 preadipocytes were cultured in vitro and treated with different concentrations of ghrelin.Proliferation of 3T3-L1 preadipocytes was evaluated by MTT method and mRNA levels of c-myc and thymidine kinase were detected by RT-PCR.Morphological changes of 3T3-L1 preadipocytes were observed and cell differentiation was measured by oil red O staining.The mRNA levels of peroxisome proliferator-activated receptor γ (PPARγ) and CAAT/enhancer binding protein (C/EBPα) in the cells at different differentiation stages were detected by RT-PCR.The results showed that ghrelin at concentrations of 10-7 to 10-15 mol/L could significantly promote preadipocyte proliferation (P<0.05),with the most pronounced effect observed at 1011mol/L (P<0.01).Treatment of 3T3-L1 preadipocytes with ghrelin significantly in-creased the mRNA levels of c-myc and thymidine kinase (P<0.01).Morphological findings demonstrated that the great amount of lipid droplets appeared in the 3T3-L1 preadipocytes treated with ghrelin.Ghrelin could morphologically induce the differentiation of 3T3-L1 preadipocytes into mature adipocytes.Ghrelin significantly increased the mRNA levels of PPART and C/EBPα during the differentiation,when compared with control group (P<0.05).The mRNA levels of PPARγ and C/EBPα were obviously up-regulated with the differentiation of preadipocytes after the treatment of ghrelin.There were significant difference in the mRNA levels of PPARγ and C/EBPα on day 2 and day 8 of the differentiation of 3T3-L1 preadipocytes (P<0.01).In conclusion,ghrelin could promote the proliferation and differentiation of 3T3-L1 preadipocytes by increasing the mRNA levels of PPARγ and C/EBPα and therefore enhance the sensitivity of adipocytes against insulin.

  5. Avaliação qualitativa de interações em redes sociais: relacionamentos no blog Martelada

    Alex Primo

    2008-09-01

    Full Text Available Este artigo busca demonstrar a diversidade de interagentes com quem um mesmo blogueiro interage e os diferentes relacionamentos mantidos. Pelo procedimento metodológico qualitativo utilizado (Primo 2006 na investigação empírica do blog Martelada, procura-se discutir as dicotomias ego/alter e laços fracos/laços fortes. A pesquisa visa observar não o aspecto de conteúdo, o que é dito, ou meramente as questões tecnológicas envolvidas, mas sim o aspecto relacional das interações. Palavras-chave: Interação mediada por computador; análise de redes sociais; blog; conversação. ABSTRACT This article aims to show the diversity of interagents with whom any given blogger interacts and the different relationships that are established in this context. Through qualitative methodological procedures used in the empirical investigation of the blog Martelada (Primo 2006, we try to discuss the ego/alter and the strong bonds/weak bonds dichotomies. This piece of research aims to analyse not what is said – the content – or purely technological questions involved, but to focus on the relational aspect of these interactions. Keywords: Computer-mediated interaction; analysis of social networks; blog; conversation.

  6. MAGNET

    Benoit Curé

    The magnet subsystems resumed operation early this spring. The vacuum pumping was restarted mid March, and the cryogenic power plant was restarted on March 30th. Three and a half weeks later, the magnet was at 4.5 K. The vacuum pumping system is performing well. One of the newly installed vacuum gauges had to be replaced at the end of the cool-down phase, as the values indicated were not coherent with the other pressure measurements. The correction had to be implemented quickly to be sure no helium leak could be at the origin of this anomaly. The pressure measurements have been stable and coherent since the change. The cryogenics worked well, and the cool-down went quite smoothly, without any particular difficulty. The automated start of the turbines had to be fine-tuned to get a smooth transition, as it was observed that the cooling power delivered by the turbines was slightly higher than needed, causing the cold box to stop automatically. This had no consequence as the cold box safety system acts to keep ...

  7. MAGNET

    B. Curé

    During the winter shutdown, the magnet subsystems went through a full maintenance. The magnet was successfully warmed up to room temperature beginning of December 2008. The vacuum was broken later on by injecting nitrogen at a pressure just above one atmosphere inside the vacuum tank. This was necessary both to prevent any accidental humidity ingress, and to allow for a modification of the vacuum gauges on the vacuum tank and maintenance of the diffusion pumps. The vacuum gauges had to be changed, because of erratic variations on the measurements, causing spurious alarms. The new type of vacuum gauges has been used in similar conditions on the other LHC experiments and without problems. They are shielded against the stray field. The lubricants of the primary and diffusion pumps have been changed. Several minor modifications were also carried out on the equipment in the service cavern, with the aim to ease the maintenance and to allow possible intervention during operation. Spare sensors have been bought. Th...

  8. Estudo das interações medicamentosas em idosos residentes em instituição de longa permanência

    Elisangela GERBER, Adriana de Oliveira CHRISTOFF

    2013-12-01

    Full Text Available Mudanças fisiológicas relacionadas à senescência levam o idoso a um consumo aumentado de medicamentos, o que o torna sujeito à prática da polifarmácia e, consequentemente, as interações medicamentosas. Algumas interações podem comprometer a segurança e efetividade do tratamento, aumentar os efeitos farmacológicos causando toxicidade, acentuar os efeitos colaterais, desenvolver uma reação adversa ao medicamento e até elevar a morbimortalidade. Desta forma, o objetivo deste trabalho foi realizar um estudo das principais interações medicamentosas através da avaliação de prescrições médicas de três indivíduos idosos residentes em instituição de longa permanência por um período de 12 meses. Os três idosos selecionados utilizavam de oito a dez medicamentos diariamente. Foram encontradas 17 possíveis interações medicamentosas, classificadas em interações farmacocinéticas, envolvendo mecanismos de absorção, distribuição e biotransformação dos fármacos e interações farmacodinâmicas por mecanismos de potencialização, antagonismo e somação. Frente aos resultados obtidos, sugeriu-se medidas corretivas afim de proporcionar segurança, eficácia terapêuticae qualidade de vida ao idoso.

  9. On (2, 3, t-Generations for the Conway Group Co2

    Jintanaporn Wattanathorn

    2012-01-01

    Full Text Available Problem statement: In this article we investigate all the (2, 3, t-generations for the Conway’s second largest sporadic simple group Co2, where t is an odd divisor of order of Co2. Approach: An (l, m, n-generated group G is a quotient group of the triangle group T (l, m, n = (x, y, z|xl = ym = zn = xyz = 1. A group G is said to be (2, 3, t-generated if it can be generated by two elements x and y such that o(x = 2, o(y = 3 and o (xy = t. Computations are carried out with the aid of computer algebra system GAP-Groups, Algorithms and Programming. Results and Conclusion: The Conway group Co2 is (2, 3, t-generated for t an odd divisor of order of Co2 except when t = 5, 7, 9.

  10. Comparison of Standard 1.5 T vs. 3 T Optimized Protocols in Patients Treated with Glatiramer Acetate. A Serial MRI Pilot Study

    Bianca Weinstock-Guttman

    2012-05-01

    Full Text Available This study explored the effect of glatiramer acetate (GA, 20 mg on lesion activity using the 1.5 T standard MRI protocol (single dose gadolinium [Gd] and 5-min delay or optimized 3 T protocol (triple dose of Gd, 20-min delay and application of an off-resonance saturated magnetization transfer pulse. A 15-month, phase IV, open-label, single-blinded, prospective, observational study included 12 patients with relapsing-remitting multiple sclerosis who underwent serial MRI scans (Days −45, −20, 0; the minus ign indicates the number of days before GA treatment; and on Days 30, 60, 90, 120, 150, 180, 270 and 360 during GA treatment on 1.5 T and 3 T protocols. Cumulative number and volume of Gd enhancing (Gd-E and T2 lesions were calculated. At Days −45 and 0, there were higher number (p < 0.01 and volume (p < 0.05 of Gd-E lesions on 3 T optimized compared to 1.5 T standard protocol. However, at 180 and 360 days of the study, no significant differences in total and cumulative number of new Gd-E and T 2 lesions were found between the two protocols. Compared to pre-treatment period, at Days 180 and 360 a significantly greater decrease in the cumulative number of Gd-E lesions (p = 0.03 and 0.021, respectively was found using the 3 T vs. the 1.5 T protocol (p = NS for both time points. This MRI mechanistic study suggests that GA may exert a greater effect on decreasing lesion activity as measured on 3 T optimized compared to 1.5 T standard protocol.

  11. Osteogenic gene expression of murine osteoblastic (MC3T3-E1) cells under cyclic tension

    Kao, C. T.; Chen, C. C.; Cheong, U.-I.; Liu, S. L.; Huang, T. H.

    2014-08-01

    Low-level laser therapy (LLLT) can promote cell proliferation. The remodeling ability of the tension side of orthodontic teeth affects post-orthodontic stability. The purpose of the present study was to investigate the osteogenic effects of LLLT on osteoblast-like cells treated with a simulated tension system that provides a mechanical tension regimen. Murine osteoblastic (MC3T3-E1) cells were cultured in a Flexcell strain unit with programmed loads of 12% elongation at a frequency of 0.5 Hz for 24 and 48 h. The cultured cells were treated with a low-level diode laser using powers of 5 J and 10 J. The proliferation of MC3T3-E1 cells was determined using the Alamar Blue assay. The expression of osteogenic genes (type I collagen (Col-1), osteopontin (OPN), osteocalcin (OC), osteoprotegerin (OPG), receptor activator of nuclear factor kappa B ligand (RANKL), bone morphologic protein (BMP-2), and bone morphologic protein (BMP-4)) in MC3T3-E1 cells was analyzed using reverse transcription polymerase chain reaction (RT-PCR). The data were analyzed using one-way analysis of variance. The proliferation rate of tension-cultured MC3T3-E1 cells under 5 J and 10 J LLLT increased compared with that of the control group (p LLLT group. Osteogenic genes (Col-1, OC, OPG and BMP-2) were significantly expressed in the MC3T3-E1 cells treated with 5 J and 10 J LLLT (p LLLT in tension-cultured MC3T3-E1 cells showed synergistic osteogenic effects, including increases in cell proliferation and Col-1, OPN, OC, OPG and BMP-2 gene expression. LLLT might be beneficial for bone remodeling on the tension side of orthodontics.

  12. Design of a loop resonator with a split-ring-resonator (SRR) for a human-body coil in 3 T MRI systems

    Son, Hyeok Woo; Cho, Young Ki; Kim, Byung Mun; Back, Hyun Man; Yoo, Hyoungsuk

    2016-04-01

    A new radio-frequency (RF) resonator for Nuclear Magnetic Resonance (NMR) imaging at clinical magnetic resonance imaging (MRI) systems is proposed in this paper. An approach based on the effects of the properties of metamaterials in split-ring resonators (SRRs) is used to design a new loop resonator with a SRR for NMR imaging. This loop resonator with a SRR is designed for NMR imaging at 3 T MRI systems. The 3D electromagnetic simulation was used to optimize the design of the proposed RF resonator and analyze it's performance at 3 T MRI systems. The proposed RF resonator provides strong penetrating magnetic fields at the center of the human phantom model, approximately 10%, as compared to the traditional loop-type RF resonator used for NMR imaging at clinical MRI systems. We also designed an 8-channel body coil for human-body NMR imaging by using the proposed loop resonator with a SRR. This body coil also produces more homogeneous and highly penetrating magnetic fields into the human phantom model.

  13. Interactions among groups of microorganisms with rhizosphere Las interacciones entre los grupos de microorganismos en la rizosfera Interações entre grupos de microrganismos com a rizosfera

    Virgínia de Fátima Bezerra Nogueira; Maryzélia Furtado de Farias; Adailson Pereira de Souza; Jussara Silva Dantas

    2010-01-01

    As propriedades físico-químicas da rizosfera têm elevada estabilidade, que, associadas ao fornecimento constante de substratos orgânicos e fatores de crescimento, favorecem intensa atividade metabólica das populações, influenciando diretamente e positivamente o tempo de geração microbiano. O solo é um local de grande número e variedade de interações biológicas, incluindo a competição, a predação, o parasitismo, o comensalismo, o mutualismo e a forésia. As interações b...

  14. Interação entre vitamina A e ferro em diferentes grupos populacionais Vitamin A and Iron interaction in different populations

    Michele Pereira Netto; Silvia Eloiza Priore; Sylvia do Carmo Castro Franceschini

    2007-01-01

    A interação entre ferro e vitamina A tem sido alvo de pesquisas científicas, visto que existem questões ainda pouco esclarecidas. Através de um levantamento bibliográfico, mediante consulta à base de dados Medline da National Library of Medicine, Estados Unidos da America, foram selecionadas publicações que tratavam sobre a interação entre ferro e vitamina A em seres humanos, a partir da década de 80 até o ano de 2003. As palavras chave utilizadas no levantamento bibliográfico foram "ferro", ...

  15. Interação Universidade-Empresa no Brasil em 2002 e 2004: Uma Aproximação a Partir dos Grupos de Pesquisa do CNPq

    Márcia Siqueira Rapini; Hérica Morais Righi

    2007-01-01

    O presente trabalho investiga a interação universidade-empresa no Brasil tendo como proxy os grupos de pesquisa cadastrados no CNPq que declararam algum relacionamento com empresa. As informações foram extraídas do Diretório dos Grupos de Pesquisa do CNPq referentes aos Censos 2002 e 2004. O exercício permite inferir panorama recente da interação entre universidades e empresas no país. Os resultados revelam que em 2002 os relacionamentos refletiam uma demanda pouco sofisticada por insumos aca...

  16. Advances in hybrid MR–PET at 3 T and 9.4 T in humans

    Hybrid MR–PET data acquisition in simultaneous mode confers a number of advantages at 3 T and 9.4 T. From an MR perspective, the potential for ultra-high resolution structural imaging is discussed and example images of the cerebellum with an isotropic resolution of 320 μm are presented. Further, metabolic imaging is discussed and high-resolution images of the sodium distribution are demonstrated. Examples of tumour imaging on a 3 T MR–PET system are included and discussed

  17. Advances in hybrid MR–PET at 3 T and 9.4 T in humans

    Jon Shah, N., E-mail: n.j.shah@fz-juelich.de [Institute of Neuroscience and Medicine-4, Research Centre Jülich, 52425 Jülich (Germany); Department of Neurology, Faculty of Medicine, JARA, RWTH Aachen University Aachen (Germany); Mauler, Jörg [Institute of Neuroscience and Medicine-4, Research Centre Jülich, 52425 Jülich (Germany); Neuner, Irene [Institute of Neuroscience and Medicine-4, Research Centre Jülich, 52425 Jülich (Germany); Department of Psychiatry, Psychotherapy and Psychosomatics, RWTH Aachen University, Aachen (Germany); Oros-Peusquens, Ana-Maria; Romanzetti, Sandro; Vahedipour, Kaveh; Felder, Jörg; Celik, Avdo [Institute of Neuroscience and Medicine-4, Research Centre Jülich, 52425 Jülich (Germany); Iida, Hidehiro [Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, 5-7-1, Fujishirodai, Suita, Osaka, 565-8565 (Japan); Langen, Karl-Josef; Herzog, Hans [Institute of Neuroscience and Medicine-4, Research Centre Jülich, 52425 Jülich (Germany)

    2013-02-21

    Hybrid MR–PET data acquisition in simultaneous mode confers a number of advantages at 3 T and 9.4 T. From an MR perspective, the potential for ultra-high resolution structural imaging is discussed and example images of the cerebellum with an isotropic resolution of 320 μm are presented. Further, metabolic imaging is discussed and high-resolution images of the sodium distribution are demonstrated. Examples of tumour imaging on a 3 T MR–PET system are included and discussed.

  18. In vivo imaging of human breast cancer mouse model with high level expression of calcium sensing receptor at 3T

    Baio, Gabriella; Tagliafico, Alberto; Neumaier, Carlo Emanuele [National Cancer Institute, Department of Diagnostic Imaging, IST, Genoa (Italy); Fabbi, Marina; Carbotti, Grazia [National Cancer Institute, Unit of Immunological Therapy, IST, Genoa (Italy); Emionite, Laura; Cilli, Michele [National Cancer Institute, Animal Facility, IST, Genoa (Italy); Salvi, Sandra; Truini, Mauro [National Cancer Institute, Department of Pathology, IST, Genoa (Italy); Ghedin, Piero; Prato, Sabina [General Electric, GE, Milano (Italy)

    2012-03-15

    To demonstrate that manganese can visualise calcium sensing receptor (CaSR)-expressing cells in a human breast cancer murine model, as assessed by clinical 3T magnetic resonance (MR). Human MDA-MB-231-Luc or MCF7-Luc breast cancer cells were orthotopically grown in NOD/SCID mice to a minimum mass of 5 mm. Mice were evaluated on T1-weighted sequences before and after intravenous injection of MnCl{sub 2}. To block the CaSR-activated Ca{sup 2+} channels, verapamil was injected at the tumour site 5 min before Mn{sup 2+} administration. CaSR expression in vivo was studied by immunohistochemistry. Contrast enhancement was observed at the tumour periphery 10 min after Mn{sup 2+} administration, and further increased up to 40 min. In verapamil-treated mice, no contrast enhancement was observed. CaSR was strongly expressed at the tumour periphery. Manganese enhanced magnetic resonance imaging can visualise CaSR-expressing breast cancer cells in vivo, opening up possibilities for a new MR contrast agent. (orig.)

  19. SU-E-J-209: Geometric Distortion at 3T in a Commercial 4D MRI-Compatible Phantom

    Fatemi-Ardekani, A; Wronski, M; Kim, A; Stanisz, G; Sarfehnia, A; Keller, B [Sunnybrook Health Sciences Centre, Toronto, ON (Canada)

    2015-06-15

    Purpose: There are very few commercial 4D phantoms that are marketed as MRI compatible. We are evaluating one such commercial phantom, made to be used with an MRI-Linear accelerator. The focus of this work is to characterize the geometric distortions produced in this phantom at 3T using 3 clinical MR pulse sequences. Methods: The CIRS MRI-Linac Dynamic Phantom (CIRSTM) under investigation in this study consists of a softwaredriven moving tumour volume within a thorax phantom body and enables dose accumulation by placing a dosimeter within the tumour volume. Our initial investigation is to evaluate the phantom in static mode prior to examining its 4D capability. The water-filled thorax phantom was scanned using a wide-bore Philips 3T Achieva MRI scanner employing a Thoracic xl coil and clinical 2D T1W FFE, 2D T1W TSE and 3D T1W TFE pulse sequences. Each of the MR image sets was rigidly fused with a reference CT image of the phantom employing a rigid registration with 6 degrees of freedom. Geometric distortions between the MR and CT image sets were measured in 3 dimensions at selected points along the periphery of the distortion grid embedded within the phantom body (11.5, 7.5 and 3 cm laterally, ant/post and sup/inf of magnetic isocenter respectively). Results: The maximal measured geometric distortions between the MR and reference CT points of interest were 0.9, 1.8 and 1.3 mm in the lateral, anteriorposterior and cranio-caudal directions, respectively. For all 3 spatial dimensions, the maximal distortions occurred for the FFE pulse sequence. Maximal distortions for the 2D FFE, 2D TSE and 3D TFE sequences were 1, 0.7 and 1.8 mm, respectively. Conclusion: Our initial static investigation of this phantom shows minimal geometric distortions at 3T along the periphery of the embedded grid. CIRS has provided us with a phantom at no charge for evaluation at 3 Tesla.

  20. On the van der Waerden numbers w(2;3,t)

    Ahmed, Tanbir; Snevily, Hunter

    2011-01-01

    We present results and conjectures on the van der Waerden numbers w(2;3,t). We have computed the new number w(2;3,19) = 349, and we provide lower bounds for 20 <= t <= 39, where for t <= 30 we conjecture these lower bounds to be exact. The lower bounds for 24 <= t <= 30 refute the conjecture that w(2;3,t) <= t^2, and we present an improved conjecture. We also investigate regularities in the good partitions (certificates) to better understand the lower bounds. We introduce *palindromic van der Waerden numbers* w^pd(k; t_0,...,t_{k-1}), defined as ordinary van der Waerden numbers w(k; t_0,...,t_{k-1}) however only allowing palindromic solutions (good partitions), defined as reading the same from both ends. Since the underlying property is non-monotonic, these numbers are actually pairs of numbers. We compute w^pd(2;3,t) for 3 <= t <= 25, and we provide lower bounds, which we conjecture to be exact, for 26 <= t <= 39. All computations are based on SAT solving, and we conclude by dis...

  1. CERN Technical Training 2005: IT3T - IT Technical Training Tutorials (Summer 2005)

    Davide Vitè

    2005-01-01

    CERN Technical Training and the Internet Services group of the IT department (IT/IS) are jointly organizing a series of free tutorials, addressing some topics of common interest: the IT Technical Training Tutorials (IT3T). The next IT3T will be offered, in English, with the following schedule: IT3T/3 - Working remotely with Windows XP: June 28 (Michel Christaller) IT3T/4 - Editing Websites with FrontPage 2003: June 30 (Andreas Wagner) The IT Technical Training Tutorials will take place in the Training Centre Auditorium (building 593, room 11), from 14h30 to 15h30. The tutorials are free of charge, but separate registration to each is required. Participation to any of the tutorials is open: attendance to any tutorial is not a prerequisite to attend subsequent ones. If you are interested in attending, please discuss with your supervisor and/or your DTO, and apply electronically via EDH. Registered participants will be invited to each tutorial; attendance will be recorded in the personal training records. Mo...

  2. CERN Technical Training 2005: IT3T - IT Technical Training Tutorials (Summer 2005)

    Davide Vitè

    2005-01-01

    CERN Technical Training and the Internet Services group of the IT department (IT/IS) are jointly organizing a series of free tutorials, addressing some topics of common interest: the IT Technical Training Tutorials (IT3T). The next IT3T will be offered, in English, with the following schedule: IT3T/3 - Working remotely with Windows XP: June 28 (Michel Christaller) IT3T/4 - Editing Websites with FrontPage 2003: June 30 (Andreas Wagner) The IT Technical Training Tutorials will take place in the Training Centre Auditorium (building 593, room 11), from 14:30 to 15:30. The tutorials are free of charge, but separate registration to each is required. Participation to any of the tutorials is open: attendance to any tutorial is not a prerequisite to attend subsequent ones. If you are interested in attending, please discuss with your supervisor and/or your DTO, and apply electronically via EDH. Registered participants will be invited to each tutorial; attendance will be recorded in the personal training records. Mo...

  3. P3T+: A Performance Estimator for Distributed and Parallel Programs

    T. Fahringer

    2000-01-01

    Full Text Available Developing distributed and parallel programs on today's multiprocessor architectures is still a challenging task. Particular distressing is the lack of effective performance tools that support the programmer in evaluating changes in code, problem and machine sizes, and target architectures. In this paper we introduce P3T+ which is a performance estimator for mostly regular HPF (High Performance Fortran programs but partially covers also message passing programs (MPI. P3T+ is unique by modeling programs, compiler code transformations, and parallel and distributed architectures. It computes at compile-time a variety of performance parameters including work distribution, number of transfers, amount of data transferred, transfer times, computation times, and number of cache misses. Several novel technologies are employed to compute these parameters: loop iteration spaces, array access patterns, and data distributions are modeled by employing highly effective symbolic analysis. Communication is estimated by simulating the behavior of a communication library used by the underlying compiler. Computation times are predicted through pre-measured kernels on every target architecture of interest. We carefully model most critical architecture specific factors such as cache lines sizes, number of cache lines available, startup times, message transfer time per byte, etc. P3T+ has been implemented and is closely integrated with the Vienna High Performance Compiler (VFC to support programmers develop parallel and distributed applications. Experimental results for realistic kernel codes taken from real-world applications are presented to demonstrate both accuracy and usefulness of P3T+.

  4. Fluorescence lifetime imaging of lipids during 3T3-L1 cell differentiation

    Song, Young Sik; Won, Young Jae; Lee, Sang-Hak; Kim, Dug Young

    2014-03-01

    Obesity is becoming a big health problem in these days. Since increased body weight is due to increased number and size of the triglyceride-storing adipocytes, many researchers are working on differentiation conditions and processes of adipocytes. Adipocytes also work as regulators of whole-body energy homeostasis by secreting several proteins that regulate processes as diverse as haemostasis, blood pressure, immune function, angiogenesis and energy balance. 3T3-L1 cells are widely used cell line for studying adipogenesis because it can differentiate into an adipocyte-like phenotype under appropriate conditions. In this paper, we propose an effective fluorescence lifetime imaging technique which can easily distinguish lipids in membrane and those in lipid droplets. Nile red dyes are attached to lipids in 3T3-L1 cells. Fluorescence lifetime images were taken for 2 week during differentiation procedure of 3T3-L1 cells into adipocytes. We used 488 nm pulsed laser with 5MHz repetition rate and emission wavelength is 520 nm of Nile Red fluorescent dye. Results clearly show that the lifetime of Nile red in lipid droplets are smaller than those in cell membrane. Our results suggest that fluorescence lifetime imaging can be a very powerful tool to monitor lipid droplet formation in adipocytes from 3T3-L1 cells.

  5. Increased Association of Dynamin Ⅱ with Myosin Ⅱ in Ras Transformed NIH3T3 Cells

    Soon-Jeong JEONG; Su-Gwan KIM; Jiyun YOO; Mi-Young HAN; Joo-Cheol PARK; Heung-Joong KIM; Seong Soo KANG; Baik-Dong CHOI; Moon-Jin JEONG

    2006-01-01

    Dynamin has been implicated in the formation of nascent vesicles through both endocytic and secretory pathways. However, dynamin has recently been implicated in altering the cell membrane shape during cell migration associated with cytoskeleton-related proteins. Myosin Ⅱ has been implicated in maintaining cell morphology and in cellular movement. Therefore, reciprocal immunoprecipitation was carried out to identify the potential relationship between dynamin Ⅱ and myosin Ⅱ. The dynamin Ⅱ expression level was higher when co-expressed with myosin Ⅱ in Ras transformed NIH3T3 cells than in normal NIH3T3 cells.Confocal microscopy also confirmed the interaction between these two proteins. Interestingly, exposing the NIH3T3 cells to platelet-derived growth factor altered the interaction and localization of these two proteins.The platelet-derived growth factor treatment induced lamellipodia and cell migration, and dynamin Ⅱ interacted with myosin Ⅱ. Grb2, a 24 kDa adaptor protein and an essential element of the Ras signaling pathway,was found to be associated with dynamin Ⅱ and myosin Ⅱ gene expression in the Ras transformed NIH3T3 cells. These results suggest that dynamin Ⅱ acts as an intermediate messenger in the Ras signal transduction pathway leading to membrane ruffling and cell migration.

  6. Quantitative PET imaging with the 3T MR-BrainPET

    The new hybrid imaging technology of MR-PET allows for simultaneous acquisition of versatile MRI contrasts and the quantitative metabolic imaging with PET. In order to achieve the quantification of PET images with minimal residual error the application of several corrections is crucial. In this work we present our results on quantification with the 3T MR BrainPET scanner

  7. Isoproterenol Increases Uncoupling, Glycolysis, and Markers of Beiging in Mature 3T3-L1 Adipocytes.

    Colette N Miller

    Full Text Available Beta-adrenergic activation stimulates uncoupling protein 1 (UCP1, enhancing metabolic rate. In vitro, most work has studied brown adipocytes, however, few have investigated more established adipocyte lines such as the murine 3T3-L1 line. To assess the effect of beta-adrenergic activation, mature 3T3-L1s were treated for 6 or 48 hours with or without isoproterenol (10 and 100 μM following standard differentiation supplemented with thyroid hormone (T3; 1 nM. The highest dose of isoproterenol increased lipid content following 48 hours of treatment. This concentration enhanced UCP1 mRNA and protein expression. The increase in UCP1 following 48 hours of isoproterenol increased oxygen consumption rate. Further, coupling efficiency of the electron transport chain was disturbed and an enhancement of glycolytic rate was measured alongside this, indicating an attempt to meet the energy demands of the cell. Lastly, markers of beige adipocytes (protein content of CD137 and gene transcript of CITED1 were also found to be upregulated at 48 hours of isoproterenol treatment. This data indicates that mature 3T3-L1 adipocytes are responsive to isoproterenol and induce UCP1 expression and activity. Further, this finding provides a model for further pharmaceutical and nutraceutical investigation of UCP1 in 3T3-L1s.

  8. 26 CFR 1.954-3T - Foreign base company sales income (temporary).

    2010-04-01

    ... (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Controlled Foreign Corporations § 1.954-3T Foreign base... 26 Internal Revenue 10 2010-04-01 2010-04-01 false Foreign base company sales income (temporary... similar establishment has substantially the same tax effect as if such branch or similar...

  9. High-resolution MR imaging of the knee at 3 T

    In order to examine the practical feasibility of using a 3.0-T MR unit to obtain high-quality, high-resolution images of the knee joint, one human cadaveric and 5 porcine knees were imaged with the 3.0-T unit. Sets of T1-weighted spin echo images were obtained with in-plane resolution of 0.195x0.39 mm and an acquisition time of approximately 5 min. Two porcine knees were also imaged with the 1.0-T unit with an identical imaging protocol and the signal-to-noise (S/N) ratios were measured on images at 3 T and 1 T. The 3-T MR system provided detailed delineation of the knees. Deep layers of the medial collateral ligament and associated fine fibers beneath the medial and lateral collateral ligament were demarcated. We observed precise demonstration of the tibial attachment of the anterior cruciate ligament, irregularity of the meniscal free edge, and conjoint tendon formation together with the lateral collateral ligament and the biceps femoris tendon. Compared to the 1-T unit, the S/N ratio with the 3-T unit was increased by a factor of 1.39 to 1.72. Due to the potential advantage of obtaining detailed images, the 3-T MR system suggests a practical utility for fine demonstration of the knee morphology

  10. 26 CFR 1.181-3T - Qualified film or television production (temporary).

    2010-04-01

    ... season of programming. (3) Exception for certain sexually explicit productions. A production does not... 26 Internal Revenue 3 2010-04-01 2010-04-01 false Qualified film or television production... (continued) § 1.181-3T Qualified film or television production (temporary). (a) In general. The...

  11. MAGNET

    Benoit Curé

    The cooling down to the nominal temperature of 4.5 K was achieved at the beginning of August, in conjunction with the completion of the installation work of the connection between the power lines and the coil current leads. The temperature gradient on the first exchanger of the cold box is now kept within the nominal range. A leak of lubricant on a gasket of the helium compressor station installed at the surface was observed and several corrective actions were necessary to bring the situation back to normal. The compressor had to be refilled with lubricant and a regeneration of the filters and adsorbers was necessary. The coil cool down was resumed successfully, and the cryogenics is running since then with all parameters being nominal. Preliminary tests of the 20kA coil power supply were done earlier at full current through the discharge lines into the dump resistors, and with the powering busbars from USC5 to UXC5 without the magnet connected. On Monday evening August 25th, at 8pm, the final commissionin...

  12. MAGNET

    Benoit Curé

    2013-01-01

    Maintenance work and consolidation activities on the magnet cryogenics and its power distribution are progressing according to the schedules. The manufacturing of the two new helium compressor frame units has started. The frame units support the valves, all the sensors and the compressors with their motors. This activity is subcontracted. The final installation and the commissioning at CERN are scheduled for March–April 2014. The overhauls of existing cryogenics equipment (compressors, motors) are in progress. The reassembly of the components shall start in early 2014. The helium drier, to be installed on the high-pressure helium piping, has been ordered and will be delivered in the first trimester of 2014. The power distribution for the helium compressors in SH5 on the 3.3kV network is progressing. The 3.3kV switches, between each compressor and its hot spare compressor, are being installed, together with the power cables for the new compressors. The 3.3kV electrical switchboards in SE5 will ...

  13. Isolation and characterization of NIH 3T3 cells expressing polyomavirus small T antigen

    The polyomavirus small T-antigen gene, together with the polyomavirus promoter, was inserted into retrovirus vector pGV16 which contains the Moloney sarcoma virus long terminal repeat and neomycin resistance gene driven by the simian virus 40 promoter. This expression vector, pGVST, was packaged into retrovirus particles by transfection of PSI2 cells which harbor packaging-defective murine retrovirus genome. NIH 3T3 cells were infected by this replication-defective retrovirus containing pGVST. Of the 15 G418-resistant cell clones, 8 express small T antigen at various levels as revealed by immunoprecipitation. A cellular protein with an apparent molecular weight of about 32,000 coprecipitates with small T antigen. Immunofluorescent staining shows that small T antigen is mainly present in the nuclei. Morphologically, cells expressing small T antigen are indistinguishable from parental NIH 3T3 cells and have a microfilament pattern similar to that in parental NIH 3T3 cells. Cells expressing small T antigen form a flat monolayer but continue to grow beyond the saturation density observed for parental NIH 3T3 cells and eventually come off the culture plate as a result of overconfluency. There is some correlation between the level of expression of small T antigen and the growth rate of the cells. Small T-antigen-expressing cells form small colonies in soft agar. However, the proportion of cells which form these small colonies is rather small. A clone of these cells tested did not form tumors in nude mice within 3 months after inoculation of 106 cells per animal. Thus, present studies establish that the small T antigen of polyomavirus is a second nucleus-localized transforming gene product of the virus (the first one being large T antigen) and by itself has a function which is to stimulate the growth of NIH 3T3 cells beyond their saturation density in monolayer culture

  14. Razão, regulação e ritmos nas interações discursivas

    Jairo Ferreira

    2001-02-01

    Full Text Available A compreensão dos processos cognitivos em interações discursivas nos marcos do estruturalismo genético de Jean Piaget permite uma síntese entre a compreensão dos processos lógicos e operatórios sugeridos pelo racionalismo, das regulações sociais através da negociação e contratos entre os interlocutores conforme a análise do discurso (Charaudeau e dos ritmos (inclusive os rituais observados pela antropologia.  O artigo discute esta perspectiva genética e depois, por inferência, sugere ligações teóricas e de método para análise sócio-cognitiva do discurso.

  15. Interação Social e Mediação em Ambientes Digitais de Aprendizagem com Sujeitos com Autismo

    Liliana M Passerino

    2009-07-01

    Full Text Available A partir de uma concepção sócio-histórica da interação social e
    considerando as Tecnologias de Comunicação e Informação  (TICs disponíveis atualmente para a construção de Ambientes Digitais de Aprendizagem (ADA procurou-se sanar a inexistência de dados empíricos relativos ao fenômeno de interação social de pessoas autistas mediado pela tecnologia. A presente pesquisa propõe uma visão diferenciada sobre os processos de interação e mediação que se estabelecem em ambientes digitais. Estruturada como um estudo multicasos com observação de grupos de autistas em atividades de
    interação mediadas por ADAs ao longo de 3 anos  identificaram-se categorias relevantes emergentes dessa mediação tecnológica com contribuições importantes para as areas envolvidas (Psicologia, Educação e Computação na construção de um ambiente digital de aprendizagem especialmente projetado levando em conta os resultados obtidos.

  16. Cultura e discurso: uma análise translinguística de interações de teletandem = Culture and discourse: a translinguistic analysis of teletandem interactions

    Zakir, Maisa de Alcântara

    2016-01-01

    Full Text Available O projeto Teletandem e Transculturalidade na interação on-line em línguas estrangeiras por webcam é desenvolvido desde 2010 e coloca aprendizes de línguas estrangeiras no Brasil em contato com aprendizes de língua portuguesa no exterior em interações via Skype. O contexto no qual este estudo se desenvolveu é denominado teletandem institucional semi-integrado, por ser integrado ao currículo da universidade estrangeira parceira do projeto e não-integrado ao currículo da universidade brasileira. O objetivo do trabalho é analisar interações de teletandem entre uma aluna do curso intermediário de língua portuguesa de uma universidade privada estadunidense e um professor aprendiz de inglês como língua estrangeira que trabalha em uma universidade pública brasileira. As interações entre os participantes da pesquisa foram analisadas na perspectiva da Análise Dialógica do Discurso, fundamentada na obra de Bakhtin e do Círculo. Os resultados da análise evidenciam os papéis sociais identificados no discurso dos interagentes em discussões sobre aspectos culturais

  17. Interações sociais de crianças pré-escolares com Síndrome de Down durante atividades extracurriculares

    Renata Valdívia Lucisano

    2013-02-01

    Full Text Available O objetivo desta pesquisa foi identificar o processo de interação social de crianças com Síndrome de Down (SD durante atividades extracurriculares na rede regular de educação infantil do município de Ribeirão Preto. Participaram da pesquisa seis crianças na faixa etária de 3 a 6 anos. Foram realizadas duas filmagens de cada criança em situações de interação social durante atividades extracurriculares, e analisadas através de quinze comportamentos, distribuídos em duas categorias de habilidades sociais: interpessoais e de autoexpressão. Os resultados demonstraram que, quanto às habilidades interpessoais, houve maior ocorrência do comportamento "ocorre interação com outra criança". Já na categoria habilidades de autoexpressão, apenas os comportamentos "sorri" e "imita outras crianças" apresentam ocorrência significativa. Os comportamentos mais frequentes encontrados neste estudo permitem compreender que o ambiente escolar torna-se um facilitador na interação da criança com SD com outras crianças de desenvolvimento típico, possibilitando o desenvolvimento das habilidades sociais esperadas.

  18. Análise de interações medicamentosas e alimentares em pacientes com AIDS em uso da TARV associada à terapia de resgate

    Adriana Antônia Cruz Furini

    2016-07-01

    Full Text Available A combinação de antirretrovirais da terapia de resgate na Síndrome da Imunodeficiência Adquirida aumenta os riscos de interações medicamentosas e alimentares. Este estudo teve como objetivo analisar o risco de interações medicamentosas e alimentares no uso da terapia antirretroviral com medicamentos do resgate por 40 pacientes com AIDS de um Hospital quaternário da região Noroeste paulista. Trata-se de um estudo exploratório-descritivo de abordagem quantitativa e qualitativa, realizado no período entre2012 e 2013. Os pacientes foram entrevistados através de questionário elaborado pela equipe multidisciplinar de saúde. As entrevistas foram realizadas pela equipe de farmacêuticos. As interações foram avaliadas por bases de dados informatizados. O esquema composto por darunavir, enfuvirtida, lamivudina, raltegravir e ritonavir foi o mais utilizado (32,5% pelos pacientes. Os antirretrovirais que mais apresentaram risco de interações alimentares foram ritonavir, darunavir e tenofovir, em 31 (77,5%, 29 (72,5% e 21 (52,5% pacientes, respectivamente. Foram identificados 87 tipos de potenciais interações medicamentosas, e sete foram classificadas como de nível maior. Neste estudo todas as prescrições apresentaram riscos para interações medicamentosas e demonstraram a importância do monitoramento pela equipe multidisciplinar. Contudo, a maioria das interações medicamentosas foi benéfica, decorrentes da potencialização do efeito terapêutico em consequência do sinergismo entre os fármacos da terapia antirretroviral. A interação entre farmacêuticos e prescritores pode contribuir para a farmacoterapia racional e segura do paciente.Palavras-chave: Síndrome de Imunodeficiência Adquirida. HIV. Antirretrovirais. Interações de Medicamentos. Interações Alimento-Droga. ABSTRACTAnalysis of drug and food interactions in AIDS patients in use of ART associated with rescue therapyThe combination of antiretroviral agents of

  19. Production of antisera and development of radioimmunoassay for serum T3, T4, and ferritin

    In this study twelve local rabbits and sixteen New-zealand rabbits were subjected to immunization against T3 and T4 immunogens. Two local sheep (ovis aris) were immunized against human liver ferritin. The T3 and T4 immunogens were prepared by conjugation of the haptens to carrier proteins (bovine serum albumin ''BSA'' and horse serum protein ''HSP''), using water soluble carboiimide as coupling agent. The local and New-zealand rabbits were immunized against these conjugates emulsified in freund's complete adjuvant (FCA) in the first and second injections, and emulsified in freund's incomplete adjuvant (FIA) in the following injections. The blood samples obtained from rabbits after each injection were tested for antibodies as well as for the effect of immunization on rabbits biochemical and haematological parameters. The blood samples obtained from sheep were tested for anti-ferritin antibodies using crude antiserum, then this antiserum was purified using ammonium sulphate. A part of it was adsorbed physically onto polystyrene beads while the other part was linked chemically to magnitisable particles inorder to develop to IRMAs. The purified antiferritin antibody was diluted 200,000 folds before being coated to polystyrene beads, and different dilutions were tried with coupling to magnetic solid phase. Optimization and validation procedures for the two IRMAs ferritin were performed. The results obtained showed poor response of rabbits to immunization against T3 and T4 immunogen conjugates, where the percent bound (B%) of tracer with the antibody ranged from (0.0-22%) for local rabbits using charcoal seperation technique, and (0.0-2.9%) using second antibody precipitation technique. The B% for the antiserum obtained from New-zealand rabbits ranged from (0.0-18.1) using second antibody precipitation technique. Serum T3, T4 and TSH of the immunized rabbits were measured and found to be not significantly different form the controls (p=0.2211, 0.098, 0.35 respectively

  20. Age dependency of myocardial triglyceride content. A 3T high-field {sup 1}H-MR spectroscopy study

    Petritsch, B.; Gassenmaier, T.; Kunz, A.S.; Donhauser, J.; Bley, T.A.; Horn, M. [University Hospital of Wuerzburg (Germany). Inst. of Diagnostic and Interventional Radiology; Goltz, J.P. [University Hospital of Schleswig-Holstein, Campus Luebeck (Germany). Clinic for Radiology and Nuclear Medicine

    2015-11-15

    The role of myocardial triglyceride (mTG) content in the aging human heart is not entirely understood. The aim of this study was to measure concentrations of mTG content from healthy volunteers and to determine the association between age, mTG content and systolic heart function. Furthermore, the technical stability of the {sup 1}H-magnetic resonance spectroscopy ({sup 1}H-MRS) and the reliability of peak evaluation at 3 T were evaluated. The total study population of 47 healthy volunteers was divided into 4 age classes, according to the age of the subjects (1{sup st} cohort 20-29 years (yrs.), n=20; 2{sup nd} cohort 30-39 yrs., n=10; 3{sup rd} cohort 40-49 yrs., n=9; 4{sup th} cohort 50-60 yrs., n=8). Cardiac MRI and double triggered {sup 1}H-MRS of the myocardium were consecutively performed using a 3 T scanner. Each participant underwent spectroscopic measurements twice in the same investigation. mTG content increases with age. The correlation of age and mTG is minimal (r=0.48; p<0.001). The following age-averaged mTG content values expressed as % of mTG signal compared to the water signal were determined for each cohort: 1{sup st} cohort 0.25 % (± 0.17); 2{sup nd} cohort 0.48 % (± 0.30); 3{sup rd} cohort 0.48 % (± 0.18); 4{sup th} cohort 0.77 % (± 0.70). There was no significant correlation (r=0.04; p=n.s.) between LV mass and mTG content in healthy volunteers. Within our cohorts, no effects of age or mTG content on systolic heart function were seen (r=-0.01; p=n.s.). The intraclass correlation coefficient of spectroscopic measurements was high (r=0.965; p<0.001). Myocardial TG content increases with age. The normal age-dependent concentration ranges of myocardial lipid metabolites reported in this study may be helpful for the correction of acquired {sup 1}H-MRS data in patients when evaluating metabolic and cardiovascular diseases in future magnetic resonance spectroscopy studies.

  1. Amide Proton Transfer Weighted Imaging of the Head and Neck at 3T: A Feasibility Study on Healthy Human Subjects and Patients with Head and Neck Cancer

    Yuan, Jing; Chen, Shuzhong; King, Ann D.; Zhou, Jinyuan; Bhatia, Kunwar S.; Zhang, Qinwei; Yeung, David Ka Wei; WEI, JUAN; Mok, Greta Seng Peng; Wang, Yi-Xiang

    2014-01-01

    The aim of this study was to explore the feasibility and repeatability of amide proton transfer weighted (APTw) MRI for the head and neck on clinical MRI scanners. Six healthy volunteers and four patients with head and neck tumors underwent APTw-MRI scanning at 3T. The APTw signal was quantified by the asymmetric magnetization transfer ratio (MTRasym) at 3.5 ppm. Z-spectra of normal tissues in the head and neck (masseter muscle, parotid glands, submandibular glands and thyroid glands) were an...

  2. Comparison of real-time water proton spectroscopy and echo-planar imaging sensitivity to the BOLD effect at 3 T and at 7 T.

    Yury Koush

    Full Text Available Gradient-echo echo-planar imaging (GE EPI is the most commonly used approach to assess localized blood oxygen level dependent (BOLD signal changes in real-time. Alternatively, real-time spin-echo single-voxel spectroscopy (SE SVS has recently been introduced for spatially specific BOLD neurofeedback at 3 T and at 7 T. However, currently it is not known how neurofeedback based on real-time SE SVS compares to real-time GE EPI-based. We therefore compared both methods at high (3 T and at ultra-high (7 T magnetic field strengths. We evaluated standard quality measures of both methods for signals originating from the motor cortex, the visual cortex, and for a neurofeedback condition. At 3 T, the data quality of the real-time SE SVS and GE EPI R2* estimates were comparable. At 7 T, the data quality of the real-time GE EPI acquisitions was superior compared to those of the real-time SE SVS. Despite the somehow lower data quality of real-time SE SVS compared to GE EPI at 7 T, SE SVS acquisitions might still be an interesting alternative. Real-time SE SVS allows for a direct and subject-specific T2* estimation and thus for a physiologically more plausible neurofeedback signal.

  3. Evaluation of acute renal colic: a comparison of non-contrast CT versus 3-T non-contrast HASTE MR urography.

    Semins, M J; Feng, Z; Trock, B; Bohlman, M; Hosek, W; Matlaga, B R

    2013-02-01

    With the introduction of a 3-T scanner, magnetic resonance urography (MRU) may be an alternative imaging modality for evaluation of acute renal colic. We performed a prospective study to compare the performance of computed tomography (CT) with half-Fourier single shot turbo spin-echo (HASTE) MRU in the evaluation of patients with suspected renal colic. Patients presenting to the emergency department with acute renal colic were eligible for inclusion. Following a standard CT stone evaluation, patients underwent a non-contrast HASTE MRU study with a 3-T scanner. The presence of perinephric fluid, hydronephrosis, ureteral obstruction, and calculus was assessed. A total of 22 patients completed the study. Twenty (91 %) were diagnosed with an upper tract stone by radiographic findings. MRU detected a discrete stone in 50 % of the patients with stones detected by CT. Perinephric fluid was noted in 12 MRUs, compared to 7 CTs. Using CT as the reference standard, the combination of stone or perinephric fluid and ureteral dilation gave MRU a sensitivity of 84 %, specificity of 100 %, and accuracy of 86 % (95 % CI 0.72-1.0). HASTE MRU with a 3-T MR scanner can reliably detect the presence of upper urinary tract obstruction. Although CT imaging remains the superior modality with which to detect calculi, MRU detects a greater number of secondary signs of upper tract obstruction. For situations in which the use of ionizing radiation is undesirable, MRU is a reasonable imaging alternative. PMID:23532422

  4. Collagen gel containing 3T3 fibroblasts (dermal equivalent for raft culture)

    sprotocols

    2014-01-01

    Author: Matt Lewis ### Ingredients for 6 x collagen matrices in a 6-well plate 1. Roughly 3x10e6 J2-3T3s (a fully confluent T75?) - 1.5mL 10x reconstitution buffer - 1.5mL 10x DMEM - 12mL rat tail type 1 collagen (>3.8mg/mL) - 10N NaOH - Glacial acetic acid (in case) ### Method 1. Pre-chill pipettes, keep collagen on ice - *The collagen solidifies above 8ºC* - Mix 1.5mL of 10x DMEM with 1.5mL of 10x reconstitution buffer, keep on ice. Count J2-3T3s...

  5. The Holy Grail in diagnostic neuroradiology: 3T or 3D?

    Pouwels, Petra J. W.; Wattjes, Mike P.

    2010-01-01

    Many technical developments keep occurring in the field of MRI that could benefit image acquisition in the field of diagnostic neuroradiology. While there is much focus on the potential advantages of 3T and higher field strengths, it is often unclear whether these are cosmetic only, or convey clinically relevant diagnostic value. The increased signal-to-noise at 3T is certainly beneficial in different ways particularly for the acquisition of isotropic 3D sequences like FLAIR. Single-slab 3D sequences can now be obtained with multiple contrasts in clinically attainable data acquisition times and could revolutionize MRI to evolve into a fundamentally multi-planar technique, rather similar to what has happened with the introduction of multi-detector row CT. PMID:21181406

  6. Human papillomavirus type 16 DNA-induced malignant transformation of NIH 3T3 cells

    A biological function for human papillomavirus 16 (HPV 16) DNA was demonstrated by transformation of NIH 3T3 cells. HPV 16 DNA has been found frequently in genital cancer and has been classified as a papillomavirus on the basis of DNA homology. A recombinant HPV 16 DNA (pSHPV16d), which contains a head-to-tail dimer of the full-length HPV 16 genome, induced morphologic transformation; the transformed cells were tumorigenic in nude mice. Expression of transforming activity was unique because of the long latency period (more than 4 weeks) required for induction of morphologic transformation and because the transfected DNA existed primarily in a multimeric form with some rearrangement. Furthermore, virus-specific RNAs were expressed in the transformants. The transformation of NIH 3T3 cells provides a model for analyzing the functions of HPV 16, which is associated with cervical carcinomas

  7. Regulation of p53 in NIH3T3 mouse fibroblasts following hyperosmotic stress

    Lambert, Ian Henry; Enghoff, Maria Stine; Brandi, Marie-Luise;

    2015-01-01

    The aim of this project was to analyze the regulation of p53 expression in NIH3T3 fibroblasts under the influence of increasing hyperosmotic stress. Expression of p53 showed a biphasic response pattern in NIH3T3 cells under increasing osmotic stress (337 mOsm to 737 mOsm) with a maximum at 587 m......Osm. Under isotonic conditions p53 expression increased after addition of the proteasome inhibitor MG132 indicating that cellular p53 levels in unperturbed cells is kept low by proteasomal degradation. However, under hypertonic conditions p53 synthesis as well as p53 degradation were significantly reduced...... and it is demonstrated that the increase in p53 expression observed when tonicity is increased from 337 to 587 mOsm reflects that degradation is more inhibited than synthesis, whereas the decrease in p53 expression at higher tonicities reflects that synthesis is more inhibited than degradation. The...

  8. High-quality genome sequence and description of Bacillus ndiopicus strain FF3T sp. nov.

    C.I. Lo

    2015-11-01

    Full Text Available Strain FF3T was isolated from the skin-flora of a 39-year-old healthy Senegalese man. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry did not allow any identification. This strain exhibited a 16S rRNA sequence similarity of 96.8% with Bacillus massiliensis, the phylogenetically closest species with standing nomenclature. Using a polyphasic study made of phenotypic and genomic analyses, strain FF3T was Gram-positive, aeroanaerobic and rod shaped and exhibited a genome of 4 068 720 bp with a G+C content of 37.03% that coded 3982 protein-coding and 67 RNA genes (including four rRNA operons. On the basis of these data, we propose the creation of Bacillus ndiopicus sp. nov.

  9. MANTIS-3T: a low-cost light-weight turreted spectral sensor

    Dirbas, Joseph; Mireles, Tony; Davies, Adam; Schoonmaker, Jon; Lovett, Alexander R.

    2005-05-01

    PAR Government Systems Corporation (PAR) has developed a low-cost, low-weight, low-profile, mission-adaptable multispectral imaging system utilizing mass-produced commercial off-the-shelf (COTS) components, for the purpose of providing continuous real-time multispectral data collection for mine counter measures (MCM), intelligence, surveillance, and reconnaissance study applications aboard low-cost, light manned and unmanned aircraft platforms. The mission adaptable narrowband tunable imaging system (MANTIS) has been integrated into a small 5" turret currently employed on a variety of small UAV platforms. The turreted MANTIS (MANTIS-3T) provides remote operator control to adjust gain, exposure, and pointing commands. The MANTIS-3T sensor will be used to collect imagery over calibration and test targets. Integration strategies and planned data collections are presented.

  10. Polyamine metabolism is involved in adipogenesis of 3T3-L1 cells

    Ishii, Ikumi; Ikeguchi, Yoshihiko; Mano, Hiroshi; Wada, Masahiro; Pegg, Anthony E.; Shirahata, Akira

    2011-01-01

    Polyamines spermidine and spermine are known to be required for mammalian cell proliferation and for embryonic development. Alpha-difluoromethylornithine (DFMO), an inhibitor of ornithine decarboxylase (ODC) a limiting enzyme of polyamine biosynthesis, depleted the cellular polyamines and prevented triglyceride accumulation and differentiation in 3T3-L1 cells. In this study, to explore the function of polyamines in adipogenesis, we examined the effect of polyamine biosynthesis inhibitors on a...

  11. Latent insulin receptors and possible receptor precursors in 3T3-L1 adipocytes.

    Deutsch, P J; Wan, C F; Rosen, O M; Rubin, C S

    1983-01-01

    Cell surface and cryptic insulin receptors were solubilized from the particulate fraction of murine 3T3-L1 adipocytes with buffer containing 1% Triton X-100. Solubilized receptors were affinity crosslinked with 125I-labeled insulin and disuccinimidyl suberate and characterized by sodium dodecyl sulfate/polyacrylamide gel electrophoresis and autoradiography after specific immunoprecipitation. Two insulin-binding polypeptides were identified: the more abundant protein had a Mr of 130,000, corre...

  12. Rosiglitazone Balances Insulin-Induced Exo- And Endocytosis In Single 3t3-L1 Adipocytes

    Velebit, Jelena; Chowdhury, Helena H.; Kreft, Marko; Zorec, Robert

    2011-01-01

    Abstract Rosiglitazone (Rosi) improves insulin sensitivity and increases the translocation of glucose transporter 4 (GLUT4) to the plasma membrane (PM). This involves the fusion of membrane-bound compartments with the plasma membrane, thus increasing the plasma membrane area. However, recent work has shown that in Rosi-pretreated 3T3-L1 adipocytes membrane area did not increase following insulin application, suggesting that the rates of exo- and endocytosis are balanced. Here we ex...

  13. Stevioside from Stevia rebaudiana Bertoni Increases Insulin Sensitivity in 3T3-L1 Adipocytes

    Nabilatul Hani Mohd-Radzman; Wan Iryani Wan Ismail; Siti Safura Jaapar; Zainah Adam; Aishah Adam

    2013-01-01

    Stevioside from Stevia rebaudiana has been reported to exert antihyperglycemic effects in both rat and human subjects. There have been few studies on these effects in vitro. In this paper, radioactive glucose uptake assay was implemented in order to assess improvements in insulin sensitivity in 3T3-L1 cells by elevation of glucose uptake following treatment with stevioside. Oil Red-O staining and MTT assay were utilized to confirm adipocyte differentiation and cell viability, respectively. Fi...

  14. Polyclonal B-cell stimulation by L3T4+ T cells in experimental leishmaniasis.

    Lohoff, M; Matzner, C; Röllinghoff, M

    1988-01-01

    The well-established polyclonal B-cell stimulation in the lymphoid organs in mice infected with Leishmania major is thought to be dependent on T cells. Here we present clear experimental evidence that this is indeed the case by showing that BALB/c-derived, L3T4-positive L. major-specific T cells induce syngeneic B cells to polyclonal proliferation and immunoglobulin production. PMID:3260894

  15. Vasopressin induces selective desensitization of its mitogenic response in Swiss 3T3 cells.

    Collins, M.K.; Rozengurt, E

    1983-01-01

    Prior incubation of quiescent cultures of Swiss 3T3 cells with vasopressin leads to loss of mitogenic stimulation on its subsequent addition in the presence of a synergistic growth factor. This desensitization is selective for vasopressin, requires prolonged incubation (half-maximal desensitization after 12 hr of treatment) for its induction, and is reversed after a 48-hr incubation in the absence of vasopressin. It is elicited by concentrations of vasopressin, and several analogues, similar ...

  16. Molecular cloning of the bombesin/gastrin-releasing peptide receptor from Swiss 3T3 cells.

    Battey, J F; Way, J M; Corjay, M H; Shapira, H; Kusano, K; Harkins, R.; Wu, J M; Slattery, T; Mann, E.; Feldman, R I

    1991-01-01

    The mammalian bombesin-like peptides gastrin-releasing peptide (GRP) and neuromedin B regulate numerous and varied cell physiologic processes in various cell types and have also been implicated as autocrine growth factors influencing the pathogenesis and progression of human small cell lung carcinomas. We report here the molecular characterization of the bombesin/GRP receptor. Structural analysis of cDNA clones isolated from Swiss 3T3 murine embryonal fibroblasts shows that the GRP receptor i...

  17. Quantifying coronary sinus flow and global LV perfusion at 3T

    Bloch Karin

    2009-06-01

    Full Text Available Abstract Background Despite the large availability of 3T MR scanners and the potential of high field imaging, this technical platform has yet to prove its usefulness in the cardiac MR setting, where 1.5T remains the established standard. Global perfusion of the left ventricle, as well as the coronary flow reserve (CFR, can provide relevant diagnostic information, and MR measurements of these parameters may benefit from increased field strength. Quantitative flow measurements in the coronary sinus (CS provide one method to investigate these parameters. However, the ability of newly developed faster MR sequences to measure coronary flow during a breath-hold at 3T has not been evaluated. Methods The aim of this work was to measure CS flow using segmented phase contrast MR (PC MR on a clinical 3T MR scanner. Parallel imaging was employed to reduce the total acquisition time. Global LV perfusion was calculated by dividing CS flow with left ventricular (LV mass. The repeatability of the method was investigated by measuring the flow three times in each of the twelve volunteers. Phantom experiments were performed to investigate potential error sources. Results The average CS flow was determined to 88 ± 33 ml/min and the deduced LV perfusion was 0.60 ± 0.22 ml/min·g, in agreement with published values. The repeatability (1-error of the three repeated measurements in each subject was on average 84%. Conclusion This work demonstrates that the combination of high field strength (3T, parallel imaging and segmented gradient echo sequences allow for quantification of the CS flow and global perfusion within a breath-hold.

  18. The intracellular mechanism of alpha-fetoprotein promoting the proliferation of NIH 3T3 cells

    2002-01-01

    AIM The existence and properties of alpha-fetoprotein (AFP) receptor on the surface of NIH 3T3 cells and the effects of AFP on cellular signal transduction pathway were investigated. METHODS The effect of AFP on the proliferation of NIH 3T3 cells was measured by incorporation of 3H-TdR. Receptor-binding assay of 125I-AFP was performed to detect the properties of AFP receptor in NIH 3T3 cells. The influences of AFP on the [cAMP]i and the activities of protein kinase A (PKA) were determined. Western blot was used to detect the change of K-ras P21 protein expression. RESULTS The proliferation of NIH 3T3 cells treated with 0-80 mg/L of AFP was significantly enhanced. The Scatchard analysis indicated that there were two classes of binding sites with KD of 2.722×10-9M (Bmax=12810 sites per cell) and 8.931× 10-SM (Bmax=l19700 sites per cell) respectively. In the presence of AFP (20 mg/L), the content of cAMP and activities of PKA were significantly elevated . The level of K-ras P21 protein was upregulated by AFP at the concentration of 20 mg/L. The monoclonal antibody against AFP could reverse the effects of AFP on the cAMP content, PKA activity and the expression of K-ras p21 gene. CONCLUSION The effect of AFP on the cell proliferation was achieved by binding its receptor to trigger the signal transduction pathway of cAMP-PKA and alter the expression of K- ras p21 gene.

  19. Xylitol does not directly affect adiponectin productionand adipogenesis in 3T3-L1 cells

    Pilaiwan Siripurkpong; Sompoch Prajan; Sudawadee Kongkhum

    2014-01-01

    Xylitol is widely used as a low-calorie sweetener in various kinds of food products, including diabetic foods. Adiponectin, secreted by adipocytes, plays a key role in carbohydrate and lipid metabolism. Low levels of plasma adiponectin are associated with cardiovascular disease and type II diabetes. The aims of this study were to determine effects of xylitol on the adipogenesis of pre-adipocytes, adiponectin synthesis and secretion. To assess adipogenesis, pre-adipocyte 3T3-L1 cel...

  20. Ginkgolide C Suppresses Adipogenesis in 3T3-L1 Adipocytes via the AMPK Signaling Pathway

    Chian-Jiun Liou

    2015-01-01

    Full Text Available Ginkgolide C, isolated from Ginkgo biloba leaves, is a flavone reported to have multiple biological functions, from decreased platelet aggregation to ameliorating Alzheimer disease. The study aim was to evaluate the antiadipogenic effect of ginkgolide C in 3T3-L1 adipocytes. Ginkgolide C was used to treat differentiated 3T3-L1 cells. Cell supernatant was collected to assay glycerol release, and cells were lysed to measure protein and gene expression related to adipogenesis and lipolysis by western blot and real-time PCR, respectively. Ginkgolide C significantly suppressed lipid accumulation in differentiated adipocytes. It also decreased adipogenesis-related transcription factor expression, including peroxisome proliferator-activated receptor and CCAAT/enhancer-binding protein. Furthermore, ginkgolide C enhanced adipose triglyceride lipase and hormone-sensitive lipase production for lipolysis and increased phosphorylation of AMP-activated protein kinase (AMPK, resulting in decreased activity of acetyl-CoA carboxylase for fatty acid synthesis. In coculture with an AMPK inhibitor (compound C, ginkgolide C also improved activation of sirtuin 1 and phosphorylation of AMPK in differentiated 3T3-L1 cells. The results suggest that ginkgolide C is an effective flavone for increasing lipolysis and inhibiting adipogenesis in adipocytes through the activated AMPK pathway.

  1. Comparison of 3 T and 7 T MRI clinical sequences for ankle imaging

    The purpose of this study was to compare 3 T and 7 T signal-to-noise and contrast-to noise ratios of clinical sequences for imaging of the ankles with optimized sequences and dedicated coils. Ten healthy volunteers were examined consecutively on both systems with three clinical sequences: (1) 3D gradient-echo, T1-weighted; (2) 2D fast spin-echo, PD-weighted; and (3) 2D spin-echo, T1-weighted. SNR was calculated for six regions: cartilage; bone; muscle; synovial fluid; Achilles tendon; and Kager's fat-pad. CNR was obtained for cartilage/bone, cartilage/fluid, cartilage/muscle, and muscle/fat-pad, and compared by a one-way ANOVA test for repeated measures. Mean SNR significantly increased at 7 T compared to 3 T for 3D GRE, and 2D TSE was 60.9% and 86.7%, respectively. In contrast, an average SNR decrease of almost 25% was observed in the 2D SE sequence. A CNR increase was observed in 2D TSE images, and in most 3D GRE images. There was a substantial benefit from ultra high-field MR imaging of ankles with routine clinical sequences at 7 T compared to 3 T. Higher SNR and CNR at ultra-high field MR scanners may be useful in clinical practice for ankle imaging. However, carefully optimized protocols and dedicated extremity coils are necessary to obtain optimal results.

  2. Prostanoid EP4 receptor is involved in suppression of 3T3-L1 adipocyte differentiation

    Prostaglandins (PGs) have been shown to play various roles in adipogenesis. In this study, we investigated on which PGE receptor subtypes are involved in the inhibition of 3T3-L1 preadipocyte differentiation. The triglyceride content of cells, used as an index of differentiation, was decreased when PGE2, the FP-agonist fluprostenol or dibutyryl cAMP, was exogenously added to differentiation cocktails. 3T3-L1 preadipocyte cells express mRNAs for the prostanoid EP4, FP, and IP receptors. PGE2 and the EP4 agonist AE1-329 increased cAMP levels in preadipocytes in a dose-dependent manner. AE1-329 suppressed the expression induction of differentiation marker genes such as resistin and peroxisome proliferator-activated receptor-γ. The inhibitory effect of PGE2 but not that of fluprostenol was reversed by the addition of the EP4 antagonist AE3-208. AE3-208 mimicked the differentiation-promoting effects of indomethacin. These results suggest that the EP4 receptor mediates the suppressive action of PGE2 in 3T3-L1 adipocyte differentiation

  3. Stevioside from Stevia rebaudiana Bertoni Increases Insulin Sensitivity in 3T3-L1 Adipocytes

    Nabilatul Hani Mohd-Radzman

    2013-01-01

    Full Text Available Stevioside from Stevia rebaudiana has been reported to exert antihyperglycemic effects in both rat and human subjects. There have been few studies on these effects in vitro. In this paper, radioactive glucose uptake assay was implemented in order to assess improvements in insulin sensitivity in 3T3-L1 cells by elevation of glucose uptake following treatment with stevioside. Oil Red-O staining and MTT assay were utilized to confirm adipocyte differentiation and cell viability, respectively. Findings from this research showed a significant increase in absorbance values in mature adipocytes following Oil Red-O staining, confirming the differentiation process. Stevioside was noncytotoxic to 3T3-L1 cells as cell viability was reduced by a maximum of 17%, making it impossible to determine its IC50. Stevioside increased glucose uptake activities by 2.1 times (p<0.001 in normal conditions and up to 4.4 times (p<0.001 in insulin-resistant states. At times, this increase was higher than that seen in positive control group treated with rosiglitazone maleate, an antidiabetic agent. Expressions of pY20 and p-IRS1 which were measured via Western blot were improved by stevioside treatment. In conclusion, stevioside has direct effects on 3T3-L1 insulin sensitivity via increase in glucose uptake and enhanced expression of proteins involved in insulin-signalling pathway.

  4. Arterial spin labelling at 3-T MR imaging for detection of individuals with Alzheimer's disease

    The purpose of this study was to determine whether arterial spin labelling (ASL) at 3-T MR imaging can be used to discriminate individuals with Alzheimer's disease (AD) from cognitively normal subjects. Twenty AD patients and 23 cognitively normal control subjects were studied using ASL on a 3-T MR imager. Absolute regional cerebral blood flow (rCBF) maps were calculated. In addition, normalized rCBF maps were obtained using CBF in the sensorimotor cortex for normalization. A voxel-wise comparison of these rCBF maps between the AD and control groups was performed using the two-sample t test. Individuals with AD were discriminated from control subjects based on mean rCBF values within a region-of-interest defined by the t test, and the discriminating performance was evaluated by the receiver operating characteristic (ROC) analysis. Comparisons of both absolute and normalized rCBF maps revealed areas of significant hypoperfusion caused by the effects of AD in the bilateral precunei and posterior cingulate gyri. ROC analyses resulted in area under the curve (AUC) values of 0.861 to 0.877 for absolute and 0.910 to 0.932 for normalized rCBF. Our results suggest that ASL at 3-T MR imaging can be used to help discriminate individuals with AD from normal subjects. (orig.)

  5. Software package r3t. Model for transport and retention in porous media. Final report

    In long-termsafety analyses for final repositories for hazardous wastes in deep geological formations the impact to the biosphere due to potential release of hazardous materials is assessed for relevant scenarios. The model for migration of wastes from repositories to men is divided into three almost independent parts: the near field, the geosphere, and the biosphere. With the development of r3t the feasibility to model the pollutant transport through the geosphere for porous or equivalent porous media in large, three-dimensional, and complex regions is established. Furthermore one has at present the ability to consider all relevant retention and interaction effects which are important for long-term safety analyses. These are equilibrium sorption, kinetically controlled sorption, diffusion into immobile pore waters, and precipitation. The processes of complexing, colloidal transport and matrix diffusion may be considered at least approximately by skilful choice of parameters. Speciation is not part of the very recently developed computer code r3t. With r3t it is possible to assess the potential dilution and the barrier impact of the overburden close to reality

  6. Radiation transformation of BALB/3T3 cells activates dominant transforming gene

    Radiation is known to induce DNA strand breaks, and cause cellular transformation. The biochemical events responsible for these effects are not well-established. The authors investigated the possible roles of gene rearrangement and gene amplification in the process of radiation transformation. BALB/3T3 cells were exposed to 100 to 400 cGy of gamma radiation, and transformed cell lines were established. These were characterized by colony-formation in soft agar and induction of in nude mice. DNA was isolated and transfected onto pre-neoplastic NIH3T3 cells. The transformation frequency increased from a control of 0.01 foci/microgram DNA (normal BALB/3T3) to 0.26 foci/microgram of radiation transformed DNA. To investigate whether a single dominant transforming gene was involved, transfection was repeated following digestion of DNA with multiple restriction endonucleases. No gross rearrangement in the DNAs of transformed cell lines was observed by the Southern-blot hybridization technique for six representative cellular oncogenes. In addition, the expression of these oncogenes was not altered as revealed by cytodot blot analysis

  7. Endoplasmic reticulum stress suppresses lipin-1 expression in 3T3-L1 adipocytes

    Takahashi, Nobuhiko, E-mail: ntkhs@hoku-iryo-u.ac.jp [Department of Internal Medicine, School of Dentistry, Health Sciences University of Hokkaido, 1757, Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1, Midorigaoka-Higashi, Asahikawa, Hokkaido 078-8510 (Japan); Yoshizaki, Takayuki [Innovation Center, Kagoshima University, 1-21-40, Korimoto, Kagoshima 890-0065 (Japan); Hiranaka, Natsumi; Suzuki, Takeshi [Department of Internal Medicine, School of Dentistry, Health Sciences University of Hokkaido, 1757, Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Yui, Tomoo; Akanuma, Masayoshi [Department of Fixed Prosthodontics and Oral Implantology, School of Dentistry, Health Sciences University of Hokkaido, 1757, Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Kanazawa, Kaoru [Department of Dental Anesthesiology, School of Dentistry, Health Sciences University of Hokkaido, 1757, Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Yoshida, Mika; Naito, Sumiyoshi [Department of Clinical Laboratory, Health Sciences University of Hokkaido, 1757, Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan); Fujiya, Mikihiro; Kohgo, Yutaka [Division of Gastroenterology and Hematology/Oncology, Department of Medicine, Asahikawa Medical University, 2-1-1-1, Midorigaoka-Higashi, Asahikawa, Hokkaido 078-8510 (Japan); Ieko, Masahiro [Department of Internal Medicine, School of Dentistry, Health Sciences University of Hokkaido, 1757, Kanazawa, Ishikari-Toubetsu, Hokkaido 061-0023 (Japan)

    2013-02-01

    Highlights: ► Lipin-1 involves lipid metabolism, adipocyte differentiation, and inflammation. ► Adipose lipin-1 expression is reduced in obesity. ► ER stress suppresses lipin-1 expression in 3T3-L1 adipocytes. ► Activation of PPAR-γ recovers ER stress-induced lipin-1 reduction. -- Abstract: Lipin-1 plays crucial roles in the regulation of lipid metabolism and cell differentiation in adipocytes. In obesity, adipose lipin-1 mRNA expression is decreased and positively correlated with systemic insulin sensitivity. Amelioration of the lipin-1 depletion might be improved dysmetabolism. Although some cytokines such as TNF-α and interleukin-1β reduces adipose lipin-1 expression, the mechanism of decreased adipose lipin-1 expression in obesity remains unclear. Recently, endoplasmic reticulum (ER) stress is implicated in the pathogenesis of obesity. Here we investigated the role of ER stress on the lipin-1 expression in 3T3-L1 adipocytes. We demonstrated that lipin-1 expression was suppressed by the treatment with ER stress inducers (tunicamycin and thapsigargin) at transcriptional level. We also showed that constitutive lipin-1 expression could be maintained by peroxisome proliferator-activated receptor-γ in 3T3-L1 adipocytes. Activation of peroxisome proliferator-activated receptor-γ recovered the ER stress-induced lipin-1 suppression. These results suggested that ER stress might be involved in the pathogenesis of obesity through lipin-1 depletion.

  8. Alteration of glycolipids in ras-transfected NIH 3T3 cells

    Glycosphingolipid alterations upon viral transformation are well documented. Transformation of mouse 3T3 cells with murine sarcoma viruses results in marked decreases in the levels of gangliosides GM1 and GD1a and an increase in gangliotriaosylceramide. The transforming oncogenes of these viruses have been identified as members of the ras gene family. The authors analyzed NIH 3T3 cells transfected with human H-, K- and N-ras oncogenes for their glycolipid composition and expression of cell surface gangliosides. Using conventional thin-layer chromatographic analysis, they found that the level of GM3 was increased and that of GD1a was slightly decreased or unchanged, and GM1 was present but not in quantifiable levels. Cell surface levels of GM1 were determined by 125I-labeled cholera toxin binding to intact cells. GD1a was determined by cholera toxin binding to cells treated with sialidase prior to toxin binding. All ras-transfected cells had decreased levels of surface GM1 and GD1 as compared to logarithmically growing normal NIH 3T3 cells. Levels of GM1 and, to a lesser extent, GD1a increased as the latter cells became confluent. Using a monoclonal antibody assay, they found that gangliotriaosylceramide was present in all ras-transfected cells studied but not in logarithmically growing untransfected cells. These results indicated that ras oncogenes derived form human tumors are capable of inducing alterations in glycolipid composition

  9. Sclerostin Enhances Adipocyte Differentiation in 3T3-L1 Cells.

    Ukita, Mayumi; Yamaguchi, Taihiko; Ohata, Noboru; Tamura, Masato

    2016-06-01

    Sclerostin, a secreted protein encoded by the Sost gene, is produced by osteocytes and is inhibited by osteoblast differentiation and bone formation. Recently, a functional association between bone and fat tissue has been suggested, and a correlation between circulating sclerostin levels and lipid metabolism has been reported in humans. However, the effects of sclerostin on adipogenesis remain unexplored. In the present study, we examined the role of sclerostin in regulating adipocyte differentiation using 3T3-L1 preadipocytes. In these cells, sclerostin enhanced adipocyte-specific gene expression and the accumulation of lipid deposits. Sclerostin also upregulated CCAAT/enhancer binding protein β expression but not cell proliferation and caspase-3/7 activities. Sclerostin also attenuated canonical Wnt3a-inhibited adipocyte differentiation. Recently, the transcriptional modulator TAZ has been involved in the canonical Wnt signaling pathway. Sclerostin reduced TAZ-responsive transcriptional activity and TAZ-responsive gene expression. Transfection of 3T3-L1 cells with TAZ siRNA increased the lipid deposits and adipogenic gene expression. These results show that sclerostin upregulates adipocyte differentiation in 3T3-L1 cells, suggesting a possible role for the osteocyte-derived sclerostin as a regulator of fat metabolism and as a reciprocal regulator of bone and adipose tissues metabolism. J. Cell. Biochem. 117: 1419-1428, 2016. © 2015 Wiley Periodicals, Inc. PMID:26553151

  10. Extract of Chaga mushroom (Inonotus obliquus) stimulates 3T3-L1 adipocyte differentiation.

    Joo, Jeong In; Kim, Dong Hyun; Yun, Jong Won

    2010-11-01

    Chaga mushroom (Inonotus obliquus) has long been used as a folk medicine due to its numerous biological functions such as antibacterial, antiallergic, antiinflammatory and antioxidative activities. In the present study, it was found that the I. obliquus hot water extract (IOWE) activated adipogenesis of 3T3-L1 preadipocytes. Even in the absence of adipogenic stimuli by insulin, the IOWE strongly induced adipogenesis of 3T3-L1 preadipocytes. The major constituent of IOWE was glucose-rich polysaccharides with a molecular mass of 149  kDa. IOWE enhanced the differentiation of 3T3-L1 preadipocytes, increasing TG (triacylglycerol) accumulation that is critical for acquisition of the adipocyte phenotype, in a dose-dependent manner. IOWE stimulated gene expression of C/EBPα (CCAAT/enhancer-binding protein α) and PPARγ (peroxisome proliferator-activated receptors γ) during adipocyte differentiation, and induced the expression of PPARγ target genes such as aP2 (adipocyte protein 2), LPL (lipoprotein lipase) and CD36 (fatty acid translocase). Immunoblot analysis revealed that IOWE increased the expression of adipogenic makers such as PPARγ and GLUT4 (glucose transporter 4). The luciferase reporter assay demonstrated that IOWE did not exhibit PPARγ ligand activity. Although these results require further investigation, the ability of natural mushroom product to increase PPARγ transcriptional activities may be expected to be therapeutic targets for dyslipidemia and type 2 diabetes. PMID:21031614