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Sample records for dendrimer-based ph-responsive mri

  1. Macromolecular and dendrimer-based magnetic resonance contrast agents

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    Bumb, Ambika; Brechbiel, Martin W. (Radiation Oncology Branch, National Cancer Inst., National Inst. of Health, Bethesda, MD (United States)), e-mail: pchoyke@mail.nih.gov; Choyke, Peter (Molecular Imaging Program, National Cancer Inst., National Inst. of Health, Bethesda, MD (United States))

    2010-09-15

    Magnetic resonance imaging (MRI) is a powerful imaging modality that can provide an assessment of function or molecular expression in tandem with anatomic detail. Over the last 20-25 years, a number of gadolinium-based MR contrast agents have been developed to enhance signal by altering proton relaxation properties. This review explores a range of these agents from small molecule chelates, such as Gd-DTPA and Gd-DOTA, to macromolecular structures composed of albumin, polylysine, polysaccharides (dextran, inulin, starch), poly(ethylene glycol), copolymers of cystamine and cystine with GD-DTPA, and various dendritic structures based on polyamidoamine and polylysine (Gadomers). The synthesis, structure, biodistribution, and targeting of dendrimer-based MR contrast agents are also discussed

  2. Dendrimer-based organic/inorganic hybrid nanoparticles in biomedical applications

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    Shen, Mingwu; Shi, Xiangyang

    2010-09-01

    This review reports some recent advances on the synthesis, self-assembly, and biofunctionalization of various dendrimer-based organic/inorganic hybrid nanoparticles (NPs) for various biomedical applications, including but not limited to protein immobilization, gene delivery, and molecular diagnosis. In particular, targeted molecular imaging of cancer using dendrimer-based organic/inorganic hybrid NPs will be introduced in detail.

  3. Emerging concepts in dendrimer-based nanomedicine: from design principles to clinical applications.

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    Kannan, R M; Nance, E; Kannan, S; Tomalia, D A

    2014-12-01

    Dendrimers are discrete nanostructures/nanoparticles with 'onion skin-like' branched layers. Beginning with a core, these nanostructures grow in concentric layers to produce stepwise increases in size that are similar to the dimensions of many in vivo globular proteins. These branched tree-like concentric layers are referred to as 'generations'. The outer generation of each dendrimer presents a precise number of functional groups that may act as a monodispersed platform for engineering favourable nanoparticle-drug and nanoparticle-tissue interactions. These features have attracted significant attention in medicine as nanocarriers for traditional small drugs, proteins, DNA/RNA and in some instances as intrinsically active nanoscale drugs. Dendrimer-based drugs, as well as diagnostic and imaging agents, are emerging as promising candidates for many nanomedicine applications. First, we will provide a brief survey of recent nanomedicines that are either approved or in the clinical approval process. This will be followed by an introduction to a new 'nanoperiodic' concept which proposes nanoparticle structure control and the engineering of 'critical nanoscale design parameters' (CNDPs) as a strategy for optimizing pharmocokinetics, pharmocodynamics and site-specific targeting of disease. This paradigm has led to the emergence of CNDP-directed nanoperiodic property patterns relating nanoparticle behaviour to critical in vivo clinical translation issues such as cellular uptake, transport, elimination, biodistribution, accumulation and nanotoxicology. With a focus on dendrimers, these CNDP-directed nanoperiodic patterns are used as a strategy for designing and optimizing nanoparticles for a variety of drug delivery and imaging applications, including a recent dendrimer-based theranostic nanodevice for imaging and treating cancer. Several emerging preclinical dendrimer-based nanotherapy concepts related to inflammation, neuro-inflammatory disorders, oncology and infectious

  4. Targeted Theranostic Approach for Glioma Using Dendrimer-Based Curcumin Nanoparticle

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    Gamage, NH; Jing, Li; Worsham, MJ; Ali, MM

    2016-01-01

    The delivery of anti-cancer agents to brain tumors represent a challenge because the blood-brain tumor barrier (BBTB) effectively limits the delivery of many agents. A new generation 3 (G3) dendrimer-based curcumin (Curc) conjugate was synthesized. The synthesized G3-Curc conjugate demonstrated full solubility in aqueous media. The in vitro study revealed that G3-Curc nanoparticles were internalized into glioma U-251 cells. Systemic delivery of G3-Curc conjugate led to preferentially accumulation in an orthotopic preclinical glioma model minimizing systemic toxic effect. Multicolor microscopy images of the tumor tissue showed that G3-Curc particles were internalized inside tumor cells selectively and further localized within nuclei. Enhanced bioavailability of G3-Curc conjugate was also observed with improved therapeutic efficacy against different cancers cells. PMID:27699139

  5. Dendrimer-based fluorescent indicators: in vitro and in vivo applications.

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    Lorenzo Albertazzi

    Full Text Available BACKGROUND: The development of fluorescent proteins and synthetic molecules whose fluorescence properties are controlled by the environment makes it possible to monitor physiological and pathological events in living systems with minimal perturbation. A large number of small organic dyes are available and routinely used to measure biologically relevant parameters. Unfortunately their application is hindered by a number of limitations stemming from the use of these small molecules in the biological environment. PRINCIPAL FINDINGS: We present a novel dendrimer-based architecture leading to multifunctional sensing elements that can overcome many of these problems. Applications in vitro, in living cells and in vivo are reported. In particular, we image for the first time extracellular pH in the brain in a mouse epilepsy model. CONCLUSION: We believe that the proposed architecture can represent a useful and novel tool in fluorescence imaging that can be widely applied in conjunction with a broad range of sensing dyes and experimental setups.

  6. Highly sensitive dendrimer-based nanoplasmonic biosensor for drug allergy diagnosis.

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    Soler, Maria; Mesa-Antunez, Pablo; Estevez, M-Carmen; Ruiz-Sanchez, Antonio Jesus; Otte, Marinus A; Sepulveda, Borja; Collado, Daniel; Mayorga, Cristobalina; Torres, Maria Jose; Perez-Inestrosa, Ezequiel; Lechuga, Laura M

    2015-04-15

    A label-free biosensing strategy for amoxicillin (AX) allergy diagnosis based on the combination of novel dendrimer-based conjugates and a recently developed nanoplasmonic sensor technology is reported. Gold nanodisks were functionalized with a custom-designed thiol-ending-polyamido-based dendron (d-BAPAD) peripherally decorated with amoxicilloyl (AXO) groups (d-BAPAD-AXO) in order to detect specific IgE generated in patient's serum against this antibiotic during an allergy outbreak. This innovative strategy, which follows a simple one-step immobilization procedure, shows exceptional results in terms of sensitivity and robustness, leading to a highly-reproducible and long-term stable surface which allows achieving extremely low limits of detection. Moreover, the viability of this biosensor approach to analyze human biological samples has been demonstrated by directly analyzing and quantifying specific anti-AX antibodies in patient's serum without any sample pretreatment. An excellent limit of detection (LoD) of 0.6ng/mL (i.e. 0.25kU/L) has been achieved in the evaluation of clinical samples evidencing the potential of our nanoplasmonic biosensor as an advanced diagnostic tool to quickly identify allergic patients. The results have been compared and validated with a conventional clinical immunofluorescence assay (ImmunoCAP test), confirming an excellent correlation between both techniques. The combination of a novel compact nanoplasmonic platform and a dendrimer-based strategy provides a highly sensitive label free biosensor approach with over two times better detectability than conventional SPR. Both the biosensor device and the carrier structure hold great potential in clinical diagnosis for biomarker analysis in whole serum samples and other human biological samples.

  7. MRI

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    MRI does not use ionizing radiation. No side effects from the magnetic fields and radio waves have been reported. The most common type of contrast (dye) used is gadolinium. It is very safe. Allergic reactions rarely ...

  8. Multifunctional dendrimer-based nanoparticles for in vivo MR/CT dual-modal molecular imaging of breast cancer

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    Li K

    2013-07-01

    Full Text Available Kangan Li,1,4,5,* Shihui Wen,2,* Andrew C Larson,4,5 Mingwu Shen,2 Zhuoli Zhang,4,5 Qian Chen,3 Xiangyang Shi,2,3 Guixiang Zhang1 1Department of Radiology, Shanghai First People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of China; 2College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, People’s Republic of China; 3State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, People’s Republic of China; 4Departments of Radiology and Biomedical Engineering, Northwestern University, Chicago, IL, USA; 5Robert H Lurie Comprehensive Cancer Center, Chicago, IL, USA *These authors contributed equally to this work Abstract: Development of dual-mode or multi-mode imaging contrast agents is important for accurate and self-confirmatory diagnosis of cancer. We report a new multifunctional, dendrimer-based gold nanoparticle (AuNP as a dual-modality contrast agent for magnetic resonance (MR/computed tomography (CT imaging of breast cancer cells in vitro and in vivo. In this study, amine-terminated generation 5 poly(amidoamine dendrimers modified with gadolinium chelate (DOTA-NHS and polyethylene glycol monomethyl ether were used as templates to synthesize AuNPs, followed by Gd(III chelation and acetylation of the remaining dendrimer terminal amine groups; multifunctional dendrimer-entrapped AuNPs (Gd-Au DENPs were formed. The formed Gd-Au DENPs were used for both in vitro and in vivo MR/CT imaging of human MCF-7 cancer cells. Both MR and CT images demonstrate that MCF-7 cells and the xenograft tumor model can be effectively imaged. The Gd-Au DENPs uptake, mainly in the cell cytoplasm, was confirmed by transmission electron microscopy. The cell cytotoxicity assay, cell morphology observation, and flow cytometry show that the developed Gd-Au DENPs have good biocompatibility in the given concentration range. Our results

  9. Microfluidic formation of pH responsive 5CB droplets decorated with PAA-b-LCP.

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    Khan, Waliullah; Choi, Jin Ho; Kim, Gyu Man; Park, Soo-Young

    2011-10-21

    We are reporting for the first time the pH responsiveness of liquid crystal (LC) microdroplets decorated with an amphiphilic block copolymer of PAA-b-LCP. We successfully demonstrated the adsorption of block copolymer on LC droplets by fluorescence microscopy and pH response to the radial-to-bipolar orientational change of the LC droplets by changing pH from 12 to 2 through the polarized optical microscope (POM). We believe that our results may pave the way for the generation of monodisperse droplets decorated by various amphiphilic block copolymers which respond to several kinds of the external stimuli. These developments may be important for potential applications of the LC droplets in sensing and encapsulation fields.

  10. Use of human amelogenin in molecular encapsulation for the design of pH responsive microparticles

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    Bonde Johan

    2012-05-01

    Full Text Available Abstract Background Proteins can be used in drug delivery systems to improve pharmacological properties of an active substance. Differences in pH between tissues can be utilized in order to achieve a targeted drug release at a specific location or tissue, such as a tumor. The enamel matrix protein amelogenin has a pH dependent solubility profile and self-assemble to form aggregates at neutral pH. This could make amelogenin useful in the design of pH responsive drug delivery systems. Results In this study amelogenin was evaluated as a pH responsive component in drug delivery applications. This was achieved by testing the ability of amelogenin to entrap/release other proteins upon changes in pH, and by testing if amelogenin could confer pH responsiveness to an existing and versatile drug delivery system, such as gelatin microparticles. Amelogenin was able to encapsulate bovine serum albumin and insulin, whichwere used as model target proteins. The composite aggregates of amelogenin and target protein were formed at neutral pH and could be reversibly solubilized at weakly acidic pH. Gelatin microparticles prepared in the presence of amelogenin, showed a modulated structure in response to pH change, when studied by scanning electron microscopy, compared to particles without amelogenin. At neutral pH amelogenin induced formation of pores in the particle surface, which were not present at acidic pH, or in particles lacking amelogenin. Conclusions The results from this study demonstrate that amelogenin can be a useful component in drug delivery systems in order to achieve a pH dependent response.

  11. CO₂ controlled flocculation of microalgae using pH responsive cellulose nanocrystals.

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    Eyley, Samuel; Vandamme, Dries; Lama, Sanjaya; Van den Mooter, Guy; Muylaert, Koenraad; Thielemans, Wim

    2015-09-14

    Cellulose nanocrystals were grafted with imidazole functionalities up to DS 0.06 using a one-pot functionalization strategy. The resulting nanocrystals were shown to have a pH responsive surface charge which was found to be positive below pH 6 and negative above pH 7. These imidazolyl cellulose nanocrystals were tested for flocculation of Chlorella vulgaris using CO2 to induce flocculation. Up to 90% flocculation efficiency was achieved with 200 mg L(-1) dose. Furthermore, the modified cellulose nanocrystals showed good compatibility with the microalgae during cultivation, giving potential for the production of reversible flocculation systems.

  12. Encapsulation of Liposomes within pH Responsive Microspheres for Oral Colonic Drug Delivery

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    M. J. Barea

    2012-01-01

    Full Text Available A novel liposome-in-microsphere (LIM formulation has been created comprising drug-loaded liposomes within pH responsive Eudragit S100 microspheres. The liposomes contained the model drug 5-ASA and were coated with chitosan in order to protect them during encapsulation within the microspheres and to improve site-specific release characteristics. In vitro drug release studies showed that LIMs prevented drug release within simulated stomach and small intestine conditions with subsequent drug release occurring in large intestine conditions. The formulation therefore has potential for oral colonic drug delivery.

  13. Rheological behavior and Ibuprofen delivery applications of pH responsive composite alginate hydrogels.

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    Jabeen, Suraya; Maswal, Masrat; Chat, Oyais Ahmad; Rather, Ghulam Mohammad; Dar, Aijaz Ahmad

    2016-03-01

    Synthesis and structural characterization of hydrogels composed of sodium alginate, polyethylene oxide and acrylic acid with cyclodextrin as the hydrocolloid prepared at different pH values is presented. The hydrogels synthesized show significant variations in rheological properties, drug encapsulation capability and release kinetics. The hydrogels prepared at lower pH (pH 1) are more elastic, have high tensile strength and remain almost unaffected by varying temperature or frequency. Further, their Ibuprofen encapsulation capacity is low and releases it slowly. The hydrogel prepared at neutral pH (pH 7) is viscoelastic, thermo-reversible and also exhibits sol-gel transition on applying frequency and changing temperature. It shows highest Ibuprofen encapsulation capacity and also optimum drug release kinetics. The hydrogel prepared at higher pH (pH 12) is more viscous, has low tensile strength, is unstable to change in temperature and has fast drug release rate. The study highlights the pH responsiveness of three composite alginate hydrogels prepared under different conditions to be employed in drug delivery applications.

  14. Hydrolyzed polyacrylamide grafted maize starch based microbeads: application in pH responsive drug delivery.

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    Setty, C Mallikarjuna; Deshmukh, Anand S; Badiger, Aravind M

    2014-09-01

    The present study details the synthesis, characterization and pharmaceutical application of hydrolysed polyacrylamide grafted maize starch (HPam-g-MS) as promising polymeric material for the development of pH responsive microbeads. Different grades of graft copolymer were synthesized by changing the net microwave irradiation time, while keeping all other factors constant. Acute oral toxicity study performed in rodents ensured the bio-safety of graft copolymer for clinical application. Various batches of aceclofenac loaded microbeads were prepared by ionic gelation method using synthesized graft copolymers and evaluated for formulation parameters. FTIR spectroscopy confirmed the chemical compatibility between drug and graft copolymer. Results of in vitro release study (USP type-II) carried out in two different pH media (pH 1.2 acid buffer and pH 7.4 phosphate buffer) showed that release rate of drug from developed microbeads was a function of both: (a) surrounding pH and (b) the matrix composition. The drug release was relatively higher at alkaline pH as compared to acidic pH and this feature is desirable from viewpoint of site specific drug delivery. A direct correlation was observed between percentage grafting and microbeads performance and it presents a scope for further research on application and optimization of HPam-g-MS based microbeads as drug delivery carriers.

  15. Ph responsive capsules containing composite coatings for corrosion inhibition in metal alloys

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    Kashi, Kiran Bhat

    Hexavalent chromes have been used as effective corrosion inhibitors due to their high inhibitor efficiency and low cost for the protection of several metal alloys. However, owing to their toxicity federal legislations restrict the use and distribution of these highly toxic materials. The need for an environmentally friendly yet effective alternative to the chrome based corrosion inhibitors has led to the investigation of rare earth metals as potential candidates. Cerium is one such rare earth metal that has received considerable attention as an alternative to hexavalent chromes. However, the high water solubility of some of the cerium salts makes it difficult for the incorporation of such salts in coatings. In this work, pH responsive microcapsules containing cerium salts were synthesized using an internally phase separated emulsion polymerization technique. Core shell microcapsule consisting of a water core containing dissolved cerium salts were synthesized. The synthesized capsules were characterized using characterization techniques such as Fourier Transform Infrared (FTIR) spectroscopy, UV-vis spectroscopy, Dynamic Mechanical Analysis (DMA), Thermo-Gravimetric Analysis (TGA), and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The structure and morphology of the capsules were studied using electron microscopy techniques. The synthesized capsules were dispersed in 2K epoxy coatings and applied on aluminum alloy 2024 T-3 and cold rolled steel substrates. These coatings were exposed to salt spray (ASTM B117) and electrochemically evaluated using electrochemical impedance spectroscopy (EIS), potentio-dynamic(PD) polarization, cyclic voltammetry(CV), open circuit potential(OCP) measurements. Localized corrosion assessment was also performed on the coated metal alloys using Scanning electrochemical microscopy (SECM) to understand the mechanism of corrosion inhibition using cerium encapsulated microcapsules.

  16. pH Responsive and Oxidation Resistant Wet Adhesive based on Reversible Catechol-Boronate Complexation.

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    Narkar, Ameya R; Barker, Brett; Clisch, Matthew; Jiang, Jingfeng; Lee, Bruce P

    2016-08-09

    A smart adhesive capable of binding to a wetted surface was prepared by copolymerizing dopamine methacrylamide (DMA) and 3-acrylamido phenylboronic acid (AAPBA). pH was used to control the oxidation state and the adhesive property of the catechol side chain of DMA and to trigger the catechol-boronate complexation. FTIR spectroscopy confirmed the formation of the complex at pH 9, which was not present at pH 3. The formation of the catechol-boronate complex increased the cross-linking density of the adhesive network. Most notably, the loss modulus values of the adhesive were more than an order of magnitude higher for adhesive incubated at pH 9 when compared to those measured at pH 3. This drastic increase in the viscous dissipation property is attributed to the introduction of reversible complexation into the adhesive network. Based on the Johnson Kendall Roberts (JKR) contact mechanics test, adhesive containing both DMA and AAPBA demonstrated strong interfacial binding properties (work of adhesion (Wadh) = 2000 mJ/m(2)) to borosilicate glass wetted with an acidic solution (pH 3). When the pH was increased to 9, Wadh values (180 mJ/m(2)) decreased by more than an order of magnitude. During successive contact cycles, the adhesive demonstrated the capability to transition reversibly between its adhesive and nonadhesive states with changing pH. Adhesive containing only DMA responded slowly to repeated changes in pH and became progressively oxidized without the protection of boronic acid. Although adhesive containing only AAPBA also demonstrated strong wet adhesion (Wadh ∼ 500 mJ/m(2)), its adhesive properties were not pH responsive. Both DMA and AAPBA are required to fabricate a smart adhesive with tunable and reversible adhesive properties.

  17. The pH response to urea and the effect of liquid flow in 'artificial mouth' microcosm plaques.

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    Sissons, C H; Wong, L; Hancock, E M; Cutress, T W

    1994-06-01

    This study examined in detailed the pH response of microcosm plaque biofilms to the application of 500 mmol/l urea, and the effect of modifying the flow rate of BMM (a basal medium containing 0.25% mucin). Microcosm plaques were cultured from the mixed salivary bacteria in a multi-plaque 'artificial mouth' supplied continuously with BMM at 3.6 ml/h per plaque, and periodically with sucrose (5 or 10%). Urea (500 mmol/l) induced a pH response that was the inverse of the Stephan pH curve induced by sucrose. In thicker plaques the ureolytic pH response was delayed and slower. With no BMM flow, the urea-induced pH curve reached a maximum and then slowly decreased indicating loss of ammonia. A flow of BMM reduced the magnitude of the pH response. Urea dilution explained (r2 = 0.97) the reduction in the maximum rate of pH rise caused by an increasing BMM flow. There were, however, additional flow-rate effects on the magnitude of the pH rise, the curve areas and the maximum rate of pH decrease back to the resting pH. These effects were greatest at low BMM flow rates, indicating that ammonia clearance may be limited at higher flow rates by the rate of intraplaque diffusion and metabolism. Application of 50 instead of 500 mmol/l urea reduced the rate of pH rise about 10-fold, and the area of the curve about seven fold. Metabolism of arginine (50 mmol/l) generated only about half the pH response of the same amount of urea.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Design, syntheses, and properties of tunable, dual-stimuli (temperature and pH) responsive copolymers

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    Manokruang, Kiattikhun

    Stimuli responsive polymers are of great interest in biorelated applications ranging from actuators, microfluidics, delivery systems and tissue scaffolds. The specifications of an appropriate polymer system that shows a response to one or more external stimuli vary from application to application, depending on desired functionality. In most cases, the response to an environmental change is desired to be sharp and fast, such as for microfluidics and actuators, while the stability of the collapsed structure is also typically required, such as in tissue scaffolds and in stimulated delivery systems. In addition, the onset of the stimulus response varies depending on application. Thus, a general design strategy for polymer systems to meet specific applications' needs can be a big challenge. This dissertation describes the design, syntheses, and aqueous phase behavior of two polymer classes that show a sharp solution phase transition in different manners: The first polymer class is in the form of a segmented/blocky copolymer and its solution phase separation is designed to occur via micellization, while the second polymer class is designed as an alternating copolymer and it exhibits a first order LCST phase behavior. Copolymers of methyl methacrylate (MMA) and methacrylic acid (MAA), poly(MMA-co-MAA)s, were prepared to have a segmented blocky comonomer distribution along the chain backbone, with sequences composed predominantly of MMA or MAA units. Turbidity (cloud point) measurements were employed to investigate the phase behavior of these copolymers in aqueous solution. The solutions showed sharp solubility transitions upon pH change, and the pH-onsets of the copolymers' transition showed a systematic dependence on the copolymers' MAA content and an almost-linear dependence on the polymer concentration. A strong hysteresis was observed when lowering versus increasing pH, indicating a stable collapsed structure. Dynamic light scattering demonstrated almost monodispersed polymer aggregates for each pH, rather than random/polydisperse structures. TEM images of the collapsed morphology showed polymer aggregates that included numerous small hydrophobic cores, demonstrating that the phase transition of these copolymers involved the formation of micelles with many hydrophobic clusters. Finally, these copolymers were used to prepare hollow microcapsules that provided an exceptional protection and a prolonged stability of an encapsulated matter at acidic conditions (pH 2) and a sharp and fast pH-triggered release at physiological conditions (pH 7). A second series of copolymers was synthesized to compose of ethylene glycol oligomers (EOm) connected in an alternating fashion with hydrophobic alkyls (EEn), (EOm-alt-EE n). Also, terpolymers were synthesized to compose of EOm connected in an alternating fashion with EEn and lysine ethyl ester (LyE), (EOm-alt-(EEn;LyE). Both copolymers and terpolymers demonstrated temperature responsive LCST phase behavior in aqueous solution, whose critical temperature is dictated by the thermodynamics of the hydrophilic/hydrophobic balance. In addition, the terpolymers' LCST can be further tuned by tailoring the ratio of EEn to LyE yielding dual responsive, viz. temperature and pH responsive, polymers upon conversion of LyE to ionizable Lysine (Lys). These last polymers that included ionizable units showed a reversible temperature and pH sensitive phase transition, allowing for such polymers to exhibit a phase separation with both-or-either temperature increase and pH-decrease. The extended phase diagrams, collected from turbidity measurements and modulated differential scanning callorimetry (MDSC), showed that the phase diagram remained a genuine LCST binodal throughout the complete concentration range. In addition, 1H-NMR provided additional strong evidence that the phase transition proceeded without micelle formation. Finally, hydrogels were prepared from EOm-alt-EEn, which exhibited reversible swelling/deswelling during temperature cycling (albeit with strong kinetic signatures). These temperature responsive hydrogels may be used in biomedical applications such as a rate-controlled swelling device.

  19. Chest MRI

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    Nuclear magnetic resonance - chest; Magnetic resonance imaging - chest; NMR - chest; MRI of the thorax; Thoracic MRI ... healthy enough to filter the contrast. During the MRI, the person who operates the machine will watch ...

  20. MRI and low back pain

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    Backache - MRI; Low back pain - MRI; Lumbar pain - MRI; Back strain - MRI; Lumbar radiculopathy - MRI; Herniated intervertebral disk - MRI; Prolapsed intervertebral disk - MRI; Slipped disk - MRI; Ruptured ...

  1. A novel thermal and pH responsive drug delivery system based on ZnO@PNIPAM hybrid nanoparticles

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    Tan, Licheng; Liu, Jian; Zhou, Weihua [Department of Chemistry, Nanchang University, Nanchang 330031 (China); Wei, Junchao, E-mail: weijunchao@ncu.edu.cn [Department of Chemistry, Nanchang University, Nanchang 330031 (China); State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, 220 Handan Road, Shanghai 200433 (China); Peng, Zhiping [Department of Chemistry, Nanchang University, Nanchang 330031 (China)

    2014-12-01

    A smart ZnO@PNIPAM hybrid was prepared by grafting thermal responsive poly(N-isopropylacrylamide) (PNIPAM) on zinc oxide (ZnO) nanoparticles via surface-initiated atom transfer radical polymerization (ATRP). The thermal gravimetric analysis (TGA) shows that the grafting amount of PNIPAM was about 38%, and the SEM images show that the PNIPAM chains can prevent the aggregation of ZnO nanoparticles. The responsive properties of ZnO@PNIPAM were measured by photoluminescence spectra, and the results demonstrate that the PNIPAM chains grafted on ZnO surfaces can realize reversible thermal responsive and photoluminescence properties. An anticancer drug, doxorubicin (Dox), was used as a model drug and loaded into the hybrid nanoparticles, and an in vitro drug release test implied that ZnO@PNIPAM could work as a thermal responsive drug delivery system. Furthermore, pH sensitive drug releases were carried out in acetate buffer at pH 5.0 and pH 6.0 and in water at pH 7.0, and the results showed evident pH dependency, showing its pH responsive properties. - Graphical abstract: In this manuscript, thermal responsive poly(N-isopropylacrylamide) (PNIPAM) was grafted on the surface of ZnO nanoparticles. The obtained ZnO@PNIPAM hybrid showed reversible thermal responsive photoluminescent properties, and can also work as a thermal and pH responsive drug delivery system. - Highlights: • The ZnO@PNIPAM hybrid was prepared via ATRP. • The ZnO@PNIPAM hybrid showed thermal responsive properties. • The ZnO@PNIPAM hybrid can work as a thermal and pH responsive drug delivery system.

  2. General Reagent Free Route to pH Responsive Polyacryloyl Hydrazide Capped Metal Nanogels for Synergistic Anticancer Therapeutics.

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    Ujjwal, Rewati Raman; Purohit, Mahaveer Prasad; Patnaik, Satyakam; Ojha, Umaprasana

    2015-06-01

    Herewith, we report a facile synthesis of pH responsive polyacryloyl hydrazide (PAH) capped silver (Ag) or gold (Au) nanogels for anticancer therapeutic applications. A cost-effective instant synthesis of PAH-Ag or PAH-Au nanoparticles (NPs) possessing controllable particle diameter and narrow size distribution was accomplished by adding AgNO3 or AuCl to the aqueous solution of PAH under ambient conditions without using any additional reagent. PAH possessing carbonyl hydrazide pendant functionality served as both reducing and capping agent to produce and stabilize the NPs. The stability analysis by UV-vis, dynamic light scattering, and transmission electron microscopy techniques suggested that these NPs may be stored in a refrigerator for at least up to 2 weeks with negligible change in conformation. The average hydrodynamic size of PAH-Ag NPs synthesized using 0.2 mmol/L AgNO3 changed from 122 to 226 nm on changing the pH of the medium from 5.4 to 7.4, which is a characteristic property of pH responsive nanogel. Camptothecin (CPT) with adequate loading efficiency (6.3%) was encapsulated in the PAH-Ag nanogels. Under pH 5.4 conditions, these nanogels released 78% of the originally loaded CPT over a period of 70 h. The antiproliferative potential of PAH-Ag-CPT nanogels (at [CPT]=0.6 μg/mL) against MCF-7 breast adeno-carcinoma cells were ∼350% higher compared to that of the free CPT as evidenced by high cellular internalization of these nanogels. Induction of apoptosis in MCF-7 breast adeno-carcinoma cells by PAH-Ag-CPT nanogels was evidenced by accumulation of late apoptotic cell population. Drug along with the PAH-Ag NPs were also encapsulated in a pH responsive hydrogel through in situ gelation at room temperature using acrylic acid as the cross-linker. The resulting hydrogel released quantitative amounts of both drug and PAH-Ag NPs over a period of 16 h. The simplicity of synthesis and ease of drug loading with efficient release render these NPs a viable candidate for various biomedical applications, and moreover this synthetic procedure may be extended to other metal NPs.

  3. Application of a pH responsive multimodal hydrophobic interaction chromatography medium for the analysis of glycosylated proteins.

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    Kallberg, K; Becker, K; Bülow, L

    2011-02-04

    Protein glycosylation has significant effects on the structure and function of proteins. The efficient separation and enrichment of glycoproteins from complex biological samples is one key aspect and represents a major bottleneck of glycoproteome research. In this paper, we have explored pH multimodal hydrophobic interaction chromatography to separate glycosylated from non-glycosylated forms of proteins. Three different proteins, ribonuclease, invertase and IgG, have been examined and different glycoforms have been identified. The media itself shows strong responsiveness to small variations in pH, which makes it possible to fine-tune the chromatographic conditions according to the properties of the protein isolated. Optimal glycoprotein separation has been obtained at pH 4. The pH responsive multimodal HIC medium in contrast to conventional HIC media is able to resolve contaminating DNA. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. MRI Scans

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    Magnetic resonance imaging (MRI) uses a large magnet and radio waves to look at organs and structures inside your body. Health care professionals use MRI scans to diagnose a variety of conditions, from ...

  5. Shoulder MRI

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    ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...

  6. Novel porous scaffolds of pH responsive chitosan/carrageenan-based polyelectrolyte complexes for tissue engineering.

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    Araujo, J V; Davidenko, N; Danner, M; Cameron, R E; Best, S M

    2014-12-01

    Polyelectrolyte complexes (PECs) represent promising materials for drug delivery and tissue engineering applications. These substances are obtained in aqueous medium without the need for crosslinking agents. PECs can be produced through the combination of oppositely charged medical grade polymers, which include the stimuli responsive ones. In this work, three-dimensional porous scaffolds were produced through the lyophilization of pH sensitive PECs made of chitosan (CS) and carrageenan (CRG). CS:CRG molar ratios of 1:1 (CSCRG1), 2:1 (CSCRG2), and 3:1 (CSCRG3) were used. The chemical compositions of the PECs, as well as their influence in the final structure of the scaffolds were meticulously studied. In addition, the pH responsiveness of the PECs in a range including the physiological pH values of 7.4 (simulating normal physiological conditions) and 4.5 (simulating inflammatory response) was assessed. Results showed that the PECs produced were stable at pH values of 7.4 and under but dissolved as the pH increased to nonphysiological values of 9 and 11. However, after dissolution, the PEC could be reprecipitated by decreasing the pH to values close to 4.5. The scaffolds obtained presented large and interconnected pores, being equally sensitive to changes in the pH. CSCRG1 scaffolds appeared to have higher hydrophilicity and therefore higher water absorption capacity. The increase in the CS:CRG molar ratios improved the scaffold mechanical properties, with CSCRG3 presenting the higher compressive modulus under wet conditions. Overall, the PEC scaffolds appear promising for tissue engineering related applications that require the use of pH responsive materials stable at physiological conditions.

  7. Fe{sub 2}O{sub 3}-Bi{sub 2}O{sub 3}-B{sub 2}O{sub 3} glasses as lithium-free nonsilicate pH responsive glasses – Compatibility between pH responsivity and hydrophobicity

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Tadanori, E-mail: hasimoto@chem.mie-u.ac.jp [Department of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-Cho, Tsu, Mie, 514-8507 (Japan); Hamajima, Mitsuaki; Ohta, Honami; Nasu, Hiroyuki; Ishihara, Atsushi [Department of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-Cho, Tsu, Mie, 514-8507 (Japan); Nishio, Yuji [HORIBA, Ltd., 2 Miyanohigasi, Kisshoin, Minami-Ku, Kyoto, 601-8510 (Japan)

    2014-02-01

    Highlights: • Fe{sub 2}O{sub 3}-rich FeBiB glasses show high pH sensitivity and short pH response time. • Bi{sub 2}O{sub 3}-rich FeBiB glasses show relatively high contact angle for water. • FeBiB glasses are lithium-free nonsilicate pH responsive ones. • pH responsivity and hydrophobicity are obtained for optimum glass compositions. - Abstract: Lithium silicate-based glasses have widely been used as commercially available pH glass electrodes. It was revealed that Ti{sup 3+}-containing titanophosphate (TiO{sub 2}-P{sub 2}O{sub 5}, TP) glasses are pH responsive as lithium-free nonsilicate glasses for the first time. TP glasses with the compatibility between pH responsivity and self-cleaning property were obtained by the sequential post-annealing (oxidation and reduction) of as-prepared glasses. Bi{sub 2}O{sub 3}-B{sub 2}O{sub 3} (BiB) glasses are relatively hydrophobic and are expected to show anti-fouling effect. They are unsuitable for pH responsive glasses, because they have high electrical resistivity. In the present study, xFe{sub 2}O{sub 3}·yBi{sub 2}O{sub 3}·(100 − x − y)B{sub 2}O{sub 3} glasses (xFeyBiB, x = 0–20 mol%, y = 20–80 mol%) glasses were selected as new pH responsive glasses with hydrophobicity, because Fe{sub 2}O{sub 3} is a representative component for causing hopping conduction to the glasses. BiB glass did not show pH responsivity, whereas xFeyBiB glasses showed good pH responsivity. xFeyBiB glasses are lithium-free nonsilicate pH responsive ones as well as TP glasses. The electrical resistivity and pH response time decreased with increasing Fe{sub 2}O{sub 3} content. The pH repeatability for standard solutions increased with increasing Bi{sub 2}O{sub 3} content. Silicate glass (20Fe70BiSi) showed better pH responsivity but lower contact angle than those of borate glass (20Fe70BiB). pH sensitivity increased in order of TP glasses (about 80%), xFeyBiB glasses (about 90%) and commercial pH responsive glass (about 100%). xFeyBiB glasses showed short pH response time compared to commercial pH responsive glass. The contact angle for water of xFeyBiB glasses was relatively high (about 90°) as well as BiB glasses, and increased slightly with increasing Bi{sub 2}O{sub 3} content regardless Fe{sub 2}O{sub 3} content. The high contact angle was related to low OH content determined by FT-IR measurement. Thus, 20Fe{sub 2}O{sub 3}·70Bi{sub 2}O{sub 3}·10B{sub 2}O{sub 3} glass was the most suitable one as pH responsive glasses with hydrophobicity. TP glasses are pH responsive ones with self-cleaning property, whereas xFeyBiB glasses are expected as pH responsive ones with anti-fouling property based on hydrophobicity.

  8. Molecular layer deposition of APTES on silicon nanowire biosensors: Surface characterization, stability and pH response

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Yuchen [Department of Electrical Engineering, University of Texas at Dallas, Richardson, TX 75080 (United States); Huang, Jie [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX 75080 (United States); Zang, Pengyuan [Department of Electrical Engineering, University of Texas at Dallas, Richardson, TX 75080 (United States); Kim, Jiyoung [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, TX 75080 (United States); Hu, Walter, E-mail: walter.hu@utdallas.edu [Department of Electrical Engineering, University of Texas at Dallas, Richardson, TX 75080 (United States)

    2014-12-15

    Graphical abstract: - Abstract: We report the use of molecular layer deposition (MLD) for depositing 3-aminopropyltriethoxysilane (APTES) on a silicon dioxide surface. The APTES monolayer was characterized using spectroscopic ellipsometry, contact angle goniometry, and atomic force microscopy. Effects of reaction time of repeating pulses and simultaneous feeding of water vapor with APTES were tested. The results indicate that the synergistic effects of water vapor and reaction time are significant for the formation of a stable monolayer. Additionally, increasing the number of repeating pulses improved the APTES surface coverage but led to saturation after 10 pulses. In comparing MLD with solution-phase deposition, the APTES surface coverage and the surface quality were nearly equivalent. The hydrolytic stability of the resulting films was also studied. The results confirmed that the hydrolysis process was necessary for MLD to obtain stable surface chemistry. Furthermore, we compared the pH sensing results of Si nanowire field effect transistors (Si NWFETs) modified by both the MLD and solution methods. The highly repeatable pH sensing results reflected the stability of APTES monolayers. The results also showed an improved pH response of the sensor prepared by MLD compared to the one prepared by the solution treatment, which indicated higher surface coverage of APTES.

  9. Molecular layer deposition of APTES on silicon nanowire biosensors: Surface characterization, stability and pH response

    Science.gov (United States)

    Liang, Yuchen; Huang, Jie; Zang, Pengyuan; Kim, Jiyoung; Hu, Walter

    2014-12-01

    We report the use of molecular layer deposition (MLD) for depositing 3-aminopropyltriethoxysilane (APTES) on a silicon dioxide surface. The APTES monolayer was characterized using spectroscopic ellipsometry, contact angle goniometry, and atomic force microscopy. Effects of reaction time of repeating pulses and simultaneous feeding of water vapor with APTES were tested. The results indicate that the synergistic effects of water vapor and reaction time are significant for the formation of a stable monolayer. Additionally, increasing the number of repeating pulses improved the APTES surface coverage but led to saturation after 10 pulses. In comparing MLD with solution-phase deposition, the APTES surface coverage and the surface quality were nearly equivalent. The hydrolytic stability of the resulting films was also studied. The results confirmed that the hydrolysis process was necessary for MLD to obtain stable surface chemistry. Furthermore, we compared the pH sensing results of Si nanowire field effect transistors (Si NWFETs) modified by both the MLD and solution methods. The highly repeatable pH sensing results reflected the stability of APTES monolayers. The results also showed an improved pH response of the sensor prepared by MLD compared to the one prepared by the solution treatment, which indicated higher surface coverage of APTES.

  10. Oxidation and pH responsive nanoparticles based on ferrocene-modified chitosan oligosaccharide for 5-fluorouracil delivery.

    Science.gov (United States)

    Xu, Youqian; Wang, Liang; Li, Ya-Kun; Wang, Cai-Qi

    2014-12-19

    Stimuli-responsive nanoparticles based on biodegradable and biocompatible saccharides are potentially superior carriers under different physical conditions. In this study, we present a detailed investigation on the oxidation and pH responses of ferrocene-modified chitosan oligosaccharide (FcCOS) nanoparticles for 5-Fluorouracil (5-FU) Delivery. The dispersion of FcCOS nanoparticles depends strongly on pH change. NaClO, H2O2 and oxygen, as oxidant models, in a weak acid solution displayed varying accelerations as the disassembly progressed. 5-FU, as a drug model, is efficiently uploaded in FcCOS nanoparticle (approximately 238 nm). The in vitro release of 5-FU from FcCOS nanoparticles studies show that the accumulative release increased with the decrease of pH under bubbled N2. Interestingly, the sample under bubbled air has a higher accumulative release up to 59.64% at pH 3.8, compared with samples under bubbled N2 just 49.02%. The results suggested that FcCOS nanoparticles disassembled faster and the release of drug molecules was accelerated because of the synergistic effect of oxidative agent and low pH. Thus, FcCOS can be developed as an effective pH and oxidation dual-responsive carrier to enhance drug efficacy for cancer treatment.

  11. Genipin Cross-Linked Chitosan-Polyvinylpyrrolidone Hydrogels: Influence of Composition and Postsynthesis Treatment on pH Responsive Behaviour

    Directory of Open Access Journals (Sweden)

    Chinyelumndu Jennifer Nwosu

    2015-01-01

    Full Text Available Understanding the factors that influence the pH responsive behaviour of biocompatible cross-linked hydrogel networks is essential when aiming to synthesise a mechanically stable and yet stimuli responsive material suitable for various applications including drug delivery and tissue engineering. In this study the behaviour of intelligent chitosan-polyvinylpyrrolidone-genipin cross-linked hydrogels is examined as a function of their composition and postsynthesis treatment. Hydrogels are synthesised with varying amounts of each component (chitosan, polyvinylpyrrolidone, and genipin and their response in a pH 2 buffer is measured optically. The influence of postsynthesis treatment on stability and smart characteristics is assessed using selected hydrogel samples synthesised at 30, 40, and 50°C. After synthesis, samples are exposed to either continuous freezing or three freeze-thaw cycles resulting in increased mechanical stability for all samples. Further morphological and mechanical characterisations have aided the understanding of how postsynthesis continual freezing or freeze-thaw manipulation affects network attributes.

  12. A two-component micelle with emergent pH responsiveness by mixing dilauroyl phosphocholine and deoxycholic acid and its delivery of proteins into the cytosol.

    Science.gov (United States)

    Miyamoto, Noriko; Fujii, Shota; Mochizuki, Shinichi; Sakurai, Kazuo; Sakaguchi, Naoki; Koiwai, Kazunori

    2017-06-01

    Providing appropriate pH responsiveness for drug delivery nanoparticles is one of the major issues in developing a new generation of delivery systems. This paper reports that, when phosphocholine and a bile acid were mixed, the resultant two-component micelle gained pH responsiveness, while the individual components did not show any such responsiveness. The pH responsiveness was shown to be determined by the chemical structure, especially the positions and chirality of the OH groups, of the bile acid, and the sensitivity was determined by the alkyl chain length of the phosphocholine. The best combination for evading endocytosis was dilauroyl phosphocholine (DLPC) and deoxycholic acid (DA). Small-angle X-ray scattering revealed that the pH responsiveness was related to the change of surface hydrophobicity, namely, decreasing pH led to protonation of the carboxylic acid, resulting in aggregation of the preceding micelles. We assume that particles that become hydrophobic in this way can start interacting with the endocytotic bilayer, which eventually leads to rupture of the endocytotic vesicle. This mechanism is well supported by the finding that fluorescein-conjugated ovalbumin proteins were transported into the cytosol when they were co-administered with DLPC/DA. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. pH responsive granulocyte colony-stimulating factor variants with implications for treating Alzheimer's disease and other central nervous system disorders.

    Science.gov (United States)

    Heinzelman, Pete; Schoborg, Jennifer A; Jewett, Michael C

    2015-10-01

    Systemic injection of granulocyte colony-stimulating factor (G-CSF) has yielded encouraging results in treating Alzheimer's Disease (AD) and other central nervous system (CNS) disorders. Making G-CSF a viable AD therapeutic will, however, require increasing G-CSF's ability to stimulate neurons within the brain. This objective could be realized by increasing transcytosis of G-CSF across the blood brain barrier (BBB). An established correlation between G-CSF receptor (G-CSFR) binding pH responsiveness and increased recycling of G-CSF to the cell exterior after endocytosis motivated development of G-CSF variants with highly pH responsive G-CSFR binding affinities. These variants will be used in future validation of our hypothesis that increased BBB transcytosis can enhance G-CSF therapeutic efficacy. Flow cytometric screening of a yeast-displayed library in which G-CSF/G-CSFR interface residues were mutated to histidine yielded a G-CSF triple His mutant (L109H/D110H/Q120H) with highly pH responsive binding affinity. This variant's KD, measured by surface plasmon resonance (SPR), increases ∼20-fold as pH decreases from 7.4 to below histidine's pKa of ∼6.0; an increase 2-fold greater than for previously reported G-CSF His mutants. Cell-free protein synthesis (CFPS) enabled expression and purification of soluble, bioactive G-CSF triple His variant protein, an outcome inaccessible via Escherichia coli inclusion body refolding. This purification and bioactivity validation will enable future identification of correlations between pH responsiveness and transcytosis in BBB cell culture model and animal experiments. Furthermore, the library screening and CFPS methods employed here could be applied to developing other pH responsive hematopoietic or neurotrophic factors for treating CNS disorders.

  14. MRI of the Prostate

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Prostate Magnetic resonance imaging (MRI) of the prostate ... limitations of MRI of the Prostate? What is MRI of the Prostate? Magnetic resonance imaging (MRI) is ...

  15. MRI zoo

    DEFF Research Database (Denmark)

    Laustsen, Christoffer

    The basic idea was to use MRI to produce a sequence of 3D gray scale image slices of various animals, subsequentlyimaged with a clinical CT system. For this purpose, these animals were used: toad, lungfish, python snake and a horseshoe crab. Each animal was sacrificed according to standard....... MRI was done using a Philips Achieva 1.5 T system and CT was performed using a Siemens Somatom system. Axial and sagittal slices were acquired using standard T1w and T2w MRI sequences, and visualization was made using the Mistar software (Apollo Imaging Technology, Melbourne, Australia). Images were...

  16. Pediatric MRI

    Data.gov (United States)

    U.S. Department of Health & Human Services — The NIH Study of Normal Brain Development is a longitudinal study using anatomical MRI, diffusion tensor imaging (DTI), and MR spectroscopy (MRS) to map pediatric...

  17. Knee MRI

    Science.gov (United States)

    ... air-conditioned and well-lit. Some scanners have music to help you pass the time. When the ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...

  18. Investigation of a potential macromolecular MRI contrast agent prepared from PPI (G = 2, polypropyleneimine, generation 2) dendrimer bifunctional chelates

    Science.gov (United States)

    Wang, Jianxin Steven

    The long-term objective is to develop magnetic resonance (MR) contrast agents that actively and passively target tumors for diagnosis and therapy. Many diagnostic imaging techniques for cancer lack specificity. A dendrimer based magnetic resonance imaging contrast agent has been developed with large proton relaxation enhancements and high molecular relaxivities. A new type of linear dendrimer based MRI contrast agent that is built from the polypropyleneimine and polyamidoamine dendrimers in which free amines have been conjugated to the chelate DTPA, which further formed the complex with Gadolinium (Gd) was studied. The specific research goals were to test the hypothesis that a linear chelate with macromolecular agents can be used in vitro and in vivo. This work successfully examined the adequacy and viability of the application for this agent in vitro and in vivo. A small animal whole body counter was designed and constructed to allow us to monitor biodistribution and kinetic mechanisms using a radioisotope labeled complex. The procedures of metal labeling, separation and purification have been established from this work. A biodistribution study has been performed using radioisotope induced organ/tissue counting and gamma camera imaging. The ratio of percentage of injected dose per gram organ/tissue for kidney and liver is 3.71 from whole body counter and 3.77 from the gamma camera. The results suggested that retention of Gd (III) is too high and a more kinetically stable chelate should be developed. The pharmacokinetic was evaluated in the whole animal model with the whole body clearance, and a kinetics model was developed. The pharmacokinetic results showed a bi-exponential decay in the animal model with two component excretion constants 1.43e(-5) and 0.0038511, which give half-lives of 3 hours and 33.6 days, respectively. Magnetic resonance imaging of this complex resulted in a 52% contrast enhancement in the rat kidney following the agents' administration in

  19. Multivalent supramolecular dendrimer-based drugs.

    Science.gov (United States)

    Galeazzi, Simone; Hermans, Thomas M; Paolino, Marco; Anzini, Maurizio; Mennuni, Laura; Giordani, Antonio; Caselli, Gianfranco; Makovec, Francesco; Meijer, E W; Vomero, Salvatore; Cappelli, Andrea

    2010-01-11

    Supramolecular complexes consisting of a hydrophobic dendrimer host [DAB-dendr-(NHCONH-Ad)(64)] as well as solubilizing and bioactive guest molecules have been synthesized using a noncovalent approach. The guest-host supramolecular assembly is first preassembled in chloroform and transferred via the neat phase to aqueous solution. The bioactive guest molecules can bind to a natural (serotonin 5-HT(3)) receptor with nanomolar affinity as well as to the synthetic dendrimer receptor in aqueous solution, going toward a dynamic multivalent supramolecular construct capable of adapting itself to a multimeric receptor motif.

  20. Dendrimer based nanotherapeutics for ocular drug delivery

    Science.gov (United States)

    Kambhampati, Siva Pramodh

    PAMAM dendrimers are a class of well-defined, hyperbranched polymeric nanocarriers that are being investigated for ocular drug and gene delivery. Their favorable properties such as small size, multivalency and water solubility can provide significant opportunities for many biologically unstable drugs and allows potentially favorable ocular biodistribution. This work exploits hydroxyl terminated dendrimers (G4-OH) as drug/gene delivery vehicles that can target retinal microglia and pigment epithelium via systemic delivery with improved efficacy at much lower concentrations without any side effects. Two different drugs Triamcinolone acetonide (TA) and N-Acetyl Cysteine (NAC) conjugated to G4-OH dendrimers showed tailorable sustained release in physiological relevant solutions and were evaluated in-vitro and in-vivo. Dendrimer-TA conjugates enhanced the solubility of TA and were 100 fold more effective at lower concentrations than free TA in its anti-inflammatory activity in activated microglia and in suppressing VEGF production in hypoxic RPE cells. Dendrimers targeted activated microglia/macrophages and RPE and retained for a period of 21 days in I/R mice model. The relative retention of intravitreal and intravenous dendrimers was comparable, if a 30-fold intravenous dose is used; suggesting intravenous route targeting retinal diseases are possible with dendrimers. D-NAC when injected intravenously attenuated retinal and choroidal inflammation, significantly reduced (˜73%) CNV growth at early stage of AMD in rat model of CNV. A combination therapy of D-NAC + D-TA significantly suppressed microglial activation and promoted CNV regression in late stages of AMD without causing side-effects. G4-OH was modified with linker having minimal amine groups and incorporation of TA as a nuclear localization enhancer resulted in compact gene vectors with favorable safety profile and achieved high levels of transgene expression in hard to transfect human retinal pigment epithelial cells (hRPE). Prepared dendrimer-gene complexes were non-toxic and achieved significant cell uptake and safe delivery of gene in to the nucleus. Further, polyethylene glycol (PEG) surface coating enhanced colloidal stability in physiological relevant solutions without affecting its transfection efficacy.

  1. Chitosan capped nanoscale Fe-MIL-88B-NH2 metal-organic framework as drug carrier material for the pH responsive delivery of doxorubicin

    Science.gov (United States)

    Sivakumar, P.; Priyatharshni, S.; Nagashanmugam, K. B.; Thanigaivelan, A.; Kumar, K.

    2017-08-01

    In recent years nanoscale metal-organic frameworks (NMOFs) are contributing as an effective material for use in drug delivery and imaging applications due to their porous surfaces and easy surface modifications. In this work, Fe-MIL-88B-NH2 NMOFs were successfully synthesized on facile hydrothermal route and 2-aminoterephthalic acid (NH2-BDC) was employed as a bridging ligand to activate amine functional groups on the surface. Amine functional groups not only serve as a structure stabilizing agent but also enhance the loading efficiency of the doxorubicin (DOX) anticancer drug. A pH responsive DOX release was realized by introducing a positively charged chitosan (Chi) capping layer. Upon Chi-coating, cleavage was observed in the Fe-MIL-88B-NH2 structure at acidic pH, while gel-like insoluble structure was formed at basic pH. By utilizing this phenomenon, a pH responsive DOX release system was developed by using Chi capped Fe-MIL-88B-NH2 NMOFs under the designed pH (4.0-8.0). The results suggest the Chi capped Fe-MIL-88B-NH2 can be a promising candidate for future pH responsive drug delivery systems.

  2. Comparison of MRI properties between derivatized DTPA and DOTA gadolinium-dendrimer conjugates

    Science.gov (United States)

    Nwe, K.; Bernardo, M; Regino, C. A. S.; Williams, M; Brechbiel, M. W.

    2010-01-01

    In this report we directly compare the in vivo and in vitro MRI properties of gadolinium-dendrimer conjugates of derivatized acyclic diethylenetriamine-N,N’,N’,N’’, N’’-pentaacetic acid (1B4M-DTPA) and macrocyclic 1,4,7,10-tetraazacyclododecane-N,N’,N’’,N’’’-tetraacetic acid (C-DOTA). The metal-ligand chelates were pre-formed in alcohol prior to conjugation to the generation 4 PAMAM dendrimer (G4D), and the dendrimer-based agents were purified by Sephadex® G-25 column. The analysis and SE-HPLC data indicated chelate to dendrimer ratios of 30:1 and 28:1 respectively. Molar relaxivity measured at pH 7.4, 22°C, and 3T are comparable (29.5 vs. 26.9 mM−1s−1), and both conjugates are equally viable as MRI contrast agents based on the images obtained. The macrocyclic agent however exhibits a faster rate of clearance in vivo (t1/2 = 16 vs. 29 min.). Our conclusion is that the macrocyclic-based agent is the more suitable agent for in vivo use for these reasons combined with kinetic inertness associated with the Gd(III) DOTA complex stability properties. PMID:20663676

  3. MRI Artifacts

    Directory of Open Access Journals (Sweden)

    Abed Al Nasser Assi

    2009-12-01

    Full Text Available   "nMagnetic resonance imaging (MRI has become more and more frequently used in medical imaging diagnostic in recent years. Radiologists and technicians working at these systems are relatively often confronted with image artifacts related to the radiowave with strong magnetic in the scanner. Many artifacts may be corrected or modulated through an understanding of their cause. This requires familiarity with scanner design; theory of operation; and image acquisition. The purpose of this review article is to present the most relevant artifacts that arise in MRI scanner, to provide some physical background on the formation of artifacts, and to suggest strategies to reduce or avoid these artifacts. The most frequent artifacts that can occur during MRI scanning are Motion related artifacts; Para-magnetic artifacts; Phase Wrap artifacts; Frequency artifacts; Susceptibility artifacts; Clipping artefact; Chemical Shift artifact and "Zebra" artefact .    "n  

  4. Portable MRI

    Energy Technology Data Exchange (ETDEWEB)

    Espy, Michelle A. [Los Alamos National Laboratory

    2012-06-29

    This project proposes to: (1) provide the power of MRI to situations where it presently isn't available; (2) perform the engineering required to move from lab to a functional prototype; and (3) leverage significant existing infrastructure and capability in ultra-low field MRI. The reasons for doing this: (1) MRI is the most powerful tool for imaging soft-tissue (e.g. brain); (2) Billions don't have access due to cost or safety issues; (3) metal will heat/move in high magnetic fields; (4) Millions of cases of traumatic brain injury in US alone; (5) even more of non-traumatic brain injury; (6) (e.g. stroke, infection, chemical exposure); (7) Need for early diagnostic; (8) 'Signature' wound of recent conflicts; (9) 22% of injuries; (10) Implications for post-traumatic stress disorder; and (11) chronic traumatic encephalopathy.

  5. Breast MRI scan

    Science.gov (United States)

    MRI - breast; Magnetic resonance imaging - breast; Breast cancer - MRI; Breast cancer screening - MRI ... radiologist) see some areas more clearly. During the MRI, the person who operates the machine will watch ...

  6. MRI Safety during Pregnancy

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z MRI Safety During Pregnancy Magnetic resonance imaging (MRI) Illness ... during the exam? Contrast material MRI during pregnancy Magnetic resonance imaging (MRI) If you are pregnant and your doctor ...

  7. MRI (Magnetic Resonance Imaging)

    Science.gov (United States)

    ... and Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options ... usually given through an IV in the arm. MRI Research Programs at FDA Magnetic Resonance Imaging (MRI) ...

  8. MRI of the Chest

    Medline Plus

    Full Text Available ... the limitations of MRI of the Chest? What is MRI of the Chest? Magnetic resonance imaging (MRI) ... ray, CT and ultrasound. top of page How is the procedure performed? MRI examinations may be performed ...

  9. MRI zoo

    DEFF Research Database (Denmark)

    Laustsen, Christoffer

    The basic idea was to use MRI to produce a sequence of 3D gray scale image slices of various animals, subsequentlyimaged with a clinical CT system. For this purpose, these animals were used: toad, lungfish, python snake and a horseshoe crab. Each animal was sacrificed according to standard proced...

  10. Generation of pH responsive fluorescent nano capsules through simple steps for the oral delivery of low pH susceptible drugs

    Science.gov (United States)

    Radhakumary, Changerath; Sreenivasan, Kunnatheeri

    2016-11-01

    pH responsive nano capsules are promising as it can encapsulate low pH susceptible drugs like insulin and guard them from the hostile environments in the intestinal tract. The strong acidity of the gastro-intestinal tract and the presence of proteolytic enzymes are the tumbling blocks for the design of drug delivery vehicles through oral route for drugs like insulin. Nano capsules are normally built over templates which are subsequently removed by further steps. Such processes are complex and often lead into deformed and collapsed capsules. In this study, we choose calcium carbonate (CaCO3) nano particles to serve as template. Over CaCO3 nanoparticles, silica layers were built followed by polymethacrylic acid chains to acquire pH responsiveness. During the polymerization process of the methacrylic acid, the calcium carbonate core particles were dissolved leading to the formation of nano hollow capsules having a size that ranges from 225 to 246 nm and thickness from 19 to 58 nm. The methodology is simple and devoid of additional steps. The nano shells exhibited 80% release of the loaded model drug, insulin at pH 7.4 while at pH 2.0 the capsules nearly stopped the release of the drug. Polymethacrylic acid shows pH responsive swelling behavior that it swells at intestinal pH (7.0-7.5) and shrinks at gastric pH (˜2.0) thus enabling the safe unloading of the drug from the nano capsules.

  11. Battlefield MRI

    Energy Technology Data Exchange (ETDEWEB)

    Espy, Michelle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-01

    Magnetic Resonance Imaging is the best method for non-invasive imaging of soft tissue anatomy, saving countless lives each year. It is regarded as the gold standard for diagnosis of mild to moderate traumatic brain injuries. Furthermore, conventional MRI relies on very high, fixed strength magnetic fields (> 1.5 T) with parts-per-million homogeneity, which requires very large and expensive magnets.

  12. Endogenous lung surfactant inspired pH responsive nanovesicle aerosols: Pulmonary compatible and site-specific drug delivery in lung metastases

    Science.gov (United States)

    Joshi, Nitin; Shirsath, Nitesh; Singh, Ankur; Joshi, Kalpana S.; Banerjee, Rinti

    2014-11-01

    Concerns related to pulmonary toxicity and non-specificity of nanoparticles have limited their clinical applications for aerosol delivery of chemotherapeutics in lung cancer. We hypothesized that pulmonary surfactant mimetic nanoparticles that offer pH responsive release specifically in tumor may be a possible solution to overcome these issues. We therefore developed lung surfactant mimetic and pH responsive lipid nanovesicles for aerosol delivery of paclitaxel in metastatic lung cancer. 100-200 nm sized nanovesicles showed improved fusogenicity and cytosolic drug release, specifically with cancer cells, thereby resulting in improved cytotoxicity of paclitaxel in B16F10 murine melanoma cells and cytocompatibility with normal lung fibroblasts (MRC 5). The nanovesicles showed airway patency similar to that of endogenous pulmonary surfactant and did not elicit inflammatory response in alveolar macrophages. Their aerosol administration while significantly improving the biodistribution of paclitaxel in comparison to Taxol (i.v.), also showed significantly higher metastastes inhibition (~75%) in comparison to that of i.v. Taxol and i.v. Abraxane. No signs of interstitial pulmonary fiborisis, chronic inflammation and any other pulmonary toxicity were observed with nanovesicle formulation. Overall, these nanovesicles may be a potential platform to efficiently deliver hydrophobic drugs as aerosol in metastatic lung cancer and other lung diseases, without causing pulmonary toxicity.

  13. MRI of the Chest

    Medline Plus

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

  14. Knee MRI scan

    Science.gov (United States)

    MRI - knee ... radiologist see certain areas more clearly. During the MRI, the person who operates the machine will watch ... less anxious. Your provider may suggest an "open" MRI, in which the machine is not as close ...

  15. MRI of the Chest

    Medline Plus

    Full Text Available ... MRI of the Chest? What is MRI of the Chest? Magnetic resonance imaging (MRI) is a noninvasive ... of page What are some common uses of the procedure? MR imaging of the chest is performed ...

  16. Play the MRI Game

    Science.gov (United States)

    ... Teachers' Questionnaire MRI Play MRI the Magnetic Miracle Game About the game In the MRI imaging technique, strong magnets and ... last will in Paris. Play the Blood Typing Game Try to save some patients and learn about ...

  17. MRI of the Chest

    Medline Plus

    Full Text Available ... MRI of the Chest? What is MRI of the Chest? Magnetic resonance imaging (MRI) is a noninvasive ... of page What are some common uses of the procedure? MR imaging of the chest is performed ...

  18. MRI of the Chest

    Medline Plus

    Full Text Available ... You may resume your usual activities and normal diet immediately after the exam. On very rare occasions, ... Magnetic Resonance Imaging (MRI) Safety MRI Safety During Pregnancy Images related to Magnetic Resonance Imaging (MRI) - Chest ...

  19. Animal MRI Core

    Data.gov (United States)

    Federal Laboratory Consortium — The Animal Magnetic Resonance Imaging (MRI) Core develops and optimizes MRI methods for cardiovascular imaging of mice and rats. The Core provides imaging expertise,...

  20. Strategy for sensor based on fluorescence emission red shift of conjugated polymers: applications in pH response and enzyme activity detection.

    Science.gov (United States)

    Tang, Yanli; Liu, Yue; Cao, Ali

    2013-01-15

    A new strategy was developed and applied in monitoring pH response and enzyme activity based on fluorescence emission red shift (FERS) of the conjugated polymer PPP-OR10 induced by the inner filter effect (IFE) of nitrobenzene derivatives. Neutral poly(p-phenylenes) functionalized with oligo(oxyethylene) side chains (PPP-OR10) was designed and synthesized by the Suzuki cross-coupling reaction. Nitrobenzene derivatives display different light absorption activities in the acidic or basic form due to adopting different electron-transition types. When environmental pH is higher than their pK(a) values, nitrobenzene derivatives exhibit strong absorbance around 400 nm, which is close to the maximal emission of polymer PPP-OR10. As a result, the maximal emission wavelength of PPP-OR10/nitrobenzene derivatives red shifts with the pH value increasing. Apparently, the IFE plays a very important role in this case. A new method has been designed that takes advantage of this pH-sensitive platform to sensor α-chymotrypsin (ChT) based on the IFE of p-nitroaniline, since the absorption spectrum of p-nitroaniline, the ChT-hydrolyzed product of N-benzoyl-L-tyrosine-p-nitroaniline (BTNA), overlaps with the emission spectrum of PPP-OR10. In addition, the present approach can detect α-chymotrypsin with a detection limit of 0.1 μM, which is lower than that of the corresponding absorption spectroscopy method. Furthermore, the pH response and enzyme detections can be carried out in 10% serum, which makes this new FERS-based strategy promising in applications in more complex conditions and a broader field.

  1. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... the limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) ... ray, CT and ultrasound. top of page How is the procedure performed? MRI examinations may be performed ...

  2. Magnetic Resonance Imaging (MRI) -- Head

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

  3. Abdominal MRI scan

    Science.gov (United States)

    Nuclear magnetic resonance - abdomen; NMR - abdomen; Magnetic resonance imaging - abdomen; MRI of the abdomen ... radiologist see certain areas more clearly. During the MRI, the person who operates the machine will watch ...

  4. MRI of the Chest

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    Full Text Available ... about pregnancy and MRI. If you have claustrophobia (fear of enclosed spaces) or anxiety, you may want ... projectiles within the MRI scanner room and may cause you and/or others nearby harm. These items ...

  5. MRI of the Chest

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    Full Text Available ... internal body structures. MRI does not use ionizing radiation (x-rays). Detailed MR images allow physicians to ... tomography (CT) scans, MRI does not utilize ionizing radiation. Instead, radiofrequency pulses re-align hydrogen atoms that ...

  6. MRI of the Chest

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    Full Text Available ... clearer and more detailed than with other imaging methods. This detail makes MRI an invaluable tool in ... might be obscured by bone with other imaging methods. The contrast material used in MRI exams is ...

  7. MRI of the Chest

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    Full Text Available ... conditions. MRI uses a powerful magnetic field, radio frequency pulses and a computer to produce detailed pictures ... with claustrophobia. Newer open MRI units provide very high quality images for many types of exams. Older ...

  8. MRI of the Chest

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    Full Text Available ... or headphones during the exam. MRI scanners are air-conditioned and well-lit. Music may be played ... the limitations of MRI of the Chest? High-quality images are assured only if you are able ...

  9. MRI of the Chest

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    Full Text Available ... clearer and more detailed than with other imaging methods. This detail makes MRI an invaluable tool in ... might be obscured by bone with other imaging methods. The contrast material used in MRI exams is ...

  10. MRI of the Chest

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    Full Text Available ... have this exam in the first trimester of pregnancy unless the potential benefit from the MRI exam ... See the Safety page for more information about pregnancy and MRI. If you have claustrophobia (fear of ...

  11. MRI of the Chest

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    Full Text Available ... top of page What are the benefits vs. risks? Benefits MRI is a noninvasive imaging technique that ... risking the side effects of conventional (catheter) angiography . Risks The MRI examination poses almost no risk to ...

  12. MRI of the Chest

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    Full Text Available ... or potentially pose a risk, depending on their nature and the strength of the MRI magnet. Many ... of the body being studied. If a contrast material will be used in the MRI exam, a ...

  13. MRI of the Chest

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    Full Text Available ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ... MRI an invaluable tool in early diagnosis and evaluation of cardiovascular conditions. MRI has proven valuable in ...

  14. MRI of the Chest

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    Full Text Available ... MRI. If you have claustrophobia (fear of enclosed spaces) or anxiety, you may want to ask your ... or headphones during the exam. MRI scanners are air-conditioned and well-lit. Music may be played ...

  15. MRI of the Chest

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    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Chest Magnetic resonance imaging (MRI) of ... Although there is no reason to believe that magnetic resonance imaging harms the fetus, pregnant women usually are ...

  16. MRI of the Chest

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    Full Text Available ... claustrophobia. Newer open MRI units provide very high quality images for many types of exams; however, older ... MRI units may not provide this same image quality. Certain types of exams cannot be performed using ...

  17. MRI of the Chest

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    Full Text Available ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ... MRI an invaluable tool in early diagnosis and evaluation of cardiovascular conditions. MRI has proven valuable in ...

  18. MRI of the Chest

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    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...

  19. MRI of the Chest

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    ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...

  20. Functional genomics of pH homeostasis in Corynebacterium glutamicum revealed novel links between pH response, oxidative stress, iron homeostasis and methionine synthesis

    Directory of Open Access Journals (Sweden)

    Persicke Marcus

    2009-12-01

    Full Text Available Abstract Background The maintenance of internal pH in bacterial cells is challenged by natural stress conditions, during host infection or in biotechnological production processes. Comprehensive transcriptomic and proteomic analyses has been conducted in several bacterial model systems, yet questions remain as to the mechanisms of pH homeostasis. Results Here we present the comprehensive analysis of pH homeostasis in C. glutamicum, a bacterium of industrial importance. At pH values between 6 and 9 effective maintenance of the internal pH at 7.5 ± 0.5 pH units was found. By DNA microarray analyses differential mRNA patterns were identified. The expression profiles were validated and extended by 1D-LC-ESI-MS/MS based quantification of soluble and membrane proteins. Regulators involved were identified and thereby participation of numerous signaling modules in pH response was found. The functional analysis revealed for the first time the occurrence of oxidative stress in C. glutamicum cells at neutral and low pH conditions accompanied by activation of the iron starvation response. Intracellular metabolite pool analysis unraveled inhibition of the TCA and other pathways at low pH. Methionine and cysteine synthesis were found to be activated via the McbR regulator, cysteine accumulation was observed and addition of cysteine was shown to be toxic under acidic conditions. Conclusions Novel limitations for C. glutamicum at non-optimal pH values were identified by a comprehensive analysis on the level of the transcriptome, proteome, and metabolome indicating a functional link between pH acclimatization, oxidative stress, iron homeostasis, and metabolic alterations. The results offer new insights into bacterial stress physiology and new starting points for bacterial strain design or pathogen defense.

  1. Immobilized Multifunctional Polymersomes on Solid Surfaces: Infrared Light-Induced Selective Photochemical Reactions, pH Responsive Behavior, and Probing Mechanical Properties under Liquid Phase.

    Science.gov (United States)

    Iyisan, Banu; Janke, Andreas; Reichenbach, Philipp; Eng, Lukas M; Appelhans, Dietmar; Voit, Brigitte

    2016-06-22

    Fixing polymersomes onto surfaces is in high demand not only for the characterization with advanced microscopy techniques but also for designing specific compartments in microsystem devices in the scope of nanobiotechnology. For this purpose, this study reports the immobilization of multifunctional, responsive, and photo-cross-linked polymersomes on solid substrates by utilizing strong adamantane-β-cyclodextrin host-guest interactions. To reduce nonspecific binding and retain better spherical shape, the level of attractive forces acting on the immobilized polymersomes was tuned through poly(ethylene glycol) passivation as well as decreased β-cyclodextrin content on the corresponding substrates. One significant feature of this system is the pH responsivity of the polymersomes which has been demonstrated by swelling of the immobilized vesicles at acidic condition through in situ AFM measurements. Also, light responsivity has been provided by introducing nitroveratryloxycarbonyl (NVOC) protected amine molecules as photocleavable groups to the polymersome surface before immobilization. The subsequent low-energy femtosecond pulsed laser irradiation resulted in the cleavage of NVOC groups on immobilized polymersomes which in turn led to free amino groups as an additional functionality. The freed amines were further conjugated with a fluorescent dye having an activated ester that illustrates the concept of bio/chemo recognition for a potential binding of biological compounds. In addition to the responsive nature, the mechanical stability of the analyzed polymersomes was supported by computing Young's modulus and bending modulus of the membrane through force curves obtained by atomic force microscopy measurements. Overall, polymersomes with a robust and pH-swellable membrane combined with effective light responsive behavior are promising tools to design smart and stable compartments on surfaces for the development of microsystem devices such as chemo/biosensors.

  2. MRI in acute poliomyelitis

    Energy Technology Data Exchange (ETDEWEB)

    Kornreich, L. [Imaging Department, The Schneider Children`s Medical Centre of Israel, Kaplan Street, Petah Tiqva 49202 (Israel)]|[Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel); Dagan, O. [The Intensive Care Unit, The Schneider Children`s Medical Centre of Israel, Beilinson Medical Campus, Petah Tiqva (Israel)]|[Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel); Grunebaum, M. [Imaging Department, The Schneider Children`s Medical Centre of Israel, Kaplan Street, Petah Tiqva 49202 (Israel)]|[Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel)

    1996-05-01

    MRI can be used in the diagnosis of anterior horn infection and for assessing the extent of disease. There are no specific MRI signs to differentiate between the various possible pathogens. This is demonstrated in the present case of poliomyelitis, in which MRI of the spine played an important role in establishing the diagnosis. (orig.). With 1 fig.

  3. MRI of the Chest

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    Full Text Available ... field of the MRI unit, metal and electronic items are not allowed in the exam room. In addition to affecting the MRI images, ... damaged pins, hairpins, metal zippers and similar metallic items, which can distort ... In most cases, an MRI exam is safe for patients with metal implants, except ...

  4. fMRI Neuroinformatics

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Christensen, Mark Schram; Madsen, Kristoffer M.

    2006-01-01

    Functional magnetic resonance imaging (fMRI) generates vast amounts of data. The handling, processing, and analysis of fMRI data would be inconceivable without computer-based methods. fMRI neuroinformatics is concerned with research, development, and operation of these methods. Reconstruction...

  5. MRI in psychiatry

    Energy Technology Data Exchange (ETDEWEB)

    Mulert, Christoph [UKE, Hamburg (Germany). Psychiatry Neuroimaging Branch; Shenton, Martha E. (ed.) [Harvard Medical School, Boston, MA (United States). Dept. of Psychiatry and Radiology

    2014-07-01

    This is the first comprehensive textbook on the use of MRI in psychiatry covering imaging techniques, brain systems and a review of findings in different psychiatric disorders. The book is divided into three sections, the first of which covers in detail all the major MRI-based methodological approaches available today, including fMRI, EEG-fMRI, DTI, and MR spectroscopy. In addition, the role of MRI in imaging genetics and combined brain stimulation and imaging is carefully explained. The second section provides an overview of the different brain systems that are relevant for psychiatric disorders, including the systems for perception, emotion, cognition, and reward. The final part of the book presents the MRI findings that are obtained in all the major psychiatric disorders using the previously discussed techniques. Numerous carefully chosen images support the informative text, making this an ideal reference work for all practitioners and trainees with an interest in this flourishing field.

  6. [Temporomandibular joint: MRI diagnostics].

    Science.gov (United States)

    Kress, B; Schmitter, M

    2005-09-01

    MRI of the temporomandibular joint (TMJ) requires 1.5 T. The radiologist must be familiar with the anatomy and pathology of the TMJ. This review gives a description of MRI protocols for the TMJ, and MRI anatomy and pathology of the TMJ (open and closed mouth) by means of MR images and drawings. Diagnosing of the TMJ related diseases depends on standardized clinical and MR examinations. Therefore close interdisciplinary cooperation between dentist and radiologist is necessary.

  7. MRI brain imaging.

    Science.gov (United States)

    Skinner, Sarah

    2013-11-01

    General practitioners (GPs) are expected to be allowed to request MRI scans for adults for selected clinically appropriate indications from November 2013 as part of the expansion of Medicare-funded MRI services announced by the Federal Government in 2011. This article aims to give a brief overview of MRI brain imaging relevant to GPs, which will facilitate explanation of scan findings and management planning with their patients. Basic imaging techniques, common findings and terminology are presented using some illustrative case examples.

  8. Magnetic Resonance Imaging (MRI) -- Head

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

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... information on the chemicals present in the body's cells, may also be performed during the MRI exam ... medically necessary. MRI may not always distinguish between cancer tissue and fluid, known as edema . MRI typically ...

  10. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive ... of page What are some common uses of the procedure? MR imaging of the head is performed ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... information on the chemicals present in the body's cells, may also be performed during the MRI exam ... medically necessary. MRI may not always distinguish between cancer tissue and fluid, known as edema . MRI typically ...

  12. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive ... of page What are some common uses of the procedure? MR imaging of the head is performed ...

  13. MRI of the Chest

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    Full Text Available ... contrast material except when absolutely necessary for medical treatment. See the MRI Safety page for more information about pregnancy and MRI. If you have claustrophobia (fear of enclosed spaces) or anxiety, you may want to ask your physician for ...

  14. MRI of the Chest

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    Full Text Available ... metallic items, which can distort MRI images removable dental work pens, pocket knives and eyeglasses body piercings In most cases, an MRI exam is safe for patients with metal implants, except for a few types. People with the ...

  15. MRI of the Chest

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    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... Magnetic resonance imaging (MRI) is a noninvasive medical test that physicians use to diagnose medical conditions. MRI ...

  16. MRI of the Chest

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    Full Text Available ... other internal body structures. MRI does not use ionizing radiation (x-rays). Detailed MR images allow physicians to ... computed tomography (CT) scans, MRI does not utilize ionizing radiation. Instead, radiofrequency pulses re-align hydrogen atoms that ...

  17. Ultrasound- and MRI-Guided Prostate Biopsy

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Ultrasound- and MRI-Guided Prostate Biopsy Ultrasound- and MRI- ... Ultrasound-and MRI-guided Prostate Biopsy? What is Ultrasound- and MRI-guided Prostate Biopsy? Ultrasound- and MRI- ...

  18. MRI in perianal fistulae

    Directory of Open Access Journals (Sweden)

    Khera Pushpinder

    2010-01-01

    Full Text Available MRI has become the method of choice for evaluating perianal fistulae due to its ability to display the anatomy of the sphincter muscles orthogonally, with good contrast resolution. In this article we give an outline of the classification of perianal fistulae and present a pictorial assay of sphincter anatomy and the MRI findings in perianal fistulae. This study is based on a retrospective analysis of 43 patients with a clinical diagnosis of perianal fistula. MRI revealed a total of 44 fistulae in 35 patients; eight patients had only perianal sinuses.

  19. Brain MRI in Parkinson's disease

    NARCIS (Netherlands)

    Meijer, F.J.A.; Goraj, B.M.

    2014-01-01

    In this review article, conventional brain MRI and advanced MRI techniques in Parkinson`s disease (PD) are discussed, with emphasis on clinical relevance. Conventional brain MRI sequences generally demonstrate limited abnormalities specific for PD and in clinical practice brain MRI is mainly used to

  20. Magnetic Resonance Imaging (MRI) -- Head

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

  1. MRI of the Chest

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    Full Text Available ... information on the chemicals present in the body's cells, may also be performed during the MRI exam ... in diagnosing a broad range of conditions, including cancer, heart and vascular disease, heart valve abnormalities, bone ...

  2. MRI of the Chest

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    Full Text Available ... it may cause some medical devices to malfunction. Most orthopedic implants pose no risk, but you should ... or if you have asthma. The contrast material most commonly used for an MRI exam contains a ...

  3. MRI of the Chest

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

  4. MRI of the Chest

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    Full Text Available ... to a CD or uploaded to a digital cloud server. MRI of the chest gives detailed pictures ... artery ( dissection ). See the MRA page for more information. top of page How should I prepare? You ...

  5. MRI of the Chest

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    Full Text Available ... your regular medications as usual. Leave jewelry at home and wear loose, comfortable clothing. You may be ... Jewelry and other accessories should be left at home, if possible, or removed prior to the MRI ...

  6. MRI of the Chest

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    Full Text Available ... imaging (MRI) exam. View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  7. Extradural spinal meningioma: MRI

    Energy Technology Data Exchange (ETDEWEB)

    Sato, N. [Department of Diagnostic Radiology, Yale University School of Medicine, P. O. Box 20 8042, New Haven, CT 06520-8042 (United States); Sze, G. [Department of Diagnostic Radiology, Yale University School of Medicine, P. O. Box 20 8042, New Haven, CT 06520-8042 (United States)

    1997-06-01

    We report a case of extradural spinal meningioma with pathologically proven features of malignant transformation. The MRI findings of extradural spinal meningioma and differences in the findings from intradural meningiomas are discussed. (orig.). With 1 fig.

  8. MRI of the Chest

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    Full Text Available ... contrast for an MRI. If you have a history of kidney disease or liver transplant, it will ... Radiology (ACR) and the Radiological Society of North America (RSNA), comprising physicians with expertise in several radiologic ...

  9. MRI of the Chest

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    Full Text Available ... a CD or uploaded to a digital cloud server. MRI of the chest gives detailed pictures of ... suggestion into the following text box: Comment: E-mail: Area code: Phone no: Thank you! Do you ...

  10. MRI of the Chest

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    Full Text Available ... pictures of organs, soft tissues, bone and virtually all other internal body structures. MRI does not use ... include: jewelry, watches, credit cards and hearing aids, all of which can be damaged pins, hairpins, metal ...

  11. MRI of the Chest

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    Full Text Available ... distinguish between cancer tissue and fluid, known as edema . MRI typically costs more and may take more ... with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes ...

  12. MRI of the Chest

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    Full Text Available ... prior to your scheduled examination. Infants and young children usually require sedation or anesthesia to complete an MRI exam without moving. Whether a child requires sedation depends on the child's age, intellectual ...

  13. MRI of the Chest

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    Full Text Available ... scanner, play the noises that the child might hear during the MRI exam, answer any questions and ... These items include: jewelry, watches, credit cards and hearing aids, all of which can be damaged pins, ...

  14. MRI of the Chest

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    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... the same effect. A very irregular heartbeat may affect the quality of images obtained using techniques that ...

  15. MRI of the Chest

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    Full Text Available ... Us News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Chest Magnetic resonance imaging ( ... the child can watch a movie while the scan is being performed. Thus, the child remains motionless ...

  16. MRI of the Chest

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    Full Text Available ... may cause some medical devices to malfunction. Most orthopedic implants pose no risk, but you should always ... metal objects. In general, metal objects used in orthopedic surgery pose no risk during MRI. However, a ...

  17. MRI of the Chest

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    Full Text Available ... devices or metal in your body. Guidelines about eating and drinking before your exam vary between facilities. ... fitting and has no metal fasteners. Guidelines about eating and drinking before an MRI exam vary with ...

  18. MRI of the Chest

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    Full Text Available ... scanner. top of page How does the procedure work? Unlike conventional x-ray examinations and computed tomography ( ... clearer and more detailed than with other imaging methods. This detail makes MRI an invaluable tool in ...

  19. MRI of the Chest

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    Full Text Available ... exam time. top of page What will I experience during and after the procedure? Most MRI exams ... uncomfortable to remain still during MR imaging. Others experience a sense of being closed-in (claustrophobia) while ...

  20. MRI of the Chest

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    Full Text Available ... will hear and feel loud tapping or thumping sounds when the coils that generate the radiofrequency pulses ... use headphones to reduce the intensity of the sounds made by the MRI machine. You may be ...

  1. MRI of the Chest

    Science.gov (United States)

    ... surgery pose no risk during MRI. However, a recently placed artificial joint may require the use of ... evaluation with additional views or a special imaging technique. A follow-up examination may also be necessary ...

  2. MRI of the Breast

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    ... surgery pose no risk during MRI. However, a recently placed artificial joint may require the use of ... evaluation with additional views or a special imaging technique. A follow-up examination may also be necessary ...

  3. MRI of the Chest

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    Full Text Available ... Infants and young children usually require sedation or anesthesia to complete an MRI exam without moving. Whether ... A physician or nurse specializing in sedation or anesthesia for children should be available during the exam ...

  4. MRI of the Chest

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    Full Text Available ... metallic items, which can distort MRI images removable dental work pens, pocket knives and eyeglasses body piercings ... from the contrast material, including nausea, headache and pain at the site of injection. Similarly, patients are ...

  5. MRI of the Chest

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    Full Text Available ... during an MRI scan, but this is rare. Tooth fillings and braces usually are not affected by ... from the contrast material, including nausea, headache and pain at the site of injection. Similarly, patients are ...

  6. MRI of the Chest

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    Full Text Available ... magnetic field is produced by passing an electric current through wire coils in most MRI units. Other ... that are detected by the coils. The electric current does not come in contact with the patient. ...

  7. MRI of the Chest

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    Full Text Available ... any recent surgeries. Some conditions, such as severe kidney disease, may prevent you from being given gadolinium contrast ... an MRI. If you have a history of kidney disease or liver transplant, it will be necessary to ...

  8. MRI of the Chest

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    Full Text Available ... provides movie-like sequential imaging of the cardiovascular system that is important to assess the health and ... the magnet. Some MRI units, called short-bore systems , are designed so that the magnet does not ...

  9. MRI of the Chest

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

  10. MRI of the Chest

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    Full Text Available ... MRI examinations may require you to receive an injection of contrast material into the bloodstream. The radiologist , ... the potential risks. Pregnant women should not receive injections of gadolinium contrast material except when absolutely necessary ...

  11. MRI of the Chest

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

  12. MRI of the Chest

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    Full Text Available ... copied to a CD or uploaded to a digital cloud server. MRI of the chest gives detailed ... the technologist if you have medical or electronic devices in your body. These objects may interfere with ...

  13. MRI of the Chest

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    Full Text Available ... data suggest that it is safe to continue breastfeeding after receiving intravenous contrast. For further information please ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...

  14. MRI of the Chest

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    Full Text Available ... evaluation with additional views or a special imaging technique. A follow-up examination may also be necessary ... vs. risks? Benefits MRI is a noninvasive imaging technique that does not involve exposure to ionizing radiation. ...

  15. MRI of the Chest

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    Full Text Available ... tissue and fluid, known as edema . MRI typically costs more and may take more time to perform ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

  16. MRI of the Chest

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    Full Text Available ... used in tattoos may contain iron and could heat up during an MRI scan, but this is ... to get a better understanding of the possible charges you will incur. Web page review process: This ...

  17. MRI of the Chest

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    Full Text Available ... may follow your regular daily routine and take food and medications as usual. Some MRI examinations may ... to iodine or x-ray contrast material, drugs, food, or the environment, or if you have asthma. ...

  18. MRI of the Chest

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    Full Text Available ... information on the chemicals present in the body's cells, may also be performed during the MRI exam ... in diagnosing a broad range of conditions, including cancer, heart and vascular disease, heart valve abnormalities, bone ...

  19. MRI of the Chest

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

  20. MRI of the Chest

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    Full Text Available ... to assess the anatomy and function of the heart and its blood flow. Tell your doctor about ... chest cavity, including the mediastinum , chest wall, pleura, heart and vessels, from almost any angle. MRI also ...

  1. MRI of the Chest

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    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... from the contrast material, including nausea, headache and pain at the site of injection. Similarly, patients are ...

  2. MRI of the Chest

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

  3. MRI of the Chest

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    Full Text Available ... and should not enter the MRI scanning area: cochlear (ear) implant some types of clips used for ... follow-up exam is done because a potential abnormality needs further evaluation with additional views or a ...

  4. MRI of the Chest

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    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... very rare occasions, a few patients experience side effects from the contrast material, including nausea, headache and ...

  5. MRI of the Chest

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

  6. MRI of the Chest

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    Full Text Available ... it is useful to bring that to the attention of the scheduler before the exam and bring ... does the equipment look like? The traditional MRI unit is a large cylinder-shaped tube surrounded by ...

  7. MRI of the Chest

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    Full Text Available ... may follow your regular daily routine and take food and medications as usual. Some MRI examinations may ... to iodine or x-ray contrast material, drugs, food, or the environment, or if you have asthma. ...

  8. MRI of the Chest

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    Full Text Available ... provides movie-like sequential imaging of the cardiovascular system that is important to assess the health and ... the magnet. Some MRI units, called short-bore systems , are designed so that the magnet does not ...

  9. MRI of the Chest

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    Full Text Available ... x-ray may be taken to detect and identify any metal objects. In general, metal objects used in orthopedic surgery pose no risk during MRI. However, a recently placed artificial joint ...

  10. MRI of the Chest

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    Full Text Available ... metal in your body. Guidelines about eating and drinking before your exam vary between facilities. Unless you ... has no metal fasteners. Guidelines about eating and drinking before an MRI exam vary with the specific ...

  11. MRI of the Chest

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    Full Text Available ... Unless you are told otherwise, take your regular medications as usual. Leave jewelry at home and wear ... your regular daily routine and take food and medications as usual. Some MRI examinations may require you ...

  12. Combined PET/MRI

    DEFF Research Database (Denmark)

    Bailey, D. L.; Pichler, B. J.; Gückel, B.

    2015-01-01

    This paper summarises key themes and discussions from the 4th international workshop dedicated to the advancement of the technical, scientific and clinical applications of combined positron emission tomography (PET)/magnetic resonance imaging (MRI) systems that was held in Tübingen, Germany, from...... February 23 to 27, 2015. Specifically, we summarise the three days of invited presentations from active researchers in this and associated fields augmented by round table discussions and dialogue boards with specific topics. These include the use of PET/MRI in cardiovascular disease, paediatrics, oncology......, neurology and multi-parametric imaging, the latter of which was suggested as a key promoting factor for the wider adoption of integrated PET/MRI. Discussions throughout the workshop and a poll taken on the final day demonstrated that attendees felt more strongly that PET/MRI has further advanced in both...

  13. MRI of the Chest

    Medline Plus

    Full Text Available ... be examined on a computer monitor, transmitted electronically, printed or copied to a CD or uploaded to ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ...

  14. MRI of the Chest

    Medline Plus

    Full Text Available ... electronic devices they may have. top of page What does the equipment look like? The traditional MRI ... to the total exam time. top of page What will I experience during and after the procedure? ...

  15. MRI of plantar fasciitis

    Energy Technology Data Exchange (ETDEWEB)

    Roger, B.; Grenier, P. [Service de Radiologie Polyvalente Diagnostique et Interventionelle, Hopital de la Pitie, 83, boulevard de l`Hopital, F-75651 Paris Cedex 13 (France)

    1997-12-01

    At present, MRI is the only imaging method that can precisely visualize lesions of the superficial plantar aponeurosis, whether they be musculoaponeurositides, enthesopathies or tears, and whether they be acute or chronic, with or without complications. By its direct visualization of the lesion, MRI enables an accurate assessment of the injury to be made and thereby better orients the therapeutic strategy. (orig.) With 11 figs., 15 refs.

  16. Posttraumatic pseudolipoma: MRI appearances

    Energy Technology Data Exchange (ETDEWEB)

    Theumann, N.; Abdelmoumene, A.; Wintermark, M.; Schnyder, P.; Gailloud, M.C.; Resnick, D. [CHUV, Department of Diagnostic and Interventional Radiology, Lausanne (Switzerland)

    2005-09-01

    The goal of this study was to describe the MRI characteristics of posttraumatic pseudolipomas. Ten patients with previous history of blunt trauma or local surgery were investigated with MRI at the level of their deformity. The etiology was blunt trauma in eight patients and postoperative trauma in two. For all patients medical documentation, in the form of clinical history and physical examination, confirmed that a visible hematoma was present acutely at the same location following the injury and that the contour deformity subsequently appeared. All patients underwent liposuction. Preoperative bilateral MRI examinations were performed on all patients. The mean clinical follow-up was 17.8 months. MRI examinations were interpreted in consensus by two experienced musculoskeletal radiologists with attention to fatty extension (subcutaneous fatty thickness and anatomical extension), asymmetry compared with the asymptomatic side, the presence or absence of fibrous septae or nonfatty components, and patterns of contrast enhancement. Ten posttraumatic pseudolipomas were identified. Clinically, they showed as subcutaneous masses with the consistency of normal adipose tissue. Their locations were the abdomen (n=1), hip (n=1), the upper thigh (n=6), the knee (n=1), and the ankle (n=1). On MRI examinations, using the contralateral side as a control, pseudolipomas appeared as focal fatty masses without a capsule or contrast enhancement. Posttraumatic pseudolipomas may develop at a site of blunt trauma or surgical procedures often antedated by a soft tissue hematoma. Characteristic MRI findings are unencapsulated subcutaneous fatty masses without contrast enhancement. (orig.)

  17. Sodium sensing in neurons with a dendrimer-based nanoprobe.

    Science.gov (United States)

    Lamy, Christophe M; Sallin, Olivier; Loussert, Céline; Chatton, Jean-Yves

    2012-02-28

    Ion imaging is a powerful methodology to assess fundamental biological processes in live cells. The limited efficiency of some ion-sensing probes and their fast leakage from cells are important restrictions to this approach. In this study, we present a novel strategy based on the use of dendrimer nanoparticles to obtain better intracellular retention of fluorescent probes and perform prolonged fluorescence imaging of intracellular ion dynamics. A new sodium-sensitive nanoprobe was generated by encapsulating a sodium dye in a PAMAM dendrimer nanocontainer. This nanoprobe is very stable and has high sodium sensitivity and selectivity. When loaded in neurons in live brain tissue, it homogenously fills the entire cell volume, including small processes, and stays for long durations, with no detectable alterations of cell functional properties. We demonstrate the suitability of this new sodium nanosensor for monitoring physiological sodium responses such as those occurring during neuronal activity.

  18. Preparation and termination of carbosilane dendrimer based on siloxane tetramer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chung Kyun; Park, Eun Mi [Donga Univ., Pusan (Korea, Republic of)

    1998-02-01

    Dendritic macromolecules of the first to fourth generation were synthesized, using alkenylation and hydrosilation cycles with allylmagnesium bromide and dichloromethylsilane as building blocks and siloxane tetramer (Me(CH{sub 2}=CH)SiO){sub 4} as core molecule. By the reaction of the dichloromethylsilyl-capped generation (G4P) with p-bromophenol, p-phenylphenol and lithium phenyethynylide, dendrimers with specific functions (G4P-BP) (Mw: 16,300), G4P-PP (16,121), and G4P-PA (11,764) have been produced. Analysis of new dendrimers by NMR, UV and MALDI mass spectrometry suggests that they are pure and unified.

  19. Multidimensional diffusion MRI

    Science.gov (United States)

    Topgaard, Daniel

    2017-02-01

    Principles from multidimensional NMR spectroscopy, and in particular solid-state NMR, have recently been transferred to the field of diffusion MRI, offering non-invasive characterization of heterogeneous anisotropic materials, such as the human brain, at an unprecedented level of detail. Here we revisit the basic physics of solid-state NMR and diffusion MRI to pinpoint the origin of the somewhat unexpected analogy between the two fields, and provide an overview of current diffusion MRI acquisition protocols and data analysis methods to quantify the composition of heterogeneous materials in terms of diffusion tensor distributions with size, shape, and orientation dimensions. While the most advanced methods allow estimation of the complete multidimensional distributions, simpler methods focus on various projections onto lower-dimensional spaces as well as determination of means and variances rather than actual distributions. Even the less advanced methods provide simple and intuitive scalar parameters that are directly related to microstructural features that can be observed in optical microscopy images, e.g. average cell eccentricity, variance of cell density, and orientational order - properties that are inextricably entangled in conventional diffusion MRI. Key to disentangling all these microstructural features is MRI signal acquisition combining isotropic and directional dimensions, just as in the field of multidimensional solid-state NMR from which most of the ideas for the new methods are derived.

  20. MRI of the lung

    Energy Technology Data Exchange (ETDEWEB)

    Kauczor, Hans-Ulrich (ed.) [University Clinic Heidelberg (Germany). Diagnostic and Interventional Radiology

    2009-07-01

    For a long time, only chest X-ray and CT were used to image lung structure, while nuclear medicine was employed to assess lung function. During the past decade significant developments have been achieved in the field of magnetic resonance imaging (MRI), enabling MRI to enter the clinical arena of chest imaging. Standard protocols can now be implemented on up-to-date scanners, allowing MRI to be used as a first-line imaging modality for various lung diseases, including cystic fibrosis, pulmonary hypertension and even lung cancer. The diagnostic benefits stem from the ability of MRI to visualize changes in lung structure while simultaneously imaging different aspects of lung function, such as perfusion, respiratory motion, ventilation and gas exchange. On this basis, novel quantitative surrogates for lung function can be obtained. This book provides a comprehensive overview of how to use MRI for imaging of lung disease. Special emphasis is placed on benign diseases requiring regular monitoring, given that it is patients with these diseases who derive the greatest benefit from the avoidance of ionizing radiation. (orig.)

  1. MRI in Japanese encephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. [Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India). Dept. of Radiology; Misra, U.K. [Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India). Dept. of Neurology; Kalita, J. [Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India). Dept. of Neurology; Salwani, V. [Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India). Dept. of Radiology; Gupta, R.K. [Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India). Dept. of Radiology; Gujral, R. [Sanjay Gandhi Post Graduate Inst. of Medical Sciences, Lucknow (India). Dept. of Radiology

    1997-03-01

    We document the MRI features in seven patients with Japanese encephalitis. MRI was carried out on a 1.5 T system within 10-60 days of onset. In all the patients MRI revealed bilateral thalamic lesions, haemorrhagic in five. Signal changes were present in the cerebrum in four patients, the midbrain and cerebellum in three each, the pons in two and the basal ganglia in one. The lesions were haemorrhagic in three of the four patients with lesions in the cortex, two of the three with lesions in the midbrain and cerebellum, but the pontine lesions were haemorrhagic in both patients. Spinal cord involvement was seen in one of the three patients who underwent MRI. In two patients MRI was repeated 3 years after the onset, showing marked reduction in abnormal signal; and all the lesions gave low signal on both T1- and T2-weighted images. Bilateral thalamic involvement, especially haemorrhagic, may be considered characteristic of Japanese encephalitis, especially in endemic areas. (orig.)

  2. MRI of oriental cholangiohepatitis

    Energy Technology Data Exchange (ETDEWEB)

    Wani, N.A., E-mail: ahmad77chinar@gmail.co [Department of Radiodiagnosis and Imaging, Sher-I-Kashmir Institute of Medical Sciences (SKIMS), Srinagar (India); Robbani, I.; Kosar, T. [Department of Radiodiagnosis and Imaging, Sher-I-Kashmir Institute of Medical Sciences (SKIMS), Srinagar (India)

    2011-02-15

    Oriental cholangiohepatitis (OCH) also called recurrent pyogenic cholangitis is characterized by intrahepatic duct calculi, strictures, and recurrent infections. In turn cholangitis can result in multiple hepatic abscesses, further biliary strictures, and in severe cases, progressive hepatic parenchymal destruction, cirrhosis, and portal hypertension. Magnetic resonance cholangiopancreatography (MRCP) and conventional T1-weighted (T1 W) and T2-weighted (T2 W) magnetic resonance imaging (MRI) findings have been described in patients with OCH. MRCP findings include duct dilation, strictures, and calculi. MRCP can help to localize the diseased ducts and determine the severity of involvement. T1 and T2 W sequences reveal the parenchymal changes of atrophy, abscess formation, and portal hypertension in addition to calculi. Post-treatment changes are also well depicted using MRI. Comprehensive, non-invasive assessment is achieved by using conventional MRI and MRCP in OCH providing a roadmap for endoscopic or surgical management.

  3. MRI of active otosclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Ziyeh, S. [Section of Neuroradiology, Universitaetsklinik Freiburg, Breisacherstrasse 64, D-79106 Freiburg (Germany); Berlis, A. [Section of Neuroradiology, Universitaetsklinik Freiburg, Breisacherstrasse 64, D-79106 Freiburg (Germany); Ross, U.H. [Department of Otolaryngology, Universitaetsklinik, Freiburg (Germany); Reinhardt, M.J. [Department of Nuclear Medicine, Universitaetsklinik, Freiburg (Germany); Schumacher, M. [Section of Neuroradiology, Universitaetsklinik Freiburg, Breisacherstrasse 64, D-79106 Freiburg (Germany)

    1997-06-01

    Our aim was to determine whether MRI reliably shows pathology in patients with active otosclerosis (otospongiosis). We studied five patients with clinical and audiometric signs of this disorder and positive findings on high-resolution CT and tympanocochlear scintigraphy. Contrast enhancement of otospongiotic lesions was found in all affected ears, and could be topographically related to demineralised otospongiotic foci on CT. In lesions in the lateral wall of the labyrinth MRI sometimes showed the pathology better than CT, where partial-volume effects could be troublesome. (orig.). With 3 figs., 1 tab.

  4. Introduction to Interventional MRI

    Institute of Scientific and Technical Information of China (English)

    Jarmo Ruohonen; William G.Bradley; Jr.MD

    2002-01-01

    An increasing number of interventional procedures are done under imaging guidance. These include biopsies, drainages and injections. Likewise, imaging guidance and monitoring have enabled the use of sophisticated techniques for minimally invasive therapy of tumors. Since MRI provides the best tissue contrast and lesion sensitivity,the use of MR-guided procedures (MRGP) is quickly gaining momentum. Special hardware and software solutions have been developed that allow more efficient interventional use of the MR scanner.This introduction summarizes the basic concepts of interventional MRI and outlines some of the applications of today and tomorrow.

  5. MRI of osteonecrosis

    Energy Technology Data Exchange (ETDEWEB)

    Saini, A. [Department of Radiology, Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex (United Kingdom); Saifuddin, A. [Department of Radiology, Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex (United Kingdom)]. E-mail: asaifuddin@aol.com

    2004-12-01

    Osteonecrosis is a relatively common condition, which may be idiopathic or secondary to a variety of clinical situations. It may involve the subarticular region of a joint, when it is commonly referred to as ischaemic necrosis, or the metaphyseal regions of long bones, when it is referred to as bone infarction. In both situations, early lesions may be radiographically occult. However, magnetic resonance imaging (MRI) is very sensitive in identifying and characterizing osteonecrosis. This review illustrates the varied MRI features of osteonecrosis that enable a confident diagnosis to be made. Complications and differential diagnosis are also considered.

  6. Ultrasound- and MRI-Guided Prostate Biopsy

    Science.gov (United States)

    ... Index A-Z Ultrasound- and MRI-Guided Prostate Biopsy Ultrasound- and MRI-guided prostate biopsy uses imaging ... Biopsy? What is Ultrasound- and MRI-guided Prostate Biopsy? Ultrasound- and MRI-guided prostate biopsies are performed ...

  7. Quality assurance in functional MRI

    DEFF Research Database (Denmark)

    Liu, Thomas T; Glover, Gary H; Mueller, Bryon A

    2015-01-01

    Over the past 20 years, functional magnetic resonance imaging (fMRI) has ben- efited greatly from improvements in MRI hardware and software. At the same time, fMRI researchers have pushed the technical limits of MRI systems and greatly in- fluenced the development of state-of-the-art systems....... Minimizing image noise and maximizing system stability is critical in fMRI because the blood oxygenation level- dependent (BOLD) signal changes that are used for most fMRI studies represent only a small fraction of the total MR signal. In addition, multiple imaging volumes must be acquired over time to track...... cognitive processes. As a result, MRI scanners must have excellent time-series stability to accurately measure BOLD signal changes over the course of a long time series (typically on the order of 10 min per scan). fMRI studies are particularly demanding on the scanner hardware because they utilize fast...

  8. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... about pregnancy and MRI. If you have claustrophobia (fear of enclosed spaces) or anxiety, you may want ... projectiles within the MRI scanner room and may cause you and/or others nearby harm. These items ...

  9. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  10. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... conditions. MRI uses a powerful magnetic field, radio frequency pulses and a computer to produce detailed pictures ... with claustrophobia. Newer open MRI units provide very high quality images for many types of exams. Older ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... The teddy bear denotes child-specific content. Related Articles and Media MR Angiography (MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging (MRI) ...

  12. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... medically necessary. MRI may not always distinguish between cancer tissue and fluid, known as edema . MRI typically ... Brain Tumors Radiation Therapy for Head and Neck Cancer Others : American Stroke Association National Stroke Association top ...

  13. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... medically necessary. MRI may not always distinguish between cancer tissue and fluid, known as edema . MRI typically ... Brain Tumors Radiation Therapy for Head and Neck Cancer Others : American Stroke Association National Stroke Association top ...

  14. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... or headphones during the exam. MRI scanners are air-conditioned and well-lit. Music may be played ... the limitations of MRI of the Head? High-quality images are assured only if you are able ...

  15. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... to remain perfectly still and follow breath-holding instructions while the images are being recorded. If you ... Images related to Magnetic Resonance Imaging (MRI) - Head Videos related to Magnetic Resonance Imaging (MRI) - Head Sponsored ...

  16. Magnetic Resonance Imaging (MRI) Safety

    Science.gov (United States)

    ... Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) Safety What is MRI and how does ... the area being scanned include: Metallic spinal rod Plates, pins, screws, or metal mesh used to repair ...

  17. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... bore which can be more comfortable for larger size patients or patients with claustrophobia. Other MRI machines ... Gallery Magnetic Resonance Imaging (MRI) procedure View full size with caption Pediatric Content Some imaging tests and ...

  18. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... Us News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging ( ... if possible, or removed prior to the MRI scan. Because they can interfere with the magnetic field ...

  19. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... have this exam in the first trimester of pregnancy unless the potential benefit from the MRI exam ... See the Safety page for more information about pregnancy and MRI. If you have claustrophobia (fear of ...

  20. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... top of page What are the benefits vs. risks? Benefits MRI is a noninvasive imaging technique that ... than 30 minutes from the onset of symptoms. Risks The MRI examination poses almost no risk to ...

  1. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... or potentially pose a risk, depending on their nature and the strength of the MRI magnet. Many ... is positioned around the head. If a contrast material will be used in the MRI exam, a ...

  2. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ... MRI an invaluable tool in early diagnosis and evaluation of many conditions, including tumors. MRI enables the ...

  3. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... Brain Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to ...

  4. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... claustrophobia. Newer open MRI units provide very high quality images for many types of exams; however, older ... MRI units may not provide this same image quality. Certain types of exams cannot be performed using ...

  5. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... claustrophobia. Newer open MRI units provide very high quality images for many types of exams. Older open MRI units may not provide this same image quality. Certain types of exams cannot be performed using ...

  6. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... is done because a potential abnormality needs further evaluation with additional views or a special imaging technique. ... MRI an invaluable tool in early diagnosis and evaluation of many conditions, including tumors. MRI enables the ...

  7. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... imaging technique that does not involve exposure to ionizing radiation. MRI can help physicians evaluate the structures of the brain and can also provide functional information (fMRI) in ...

  8. Magnetic Resonance Imaging (MRI) -- Head

    Science.gov (United States)

    ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...

  10. Getting an MRI (For Kids)

    Medline Plus

    Full Text Available ... dientes Video: Getting an X-ray Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) Print A A A en español Obtención de una resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed pictures of ...

  11. Getting an MRI (For Kids)

    Science.gov (United States)

    ... dientes Video: Getting an X-ray Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) Print A A A en español Obtención de una resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed pictures of ...

  12. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... field of the MRI unit, metal and electronic items are not allowed in the exam room. In addition to affecting the MRI images, ... damaged pins, hairpins, metal zippers and similar metallic items, which can distort ... In most cases, an MRI exam is safe for patients with metal implants, except ...

  13. Less Confusion in Diffusion MRI

    NARCIS (Netherlands)

    Tax, C.M.W.

    2016-01-01

    With its unique ability to investigate tissue architecture and microstructure in vivo, diffusion MRI (dMRI) has gained tremendous interest and the society has been continuously triggered to develop novel dMRI image analysis approaches. With the overwhelming amount of strategies currently available i

  14. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI an invaluable tool in early diagnosis and evaluation of many conditions, including tumors. MRI enables the discovery of abnormalities that might be obscured by bone with other imaging methods. The contrast material used in MRI exams is less likely to ...

  15. MRI of intact plants.

    NARCIS (Netherlands)

    As, H. van; Scheenen, T.W.J.; Vergeldt, F.J.

    2009-01-01

    Nuclear magnetic resonance imaging (MRI) is a non-destructive and non-invasive technique that can be used to acquire two- or even three-dimensional images of intact plants. The information within the images can be manipulated and used to study the dynamics of plant water relations and water transpor

  16. MRI of intact plants

    NARCIS (Netherlands)

    As, van H.; Scheenen, T.; Vergeldt, F.J.

    2009-01-01

    Nuclear magnetic resonance imaging (MRI) is a non-destructive and non-invasive technique that can be used to acquire two- or even three-dimensional images of intact plants. The information within the images can be manipulated and used to study the dynamics of plant water relations and water transpor

  17. MRI of the Chest

    Medline Plus

    Full Text Available ... MRI. If you have a history of kidney disease or liver transplant, it will be necessary to perform a blood test to determine whether the kidneys are functioning adequately. Women should always inform their physician or technologist if ...

  18. MRI of the Chest

    Medline Plus

    Full Text Available ... the radiologist know if you have any serious health problems, or if you have had any recent surgeries. Some conditions, such as severe kidney disease, may prevent you from being given gadolinium contrast for an MRI. If you have a history of kidney disease or liver transplant, it will ...

  19. IMAGING (MRI) FINDINGS

    African Journals Online (AJOL)

    maxillary lesions frequently affect the alveolar ridge and body. Maxillary lesions ... lesion can occur centrally in the medullary bone or develop. *Correspondence: ... could not be picked up from this view as MRI cannot image bone. Fig 3: Computed ... cross-section of the lesion will fall in the focal trough. When the lesion is ...

  20. MRI of the Chest

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    Full Text Available ... of which shows a thin slice of the body. The images can then be studied from different angles by ... bear denotes child-specific content. Related Articles and Media MR ... Images related to Magnetic Resonance Imaging (MRI) - Chest Sponsored ...

  1. MRI of the Chest

    Medline Plus

    Full Text Available ... or anesthesia. Alternatively, certain pediatric facilities have child life personnel who can work with younger children to help avoid the need ... MRI units may not provide this same image quality. Certain types of exams cannot be ... work? Unlike conventional x-ray examinations and computed tomography ( ...

  2. MRI in suspected appendicitis

    NARCIS (Netherlands)

    Leeuwenburgh, M.M.N.

    2014-01-01

    Dit proefschrift richt zich op de optimalisatie van beeldvormende diagnostiek bij patiënten met een klinische verdenking op appendicitis, waarbij het gebruik van ‘magnetic resonance imaging’ (MRI) wordt verkend. Het proefschrift omvat de resultaten van de OPTIMAP-studie (OPTimisation of IMaging Appe

  3. Vesicouterine fistula: MRI diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, J.M.; Lomas, D.J. [Dept. of Radiology, Addenbrooke' s Hospital and University of Cambridge, Cambridge (United Kingdom); Lee, G.; Doble, A. [Dept. of Urology, Addenbrooke' s Hospital and University of Cambridge (United Kingdom); Sharma, S.D. [Dept. of Urology, Peterborough NHS Trust Hospital (United Kingdom)

    1999-07-01

    A case of vesicouterine fistula in a young woman following caesarean section is presented. The diagnosis was established successfully using heavily T2-weighted MRI which clearly demonstrated fluid within the fistula, obviating the need for conventional radiographic contrast examination. (orig.)

  4. MRI in suspected appendicitis

    NARCIS (Netherlands)

    Leeuwenburgh, M.M.N.

    2014-01-01

    Dit proefschrift richt zich op de optimalisatie van beeldvormende diagnostiek bij patiënten met een klinische verdenking op appendicitis, waarbij het gebruik van ‘magnetic resonance imaging’ (MRI) wordt verkend. Het proefschrift omvat de resultaten van de OPTIMAP-studie (OPTimisation of IMaging

  5. MRI of the Chest

    Medline Plus

    Full Text Available ... can be arranged for those patients who anticipate anxiety, but fewer than one in 20 require medication. It is normal for ... are sometimes the best way to see if treatment is working or if a finding is stable or ... than with other imaging methods. This detail makes MRI an invaluable tool in ...

  6. Sinus MRI scan

    Science.gov (United States)

    ... A CT scan may be preferred in emergency cases, since it is faster and often available in the emergency room. Note: MRI is not as effective as CT in defining the anatomy of the sinuses, and therefore is not typically used for suspected acute sinusitis.

  7. MRI of the Chest

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... Magnetic resonance imaging (MRI) is a noninvasive medical test that physicians use to diagnose and treat medical ...

  8. MRI of the Chest

    Medline Plus

    Full Text Available ... follow your regular daily routine and take food and medications as usual. Some MRI examinations may require you ... material is injected. Such reactions are usually mild and easily controlled by medication. If you experience allergic symptoms, a radiologist or ...

  9. MRI of the cardiomyopathies

    Energy Technology Data Exchange (ETDEWEB)

    Di Cesare, Ernesto E-mail: ernesto.dicesare@cc.univaq.it

    2001-06-01

    We examined the potentialities of Magnetic resonance imaging (MRI) in the evaluation of the main cardiomyopathies: hypertrophic, dilated, restrictive and arrhythmogenic right ventricular. The hypertrophic cardiomyopathy is generally adequately investigated by echocardiography, that well defines the myocardial thickening and the obstruction of the left ventricular output. However, by echocardiography we still have difficulties in the evaluation of the apex of the left ventricle and the right ventricle involvement. MRI provides a complete evaluation of the heart with a clear evidence also of the echocardiographic dark zones by means of a clear evidence of the apex of the right ventricle. The dilated form is also well investigated by MRI that provides a clear evaluation of the volumes, mass and ejection fraction by means of the 3D analysis including conditions of the ventricular remodelling. Moreover, this technique helps in the differential diagnosis of acute myocarditis. In the acute phase of myocarditis (first 2 weeks), in fact, the myocardium produces high signal intensity on the T2 weighted sequences due to the presence of oedema. The third form of cardiomyopathy is the restrictive one, characterised by reduced diastolic filling and diastolic volume, normality of the systolic function and parietal thickness, interstitial fibrosis and enlargement of both atria. The mean potentiality of MRI is related to the differential diagnosis with constrictive pericarditis. Only in the former, the pericardium appears irregularly thickened with areas exceeding 4 mm of pericardial thickness. Finally, the right ventricular arrhythmogenic cardiomyopathy represents the main indication to MRI evaluation. With this imaging modality we are can obtain a clear morpho-functional evaluation of the right ventricle and distinguish the intramyocardial adipose substitution characterised by areas of high signal in the myocardium.

  10. MRI of cardiovascular malformations

    Energy Technology Data Exchange (ETDEWEB)

    Kastler, Bruno [Centre Hospitalier Univ. Jean Minjoz, Besancon (France); Universite de Franche-Comte, Besancon (FR). Lab. I4S (Health, Innovation, Intervention, Imaging, Engineering); Centre Hospitalier Sherbrooke Univ., PQ (Canada). Dept. of Radiology

    2011-07-01

    MRI is a non-invasive and non-ionizing imaging modality that is perfectly suited for the diagnosis and follow-up of both pediatric and adult congenital heart disease. It provides a large field of view and has the unique ability to depict complex cardiac and vascular anatomy and to measure cardiac function and flow within one examination. MRI is the ideal complement to echocardiography whenever the information provided by the latter is limited. This book has been conceived as a self-teaching manual that will assist qualified radiologists, cardiologists, and pediatricians, as well as those in training. It is richly illustrated with numerous images and drawings that cover all usual and most unusual anomalies. The principal author, Professor Bruno Kastler, is head of radiology at Besancon University Hospital, France and is board certified in both radiology and cardiology. (orig.)

  11. MRI of the shoulder

    Energy Technology Data Exchange (ETDEWEB)

    Vahlensieck, M.

    2000-02-01

    Shoulder imaging is one of the major applications in musculoskeletal MRI. In order to analyze the images it is important to keep informed about anatomical and pathological findings and publications. In this article MRI technique, anatomy and pathology is reviewed. Technical considerations about MR sequences and examination strategy are only shortly discussed with emphasis on turbo spin echo and short T1 inversion recovery imaging. Basic anatomy as well as recent findings, including macroscopic aspects of the supraspinatus fat pad, composition of the supraspinatus muscle belly, and variability of the glenohumeral ligaments or coracoid ligament, are presented. Basic pathological conditions are described in detail, e. g. instability particularly problems in differentiating the various subtypes of labral pathology. Rotator cuff diseases are elucidated with emphasis on some rarer entities such as subscapularis calcifying tendinitis, coracoid impingement, chronic bursitis producing the double-line sign, prominent coraco-acromial ligament and the impingement due to an inflamed os acromiale. (orig.)

  12. MRI (Magnetic Resonance Imager)

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Yoshinori [Toshiba Corp., Kawasaki, Kanagawa (Japan)

    1995-05-01

    MRI is a widely used diagnostic imaging modality because it has excellent diagnostic capabilities, is safe to use and generates images not affected by bone artifacts. Images are obtained by utilizing the phenomenon of Nuclear Magnetic Resonance (NMR) by which protons located in a static magnetic field absorb radio frequency (RF) pulses with a specific frequency and release a part of the energy as a NMR signal. Potentially MRI has the ability to provide functional and metabolic information (such as flow, temperature, diffusion, neuron activity) in addition to morphological information. This paper describes the imaging principles and provides a general outline of some applications: flow imaging, metabolite imaging and temperature imaging. (J.P.N.).

  13. Superconducting magnets for MRI

    Energy Technology Data Exchange (ETDEWEB)

    Williams, J.E.

    1984-08-01

    Three types of magnets are currently used to provide the background field required for magnet resonance imaging (MRI). (i) Permanent magnets produce fields of up to 0.3 T in volumes sufficient for imaging the head or up to 0.15 T for whole body imaging. Cost and simplicity of operation are advantages, but relatively low field, weight (up to 100 tonnes) and, to a small extent, instability are limitations. (ii) Water-cooled magnets provide fields of up to 0.25 T in volumes suitable for whole body imaging, but at the expense of power (up to 150 kW for 0.25 T) and water-cooling. Thermal stability of the field requires the maintenance of constant temperature through periods both of use and of quiescence. (iii) Because of the limitations imposed by permanent and resistive magnets, particularly on field strength, the superconducting magnet is now most widely used to provide background fields of up to 2 T for whole body MRI. It requires very low operating power and that only for refrigeration. Because of the constant low temperature, 4.2 K, at which its stressed structure operates, its field is stable. The following review deals principally with superconducting magnets for MRI. However, the sections on field analysis apply to all types of magnet and the description of the source terms of circular coils and of the principals of design of solenoids apply equally to resistive solenoidal magnets.

  14. Pediatric elbow fractures: MRI evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Beltran, J. (Dept. of Radiology, Hospital for Joint Diseases, New York, NY (United States)); Rosenberg, Z.S. (Dept. of Radiology, Hospital for Joint Diseases, New York, NY (United States)); Kawelblum, M. (Dept. of Orthopaedic Surgery, Hospital for Joint Diseases, New York, NY (United States)); Montes, L. (Dept. of Radiology, Beth Israel Medical Center, New York, NY (United States)); Bergman, A.G. (Dept. of Radiology, Stanford Univ., School of Medicine, CA (United States)); Strongwater, A. (Dept. of Orthopaedic Surgery, Hospital for Joint Diseases, New York, NY (United States))

    1994-05-01

    Magnetic resonance imaging (MRI) was performed in eight patients under the age of 8 years who suffered elbow fractures, to assess possible fracture extension into the distal nonossified epiphysis of the humerus in seven cases and to determine the displacement and location of the radial head in one case. MRI allowed accurate depiction of the fracture line when it extended into the cartilaginous epiphysis. In four cases, MRI findings were confirmed at surgery. In five cases, surgery was obviated because no articular extension of the fracture was seen on MRI (4 cases) or because no displacement was noted (1 case). In one patient, the plain film diagnosis of a Salter type II fracture was changed to Salter type IV on the basis of the MRI findings. It is concluded that MRI might play a role in the preoperative evaluation of pediatric patients presenting with elbow trauma when extension of the fracture cannot be determined with routine radiographic studies. (orig.)

  15. Pigmented villonodular synovitis: MRI characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, T.H. [Dept. of Radiology, Univ. of California, San Diego, CA (United States)]|[Veterans Administration Medical Center, San Diego, CA (United States); Sartoris, D.J. [Dept. of Radiology, Univ. of California, San Diego, CA (United States)]|[Veterans Administration Medical Center, San Diego, CA (United States); Schweitzer, M.E. [Dept. of Radiology, Thomas Jefferson Univ. Hospital, Philadelphia, PA (United States); Resnick, D.L. [Dept. of Radiology, Univ. of California, San Diego, CA (United States)]|[Veterans Administration Medical Center, San Diego, CA (United States)

    1995-01-01

    The magnetic resonance imaging (MRI) scans of 26 patients with histopathologically proven pigmented villonodular synovitis (PVNS), involving joints but excluding tendon sheaths, were reviewed retrospectively. The purpose of this study is to define the spectrum and frequency of MRI characteristics for PVNS using conventional spin echo (in two cases before and after intravenous administration of gadopentate dimeglumine) and also gradient echo techniques. A cystic variety is presented, the MRI appearances of which have not been found in a review of the literature. (orig.)

  16. MRI assessment program. Consensus statement on clinical efficacy of MRI

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    This consensus statement is largely based on the experience gained at the MRI units at the four hospitals which have operated scanners in the MRI program. It reflects the considered opinion of the radiologists responsible for the MRI services at those hospitals. Account has also been taken of relevant overseas data. This collection of opinion relates particularly to comparison with other imaging modalities. The specific comments will require further consideration as technical developments with MRI become available, additional experience is gained with gadolinium contrast material and additional data are obtained on the influence of MRI on patient management. MRI, at present, is used either to improve diagnostic accuracy when other tests are negative or equivocal, when there is strong clinical suspicion of disease, or to improve surgical or other management planning when the diagnosis known. In some situations (eg syringomyelia, congenital spinal disease, posterior fossa/cerebello-pontine angle tumours) it may entirely replace other tests (eg myelography, air contrast, CT) which are substantially less accurate and/or more invasive. In other situations (eg hemispheric brain tumours, lumbar disc protrusions) when other tests, such as CT, can be as accurate, MRI is not usually or initially indicated because it is currently more expensive and of limited availability. However, balanced against this is the fact that it does not expose the patient to potentially harmful ionising radiation. It is also stressed that MRI images depend on complex, widely variable and, as yet, incompletely understood parameters. There is concern that this may result in false positive diagnoses, especially where MRI is used alone as a screening test, or used as the initial test. For several reasons (availability, cost, medical and diagnostic efficacy), the specific comments on indications for MRI presented are based upon the assumption that MRI is a tertiary and complementary imaging examination

  17. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles ... Videos related to Magnetic Resonance Imaging (MRI) - Head Sponsored ...

  18. MRI of the Fetal Brain.

    Science.gov (United States)

    Weisstanner, C; Kasprian, G; Gruber, G M; Brugger, P C; Prayer, D

    2015-10-01

    The purpose of this article is to provide an overview of the possibilities for fetal magnetic resonance imaging (MRI) in the evaluation of the fetal brain. For brain pathologies, fetal MRI is usually performed when an abnormality is detected by previous prenatal ultrasound, and is, therefore, an important adjunct to ultrasound. The most commonly suspected brain pathologies referred to fetal MRI for further evaluation are ventriculomegaly, missing corpus callosum, and abnormalities of the posterior fossa. We will briefly discuss the most common indications for fetal brain MRI, as well as recent advances.

  19. Ovarian cysts on prenatal MRI

    Energy Technology Data Exchange (ETDEWEB)

    Nemec, Ursula [Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Nemec, Stefan F., E-mail: stefan.nemec@meduniwien.ac.at [Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Medical Genetics Institute, Cedars Sinai Medical Center, 8700 Beverly Boulevard, PACT Suite 400, Los Angeles, CA 90048 (United States); Bettelheim, Dieter [Department of Obstetrics and Gynaecology, Division of Prenatal Diagnosis and Therapy, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Brugger, Peter C. [Center of Anatomy and Cell Biology, Integrative Morphology Group, Medical University Vienna, Waehringerstrasse 13, A-1090 Vienna (Austria); Horcher, Ernst [Department of Pediatric Surgery, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Schoepf, Veronika [Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Graham, John M.; Rimoin, David L. [Medical Genetics Institute, Cedars Sinai Medical Center, 8700 Beverly Boulevard, PACT Suite 400, Los Angeles, CA 90048 (United States); Weber, Michael; Prayer, Daniela [Department of Radiology, Division of Neuroradiology and Musculoskeletal Radiology, Medical University Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria)

    2012-08-15

    Objective: Ovarian cysts are the most frequently encountered intra-abdominal masses in females in utero. They may, at times, require perinatal intervention. Using magnetic resonance imaging (MRI) as an adjunct to ultrasonography (US) in prenatal diagnosis, we sought to demonstrate the ability to visualize ovarian cysts on prenatal MRI. Materials and methods: This retrospective study included 17 fetal MRI scans from 16 female fetuses (23-37 gestational weeks) with an MRI diagnosis of ovarian cysts after suspicious US findings. A multiplanar MRI protocol was applied to image and to characterize the cysts. The US and MRI findings were compared, and the prenatal findings were compared with postnatal imaging findings or histopathology. Results: Simple ovarian cysts were found in 10/16 cases and complex cysts in 7/16 cases, including one case with both. In 11/16 (69%) cases, US and MRI diagnoses were in agreement, and, in 5/16 (31%) cases, MRI specified or expanded the US diagnosis. In 6/16 cases, postnatal US showed that the cysts spontaneously resolved or decreased in size, and in 1/16 cases, postnatal imaging confirmed a hemorrhagic cyst. In 4/16 cases, the prenatal diagnoses were confirmed by surgery/histopathology, and for the rest, postnatal correlation was not available. Conclusion: Our results illustrate the MRI visualization of ovarian cysts in utero. In most cases, MRI will confirm the US diagnosis. In certain cases, MRI may provide further diagnostic information, additional to US, which is the standard technique for diagnosis, monitoring, and treatment planning.

  20. MRI in intraspinal tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, R.K. (Dept. of Radiology, Sanjay Gandhi Postgraduate Inst. of Medical Sciences, Lucknow (India)); Gupta, S. (Dept. of Radiology, Sanjay Gandhi Postgraduate Inst. of Medical Sciences, Lucknow (India)); Kumar, S. (Dept. of Radiology, Sanjay Gandhi Postgraduate Inst. of Medical Sciences, Lucknow (India)); Kohli, A. (Dept. of Neurology, Sanjay Gandhi Postgraduate Inst. of Medical Sciences, Lucknow (India)); Misra, U.K. (Dept. of Neurology, Sanjay Gandhi Postgraduate Inst. of Medical Sciences, Lucknow (India)); Gujral, R.B. (Dept. of Radiology, Sanjay Gandhi Postgraduate Inst. of Medical Sciences, Lucknow (India))

    1994-01-01

    We studied 20 patients with intraspinal tuberculosis (TB), to characterise the MRI features of tuberculous meningitis and myelitis. MRI leptomeningitis and intramedullary involvement in 11 patients, intramedullary lesions alone in 5, leptomeningitis alone in 2, and isolated extradural disease in 2. TB leptomeningitis was characterised by loculation of the cerebrospinal fluid (CSF), nerve root thickening and clumping (seen only in the lumbar region) or complete obliteration of the subarachnoid space on unenhanced images. Gd-DTPA-enhanced images proved useful in 6 cases, revealing linear enhancement of the surface of the spinal cord and nerve roots or plaque-like enhancement of the dura-arachnoid mater complex. Intramedullary lesions included tuberculomas (8), cord oedema (5) and cavitation (3). In seven cases of intramedullary tuberculoma multiple lesions with skip areas were seen, without significant cord swelling. One patient had an isolated lesion in the conus medullaris. The lesions were iso- or hypointense on T1-weighted images, iso-, hypo- or hyperintense on T2-weighted images and showed rim or nodular enhancement with contrast medium. (orig.)

  1. MRI of the cartilage

    Energy Technology Data Exchange (ETDEWEB)

    Imhof, H.; Noebauer-Huhmann, I.-M.; Krestan, C.; Gahleitner, A.; Marlovits, S.; Trattnig, S. [Department of Osteology, Universitaetklinik fuer Radiodiagnostik, AKH-Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria); Sulzbacher, I. [Universitaetsklinik fuer Pathologie Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria)

    2002-11-01

    With the introduction of fat-suppressed gradient-echo and fast spin-echo (FSE) sequences in clinical routine MR visualization of the hyaline articular cartilage is routinely possible in the larger joints. While 3D gradient-echo with fat suppression allows exact depiction of the thickness and surface of cartilage, FSE outlines the normal and abnormal internal structures of the hyaline cartilage; therefore, both sequences seem to be necessary in a standard MRI protocol for cartilage visualization. In diagnostically ambiguous cases, in which important therapeutic decisions are required, direct MR arthrography is the established imaging standard as an add-on procedure. Despite the social impact and prevalence, until recent years there was a paucity of knowledge about the pathogenesis of cartilage damage. With the introduction of high-resolution MRI with powerful surface coils and fat-suppression techniques, visualization of the articular cartilage is now routinely possible in many joints. After a short summary of the anatomy and physiology of the hyaline cartilage, the different MR imaging methods are discussed and recommended standards are suggested. (orig.)

  2. MRI of ranulas

    Energy Technology Data Exchange (ETDEWEB)

    Kurabayashi, T.; Ida, M.; Ohbayashi, N.; Yoshino, N.; Tetsumura, A.; Sasaki, T. [Graduate School, Tokyo Medical and Dental Univ. (Japan); Yasumoto, M. [Dept. of Radiology, Tokyo Medical and Dental Univ. (Japan)

    2000-12-01

    We reviewed the MRI of 20 patients with a ranula (8 simple and 12 plunging) and ten with other cystic masses in the floor of the mouth and/ or suprahyoid portion of the neck (three haemangiomas, two neuromas, one monomorphic adenoma, one lipoma, two lateral cervical cysts and one dermoid cyst). Histological diagnoses were obtained in all cases with the exception of one presumed haemangioma. Ranulas were all well-defined, homogeneous masses giving low signal on T1-and markedly high signal on T2-weighted images. While simple ranulas were all confined to the sublingual space, plunging ranulas were centered on the submandibular space and tended to spill into one or more adjacent spaces. They extended into the sublingual space anteriorly (producung a so-called tail sign) in eight of 12 cases and into the parapharyngeal space superiorly in five. Although they sometimes filled a considerable part of the parapharyngeal space, displacement of surrounding muscles or vessels was usually slight, which was thought to reflect the nature of extravasation pseudocysts. All other cystic masses in our study had one or more MRI finding different from those of ranulas and could be easily differentiated from them. (orig.)

  3. MRI Findings In Dengue Encephalitis

    Directory of Open Access Journals (Sweden)

    Ashraf V.V

    2004-01-01

    Full Text Available Neurological manifestations are rare in dengue fever. Two cases with encephalopathy and systemic features of dengue fever with abnormal CSF and MR imaging are reported. Striking MRI finding was bilateral symmetrical thalamic lesions similar to those reported in Japanese encephalitis. This report highlights that MRI findings can be similar in dengue and Japanese encephalitis.

  4. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... contrast material except when absolutely necessary for medical treatment. See the MRI Safety page for more information about pregnancy and MRI. If you have claustrophobia (fear of enclosed spaces) or anxiety, you may want to ask your physician for ...

  5. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... metallic items, which can distort MRI images removable dental work pens, pocket knives and eyeglasses body piercings In most cases, an MRI exam is safe for patients with metal implants, except for a few types. People with the ...

  6. Postmortem MRI of bladder agenesis

    Energy Technology Data Exchange (ETDEWEB)

    Barber, Brendan R. [St George' s Hospital, Radiology Department, London (United Kingdom); Weber, Martin A. [Great Ormond Street Hospital for Children, Department of Histopathology, London (United Kingdom); Bockenhauer, Detlef [Great Ormond Street Hospital for Children, Department of Nephrology, London (United Kingdom); Hiorns, Melanie P.; McHugh, Kieran [Great Ormond Street Hospital for Children, Radiology Department, London (United Kingdom)

    2011-01-15

    We report a 35-week preterm neonate with bladder agenesis and bilateral dysplastic kidneys. A suprapubic catheter was inadvertently inserted into one of the larger inferior cysts of the left dysplastic kidney. A postmortem MRI scan was performed with the findings being confirmed on autopsy. We are unaware of another postmortem MRI study demonstrating bladder agenesis. (orig.)

  7. Molecular MRI of Atherosclerotic lesions

    NARCIS (Netherlands)

    Adel, Brigit den

    2013-01-01

    This thesis describes the use of MRI contrast agents and vessel wall parameters to image different stages of atherosclerosis. Chapter 2 summerizes different MRI contrast agents targeted towards vulnerable plaques that have been presented in literature. Chapter 3 illustrates accumulation of paramagn

  8. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  9. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... can help physicians evaluate the structures of the brain and can also provide functional information (fMRI) in ...

  10. MRI atlas of ectopic endometriosis.

    Science.gov (United States)

    Dallaudière, B; Salut, C; Hummel, V; Pouquet, M; Piver, P; Rouanet, J-P; Maubon, A

    2013-03-01

    Ectopic endometriosis is a common condition which is often underdiagnosed, where MRI can help make a diagnosis simply, non-invasively and without irradiation. However, imagery signs of it are enormously polymorphic with a wide range of possible locations. In this paper, we have tried to illustrate comprehensively all its MRI appearances depending on the different locations where it occurs.

  11. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... Magnetic resonance imaging (MRI) is a noninvasive medical test that physicians use to diagnose medical conditions. MRI ...

  12. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  13. A Technique for Generating Volumetric Cine MRI (VC-MRI)

    Science.gov (United States)

    Harris, Wendy; Ren, Lei; Cai, Jing; Zhang, You; Chang, Zheng; Yin, Fang-Fang

    2016-01-01

    Purpose To develop a technique to generate on-board volumetric-cine MRI (VC-MRI) using patient prior images, motion modeling and on-board 2D-cine MRI. Methods One phase of a 4D-MRI acquired during patient simulation is used as patient prior images. 3 major respiratory deformation patterns of the patient are extracted from 4D-MRI based on principal-component-analysis. The on-board VC-MRI at any instant is considered as a deformation of the prior MRI. The deformation field is represented as a linear combination of the 3 major deformation patterns. The coefficients of the deformation patterns are solved by the data fidelity constraint using the acquired on-board single 2D-cine MRI. The method was evaluated using both XCAT simulation of lung cancer patients and MRI data from four real liver cancer patients. The accuracy of the estimated VC-MRI was quantitatively evaluated using Volume-Percent-Difference(VPD), Center-of-Mass-Shift(COMS), and target tracking errors. Effects of acquisition orientation, region-of-interest(ROI) selection, patient breathing pattern change and noise on the estimation accuracy were also evaluated. Results Image subtraction of ground-truth with estimated on-board VC-MRI shows fewer differences than image subtraction of ground-truth with prior image. Agreement between profiles in the estimated and ground-truth VC-MRI was achieved with less than 6% error for both XCAT and patient data. Among all XCAT scenarios, the VPD between ground-truth and estimated lesion volumes was on average 8.43±1.52% and the COMS was on average 0.93±0.58mm across all time-steps for estimation based on the ROI region in the sagittal cine images. Matching to ROI in the sagittal view achieved better accuracy when there was substantial breathing pattern change. The technique was robust against noise levels up to SNR=20. For patient data, average tracking errors were less than 2 mm in all directions for all patients. Conclusions Preliminary studies demonstrated the

  14. Visualizing electromagnetic vacuum by MRI

    CERN Document Server

    Chandrashekar, Chandrika S; Chandrashekar, S; Taylor, Erika A; Taylor, Deanne M

    2016-01-01

    Based upon Maxwell's equations, it has long been established that oscillating electromagnetic (EM) fields incident upon a metal surface decay exponentially inside the conductor, leading to a virtual EM vacuum at sufficient depths. Magnetic resonance imaging (MRI) utilizes radiofrequency (r.f.) EM fields to produce images. Here we present the first visualization of an EM vacuum inside a bulk metal strip by MRI, amongst several novel findings. We uncover unexpected MRI intensity patterns arising from two orthogonal pairs of faces of a metal strip, and derive formulae for their intensity ratios. Further, we furnish chemical shift imaging (CSI) results that discriminate different faces (surfaces) of a metal block according to their distinct nuclear magnetic resonance (NMR) chemical shifts, which holds much promise for monitoring surface chemical reactions noninvasively. Bulk metals are ubiquitous, and MRI is a premier noninvasive diagnostic tool. Combining the two, the emerging field of bulk metal MRI can be expe...

  15. Fast Reference-Based MRI

    CERN Document Server

    Weizman, Lior; Ben-Basaht, Dafna

    2015-01-01

    In many clinical MRI scenarios, existing imaging information can be used to significantly shorten acquisition time or to improve Signal to Noise Ratio (SNR). In some cases, a previously acquired image can serve as a reference image, that may exhibit similarity to the image being acquired. Examples include similarity between adjacent slices in high resolution MRI, similarity between various contrasts in the same scan and similarity between different scans of the same patient. In this paper we present a general framework for utilizing reference images for fast MRI. We take into account that the reference image may exhibit low similarity with the acquired image and develop an iterative weighted approach for reconstruction, which tunes the weights according to the degree of similarity. Experiments demonstrate the performance of the method in three different clinical MRI scenarios: SNR improvement in high resolution brain MRI, utilizing similarity between T2-weighted and fluid-attenuated inversion recovery (FLAIR)...

  16. MRI findings in Hirayama disease.

    Science.gov (United States)

    Raval, Monali; Kumari, Rima; Dung, Aldrin Anthony Dung; Guglani, Bhuvnesh; Gupta, Nitij; Gupta, Rohit

    2010-11-01

    The objective of the study was to study the magnetic resonance imaging (MRI) features of Hirayama disease on a 3 Tesla MRI scanner. Nine patients with clinically suspected Hirayama disease were evaluated with neutral position, flexion, contrast-enhanced MRI and fast imaging employing steady-state acquisition (FIESTA) sequences. The spectrum of MRI features was evaluated and correlated with the clinical and electromyography findings. MRI findings of localized lower cervical cord atrophy (C5-C7), abnormal curvature, asymmetric cord flattening, loss of attachment of the dorsal dural sac and subjacent laminae in the neutral position, anterior displacement of the dorsal dura on flexion and a prominent epidural space were revealed in all patients on conventional MRI as well as with the dynamic 3D-FIESTA sequence. Intramedullary hyperintensity was seen in four patients on conventional MRI and on the 3D-FIESTA sequence. Flow voids were seen in four patients on conventional MRI sequences and in all patients with the 3D-FIESTA sequence. Contrast enhancement of the epidural component was noted in all the five patients with thoracic extensions. The time taken for conventional and contrast-enhanced MRI was about 30-40 min, while that for the 3D-FIESTA sequence was 6 min. Neutral and flexion position MRI and the 3D-FIESTA sequence compliment each other in displaying the spectrum of findings in Hirayama disease. A flexion study should form an essential part of the screening protocol in patients with suspected Hirayama disease. Newer sequences such as the 3D-FIESTA may help in reducing imaging time and obviating the need for contrast.

  17. MRI findings in Hirayama disease

    Directory of Open Access Journals (Sweden)

    Raval Monali

    2010-01-01

    Full Text Available The objective of the study was to study the magnetic resonance imaging (MRI features of Hirayama disease on a 3 Tesla MRI scanner. Nine patients with clinically suspected Hirayama disease were evaluated with neutral position, flexion, contrast-enhanced MRI and fast imaging employing steady-state acquisition (FIESTA sequences. The spectrum of MRI features was evaluated and correlated with the clinical and electromyography findings. MRI findings of localized lower cervical cord atrophy (C5-C7, abnormal curvature, asymmetric cord flattening, loss of attachment of the dorsal dural sac and subjacent laminae in the neutral position, anterior displacement of the dorsal dura on flexion and a prominent epidural space were revealed in all patients on conventional MRI as well as with the dynamic 3D-FIESTA sequence. Intramedullary hyperintensity was seen in four patients on conventional MRI and on the 3D-FIESTA sequence. Flow voids were seen in four patients on conventional MRI sequences and in all patients with the 3D-FIESTA sequence. Contrast enhancement of the epidural component was noted in all the five patients with thoracic extensions. The time taken for conventional and contrast-enhanced MRI was about 30-40 min, while that for the 3D-FIESTA sequence was 6 min. Neutral and flexion position MRI and the 3D-FIESTA sequence compliment each other in displaying the spectrum of findings in Hirayama disease. A flexion study should form an essential part of the screening protocol in patients with suspected Hirayama disease. Newer sequences such as the 3D-FIESTA may help in reducing imaging time and obviating the need for contrast.

  18. MRI of plants and foods

    Science.gov (United States)

    Van As, Henk; van Duynhoven, John

    2013-04-01

    The importance and prospects for MRI as applied to intact plants and to foods are presented in view of one of humanity's most pressing concerns, the sustainable and healthy feeding of a worldwide increasing population. Intact plants and foods have in common that their functionality is determined by complex multiple length scale architectures. Intact plants have an additional level of complexity since they are living systems which critically depend on transport and signalling processes between and within tissues and organs. The combination of recent cutting-edge technical advances and integration of MRI accessible parameters has the perspective to contribute to breakthroughs in understanding complex regulatory plant performance mechanisms. In food science and technology MRI allows for quantitative multi-length scale structural assessment of food systems, non-invasive monitoring of heat and mass transport during shelf-life and processing, and for a unique view on food properties under shear. These MRI applications are powerful enablers of rationally (re)designed food formulations and processes. Limitations and bottlenecks of the present plant and food MRI methods are mainly related to short T2 values and susceptibility artefacts originating from small air spaces in tissues/materials. We envisage cross-fertilisation of solutions to overcome these hurdles in MRI applications in plants and foods. For both application areas we witness a development where MRI is moving from highly specialised equipment to mobile and downscaled versions to be used by a broad user base in the field, greenhouse, food laboratory or factory.

  19. fMRI adaptation revisited.

    Science.gov (United States)

    Larsson, Jonas; Solomon, Samuel G; Kohn, Adam

    2016-07-01

    Adaptation has been widely used in functional magnetic imaging (fMRI) studies to infer neuronal response properties in human cortex. fMRI adaptation has been criticized because of the complex relationship between fMRI adaptation effects and the multiple neuronal effects that could underlie them. Many of the longstanding concerns about fMRI adaptation have received empirical support from neurophysiological studies over the last decade. We review these studies here, and also consider neuroimaging studies that have investigated how fMRI adaptation effects are influenced by high-level perceptual processes. The results of these studies further emphasize the need to interpret fMRI adaptation results with caution, but they also provide helpful guidance for more accurate interpretation and better experimental design. In addition, we argue that rather than being used as a proxy for measurements of neuronal stimulus selectivity, fMRI adaptation may be most useful for studying population-level adaptation effects across cortical processing hierarchies.

  20. Situs anomalies on prenatal MRI.

    Science.gov (United States)

    Nemec, Stefan F; Brugger, Peter C; Nemec, Ursula; Bettelheim, Dieter; Kasprian, Gregor; Amann, Gabriele; Rimoin, David L; Graham, John M; Prayer, Daniela

    2012-04-01

    Situs anomalies refer to an abnormal organ arrangement, which may be associated with severe errors of development. Due regard being given to prenatal magnetic resonance imaging (MRI) as an adjunct to ultrasonography (US), this study sought to demonstrate the in utero visualization of situs anomalies on MRI, compared to US. This retrospective study included 12 fetuses with situs anomalies depicted on fetal MRI using prenatal US as a comparison modality. With an MRI standard protocol, the whole fetus was assessed for anomalies, with regard to the position and morphology of the following structures: heart; venous drainage and aorta; stomach and intestines; liver and gallbladder; and the presence and number of spleens. Situs inversus totalis was found in 3/12 fetuses; situs inversus with levocardia in 1/12 fetuses; situs inversus abdominis in 2/12 fetuses; situs ambiguous with polysplenia in 3/12 fetuses, and with asplenia in 2/12 fetuses; and isolated dextrocardia in 1/12 fetuses. Congenital heart defects (CHDs), vascular anomalies, and intestinal malrotations were the most frequent associated malformations. In 5/12 cases, the US and MRI diagnoses were concordant. Compared to US, in 7/12 cases, additional MRI findings specified the situs anomaly, but CHDs were only partially visualized in six cases. Our initial MRI results demonstrate the visualization of situs anomalies and associated malformations in utero, which may provide important information for perinatal management. Using a standard protocol, MRI may identify additional findings, compared to US, which confirm and specify the situs anomaly, but, with limited MRI visualization of fetal CHDs. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  1. MRI of congenital urethroperineal fistula

    Energy Technology Data Exchange (ETDEWEB)

    Ghadimi-Mahani, Maryam; Dillman, Jonathan R.; Pai, Deepa; DiPietro, Michael [C. S. Mott Children' s Hospital, Department of Radiology, Section of Pediatric Radiology, University of Michigan Health System, Ann Arbor, MI (United States); Park, John [C. S. Mott Children' s Hospital, Department of Pediatric Urology, University of Michigan Health System, Ann Arbor, MI (United States)

    2010-12-15

    We present the MRI features of a congenital urethroperineal fistula diagnosed in a 12-year-old boy being evaluated after a single urinary tract infection. This diagnosis was initially suggested by voiding cystourethrogram and confirmed by MRI. Imaging revealed an abnormal fluid-filled tract arising from the posterior urethra and tracking to the perineal skin surface that increased in size during micturition. Surgical resection and histopathological evaluation of the abnormal tract confirmed the diagnosis of congenital urethroperineal fistula. MRI played important roles in confirming the diagnosis and assisting surgical planning. (orig.)

  2. [Standartization of MRI studies in multiple sclerosis].

    Science.gov (United States)

    Bryukhov, V V; Krotenkova, I A; Morozova, S N; Krotenkova, M V

    2016-01-01

    The use of magnetic resonance imaging (MRI) in patients with multiple sclerosis has markedly increased in recent years. The main task of the MRI studies after the diagnosis of multiple sclerosis is to assess the dynamics of MRI for determining disease progression and monitoring the efficacy of therapy. In this regard, it is very important to obtain the most identical baseline and follow-up MRI that is possible when a single standard protocol is used. This article presents the protocol of brain MRI and spinal cord MRI and interpretation of MRI studies in patients with multiple sclerosis.

  3. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... type your comment or suggestion into the following text box: Comment: E-mail: Area code: Phone no: ... Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging ( ...

  4. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... or headphones during the exam. MRI scanners are air-conditioned and well-lit. Music may be played ... MR angiography (MRA) provides detailed images of blood vessels in the brain—often without the need for ...

  5. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... it may cause some medical devices to malfunction. Most orthopedic implants pose no risk, but you should ... copied to a CD. Currently, MRI is the most sensitive imaging test of the head (particularly the ...

  6. Magnetic Resonance Imaging (MRI) -- Head

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

  7. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... imaging methods. This exam does not use ionizing radiation and may require an injection of a contrast ... internal body structures. MRI does not use ionizing radiation (x-rays). Detailed MR images allow physicians to ...

  8. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... to a CD or uploaded to a digital cloud server. Currently, MRI is the most sensitive imaging ... than other imaging modalities. top of page Additional Information and Resources RTAnswers.org : Radiation Therapy for Brain ...

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... are clearer and more detailed than other imaging methods. This exam does not use ionizing radiation and ... clearer and more detailed than with other imaging methods. This detail makes MRI an invaluable tool in ...

  10. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... your regular medications as usual. Leave jewelry at home and wear loose, comfortable clothing. You may be ... Jewelry and other accessories should be left at home, if possible, or removed prior to the MRI ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... Imaging (MRI) procedure View full size with caption Pediatric Content Some imaging tests and treatments have special pediatric considerations. The teddy bear denotes child-specific content. ...

  12. MRI of orbital hydroxyapatite implants

    Energy Technology Data Exchange (ETDEWEB)

    Flanders, A.E. [Dept. of Radiology, Thomas Jefferson Univ. Hospital, Philadelphia, PA (United States); De Potter, P. [Dept. of Ophthalmology, Wills Eye Inst., Philadelphia, PA (United States); Rao, V.M. [Dept. of Radiology, Thomas Jefferson Univ. Hospital, Philadelphia, PA (United States); Tom, B.M. [Dept. of Radiology, Thomas Jefferson Univ. Hospital, Philadelphia, PA (United States); Shields, C.L. [Dept. of Ophthalmology, Wills Eye Inst., Philadelphia, PA (United States); Shields, J.A. [Dept. of Ophthalmology, Wills Eye Inst., Philadelphia, PA (United States)

    1996-04-01

    Our aim was to use MRI for the postsurgical assessment of a new form of integrated orbital implant composed of a porous calcium phosphate hydroxyapatite substrate. We studied ten patients 24-74 years of age who underwent enucleation and implantation of a hydroxyapatite ball; 5-13 months after surgery, each patient was examined by spin-echo MRI, with fat suppression and gadolinium enhancement. Fibrovascular ingrowth was demonstrated in all ten patients as areas of enhancement at the periphery of the hydroxyapatite sphere that extended to the center to a variable degree. The radiologist should aware of the MRI appearances of the coralline hydroxyapatite orbital implant since it is now widely used following enucleation. MRI is a useful means to determine successful incorporation of the substrate into the orbital tissues. The normal pattern of contrast enhancement should not be mistaken for recurrent tumor or infection. (orig.)

  13. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... copied to a CD or uploaded to a digital cloud server. Currently, MRI is the most sensitive ... food, or the environment, or if you have asthma. The contrast material most commonly used for an ...

  14. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... contrast for an MRI. If you have a history of kidney disease or liver transplant, it will ... Radiology (ACR) and the Radiological Society of North America (RSNA), comprising physicians with expertise in several radiologic ...

  15. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... can help diagnose conditions such as: brain tumors stroke infections developmental anomalies hydrocephalus — dilatation of fluid spaces ... MRA page for more information. MRI can detect stroke at a very early stage by mapping the ...

  16. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... a CD or uploaded to a digital cloud server. Currently, MRI is the most sensitive imaging test ... suggestion into the following text box: Comment: E-mail: Area code: Phone no: Thank you! Do you ...

  17. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... pictures of organs, soft tissues, bone and virtually all other internal body structures. MRI does not use ... include: jewelry, watches, credit cards and hearing aids, all of which can be damaged pins, hairpins, metal ...

  18. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... It can help diagnose conditions such as: brain tumors stroke infections developmental anomalies hydrocephalus — dilatation of fluid ... early diagnosis and evaluation of many conditions, including tumors. MRI enables the discovery of abnormalities that might ...

  19. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... the same effect. A very irregular heartbeat may affect the quality of images obtained using techniques that ...

  20. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... may cause some medical devices to malfunction. Most orthopedic implants pose no risk, but you should always ... metal objects. In general, metal objects used in orthopedic surgery pose no risk during MRI. However, a ...

  1. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... devices or metal in your body. Guidelines about eating and drinking before your exam vary between facilities. ... fitting and has no metal fasteners. Guidelines about eating and drinking before an MRI exam vary with ...

  2. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI. For more information, consult your radiologist. The computer workstation that processes the imaging information is located ... not come in contact with the patient. A computer then processes the signals and generates a series ...

  3. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... scanner. top of page How does the procedure work? Unlike conventional x-ray examinations and computed tomography ( ... clearer and more detailed than with other imaging methods. This detail makes MRI an invaluable tool in ...

  4. Magnetic Resonance Imaging (MRI) - Spine

    Science.gov (United States)

    ... their nature and the strength of the MRI magnet. Many implanted devices will have a pamphlet explaining ... large cylinder-shaped tube surrounded by a circular magnet. You will lie on a moveable examination table ...

  5. MRI appearance of muscle denervation

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, S. [University Hospital of Wales, Department of Radiology, Cardiff (United Kingdom); Venkatanarasimha, N.; Walsh, M.A.; Hughes, P.M. [Derriford Hospital, Department of Radiology, Plymouth (United Kingdom)

    2008-05-15

    Muscle denervation results from a variety of causes including trauma, neoplasia, neuropathies, infections, autoimmune processes and vasculitis. Traditionally, the diagnosis of muscle denervation was based on clinical examination and electromyography. Magnetic resonance imaging (MRI) offers a distinct advantage over electromyography, not only in diagnosing muscle denervation, but also in determining its aetiology. MRI demonstrates characteristic signal intensity patterns depending on the stage of muscle denervation. The acute and subacutely denervated muscle shows a high signal intensity pattern on fluid sensitive sequences and normal signal intensity on T1-weighted MRI images. In chronic denervation, muscle atrophy and fatty infiltration demonstrate high signal changes on T1-weighted sequences in association with volume loss. The purpose of this review is to summarise the MRI appearance of denervated muscle, with special emphasis on the signal intensity patterns in acute and subacute muscle denervation. (orig.)

  6. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... are clearer and more detailed than other imaging methods. This exam does not use ionizing radiation and ... clearer and more detailed than with other imaging methods. This detail makes MRI an invaluable tool in ...

  7. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... exam time. top of page What will I experience during and after the procedure? Most MRI exams ... uncomfortable to remain still during MR imaging. Others experience a sense of being closed-in (claustrophobia) while ...

  8. Magnetic Resonance Imaging (MRI) -- Head

    Science.gov (United States)

    ... surgery pose no risk during MRI. However, a recently placed artificial joint may require the use of ... evaluation with additional views or a special imaging technique. A follow-up examination may also be necessary ...

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... let the radiologist know about them. Parents or family members who accompany patients into the scanning room ... MRI examination poses almost no risk to the average patient when appropriate safety guidelines are followed. If ...

  10. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... metallic items, which can distort MRI images removable dental work pens, pocket knives and eyeglasses body piercings ... from the contrast material, including nausea, headache and pain at the site of injection. Similarly, patients are ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... during an MRI scan, but this is rare. Tooth fillings and braces usually are not affected by ... from the contrast material, including nausea, headache and pain at the site of injection. Similarly, patients are ...

  12. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... magnetic field is produced by passing an electric current through wire coils in most MRI units. Other ... that are detected by the coils. The electric current does not come in contact with the patient. ...

  13. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... will hear and feel loud tapping or thumping sounds when the coils that generate the radiofrequency pulses ... use headphones to reduce the intensity of the sounds made by the MRI machine. You may be ...

  14. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... copied to a CD or uploaded to a digital cloud server. Currently, MRI is the most sensitive ... the radiologist know if you have any serious health problems, or if you have had any recent ...

  15. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... any recent surgeries. Some conditions, such as severe kidney disease, may prevent you from being given gadolinium contrast ... an MRI. If you have a history of kidney disease or liver transplant, it will be necessary to ...

  16. Magnetic Resonance Imaging (MRI) -- Head

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

  17. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... not use ionizing radiation and may require an injection of a contrast material called gadolinium, which is ... MRI examinations may require you to receive an injection of contrast material into the bloodstream. The radiologist , ...

  18. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... stroke infections developmental anomalies hydrocephalus — dilatation of fluid spaces within the brain (ventricles) causes of epilepsy (seizure) ... MRI. If you have claustrophobia (fear of enclosed spaces) or anxiety, you may want to ask your ...

  19. Magnetic Resonance Imaging (MRI) -- Head

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

  20. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... multiple sclerosis disorders of the eye and inner ear disorders of pituitary gland vascular problems, such as ... should not enter the MRI scanning area: cochlear (ear) implant some types of clips used for brain ...

  1. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... head is performed for a number of abrupt onset or long-standing symptoms. It can help diagnose ... often within less than 30 minutes from the onset of symptoms. Risks The MRI examination poses almost ...

  2. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... copied to a CD or uploaded to a digital cloud server. Currently, MRI is the most sensitive ... the technologist if you have medical or electronic devices in your body. These objects may interfere with ...

  3. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... data suggest that it is safe to continue breastfeeding after receiving intravenous contrast. For further information please ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...

  4. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... spaces within the brain (ventricles) causes of epilepsy (seizure) hemorrhage in selected trauma patients certain chronic conditions, ... A person who is very large may not fit into the opening of certain types of MRI ...

  5. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... digital cloud server. Currently, MRI is the most sensitive imaging test of the head (particularly the brain) ... contrast material in patients with very poor kidney function. Careful assessment of kidney function before considering a ...

  6. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... tissue and fluid, known as edema . MRI typically costs more and may take more time to perform ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

  7. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... may follow your regular daily routine and take food and medications as usual. Some MRI examinations may ... to iodine or x-ray contrast material, drugs, food, or the environment, or if you have asthma. ...

  8. Metalloprotein-based MRI probes.

    Science.gov (United States)

    Matsumoto, Yuri; Jasanoff, Alan

    2013-04-17

    Metalloproteins have long been recognized as key determinants of endogenous contrast in magnetic resonance imaging (MRI) of biological subjects. More recently, both natural and engineered metalloproteins have been harnessed as biotechnological tools to probe gene expression, enzyme activity, and analyte concentrations by MRI. Metalloprotein MRI probes are paramagnetic and function by analogous mechanisms to conventional gadolinium or iron oxide-based MRI contrast agents. Compared with synthetic agents, metalloproteins typically offer worse sensitivity, but the possibilities of using protein engineering and targeted gene expression approaches in conjunction with metalloprotein contrast agents are powerful and sometimes definitive strengths. This review summarizes theoretical and practical aspects of metalloprotein-based contrast agents, and discusses progress in the exploitation of these proteins for molecular imaging applications.

  9. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... can help diagnose conditions such as: brain tumors stroke infections developmental anomalies hydrocephalus — dilatation of fluid spaces ... MRA page for more information. MRI can detect stroke at a very early stage by mapping the ...

  10. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  11. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... Examples include but are not limited to: artificial heart valves implanted drug infusion ports artificial limbs or ... imaging based on the electrical activity of the heart, such as electrocardiography (EKG). MRI generally is not ...

  12. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... from the contrast material, including nausea, headache and pain at the site of injection. Similarly, patients are ...

  13. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  14. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... and should not enter the MRI scanning area: cochlear (ear) implant some types of clips used for ... follow-up exam is done because a potential abnormality needs further evaluation with additional views or a ...

  15. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... very rare occasions, a few patients experience side effects from the contrast material, including nausea, headache and ...

  16. Magnetic Resonance Imaging (MRI) -- Head

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

  17. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... it is useful to bring that to the attention of the scheduler before the exam and bring ... does the equipment look like? The traditional MRI unit is a large cylinder-shaped tube surrounded by ...

  18. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... may follow your regular daily routine and take food and medications as usual. Some MRI examinations may ... to iodine or x-ray contrast material, drugs, food, or the environment, or if you have asthma. ...

  19. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... x-ray may be taken to detect and identify any metal objects. In general, metal objects used in orthopedic surgery pose no risk during MRI. However, a recently placed artificial joint ...

  20. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... metal in your body. Guidelines about eating and drinking before your exam vary between facilities. Unless you ... has no metal fasteners. Guidelines about eating and drinking before an MRI exam vary with the specific ...

  1. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... Unless you are told otherwise, take your regular medications as usual. Leave jewelry at home and wear ... your regular daily routine and take food and medications as usual. Some MRI examinations may require you ...

  2. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... tumors stroke infections developmental anomalies hydrocephalus — dilatation of fluid spaces within the brain (ventricles) causes of epilepsy ( ... may not always distinguish between cancer tissue and fluid, known as edema . MRI typically costs more and ...

  3. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... page Additional Information and Resources RTAnswers.org : Radiation Therapy for Brain Tumors Radiation Therapy for Head and ...

  4. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... page Additional Information and Resources RTAnswers.org : Radiation Therapy for Brain Tumors Radiation Therapy for Head and ...

  5. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... into the bloodstream. The radiologist , technologist or a nurse may ask if you have allergies of any ... be used in the MRI exam, a physician, nurse or technologist will insert an intravenous (IV) catheter, ...

  6. MRI of the Musculoskeletal System

    Science.gov (United States)

    ... receive injections of gadolinium contrast material except when absolutely necessary for medical treatment. See the Safety page ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ...

  7. Magnetic Resonance Imaging (MRI) - Spine

    Science.gov (United States)

    ... receive injections of gadolinium contrast material except when absolutely necessary for medical treatment. See the Safety page ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ...

  8. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... be examined on a computer monitor, transmitted electronically, printed or copied to a CD or uploaded to ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ...

  9. MRI and intraocular tamponade media

    Energy Technology Data Exchange (ETDEWEB)

    Manfre, I. (Dept. of Neuroradiology, Inst. of Neurosurgery, Univ. of Catania (Italy)); Fabbri, G. (Dept. of Neuroradiology, Inst. of Neurosurgery, Univ. of Catania (Italy)); Avitabile, T. (Inst. of Ophthalmology, Univ. of Catania (Italy)); Biondi, P. (Inst. of Ophthalmology, Univ. of Catania (Italy)); Reibaldi, A. (Inst. of Ophthalmology, Univ. of Catania (Italy)); Pero, G. (Dept. of Neuroradiology, Inst. of Neurosurgery, Univ. of Catania (Italy))

    1993-05-01

    Thirteen patients who underwent surgery for retinal detachment and injection of intraocular tamponade media (silicone oil, flurosilicone oil, or perfluoro-carbon liquid) underwent magnetic resonance imaging (MRI), using spin-echo T1- and T2-weighted images. The ophthalmic tamponade media showed different signal intensity, according to their chemical structure. Unlike ophthalmoscopy or ultrasonography, MRI showed no oil-related artefact, making possible recognition of recurrent retinal detachment. (orig.)

  10. MRI evaluation of vascular dementia

    Institute of Scientific and Technical Information of China (English)

    Yicheng Liu; Hongxing Zhang; Wei Huang; Wenjun Wan; Hongfen Peng

    2006-01-01

    OBJECTTVE: To explain the association between vascular dementia and the cranial MRI manifestations, and recognize the value of cranial MRI in the early diagnosis of vascular dementia and the assessment of disease conditions.DATA SOURCES: Pubmed database was searched to identify articles about the cranial MRI manifestations of patients with vascular dementia published in English from January 1992 to June 2006 by using the key words of "MRI, vascular dementia". Others were collected by searching the name of journals and title of articles in the Chinese full-text journal database.STUDY SELECTTON: The collected articles were primarily checked, those correlated with the cranial MRI manifestations of patients with vascular dementia were selected, while the obviously irrelative ones were excluded, and the rest were retrieved manually, the full-texts were searched.DATA EXTRACTION: Totally 255 articles were collected, 41 of them were involved, and the other 214 were excluded.DATA SYNTHESIS: MRI can be taken as one of the effective methods for the early diagnosis and disease evaluation of vascular dementia. White matter lesions are the important risk factors of vascular dementia.Vascular dementia is accompanied by the atrophy of related brain sites, but further confirmation is needed to investigate whether there is significant difference. MRI can be used to quantitatively investigate the infarcted sites and sizes of patients with vascular dementia after infarction, but there is still lack of systematic investigation on the association of the infarcted sites and sizes with the cognitive function of patients with vascular dementia.CONCLUSTON: Cranial MRI can detect the symptoms of vascular dementia at early period, so that corresponding measures can be adopted to prevent and treat vascular dementia in time.

  11. MRI in acute disseminated encephalomyelitis

    Energy Technology Data Exchange (ETDEWEB)

    Caldemeyer, K.S. (Div. of Neuroradiology, Dept. of Radiology, Indiana Univ. School of Medicine, Indianapolis, IN (United States)); Smith, R.R. (Div. of Neuroradiology, Dept. of Radiology, Indiana Univ. School of Medicine, Indianapolis, IN (United States)); Harris, T.M. (Div. of Neuroradiology, Dept. of Radiology, Indiana Univ. School of Medicine, Indianapolis, IN (United States)); Edwards, M.K. (Div. of Neuroradiology, Dept. of Radiology, Indiana Univ. School of Medicine, Indianapolis, IN (United States))

    1994-04-01

    A retrospective analysis of CT and MRI studies in 12 patients with a clinical diagnosis of acute disseminated encephalomyelitis (ADEM) was performed. MRI was the definitive modality for the assessment of the lesions of ADEM: all patients had abnormalities consistent with the clinical diagnosis. Ten had abnormalities in the brain, three spinal cord lesions, and three showed evidence of optic neuritis. CT was normal in 6 of the 7 patients in which it was performed. (orig.)

  12. Congenital dacryocystocele: prenatal MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Yazici, Zeynep [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Uludag University, Department of Radiology, Faculty of Medicine, Bursa (Turkey); Kline-Fath, Beth M.; Rubio, Eva I.; Calvo-Garcia, Maria A.; Linam, Leann E. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Yazici, Bulent [Uludag University, Department of Ophthalmology, Faculty of Medicine, Bursa (Turkey)

    2010-12-15

    Congenital dacryocystocele can be diagnosed prenatally by imaging. Prenatal MRI is increasingly utilized for fetal diagnosis. To present the radiological and clinical features of seven fetuses with congenital dacryocystocele diagnosed with prenatal MRI. The institutional database of 1,028 consecutive prenatal MR examinations performed during a period of 4 years was reviewed retrospectively. The cases of congenital dacryocystocele were identified by reading the report of each MRI study. The incidence of dacryocystocele diagnosed with prenatal MRI was 0.7% (n=7/1,028). The dacryocystocele was bilateral in three fetuses. Mean gestational age at the time of diagnosis was 31 weeks. The indication for prenatal MRI was the presence or the suspicion of central nervous system abnormality in six fetuses and diaphragmatic hernia in one. Dacryocystocele was associated with an intranasal cyst in six of ten eyes. Prenatal sonography revealed dacryocystocele in only two of seven fetuses. Of eight eyes with postnatal follow-up, four did not have any lacrimal symptoms. Prenatal MRI can delineate congenital dacryocystocele more clearly and in a more detailed fashion than ultrasonography. Presence of dacryocystocele was symptomatic in only 50% of our patients, supporting that prenatal diagnosis of dacryocystocele might follow a benign course. (orig.)

  13. Compressed sensing for body MRI.

    Science.gov (United States)

    Feng, Li; Benkert, Thomas; Block, Kai Tobias; Sodickson, Daniel K; Otazo, Ricardo; Chandarana, Hersh

    2017-04-01

    The introduction of compressed sensing for increasing imaging speed in magnetic resonance imaging (MRI) has raised significant interest among researchers and clinicians, and has initiated a large body of research across multiple clinical applications over the last decade. Compressed sensing aims to reconstruct unaliased images from fewer measurements than are traditionally required in MRI by exploiting image compressibility or sparsity. Moreover, appropriate combinations of compressed sensing with previously introduced fast imaging approaches, such as parallel imaging, have demonstrated further improved performance. The advent of compressed sensing marks the prelude to a new era of rapid MRI, where the focus of data acquisition has changed from sampling based on the nominal number of voxels and/or frames to sampling based on the desired information content. This article presents a brief overview of the application of compressed sensing techniques in body MRI, where imaging speed is crucial due to the presence of respiratory motion along with stringent constraints on spatial and temporal resolution. The first section provides an overview of the basic compressed sensing methodology, including the notion of sparsity, incoherence, and nonlinear reconstruction. The second section reviews state-of-the-art compressed sensing techniques that have been demonstrated for various clinical body MRI applications. In the final section, the article discusses current challenges and future opportunities. 5 J. Magn. Reson. Imaging 2017;45:966-987. © 2016 International Society for Magnetic Resonance in Medicine.

  14. MRI of the Achilles tendon

    Energy Technology Data Exchange (ETDEWEB)

    Naegele, M.; Lienemann, A.; Hahn, D.; Lissner, J.; Boehm, P.

    1987-06-01

    The Achilles tendon and preachillar space of 30 patients was studied by MRI. A surface coil (Helmholtz' principle) was applied and all patients were examined with a superconducting magnet operating at 1.0 Tesla field strength. The purpose of the study was to illustrate pathological changes of the tendon and the surrounding soft tissue. In 3 cases MRI diagnosed a total rupture of the Achilles tendon. Furthermore, the strain of the tendon and side effects of an inflammatory process could be demonstrated. The use of a surface coil yields a high resolution of the normal anatomy of the region and of the pathological changes of the tendon and the surrounding soft tissue structures. The advantages of MRI for Achilles tendon diagnostics against competitive modalities are 1) excellent soft tissue contrast, 2) multiplanar imaging, 3) as well as exact delineation and visualisation of the lesion.

  15. Interstitial pregnancy: role of MRI

    Energy Technology Data Exchange (ETDEWEB)

    Filhastre, M.; Lesnik, A. [Lapeyronie Hospital, Department of Radiology, Montpellier Cedex 5 (France); Dechaud, H.; Taourel, P. [Arnaud de Villeneuve Hospital, Department of Gynecology, Montpellier (France)

    2005-01-01

    We report the MRI features of two cases of interstitial pregnancy. In both cases, MRI was able to localize the ectopic pregnancy by showing a gestational structure surrounded by a thick wall in the upper part of the uterine wall separated from the endometrium by an uninterrupted junctional zone. Because US may confuse angular and interstitial pregnancies and because interstitial pregnancy has a particular evolutive course, MR imaging may play a key role in the diagnosis and management of women with interstitial pregnancy. (orig.)

  16. MRI in Optic Neuritis: Structure, Function, Interactions

    DEFF Research Database (Denmark)

    Fuglø, Dan

    2011-01-01

    resonance imaging (MRI), and the visual evoked potential (VEP) continues to show a delayed P100 indicating persistent demyelination. The explanation for this apparent discrepancy between structure and function could be due to either a redundancy in the visual pathways so that some degree of signal loss...... are low. Functional MRI (fMRI) is a non-invasive technique that can measure brain activity with a high spatial resolution. Recently, technical and methodological advancements have made it feasible to record VEPs and fMRI simultaneously and the relationship between averaged VEPs and averaged fMRI signals...... have been described. Still, to take full advantage of simultaneously recorded VEP-fMRI one would ideally want to track single-trial changes in the VEP and use this information in the fMRI analysis. In order to do this we examined 10 healthy volunteers with simultaneous VEP-fMRI. Different measures...

  17. Anaesthesia for MRI: ….child's play?

    African Journals Online (AJOL)

    Adele

    ing for magnetic resonance imaging (MRI). Attention will be fo- ... The clinical applications for MRI continue to ... Nuclear magnetic resonance(NMR) is a phenomenon that was .... Electrical power consists of isolated circuits with filtered 120V.

  18. Moyamoya disease: diagnostic accuracy of MRI

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, I. [Dept. of Radiology, Faculty of Medicine, Tokyo Medical and Dental Univ. (Japan); Suzuki, [Dept. of Radiology, Faculty of Medicine, Tokyo Medical and Dental Univ. (Japan); Matsushima, Y. [Dept. of Neurosurgery, Faculty of Medicine, Tokyo Medical and Dental Univ. (Japan)

    1995-07-01

    MRI may be employed to investigate moyamoya disease, since it provides vascular information without use of contrast medium. We reported the usefulness and limitations of MR angiography (MRA) in moyamoya disease. To our knowledge, no report has appeared dealing with the diagnostic accuracy of MRI in a large number of cases of moyamoya disease, although MRI is used more commonly than MRA. We therefore undertook to evaluate the accuracy of MRI in moyamoya disease. (orig.)

  19. Breast MRI in high risk patients

    NARCIS (Netherlands)

    A.I.M. Obdeijn (Inge-Marie)

    2015-01-01

    markdownabstractAbstract In this thesis we address various indications of breast MRI, with the emphasis on the value of MRI in screening of women with high genetic risk for breast cancer, and especially in BRCA1 mutation carriers. We showed that in the era of up-to-date MRI expertise and digital

  20. MRI of rectal stromal tumour

    DEFF Research Database (Denmark)

    Dam, Claus; Lindebjerg, Jan; Rafaelsen, Søren Rafael

    2012-01-01

    to be aware of for the rectal multidisciplinary team. On suspicion of GIST, patients should be referred to a sarcoma centre. The diagnosis of rectal GIST can be suggested on MRI by the presence of a well-defined heterogeneously large mass with a necrotic center associated with a prominent extra...

  1. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI. If you have a history of kidney disease or liver transplant, it will be necessary to perform a blood test to determine whether the kidneys are functioning adequately. Women should always inform their physician or technologist if ...

  2. Getting an MRI (For Kids)

    Medline Plus

    Full Text Available ... Q&A Movies & More Quizzes Kids' Dictionary of Medical Words En Español What Other ... de una resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed pictures of the inside of ...

  3. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... the radiologist know if you have any serious health problems, or if you have had any recent surgeries. Some conditions, such as severe kidney disease, may prevent you from being given gadolinium contrast for an MRI. If you have a history of kidney disease or liver transplant, it will ...

  4. Getting an MRI (For Kids)

    Medline Plus

    Full Text Available ... More Quizzes Kids' Dictionary of Medical Words En Español What Other Kids Are Reading What to Do ... an MRI (Video) Print A A A en español Obtención de una resonancia magnética, RM (video) An ...

  5. MRI of plants and foods

    NARCIS (Netherlands)

    As, van H.; Duynhoven, van J.P.M.

    2013-01-01

    The importance and prospects for MRI as applied to intact plants and to foods are presented in view of one of humanity's most pressing concerns, the sustainable and healthy feeding of a worldwide increasing population. Intact plants and foods have in common that their functionality is determined by

  6. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... distinguish between cancer tissue and fluid, known as edema . MRI typically costs more and may take more time to perform than other imaging modalities. top of page Additional Information and Resources RTAnswers.org : Radiation Therapy for Brain Tumors Radiation Therapy for Head and ...

  7. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... of which shows a thin slice of the body. The images can then be studied from different angles by ... mail: Area code: Phone no: Thank you! ... Related Articles and Media MR Angiography (MRA) Magnetic Resonance, Functional (fMRI) - Brain ...

  8. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... E-mail: Area code: Phone no: Thank you! Images × Image Gallery Magnetic Resonance Imaging (MRI) procedure View full ... address): From (your name): Your e-mail address: Personal message (optional): Bees: Wax: Notice: RadiologyInfo respects your ...

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... very early stage by mapping the motion of water molecules in the tissue. This water motion, known as diffusion, is impaired by most ... that time the imaging based on the electrical activity of the heart, such as electrocardiography (EKG). MRI ...

  10. Getting an MRI (For Kids)

    Medline Plus

    Full Text Available ... More Quizzes Kids' Dictionary of Medical Words En Español What Other Kids Are Reading 7 Videos: Kids ... an MRI (Video) Print A A A en español Obtención de una resonancia magnética, RM (video) An ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... over time. Follow-up examinations are sometimes the best way to see if treatment is working or if a finding is stable or changed over time. top of page What are the benefits vs. risks? Benefits MRI is a noninvasive imaging technique ...

  12. MRI findings in cranial eumycetoma

    Directory of Open Access Journals (Sweden)

    Munawwar Ahmed

    2011-01-01

    Full Text Available Cranial eumycetoma (CE due to direct inoculation of Madurella grisea into the scalp is extremely rare. We describe a case of CE caused by direct inoculation of M. grisea with the characteristic MRI findings of the "dot-in-circle" sign and a conglomeration of multiple, extremely hypointense "dots."

  13. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... very early stage by mapping the motion of water molecules in the tissue. This water motion, known as diffusion, is impaired by most ... the limitations of MRI of the Head? High-quality images are assured only if you are able ...

  14. Brain MRI of diabetes Mellitus

    Energy Technology Data Exchange (ETDEWEB)

    Araki, Yutaka; Tanaka, Hisashi; Ohtani, Masatoshi; Yamamoto, Hiroshi; Yamamoto, Tadashi; Tsukaguchi, Isao (Osaka Rosai Hospital, Sakai (Japan))

    1993-11-01

    One hundred and fifty-nine patients with diabetes mellitus (DM) and 2,566 patients without DM were studied on brain MRI. The results taught us that the incidence of cerebral atrophy was significantly higher in DM patients than in controls. Unexpectedly, the incidence of cerebral infarction showed no significant difference between the two groups. (author).

  15. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... very early stage by mapping the motion of water molecules in the tissue. This water motion, known as diffusion, is impaired by most ... the limitations of MRI of the Head? High-quality images are assured only if you are able ...

  16. MRI of medulloblastoma in adults

    Energy Technology Data Exchange (ETDEWEB)

    Malheiros, S.M.F.; Santos, A.J.; Borges, L.R.R.; Guimaraes, I.F.; Franco, C.M.R.; Gabbai, A.A. [Department of Neurology, Universidade Federal de Sao Paulo Rua Botucatu 740, SP 04023-900, Sao Paulo (Brazil); Carrete, H. [Department of Radiology, Universidade Federal de Sao Paulo Rua Botucatu 740, SP 04023-900, Sao Paulo (Brazil); Stavale, J.N.; Pelaez, M.P. [Department of Pathology, Universidade Federal de Sao Paulo Rua Botucatu 740, SP 04023-900, Sao Paulo (Brazil)

    2003-07-01

    Medulloblastoma has variable appearances on MRI in both children and adults. Adults are more likely to have heterogeneous cerebellar hemisphere tumours, and this is thought to be related to the greater prevalence of desmoplastic tumours in adulthood. Few studies have addressed the MRI features of adult medulloblastoma and the specific characteristics of desmoplastic and classic tumours have not been analysed. Our aim was to analyse the imaging characteristics of desmoplastic (DM) and classic (CM) medulloblastomas in adult. We retrospectively studied preoperative MRI of six men and three women, median age 33 years, range 23-53 years, with pathologically proved medulloblastomas. There were six (67%) with DM. The tumour was in the cerebellar hemisphere in eight patients (89%), including the three with CM, one of which was bilateral. All tumours were heterogeneous, giving predominantly low or isointense signal on T1- and isointense signal on T2-weighted images. Cystic or necrotic areas in all patients were particularly visible on T2-weighted images. Contrast enhancement was absent in one DM and varied from slight to intense in eight (three CM), homogeneous in one DM and patchy in seven. All tumours extended to the surface of the cerebellum and two had well-defined margins. MRI does not allow a clear distinction between DM and CM in adults. (orig.)

  17. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician ... Magnetic resonance imaging (MRI) is a noninvasive medical test that physicians use to diagnose and treat medical ...

  18. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... follow your regular daily routine and take food and medications as usual. Some MRI examinations may require you ... material is injected. Such reactions are usually mild and easily controlled by medication. If you experience allergic symptoms, a radiologist or ...

  19. fMRI-BCI: a Review

    Institute of Scientific and Technical Information of China (English)

    Da-Huan Li; Qin Gao; Wei-Shuai Lü; Hua-Fu Chen

    2009-01-01

    Functional magnetic resonance imaging (fMRI) is a new tool for brain-computer interface (BCI).This paper presents an overview to fMRI-BCI.Our attention is mainly put on the methods of signal acquisition,signal preprocessing,and signal analysis of basic fMRI-BCI structure.The available softwares and the applications of fMRI-BCI are briefly introduced.At last,we suggest focusing on some technologies to make fMRI-BCI more perfect.

  20. MRI of the placenta - a short review.

    Science.gov (United States)

    Dekan, Sabine; Linduska, Nina; Kasprian, Gregor; Prayer, Daniela

    2012-05-01

    While ultrasound is still the gold standard method of placental investigation, magnetic resonance imaging (MRI) has certain benefits. In advanced gestational age, obese women, and posterior placental location, MRI is advantageous due to the larger field of view and its multiplanar capabilities. Some pathologies are seen more clearly in MRI, such as infarctions and placental invasive disorders. The future development is towards functional placental MRI. Placental MRI has become an important complementary method for evaluation of placental anatomy and pathologies contributing to fetal problems such as intrauterine growth restriction.

  1. Advances in Clinical PET/MRI Instrumentation.

    Science.gov (United States)

    Herzog, Hans; Lerche, Christoph

    2016-04-01

    In 2010, the first whole-body PET/MRI scanners installed for clinical use were the sequential Philips PET/MRI with PMT-based, TOF-capable technology and the integrated simultaneous Siemens PET/MRI. Avalanche photodiodes as non-magneto-sensitive readout electronics allowed PET integrated within the MRI. The experiences with these scanners showed that improvements of software aspects, such as attenuation correction, were necessary and that efficient protocols combining optimally PET and MRI must be still developed. In 2014, General Electric issued an integrated PET/MRI with SiPM-based PET detectors, allowing TOF-PET. Looking at the MRI components of current PET/MR imaging systems, primary improvements come from sequences and new coils.

  2. Integration of DCE-MRI and DW-MRI Quantitative Parameters for Breast Lesion Classification

    Directory of Open Access Journals (Sweden)

    Roberta Fusco

    2015-01-01

    Full Text Available Objective. The purpose of our study was to evaluate the diagnostic value of an imaging protocol combining dynamic contrast-enhanced MRI (DCE-MRI and diffusion-weighted MRI (DW-MRI in patients with suspicious breast lesions. Materials and Methods. A total of 31 breast lesions (15 malignant and 16 benign proved by histological examination in 26 female patients were included in this study. For both DCE-MRI and DW-MRI model free and model based parameters were computed pixel by pixel on manually segmented ROIs. Statistical procedures included conventional linear analysis and more advanced techniques for classification of lesions in benign and malignant. Results. Our findings indicated no strong correlation between DCE-MRI and DW-MRI parameters. Results of classification analysis show that combining of DCE parameters or DW-MRI parameter, in comparison of single feature, does not yield a dramatic improvement of sensitivity and specificity of the two techniques alone. The best performance was obtained considering a full combination of all features. Moreover, the classification results combining all features are dominated by DCE-MRI features alone. Conclusion. The combination of DWI and DCE-MRI does not show a potential to dramatically increase the sensitivity and specificity of breast MRI. DCE-MRI alone gave the same performance as in combination with DW-MRI.

  3. MRI in subacute sclerosing panencephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Tuncay, R. [Department of Neurology, Istanbul Medical Faculty, University of Istanbul (Turkey); Akman-Demir, G. [Department of Neurology, Istanbul Medical Faculty, University of Istanbul (Turkey); Goekyigit, A. [Department of Neurology, Istanbul Medical Faculty, University of Istanbul (Turkey); Eraksoy, M. [Department of Neurology, Istanbul Medical Faculty, University of Istanbul (Turkey); Barlas, M. [Department of Neurology, Istanbul Medical Faculty, University of Istanbul (Turkey); Tolun, R. [Department of Neurology, Istanbul Medical Faculty, University of Istanbul (Turkey); Guersoy, G. [Department of Neurology, Istanbul Medical Faculty, University of Istanbul (Turkey)

    1996-10-01

    Subacute sclerosing panencephalitis (SSPE) is a progressive, slow virus infection of the brain, caused by the measles virus, attacking children and young adults. We investigated 15 patients with SSPE by MRI, with 5 normal and 10 pathological results. In the early period, lesions were in the grey matter and subcortical white matter. They were asymmetrical and had a predilection for the posterior parts of the hemispheres. Later, high-signal changes in deep white matter and severe cerebral atrophy were observed. Parenchymal lesions significantly correlated with the duration of disease. A significant relationship between MRI findings and clinical stage was observed in the 1st year of the disease. (orig.). With 4 figs., 1 tab.

  4. MRI morphometry in Alzheimer's disease.

    Science.gov (United States)

    Matsuda, Hiroshi

    2016-09-01

    MRI based evaluation of brain atrophy is regarded as a valid method to stage the disease and to assess progression in Alzheimer's disease (AD). Volumetric software programs have made it possible to quantify gray matter in the human brain in an automated fashion. At present, voxel based morphometry (VBM) is easily applicable to the routine clinical procedure with a short execution time. The importance of the VBM approach is that it is not biased to one particular structure and is able to assess anatomical differences throughout the brain. Stand-alone VBM software running on Windows, Voxel-based Specific Regional analysis system for AD (VSRAD), has been widely used in the clinical diagnosis of AD in Japan. On the other hand, recent application of graph theory to MRI has made it possible to analyze changes in structural connectivity in AD.

  5. MRI of Wolfram syndrome (DIDMOAD)

    Energy Technology Data Exchange (ETDEWEB)

    Galluzzi, P.; Filosomi, G.; Vallone, I.M.; Venturi, C. [Dept. of Neuroradiology, Policlinico ' ' Le Scotte' ' , Siena (Italy); Bardelli, A.M. [Dept. of Ophthalmological Sciences, Unit of Paediatric Ophthalmology, University of Siena (Italy)

    1999-10-01

    Wolfram syndrome (DIDMOAD) is a rare diffuse neurodegenerative disorder characterised by diabetes insipidus, diabetes mellitus, optic atrophy, deafness, and a wide variety of abnormalities of the central nervous system, urinary tract and endocrine glands. It may be familial or sporadic. Reported features on MRI of the brain are absence of the physiological high signal of the posterior lobe of the pituitary, shrinkage of optic nerves, chiasm and tracts, atrophy of the hypothalamic region, brain stem, cerebellum, and cerebral cortex. We report a 12-year-old girl with a 5-year history without brain stem, cerebellar or cerebral atrophy. MRI showed an unusual feature: a focus of high signal on PD- and T2-weighted images in the right substantia nigra. This is consistent with previously reported neuropathological post-mortem studies, but has never been reported in vivo. (orig.)

  6. MRI of vulvar Crohn disease

    Energy Technology Data Exchange (ETDEWEB)

    Pai, Deepa; Dillman, Jonathan R.; Mahani, Maryam Ghadimi; Strouse, Peter J. [University of Michigan Health System, Department of Radiology, Section of Pediatric Radiology, C.S. Mott Children' s Hospital, F3503, Ann Arbor, MI (United States); Adler, Jeremy [University of Michigan Health System, Department of Pediatrics and Communicable Diseases, Division of Pediatric Gastroenterology, C. S. Mott Children' s Hospital, Ann Arbor, MI (United States)

    2011-04-15

    Crohn disease is a chronic granulomatous inflammatory disorder that most commonly affects the gastrointestinal tract, particularly the distal small bowel and colon. While certain extraintestinal manifestations of Crohn disease are relatively common and well-known, others, such as metastatic cutaneous involvement, are quite rare and may be difficult to recognize, particularly in the pediatric population. This case report illustrates the magnetic resonance imaging (MRI) appearance of vulvar region cutaneous Crohn disease in an 11-year-old girl. (orig.)

  7. Neurosarcoidosis with unusual MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Handler, M.S. (Dept. of Pathology and Oncology, Kansas Univ. Medical Center, KS (United States)); Johnson, L.M. (Dept. of Neurology, Kansas Univ. Medical Center, KS (United States)); Dick, A.R. (Dept. of Neurology, Kansas Univ. Medical Center, KS (United States)); Batnitzky, S. (Dept. of Diagnostic Radiology, Kansas Univ. Medical Center, KS (United States))

    1993-02-01

    This 53-year-old white male presented with a 4-month-history of weakness and pain. Despite an initial partial response to steroid therapy, his neurologic deterioration progressed culminating in paraparesis, paresthesias, urinary incontinence, altered mentation and a 20 Ib weight loss. A gadolinium-enhanced MRI study showed a pattern suggestive of perivascular involvement. A subsequent cerebral biopsy was diagnostic for neurosarcoidosis. (orig.)

  8. High Spatiotemporal Resolution Prostate MRI

    Science.gov (United States)

    2016-09-01

    for time- resolved contrast-enhanced MR angiography (CE-MRA) using two-dimensional (2D) SENSE acceleration (10). For this work the slab ...orientation was approximately axial but with slight forward tilting to align the slab select direction with the central axis of the prostate gland as... composite images was then provided to each reviewer. The two radiologist reviewers (ATF, five years experience in prostate MRI; AK, 20 years

  9. MRI-induced retrocalcaneal bursitis

    Energy Technology Data Exchange (ETDEWEB)

    Tol, J.L.; Dijk, C.N. van [Dept. of Orthopaedic Surgery, University of Amsterdam (Netherlands); Maas, M. [Dept. of Radiology, University of Amsterdam (Netherlands)

    1999-10-01

    This case report describes a patient with acute retrocalcaneal bursitis, which developed after MRI examination of the ankle. The sagittal T2*-weighted gradient echo sequence revealed an extensive susceptibility artifact in the area surrounding the Achilles tendon near its insertion at the os calcis. This artifact was caused by postsurgical metallic particles. We postulate that these particles were mechanically stimulated by the magnetic field and induced the inflammatory response. (orig.)

  10. MRI findings of extramedullary haemopoiesis

    Energy Technology Data Exchange (ETDEWEB)

    Chourmouzi, D.; Pistevou-Gompaki, K.; Plataniotis, G.; Skaragas, G.; Papadopoulos, L.; Drevelegas, A. [Dept. of Diagnostic Radiology and Radiation Oncology, AHEPA University Hospital, Thessaloniki (Greece)

    2001-09-01

    Extramedullary haemopoiesis (EH) is a compensatory process associated with chronic haemolytic anaemia. It is rare, however, for such an abnormality to cause spinal cord compression. We present two patients with known beta-thalassaemia intermedia who developed spinal cord compression due to masses of extramedullary haematopoietic tissue in the epidural space of the thoracic spine. The EH masses were diagnosed by MRI as an isointense epidural lesion on both T1- and T2-weighted images, compressing severely the spinal cord. After administration of a paramagnetic agent, an intermediate enhancement of the masses was evident. All the vertebral bodies had low to intermediate signal intensity as a result of displacement of fatty marrow by haematopoietic marrow. Expansion of thoracic ribs with bilateral paravertebral masses were characteristic. A small dose of radiotherapy was given and marked improvement in neurological symptoms was evident. An MRI examination established shrinkage of the mass and decompression of spinal cord. The role of MRI in diagnosis of EH masses is essential and radiation therapy is a very effective treatment for this rare complication. (orig.)

  11. MRI characteristics of midbrain tumours

    Energy Technology Data Exchange (ETDEWEB)

    Sun, B. [Chinese Academy of Medical Science, Beijing (China). Neurosurgical Inst.]|[Department of Neuroradiology, Beijing Tiantan Hospital (China); Wang, C.C.; Wang, J. [Chinese Academy of Medical Science, Beijing (China). Neurosurgical Inst.

    1999-03-01

    We diagnosed 60 cases of midbrain tumours by MRI between 1993 to 1997. There were 39 males and 21 females, aged 2-64 years, mean 25.6 years. We found 38 patients with true intramedullary midbrain tumours, 11 predominantly in the tectum, 20 in the tegmentum and 7 with a downward extension to the pons; there were 7 within the cerebral aqueduct. There were 22 patients with infiltrating midbrain tumours extending from adjacent structures, 11 cases each from the thalamus and pineal region. All patients received surgical treatment. Gross total resection was achieved in 42 cases, subtotal (> 75 %) resection in 18. Pathological diagnoses included 16 low-grade and 15 high-grade astrocytomas; 5 oligodendroastrocytomas; 2 ependymomas; 11 glioblastomas; and 11 pineal parenchymal or germ-cell tumours. Midbrain tumours are a heterogeneous group of neoplasms, with wide variation in clinical and MRI features, related to the site and type of tumour. MRI not only allows precise analysis of their growth pattern, but also can lead to a correct preoperative diagnosis in the majority of cases. (orig.) (orig.) With 3 figs., 3 tabs., 19 refs.

  12. MRI after successful lumbar discectomy

    Energy Technology Data Exchange (ETDEWEB)

    Goethem, J.W.M. van [Department of Radiology, University of Antwerp, Wilrijkstraat 10, B-2650 Edegem (Belgium); Kelft, E. van de [Department of Neurosurgery, University of Antwerp, Edegem (Belgium); Biltjes, I.G.G.M. [Department of Radiology, University of Antwerp, Wilrijkstraat 10, B-2650 Edegem (Belgium); Hasselt, B.A.A.M. van [Department of Radiology, University of Antwerp, Wilrijkstraat 10, B-2650 Edegem (Belgium); Hauwe, L. van den [Department of Radiology, University of Antwerp, Wilrijkstraat 10, B-2650 Edegem (Belgium); Parizel, P.M. [Department of Radiology, University of Antwerp, Wilrijkstraat 10, B-2650 Edegem (Belgium); Schepper, A.M.A. de [Department of Radiology, University of Antwerp, Wilrijkstraat 10, B-2650 Edegem (Belgium)

    1996-05-01

    Our aim was to establish the normal range of MRI findings after successful lumbar discectomy. We prospectively examined 34 consecutive patients with an excellent clinical outcome by MRI 6 weeks and 6 months after surgery. All examinations included sagittal and axial spin-echo (SE) T1-weighted images before and after intravenous gadolinium-DTPA and fast SE T2-weighted images. Contrast enhancement along the surgical tract was seen in all patients 6 weeks and 6 months after surgery. After 6 months minimal or no mass effect on the dural sac by epidural scar was seen. In 20 % of patients there was recurrent disc herniation, with mass effect. Enhancing nerve roots were seen in 20 % of patients 6 weeks postoperatively, and half of these were associated with recurrent disc herniation at the same side. None of these patients still showed nerve root enhancement 6 months after surgery. Postoperative MRI studies must be interpreted with great care since the features described in the failed back surgery syndrome are also found, to some extent, in asymptomatic postoperative patients. (orig.). With 7 figs., 2 tabs.

  13. Fetal ocular measurements by MRI.

    Science.gov (United States)

    Li, Xiao Bing; Kasprian, Gregor; Hodge, Jacqueline C; Jiang, Xiao Li; Bettelheim, Dieter; Brugger, Peter C; Prayer, Daniela

    2010-11-01

    To present fetal magnetic resonance imaging (MRI) ocular measurement ranges by gestational age (GA) in normal and growth-restricted fetuses. A total of 298 pregnant women from the 18th to the 39th week of gestation were imaged using MRI. Ocular measurements including binocular distance (BOD), interocular distance (IOD), transverse ocular diameter (OD) and anterior-posterior (AP) OD were measured. The curve estimation analyses for linear, logarithmic and quadratic models were performed. The ocular measurements of the fetuses with intrauterine growth restriction (IUGR) were compared with that of the normal fetuses. The fetal eye resembles an ellipsoid with significantly longer OD and shorter AP (t = - 22.07, p < 0.001). The quadratic model was the best model in predicting growth of the fetal BOD, IOD, OD and AP. The ocular measurements of the fetuses with IUGR were significantly different from that of the normal fetuses (BOD: t = 3.58, p < 0.001; IOD: t = 5.73, p < 0.001; OD: t = 3.52, p < 0.001; AP: t = 2.19, p < 0.05). Fetal ocular growth can be readily assessed by fetal MRI. Using the normative data provided in this study, fetal ocular anomalies may be detected. Ocular size is frequently reduced in the condition of IUGR, with potential pathologic impact on postnatal vision.

  14. MRI in insulinomas; Preliminary findings

    Energy Technology Data Exchange (ETDEWEB)

    Liessi, Guido (Ospedale Civile, Castelfranco Veneto (Italy). Servizio di Radiologia); Pasquali, Claudio; Alfano D' Andrea, Alfonso; Pedrazzoli, Sergio (Padova Universita, I Cattedra di: Patologia Speciale Chirurgica (Italy). Istituto di Clinica Chirurgica); Scandellari, Cesare (Padova Universita, Cattedra di Medicina Interna V (Italy). Istituto di Semeiotica Medica)

    After establishing the diagnosis of an insulinoma, most surgeons prefer preoperative localization. Selective arteriography is usually considered the gold standard for this purpose. Recently, computed tomography (CT) and preoperative US have contended the role to angiography. MRI has been used in few cases of endocrine pancreatic tumors, and its role in this particular field has to be defined. Between November 1988-September 1990 7 adult patients who had undergone surgery were evaluated. Eight tumors were resected in 6 patients who were cured; in an 18-year-old woman surgical treatment was unsuccessful. Arterio-graphy, CT, preoperative US, MRI and intraoperative US detected 2, 6, 6, 5 and 6 tumors respectively. Two insulinomas (0.2 and 0.7 cm) were found at histologic examination in resected specimen. The ability of intra-operative US and careful surgical exploration to resolve more than 90 percent of cases makes the preoperative use of arteriography and CT questionable value. If further experience confirms these findings, US and MRI may suffice. (author). 13 refs.; 3 figs.; 1 tab.

  15. MRI findings of juvenile psoriatic arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Edward Y.; Kleinman, Paul K. [Harvard Medical School, Department of Radiology, Boston, MA (United States); Children' s Hospital Boston, MA (United States); Sundel, Robert P.; Kim, Susan [Harvard Medical School, Rheumatology Program, Division of Immunology and the Department of Pediatrics, Boston, MA (United States); Children' s Hospital Boston, MA (United States); Zurakowski, David [Harvard Medical School, Department of Radiology, Boston, MA (United States); Harvard Medical School, Department of Orthopaedic Surgery, Boston, MA (United States); Children' s Hospital Boston, MA (United States)

    2008-11-15

    The aim of this study was to describe the magnetic resonance imaging (MRI) features of juvenile psoriatic arthritis (JpsA) in children in order to facilitate early diagnosis and proper management. Two pediatric radiologists retrospectively reviewed in consensus a total of 37 abnormal MRI examinations from 31 pediatric patients (nine boys, 22 girls; age range 1-17 years; mean age 9.4 years) who had a definite diagnosis of JpsA and underwent MRI. Each MRI was evaluated for synovium abnormality (thickening and enhancement), joint effusion (small, moderate, and large), bone marrow abnormality (edema, enhancement, and location of abnormality), soft tissue abnormality (edema, enhancement, atrophy, and fatty infiltration), tendon abnormality (thickening, edema, tendon sheath fluid, and enhancement), and articular abnormality (joint space narrowing and erosion). The distribution of abnormal MRI findings among the six categories for the 37 MRI examinations was evaluated. The number of abnormal MRI findings for each MRI examination was assessed. Age at MRI examination and all six categories of abnormal MRI findings according to gender were evaluated. There were a total 96 abnormal MRI findings noted on 37 abnormal MRI examinations from 31 pediatric patients. The 37 abnormal MRI examinations included MRI of the hand (n=8), knee (n = 8), ankle (n = 5), pelvis (n = 5), temporomandibular joint (n = 4), wrist (n = 3), foot (n = 2), elbow (n = 1), and shoulder (n = 1). Twenty-eight diffuse synovial thickening and/or enhancement were the most common MRI abnormality (29.2%). Joint effusion comprised 22 abnormal MRI findings (22.9%). There were 16 abnormal MRI bone marrow edema and/or enhancement findings (16.7%), and in seven (7.3%) the edema involved non-articular sites. Soft tissue abnormality manifested as edema and/or enhancement constituted 14 abnormal MRI findings (14.5%). There were ten MRI abnormalities (10.4%) involving tendons. Articular abnormality seen as joint space

  16. The diagnostic utility of MRI in spondyloarthritis

    DEFF Research Database (Denmark)

    Pedersen, Susanne J; Weber, Ulrich; Østergaard, Mikkel

    2012-01-01

    The recently developed Assessment of SpondyloArthritis international Society (ASAS) classification criteria for axial and peripheral spondyloarthritis (SpA) are the first criteria ever to include findings on magnetic resonance imaging (MRI) of the sacroiliac joints. Features indicating sacroiliac...... joint inflammation on MRI are weighted equally to structural changes on conventional radiography, and thus MRI has become an important tool for use in daily practice to evaluate patients with clinically suspected early spondyloarthritis. However, MRI can also detect structural changes such as erosions...... and fat infiltrations, and recent studies suggest that assessment of both inflammatory and structural changes of the sacroiliac joints may improve the diagnostic utility of MRI. The present article reviews the evidence for the use of sacroiliac joint and spinal MRI to assess patients with axial...

  17. Moyamoya disease: diagnostic accuracy of MRI.

    Science.gov (United States)

    Yamada, I; Suzuki, S; Matsushima, Y

    1995-07-01

    Our purpose was to evaluate the diagnostic accuracy of MRI in moyamoya disease. We studied 30 patients with this disease, comparing MRI and angiographic findings. The diagnostic value of MRI was evaluated for occlusive lesions, collateral vessels, and parenchymal lesions. In all patients bilateral occlusion or stenosis of the supraclinoid internal carotid artery and proximal anterior and middle cerebral arteries was clearly shown by MRI, and staging of the extent of occlusion agreed with angiographic staging in 44 (73%) of 60 arteries. MRI, particularly coronal images, clearly showed basal cerebral moyamoya vessels in 54 hemispheres, and 45 of a total of 71 large leptomeningeal and transdural collateral vessels were identified. MRI also showed parenchymal lesions in 48 (80%) hemispheres, and the extent of occlusion in the anterior and posterior circulations respectively correlated with white matter and cortical and/or subcortical infarcts.

  18. MRI in patients with low back pain

    DEFF Research Database (Denmark)

    Jensen, Rikke Krüger; Manniche, Claus; Leboeuf-Yde, Charlotte

    MRI in LBP patients: good or bad? Background: The routine use of radiology is presently discouraged in patients with low back pain (LBP). MRI provides clinicians and patients with detailed knowledge of the spinal structures and has no known physical side effects. It is possible that detailed insi......, the management strategy of performing an MRI already at the start of the treatment did reduce the duration of treatment and number of contacts with clinicians, thus saving both time and money....

  19. Competitive advantage of PET/MRI.

    Science.gov (United States)

    Jadvar, Hossein; Colletti, Patrick M

    2014-01-01

    Multimodality imaging has made great strides in the imaging evaluation of patients with a variety of diseases. Positron emission tomography/computed tomography (PET/CT) is now established as the imaging modality of choice in many clinical conditions, particularly in oncology. While the initial development of combined PET/magnetic resonance imaging (PET/MRI) was in the preclinical arena, hybrid PET/MR scanners are now available for clinical use. PET/MRI combines the unique features of MRI including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most evidence for the potential clinical utility of PET/MRI is based on studies performed with side-by-side comparison or software-fused MRI and PET images. Data on distinctive utility of hybrid PET/MRI are rapidly emerging. There are potential competitive advantages of PET/MRI over PET/CT. In general, PET/MRI may be preferred over PET/CT where the unique features of MRI provide more robust imaging evaluation in certain clinical settings. The exact role and potential utility of simultaneous data acquisition in specific research and clinical settings will need to be defined. It may be that simultaneous PET/MRI will be best suited for clinical situations that are disease-specific, organ-specific, related to diseases of the children or in those patients undergoing repeated imaging for whom cumulative radiation dose must be kept as low as reasonably achievable. PET/MRI also offers interesting opportunities for use of dual modality probes. Upon clear definition of clinical utility, other important and practical issues related to business operational model, clinical workflow and reimbursement will also be resolved. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  20. fMRI-compatible rehabilitation hand device

    OpenAIRE

    Tzika Aria; Astrakas Loukas; Weinberg Brian; Triantafyllou Christina; Muto Andrew; Khanicheh Azadeh; Mavroidis Constantinos

    2006-01-01

    Abstract Background Functional magnetic resonance imaging (fMRI) has been widely used in studying human brain functions and neurorehabilitation. In order to develop complex and well-controlled fMRI paradigms, interfaces that can precisely control and measure output force and kinematics of the movements in human subjects are needed. Optimized state-of-the-art fMRI methods, combined with magnetic resonance (MR) compatible robotic devices for rehabilitation, can assist therapists to quantify, mo...

  1. MRI of Adnexal Masses in Pregnancy

    Science.gov (United States)

    Telischak, Nicholas A.; Yeh, Benjamin M.; Joe, Bonnie N.; Westphalen, Antonio C.; Poder, Liina; Coakley, Fergus V.

    2009-01-01

    OBJECTIVE The objective of this article is to provide a practical review of the incremental benefit of MRI in the assessment of adnexal masses in pregnancy. CONCLUSION MRI can assist sonographic assessment of adnexal masses in pregnancy by depicting the characteristic findings of exophytic leiomyoma, red degeneration of leiomyoma, endometrioma, decidualized endometrioma, and massive ovarian edema. Accordingly, MRI should be considered as a useful adjunct when sonography is inconclusive or insufficient to guide management of adnexal masses discovered in pregnancy. PMID:18647903

  2. MRI of sequela of transverse myelitis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.C.; Lee, S.K.; Ho, Y.J. (Taichung Veterans General Hospital (Taiwan). Dept. of Radiology); Lee, K.R. (National Tsing-Hua Univ., Hsin-Chu (Taiwan). Inst. of Life Science); Mak, S.C.; Chi, C.S. (Taichung Veterans General Hospital (Taiwan). Dept. of Pediatrics)

    1992-09-01

    A 4-year-old boy developed acute paraplegia, associated with sensory impairement and bowel and urinary dysfunction after an URI. MRI showed diffuse hyperintensity in T2WI in the spinal cord below the T6 level. Acute transverse myelitis was diagnosed based on the clinical presentations and MRI findings. The patient had poor recovery and two months later, a follow-up MRI disclosed a severer diffuse atrophic change of the spinal cord in the affected segment. (orig.).

  3. Navicular bone position determined by positional MRI

    DEFF Research Database (Denmark)

    Hansen, Philip; Johannsen, Finn E; Hangaard, Stine

    2016-01-01

    OBJECTIVE: To examine intraobserver, interobserver and between-day reproducibility of positional MRI for evaluation of navicular bone height (NVH) and medial navicular position (MNP). MATERIALS AND METHODS: Positional MRI (pMRI) of the foot was performed on ten healthy participants (0.25 T G......: Navicular height and medial navicular position can be measured by pMRI in a very reproducible manner within and between observers. Increased measurement variation is observed between-days in supine position, which may be due to small positional differences or other unknown biomechanical factors....

  4. MRI of the lungs in children

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, Wolfgang [Paediatric Radiology in the Department of Diagnostic and Interventional Radiology, University Hospital Leipzig (Germany)], E-mail: wolfgang.hirsch@medizin.uni-leipzig.de; Sorge, Ina; Krohmer, Svetlana; Weber, Dana [Paediatric Radiology in the Department of Diagnostic and Interventional Radiology, University Hospital Leipzig (Germany); Meier, Konstanze [Department of Paediatrics, University Hospital Leipzig (Germany); Till, Holger [Department of Paediatric Surgery, University Hospital Leipzig (Germany)

    2008-11-15

    Lung diseases of children often need diagnostic imaging beyond X-ray. Although CT is considered the gold standard of lung imaging, MRI is sufficient to answer most of the questions raised. After all, the exposure to radiation caused by one CT examination corresponds to approximately the effective dose of 200 chest radiographs. What is MRI's potential in the lung today? In diseases with alveolar pathology, cardiac- and respiratory-triggered MRI examinations are roughly equivalent to CT examinations. Distinct interstitial processes are easily diagnosable using MRI. Early interstitial processes may be missed by MRI, but conventional plain films fail to recognize them just as often. For identification of lung metastases, CT is still used as the initial diagnostic measure. Subsequent therapy monitoring may then be carried out with the help of MRI. Small bullae and pulmonary emphysema at present pose a problem to MRI. On the other hand, MRI is reliable for follow-up examinations in inflammatory diseases or for imaging of complications, and the increased use of lung MRI as an alternative to chest CT may contribute immensely to reducing radiation exposure in children.

  5. Preoperative diagnosis of primary hyperparathyroidism by MRI

    Energy Technology Data Exchange (ETDEWEB)

    Inouye, Takahiro; Tomita, Toshiki; Nitta, Seiichi [Tochigi Prefecture Saiseikai Utsunomiya Hospital (Japan); Kanou, Shigeru; Sato, Toshihiko

    1996-06-01

    We evaluated 12 patients with primary hyperparathyroidism by MRI. Nine patients presented parathyroid adenomas and the others hypertrophy of the parathyroid. Abnormal parathyroid was detected in 10 patients (83%) by T2-weighed image. And abnormal parathyroid was detected in one of the other two cases by MRI combined with {sup 99m}Tc{center_dot}MIBI-{sup 99m}Tc subtraction scintigraphy. Although we usually employ the axial view of MRI, it is incompatible with the operative field. We therefore hope that three-dimensional MRI will become compatible with the operative field in the future. (author)

  6. MRI of central nervous system anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Izawa, M.; Oikawa, A.; Matoba, A.

    1987-05-01

    MRI was very useful in the evaluation of congenital anomalies of central nervous system as well as other nervous system disease with three-dimensional spatial resolution. We had experienced MRI of central nervous system anomalies, demonstrated characterisitic findings in each anomaly. MRI is useful to observe the coronal, horizontal and sagittal images of the brain and spinal cord in order to discuss the etiological mechanisms of spinal dysraphysm and its associated anomalies. In case of spina bifida cystica MRI was available to decide operative indication for radical operation and tetherd cord developed from postoperative scar or accompanied intraspinal lesions.

  7. Breast MRI in high risk patients

    OpenAIRE

    Obdeijn, Inge-Marie

    2015-01-01

    markdownabstractAbstract In this thesis we address various indications of breast MRI, with the emphasis on the value of MRI in screening of women with high genetic risk for breast cancer, and especially in BRCA1 mutation carriers. We showed that in the era of up-to-date MRI expertise and digital mammography the screening efficacy is improved. However, the additional value of mammography over MRI is little while at the same time BRCA carriers are more sensitive the risks of low dose radiation ...

  8. MRI of nasopharyngeal adenoid hypertrophy.

    Science.gov (United States)

    Surov, Alexey; Ryl, Ina; Bartel-Friedrich, Sylvia; Wienke, Andreas; Kösling, Sabrina

    2016-10-01

    Nasopharyngeal adenoid hypertrophy (NAH) is a typical benign lesion. Due to involution, nasopharyngeal lymphatic tissue usually is not found in adults beyond the 30th to 40th year of life. However, occasionally NAH has been recognized after the 50th or 60th year. The aim of this study is to identify the frequency of NAH and to analyze its MRI findings in different age groups. From 2007 to 2011, 6693 MR investigations of the head were performed at our institution. MRI was obtained with a 1.5 T MRI device. NAH was identified in 18.0% of the patients. The frequency of NAH varied from 60.3% to 1.0% in the different age groups. The mean size of NAH was 23.2 ± 4.5 mm in cranio-caudal, 31.1 ± 5.2 mm in left-right, and 14.2 ± 4.1 mm in the anterior-posterior direction. The left-right and cranio-caudal sizes of NAH were largest in the 0-9 age group and decreased with age. On T1-w images most lesions (95.4%) were hypointense in comparison to the adjacent musculature. On T2-w fat-saturated images 82.4% of the lesions were hyperintense. After intravenous administration of contrast medium most lesions showed a slight enhancement (58.6%). Moderate enhancement was seen in 32.4% and a marked enhancement was identified in 9.0%. In the 0-9 age group most lesions showed a slight enhancement. Cysts within NAH were identified in 433 cases (35.9%). The frequency of cysts increased continuously with age, namely from 10.9% to 65.2%.

  9. Compressive myelopathy in fluorosis: MRI

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, R.K. [MR Section, Department of Radiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow-226014 (India); Agarwal, P. [MR Section, Department of Radiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow-226014 (India); Kumar, S. [MR Section, Department of Radiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow-226014 (India); Surana, P.K. [Department of Neurology, SGPGIMS, Lucknow-226014 (India); Lal, J.H. [MR Section, Department of Radiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow-226014 (India); Misra, U.K. [Department of Neurology, SGPGIMS, Lucknow-226014 (India)

    1996-05-01

    We examined four patients with fluorosis, presenting with compressive myelopathy, by MRI, using spin-echo and fast low-angle shot sequences. Cord compression due to ossification of the posterior longitudinal ligament (PLL) and ligamentum flavum (LF) was demonstrated in one and ossification of only the LF in one. Marrow signal was observed in the PLL and LF in all the patients on all pulse sequences. In patients with compressive myelopathy secondary to ossification of PLL and/or LF, fluorosis should be considered as a possible cause, especially in endemic regions. (orig.). With 2 figs., 1 tab.

  10. MRI versus radiography of acromioclavicular joint dislocation.

    Science.gov (United States)

    Nemec, Ursula; Oberleitner, Gerhard; Nemec, Stefan F; Gruber, Michael; Weber, Michael; Czerny, Christian; Krestan, Christian R

    2011-10-01

    Acromioclavicular joint injuries are usually diagnosed by clinical and radiographic assessment with the Rockwood classification, which is crucial for treatment planning. In view of the implementation of MRI for visualization of the acromioclavicular joint, the purpose of this study was to describe the MRI findings of acromioclavicular joint dislocation in comparison with the radiographic findings. Forty-four patients with suspected unilateral acromioclavicular joint dislocation after acute trauma were enrolled in this prospective study. All patients underwent digital radiography and 1-T MRI with a surface phased-array coil. MRI included coronal proton density-weighted turbo spin-echo and coronal 3D T1-weighted fast field-echo water-selective sequences. The Rockwood classification was used to assess acromioclavicular joint injuries at radiography and MRI. An adapted Rockwood classification was used for MRI evaluation of the acromioclavicular joint ligaments. The classifications of acromioclavicular joint dislocations diagnosed with radiography and MRI were compared. Among 44 patients with Rockwood type I-IV injuries on radiographs, classification on radiographs and MR images was concordant in 23 (52.2%) patients. At MRI, the injury was reclassified to a less severe type in 16 (36.4%) patients and to a more severe type in five (11.4%) patients. Compared with the findings according to the original Rockwood system, with the adapted system that included MRI findings, additional ligamentous lesions were found in 11 (25%) patients. In a considerable number of patients, the MRI findings change the Rockwood type determined with radiography. In addition to clinical assessment and radiography, MRI may yield important findings on ligaments that may influence management.

  11. ORIGINAL ARTICLE CASE REPORT Functional MRI in pre-surgical ...

    African Journals Online (AJOL)

    CASE REPORT. Functional magnetic resonance imaging (fMRI) is an MRI technique ... most promising direct clinical application is in pre-surgical planning, where fMRI is ... robust and established, although it is interesting to note that recent.

  12. Central nervous system tuberculosis: MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kioumehr, F.; Dadsetan, M.R.; Rooholamini, S.A.; Au, A.

    1994-02-01

    The MRI findings of 18 proven cases of central nervous system (CNS) tuberculosis were reviewed; 10 patients were seropositive for HIV. All had medical, laboratory, or surgical proof of CNS tuberculosis. Eleven patients had meningitis, of whom two also had arachnoiditis. Five patients had focal intra-axial tuberculomas: four brain masses and one an intramedullary spinal lesion. Two patients had focal extra-axial tuberculomas: one in the pontine cistern, and one in the spine. In all 11 patients with meningitis MRI showed diffuse, thick, meningeal enhancement. All intraparenchymal tuberculomas showed low signal intensity on T2-weighted images and ring or nodular enhancement. The extra-axial tuberculomas had areas isointense or hypointense relative to normal brain and spinal cord on T2-weighted images. Although tuberculous meningitis cannot be differentiated from other meningitides on the basis of MR findings, intraparenchymal tuberculomas show characteristic T2 shortening, not found in most other space-occupying lesions. In the appropriate clinical setting, tuberculoma should be considered. (orig.)

  13. Physics of MRI: a primer.

    Science.gov (United States)

    Plewes, Donald B; Kucharczyk, Walter

    2012-05-01

    This article is based on an introductory lecture given for the past many years during the "MR Physics and Techniques for Clinicians" course at the Annual Meeting of the ISMRM. This introduction is not intended to be a comprehensive overview of the field, as the subject of magnetic resonance imaging (MRI) physics is large and complex. Rather, it is intended to lay a conceptual foundation by which magnetic resonance image formation can be understood from an intuitive perspective. The presentation is nonmathematical, relying on simple models that take the reader progressively from the basic spin physics of nuclei, through descriptions of how the magnetic resonance signal is generated and detected in an MRI scanner, the foundations of nuclear magnetic resonance (NMR) relaxation, and a discussion of the Fourier transform and its relation to MR image formation. The article continues with a discussion of how magnetic field gradients are used to facilitate spatial encoding and concludes with a development of basic pulse sequences and the factors defining image contrast.

  14. Childhood moyamoya disease: hemodynamic MRI

    Energy Technology Data Exchange (ETDEWEB)

    Tzika, A.A. [Department of Radiology, Children`s Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States); Robertson, R.L. [Department of Radiology, Children`s Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States); Barnes, P.D. [Department of Radiology, Children`s Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States); Vajapeyam, S. [Department of Radiology, Children`s Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States); Burrows, P.E. [Department of Radiology, Children`s Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States); Treves, S.T. [Department of Radiology, Children`s Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States); Scott, R.M. l [Department of Radiology, Children`s Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115 (United States)

    1997-09-01

    Background. Childhood moyamoya disease is a rare progressive cerebrovascular disease. Objective. To evaluate cerebral hemodynamics using dynamic Gd-DTPA-enhanced imaging in children with moyamoya disease. Materials and methods. Eight children (2-11 years of age) with the clinical and angiographic findings typical of moyamoya disease, before and/or after surgical intervention (pial synangiosis), underwent conventional MR imaging (MRI) and hemodynamic MR imaging (HMRI). HMRI used a spoiled gradient-echo with low flip angle (10 deg) and long TE (TR/TE = 24/15 ms) to minimize T 1 effects and emphasize T 2{sup *} weighting. Raw and calculated hemodynamic images were reviewed. Three-dimensional time-of-flight MR angiography (MRA) and perfusion brain single photon emission computed tomography (SPECT) were also performed. Results. Abnormal hemodynamic maps resulting from vascular stenosis or occlusion and basal collaterals were observed in six patient studies. HMRI depicted perfusion dynamics of affected cerebrovascular territories, detected cortical perfusion deficits, and complemented conventional MRI and MRA. HMRI findings were consistent with those of catheter angiography and perfusion SPECT. Conclusion. Our preliminary experience suggests that HMRI may be of value in the preoperative and postoperative evaluation of surgical interventions in moyamoya disease. (orig.). With 4 figs., 3 tabs.

  15. Anencephaly: MRI findings and pathogenetic theories.

    Science.gov (United States)

    Calzolari, Ferdinando; Gambi, Beatrice; Garani, Giampaolo; Tamisari, Lalla

    2004-12-01

    We describe the MRI appearances of an anencephalic newborn who survived for 13 h; particularities of this case are male gender and the absence of other associated malformations. Moreover, we discuss the pathogenetic theories of anencephaly, correlating MRI findings with embryological data. An exencephaly-anencephaly sequence due to amnion rupture is hypothesized.

  16. Anencephaly: MRI findings and pathogenetic theories

    Energy Technology Data Exchange (ETDEWEB)

    Calzolari, Ferdinando [Azienda Ospedaliera Universitaria, Department of Neuroradiology, Ferrara (Italy); Gambi, Beatrice [Ospedale S. Donato, Neonatal Unit, Arezzo (Italy); Garani, Giampaolo; Tamisari, Lalla [Universita degli Studi, Neonatal Unit, Ferrara (Italy)

    2004-12-01

    We describe the MRI appearances of an anencephalic newborn who survived for 13 h; particularities of this case are male gender and the absence of other associated malformations. Moreover, we discuss the pathogenetic theories of anencephaly, correlating MRI findings with embryological data. An exencephaly-anencephaly sequence due to amnion rupture is hypothesized. (orig.)

  17. Paradigm shift in MRI for sciatica

    NARCIS (Netherlands)

    Barzouhi, Abdelilah el

    2013-01-01

    In contrast with the intuitive feeling of physicians many worrisome MRI findings do not correlate with patient outcome in patients with sciatica. Physicians should for example not automatically ascribe persistent or recurrent symptoms of sciatica to the presence of abnormalities visible on MRI. This

  18. Cardiac MRI of the athlete's heart

    NARCIS (Netherlands)

    Prakken, N.H.J.

    2010-01-01

    The increase in pre-participation cardiovascular screening using the Lausanne protocol will ultimately lead to an increased use of cardiac MRI and MDCT in the cardiovascular work-up of athletes. The role of cardiac MRI is well established in the evaluation of cardiomyopathies, myocarditis, aortic st

  19. Cardiac MRI of the athlete's heart

    NARCIS (Netherlands)

    Prakken, N.H.J.

    2010-01-01

    The increase in pre-participation cardiovascular screening using the Lausanne protocol will ultimately lead to an increased use of cardiac MRI and MDCT in the cardiovascular work-up of athletes. The role of cardiac MRI is well established in the evaluation of cardiomyopathies, myocarditis, aortic

  20. A low-cost MRI compatible keyboard

    DEFF Research Database (Denmark)

    Jensen, Martin Snejbjerg; Heggli, Ole Adrian; Alves da Mota, Patricia

    2017-01-01

    , presenting a challenging environment for playing an instrument. Here, we present an MRI-compatible polyphonic keyboard with a materials cost of 850 $, designed and tested for safe use in 3T (three Tesla) MRI-scanners. We describe design considerations, and prior work in the field. In addition, we provide...

  1. Functional MRI of Language Processing and Recovery

    NARCIS (Netherlands)

    C. Méndez Orellana (Carolina)

    2015-01-01

    markdownabstract__Abstract__ My thesis describe the utility of implementing fMRI to investigate how the language system is reorganized in brain damaged patients. Specifically for aphasia research fMRI allows to show how specific language treatment methods have the potential to enhance language

  2. MRI for clinically suspected appendicitis during pregnancy.

    NARCIS (Netherlands)

    Cobben, L.P.; Groot, I.; Haans, L.; Blickman, J.G.; Puylaert, J.

    2004-01-01

    OBJECTIVE: The purpose of this study was to evaluate whether MRI can be used to accurately diagnose or exclude appendicitis in pregnant patients with clinically suspected appendicitis. CONCLUSION: Our results suggest that MRI is helpful in the examination and diagnosis of acute appendicitis in pregn

  3. [Anatomic variants of Meckel's cave on MRI].

    Science.gov (United States)

    Benoudiba, F; Hadj-Rabia, M; Iffenecker, C; Fuerxer, F; Bekkali, F; Francke, J P; Doyon, D

    1998-10-01

    Magnetic resonance imaging (MRI) gives an accurate analysis of Meckel's cave variability. Images were acquired in 50 patients with several sections for anatomical comparison. Using several sections, MRI is a suitable method for better analysis of the trigeminal cistern. The most frequent findings are symmetrical trigeminal cisterns. Expansion of Meckel's cave or its disappearance has pathological significance.

  4. MRI in acute phase of whiplash injury

    Energy Technology Data Exchange (ETDEWEB)

    Fagerlund, M. [Dept. of Diagnostic Radiology, Univ. Hospital of Northern Sweden, Umeaa (Sweden); Bjoernebrink, J. [Dept. of Diagnostic Radiology, Univ. Hospital of Northern Sweden, Umeaa (Sweden); Pettersson, K. [Dept. of Orthopaedic Surgery, Univ. Hospital of Northern Sweden, Umeaa (Sweden); Hildingsson, C. [Dept. of Orthopaedic Surgery, Univ. Hospital of Northern Sweden, Umeaa (Sweden)

    1995-11-01

    A prospective MRI study of 39 whiplash patients was performed and the results were compared with the clinical findings within 15 days after trauma. The MRI parameters included disc bulging either with impingement on the anterior epidural space or with medullary compression, foraminal stenosis, dorsal ligament thickening, osteophyte extension and intramedullary or paravertebral soft tissue injury. All changes were graded visually on a four-point scale (no, some, moderate or extensive changes). After the MRI evaluation was made the clinical findings were analysed by two orthopaedic surgeons using a specially designed protocol. With MRI 29 patients (74 %) showed no or only slight changes, and were thus regarded as normal variations. Of these, 10 of 29 patients (34 %) had as the only symptom pain in the head or in the neck, 19 of 29 patients (66 %) showed neurological changes, either paresthesias, sensory deficits or weakness of upper extremities. In 10 (26 %) patients with moderate or extensive MRI changes, 3 of 10 (33 %) had only head or neck pain, or both, and 7 of 10 (66 %) had neurological changes. Use of MRI in whiplash injury is helpful, but it is not the first-choice radiological examination method. Despite neurological changes, the frequency of true traumatic lesions is low. There is no clear correlation between the patients` subjective symptoms or clinical signs and the findings with MRI. However, MRI can be used to find patients with disk herniation that can be treated surgically. (orig.)

  5. MRI study of lumbosacral lipoma in children

    Energy Technology Data Exchange (ETDEWEB)

    Taviere, V.; Brunelle, F.; Baraton, J.; Teman, M.; Pierre-Kahn, A.; Lallemand, D.

    1989-06-01

    We report our experience with 16 cases of lumbosacral lipoma and MRI in children. From these observations, MRI appears to be a suitable examination. The exact situation of the cord and the lipoma is clearly seen. Associated anomalies such as syringomyelia is also clearly demonstrated.

  6. Comparison of static MRI and pseudo-dynamic MRI in temporomandibular joint disorder patients

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Ho; Yun, Kyoung In [Eulji Univ. School of Medicine, Seoul (Korea, Republic of); Park, In Woo; Choi, Hang Moon; Park, Moon Soo [Kangnung National Univ. College of Dentistry, Kangnung (Korea, Republic of)

    2006-12-15

    The purpose of this study was to elevate comparison of static MRI and pseudo-dynamic (cine) MRI in temporomandibular joint (TMJ) disorder patients. In this investigation, 33 patients with TMJ disorders were examined using both conventional static MRI and pseudo-dynamic MRI. Multiple spoiled gradient recalled acquisition in the steady state (SPGR) images were obtained when mouth opened and closed. Proton density weighted images were obtained at the closed and open mouth position in static MRI. Two oral and maxillofacial radiologists evaluated location of the articular disk, movement of condyle and bony change respectively and the posterior boundary of articular disk was obtained. No statistically significant difference was found in the observation of articular disk position, mandibular condylar movement and posterior boundary of articular disk using static MRI and pseudo-dynamic MRI (P>0.05). Statistically significant difference was noted in bony changes of condyle using static MRI and pseudo-dynamic MRI (P<0.05). This study showed that pseudo-dynamic MRI didn't make a difference in diagnosing internal derangement of TMJ in comparison with static MRI. But it was considered as an additional method to be supplemented in observing bony change.

  7. MRI and CT patterns of neurocysticercosis

    Energy Technology Data Exchange (ETDEWEB)

    Rodiek, S.O.; Rupp, N.; Einsiedel, H. von

    1987-05-01

    MRI and CT manifestations were studied in five cases of neurocysticercosis. As demonstrated by long-term follow-ups the disease usually causes multiple lesions the morphology of which depends on the life cycle of the parasite. Tissue lesions consist of three main types: 1) vital cysticerci, 2) inflammatory parenchymatous reactions following degenerating cysts and 3) calcified granulomas. MRI provides all information that is given by CT except for small calcifications which are usually missed. Morphological details of vital cysticerci like cysts wall and scolex are better outlined by MRI. When i.v. contrast medium is applied, it leads to nodular or annular enhancement of inflamed tissue. The sensitivity of MRI towards edema caused by parasite exceeds that of CT by several weeks. CT and MRI are complementary methods providing at the present time the highest degree of specificity in diagnosing neurocysticercosis.

  8. fMRI. Basics and clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Ulmer, Stephan; Jansen, Olav (eds.) [University Hospital of Schleswig-Holstein, Kiel (Germany). Inst. of Neuroradiology, Neurocenter

    2010-07-01

    Functional MRI (fMRI) and the basic method of BOLD imaging were introduced in 1993 by Seiji Ogawa. From very basic experiments, fMRI has evolved into a clinical application for daily routine brain imaging. There have been various improvements in both the imaging technique as such as well as in the statistical analysis. In this volume, experts in the field share their knowledge and point out possible technical barriers and problems explaining how to solve them. Starting from the very basics on the origin of the BOLD signal, the book covers technical issues, anatomical landmarks, presurgical applications, and special issues in various clinical fields. Other modalities for brain mapping such as PET, TMS, and MEG are also compared with fMRI. This book is intended to give a state-of-the-art overview and to serve as a reference and guide for clinical applications of fMRI. (orig.)

  9. Clinical functional MRI. Presurgical functional neuroimaging

    Energy Technology Data Exchange (ETDEWEB)

    Stippich, C. (ed.) [Heidelberg Univ. (Germany). Div. of Neuroradiology

    2007-07-01

    Functional magnetic resonance imaging (fMRI) permits noninvasive imaging of the ''human brain at work'' under physiological conditions. This is the first textbook on clinical fMRI. It is devoted to preoperative fMRI in patients with brain tumors and epilepsies, which are the most well-established clinical applications. By localizing and lateralizing specific brain functions, as well as epileptogenic zones, fMRI facilitates the selection of a safe treatment and the planning and performance of function-preserving neurosurgery. State of the art fMRI procedures are presented, with detailed consideration of the physiological and methodological background, imaging and data processing, normal and pathological findings, diagnostic possibilities and limitations, and other related techniques. All chapters are written by recognized experts in their fields, and the book is designed to be of value to beginners, trained clinicians and experts alike. (orig.)

  10. Diagnostic pitfalls in fetal brain MRI.

    Science.gov (United States)

    Al-Mukhtar, Ali; Kasprian, Gregor; Schmook, Maria T; Brugger, Peter C; Prayer, Daniela

    2009-08-01

    Recent technological advances in fetal magnetic resonance imaging (MRI) and increased reliability of MRI in depicting abnormalities and lesions, especially in the central nervous system, are increasingly bringing up challenging issues with regard to accurate diagnosis. There are also pitfalls not only attributable to image acquisition but also in clinical interpretation. The misinterpretation of findings because of insufficient knowledge about fetal brain development as visualized by MRI may also be regarded as an important limitation of fetal MRI. We provide an overview of the most common pitfalls experienced in fetal MRI in routine practice, demonstrate how to identify some of the factors that lead to imaging misinterpretation, and suggest ways to tackle these problems, with an emphasis on MR techniques and image calibration.

  11. Open magnetic resonance imaging (MRI) scanners.

    Science.gov (United States)

    Hailey, D

    2006-11-01

    (1) In most MRI scanners, the patient examination table fits inside a long cylindrical tube. Large patients cannot be accommodated, and some persons experience claustrophobic reactions. Open MRI systems, in which the patient is placed between two plates, overcome these disadvantages. (2) Open MRI scanners are widely used in health care. High-field closed MRI systems are preferred for many examinations. (3) Early versions of open MRI scanners had low magnetic field strength, gave poorer image quality than most closed systems, and required longer examination times. Newer open scanners include machines with higher magnetic field strengths and improved image quality. (4) Closed high magnetic field scanners with short magnets and wide bore tubes offer improved comfort to patients, and may be an alternative to open scanners. (5) There is interest in using open systems for intra-operative and image-guided interventions.

  12. MRI findings in 100 epileptic children

    Energy Technology Data Exchange (ETDEWEB)

    Suzukawa, Junko; Sugimoto, Tateo; Araki, Atsushi (Kansai Medical School, Moriguchi, Osaka (Japan)) (and others)

    1993-02-01

    Findings of magnetic resonance imaging (MRI) of the brain were retrospectively reviewed in 100 consecutive pediatric patients with epilepsy in relation to the type of epilepsy and prognosis. There were 65 boys and 35 girls, ranging in age from 3 months to 25 years. Among 100 patients, 67 (a total of 102 lesions) showed abnormal findings on MRI. Morphological abnormalities, including ventricular enlargement, atrophy and malformation, were seen in 54 patients. Periventricular (n=14), frontal (n=3), temporal (n=8) and occipital (n=7) areas were of high signal intensity on T2-weighted images. According to the type of epilepsy, MRI abnormality was seen in 34 (61%) of 56 patients with partial seizures and 33 (76%) of 44 patients with generalized seizures. When associated with cerebral palsy and mental retardation, the incidence of MRI abnormality was high. There was no sigificant correlation between MRI findings and prognosis. (N.K.).

  13. NMR, MRI, and spectroscopic MRI in inhomogeneous fields

    Science.gov (United States)

    Demas, Vasiliki; Pines, Alexander; Martin, Rachel W; Franck, John; Reimer, Jeffrey A

    2013-12-24

    A method for locally creating effectively homogeneous or "clean" magnetic field gradients (of high uniformity) for imaging (with NMR, MRI, or spectroscopic MRI) both in in-situ and ex-situ systems with high degrees of inhomogeneous field strength. THe method of imaging comprises: a) providing a functional approximation of an inhomogeneous static magnetic field strength B.sub.0({right arrow over (r)}) at a spatial position {right arrow over (r)}; b) providing a temporal functional approximation of {right arrow over (G)}.sub.shim(t) with i basis functions and j variables for each basis function, resulting in v.sub.ij variables; c) providing a measured value .OMEGA., which is an temporally accumulated dephasing due to the inhomogeneities of B.sub.0({right arrow over(r)}); and d) minimizing a difference in the local dephasing angle .phi.({right arrow over (r)},t)=.gamma..intg..sub.0.sup.t{square root over (|{right arrow over (B)}.sub.1({right arrow over (r)},t')|.sup.2+({right arrow over (r)}{right arrow over (G)}.sub.shimG.sub.shim(t')+.parallel.{right arrow over (B)}.sub.0({right arrow over (r)}).parallel..DELTA..omega.({right arrow over (r)},t'/.gamma/).sup.2)}dt'-.OMEGA. by varying the v.sub.ij variables to form a set of minimized v.sub.ij variables. The method requires calibration of the static fields prior to minimization, but may thereafter be implemented without such calibration, may be used in open or closed systems, and potentially portable systems.

  14. MRI-conditional pacemakers: current perspectives

    Directory of Open Access Journals (Sweden)

    Ferreira AM

    2014-05-01

    Full Text Available António M Ferreira,1,2 Francisco Costa,2 António Tralhão,2 Hugo Marques,3 Nuno Cardim,1 Pedro Adragão1,2 1Cardiology Department, Hospital da Luz, 2Cardiology Department, Hospital Santa Cruz- CHLO, 3Radiology Department, Hospital da Luz, Lisbon, Portugal Abstract: Use of both magnetic resonance imaging (MRI and pacing devices has undergone remarkable growth in recent years, and it is estimated that the majority of patients with pacemakers will need an MRI during their lifetime. These investigations will generally be denied due to the potentially dangerous interactions between cardiac devices and the magnetic fields and radiofrequency energy used in MRI. Despite the increasing reports of uneventful scanning in selected patients with conventional pacemakers under close surveillance, MRI is still contraindicated in those circumstances and cannot be considered a routine procedure. These limitations prompted a series of modifications in generator and lead engineering, designed to minimize interactions that could compromise device function and patient safety. The resulting MRI-conditional pacemakers were first introduced in 2008 and the clinical experience gathered so far supports their safety in the MRI environment if certain conditions are fulfilled. With this technology, new questions and controversies arise regarding patient selection, clinical impact, and cost-effectiveness. In this review, we discuss the potential risks of MRI in patients with electronic cardiac devices and present updated information regarding the features of MRI-conditional pacemakers and the clinical experience with currently available models. Finally, we provide some guidance on how to scan patients who have these devices and discuss future directions in the field. Keywords: pacemakers, magnetic resonance imaging, MRI, MRI-conditional devices, safety

  15. Fetal MRI: techniques and protocols

    Energy Technology Data Exchange (ETDEWEB)

    Prayer, Daniela [Department of Neuroradiology, University Clinics of Radiodiagnostics, Medical University Vienna, Waehringerguertel 18-10, 1090, Vienna (Austria); Brugger, Peter Christian [Department of Anatomy, Integrative Morphology Group, Medical University Vienna (Austria); Prayer, Lucas [Diagnosezentrum Urania, Vienna (Austria)

    2004-09-01

    The development of ultrafast sequences has led to a significant improvement in fetal MRI. Imaging protocols have to be adjusted to the rapidly developing fetal central nervous system (CNS) and to the clinical question. Sequence parameters must be changed to cope with the respective developmental stage, to produce images free from motion artefacts and to provide optimum visualization of the region and focus of interest. In contrast to postnatal studies, every suspect fetal CNS abnormality requires examination of the whole fetus and the extrafetal intrauterine structures including the uterus. This approach covers both aspects of fetal CNS disorders: isolated and complex malformations and cerebral lesions arising from the impaired integrity of the feto-placental unit. (orig.)

  16. Combined PET/MRI scanner

    Science.gov (United States)

    Schlyer, David; Woody, Craig L.; Rooney, William; Vaska, Paul; Stoll, Sean; Pratte, Jean-Francois; O'Connor, Paul

    2007-10-23

    A combined PET/MRI scanner generally includes a magnet for producing a magnetic field suitable for magnetic resonance imaging, a radiofrequency (RF) coil disposed within the magnetic field produced by the magnet and a ring tomograph disposed within the magnetic field produced by the magnet. The ring tomograph includes a scintillator layer for outputting at least one photon in response to an annihilation event, a detection array coupled to the scintillator layer for detecting the at least one photon outputted by the scintillator layer and for outputting a detection signal in response to the detected photon and a front-end electronic array coupled to the detection array for receiving the detection signal, wherein the front-end array has a preamplifier and a shaper network for conditioning the detection signal.

  17. MRI visualisation by digitally reconstructed radiographs

    Science.gov (United States)

    Serrurier, Antoine; Bönsch, Andrea; Lau, Robert; Deserno, Thomas M.

    2015-03-01

    Visualising volumetric medical images such as computed tomography and magnetic resonance imaging (MRI) on picture archiving and communication systems (PACS) clients is often achieved by image browsing in sagittal, coronal or axial views or three-dimensional (3D) rendering. This latter technique requires fine thresholding for MRI. On the other hand, computing virtual radiograph images, also referred to as digitally reconstructed radiographs (DRR), provides in a single two-dimensional (2D) image a complete overview of the 3D data. It appears therefore as a powerful alternative for MRI visualisation and preview in PACS. This study describes a method to compute DRR from T1-weighted MRI. After segmentation of the background, a histogram distribution analysis is performed and each foreground MRI voxel is labeled as one of three tissues: cortical bone, also known as principal absorber of the X-rays, muscle and fat. An intensity level is attributed to each voxel according to the Hounsfield scale, linearly related to the X-ray attenuation coefficient. Each DRR pixel is computed as the accumulation of the new intensities of the MRI dataset along the corresponding X-ray. The method has been tested on 16 T1-weighted MRI sets. Anterior-posterior and lateral DRR have been computed with reasonable qualities and avoiding any manual tissue segmentations. This proof-of-concept holds for research application for use in clinical PACS.

  18. Fetal MRI of clubfoot associated with myelomeningocele

    Energy Technology Data Exchange (ETDEWEB)

    Servaes, Sabah; Hernandez, Andrea; Gonzalez, Leonardo; Victoria, Teresa; Jaramillo, Diego; Christopher Edgar, J.; Johnson, Ann [Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); Johnson, Mark [Children' s Hospital of Philadelphia, Department of Fetal Surgery, Philadelphia, PA (United States)

    2010-12-15

    The sensitivity and specificity of evaluating clubfoot deformity by MR in high-risk fetuses is currently unknown. To correlate fetal MRI with US in the assessment of clubfoot and to identify the MRI features most characteristic of clubfoot. With IRB approval and informed consent, the presence of fetal clubfoot was prospectively evaluated in mothers referred for MRI for a fetus with myelomeningocele. Two radiologists blind to the US results independently reviewed the MRI for the presence of clubfoot. MRI results were compared with US results obtained the same day and birth outcomes. Of 20 patients enrolled, there were 13 clubfeet. Interobserver agreement for the presence of clubfoot was 100%. The sensitivity of the MRI exam was 100% and the specificity 85.2%. A dedicated sagittal imaging plane through the ankle region allowed the most confident diagnosis; medial deviation of the foot relative to the leg was seen in all 13 fetuses with clubfoot. The correlation of fetal MRI with US in the evaluation of clubfoot yields a sensitivity of 100% and specificity of 85.2%. The sagittal plane provided the most useful information. (orig.)

  19. Lung MRI for experimental drug research

    Energy Technology Data Exchange (ETDEWEB)

    Beckmann, Nicolau [Discovery Technologies, Novartis Institutes for BioMedical Research, Lichtstr. 35, WSJ-386.2.09, CH-4002 Basel (Switzerland)], E-mail: nicolau.beckmann@novartis.com; Cannet, Catherine [Discovery Technologies, Novartis Institutes for BioMedical Research, Lichtstr. 35, WSJ-386.2.09, CH-4002 Basel (Switzerland); Karmouty-Quintana, Harry [Discovery Technologies, Novartis Institutes for BioMedical Research, Lichtstr. 35, WSJ-386.2.09, CH-4002 Basel (Switzerland); Meakins-Christie Laboratories, McGill University, Montreal, Canada H2X 2P2 (Canada); Tigani, Bruno; Zurbruegg, Stefan [Discovery Technologies, Novartis Institutes for BioMedical Research, Lichtstr. 35, WSJ-386.2.09, CH-4002 Basel (Switzerland); Ble, Francois-Xavier [Discovery Technologies, Novartis Institutes for BioMedical Research, Lichtstr. 35, WSJ-386.2.09, CH-4002 Basel (Switzerland); Respiratory Diseases Department, Novartis Institutes for BioMedical Research, CH-4056 Basel (Switzerland); Faculty of Pharmacy, University Louis Pasteur-Strasbourg-I, F-67401 Illkirch (France); Cremillieux, Yannick [University of Lyon-1, Laboratory of Nuclear Magnetic Resonance, Centre National de la Recherche Scientifique (CNRS), F-69622 Villeurbanne (France); Trifilieff, Alexandre [Respiratory Diseases Department, Novartis Institutes for BioMedical Research, CH-4056 Basel (Switzerland)

    2007-12-15

    Current techniques to evaluate the efficacy of potential treatments for airways diseases in preclinical models are generally invasive and terminal. In the past few years, the flexibility of magnetic resonance imaging (MRI) to obtain anatomical and functional information of the lung has been explored with the scope of developing a non-invasive approach for the routine testing of drugs in models of airways diseases in small rodents. With MRI, the disease progression can be followed in the same animal. Thus, a significant reduction in the number of animals used for experimentation is achieved, as well as minimal interference with their well-being and physiological status. In addition, under certain circumstances the duration of the observation period after disease onset can be shortened since the technique is able to detect changes before these are reflected in parameters of inflammation determined using invasive procedures. The objective of this article is to briefly address MRI techniques that are being used in experimental lung research, with special emphasis on applications. Following an introduction on proton techniques and MRI of hyperpolarized gases, the attention is shifted to the MRI analysis of several aspects of lung disease models, including inflammation, ventilation, emphysema, fibrosis and sensory nerve activation. The next subject concerns the use of MRI in pharmacological studies within the context of experimental lung research. A final discussion points towards advantages and limitations of MRI in this area.

  20. MRI of car occupants with whiplash injury

    Energy Technology Data Exchange (ETDEWEB)

    Voyvodic, F. [Dept. of Radiology, Flinders Medical Centre, Bedford Park, SA (Australia); Dolinis, J. [National Injury Surveillance Unit, Bedford Park, SA (Australia)]|[National Health and Medical Research Council Road Accident Research Unit, Univ. of Adelaide, SA (Australia); Moore, V.M. [National Health and Medical Research Council Road Accident Research Unit, Univ. of Adelaide, SA (Australia); Ryan, G.A. [National Health and Medical Research Council Road Accident Research Unit, Univ. of Adelaide, SA (Australia); Slavotinek, J.P. [Dept. of Radiology, Flinders Medical Centre, Bedford Park, SA (Australia); Whyte, A.M. [Ashford Hospital Specialist Centre, SA (Australia); Hoile, R.D. [Ashford Hospital Specialist Centre, SA (Australia); Taylor, G.W. [National Health and Medical Research Council Road Accident Research Unit, Univ. of Adelaide, SA (Australia)

    1997-01-01

    Our purpose was to document and investigate the prognostic significance of features seen on MRI of patients with whiplash injury following relatively minor road traffic crashes. MRI was obtained shortly and at 6 months after the crash using a 0.5 T imager. The images were assessed independently by two radiologists for evidence of fracture or other injury; loss of lordosis and spondylosis were also recorded. Clinical examinations were used to assess the status of patients initially and at 6 months. The results of the independent MRI and clinical investigations were then examined for association using statistical tests. Initial MRI was performed on 29 patients, of whom 19 had repeat studies at 6 months; 48 examinations were thus examined. Apart from spondylosis and loss of lordosis, only one abnormality was detected: an intramedullary lesion consistent with a small cyst or syrinx. There were no statistically significant associations between the outcome of injury and spondylosis or loss of lordosis. No significant changes were found when comparing the initial and follow-up MRI. It appears that MRI of patients with relatively less severe whiplash symptoms reveals a low frequency of abnormalities, apart from spondylosis and loss of lordosis, which have little short-term prognostic value. Routine investigation of such patients with MRI is not justified in view of the infrequency of abnormalities detected, the lack of prognostic value and the high cost of the procedure. (orig.). With 1 fig., 1 tab.

  1. Application of functional MRI in epilepsy

    Institute of Scientific and Technical Information of China (English)

    YU Ai-hong; LI Kun-cheng; PIAO Chang-fu; LI Hong-li

    2005-01-01

    Objective To review the recent development of functional MRI application in epilepsy. Data sources Both Chinese and English language literatures were researched using MEDLINE/ CD ROM (1996-2005) and the Chinese Biomedical Literature Disk (1996-2005). Study selection Published articles about functional MRI application and epilepsy were selected.Data extraction Data were mainly extracted from 38 articles which are listed in the reference section of this review.Results fMRI can be used to localize seizure foci through detecting these cerebral hemodynamic changes produced by epileptiform discharges. EEG-triggered fMRI, which has higher spatial and temporal resolution, helps to detect the spatiotemporal pattern of spike origin and propagation, and define localization of the epileptogenic focus. fMRI is also useful in language and memory cognitive function assessment and presurgical assessment of refractory epilepsy. Atypically distributed cognitive function areas can be detected by fMRI, because of cortical language and memory areas reorganization during long-term epileptic activity in patients with epilepsy. Conclusions fMRI technique plays a very important role in cognitive function and presurgical assessment of patients with epilepsy. It is meaningful for understanding pathogenesis of epilepsy.

  2. Recommendations for Real-Time Speech MRI

    Science.gov (United States)

    Lingala, Sajan Goud; Sutton, Brad P.; Miquel, Marc E.; Nayak, Krishna S.

    2016-01-01

    Real-time magnetic resonance imaging (RT-MRI) is being increasingly used for speech and vocal production research studies. Several imaging protocols have emerged based on advances in RT-MRI acquisition, reconstruction, and audio-processing methods. This review summarizes the state-of-the-art, discusses technical considerations, and provides specific guidance for new groups entering this field. We provide recommendations for performing RT-MRI of the upper airway. This is a consensus statement stemming from the ISMRM-endorsed Speech MRI summit held in Los Angeles, February 2014. A major unmet need identified at the summit was the need for consensus on protocols that can be easily adapted by researchers equipped with conventional MRI systems. To this end, we provide a discussion of tradeoffs in RT-MRI in terms of acquisition requirements, a priori assumptions, artifacts, computational load, and performance for different speech tasks. We provide four recommended protocols and identify appropriate acquisition and reconstruction tools. We list pointers to open-source software that facilitate implementation. We conclude by discussing current open challenges in the methodological aspects of RT-MRI of speech. PMID:26174802

  3. MRI of anterior cruciate ligament autografts

    Energy Technology Data Exchange (ETDEWEB)

    Ogi, Shigeyuki; Ariizumi, Mitsuko; Yamagishi, Tsuneo [The Aoyama Tokyo Metropolitan office' s Hospital (Japan); Agata, Toshihiko; Tada, Shinpei; Fukuda, Kunihiko

    2000-09-01

    The purpose of this study was to assess the usefulness of MRI in the evaluation of autografts after anterior cruciate ligament reconstruction. The subjects were 110 patients with anterior cruciate ligament reconstruction using patellar tendon autografts who underwent clinical examination, MRI, and arthroscopy of the knee. T1- and T2-weighted MR images were obtained in sagittal plane. Clinical findings were categorized into three groups: normal, borderline, and abnormal. The MRI appearances of the autografts were categorized into three types: straight continuous band (type I), interrupted band (type II) and generalized increased intensity band (type III). The clinical findings and MRI findings were compared with arthroscopic findings. Ninety-six percent of the type I showed no autograft tear on arthroscopy. In comparison with the clinical findings, MRI was found to be well correlated with arthroscopic findings. In conclusion, if the clinical findings are normal, patients are to be followed-up without MRI and arthroscopy. However, if clinical findings are either borderline or abnormal, MRI should be performed prior to arthroscopy. (author)

  4. MRI findings in acute Hendra virus meningoencephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Nakka, P.; Amos, G.J. [Department of Diagnostic Radiology, Princess Alexandra Hospital, Woolloongabba, Qld 4102 (Australia); Saad, N., E-mail: nivena100@hotmail.com [Department of Diagnostic Radiology, Princess Alexandra Hospital, Woolloongabba, Qld 4102 (Australia); Jeavons, S. [Department of Diagnostic Radiology, Princess Alexandra Hospital, Woolloongabba, Qld 4102 (Australia)

    2012-05-15

    Aim: To describe serial changes in brain magnetic resonance imaging (MRI) in acute human infection from two outbreaks of Hendra virus (HeV), relate these changes to disease prognosis, and compare HeV encephalitis to reported cases of Nipah virus encephalitis. Materials and methods: The MRI images of three human cases (two of which were fatal) of acute HeV meningoencephalitis were reviewed. Results: Cortical selectivity early in the disease is evident in all three patients, while deep white matter involvement appears to be a late and possibly premorbid finding. This apparent early grey matter selectivity may be related to viral biology or ribavirin pharmacokinetics. Neuronal loss is evident at MRI, and the rate of progression of MRI abnormalities can predict the outcome of the infection. In both fatal cases, the serial changes in the MRI picture mirrored the clinical course. Conclusion: This is the first comprehensive report of serial MRI findings in acute human cerebral HeV infection from two outbreaks. The cortical selectivity appears to be an early finding while deep white matter involvement a late, and possibly premorbid, finding. In both fatal cases, the serial changes in MRI mirrored the clinical course.

  5. 6{sup th} interventional MRI symposium. Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The ongoing progress in the field of interventional MRI and the great success of our last symposium 2004 in Boston have stimulated us to organize the 6th Interventional MRI Symposium to be held September 15-16, 2006 in Leipzig. This meeting will highlight ground-breaking research as well as cutting-edge reports from many groups. The symposium also provides a forum to network with leaders and innovators in the field. Session topics are: intraoperative MRI, vascular applications, targeted drug delivery, cryotherapy, thermometry, pulse sequences, LITT, percutaneous procedures, navigation, robotics, focused ultrasound. (uke)

  6. Developments in boron magnetic resonance imaging (MRI)

    Energy Technology Data Exchange (ETDEWEB)

    Schweizer, M.

    1995-11-01

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

  7. Late Adverse Events after Enhanced and Unenhanced MRI and CT

    DEFF Research Database (Denmark)

    Azzouz, Manal; Rømsing, Janne; Thomsen, Henrik S.

    2014-01-01

    of LAEs was significantly higher in the enhanced MRI (38%) and CT (27%) groups than unenhanced MRI (20%) and CT (16%) groups. The frequency of nausea, dizziness, abdominal pain and diarrhoea was significantly higher in the enhanced MRI group than in the MRI control group, while taste sensation...

  8. Design of dendrimer-based drug delivery nanodevices with enhanced therapeutic efficacies

    Science.gov (United States)

    Kannan, Rangaramanujam

    2007-03-01

    Dendrimers and hyperbranched polymers possess highly branched architectures, with a large number of controllable, tailorable, `peripheral' functionalities. Since the surface chemistry of these materials can be modified with relative ease, these materials have tremendous potential in targeted drug delivery. They have significant potential compared to liposomes and nanoparticles, because of the reduced macrophage update, increased cellular transport, and the ability to modulate the local environment through functional groups. We are developing nanodevices based on dendritic systems for drug delivery, that contain a high drug payload, ligands, and imaging agents, resulting in `smart' drug delivery devices that can target, deliver, and signal. In collaboration with the Children's Hospital of Michigan, Karmanos Cancer Institute, and College of Pharmacy, we are testing the in vitro and in vivo response of these nanodevices, by adapting the chemistry for specific clinical applications such as asthma and cancer. These materials are characterized by UV/Vis spectroscopy, flow cytometry, fluorescence/confocal microscopy, and appropriate animal models. Our results suggest that: (1) We can prepare drug-dendrimer conjugates with drug payloads of greater than 50%, for a variety of drugs; (2) The dendritic polymers are capable of transporting and delivering drugs into cells faster than free drugs, with superior therapeutic efficiency. This can be modulated by the surface functionality of the dendrimer; (3) For chemotherapy drugs, the conjugates are a factor of 6-20 times more effective even in drug-resistant cell lines; (4) For corticosteroidal drugs, the dendritic polymers provide higher drug residence times in the lung, allowing for passive targeting. The ability of the drug-dendrimer-ligand conjugates to target specific asthma and cancer cells is currently being explored using in vitro and in vivo animal models.

  9. Dendrimer-Based Selective Proteostasis-Inhibition Strategy to Control NSCLC Growth and Progression

    Science.gov (United States)

    Walworth, Kyla; Bodas, Manish; Campbell, Ryan John; Swanson, Doug; Sharma, Ajit; Vij, Neeraj

    2016-01-01

    Elevated valosin containing protein (VCP/p97) levels promote the progression of non-small cell lung carcinoma (NSCLC). Although many VCP inhibitors are available, most of these therapeutic compounds have low specificity for targeted tumor cell delivery. Hence, the primary aim of this study was to evaluate the in vitro efficacy of dendrimer-encapsulated potent VCP-inhibitor drug in controlling non-small cell lung carcinoma (NSCLC) progression. The VCP inhibitor(s) (either in their pure form or encapsulated in generation-4 PAMAM-dendrimer with hydroxyl surface) were tested for their in vitro efficacy in modulating H1299 (NSCLC cells) proliferation, migration, invasion, apoptosis and cell cycle progression. Our results show that VCP inhibition by DBeQ was significantly more potent than NMS-873 as evident by decreased cell proliferation (p<0.0001, MTT-assay) and migration (p<0.05; scratch-assay), and increased apoptosis (p<0.05; caspase-3/7-assay) as compared to untreated control cells. Next, we found that dendrimer-encapsulated DBeQ (DDNDBeQ) treatment increased ubiquitinated-protein accumulation in soluble protein-fraction (immunoblotting) of H1299 cells as compared to DDN-control, implying the effectiveness of DBeQ in proteostasis-inhibition. We verified by immunostaining that DDNDBeQ treatment increases accumulation of ubiquitinated-proteins that co-localizes with an ER-marker, KDEL. We observed that proteostasis-inhibition with DDNDBeQ, significantly decreased cell migration rate (scratch-assay and transwell-invasion) as compared to the control-DDN treatment (p<0.05). Moreover, DDNDBeQ treatment showed a significant decrease in cell proliferation (p<0.01, MTT-assay) and increased caspase-3/7 mediated apoptotic cell death (p<0.05) as compared to DDN-control. This was further verified by cell cycle analysis (propidium-iodide-staining) that demonstrated significant cell cycle arrest in the G2/M-phase (p<0.001) by DDNDBeQ treatment as compared to control-DDN. Moreover, we confirmed by clonogenic-assay that DDNDBeQ treatment significantly (p<0.001) inhibits H1299 colony-formation as compared to control/DDN. Overall, encapsulation of potent VCP-inhibitor DBeQ into a dendrimer allows selective VCP-mediated proteostasis-inhibition for controlling NSCLC-tumor growth and progression to allow tumor-targeted sustained drug delivery. PMID:27434122

  10. Polyamidoamine dendrimer-based binders for high-loading lithium–sulfur battery cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Priyanka; Nandasiri, Manjula I.; Lv, Dongping; Schwarz, Ashleigh M.; Darsell, Jens T.; Henderson, Wesley A.; Tomalia, Donald A.; Liu, Jun; Zhang, Ji-Guang; Xiao, Jie

    2016-01-01

    Lithium-sulfur (Li-S) batteries are regarded as one of the most promising candidates for next generation energy storage systems because of their ultra high theoretical specific energy. To realize the practical application of Li-S batteries, however, a high S active material loading is essential (>70 wt% in the carbon-sulfur (C-S) composite cathode and >2 mg cm-2 in the electrode). A critical challenge to achieving this high capacity in practical electrodes is the dissolution of the longer lithium polysulfide reaction intermediates in the electrolyte (resulting in loss of active material from the cathode and contamination of the anode due to the polysulfide shuttle mechanism). The binder material used for the cathode is therefore crucial as this is a key determinant of the bonding interactions between the active material (S) and electronic conducting support (C), as well as the maintenance of intimate contact between the electrode materials and current collector. The battery performance can thus be directly correlated with the choice of binder, but this has received only minimal attention in the relevant Li-S battery published literature. Here, we investigated the application of polyamidoamine (PAMAM) dendrimers as functional binders in Li-S batteries—a class of materials which has been unexplored for electrode design. By using dendrimers, it is demonstrated that high S loadings (>4 mg cm-2) can be easily achieved using "standard" (not specifically tailored) materials and simple processing methods. An exceptional electrochemical cycling performance was obtained (as compared to cathodes with conventional linear polymeric binders such as carboxymethyl cellulose (CMC) and styrene-butadiene rubber (SBR)) with >100 cycles and 85-98% capacity retention, thus demonstrating the significant utility of this new binder architecture which exhibits critical physicochemical properties and flexible nanoscale design parameters (CNDP's).

  11. Design, synthesis, characterization and drug release kinetics of PAMAM dendrimer based drug formulations

    Science.gov (United States)

    Kurtoglu, Yunus Emre

    The drug release characteristics of G4-polyamidoamine (PAMAM) dendrimer-ibuprofen conjugates with ester, amide, and peptide linkers were investigated, in addition to a linear PEG-ibuprofen conjugate to understand the effect of architecture and linker on drug release. Ibuprofen was directly conjugated to NH2 -terminated dendrimer by an amide bond and OH-terminated dendrimer by an ester bond. A tetra-peptide linked dendrimer conjugate and a linear mPEG-ibuprofen conjugate were also studied for comparison to direct linked dendrimer conjugates. It is demonstrated that the 3-D nanoscale architecture of PAMAM dendrimer-drug conjugates, along with linking chemistry govern the drug release mechanisms as well as kinetics. Understanding these structural effects on their drug release characteristics is crucial for design of dendrimer conjugates with high efficacy such as poly(amidoamine) dendrimer-N-Acetylcysteine conjugates with disulfide linkages. N-Acetylcysteine (NAC) is an anti-inflammatory agent with significant potential for clinical use in the treatment of neuroinflammation, stroke and cerebral palsy. A poly(amidoamine) dendrimer-NAC conjugate that contains a disulfide linkage was synthesized and evaluated for its release kinetics in the presence of glutathione (GSH), Cysteine (Cys), and bovine serum albumin (BSA) at both physiological and lysosomal pH. FITC-labeled conjugates showed that they enter cells rapidly and localize in the cytoplasm of lipopolysaccharide (LPS)-activated microglial cells. The efficacy of the dendrimer-NAC conjugate was measured in activated microglial cells using reactive oxygen species (ROS) assays. The conjugates showed an order of magnitude increase in anti-oxidant activity compared to free drug. When combined with intrinsic and ligand-based targeting with dendrimers, these types of GSH sensitive nanodevices can lead to improved drug release profiles and in vivo efficacy.

  12. Experimental and theoretical investigations in stimuli responsive dendrimer-based assemblies

    Science.gov (United States)

    Molla, Mijanur Rahaman; Rangadurai, Poornima; Pavan, Giovanni M.; Thayumanavan, S.

    2015-02-01

    Stimuli-responsive macromolecular assemblies are of great interest in drug delivery applications, as it holds the promise to keep the drug molecules sequestered under one set of conditions and release them under another. The former set of conditions could represent circulation, while the latter could represent a disease location. Over the past two decades, sizeable contributions to this field have come from dendrimers, which along with their monodispersity, provide great scope for structural modifications at the molecular level. In this paper, we briefly discuss the various synthetic strategies that have been developed so far to obtain a range of functional dendrimers. We then discuss the design strategies utilized to introduce stimuli responsive elements within the dendritic architecture. The stimuli itself are broadly classified into two categories, viz. extrinsic and intrinsic. Extrinsic stimuli are externally induced such as temperature and light variations, while intrinsic stimuli involve physiological aberrations such as variations in pH, redox conditions, proteins and enzyme concentrations in pathological tissues. Furthermore, the unique support from molecular dynamics (MD) simulations has been highlighted. MD simulations have helped back many of the observations made from assembly formation properties to rationalized the mechanism of drug release and this has been illustrated with discussions on G4 PPI (Poly propylene imine) dendrimers and biaryl facially amphiphilic dendrimers. The synergy that exists between experimental and theoretical studies open new avenues for the use of dendrimers as versatile drug delivery systems.

  13. Dendrimer-Based Selective Proteostasis-Inhibition Strategy to Control NSCLC Growth and Progression.

    Directory of Open Access Journals (Sweden)

    Kyla Walworth

    Full Text Available Elevated valosin containing protein (VCP/p97 levels promote the progression of non-small cell lung carcinoma (NSCLC. Although many VCP inhibitors are available, most of these therapeutic compounds have low specificity for targeted tumor cell delivery. Hence, the primary aim of this study was to evaluate the in vitro efficacy of dendrimer-encapsulated potent VCP-inhibitor drug in controlling non-small cell lung carcinoma (NSCLC progression. The VCP inhibitor(s (either in their pure form or encapsulated in generation-4 PAMAM-dendrimer with hydroxyl surface were tested for their in vitro efficacy in modulating H1299 (NSCLC cells proliferation, migration, invasion, apoptosis and cell cycle progression. Our results show that VCP inhibition by DBeQ was significantly more potent than NMS-873 as evident by decreased cell proliferation (p<0.0001, MTT-assay and migration (p<0.05; scratch-assay, and increased apoptosis (p<0.05; caspase-3/7-assay as compared to untreated control cells. Next, we found that dendrimer-encapsulated DBeQ (DDNDBeQ treatment increased ubiquitinated-protein accumulation in soluble protein-fraction (immunoblotting of H1299 cells as compared to DDN-control, implying the effectiveness of DBeQ in proteostasis-inhibition. We verified by immunostaining that DDNDBeQ treatment increases accumulation of ubiquitinated-proteins that co-localizes with an ER-marker, KDEL. We observed that proteostasis-inhibition with DDNDBeQ, significantly decreased cell migration rate (scratch-assay and transwell-invasion as compared to the control-DDN treatment (p<0.05. Moreover, DDNDBeQ treatment showed a significant decrease in cell proliferation (p<0.01, MTT-assay and increased caspase-3/7 mediated apoptotic cell death (p<0.05 as compared to DDN-control. This was further verified by cell cycle analysis (propidium-iodide-staining that demonstrated significant cell cycle arrest in the G2/M-phase (p<0.001 by DDNDBeQ treatment as compared to control-DDN. Moreover, we confirmed by clonogenic-assay that DDNDBeQ treatment significantly (p<0.001 inhibits H1299 colony-formation as compared to control/DDN. Overall, encapsulation of potent VCP-inhibitor DBeQ into a dendrimer allows selective VCP-mediated proteostasis-inhibition for controlling NSCLC-tumor growth and progression to allow tumor-targeted sustained drug delivery.

  14. Nanoparticulate platinum films on gold using dendrimer-based wet chemical method

    Indian Academy of Sciences (India)

    S Raghu; Sheela Berchmans; K L N Phani; V Yegnaraman

    2005-11-01

    There is a growing interest in devising wet chemical alternatives for physical deposition methods for applications involving thin films, e.g., catalysis. Deposition of platinum on thin gold films is often a problem leading to incomplete coverage and improper adhesion to solid surfaces. Gold substrates often need pre-activation for achieving complete coverage. We demonstrate here that dendrimers with proper functionalities and size work as well-defined nucleating agents and adhesion promoters. This feature is demonstrated using an amine-terminated dendrimer of generation 4.0. This approach allows one to obtain adherent nanoparticulate films of platinum on gold. Unlike other nucleating agents and adhesion promoting compounds, dendrimers have a well-defined ordered structure in terms of their space filling ability. The stability of the films obtained with adsorbed dendrimers is emonstrated using the electrocatalytic reactions of fuels like methanol. The films formed without dendrimers cannot sustain the electro-oxidation currents due to the instability of the films while the films formed with dendrimers can sustain currents for longer duration and for several cycles. The dendrimer-derived Pt films exhibit higher catalytic activity compared to other methods.

  15. Development and validation of an MRI reference criterion for defining a positive SIJ MRI in spondyloarthritis

    DEFF Research Database (Denmark)

    Weber, Ulrich; Zubler, Veronika; Pedersen, Susanne J

    2012-01-01

    OBJECTIVE: To validate an MRI reference criterion for a positive SIJ MRI based on the level of confidence in classification of spondyloarthritis (SpA) by expert MRI readers. METHODS: Four readers assessed SIJ MRI in two inception cohorts (A/B) of 157 consecutive back pain patients ≤50 years...... (0=definitely not; 10=definite). The MRI reference criterion was pre-specified as the majority of readers recording a confidence of 8-10; absence of SpA required all readers to record Non-SpA (confidence 0-4). We calculated inter-reader reliability and agreement between MRI-based and clinical...... classification using kappa statistics. We estimated cut-off values for MRI lesions attaining specificity `0.90 for SpA. RESULTS: 76.4%/71.6% of subjects in cohorts A/B met the MRI criterion. Kappa values for inter-reader agreement were 0.76/0.80, and between MRI-based and clinical assessment 0.93/0.57. Using...

  16. Diagnosis of Chiari III malformation by second trimester fetal MRI with postnatal MRI and CT correlation

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Alice B.; Glenn, Orit A. [University of California, San Francisco, Department of Radiology, San Francisco, CA (United States); Gupta, Nalin [University of California, San Francisco, Department of Neurosurgery, San Francisco, CA (United States); Otto, Carl [California Pacific Medical Center, Department of Perinatology, San Francisco, CA (United States)

    2007-10-15

    We report a case of Chiari III malformation diagnosed by fetal MRI. Ultrasound (US) performed at a gestational age of 18 weeks demonstrated a posterior skull base cyst. Repeat US at 19 weeks demonstrated neural tissue in the cyst, consistent with an encephalocele. MR imaging at 23 weeks confirmed the presence of an occipital encephalocele, demonstrated additional bony defect in the upper cervical spine, and identified abnormal morphology and position of the brainstem consistent with the diagnosis of Chiari III. Postnatal MRI and CT confirmed the fetal MRI findings and demonstrate the utility of fetal MRI in the early evaluation of songraphically detected posterior fossa abnormalities. (orig.)

  17. Superresolution improves MRI cortical segmentation with FACE

    DEFF Research Database (Denmark)

    Eskildsen, Simon Fristed; Manjón, José V.; Coupé, Pierrick

    Brain cortical surface extraction from MRI has applications for measurement of gray matter (GM) atrophy, functional mapping, source localization and preoperative neurosurgical planning. Accurate cortex segmentation requires high resolution morphological images and several methods for extracting...

  18. PET/MRI in cancer patients

    DEFF Research Database (Denmark)

    Kjær, Andreas; Loft, Annika; Law, Ian

    2013-01-01

    described include brain tumors, pediatric oncology as well as lung, abdominal and pelvic cancer. In general the cases show that PET/MRI performs well in all these types of cancer when compared to PET/CT. However, future large-scale clinical studies are needed to establish when to use PET/MRI. We envision...... Medicine & PET at Rigshospitalet in Copenhagen we installed an integrated PET/MRI in December 2011. Here, we describe our first clinical PET/MR cases and discuss some of the areas within oncology where we envision promising future application of integrated PET/MR imaging in clinical routine. Cases...... that PET/MRI in oncology will prove to become a valuable addition to PET/CT in diagnosing, tailoring and monitoring cancer therapy in selected patient populations....

  19. 2015 MICCAI Workshop on Computational Diffusion MRI

    CERN Document Server

    Ghosh, Aurobrata; Kaden, Enrico; Rathi, Yogesh; Reisert, Marco

    2016-01-01

    These Proceedings of the 2015 MICCAI Workshop “Computational Diffusion MRI” offer a snapshot of the current state of the art on a broad range of topics within the highly active and growing field of diffusion MRI. The topics vary from fundamental theoretical work on mathematical modeling, to the development and evaluation of robust algorithms, new computational methods applied to diffusion magnetic resonance imaging data, and applications in neuroscientific studies and clinical practice. Over the last decade interest in diffusion MRI has exploded. The technique provides unique insights into the microstructure of living tissue and enables in-vivo connectivity mapping of the brain. Computational techniques are key to the continued success and development of diffusion MRI and to its widespread transfer into clinical practice. New processing methods are essential for addressing issues at each stage of the diffusion MRI pipeline: acquisition, reconstruction, modeling and model fitting, image processing, fiber t...

  20. PET/MRI in cancer patients

    DEFF Research Database (Denmark)

    Kjær, Andreas; Loft, Annika; Law, Ian

    2013-01-01

    Combined PET/MRI systems are now commercially available and are expected to change the medical imaging field by providing combined anato-metabolic image information. We believe this will be of particular relevance in imaging of cancer patients. At the Department of Clinical Physiology, Nuclear...... described include brain tumors, pediatric oncology as well as lung, abdominal and pelvic cancer. In general the cases show that PET/MRI performs well in all these types of cancer when compared to PET/CT. However, future large-scale clinical studies are needed to establish when to use PET/MRI. We envision...... that PET/MRI in oncology will prove to become a valuable addition to PET/CT in diagnosing, tailoring and monitoring cancer therapy in selected patient populations....

  1. MRI findings of Guillain-Barre syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Park, Won Kyu; Lee, Hwa Jin; Byun, Woo Mok [Yeungnam Univ. College of Medicine, Taegu (Korea, Republic of)

    1997-04-01

    To evaluate MRI findings of Guillain-Barre syndrome. In six patients with Guillain-Barre syndrome diagnosed by clinical, cerebrospinal fluid and electrophysiologic findings, a retrospective review of MR findings was conducted. Follow-up MRI scans were carried out in two patients showing minimal clinical improvement. Marked or moderate enhancement of thickened nerve roots was seen in all cases on gadopentetate dimeglumine enhanced axial T1-weighted images. Two patterns were seen; one was even enhancement of both anterior and posterior nerve roots (n=1) and the other was enhancement of anterior nerve roots only (n=5). Enhancement and thickness of nerve roots was seen to have slightly decreased on MRI follow-up at 32 and 50 days; clinical and electrophysiologic examination showed minimal improvement. Although MRI findings of nerve root enhancement are nonspecific and can be seen in neoplastic and other inflammatory diseases, the enhancement of thickened anterior nerve roots within the cal sac suggests Guillain-Barre syndrome.

  2. MRI Reporter Genes for Noninvasive Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Caixia Yang

    2016-05-01

    Full Text Available Magnetic resonance imaging (MRI is one of the most important imaging technologies used in clinical diagnosis. Reporter genes for MRI can be applied to accurately track the delivery of cell in cell therapy, evaluate the therapy effect of gene delivery, and monitor tissue/cell-specific microenvironments. Commonly used reporter genes for MRI usually include genes encoding the enzyme (e.g., tyrosinase and β-galactosidase, the receptor on the cells (e.g., transferrin receptor, and endogenous reporter genes (e.g., ferritin reporter gene. However, low sensitivity limits the application of MRI and reporter gene-based multimodal imaging strategies are common including optical imaging and radionuclide imaging. These can significantly improve diagnostic efficiency and accelerate the development of new therapies.

  3. MRI Helps Assess Fetal Brain Abnormalities

    Science.gov (United States)

    ... authors. The study was published Dec. 14 in The Lancet . "Adding an MRI scan when a problem is ... practice as soon as possible, he said. SOURCE: The Lancet , news release, Dec. 14, 2016 HealthDay Copyright (c) ...

  4. MRI manifestations of enlarged superior ophthalmic vein

    Institute of Scientific and Technical Information of China (English)

    WEI Rui-li; MA Xiao-ye; CAI Ji-ping; ZHU Huang

    2002-01-01

    Objective:To assess MRI in the evaluation of enlarged superior ophthalmic vein (SOV). Methods: MRI manifestations and etiology of forty-six patients with enlarged SOV were analyzed. Results: SOV enlargement was noted to occur in carotid-cavernous fistula, ophthalmic Graves'disease, Tolosa-Hunt syndrome, inflammation at the apex of the orbit, orbital pseudotumor and thrombosis of cavernous sinus. The dilated vein appeared as signal void tubular shadows on both T1 and T2 weighted images. The diameter of the enlarged vein was 3.5-6.0 mm. Extraocular muscle enlargement, orbital pathologies, enlarged carotid cavernous sinus etc were also revealed by MRI. Conclusion: The dilated SOV may be well demonstrated by MRI. The etiological diagnosis of enlarged SOV can be made in combination with the associated findings.

  5. MRI finding of ethylmalonic encephalopathy: case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Yong; Lee, Shi Kyung; Han, Chun Hwan; Rho, Eun Jin [Kangnam General Hospital Public Corporation, Seoul (Korea, Republic of)

    2002-12-01

    Ethylmalonic encephalopathy is a rare syndrom characterized by developmental delay, acrocyanosis, petechiae, chronic diarrhea, and ethylmalonic, lactic, and methylsuccinic aciduria. We report the MRI finding of ethylmalonic encephalopathy including previously unreported intracranial hematoma.

  6. Magnetic Resonance, Functional (fMRI) -- Brain

    Science.gov (United States)

    ... their nature and the strength of the MRI magnet. Many implanted devices will have a pamphlet explaining ... large cylinder-shaped tube surrounded by a circular magnet. You will lie on a moveable examination table ...

  7. Multichannel Compressive Sensing MRI Using Noiselet Encoding

    CERN Document Server

    Pawar, Kamlesh; Zhang, Jingxin

    2014-01-01

    The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP) of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS). In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI, and presents a method to design the pulse sequence for the noiselet encoding. This novel encoding scheme is combined with the multichannel compressive sensing (MCS) framework to take the advantage of multichannel data acquisition used in MRI scanners. An empirical RIP a...

  8. MRI findings of mucocele in the sinuses

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, Toshio; Hori, Yoshiro; Kumazawa, Tadachika; Kato, Tsutomu; Tanaka, Yoshimasa; Yamauchi, Yasuo; Matsumura, Hiroshi (Kansai Medical School, Moriguchi, Osaka (Japan))

    1989-07-01

    Eight patients with pyocele or mucocele in the frontal, ethmoidal and sphenoidal sinuses were examined with magnetic resonance imaging (MRI) and the results were compared with conventional tomography and CT results. CT is a useful tool in detecting mucocele in the sinuses, however, it has limitation of evaluating the qualitative and solid structural changes. MRI is able to show the entire feature of cysts with multidirectional imaging, and the extent of the cysts especially to the orbit and skull base could be identified three-dimensionally. Long spin echo (SE) image showed a higher signal intensity than short SE image in all cases and it was possible to diagnose the content of the cysts and to differetiate between cyst and tumor. Bone destruction could not be visualized by MRI, therefore, CT should be used in combination with MRI in selected cases. (author).

  9. Utility of functional MRI in pediatric neurology.

    Science.gov (United States)

    Freilich, Emily R; Gaillard, William D

    2010-01-01

    Functional MRI (fMRI), a tool increasingly used to study cognitive function, is also an important tool for understanding not only normal development in healthy children, but also abnormal development, as seen in children with epilepsy, attention-deficit/hyperactivity disorder, and autism. Since its inception almost 15 years ago, fMRI has seen an explosion in its use and applications in the adult literature. However, only recently has it found a home in pediatric neurology. New adaptations in study design and technologic advances, especially the study of resting state functional connectivity as well as the use of passive task design in sedated children, have increased the utility of functional imaging in pediatrics to help us gain understanding into the developing brain at work. This article reviews the background of fMRI in pediatrics and highlights the most recent literature and clinical applications.

  10. PET/MRI in cancer patients

    DEFF Research Database (Denmark)

    Kjær, Andreas; Loft, Annika; Law, Ian

    2013-01-01

    Combined PET/MRI systems are now commercially available and are expected to change the medical imaging field by providing combined anato-metabolic image information. We believe this will be of particular relevance in imaging of cancer patients. At the Department of Clinical Physiology, Nuclear...... described include brain tumors, pediatric oncology as well as lung, abdominal and pelvic cancer. In general the cases show that PET/MRI performs well in all these types of cancer when compared to PET/CT. However, future large-scale clinical studies are needed to establish when to use PET/MRI. We envision...... that PET/MRI in oncology will prove to become a valuable addition to PET/CT in diagnosing, tailoring and monitoring cancer therapy in selected patient populations....

  11. Brain MRI Findings in Congenital Muscular Dystrophy

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2006-03-01

    Full Text Available Brain magnetic resonance imaging (MRI findings in 13 patients with congenital muscular dystrophy (MDCIC and Fukutin-related protein (FKRP gene mutations were retrospectively reviewed in a study at Hammersmith Hospital, London, UK, and European centers.

  12. On clustering fMRI time series

    DEFF Research Database (Denmark)

    Goutte, C; Toft, P; Rostrup, E

    1999-01-01

    Analysis of fMRI time series is often performed by extracting one or more parameters for the individual voxels. Methods based, e.g., on various statistical tests are then used to yield parameters corresponding to probability of activation or activation strength. However, these methods do not indi......Analysis of fMRI time series is often performed by extracting one or more parameters for the individual voxels. Methods based, e.g., on various statistical tests are then used to yield parameters corresponding to probability of activation or activation strength. However, these methods do...... between the activation stimulus and the fMRI signal. We present two different clustering algorithms and use them to identify regions of similar activations in an fMRI experiment involving a visual stimulus....

  13. MRI of the Body (Chest, Abdomen, Pelvis)

    Science.gov (United States)

    ... receive injections of gadolinium contrast material except when absolutely necessary for medical treatment. See the Safety page ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ...

  14. Can unenhanced multiparametric MRI substitute gadolinium-enhanced MRI in the characterization of vertebral marrow infiltrative lesions?

    Directory of Open Access Journals (Sweden)

    Dalia Z. Zidan

    2014-06-01

    Conclusion: Unenhanced-multiparametric MRI is compatible with gadolinium-enhanced MRI in reliable characterization of marrow infiltrative lesions. The routine MRI protocol of cancer patients should be altered to accommodate the evolving MRI technology and cost effectively substitute the need for a gadolinium enhanced scan.

  15. Infantile Refsum disease: serial evaluation with MRI.

    Science.gov (United States)

    Cakirer, Sinan; Savas, Mahmut R

    2005-02-01

    Refsum disease is a rare metabolic disorder, which is characterized by the accumulation of phytanic acid in the blood and tissues, including the brain. A variant of this condition that occurs in young children is called infantile Refsum disease. The MRI findings of symmetrical signal change involving the corticospinal tracts, cerebellar dentate nuclei, and corpus callosum are characteristic. We report the serial MRI findings of a child with this rare metabolic disorder.

  16. Infantile Refsum disease: serial evaluation with MRI

    Energy Technology Data Exchange (ETDEWEB)

    Cakirer, Sinan; Savas, Mahmut R. [Sisli Etfal Hospital, Neuroradiology Section, Department of Radiology, Istanbul (Turkey)

    2005-02-01

    Refsum disease is a rare metabolic disorder, which is characterized by the accumulation of phytanic acid in the blood and tissues, including the brain. A variant of this condition that occurs in young children is called infantile Refsum disease. The MRI findings of symmetrical signal change involving the corticospinal tracts, cerebellar dentate nuclei, and corpus callosum are characteristic. We report the serial MRI findings of a child with this rare metabolic disorder. (orig.)

  17. POEMS syndrome: radiographic appearance with MRI correlation

    Energy Technology Data Exchange (ETDEWEB)

    Chong, Suzanne T. [Western Pennsylvania Hospital, Department of Diagnostic Radiology, Pittsburgh, Pennsylvania (United States); University of Michigan, Department of Radiology, Ann Arbor, MI (United States); Beasley, H.S. [Western Pennsylvania Hospital, Department of Diagnostic Radiology, Pittsburgh, Pennsylvania (United States); Daffner, Richard H. [Allegheny General Hospital, Department of Diagnostic Radiology, Section of Musculoskeletal/Trauma Radiology, Pittsburgh, Pennsylvania (United States)

    2006-09-15

    POEMS syndrome is a rare disorder in which patients present with the hallmark signs of polyneuropathy, organomegaly, endocrinopathy, M protein and skin changes. Many other clinical findings are also often present, most notably osseous lesions. The MRI appearance of the bony lesions in POEMS syndrome has been described in five cases, four of which are in the non-English literature. We report the MRI appearance of the osseous lesions in a patient with POEMS syndrome who presented with sciatic neuropathy. (orig.)

  18. Quantitative Cerebral Blood Flow Measurements Using MRI

    OpenAIRE

    Muir, Eric R; Watts, Lora Talley; Tiwari, Yash Vardhan; Bresnen, Andrew; Timothy Q Duong

    2014-01-01

    Magnetic resonance imaging utilized as a quantitative and noninvasive method to image cerebral blood flow. The two most common techniques used to detect cerebral blood flow are dynamic susceptibility contrast (DSC) perfusion MRI and arterial spin labeling perfusion MRI. Herein we describe the use of these two techniques to measure cerebral blood flow in rodents, including methods, analysis, and important considerations when utilizing these techniques.

  19. MRI Brain Tumor Segmentation Methods- A Review

    OpenAIRE

    Gursangeet, Kaur; Jyoti, Rani

    2016-01-01

    Medical image processing and its segmentation is an active and interesting area for  researchers. It has reached at the tremendous place in diagnosing tumors after the discovery of CT and MRI. MRI is an useful tool to detect the brain tumor and segmentation is performed to carry out the useful portion from an image. The purpose of this paper is to provide an overview of different image segmentation methods like watershed algorithm, morphological operations, neutrosophic sets, thresholding, K-...

  20. Pharmacological fMRI; a clinical exploration

    OpenAIRE

    Goekoop, R.

    2006-01-01

    Dit proefschrift beschrijft de resultaten van een verkennend onderzoek naar een nieuwe techniek die gebruikt kan worden om de effecten van geneesmiddelen op hersenaktiviteit af te beelden: pharmacologische functionele magnetic resonance imaging (farmacologische fMRI of phMRI). Met behulp van deze techniek werden de effecten onderzocht van drie verschillende medicijnen (de bètablokker propranolol, de selectieve oestrogeen-receptor modulator (SERM) raloxifene en de cholinesteraseremmer galantam...

  1. MRI and MRS of human brain tumors.

    Science.gov (United States)

    Hou, Bob L; Hu, Jiani

    2009-01-01

    The purpose of this chapter is to provide an introduction to magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) of human brain tumors, including the primary applications and basic terminology involved. Readers who wish to know more about this broad subject should seek out the referenced books (1. Tofts (2003) Quantitative MRI of the brain. Measuring changes caused by disease. Wiley; Bradley and Stark (1999) 2. Magnetic resonance imaging, 3rd Edition. Mosby Inc; Brown and Semelka (2003) 3. MRI basic principles and applications, 3rd Edition. Wiley-Liss) or reviews (4. Top Magn Reson Imaging 17:127-36, 2006; 5. JMRI 24:709-724, 2006; 6. Am J Neuroradiol 27:1404-1411, 2006).MRI is the most popular means of diagnosing human brain tumors. The inherent difference in the magnetic resonance (MR) properties of water between normal tissues and tumors results in contrast differences on the image that provide the basis for distinguishing tumors from normal tissues. In contrast to MRI, which provides spatial maps or images using water signals of the tissues, proton MRS detects signals of tissue metabolites. MRS can complement MRI because the observed MRS peaks can be linked to inherent differences in biochemical profiles between normal tissues and tumors.The goal of MRI and MRS is to characterize brain tumors, including tumor core, edge, edema, volume, types, and grade. The commonly used brain tumor MRI protocol includes T2-weighted images and T1-weighted images taken both before and after the injection of a contrast agent (typically gadolinium: Gd). The commonly used MRS technique is either point-resolved spectroscopy (PRESS) or stimulated echo acquisition mode (STEAM).

  2. PET/MRI. Methodology and clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Carrio, Ignasi [Autonomous Univ. of Barcelona, Hospital Sant Pau (Spain). Dept. Medicina Nuclear; Ros, Pablo (ed.) [Univ. Hospitals Case, Medical Center, Cleveland, OH (United States). Dept. of Radiology

    2014-04-01

    Provides detailed information on the methodology and equipment of MRI-PET. Covers a wide range of clinical applications in oncology, cardiology, and neurology. Written by an international group of experts in MRI and PET. PET/MRI is an exciting novel diagnostic imaging modality that combines the precise anatomic and physiologic information provided by magnetic resonance imaging (MRI) with the molecular data obtained with positron emission tomography (PET). PET/MRI offers the promise of a simplified work flow, reduced radiation, whole-body imaging with superior soft tissue contrast, and time of flight physiologic information. It has been described as the pathway to molecular imaging in medicine. In compiling this textbook, the editors have brought together a truly international group of experts in MRI and PET. The book is divided into two parts. The first part covers methodology and equipment and comprises chapters on basic molecular medicine, development of specific contrast agents, MR attenuation and validation, quantitative MRI and PET motion correction, and technical implications for both MRI and PET. The second part of the book focuses on clinical applications in oncology, cardiology, and neurology. Imaging of major neoplasms, including lymphomas and tumors of the breast, prostate, and head and neck, is covered in individual chapters. Further chapters address functional and metabolic cardiovascular examinations and major central nervous system applications such as brain tumors and dementias. Risks, safety aspects, and healthcare costs and impacts are also discussed. This book will be of interest to all radiologists and nuclear medicine physicians who wish to learn more about the latest developments in this important emerging imaging modality and its applications.

  3. MRI - with applications in neurological disorders

    OpenAIRE

    Blockx, Ines; Delgado y Palacios, Rafael; Van der Linden, Annemie

    2013-01-01

    MRI has developed into one of the most powerful techniques for both experimental and clinical research.  Nowadays, it has become the imaging method of choice for modern medical imaging and its success is due to its  versatile nature. In addition, it is noninvasive and offers the advantage of imaging at relatively high spatial as well as high temporal resolution. The main advantage of MRI compared with other common imaging techniques such as  posi...

  4. Vertebral involvement in SAPHO syndrome: MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Nachtigal, A.; Cardinal, E.; Bureau, N.J. [Dept. of Radiology, Univ. de Montreal, QC (Canada); Sainte-Marie, L.G. [Dept. of Internal Medicine, Univ. de Montreal, QC (Canada); Milette, F. [Department of Pathology, Univ. de Montreal, QC (Canada)

    1999-03-01

    We report on the MRI findings in the vertebrae and surrounding soft tissues in two patients with the SAPHO syndrome (Synovitis, Acne, Pustulosis, Hyperostosis, Osteitis). The MRI findings include abnormal bone marrow signal, either focal or diffuse, of the vertebral bodies and posterior elements; hyperintense paravertebral soft tissue swelling and abnormal signal of the intervertebral discs. These changes are consistent with discitis and osteitis. (orig.) With 6 figs., 17 refs.

  5. Diffusion MRI and its role in neuropsychology

    Science.gov (United States)

    Mueller, Bryon A; Lim, Kelvin O; Hemmy, Laura; Camchong, Jazmin

    2015-01-01

    Diffusion Magnetic Resonance Imaging (dMRI) is a popular method used by neuroscientists to uncover unique information about the structural connections within the brain. dMRI is a non-invasive imaging methodology in which image contrast is based on the diffusion of water molecules in tissue. While applicable to many tissues in the body, this review focuses exclusively on the use of dMRI to examine white matter in the brain. In this review, we begin with a definition of diffusion and how diffusion is measured with MRI. Next we introduce the diffusion tensor model, the predominant model used in dMRI. We then describe acquisition issues related to acquisition parameters and scanner hardware and software. Sources of artifacts are then discussed, followed by a brief review of analysis approaches. We provide an overview of the limitations of the traditional diffusion tensor model, and highlight several more sophisticated non-tensor models that better describe the complex architecture of the brain’s white matter. We then touch on reliability and validity issues of diffusion measurements. Finally, we describe examples of ways in which dMRI has been applied to studies of brain disorders and how identified alterations relate to symptomatology and cognition. PMID:26255305

  6. MRI of radiographically occult ischial apophyseal avulsions

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, Arthur B. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, MLC 5031, Cincinnati, OH (United States); Children' s Hospital of Wisconsin, Milwaukee, WI (United States); Laor, Tal; Zbojniewicz, Andrew M.; Anton, Christopher G. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, MLC 5031, Cincinnati, OH (United States)

    2012-11-15

    Acute avulsions of unossified ischial apophyses in children may go undetected on radiography. Therapy includes rest and rehabilitation; however, substantial displacement may require surgery. Our purpose is to illustrate the utility of MRI in the detection of these radiographically occult injuries in skeletally immature children. This retrospective study of more than 5 years included children with ischial avulsions who were evaluated with both radiography and MRI within 3 weeks of acute injury. Initially, radiographs were reviewed to identify those children with unossified ischial apophyses. Subsequently, their MRI examinations were assessed for physeal disruption, bone/soft tissue edema, periosteal/perichondrial elevation and disruption. Initial and follow-up radiographs (if available) were reviewed. Patient age, symptoms and offending activity were determined from clinical records. Five children met inclusion criteria. All initial radiographs were normal. MRI showed: edema (n = 5), periosteal elevation (n = 4), periosteal/perichondrial disruption (n = 4), >5.5 mm displacement (n = 0). Follow-up radiographs in two children (2 and 2.5 months from MRI) showed osseous ischial irregularity. The apophyses remained unossified. Acute unossified ischial apophyseal avulsions in children may be radiographically undetected. In the setting of correlative clinical symptoms, MRI can be used to identify these injuries and to help direct appropriate therapy. (orig.)

  7. Diffusion MRI and its Role in Neuropsychology.

    Science.gov (United States)

    Mueller, Bryon A; Lim, Kelvin O; Hemmy, Laura; Camchong, Jazmin

    2015-09-01

    Diffusion Magnetic Resonance Imaging (dMRI) is a popular method used by neuroscientists to uncover unique information about the structural connections within the brain. dMRI is a non-invasive imaging methodology in which image contrast is based on the diffusion of water molecules in tissue. While applicable to many tissues in the body, this review focuses exclusively on the use of dMRI to examine white matter in the brain. In this review, we begin with a definition of diffusion and how diffusion is measured with MRI. Next we introduce the diffusion tensor model, the predominant model used in dMRI. We then describe acquisition issues related to acquisition parameters and scanner hardware and software. Sources of artifacts are then discussed, followed by a brief review of analysis approaches. We provide an overview of the limitations of the traditional diffusion tensor model, and highlight several more sophisticated non-tensor models that better describe the complex architecture of the brain's white matter. We then touch on reliability and validity issues of diffusion measurements. Finally, we describe examples of ways in which dMRI has been applied to studies of brain disorders and how identified alterations relate to symptomatology and cognition.

  8. Pediatric multifocal liver lesions evaluated by MRI

    Directory of Open Access Journals (Sweden)

    Majed Almotairi

    2015-01-01

    Full Text Available Objective: The purpose of this study is to present our experience with MRI evaluation of multifocal liver lesions in children and describe the MRI characteristics of these lesions. Patients and Methods: A retrospective review of consecutive MRI exams performed for the evaluation of multiple liver lesions between 1 January 2007 and 31 December 2012 was done to note the number of lesions, the size of the largest lesion, MR signal characteristics, and background liver. Final diagnosis was assigned to each case based on pathology in the available cases and a combination of clinical features, imaging features, and follow-up in the remaining cases. Results: A total of 48 children (22 boys, 26 girls; age between 3 months and 18 years with average age 10.58 years and median age 11 years were included in the study. Totally 51 lesion diagnoses were seen in 48 children that included 17 focal nodular hyperplasia (FNH, 8 hemangiomas, 7 metastases, 6 regenerative nodules, 3 adenomas, 3 abscesses, and one each of angiomyolipoma, epithelioid hemangioendothelioma, focal fatty infiltration, hepatocellular carcinoma, hepatic infarction, nodular regenerative hyperplasia, and hepatic cyst. Background liver was normal in 33, cirrhotic in 10, fatty in 3, and siderotic in 2 children. Most FNH, hemangiomas, and regenerative nodules showed characteristic MRI features, while metastases were variable in signal pattern. Conclusion: Many commonly seen multifocal liver lesions in children have characteristic MRI features. MRI can help to arrive at reasonable differential diagnoses for multifocal liver lesions in children and guide further investigation and management.

  9. Shoulder MRI after surgical treatment of instability

    Energy Technology Data Exchange (ETDEWEB)

    Vahlensieck, Martin [University of Bonn, Department of Radiology, Sigmund-Freud-Strasse 25, 53105 Bonn (Germany); Lang, Philipp [University of California San Francisco, Department of Radiology, 505 Pamassus Avenue, San Francisco, CA 94143 (United States); Wagner, Ulli [University of Bonn, Department of Orthopedic Surgery, Sigmund-Freud-Strasse 25, 53105 Bonn (Germany); Moeller, Frank [University of Bonn, Department of Orthopedic Surgery, Sigmund-Freud-Strasse 25, 53105 Bonn (Germany); Deimling, Urs van [University of Bonn, Department of Orthopedic Surgery, Sigmund-Freud-Strasse 25, 53105 Bonn (Germany); Genant, H.K. [University of California San Francisco, Department of Radiology, 505 Pamassus Avenue, San Francisco, CA 94143 (United States); Schild, Hans H. [University of Bonn, Department of Radiology, Sigmund-Freud-Strasse 25, 53105 Bonn (Germany)

    1999-04-01

    Objective: To analyze magnetic resonance imaging (MRI) findings of the shoulder after an instability operation. Materials and methods: Physical examinations, radiographs and MRI of 10 patients after anterior glenoid bone block insertion for ventral instability were compared. MRI included T{sub 1}-weighted spin-echo (TR=600, TE=20 ms) and T{sub 2}*-weighted gradient-echo sequences (TE=600, TE=18, Flip=30 deg.) in the axial, oblique-coronal and oblique-sagittal planes. Results: No patient suffered from recurrent subluxation. We found fusion of the bone block with the anterior glenoid in seven cases, dislocation of the bone block without contact to the glenoid in one case, and no visible bone block in two cases. On MRI, the bone block showed either signal intensity equivalent to fatty bone marrow (n=4) or was devoid of signal consistent with cortical bone or bone sclerosis (n=4). In all patients, a low signal intensity mass, 2-4 cm in diameter, was visible next to the glenoid insertion site. Conclusion: Insertion of a bone block onto the anterior glenoid induces formation of scar tissue, increasing the stability of the shoulder joint. This scar is well visible on MRI and forms independently of the behavior of the bone block itself. MRI is ideally suited for evaluating postoperative shoulder joints after bone-grafting procedures.

  10. MRI of perinatal brain injury

    Energy Technology Data Exchange (ETDEWEB)

    Rutherford, Mary; Allsop, Joanna [Imperial College, Robert Steiner MR Unit, Perinatal Imaging, MRC Clinical Sciences Centre, Hammersmith Hospital, London (United Kingdom); Martinez Biarge, Miriam [La Paz University Hospital, Dept of Neonatology, Madrid (Spain); Counsell, Serena [Imperial College, Robert Steiner MR Unit, Neonatal Medicine, MRC Clinical Sciences Centre, Hammersmith Hospital, London (United Kingdom); Cowan, Frances [Imperial College, Dept of Paediatrics, Hammersmith Hospital, London (United Kingdom)

    2010-06-15

    MRI is invaluable in assessing the neonatal brain following suspected perinatal injury. Good quality imaging requires adaptations to both the hardware and the sequences used for adults or older children. The perinatal and postnatal details often predict the pattern of lesions sustained and should be available to aid interpretation of the imaging findings. Perinatal lesions, the pattern of which can predict neurodevelopmental outcome, are at their most obvious on conventional imaging between 1 and 2 weeks from birth. Very early imaging during the first week may be useful to make management decisions in ventilated neonates but brain abnormalities may still be subtle using conventional sequences. Diffusion-weighted imaging (DWI) is very useful for the early identification of ischaemic tissue in the neonatal brain but may underestimate the final extent of injury, particularly basal ganglia and thalamic lesions. MR imaging is an excellent predictor of outcome following perinatal brain injury and can therefore be used as a biomarker in interventional trials designed to reduce injury and improve neurodevelopmental outcome. (orig.)

  11. PH-Responsive mechanised nanoparticles gated by semirotaxanes

    KAUST Repository

    Khashab, Niveen M.

    2009-01-01

    A [2]pseudorotaxane-based mechanised nanoparticle system, which operates within an aqueous acidic environment, has been prepared and characterised; this integrated system affords both water-soluble stalk and ring components in an effort to improve the biocompatibility of these promising new drug delivery vehicles. © The Royal Society of Chemistry 2009.

  12. Engineering a pH responsive pore forming protein

    Science.gov (United States)

    Kisovec, Matic; Rezelj, Saša; Knap, Primož; Cajnko, Miša Mojca; Caserman, Simon; Flašker, Ajda; Žnidaršič, Nada; Repič, Matej; Mavri, Janez; Ruan, Yi; Scheuring, Simon; Podobnik, Marjetka; Anderluh, Gregor

    2017-01-01

    Listeriolysin O (LLO) is a cytolysin capable of forming pores in cholesterol-rich lipid membranes of host cells. It is conveniently suited for engineering a pH-governed responsiveness, due to a pH sensor identified in its structure that was shown before to affect its stability. Here we introduced a new level of control of its hemolytic activity by making a variant with hemolytic activity that was pH-dependent. Based on detailed structural analysis coupled with molecular dynamics and mutational analysis, we found that the bulky side chain of Tyr406 allosterically affects the pH sensor. Molecular dynamics simulation further suggested which other amino acid residues may also allosterically influence the pH-sensor. LLO was engineered to the point where it can, in a pH-regulated manner, perforate artificial and cellular membranes. The single mutant Tyr406Ala bound to membranes and oligomerized similarly to the wild-type LLO, however, the final membrane insertion step was pH-affected by the introduced mutation. We show that the mutant toxin can be activated at the surface of artificial membranes or living cells by a single wash with slightly acidic pH buffer. Y406A mutant has a high potential in development of novel nanobiotechnological applications such as controlled release of substances or as a sensor of environmental pH. PMID:28176876

  13. pH Responsiveness of hydrogels formed by telechelic polyampholytes.

    Science.gov (United States)

    Dyakonova, Margarita A; Gotzamanis, George; Niebuur, Bart-Jan; Vishnevetskaya, Natalya S; Raftopoulos, Konstantinos N; Di, Zhenyu; Filippov, Sergey K; Tsitsilianis, Constantinos; Papadakis, Christine M

    2017-05-21

    We investigate the influence of pH on the rheological and structural properties of hydrogels formed by hydrophobic association of the sticky ends of the triblock terpolymer poly(methyl methacrylate)-b-poly(2-(diethylamino)ethyl methacrylate-co-methacrylic acid)-b-poly(methyl methacrylate) (PMMA-b-P(DEA-co-MAA)-b-PMMA). The middle block is a weak polyampholyte having a pH dependent charge density and sign, which enables tuning of the rheological and structural properties by pH variation. Small-angle neutron scattering (SANS) studies of solutions in D2O at 0.05 wt% and pH 3.0 reveal clusters of interconnected spherical micelles having PMMA cores, stabilized by repulsive ionic interactions in the middle polyampholyte block. With increasing pH, the degree of ionization of the DEA units decreases, whereas the one of the MAA units increases, resulting in a complete loss of the correlation between these micelles. At a concentration of 3 wt% at low pH values, the system forms a gel with charged fuzzy spheres from PMMA interacting via a screened Coulomb potential. With increasing pH, the gel disintegrates due to the decrease in the effective charge on the micelles. At both concentrations, the hydrophobic aggregation of micelles is observed near the isoelectric point. At pH 3.0-7.4, the autocorrelation functions measured by rotational dynamic light scattering at 3 wt% exhibit a decay steeper than single exponential, which confirms that the gels are frozen, presumably due to the glassy PMMA cores and hydrophobic interpolyelectrolyte complexes. At pH 11, the diffusion of single micelles is observed in addition to the frozen dynamics.

  14. Engineering a pH responsive pore forming protein

    Science.gov (United States)

    Kisovec, Matic; Rezelj, Saša; Knap, Primož; Cajnko, Miša Mojca; Caserman, Simon; Flašker, Ajda; Žnidaršič, Nada; Repič, Matej; Mavri, Janez; Ruan, Yi; Scheuring, Simon; Podobnik, Marjetka; Anderluh, Gregor

    2017-02-01

    Listeriolysin O (LLO) is a cytolysin capable of forming pores in cholesterol-rich lipid membranes of host cells. It is conveniently suited for engineering a pH-governed responsiveness, due to a pH sensor identified in its structure that was shown before to affect its stability. Here we introduced a new level of control of its hemolytic activity by making a variant with hemolytic activity that was pH-dependent. Based on detailed structural analysis coupled with molecular dynamics and mutational analysis, we found that the bulky side chain of Tyr406 allosterically affects the pH sensor. Molecular dynamics simulation further suggested which other amino acid residues may also allosterically influence the pH-sensor. LLO was engineered to the point where it can, in a pH-regulated manner, perforate artificial and cellular membranes. The single mutant Tyr406Ala bound to membranes and oligomerized similarly to the wild-type LLO, however, the final membrane insertion step was pH-affected by the introduced mutation. We show that the mutant toxin can be activated at the surface of artificial membranes or living cells by a single wash with slightly acidic pH buffer. Y406A mutant has a high potential in development of novel nanobiotechnological applications such as controlled release of substances or as a sensor of environmental pH.

  15. pH Responsive Microcapsules for Corrosion Control

    Science.gov (United States)

    Calle, Luz Marina; Li, Wenyan; Muehlberg, Aaron; Boraas, Samuel; Webster, Dean; JohnstonGelling, Victoria; Croll, Stuart; Taylor, S Ray; Contu, Francesco

    2008-01-01

    The best coatings for corrosion protection provide not only barriers to the environment, but also a controlled release of a corrosion inhibitor, as demanded by the presence of corrosion or mechanical damage. NASA has developed pH sensitive microcapsules (patent pending) that can release their core contents when corrosion starts. The objectives of the research presented here were to encapsulate non-toxic corrosion inhibitors, to incorporate the encapsulated inhibitors into paint formulations, and to test the ability of the paints to control corrosion. Results showed that the encapsulated corrosion inhibitors, specifically Ce(NO3)3 , are effective to control corrosion over long periods of time when incorporated at relatively high pigment volume concentrations into a paint formulation.

  16. A 4-channel 3 Tesla phased array receive coil for awake rhesus monkey fMRI and diffusion MRI experiments

    OpenAIRE

    Khachaturian, Mark Haig

    2010-01-01

    Awake monkey fMRI and diffusion MRI combined with conventional neuroscience techniques has the potential to study the structural and functional neural network. The majority of monkey fMRI and diffusion MRI experiments are performed with single coils which suffer from severe EPI distortions which limit resolution. By constructing phased array coils for monkey MRI studies, gains in SNR and anatomical accuracy (i.e., reduction of EPI distortions) can be achieved using parallel imaging. The major...

  17. "MRI Stealth" robot for prostate interventions.

    Science.gov (United States)

    Stoianovici, Dan; Song, Danny; Petrisor, Doru; Ursu, Daniel; Mazilu, Dumitru; Muntener, Michael; Mutener, Michael; Schar, Michael; Patriciu, Alexandru

    2007-01-01

    The paper reports an important achievement in MRI instrumentation, a pneumatic, fully actuated robot located within the scanner alongside the patient and operating under remote control based on the images. Previous MRI robots commonly used piezoelectric actuation limiting their compatibility. Pneumatics is an ideal choice for MRI compatibility because it is decoupled from electromagnetism, but pneumatic actuators were hardly controllable. This achievement was possible due to a recent technology breakthrough, the invention of a new type of pneumatic motor, PneuStep 1, designed for the robot reported here with uncompromised MRI compatibility, high-precision, and medical safety. MrBot is one of the "MRI stealth" robots today (the second is described in this issue by Zangos et al.). Both of these systems are also multi-imager compatible, being able to operate with the imager of choice or cross-imaging modalities. For MRI compatibility the robot is exclusively constructed of nonmagnetic and dielectric materials such as plastics, ceramics, crystals, rubbers and is electricity free. Light-based encoding is used for feedback, so that all electric components are distally located outside the imager's room. MRI robots are modern, digital medical instruments in line with advanced imaging equipment and methods. These allow for accessing patients within closed bore scanners and performing interventions under direct (in scanner) imaging feedback. MRI robots could allow e.g. to biopsy small lesions imaged with cutting edge cancer imaging methods, or precisely deploy localized therapy at cancer foci. Our robot is the first to show the feasibility of fully automated in-scanner interventions. It is customized for the prostate and operates transperineally for needle interventions. It can accommodate various needle drivers for different percutaneous procedures such as biopsy, thermal ablations, or brachytherapy. The first needle driver is customized for fully automated low

  18. MRI-guided stereotactic neurosurgical procedures in a diagnostic MRI suite: Background and safe practice recommendations.

    Science.gov (United States)

    Larson, Paul S; Willie, Jon T; Vadivelu, Sudhakar; Azmi-Ghadimi, Hooman; Nichols, Amy; Fauerbach, Loretta Litz; Johnson, Helen Boehm; Graham, Denise

    2017-07-01

    The development of navigation technology facilitating MRI-guided stereotactic neurosurgery has enabled neurosurgeons to perform a variety of procedures ranging from deep brain stimulation to laser ablation entirely within an intraoperative or diagnostic MRI suite while having real-time visualization of brain anatomy. Prior to this technology, some of these procedures required multisite workflow patterns that presented significant risk to the patient during transport. For those facilities with access to this technology, safe practice guidelines exist only for procedures performed within an intraoperative MRI. There are currently no safe practice guidelines or parameters available for facilities looking to integrate this technology into practice in conventional MRI suites. Performing neurosurgical procedures in a diagnostic MRI suite does require precautionary measures. The relative novelty of technology and workflows for direct MRI-guided procedures requires consideration of safe practice recommendations, including those pertaining to infection control and magnet safety issues. This article proposes a framework of safe practice recommendations designed for assessing readiness and optimization of MRI-guided neurosurgical interventions in the diagnostic MRI suite in an effort to mitigate patient risk. The framework is based on existing clinical evidence, recommendations, and guidelines related to infection control and prevention, health care-associated infections, and magnet safety, as well as the clinical and practical experience of neurosurgeons utilizing this technology. © 2017 American Society for Healthcare Risk Management of the American Hospital Association.

  19. Multichannel compressive sensing MRI using noiselet encoding.

    Directory of Open Access Journals (Sweden)

    Kamlesh Pawar

    Full Text Available The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS. In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI. Based on an empirical RIP analysis that compares the multichannel noiselet and multichannel Fourier measurement matrices in CS-MRI, we propose a multichannel compressive sensing (MCS framework to take the advantage of multichannel data acquisition used in MRI scanners. Simulations are presented in the MCS framework to compare the performance of noiselet encoding reconstructions and Fourier encoding reconstructions at different acceleration factors. The comparisons indicate that multichannel noiselet measurement matrix has better RIP than that of its Fourier counterpart, and that noiselet encoded MCS-MRI outperforms Fourier encoded MCS-MRI in preserving image resolution and can achieve higher acceleration factors. To demonstrate the feasibility of the proposed noiselet encoding scheme, a pulse sequences with tailored spatially selective RF excitation pulses was designed and implemented on a 3T scanner to acquire the data in the noiselet domain from a phantom and a human brain. The results indicate that noislet encoding preserves image resolution better than Fouirer encoding.

  20. Sodium MRI in human heart: a review.

    Science.gov (United States)

    Bottomley, Paul A

    2016-02-01

    This paper offers a critical review of the properties, methods and potential clinical application of sodium ((23)Na) MRI in human heart. Because the tissue sodium concentration (TSC) in heart is about ~40 µmol/g wet weight, and the (23)Na gyromagnetic ratio and sensitivity are respectively about one-quarter and one-11th of that of hydrogen ((1)H), the signal-to-noise ratio of (23)Na MRI in the heart is about one-6000th of that of conventional cardiac (1)H MRI. In addition, as a quadrupolar nucleus, (23)Na exhibits ultra-short and multi-component relaxation behavior (T1 ~ 30 ms; T2 ~ 0.5-4 ms and 12-20 ms), which requires fast, specialized, ultra-short echo-time MRI sequences, especially for quantifying TSC. Cardiac (23)Na MRI studies from 1.5 to 7 T measure a volume-weighted sum of intra- and extra-cellular components present at cytosolic concentrations of 10-15 mM and 135-150 mM in healthy tissue, respectively, at a spatial resolution of about 0.1-1 ml in 10 min or so. Currently, intra- and extra-cellular sodium cannot be unambiguously resolved without the use of potentially toxic shift reagents. Nevertheless, increases in TSC attributable to an influx of intra-cellular sodium and/or increased extra-cellular volume have been demonstrated in human myocardial infarction consistent with prior animal studies, and arguably might also be seen in future studies of ischemia and cardiomyopathies--especially those involving defects in sodium transport. While technical implementation remains a hurdle, a central question for clinical use is whether cardiac (23)Na MRI can deliver useful information unobtainable by other more convenient methods, including (1)H MRI.

  1. Multichannel compressive sensing MRI using noiselet encoding.

    Science.gov (United States)

    Pawar, Kamlesh; Egan, Gary; Zhang, Jingxin

    2015-01-01

    The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP) of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS). In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI. Based on an empirical RIP analysis that compares the multichannel noiselet and multichannel Fourier measurement matrices in CS-MRI, we propose a multichannel compressive sensing (MCS) framework to take the advantage of multichannel data acquisition used in MRI scanners. Simulations are presented in the MCS framework to compare the performance of noiselet encoding reconstructions and Fourier encoding reconstructions at different acceleration factors. The comparisons indicate that multichannel noiselet measurement matrix has better RIP than that of its Fourier counterpart, and that noiselet encoded MCS-MRI outperforms Fourier encoded MCS-MRI in preserving image resolution and can achieve higher acceleration factors. To demonstrate the feasibility of the proposed noiselet encoding scheme, a pulse sequences with tailored spatially selective RF excitation pulses was designed and implemented on a 3T scanner to acquire the data in the noiselet domain from a phantom and a human brain. The results indicate that noislet encoding preserves image resolution better than Fouirer encoding.

  2. 乳腺疾病的 MRI 诊断%MRI dia gnosis the breast diseases

    Institute of Scientific and Technical Information of China (English)

    杨正军; 郭周中; 赵双全

    2012-01-01

      Objective:To investigate the application value of MRI in the diagno sis of breast diseases.Methods: The clinical data of 126 cases of patients with breast disease confirmed by surgical biopsy was analyzed retrospectively.The MRI findings of breast lesions were analyzed.The MRI features of benign and malignant lesions were compared.Results 77 cases with benign lesions were eccentric strengthening, while 49 cases with malignant lesions being concentric strengthening. Besides,the contrast of both enhanced MRI and time intensity curve type between benign and malignant lesions,which had significant differences (P ﹤ 0.05,P ﹤ 0.01).Conclusions MRI imaging examination has a high clinical value in the differential diagnosis of benign and malignant breast lesions.%  目的探讨 MRI 对乳腺疾病的临床应用价值.方法回顾性分析126例经手术病理证实的乳腺疾病患者病例资料,分析乳腺病变的 MRI 检查结果,对比良、恶性病变的 MRI 特点.结果126例患者中,良性病变者77例为离心性强化,恶性病变者49例为向心性强化,且良恶性病变的 MRI 增强对比及时间强度曲线分型对比均具有显著性差异(P ﹤0.05,P ﹤0.01).结论 MRI 影像学检查技术在鉴别诊断乳腺良恶性病变时具有很高的临床价值.

  3. Value of repeat brain MRI in children with focal epilepsy and negative findings on initial MRI

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Tae Yeon; Kim, Ji Hye; Lee, Jee Hun; Yoo, So Young; Hwang, Sook Min; Lee, Mun Hyang [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2017-08-01

    To evaluate the value of repeat brain magnetic resonance imaging (MRI) in identifying potential epileptogenic lesions in children with initial MRI-negative focal epilepsy. Our Institutional Review Board approved this retrospective study and waived the requirement for informed consent. During a 15-year period, 257 children (148 boys and 109 girls) with initial MRI-negative focal epilepsy were included. After re-evaluating both initial and repeat MRIs, positive results at repeat MRI were classified into potential epileptogenic lesions (malformation of cortical development and hippocampal sclerosis) and other abnormalities. Contributing factors for improved lesion conspicuity of the initially overlooked potential epileptogenic lesions were analyzed and classified into lesion factors and imaging factors. Repeat MRI was positive in 21% (55/257) and negative in 79% cases (202/257). Of the positive results, potential epileptogenic lesions comprised 49% (27/55) and other abnormalities comprised 11% of the cases (28/257). Potential epileptogenic lesions included focal cortical dysplasia (n = 11), hippocampal sclerosis (n = 10), polymicrogyria (n = 2), heterotopic gray matter (n = 2), microlissencephaly (n = 1), and cortical tumor (n = 1). Of these, seven patients underwent surgical resection. Contributing factors for new diagnoses were classified as imaging factors alone (n = 6), lesion factors alone (n = 2), both (n = 18), and neither (n = 1). Repeat MRI revealed positive results in 21% of the children with initial MRI-negative focal epilepsy, with 50% of the positive results considered as potential epileptogenic lesions. Enhanced MRI techniques or considering the chronological changes of lesions on MRI may improve the diagnostic yield for identification of potential epileptogenic lesions on repeat MRI.

  4. MRI & MR SPECTROSCOPIC EVALUATION OF PROSTATIC CARCINOMA

    Directory of Open Access Journals (Sweden)

    Rupak

    2015-09-01

    Full Text Available BACKGROUND : Prostate cancer is the most common malignancy among men more than fifty years of age (Cancer foundation of India. Imaging may help in clarifying several important issues in localized prostate cancer. MRI provides the best depiction of the contours of the prostate as well as its internal zonal anatomy. Recent evidence suggests that multi - parametric MRI could improve the accuracy of diagnostic assessment in prostate cancer. In addition, MRI also allows functional assessment with techniques such as diffusion - weighted MRI (DWI, MR spectroscopy (MRS, and dynamic contrast enhanced MRI (DCE - MRI. Strong opinions are held about the need for endorectal coil imaging. Endorectal coils provide large gains in signal with reductions in noise, most noticeably at 1.5 T; however, endorectal coils are uncomfortable and expensive. At 3 T, the need for endorectal coils has been debated. Clearly, the highest - quality MRI results from the combined use of endorectal coils and phased array body coils at 3 T. Prostate cancer is associated with proportionately lower levels of citrate and higher levels of choline and creatine than are seen in benign prostatic hyperplasia (BPH or in normal prostate tissu e. This difference can be detected by magnetic resonance spectroscopic imaging (MRSI. MRSI uses a strong magnetic field to obtain metabolic information (spectra that identifies the relative concentrations of various metabolites in the cell cytoplasm and the extracellular space. This technique can identify metabolic differences in prostate tissue (BPH, prostate cance r, and normal prostate tissue. AIM: To evaluate the role of MRI and MR Spectroscopy in the diagnosis of prostatic carcinoma by pelvic phased array coil in the detection of prostatic carcinoma in men with Prostatomegaly & elevated PSA levels and establishing statistical analysis of the same. METHOD: A prospective study of minimum 50 consecutive cases with Prostatomegaly & raised PSA levels

  5. Fetal MRI in experimental tracheal occlusion

    Energy Technology Data Exchange (ETDEWEB)

    Wedegaertner, Ulrike [Department of Diagnostic and Interventional Radiology, Universitaetsklinikum Hamburg-Eppendorf, Martinistrasse 52, 20251 Hamburg (Germany)]. E-mail: wedegaer@uke.uni-hamburg.de; Schroeder, Hobe J. [Experimental Gynecology, Department of Obstetrics and Prenatal Medicine, Universitaetsklinikum Hamburg-Eppendorf, Hamburg (Germany); Adam, Gerhard [Department of Diagnostic and Interventional Radiology, Universitaetsklinikum Hamburg-Eppendorf, Hamburg (Germany)

    2006-02-15

    Congenital diaphragmatic hernia (CDH) is associated with a high mortality, which is mainly due to pulmonary hypoplasia and secondary pulmonary hypertension. In severely affected fetuses, tracheal occlusion (TO) is performed prenatally to reverse pulmonary hypoplasia, because TO leads to accelerated lung growth. Prenatal imaging is important to identify fetuses with pulmonary hypoplasia, to diagnose high-risk fetuses who would benefit from TO, and to monitor the effect of TO after surgery. In fetal imaging, ultrasound (US) is the method of choice, because it is widely available, less expensive, and less time-consuming to perform than magnetic resonance imaging (MRI). However, there are some limitations for US in the evaluation of CDH fetuses. In those cases, MRI is helpful because of a better tissue contrast between liver and lung, which enables evaluation of liver herniation for the diagnosis of a high-risk fetus. MRI provides the ability to determine absolute lung volumes to detect lung hypoplasia. In fetal sheep with normal and hyperplastic lungs after TO, lung growth was assessed on the basis of cross-sectional US measurements, after initial lung volume determination by MRI. To monitor fetal lung growth after prenatal TO, both MRI and US seem to be useful methods.

  6. Localization of spinal tumors by MRI

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Mutsumasa; Sakamoto, Yuji; Kojima, Ryutaro; Yamashita, Yasuyuki; Bussaka, Hiromasa

    1989-02-01

    Exact localization of the spinal tumors is particularly important for differential diagnosis and surgery. Therefore, it was attempted to evauate the diagnostic accuracy of MRI in localizing the spinal tumors exactly. Nineteen cases of spinal cord tumors, being localized in the intradural extramedullary, extradural and both intradural and extradural spaces, were studied with MRI. Intradural extramedullary tumors showed small CSF spaces just below and above the tumor which were demonstrated as CSF intensity on T1 and T2 weighted images. Although extradural tumors did not show CSF spaces, there was extradural sign or dural density between the tumor and the spinal cord. Intradural and extradural tumors were outlined as having both characteristics. Signal intensities of the spinal tumors were not characteristic for specific histology. Gd-DTPA was quite useful for accurate localization of the tumors. In comparison with myelography, MRI was superior to myelography in extradural tumors and equally useful for intradural and extradural tumors, but it was less diagnostic in intradural extramedullary tumors. In general, MRI was quite useful in localizing the spinal tumors exactly and the accuracy of MRI was quite high. In the near future this technique will replace myelography and other radiologic methods.

  7. Transition from Collisionless to Collisional MRI

    Energy Technology Data Exchange (ETDEWEB)

    Prateek Sharma; Gregory W. Hammett; Eliot Quataert

    2003-07-24

    Recent calculations by Quataert et al. (2002) found that the growth rates of the magnetorotational instability (MRI) in a collisionless plasma can differ significantly from those calculated using MHD. This can be important in hot accretion flows around compact objects. In this paper, we study the transition from the collisionless kinetic regime to the collisional MHD regime, mapping out the dependence of the MRI growth rate on collisionality. A kinetic closure scheme for a magnetized plasma is used that includes the effect of collisions via a BGK operator. The transition to MHD occurs as the mean free path becomes short compared to the parallel wavelength 2*/k(sub)||. In the weak magnetic field regime where the Alfven and MRI frequencies w are small compared to the sound wave frequency k(sub)||c(sub)0, the dynamics are still effectively collisionless even if omega << v, so long as the collision frequency v << k(sub)||c(sub)0; for an accretion flow this requires n less than or approximately equal to *(square root of b). The low collisionality regime not only modifies the MRI growth rate, but also introduces collisionless Landau or Barnes damping of long wavelength modes, which may be important for the nonlinear saturation of the MRI.

  8. Lunate chondromalacia: evaluation of routine MRI sequences.

    Science.gov (United States)

    Bordalo-Rodrigues, Marcelo; Schweitzer, Mark; Bergin, Diane; Culp, Randall; Barakat, Mohamed S

    2005-05-01

    Chondromalacia is a commonly encountered abnormality at arthroscopy and may be responsible for significant clinical symptoms and disability. In the wrist, the most common location for chondromalacia is the lunate bone. Consequently, we sought to study the accuracy of clinical MRI in the assessment of lunate articular cartilage. MR images of 34 patients who underwent arthroscopy and had an MRI examination within 1 month of surgery were evaluated by two reviewers for the presence and location of lunate cartilage defects and subchondral edema. Lunate cartilage defects were seen on MRI in 10 of the 13 patients with chondromalacia, but these defects were also incorrectly noted in three of 21 of patients without chondromalacia. The visible locations for cartilage defects were the ulnar aspect of the proximal lunate bone (n = 3), radial aspect of the proximal lunate bone (n = 4), ulnar aspect of the distal lunate bone (n = 2), and radial aspect of the distal lunate bone (n = 1). Subchondral marrow edema was observed in six of the 10 patients with chondromalacia seen on MRI; in all six patients, the edema was seen in the same quadrant as the cartilage defect. Marrow edema was detected in one patient without chondromalacia. We conclude that lunate chondromalacia can be accurately assessed using routine MRI sequences, although there are occasional false-positive interpretations.

  9. Low Field Squid MRI Devices, Components and Methods

    Science.gov (United States)

    Penanen, Konstantin I. (Inventor); Eom, Byeong H. (Inventor); Hahn, Inseob (Inventor)

    2014-01-01

    Low field SQUID MRI devices, components and methods are disclosed. They include a portable low field (SQUID)-based MRI instrument and a portable low field SQUID-based MRI system to be operated under a bed where a subject is adapted to be located. Also disclosed is a method of distributing wires on an image encoding coil system adapted to be used with an NMR or MRI device for analyzing a sample or subject and a second order superconducting gradiometer adapted to be used with a low field SQUID-based MRI device as a sensing component for an MRI signal related to a subject or sample.

  10. MRI tracheomalacia (TM) assessment in pediatric patients

    DEFF Research Database (Denmark)

    Ciet, P.; Wielopolski, P.; Lever, S.

    Purpose: TM is an excessive narrowing of the intrathoracic part of the trachea. TM is a common congenital pediatric anomaly, but it’s often not recognized due to its unspecific clinical presentation. The aims of our study are: 1) to develop cine-MRI sequences to visualize central airways in static...... spirometry controlled breathing maneuvers (peak flow and coughing) using a MRI compatible spirometer. “Static” 13-second breath-hold scans covering the entire thoracic region were acquired at end-inspiration and end-expiration using a 3D GRE with TR/TE=1.2/0.5 ms, alpha = 2, sagittal isotropic volume (2.8) x...... breathing maneuvers. Images of central airways during static and dynamic conditions were acquired and could be analyzed. Three out of the 8 children had a TM just above the carina during forced expiration, confirmed by bronchoscopy. Conclusion: This pilot study shows that Dynamic-MRI is feasible...

  11. MRI in Leber's hereditary optic neuropathy

    DEFF Research Database (Denmark)

    Matthews, Lucy; Enzinger, Christian; Fazekas, Franz

    2015-01-01

    mechanism involving mitochondrial dysfunction. OBJECTIVE: The primary aim was to define MRI features of LMS and LHON, and to assess the proportions of individuals displaying features typical of MS. Secondarily, we investigated the effect of gender on the risk of developing white matter lesions...... in the context of LHON. METHODS: A blinded standardised review of conventional brain MRIs of 30 patients with MS, 31 patients with LHON and 11 patients with LMS was conducted by three independent experts in the field. MS-like MRI features were assessed. RESULTS: All patients with LMS and 26% of patients...... with LHON had white matter lesions. Of these, all patients with LMS and 25% with LHON were found to have an MRI appearance typical of MS. Female patients with LHON had a significantly greater risk of having white matter lesions consistent with MS compared with male patients (relative risk 8.3). CONCLUSIONS...

  12. MRI features of tuberculosis of the knee

    Energy Technology Data Exchange (ETDEWEB)

    Sanghvi, Darshana A.; Iyer, Veena R.; Deshmukh, Tejaswini; Hoskote, Sumedh S. [Seth GS Medical College and KEM Hospital, Department of Radiology, Mumbai (India)

    2009-03-15

    The objective of this study was to describe the magnetic resonance imaging (MRI) features of tuberculosis (TB) of the knee joint. The MRI features in 15 patients with TB of the knee, as confirmed by histology of the biopsied joint synovium, were reviewed retrospectively. The images were assessed for intra-articular and peri-articular abnormalities. All patients had florid synovial proliferation. The proliferating synovium showed intermediate to low T2 signal intensity. In the patients who were administered intravenous contrast, the hypertrophic synovium was intensely enhancing. Marrow edema (n = 9), osteomyelitis (n = 4), cortical erosions (n = 5), myositis (n = 6), cellulitis (n = 2), abscesses (n = 3), and skin ulceration/sinus formation (n = 2) were seen in the adjacent bone and soft tissue. Synovial proliferation associated with tuberculous arthritis is typically hypointense on T2-weighted images. This appearance, in conjunction with other peri-articular MRI features described, can help in distinguishing TB arthritis from other proliferating synovial arthropathies. (orig.)

  13. Acute encephalitis associated with measles: MRI features

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.Y.; Cho, W.H.; Kim, S.H. [Department of Radiology, Sanggye Paik Hospital, Inje University, 760-1 Sanggye-7 dong, Nowon-gu, Seoul 139707 (Korea); Kim, H.D. [Department of Paediatrics, Sanggye Paik Hospital, Inje University, 760-1 Sanggye-7 dong, Nowon-gu, Seoul 139707 (Korea); Kim, I.O. [Department of Radiology, Seoul National University Hospital, 28, Yongon-dong, Chongno-gu, Seoul 110744 (Korea)

    2003-02-01

    We document the MRI features in six patients aged 5-14 years with acute encephalitis following measles. The diagnosis was made on a characteristic morbiliform rash and detection of specific IgM and IgG antibodies. The symptoms of encephalitis occurred 1-11 days after the appearance of the rash. All patients underwent MRI within 1-4 days of the onset of neurological symptoms. Diffusion weighted images (DWI) were obtained in three patients. In all patients, T2-weighted images showed widely distributed, multifocal high signal in both cerebral hemispheres with swelling of the cortex, with bilateral, symmetrical involvement of the putamen and caudate nucleus. The lesions had showed low apparent diffusion coefficients. Three patients showed subacute gyriform haemorrhage, and asymmetrical gyriform contrast enhancement on follow-up MRI. (orig.)

  14. Organizing Knowing in Interdisciplinary MRI Practice

    DEFF Research Database (Denmark)

    Yoshinaka, Yutaka

    's CT-scan and X-ray machines, were to take on MRI scanning, on an albeit rotational basis. Opening up to a broader group of operators to the scanning practice was to allow for organizational flexibility and a broader basis for competence building among radiology staff, where different occupational......This paper addresses organizational knowledge practices pertaining to the interdisciplinary work of Magnetic Resonance Imaging (MRI) at a hospital radiology department. The setting occasions an interesting venue for exploring domestication of MRI as it unfolds in distributed settings of collective......, facilitating, and yet, in tension with, efforts at organizational transformation – its occasioning(s), mediations and contingent effects. The case study is based on direct observation and interviews, exploring and drawing upon the idea of different units of analysis as a methodological means to address...

  15. MRI findings in the painful hemiplegic shoulder

    Energy Technology Data Exchange (ETDEWEB)

    Tavora, D.G.F., E-mail: danielgurgel@sarah.b [Department of Radiology, Sarah Network of Hospitals for Rehabilitation, Fortaleza (Brazil); Gama, R.L.; Bomfim, R.C. [Department of Radiology, Sarah Network of Hospitals for Rehabilitation, Fortaleza (Brazil); Nakayama, M. [Department of Radiology, Federal University of Grande Dourados, Dourados (Brazil); Silva, C.E.P. [Department of Statistics, Sarah Network of Hospitals for Rehabilitation, Fortaleza (Brazil)

    2010-10-15

    Aim: To evaluate the magnetic resonance imaging (MRI) findings in painful hemiplegic shoulder (PHS) in hemiplegic post-stroke patients. Materials and methods: Patients with hemiplegia following their first cerebrovascular accident who were admitted to the Sarah Network of Hospitals for Rehabilitation were studied. Forty-five patients with pain in the hemiplegic shoulder and 23 post-stroke patients without shoulder pain were investigated. MRI and radiographic findings of the hemiplegic and contralateral asymptomatic shoulders were evaluated. Results: Some MRI findings were more frequent in PHS group, including synovial capsule thickening, synovial capsule enhancement, and enhancement in the rotator cuff interval. Conclusions: Adhesive capsulitis was found to be a possible cause of PHS.

  16. Dynamic MRI study for breast tumors

    Energy Technology Data Exchange (ETDEWEB)

    Seki, Tsuneaki (Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine)

    1990-10-01

    Application of MRI for diagnosis of breast tumors was retrospectively examined in 103 consecutive cases. Contrast enhancement, mostly by dynamic study, was performed in 83 cases using Gd-DTPA and 0.5 T superconductive apparatus. Results were compared to those of mammography and sonography. On dynamic study, carcinoma showed abrupt rise of signal intensity with clear-cut peak formation in early phase, while benign fibroadenoma showed slow rise of signal intensity and prolonged enhancement without peak formation. In 12 of 33 carcinomas (33%), peripheral ring enhancement was noted reflecting vascular stroma of histologic sections. All fibroadenomas showed homogenous enhancement without peripheral ring. In MRI, sensitivity, specificity, and accuracy were 86%, 96%, 91%. In mammography 82%, 95%, 87% and in ultrasonography 91%, 95%, 93%. Although MRI should not be regarded as routine diagnostic procedure because of expense and limited availability, it may afford useful additional information when standard mammographic findings are not conclusive. (author).

  17. MRI Findings of Rectal Submucosal Tumors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hon Soul; Kim, Joo Hee; Lim, Joon Seok; Choi, Jin Young; Chung, Yong Eun; Park, Mi Suk; Kim, Myeong Jin; Kim, Ki Whang; Kim, Sang Kyum [Yonsei University Health System, Seoul (Korea, Republic of)

    2011-08-15

    Rectal submucosal lesions encompass a wide variety of benign and malignant tumors involving the rectum. With optical colonoscopy, any mass-like protrusion covered by normal mucosa, whether the underlying process is intramural or extramural in origin, may be reported as a submucosal lesion. Whereas the assessment of submucosal lesions may be limited with performing optical colonoscopy, cross-sectional imaging such as CT, transrectal ultrasonography and MRI allows the evaluation of perirectal tissues and pelvic organs in addition to the entire thickness of the rectum, and so this is advantageous for the assessment of rectal submucosal tumors. Among these, MRI is the best investigative modality for soft tissue characterization. Therefore, knowledge of the MRI features of rectal submucosal tumors can help achieve accurate preoperative diagnoses and facilitate the appropriate management.

  18. Monkey cortex through fMRI glasses.

    Science.gov (United States)

    Vanduffel, Wim; Zhu, Qi; Orban, Guy A

    2014-08-06

    In 1998 several groups reported the feasibility of fMRI experiments in monkeys, with the goal to bridge the gap between invasive nonhuman primate studies and human functional imaging. These studies yielded critical insights in the neuronal underpinnings of the BOLD signal. Furthermore, the technology has been successful in guiding electrophysiological recordings and identifying focal perturbation targets. Finally, invaluable information was obtained concerning human brain evolution. We here provide a comprehensive overview of awake monkey fMRI studies mainly confined to the visual system. We review the latest insights about the topographic organization of monkey visual cortex and discuss the spatial relationships between retinotopy and category- and feature-selective clusters. We briefly discuss the functional layout of parietal and frontal cortex and continue with a summary of some fascinating functional and effective connectivity studies. Finally, we review recent comparative fMRI experiments and speculate about the future of nonhuman primate imaging.

  19. Placenta percreta: methotrexate treatment and MRI findings.

    Science.gov (United States)

    Heiskanen, Nonna; Kröger, Jaana; Kainulainen, Sakari; Heinonen, Seppo

    2008-02-01

    Our patient was a 24-year-old gravida 2 para 0 woman. After delivery, placenta percreta was noticed. There was no postpartum hemorrhage, and the patient desired future pregnancies. Although placenta percreta is rare, its sequelae include potentially lethal hemorrhage and loss of reproduction function. Placenta percreta was confirmed histologically and with ultrasonography and magnetic resonance imaging (MRI). Placenta percreta was treated conservatively with methotrexate. On follow-up, MRI showed a small calcified transmural extension of the placenta throughout the uterus in the right fundal area. Color Doppler ultrasonography showed no blood flow in the corresponding area, and maternal serum human chorionic gonadotropin (hCG) was undetectable. Use of MRI is a new method to detect abnormal placentation, and it could be used on follow-up in selective cases with other follow-up modalities. However, it seems likely that conservative management to preserve future fertility remains a secured and reasonable alternative when a patient has no active bleeding.

  20. MRI findings of treated bacterial septic arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Bierry, Guillaume; Huang, Ambrose J.; Chang, Connie Y.; Torriani, Martin; Bredella, Miriam A. [Massachusetts General Hospital and Harvard Medical School, Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States)

    2012-12-15

    The purpose of this study was to report the MRI findings that can be encountered in successfully treated bacterial septic arthritis. The study included 12 patients (8 male and 4 female; mean age 38 years, range 9-85) with 13 proven cases of bacterial septic arthritis. The joints involved were hip (n = 3), knee (n = 3), shoulder (n = 2), sacroiliac (n = 2), ankle (n = 1), wrist (n = 1), and elbow (n = 1). MRI examinations following surgical debridement and at initiation of antibiotic therapy and after successful treatment were compared for changes in effusion, synovium, bone, and periarticular soft tissues. Imaging findings were correlated with microbiological and clinical findings. Joint effusions were present in all joints at baseline and regressed significantly at follow-up MRI (p = 0.001). Abscesses were present in 5 cases (38 %), and their sizes decreased significantly at follow-up (p = 0.001). Synovial enhancement and thickening were observed in all joints at both baseline and follow-up MRI. Myositis/cellulitis was present in 10 cases (77 %) at baseline and in 8 cases (62 %) at follow-up MRI. Bone marrow edema was present in 10 joints (77 %) at baseline and persisted in 8 joints (62 %). Bone erosions were found in 8 joints (62 %) and persisted at follow-up MRI in all cases. The sizes of joint effusions and abscesses appear to be the factors with the most potential for monitoring therapy for septic arthritis, since both decreased significantly following successful treatment. Synovial thickening and enhancement, periarticular myositis/cellulitis, and bone marrow edema can persist even after resolution of the infection. (orig.)

  1. Pharmacological MRI (phMRI) of the Human Central Nervous System.

    Science.gov (United States)

    Lanfermann, H; Schindler, C; Jordan, J; Krug, N; Raab, P

    2015-10-01

    Pharmacological magnetic resonance imaging (phMRI) of the central nervous system (CNS) addresses the increasing demands in the biopharma industry for new methods that can accurately predict, as early as possible, whether novel CNS agents will be effective and safe. Imaging of physiological and molecular-level function can provide a more direct measure of a drug mechanism of action, enabling more predictive measures of drug activity. The availability of phMRI of the nervous system within the professional infrastructure of the Clinical Research Center (CRC) Hannover as proof of concept center ensures that advances in basic science progress swiftly into benefits for patients. Advanced standardized MRI techniques including quantitative MRI, kurtosis determination, functional MRI, and spectroscopic imaging of the entire brain are necessary for phMRI. As a result, MR scanners will evolve into high-precision measuring instruments for assessment of desirable and undesirable effects of drugs as the basic precondition for individually tailored therapy. The CRC's Imaging Unit with high-end large-scale equipment will allow the following unique opportunities: for example, identification of MR-based biomarkers to assess the effect of drugs (surrogate parameters), establishment of normal levels and reference ranges for MRI-based biomarkers, evaluation of the most relevant MRI sequences for drug monitoring in outpatient care. Another very important prerequisite for phMRI is the MHH Core Facility as the scientific and operational study unit of the CRC partner Hannover Medical School. This unit is responsible for the study coordination, conduction, complete study logistics, administration, and application of the quality assurance system based on required industry standards.

  2. Bayesian segmentation of brainstem structures in MRI

    DEFF Research Database (Denmark)

    Iglesias, Juan Eugenio; Van Leemput, Koen; Bhatt, Priyanka

    2015-01-01

    In this paper we present a method to segment four brainstem structures (midbrain, pons, medulla oblongata and superior cerebellar peduncle) from 3D brain MRI scans. The segmentation method relies on a probabilistic atlas of the brainstem and its neighboring brain structures. To build the atlas, we...... the brainstem structures in novel scans. Thanks to the generative nature of the scheme, the segmentation method is robust to changes in MRI contrast or acquisition hardware. Using cross validation, we show that the algorithm can segment the structures in previously unseen T1 and FLAIR scans with great accuracy...

  3. MRI of Enterovirus 71 myelitis with monoplegia

    Energy Technology Data Exchange (ETDEWEB)

    Shen, W.C. [Department of Radiology, and School of Medicine, China Medical College, China Medical College Hospital, Taiwan (Taiwan); Tsai, C.H. [Department of Paediatrics, and School of Medicine, China Medical College, China Medical College Hospital, Taiwan (Taiwan); Chiu, H.H. [Department of Paediatrics, China Medical College Hospital, No. 2 Yuh-Der Road, 407 Taichung, Taiwan (Taiwan); Chow, K.C. [Department of Medical Research, China Medical College Hospital, Taichung, Taiwan (Taiwan)

    2000-02-01

    We report two boys diagnosed as having herpangina and hand-foot-mouth disease complicated by monoplegia during the outbreak enterovirus infection in Taiwan in 1998. Enterovirus 71 was identified in the stool and throat swab; neither polio nor Coxsackie viruses was identified. MRI showed unilateral lesions in the anterior horns of the spinal cord at T11-12 and C2-5. Although the MRI findings and sites of these lesions were similar to those of poliovirus-associated poliomyelitis, the virological data indicated that these boys were infected with enterovirus type 71. (orig.)

  4. MRI and pathology in persistent postherniotomy pain

    DEFF Research Database (Denmark)

    Aasvang, Eske Kvanner; Jensen, Karl-Erik; Fiirgaard, Bente

    2009-01-01

    groins versus unoperated and pain-free groins. RESULTS: Interobserver agreement was poor, ranging from kappa = 0.24 to 0.55 ("fair" to "moderate") except for "contrast enhancement in groin" (kappa = 0.69, substantial). Pathologic changes in the form of "contrast enhancement in groin," "edema......: Interobserver agreement is low and MRI-assessed pathology unspecific for persistent postherniotomy pain. Additional studies are required on interobserver agreement for pathology before MRI can be recommended as guidance and indication for surgical treatment of persistent postherniotomy pain....

  5. MRI of breast implant-related complications

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Seung Hae; Kook, Shin Ho; Kim, Jong Wook; Ahn, Sung Yul; Cha, Dong Sup; Whang, Kwi Whan; Pae, Won Kil; Park, Yong Lai; Lee, Young Uk; Park, Hae Won; Kim, Myung Sook [Kangbuk Samsung Hospital, Seoul (Korea, Republic of)

    1998-06-01

    The purpose of this study is to assess the usefulness of MRI in the preoperative diagnosis of breast implant-related complications. Thirty four breast implants in 17 patients were examined. Eight breasts had a history of repeated surgery due to rupture and in eight others, simultaneous interstitial silicone injection had been performed. MR images of the 34 implants were prospectively analyzed for implant-related complications, without prior clinical information, and the findings were compared with the results of surgery. MRI was an effective and useful method for the preoperative evaluation of implant-related complications; degree of contracture was successfully predicted. (author). 18 refs., 2 tabs., 5 figs.

  6. Imaging the premature brain: ultrasound or MRI?

    Energy Technology Data Exchange (ETDEWEB)

    Vries, Linda S. de; Benders, Manon J.N.L.; Groenendaal, Floris [UMC Utrecht, Department of Neonatology, Wilhelmina Children' s Hospital, PO Box 85090, Utrecht (Netherlands)

    2013-09-15

    Neuroimaging of preterm infants has become part of routine clinical care, but the question is often raised on how often cranial ultrasound should be done and whether every high risk preterm infant should at least have one MRI during the neonatal period. An increasing number of centres perform an MRI either at discharge or around term equivalent age, and a few centres have access to a magnet in or adjacent to the neonatal intensive care unit and are doing sequential MRIs. In this review, we try to discuss when best to perform these two neuroimaging techniques and the additional information each technique may provide. (orig.)

  7. Diagnostic value of MRI in tuberculous meningitis

    Energy Technology Data Exchange (ETDEWEB)

    Tayfun, C. [Dept. of Diagnostic Radiology, Guelhane Military Medical Academy and Medical School, Ankara (Turkey); Uecoez, T. [Dept. of Diagnostic Radiology, Guelhane Military Medical Academy and Medical School, Ankara (Turkey); Tasar, M [Dept. of Diagnostic Radiology, Guelhane Military Medical Academy and Medical School, Ankara (Turkey); Atac, K. [Dept. of Diagnostic Radiology, Guelhane Military Medical Academy and Medical School, Ankara (Turkey); Ogur, E. [Dept. of Diagnostic Radiology, Guelhane Military Medical Academy and Medical School, Ankara (Turkey); Oeztuerk, T. [Dept. of Diagnostic Radiology, Guelhane Military Medical Academy and Medical School, Ankara (Turkey); Yinanc, M.A. [Dept. of Diagnostic Radiology, Guelhane Military Medical Academy and Medical School, Ankara (Turkey)

    1996-06-01

    In this study 15 patients with clinical findings and positive cerebrospinal fluid analyses for tuberculous meningitis were evaluated with magnetic resonance imaging (MRI). Tuberculous meningitis was diagnosed in 11 cases when thick meningeal enhancement was present after intravenous injection of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) in T1-weighted images. Intra-axial tuberculomas were present in 8 patients, 2 of whom had intra-axial tuberculomas without MRI evidence of meningitis. Tuberculomas showed ring or nodular enhancement in postcontrast T1-weighted images, but the most significant MR feature of intraparenchymal tuberculomas was the hypointense appearance of the lesions on T2-weighted images. (orig.)

  8. Striatocapsular infarction: MRI and MR angiography

    Energy Technology Data Exchange (ETDEWEB)

    Croisille, P. (Dept. of Neuroradiology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Turjman, F. (Dept. of Neuroradiology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Croisile, B. (Dept. of Neurology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Tournut, P. (Dept. of Neuroradiology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Laharotte, J.C. (Dept. of Neuroradiology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Aimard, G. (Dept. of Neurology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Trillet, M. (Dept. of Neurology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Duquesnel, J. (Dept. of Neuroradiology, Hopital Neurologique et Neurochirurgical Pierre Wertheimer, Lyon (France)); Froment, J.C. (Dept. of Neuroradiology, Hopital Neurologique et Neurochirurgical Pierre

    1994-08-01

    We present a case of left striatocapsular infarction manifest clinically as a transient right hemiparesis. MRI showed a left striatocapsular infarct. Striatocapsular infarction, unlike lacunar infarction, is often associated with occlusive disease of the carotid artery. In order to screen the carotid vessels, cervical MR angiography (MRA) was performed during the same examination, demonstrating a left internal carotid artery occlusion, confirmed by contrast arteriography. MRA, a noninvasive modality, can be a useful adjunct to MRI, when diagnostic information concerning the cervical carotid artery is needed. (orig.)

  9. Isovaleric acidaemia: cranial CT and MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Sogut, Ayhan; Acun, Ceyda; Tomsac, Nazan; Demirel, Fatma [Department of Paediatrics, Karaelmas University, Zonguldak (Turkey); Aydin, Kubilay [Department of Radiology, Istanbul Medical School, Istanbul University, Camlikyolu, B. mehmetpasa sokak yavuz apt. No:10/10, Etiler, Istanbul (Turkey); Aktuglu, Cigdem [Department of Paediatrics, Cerrahpasa Medical School, Istanbul University, Istanbul (Turkey)

    2004-02-01

    Isovaleric acidaemia is an inborn error of leucine metabolism due to deficiency of isovaleryl-CoA dehydrogenase, which results in accumulation of isovaleric acid in body fluids. There are acute and chronic-intermittent forms of the disease. We present the cranial CT and MRI findings of a 19-month-old girl with the chronic-intermittent form of isovaleric acidaemia. She presented with severe metabolic acidosis, hyperglycaemia, glycosuria, ketonuria and acute encephalopathy. Cranial CT revealed bilateral hypodensity of the globi pallidi. MRI showed signal changes in the globi pallidi and corticospinal tracts of the mesencephalon, which were hypointense on T1-weighted and hyperintense on T2-weighted images. (orig.)

  10. In vitro MRI of brain development

    Energy Technology Data Exchange (ETDEWEB)

    Rados, Marko [Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 12, 10000 Zagreb (Croatia); Clinical Hospital Center Zagreb, School of Medicine, University of Zagreb, Kispaticeva 12, 10000 Zagreb (Croatia); Judas, Milos [Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 12, 10000 Zagreb (Croatia); Kostovic, Ivica [Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 12, 10000 Zagreb (Croatia)]. E-mail: ikostov@hiim.h

    2006-02-15

    In this review, we demonstrate the developmental appearance, structural features, and reorganization of transient cerebral zones and structures in the human fetal brain using a correlative histological and MRI analysis. The analysis of postmortem aldehyde-fixed specimens (age range: 10 postovulatory weeks to term) revealed that, at 10 postovulatory weeks, the cerebral wall already has a trilaminar appearance and consists of: (1) a ventricular zone of high cell-packing density; (2) an intermediate zone; (3) the cortical plate (in a stage of primary consolidation) with high MRI signal intensity. The anlage of the hippocampus is present as a prominent bulging in the thin limbic telencephalon. The early fetal telencephalon impar also contains the first commissural fibers and fornix bundles in the septal area. The ganglionic eminence is clearly visible as an expanded continuation of the proliferative ventricular zone. The basal ganglia showed an initial aggregation of cells. The most massive fiber system is in the hemispheric stalk, which is in continuity with thalamocortical fibers. During the mid-fetal period (15-22 postovulatory weeks), the typical fetal lamination pattern develops and the cerebral wall consists of the following zones: (a) a marginal zone (visible on MRI exclusively in the hippocampus); (b) the cortical plate with high cell-packing density and high MRI signal intensity; (c) the subplate zone, which is the most prominent zone rich in extracellular matrix and with a very low MRI signal intensity; (d) the intermediate zone (fetal 'white matter'); (e) the subventricular zone; (f) the periventricular fiber-rich zone; (g) the ventricular zone. The ganglionic eminence is still a very prominent structure with an intense proliferative activity. During the next period (22-26 postovulatory weeks), there is the developmental peak of transient MRI features, caused by the high content of hydrophyllic extracellular matrix in the subplate zone and the

  11. Support Vector Machine Classification For MRI Images

    OpenAIRE

    Rajeswari S; Theiva Jeyaselvi. K

    2012-01-01

    -Magnetic resonance imaging (MRI) is an imaging technique that has played an important role in neuro science research for studying brain images. Classification is an important part in order to distinguish between normal patients and those who have the p o s s i b i l i t y o f h a v i n g a b n o r m a l i t i e s o r tumor. In this paper, we have obtained the texture based features such as GLCM (Grey Level Co-occurrence Matrix) of MRI images. To select the discriminative features among them ...

  12. [Advanced MRI techniques of the fetal brain].

    Science.gov (United States)

    Schöpf, V; Dittrich, E; Berger-Kulemann, V; Kasprian, G; Kollndorfer, K; Prayer, D

    2013-02-01

    Evaluation of the normal and pathological fetal brain. Magnetic resonance imaging (MRI). Advanced MRI of the fetal brain. Diffusion tensor imaging (DTI) is used in clinical practice, all other methods are used at a research level. Serving as standard methods in the future. Combined structural and functional data for all gestational ages will allow more specific insight into the developmental processes of the fetal brain. This gain of information will help provide a common understanding of complex spatial and temporal procedures of early morphological features and their impact on cognitive and sensory abilities.

  13. MRI imaging of tuberculum sellae meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Kuchiki, Megumi; Hosoya, Takaaki; Watanabe, Nami; Nagahata, Morio; Yamaguchi, Koichi [Yamagata Univ. (Japan). School of Medicine

    1996-02-01

    We reviewed three MRI cases of suprasellar meningioma in comparison with the other sella region tumors. T1-weighted images of pre- and post contrast enhancement could clearly delineate the optic chiasm, optic nerve and pituitary gland. MRI findings of tuberculum sellae meningioma were characterized as follows. The pituitary gland was easily identified and compressed postero-inferiorly in the sella. The pituitary stalk was backward compressed by the tumor. The optic chiasm was compressed posteriorly or postero-superiorly by the tumor. It was important for its differential diagnosis to identify the displacement direction of the structures in and around the sella. (author).

  14. Lymphocytic adenohypophysitis: skull radiographs and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Saiwai, S.; Miyamoto, T. [Department of Radiology, Kobe Central Municipal Hospital, Hyogo (Japan); Inoue, Y.; Nemoto, Y.; Tashiro, T. [Department of Radiology, Osaka City University Medical School (Japan); Ishihara, T. [Department of Endocrinology, Kobe Central Municipal Hospital, Hyogo (Japan); Matsumoto, S. [Department of Neurosurgery, Kobe Central Municipal Hospital, Hyogo (Japan); Hakuba, A. [Department of Neurosurgery, Osaka City University Medical School, 1-5-7 Asahimachi, Abeno, Osaka, 545 (Japan)

    1998-02-01

    We report the skull radiograph, CT and MRI findings in three patients with lymphocytic adenohypophysitis mimicking pituitary adenoma. All cases were associated with pregnancy. CT demonstrated a pituitary mass but did not differentiate lymphocytic adenohypophysitis from pituitary adenoma. The skull radiographs showed either a normal sella turcica or minimal abnormalities; they did not show ballooning or destruction. The MRI appearances were distinctive: relatively low signal on T1-weighted images; preservation of the bright posterior pituitary lobe despite the presence of a relatively large pituitary mass, less common in macroadenomas; marked contrast enhancement compared with pituitary macroadenomas; and dural enhancement adjacent to a pituitary mass. (orig.) With 3 figs., 1 tab., 40 refs.

  15. Temperature mapping of thermal ablation using MRI.

    Science.gov (United States)

    Samset, Eigil

    2006-01-01

    MRI is a unique tool for minimally invasive thermal ablation in that it can provide both targeting, monitoring and control during the procedure. Monitoring is achieved by using MRI temperature mapping. In this review the relevant physics is explained as a background to the state-of-the-art methods for computing temperature maps as well as the more cutting edge methods. The review covers both methods to monitor heating and cooling of tissue and explains temperature mapping using Proton Resonance Frequency shift, T1 mapping, diffusion mapping, R2* mapping and thermal models.

  16. FULLY AUTOMATIC FRAMEWORK FOR SEGMENTATION OF BRAIN MRI IMAGE

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Automaticbraintissuesegmentationfrommag neticresonanceimages(MRI)isofgreatimportance forresearchandclinicalstudyofmuchneurological pathology.Duringthepastdecade,theMRIhashad agreatimpactonthediagnosticimagingofmosthu manorgansystem.ThesegmentationofbrainMRI imagesplaysanimportantroleinthevolumerecon structionforavarietyofmedicalimageanalysis, computer aideddiagnosis,three dimensionalrecon structionandvisualizationapplications.Theaccu rateSegmentationofMRimagesintodifferenttis sueclasses,especiallygray...

  17. Fetal MRI in Prenatal Diagnosis of CNS Abnormalities

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2009-02-01

    Full Text Available The value of fetal MRI (fMRI compared to ultrasound in the prenatal detection of CNS abnormalities and impact on counseling were determined in 25 pregnant women examined at University of Dusseldorf, Germany.

  18. In utero MRI diagnosis of fetal malformations in oligohydramnios

    Directory of Open Access Journals (Sweden)

    Ahmed Hesham Said

    2016-12-01

    Conclusion: MRI is valuable in evaluating suspected fetal malformations especially those related to brain and urinary system when ultrasound is inconclusive owing to oligohydramnios. Fetal MRI can add findings that may modify prenatal diagnosis.

  19. Evaluation of MRI-TRUS fusion versus cognitive registration accuracy for MRI-targeted, TRUS-guided prostate biopsy.

    Science.gov (United States)

    Cool, Derek W; Zhang, Xuli; Romagnoli, Cesare; Izawa, Jonathan I; Romano, Walter M; Fenster, Aaron

    2015-01-01

    The purpose of this article is to compare transrectal ultrasound (TRUS) biopsy accuracies of operators with different levels of prostate MRI experience using cognitive registration versus MRI-TRUS fusion to assess the preferred method of TRUS prostate biopsy for MRI-identified lesions. SUBJECTS AND METHODS; One hundred patients from a prospective prostate MRI-TRUS fusion biopsy study were reviewed to identify all patients with clinically significant prostate adenocarcinoma (PCA) detected on MRI-targeted biopsy. Twenty-five PCA tumors were incorporated into a validated TRUS prostate biopsy simulator. Three prostate biopsy experts, each with different levels of experience in prostate MRI and MRI-TRUS fusion biopsy, performed a total of 225 simulated targeted biopsies on the MRI lesions as well as regional biopsy targets. Simulated biopsies performed using cognitive registration with 2D TRUS and 3D TRUS were compared with biopsies performed under MRI-TRUS fusion. Two-dimensional and 3D TRUS sampled only 48% and 45% of clinically significant PCA MRI lesions, respectively, compared with 100% with MRI-TRUS fusion. Lesion sampling accuracy did not statistically significantly vary according to operator experience or tumor volume. MRI-TRUS fusion-naïve operators showed consistent errors in targeting of the apex, midgland, and anterior targets, suggesting that there is biased error in cognitive registration. The MRI-TRUS fusion expert correctly targeted the prostate apex; however, his midgland and anterior mistargeting was similar to that of the less-experienced operators. MRI-targeted TRUS-guided prostate biopsy using cognitive registration appears to be inferior to MRI-TRUS fusion, with fewer than 50% of clinically significant PCA lesions successfully sampled. No statistically significant difference in biopsy accuracy was seen according to operator experience with prostate MRI or MRI-TRUS fusion.

  20. Standard high-resolution pelvic MRI vs. low-resolution pelvic MRI in the evaluation of deep infiltrating endometriosis

    Energy Technology Data Exchange (ETDEWEB)

    Scardapane, Arnaldo; Lorusso, Filomenamila; Ferrante, Annunziata; Stabile Ianora, Amato Antonio; Angelelli, Giuseppe [University Hospital ' ' Policlinico' ' of Bari, Interdisciplinary Department of Medicine, Bari (Italy); Scioscia, Marco [Sacro Cuore Don Calabria General Hospital, Department of Obstetrics and Gynecology, Negrar, Verona (Italy)

    2014-10-15

    To compare the capabilities of standard pelvic MRI with low-resolution pelvic MRI using fast breath-hold sequences to evaluate deep infiltrating endometriosis (DIE). Sixty-eight consecutive women with suspected DIE were studied with pelvic MRI. A double-acquisition protocol was carried out in each case. High-resolution (HR)-MRI consisted of axial, sagittal, and coronal TSE T2W images, axial TSE T1W, and axial THRIVE. Low-resolution (LR)-MRI was acquired using fast single shot (SSH) T2 and T1 images. Two radiologists with 10 and 2 years of experience reviewed HR and LR images in two separate sessions. The presence of endometriotic lesions of the uterosacral ligament (USL), rectovaginal septum (RVS), pouch of Douglas (POD), and rectal wall was noted. The accuracies of LR-MRI and HR-MRI were compared with the laparoscopic and histopathological findings. Average acquisition times were 24 minutes for HR-MRI and 7 minutes for LR-MRI. The more experienced radiologist achieved higher accuracy with both HR-MRI and LR-MRI. The values of sensitivity, specificity, PPV, NPV, and accuracy did not significantly change between HR and LR images or interobserver agreement for all of the considered anatomic sites. LR-MRI performs as well as HR-MRI and is a valuable tool for the detection of deep endometriosis extension. (orig.)