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Sample records for surveys magnetic resonance

  1. Cardiovascular magnetic resonance activity in the United Kingdom: a survey on behalf of the british society of cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Dargie Henry J

    2011-10-01

    Full Text Available Abstract Background The indications, complexity and capabilities of cardiovascular magnetic resonance (CMR have rapidly expanded. Whether actual service provision and training have developed in parallel is unknown. Methods We undertook a systematic telephone and postal survey of all public hospitals on behalf of the British Society of Cardiovascular Magnetic Resonance to identify all CMR providers within the United Kingdom. Results Of the 60 CMR centres identified, 88% responded to a detailed questionnaire. Services are led by cardiologists and radiologists in equal proportion, though the majority of current trainees are cardiologists. The mean number of CMR scans performed annually per centre increased by 44% over two years. This trend was consistent across centres of different scanning volumes. The commonest indication for CMR was assessment of heart failure and cardiomyopathy (39%, followed by coronary artery disease and congenital heart disease. There was striking geographical variation in CMR availability, numbers of scans performed, and distribution of trainees. Centres without on site scanning capability refer very few patients for CMR. Just over half of centres had a formal training programme, and few performed regular audit. Conclusion The number of CMR scans performed in the UK has increased dramatically in just two years. Trainees are mainly located in large volume centres and enrolled in cardiology as opposed to radiology training programmes.

  2. Magnetic Resonance (MR) Defecography

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Magnetic Resonance (MR) Defecography Magnetic resonance (MR) defecography is a ... the limitations of MRI defecography? What is magnetic resonance (MR) defecography? Magnetic resonance imaging (MRI) is a ...

  3. 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) ...

  4. Magnetic Resonance Imaging

    Science.gov (United States)

    ... specific information about your own examination. What is magnetic resonance imaging (MRI)? What is MRI used for? How safe ... What is the MRI examination like? What is magnetic resonance imaging (MRI)? MRI, or magnetic resonance imaging, is a ...

  5. Studying Autism Spectrum Disorder with Structural and Diffusion Magnetic Resonance Imaging: A Survey

    Science.gov (United States)

    Ismail, Marwa M. T.; Keynton, Robert S.; Mostapha, Mahmoud M. M. O.; ElTanboly, Ahmed H.; Casanova, Manuel F.; Gimel'farb, Georgy L.; El-Baz, Ayman

    2016-01-01

    Magnetic resonance imaging (MRI) modalities have emerged as powerful means that facilitate non-invasive clinical diagnostics of various diseases and abnormalities since their inception in the 1980s. Multiple MRI modalities, such as different types of the sMRI and DTI, have been employed to investigate facets of ASD in order to better understand this complex syndrome. This paper reviews recent applications of structural magnetic resonance imaging (sMRI) and diffusion tensor imaging (DTI), to study autism spectrum disorder (ASD). Main reported findings are sometimes contradictory due to different age ranges, hardware protocols, population types, numbers of participants, and image analysis parameters. The primary anatomical structures, such as amygdalae, cerebrum, and cerebellum, associated with clinical-pathological correlates of ASD are highlighted through successive life stages, from infancy to adulthood. This survey demonstrates the absence of consistent pathology in the brains of autistic children and lack of research investigations in patients under 2 years of age in the literature. The known publications also emphasize advances in data acquisition and analysis, as well as significance of multimodal approaches that combine resting-state, task-evoked, and sMRI measures. Initial results obtained with the sMRI and DTI show good promise toward the early and non-invasive ASD diagnostics. PMID:27242476

  6. Studying Autism Spectrum Disorder with Structural and Diffusion Magnetic Resonance Imaging: A Survey

    Directory of Open Access Journals (Sweden)

    Marwa Maher Tawfik Ismail

    2016-05-01

    Full Text Available Magnetic resonance imaging (MRI modalities have emerged as powerful means that facilitatenon-invasive clinical diagnostics of various diseases and abnormalities since their inception in the1980s. Multiple MRI modalities, such as different types of the sMRI and DTI, have been employedto investigate facets of ASD in order to better understand this complex syndrome. This paperreviews recent applications of structural magnetic resonance imaging (sMRI and diffusion tensorimaging (DTI, to study autism spectrum disorder (ASD. Main reported findings are sometimescontradictory due to different age ranges, hardware protocols, population types, numbers of participants,and image analysis parameters. The primary anatomical structures, such as amygdalae,cerebrum, and cerebellum, associated with clinical-pathological correlates of ASD are highlightedthrough successive life stages, from infancy to adulthood. This survey demonstrates the absenceof consistent pathology in the brains of autistic children and lack of research investigations in patientsunder two years of age in the literature. The known publications also emphasize advancesin data acquisition and analysis, as well as significance of multimodal approaches that combineresting-state, task-evoked, and sMRI measures. Initial results obtained with the sMRI and DTIshow good promise towards the early and non-invasive ASD diagnostics.

  7. Magnetic resonance angiography

    Science.gov (United States)

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

  8. Using magnetic resonance imaging in diagnosing dementia: a Dutch outpatient memory clinics survey.

    Science.gov (United States)

    Boelaarts, Leo; Scheltens, Philip; de Jonghe, Jos

    2014-01-01

    In the Netherlands, dementia syndromes are diagnosed in specialized memory outpatient clinics (MC). Many radiologists are not trained to assess magnetic resonance imaging (MRI) scans with respect to possible radiological changes that may indicate neurodegenerative disease. This is a cross-sectional descriptive study. A survey was sent to all Dutch MC and included questions as to how MRI scans are assessed by radiologists and how these assessments are used in the diagnostic process. In most MC, radiologists report on typical Alzheimer pathology and large vessel disease. Small vessel disease and other anatomical changes signifying neurodegenerative disease frequently are not assessed. In the majority of MC, the radiological assessment is not standardized, and physicians assess MRI for themselves to use this information to discuss the consensus diagnosis subsequently. MRI assessment by radiologists in Dutch MC probably underestimates the presence of cerebrovascular and neurodegenerative disease. The validity of standardized assessment protocols in routine clinical practice deserves further study, as the implementation of standardization outside research settings could improve diagnostic accuracy.

  9. Single-centre survey of the application of cardiovascular magnetic resonance in clinical routine.

    Science.gov (United States)

    von Knobelsdorff-Brenkenhoff, Florian; Bublak, Angelika; El-Mahmoud, Sana; Wassmuth, Ralf; Opitz, Christian; Schulz-Menger, Jeanette

    2013-01-01

    Awareness of cardiovascular magnetic resonance (CMR) is growing due to increasing evidence for providing relevant functional and morphologic information. This single-centre survey aimed at providing descriptive data about the clinical application and potential impact of CMR. All 2598 clinically indicated CMR exams were prospectively registered during 1 year in one single centre. Detailed data of the individual patient and procedural information of each exam were collected. In a simulation of CMR-based clinical decision-making in a subgroup of 250 cases, the influence of CMR on further diagnostic testing and answering the clinical question was estimated. Inflammatory (31%) and coronary (28%) heart disease were the most frequent indications. The exams were fast (98% overcome claustrophobia in 3.8%. Two per cent of all exams were terminated prematurely. No severe adverse events occurred. All moderate adverse events (0.5%) were associated with stress medication (1.7% of all stress tests) or contrast media (0.15% of all contrast enhanced studies). In the simulation, CMR influenced the individual selection of diagnostic testing and provided valuable information to establish or exclude a diagnosis. This single-centre experience demonstrated a versatile application of CMR at reasonable time expense, safety, and robustness. The simulation of CMR-based decision-making indicated that CMR may influence patient management.

  10. Magnetic Resonance Imaging (MRI) -- Head

    Science.gov (United States)

    ... 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 ...

  11. Magnetic Resonance Imaging (MRI) - Spine

    Science.gov (United States)

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

  12. Magnetic Resonance Force Microscopy System

    Data.gov (United States)

    Federal Laboratory Consortium — The Magnetic Resonance Force Microscopy (MRFM) system, developed by ARL, is the world's most sensitive nuclear magnetic resonance (NMR) spectroscopic analysis tool,...

  13. Magnetic Resonance Sensors

    Directory of Open Access Journals (Sweden)

    Robert H. Morris

    2014-11-01

    Full Text Available Magnetic Resonance finds countless applications, from spectroscopy to imaging, routinely in almost all research and medical institutions across the globe. It is also becoming more frequently used for specific applications in which the whole instrument and system is designed for a dedicated application. With beginnings in borehole logging for the petro-chemical industry Magnetic Resonance sensors have been applied to fields as varied as online process monitoring for food manufacture and medical point of care diagnostics. This great diversity is seeing exciting developments in magnetic resonance sensing technology published in application specific journals where they are often not seen by the wider sensor community. It is clear that there is enormous interest in magnetic resonance sensors which represents a significant growth area. The aim of this special edition of Sensors was to address the wide distribution of relevant articles by providing a forum to disseminate cutting edge research in this field in a single open source publication.[...

  14. Ghost magnetic resonance angiography

    National Research Council Canada - National Science Library

    Koktzoglou, Ioannis; Edelman, Robert R

    2009-01-01

    Traditional methods for magnetic resonance angiography (MRA) involve the radiofrequency excitation of vascular spins within a selected region of tissue, followed by gradient localization and imaging of those spins within that same region...

  15. Magnetic Resonance Sensors

    OpenAIRE

    Morris, RH; Newton, MI

    2014-01-01

    Magnetic Resonance finds countless applications, from spectroscopy to imaging, routinely in almost all research and medical institutions across the globe. It is also becoming more frequently used for specific applications in which the whole instrument and system is designed for a dedicated application. With beginnings in borehole logging for the petro-chemical industry Magnetic Resonance sensors have been applied to fields as varied as online process monitoring for food manufacture and medica...

  16. Nuclear Magnetic Resonance Spectroscopy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 1. Nuclear Magnetic Resonance Spectroscopy. Susanta Das. General Article Volume 9 Issue 1 January 2004 pp 34-49. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/009/01/0034-0049. Keywords.

  17. Interventional Cardiovascular Magnetic Resonance Imaging

    Science.gov (United States)

    Saikus, Christina E.; Lederman, Robert J.

    2010-01-01

    Cardiovascular magnetic resonance (CMR) combines excellent soft-tissue contrast, multiplanar views, and dynamic imaging of cardiac function without ionizing radiation exposure. Interventional cardiovascular magnetic resonance (iCMR) leverages these features to enhance conventional interventional procedures or to enable novel ones. Although still awaiting clinical deployment, this young field has tremendous potential. We survey promising clinical applications for iCMR. Next, we discuss the technologies that allow CMR-guided interventions and, finally, what still needs to be done to bring them to the clinic. PMID:19909937

  18. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) uses a powerful magnetic field, radio waves ...

  19. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    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 magnetic field, radio waves and a computer to produce ...

  20. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) uses a powerful magnetic field, radio ...

  1. Geometric survey on magnetic resonance imaging of growth hormone producing pituitary adenoma.

    Science.gov (United States)

    Bakhtiar, Yuriz; Hanaya, Ryosuke; Tokimura, Hiroshi; Hirano, Hirofumi; Oyoshi, Tatsuki; Fujio, Shingo; Bohara, Manoj; Arita, Kazunori

    2014-04-01

    Apart from the radiologic features regarding size and invasiveness, we had noticed some differences in morphology among types of pituitary adenomas. We conducted this study to verify the differences in radiologic morphology between growth hormone producing pituitary adenomas (GHoma) and nonfunctioning pituitary adenomas (NFoma). Pre-surgical magnetic resonance images (MRIs) were assessed in 50 cases of GHoma and 50 cases of NFoma. Geometric parameters on MRI were set in accordance with sellar anatomy. Intensity of T1-weighted image was not different between the two groups, but hypo-intensity of T2-weighted image was more frequently seen in GHoma. Predominant inferior extension of tumor was seen mostly in GHoma (88 vs. 38%). Extension of the tumor to the superior compartment of cavernous sinus was more frequent in NFoma. Pituitary gland was generally located superior to GHoma and postero-superior to NFoma. Growth characteristics of pituitary adenoma were confirmed to differ between GHoma and NFoma.

  2. Magnetic Resonance Safety

    OpenAIRE

    Sammet, Steffen

    2016-01-01

    Magnetic Resonance Imaging (MRI) has a superior soft-tissue contrast compared to other radiological imaging modalities and its physiological and functional applications have led to a significant increase in MRI scans worldwide. A comprehensive MRI safety training to protect patients and other healthcare workers from potential bio-effects and risks of the magnetic fields in an MRI suite is therefore essential. The knowledge of the purpose of safety zones in an MRI suite as well as MRI appropri...

  3. Nuclear Magnetic Resonance

    Indian Academy of Sciences (India)

    IAS Admin

    This article summarizes the early history of nuclear magnetic resonance (NMR) during the first 25–30 years. The method- ology went through vigorous growth and development during this time, laying the theoretical basis for understanding a wide array of applications. The stage was set for the breath- taking advances the ...

  4. Functional Magnetic Resonance Imaging

    Science.gov (United States)

    Voos, Avery; Pelphrey, Kevin

    2013-01-01

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

  5. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... information on the chemicals present in the body's cells, may also be performed during the MRI exam ... and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging ( ...

  6. Magnetic Resonance Imaging (MRI) Safety

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) Safety What is MRI and how does it ... and MRI Breast-feeding and MRI What is MRI and how does it work? Magnetic resonance imaging, ...

  7. 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 ...

  8. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... the same effect. A very irregular heartbeat may affect the quality of images obtained using techniques that ... and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging ( ...

  9. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... 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 ...

  10. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... data suggest that it is safe to continue breastfeeding after receiving intravenous contrast. For further information please ... Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic Resonance Imaging ( ...

  11. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... for Brain Tumors Radiation Therapy for Head and Neck Cancer Others : American Stroke Association National Stroke Association ... MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging ( ...

  12. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... may sense a temporary metallic taste in their mouth after the contrast injection. If you do not ... Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic Resonance Imaging ( ...

  13. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... and You Take our survey Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) ... Carotid Intima-Media Thickness Test Medical Imaging Costs Video: Abdominal Ultrasound Video: Pelvic Ultrasound Radiology and You ...

  14. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    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 ...

  15. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) uses a powerful ... of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a noninvasive medical ...

  16. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging ( ... the limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a ...

  17. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  18. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) ... limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a noninvasive ...

  19. Molecular Cardiovascular Magnetic Resonance

    DEFF Research Database (Denmark)

    Bender, Yvonne Y; Pfeifer, Andreas; Ebersberger, Hans U

    2016-01-01

    In the Western world and developing countries, the number one causes of mortality and morbidity result from cardiovascular diseases. Cardiovascular diseases represent a wide range of pathologies, including myocardial infarction, peripheral vascular disease, and cerebrovascular disease, which...... impact on society, there are still limitations in the early diagnosis and the prevention of the disease. Current imaging methods mainly focus on morphological changes that occur at an advanced disease stage, e.g., degree of stenosis. Cardiovascular magnetic resonance imaging and specifically molecular...... cardiovascular magnetic resonance imaging are capable to reveal pathophysiological changes already occurring during early atherosclerotic plaque formation. This allows for the assessment of cardiovascular disease on a level, which goes beyond morphological or anatomical criteria. In this review, we...

  20. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... magnetic resonance imaging (MRI) uses a powerful magnetic field, radio waves and a computer to produce detailed ... problems, medications, recent surgeries and allergies. The magnetic field is not harmful, but it may cause some ...

  1. [Nuclear magnetic resonance tomography].

    Science.gov (United States)

    Ganssen, A; Loeffler, W; Oppelt, A; Schmidt, F

    1981-04-01

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

  2. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... techniques that time the imaging based on the electrical activity of the heart, such as electrocardiography (ECG). ... Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging (MRI) Safety Contrast Materials Children ...

  3. Cardiovascular Magnetic Resonance Imaging

    Science.gov (United States)

    Pelc, Norbert

    2000-03-01

    Cardiovascular diseases are a major source of morbidity and mortality in the United States. Early detection of disease can often be used to improved outcomes, either through direct interventions (e.g. surgical corrections) or by causing the patient to modify his or her behavior (e.g. smoking cessation or dietary changes). Ideally, the detection process should be noninvasive (i.e. it should not be associated with significant risk). Magnetic Resonance Imaging (MRI) refers to the formation of images by localizing NMR signals, typically from protons in the body. As in other applications of NMR, a homogeneous static magnetic field ( ~0.5 to 4 T) is used to create ``longitudinal" magnetization. A magnetic field rotating at the Larmor frequency (proportional to the static field) excites spins, converting longitudinal magnetization to ``transverse" magnetization and generating a signal. Localization is performed using pulsed gradients in the static field. MRI can produce images of 2-D slices, 3-D volumes, time-resolved images of pseudo-periodic phenomena such as heart function, and even real-time imaging. It is also possible to acquire spatially localized NMR spectra. MRI has a number of advantages, but perhaps the most fundamental is the richness of the contrast mechanisms. Tissues can be differentiated by differences in proton density, NMR properties, and even flow or motion. We also have the ability to introduce substances that alter NMR signals. These contrast agents can be used to enhance vascular structures and measure perfusion. Cardiovascular MRI allows the reliable diagnosis of important conditions. It is possible to image the blood vessel tree, quantitate flow and perfusion, and image cardiac contraction. Fundamentally, the power of MRI as a diagnostic tool stems from the richness of the contrast mechanisms and the flexibility in control of imaging parameters.

  4. Advances in magnetic resonance 11

    CERN Document Server

    Waugh, John S

    2013-01-01

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

  5. Advances in magnetic resonance 6

    CERN Document Server

    Waugh, John S

    2013-01-01

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

  6. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... an IV line, into a vein in your hand or arm. A saline solution may be used ... Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...

  7. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... Videos About Us News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic ... very early stage by mapping the motion of water molecules in the tissue. This water motion, known ...

  8. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  9. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... a CD or uploaded to a digital cloud server. Currently, MRI is the most sensitive imaging test ... Brain Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...

  10. 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 ... Brain Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...

  11. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... resonance imaging (MRI) 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 ...

  12. Partially orthogonal resonators for magnetic resonance imaging

    Science.gov (United States)

    Chacon-Caldera, Jorge; Malzacher, Matthias; Schad, Lothar R.

    2017-02-01

    Resonators for signal reception in magnetic resonance are traditionally planar to restrict coil material and avoid coil losses. Here, we present a novel concept to model resonators partially in a plane with maximum sensitivity to the magnetic resonance signal and partially in an orthogonal plane with reduced signal sensitivity. Thus, properties of individual elements in coil arrays can be modified to optimize physical planar space and increase the sensitivity of the overall array. A particular case of the concept is implemented to decrease H-field destructive interferences in planar concentric in-phase arrays. An increase in signal to noise ratio of approximately 20% was achieved with two resonators placed over approximately the same planar area compared to common approaches at a target depth of 10 cm at 3 Tesla. Improved parallel imaging performance of this configuration is also demonstrated. The concept can be further used to increase coil density.

  13. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging ( ...

  14. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... have special pediatric considerations. 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) ...

  15. Advances in magnetic resonance 12

    CERN Document Server

    Waugh, John S

    2013-01-01

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

  16. Market applications of Resistivity, Induced Polarisation, Magnetic Resonance and Electromagnetic methods for Groundwater Investigations, Mining Exploration, Environmental and Engineering Surveys

    Science.gov (United States)

    Bernard, J.

    2012-12-01

    The Manufacturers of geophysical instruments have been facing these past decades the fast evolution of the electronics and of the computer sciences. More automatisms have been introduced into the equipment and into the processing and interpretation software which may let believe that conducting geophysical surveys requires less understanding of the method and less experience than in the past. Hence some misunderstandings in the skills that are needed to make the geophysical results well integrated among the global information which the applied geologist needs to acquire to be successful in his applications. Globally, the demand in geophysical investigation goes towards more penetration depth, requiring more powerful transmitters, and towards a better resolution, requiring more data such as in 3D analysis. Budgets aspects strongly suggest a high efficiency in the field associated to high speed data processing. The innovation is required in all aspects of geophysics to fit with the market needs, including new technological (instruments, software) and methodological (methods, procedures, arrays) developments. The structures in charge of the geophysical work can be public organisations (institutes, ministries, geological surveys,…) or can come from the private sector (large companies, sub-contractors, consultants, …), each one of them getting their own constraints in the field work and in the processing and interpretation phases. In the applications concerning Groundwater investigations, Mining Exploration, Environmental and Engineering surveys, examples of data and their interpretation presently carried out all around the world will be presented for DC Resistivity (Vertical Electrical Sounding, 2D, 3D Resistivity Imaging, Resistivity Monitoring), Induced Polarisation (Time Domain 2D, 3D arrays for mining and environmental), Magnetic Resonance Sounding (direct detection and characterisation of groundwater) and Electromagnetic (multi-component and multi

  17. Low field magnetic resonance imaging

    Science.gov (United States)

    Pines, Alexander; Sakellariou, Dimitrios; Meriles, Carlos A.; Trabesinger, Andreas H.

    2010-07-13

    A method and system of magnetic resonance imaging does not need a large homogenous field to truncate a gradient field. Spatial information is encoded into the spin magnetization by allowing the magnetization to evolve in a non-truncated gradient field and inducing a set of 180 degree rotations prior to signal acquisition.

  18. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... Children’s magnetic resonance imaging (MRI) uses a powerful magnetic field, radio waves and a computer to produce detailed ... health problems, medications, recent surgeries and allergies. The magnetic field is not harmful, but it may cause some ...

  19. Advances in magnetic resonance 1

    CERN Document Server

    Waugh, John S

    2013-01-01

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

  20. Advances in magnetic resonance 9

    CERN Document Server

    Waugh, John S

    2013-01-01

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

  1. Nuclear magnetic resonance contrast agents

    Science.gov (United States)

    Smith, P.H.; Brainard, J.R.; Jarvinen, G.D.; Ryan, R.R.

    1997-12-30

    A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC{sub 16}H{sub 14}N{sub 6}. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques. 10 figs.

  2. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Recently posted: Carotid Intima-Media Thickness Test Medical Imaging Costs Video: Abdominal Ultrasound Video: Pelvic Ultrasound Radiology and You Take our survey Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot ...

  3. Magnetic resonance imaging (MRI) in syringomyelia

    NARCIS (Netherlands)

    H.L.J. Tanghe (Hervé)

    1995-01-01

    textabstractBased on an own material of 19 patients with syringomyelia and on the related literature a survey is given on the diagnosis, differential diagnosis, postoperative evaluation and the dynamics of CSF and cyst fluids, using magnetic resonance imaging (MRI). The following conclusions can

  4. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging (MRI) Safety Contrast Materials Children and Radiation Safety Videos related to Children’s ( ...

  5. Magnetic resonance imaging the basics

    CERN Document Server

    Constantinides, Christakis

    2014-01-01

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

  6. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... be necessary. Your doctor will explain the exact reason why another exam is requested. Sometimes a follow- ... necessary in trauma situations. Although there is no reason to believe that magnetic resonance imaging harms the ...

  7. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... and may cause you and/or others nearby harm. These items include: jewelry, watches, credit cards and ... no reason to believe that magnetic resonance imaging harms the fetus, pregnant women usually are advised not ...

  8. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... have a personal story about radiology? Share your patient story here Images ... (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging (MRI) ...

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... scanner. top of page How does the procedure work? Unlike conventional x-ray examinations and computed tomography ( ... that magnetic resonance imaging harms the fetus, pregnant women usually are advised not to have an MRI ...

  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. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... or thyroid problems. Any of these conditions may influence the decision on whether contrast material will be ... bear denotes child-specific content. Related Articles and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's ( ...

  12. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... monitors so that your child may watch a movie or TV show during the exam. It is ... patient for magnetic resonance imaging (MRI) exam. View full size with caption Pediatric Content Some imaging tests ...

  13. 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) is a noninvasive ... top of page What are some common uses of the procedure? MR imaging of the head is ...

  14. Magnetic Resonance Imaging (MRI) -- Head

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

  15. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... have a personal story about radiology? Share your patient story here Images × Image Gallery Magnetic Resonance Imaging (MRI) procedure View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  16. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... patient story here Images × Image Gallery Radiologist prepping patient for magnetic resonance imaging (MRI) exam. View full size with caption Pediatric Content Some imaging tests and treatments have special ...

  17. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... are the limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging ( ... brain) in routine clinical practice. top of page What are some common uses of the procedure? MR ...

  18. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... story about radiology? Share your patient story here Images × Image Gallery Magnetic Resonance Imaging (MRI) procedure View full ... possible charges you will incur. Web page review process: This Web page is reviewed regularly by a ...

  19. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... story about radiology? Share your patient story here Images × Image Gallery Radiologist prepping patient for magnetic resonance imaging ( ... possible charges you will incur. Web page review process: This Web page is reviewed regularly by a ...

  20. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... bones of the skull and spine without radiation. MRI of the brain and spine is used to: detect a variety ... and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT ... and Radiation Safety ...

  1. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    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 ...

  2. Advances in magnetic resonance 4

    CERN Document Server

    Waugh, John S

    2013-01-01

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

  3. Advances in magnetic resonance 2

    CERN Document Server

    Waugh, John S

    2013-01-01

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

  4. Magnetic resonance imaging; Imagerie par resonance magnetique

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-04-01

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

  5. Advances in magnetic resonance 5

    CERN Document Server

    Waugh, John S

    2013-01-01

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

  6. Magnetic Resonance Force Microscope Development

    Energy Technology Data Exchange (ETDEWEB)

    Hammel, P.C.; Zhang, Z.; Suh, B.J.; Roukes, M.L.; Midzor, M.; Wigen, P.E.; Childress, J.R.

    1999-06-03

    Our objectives were to develop the Magnetic Resonance Force Microscope (MRFM) into an instrument capable of scientific studies of buried structures in technologically and scientifically important electronic materials such as magnetic multilayer materials. This work resulted in the successful demonstration of MRFM-detected ferromagnetic resonance (FMR) as a microscopic characterization tool for thin magnetic films. Strong FMR spectra obtained from microscopic Co thin films (500 and 1000 angstroms thick and 40 x 200 microns in lateral extent) allowed us to observe variations in sample inhomogeneity and magnetic anisotropy field. We demonstrated lateral imaging in microscopic FMR for the first time using a novel approach employing a spatially selective local field generated by a small magnetically polarized spherical crystallite of yttrium iron garnet. These successful applications of the MRFM in materials studies provided the basis for our successful proposal to DOE/BES to employ the MRF M in studies of buried interfaces in magnetic materials.

  7. Magnetic resonance imaging

    Science.gov (United States)

    Liu, Wei; Fan, Jin; Bai, Jianling; Tang, Pengyu; Chen, Jian; Luo, Yongjun; Zhou, Kuai; Cai, Weihua

    2017-01-01

    Abstract Background and Objectives: Convincing evidence supporting the use of magnetic resonance imaging (MRI) as an effective tool for evaluating cervical sagittal alignment is lacking. This study aims to analyze the differences and correlations between cervical sagittal parameters on x-ray and MRI in patients with cervical disc herniation and to determine whether MRI could substitute for cervical x-ray for measurement of cervical sagittal parameters. Methods: One hundred forty-three adults with cervical disc herniation were recruited. Each patient had both an x-ray and MRI examination of the cervical spine. The cervical sagittal parameters were measured and compared on x-ray and MRI including: C2–C7 Cobb angle, C2–C7 sagittal vertical axis (C2–C7 SVA), cervical tilt (CT), T1 Slope (T1S), and neck tilt (NT). The data were analyzed using a paired-samples t test, a Pearson correlation test, and linear regression. Results: The values of C2–C7 Cobb angle, C2–C7 SVA, CT and T1S on X-ray were larger than those on MRI (P sagittal parameters had a significant correlation with the corresponding one on MRI (r = 0.699, 0.585, 0.574, 0.579 and 0.613, respectively) (C2–C7 Cobb MRI = 0.957 + 0.721 C2–C7 Cobb X, C2–C7 SVA MRI = 6.423 + 0.500 C2–C7 SVAX, CT MRI = 3.121 + 0.718 CTX, T1S MRI = 7.416 + 0.613 T1SX, NT MRI = 22.548 + 0.601 NTX). Conclusion: Although MRI and x-ray measurements of cervical sagittal parameters were different, there were significant correlations between the results. MRI could be used to evaluate the sagittal balance of the cervical spine with great reliability. PMID:28953681

  8. The skeleton in congenital, generalized lipodystrophy: evaluation using whole-body radiographic surveys, magnetic resonance imaging and technetium-99m bone scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Fleckenstein, J.L.; Bonte, F.J. (Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Radiology); Garg, A. (Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Internal Medicine); Vuitch, M.F. (Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Pathology); Peshock, R.M. (Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Radiology Univ. of Texas Southwestern Medical Center, Dallas, TX (United States). Dept. of Internal Medicine)

    1992-08-01

    Congenital generalized lipodystrophy (CGL) is a rare genetic disease characterized by the absence of body fat from birth. Focal bone lesions have also been reported, but their pathophysiology is poorly understood. To characterize skeletal abnormalities further in 3 patients with CGL, we employed whole-body radiographic skeletal surveys, magnetic resonance imaging (MRI, including gadolinium enhancement), and triple phase technetium-99m methylene diphosphonate bone scintigraphy. We conclude that the appendicular skeleton of patients with CGL is diffusely abnormal and is predisposed to focal osteolysis and cyst formation. (orig./DG).

  9. Bifurcation magnetic resonance in films magnetized along hard magnetization axis

    Energy Technology Data Exchange (ETDEWEB)

    Vasilevskaya, Tatiana M., E-mail: t_vasilevs@mail.ru [Ulyanovsk State University, Leo Tolstoy 42, 432017 Ulyanovsk (Russian Federation); Sementsov, Dmitriy I.; Shutyi, Anatoliy M. [Ulyanovsk State University, Leo Tolstoy 42, 432017 Ulyanovsk (Russian Federation)

    2012-09-15

    We study low-frequency ferromagnetic resonance in a thin film magnetized along the hard magnetization axis performing an analysis of magnetization precession dynamics equations and numerical simulation. Two types of films are considered: polycrystalline uniaxial films and single-crystal films with cubic magnetic anisotropy. An additional (bifurcation) resonance initiated by the bistability, i.e. appearance of two closely spaced equilibrium magnetization states is registered. The modification of dynamic modes provoked by variation of the frequency, amplitude, and magnetic bias value of the ac field is studied. Both steady and chaotic magnetization precession modes are registered in the bifurcation resonance range. - Highlights: Black-Right-Pointing-Pointer An additional bifurcation resonance arises in a case of a thin film magnetized along HMA. Black-Right-Pointing-Pointer Bifurcation resonance occurs due to the presence of two closely spaced equilibrium magnetization states. Black-Right-Pointing-Pointer Both regular and chaotic precession modes are realized within bifurcation resonance range. Black-Right-Pointing-Pointer Appearance of dynamic bistability is typical for bifurcation resonance.

  10. Magnetic resonance sounding survey data collected in the North Platte, Twin Platte, and South Platte Natural Resource Districts, Western Nebraska, Fall 2012

    Science.gov (United States)

    Kass, Mason A.; Bloss, Benjamin R.; Irons, Trevor P.; Cannia, James C.; Abraham, Jared D.

    2014-01-01

    This report is a release of digital data and associated survey descriptions from a series of magnetic resonance soundings (MRS, also known as surface nuclear magnetic resonance) that was conducted during October and November of 2012 in areas of western Nebraska as part of a cooperative hydrologic study by the North Platte Natural Resource District (NRD), South Platte NRD, Twin Platte NRD, the Nebraska Environmental Trust, and the U.S. Geological Survey (USGS). The objective of the study was to delineate the base-of-aquifer and refine the understanding of the hydrologic properties in the aquifer system. The MRS technique non-invasively measures water content in the subsurface, which makes it a useful tool for hydrologic investigations in the near surface (up to depths of approximately 150 meters). In total, 14 MRS production-level soundings were acquired by the USGS over an area of approximately 10,600 square kilometers. The data are presented here in digital format, along with acquisition information, survey and site descriptions, and metadata.

  11. Advances in magnetic resonance 8

    CERN Document Server

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 8 describes the magnetic resonance in spin polarization and saturation transfer. This book discusses the theory of chemically induced dynamic spin polarization; basic results for the radical-pair mechanism; and optical spin polarization in molecular crystals. The theory of optical electronic polarization (OEP); NMR in flowing systems; and applications of NMR in a flowing liquid are also elaborated. This text likewise covers the saturation transfer spectroscopy; studies of spin labels in the intermediate and fast motion regions; and spin-density matrix and

  12. Migraine and magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Younis, Samaira; Hougaard, Anders; Vestergaard, Mark B.

    2017-01-01

    Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation in the meth......Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation...

  13. Clinical, magnetic-resonance imaging and surgical findings in patients with temporomandibular joint disorders - a survey of 47 patients

    Energy Technology Data Exchange (ETDEWEB)

    Raustia, A.M. (Dept. of Prosthodontics and Stomatognathic Physiology, Inst. of Dentistry, Oulu Univ., Aapistie (Finland)); Pyhtinen, J. (Dept. of Diagnostic Radiology, University Central Hospital, Oulu (Finland)); Pernu, H. (Dept. of Oral and Maxillofacial Surgery, Inst. of Dentistry, Oulu Univ. (Finland))

    1994-05-01

    The purpose of this study was to evaluate and correlate the clinical, magnetic-resonance imaging (MRI), and surgical findings in 47 patients with temporomandibular joint (TMJ) disorders. 51 TMJs (24 right, 27 left) were operated on, because 4 patients underwent treatment of both TMJs. The best correlation between MRI and surgical findings was noted in connection with position of the disk. This was surgically confirmed altogether in 88% of cases (45/51). The clinical diagnosis was confirmed by surgical findings in 75% of cases of anterior dislocation of the disk with reduction and 89% of cases of anterior dislocation of the disk without reduction. Bone changes noted by MRI were confirmed by surgery in 71% of cases. MRI was excellent especially relating to disk position and changes in disk morphology. The results show also that there are findings using MRI, e.g. of joint effusion, which cannot be confirmed during surgery. (orig.)

  14. 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 ...

  15. Children's (Pediatric) Magnetic Resonance Imaging

    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 ...

  16. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... the brain caused by an injury or a stroke diagnose infectious or autoimmune diseases like encephalopathy or ... broad range of conditions, including cancer, heart and vascular disease, and muscular and bone ... (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging ( ...

  17. Evanescent Waves Nuclear Magnetic Resonance

    DEFF Research Database (Denmark)

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

    2016-01-01

    Nuclear Magnetic Resonance spectroscopy and imaging can be classified as inductive techniques working in the near- to far-field regimes. We investigate an alternative capacitive detection with the use of micrometer sized probes positioned at sub wavelength distances of the sample in order...

  18. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... are the limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is ... top of page What are some common uses of the procedure? MRI is used to help diagnose ...

  19. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... What are the limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) ... to a digital cloud server. top of page What are some common uses of the procedure? MRI ...

  20. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... of which shows a thin slice of the body. The images can then be studied from different angles by ... about radiology? Share your patient story here Images ... Articles and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's ( ...

  1. 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 ... about radiology? Share your patient story here Images ... Related Articles and Media MR Angiography (MRA) Magnetic Resonance, Functional (fMRI) - Brain ...

  2. 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 ...

  3. Magnetic Resonance with Squeezed Microwaves

    Science.gov (United States)

    Bienfait, A.; Campagne-Ibarcq, P.; Kiilerich, A. H.; Zhou, X.; Probst, S.; Pla, J. J.; Schenkel, T.; Vion, D.; Esteve, D.; Morton, J. J. L.; Moelmer, K.; Bertet, P.

    2017-10-01

    Vacuum fluctuations of the electromagnetic field set a fundamental limit to the sensitivity of a variety of measurements, including magnetic resonance spectroscopy. We report the use of squeezed microwave fields, which are engineered quantum states of light for which fluctuations in one field quadrature are reduced below the vacuum level, to enhance the detection sensitivity of an ensemble of electronic spins at millikelvin temperatures. By shining a squeezed vacuum state on the input port of a microwave resonator containing the spins, we obtain a 1.2-dB noise reduction at the spectrometer output compared to the case of a vacuum input. This result constitutes a proof of principle of the application of quantum metrology to magnetic resonance spectroscopy.

  4. Magnetic Resonance Imaging (MRI): Brain (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Magnetic Resonance Imaging (MRI): Brain KidsHealth / For Parents / Magnetic Resonance Imaging (MRI): Brain What's in this article? What It ...

  5. Magnetic Resonance Imaging (MRI): Dynamic Pelvic Floor

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) – Dynamic Pelvic Floor Dynamic pelvic floor magnetic resonance imaging (MRI) is a noninvasive test that uses a ...

  6. International Society for Magnetic Resonance in Medicine

    Science.gov (United States)

    ... information. And check out the MRM blog: Magnetic Resonance in Medicine Highlights Featured Journal Research Submit Research | ... Meetings Connect With Us International Society for Magnetic Resonance in Medicine 2300 Clayton Road, Suite 620 | Concord, ...

  7. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

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

  8. Magnetic Resonance Imaging (MRI) (For Parents)

    Science.gov (United States)

    ... Help a Child Cope With a Parent's Suicide? Magnetic Resonance Imaging (MRI) KidsHealth > For Parents > Magnetic Resonance Imaging (MRI) Print A A A What's ... Child If You Have Questions What It Is Magnetic resonance imaging (MRI) is a safe and painless ...

  9. Accuracy of color Doppler ultrasonography and magnetic resonance imaging in diagnosis of placenta accreta: A survey of 82 cases.

    Science.gov (United States)

    Ayati, Sedigheh; Leila, Leila; Pezeshkirad, Masoud; Seilanian Toosi, Farokh; Nekooei, Sirous; Shakeri, Mohammad Taghi; Golmohammadi, Mansoureh Sadat

    2017-04-01

    Placenta adhesive disorder (PAD) is one of the most common causes of postpartum hemorrhage and peripartum hysterectomy. The main risk factors are placenta previa and prior uterine surgery such as cesarean section. Diagnosis of placenta adhesive disorders can lead to a decrease of maternal mortality and morbidities. The purpose of this study was to compare the accuracy of color Doppler ultrasonography and magnetic resonance imaging (MRI) in the diagnosis of PADs. In this is cross-sectional study, Eighty-two pregnant women who were high risk for PAD underwent color Doppler ultrasound and MRI after 18 weeks of gestation. The sonographic and MRI findings were compared with the final pathologic or clinical findings. PDoppler sonography sensitivity was 87% and MRI sensitivity was 76% (p=0.37). Doppler sonography specificity was 63% and MRI specificity was 83% (p=0.01). Women with high-risk factors for PAD should undergo Doppler ultrasonography at first. When results on Doppler sonography are equivocal for PAD, MRI can be performed due to its high specificity.

  10. Resonant magnetic fields from inflation

    CERN Document Server

    Byrnes, Christian T; Jain, Rajeev Kumar; Urban, Federico R

    2012-01-01

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

  11. Magnetic resonance tomography in syringomyelia

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, D.; Treisch, J.; Hertel, G.; Schoerner, W.; Fiegler, W.

    1985-12-01

    Thirteen patients with a clinical diagnosis of syringomyelia were examined by nuclear tomography (0.35 T magnet) in the spin-echo mode. In all thirteen patients, the T1 images (Se 400/35) showed a longitudinal cavity with a signal intensity of CSF. The shape and extent of the syrinx could be adequately demonstrated in 12 of the 13 examinations. Downward displacement of the cerebellar tonsils was seen in eight cases. The examination took between half and one hour. Advantages of magnetic resonance tomography (nuclear tomography) include the absence of artifacts, images in the line of the lesion and its non-invasiveness.

  12. Magnetic resonance imaging in hemosiderosis

    Energy Technology Data Exchange (ETDEWEB)

    Kessing, P.H.L.; Falke, T.H.M.; Steiner, R.M.; Bloem, H.; Peters, A. (Rijksuniversiteit Leiden (Netherlands). Academisch Ziekenhuis)

    1985-01-15

    The case of a patient with iron deposition disease is presented to illustrate the value of magnetic resonance imaging (MRI) in the evaluation of this entity. The image characteristics of MRI are discussed and the results are compared with those of computer tomography (CT). The importance of a decrease in T2 relaxation time as the determinant parameter for signal intensity in MRI of the liver in such patients is emphasized.

  13. Magnetic resonance and its applications

    CERN Document Server

    Chizhik, Vladimir I; Donets, Alexey V; Frolov, Vyacheslav V; Komolkin, Andrei V; Shelyapina, Marina G

    2014-01-01

    The book provides a basic understanding of the underlying theory, fundamentals and applications of magnetic resonance The book implies a few levels of the consideration (from simple to complex) of phenomena, that can be useful for different groups of readers The introductory chapter provides the necessary underpinning knowledge for newcomers to the methods The exposition of theoretical materials goes from initial to final formulas through detailed intermediate expressions.

  14. Advances in magnetic resonance 3

    CERN Document Server

    Waugh, John S

    2013-01-01

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

  15. [Use of magnetic resonance imaging].

    Science.gov (United States)

    Chabanova, Elizaveta; Larsen, Lone; Løgager, Vibeke Berg; Møller, Jakob M; Thomsen, Henrik S

    2014-01-06

    Magnetic resonance imaging (MRI) is one of the four imaging modalities used in radiology. In contrast to computed tomography (CT), it does not use radiation. MRI is still developing and the diagnostic capabilities are growing. There are many indications for MRI and in some fields it has replaced CT. With few exceptions MRI is used mainly for elective examinations, and because of the new techniques like diffusion and perfusion MRI in cancer imaging the use is increasing both with regard to work-up and follow-up. For non-malignant lesions MRI is increasingly used thanks to its great soft-tissue contrast capabilities.

  16. Tunable Magnetic Resonance in Microwave Spintronics Devices

    Science.gov (United States)

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

    2015-01-01

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

  17. Migraine and magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Younis, Samaira; Hougaard, Anders; Vestergaard, Mark B.

    2017-01-01

    Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation in the meth......Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation...... in the methodology and quality of the MRS migraine studies over time, some results were consistent and reproducible. 31P-MRS studies suggested reduced availability of neuronal energy and implied a mitochondrial dysfunction in the migraine brain. 1H-MRS studies reported interictal abnormalities in the excitatory...... and inhibitory neurotransmitters, glutamate and g-aminobutyric acid (GABA), suggesting persistent altered excitability in migraine patients. N-Acetylaspartate levels were decreased in migraine, probably due to a mitochondrial dysfunction and abnormal energy metabolism. The reported abnormalities may increase...

  18. Improvements in Mechanical Detection of Magnetic Resonance

    National Research Council Canada - National Science Library

    Fainchtein, Raul

    2005-01-01

    This program intended to provide substantial improvements to conditions that affect imaging nanoscale structures with atomic resolution and chemical specificity by magnetic resonance force microscopy...

  19. Magnetic Resonance Imaging of Electrolysis.

    Science.gov (United States)

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

    2015-01-01

    This study explores the hypothesis that Magnetic Resonance Imaging (MRI) can image the process of electrolysis by detecting pH fronts. The study has relevance to real time control of cell ablation with electrolysis. To investigate the hypothesis we compare the following MR imaging sequences: T1 weighted, T2 weighted and Proton Density (PD), with optical images acquired using pH-sensitive dyes embedded in a physiological saline agar solution phantom treated with electrolysis and discrete measurements with a pH microprobe. We further demonstrate the biological relevance of our work using a bacterial E. Coli model, grown on the phantom. The results demonstrate the ability of MRI to image electrolysis produced pH changes in a physiological saline phantom and show that these changes correlate with cell death in the E. Coli model grown on the phantom. The results are promising and invite further experimental research. PMID:25659942

  20. Magnetic Resonance Imaging of Neurosarcoidosis

    Directory of Open Access Journals (Sweden)

    Daniel T Ginat

    2011-01-01

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

  1. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

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

  2. Single voxel magnetic resonance spectroscopy in distinguishing ...

    African Journals Online (AJOL)

    Objective: Assess diagnostic utility of combined magnetic resonance imaging and magnetic resonance spectroscopy (MRI, MRS) in differentiating focal neoplastic lesions from focal non- neoplastic (infective or degenerative) brain lesions. Design: Descriptive, analytical - prospective study. Setting: The Aga Khan University ...

  3. Intraoperative magnetic resonance imaging and meningioma surgery

    African Journals Online (AJOL)

    Objective: To determine if intraoperative magnetic resonance imaging improves surgical resection and postoperative outcome of intracranial meningioma. Study design: Prospective, non-randomized, cohort study. Method: Intraoperative Magnetic Resonance Imaging (iMRI) was used to evaluate patients with meningioma ...

  4. Magnetic resonance imaging of the prostate

    DEFF Research Database (Denmark)

    Iversen, P; Kjaer, L; Thomsen, C

    1988-01-01

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

  5. Magnetic resonance imaging of the prostate

    DEFF Research Database (Denmark)

    Iversen, P; Kjaer, L; Thomsen, C

    1987-01-01

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

  6. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

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

  7. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Science.gov (United States)

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

  8. Functional Magnetic Resonance Imaging and Pediatric Anxiety

    Science.gov (United States)

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

    2008-01-01

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

  9. resonant inverter supplied interior permanent magnet (ipm)

    African Journals Online (AJOL)

    user

    ABSTRACT. In this paper, rotor position in relation to the resonant frequency component current in the stator winding of DC-voltage link resonant inverter supplied Interior Permanent Magnet. (IPM) motor has been developed. Six reference frames are used to relate the rotor position angle to the resonant frequency ...

  10. Multidimensionally encoded magnetic resonance imaging.

    Science.gov (United States)

    Lin, Fa-Hsuan

    2013-07-01

    Magnetic resonance imaging (MRI) typically achieves spatial encoding by measuring the projection of a q-dimensional object over q-dimensional spatial bases created by linear spatial encoding magnetic fields (SEMs). Recently, imaging strategies using nonlinear SEMs have demonstrated potential advantages for reconstructing images with higher spatiotemporal resolution and reducing peripheral nerve stimulation. In practice, nonlinear SEMs and linear SEMs can be used jointly to further improve the image reconstruction performance. Here, we propose the multidimensionally encoded (MDE) MRI to map a q-dimensional object onto a p-dimensional encoding space where p > q. MDE MRI is a theoretical framework linking imaging strategies using linear and nonlinear SEMs. Using a system of eight surface SEM coils with an eight-channel radiofrequency coil array, we demonstrate the five-dimensional MDE MRI for a two-dimensional object as a further generalization of PatLoc imaging and O-space imaging. We also present a method of optimizing spatial bases in MDE MRI. Results show that MDE MRI with a higher dimensional encoding space can reconstruct images more efficiently and with a smaller reconstruction error when the k-space sampling distribution and the number of samples are controlled. Copyright © 2012 Wiley Periodicals, Inc.

  11. Nuclear Magnetic Resonance imaging; Resonance magnetique nucleaire

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-06-01

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

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

    Directory of Open Access Journals (Sweden)

    K. Bartušek

    2003-01-01

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

  13. Magnetic resonance image guided brachytherapy.

    Science.gov (United States)

    Tanderup, Kari; Viswanathan, Akila N; Kirisits, Christian; Frank, Steven J

    2014-07-01

    The application of magnetic resonance image (MRI)-guided brachytherapy has demonstrated significant growth during the past 2 decades. Clinical improvements in cervix cancer outcomes have been linked to the application of repeated MRI for identification of residual tumor volumes during radiotherapy. This has changed clinical practice in the direction of individualized dose administration, and resulted in mounting evidence of improved clinical outcome regarding local control, overall survival as well as morbidity. MRI-guided prostate high-dose-rate and low-dose-rate brachytherapies have improved the accuracy of target and organs-at-risk delineation, and the potential exists for improved dose prescription and reporting for the prostate gland and organs at risk. Furthermore, MRI-guided prostate brachytherapy has significant potential to identify prostate subvolumes and dominant lesions to allow for dose administration reflecting the differential risk of recurrence. MRI-guided brachytherapy involves advanced imaging, target concepts, and dose planning. The key issue for safe dissemination and implementation of high-quality MRI-guided brachytherapy is establishment of qualified multidisciplinary teams and strategies for training and education. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Virtual special issue: Magnetic resonance at low fields

    Science.gov (United States)

    Blümich, Bernhard

    2017-01-01

    It appears to be a common understanding that low magnetic fields need to be avoided in magnetic resonance, as sensitivity and the frequency dispersion of the chemical shift increase with increasing field strength. But there many reasons to explore magnetic resonance at low fields. The instrumentation tends to be far less expensive than high-field equipment, magnets are smaller and lighter, internal gradients in heterogeneous media are smaller, conductive media and even metals become transparent at low frequencies to electromagnetic fields, and new physics and phenomena await to be discovered. On account of an increasing attention of the scientific community to magnetic resonance at low field, we have decided to launch JMR's Virtual Special Issue Series with this compilation about Low-Field Magnetic Resonance. This topic, for which we have chosen to focus on articles reporting measurements at fields lower than 2 T, is of widespread interest to our readership. We are therefore happy to offer to this constituency a selected outlook based on papers published during the last five years (volumes 214-270) in the pages of The Journal of Magnetic Resonance. A brief survey of the topics covered in this Virtual Special Issue follows.

  15. Microscopic FMR Using Magnetic Resonance Force Microscopy

    Science.gov (United States)

    Zhang, Z.; Hammel, P. C.; Wigen, P. E.

    1996-03-01

    Magnetic resonance force microscopy (MRFM) is a new 3-D imaging technique with ultra-high spatial resolution. This technique, discussed primarily in the context of nuclear magnetic resonance, can also be applied as a microscopic ferromagnetic resonance probe to investigate the distributions of magnetic anisotropy and magnetic exchange interactions within magnetic materials (for example, magnetic multilayer systems). We report the first MRFM experiment on a single crystal Yittrium Iron Garnet film. A non-resonance mode and a family of magneto-static modes were observed in the MRFM spectra. The non-resonance mode is due to the response of the sample magnetization to the applied, time dependent bias field. This will be the main noise source when a magnet is mounted on the cantilever, an arrangement which is necessary in order to perform 3-D imaging in MRFM. The behavior of the magneto-static modes is in qualitative accord with theoretical expectations. The MRFM signal intensity is so large that the experiment is performed under ambient pressure instead of vacuum to reduce the response of the detector (cantilever). This indicates that MRFM will allow micron or sub-micron spatial resolution in studies of a wide variety of magnetic materials.

  16. Influence of Magnetic Resonance Imaging Features on Surgical Decision-Making in Degenerative Cervical Myelopathy: Results from a Global Survey of AOSpine International Members.

    Science.gov (United States)

    Nouri, Aria; Martin, Allan R; Nater, Anick; Witiw, Christopher D; Kato, So; Tetreault, Lindsay; Reihani-Kermani, Hamed; Santaguida, Carlo; Fehlings, Michael G

    2017-09-01

    We conducted a survey to understand how specific pathologic features on magnetic resonance imaging (MRI) influence surgeons toward an anterior or posterior surgical approach in degenerative cervical myelopathy (DCM). A questionnaire was sent out to 6179 AOSpine International members via e-mail. This included 18 questions on a 7-point Likert scale regarding how MRI features influence the respondent's decision to perform an anterior or posterior surgical approach. Influence was classified based on the mean and mode. Variations in responses were assessed by region and training. Of 513 respondents, 51.7% were orthopedic surgeons, 36.8% were neurosurgeons, and the remainder were fellows, residents, or other. In ascending order, multilevel bulging disks, cervical kyphosis, and a high degree of anterior cord compression had a moderate to strong influence toward an anterior approach. A high degree of posterior cord compression had a moderate to strong influence, whereas multilevel compression, ossification of the posterior longitudinal ligament, ligamentum flavum enlargement, and congenital stenosis had a moderate influence toward a posterior approach. Neurosurgeons chose anterior approaches more and posterior approaches less in comparison with orthopedic surgeons (P < 0.01). Of note, 59.8% of respondents were equally comfortable performing multilevel (3 or more levels) anterior and posterior procedures, whereas 61.5% did not feel comfortable in determining the surgical approach based on MRI alone. Specific DCM pathology influences the choice for anterior or posterior surgical approach. These data highlight factors based on surgeon experience, training, and region of practice. They will be helpful in defining future areas of investigation in an effort to provide individualized surgical strategies and optimize patient outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Reducing Field Distortion in Magnetic Resonance Imaging

    Science.gov (United States)

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

    2010-01-01

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

  18. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

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    Full Text Available ... Imaging Costs Video: Abdominal Ultrasound Video: Pelvic Ultrasound Radiology and You Sponsored by Image/Video Gallery Your ... Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot org Hello, I’m Dr. Elliot ...

  19. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Lung Cancer Awareness Month Recently posted: Carotid Intima-Media Thickness Test Medical Imaging Costs Video: Abdominal Ultrasound Video: Pelvic Ultrasound Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography ( ...

  20. single voxel magnetic resonance spectroscopy in distinguishing

    African Journals Online (AJOL)

    2011-03-03

    Mar 3, 2011 ... magnetic resonance spectroscopy (MRI, MRS) in differentiating focal neoplastic lesions from focal non- neoplastic (infective or degenerative) brain lesions. Design: Descriptive, analytical - prospective study. Setting: The Aga Khan University MRI department. Subject: Seventy four consecutive patients.

  1. Review of cardiovascular magnetic resonance in human ...

    African Journals Online (AJOL)

    In recent times, cardiovascular magnetic resonance (CMR) imaging has emerged as the gold standard tool for assessment of a variety of indications, allowing comprehensive characterisation of functional, morphological, metabolic and haemodynamic sequelae of several cardiovascular pathologies. Furthermore, continued ...

  2. The role of magnetic resonance cholangiopancreatography and ...

    African Journals Online (AJOL)

    ) is accepted as the gold standard, there is a place for magnetic resonance cholangiopancreatography (MRCP) and diffusion-weighted imaging (DWI) in the diagnosis of obstructive biliary disorders. Aim: To compare the findings of MRCP with ...

  3. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Video: Pelvic Ultrasound Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography ( ... pictures of the major blood vessels throughout your body. It may be performed with or without contrast ...

  4. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

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    Full Text Available ... Dr. Elliot Fishman, a radiologist at Johns Hopkins Hospital in Baltimore, Maryland. I’d like to talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. ...

  5. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... with you about magnetic resonance angiography, or as it’s commonly known, MRA. MRA is a noninvasive test ... of the major blood vessels throughout your body. It may be performed with or without contrast material ...

  6. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... mild sedative prior to the examination. For more information about Magnetic Resonance Angiography of MRA or any ... Inc. (RSNA). To help ensure current and accurate information, we do not permit copying but encourage linking ...

  7. Magnetic Resonance Spectroscopy of Breast Disease

    National Research Council Canada - National Science Library

    Ikeda, Debra

    2001-01-01

    We have developed a unique magnetic resonance imaging multi voxel pulse sequence producing spectroscopic images of key metabolites found in breast cancer, and validated our work with in vitro spectra and pathology...

  8. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Index A-Z Spotlight Recently posted: Carotid Intima-Media Thickness Test Medical Imaging Costs Video: Abdominal Ultrasound Video: Pelvic Ultrasound Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography ( ...

  9. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... of Radiology (IDoR) Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography ( ... pictures of the major blood vessels throughout your body. It may be performed with or without contrast ...

  10. Magnetic resonance force microscopy using ferromagnetic resonance of a magnetic tip excited by microwave transmission via a coaxial resonator

    Science.gov (United States)

    Kinoshita, Yukinori; Li, Yan Jun; Yoshimura, Satoru; Saito, Hitoshi; Sugawara, Yasuhiro

    2017-12-01

    The present work proposes magnetic resonance force microscopy (MRFM) based on ferromagnetic resonance (FMR) modulation of a magnetic tip using microwave transmission via a coaxial resonator instead of using conventional microwave irradiation by an external antenna. In this MRFM, the coaxial resonator is electrically connected to the magnetic cantilever tip, which enables simple implementation of FMR excitation of a magnetic tip in conventional magnetic force microscopy. The FMR frequency of the tip can be easily extracted from the reflection spectrum of a transmission line connected to the magnetic tip. The excitation of tip FMR is confirmed from the microwave frequency dependence of the mechanical response of the tip oscillation. This MRFM is effective for extracting the magnetic interaction force near a sample surface without perturbation of its magnetic state. Nanometer-scale imaging of magnetic domain structures on a demagnetized thin-film permanent magnet is successfully demonstrated.

  11. Can magnetic resonance imaging differentiate undifferentiated arthritis?

    DEFF Research Database (Denmark)

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

    2005-01-01

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

  12. Nuclear Magnetic Resonance Imaging: Current Capabilities

    OpenAIRE

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

    1982-01-01

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

  13. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... flow to the heart muscle evaluate findings following cardiovascular surgery In the abdominal and pelvic region, MRI ... the magnet. Some MRI units, called short-bore systems , are designed so that the magnet does not ...

  14. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

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

  15. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  16. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI) of the head uses a powerful magnetic field, radio waves and a computer to produce detailed ... there’s a possibility you are pregnant. The magnetic field is not harmful, but it may cause some ...

  17. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... help detect certain chronic diseases of the nervous system, such as multiple sclerosis diagnose problems with the ... the magnet. Some MRI units, called short-bore systems , are designed so that the magnet does not ...

  18. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... 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 ...

  19. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... 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. Your child will lie on a moveable examination ...

  20. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... ports artificial limbs or metallic joint prostheses implanted nerve stimulators metal pins, screws, plates, stents or surgical ... the magnet. Some MRI units, called short-bore systems , are designed so that the magnet does not ...

  1. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    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 ...

  2. Magnetic resonance force detection using a membrane resonator.

    Science.gov (United States)

    Scozzaro, N; Ruchotzke, W; Belding, A; Cardellino, J; Blomberg, E C; McCullian, B A; Bhallamudi, V P; Pelekhov, D V; Hammel, P C

    2016-10-01

    The availability of compact, low-cost magnetic resonance imaging instruments would further broaden the substantial impact of this technology. We report highly sensitive detection of magnetic resonance using low-stress silicon nitride (SiNx) membranes. We use these membranes as low-loss, high-frequency mechanical oscillators and find they are able to mechanically detect spin-dependent forces with high sensitivity enabling ultrasensitive magnetic resonance detection. The high force detection sensitivity stems from their high mechanical quality factor Q∼10(6)[1,2] combined with the low mass of the resonator. We use this excellent mechanical force sensitivity to detect the electron spin magnetic resonance using a SiNx membrane as a force detector. The demonstrated force sensitivity at 300K is 4fN/Hz, indicating a potential low temperature (4K) sensitivity of 25aN/Hz. Given their sensitivity, robust construction, large surface area and low cost, SiNx membranes can potentially serve as the central component of a compact room-temperature ESR and NMR instrument having spatial resolution superior to conventional approaches. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Magnetic nanoparticles in magnetic resonance imaging and diagnostics.

    Science.gov (United States)

    Rümenapp, Christine; Gleich, Bernhard; Haase, Axel

    2012-05-01

    Magnetic nanoparticles are useful as contrast agents for magnetic resonance imaging (MRI). Paramagnetic contrast agents have been used for a long time, but more recently superparamagnetic iron oxide nanoparticles (SPIOs) have been discovered to influence MRI contrast as well. In contrast to paramagnetic contrast agents, SPIOs can be functionalized and size-tailored in order to adapt to various kinds of soft tissues. Although both types of contrast agents have a inducible magnetization, their mechanisms of influence on spin-spin and spin-lattice relaxation of protons are different. A special emphasis on the basic magnetism of nanoparticles and their structures as well as on the principle of nuclear magnetic resonance is made. Examples of different contrast-enhanced magnetic resonance images are given. The potential use of magnetic nanoparticles as diagnostic tracers is explored. Additionally, SPIOs can be used in diagnostic magnetic resonance, since the spin relaxation time of water protons differs, whether magnetic nanoparticles are bound to a target or not.

  4. Magnetic resonance imaging of the fetal brain.

    Science.gov (United States)

    Tee, L Mf; Kan, E Yl; Cheung, J Cy; Leung, W C

    2016-06-01

    This review covers the recent literature on fetal brain magnetic resonance imaging, with emphasis on techniques, advances, common indications, and safety. We conducted a search of MEDLINE for articles published after 2010. The search terms used were "(fetal OR foetal OR fetus OR foetus) AND (MR OR MRI OR [magnetic resonance]) AND (brain OR cerebral)". Consensus statements from major authorities were also included. As a result, 44 relevant articles were included and formed the basis of this review. One major challenge is fetal motion that is largely overcome by ultra-fast sequences. Currently, single-shot fast spin-echo T2-weighted imaging remains the mainstay for motion resistance and anatomical delineation. Recently, a snap-shot inversion recovery sequence has enabled robust T1-weighted images to be obtained, which is previously a challenge for standard gradient-echo acquisitions. Fetal diffusion-weighted imaging, diffusion tensor imaging, and magnetic resonance spectroscopy are also being developed. With multiplanar capabilities, superior contrast resolution and field of view, magnetic resonance imaging does not have the limitations of sonography, and can provide additional important information. Common indications include ventriculomegaly, callosum and posterior fossa abnormalities, and twin complications. There are safety concerns about magnetic resonance-induced heating and acoustic damage but current literature showed no conclusive evidence of deleterious fetal effects. The American College of Radiology guideline states that pregnant patients can be accepted to undergo magnetic resonance imaging at any stage of pregnancy if risk-benefit ratio to patients warrants that the study be performed. Magnetic resonance imaging of the fetal brain is a safe and powerful adjunct to sonography in prenatal diagnosis. It can provide additional information that aids clinical management, prognostication, and counselling.

  5. Coherence of magnetic resonators in a metamaterial

    Directory of Open Access Journals (Sweden)

    Yumin Hou

    2013-12-01

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

  6. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... imaging (MRI) of the head uses a powerful magnetic field, radio waves and a computer to produce detailed ... whether there’s a possibility you are pregnant. The magnetic field is not harmful, but it may cause some ...

  7. Magnetic material arrangement in oriented termites: a magnetic resonance study

    Science.gov (United States)

    Alves, O. C.; Wajnberg, E.; de Oliveira, J. F.; Esquivel, D. M. S.

    2004-06-01

    Temperature dependence of the magnetic resonance is used to study the magnetic material in oriented Neocapritermes opacus (N.o.) termite, the only prey of the migratory ant Pachycondyla marginata (P.m.). A broad line in the g=2 region, associated to isolated nanoparticles shows that at least 97% of the magnetic material is in the termite's body (abdomen + thorax). From the temperature dependence of the resonant field and from the spectral linewidths, we estimate the existence of magnetic nanoparticles 18.5 ± 0.3 nm in diameter and an effective magnetic anisotropy constant, Keff between 2.1 and 3.2 × 10 4 erg/cm 3. A sudden change in the double integrated spectra at about 100 K for N.o. with the long body axis oriented perpendicular to the magnetic field can be attributed to the Verwey transition, and suggests an organized film-like particle system.

  8. Magnetic resonance elastography: Inversions in bounded media.

    Science.gov (United States)

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

    2009-12-01

    Magnetic resonance elastography is a noninvasive imaging technique capable of quantifying and spatially resolving the shear stiffness of soft tissues by visualization of synchronized mechanical wave displacement fields. However, magnetic resonance elastography inversions generally assume that the measured tissue motion consists primarily of shear waves propagating in a uniform, infinite medium. This assumption is not valid in organs such as the heart, eye, bladder, skin, fascia, bone and spinal cord, in which the shear wavelength approaches the geometric dimensions of the object. The aim of this study was to develop and test mathematical inversion algorithms capable of resolving shear stiffness from displacement maps of flexural waves propagating in bounded media such as beams, plates, and spherical shells, using geometry-specific equations of motion. Magnetic resonance elastography and finite element modeling of beam, plate, and spherical shell phantoms of various geometries were performed. Mechanical testing of the phantoms agreed with the stiffness values obtained from finite element modeling and magnetic resonance elastography data, and a linear correlation of r(2) >or= 0.99 was observed between the stiffness values obtained using magnetic resonance elastography and finite element modeling data. In conclusion, we have demonstrated new inversion methods for calculating shear stiffness that may be more appropriate for waves propagating in bounded media. (c) 2009 Wiley-Liss, Inc.

  9. Magnetic resonance imaging by using nano-magnetic particles

    Science.gov (United States)

    Shokrollahi, H.; Khorramdin, A.; Isapour, Gh.

    2014-11-01

    Magnetism and magnetic materials play a major role in various biological applications, such as magnetic bioseparation, magnetic resonance imaging (MRI), hyperthermia treatment of cancer and drug delivery. Among these techniques, MRI is a powerful method not only for diagnostic radiology but also for therapeutic medicine that utilizes a magnetic field and radio waves. Recently, this technique has contributed greatly to the promotion of the human quality life. Thus, this paper presents a short review of the physical principles and recent advances of MRI, as well as providing a summary of the synthesis methods and properties of contrast agents, like different core materials and surfactants.

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

    KAUST Repository

    Fridjonsson, Einar Orn

    2015-03-01

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

  11. Magnetic Resonance Imaging (MRI) -- Head

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  12. Children's (Pediatric) Magnetic Resonance Imaging

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  13. Magnetic Resonance Imaging (MRI) -- Head

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

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  16. Children's (Pediatric) Magnetic Resonance Imaging

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  20. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... The magnetic field is produced by passing an electric current through wire coils in most MRI units. Other coils, located in the machine and in some cases, placed around the part ...

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    Full Text Available ... traditional MRI unit is a large cylinder-shaped tube surrounded by a circular magnet. You will lie ... your skin at the site of the IV tube insertion. Some patients may sense a temporary metallic ...

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

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    Full Text Available ... This exam does not use ionizing radiation and may require an injection of a contrast material called ... The magnetic field is not harmful, but it may cause some medical devices to malfunction. Most orthopedic ...

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  8. Magnetic Resonance Imaging (MRI) -- Head

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  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... they may move during the scan, possibly causing blindness. Dyes used in tattoos may contain iron and ... also screened for safety in the magnetic environment. Children will be given appropriately sized earplugs or headphones ...

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  12. Children's (Pediatric) Magnetic Resonance Imaging

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  13. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... detail makes MRI an invaluable tool in early diagnosis and evaluation of many conditions, including tumors. MRI ... the technologist or nurse will monitor your vital signs to minimize this risk. Although the strong magnetic ...

  14. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... detail makes MRI an invaluable tool in early diagnosis and evaluation of many focal lesions and tumors ... the technologist or nurse monitors your child’s vital signs to minimize this risk. Although the strong magnetic ...

  15. Children's (Pediatric) Magnetic Resonance Imaging

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  16. Children's (Pediatric) Magnetic Resonance Imaging

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  17. Magnetic Resonance Imaging (MRI) -- Head

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

  18. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... scanner. top of page How does the procedure work? Unlike conventional x-ray examinations and computed tomography ( ... as long as they are also screened for safety in the magnetic environment. Children will be given ...

  19. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... scanner. top of page How does the procedure work? Unlike conventional x-ray examinations and computed tomography ( ... as long as they are also screened for safety in the magnetic environment. Children will be given ...

  20. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... the head uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of ... the body being imaged, send and receive radio waves, producing signals that are detected by the coils. ...

  1. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... imaging (MRI) uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of ... the body being imaged, send and receive radio waves, producing signals that are detected by the coils. ...

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    Full Text Available ... and extremities. Tell your doctor about your child’s health problems, medications, recent surgeries and allergies. The magnetic ... the radiologist if your child has any serious health problems or has recently had surgery. Some conditions, ...

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    Full Text Available ... with no reports of any ill effects on pregnant women or their unborn babies. However, because the unborn baby will be in a strong magnetic field, pregnant women should not have this exam in the first ...

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

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

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    Full Text Available ... if possible, or removed prior to the MRI scan. Because they can interfere with the magnetic field ... particularly important because they may move during the scan, possibly causing blindness. Dyes used in tattoos may ...

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    Full Text Available ... unborn baby will be in a strong magnetic field, pregnant women should not have this exam in the first three to four months of pregnancy unless the potential benefit from the MRI exam is assumed to ...

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    Full Text Available ... and send a signed report to your primary care or referring physician, who will share the results ... magnetic field is not harmful in itself, implanted medical devices that contain metal may malfunction or cause ...

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    Full Text Available ... a large cylinder-shaped tube surrounded by a circular magnet. You will lie on a moveable examination ... at a very early stage by mapping the motion of water molecules in the tissue. This water ...

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    Full Text Available ... the radiofrequency pulses are activated. Some centers provide earplugs, while others use headphones to reduce the intensity ... magnetic environment. Children will be given appropriately sized earplugs or headphones during the exam. MRI scanners are ...

  12. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... conditions. MRI uses a powerful magnetic field, radio frequency pulses and a computer to produce detailed pictures ... does not completely surround you. Some newer MRI machines have a larger diameter bore which can be ...

  13. 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 ... does not completely surround you. Some newer MRI machines have a larger diameter bore which can be ...

  14. MAGNETIC RESONANCE SEMIOTICS OF BREAST CANCER

    Directory of Open Access Journals (Sweden)

    S. V. Serebryakova

    2009-01-01

    Full Text Available Breast cancer (BC that is the most common malignancy in women presents an indubitable threat to their life and health. The basis for this investigation was magnetic resonance imaging (MRI data of 203 women with histologically verified malignan- cies. The patients' mean age was 53±10.2 years. The paper describes the magnetic resonance semiotics of BC; the authors have developed criteria for dynamic contrast-enhanced magnetic resonance mammography used in the differential diagnosis of nodules.Due to high soft-tissue contrast, the use of thin sections, and the possibility of examining in any projection, MRI allows one not only to accurately visualize a pathological mass as compared with X-ray mammography or ultrasound study, but also to characterize its vascularization, which is a major criteria for the differential diagnosis of benign and malignant breast nodules.

  15. Magnetic resonance enterography in pediatric celiac disease.

    Science.gov (United States)

    Koc, Gonca; Doganay, Selim; Sevinc, Eylem; Deniz, Kemal; Chavhan, Govind; Gorkem, Sureyya B; Karacabey, Neslihan; Dogan, Mehmet S; Coskun, Abdulhakim; Aslan, Duran

    To assess if magnetic resonance enterography is capable of showing evidence/extent of disease in pediatric patients with biopsy-proven celiac disease by comparing with a control group, and to correlate the magnetic resonance enterography findings with anti-endomysial antibody level, which is an indicator of gluten-free dietary compliance. Thirty-one pediatric patients (mean age 11.7±3.1 years) with biopsy-proven celiac disease and 40 pediatric patients as a control group were recruited in the study. The magnetic resonance enterography images of both patients with celiac disease and those of the control group were evaluated by two pediatric radiologists in a blinded manner for the mucosal pattern, presence of wall thickening, luminal distention of the small bowel, and extra-intestinal findings. Patient charts were reviewed to note clinical features and laboratory findings. The histopathologic review of the duodenal biopsies was re-conducted. The mean duration of the disease was 5.6±1.8 years (range: 3-7.2 years). In 24 (77%) of the patients, anti-endomysial antibody levels were elevated (mean 119.2±66.6RU/mL). Magnetic resonance enterography revealed normal fold pattern in all the patients. Ten (32%) patients had enlarged mesenteric lymph nodes. Although a majority of the patients had elevated anti-endomysial antibody levels indicating poor dietary compliance, magnetic resonance enterography did not show any mucosal abnormality associated with the inability of magnetic resonance enterography to detect mild/early changes of celiac disease in children. Therefore, it may not be useful for the follow-up of pediatric celiac disease. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  16. Introduction to magnetic resonance methods in photosynthesis

    OpenAIRE

    Huber, Martina

    2009-01-01

    Electron paramagnetic resonance (EPR) and, more recently, solid-state nuclear magnetic resonance (NMR) have been employed to study photosynthetic processes, primarily related to the light-induced charge separation. Information obtained on the electronic structure, the relative orientation of the cofactors, and the changes in structure during these reactions should help to understand the efficiency of light-induced charge separation. A short introduction to the observables derived from magneti...

  17. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... if a finding is stable or changed over time. top of page What are the benefits vs. risks? Benefits MRI is a ... resonance imaging harms the fetus, pregnant women usually are advised not to have an ... take more time to perform than other imaging modalities. top of ...

  18. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... taking our brief survey: Survey Do you have a personal story about radiology? Share your patient story ... encourage linking to this site. × Recommend RadiologyInfo to a friend Send to (friend's e-mail address): From ( ...

  19. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... taking our brief survey: Survey Do you have a personal story about radiology? Share your patient story ... encourage linking to this site. × Recommend RadiologyInfo to a friend Send to (friend's e-mail address): From ( ...

  20. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic ... patient to have an allergy to a gadolinium-based contrast agent used for MRI than the iodine- ...

  1. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... come. The MR scanner captures this energy and creates a picture of the tissues scanned based on this information. The magnetic field is produced by passing an electric current through wire coils in most MRI units. Other coils, located in the machine and in some cases, placed around the part ...

  2. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... come. The MR scanner captures this energy and creates a picture of the tissues scanned based on this information. The magnetic field is produced by passing an electric current through wire coils in most MRI units. Other coils, located in the machine and in some cases, placed around the part ...

  3. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... with the magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... into the scanning room also need to remove metal objects and notify the technologist of any medical or electronic devices they may have. If your child has ...

  4. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... with the magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... into the scanning room also need to remove metal objects and notify the technologist of any medical or electronic devices they may have. top of page What ...

  5. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... a powerful magnetic field, radio waves and a computer to produce detailed pictures of the inside of your child’s body. MRI may be used to help diagnose or monitor treatment for a variety of conditions within the brain, chest, abdomen, pelvis and extremities. Tell your doctor ...

  6. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... a powerful magnetic field, radio waves and a computer to produce detailed pictures of the brain and other cranial structures that are clearer and ... The images can then be examined on a computer monitor, transmitted electronically, printed ... in routine clinical practice. top of page What ...

  7. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... ill effects on pregnant women or their unborn babies. However, because the unborn baby will be in a strong magnetic field, pregnant ... intravenous contrast indicate mothers should not breastfeed their babies for 24-48 hours after contrast medium is ...

  8. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... and extremities. Tell your doctor about your child’s health problems, medications, recent surgeries and allergies. The magnetic field is not harmful, but it may cause some medical devices to malfunction. Most orthopedic implants pose no risk, but you should always tell the technologist if ...

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... You may resume your usual activities and normal diet immediately after the exam. On very rare occasions, ... imaging based on the electrical activity of the heart, such as electrocardiography (EKG). MRI generally is not recommended for ... Tumors Images related to Magnetic ...

  10. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... pieces of metal which may be present in your child’s body due to prior accidents. Foreign bodies near and especially lodged in the eyes are particularly important. Tooth fillings and braces usually are not affected by the magnetic field, but they may distort ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... the head uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of the brain and other cranial structures that are clearer and more detailed than other imaging methods. This exam does not use ionizing radiation and may require an injection of a ...

  12. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... imaging (MRI) uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of the inside of your child’s body. MRI may be used to help diagnose or monitor treatment for a variety of conditions within the brain, chest, abdomen, pelvis and extremities. Tell your doctor ...

  13. A hyperpolarized equilibrium for magnetic resonance

    OpenAIRE

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

    2013-01-01

    Nuclear magnetic resonance spectroscopy and imaging (MRI) play an indispensable role in science and healthcare but use only a tiny fraction of their potential. No more than ≈10 p.p.m. of all 1H nuclei are effectively detected in a 3-Tesla clinical MRI system. Thus, a vast array of new applications lays dormant, awaiting improved sensitivity. Here we demonstrate the continuous polarization of small molecules in solution to a level that cannot be achieved in a viable magnet. The magnetization d...

  14. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

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    Full Text Available ... problems, recent surgeries and allergies. If you’re female and there’s a possibility that you’re pregnant ... doctor for a mild sedative prior to the examination. For more information about Magnetic Resonance Angiography of MRA or any specific ... Sponsored by About Us | ...

  15. Magnetic resonance imaging in radiotherapy treatment planning

    NARCIS (Netherlands)

    Moerland, Marinus Adriaan

    1996-01-01

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

  16. Magnetic resonance imaging study of corpus callosum

    African Journals Online (AJOL)

    2014-11-02

    Nov 2, 2014 ... We recruited 58 chronically schizophrenic patients with different subtypes, and 31 age-and-gender matched healthy controls. The callosum was extracted from a midsagittal slice from T1 weighted magnetic resonance images, and areas of the total CC, its five subregions,. CC length and total brain volume ...

  17. ORIGINAL ARTICLE Multimodal magnetic resonance imaging ...

    African Journals Online (AJOL)

    tumours and the peritumoural oedema. Multimodal magnetic resonance imaging increases the overall diagnostic accuracy in brain tumours: Correlation with histopathology. K Abul-Kasim, M Thurnher, S Puchner, P Sundgren. Faculty of Medicine, Lund University, Division of Neuroradiology, Diagnostic Centre for Imaging ...

  18. Modelling Strategies for Functional Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Madsen, Kristoffer Hougaard

    2009-01-01

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

  19. Sensorineural hearing loss after magnetic resonance imaging

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  20. Functional Magnetic Resonance Imaging in Consumer Research

    DEFF Research Database (Denmark)

    Reimann, Martin; Schilke, Oliver; Weber, Bernd

    2011-01-01

    Although the field of psychology is undergoing an immense shift toward the use of functional magnetic resonance imaging (fMRI), the application of this methodology to consumer research is relatively new. To assist consumer researchers in understanding fMRI, this paper elaborates on the findings...

  1. Evaluation of nuclear magnetic resonance spectroscopy variability

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-01

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

  2. Measurement of myocardial perfusion using magnetic resonance

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  3. Monitoring angiogenesis using magnetic resonance methods

    DEFF Research Database (Denmark)

    Peters, David Alberg

    2008-01-01

    and the involved signaling molecules. Subsequently, a short review of contrast agents and perfusion measurements is given. Finally, methods for monitoring angiogenesis using magnetic resonance imaging are reviewed. A method for monitoring early stages of angiogenesis as well as the effect of anti...

  4. Moving dislocations studied by nuclear magnetic resonance

    NARCIS (Netherlands)

    Hut, Gezinus

    1976-01-01

    In this thesis a new approach to the study of moving dislocations in crystalline solids during plastic deformation will be presented. Since the process of dislocation motion is made up of atomic movements nuclear magnetic resonance techniques should offer a possibility to determine the manner in

  5. Magnetic resonance imaging of breast prostheses

    African Journals Online (AJOL)

    G5

    ... these two signs,. 7. SA JOURNAL OF RADIOLOGY • October 2005. REVIEW ARTICLE. Magnetic resonance imaging of breast prostheses. P Corr. FFRad (D) SA. P Seolall. Nat Dip Rad (D). H Booth. Nat Dip Rad (D). Department of Radiology. Nelson Mandela School of Medicine and Inkosi Albert Luthuli Hospital. Durban ...

  6. Nuclear Magnetic Resonance Technology for Medical Studies.

    Science.gov (United States)

    Budinger, Thomas F.; Lauterbur, Paul C.

    1984-01-01

    Reports on the status of nuclear magnetic resonance (NMR) from theoretical and clinical perspectives, reviewing NMR theory and relaxation parameters relevant to NMR imaging. Also reviews literature related to modern imaging strategies, signal-to-noise ratio, contrast agents, in vivo spectroscopy, spectroscopic imaging, clinical applications, and…

  7. Magnetic Resonance Lithography with Nanometer Resolution

    Directory of Open Access Journals (Sweden)

    Fahad AlGhannam

    2016-04-01

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

  8. Breast magnetic resonance imaging guided biopsy

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Bo La; Kim, Sun Mi; Jang, Mi Jung [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Cho, Nariya; Moon, Woo Kyung [Dept. of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Kim, Hak Hee [Dept. of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

    2016-06-15

    Despite the high sensitivity of breast magnetic resonance imaging (MRI), pathologic confirmation by biopsy is essential because of limited specificity. MRI-guided biopsy is required in patients with lesions only seen on MRI. We review preprocedural considerations and the technique of MRI-guided biopsy, challenging situations and trouble-shooting, and correlation of radiologic and pathologic findings.

  9. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions ... Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot org Hello, I’m Dr. Elliot Fishman, ...

  10. Magnetic resonance imaging study of corpus callosum ...

    African Journals Online (AJOL)

    We recruited 58 chronically schizophrenic patients with different subtypes, and 31 age-and-gender matched healthy controls. The callosum was extracted from a midsagittal slice from T1 weighted magnetic resonance images, and areas of the total CC, its five subregions, CC length and total brain volume were compared ...

  11. Numerical methods in electron magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Soernes, A.R

    1998-07-01

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

  12. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Radiology (IDoR) Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) ... Carotid Intima-Media Thickness Test Medical Imaging Costs Video: Abdominal Ultrasound Video: Pelvic Ultrasound November 8 is ...

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

    Science.gov (United States)

    ... parts of the body and determine the presence of certain diseases. The images can then be examined on a computer monitor, transmitted electronically, printed or copied to a CD or uploaded to a digital cloud server. Functional magnetic resonance imaging (fMRI) is ...

  14. Magnetic resonance imaging of infectious myositis

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Ji Young; Kim, Jee Young; Kim, Sang Heum; Jung, Youn Ju; Cha, Eun Suk; Park, Joung Mi; Park, Young Ha [The Catholic Univ., College of Medicine, Suwon (Korea, Republic of)

    1998-09-01

    To describe the findings of magnetic resonance imaging in infectious myositis and to determine their value for differentiation between ruberculous and bacterial myositis. Magnetic resonance images of ten proven cases of infectious myositis (five tuberculous and five bacterial) were retrospectively reviewed in the light of clinical and laboratory findings. On the basis of magnetic resonance images, signal intensity of the mass, the presence or absence of an abscess, signal intensity of the peripheral wall, patterns of contrast enhancement, and associated findings were evaluated. Compared with those of bacterial myositis, the symptoms of tuberculous myositis lasted longer but there were no difinite local inflammatory signs. In three of five cases of bacterial myositis there were specific medical records;trauma in two cases and systemic lupus erythematosus in one. All tuberculous myositis cases involved a single muscle, but bacterial myositis affected multipe muscles in three cases(60%). All but one case showed a mass in the involved muscles. In one bacterial case, there was diffuse swelling in the involved muscle. On T1-weighted images, eight infectious cases showed low signal intensity;two, of the bactrerial type, showed subtle increased signal intensity. all cases demonstrated high signal intensity on t2-weighted images. The signal intensity of peripheral wall was slightly increased on T1-weighted images, but low on T2-weighted. In four cases there was associated cellulitis, and in one case each, adjacent joint effusion and deep vein thrombosis were seen. After gadolinium infusion, peripheral rim enhancement was noted in nine cases and heterogeneous enhancement in one. After magnetic resonance imaging of infectious myositis, the characteristic finding was an abscessed lesion, with the peripheral wall showing high signal intensity on T1-weighted images and low signal intensity on T2 weighted. Although we found it difficult to differentiate bacterial from tuberculous

  15. The working principle of magnetic resonance therapy

    CERN Document Server

    Brizhik, Larissa; Fermi, Enrico

    2015-01-01

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

  16. Magnetic resonance imaging in inflammatory rheumatoid diseases.

    Science.gov (United States)

    Sudoł-Szopińska, Iwona; Mróz, Joanna; Ostrowska, Monika; Kwiatkowska, Brygida

    2016-01-01

    Magnetic resonance (MR) is used more and more frequently to diagnose changes in the musculoskeletal system in the course of rheumatic diseases, at their initial assessment, for treatment monitoring and for identification of complications. The article presents the history of magnetic resonance imaging, the basic principles underlying its operation as well as types of magnets, coils and MRI protocols used in the diagnostic process of rheumatic diseases. It enumerates advantages and disadvantages of individual MRI scanners. The principles of MRI coil operation are explained, and the sequences used for MR image analysis are described, particularly in terms of their application in rheumatology, including T1-, T2-, PD-weighted, STIR/TIRM and contrast-enhanced T1-weighted images. Furthermore, views on the need to use contrast agents to optimise diagnosis, particularly in synovitis-like changes, are presented. Finally, methods for the assessment of MR images are listed, including the semi-quantitative method by RAMRIS and quantitative dynamic examination.

  17. Magnetic resonance imaging of aneurysmal subarachnoid hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Toshihide; Shimosegawa, Eku; Inugami, Atsushi; Shishido, Fumio; Fujita, Hideaki; Ito, Hiroshi; Uemura, Kazuo; Yasui, Nobuyuki (Research Inst. of Brain and Blood Vessels, Akita (Japan))

    1991-11-01

    Magnetic resonance imaging of subarachnoid hemorrhage (SAH) due to aneurysm rupture was evaluated in relation to CT findings in nine patients. Six patients were studied within 3 days and the other three patients were studied 4 to 6 days from the ictus of SAH using a 0.5 Tesla superconducting unit. In all of the patients, hematoma in the subarachnoid space and ventricles was demonstrated by the proton density-weighted spin echo sequence, which showed that bloody cerebrospinal fluid (CSF) had a higher signal intensity than brain tissue or normal CSF. Magnetic resonance imaging was more sensitive in detecting SAH and more informative as to the site of the ruptured aneurysm than CT. Despite some limitations in applying it to patients with acute SAH, magnetic resonace imaging has clear advantages in the diagnosis of SAH. (author).

  18. Magnetic Resonance Imaging (MRI): Lumbar Spine (For Parents)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Magnetic Resonance Imaging (MRI): Lumbar Spine KidsHealth / For Parents / Magnetic Resonance Imaging (MRI): Lumbar Spine What's in this article? What ...

  19. Role of magnetic resonance venography in evaluation of cerebral ...

    African Journals Online (AJOL)

    Eman Abd-El Latif Abd-Elaziz El Damarawy

    2011-12-14

    Dec 14, 2011 ... Abbreviations: MRI, magnetic resonance imaging; MRV, magnetic resonance venography; SSS, superior sagittal sinus; CVO, cerebral venous occlusion; CVT, cerebral venous thrombosis; DSA, digital subtraction angiography; CT, computed tomography; CTV, computed tomography venography; CVST ...

  20. Brain magnetic resonance imaging examination in a patient with non-magnetic resonance conditional pacemaker

    Directory of Open Access Journals (Sweden)

    Toshiko Nakai, MD

    2017-10-01

    Full Text Available Clinical dilemmas arise when patients with a non-magnetic resonance (MR conditional pacemaker are required to undergo magnetic resonance imaging (MRI. We encountered a pacemaker patient with debilitating non-motor symptoms of Parkinson׳s disease, who required an MRI prior to deep brain stimulation (DBS surgery. MRI was performed safely without adverse events despite the presence of a conventional pacemaker.

  1. Brain magnetic resonance imaging and magnetic resonance spectroscopy findings of children with kernicterus

    OpenAIRE

    Sarı, Sahabettin; Yavuz, Alpaslan; Batur, Aabdussamet; Bora, Aydın; Caksen, Huseyin

    2015-01-01

    Summary Background The term kernicterus, or bilirubin encephalopathy, is used to describe pathological bilirubin staining of the basal ganglia, brain stem, and cerebellum, and is associated with hyperbilirubinemia. Kernicterus generally occurs in untreated hyperbilirubinemia or cases where treatment is delayed. Magnetic resonance imaging (MRI)-based studies have shown characteristic findings in kernicterus. The objective of our study was to describe the role of 1H magnetic resonance spectrosc...

  2. Spin echo magnetic resonance imaging.

    Science.gov (United States)

    Jung, Bernd André; Weigel, Matthias

    2013-04-01

    The spin echo sequence is a fundamental pulse sequence in MRI. Many of today's applications in routine clinical use are based on this elementary sequence. In this review article, the principles of the spin echo formation are demonstrated on which the generation of the fundamental image contrasts T1, T2, and proton density is based. The basic imaging parameters repetition time (TR) and echo time (TE) and their influence on the image contrast are explained. Important properties such as the behavior in multi-slice imaging or in the presence of flow are depicted and the basic differences with gradient echo imaging are illustrated. The characteristics of the spin echo sequence for different magnetic field strengths with respect to clinical applications are discussed. Copyright © 2013 Wiley Periodicals, Inc.

  3. 76 FR 58281 - Magnetic Resonance Imaging Safety; Public Workshop

    Science.gov (United States)

    2011-09-20

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

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

    African Journals Online (AJOL)

    Magnetic resonance (MR) imaging was performed at 1.5 Tesla MR system using a standard head coil. Imaging included conventional MRI and proton magnetic resonance spectroscopy. Proton magnetic resonance spectroscopy was done using either single or multi-voxel technique. Surgical biopsy was then performed to ...

  5. Renal ablation using magnetic resonance-guided high intensity focused ultrasound: Magnetic resonance imaging and histopathology assessment

    OpenAIRE

    Saeed, Maythem; Krug, Roland; Do, Loi; Steven W. Hetts; Wilson, Mark W.

    2016-01-01

    AIM: To use magnetic resonance-guided high intensity focused ultrasound (MRg-HIFU), magnetic resonance imaging (MRI) and histopathology for noninvasively ablating, quantifying and characterizing ablated renal tissue.

  6. Magnetic Resonance Imaging Methods in Soil Science

    Science.gov (United States)

    Pohlmeier, A.; van Dusschoten, D.; Blümler, P.

    2009-04-01

    Magnetic Resonance Imaging (MRI) is a powerful technique to study water content, dynamics and transport in natural porous media. However, MRI systems and protocols have been developed mainly for medical purposes, i.e. for media with comparably high water contents and long relaxation times. In contrast, natural porous media like soils and rocks are characterized by much lower water contents, typically 0 Raich H, and Blümler P, Concepts in Magn. Reson. B 23B, 16-25 (2004) 4) Pohlmeier et al. Magn. Res. Imag. doi:10.1016/j.mri.2008.06.007 (2008)

  7. Advances in magnetic and optical resonance

    CERN Document Server

    Warren, Warren S

    2013-01-01

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

  8. A hyperpolarized equilibrium for magnetic resonance

    Science.gov (United States)

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

    2013-12-01

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

  9. Magnetic mineral exploration using ground magnetic survey data of ...

    African Journals Online (AJOL)

    Ground magnetic survey is an essential geophysical method employed in locating subsurface magnetic materials for possible exploration. In geophysics, the anomalous magnetization might be associated with local mineralization that is potentially of commercial interest. Hence a ground magnetic survey was carried out at a ...

  10. A Portable Nuclear Magnetic Resonance Sensor System

    Directory of Open Access Journals (Sweden)

    R. Dykstra

    2008-04-01

    Full Text Available Nuclear Magnetic Resonance (NMR is a relatively complex technique and normally requires expensive equipment, however with advances in computing, electronics and permanent magnet technologies, NMR is becoming more feasible as a non-invasive tool for industry. The strength of NMR is its ability to probe at the molecular level and hence gain information about molecular structure, organization, abundance and orientation. This paper presents some of the work being undertaken in developing portable NMR systems for the non-destructive testing of materials such as polymer composites, rubber, timber and concrete.

  11. Magnetic resonance imaging findings in tuberculous meningoencephalitis

    Energy Technology Data Exchange (ETDEWEB)

    Pui, M.H.; Memon, W.A. [Aga Khan Univ. Hospital, Dept. of Radiology, Karachi (Pakistan)

    2001-02-01

    To evaluate the efficacy of magnetic resonance imaging (MRI) for distinguishing tuberculosis from other types of meningoencephalitis. MRIs of 100 patients with tuberculous (50), pyogenic (33), viral (14), or fungal (3) meningoencephalitis were analyzed independently by 2 radiologists. Number, size, location, signal characteristics, surrounding edema, and contrast enhancement pattern of nodular lesions; location and pattern of meningeal enhancement; extent of infarct or encephalitis and hydrocephalus were evaluated. Contrast-enhancing nodular lesions were detected in patients with tuberculous (43 of 50 patients), pyogenic (9 of 33), and fungal (3 of 3) infections. No nodules were detected in patients with viral meningoencephalitis. Using the criteria of 1 or more solid rim or homogeneously enhancing nodules smaller than 2 cm, the sensitivity, specificity and accuracy for diagnosing tuberculous meningitis were 86.0%, 90.0% and 88.0%, respectively. Magnetic resonance imaging is useful in distinguishing tuberculous from pyogenic, viral and fungal meningoencephalitis. (author)

  12. Contribution of magnetic resonance imaging in rheumatology

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-11-01

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

  13. Magnetic resonance semiotics of breast fibroadenomas

    Directory of Open Access Journals (Sweden)

    S. V. Serebryakova

    2010-01-01

    Full Text Available Various benign breast abnormalities are diagnosed in 60% of women in Russia today. This is associated with failure of preoperative recognition of the histological class of an identified nodular mass – its detection is an indication for surgical treatment. By using 67 histologically verified breast fibroadenomas (FA as an example, the authors describe their magnetic resonance semiotics and present the differential diagnostic criteria used during dynamic contrast-enhanced magnetic resonance mammography. FAs are characterized by well-defined uniform outlines, homogeneous internal structure, centrifugal and homogeneous accumulation of contrast media through- out the study, without deforming the breast vasculature around. One of the criteria that permit differential diagnosis of FA with malignan- cies is their estimated vascularization.

  14. Magnetic resonance tomography of the penis

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, H.; Taieb, A.; Vadrot, D.

    1986-03-01

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

  15. Caroli's disease: magnetic resonance imaging features.

    Science.gov (United States)

    Guy, France; Cognet, François; Dranssart, Marie; Cercueil, Jean-Pierre; Conciatori, Laurent; Krausé, Denis

    2002-11-01

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

  16. [Nuclear magnetic resonance tomography in gynecologic tumors].

    Science.gov (United States)

    Pfändner, K; Hötzinger, H; Atzinger, A; Ries, G

    1983-09-01

    The article discusses initial experiences of NMR examinations of carcinoma of the uterus and cervix uteri (resistive magnet, NMR prototype of Siemens). All examined carcinomas show prolonged relaxation times. Variation of measurement parameters results in good optical presentation of carcinoma tissue in the resonance scans. The results are compared with those of CT-scans and in one case with the site of the operation.

  17. NON-CONTRAST MAGNETIC RESONANCE UROGRAPHY

    OpenAIRE

    Arpita C; Nava Kishore K; Ananda Reddy C; Dushyanth M

    2016-01-01

    BACKGROUND AND PURPOSE Magnetic Resonance (MR) urography with its optimal contrast resolution and lack of ionizing radiation provides a comprehensive examination of the entire urinary tract noninvasively. MR urography is clinically useful in the evaluation of suspected urinary tract obstruction, haematuria, congenital anomalies, and surgically altered anatomy. It is particularly useful in cases of where there is contraindication of ionizing radiation and in paediatric and pregn...

  18. Nuclear magnetic resonance in Kondo lattice systems

    Science.gov (United States)

    Curro, Nicholas J.

    2016-06-01

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

  19. Breast Tissue Metabolism by Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    Jagannathan, Naranamangalam R; Sharma, Uma

    2017-06-07

    Metabolic alterations are known to occur with oncogenesis and tumor progression. During malignant transformation, the metabolism of cells and tissues is altered. Cancer metabolism can be studied using advanced technologies that detect both metabolites and metabolic activities. Identification, characterization, and quantification of metabolites (metabolomics) are important for metabolic analysis and are usually done by nuclear magnetic resonance (NMR) or by mass spectrometry. In contrast to the magnetic resonance imaging that is used to monitor the tumor morphology during progression of the disease and during therapy, in vivo NMR spectroscopy is used to study and monitor tumor metabolism of cells/tissues by detection of various biochemicals or metabolites involved in various metabolic pathways. Several in vivo, in vitro and ex vivo NMR studies using ¹H and 31P magnetic resonance spectroscopy (MRS) nuclei have documented increased levels of total choline containing compounds, phosphomonoesters and phosphodiesters in human breast cancer tissues, which is indicative of altered choline and phospholipid metabolism. These levels get reversed with successful treatment. Another method that increases the sensitivity of substrate detection by using nuclear spin hyperpolarization of 13C-lableled substrates by dynamic nuclear polarization has revived a great interest in the study of cancer metabolism. This review discusses breast tissue metabolism studied by various NMR/MRS methods.

  20. Breast Tissue Metabolism by Magnetic Resonance Spectroscopy

    Directory of Open Access Journals (Sweden)

    Naranamangalam R. Jagannathan

    2017-06-01

    Full Text Available Metabolic alterations are known to occur with oncogenesis and tumor progression. During malignant transformation, the metabolism of cells and tissues is altered. Cancer metabolism can be studied using advanced technologies that detect both metabolites and metabolic activities. Identification, characterization, and quantification of metabolites (metabolomics are important for metabolic analysis and are usually done by nuclear magnetic resonance (NMR or by mass spectrometry. In contrast to the magnetic resonance imaging that is used to monitor the tumor morphology during progression of the disease and during therapy, in vivo NMR spectroscopy is used to study and monitor tumor metabolism of cells/tissues by detection of various biochemicals or metabolites involved in various metabolic pathways. Several in vivo, in vitro and ex vivo NMR studies using 1H and 31P magnetic resonance spectroscopy (MRS nuclei have documented increased levels of total choline containing compounds, phosphomonoesters and phosphodiesters in human breast cancer tissues, which is indicative of altered choline and phospholipid metabolism. These levels get reversed with successful treatment. Another method that increases the sensitivity of substrate detection by using nuclear spin hyperpolarization of 13C-lableled substrates by dynamic nuclear polarization has revived a great interest in the study of cancer metabolism. This review discusses breast tissue metabolism studied by various NMR/MRS methods.

  1. Breast Tissue Metabolism by Magnetic Resonance Spectroscopy

    Science.gov (United States)

    Jagannathan, Naranamangalam R.; Sharma, Uma

    2017-01-01

    Metabolic alterations are known to occur with oncogenesis and tumor progression. During malignant transformation, the metabolism of cells and tissues is altered. Cancer metabolism can be studied using advanced technologies that detect both metabolites and metabolic activities. Identification, characterization, and quantification of metabolites (metabolomics) are important for metabolic analysis and are usually done by nuclear magnetic resonance (NMR) or by mass spectrometry. In contrast to the magnetic resonance imaging that is used to monitor the tumor morphology during progression of the disease and during therapy, in vivo NMR spectroscopy is used to study and monitor tumor metabolism of cells/tissues by detection of various biochemicals or metabolites involved in various metabolic pathways. Several in vivo, in vitro and ex vivo NMR studies using 1H and 31P magnetic resonance spectroscopy (MRS) nuclei have documented increased levels of total choline containing compounds, phosphomonoesters and phosphodiesters in human breast cancer tissues, which is indicative of altered choline and phospholipid metabolism. These levels get reversed with successful treatment. Another method that increases the sensitivity of substrate detection by using nuclear spin hyperpolarization of 13C-lableled substrates by dynamic nuclear polarization has revived a great interest in the study of cancer metabolism. This review discusses breast tissue metabolism studied by various NMR/MRS methods. PMID:28590405

  2. Different neural manifestations of two slow frequency bands in resting functional magnetic resonance imaging: a systemic survey at regional, interregional, and network levels.

    Science.gov (United States)

    Xue, Shao-Wei; Li, Da; Weng, Xu-Chu; Northoff, Georg; Li, Dian-Wen

    2014-05-01

    Temporal and spectral perspectives are two fundamental facets in deciphering fluctuating signals. In resting state, the dynamics of blood oxygen level-dependent (BOLD) signals recorded by functional magnetic resonance imaging (fMRI) have been proven to be strikingly informative (0.01-0.1 Hz). The distinction between slow-4 (0.027-0.073 Hz) and slow-5 (0.01-0.027 Hz) has been described, but the pertinent data have never been systematically investigated. This study used fMRI to measure spontaneous brain activity and to explore the different spectral characteristics of slow-4 and slow-5 at regional, interregional, and network levels, respectively assessed by regional homogeneity (ReHo) and mean amplitude of low-frequency fluctuation (mALFF), functional connectivity (FC) patterns, and graph theory. Results of paired t-tests supported/replicated recent research dividing low-frequency BOLD fluctuation into slow-4 and slow-5 for ReHo and mALFF. Interregional analyses showed that for brain regions reaching statistical significance, FC strengths at slow-4 were always weaker than those at slow-5. Community detection algorithm was applied to FC data and unveiled two modules sensitive to frequency effects: one comprised sensorimotor structure, and the other encompassed limbic/paralimbic system. Graph theoretical analysis verified that slow-4 and slow-5 differed in local segregation measures. Although the manifestation of frequency differences seemed complicated, the associated brain regions can be grossly categorized into limbic/paralimbic, midline, and sensorimotor systems. Our results suggest that future resting fMRI research addressing the three above systems either from neuropsychiatric or psychological perspectives may consider using spectrum-specific analytical strategies.

  3. Portal biliopathy, magnetic resonance imaging and magnetic resonance cholangiopancreatography findings: a case series.

    Science.gov (United States)

    Baskan, Ozdil; Erol, Cengiz; Sahingoz, Yusuf

    2016-02-01

    Portal biliopathy (PB) is a rare disorder, characterized by biliary ductal and gallbladder wall abnormalities seen in patients with portal hypertension. It most commonly occurs due to idiopathic extrahepatic portal vein obstruction (EHPVO). The abnormalities consist mainly of bile duct compression, stenoses, fibrotic strictures and dilation of both extrahepatic and intrahepatic bile ducts, as well as gallbladder varices. PB may mimic cholangiocarcinoma, sclerosing cholangitis, or choledocholithiasis. Misdiagnosis can be avoided using appropriate imaging modalities to prevent complications. We present the magnetic resonance imaging (MRI) and magnetic resonance cholangiography (MRCP) features of three patients with PB. © The Author(s) 2014. Published by Oxford University Press and the Digestive Science Publishing Co. Limited.

  4. Accuracy of magnetic resonance based susceptibility measurements

    Science.gov (United States)

    Erdevig, Hannah E.; Russek, Stephen E.; Carnicka, Slavka; Stupic, Karl F.; Keenan, Kathryn E.

    2017-05-01

    Magnetic Resonance Imaging (MRI) is increasingly used to map the magnetic susceptibility of tissue to identify cerebral microbleeds associated with traumatic brain injury and pathological iron deposits associated with neurodegenerative diseases such as Parkinson's and Alzheimer's disease. Accurate measurements of susceptibility are important for determining oxygen and iron content in blood vessels and brain tissue for use in noninvasive clinical diagnosis and treatment assessments. Induced magnetic fields with amplitude on the order of 100 nT, can be detected using MRI phase images. The induced field distributions can then be inverted to obtain quantitative susceptibility maps. The focus of this research was to determine the accuracy of MRI-based susceptibility measurements using simple phantom geometries and to compare the susceptibility measurements with magnetometry measurements where SI-traceable standards are available. The susceptibilities of paramagnetic salt solutions in cylindrical containers were measured as a function of orientation relative to the static MRI field. The observed induced fields as a function of orientation of the cylinder were in good agreement with simple models. The MRI susceptibility measurements were compared with SQUID magnetometry using NIST-traceable standards. MRI can accurately measure relative magnetic susceptibilities while SQUID magnetometry measures absolute magnetic susceptibility. Given the accuracy of moment measurements of tissue mimicking samples, and the need to look at small differences in tissue properties, the use of existing NIST standard reference materials to calibrate MRI reference structures is problematic and better reference materials are required.

  5. Gadolinium-Enhanced Magnetic Resonance Angiography for Pulmonary Embolism

    Science.gov (United States)

    Stein, Paul D.; Chenevert, Thomas L.; Fowler, Sarah E.; Goodman, Lawrence R.; Gottschalk, Alexander; Hales, Charles A.; Hull, Russell D.; Jablonski, Kathleen A.; Leeper, Kenneth V.; Naidich, David P.; Sak, Daniel J.; Sostman, H. Dirk; Tapson, Victor F.; Weg, John G.; Woodard, Pamela K.

    2011-01-01

    Background The accuracy of gadolinium-enhanced magnetic resonance pulmonary angiography and magnetic resonance venography for diagnosing pulmonary embolism has not been determined conclusively. Objective To investigate performance characteristics of magnetic resonance angiography, with or without magnetic resonance venography, for diagnosing pulmonary embolism. Design Prospective, multicenter study from 10 April 2006 to 30 September 2008. (ClinicalTrials.gov registration number: NCT00241826) Setting 7 hospitals and their emergency services. Patients 371 adults with diagnosed or excluded pulmonary embolism. Measurements Sensitivity, specificity, and likelihood ratios were measured by comparing independently read magnetic resonance imaging with the reference standard for diagnosing pulmonary embolism. Reference standard diagnosis or exclusion was made by using various tests, including computed tomographic angiography and venography, ventilation–perfusion lung scan, venous ultra-sonography, D-dimer assay, and clinical assessment. Results Magnetic resonance angiography, averaged across centers, was technically inadequate in 25% of patients (92 of 371). The proportion of technically inadequate images ranged from 11% to 52% at various centers. Including patients with technically inadequate images, magnetic resonance angiography identified 57% (59 of 104) with pulmonary embolism. Technically adequate magnetic resonance angiography had a sensitivity of 78% and a specificity of 99%. Technically adequate magnetic resonance angiography and venography had a sensitivity of 92% and a specificity of 96%, but 52% of patients (194 of 370) had technically inadequate results. Limitation A high proportion of patients with suspected embolism was not eligible or declined to participate. Conclusion Magnetic resonance pulmonary angiography should be considered only at centers that routinely perform it well and only for patients for whom standard tests are contraindicated. Magnetic

  6. Magnetic resonance spectroscopy of the human brain

    Science.gov (United States)

    Strózik-Kotlorz, D.

    2014-01-01

    I give a brief description of the magnetic resonance spectroscopy (MRS) in the human brain examinations. MRS allows a noninvasive chemical analysis of the brain using a standard high field MR system. Nowadays, the dominant form of MR brain spectroscopy is proton spectroscopy. Two main techniques of MRS, which utilize the chemical shift of metabolites in the external magnetic field, are SVS (single voxel) and CSI (single slice). The major peaks in the spectrum of a normal brain include NAA, Cr, Cho and m-Ins, which are neuronal, energetic, membrane turnover and glial markers, respectively. In disease, two pathological metabolites can be found in the brain spectra: Lac, which is end product of anaerobic glycolysis and Lip, which is a marker of membrane breakdown, occurring in necrosis. The common way to analyze clinical spectra is to determine metabolite ratios, e.g. NAA/Cr, Cho/Cr, Cho/NAA. This analysis permits a safe and noninvasive examination of the brain tissue as each disease state has its own characteristic spectroscopic image. MRS is a valuable diagnostic tool in such clinical applications as detecting brain tumors and differentiating tumors from inflammatory and infectious processes. Proton MRS is also very helpful in diagnostic of ischemic lesions, Alzheimer's disease and hepatic encephalopathy. The MRS brain spectra should always be correlated with the Magnetic Resonance Imaging (MRI) results and alone cannot make neurological diagnosis.

  7. Magnetic resonance imaging of valvular heart disease

    DEFF Research Database (Denmark)

    Søndergaard, Lise; Ståhlberg, F; Thomsen, C

    1999-01-01

    The optimum management of patients with valvular heart diseases requires accurate and reproducible assessment of the valvular lesion and its hemodynamic consequences. Magnetic resonance imaging (MRI) techniques, such as volume measurements, signal-void phenomena, and velocity mapping, can be used...... in an integrated approach to gain qualitative and quantitative information on valvular heart disease as well as ventricular dimensions and functions. Thus, MRI may be advantageous to the established diagnostic tools in assessing the severity of valvular heart disease as well as monitoring the lesion and predicting...... the optimal timing for valvular surgery. This paper reviews the validation of these MRI techniques in assessing valvular heart disease and discusses some typical pitfalls of the techniques, including suggestions for solutions.J. Magn. Reson. Imaging 1999;10:627-638....

  8. Role of magnetic resonance venography in evaluation of cerebral ...

    African Journals Online (AJOL)

    Eman Abd-El Latif Abd-Elaziz El Damarawy

    2011-12-14

    Dec 14, 2011 ... Objective: To assess the role of magnetic resonance venography in the evaluation of cerebral veins and sinuses occlusion. Methods: The study was conducted on 15 patients with cerebral venous occlusion and subjected to. MRI and MRV. Abbreviations: MRI, magnetic resonance imaging; MRV, magnetic.

  9. Molecular structure and motion in zero field magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Jarvie, T.P.

    1989-10-01

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

  10. Magnetic resonance imaging of cleft palate

    Energy Technology Data Exchange (ETDEWEB)

    Naito, Yasushi; Tasaka, Yasuyuki; Honjo, Iwao; Nishimura, Kazumasa; Nakano, Yoshihisa

    1987-03-01

    Magnetic resonance imaging (MRI) of the nasopharynx and the eustachian tube was performed in five patients with cleft palate and compared with the results of those without this anomaly. Various degrees of deformity of the eustachian tube cartilage were found in cleft palate patients. The levator veli palatini muscles were situated more laterally in cleft palate patients than in normal subjects. Also, changes in the position of these muscles after palatoplasty were clearly depicted by MRI. Besides several autopsy reports, this is the first demonstration of the characteristic anomaly around the eustachian tube by a non-invasive method.

  11. Fetal fat measurement by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Deans, H.E.; Smith, F.W.; Law, A.N. (Royal Infirmary, Aberdeen (UK)); Lloyd, D.J.; Sutherland, H.W. (Aberdeen Maternity Hospital (UK))

    1989-07-01

    A method to assess the average percentage of fetal fat with respect to other fetal tissue is described. This method was then used to assess the percentage of fat in 13 normal fetuses who had a magnetic resonance imaging (MRI) examination late in pregnancy (38-41 weeks). The scans of a further 13 fetuses of diabetic mothers and one case of intrauterine growth retardation (IUGR), all of whom had MRI examinations in the last 3 years, were reviewed and similar calculations were carried out. Whilst the percentage fat range in the normal group was large, it was still possible to discern a difference between the normal, diabetic and IUGR cases. (author).

  12. Interactive Real-time Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Brix, Lau

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

  13. Cine magnetic resonance imaging of ocular motility.

    Science.gov (United States)

    Cadera, W; Viirre, E; Karlik, S

    1992-01-01

    We describe a technique of generation of a cine motion picture of ocular movements in a patient with Duane Type II exotropia. With the magnetic resonance scanning unit, multiple scans can be sequenced to give a graphic animation to the eyes as targets are fixated across the visual field. With this technique, we were able to clearly view the contractility of the extraocular muscles and note the changes in pulling directions of the muscles in this patient. The restriction of movement due to the cocontraction of the horizontal rectus muscles was readily apparent.

  14. Magnetic resonance imaging of cervical myelopathy

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-03-01

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

  15. Magnetic Resonance Imaging of Thyroid and Parathyroid

    Directory of Open Access Journals (Sweden)

    Miguel GONZALO-DOMÍNGUEZ

    2017-05-01

    Full Text Available Introduction: The assessment of the thyroid and parathyroid pathology is usually achieved with ultrasounds. There are several systems of classification that are internationally accepted in neoplastic disease, such as TIRADS system, and there are well-defined patterns for ultrasound imaging in inflammatory disease. Material and methods: However, there are specific needs that require magnetic resonance imaging. We review the main indications of MRI in the evaluation of thyroid and parathyroid in 64 patients and determine which protocols are more appropriate and which sequences are better for a proper characterization. Results: Then we review the semiology obtained by this technique, making correlation with disease processes affecting these cervical structures.

  16. MRCP. Magnetic resonance cholangiopancreatography; MRCP. Magnetresonanzcholangiopankreatografie

    Energy Technology Data Exchange (ETDEWEB)

    Kinner, Sonja [Wisconsin-Madison Univ., Madison, WI (United States). Dept. of Radiology; Lauenstein, Thomas [Evangelisches Krankenhaus Duesseldorf (Germany). Radiologie

    2016-06-15

    Magnetic resonance cholangiopancreatography (MRCP) is a special MR technique to display and analyze the biliary tract and pancreatic ducts. MRCP sequences are equivalent to endoscopic retrograde cholangiopancreatography (ERCP) for diagnostic purposes due to technical developments of the classical T2 weighted MRCP sequences and the availability of contrast enhanced T1 weighted sequences. Therefore, MRCP plays a fundamental role in the diagnoses of hepatobliary and pancreatic diseases, which are presented in this review article as are technical details of sequence acquisitions and the underlying anatomy.

  17. Structural magnetic resonance imaging in epilepsy

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-01-15

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

  18. 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.

  19. Magnetic resonance spectroscopy studies in migraine

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-06-01

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

  20. Magnetic resonance in hearing loss and vertigo

    Directory of Open Access Journals (Sweden)

    Manuel Ángel MARTÍN-PÉREZ

    2017-03-01

    Full Text Available Introduction and objective: Hearing loss and vertiginous syndrome represent an important part of the otorhinolaryngology clinic. The role of the radiologist plays in their workup become fundamental. Studies using magnetic resonance imaging (MRI are essential to guide or give the diagnosis in these cases. Method: After performing a retrospective analysis of 456 MRI studies of patients with these symptoms, we conducted a review of the main pathologies recorded that can cause these symptoms. Results: We classify into vascular disorders and other variants, tumor pathology, malformations and inflammatory pathology; We also describe the most relevant findings on MRI and illustrated with examples of our center.

  1. Magnetic resonance imaging characteristics of granulomatous mastitis.

    Science.gov (United States)

    Chu, Amanda N; Seiler, Stephen J; Hayes, Jody C; Wooldridge, Rachel; Porembka, Jessica H

    Granulomatous mastitis (GM) is a benign chronic inflammatory condition of the breast. This study was performed to determine the utility of magnetic resonance imaging (MRI) in differentiating GM from malignancy. MRI findings in 12 women with clinical or histopathologically-proven GM were retrospectively reviewed. Non-mass enhancement on MRI was present in all 12 patients with clustered ring enhancement being the most common pattern (n=7, 58%). Architectural distortion (n=10, 83%), skin thickening (n=10, 83%) and focal skin enhancement (n=10, 83%) were also very common. MRI features of GM are often identical to features considered suspicious for malignancy on MRI. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Magnetic resonance imaging of acute pulmonary embolism

    Energy Technology Data Exchange (ETDEWEB)

    Fink, Christian; Schoenberg, Stefan O. [University Hospital Mannheim, Medical Faculty Mannheim-University of Heidelberg, Department of Clinical Radiology, Mannheim (Germany); Ley, Sebastian; Kauczor, H.U. [Deutsches Krebsforschungszentrum, Department of Radiology, Heidelberg (Germany); Reiser, Maximilian F. [University Hospitals Grosshadern, Ludwig-Maximilians-University of Munich, Department of Clinical Radiology, Munich (Germany)

    2007-10-15

    Pulmonary embolism (PE) is a very common and potentially life-threatening disease. In comparison with CT, the clinical relevance of magnetic resonance imaging (MRI) for the assessment of PE is low. Nevertheless, as there are some potential advantages of MRI over CT (e.g. radiation free method, better safety profile of MR contrast media, capability of functional imaging). In certain patient, groups MRI might therefore be considered as a valuable alternative in the assessment of suspected PE. This article reviews the relevant MRI techniques for the evaluation of PE and gives an overview of the current literature for contrast-enhanced MR angiography of PE. (orig.)

  3. Magnetic resonance images of chronic patellar tendinitis

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-01-01

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

  4. Magnetic resonance-guided prostate interventions.

    Science.gov (United States)

    Haker, Steven J; Mulkern, Robert V; Roebuck, Joseph R; Barnes, Agnieska Szot; Dimaio, Simon; Hata, Nobuhiko; Tempany, Clare M C

    2005-10-01

    We review our experience using an open 0.5-T magnetic resonance (MR) interventional unit to guide procedures in the prostate. This system allows access to the patient and real-time MR imaging simultaneously and has made it possible to perform prostate biopsy and brachytherapy under MR guidance. We review MR imaging of the prostate and its use in targeted therapy, and describe our use of image processing methods such as image registration to further facilitate precise targeting. We describe current developments with a robot assist system being developed to aid radioactive seed placement.

  5. Hair product artifact in magnetic resonance imaging.

    Science.gov (United States)

    Chenji, Sneha; Wilman, Alan H; Mah, Dennell; Seres, Peter; Genge, Angela; Kalra, Sanjay

    2017-01-01

    The presence of metallic compounds in facial cosmetics and permanent tattoos may affect the quality of magnetic resonance imaging. We report a case study describing a signal artifact due to the use of a leave-on powdered hair dye. On reviewing the ingredients of the product, it was found to contain several metallic compounds. In lieu of this observation, we suggest that MRI centers include the use of metal- or mineral-based facial cosmetics or hair products in their screening protocols. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Contrast Agent in Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Vu-Quang, Hieu

    2015-01-01

    Nanoparticles have been employed as contrast agent in magnetic resonance imaging (MRI) in order to improve sensitivity and accuracy in diagnosis. In addition, these contrast agents are potentially combined with other therapeutic compounds or near infrared bio-imaging (NIR) fluorophores to obtain...... theranostic or dual imaging purposes, respectively. There were two main types of MRI contrast agent that were synthesized during this PhD project including fluorine containing nanoparticles and magnetic nanoparticles. In regard of fluorine containing nanoparticles, there were two types contrast agent...... that were synthesized in project I and II. In project I, Poly (lactic-co-glycolic acid)-block-poly (ethylene glycol)-Folate Pefluorooctyl Bromide/Indocyanine green/ Doxorubicin (PLGA-PEG-Folate PFOB/ICG/Dox) has been formulated for the dual imaging NIR and 19F MRI as well as in the combination of Dox...

  7. Clinical applications of cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Marcu, C.B.; Beek, A.M.; Van Rossum, A.C. [Hospital of Saint Raphael, Cardiac Diagnostic Unit, New Haven, CT (United States)], E-mail: bogmarcu@pol.net

    2006-10-15

    Cardiovascular magnetic resonance imaging (MRI) has evolved from an effective research tool into a clinically proven, safe and comprehensive imaging modality. It provides anatomic and functional information in acquired and congenital heart disease and is the most precise technique for quantification of ventricular volumes, function and mass. Owing to its excellent interstudy reproducibility, cardiovascular MRI is the optimal method for assessment of changes in ventricular parameters after therapeutic intervention. Delayed contrast enhancement is an accurate and robust method used in the diagnosis of ischemic and nonischemic cardiomyopathies and less common diseases, such as cardiac sarcoidosis and myocarditis. First-pass magnetic contrast myocardial perfusion is becoming an alternative to radionuclide techniques for the detection of coronary atherosclerotic disease. In this review we outline the techniques used in cardiovascular MRI and discuss the most common clinical applications. (author)

  8. Nanoscale nuclear magnetic resonance with chemical resolution

    Science.gov (United States)

    Aslam, Nabeel; Pfender, Matthias; Neumann, Philipp; Reuter, Rolf; Zappe, Andrea; Fávaro de Oliveira, Felipe; Denisenko, Andrej; Sumiya, Hitoshi; Onoda, Shinobu; Isoya, Junichi; Wrachtrup, Jörg

    2017-07-01

    Nuclear magnetic resonance (NMR) spectroscopy is a key analytical technique in chemistry, biology, and medicine. However, conventional NMR spectroscopy requires an at least nanoliter-sized sample volume to achieve sufficient signal. We combined the use of a quantum memory and high magnetic fields with a dedicated quantum sensor based on nitrogen vacancy centers in diamond to achieve chemical shift resolution in 1H and 19F NMR spectroscopy of 20-zeptoliter sample volumes. We demonstrate the application of NMR pulse sequences to achieve homonuclear decoupling and spin diffusion measurements. The best measured NMR linewidth of a liquid sample was ~1 part per million, mainly limited by molecular diffusion. To mitigate the influence of diffusion, we performed high-resolution solid-state NMR by applying homonuclear decoupling and achieved a 20-fold narrowing of the NMR linewidth.

  9. Multiparametric magnetic resonance imaging findings of prostatic pure leiomyomas

    OpenAIRE

    Mussi, Thais Caldara; Costa,Yves Bohrer; Obara, Marcos Takeo; de Queiroz, Marcos Roberto Gomes; Garcia, Rodrigo Gobbo; Longo, José Antonio Domingos Cianciarulo; Lemos, Gustavo Caserta; Baroni, Ronaldo Hueb

    2016-01-01

    ABSTRACT Objective: To describe the imaging findings of prostatic tumors nonadenocarcinoma on multiparametric magnetic resonance imaging. Methods: A total of 200 patients underwented multiparametric magnetic resonance imaging of the prostate for screening for prostate cancer, from August 2013 to September 2014, followed by biopsy with ultrasound/magnetic resonance imaging fusion. Results: We found three pathologic proved cases of prostatic pure leiomyomas (0.02%) in our series and describe...

  10. [Cardiac magnetic resonance and uremic cardiomyopathy].

    Science.gov (United States)

    Di Lullo, L; Gorini, A; Rivera, R; De Pascalis, A; Bellasi, A; Russo, D; Barbera, V; Ronco, C; Balducci, A; Santoboni, A

    2014-01-01

    Cardiovascular disease (CV) represents the main risk factor for morbidity and mortality in chronic kidney disease (CKD) patients. Large epidemiological studies have shown direct association between severity of CKD and CV event rates. Although patients with end-stage renal disease (ESRD), including dialysis ones, are at greater CV risk, cardiovascular involvement is already evident at the early stages of CKD. End-stage CKD is characterized conventional atherosclerotic risk factor but they cannot account for CV risk as reflected in high rates of sudden cardiac death, heart failure and myocardial infarction. Non-atherosclerotic processes, including left ventricular hypertrophy and fibrosis, mostly account for the excess risk of CV. Employment of cardiac magnetic resonance (CMR) in CKD has brought an improved understanding of the adverse CV changes, known as uremic cardiomyopathy. It is due to ability of cardiac magnetic resonance to provide a comprehensive non - invasive examination of cardiac structure and function, arterial function, myocardial tissue characterization (T1 mapping and inversion recovery imaging), and myocardial metabolic function (spectroscopy).

  11. Magnetic Resonance Microscopy of the Lung

    Science.gov (United States)

    Johnson, G. Allan

    1999-11-01

    The lung presents both challenges and opportunities for study by magnetic resonance imaging (MRI). The technical challenges arise from respiratory and cardiac motion, limited signal from the tissues, and unique physical structure of the lung. These challenges are heightened in magnetic resonance microscopy (MRM) where the spatial resolution may be up to a million times higher than that of conventional MRI. The development of successful techniques for MRM of the lung present enormous opportunities for basic studies of lung structure and function, toxicology, environmental stress, and drug discovery by permitting investigators to study this most essential organ nondestructively in the live animal. Over the last 15 years, scientists at the Duke Center for In Vivo Microscopy have developed techniques for MRM in the live animal through an interdisciplinary program of biology, physics, chemistry, electrical engineering, and computer science. This talk will focus on the development of specialized radiofrequency coils for lung imaging, projection encoding methods to limit susceptibility losses, specialized support structures to control and monitor physiologic motion, and the most recent development of hyperpolarized gas imaging with ^3He and ^129Xe.

  12. Magnetic resonance imaging of the bone marrow

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-08-01

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

  13. Magnetic resonance imaging of granular materials

    Science.gov (United States)

    Stannarius, Ralf

    2017-05-01

    Magnetic Resonance Imaging (MRI) has become one of the most important tools to screen humans in medicine; virtually every modern hospital is equipped with a Nuclear Magnetic Resonance (NMR) tomograph. The potential of NMR in 3D imaging tasks is by far greater, but there is only "a handful" of MRI studies of particulate matter. The method is expensive, time-consuming, and requires a deep understanding of pulse sequences, signal acquisition, and processing. We give a short introduction into the physical principles of this imaging technique, describe its advantages and limitations for the screening of granular matter, and present a number of examples of different application purposes, from the exploration of granular packing, via the detection of flow and particle diffusion, to real dynamic measurements. Probably, X-ray computed tomography is preferable in most applications, but fast imaging of single slices with modern MRI techniques is unmatched, and the additional opportunity to retrieve spatially resolved flow and diffusion profiles without particle tracking is a unique feature.

  14. Clinical application of functional magnetic resonance imaging

    CERN Document Server

    Alwatban, A Z W

    2002-01-01

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

  15. Magnetic resonance imaging of fetal pelvic cysts.

    Science.gov (United States)

    Archontaki, Styliani; Vial, Yvan; Hanquinet, Sylviane; Meuli, Reto; Alamo, Leonor

    2016-12-01

    The detection of fetal anomalies has improved in the last years as a result of the generalization of ultrasound pregnancy screening exams. The presence of a cystic imaging in the fetal pelvis is a relatively common finding, which can correspond to a real congenital cystic lesion or result from the anomalous liquid accumulation in a whole pelvic organ, mainly the urinary bladder, the uterus, or the vagina. In selected cases with poor prognosis and/or inconclusive echographic findings, magnetic resonance may bring additional information in terms of the characterization, anatomical location, and real extension of the pathology. This pictorial essay describes the normal pelvic fetal anatomy, as well as the most common pelvic cysts. It also describes the causes of an anomalous distension of the whole pelvic organs detected in utero, with emphasis on prenatal magnetic resonance imaging exams. Moreover, it proposes practical teaching points to reduce the differential diagnosis of these lesions based on the sex of the fetus, the division of the pelvis in anatomical spaces, and the imaging findings of the pathology. Finally, it discusses the real utility of complementary MRI.

  16. Magnetic resonance spectroscopy in cancer diagnostics

    Directory of Open Access Journals (Sweden)

    Ana Margarida Abrantes

    2011-12-01

    Full Text Available Magnetic resonance spectroscopy (MRS is one of the most powerful analytical techniques, being frequently used to derive physical, chemical, electronic, and structural information about molecules. Considering its potentialities and its evolution as cell/tissue response predictor, it can be used to detect changes in the tumor pathophysiology before, during, and after treatment. Of particular relevance to this analysis, due to its higher sensitivity, is proton magnetic resonance spectroscopy (1H-MRS either applied directly in vivo or by using tumor biopsies and high-rotation magic angle spinning (HRMAS. Several metabolites have been quantified in several tumors, including creatine and phosphocreatine, choline, lactate and myoinositol, and used for distinguishing different cancer types. Several advantages characterize this technique including swiftness and ability to support the characterization of tumoral lesions on the basis of their biochemical composition, which may provide additional diagnostic and prognostic information as an adjunct to routine histological assessment. Many tumors have already been studied by 1H-MRS, and there is growing interest in studying others in order to establish extended metabolite databases which could help in their identification and characterization.

  17. Magnetic resonance imaging findings in adnexial torsion

    Directory of Open Access Journals (Sweden)

    Ronald Meira Castro Trindade

    2010-03-01

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

  18. Magnetic resonance imaging findings in adnexial torsion

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-01-15

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

  19. Resonances and dipole moments in dielectric, magnetic, and magnetodielectric cylinders

    DEFF Research Database (Denmark)

    Dirksen, A.; Arslanagic, Samel; Breinbjerg, Olav

    2011-01-01

    An eigenfunction solution to the problem of plane wave scattering by dielectric, magnetic, and magnetodielectric cylinders is used for a systematic investigation of their resonances. An overview of the resonances with electric and magnetic dipole moments, needed in, e.g., the synthesis of metamat......An eigenfunction solution to the problem of plane wave scattering by dielectric, magnetic, and magnetodielectric cylinders is used for a systematic investigation of their resonances. An overview of the resonances with electric and magnetic dipole moments, needed in, e.g., the synthesis...

  20. Non-contrast-enhanced magnetic resonance angiography: techniques and applications.

    Science.gov (United States)

    Blankholm, Anne Dorte; Ringgaard, Steffen

    2012-01-01

    Non-contrast-enhanced magnetic resonance angiography has gained renewed interest since the discovery of the association between gadolinium-based contrast agents and nephrogenic systemic fibrosis. The following article is an overview of the different magnetic resonance angiography sequences, the technical possibilities and new developments. Clinical options and recent advancements will be highlighted, and recommendations for non-contrast-enhanced magnetic resonance angiography techniques in different anatomical regions will be given. Furthermore, the authors seek to predict the future of non-contrast-enhanced magnetic resonance angiography, with special focus on patients at risk.

  1. Structural Magnetic Resonance Imaging of the Adolescent Brain

    National Research Council Canada - National Science Library

    GIEDD, JAY N

    2004-01-01

    A bstract : Magnetic resonance imaging (MRI) provides accurate anatomical brain images without the use of ionizing radiation, allowing longitudinal studies of brain morphometry during adolescent development...

  2. Chiral discrimination in nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Lazzeretti, Paolo

    2017-11-01

    Chirality is a fundamental property of molecules whose spatial symmetry is characterized by the absence of improper rotations, making them not superimposable to their mirror image. Chiral molecules constitute the elementary building blocks of living species and one enantiomer is favoured in general (e.g. L-aminoacids and D-sugars pervade terrestrial homochiral biochemistry) because most chemical reactions producing natural substances are enantioselective. Since the effect of chiral chemicals and drugs on living beings can be markedly different between enantiomers, the quest for practical spectroscopical methods to scrutinize chirality is an issue of great importance and interest. Nuclear magnetic resonance (NMR) is a topmost analytical technique, but spectrometers currently used are ‘blind’ to chirality, i.e. unable to discriminate the two mirror-image forms of a chiral molecule, because, in the absence of a chiral solvent, the spectral parameters, chemical shifts and spin-spin coupling constants are identical for enantiomers. Therefore, the development of new procedures for routine chiral recognition would offer basic support to scientists. However, in the presence of magnetic fields, a distinction between true and false chirality is mandatory. The former epitomizes natural optical activity, which is rationalized by a time-even pseudoscalar, i.e. the trace of a second-rank tensor, the mixed electric dipole/magnetic dipole polarizability. The Faraday effect, magnetic circular dichroism and magnetic optical activity are instead related to a time-odd axial vector. The present review summarizes recent theoretical and experimental efforts to discriminate enantiomers via NMR spectroscopy, with the focus on the deep connection between chirality and symmetry properties under the combined set of fundamental discrete operations, namely charge conjugation, parity (space inversion) and time (motion) reversal.

  3. Spin Resonance and Magnetic Order in an Unconventional Superconductor

    Science.gov (United States)

    Mazzone, D. G.; Raymond, S.; Gavilano, J. L.; Steffens, P.; Schneidewind, A.; Lapertot, G.; Kenzelmann, M.

    2017-11-01

    Unconventional superconductivity in many materials is believed to be mediated by magnetic fluctuations. It is an open question how magnetic order can emerge from a superconducting condensate and how it competes with the magnetic spin resonance in unconventional superconductors. Here we study a model d -wave superconductor that develops spin-density wave order, and find that the spin resonance is unaffected by the onset of static magnetic order. This result suggests a scenario, in which the resonance in Nd0.05Ce0.95CoIn5 is a longitudinal mode with fluctuating moments along the ordered magnetic moments.

  4. Spin Resonance and Magnetic Order in an Unconventional Superconductor.

    Science.gov (United States)

    Mazzone, D G; Raymond, S; Gavilano, J L; Steffens, P; Schneidewind, A; Lapertot, G; Kenzelmann, M

    2017-11-03

    Unconventional superconductivity in many materials is believed to be mediated by magnetic fluctuations. It is an open question how magnetic order can emerge from a superconducting condensate and how it competes with the magnetic spin resonance in unconventional superconductors. Here we study a model d-wave superconductor that develops spin-density wave order, and find that the spin resonance is unaffected by the onset of static magnetic order. This result suggests a scenario, in which the resonance in Nd_{0.05}Ce_{0.95}CoIn_{5} is a longitudinal mode with fluctuating moments along the ordered magnetic moments.

  5. Ferromagnetic resonance of particulate magnetic recording tapes

    Science.gov (United States)

    Netzelmann, U.

    1990-08-01

    The room-temperature ferromagnetic resonance (FMR) spectra of γ-Fe2O3, CrO2, and barium ferrite particulate magnetic recording tapes have been measured at microwave frequencies of 9.35 and 35 GHz for various orientations of the static and high-frequency magnetic fields with respect to the tape. For CrO2 tapes, the influence of the width of the angular distribution of the particle orientations on the FMR spectra has been studied from the nearly isotropic case up to the highly oriented case. Hysteretic behavior for a CrO2 tape as well as the effect of tape calendering for a γ-Fe2O3 tape has been observed by FMR. Experimental results are found to be in reasonable agreement with results of theoretical calculations based on a model of an ellipsoidal single-domain particle with both shape and magnetocrystalline anisotropy. Magnetostatic interaction inside the magnetic film has been introduced by expressing the total magnetostatic energy as a combination of a part dependent on particle shape and a part dependent on the shape of the tape. As a result of a comparison of experimental data with calculated data from the model, the magnetocrystalline easy axis of the CrO2 particles is found to be parallel with the particle axis.

  6. Studies of the heart using magnetic resonance.

    Science.gov (United States)

    Longmore, D; Forbat, S

    1992-01-01

    Cardiovascular medicine is based on high-technology management of end-stage disease. Preventive medicine is preferable but, before magnetic resonance (MR), there was no noninvasive, safe, repeatable method of detecting occlusive vascular disease, which accounts for more deaths than any other disease at a presymptomatic stage. Demographic and animal studies show that occlusive vascular disease is not a normal aging process and is reversible. There was no method of monitoring the efficacy of preventive and therapeutic measures other than long, expensive, and sometimes inconclusive clinical trials. The rate of precession of atomic nuclei in a magnetic field is related to field strength. Creating a unique magnetic field in each volume of interest allows analysis of emitted radio signals to produce an image containing information about movement and local biochemical environments. MR produces accurate high resolution anatomical images and functional information including blood flow. It is already established as a method of choice in clinical cardiology for congenital heart disease and aortic disease. It is becoming established as a method of evaluating cardiovascular-active drugs, and in the future MR will be used for diagnosis and as a population-screening instrument for all cardiovascular disease including coronary artery disease.

  7. Airborne Magnetic (AM) Surveys in Mareci

    OpenAIRE

    , M Shabani; , B Muqa

    2016-01-01

    Airborne magnetic survey on Mareci region, were carried out during 2006. Mareci’s area is known for a complex geological setings. Inherent, geological construction have affects in measured parameters of the total intensity of magnetic field. The size of the magnetic field intensity is influenced by the presence of certain minerals and iron-feromagnetice sulfur, which build mineralogy of geological formations. Magnetic anomalies had the highest intensity of magnetic field in Koznica ultrabasic...

  8. Magnetic Nanoparticles Aggregation in Magnetic Gel Studied by Electron Magnetic Resonance (EMR

    Directory of Open Access Journals (Sweden)

    Olga N. Sorokina

    2012-04-01

    Full Text Available Aggregation of magnetic nanoparticles immobilized in polymer gels was studied by ferromagnetic resonance and paramagnetic sensor techniques. Ferromagnetic resonance spectra of magnetic gels prepared in the presence of external magnetic field of 1.5 kG were compared to the spectra of gels synthesized in the absence of a magnetic field. Application of a magnetic field led to formation of linear aggregates of magnetic particles in the polymer matrix. The aggregates did not come apart after the field was switched off. The fraction of aggregated particles (of 62(6% and aspect ratio (elongation of the aggregates (12.6(1.3 was determined using paramagnetic sensor technique.

  9. Magnetic resonance imaging of intervertebral disc degeneration

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-02-01

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

  10. Magnetic resonance imaging of facial muscles

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-11-15

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

  11. Magnetic resonance imaging in acute physeal injuries

    Energy Technology Data Exchange (ETDEWEB)

    White, P.G. [Dept. of Radiology, McMaster Univ. Medical Centre, Hamilton, ON (Canada); Mah, J.Y. [Dept. of Orthopedics, McMaster Univ. Medical Centre, Hamilton, ON (Canada); Friedman, L. [Dept. of Radiology, McMaster Univ. Medical Centre, Hamilton, ON (Canada)

    1994-11-01

    Magnetic resonance imaging (MRI) permits noninvasive evaluation of the cartilage of the growth plate and epiphysis. This paper reports three cases where MRI was used to supplement conventional radiography in the assessment of acute physeal injuries. In the first patient, MRI was used for postoperative assessment of a radial neck fracture, avoiding further surgical exploration. In the second case, MRI was compared with ultrasonography in the diagnosis of proximal humeral epiphyseal separation in a neonate. In the third case, MRI and computed tomography were compared in evaluation of a Salter-Harris type 4 distal femur fracture. In all cases MRI was diagnostic. MRI is the investigation of choice in acute complex physeal injuries, and is particularly appropriate for use prior to the appearance of the secondary ossification center. (orig.)

  12. Cryogenic Preamplifiers for Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Johansen, Daniel H.; Sanchez-Heredia, Juan D.; Petersen, Jan R.

    2018-01-01

    Pursuing the ultimate limit of detection in magnetic resonance imaging (MRI) requires cryogenics to decrease the thermal noise of the electronic circuits. As cryogenic coils for MRI are slowly emerging cryogenic preamplifiers are required to fully exploit their potential. A cryogenic preamplifier...... operated at 77 K is designed and implemented for C imaging at 3 T (32.13 MHz), using off-the-shelves components. The design is based on a high electron mobility transistor (ATF54143) in a common source configuration. Required auxiliary circuitry for optimal cryogenic preamplifier performance is also...... presented consisting of a voltage regulator (noise free supply voltage and optimal power consumption), switch, and trigger (for active detuning during transmission to protect the preamplifier). A gain of 18 dB with a noise temperature of 13.7 K is achieved. Performing imaging experiments in a 3 T scanner...

  13. [Magnetic resonance tomography: potentials of molecular imaging].

    Science.gov (United States)

    Hiller, Karl-Heinz; Faber, Cornelius; Neuberger, Thomas; Köhler, Sascha; Stroh, Albrecht; Zimmer, Claus; Jakob, Peter

    2005-01-01

    Molecular imaging is "the in-vivo characterization and measurement of biological processes at the cellular and molecular level" and allows the imaging of molecular abnormalities associated with diseases long before morphological changes can be detected. At present, the use of magnetic resonance imaging (MRI) for molecular and cellular imaging is rapidly increasing. MRI is a very attractive candidate, since current MRI protocols already provide anatomic, functional, and biochemical information of excellent image quality and with high spatial resolution. Combining this high spatial resolution/high contrast imaging modality with specific MRI contrast imaging agents for molecular imaging is currently the focus of research in many laboratories worldwide. This paper summarizes the rationale for molecular MRI imaging and describes the basic features of modern molecular imaging strategies with MRI. Finally, a special focus is given to the growing field of applications, e.g., stem cell imaging, imaging of apoptosis, plaques, and other biological targets of interest.

  14. Magnetic resonance imaging for cardiac tumors

    Energy Technology Data Exchange (ETDEWEB)

    Niwa, Koichiro; Tashima, Kazuyuki; Okajima, Yoshitomo; Nakajima, Hiromichi; Terai, Masaru; Nakajima, Hironori; Harada, Tsutomu; Ishida, Yoshikazu.

    1988-09-01

    We performed magnetic resonance imaging (MRI) in 4 patients with cardiac tumor (1 with rhabdomyoma, 1 with left atrial myxoma, and 2 with tumor of the left ventricular wall) for morphological evaluation of the tumor. ECG-gated MRI was performed by the spin echo imaging technique using a superconducting MRI system operating at 0.5 tesla. Spatial extension of the tumor was clearly demonstrated in all the patients. Gadolinium-DTPA (Gd-DTPA), was used in the 2 patients with tumor of the left ventricular myocardium to enhance the contrast, and allowed clear visualization of the tumor. These findings show the usefulness of MRI and MRI with Gd-DTPA for morphological evaluation of cardiac tumor.

  15. Magnetic resonance urography by virtual reality modelling.

    Science.gov (United States)

    Beigi, Navid; Sangild, Thomas; Terkildsen, Søren Vorre; Deding, Dorthe; Stødkilde-Jørgensen, Hans; Pedersen, Michael

    2003-01-01

    The purpose of this study was to create a 3D visualization of the urinary tract by a novel virtual reality approach, and to evaluate the usefulness of this method for papillary classification as compared with 2D urogram obtained by maximum intensity projection (MIP). In one healthy pig, magnetic resonance urography was performed using a T1-weighted 3D gradient echo pulse sequence. Post-processing was performed by means of an MIP algorithm and by using 3D virtual reality modelling, followed by manual classification of papillae as being either simple or compound. The 2D MIP urogram demonstrated 6 simple and 6 compound papillae, whereas the 3D urogram demonstrated 5 simple and 7 compound papillae. In both urograms, some papillae were unsuccessfully classified. The possibility of using virtual reality devices allowed 3D rotation and offered additional diagnostic information. However, further studies should reveal its feasibility in diseased kidneys.

  16. Two-dimensional nuclear magnetic resonance petrophysics.

    Science.gov (United States)

    Sun, Boqin; Dunn, Keh-Jim

    2005-02-01

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

  17. Magnetic resonance imaging of ovarian cystic tumor

    Energy Technology Data Exchange (ETDEWEB)

    Wakabayashi, Yukari; Kawana, Kouji; Iiyama, Motoko; Abe, Kimihiko; Yachida, Meri; Amino, Saburou; Kotake, Fumio

    1988-11-01

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

  18. [Magnetic resonance urography in pediatric urology].

    Science.gov (United States)

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

    2012-12-01

    Magnetic resonance urography (MRU) provides high resolution imaging of the urogenital system and the use of paramagnetic contrast agents enables a functional depiction. This review summarizes existing data concerning this diagnostic procedure in pediatric urology. A systematic search and assessment of the literature was performed.A total of 12 studies were reviewed in detail. In mostly small study populations a great heterogeneity concerning methodology, use of comparative examinations and standards of reference was noted. Besides the quality of anatomical imaging, the functional study of renal excretory function and differential renal function was also assessed. Only a few studies performed statistical analyses.The authors' rating of MRU was mostly positive. Due to methodical weaknesses, lack of independent standards of reference and statistical analyses the overall level of evidence was low. Further high quality studies will be necessary to assess the value of MRU for the diagnostic workup in pediatric urology.

  19. Magnetic resonance imaging of cerebrotendinous xanthomatosis

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-02-01

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

  20. Magnetic resonance imaging of pancreatitis: An update

    Science.gov (United States)

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

    2014-01-01

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

  1. Cardiovascular magnetic resonance in hypertrophic cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-03-15

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

  2. Magnetic Resonance Imaging in Amyotrophic Lateral Sclerosis

    Directory of Open Access Journals (Sweden)

    Katja Kollewe

    2012-01-01

    Full Text Available Amyotrophic lateral sclerosis (ALS is a rapidly progressing neurodegenerative disorder which is incurable to date. As there are many ongoing studies with therapeutic candidates, it is of major interest to develop biomarkers not only to facilitate early diagnosis but also as a monitoring tool to predict disease progression and to enable correct randomization of patients in clinical trials. Magnetic resonance imaging (MRI has made substantial progress over the last three decades and is a practical, noninvasive method to gain insights into the pathology of the disease. Disease-specific MRI changes therefore represent potential biomarkers for ALS. In this paper we give an overview of structural and functional MRI alterations in ALS with the focus on task-free resting-state investigations to detect cortical network failures.

  3. Chest magnetic resonance imaging: a protocol suggestion

    Directory of Open Access Journals (Sweden)

    Bruno Hochhegger

    2015-12-01

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

  4. Quantum information processing and nuclear magnetic resonance

    CERN Document Server

    Cummins, H K

    2001-01-01

    as spectrometer pulse sequence programs. Quantum computers are information processing devices which operate by and exploit the laws of quantum mechanics, potentially allowing them to solve problems which are intractable using classical computers. This dissertation considers the practical issues involved in one of the more successful implementations to date, nuclear magnetic resonance (NMR). Techniques for dealing with systematic errors are presented, and a quantum protocol is implemented. Chapter 1 is a brief introduction to quantum computation. The physical basis of its efficiency and issues involved in its implementation are discussed. NMR quantum information processing is reviewed in more detail in Chapter 2. Chapter 3 considers some of the errors that may be introduced in the process of implementing an algorithm, and high-level ways of reducing the impact of these errors by using composite rotations. Novel general expressions for stabilising composite rotations are presented in Chapter 4 and a new class o...

  5. [Gastric magnetic resonance study (methods, semiotics)].

    Science.gov (United States)

    Stashuk, G A

    2003-01-01

    The paper shows the potentialities of gastric study by magnetic resonance imaging (MRI). The methodic aspects of gastric study have been worked out. The MRI-semiotics of the unchanged and tumor-affected wall of the stomach and techniques in examining patients with gastric cancer of various sites are described. Using the developed procedure, MRI was performed in 199 patients, including 154 patients with gastric pathology and 45 control individuals who had no altered gastric wall. Great emphasis is placed on the role of MRI in the diagnosis of endophytic (diffuse) gastric cancer that is of priority value in its morphological structure. MRI was found to play a role in the diagnosis of the spread of a tumorous process both along the walls of the stomach and to its adjacent anatomic structures.

  6. Cardiovascular magnetic resonance in carotid atherosclerotic disease

    Directory of Open Access Journals (Sweden)

    Chen Huijun

    2009-12-01

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

  7. Automated Segmentation of Cardiac Magnetic Resonance Images

    DEFF Research Database (Denmark)

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

    2001-01-01

    Magnetic resonance imaging (MRI) has been shown to be an accurate and precise technique to assess cardiac volumes and function in a non-invasive manner and is generally considered to be the current gold-standard for cardiac imaging [1]. Measurement of ventricular volumes, muscle mass and function...... is based on determination of the left-ventricular endocardial and epicardial borders. Since manual border detection is laborious, automated segmentation is highly desirable as a fast, objective and reproducible alternative. Automated segmentation will thus enhance comparability between and within cardiac...... studies and increase accuracy by allowing acquisition of thinner MRI-slices. This abstract demonstrates that statistical models of shape and appearance, namely the deformable models: Active Appearance Models, can successfully segment cardiac MRIs....

  8. Magnetic resonance imaging of pericardial diseases

    Energy Technology Data Exchange (ETDEWEB)

    Niwa, Koichiro; Tashima, Kazuyuki; Okajima, Yoshitomo; Nakajima, Hiromichi; Terai, Masaru; Nakajima, Hironori

    1988-10-01

    We performed magnetic resonance imaging (MRI) in 4 patients, ranged from 4 to 15 years in age, with pericardial disease (1 with pericaditis with JRA, 1 with chylopericardium, and 2 with pericarditis) for morphological and histological evaluation of the percardial disease. ECG-gated MRI was performed by the spin echo method using a superconducting MRI system operating at 0.5 tesla. In all the patients pericardial diseases were clearly demonstrated. MRI visualized the thickened pericardium as 2 to 4 mm thick curvilinear line of high signal intensity in all the patients. Pericardial effusion was detected in all the patients. Two of them showed low signal intensity and 1 showed high signal intensity. Pericardial effusion in patient with chylopericardium had markedly high signal intensity, similar to that of the subcutaneous far tissue. MRI appears to be an important modality for the evaluation of pericardial disease.

  9. Rotating-frame gradient fields for magnetic resonance imaging and nuclear magnetic resonance in low fields

    Science.gov (United States)

    Bouchard, Louis-Serge; Pines, Alexander; Demas, Vasiliki

    2014-01-21

    A system and method for Fourier encoding a nuclear magnetic resonance (NMR) signal is disclosed. A static magnetic field B.sub.0 is provided along a first direction. An NMR signal from the sample is Fourier encoded by applying a rotating-frame gradient field B.sub.G superimposed on the B.sub.0, where the B.sub.G comprises a vector component rotating in a plane perpendicular to the first direction at an angular frequency .omega.in a laboratory frame. The Fourier-encoded NMR signal is detected.

  10. Optimal sequence for magnetic resonance cholangiopancreatography

    Energy Technology Data Exchange (ETDEWEB)

    Kanzaki, Hiroshi; Akata, Soichi; Ozuki, Taizo; Abe, Kimihiko [Tokyo Medical Coll. (Japan)

    2001-09-01

    Magnetic resonance cholangiopancreatography (MRCP) has attracted attention as a useful examination for abnormalities of the pancreaticobiliary system, because it is a simple procedure. Since there are few detailed reports on optimal sequences for MRCP, we attempted to clarify the topic. The magnetic resonance imaging (MRI) equipment we used was a 1.0 Tesla super-conductive type. A fast spin echo (16 echo train) was used, and the echo space was set at 17 msec. TE was changed from 17 msec to 272 msec in 17 msec increments. TR was changed from 1,000 msec to 9,000 msec by 1,000 msec increments. Bile juice which had been collected from the PTCD tube of a patient with common bile duct cancer, was put in a test tube of 10 mm internal diameter. Saline was used as a substitute for pancreatic juice, because collection of pancreatic juice was difficult. Fat was used for contrast. Each signal intensity inside the test tube was measured and evaluated. We attempted to evaluate the signal of gastric juice by adding blueberry juice, making use of its manganese ion (Mn{sup ++}). With longer TR, the signal intensities of bile and pancreas juice increased. As TE became longer, the signal intensities of bile and pancreas juice decreased slightly, while that of fat decreased much more. In MRCP, it is necessary to set up a long TE to increase the relative signal intensity difference of fat in bile and pancreas juice. The signal intensity of gastric juice was made to disappear by the addition of blueberry juice diluted to a ratio of 1:3. (author)

  11. Categorization of aortic aneurysm thrombus morphology by magnetic resonance imaging

    DEFF Research Database (Denmark)

    de la Motte, Louise; Pedersen, Mads Møller; Thomsen, Carsten

    2013-01-01

    Magnetic resonance imaging (MRI) has been proposed for qualitative categorization of intraluminal thrombus morphology. We aimed to correlate the qualitative MRI categorization previously described to quantitative measurements of signal intensity and to compare morphological characteristics...... of intraluminal thrombus specimens to the appearance on magnetic resonance imaging....

  12. Magnetic resonance advection imaging of cerebrovascular pulse dynamics.

    Science.gov (United States)

    Voss, Henning U; Dyke, Jonathan P; Tabelow, Karsten; Schiff, Nicholas D; Ballon, Douglas J

    2017-04-01

    We analyze the pulsatile signal component of dynamic echo planar imaging data from the brain by modeling the dependence between local temporal and spatial signal variability. The resulting magnetic resonance advection imaging maps depict the location of major arteries. Color direction maps allow for visualization of the direction of blood vessels. The potential significance of magnetic resonance advection imaging maps is demonstrated on a functional magnetic resonance imaging data set of 19 healthy subjects. A comparison with the here introduced pulse coherence maps, in which the echo planar imaging signal is correlated with a cardiac pulse signal, shows that the magnetic resonance advection imaging approach results in a better spatial definition without the need for a pulse reference. In addition, it is shown that magnetic resonance advection imaging velocities can be estimates of pulse wave velocities if certain requirements are met, which are specified. Although for this application magnetic resonance advection imaging velocities are not quantitative estimates of pulse wave velocities, they clearly depict local pulsatile dynamics. Magnetic resonance advection imaging can be applied to existing dynamic echo planar imaging data sets with sufficient spatiotemporal resolution. It is discussed whether magnetic resonance advection imaging might have the potential to evolve into a biomarker for the health of the cerebrovascular system.

  13. Magnetic Resonance in Food Science - Food for Thought

    NARCIS (Netherlands)

    Duynhoven, van J.P.M.; Belton, P.S.; Webb, G.A.; As, van H.

    2013-01-01

    There are many challenges and problems in food science and magnetic resonance methods may be used to provide answers and deepen both fundamental and practical knowledge. This book presents innovations in magnetic resonance and in particular applications to understanding the functionality of foods,

  14. Resonance magnetic x-ray scattering study of erbium

    DEFF Research Database (Denmark)

    Sanyal, M.K.; Gibbs, D.; Bohr, J.

    1994-01-01

    The magnetic phases of erbium have been studied by resonance x-ray-scattering techniques. When the incident x-ray energy is tuned near the L(III) absorption edge, large resonant enhancements of the magnetic scattering are observed above 18 K. We have measured the energy and polarization dependence...

  15. Nuclear magnetic resonance force microscopy at millikelvin temperatures

    NARCIS (Netherlands)

    Haan, Arthur Mattheus Johannes den

    2016-01-01

    Nuclear magnetic resonance force microscopy (MRFM) is a technique which combines magnetic resonance imaging (MRI) with scanning probe microscopy (SPM). The final goal is to develop this technique to such a level that the atomic structure of a virus or protein can be revealed by this microscope. This

  16. Selectivity in multiple quantum nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Warren Sloan [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division

    1980-11-01

    The observation of multiple-quantum nuclear magnetic resonance transitions in isotropic or anisotropic liquids is shown to give readily interpretable information on molecular configurations, rates of motional processes, and intramolecular interactions. However, the observed intensity of high multiple-quantum transitions falls off dramatically as the number of coupled spins increases. The theory of multiple-quantum NMR is developed through the density matrix formalism, and exact intensities are derived for several cases (isotropic first-order systems and anisotropic systems with high symmetry) to shown that this intensity decrease is expected if standard multiple-quantum pulse sequences are used. New pulse sequences are developed which excite coherences and produce population inversions only between selected states, even though other transitions are simultaneously resonant. One type of selective excitation presented only allows molecules to absorb and emit photons in groups of n. Coherent averaging theory is extended to describe these selective sequences, and to design sequences which are selective to arbitrarily high order in the Magnus expansion. This theory and computer calculations both show that extremely good selectivity and large signal enhancements are possible.

  17. Magnetic resonance spectroscopy as a diagnostic modality for carcinoma thyroid

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Nikhil [Department of Surgery, Maulana Azad Medical College, Lok Nayak Hospital, New Delhi (India)], E-mail: nikhil_ms26@yahoo.co.in; Kakar, Arun K. [Department of Surgery, Maulana Azad Medical College, Lok Nayak Hospital, New Delhi (India); Chowdhury, Veena [Department of Radiodiagnosis, Maulana Azad Medical College, Lok Nayak Hospital, New Delhi (India); Gulati, Praveen [MR Centre, A-23 Green Park, New Delhi (India); Shankar, L. Ravi [Department of Radioiodine Uptake and Imaging, Institute of Nucler Medicine and Allied Sciences (INMAS), Timarpur, New Delhi (India); Vindal, Anubhav [Department of Surgery, Maulana Azad Medical College, Lok Nayak Hospital, New Delhi (India)

    2007-12-15

    Aim: The aim of this study was to observe the findings of magnetic resonance spectroscopy of solitary thyroid nodules and its correlation with histopathology. Materials and methods: In this study, magnetic resonance spectroscopy was carried out on 26 patients having solitary thyroid nodules. Magnetic resonance spectroscopy (MRS) was performed on a 1.5 T super conductive system with gradient strength of 33 mTs. Fine needle aspiration cytology was done after MRS. All 26 patients underwent surgery either because of cytopathologically proven malignancy or because of cosmetic reasons. Findings of magnetic resonance spectroscopy were compared with histopathology of thyroid specimens. Results and conclusion: It was seen that presence or absence of choline peak correlates very well with presence or absence of malignant foci with in the nodule (sensitivity = 100%; specificity = 88.88%). These results indicate that magnetic resonance spectroscopy may prove to be an useful diagnostic modality for carcinoma thyroid.

  18. The electrically detected magnetic resonance microscope: combining conductive atomic force microscopy with electrically detected magnetic resonance.

    Science.gov (United States)

    Klein, Konrad; Hauer, Benedikt; Stoib, Benedikt; Trautwein, Markus; Matich, Sonja; Huebl, Hans; Astakhov, Oleksandr; Finger, Friedhelm; Bittl, Robert; Stutzmann, Martin; Brandt, Martin S

    2013-10-01

    We present the design and implementation of a scanning probe microscope, which combines electrically detected magnetic resonance (EDMR) and (photo-)conductive atomic force microscopy ((p)cAFM). The integration of a 3-loop 2-gap X-band microwave resonator into an AFM allows the use of conductive AFM tips as a movable contact for EDMR experiments. The optical readout of the AFM cantilever is based on an infrared laser to avoid disturbances of current measurements by absorption of straylight of the detection laser. Using amorphous silicon thin film samples with varying defect densities, the capability to detect a spatial EDMR contrast is demonstrated. Resonant current changes as low as 20 fA can be detected, allowing the method to realize a spin sensitivity of 8×10(6)spins/√Hz at room temperature.

  19. Resonant inverter supplied Interior Permanent Magnet (IPM) motor ...

    African Journals Online (AJOL)

    In this paper, rotor position in relation to the resonant frequency component current in the stator winding of DC-voltage link resonant inverter supplied Interior Permanent Magnet (IPM) motor has been developed. Six reference frames are used to relate the rotor position angle to the resonant frequency component current ...

  20. Magnetic resonance imaging of oscillating electrical currents.

    Science.gov (United States)

    Halpern-Manners, Nicholas W; Bajaj, Vikram S; Teisseyre, Thomas Z; Pines, Alexander

    2010-05-11

    Functional MRI has become an important tool of researchers and clinicians who seek to understand patterns of neuronal activation that accompany sensory and cognitive processes. However, the interpretation of fMRI images rests on assumptions about the relationship between neuronal firing and hemodynamic response that are not firmly grounded in rigorous theory or experimental evidence. Further, the blood-oxygen-level-dependent effect, which correlates an MRI observable to neuronal firing, evolves over a period that is 2 orders of magnitude longer than the underlying processes that are thought to cause it. Here, we instead demonstrate experiments to directly image oscillating currents by MRI. The approach rests on a resonant interaction between an applied rf field and an oscillating magnetic field in the sample and, as such, permits quantitative, frequency-selective measurements of current density without spatial or temporal cancellation. We apply this method in a current loop phantom, mapping its magnetic field and achieving a detection sensitivity near the threshold required for the detection of neuronal currents. Because the contrast mechanism is under spectroscopic control, we are able to demonstrate how ramped and phase-modulated spin-lock radiation can enhance the sensitivity and robustness of the experiment. We further demonstrate the combination of these methods with remote detection, a technique in which the encoding and detection of an MRI experiment are separated by sample flow or translation. We illustrate that remotely detected MRI permits the measurement of currents in small volumes of flowing water with high sensitivity and spatial resolution.

  1. Italian registry of cardiac magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Francone, Marco [Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome (Italy); Di Cesare, Ernesto, E-mail: ernesto.dicesare@cc.univaq.it [Dipartimento di Scienze Cliniche Applicate e Biotecnologie, Università di L’Aquila (Italy); Cademartiri, Filippo [Cardio-Vascular Imaging Unit, Giovanni XXIII Hospital, Monastier di Treviso, TV (Italy); Erasmus Medical Center University, Rotterdam (Netherlands); Pontone, Gianluca [IRCCS Centro Cardiologico Monzino (Italy); Lovato, Luigi [Policlinico S. Orsola Bologna (Italy); Matta, Gildo [Azienda ospedaliera G Brotzu Cagliari (Italy); Secchi, Francesco [IRCCS Policlinico San Donato, Radiology Unit, Milan (Italy); Maffei, Erica [Cardio-Vascular Imaging Unit, Giovanni XXIII Hospital, Monastier di Treviso, TV (Italy); Erasmus Medical Center University, Rotterdam (Netherlands); Pradella, Silvia [Azienda Ospedaliera Universitaria Careggi (Italy); Carbone, Iacopo [Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome (Italy); Marano, Riccardo [Policlinico Gemelli, Università Cattolica Roma (Italy); Bacigalupo, Lorenzo [Ospedale Galliera, Genova (Italy); Chiodi, Elisabetta [Ospedale S. Anna Ferrara (Italy); Donato, Rocco [Azienda Ospedaliera Universitaria G. Martino, Me (Italy); Sbarbati, Stefano [Ospedale Madre Giuseppina Vannini, Roma (Italy); De Cobelli, Francesco [IRCCS S. Raffaele, Università Vita Salute, Milano (Italy); Di Renzi, Paolo [Fate Bene Fratelli Isola tiberina, Roma (Italy); Ligabue, Guido; Mancini, Andrea [Azienda Ospedaliera-Universitaria Policlinico di Modena (Italy); Palmieri, Francesco [Diparimento di Diagnostica per immagini e radiologia interventistica, Ospedale S. Maria delle Grazie, Pozzuoli, Napoli (Italy); and others

    2014-01-15

    Objectives: Forty sites were involved in this multicenter and multivendor registry, which sought to evaluate indications, spectrum of protocols, impact on clinical decision making and safety profile of cardiac magnetic resonance (CMR). Materials and methods: Data were prospectively collected on a 6-month period and included 3376 patients (47.2 ± 19 years; range 1–92 years). Recruited centers were asked to complete a preliminary general report followed by a single form/patient. Referral physicians were not required to exhibit any specific certificate of competency in CMR imaging. Results: Exams were performed with 1.5 T scanners in 96% of cases followed by 3 T (3%) and 1 T (1%) magnets and contrast was administered in 84% of cases. The majority of cases were performed for the workup of inflammatory heart disease/cardiomyopathies representing overall 55.7% of exams followed by the assessment of myocardial viability and acute infarction (respectively 6.9% and 5.9% of patients). In 49% of cases the final diagnosis provided was considered relevant and with impact on patient's clinical/therapeutic management. Safety evaluation revealed 30 (0.88%) clinical events, most of which due to patient's preexisting conditions. Radiological reporting was recorded in 73% of exams. Conclusions: CMR is performed in a large number of centers in Italy with relevant impact on clinical decision making and high safety profile.

  2. Parametric resonance induced chaos in magnetic damped driven pendulum

    Energy Technology Data Exchange (ETDEWEB)

    Khomeriki, Giorgi, E-mail: giokhomeriki123@gmail.com

    2016-07-15

    A damped driven pendulum with a magnetic driving force, appearing from a solenoid, where ac current flows is considered. The solenoid acts on the magnet, which is located at a free end of the pendulum. In this system the existence and interrelation of chaos and parametric resonance is theoretically examined. Derived analytical results are supported by numerical simulations and conducted experiments. - Highlights: • A damped magnetic pendulum is considered driven by off resonant magnetic field. • Our system is chaotic only when the conditions for parametric resonance are fulfilled. • Conducted experiments give a good agreement with theory and numerical simulations. • Calculated Lyapunov exponents are compared with parametric instability growth rates.

  3. Clinical application of functional magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Alwatban, Adnan Z.W

    2002-07-01

    The work described in this thesis was carried out at the Magnetic Resonance Centre of the University of Nottingham during the time from May 1998 to April 2001, and is the work of the author except where indicated by reference. The main source of signal changes in functional magnetic resonance imaging (fMRJ) is the fluctuation of paramagnetic deoxyhaemoglobin in the venous blood during different states of functional performance. For the work of this thesis, fMRI studies were carried out using a 3 T MR system with an echo planar imaging (EPI) pulse sequence. Hearing research utilising fMRI has been previously reported in normal subjects. Hearing fMRI is normally performed by stimulating the auditory cortex via an acoustic task presentation such as music, tone, etc. However, performing the same research on deaf subjects requires special equipment to be designed to allow direct stimulation of the auditory nerve. In this thesis, a new method of direct electrical stimulation of the auditory nerve is described that uses a transtympanic electrode implanted onto the surface of the cochlea. This approach would however, result in electromotive forces (EMFs) being induced by the time varying magnetic field, which would lead to current flow and heating, as well as deflection of the metallic electrode within the static magnetic field, and image distortion due to the magnetic susceptibility difference. A gold-plated tungsten electrode with a zero magnetic susceptibility was developed to avoid image distortion. Used with carbon leads and a carbon reference pad, it enabled safe, distortion-free fMRI studies of deaf subjects. The study revealed activation of the primary auditory cortex. This fMRI procedure can be used to demonstrate whether the auditory pathway is fully intact, and may provide a useful method for pre-operative assessment of candidates for cochlear implantation. Glucose is the energy source on which the function of the human brain is entirely dependent. Failure to

  4. Waveguide volume probe for magnetic resonance imaging and spectroscopy

    DEFF Research Database (Denmark)

    2015-01-01

    The present disclosure relates to a probe for use within the field of nuclear magnetic resonance, such as magnetic resonance imaging (MRI), and magnetic resonance spectroscopy (MRS)). One embodiment relates to an RF probe for magnetic resonance imaging and/or spectroscopy comprising a conductive...... non-magnetic hollow waveguide having an internal volume and at least one open end, one or more capacitors and at least a first conductive non-magnetic wire, wherein said first conductive wire connects at least one of said one or more capacitors to opposite walls of one open end of the waveguide...... and wherein said first conductive wire and said one or more capacitors are located outside of said internal volume, wherein the internal volume of the hollow waveguide defines an imaging volume or sample volume....

  5. Controlling interactions between highly magnetic atoms with Feshbach resonances.

    Science.gov (United States)

    Kotochigova, Svetlana

    2014-09-01

    This paper reviews current experimental and theoretical progress in the study of dipolar quantum gases of ground and meta-stable atoms with a large magnetic moment. We emphasize the anisotropic nature of Feshbach resonances due to coupling to fast-rotating resonant molecular states in ultracold s-wave collisions between magnetic atoms in external magnetic fields. The dramatic differences in the distribution of resonances of magnetic (7)S3 chromium and magnetic lanthanide atoms with a submerged 4f shell and non-zero electron angular momentum is analyzed. We focus on dysprosium and erbium as important experimental advances have been recently made to cool and create quantum-degenerate gases for these atoms. Finally, we describe progress in locating resonances in collisions of meta-stable magnetic atoms in electronic P-states with ground-state atoms, where an interplay between collisional anisotropies and spin-orbit coupling exists.

  6. Quantifying mixing using magnetic resonance imaging.

    Science.gov (United States)

    Tozzi, Emilio J; McCarthy, Kathryn L; Bacca, Lori A; Hartt, William H; McCarthy, Michael J

    2012-01-25

    Mixing is a unit operation that combines two or more components into a homogeneous mixture. This work involves mixing two viscous liquid streams using an in-line static mixer. The mixer is a split-and-recombine design that employs shear and extensional flow to increase the interfacial contact between the components. A prototype split-and-recombine (SAR) mixer was constructed by aligning a series of thin laser-cut Poly (methyl methacrylate) (PMMA) plates held in place in a PVC pipe. Mixing in this device is illustrated in the photograph in Fig. 1. Red dye was added to a portion of the test fluid and used as the minor component being mixed into the major (undyed) component. At the inlet of the mixer, the injected layer of tracer fluid is split into two layers as it flows through the mixing section. On each subsequent mixing section, the number of horizontal layers is duplicated. Ultimately, the single stream of dye is uniformly dispersed throughout the cross section of the device. Using a non-Newtonian test fluid of 0.2% Carbopol and a doped tracer fluid of similar composition, mixing in the unit is visualized using magnetic resonance imaging (MRI). MRI is a very powerful experimental probe of molecular chemical and physical environment as well as sample structure on the length scales from microns to centimeters. This sensitivity has resulted in broad application of these techniques to characterize physical, chemical and/or biological properties of materials ranging from humans to foods to porous media (1, 2). The equipment and conditions used here are suitable for imaging liquids containing substantial amounts of NMR mobile (1)H such as ordinary water and organic liquids including oils. Traditionally MRI has utilized super conducting magnets which are not suitable for industrial environments and not portable within a laboratory (Fig. 2). Recent advances in magnet technology have permitted the construction of large volume industrially compatible magnets suitable for

  7. Linear electric field effects in magnetic anisotropy and ferromagnetic resonance

    Science.gov (United States)

    Rado, George T.

    1980-01-01

    The concept, theory and measurement of electric-field-dependent macroscopic magnetic anisotropy energies are reviewed with examples involving magnetite and lithium ferrite. Also discussed are applications to the elucidation of magnetization processes, the determination of magnetic symmetry and the shifting of a ferromagnetic resonance with an applied electric field.

  8. Three-dimensional magnetic resonance imaging for groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Legchenko, A; Descloitres, M; Guyard, H [IRD/ UJF-Grenoble 1/CNRS/G-INP, LTHE UMR 5564, Grenoble F-38041 (France); Vincent, C [Laboratoire de Glaciologie et Geophysique de l' Environnement and CNRS-LGGE, 38041 Grenoble Cedex 9 (France); Garambois, S [Institut des Sciences de la terre (ISTerre), Universite Joseph Fourier and CNRS, BP 53, 38041 Grenoble Cedex 9 (France); Chalikakis, K [Universite d' Avignon, UMR EMMAH (UAPV-INRA), 33, rue Pasteur, 84000 Avignon (France); Ezersky, M, E-mail: anatoli.legtchenko@ird.fr [Geophysical Institute of Israel, BP182, Lod 71100 (Israel)

    2011-02-15

    The surface nuclear magnetic resonance method (SNMR) is an established geophysical tool routinely used for investigating one-dimensional (1D) and sometimes 2D subsurface water-saturated formations. We have expanded the tool by developing a 3D application. 3D-SNMR is a large-scale method that allows magnetic resonance imaging of groundwater down to about 80 m. Similar to most surface geophysical methods, 3D-SNMR has limited resolution, but it is effective for investigating water-saturated geological formations larger than several tens of meters. Because the performance of the method depends on variable survey conditions, we cannot estimate it in general. For demonstration purposes, we present an example of numerical modeling under fixed conditions. Results show that under certain conditions it is possible to detect a water volume as small as 500 m{sup 3} and the detection threshold depends on the ambient electromagnetic noise magnitude and on the location of the target volume relative to the SNMR loops. The 3D-SNMR method was used to investigate accumulated water within the Tete Rousse glacier (French Alps). Inversion of the field measurements made it possible to locate the principal reservoir in the central part of the glacier and estimate the volume of accumulated water. These results were verified by 20 boreholes installed after the 3D-SNMR results were obtained and by pumping water out of the glacier. Very good correspondence between the 3D-SNMR and borehole results was observed.

  9. Asbestos-related pericardial thickening detected by magnetic resonance imaging.

    Science.gov (United States)

    Jarad, N A; Underwood, S R; Rudd, R M

    1993-05-01

    Magnetic resonance imaging was performed in four male asbestos workers in whom the chest radiograph revealed pleural but not pulmonary or pericardial disease. Patients underwent thoracic multislice spin echo imaging, with measurement of left and right ventricular volumes at end-diastole and end-systole, and a study of the flow in the superior vena cava as an indirect measure to the filling of the right ventricle. Patients also underwent respiratory function tests and high-resolution computed tomography (HRCT). Magnetic resonance, but not HRCT, showed pericardial thickening in two patients. Magnetic resonance demonstrated reduced diastolic flow in the superior vena cava in one patient, reflecting impaired right ventricular filling. All other magnetic resonance measurements of cardiac function were normal. HRCT demonstrated mild asbestosis in three patients in which neither the chest radiograph nor magnetic resonance showed signs of parenchymal disease, and pericardiac calcification without thickening in one patient. It is concluded that magnetic resonance is superior to HRCT in identifying pericardial thickening, but that HRCT is superior to magnetic resonance in identifying asbestos-related pleural and pulmonary disease.

  10. Magnetic resonance imaging in 122 children with spastic cerebral palsy.

    Science.gov (United States)

    Kwong, Karen L; Wong, Yiu C; Fong, Chek M; Wong, Sik N; So, Kwan T

    2004-09-01

    The interrelationship between magnetic resonance imaging findings, types of cerebral palsy, and gestation was studied. We analyzed the magnetic resonance imaging of brain in 122 children with spastic cerebral palsy. Forty-three patients had spastic hemiplegia, 61 had spastic diplegia, and 18 had spastic tetraplegia. Magnetic resonance imaging abnormalities were observed in 75% of patients. Periventricular leukomalacia accounted for 66% of abnormalities observed in patients with spastic diplegia; other types of brain lesions were uncommon. In patients with spastic tetraplegia, two types of magnetic resonance imaging abnormalities predominated: congenital brain anomalies and term-type brain injuries, 42% and 33% respectively. Types of magnetic resonance imaging abnormalities were more heterogeneous in patients with spastic hemiplegia. Preterm brain injuries (periventricular leukomalacia and posthemorrhagic porencephaly) were observed often in patients born at preterm but were also observed in patients born at term. Term-type brain injuries (term-type border-zone infarct, basal ganglia-thalamic lesion, subcortical leukomalacia, and multicystic encephalomalacia) were observed only in patients born at or near term. We conclude that magnetic resonance imaging findings for patients with spastic cerebral palsy were closely related to types of cerebral palsy and gestation at birth. Magnetic resonance imaging in patients with perinatal brain injury may reflect pathologic changes and is useful in understanding and evaluating cerebral palsy.

  11. Magnetic circuit modifications in resonant vibration harvesters

    Science.gov (United States)

    Szabo, Zoltan; Fiala, Pavel; Dohnal, Premysl

    2018-01-01

    The paper discusses the conclusions obtained from a research centered on a vibration-powered milli- or micro generator (MG) operating as a harvester to yield the maximum amount of energy transferred by the vibration of an independent system. The investigation expands on the results proposed within papers that theoretically define the properties characterizing the basic configurations of a generator based on applied Faraday's law of induction. We compared two basic principles of circuit closing in a magnetic circuit that, fully or partially, utilizes a ferromagnetic material, and a large number of generator design solutions were examined and tested. In the given context, the article brings a compact survey of the rules facilitating energy transformation and the designing of harvesters.

  12. Science Drivers and Technical Challenges for Advanced Magnetic Resonance

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Karl T.; Pruski, Marek; Washton, Nancy M.; Lipton, Andrew S.

    2013-03-07

    This report recaps the "Science Drivers and Technical Challenges for Advanced Magnetic Resonance" workshop, held in late 2011. This exploratory workshop's goal was to discuss and address challenges for the next generation of magnetic resonance experimentation. During the workshop, participants from throughout the world outlined the science drivers and instrumentation demands for high-field dynamic nuclear polarization (DNP) and associated magnetic resonance techniques, discussed barriers to their advancement, and deliberated the path forward for significant and impactful advances in the field.

  13. Advances in cardiac magnetic resonance imaging of congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Driessen, Mieke M.P. [University of Utrecht, University Medical Center Utrecht, Department of Radiology, PO Box 85500, Utrecht (Netherlands); University of Utrecht, University Medical Center Utrecht, Department of Cardiology, PO Box 85500, Utrecht (Netherlands); The Interuniversity Cardiology Institute of the Netherlands (ICIN) - Netherlands Heart Institute, PO Box 19258, Utrecht (Netherlands); Breur, Johannes M.P.J. [Wilhelmina Children' s Hospital, University Medical Center Utrecht, Department of Pediatric Cardiology, PO Box 85500, Utrecht (Netherlands); Budde, Ricardo P.J.; Oorschot, Joep W.M. van; Leiner, Tim [University of Utrecht, University Medical Center Utrecht, Department of Radiology, PO Box 85500, Utrecht (Netherlands); Kimmenade, Roland R.J. van; Sieswerda, Gertjan Tj [University of Utrecht, University Medical Center Utrecht, Department of Cardiology, PO Box 85500, Utrecht (Netherlands); Meijboom, Folkert J. [University of Utrecht, University Medical Center Utrecht, Department of Cardiology, PO Box 85500, Utrecht (Netherlands); Wilhelmina Children' s Hospital, University Medical Center Utrecht, Department of Pediatric Cardiology, PO Box 85500, Utrecht (Netherlands)

    2015-01-01

    Due to advances in cardiac surgery, survival of patients with congenital heart disease has increased considerably during the past decades. Many of these patients require repeated cardiovascular magnetic resonance imaging to assess cardiac anatomy and function. In the past decade, technological advances have enabled faster and more robust cardiovascular magnetic resonance with improved image quality and spatial as well as temporal resolution. This review aims to provide an overview of advances in cardiovascular magnetic resonance hardware and acquisition techniques relevant to both pediatric and adult patients with congenital heart disease and discusses the techniques used to assess function, anatomy, flow and tissue characterization. (orig.)

  14. Magnetic resonance imaging of primary vaginal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, M.B. [Department of Diagnostic Radiology, Christie Hospital NHS Trust, Withington, Manchester (United Kingdom)]. E-mail: ben.taylor@christie-tr.nwest.nhs.uk; Dugar, N. [Department of Diagnostic Radiology, Christie Hospital NHS Trust, Withington, Manchester (United Kingdom); Davidson, S.E. [Radiation Oncology, Christie Hospital NHS Trust, Withington, Manchester (United Kingdom); Carrington, B.M. [Department of Diagnostic Radiology, Christie Hospital NHS Trust, Withington, Manchester (United Kingdom)

    2007-06-15

    Aims: To describe the magnetic resonance imaging (MRI) features of vaginal carcinoma and to suggest a role for MRI in its management. Materials and methods: Twenty-five patients with primary vaginal carcinoma treated at our institution between 1996 and 2005 were included in the study. The MRI examinations were reviewed and tumour dimensions, signal characteristics and involvement of pelvic structures were documented, as were sites of enlarged lymph nodes and metastases. Details of patient treatment and outcome were obtained from the clinical notes. Results: The median patient age was 54 years (range 31-86 years). Tumour maximum diameter ranged from 1.6-11.3 cm (mean 3.7 cm). Most tumours were of iso-intense signal to muscle on T1-weighted images and hyper-intense to muscle on T2-weighted images. Eighty-eight percent of patients had tumour extending beyond the vagina and 56% of patients had Figo stage III or above tumours. Sixteen patients were treated with radiotherapy (two with chemoradiotherapy), five with surgery and four with supportive care. Ten patients (40%) died of their disease during the study period. The MRI stage of the tumour correlated with survival. Conclusion: MRI identified over 95% of primary vaginal tumours in the present study, enabled radiological staging, which correlated with outcome, and provided information of use in treatment planning.

  15. Magnetic resonance imaging of the normal placenta

    Energy Technology Data Exchange (ETDEWEB)

    Blaicher, Wibke [Department of Gynecology and Obstetrics, University Hospital Vienna (Austria)]. E-mail: wibke.blaicher@meduniwien.ac.at; Brugger, Peter C. [Center of Anatomy and Cell Biology, University Hospital of Vienna (Austria); Mittermayer, Christoph [Department of Pediatrics, Division of Neonatology and Intensive Care, University Hospital of Vienna (Austria); Schwindt, Jens [Department of Pediatrics, Division of Neonatology and Intensive Care, University Hospital of Vienna (Austria); Deutinger, Josef [Department of Gynecology and Obstetrics, University Hospital Vienna (Austria); Bernaschek, Gerhard [Department of Gynecology and Obstetrics, University Hospital Vienna (Austria); Prayer, Daniela [Department of Radiology, Division of Neuroradiology, University Hospital of Vienna (Austria)

    2006-02-15

    The goal of this study was to provide a representative description of the normal placenta with contrast medium-free magnetic resonance imaging (MRI) in order to determine a standard of reference. One hundred consecutive singleton pregnancies were investigated by MRI without application of a contrast medium. The mean gestational age (GA) at the time of investigation was 29.5 weeks (range 19-40). Patients with suspected utero-placental insufficiency (UPI) or placental anomalies were excluded. Signal intensities were assessed and correlated with the respective GA. Antenatal MRI without contrast medium was able to depict placental status and morphological changes during gestation. A regular homogeneous structure was found in weeks 19-23. Subsequently, sporadic, slightly marked lobules appeared, which increased in number and markedness with ongoing gestation. Stratification of the lobules was observed after 36 weeks. The ratio of placental and amniotic fluid signal intensities decreased significantly with higher GA and with placental grading. MRI is well suited as an imaging method for the placenta. Our data may be used as a reference in the assessment of the placenta on MRI, and may have further clinical impact with respect to the determination of UPI.

  16. Magnetic Resonance Imaging Features of Neuromyelitis Optica

    Energy Technology Data Exchange (ETDEWEB)

    You, Sun Kyung; Song, Chang June; Park, Woon Ju; Lee, In Ho; Son, Eun Hee [Chungnam National University College of Medicine, Chungnam National University Hospital, Daejeon (Korea, Republic of)

    2013-03-15

    To report the magnetic resonance (MR) imaging features of the spinal cord and brain in patients of neuromyelitis optica (NMO). Between January 2001 and March 2010, the MR images (spinal cord, brain, and orbit) and the clinical and serologic findings of 11 NMO patients were retrospectively reviewed. The contrast-enhancement of the spinal cord was performed (20/23). The presence and pattern of the contrast-enhancement in the spinal cord were classified into 5 types. Acute myelitis was monophasic in 8 patients (8/11, 72.7%); and optic neuritis preceded acute myelitis in most patients. Longitudinally extensive cord lesion (average, 7.3 vertebral segments) was involved. The most common type was the diffuse and subtle enhancement of the spinal cord with a multifocal nodular, linear or segmental intense enhancement (45%). Most of the brain lesions (5/11, 10 lesions) were located in the brain stem, thalamus and callososeptal interphase. Anti-Ro autoantibody was positive in 2 patients, and they showed a high relapse rate of acute myelitis. Anti-NMO IgG was positive in 4 patients (4/7, 66.7%). The imaging findings of acute myelitis in NMO may helpful in making an early diagnosis of NMO which can result in a severe damage to the spinal cord, and to make a differential diagnosis of multiple sclerosis and inflammatory diseases of the spinal cord such as toxocariasis.

  17. Magnetic Resonance Imaging at Ultrahigh Fields

    Science.gov (United States)

    Uğurbil, Kamil

    2014-01-01

    Since the introduction of 4 T human systems in three academic laboratories circa 1990, rapid progress in imaging and spectroscopy studies in humans at 4 T and animal model systems at 9.4 T have led to the introduction of 7 T and higher magnetic fields for human investigation at about the turn of the century. Work conducted on these platforms has demonstrated the existence of significant advantages in SNR and biological information content at these ultrahigh fields, as well as the presence of numerous challenges. Primary difference from lower fields is the deviation from the near field regime; at the frequencies corresponding to hydrogen resonance conditions at ultrahigh fields, the RF is characterized by attenuated traveling waves in the human body, which leads to image nonuniformities for a given sample-coil configuration because of interferences. These nonuniformities were considered detrimental to the progress of imaging at high field strengths. However, they are advantageous for parallel imaging for signal reception and parallel transmission, two critical technologies that account, to a large extend, for the success of ultrahigh fields. With these technologies, and improvements in instrumentation and imaging methods, ultra-high fields have provided unprecedented gains in imaging of brain function and anatomy, and started to make inroads into investigation of the human torso and extremities. As extensive as they are, these gains still constitute a prelude to what is to come given the increasingly larger effort committed to ultrahigh field research and development of ever better instrumentation and techniques. PMID:24686229

  18. Magnetic resonance imaging of navicular bursa adhesions.

    Science.gov (United States)

    Holowinski, Maureen E; Solano, Mauricio; Maranda, Louise; García-López, José M

    2012-01-01

    Adhesions occur in the navicular bursa between the deep digital flexor tendon (DDFT) and other structures. Our objectives were to describe the appearance of navicular bursa adhesions on high-field magnetic resonance (MR) images, to compare these findings to findings at navicular bursoscopy, and to determine the prevalence of lesions in the remainder of the podotrochlear apparatus. Sixteen forelimbs from 14 horses that underwent MR imaging and navicular bursoscopy were evaluated. Adhesions were considered type 1 when characterized by a discontinuity in the navicular bursa fluid signal between two structures, type 2 when the navicular bursa fluid signal was disrupted and ill-defined tissue was present between two structures, and type 3 when the fluid signal was disrupted and well-defined tissue was present between two structures. Twenty-six adhesions were suspected on MR images and nineteen were visualized at surgery. The positive predictive value was 50% for type 1 adhesions, 67% for type 2 adhesions, and 100% for type 3 adhesions. Additional lesions were detected in the navicular bursa in 15 limbs, the DDFT in 13, the navicular bone in 15, the collateral sesamoidean ligaments in 9, and the distal sesamoidean impar ligament in 8. A discontinuity in the navicular bursa fluid signal with well-defined tissue between two structures detected on high-field MR images is diagnostic for a navicular bursa adhesion. Additional lesions in the podotrochlear apparatus are common in horses with navicular bursa adhesions. © 2012 Veterinary Radiology & Ultrasound.

  19. Magnetic resonance imaging in diffuse brain injury

    Energy Technology Data Exchange (ETDEWEB)

    Yokota, Hiroyuki; Yasuda, Kazuhiro; Mashiko, Kunihiro; Henmi, Hiroshi; Otsuka, Toshibumi; Kobayashi, Shiro; Nakazawa, Shozo (Nippon Medical School, Tokyo (Japan))

    1992-01-01

    Forty cases diagnosed as diffuse brain injury (DBI) were studied by magnetic resonance imaging (MRI) performed within 3 days after injury. These cases were divided into two groups, which were the concussion group and diffuse axonal injury (DAI) group established by Gennarelli. There were no findings on computerized tomography (CT) in the concussion group except for two cases which had a brain edema or subarachnoid hemorrhage. But on MRI, high intensity areas on T2 weighted imaging were demonstrated in the cerebral white matter in this group. Many lesions in this group were thought to be edemas of the cerebral white matter, because of the fact that on serial MRI, they were isointense. In mild types of DAI, the lesions on MRI were located only in the cerebral white matter, whereas, in the severe types of DAI, lesions were located in the basal ganglia, the corpus callosum, the dorsal part of the brain stem as well as in the cerebral white matter. As for CT findings, parenchymal lesions were not visualized especially in mild DAI. Our results suggested that the lesions in cerebral concussion were edemas in cerebral white matter. In mild DAI they were non-hemorrhagic contusion; and in severe DAI they were hemorrhagic contusions in the cerebral white matter, the basal ganglia, the corpus callosum or the dorsal part of the brain stem. (author).

  20. Magnetic resonance imaging of intracavernous pathology

    Energy Technology Data Exchange (ETDEWEB)

    Komiyama, Masaki; Yasui, Toshihiro; Yagura, Hisatsugu; Fu, Yoshihiko; Baba, Mitsuru (Baba Memorial Hospital, Sakai, Osaka (Japan)); Hakuba, Akira; Nishimura, Shuro

    1989-07-01

    To evaluate the usefulness of magnetic resonance (MR) imaging of intracavernous pathology, T{sub 1}-weighted spin echo images of four vascular lesions and 10 neoplastic lesions with surgically confirmed cavernous sinus (CS) invasion were reviewed retrospectively. In one case of traumatic carotid-cavernous fistula (CCF) and one of dural arteriovenous malformation (AVM), the internal carotid artery (ICA) and rapid shunted flow were depicted as signal voids, and the relationship between the ICA and shunted flow was clearly shown. Normal venous flow appeared as a low-intensity area and was observed even in the presence of the CCF and dural AVM. In two cases of thrombosed aneurysms, the thrombosis was clearly demonstrated, along with patent arterial flow in one case; in the other case, however, it was impossible to differentiate patent arterial flow from calcification. The intensity of all neoplastic lesions was similar to that of the cerebral cortex. The relationship between the ICA and the tumors was clearly demonstrated. The visual pathways were also plainly shown unless they were involved, or markedly compressed, by tumor. CS invasion was strongly associated with four findings: (1) encasement of the ICA by the tumor; (2) marked displacement of the ICA; (3) absence of low intensity, which reflects normal venous flow, in the CS; and (4) extension of extrasellar tumors to the medial wall or of intrasellar tumors to the lateral wall. MR imaging was judged promising in the evaluation of intracavernous pathology. (author).

  1. Magnetic resonance imaging for characterizing myocardial diseases.

    Science.gov (United States)

    Saeed, Maythem; Liu, Hui; Liang, Chang-Hong; Wilson, Mark W

    2017-09-01

    The National Institute of Health defined cardiomyopathy as diseases of the heart muscle. These myocardial diseases have different etiology, structure and treatment. This review highlights the key imaging features of different myocardial diseases. It provides information on myocardial structure/orientation, perfusion, function and viability in diseases related to cardiomyopathy. The standard cardiac magnetic resonance imaging (MRI) sequences can reveal insight on left ventricular (LV) mass, volumes and regional contractile function in all types of cardiomyopathy diseases. Contrast enhanced MRI sequences allow visualization of different infarct patterns and sizes. Enhancement of myocardial inflammation and infarct (location, transmurality and pattern) on contrast enhanced MRI have been used to highlight the key differences in myocardial diseases, predict recovery of function and healing. The common feature in many forms of cardiomyopathy is the presence of diffuse-fibrosis. Currently, imaging sequences generating the most interest in cardiomyopathy include myocardial strain analysis, tissue mapping (T1, T2, T2*) and extracellular volume (ECV) estimation techniques. MRI sequences have the potential to decode the etiology by showing various patterns of infarct and diffuse fibrosis in myocarditis, amyloidosis, sarcoidosis, hypertrophic cardiomyopathy due to aortic stenosis, restrictive cardiomyopathy, arrythmogenic right ventricular dysplasia and hypertension. Integrated PET/MRI system may add in the future more information for the diagnosis and progression of cardiomyopathy diseases. With the promise of high spatial/temporal resolution and 3D coverage, MRI will be an indispensible tool in diagnosis and monitoring the benefits of new therapies designed to treat myocardial diseases.

  2. Statistical normalization techniques for magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Russell T. Shinohara

    2014-01-01

    Full Text Available While computed tomography and other imaging techniques are measured in absolute units with physical meaning, magnetic resonance images are expressed in arbitrary units that are difficult to interpret and differ between study visits and subjects. Much work in the image processing literature on intensity normalization has focused on histogram matching and other histogram mapping techniques, with little emphasis on normalizing images to have biologically interpretable units. Furthermore, there are no formalized principles or goals for the crucial comparability of image intensities within and across subjects. To address this, we propose a set of criteria necessary for the normalization of images. We further propose simple and robust biologically motivated normalization techniques for multisequence brain imaging that have the same interpretation across acquisitions and satisfy the proposed criteria. We compare the performance of different normalization methods in thousands of images of patients with Alzheimer's disease, hundreds of patients with multiple sclerosis, and hundreds of healthy subjects obtained in several different studies at dozens of imaging centers.

  3. Nuclear magnetic resonance imaging of the kidney

    Energy Technology Data Exchange (ETDEWEB)

    Hricak, H.; Crooks, L.; Sheldon, P.; Kaufman, L.

    1983-02-01

    The role of nuclear magnetic resonance (NMR) imaging of the kidney was analyzed in 18 persons (6 normal volunteers, 3 patients with pelvocaliectasis, 2 with peripelvic cysts, 1 with renal sinus lipomatosis, 3 with renal failure, 1 with glycogen storage disease, and 2 with polycystic kidney disease). Ultrasound and/or computed tomography (CT) studies were available for comparison in every case. In the normal kidney distinct anatomical structures were clearly differentiated by NMR. The best anatomical detail ws obtained with spin echo (SE) imaging, using a pulse sequence interval of 1,000 msec and an echo delay time of 28 msec. However, in the evaluation of normal and pathological conditions, all four intensity images (SE 500/28, SE 500/56, SE 1,000/28, and SE 1,000/56) have to be analyzed. No definite advantage was found in using SE imaging with a pulse sequence interval of 1,500 msec. Inversion recovery imaging enhanced the differences between the cortex and medulla, but it had a low signal-to-noise level and, therefore, a suboptimal overall resolution. The advantages of NMR compared with CT and ultrasound are discussed, and it is concluded that NMR imaging will prove to be a useful modality in the evaluation of renal disease.

  4. Monitoring angiogenesis using magnetic resonance methods

    DEFF Research Database (Denmark)

    Holm, David Alberg

    2008-01-01

    When a tumor reaches a certain size it can no longer rely on passive perfusion for nutrition. The tumor therefore emits signaling molecules which stimulating surrounding vessels to divide and grow towards the tumor, a process known as angiogenesis. Very little angiogenesis is present in healthy a...... in a transgenic mouse model. The last manuscript presents a new method for in vivo cell labeling. This method could find use in studying the metastatic spread of cancer cells throughout the body.......-angiogenic treatment is presented in the first manuscript. In the second and third manuscript, two separate methods of quantifying perfusion, blood volume and vessel permeability are presented. The methods are used to show that drug delivery to a xenografted tumor is plausible and to show possible vascular maturation...... and the involved signaling molecules. Subsequently, a short review of contrast agents and perfusion measurements is given. Finally, methods for monitoring angiogenesis using magnetic resonance imaging are reviewed. A method for monitoring early stages of angiogenesis as well as the effect of anti...

  5. Magnetic resonance tomography of the knee joint

    Energy Technology Data Exchange (ETDEWEB)

    Puig, Stefan; Kuruvilla, Yojena Chittazhathu Kurian; Ebner, Lukas [University Hospital, University of Berne, Department of Interventional, Pediatric and Diagnostic Radiology Inselspital, Berne (Switzerland); Endel, Gottfried [Main Association of Austrian Social Insurance Institutions, Vienna (Austria)

    2015-10-15

    To compare the diagnostic performance of magnetic resonance imaging (MRI) in terms of sensitivity and specificity using a field strength of <1.0 T (T) versus ≥1.5 T for diagnosing or ruling out knee injuries or knee pathologies. The systematic literature research revealed more than 10,000 references, of which 1598 abstracts were reviewed and 87 full-text articles were retrieved. The further selection process resulted in the inclusion of four systematic reviews and six primary studies. No differences could be identified in the diagnostic performance of low- versus high-field MRI for the detection or exclusion of meniscal or cruciate ligament tears. Regarding the detection or grading of cartilage defects and osteoarthritis of the knee, the existing evidence suggests that high-field MRI is tolerably specific but not very sensitive, while there is literally no evidence for low-field MRI because only a few studies with small sample sizes and equivocal findings have been performed. We can recommend the use of low-field strength MRI systems in suspected meniscal or cruciate ligament injuries. This does, however, not apply to the diagnosis and grading of knee cartilage defects and osteoarthritis because of insufficient evidence. (orig.)

  6. Magnetic resonance tomography in confirmed multiple sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Uhlenbrock, D.; Dickmann, E.; Beyer, H.K.; Gehlen, W.

    1985-03-01

    The authors report on 21 cases of confirmed multiple sclerosis examined by both CT and magnetic resonance tomography. To safeguard the results, strict criteria were applied in accordance with the suggestions made by neurological work teams. Pathological lesions were seen in 20 patients; the MR image did not reveal anything abnormal in one case. On the average, 10.3 lesions were seen in the MR tomogram, whereas CT images showed on the average only 2.1 foci. The size and number of lesions in the MR tomogram were independent of the duration of the disease, the presented clinical symptoms, or the type of treatment at the time of examination. Evidently the sensitivity of MR tomography is very high in MS patients, but it has not yet been clarified to what extent this applies also to the specificity. Further research is mandatory. First experiences made by us show that lesions of a similar kind can also occur in diseases such as malignant lymphoma involving the brain, in vitamin B 12 deficiency syndrome, or encephalitis, and can become manifest in the MR tomogram.

  7. Cardiovascular magnetic resonance in wet beriberi

    Directory of Open Access Journals (Sweden)

    Giri Shivraman

    2011-08-01

    Full Text Available Abstract The clinical presentation of beriberi can be quite varied. In the extreme form, profound cardiovascular involvement leads to circulatory collapse and death. This case report is of a 72 year-old male who was admitted to the Neurology inpatient ward with progressive bilateral lower extremity weakness and parasthesia. He subsequently developed pulmonary edema and high output cardiac failure requiring intubation and blood pressure support. With the constellation of peripheral neuropathy, encephalopathy, ophthalmoplegia, unexplained heart failure, and lactic acidosis, thiamine deficiency was suspected. He was empirically initiated on thiamine replacement therapy and his thiamine level pre-therapy was found to be 23 nmol/L (Normal: 80-150 nmol/L, consistent with the diagnosis of beriberi. Cardiovascular magnetic resonance (CMR showed severe left ventricular systolic dysfunction, markedly increased myocardial T2, and minimal late gadolinium enhancement (LGE. After 5 days of daily 100 mg IV thiamine and supportive care, the hypotension resolved and the patient was extubated and was released from the hospital 3 weeks later. Our case shows via CMR profound myocardial edema associated with wet beriberi.

  8. Magnetic resonance imaging in retropharyngeal tendinitis

    Energy Technology Data Exchange (ETDEWEB)

    Ekbon, K.; Annell, K.; Traeff, J.; Torhall, J. (Soeder Hospital, Stockholm (Sweden))

    1994-08-01

    Seven consecutive patients with acute retropharyngeal tendinitis underwent plain X-ray and magnetic resonance imaging (MRI) of the cervical spine. All seven had marked soft tissue swelling anterior to C1 and C2 on plain X-ray, and soft tissue calcification at this level was present in five of them. On MRI, there was markedly increased signal intensity on T[sub 2]-weighted images in the acute phase and intermediate signal intensity on T[sub 1]-weighted images, anterior to the level of CI and C2, often extending as far down as C6. These changes correlated well with the soft tissue swelling seen on conventional X-ray of the cervical spine. The maximum mid-sagittal thickness of the soft issues was significantly greater in the tendinitis patients than in 12 control subjects free of symptoms from the pharynx or the cervical spine. Treatment with non-steroidal anti-inflammatory drugs rapidly alleviated symptoms, and at follow-up MRI showed regression or complete restitution of the changes. In conclusion, MRI can visualize the edematous changes in the longus colli muscle and adds useful diagnostic information in suspected cases of acute retropharyngeal tendinitis. 9 refs., 4 figs., 3 tabs.

  9. Quantum information processing and nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Cummins, H.K

    2001-07-01

    Quantum computers are information processing devices which operate by and exploit the laws of quantum mechanics, potentially allowing them to solve problems which are intractable using classical computers. This dissertation considers the practical issues involved in one of the more successful implementations to date, nuclear magnetic resonance (NMR). Techniques for dealing with systematic errors are presented, and a quantum protocol is implemented. Chapter 1 is a brief introduction to quantum computation. The physical basis of its efficiency and issues involved in its implementation are discussed. NMR quantum information processing is reviewed in more detail in Chapter 2. Chapter 3 considers some of the errors that may be introduced in the process of implementing an algorithm, and high-level ways of reducing the impact of these errors by using composite rotations. Novel general expressions for stabilising composite rotations are presented in Chapter 4 and a new class of composite rotations, tailored composite rotations, presented in Chapter 5. Chapter 6 describes some of the advantages and pitfalls of combining composite rotations. Experimental evaluations of the composite rotations are given in each case. An actual implementation of a quantum information protocol, approximate quantum cloning, is presented in Chapter 7. The dissertation ends with appendices which contain expansions of some equations and detailed calculations of certain composite rotation results, as well as spectrometer pulse sequence programs. (author)

  10. Magnetic resonance imaging of suspected atrial tumors.

    Science.gov (United States)

    Menegus, M A; Greenberg, M A; Spindola-Franco, H; Fayemi, A

    1992-05-01

    Two-dimensional echocardiography has become the standard technique for evaluation of cardiac and paracardiac mass lesions. We have used magnetic resonance imaging (MRI) as an independent assessment of cardiac-associated masses in patients with echocardiograms demonstrating sessile atrial tumors. MRI was performed in seven patients, ages 33 to 84, whose echocardiographic diagnoses included left atrial mass (five), right atrial mass (one), and interatrial mass (one). In four of the patients with a diagnosis of left atrial mass, MRI showed extracardiac compression of the atrium, simulating a tumor (hiatal hernia, tortuous descending aorta, bronchogenic cyst). MRI was entirely normal in one patient with an apparent left atrial mass. MRI elucidated extension of an extracavitary mass into the interatrial septum in two patients. One of these patients with an echocardiographic right atrial mass had extension of a lipoma into the interatrial septum without atrial tumor. MRI confirmed the echocardiographic diagnosis of an interatrial mass in the other patient. We conclude that MRI, because of its ability to define anatomic relationships and tissue characteristics, is a powerful noninvasive tool for evaluating suspected cardiac mass lesions. Although echocardiography remains the primary screening test for the detection of cardiac masses, MRI is a more specific modality for precise diagnosis. Correct MRI interpretation may obviate the need for invasive studies or surgery.

  11. Magnetic Resonance Imaging of Cartilage Repair

    Science.gov (United States)

    Trattnig, Siegfried; Winalski, Carl S.; Marlovits, Stephan; Jurvelin, Jukka S.; Welsch, Goetz H.; Potter, Hollis G.

    2011-01-01

    Articular cartilage lesions are a common pathology of the knee joint, and many patients may benefit from cartilage repair surgeries that offer the chance to avoid the development of osteoarthritis or delay its progression. Cartilage repair surgery, no matter the technique, requires a noninvasive, standardized, and high-quality longitudinal method to assess the structure of the repair tissue. This goal is best fulfilled by magnetic resonance imaging (MRI). The present article provides an overview of the current state of the art of MRI of cartilage repair. In the first 2 sections, preclinical and clinical MRI of cartilage repair tissue are described with a focus on morphological depiction of cartilage and the use of functional (biochemical) MR methodologies for the visualization of the ultrastructure of cartilage repair. In the third section, a short overview is provided on the regulatory issues of the United States Food and Drug Administration (FDA) and the European Medicines Agency (EMEA) regarding MR follow-up studies of patients after cartilage repair surgeries. PMID:26069565

  12. Bolus characteristics based on Magnetic Resonance Angiography

    Directory of Open Access Journals (Sweden)

    Bi Xiaoming

    2006-10-01

    Full Text Available Abstract Background A detailed contrast bolus propagation model is essential for optimizing bolus-chasing Computed Tomography Angiography (CTA. Bolus characteristics were studied using bolus-timing datasets from Magnetic Resonance Angiography (MRA for adaptive controller design and validation. Methods MRA bolus-timing datasets of the aorta in thirty patients were analyzed by a program developed with MATLAB. Bolus characteristics, such as peak position, dispersion and bolus velocity, were studied. The bolus profile was fit to a convolution function, which would serve as a mathematical model of bolus propagation in future controller design. Results The maximum speed of the bolus in the aorta ranged from 5–13 cm/s and the dwell time ranged from 7–13 seconds. Bolus characteristics were well described by the proposed propagation model, which included the exact functional relationships between the parameters and aortic location. Conclusion The convolution function describes bolus dynamics reasonably well and could be used to implement the adaptive controller design.

  13. Cardiovascular magnetic resonance in pericardial diseases

    Directory of Open Access Journals (Sweden)

    Francone Marco

    2009-05-01

    Full Text Available Abstract The pericardium and pericardial diseases in particular have received, in contrast to other topics in the field of cardiology, relatively limited interest. Today, despite improved knowledge of pathophysiology of pericardial diseases and the availability of a wide spectrum of diagnostic tools, the diagnostic challenge remains. Not only the clinical presentation may be atypical, mimicking other cardiac, pulmonary or pleural diseases; in developed countries a shift for instance in the epidemiology of constrictive pericarditis has been noted. Accurate decision making is crucial taking into account the significant morbidity and mortality caused by complicated pericardial diseases, and the potential benefit of therapeutic interventions. Imaging herein has an important role, and cardiovascular magnetic resonance (CMR is definitely one of the most versatile modalities to study the pericardium. It fuses excellent anatomic detail and tissue characterization with accurate evaluation of cardiac function and assessment of the haemodynamic consequences of pericardial constraint on cardiac filling. This review focuses on the current state of knowledge how CMR can be used to study the most common pericardial diseases.

  14. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... is a noninvasive test that uses a powerful magnetic field and a computer to produce detailed pictures of ... your body as these can interfere with the magnetic field of the MRI unit. The magnetic field is ...

  15. Preoperative functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS)

    DEFF Research Database (Denmark)

    Hartwigsen, G.; Siebner, Hartwig R.; Stippich, C.

    2010-01-01

    of essential cortex, it cannot provide information preoperatively for surgical planning.Brain imaging techniques such as functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG) and transcranial magnetic stimulation (TMS) are increasingly being used to localize functionally critical cortical...

  16. Focus on advanced magnetic resonance techniques in clinical practice: magnetic resonance neurography.

    Science.gov (United States)

    Carpenter, Elizabeth L; Bencardino, Jenny T

    2015-05-01

    Magnetic resonance neurography (MRN) provides the greatest degree of soft tissue contrast in the evaluation of peripheral nerves. Utilization of MRN relies on (1) peripheral nerve anatomy, (2) the spectrum of pathology, and (3) familiarity with dedicated MR imaging techniques. Although there remain several pitfalls in MRN imaging, awareness of these pitfalls improves imaging quality and limits misinterpretation. Most importantly, maintaining a direct line of communication with the referring clinician allows for the greatest degree of diagnostic accuracy. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Radiofrequency coils for magnetic resonance applications: theory, design, and evaluation.

    Science.gov (United States)

    Giovannetti, Giulio; Hartwig, Valentina; Positano, Vincenzo; Vanello, Nicola

    2014-01-01

    Magnetic resonance imaging and magnetic resonance spectroscopy are noninvasive diagnostic techniques based on the phenomenon of nuclear magnetic resonance. Radiofrequency coils are key components in both the transmission and receiving phases of magnetic resonance systems. Transmitter coils have to produce a highly homogeneous alternating field in a wide field of view, whereas receiver coils have to maximize signal detection while minimizing noise. Development of modern magnetic resonance coils often is based on numerical methods for simulating and predicting coil performance. Numerical methods allows the behavior of the coil in the presence of realistic loads to be simulated and the coil's efficiency at high magnetic fields to be investigated. After being built, coils have to be characterized in the laboratory to optimize their setting and performance by extracting several quality indices. Successively, coils performance has to be evaluated in a scanner using standardized image quality parameters with phantom and human experiments. This article reviews the principles of radiofrequency coils, coil performance parameters, and their estimation methods using simulations, workbench, and magnetic resonance experiments. Finally, an overview of future developments in radiofrequency coils technology is included.

  18. Magnetomechanical coupling and ferromagnetic resonance in magnetic nanoparticles

    Science.gov (United States)

    Keshtgar, Hedyeh; Streib, Simon; Kamra, Akashdeep; Blanter, Yaroslav M.; Bauer, Gerrit E. W.

    2017-04-01

    We address the theory of the coupled lattice and magnetization dynamics of freely suspended single-domain nanoparticles. Magnetic anisotropy generates low-frequency satellite peaks in the microwave absorption spectrum and a blueshift of the ferromagnetic resonance (FMR) frequency. The low-frequency resonances are very sharp with maxima exceeding that of the FMR, because their magnetic and mechanical precessions are locked, thereby suppressing the effective Gilbert damping. Magnetic nanoparticles can operate as nearly ideal motors that convert electromagnetic into mechanical energy. The Barnett damping term is essential for obtaining physically meaningful results.

  19. Magnetic resonance imaging in classification of congenital muscular dystrophies with brain abnormalities

    NARCIS (Netherlands)

    vanderKnaap, MS; Smit, LME; Barth, PG; CatsmanBerrevoets, CE; Brouwer, OF; Begeer, JH; deCoo, IFM; Valk, J.

    A survey was performed of magnetic resonance imaging (MRI) findings in 21 patients with congenital muscular dystrophy (QID) with cerebral abnormalities to evaluate the contribution of MRI to the classification of CMD patients. In 5 patients with Walker-Warburg syndrome (WWS), MRI showed

  20. Magnetic resonance imaging in classification of congenital muscular dystrophies with brain abnormalities

    NARCIS (Netherlands)

    van der Knaap, M. S.; Smit, L. M.; Barth, P. G.; Catsman-Berrevoets, C. E.; Brouwer, O. F.; Begeer, J. H.; de Coo, I. F.; Valk, J.

    1997-01-01

    A survey was performed of magnetic resonance imaging (MRI) findings in 21 patients with congenital muscular dystrophy (CMD) with cerebral abnormalities to evaluate the contribution of MRI to the classification of CMD patients. In 5 patients with Walker-Warburg syndrome (WWS), MRI showed

  1. Serial magnetic resonance imaging of central pontine myelinolysis

    NARCIS (Netherlands)

    Buis, CI; Wijdicks, EFM

    Central Pontine Myelinolysis (CPM) is a rare neurologic complication after liver transplantation. The true incidence of CPM after orthotopic liver tranplantation remains an estimate. However, with the introduction of magnetic resonance imaging, early recognition became feasible. In this report, we

  2. Diffusion-weighted magnetic resonance imaging in ileocolonic Crohn's disease

    DEFF Research Database (Denmark)

    Juel, Mie A; Rafaelsen, Søren Rafael; Nathan, Torben

    Background: Diffusion-weighted magnetic resonance imaging (dw- MRI) utilizes differences in the motion of water molecules between tissues for image formation without administration of contrast materials. Inflammation in the bowel wall slows water transit resulting in lower apparent diffusions...

  3. Enhancing contrast of magnetic resonance imaging in patients with ...

    African Journals Online (AJOL)

    DTPA), a recent magnetic resonance imaging (MRI) contrast agent, in hepatobiliary system of patients with liver cirrhosis. Methods: Liver cirrhosis patients that underwent contrast MRI examination at Renai Hospital, Taipei City, Taiwan were ...

  4. Magnetic resonance imaging of head and neck vascular anomalies ...

    African Journals Online (AJOL)

    Magnetic resonance imaging of head and neck vascular anomalies: pearls and pitfalls. Shaimaa Abdelsattar Mohammad, Amr Abdelhamid Abou Zeid, Ahmed M. Fawzi, Mohamed M. Dahab, Iman A. Ragab, Osama El-Naggar ...

  5. Normal perinatal and paediatric postmortem magnetic resonance imaging appearances

    Energy Technology Data Exchange (ETDEWEB)

    Arthurs, Owen J. [Department of Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London (United Kingdom); UCL Institute of Child Health, London (United Kingdom); Barber, Joy L. [Department of Radiology, Great Ormond Street Hospital for Children NHS Foundation Trust, London (United Kingdom); Taylor, Andrew M. [Cardiorespiratory Division, Great Ormond Street Hospital for Children NHS Foundation Trust, London (United Kingdom); UCL Institute of Cardiovascular Science, Centre for Cardiovascular Imaging, London (United Kingdom); Sebire, Neil J. [UCL Institute of Child Health, London (United Kingdom); Department of Histopathology, Great Ormond Street Hospital for Children NHS Foundation Trust, London (United Kingdom)

    2015-04-01

    As postmortem imaging becomes more widely used following perinatal and paediatric deaths, the correct interpretation of images becomes imperative, particularly given the increased use of postmortem magnetic resonance imaging. Many pathological processes may have similar appearances in life and following death. A thorough knowledge of normal postmortem changes is therefore required within postmortem magnetic resonance imaging to ensure that these are not mistakenly interpreted as significant pathology. Similarly, some changes that are interpreted as pathological if they occur during life may be artefacts on postmortem magnetic resonance imaging that are of limited significance. This review serves to illustrate briefly those postmortem magnetic resonance imaging changes as part of the normal changes after death in fetuses and children, and highlight imaging findings that may confuse or mislead an observer to identifying pathology where none is present. (orig.)

  6. Magnetic resonance tomography for trauma of the cervical spine

    Energy Technology Data Exchange (ETDEWEB)

    Meydam, K.; Sehlen, S.; Schlenkhoff, D.; Kiricuta, J.C.; Beyer, H.K.

    1986-12-01

    Twenty patients who had suffered spinal trauma were examined by magnetic resonance tomography. Fifteen patients with first degree trauma in Erdmann's classification showed no abnormality. Magnetic resonance tomography of the cervical spine appears to be a suitable method for investigating patients with whiplash injuries. It is indicated following severe flexion injuries with subluxations and neurological symptoms, since it is the only method that can demonstrate the spinal cord directly and completely and show the extent of cord compression. For patients with thoracic trauma and rapidly developing neurological symptoms, magnetic resonance tomography is ideal for showing post-traumatic syringomyelia. Magnetic resonance tomography following whiplash injuries is recommended if plain films of the cervical spine show any abnormalities, as well as for the investigation of acute or sub-acute neurological abnormalities. The various findings are discussed.

  7. Cellular solid-state Nuclear Magnetic Resonance spectroscopy

    NARCIS (Netherlands)

    Renault, M.A.M.; Tommassen-van Boxtel, H.A.M.; Bos, M.P.; Post, J.A.; Tommassen, J.P.M.; Baldus, M.

    2012-01-01

    Decrypting the structure, function, and molecular interactions of complex molecular machines in their cellular context and at atomic resolution is of prime importance for understanding fundamental physiological processes. Nuclear magnetic resonance is a wellestablished imaging method that can

  8. Nuclear magnetic resonance data of C4H8S

    Science.gov (United States)

    Mikhova, B. M.

    This document is part of Part 6 `Organic Metalloid Compounds' of Subvolume D 'Chemical Shifts and Coupling Constants for Carbon-13' of Landolt-Börnstein III/35 'Nuclear Magnetic Resonance Data', Group III 'Condensed Matter'.

  9. Correlation of magnetic resonance imaging tumor volume with histopathology.

    Science.gov (United States)

    Turkbey, Baris; Mani, Haresh; Aras, Omer; Rastinehad, Ardeshir R; Shah, Vijay; Bernardo, Marcelino; Pohida, Thomas; Daar, Dagane; Benjamin, Compton; McKinney, Yolanda L; Linehan, W Marston; Wood, Bradford J; Merino, Maria J; Choyke, Peter L; Pinto, Peter A

    2012-10-01

    The biology of prostate cancer may be influenced by the index lesion. The definition of index lesion volume is important for appropriate decision making, especially for image guided focal treatment. We determined the accuracy of magnetic resonance imaging for determining index tumor volume compared with volumes derived from histopathology. We evaluated 135 patients (mean age 59.3 years) with a mean prostate specific antigen of 6.74 ng/dl who underwent multiparametric 3T endorectal coil magnetic resonance imaging of the prostate and subsequent radical prostatectomy. Index tumor volume was determined prospectively and independently by magnetic resonance imaging and histopathology. The ellipsoid formula was applied to determine histopathology tumor volume, whereas manual tumor segmentation was used to determine magnetic resonance tumor volume. Histopathology tumor volume was correlated with age and prostate specific antigen whereas magnetic resonance tumor volume involved Pearson correlation and linear regression methods. In addition, the predictive power of magnetic resonance tumor volume, prostate specific antigen and age for estimating histopathology tumor volume (greater than 0.5 cm(3)) was assessed by ROC analysis. The same analysis was also conducted for the 1.15 shrinkage factor corrected histopathology data set. There was a positive correlation between histopathology tumor volume and magnetic resonance tumor volume (Pearson coefficient 0.633, p histopathology tumor volume (Pearson coefficient 0.237, p = 0.003). On linear regression analysis histopathology tumor volume and magnetic resonance tumor volume were correlated (r(2) = 0.401, p histopathology were 0.949 (p histopathology. Magnetic resonance imaging can accurately estimate index tumor volume as determined by histology. Magnetic resonance imaging has better accuracy in predicting histopathology tumor volume in tumors larger than 0.5 cm(3) than prostate specific antigen and age. Index tumor volume as

  10. Diffusion and Perfusion Magnetic Resonance Imaging:Fundamentals and Advances

    OpenAIRE

    Assili, Sanam

    2016-01-01

    Over the past few decades, magnetic resonance imaging has been utilized as a powerful imaging modality to evaluate the structure and function of various organs in the human body,such as the brain. Additionally, diffusion and perfusion MR imaging have been increasingly used in neurovascular clinical applications. In diffusion-weighted magnetic resonance imaging, the mobility of water molecules is explored in order to obtain information about the microscopic behavior of the tissues. In contrast...

  11. Diagnosing Autism Spectrum Disorder through Brain Functional Magnetic Resonance Imaging

    Science.gov (United States)

    2016-03-01

    Diagnosing Autism Spectrum Disorder through Brain Functional Magnetic Resonance Imaging THESIS MARCH 2016 Kyle A. Palko, Second Lieutenant, USAF AFIT...declared a work of the U.S. Government and is not subject to copyright protection in the United States. AFIT-ENC-MS-16-M-123 DIAGNOSING AUTISM SPECTRUM...PUBLIC RELEASE; DISTRIBUTION UNLIMITED. AFIT-ENC-MS-16-M-123 DIAGNOSING AUTISM SPECTRUM DISORDER THROUGH BRAIN FUNCTIONAL MAGNETIC RESONANCE IMAGING Kyle

  12. Quantification of aortic regurgitation by magnetic resonance velocity mapping

    DEFF Research Database (Denmark)

    Søndergaard, Lise; Lindvig, K; Hildebrandt, P

    1993-01-01

    The use of magnetic resonance (MR) velocity mapping in the quantification of aortic valvular blood flow was examined in 10 patients with angiographically verified aortic regurgitation. MR velocity mapping succeeded in identifying and quantifying the regurgitation in all patients, and the regurgit......The use of magnetic resonance (MR) velocity mapping in the quantification of aortic valvular blood flow was examined in 10 patients with angiographically verified aortic regurgitation. MR velocity mapping succeeded in identifying and quantifying the regurgitation in all patients...

  13. Lymphoma of uterine cervix: magnetic resonance imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Kanaan, Daniel; Constantino, Carolina Pesce Lamas; Souza, Rodrigo Canellas de, E-mail: daniel.kanaan@hotmail.com [Department of Radiology, Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Parente, Daniella Braz [Instituto D' Or de Pesquisa e Ensino, Rio de Janeiro, RJ (Brazil)

    2012-05-15

    Lymphoma of the cervix is a rare disease. About 1.0% to 1.5% of extranodal lymphomas originates in the female genital tract. The clinical presentation of this condition is nonspecific and magnetic resonance imaging is important for diagnostic elucidation. The present report describes the case of a 80-year-old patient with lumbar pain, whose magnetic resonance imaging showed a large uterine mass. The final diagnosis was lymphoma. (author)

  14. Magnetic Resonance Imaging Studies of Postpartum Depression: An Overview

    OpenAIRE

    Fiorelli, Marco; Aceti, Franca; Marini, Isabella; Giacchetti, Nicoletta; Macci, Enrica; Tinelli, Emanuele; Calistri, Valentina; Meuti, Valentina; Caramia, Francesca; Biondi, Massimo

    2015-01-01

    Postpartum depression is a frequent and disabling condition whose pathophysiology is still unclear. In recent years, the study of the neural correlates of mental disorders has been increasingly approached using magnetic resonance techniques. In this review we synthesize the results from studies on postpartum depression in the context of structural, functional, and spectroscopic magnetic resonance studies of major depression as a whole. Compared to the relative wealth of data available for maj...

  15. Patient perception of magnetic resonance arthrography

    Energy Technology Data Exchange (ETDEWEB)

    Robbins, M.I.; Anzilotti, K.F. Jr.; Katz, L.D.; Lange, R.C. [Dept. of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT (United States)

    2000-05-01

    Objective. Magnetic resonance (MR) arthrography has been demonstrated to be more accurate than MR imaging alone in the identification of a variety of musculoskeletal pathology. While the complication rate of intra-articular gadolinium: saline injection has been shown to be relatively low, MR arthrography is more invasive, painful, and costly, and less convenient, than MR imaging alone. The purpose of this study was to evaluate patients' perception of the fear and discomfort, and to assess their overall acceptance of the intra-articular gadolinium injection.Design and patients. Between October 1997 and January 1998, 113 outpatients who were referred to Yale-New Haven Hospital for MR arthrography of the ankle, elbow, hip, knee, shoulder, or wrist were asked to complete a questionnaire rating their fear of factors most commonly associated with the procedure including ''pain'', ''needles'', ''complications'', and ''discovery of results that would lead to surgery''. In addition, after having undergone the intra-articular gadolinium:saline injection, patients were asked to rate their perception of pain.Results. While many patients expressed fear of ''pain'' and ''needles'', after having undergone the injection their overall pain rating score was low. Only 6% actually found gadolinium arthrography more painful than expected.Conclusion. Despite the fact that patients expressed apprehension about certain aspects of MR arthrography, subjects who underwent the intra-articular gadolinium injection considered the discomfort less than expected. Clinicians should not hesitate to order MR arthrography because the accuracy of the procedure is high enough that patients accept the discomfort. (orig.)

  16. [Magnetic resonance imaging without sedation in neonates].

    Science.gov (United States)

    Ureta-Velasco, N; Martínez-de Aragón, A; Moral-Pumarega, M T; Núñez-Enamorado, N; Bergón-Sendín, E; Pallás-Alonso, C R

    2015-05-01

    The ability to perform magnetic resonance imaging (MRI) without sedation in the neonatal period increases patient safety, availability and profitability of the diagnostic tool. The aim in this study was to evaluate a new protocol of MRI without sedation during a 20-month period. In the protocol, the patients are prepared in the neonatal unit. Prospective descriptive study, from May 2012 to December 2013. Patients included were neonates requiring MRI, clinically stable and not requiring ventilatory support. The method was based on the application of developmental centered care and the use of a vacuum matress to immobilize the baby. The principal outcome parameter of interest was the percentage of succesfully completed MRIs. The duration of the MRI and the number of interruptions, was also studied from October 2012. A total of 43 MRIs without sedation were carried out on 42 patients: 41 cerebral and 2 spinal. The success rate was 97.7% (42/43). The mean MRI time was 26.3 minutes (95% CI 23.3-29.3 mins; range 16-50 mins). MRIs were completed without interruption in 20 of the 34 cases (58%) in which the duration was recorded. The number of interruptions per procedure varied from 0 to 3, with a mean of 0.6 (95% CI 0.3-0.8) and a median of 0. The protocol had a success rate of over 90%. Thus MRI without sedation seems applicable in Spanish hospitals, with most of the preparation being performed in the neonatal unit, in order to reduce the occupation of the MRI unit, as well as minimizing stress to the baby. Copyright © 2014 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.

  17. Magnetic Resonance Imaging in Postprostatectomy Radiotherapy Planning

    Energy Technology Data Exchange (ETDEWEB)

    Sefrova, Jana, E-mail: sefrova@post.cz [Department of Oncology and Radiotherapy, University Hospital Hradec Kralove, Hradec Kralove (Czech Republic); Odrazka, Karel [Department of Clinical and Radiation Oncology, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); First and Third Faculty of Medicine, Charles University in Prague, Prague (Czech Republic); Paluska, Petr [Department of Oncology and Radiotherapy, University Hospital Hradec Kralove, Hradec Kralove (Czech Republic); Belobradek, Zdenek [Department of Radiology, University Hospital Hradec Kralove, Hradec Kralove (Czech Republic); Brodak, Milos [Department of Urology, University Hospital Hradec Kralove, Hradec Kralove (Czech Republic); Dolezel, Martin [Department of Clinical and Radiation Oncology, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); First and Third Faculty of Medicine, Charles University in Prague, Prague (Czech Republic); Prosvic, Petr [Department of Urology, Regional Hospital Nachod, Nachod (Czech Republic); Macingova, Zuzana; Vosmik, Milan [Department of Oncology and Radiotherapy, University Hospital Hradec Kralove, Hradec Kralove (Czech Republic); Hoffmann, Petr [Department of Radiology, University Hospital Hradec Kralove, Hradec Kralove (Czech Republic); Louda, Miroslav [Department of Urology, University Hospital Hradec Kralove, Hradec Kralove (Czech Republic); Nejedla, Anna [Department of Oncology and Radiotherapy, University Hospital Hradec Kralove, Hradec Kralove (Czech Republic)

    2012-02-01

    Purpose: To investigate whether the use of magnetic resonance imaging (MRI) in prostate bed treatment planning could influence definition of the clinical target volume (CTV) and organs at risk. Methods and Materials: A total of 21 consecutive patients referred for prostate bed radiotherapy were included in the present retrospective study. The CTV was delineated according to the European Organization for Research and Treatment of Cancer recommendations on computed tomography (CT) and T{sub 1}-weighted (T{sub 1}w) and T{sub 2}-weighted (T{sub 2}w) MRI. The CTV magnitude, agreement, and spatial differences were evaluated on the planning CT scan after registration with the MRI scans. Results: The CTV was significantly reduced on the T{sub 1}w and T{sub 2}w MRI scans (13% and 9%, respectively) compared with the CT scans. The urinary bladder was drawn smaller on the CT scans and the rectum was smaller on the MRI scans. On T{sub 1}w MRI, the rectum and urinary bladder were delineated larger than on T{sub 2}w MRI. Minimal agreement was observed between the CT and T{sub 2}w images. The main spatial differences were measured in the superior and superolateral directions in which the CTV on the MRI scans was 1.8-2.9 mm smaller. In the posterior and inferior border, no difference was seen between the CT and T{sub 1}w MRI scans. On the T{sub 2}w MRI scans, the CTV was larger in these directions (by 1.3 and 1.7 mm, respectively). Conclusions: The use of MRI in postprostatectomy radiotherapy planning resulted in a reduction of the CTV. The main differences were found in the superior part of the prostate bed. We believe T{sub 2}w MRI enables more precise definition of prostate bed CTV than conventional planning CT.

  18. Cardiac magnetic resonance elastography. Initial results.

    Science.gov (United States)

    Elgeti, Thomas; Rump, Jens; Hamhaber, Uwe; Papazoglou, Sebastian; Hamm, Bernd; Braun, Jürgen; Sack, Ingolf

    2008-11-01

    To develop cardiac magnetic resonance elastography (MRE) for noninvasively measuring left ventricular (LV) pressure-volume (P-V) work. The anterior chest wall of 8 healthy volunteers was vibrated by 24.3-Hz acoustic waves for stimulating oscillating shear deformation in myocardium and adjacent blood. The induced motion was recorded by an electrocardiogram-gated, vibration-synchronized and segmented gradient-recalled echo MRE sequence acquiring 360 phase-contrast wave images with a temporal resolution of 5.16 milliseconds in the short-axis view during controlled breathing. Relative changes in wave amplitudes served as a measure of LV pressure variation during the cardiac cycle. MRE pressure data were combined with LV volumes obtained from segmentation of 3D cine-steady-state free precession data sets. Shear wave amplitudes decreased from diastole to systole, which reflects the dynamics of myocardial shear modulus variations during the cardiac cycle. Assuming spherical shear stress, a linear relationship between myocardial stiffness and LV pressure was derived. The MRE-measured pressure was plotted as a function of LV volumes. Characteristic P-V cycles displayed an isovolumetric increase in pressure during early systole, whereas less pronounced volume conservation was observed in early diastole. Mean cardiac P-V work in all volunteers was 0.85 +/- 0.11 J. In vivo cardiac MRE is a noninvasive method for measuring pressure-related heart function determined by shear modulus variations in the LV wall. This is the first noninvasive mechanical test of cardiac work in the human heart and is potentially useful for assessing pathologies associated with increased myocardial stiffness such as diastolic dysfunction.

  19. Can magnetic resonance spectroscopy differentiate endometrial cancer?

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jie; Cai, Shifeng; Han, Xue; Liu, Qingwei; Xin, Yinghui [Shandong University, Department of Radiology, Shandong Provincial Hospital, Jinan (China); Li, Changzhong; Yang, Chunrun [Shandong University, Department of Obstetrics and Gynecology, Shandong Provincial Hospital, Jinan (China); Sun, Xichao; Zong, Yuanyuan [Shandong University, Department of Pathology, Shandong Provincial Hospital, Jinan (China); Fu, Caixia [Siemens Shenzhen Magnetic Resonance Ltd., Siemens MRI Center, Shenzhen (China)

    2014-10-15

    To investigate whether the choline-containing compounds (Cho) obtained from three-dimensional {sup 1}H magnetic resonance (MR) spectroscopy can differentiate endometrial cancer (ECa) from benign lesions in endometria or in submucosa (BLs-ESm) and is associated with the aggressiveness of ECa. Fifty-seven patients (ECa, 38; BLs-ESm, 19) underwent preoperative multi-voxel MR spectroscopy at 3.0 T. The ratio of the sum of the Cho peak integral to the sum of the unsuppressed water peak integral (Cho/water) and the coefficient of variation (CV) used to describe the variability of Cho/water in one lesion were calculated. Mean Cho/water (±standard deviation [SD]) was (3.02 ± 1.43) x 10{sup -3} for ECa and (1.68 ± 0.33) x 10{sup -3} for BLs-ESm (p < 0.001). Mean Cho/water was (4.42 ± 1.53) x 10{sup -3} for type II ECa and (2.65 ± 1.17) x 10{sup -3} for type I ECa (p = 0.001). There were no significant differences among different stages of ECa (p = 0.107) or different grades of ECa (p = 0.142). The Cho/water was positively correlated with tumour stage (r = 0.386, p = 0.017) and size (r = 0.333, p = 0.041). The CV was also positively correlated with tumour stage (r = 0.537, p = 0.001) and size (r = 0.34, p = 0.037). The Cho/water can differentiate ECa from BLs-ESm and differentiate type II from type I ECa, but cannot differentiate different stages of ECa or different grades of ECa. Cho/water increased with the increase of tumour stage and size. (orig.)

  20. Magnetic resonance imaging of spinal dysraphism

    Energy Technology Data Exchange (ETDEWEB)

    Akino, Minoru; Isu, Toyohiko; Iwasaki, Yoshinobu; Abe, Hiroshi; Abe, Satoru; Miyasaka, Kazuo; Nomura, Mikio; Saito, Hisatoshi.

    1988-04-01

    Nineteen patients with lumbosacral spina bifida were studied by magnetic resonance imaging (MRI) and were divided into two groups: those with lumbosacral lipoma and those with meningomyelocele. All of the patients with meningomyelocele underwent surgery soon after birth for closure of the skin defect. Whenever possible, examination was not confined to the lumbosacral area but also included the brain and other portions of the spinal cord. Certain similarities and differences in pathology were ascertained in the two groups. The tethered cords were the same in both groups. However, Chiari malformations were observed only in patients with meningomyelocele, and hydrocephalus occurred only in patients with Chiari malformations. Syringomyelia and scoliosis were detected in both groups, but scoliosis was more prevalent in the meningomyelocele group. There appeared to be a correlation between scoliosis and syringomyelia; in five of the seven cases of syringomyelia, the locations of the scoliosis and syringomyelia were the same. With MRI, these complex pathologies, including tethered cord, syringomyelia, scoliosis, Chiari malformations, and hydrocephalus, were easily visualized. The superiority of MRI over conventional X-ray technology has been well established. First, a direct image of the spinal cord is obtained. Second, there is no necessity for injection of contrast material into the intrathecal space. Third, any scanning field is possible. There are also some disadvantages with MRI. First, the spatial resolution is inferior to that of high-resolution computed tomography. Second, MRI cannot provide information concerning bone cortex. Therefore, bone involvement cannot be accurately diagnosed. However, in the assessment of spinal dysraphism, MRI is an excellent diagnostic tool and should be the preferred method of diagnosing spinal dysraphism.

  1. Brain magnetic resonance imaging and magnetic resonance spectroscopy findings of children with kernicterus.

    Science.gov (United States)

    Sarı, Sahabettin; Yavuz, Alpaslan; Batur, Aabdussamet; Bora, Aydın; Caksen, Huseyin

    2015-01-01

    The term kernicterus, or bilirubin encephalopathy, is used to describe pathological bilirubin staining of the basal ganglia, brain stem, and cerebellum, and is associated with hyperbilirubinemia. Kernicterus generally occurs in untreated hyperbilirubinemia or cases where treatment is delayed. Magnetic resonance imaging (MRI)-based studies have shown characteristic findings in kernicterus. The objective of our study was to describe the role of (1)H magnetic resonance spectroscopy (MRS) in demonstrating these metabolic changes and to review conventional MRI findings of kernicterus. Forty-eight pediatric cases with kernicterus were included in this study. MRI and MRS examinations were performed on variable dates (10-29 days after birth). NAA, Cr, Cho, NAA/Cr, NAA/Cho, and Cho/Cr values were evaluated visually and by computer analysis. There was no statistically significant difference between the NAA and Cho levels in the acute kernicterus patients and the control group (healthy patients), whereas both were significantly elevated in the chronic kernicterus patients. Both the mean NAA/Cr and Cho/Cr ratio values were significantly higher in the acute and chronic cases compared to the control group. The NAA/Cho ratio value was statistically lower in the acute cases than in the control group while it was similar in the chronic cases. Conventional MR imaging and (1)H-MRS are important complementary tools in the diagnostics of neonatal bilirubin encephalopathy. This study provided important information for applying these MR modalities in the evaluation of neonates with bilirubin encephalopathy.

  2. Pressure-driven amplification and penetration of resonant magnetic perturbations

    Energy Technology Data Exchange (ETDEWEB)

    Loizu, J. [Max-Planck-Institut für Plasmaphysik, D-17491 Greifswald (Germany); Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543 (United States); Hudson, S. R.; Lazerson, S. A.; Bhattacharjee, A. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543 (United States); Helander, P. [Max-Planck-Institut für Plasmaphysik, D-17491 Greifswald (Germany)

    2016-05-15

    We show that a resonant magnetic perturbation applied to the boundary of an ideal plasma screw-pinch equilibrium with nested surfaces can penetrate inside the resonant surface and into the core. The response is significantly amplified with increasing plasma pressure. We present a rigorous verification of nonlinear equilibrium codes against linear theory, showing excellent agreement.

  3. Magnetic Resonance Imaging: Window to a Watery World

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 5. Magnetic Resonance Imaging: Window to a Watery World. Kavita Dorai. General Article Volume 9 Issue 5 May 2004 pp 19-32. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/009/05/0019-0032 ...

  4. Magnetic resonance imaging and nuclear magnetic resonance investigations of bentonite systems

    Energy Technology Data Exchange (ETDEWEB)

    Dvinskikh, Sergey V.; Furo, Istvan (Industrial NMR Centre and Div. of Physical Chemistry, Dept. of Chemistry, Royal Institute of Technology, Stockholm (Sweden))

    2009-09-15

    This report summarizes results from a set of magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) experiments performed on Ca and Na montmorillonite samples interacting with water. The primary goal with these studies was to provide, in a non-invasive manner, a quantitative measure of bentonite distribution in extended samples during and after different physical processes such as swelling and sedimentation and on the time scale from minutes to years. Additionally, we also studied the distribution of foreign particles (such as native minerals as well as magnetic model particles) within bentonite systems and performed some diffusion NMR experiments with the aim of characterizing the state of colloids that form after clay dissolution. Both natural montmorillonites and purified and ion-exchanged montmorillonite clays were investigated. The primary variables were clay composition and water ionic strength. Bulk samples confined in a vertical tube and in a horizontal channel were investigated. A critical issue for the stability of clay buffer layer in deep underground repository is to prevent or minimize the release of clay particles into the water phase. In our experiments, the most significant particle losses were found for Na-MX80 clay exposed to water with low ionic strength. With increasing the concentration of CaCl{sub 2} in the water phase both swelling and particle release are slowed down but not completely eliminated due probably to gradual change of water ion content via ion exchange with the clay itself. For natural MX80 samples, in spite of significant swelling expansion, no clay particle release above the sensitivity limit of 0.001 volume% was observed. Ca-MX80 exhibited the smallest expansion and no trace of clay particle released into the aqueous phase

  5. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... can interfere with the magnetic field of the MRI unit. The magnetic field is not harmful in ... malfunction or cause problems during the examination. Most MRI exams are relatively painless. However, some patients may ...

  6. Breast magnetic resonance imaging for the interventionalist: magnetic resonance imaging-guided vacuum-assisted breast biopsy.

    Science.gov (United States)

    Brennan, Sandra B

    2014-03-01

    Magnetic resonance Imaging-guided breast biopsy is an essential component of breast imaging practices offering breast magnetic resonance imaging. Careful planning and preparation allow for an efficient and successful biopsy. Deliberate positioning and controlled compression are keys to a comfortable and cooperative patient. The biopsy is only complete once imaging-histologic correlation has been made by the radiologist. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. In vivo magnetic resonance spectroscopy: basic methodology and clinical applications.

    NARCIS (Netherlands)

    Graaf, M. van der

    2010-01-01

    The clinical use of in vivo magnetic resonance spectroscopy (MRS) has been limited for a long time, mainly due to its low sensitivity. However, with the advent of clinical MR systems with higher magnetic field strengths such as 3 Tesla, the development of better coils, and the design of optimized

  8. Evaluation of left ventricular volumes measured by magnetic resonance imaging

    DEFF Research Database (Denmark)

    Møgelvang, J; Thomsen, C; Mehlsen, J

    1986-01-01

    Left ventricular end-diastolic and end-systolic volumes were determined in 17 patients with different levels of left ventricular function by magnetic resonance imaging (MRI). A 1.5 Tesla Magnet was used obtaining ECG triggered single and multiple slices. Calculated cardiac outputs were compared...

  9. Tools and methods for teaching magnetic resonance concepts and techniques

    DEFF Research Database (Denmark)

    Hanson, L.G.

    2012-01-01

    and MRI education. After a few minutes of use, any user with minimal experience of magnetism will be able to explain the basic magnetic resonance principle. A second piece of software, the Bloch Simulator, aims much further, as it can be used to demonstrate and explore a wide range of phenomena including...

  10. Pulse Design in Solid-State Nuclear Magnetic Resonance

    DEFF Research Database (Denmark)

    Palani, Ravi Shankar

    The work presented in this dissertation is centred on the theory of experimental methods in solid-state Nuclear Magnetic Resonance (NMR) spectroscopy, which deals with interaction of electromagnetic radiation with nuclei in a magnetic field and possessing a fundamental quantum mechanical property...

  11. Ferromagnetic resonance of isotropic heterogeneous magnetic materials: theory and experiments

    CERN Document Server

    Chevalier, A; Le Floc'h, M

    2000-01-01

    Experimental variations of the ferromagnetic resonance (FMR) recorded on soft composite bodies are presented and their interpretation is undertaken. A successful application is performed for the Kittel expression of the FMR, initially written for an ellipsoid placed in vacuum, to a magnetic inclusion of the composite. This model includes the demagnetizing effects due to the magnetic inclusions.

  12. Magnetic resonance of atomic hydrogen at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, W.N.; Morrow, M.; Jochemsen, R.; Berlinsky, A.J. (British Columbia Univ., Vancouver (Canada). Dept. of Physics)

    1982-07-01

    This article reviews the present state of magnetic resonance studies of atomic hydrogen gas at low temperatures. The various types of resonances that can be exploited are discussed and the paper ends with a review of the existing experimental data. It will be seen that up to the present, essentially all of the results have been derived from pulsed magnetic resonance of the 1420 MHz zero field hyperfine transition, and the many interesting results expected of the high field experiments are yet to appear.

  13. Transient magnetization dynamics of spin-torque oscillator and magnetic dot coupled by magnetic dipolar interaction: Reading of magnetization direction using magnetic resonance

    Science.gov (United States)

    Kanao, Taro; Suto, Hirofumi; Kudo, Kiwamu; Nagasawa, Tazumi; Mizushima, Koichi; Sato, Rie

    2018-01-01

    We study the magnetization dynamics of a spin-torque oscillator (STO) and a magnetic dot coupled by a magnetic dipolar field using micromagnetic simulation with the aim of developing a read method in magnetic recording that uses magnetic resonance. We propose an STO with a perpendicularly magnetized free layer and an in-plane-magnetized fixed layer as a suitable STO for this resonance read method. When the oscillation frequency of the STO is near the ferromagnetic resonance (FMR) frequency of the magnetic dot, the oscillation amplitude of the STO decreases because FMR excited in the magnetic dot causes additional dissipation. To estimate the read rate of the resonance read method, we study the transient magnetization dynamics to the coupled oscillation state from an initial state where the STO is in a free-running state and the magnetic dot is in a stationary stable state. The STO shows transient dynamics within a time scale of 1 ns, which means that the STO can perform resonance reading with a response time within this time scale. This response time is shorter when the separation length between the STO and the magnetic dot is shorter, which indicates that the response speed can become faster by increasing the strength of the interaction between the STO and the magnetic dot. Successive reads are demonstrated by moving the STO over an array of magnetic dots.

  14. Dynamical Nuclear Magnetic Resonance Imaging of Micron-scale Liquids

    Science.gov (United States)

    Sixta, Aimee; Choate, Alexandra; Maeker, Jake; Bogat, Sophia; Tennant, Daniel; Mozaffari, Shirin; Markert, John

    We report our efforts in the development of Nuclear Magnetic Resonance Force Microscopy (NMRFM) for dynamical imaging of liquid media at the micron scale. Our probe contains microfluidic samples sealed in thin-walled (µm) quartz tubes, with a micro-oscillator sensor nearby in vacuum to maintain its high mechanical resonance quality factor. Using 10 µm spherical permalloy magnets at the oscillator tips, a 3D T1-resolved image of spin density can be obtained by reconstruction from our magnetostatics-modelled resonance slices; as part of this effort, we are exploring single-shot T1 measurements for faster dynamical imaging. We aim to further enhance imaging by using a 2 ω technique to eliminate artifact signals during the cyclic inversion of nuclear spins. The ultimate intent of these efforts is to perform magnetic resonance imaging of individual biological cells.

  15. NON-CONTRAST MAGNETIC RESONANCE UROGRAPHY

    Directory of Open Access Journals (Sweden)

    Arpita C

    2016-07-01

    Full Text Available BACKGROUND AND PURPOSE Magnetic Resonance (MR urography with its optimal contrast resolution and lack of ionizing radiation provides a comprehensive examination of the entire urinary tract noninvasively. MR urography is clinically useful in the evaluation of suspected urinary tract obstruction, haematuria, congenital anomalies, and surgically altered anatomy. It is particularly useful in cases of where there is contraindication of ionizing radiation and in paediatric and pregnant patients. The common MR urographic techniques are: Static-fluid MR urography and excretory MR urography. Static-fluid MR urography uses of heavily T2-weighted sequences to image the urinary tract as a static collection of fluid, can be repeated sequentially (Cine MR urography to better demonstrate the ureters in their entirety and to confirm the presence of fixed stenoses. Excretory MR urography is performed during the excretory phase of enhancement after the intravenous administration of gadolinium-based contrast material; thus, the patient must have sufficient renal function to allow the excretion. Static-fluid and excretory MR urography can be combined with conventional MR imaging for comprehensive evaluation of the urinary tract. The limitations are limited availability, high cost, relatively long examination time, low spatial resolution compared to IVU (Intravenous Urogram and CT Urography; sensitivity to motion (breathing and ureteral peristalsis inherent contraindications like patients with pacemakers, claustrophobia, and relative insensitivity for calcification and ureteric calculi. In this article, an attempt has been made to demonstrate the potential of static-fluid MRU to demonstrate a spectrum of urologic pathology involving the kidneys, ureters, and bladder while discussing the limitations. METHODS Thirty patients with urinary tract abnormalities were evaluated with MR urography performed between May 2014 to April 2016 using routine MR sequences and

  16. Filling defect artefacts in magnetic resonance urography

    Energy Technology Data Exchange (ETDEWEB)

    Girish, G.; Chooi, W.K.; Morcos, S.K. [Department of Diagnostic Imaging, Northern General Hospital, Sheffield Teaching Hospitals NHS Trust, S5 7AU, Sheffield (United Kingdom)

    2004-01-01

    The aim of this study was to determine the prevalence of filling defect artefacts (FDA) in magnetic resonance urography (MRU). Retrospectively, we assessed MRU examinations of 45 patients with neurogenic bladder dysfunction (21 men, 24 women; mean age 35 years, age range 18-71 years). The MRU was performed 30 min after intramuscular injection of 20 mg frusemide using heavily T2-weighted fast-spin-echo techniques [axial, thick coronal slab, coronal maximum intensity projection (MIP) images] with fat saturation. The images were reviewed by two observers to determine the presence of filling defects and dilatation of pelvicalyceal system and ureters. The filling defects were classified into central, eccentric and complete. Clinical course and plain films were reviewed to determine significance of the detected filling defects. True filling defects were observed in 5 patients (11%) and all due to stones seen on the plain radiograph of the abdomen. Filling defects artefacts (FDAs) were seen in 23 patients (51%; 17 pelvicalyceal system, 17 upper third of ureters, 7 mid ureters and 1 distal ureter). No stones were seen on the plain radiograph of these patients and they had a favourable clinical course for over 24 months. The true filling defects were large in size, eccentric in position and seen in more than one sequence of the MRU examination (axial, n=5; slab, n=5; and MIP, n=4). Four (80%) of the patients with true defects and 21 (91%) of those with FDAs had dilatation of the pelvicalyceal system and ureters. The FDAs were small in size, centrally placed (74%) and always seen in axial images, rarely in slab images (2 cases) and not seen in MIP images. Artefactual filling defects can be seen in MRU examinations. The cause of the FDAs is not fully explained and could be secondary to turbulent and fast flow of the urine. Some of the FDAs seen in the calyces could be due to the tips of the papillae. Awareness of such defects obviates misinterpretation and prevents

  17. Magnetic resonance imaging of pituitary adenoma

    Energy Technology Data Exchange (ETDEWEB)

    Handa, Yuji; Hayashi, Minoru; Kubota, Toshihiko; Satoh, Kazufumi; Kobayashi, Hidenori; Kawano, Hirokazu; Kabuto, Masanori; Okumura, Ryousuke

    1988-04-01

    The magnetic resonance (MR) images of eight patients with pituitary macroadenoma, confirmed by means of CT, were evaluated retrospectively. The examinations were performed with a 0.35 T MR system using short repetition (TR) (T/sub 1/-weighted) and long TR (T/sub 2/-weighted) spin-echo sequences. T/sub 1/-weighted images were obtained on coronal, sagittal, or axial planes with all patients, while T/sub 2/-weighted images were routinely obtained on the axial plane with all patients and on the sagittal or coronal plane in some cases. Detailed information as to the size, configuration, and anatomical relationship, particularly to the optic tract, of the pituitary adenoma were well visualized on sagittal or coronal T/sub 1/-weighted images. The signal intensities from the tumor on T/sub 1/-weighted of T/sub 2/-weighted images were evaluated as iso-, hypo- or hyper-intense with respect to the cortical gray matter. The signal intensities from three non-functioning pituitary adenomas varied from low- to high-intense on the T/sub 1/- or T/sub 2/-weighted images. All the two growth-hormone-producing adenomas showed iso-intense signal intensities on both T/sub 1/- and T/sub 2/-weighted images. One of the two prolactine-producing adenomas were iso-intense on a T/sub 1/-weighted image and low-intense on a T/sub 2/-weighted image, while the other adenoma, when treated with bromocriptine, was iso-intense on both T/sub 1/- and T/sub 2/-weighted images. One adenocorticotropic hormone-producing adenoma was iso-intense on T/sub 1/-weighted and high-intense on T/sub 2/-weighted images. Although the signal intensities on the images, particularly the T/sub 2/-weighted images, were variable, regardless of the type of adenoma, it is presumed that the MR signal arising from a pituitary adenoma affected by the biological or pathological state of the tumor cells.

  18. Tools and methods for teaching magnetic resonance concepts and techniques

    DEFF Research Database (Denmark)

    Hanson, L.G.

    2012-01-01

    Teaching of MRI methodology can be challenging for teachers as well as students. To support student learning, two graphical simulators for exploration of basic magnetic resonance principles are here introduced. The first implements a simple compass needle analogy implemented for day one of NMR...... and MRI education. After a few minutes of use, any user with minimal experience of magnetism will be able to explain the basic magnetic resonance principle. A second piece of software, the Bloch Simulator, aims much further, as it can be used to demonstrate and explore a wide range of phenomena including...

  19. An Evolutionary Algorithm for Enhanced Magnetic Resonance Imaging Classification

    OpenAIRE

    T.S. Murunya; S. Audithan

    2014-01-01

    This study presents an image classification method for retrieval of images from a multi-varied MRI database. With the development of sophisticated medical imaging technology which helps doctors in diagnosis, medical image databases contain a huge amount of digital images. Magnetic Resonance Imaging (MRI) is a widely used imaging technique which picks signals from a body's magnetic particles spinning to magnetic tune and through a computer converts scanned data into pictures of internal organs...

  20. Spin microscope based on optically detected magnetic resonance

    Science.gov (United States)

    Berman, Gennady P.; Chernobrod, Boris M.

    2007-12-11

    The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

  1. deductions from ground magnetic survey.

    African Journals Online (AJOL)

    2007-09-30

    Sep 30, 2007 ... are likely related to unexposed Younger Granite intrusions,. Keywords: Magnetic, regional field, upward continuation, structural boundaries,. Analytic. Introduction ..... for Rapid Digital. Aeromagnetic. Interpretation,. Geophysics,36, 891- 918. Kangkolo, R.' (1984): Interpretation of. Aeromagnetic Data Over a.

  2. Three-dimensional magnetic recording using ferromagnetic resonance

    Science.gov (United States)

    Suto, Hirofumi; Kudo, Kiwamu; Nagasawa, Tazumi; Kanao, Taro; Mizushima, Koichi; Sato, Rie

    2016-07-01

    To meet the ever-increasing demand for data storage, future magnetic recording devices will need to be made three-dimensional by implementing multilayer recording. In this article, we present methods of detecting and manipulating the magnetization direction of a specific layer selectively in a vertically stacked multilayer magnetic system, which enable layer-selective read and write operations in three-dimensional magnetic recording devices. The principle behind the methods is ferromagnetic resonance excitation in a microwave magnetic field. By designing each magnetic recording layer to have a different ferromagnetic resonance frequency, magnetization excitation can be induced individually in each layer by tuning the frequency of an applied microwave magnetic field, and this selective magnetization excitation can be utilized for the layer-selective operations. Regarding media for three-dimensional recording, when layers of a perpendicular magnetic material are vertically stacked, dipolar interaction between multiple recording layers arises and is expected to cause problems, such as degradation of thermal stability and switching field distribution. To solve these problems, we propose the use of an antiferromagnetically coupled structure consisting of hard and soft magnetic layers. Because the stray fields from these two layers cancel each other, antiferromagnetically coupled media can reduce the dipolar interaction.

  3. Chronic hepatosplenic schistosomiasis mansoni: magnetic resonance imaging and magnetic resonance angiography findings

    Energy Technology Data Exchange (ETDEWEB)

    Bezerra, A.S.; D' Ippolito, G.; Caldana, R.P.; Cecin, A.O.; Ahmed, M.; Szejnfeld, J. [Dept. of Diagnostic Imaging, Federal Univ. of Sao Paulo, Sao Paulo (Brazil)

    2007-02-15

    Purpose: To evaluate the hepatosplenic manifestations and the portal venous system in patients with chronic infection by Schistosoma mansoni. Material and Methods: A cross-sectional observational study was performed in 28 patients with chronic hepatosplenic schistosomiasis submitted to magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) of the abdomen. Images were interpreted independently by two radiologists to determine the reproducibility of image interpretation and who evaluated the presence of morphological alterations in the liver and spleen, such as hepatosplenomegaly, hepatic fissure widening, periportal fibrosis, and the presence of siderotic nodules. Interobserver and intra-observer agreement were measured with the kappa and intraclass correlation tests. Evaluation of venous collateral pathways and portal and splenic veins was done in consensus by both examiners. Results: Observers identified enlargement of the left lobe (78.5-92.8%) and caudate-to-right-lobe ratio (78.5-92.8%), irregularity of hepatic contours (89.2-96.4%), fissure widening (89.2-100%), and splenic siderotic nodules (84.2%). Splenomegaly, heterogeneity of hepatic parenchyma, peripheral hepatic vessels, and periportal fibrosis were observed in 100% of patients. MRI findings presented almost perfect interobserver (kappa 0.65-1) and intra-observer (kappa = 0.73-1 for observer 1, and kappa = 0.65-1 for observer 2) agreement for the variables analyzed. MRA showed the presence of collateral pathways in the majority of patients (71.4%) along with widening of portal and splenic veins. Conclusion: Using MRI, hepatosplenic alterations in schistosomiasis are characterized by heterogeneity of hepatic parenchyma, presence of peripheral perihepatic vessels, periportal fibrosis, splenomegaly, siderotic nodules, and the presence of venous collateral pathways.

  4. Magnetic resonance imaging use by primary care physicians.

    Science.gov (United States)

    Baldor, R A; Quirk, M E; Dohan, D

    1993-03-01

    Magnetic resonance imaging (MRI) has recently been introduced in the United States as an imaging technique for clinical use. Initially used by neurologists to view the brain stem, its indications have rapidly expanded to include spine, pelvis, bone marrow, and joints. This has raised concerns over the appropriate, cost-effective use of such an expensive technology. This paper examines MRI scanning patterns that have developed over time in central Massachusetts and surveys primary care knowledge, attitudes, and patterns of utilization. The two MRI centers in central Massachusetts were surveyed for information about the number and types of scans ordered and the specialties of the physicians who ordered the scans. Questionnaires were sent to primary care physicians in Worcester County to assess knowledge and attitudes about MRI and utilization. The data demonstrate changing patterns of MRI utilization over time. Orthopedics has been the specialty with the greatest increase in use, now slightly surpassing neurology in the total number of scans ordered. Primary care physician use has doubled over this same period. Not all primary care physicians utilize MRI, but those who have used the technology have familiarized themselves with its indications and problems and have a better knowledge about its costs. Utilization patterns of MRI have changed considerably in a short time, with primary care physicians requesting use of this new technology much more frequently than when it was first introduced.

  5. Comparison of nuclear electric resonance and nuclear magnetic resonance in integer and fractional quantum Hall states

    Directory of Open Access Journals (Sweden)

    Toru Tomimatsu

    2015-08-01

    Full Text Available Electric-field-induced nuclear resonance (NER: nuclear electric resonance involving quantum Hall states (QHSs was studied at various filling factors by exploiting changes in nuclear spins polarized at quantum Hall breakdown. Distinct from the magnetic dipole interaction in nuclear magnetic resonance, the interaction of the electric-field gradient with the electric quadrupole moment plays the dominant role in the NER mechanism. The magnitude of the NER signal strongly depends on whether electronic states are localized or extended. This indicates that NER is sensitive to the screening capability of the electric field associated with QHSs.

  6. Magnetic Resonance Imaging Studies of Postpartum Depression: An Overview

    Directory of Open Access Journals (Sweden)

    Marco Fiorelli

    2015-01-01

    Full Text Available Postpartum depression is a frequent and disabling condition whose pathophysiology is still unclear. In recent years, the study of the neural correlates of mental disorders has been increasingly approached using magnetic resonance techniques. In this review we synthesize the results from studies on postpartum depression in the context of structural, functional, and spectroscopic magnetic resonance studies of major depression as a whole. Compared to the relative wealth of data available for major depression, magnetic resonance studies of postpartum depression are limited in number and design. A systematic literature search yielded only eleven studies conducted on about one hundred mothers with postpartum depression overall. Brain magnetic resonance findings in postpartum depression appear to replicate those obtained in major depression, with minor deviations that are not sufficient to delineate a distinct neurobiological profile for this condition, due to the small samples used and the lack of direct comparisons with subjects with major depression. However, it seems reasonable to expect that studies conducted in larger populations, and using a larger variety of brain magnetic resonance techniques than has been done so far, might allow for the identification of neuroimaging signatures for postpartum depression.

  7. Magnetic resonance imaging in the evaluation of periosteal reactions

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira-Barbosa, Marcello Henrique; Trad, Clovis Simao; Muglia, Valdair Francisco; Elias Junior, Jorge; Simao, Marcelo Novelino, E-mail: marcello@fmrp.usp.b [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Centro de Ciencias das Imagens e Fisica Medica; Sa, Jose Luiz de [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Hospital das Clinicas; Oliveira, Rodrigo Cecilio Vieira de [Clinica de Diagnostico por Imagem Tomoson, Aracatuba, SP (Brazil); Engel, Edgard Eduard [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Dept. de Biomecanica, Medicina e Reabilitacao do Aparelho Locomotor

    2010-07-15

    The objective of the present essay was to encourage a careful evaluation of periosteal reactions on magnetic resonance images. The initial approach to bone lesions is made by conventional radiography and, based on the imaging findings, periosteal reactions are classified into classical subtypes. Although magnetic resonance imaging is considered as the gold standard for local staging of bone tumors, the utilization of such method in the study of periosteal reactions related to focal bone lesions has been poorly emphasized, with relatively few studies approaching this subject. The literature review revealed a study describing an experimental animal model of osteomyelitis suggesting that magnetic resonance imaging is superior to other imaging methods in the early identification of periosteal reactions. Another study has suggested a good correlation between conventional radiography and magnetic resonance imaging in the identification and classification of periosteal reactions in cases of osteosarcoma. The present essay illustrates cases of periosteal reactions observed at magnetic resonance imaging in correlation with findings of conventional radiography or other imaging methods. (author)

  8. Magnetic Resonance Imaging Studies of Postpartum Depression: An Overview.

    Science.gov (United States)

    Fiorelli, Marco; Aceti, Franca; Marini, Isabella; Giacchetti, Nicoletta; Macci, Enrica; Tinelli, Emanuele; Calistri, Valentina; Meuti, Valentina; Caramia, Francesca; Biondi, Massimo

    2015-01-01

    Postpartum depression is a frequent and disabling condition whose pathophysiology is still unclear. In recent years, the study of the neural correlates of mental disorders has been increasingly approached using magnetic resonance techniques. In this review we synthesize the results from studies on postpartum depression in the context of structural, functional, and spectroscopic magnetic resonance studies of major depression as a whole. Compared to the relative wealth of data available for major depression, magnetic resonance studies of postpartum depression are limited in number and design. A systematic literature search yielded only eleven studies conducted on about one hundred mothers with postpartum depression overall. Brain magnetic resonance findings in postpartum depression appear to replicate those obtained in major depression, with minor deviations that are not sufficient to delineate a distinct neurobiological profile for this condition, due to the small samples used and the lack of direct comparisons with subjects with major depression. However, it seems reasonable to expect that studies conducted in larger populations, and using a larger variety of brain magnetic resonance techniques than has been done so far, might allow for the identification of neuroimaging signatures for postpartum depression.

  9. Dynamic magnetic susceptibility and electrical detection of ferromagnetic resonance

    Science.gov (United States)

    Zhang, Yin; Wang, X. S.; Yuan, H. Y.; Kang, S. S.; Zhang, H. W.; Wang, X. R.

    2017-03-01

    The dynamic magnetic susceptibility of magnetic materials near ferromagnetic resonance (FMR) is very important in interpreting the dc voltage obtained in its electrical detection. Based on the causality principle and the assumption that the usual microwave absorption lineshape of a homogeneous magnetic material around FMR is Lorentzian, the general forms of the dynamic magnetic susceptibility of an arbitrary sample and the corresponding dc voltage lineshapes of its electrical detection were obtained. Our main findings are as follows. (1) The dynamic magnetic susceptibility is not a Polder tensor for a material with an arbitrary magnetic anisotropy. The two off-diagonal matrix elements of the tensor near FMR are not, in general, opposite to each other. However, the linear response coefficient of the magnetization to the total radio frequency (rf) field (the sum of the external and internal rf fields due to precessing magnetization is a quantity which cannot be measured directly) is a Polder tensor. This may explain why the two off-diagonal susceptibility matrix elements were always wrongly assumed to be opposite to each other in almost all analyses. (2) The frequency dependence of dynamic magnetic susceptibility near FMR is fully characterized by six real numbers, while its field dependence is fully characterized by seven real numbers. (3) A recipe of how to determine these numbers by standard microwave absorption measurements for a sample with an arbitrary magnetic anisotropy is proposed. Our results allow one to unambiguously separate the contribution of the anisotropic magnetoresistance to the dc voltage signals from the anomalous Hall effect. With these results, one can reliably extract the information of spin pumping and the inverse spin-Hall effect, and determine the spin-Hall angle. (4) In the case that resonance frequency is not sensitive to the applied static magnetic field, the field dependence of the matrix elements of dynamic magnetic susceptibility, as

  10. Non-resonant magnetic braking on JET and TEXTOR

    DEFF Research Database (Denmark)

    Sun, Y.; Liang, Y.; Shaing, K.C.

    2012-01-01

    The non-resonant magnetic braking effect induced by a non-axisymmetric magnetic perturbation is investigated on JET and TEXTOR. The collisionality dependence of the torque induced by the n = 1, where n is the toroidal mode number, magnetic perturbation generated by the error field correction coils...... in the 1/ν regime. The strongest NTV torque on JET is also located near the plasma core. The magnitude of the NTV torque strongly depends on the plasma response, which is also discussed in this paper. There is no obvious braking effect with n = 2 magnetic perturbation generated by the dynamic ergodic...

  11. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... known, MRA. MRA is a noninvasive test that uses a powerful magnetic field and a computer to ... About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2017 Radiological Society of ...

  12. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... an MRA scan, there are several things you can do to prepare for the examination. First of ... medical devices implanted in your body as these can interfere with the magnetic field of the MRI ...

  13. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... Transcript Welcome to Radiology Info dot org Hello, I’m Dr. Elliot Fishman, a radiologist at Johns Hopkins Hospital in Baltimore, Maryland. I’d like to talk with you about magnetic ...

  14. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... it’s commonly known, MRA. MRA is a noninvasive test that uses a powerful magnetic field and a computer to produce detailed pictures of the major blood vessels throughout your body. It may be performed ...

  15. Imaging using long range dipolar field effects Nuclear magnetic resonance

    CERN Document Server

    Gutteridge, S

    2002-01-01

    The work in this thesis has been undertaken by the except where indicated in reference, within the Magnetic Resonance Centre, at the University of Nottingham during the period from October 1998 to March 2001. This thesis details the different characteristics of the long range dipolar field and its application to magnetic resonance imaging. The long range dipolar field is usually neglected in nuclear magnetic resonance experiments, as molecular tumbling decouples its effect at short distances. However, in highly polarised samples residual long range components have a significant effect on the evolution of the magnetisation, giving rise to multiple spin echoes and unexpected quantum coherences. Three applications utilising these dipolar field effects are documented in this thesis. The first demonstrates the spatial sensitivity of the signal generated via dipolar field effects in structured liquid state samples. The second utilises the signal produced by the dipolar field to create proton spin density maps. Thes...

  16. Silicon nanoparticles as hyperpolarized magnetic resonance imaging agents.

    Science.gov (United States)

    Aptekar, Jacob W; Cassidy, Maja C; Johnson, Alexander C; Barton, Robert A; Lee, Menyoung; Ogier, Alexander C; Vo, Chinh; Anahtar, Melis N; Ren, Yin; Bhatia, Sangeeta N; Ramanathan, Chandrasekhar; Cory, David G; Hill, Alison L; Mair, Ross W; Rosen, Matthew S; Walsworth, Ronald L; Marcus, Charles M

    2009-12-22

    Magnetic resonance imaging of hyperpolarized nuclei provides high image contrast with little or no background signal. To date, in vivo applications of prehyperpolarized materials have been limited by relatively short nuclear spin relaxation times. Here, we investigate silicon nanoparticles as a new type of hyperpolarized magnetic resonance imaging agent. Nuclear spin relaxation times for a variety of Si nanoparticles are found to be remarkably long, ranging from many minutes to hours at room temperature, allowing hyperpolarized nanoparticles to be transported, administered, and imaged on practical time scales. Additionally, we demonstrate that Si nanoparticles can be surface functionalized using techniques common to other biologically targeted nanoparticle systems. These results suggest that Si nanoparticles can be used as a targetable, hyperpolarized magnetic resonance imaging agent with a large range of potential applications.

  17. Magnetic resonance spectroscopy and imaging for the study of fossils.

    Science.gov (United States)

    Giovannetti, Giulio; Guerrini, Andrea; Salvadori, Piero A

    2016-07-01

    Computed tomography (CT) has long been used for investigating palaeontological specimens, as it is a nondestructive technique which avoids the need to dissolve or ionize the fossil sample. However, magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) have recently gained ground as analytical tools for examination of palaeontological samples, by nondestructively providing information about the structure and composition of fossils. While MRI techniques are able to reveal the three-dimensional geometry of the trace fossil, MRS can provide information on the chemical composition of the samples. The multidimensional nature of MR (magnetic resonance) signals has potential to provide rich three-dimensional data on the palaeontological specimens and also to help in elucidating paleopathological and paleoecological questions. In this work the verified applications and the emerging uses of MRI and MRS in paleontology are reviewed, with particular attention to fossil spores, fossil plants, ambers, fossil invertebrates, and fossil vertebrate studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Magnetic resonance neurography for the identification of pudendal neuralgia

    Directory of Open Access Journals (Sweden)

    Claudia P. Cejas

    2017-06-01

    Full Text Available The pudendal nerve entrapment is an entity understudied by diagnosis imaging. Various causes are recognized in relation to difficult labors, rectal, perineal, urological and gynecological surgery, pelvic trauma fracture, bones tumors and compression by tumors or pelvic pseudotumors. Pudendal neuropathy should be clinically suspected, and confirmed by different methods such as electrofisiological testing: evoked potentials, terminal motor latency test and electromyogram, neuronal block and magnetic resonance imaging. The radiologist should be acquainted with the complex anatomy of the pelvic floor, particularly on the path of pudendal nerve studied by magnetic resonance imaging. High resolution magnetic resonance neurography should be used as a complementary diagnostic study along with clinical and electrophysiological examinations in patients with suspected pudendal nerve neuralgia.

  19. Renal relevant radiology: renal functional magnetic resonance imaging.

    Science.gov (United States)

    Ebrahimi, Behzad; Textor, Stephen C; Lerman, Lilach O

    2014-02-01

    Because of its noninvasive nature and provision of quantitative measures of a wide variety of physiologic parameters, functional magnetic resonance imaging (MRI) shows great potential for research and clinical applications. Over the past decade, application of functional MRI extended beyond detection of cerebral activity, and techniques for abdominal functional MRI evolved. Assessment of renal perfusion, glomerular filtration, interstitial diffusion, and parenchymal oxygenation turned this modality into an essential research and potentially diagnostic tool. Variations in many renal physiologic markers can be detected using functional MRI before morphologic changes become evident in anatomic magnetic resonance images. Moreover, the framework of functional MRI opened a window of opportunity to develop novel pathophysiologic markers. This article reviews applications of some well validated functional MRI techniques, including perfusion, diffusion-weighted imaging, and blood oxygen level-dependent MRI, as well as some emerging new techniques such as magnetic resonance elastography, which might evolve into clinically useful tools.

  20. On-wafer magnetic resonance of magnetite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Little, Charles A.E., E-mail: caelittle@gmail.com; Russek, Stephen E., E-mail: stephen.russek@nist.gov; Booth, James C., E-mail: james.booth@nist.gov; Kabos, Pavel, E-mail: pavel.kabos@nist.gov; Usselman, Robert J., E-mail: robertusselman@gmail.com

    2015-11-01

    Magnetic resonance measurements of ferumoxytol and TEMPO were made using an on-wafer transmission line technique with a vector network analyzer, allowing for broadband measurements of small sample volumes (4 nL) and small numbers of spins (1 nmol). On-wafer resonance measurements were compared with standard single-frequency cavity-based electron paramagnetic resonance (EPR) measurements using a new power conservation approach and the results show similar line shape. On-wafer magnetic resonance measurements using integrated microfluidics and microwave technology can significantly reduce the cost and sample volumes required for EPR spectral analysis and allow for integration of EPR with existing lab-on-a-chip processing and characterization techniques for point-of-care medical diagnostic applications. - Highlights: • On-wafer measurements showed similar line shape to traditional cavity-based EPR. • New power conservation approach alleviates de-embedding ambiguities. • Allows for measurements of small sample volumes and small number of spins.

  1. Novel Magnetic Resonance Imaging Findings in Children With Intracranial Hypertension.

    Science.gov (United States)

    Hirfanoglu, Tugba; Aydin, Kursad; Serdaroglu, Ayse; Havali, Cengiz

    2015-08-01

    Increased intracranial hypertension is defined as elevated intracranial pressure with absence of hydrocephalus, vascular or structural abnormalities, and normal cerebrospinal fluid content. Magnetic resonance imaging abnormalities of the optic nerve and sheath that have been described in adults include increased nerve tortuosity, flattening in posterior aspect of globe, intraocular protrusion of the optic nerve, and enlarged optic nerve sheath. We evaluated accuracy of those proposed markers on magnetic resonance imaging in children with increased intracranial hypertension that are described in adults. Eleven patients between 3 and 15 years of age with intracranial hypertension were selected for re-evaluation of magnetic resonance imaging that had been previously described as normal to determine the presence of: (1) increased tortuosity and elongation of the optic nerve; (2) enlargement of the optic nerve sheath on axial and coronal T2 so called by us "target sign" and postcontrast T1 sequences; (3) flattening in posterior aspect of the globe; and (4) intraocular protrusion of the optic nerve head. Of the 11 patients, tortuosity of the optic nerve (10/11, 90.9%) and enlarged optic nerve sheath--target sign (7/11, 63.6%)--were the most common findings. Flattening in the posterior aspect of globe (5/11, 45.5%) and intraocular protrusion (3/11, 27.3%) were also detected as a novel magnetic resonance imaging findings. Magnetic resonance imaging findings of the optic nerve and sheath include valuable signs of intracranial hypertension not only in adults but also in children. This is the first detailed analysis of the magnetic resonance imaging findings in children with increased intracranial hypertension. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Solid-state magnetometer using electrically detected magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Jander, A., E-mail: jander@eecs.oregonstate.ed [Oregon State University, Corvallis, OR 97331 (United States); Dhagat, P. [Oregon State University, Corvallis, OR 97331 (United States)

    2010-05-15

    A silicon-based magnetometer utilizing spin-dependent recombination to electrically detect electron spin resonance is described. Electronic tracking of the resonant frequency provides an absolute, calibration-free measure of the magnetic field. The magnetometer can potentially be implemented entirely in conventional complementary metal-oxide-semiconductor (CMOS) integrated circuit technology. Based on published results for spin-dependent recombination in semiconductor diodes, an estimate of the achievable sensitivity and power consumption of an integrated magnetometer is derived.

  3. Coplanar photonic bandgap resonators for low temperature electron and nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Sigillito, A. J.; Tyryshkin, A. M.; Lyon, S. A.

    In recent years, superconducting coplanar waveguide (CPW) resonators have become a useful tool for low temperature pulsed electron spin resonance (ESR), even at dilution refrigerator temperatures. Their small mode volumes make CPW resonators particularly well suited to measuring small numbers of spins near the resonator surface, since in this region the spin sensitivity is very high. While these resonators have proven useful for ESR at single microwave frequencies, it is difficult to also manipulate nuclear spins in electron-nuclear-double resonance (ENDOR) experiments, since manipulation of nuclear spins requires radio frequency (RF) magnetic fields. Ideally one would simply generate these fields by passing RF currents through the CPW, but because conventional CPW resonators are capacitively coupled, they will not transmit low-frequency RF currents. In this talk, we discuss the use of one dimensional photonic bandgap (PBG) resonators to overcome this challenge. PBG resonators are a promising alternative to conventional CPW resonators since they offer high quality factors at microwave frequencies, while simultaneously allowing transmission of nonresonant RF currents below the photonic bandgap. Here, we will discuss PBG resonator designs and present data showing their use for low temperature ESR of donors in 28Si. Initial ENDOR results will also be presented.

  4. Advanced magnetic resonance imaging techniques for patients with hemifacial spasm.

    Science.gov (United States)

    Port, John D

    2002-01-01

    To review the underlying causes, diagnostic issues, and treatment of hemifacial spasm, with emphasis on advanced MRI techniques. Brief technical note. High-resolution T1- and T2-weighted spin-echo and/or gradient echo imaging of the posterior fossa should be performed with the use of intravenous gadolinium for maximum contrast between CSF, vessel, and nerve. Magnetic resonance angiography is often useful, and new state-of-the-art sequences provide more detail. As MRI techniques improve, diagnosis and treatment of patients with hemifacial spasm will become easier. Ophthalmologists should be aware of these new magnetic resonance techniques.

  5. Unusual Presentation of Popliteal Cyst on Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Ohishi

    2016-01-01

    Full Text Available Popliteal cyst commonly presents as an ellipsoid mass with uniform low signal intensity on T1-weighted magnetic resonance images and high signal intensity on T2-weighted images. Here, we describe a popliteal cyst with unusual appearance on magnetic resonance imaging, including heterogeneous intermediate signal intensity on T2-weighted images. Arthroscopic cyst decompression revealed that the cyst was filled with necrotic synovial villi, indicative of rheumatoid arthritis. Arthroscopic enlargement of unidirectional valvular slits with synovectomy was useful for the final diagnosis and treatment.

  6. Magnetic Resonance Spectroscopy of siRNA-Based Cancer Therapy.

    Science.gov (United States)

    Penet, Marie-France; Chen, Zhihang; Mori, Noriko; Krishnamachary, Balaji; Bhujwalla, Zaver M

    2016-01-01

    Small interfering RNA (siRNA) is routinely used as a biological tool to silence specific genes, and is under active investigation in cancer treatment strategies. Noninvasive magnetic resonance spectroscopy (MRS) provides the ability to assess the functional effects of siRNA-mediated gene silencing in cultured cancer cells, and following nanoparticle-based delivery in tumors in vivo. Here we describe the use of siRNA to downregulate choline kinase, a critical enzyme in choline phospholipid metabolism of cancer cells and tumors, and the use of (1)H MRS of cells and (1)H magnetic resonance spectroscopic imaging (MRSI) of tumors to assess the efficacy of the downregulation.

  7. Development of magnetic resonance technology for noninvasive boron quantification

    Energy Technology Data Exchange (ETDEWEB)

    Bradshaw, K.M.

    1990-11-01

    Boron magnetic resonance imaging (MRI) and spectroscopy (MRS) were developed in support of the noninvasive boron quantification task of the Idaho National Engineering Laboratory (INEL) Power Burst Facility/Boron Neutron Capture Therapy (PBF/BNCT) program. The hardware and software described in this report are modifications specific to a GE Signa{trademark} MRI system, release 3.X and are necessary for boron magnetic resonance operation. The technology developed in this task has been applied to obtaining animal pharmacokinetic data of boron compounds (drug time response) and the in-vivo localization of boron in animal tissue noninvasively. 9 refs., 21 figs.

  8. Electrical resistivity tomography and magnetic surveys: applications ...

    African Journals Online (AJOL)

    A study aimed at evaluating the competence of the near surface formations as foundation materials has been undertaken at the site of the newly established Wolkite University Campus. Integrated geophysical surveys involving 2D Electrical Resistivity Tomography (ert), Vertical Electrical Sounding (ves) and magnetic ...

  9. Research on Wireless Power Transfer System via Magnetically Coupled Resonance

    Directory of Open Access Journals (Sweden)

    ZHU Meng

    2017-04-01

    Full Text Available In order to extend the transmission distance and improve the transmission efficiency of the traditional wireless power transmission(WPTsystem composed with the transmitting and receiving coil resonators based on magnetic resonance coupling,we proposed an effective method to add a magnetic core between repeating coil and receiving coil based on the single repeating three coils mode. This paper deduced a mathematical expression of the transmission efficiency,and built a model by the circuit theory,and also simulated the transmission system added with the magnetic core between repeating and receiving coil. Then we selected the flat magnetic core for test. At last,we verified the feasibility of the proposal by actual experiment.

  10. Magnetic resonance imaging without field cycling at less than earth's magnetic field

    Science.gov (United States)

    Lee, Seong-Joo; Shim, Jeong Hyun; Kim, Kiwoong; Yu, Kwon Kyu; Hwang, Seong-min

    2015-03-01

    A strong pre-polarization field, usually tenths of a milli-tesla in magnitude, is used to increase the signal-to-noise ratio in ordinary superconducting quantum interference device-based nuclear magnetic resonance/magnetic resonance imaging experiments. Here, we introduce an experimental approach using two techniques to remove the need for the pre-polarization field. A dynamic nuclear polarization (DNP) technique enables us to measure an enhanced resonance signal. In combination with a π / 2 pulse to avoid the Bloch-Siegert effect in a micro-tesla field, we obtained an enhanced magnetic resonance image by using DNP technique with a 34.5 μT static external magnetic field without field cycling. In this approach, the problems of eddy current and flux trapping in the superconducting pickup coil, both due to the strong pre-polarization field, become negligible.

  11. Magnetic resonance imaging without field cycling at less than earth's magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seong-Joo, E-mail: sj.lee@kriss.re.kr; Shim, Jeong Hyun; Kim, Kiwoong; Yu, Kwon Kyu; Hwang, Seong-min [Center for Biosignals, Korea Research Institute of Standards and Science (KRISS), 267 Gajeong-ro, Yuseong-gu, Daejeon 305-340 (Korea, Republic of)

    2015-03-09

    A strong pre-polarization field, usually tenths of a milli-tesla in magnitude, is used to increase the signal-to-noise ratio in ordinary superconducting quantum interference device-based nuclear magnetic resonance/magnetic resonance imaging experiments. Here, we introduce an experimental approach using two techniques to remove the need for the pre-polarization field. A dynamic nuclear polarization (DNP) technique enables us to measure an enhanced resonance signal. In combination with a π/2 pulse to avoid the Bloch-Siegert effect in a micro-tesla field, we obtained an enhanced magnetic resonance image by using DNP technique with a 34.5 μT static external magnetic field without field cycling. In this approach, the problems of eddy current and flux trapping in the superconducting pickup coil, both due to the strong pre-polarization field, become negligible.

  12. Resonant tunnel magnetoresistance in a double magnetic tunnel junction

    KAUST Repository

    Useinov, Arthur

    2011-08-09

    We present quasi-classical approach to calculate a spin-dependent current and tunnel magnetoresistance (TMR) in double magnetic tunnel junctions (DMTJ) FML/I/FMW/I/FMR, where the magnetization of the middle ferromagnetic metal layer FMW can be aligned parallel or antiparallel with respect to the fixed magnetizations of the left FML and right FMR ferromagnetic electrodes. The transmission coefficients for components of the spin-dependent current, and TMR are calculated as a function of the applied voltage. As a result, we found a high resonant TMR. Thus, DMTJ can serve as highly effective magnetic nanosensor for biological applications, or as magnetic memory cells by switching the magnetization of the inner ferromagnetic layer FMW.© Springer Science+Business Media, LLC 2011.

  13. Complications after liver transplantation: evaluation with magnetic resonance imaging, magnetic resonance cholangiography, and 3-dimensional contrast-enhanced magnetic resonance angiography in a single session

    Energy Technology Data Exchange (ETDEWEB)

    Boraschi, P.; Donati, F.; Gigoni, R. [Pisa Univ. Hospital, Second Dept. of Radiology, Pisa (Italy)], E-mail: p.boraschi@do.med.unipi.it; Salemi, S. [Univ. of Pisa, Diagnostic and Interventional Radiology, Pisa (Italy); Urbani, L.; Filipponi, F. [Univ. of Pisa, Liver Transplant Unit of the Dept. of Oncology, Transplants and Advanced Technologies in Medicine, Pisa (Italy); Falaschi, F. [Pisa Univ. Hospital, Second Dept. of Radiology, Pisa (Italy); Bartolozzi, C. [Univ. of Pisa, Diagnostic and Interventional Radiology, Pisa (Italy)

    2008-12-15

    To evaluate a comprehensive magnetic resonance imaging (MRI) protocol as noninvasive diagnostic modality for simultaneous detection of parenchymal, biliary, and vascular complications after liver transplantation. Fifty-two liver transplant recipients suspected to have parenchymal, biliary, and (or) vascular complications underwent our MRI protocol at 1.5T unit using a phased array coil. After preliminary acquisition of axial T{sub 1}w and T{sub 2}w sequences, magnetic resonance cholangiography (MRC) was performed through a breath-hold, thin- and thick-slab, single-shot T{sub 2}w sequence in the coronal plane. Contrast-enhanced magnetic resonance angiography (CEMRA) was obtained using a 3-dimensional coronal spoiled gradient-echo sequence, which enabled acquisition of 32 partitions 2.0 mm thick. A fixed dose of 20 ml gadobenate dimeglumine was administered at 2 mL/s. A post-contrast T{sub 1}w sequence was also performed. Two observers in conference reviewed source images and 3-dimensional reconstructions to determine the presence of parenchymal, biliary, and vascular complications. MRI findings were correlated with surgery, endoscopic retrograde cholangiography (ERC), biopsy, digital subtraction angiography (DSA), and imaging follow-up. MRI revealed abnormal findings in 32 out of 52 patients (61%), including biliary complications (anastomotic and nonanastomotic strictures, and lithiasis) in 31, vascular disease (hepatic artery stenosis and thrombosis) in 9, and evidence of hepatic abscess and hematoma in 2. ERC confirmed findings of MRC in 30 cases, but suggested disease underestimation in 2. DSA confirmed 7 magnetic resonance angiogram (MRA) findings, but suggested disease overestimation in 2. MRI combined with MRC and CEMRA can provide a comprehensive assessment of parenchymal, biliary, and vascular complications in most recipients of liver transplantation. (author)

  14. Quadrupole shift of nuclear magnetic resonance of donors in silicon at low magnetic field

    Science.gov (United States)

    Mortemousque, P. A.; Rosenius, S.; Pica, G.; Franke, D. P.; Sekiguchi, T.; Truong, A.; Vlasenko, M. P.; Vlasenko, L. S.; Brandt, M. S.; Elliman, R. G.; Itoh, K. M.

    2016-12-01

    Shifts from the expected nuclear magnetic resonance frequencies of antimony and bismuth donors in silicon of greater than a megahertz are observed in electrically detected magnetic resonance spectra. Defects created by ion implantation of the donors are discussed as the source of effective electric field gradients generating these shifts via quadrupole interaction with the nuclear spins. The experimental results are modeled quantitatively by molecular orbital theory for a coupled pair consisting of a donor and a spin-dependent recombination readout center.

  15. Quadrupole Shift of Nuclear Magnetic Resonance of Donors in Silicon at Low Magnetic Field

    OpenAIRE

    Mortemousque, P. A.; Rosenius, S.; Pica, G.; Franke, D. P.; Sekiguchi, T.; Truong, A.; Vlasenko, M. P.; Vlasenko, L.S.; Brandt, M. S.; Elliman, R. G.; Itoh, K. M.

    2015-01-01

    Shifts from the expected nuclear magnetic resonance frequencies of antimony and bismuth donors in silicon of greater than a megahertz are observed in electrically detected magnetic resonance spectra. Defects created by ion implantation of the donors are discussed as the source of effective electric field gradients generating these shifts via quadrupole interaction with the nuclear spins. The experimental results are modeled quantitatively by molecular orbital theory for a coupled pair consist...

  16. Your Radiologist Explains Magnetic Resonance Angiography (MRA)

    Medline Plus

    Full Text Available ... is a noninvasive test that uses a powerful magnetic field and a computer to produce detailed pictures of the major blood vessels throughout your body. It may be performed with or without contrast material which, if needed, will be injected into a ...

  17. Underground application of magnetic resonance soundings

    CSIR Research Space (South Africa)

    Greben, JM

    2011-10-01

    Full Text Available operations. In the usual surface based measurements, with horizontal loop and water layer, the geometry of the problem can be summarized by the value of the inclination of the Earth magnetic field. For MRS measurements under the geometric conditions...

  18. RESONANCE

    Indian Academy of Sciences (India)

    Nuclear magnetic resonance (NMR) is a mani- festation of an intrinsic property of the nucleus, i.e. nuclear spin angular momen- tum. Spin angular momentum gives rise to magnetic moments. Thus, nuclei that pos- sess net magnetic moments behave like very small bar magnets. NMR spectroscopy in- volves the study of the ...

  19. Parametric Resonance of Magnetization Excited by Electric Field.

    Science.gov (United States)

    Chen, Yu-Jin; Lee, Han Kyu; Verba, Roman; Katine, Jordan A; Barsukov, Igor; Tiberkevich, Vasil; Xiao, John Q; Slavin, Andrei N; Krivorotov, Ilya N

    2017-01-11

    Manipulation of magnetization by electric field is a central goal of spintronics because it enables energy-efficient operation of spin-based devices. Spin wave devices are promising candidates for low-power information processing, but a method for energy-efficient excitation of short-wavelength spin waves has been lacking. Here we show that spin waves in nanoscale magnetic tunnel junctions can be generated via parametric resonance induced by electric field. Parametric excitation of magnetization is a versatile method of short-wavelength spin wave generation, and thus, our results pave the way toward energy-efficient nanomagnonic devices.

  20. Calix[4]arenes as Molecular Platforms in Magnetic Resonance Imaging

    NARCIS (Netherlands)

    Schühle, D.T.

    2009-01-01

    Magnetic resonance imaging (MRI) is an important tool in medical diagnosis. It uses non-ionizing radio-frequency radiation and produces images with excellent resolution. To increase the contrast, Gd(III)-containing compounds are applied leading to a brightening of the area of interest. The

  1. The role of diffusion weighted magnetic resonance imaging in ...

    African Journals Online (AJOL)

    Shaimaa R.A. Fadeel

    2015-06-16

    Jun 16, 2015 ... etal lobes toward the frontal and temporal lobes. Sensory fibers myelinate before motor fibers, and projection pathways earlier than association pathways; sensitive, visual, and audi- tory tracts are already myelinated at birth.3. Diffusion magnetic resonance imaging (DWI) studies the diffusivity of water, i.e. ...

  2. Magnetic resonance imaging in HTLV-I associated myelopathy

    Directory of Open Access Journals (Sweden)

    Aílton Melo

    1993-09-01

    Full Text Available Magnetic resonance imaging of the brain and spinal cord were carried out for seventeen consecutive patients with HTLV-1 associated myelopathy (HAM. Eight patients had brain abnormalities and four had decreased thoracic spinal cord diameter. Brain lesions were mostly located in subcortical and periventricular areas. Our data suggest that diffuse central nervous system lesions are present in patients with HAM.

  3. Magnetic resonance microscopy of iron transport in methanogenic granules

    NARCIS (Netherlands)

    Bartacek, J.; Vergeldt, F.J.; Gerkema, E.; Jenicek, P.; Lens, P.; As, van H.

    2009-01-01

    Interactions between anaerobic biofilms and heavy metals such as iron, cobalt or nickel are largely unknown. Magnetic resonance imaging (MRI) is a non-invasive method that allows in situ studies of metal transport within biofilm matrixes. The present study investigates quantitatively the penetration

  4. Magnetic resonance imaging of vessel wall morphology and function

    NARCIS (Netherlands)

    Kröner, Eleanore Sophie Jeanine

    2015-01-01

    This thesis evaluates morphological and functional vessel wall properties measured by magnetic resonance imaging techniques in healthy volunteers and patients with various diseases (i.e. Marfan syndrome patients (MFS), patients with thoracic aortic aneurysm and patients with a previous myocardial

  5. Clinically relevant magnetic resonance imaging (MRI) findings in ...

    African Journals Online (AJOL)

    Background: Shoulder pain is the most common and well-documented site of musculoskeletal pain in elite swimmers. Structural abnormalities on magnetic resonance imaging (MRI) of elite swimmers' symptomatic shoulders are common. Little has been documented about the association between MRI findings in the ...

  6. The role of Magnetic Resonance Imaging and Visual Evoked ...

    African Journals Online (AJOL)

    Introduction: To report our experience in management of patients with optic neuritis. The effects of brain magnetic resonance imaging and visual evoked potential on management were investigated. Methods: This is a four years clinical trial that included patients presenting with first attack of optic neuritis older than 16 years ...

  7. Magnetic resonance imaging of peripheral joints in rheumatic diseases

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Duer, Anne; Møller, Uffe

    2004-01-01

    The need for better methods than the conventional clinical, biochemical and radiographical examinations in the management of inflammatory joint diseases is evident, since these methods are not sensitive or specific to early pathologies and subtle changes. Magnetic resonance imaging (MRI) offers...

  8. Impact of magnetic resonance urography and ultrasonography on ...

    African Journals Online (AJOL)

    Impact of magnetic resonance urography and ultrasonography on diagnosis and management of hydronephrosis and megaureter in paediatric patients. ... Diagnosis was established in all patients by multimodulary imaging work-up including micturating cysto-urethrography, MAG3 renography, US and MRU and could be ...

  9. Magnetic resonance in hematological diseases. Imaging of bone marrow

    DEFF Research Database (Denmark)

    Jensen, K.E.

    1995-01-01

    Magnetic resonance imaging (MRI) is a highly sensitive alternative to plain radiography, CT, and radionuclide studies for the imaging of normal and abnormal bone marrow. The cellularity and the corresponding fat/water ratio within the bone marrow show clear changes in haematological diseases...

  10. Evaluation of right ventricular volumes measured by magnetic resonance imaging

    DEFF Research Database (Denmark)

    Møgelvang, J; Stubgaard, M; Thomsen, C

    1988-01-01

    Right ventricular volumes were determined in 12 patients with different levels of right and left ventricular function by magnetic resonance imaging (MRI) using an ECG gated multisection technique in planes perpendicular to the diastolic position of the interventricular septum. Right ventricular...

  11. Static fluid magnetic resonance urography in evaluation of ureteral ...

    African Journals Online (AJOL)

    Introduction: Ectopic ureters are often very difficult to diagnose with conventional imaging modalities especially in children. Magnetic resonance urography (MRU) has been recently investigated as a problem-solving tool for the evaluation of various congenital urogenital anomalies with favorable results. Aim of the work: To ...

  12. Anatomical and magnetic resonance imaging study of the medial ...

    African Journals Online (AJOL)

    Sally Mahmood Mohamed Hussin Omar

    2015-07-10

    Jul 10, 2015 ... Anatomical and magnetic resonance imaging study of the medial collateral ligament of the ankle joint. Sally Mahmood Mohamed Hussin Omar a. , Fardos Ahmed El-Kalaa a. ,. El Sebai Farag Ali b. , Ali Ali Abd El-Karim c. , Nancy Mohamed El Sekily d,. * a Department of Anatomy and Embryology, Faculty of ...

  13. Monitoring of abdominal Staphylococcus aureus infection using magnetic resonance imaging

    DEFF Research Database (Denmark)

    Kromrey, M L; Göhler, A; Friedrich, N

    2017-01-01

    To establish a routine workflow for in vivo magnetic resonance imaging (MRI) of mice infected with bacterial biosafety level 2 pathogens and to generate a mouse model for systemic infection with Staphylococcus aureus suitable for monitoring by MRI. A self-contained acrylic glass animal bed...

  14. Magnetic resonance imaging in rheumatoid arthritis advances and research priorities

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; McQueen, FM; Bird, P

    2005-01-01

    Magnetic resonance imaging (MRI) has now been used extensively in cross-sectional and observational studies as well as in controlled clinical trials to assess disease activity and joint damage in rheumatoid arthritis (RA). MRI measurements or scores for erosions, bone edema, and synovitis have been...

  15. Functional magnetic resonance imaging of the primary motor cortex ...

    Indian Academy of Sciences (India)

    Functional magnetic resonance imaging (fMRI) studies have been performed on 20 right handed volunteers at 1.5 Tesla using echo planar imaging (EPI) protocol. Index finger tapping invoked localized activation in the primary motor area. Consistent and highly reproducible activation in the primary motor area was observed ...

  16. Quantitative magnetic resonance imaging of cortical multiple sclerosis pathology

    DEFF Research Database (Denmark)

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

    2012-01-01

    Although significant improvements have been made regarding the visualization and characterization of cortical multiple sclerosis (MS) lesions using magnetic resonance imaging (MRI), cortical lesions (CL) continue to be under-detected in vivo, and we have a limited understanding of the causes of GM...

  17. Update on the OMERACT Magnetic Resonance Imaging Task Force

    DEFF Research Database (Denmark)

    Conaghan, Philip G; McQueen, Fiona M; Bird, Paul

    2014-01-01

    Magnetic resonance imaging (MRI) provides an important biomarker across a range of rheumatological diseases. At the Outcome Measures in Rheumatology (OMERACT) 11 meeting, the MRI task force continued its work of developing and improving the use of MRI outcomes for use in clinical trials...

  18. Anatomical and magnetic resonance imaging study of the medial ...

    African Journals Online (AJOL)

    Anatomical and magnetic resonance imaging study of the medial collateral ligament of the ankle joint. Sally Mahmood Mohamed Hussin Omar, Fardos Ahmed El-Kalaa, El Sebai Farag Ali, Ali Ali Abd El-Karim, Nancy Mohamed El Sekily ...

  19. The role of diffusion weighted magnetic resonance imaging in ...

    African Journals Online (AJOL)

    Shaimaa R.A. Fadeel

    2015-06-16

    Jun 16, 2015 ... The role of diffusion weighted magnetic resonance imaging in assessment of normal myelination in infantile brain. Shaimaa R.A. Fadeel. 1. , Moataz M. Montasser *, Ashraf N. Etaby. 2. ,. Reda M.A. Darweesh. 3. Department of Radiology, Faculty of Medicine, Alexandria University, Egypt. Received 2 June ...

  20. Value of diffusion weighted magnetic resonance imaging in the ...

    African Journals Online (AJOL)

    Ahmad Hafez Ahmad Alsayed Afifi

    2012-10-12

    Oct 12, 2012 ... Value of diffusion weighted magnetic resonance imaging in the prediction of cancer prostate. Ahmad Hafez Ahmad Alsayed Afifi a,. *, Ashraf Naguib Etaby a. ,. Mohamad Alsayed Yousef Ahmad b. , Yasmin Tarek Farghaly a a Radiology Department, Faculty of Medicine, Alexandria University, Egypt.