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Sample records for resonance imaging predictors

  1. Temporomandibular joint involvement in juvenile idiopathic arthritis: clinical predictors of magnetic resonance imaging signs

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    Argyropoulou, Maria I.; Margariti, Persefoni N.; Astrakas, Loukas; Kosta, Paraskevi [Medical School University of Ioannina, Department of Radiology, Ioannina (Greece); Karali, Aikaterini; Alfandaki, Sapfo; Siamopoulou, Antigoni [University of Ioannina, Department of Child Health, Medical School, Ioannina (Greece)

    2009-03-15

    The aim of the study was to define clinical predictors of magnetic resonance imaging (MRI) findings of temporomandibular joint (TMJ) involvement in juvenile idiopathic arthritis (JIA). Forty-six patients, aged 2.08-36.7 years, with JIA (oligoartitular 18, polyarticular 17, systemic type 11) were examined with standard plain and contrast-enhanced sequences. Of 88 TMJs examined, an abnormal condyle was observed in 32%, flattened articular eminence in 27%, flattened articular disk in 17%, intra-articular fluid in 10%, enhancing pannus in 45% and restricted condylar motion in 9%. Logistic regression analysis revealed that for abnormal condyle and flattened articular eminence, independent predictors were type of JIA (P < 0.015), age at onset (P < 0.038), and duration of disease activity (P < 0.001). Plots of the logistic regression models showed that TMJ involvement approached certainty for systemic sooner than for the other JIA types. Pannus was present with probability >0.5 when the disease started before 4 years of age. In conclusion, the systemic type of JIA, young age at onset and long duration of activity are risk factors for TMJ damage. MRI of the TMJ should be performed in patients who are less than 4 years of age at the onset of JIA, and in those with the systemic type, whatever the age of onset. (orig.)

  2. Magnetic resonance imaging findings as predictors of clinical outcome in patients with sciatica receiving active conservative treatment

    DEFF Research Database (Denmark)

    Jensen, Tue Secher; Albert, Hanne B; Sorensen, Joan S

    2007-01-01

    OBJECTIVE: The aims of this study were to investigate the possible prognostic value of disk-related magnetic resonance imaging (MRI) findings in relation to recovery at 14 months in patients with severe sciatica, and whether improvement of disk herniation and/or nerve root compromise is concurrent...... disability score of 3 or less. Potential predictors of interest were disk-related MRI findings in the lumbar spine. Bi- and multivariate logistic regression analyses were used to identify any predictors of recovery. Age, sex, and treatment were included in the analyses as possible confounding....../modifying factors. RESULTS: According to the definitions used, 53% of 154 patients recovered; 63% of men (n = 84) and 40% of women (n = 70). In the multivariate analyses, broad-based protrusions, extrusions, and male sex were found to be predictive of a positive outcome. Sex was identified as a true confounder...

  3. Clinical and magnetic resonance imaging predictors of disease progression in multiple sclerosis: a nine-year follow-up study.

    Science.gov (United States)

    Lavorgna, L; Bonavita, S; Ippolito, D; Lanzillo, R; Salemi, G; Patti, F; Valentino, P; Coniglio, G; Buccafusca, M; Paolicelli, D; d'Ambrosio, A; Bresciamorra, V; Savettieri, G; Zappia, M; Alfano, B; Gallo, A; Simone, Il; Tedeschi, G

    2014-02-01

    The objective of this paper is to identify clinical or magnetic resonance imaging (MRI) predictors of long-term clinical progression in a large cohort of multiple sclerosis (MS) patients. A total of 241 relapsing-remitting (RR) MS patients were included in a nine-year follow-up (FU) study. The reference MRIs were acquired at baseline (BL) as part of a multicenter, cross-sectional, clinical-MRI study. Volumetric MRI metrics were measured by a fully automated, operator-independent, multi-parametric segmentation method. Clinical progression was evaluated as defined by: conversion from RR to secondary progressive (SP) disease course; progression of Expanded Disability Status Scale (EDSS); achievement and time to reach EDSS 4. We concluded that conversion from RR to SP (OR 0.79; CI 0.7-0.9), progression of EDSS (OR 0.85; CI 0.77-0.93), achievement of EDSS 4 (OR 0.8; CI 0.7-0.9), and time to reach EDSS 4 (HR 0.88; CI 0.82-0.94) were all predicted by BL gray matter (GM) volume and, except for progression of EDSS, by BL EDSS (respectively: (OR 2.88; CI 1.9-4.36), (OR 2.7; CI 1.7-4.2), (HR 3.86; CI 1.94-7.70)). BL GM volume and EDSS are the best long-term predictors of disease progression in RRMS patients with a relatively long and mild disease.

  4. MRI (Magnetic Resonance Imaging)

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    ... 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) ...

  5. [Magnetic Resonance Imaging Conversion Predictors of Clinically Isolated Syndrome to Multiple Sclerosis].

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    Peixoto, Sara; Abreu, Pedro

    2016-11-01

    Introdução: A síndrome clinicamente isolada é uma forma de apresentação da esclerose múltipla, doença desmielinizante crónica do sistema nervoso central, e define-se por um único episódio clínico sugestivo de desmielinização. Porém, doentes com esta síndrome podem não desenvolver novos sintomas ou lesões, mesmo após longos períodos de seguimento, não cumprindo os critérios de diagnóstico da doença. Aqui serão revistas, na síndrome clinicamente isolada, as alterações na ressonância magnética que melhor predizem a conversão em esclerose múltipla. Material e Métodos: Pesquisaram-se na base de dados da PubMed artigos publicados entre janeiro de 2010 e junho de 2015 usando os termos ‘clinically isolated syndrome’, ‘cis’, ‘multiple sclerosis’, ‘magnetic resonance imaging’, ‘magnetic resonance’ e ‘mri’. Resultados: Carga lesional, localização das lesões, critérios de Barkhof e áreas/volumes de estruturas cerebrais foram as alterações na ressonância magnética convencional encontradas nos artigos incluídos nesta revisão. As técnicas não convencionais estudadas foram a dupla inversão-recuperação, a transferência de magnetização, a espectroscopia e a imagem de tensor de difusão. Discussão: Enquanto o número de lesões e a sua localização têm um papel claro na previsão da conversão da síndrome clinicamente isolada em esclerose múltipla, as técnicas não convencionais e as restantes alterações na ressonância magnética necessitam de mais estudos para confirmar a sua capacidade de prever o desenvolvimento da doença. Conclusão: Para além do valor preditivo das alterações já citadas, no futuro, diferentes achados neurorradiológicos na síndrome clinicamente isolada poderão ser considerados para os critérios de diagnóstico da esclerose múltipla e/ou modificar as recomendações sobre o seu tratamento.

  6. Predictors of Morbidity and Cleavage Plane in Surgical Resection of Pure Convexity Meningiomas Using Cerebrospinal Fluid Sensitive Image Subtraction Magnetic Resonance Imaging

    Science.gov (United States)

    THENIER-VILLA, José LUIS; CAMPOVERDE, Raúl ALEJANDRO GALÁRRAGA; DE LA LAMA ZARAGOZA, Adolfo RAMÓN; ALONSO, Cesáreo CONDE

    2017-01-01

    Meningiomas are the most common primary intracranial tumors. Since the adhesions in the plane of dissection are of interest in surgical planning, we suggest that digital image subtraction of FLAIR data from the T2 sequence of MRI may represent better the CSF spaces in the brain–tumor interface and may be a predictor of the intraoperative cleavage plane. From 2006 to 2016, 83 convexity meningiomas were resected in the Department of Neurosurgery of the University Hospital Complex of Vigo, an analysis of preoperative MRI was performed to assess peritumoral edema (PTE), tumor volume, among others; a digital subtraction of T2-FLAIR sequences was performed and analyzed in relationship to the cleavage plane described in the intraoperative report and postoperative neurological deficits. Simpson grade 1 resection was achieved in 85.54%, the overall 5-year PFS was 93.75%. Our rate of permanent new neurological deficit was 4.82% and the overall complication rate of 14.46%. The grade of PTE was proportional to tumor volume, 20 ± 2.8, 30 ± 5.3, and 34 ± 4.3 cm3 for grades 1, 2, and 3, respectively, positive cleft sign on image subtraction was predictive of good intraoperative cleavage plane and low grade cleavage plane (P = 0.04), and was a protective factor for postoperative neurological deficit (P = 0.02). Positive cleft sign in T2-FLAIR digital subtraction image is an independent predictor of good intraoperative cleavage plane, PTE is an independent predictor of the bad cleavage plane. Negative cleft sign in the image subtraction and a bad intraoperative cleavage plane are predictors of postoperative neurological deficit. PMID:27580930

  7. Routine clinical measures of adiposity as predictors of visceral fat in adolescence: a population-based magnetic resonance imaging study.

    Directory of Open Access Journals (Sweden)

    Katie Goodwin

    Full Text Available OBJECTIVE: Visceral fat (VF increases cardiometabolic risk more than fat stored subcutaneously. Here, we investigated how well routine clinical measures of adiposity, namely body mass index (BMI and waist circumference (waist, predict VF and subcutaneous fat (SF in a large population-based sample of adolescents. As body-fat distribution differs between males and females, we performed these analyses separately in each sex. DESIGN AND METHODS: VF and SF were measured by magnetic resonance imaging in 1,002 adolescents (482 males, age 12-18 years. Relationships of BMI and waist with VF and SF were tested in multivariable analyses, which adjusted for potentially confounding effects of age and height. RESULTS: In both males and females, BMI and waist were highly correlated with VF and SF, and explained 55-76% of their total variance. When VF was adjusted for SF, however, BMI and waist explained, respectively, only 0% and 4% of VF variance in males, and 4% and 11% of VF variance in females. In contrast, when SF was adjusted for VF, BMI and waist explained, respectively, 36% and 21% of SF variance in males, and 48% and 23% of SF variance in females. These relationships were similar during early and late puberty. CONCLUSIONS AND RELEVANCE: During adolescence, routine clinical measures of adiposity predict well SF but not VF. This holds for both sexes and throughout puberty. Further longitudinal studies are required to assess how well these measures predict changes of VF and SF over time. Given the clinical importance of VF, development of cost-effective imaging techniques and/or robust biomarkers of VF accumulation that would be suitable in everyday clinical practice is warranted.

  8. Magnetic Resonance Imaging (MRI) -- Head

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

  9. Parallel Magnetic Resonance Imaging

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    Uecker, Martin

    2015-01-01

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

  10. Magnetic Resonance Imaging (MRI) -- Head

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

  11. Magnetic resonance imaging-determined synovial membrane volume as a marker of disease activity and a predictor of progressive joint destruction in the wrists of patients with rheumatoid arthritis

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Hansen, M; Stoltenberg, M;

    1999-01-01

    OBJECTIVE: To evaluate the synovial membrane volume, determined by magnetic resonance imaging (MRI), as a marker of joint disease activity and a predictor of progressive joint destruction in rheumatoid arthritis (RA). METHODS: Twenty-six patients with RA, randomized to receive disease-modifying a......OBJECTIVE: To evaluate the synovial membrane volume, determined by magnetic resonance imaging (MRI), as a marker of joint disease activity and a predictor of progressive joint destruction in rheumatoid arthritis (RA). METHODS: Twenty-six patients with RA, randomized to receive disease......-Pratt analysis). The rate of erosive progression on MRI was highly correlated with baseline scores and, particularly, with area under the curve (AUC) values of synovial membrane volume (Spearman's sigma = 0.69, P

  12. Magnetic resonance imaging-determined synovial membrane volume as a marker of disease activity and a predictor of progressive joint destruction in the wrists of patients with rheumatoid arthritis

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Hansen, M; Stoltenberg, M

    1999-01-01

    OBJECTIVE: To evaluate the synovial membrane volume, determined by magnetic resonance imaging (MRI), as a marker of joint disease activity and a predictor of progressive joint destruction in rheumatoid arthritis (RA). METHODS: Twenty-six patients with RA, randomized to receive disease-modifying a......OBJECTIVE: To evaluate the synovial membrane volume, determined by magnetic resonance imaging (MRI), as a marker of joint disease activity and a predictor of progressive joint destruction in rheumatoid arthritis (RA). METHODS: Twenty-six patients with RA, randomized to receive disease......-Pratt analysis). The rate of erosive progression on MRI was highly correlated with baseline scores and, particularly, with area under the curve (AUC) values of synovial membrane volume (Spearman's sigma = 0.69, P

  13. 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…

  14. 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…

  15. Predictors of long-term pain and disability in patients with low back pain investigated by magnetic resonance imaging: A longitudinal study

    Directory of Open Access Journals (Sweden)

    Sampson Madeleine

    2011-10-01

    Full Text Available Abstract Background It is possible that clinical outcome of low back pain (LBP differs according to the presence or absence of spinal abnormalities on magnetic resonance imaging (MRI, in which case there could be value in using MRI findings to refine case definition of LBP in epidemiological research. We therefore conducted a longitudinal study to explore whether spinal abnormalities on MRI for LBP predict prognosis after 18 months. Methods A consecutive series of patients aged 20-64 years, who were investigated by MRI because of mechanical LBP (median duration of current episode 16.2 months, were identified from three radiology departments, and those who agreed completed self-administered questionnaires at baseline and after a mean follow-up period of 18.5 months (a mean of 22.2 months from MRI investigation. MRI scans were assessed blind to other clinical information, according to a standardised protocol. Associations of baseline MRI findings with pain and disability at follow-up, adjusted for treatment and for other potentially confounding variables, were assessed by Poisson regression and summarised by prevalence ratios (PRs with their 95% confidence intervals (CIs. Results Questionnaires were completed by 240 (74% of the patients who had agreed to be followed up. Among these 111 men and 129 women, 175 (73% reported LBP in the past four weeks, 89 (37% frequent LBP, and 72 (30% disabling LBP. In patients with initial disc degeneration there was an increased risk of frequent (PR 1.3, 95%CI 1.0-1.9 and disabling LBP (PR 1.7, 95%CI 1.1-2.5 at follow-up. No other associations were found between MRI abnormalities and subsequent outcome. Conclusions Our findings suggest that the MRI abnormalities examined are not major predictors of outcome in patients with LBP. They give no support to the use of MRI findings as a way of refining case definition for LBP in epidemiological research.

  16. Children's (Pediatric) Magnetic Resonance Imaging

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

  17. Children's (Pediatric) Magnetic Resonance Imaging

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

  18. MRI (Magnetic Resonance Imager)

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

    1995-05-01

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

  19. Magnetic Resonance Imaging (MRI) -- Head

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

  20. Children's (Pediatric) Magnetic Resonance Imaging

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    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 ...

  1. Children's (Pediatric) Magnetic Resonance Imaging

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    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 ...

  2. Children's (Pediatric) Magnetic Resonance Imaging

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    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 ...

  3. Magnetic Resonance Imaging (MRI) -- Head

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  4. Children's (Pediatric) Magnetic Resonance Imaging

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  5. Children's (Pediatric) Magnetic Resonance Imaging

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  6. Magnetic Resonance Imaging (MRI) -- Head

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

  7. 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.

  8. Magnetic Resonance Imaging (MRI) -- Head

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

  9. Magnetic Resonance Imaging (MRI) -- Head

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

  10. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... 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) ...

  11. 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.

  12. Magnetic Resonance Imaging (MRI) -- Head

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

  13. Magnetic resonance imaging; Imagerie par resonance magnetique

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    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.).

  14. Intraoperative magnetic resonance imaging.

    Science.gov (United States)

    Hall, Walter A; Truwit, Charles L

    2011-01-01

    Neurosurgeons have become reliant on image-guidance to perform safe and successful surgery both time-efficiently and cost-effectively. Neuronavigation typically involves either rigid (frame-based) or skull-mounted (frameless) stereotactic guidance derived from computed tomography (CT) or magnetic resonance imaging (MRI) that is obtained days or immediately before the planned surgical procedure. These systems do not accommodate for brain shift that is unavoidable once the cranium is opened and cerebrospinal fluid is lost. Intraoperative MRI (ioMRI) systems ranging in strength from 0.12 to 3 Tesla (T) have been developed in part because they afford neurosurgeons the opportunity to accommodate for brain shift during surgery. Other distinct advantages of ioMRI include the excellent soft tissue discrimination, the ability to view the surgical site in three dimensions, and the ability to "see" tumor beyond the surface visualization of the surgeon's eye, either with or without a surgical microscope. The enhanced ability to view the tumor being biopsied or resected allows the surgeon to choose a safe surgical corridor that avoids critical structures, maximizes the extent of the tumor resection, and confirms that an intraoperative hemorrhage has not resulted from surgery. Although all ioMRI systems allow for basic T1- and T2-weighted imaging, only high-field (>1.5 T) MRI systems are capable of MR spectroscopy (MRS), MR angiography (MRA), MR venography (MRV), diffusion-weighted imaging (DWI), and brain activation studies. By identifying vascular structures with MRA and MRV, it may be possible to prevent their inadvertent injury during surgery. Biopsying those areas of elevated phosphocholine on MRS may improve the diagnostic yield for brain biopsy. Mapping out eloquent brain function may influence the surgical path to a tumor being resected or biopsied. The optimal field strength for an ioMRI-guided surgical system and the best configuration for that system are as yet

  15. Magnetic Resonance Imaging (MRI) -- Head

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

  16. Magnetic Resonance Imaging (MRI) -- Head

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

  17. Children's (Pediatric) Magnetic Resonance Imaging

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  18. Magnetic Resonance Imaging (MRI) -- Head

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

  19. Magnetic Resonance Imaging (MRI) -- Head

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

  20. Magnetic Resonance Imaging (MRI) -- Head

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

  1. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... E-mail: Area code: Phone no: Thank you! Images × Image Gallery Radiologist prepping patient for magnetic resonance imaging ( ... address): From (your name): Your e-mail address: Personal message (optional): Bees: Wax: Notice: RadiologyInfo respects your ...

  2. Magnetic Resonance Imaging (MRI) -- Head

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  3. Children's (Pediatric) Magnetic Resonance Imaging

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

  4. Children's (Pediatric) Magnetic Resonance Imaging

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    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 ( ...

  5. Magnetic Resonance Imaging (MRI) -- Head

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

  6. Magnetic Resonance Imaging (MRI) Safety

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

  7. 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...

  8. Magnetic Resonance Imaging (MRI) -- Head

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

  9. Magnetic Resonance Imaging (MRI) -- Head

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    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. ...

  10. Children's (Pediatric) Magnetic Resonance Imaging

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    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 ...

  11. Magnetic Resonance Imaging (MRI) -- Head

    Science.gov (United States)

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

  12. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  13. 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 ...

  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 and treat medical ...

  16. Magnetic Resonance Imaging (MRI) -- Head

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

  17. magnetic resonance imaging,etc.

    Institute of Scientific and Technical Information of China (English)

    张福基

    1998-01-01

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

  18. Dynamic Contrast-Enhanced Magnetic Resonance Imaging as a Predictor of Outcome in Head-and-Neck Squamous Cell Carcinoma Patients With Nodal Metastases

    Energy Technology Data Exchange (ETDEWEB)

    Shukla-Dave, Amita, E-mail: davea@mskcc.org [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Lee, Nancy Y. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Jansen, Jacobus F.A. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Thaler, Howard T. [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Stambuk, Hilda E. [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Fury, Matthew G. [Department of Medical Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Patel, Snehal G. [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Moreira, Andre L. [Department of Pathology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Sherman, Eric [Department of Medical Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Karimi, Sasan [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Wang, Ya [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Kraus, Dennis; Shah, Jatin P. [Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Pfister, David G. [Department of Medical Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); and others

    2012-04-01

    Purpose: Dynamic contrast-enhanced MRI (DCE-MRI) can provide information regarding tumor perfusion and permeability and has shown prognostic value in certain tumors types. The goal of this study was to assess the prognostic value of pretreatment DCE-MRI in head and neck squamous cell carcinoma (HNSCC) patients with nodal disease undergoing chemoradiation therapy or surgery. Methods and Materials: Seventy-four patients with histologically proven squamous cell carcinoma and neck nodal metastases were eligible for the study. Pretreatment DCE-MRI was performed on a 1.5T MRI. Clinical follow-up was a minimum of 12 months. DCE-MRI data were analyzed using the Tofts model. DCE-MRI parameters were related to treatment outcome (progression-free survival [PFS] and overall survival [OS]). Patients were grouped as no evidence of disease (NED), alive with disease (AWD), dead with disease (DOD), or dead of other causes (DOC). Prognostic significance was assessed using the log-rank test for single variables and Cox proportional hazards regression for combinations of variables. Results: At last clinical follow-up, for Stage III, all 12 patients were NED. For Stage IV, 43 patients were NED, 4 were AWD, 11 were DOD, and 4 were DOC. K{sup trans} is volume transfer constant. In a stepwise Cox regression, skewness of K{sup trans} (volume transfer constant) was the strongest predictor for Stage IV patients (PFS and OS: p <0.001). Conclusion: Our study shows that skewness of K{sup trans} was the strongest predictor of PFS and OS in Stage IV HNSCC patients with nodal disease. This study suggests an important role for pretreatment DCE-MRI parameter K{sup trans} as a predictor of outcome in these patients.

  19. Magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bushong, S.C.

    1988-01-01

    This book introduces the fundamentals and principles of MRI, its capabilities and various techniques of application. Appropriate background for MRI is provided, including basic nuclear magnetic phenomena, modifications required for imaging, the current state of clinical knowledge and a survey of the future potential for in vivo MRI.

  20. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... this is the case, you will be given instructions for your child about not eating or drinking several hours prior ... MRI) Safety Contrast Materials Children and Radiation Safety Videos related to Children’s (Pediatric) Magnetic Resonance Imaging Sponsored by Please note ...

  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 ... mail: Area code: Phone no: Thank you! ... Related Articles and Media MR Angiography (MRA) Magnetic Resonance, Functional (fMRI) - Brain ...

  2. 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 ... ray, CT and ultrasound. top of page How is the procedure performed? MRI examinations may be performed ...

  3. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  4. 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 ...

  5. 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

  6. 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.

  7. Magnetic resonance imaging assessment of intraventricular dyssynchrony and delayed enhancement as predictors of response to cardiac resynchronization therapy in patients with heart failure of ischaemic and non-ischaemic etiologies

    Energy Technology Data Exchange (ETDEWEB)

    Petryka, Joanna, E-mail: joannapetryka@hotmail.com [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Miśko, Jolanta [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Radiology, Institute of Cardiology, Warsaw (Poland); Przybylski, Andrzej [Department of Arrhythmia, Institute of Cardiology, Warsaw (Poland); Śpiewak, Mateusz [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Małek, Łukasz A. [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Cardiology and Interventional Angiology, Institute of Cardiology, Warsaw (Poland); Werys, Konrad [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Mazurkiewicz, Łukasz [Cardiovascular Magnetic Resonance Unit, Institute of Cardiology, Warsaw (Poland); Department of Cardiomyopathy, Institute of Cardiology, Warsaw (Poland); Gepner, Katarzyna [Department of Coronary Artery Disease, Institute of Cardiology, Warsaw (Poland); Croisille, Pierre [Creatis Laboratory, UMR CNRS 5515, INSERM, U1044, CHU Saint-Etienne, Universite de Lyon (France); Demkow, Marcin [Department of Coronary Artery Disease and Structural Heart Diseases, Institute of Cardiology, Warsaw (Poland); Rużyłło, Witold [Institute of Cardiology, Warsaw (Poland)

    2012-10-15

    Purpose: To assess the value of dyssynchrony and myocardial viability assessment by cardiac magnetic resonance (CMR) in prediction of response to cardiac resynchronization therapy (CRT) in patients with heart failure (HF) of both ischaemic and non-ischaemic etiologies. Materials and methods: Patients scheduled for CRT in NYHA class II–IV, left ventricular ejection fraction <35%, QRS ≥ 120 ms were included. Tagged cine and late gadolinium enhancement (LGE) images were performed. Dyssynchrony was assessed with inTag toolbox and LGE was quantified using cutoff value at half of maximal signal in the scar. Cardiopulmonary exercise test, echocardiography and blood testing for NT-proBNP levels were done at baseline and 6 months after CRT. Results: 52 patients (age 60.3 ± 13 years) were included. 26 patients (50%) met response criteria. The ischaemic etiology of HF was more frequent (69% vs. 31%, p = 0.002), the percent of LGE was higher (7.7% [0–13.5%] vs. 19.0% (0–31.9%], p = 0.013), regional vector of circumferential strain variance (RVV) was lower (0.27 ± 0.08 vs. 0.34 ± 0.09, p = 0.009) and uniformity of radial strain was higher (0.72 ± 0.25 vs. 0.56 ± 0.29, p = 0.046) in non-responders vs. responders. Multivariate logistic regression showed that RVV predicted response to CRT (HR 2.3, 95% CI 1.02–5.02, p = 0.0430) independently of LGE and the etiology of heart failure. In the subgroup of patients with ischaemic HF the extend of transmural scar within myocardium was higher in non-responders vs. responders (26.3% vs. 15.0% respectively, p = 0.01) and was a predictor of response to CRT in univariable analysis (HR 0.87, 95% CI 0.77–0.98, p = 0.025) providing the sensitivity of 76% and specificity of 75% at the cutoff point of 18% in the prediction of poor response to CRT. In patients with non-ischaemic HF QRS was wider (162 ms vs. 140 ms, p = 0.04), regional vector of strain variance (RVV) was higher (0.39 vs. 0.25, p = 0.002) and uniformity of radial

  8. 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....

  9. 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....

  10. Magnetic resonance images of hematospermia

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Norio; Miki, Kenta; Kato, Nobuki; Furuta, Nozomu; Ohishi, Yukihiko [Jikei Univ., Tokyo (Japan). School of Medicine; Kondo, Naoya; Tashiro, Kazuya

    1998-12-01

    We performed MRI (magnetic resonance imaging) in the pelvic region of 70 cases with hematospermia and conducted a study on the abnormal MRI findings to which hematospermia could be attributed. We conducted a study on the morphological anomaly and change in the signal intensity in the prostate gland and of the seminal vesicle as well as on the presence or absence of dilation in the plexus venous surrounding the deferent duct or the prostate gland out of the abnormal MRI findings. As for the seminal vesicle, the patients whose seminal vesicle was seen in higher intensity than the prostate gland in T1 weighted images were diagnosed as having hemorrhagic focus and the patients whose seminal vesicle was seen in low intensity both in T1 and T2 weighted images were diagnosed as having fibrosis caused by chronic inflammation. Abnormal MRI findings were seen in 40 out of the 70 cases (57%). Anomaly in the prostate gland was indicated in 6 (9%) cases. Abnormality in the seminal vesicle was indicated in 30 cases (43%) including hemorrhage of seminal vesicle in 25 cases, chronic inflammation in five cases and cyst of seminal vesicle in one case. In conducting an examination of the patients with hematospermia, MRI is the nonivasive and reproducible method and it is possible to identify the hemorrhagic region. Therefore, MRI is thought to be useful to identify the causal organs of hematospermia. (author)

  11. Aortic dissection: magnetic resonance imaging.

    Science.gov (United States)

    Amparo, E G; Higgins, C B; Hricak, H; Sollitto, R

    1985-05-01

    Fifteen patients with suspected or known aortic dissection were imaged with magnetic resonance (MR). Thirteen of these patients were eventually shown to have dissection. In most instances the diagnosis was established by aortography and/or computed tomography (CT) prior to the MR study. Surgical proof (6/13) and/or aortographic proof (10/13) were available in 11/13 patients with aortic dissection. MR demonstrated the intimal flap and determined whether the dissection was type A or type B. In addition, MR: differentiated between the true and false lumens; determined the origins of the celiac, superior mesenteric, and renal arteries from the true or false lumen in the cases where the dissection extended into the abdominal aorta (8/12); allowed post-surgical surveillance of the dissection; and identified aortoannular ectasia in the three patients who had Marfan syndrome. In addition to the 13 cases with dissection, there were two cases in whom the diagnosis of dissection was excluded by MR. Our early experience suggests that MR can serve as the initial imaging test in clinically suspected cases of aortic dissection and that the information provided by MR is sufficient to manage many cases. Additionally, MR obviates the use of iodinated contrast media.

  12. Magnetic resonance imaging of hemochromatosis arthropathy

    Energy Technology Data Exchange (ETDEWEB)

    Eustace, S. [Dept. of Radiology, Deaconess Hospital and Harvard Medical School, Boston, MA (United States); Buff, B. [Dept. of Radiology, Deaconess Hospital and Harvard Medical School, Boston, MA (United States); McCarthy, C. [The Inst. of Radiological Sciences, Mater Hospital, Dublin (Ireland); MacMathuana, P. [The Inst. of Radiological Sciences, Mater Hospital, Dublin (Ireland); Gilligan, P. [The Inst. of Radiological Sciences, Mater Hospital, Dublin (Ireland); Ennis, J.T. [The Inst. of Radiological Sciences, Mater Hospital, Dublin (Ireland)

    1994-10-01

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

  13. 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.…

  14. 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.…

  15. Enhancement of Magnetic Resonance Imaging with Metasurfaces

    NARCIS (Netherlands)

    Slobozhanyuk, Alexey P; Poddubny, Alexander N; Raaijmakers, AJE; van den Berg, CAT; Kozachenko, Alexander V; Dubrovina, Irina A; Melchakova, Irina V; Kivshar, Yuri S; Belov, Pavel A

    2016-01-01

    It is revealed that the unique properties of ultrathin metasurface resonators can improve magnetic resonance imaging dramatically. A metasurface formed when an array of metallic wires is placed inside a scanner under the studied object and a substantial enhancement of the radio-frequency magnetic

  16. 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...... 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....

  17. 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....

  18. Electron Paramagnetic Resonance Imaging: 1. CW-EPR Imaging

    Indian Academy of Sciences (India)

    2016-07-01

    Twentieth century bore witness to remarkable scientists whohave advanced our understanding of the brain. Among them,EPR (Electron Paramagnetic Resonance) imaging is particularlyuseful in monitoring hypoxic zones in tumors which arehighly resistant to radiation and chemotherapeutic treatment.This first part of the article covers aspects of CW(continuous wave) imaging with details of FT (pulsed FourierTransform)-EPR imaging covered in Part 2, to be publishedin the next issue of Resonance.

  19. Children's (Pediatric) Magnetic Resonance Imaging

    Science.gov (United States)

    ... being imaged, send and receive radio waves, producing signals that are detected by the coils. The electric current does not come in contact with the patient. A computer then processes the signals and generates a series of images, each of ...

  20. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... a radiologist or other physician. To locate a medical imaging or radiation oncology provider in your community, you ... not provide cost information. The costs for specific medical imaging tests, treatments and procedures may vary by geographic ...

  1. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... a radiologist or other physician. To locate a medical imaging or radiation oncology provider in your community, you ... not provide cost information. The costs for specific medical imaging tests, treatments and procedures may vary by geographic ...

  2. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... you! Do you have a personal story about radiology? Share your patient story here Images × Image Gallery ... reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of North America ( ...

  3. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... you! Do you have a personal story about radiology? Share your patient story here Images × Image Gallery ... reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of North America ( ...

  4. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  5. Magnetic Resonance Imaging (MRI) -- Head

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

  6. Magnetic Resonance Imaging (MRI) -- Head

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

  7. Children's (Pediatric) Magnetic Resonance Imaging

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

  8. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  9. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    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. ...

  10. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  11. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

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

  12. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... computer then processes the signals and generates a series of images, each of which shows a thin ... into the intravenous line (IV) after an initial series of scans. Additional series of images will be ...

  13. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... are clearer and more detailed than other imaging methods. This exam does not use ionizing radiation and ... evaluation with additional views or a special imaging technique. A follow-up examination may also be necessary ...

  14. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

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

  15. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

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

  16. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  17. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... determine the presence of certain diseases. The images can then be examined on a computer monitor, transmitted ... for imaging the joints and bones, where it can help: diagnose sports-related injuries detect the presence ...

  18. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  19. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... used to help your child stay still and maintain the correct position during imaging. Devices that contain ... between imaging sequences, but will be asked to maintain his/her position without movement as much as ...

  20. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... being imaged, send and receive radio waves, producing signals that are detected by the coils. The electric ... with the patient. A computer then processes the signals and generates a series of images, each of ...

  1. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... being imaged, send and receive radio waves, producing signals that are detected by the coils. The electric ... with the patient. A computer then processes the signals and generates a series of images, each of ...

  2. 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 ... is normal for the area of your child’s body being imaged to feel slightly ... still while the images are being obtained, which is typically only a ...

  3. 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 ... It is normal for the area of your body being imaged to feel slightly warm, but ... still while the images are being obtained, which is typically only a ...

  4. 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...

  5. Brain Morphometry Using Anatomical Magnetic Resonance Imaging

    Science.gov (United States)

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

    2008-01-01

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

  6. Magnetic Resonance Imaging in Biomedical Engineering

    Science.gov (United States)

    Kaśpar, Jan; Hána, Karel; Smrčka, Pavel; Brada, Jiří; Beneš, Jiří; Šunka, Pavel

    2007-11-01

    The basic principles of magnetic resonance imaging covering physical principles and basic imaging techniques will be presented as a strong tool in biomedical engineering. Several applications of MRI in biomedical research practiced at the MRI laboratory of the FBMI CTU including other laboratory instruments and activities are introduced.

  7. Magnetic resonance imaging in radiotherapy treatment planning

    NARCIS (Netherlands)

    Moerland, Marinus Adriaan

    2001-01-01

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

  8. Magnetic Resonance Image Wavelet Enhancer

    Science.gov (United States)

    2007-11-02

    1Departamento de Ingenieria Electrica, UAM Iztapalapa, Mexico−DF, 09340, Mexico email:arog@xanum.uam.mx. Magnetic Resonance Centre, School of Physics...Number Task Number Work Unit Number Performing Organization Name(s) and Address(es) Departamento de Ingenieria Electrica, UAM Iztapalapa, Mexico-DF

  9. Tutte polynomial in functional magnetic resonance imaging

    Science.gov (United States)

    García-Castillón, Marlly V.

    2015-09-01

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

  10. Introduction to Magnetic Resonance Imaging Techniques

    OpenAIRE

    2009-01-01

    It is quite possible to acquire images with an MR scanner without understanding the principles behind it, but choosing the best parameters and methods, and interpreting images and artifacts, requires understanding. This text serves as an introduction to magnetic resonance imaging techniques. It is aimed at beginners in possession of only a minimal level of technical expertise, yet it introduces aspects of MR that are typically considered technically challenging. The notes were written in conn...

  11. Magnetic resonance imaging of iliotibial band syndrome.

    Science.gov (United States)

    Ekman, E F; Pope, T; Martin, D F; Curl, W W

    1994-01-01

    Seven cases of iliotibial band syndrome and the pathoanatomic findings of each, as demonstrated by magnetic resonance imaging, are presented. These findings were compared with magnetic resonance imaging scans of 10 age- and sex-matched control knees without evidence of lateral knee pain. Magnetic resonance imaging signal consistent with fluid was seen deep to the iliotibial band in the region of the lateral femoral epicondyle in five of the seven cases. Additionally, when compared with the control group, patients with iliotibial band syndrome demonstrated a significantly thicker iliotibial band over the lateral femoral epicondyle (P iliotibial band in the disease group was 5.49 +/- 2.12 mm, as opposed to 2.52 +/- 1.56 mm in the control group. Cadaveric dissections were performed on 10 normal knees to further elucidate the exact nature of the area under the iliotibial band. A potential space, i.e., a bursa, was found between the iliotibial band and the knee capsule. This series suggests that magnetic resonance imaging demonstrates objective evidence of iliotibial band syndrome and can be helpful when a definitive diagnosis is essential. Furthermore, correlated with anatomic dissection, magnetic resonance imaging identifies this as a problem within a bursa beneath the iliotibial band and not a problem within the knee joint.

  12. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... being imaged, send and receive radio waves, producing signals that are detected by the coils. The electric current does not come in contact with the patient. A computer then processes the signals and generates a series of images, each of ...

  13. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... being imaged, send and receive radio waves, producing signals that are detected by the coils. The electric current does not come in contact with the patient. A computer then processes the signals and generates a series of images, each of ...

  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. Pituitary magnetic resonance imaging in Cushing's disease.

    Science.gov (United States)

    Vitale, Giovanni; Tortora, Fabio; Baldelli, Roberto; Cocchiara, Francesco; Paragliola, Rosa Maria; Sbardella, Emilia; Simeoli, Chiara; Caranci, Ferdinando; Pivonello, Rosario; Colao, Annamaria

    2017-03-01

    Adrenocorticotropin-secreting pituitary tumor represents about 10 % of pituitary adenomas and at the time of diagnosis most of them are microadenomas. Transsphenoidal surgery is the first-line treatment of Cushing's disease and accurate localization of the tumor within the gland is essential for selectively removing the lesion and preserving normal pituitary function. Magnetic resonance imaging is the best imaging modality for the detection of pituitary tumors, but adrenocorticotropin-secreting pituitary microadenomas are not correctly identified in 30-50 % of cases, because of their size, location, and enhancing characteristics. Several recent studies were performed with the purpose of better localizing the adrenocorticotropin-secreting microadenomas through the use in magnetic resonance imaging of specific sequences, reduced contrast medium dose and high-field technology. Therefore, an improved imaging technique for pituitary disease is mandatory in the suspect of Cushing's disease. The aims of this paper are to present an overview of pituitary magnetic resonance imaging in the diagnosis of Cushing's disease and to provide a magnetic resonance imaging protocol to be followed in case of suspicion adrenocorticotropin-secreting pituitary adenoma.

  16. Magnetic Resonance Imaging (MRI) -- Head

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  18. Children's (Pediatric) Magnetic Resonance Imaging

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  19. Magnetic Resonance Imaging (MRI) -- Head

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  20. Children's (Pediatric) Magnetic Resonance Imaging

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  1. Children's (Pediatric) Magnetic Resonance Imaging

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  8. Children's (Pediatric) Magnetic Resonance Imaging

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  10. Magnetic Resonance Imaging (MRI) -- Head

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  11. Children's (Pediatric) Magnetic Resonance Imaging

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  12. Magnetic Resonance Imaging (MRI) -- Head

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  14. Magnetic Resonance Imaging (MRI) -- Head

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  15. Magnetic Resonance Imaging (MRI) -- Head

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  16. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... top of page What are the benefits vs. risks? Benefits MRI is a noninvasive imaging technique that ... used for conventional x-rays and CT scanning. Risks The MRI examination poses almost no risk to ...

  17. Magnetic Resonance Imaging (MRI) -- Head

    Science.gov (United States)

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

  18. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... food or drink beforehand, especially if sedation or anesthesia is to be used. In general, children who ... metallic items, which can distort MRI images removable dental work pens, pocket knives and eyeglasses body piercings ...

  19. Children's (Pediatric) Magnetic Resonance Imaging

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  20. Magnetic Resonance Imaging (MRI) -- Head

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  1. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... to cancer treatment MRI is often the best choice for imaging the joints and bones, where it ... regular daily routine and have him/her take food and medications as usual. Some MRI examinations may ...

  2. Children's (Pediatric) Magnetic Resonance Imaging

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  3. Magnetic Resonance Imaging (MRI) -- Head

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  4. Magnetic Resonance Imaging (MRI) -- Head

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  5. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... wide range of conditions in children due to injury, illness or congenital abnormalities. When imaging of a ... detect damage to the brain caused by an injury or a stroke diagnose infectious or autoimmune diseases ...

  6. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... eating and drinking before your exam vary between facilities. Unless you are told otherwise, take your regular ... with the specific exam and with the imaging facility. Unless you are told otherwise, you may follow ...

  7. Magnetic Resonance Imaging (MRI) -- Head

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

  8. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... available for immediate assistance. top of page Who interprets the results and how do we get them? ... radiologist, a physician specifically trained to supervise and interpret radiology examinations, will analyze the images and send ...

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... available for immediate assistance. top of page Who interprets the results and how do I get them? ... radiologist, a physician specifically trained to supervise and interpret radiology examinations, will analyze the images and send ...

  10. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... examinations may require your child to receive an injection of contrast material into the bloodstream. The radiologist , ... images will be taken during or following the injection. When the examination is complete, you and your ...

  11. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... to cancer treatment MRI is often the best choice for imaging the joints and bones, where it ... or thyroid problems. Any of these conditions may influence the decision on whether contrast material will be ...

  12. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... a physician specifically trained to supervise and interpret radiology examinations, will analyze the images and send a ... reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of North America ( ...

  13. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... a physician specifically trained to supervise and interpret radiology examinations, will analyze the images and send a ... is given. However, both the American College of Radiology (ACR) and the European Society of Urogenital Radiology ...

  14. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... a computer to produce detailed pictures of the brain and other cranial structures that are clearer and ... sensitive imaging test of the head (particularly the brain) in routine clinical practice. top of page What ...

  15. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... treatment for a variety of conditions within the brain, chest, abdomen, pelvis and extremities. Tell your doctor ... or congenital abnormalities. When imaging of a child’s brain and spinal cord is needed, MRI is useful ...

  16. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... early stage by mapping the motion of water molecules in the tissue. This water motion, known as ... still during imaging. A person who is very large may not fit into the opening of certain ...

  17. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... response to cancer treatment MRI is often the best choice for imaging the joints and bones, where ... over time. Follow-up examinations are sometimes the best way to see if treatment is working or ...

  18. Magnetic Resonance Imaging (MRI) -- Head

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

  19. Magnetic Resonance Imaging (MRI) -- Head

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

  20. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... the heart, such as electrocardiography (ECG). MRI typically costs more and may take more time to perform ... accredited facilities database . This website does not provide cost information. The costs for specific medical imaging tests, ...

  1. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... determine the presence of certain diseases. The images can then be examined on a computer monitor, transmitted ... of abrupt onset or long-standing symptoms. It can help diagnose conditions such as: brain tumors stroke ...

  2. Magnetic Resonance Imaging (MRI) -- Head

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

  3. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... a computer to produce detailed pictures of the brain and other cranial structures that are clearer and ... sensitive imaging test of the head (particularly the brain) in routine clinical practice. top of page What ...

  4. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... treatment for a variety of conditions within the brain, chest, abdomen, pelvis and extremities. Tell your doctor ... or congenital abnormalities. When imaging of a child’s brain and spinal cord is needed, MRI is useful ...

  5. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... in children due to injury, illness or congenital abnormalities. When imaging of a child’s brain and spinal ... to: detect a variety of brain conditions and abnormalities like cysts, tumors, bleeding, swelling, or problems with ...

  6. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... different angles by the interpreting radiologist. Frequently, the differentiation of abnormal (diseased) tissue from normal tissues is ... exposure to ionizing radiation. MR imaging of the soft-tissue structures of the body—such as the ...

  7. Magnetic Resonance Imaging (MRI) -- Head

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

  8. Magnetic Resonance Imaging (MRI) -- Head

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

  9. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... produce detailed pictures of the brain and other cranial structures that are clearer and more detailed than ... cases. MR images of the brain and other cranial structures are clearer and more detailed than with ...

  10. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... wide range of conditions in children due to injury, illness or congenital abnormalities. When imaging of a ... detect damage to the brain caused by an injury or a stroke diagnose infectious or autoimmune diseases ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... clinical practice. top of page What are some common uses of the procedure? MR imaging of the ... with iodine contrast allergy. It is far less common for a patient to have an allergy to ...

  12. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... This website does not provide cost information. The costs for specific medical imaging tests, treatments and procedures may vary by geographic region. Discuss the fees associated with your prescribed procedure with your doctor, the ...

  13. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... This website does not provide cost information. The costs for specific medical imaging tests, treatments and procedures may vary by geographic region. Discuss the fees associated with your prescribed procedure with your doctor, the ...

  14. High speed functional magnetic resonance imaging

    CERN Document Server

    Gibson, A M

    2002-01-01

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

  15. Magnetic resonance imaging in Mexico

    Science.gov (United States)

    Rodriguez, A. O.; Rojas, R.; Barrios, F. A.

    2001-10-01

    MR imaging has experienced an important growth worldwide and in particular in the USA and Japan. This imaging technique has also shown an important rise in the number of MR imagers in Mexico. However, the development of MRI has followed a typical way of Latin American countries, which is very different from the path shown in the industrialised countries. Despite the fact that Mexico was one the very first countries to install and operate MR imagers in the world, it still lacks of qualified clinical and technical personnel. Since the first MR scanner started to operate, the number of units has grown at a moderate space that now sums up approximately 60 system installed nationwide. Nevertheless, there are no official records of the number of MR units operating, physicians and technicians involved in this imaging modality. The MRI market is dominated by two important companies: General Electric (approximately 51%) and Siemens (approximately 17.5%), the rest is shared by other five companies. According to the field intensity, medium-field systems (0.5 Tesla) represent 60% while a further 35% are 1.0 T or higher. Almost all of these units are in private hospitals and clinics: there is no high-field MR imagers in any public hospital. Because the political changes in the country, a new public plan for health care is still in the process and will be published soon this year. This plan will be determined by the new Congress. North American Free Trade Agreement (NAFTA) and president Fox. Experience acquired in the past shows that the demand for qualified professionals will grow in the new future. Therefore, systematic training of clinical and technical professionals will be in high demand to meet the needs of this technique. The National University (UNAM) and the Metropolitan University (UAM-Iztapalapa) are collaborating with diverse clinical groups in private facilities to create a systematic training program and carry out research and development in MRI

  16. Magnetic resonance imaging in rheumatology. An overview.

    Science.gov (United States)

    Nissenbaum, M A; Adamis, M K

    1994-05-01

    Magnetic resonance (MR) imaging has revolutionized the assessment of pathology involving the musculoskeletal system. The soft tissue contrast, superb resolution, multiplanar acquisition potential, and the ability to monitor physiologic processes combine the best features of other imaging modalities. The sensitivity and specificity of MR imaging for a wide range of disease processes matches or supersedes conventional radiology, nuclear medicine, and clinical examination. This article provides a brief overview of the use of MR imaging for some of the more common clinical situations confronting the rheumatologist.

  17. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... monitor infectious or inflammatory disorders monitor response to cancer treatment MRI is often the best choice for imaging the joints and bones, where it can help: diagnose sports-related injuries detect ... bone cancer inspect the marrow for leukemia and other diseases ...

  18. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... or headphones during the exam. MRI scanners are air-conditioned and well-lit. Music may be played ... are the limitations of Children’s (Pediatric) MRI? High-quality images are assured only if your child is ...

  19. Magnetic Resonance Imaging (MRI) -- Head

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

  20. Magnetic Resonance Imaging (MRI) -- Head

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

  1. Children's (Pediatric) Magnetic Resonance Imaging

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

  2. Magnetic Resonance Imaging (MRI) -- Head

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

  3. Magnetic Resonance Imaging (MRI) -- Head

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

  4. Magnetic Resonance Imaging (MRI) -- Head

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

  5. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... the specific exam and also with the imaging facility. Unless you are told otherwise, follow your child’s ... Please note RadiologyInfo.org is not a medical facility. Please contact your physician with specific medical questions ...

  6. Magnetic Resonance Imaging (MRI) -- Head

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

  7. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... Español More Info Images/Videos About Us News Physician Resources Professions Site Index A-Z Children’s (Pediatric) ... brain, chest, abdomen, pelvis and extremities. Tell your doctor about your child’s health problems, medications, recent surgeries ...

  8. Magnetic Resonance Imaging (MRI) -- Head

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

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    Full Text Available ... a radiologist or other physician. To locate a medical imaging or radiation oncology provider in your community, you can search the ACR- ... with your prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a better understanding of the possible ...

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    Full Text Available ... a radiologist or other physician. To locate a medical imaging or radiation oncology provider in your community, you can search the ACR- ... with your prescribed procedure with your doctor, the medical facility staff and/or your insurance provider to get a better understanding of the possible ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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

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    Full Text Available ... or suggestion into the following text box: Comment: E-mail: Area code: Phone no: Thank you! Images × ... Recommend RadiologyInfo to a friend Send to (friend's e-mail address): From (your name): Your e-mail ...

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  14. Children's (Pediatric) Magnetic Resonance Imaging

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

  15. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... wide range of conditions in children due to injury, illness or congenital abnormalities. When imaging of a child’s brain and spinal cord is needed, MRI is useful because of its ability to see through the skull and the bones of the skull and spine ...

  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. Fetal Cerebral Magnetic Resonance Imaging Beyond Morphology.

    Science.gov (United States)

    Jakab, András; Pogledic, Ivana; Schwartz, Ernst; Gruber, Gerlinde; Mitter, Christian; Brugger, Peter C; Langs, Georg; Schöpf, Veronika; Kasprian, Gregor; Prayer, Daniela

    2015-12-01

    The recent technological advancement of fast magnetic resonance imaging (MRI) sequences allowed the inclusion of diffusion tensor imaging, functional MRI, and proton MR spectroscopy in prenatal imaging protocols. These methods provide information beyond morphology and hold the key to improving several fields of human neuroscience and clinical diagnostics. Our review introduces the fundamental works that enabled these imaging techniques, and also highlights the most recent contributions to this emerging field of prenatal diagnostics, such as the structural and functional connectomic approach. We introduce the advanced image processing approaches that are extensively used to tackle fetal or maternal movement-related image artifacts, and which are necessary for the optimal interpretation of such imaging data. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Magnetic resonance imaging of syringomyelia

    Energy Technology Data Exchange (ETDEWEB)

    Itabashi, Takashi; Shimizu, Kou; Yuyama, Takuo and others

    1988-02-01

    Forty-five patients with syringomyelia were studied with MR imaging. They were classified into four groups. Twenty-one patients were associated with Chiari malformation, and eight with intramedullary tumors. Nine patients had idiopathic syringomyelia, and seven had posttraumatic syringomyelia. Thirty-three of them were also studied with delayed CT myelography (DCTM). The results of DCTM had a good correlation with those of MR imaging except for five cases who did not show positive contrast accumulation in the cord. Fluid pulsation in the syrinx was shown with long-TR, long-TE pulse sequences as an area of signal void within the cord. These signs of signal void were visualized on sixteen out of twenty-one Chiari malformation associated cases, on four of nine idiopathic cases, on two of seven posttraumatic cases, and on none of eight tumor-associated cases. Cardiac gated multi-phase imaging was applied and reviewed on the cinemode display, and effects of CSF pulsatile motion were discussed. This technique clearly showed the fine changes of signal intensities from systolic phase to diastolic phase, and was expected to play a significant role on the investigation of CSF motion in syringomyelia.

  19. Magnetic resonance acoustic radiation force imaging.

    Science.gov (United States)

    McDannold, Nathan; Maier, Stephan E

    2008-08-01

    Acoustic radiation force impulse imaging is an elastography method developed for ultrasound imaging that maps displacements produced by focused ultrasound pulses systematically applied to different locations. The resulting images are "stiffness weighted" and yield information about local mechanical tissue properties. Here, the feasibility of magnetic resonance acoustic radiation force imaging (MR-ARFI) was tested. Quasistatic MR elastography was used to measure focal displacements using a one-dimensional MRI pulse sequence. A 1.63 or 1.5 MHz transducer supplied ultrasound pulses which were triggered by the magnetic resonance imaging hardware to occur before a displacement-encoding gradient. Displacements in and around the focus were mapped in a tissue-mimicking phantom and in an ex vivo bovine kidney. They were readily observed and increased linearly with acoustic power in the phantom (R2=0.99). At higher acoustic power levels, the displacement substantially increased and was associated with irreversible changes in the phantom. At these levels, transverse displacement components could also be detected. Displacements in the kidney were also observed and increased after thermal ablation. While the measurements need validation, the authors have demonstrated the feasibility of detecting small displacements induced by low-power ultrasound pulses using an efficient magnetic resonance imaging pulse sequence that is compatible with tracking of a dynamically steered ultrasound focal spot, and that the displacement increases with acoustic power. MR-ARFI has potential for elastography or to guide ultrasound therapies that use low-power pulsed ultrasound exposures, such as drug delivery.

  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. Dark Field Imaging of Plasmonic Resonator Arrays

    Science.gov (United States)

    Aydinli, Atilla; Balci, Sinan; Karademir, Ertugrul; Kocabas, Coskun

    2012-02-01

    We present critical coupling of electromagnetic waves to plasmonic cavity arrays fabricated on Moir'e surfaces. The critical coupling condition depends on the superperiod of Moir'e surface, which also defines the coupling between the cavities. Complete transfer of the incident power can be achieved for traveling wave plasmonic resonators, which have relatively short superperiod. When the superperiod of the resonators increases, the coupled resonators become isolated standing wave resonators in which complete transfer of the incident power is not possible. Dark field plasmon microscopy imaging and polarization dependent spectroscopic reflection measurements reveal the critical coupling conditions of the cavities. We image the light scattered from SPPs in the plasmonic cavities excited by a tunable light source. Tuning the excitation wavelength, we measure the localization and dispersion of the plasmonic cavity mode. Dark field imaging has been achieved in the Kretschmann configuration using a supercontinuum white light laser equipped with an acoustooptic tunable filter. Polarization dependent spectroscopic reflection and dark field imaging measurements are correlated and found to be in agreement with FDTD simulations.

  2. 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 proje...

  3. Nanostructured imaging surface plasmon resonance biosensing

    NARCIS (Netherlands)

    Joshi, Sweccha

    2017-01-01

    The testing and further development of a prototype nanostructured imaging surface plasmon resonance (iSPR) biosensor, with a focus on surface modification and detailed characterization of the biosensor chip and in-field and at-line applicability in the food industry is described. Furthermore, a simp

  4. Magnetic resonance imaging in acute tendon ruptures

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-11-01

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

  5. Nanostructured imaging surface plasmon resonance biosensing

    NARCIS (Netherlands)

    Joshi, Sweccha

    2017-01-01

    The testing and further development of a prototype nanostructured imaging surface plasmon resonance (iSPR) biosensor, with a focus on surface modification and detailed characterization of the biosensor chip and in-field and at-line applicability in the food industry is described. Furthermore, a

  6. 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.

  7. Was magnetic resonance imaging scan contraindicated?

    Science.gov (United States)

    Rafiq, Muhammad Khizar

    2010-01-01

    An intravenous drug abuser with a retained needle posed a management problem at a neurosurgical unit, having declined magnetic resonance imaging (MRI) on safety grounds. However, later, having been assessed by the senior radiologist, she went though the MRI scan safely.

  8. 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

  9. Sports health magnetic resonance imaging challenge.

    Science.gov (United States)

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

    2010-11-01

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

  10. 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 be

  11. 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 proje...

  12. Magnetic resonance imaging of uveitis

    Energy Technology Data Exchange (ETDEWEB)

    Li, Charles Q.; Mafee, Mahmood F. [University of California, San Diego, Department of Radiology, San Diego, CA (United States); Cho, Aaron A. [Naval Medical Center, San Diego, CA (United States); Edward, Neeraj J. [University of Cincinnati, Department of Anesthesiology, Cincinnati, OH (United States); Edward, Deepak P. [King Khaled Eye Specialist Hospital, Riyadh (Saudi Arabia); Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD (United States); Fajardo, Roman G. [University of California, San Diego, Shiley Eye Center, La Jolla, CA (United States)

    2015-08-15

    Uveitis is a term used to describe inflammation of the choroid, iris, or ciliary body, which make up the uveal tract. It can be idiopathic or associated with a systemic disease which may be infectious or noninfectious. With the exception of B-scan ultrasonography, current imaging methods for diagnosing and monitoring uveitis are predominately non-radiologic. Although MRI has been anecdotally shown to detect various inflammatory conditions of the globe, such as posterior scleritis, endophthalmitis, and posterior uveitis secondary to Vogt-Koyanagi-Harada disease, a more comprehensive review of the MRI findings in uveitis of various etiologies is presented here. The MRI and CT studies of seven patients with uveitis and the clinical history of three of them (not available in four patients) were reviewed. Etiologies included ankylosing spondylitis, relapsing polychondritis, Vogt-Koyanagi-Harada disease, sarcoidosis, and tuberculosis. Increased gadolinium enhancement of the uveal tract, which is visualized as the enhancing layer immediately deep to the low-signal sclera, was seen on all six MRI studies. Diffusion-weighted imaging of a case with posterior uveitis and subretinal effusions revealed restriction within the uvea and effusions. Two patients had inflammatory nodules adherent to the uvea, two patients had vitreous humor abnormalities, and one patient exhibited proximal perineural and perimuscular spread of enhancement. Uveoscleral thickening and enhancement with a posterior calcification were observed in the patient with chronic uveitis imaged with CT. Increased uveal tract enhancement is a common finding in patients with uveitis, regardless of anatomic distribution and etiology. MRI can also further evaluate complications of uveitis and help differentiate it from masquerade syndromes. (orig.)

  13. Magnetic resonance imaging based functional imaging in paediatric oncology.

    Science.gov (United States)

    Manias, Karen A; Gill, Simrandip K; MacPherson, Lesley; Foster, Katharine; Oates, Adam; Peet, Andrew C

    2017-02-01

    Imaging is central to management of solid tumours in children. Conventional magnetic resonance imaging (MRI) is the standard imaging modality for tumours of the central nervous system (CNS) and limbs and is increasingly used in the abdomen. It provides excellent structural detail, but imparts limited information about tumour type, aggressiveness, metastatic potential or early treatment response. MRI based functional imaging techniques, such as magnetic resonance spectroscopy, diffusion and perfusion weighted imaging, probe tissue properties to provide clinically important information about metabolites, structure and blood flow. This review describes the role of and evidence behind these functional imaging techniques in paediatric oncology and implications for integrating them into routine clinical practice. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Magnetic resonance images of ameloblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Duk; Kim, Jin Soo [Chosun University College of Medicine, Gwangju (Korea, Republic of)

    2005-12-15

    To classify and describe the characteristic features of MRI of some ameloblastoma variants. The MR images, CT images, and panoramic radiographs in 5 cases were retrospectively examined as follows. First, the contents of ameloblastomas were divided into two portions of either solid or cystic components on the basis of MR signal intensities. The signal intensity within the solid or cystic portions was classified as homogeneous or heterogenous. Next, the characteristic internal feature of the lesion in T1W1 or T2W1 was described. The signal intensities were classified into low, intermediate, slightly high, high, and strong high signal intensity. Uni cystic lesion showed homogeneous high signal intensity (SI) on T2W2 and the rim enhancement of the surrounding area including the mural nodule and the thick wall except the central portion on Gd-T1W1. Solid type revealed heterogeneous and high SI area with strong high SI area on T2W2. On Gd-T1W1, the area corresponding to the low signal spot on T1W1 and the strong high signal spot on T2W1 showed low SI. Hybrid type showed slightly enhanced capsular structures and low SI for the round bony septa and the areas connecting the mixed and cystic lesions on T2W1 and Gd-T1W1. MRI could easily assess the relationship between the mixed and cystic findings in ameloblastoma.

  15. Neural network segmentation of magnetic resonance images

    Science.gov (United States)

    Frederick, Blaise

    1990-07-01

    Neural networks are well adapted to the task of grouping input patterns into subsets which share some similarity. Moreover once trained they can generalize their classification rules to classify new data sets. Sets of pixel intensities from magnetic resonance (MR) images provide a natural input to a neural network by varying imaging parameters MR images can reflect various independent physical parameters of tissues in their pixel intensities. A neural net can then be trained to classify physically similar tissue types based on sets of pixel intensities resulting from different imaging studies on the same subject. A neural network classifier for image segmentation was implemented on a Sun 4/60 and was tested on the task of classifying tissues of canine head MR images. Four images of a transaxial slice with different imaging sequences were taken as input to the network (three spin-echo images and an inversion recovery image). The training set consisted of 691 representative samples of gray matter white matter cerebrospinal fluid bone and muscle preclassified by a neuroscientist. The network was trained using a fast backpropagation algorithm to derive the decision criteria to classify any location in the image by its pixel intensities and the image was subsequently segmented by the classifier. The classifier''s performance was evaluated as a function of network size number of network layers and length of training. A single layer neural network performed quite well at

  16. 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.).

  17. Magnetic Resonance Imaging in ADNI

    Science.gov (United States)

    Jack, Clifford R.; Barnes, Josephine; Bernstein, Matt A.; Borowski, Bret J.; Brewer, James; Clegg, Shona; Dale, Anders M.; Carmichael, Owen; Ching, Christopher; DeCarli, Charles; Desikan, Rahul S.; Fennema-Notestine, Christine; Fjell, Anders M.; Fletcher, Evan; Fox, Nick C.; Gunter, Jeff; Gutman, Boris A.; Holland, Dominic; Hua, Xue; Insel, Philip; Kantarci, Kejal; Killiany, Ron J.; Krueger, Gunnar; Leung, Kelvin K.; Mackin, Scott; Maillard, Pauline; Molone, Ian; Mattsson, Niklas; McEvoy, Linda; Modat, Marc; Mueller, Susanne; Nosheny, Rachel; Ourselin, Sebastien; Schuff, Norbert; Senjem, Matthew L.; Simonson, Alix; Thompson, Paul M.; Rettmann, Dan; Vemuri, Prashanthi; Walhovd, Kristine; Zhao, Yansong; Zuk, Samantha; Weiner, Michael

    2015-01-01

    INTRODUCTION ADNI is now in its 10th year. The primary objective of the MRI core of ADNI has been to improve methods for clinical trials in Alzheimer’s disease and related disorders. METHODS We review the contributions of the MRI core from present and past cycles of ADNI (ADNI 1, GO and 2). We also review plans for the future – ADNI 3. RESULTS Contributions of the MRI core include creating standardized acquisition protocols and quality control methods; examining the effect of technical features of image acquisition and analysis on outcome metrics; deriving sample size estimates for future trials based on those outcomes; and piloting the potential utility of MR perfusion, diffusion, and functional connectivity measures in multicenter clinical trials. DISCUSSION Over the past decade the MRI core of ADNI has fulfilled its mandate of improving methods for clinical trials in Alzheimer’s disease and will continue to do so in the future. PMID:26194310

  18. Resonance Energy Transfer Molecular Imaging Application in Biomedicine

    Directory of Open Access Journals (Sweden)

    NIE Da-hong1,2;TANG Gang-hua1,3

    2016-11-01

    Full Text Available Resonance energy transfer molecular imaging (RETI can markedly improve signal intensity and tissue penetrating capacity of optical imaging, and have huge potential application in the deep-tissue optical imaging in vivo. Resonance energy transfer (RET is an energy transition from the donor to an acceptor that is in close proximity, including non-radiative resonance energy transfer and radiative resonance energy transfer. RETI is an optical imaging technology that is based on RET. RETI mainly contains fluorescence resonance energy transfer imaging (FRETI, bioluminescence resonance energy transfer imaging (BRETI, chemiluminescence resonance energy transfer imaging (CRETI, and radiative resonance energy transfer imaging (RRETI. RETI is the hot field of molecular imaging research and has been widely used in the fields of biology and medicine. This review mainly focuses on RETI principle and application in biomedicine.

  19. Magnetic resonance imaging of rat fetuses

    Energy Technology Data Exchange (ETDEWEB)

    Igarashi, Yo; Kawanishi, Hiroaki (Imamichi Institute for Animal Reproduction, Ibaraki (Japan)); Hasegawa, Kenichi; Otsu, Shinichi

    1993-06-01

    The internal structures of rat fetuses on day 18.0 of pregnancy were studied by magnetic resonance imaging in 1-mm sagittal slices. Each organ was represented as white to gray images different in tone according to the [sup 1]H proton content and the relaxation time. In solid organs, portions with high cell density were seen as white areas and those with low cell density as gray areas. In the tubular organs, the margins were imaged as white and the lumina as gray. (author).

  20. Magnetic resonance imaging of acoustic neuroma

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-03-01

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

  1. 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).

  2. Enhancement of magnetic resonance imaging with metasurfaces

    CERN Document Server

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

    2015-01-01

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

  3. Stafne bone cavity--magnetic resonance imaging.

    Science.gov (United States)

    Segev, Yoram; Puterman, Max; Bodner, Lipa

    2006-07-01

    A case of Stafne bone cavity (SBC) affecting the body of the mandible of a 51-year-old female is reported. The imaging modalities included panoramic radiograph, computed tomography (CT) and magnetic resonance (MR) imaging. Panoramic radiograph and CT were able to determine the outline of the cavity and its three dimensional shape, but failed to precisely diagnose the soft tissue content of the cavity. MR imaging demonstrated that the bony cavity is filled with soft tissue that is continuous and identical in signal with that of the submandibular salivary gland. Based on the MR imaging a diagnosis of SBC was made and no further studies or surgical treatment were initiated. MR imaging should be considered the diagnostic technique in cases where SBC is suspected. Recognition of the lesion should preclude any further treatment or surgical exploration.

  4. Lossless Compression of Medical Images Using 3D Predictors.

    Science.gov (United States)

    Lucas, Luis; Rodrigues, Nuno; Cruz, Luis; Faria, Sergio

    2017-06-09

    This paper describes a highly efficient method for lossless compression of volumetric sets of medical images, such as CTs or MRIs. The proposed method, referred to as 3D-MRP, is based on the principle of minimum rate predictors (MRP), which is one of the state-of-the-art lossless compression technologies, presented in the data compression literature. The main features of the proposed method include the use of 3D predictors, 3D-block octree partitioning and classification, volume-based optimisation and support for 16 bit-depth images. Experimental results demonstrate the efficiency of the 3D-MRP algorithm for the compression of volumetric sets of medical images, achieving gains above 15% and 12% for 8 bit and 16 bit-depth contents, respectively, when compared to JPEG-LS, JPEG2000, CALIC, HEVC, as well as other proposals based on MRP algorithm.

  5. 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)......). In this report, a case of bilateral sensorineural hearing loss in an otherwise healthy patient underwent brain MRI was described. The patient's hearing loss was accompanied with tinnitus and was not improved after 3 months of followup.......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...

  6. 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....

  7. 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)

  8. 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.

  9. "PALPATION BY IMAGING": MAGNETIC RESONANCE ELASTOGRAPHY

    Institute of Scientific and Technical Information of China (English)

    Lei Xu; Pei-yi Gao

    2006-01-01

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

  10. Perfusion magnetic resonance imaging of the liver

    Institute of Scientific and Technical Information of China (English)

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

    2010-01-01

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

  11. Magnetic Resonance Imaging of Thyroid and Parathyroid

    Directory of Open Access Journals (Sweden)

    Miguel Gonzalo-Domínguez

    2016-11-01

    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.

  12. Resonance Light Scattering Imaging Determination of Heparin

    Institute of Scientific and Technical Information of China (English)

    Hong Ping GUO; Cheng Zhi HUANG; Jian LING

    2006-01-01

    A laser-induced resonance light scattering (RLS) imaging method to determine heparin is described based on the high light scattering emission power of the aggregation species of heparin with α, β, γ, δtetra(4-trimethylaminoniumphenyl)prophyrin (TAPP) in solution. By imaging the light scattering signals of the aggregation species, we proposed the method to determine the heparin with a detection range of 0.02 - 0.6 μg/mL and the detection limit (3 σ) of 1.3 ng/mL.

  13. [Magnetic resonance imaging of the temporomandibular joint].

    Science.gov (United States)

    Ros Mendoza, L H; Cañete Celestino, E; Velilla Marco, O

    2008-01-01

    The temporomandibular joint (TMJ) is a small joint with complex anatomy and function. Diverse pathologies with very different symptoms can affect the TMJ. While various imaging techniques such as plain-film radiography and computed tomography can be useful, magnetic resonance imaging's superior contrast resolution reveals additional structures like the articular disk, making this technique essential for accurate diagnosis and treatment planning. We analyze the MRI signs of the different pathologies that can affect the TMJ from the structural and functional points of view.

  14. 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.

  15. Chest magnetic resonance imaging: a protocol suggestion*

    Science.gov (United States)

    Hochhegger, Bruno; de Souza, Vinícius Valério Silveira; Marchiori, Edson; Irion, Klaus Loureiro; Souza Jr., Arthur Soares; Elias Junior, Jorge; Rodrigues, Rosana Souza; Barreto, Miriam Menna; Escuissato, Dante Luiz; Mançano, Alexandre Dias; Araujo Neto, César Augusto; Guimarães, Marcos Duarte; Nin, Carlos Schuler; Santos, Marcel Koenigkam; Silva, Jorge Luiz Pereira e

    2015-01-01

    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. PMID:26811555

  16. Functional magnetic resonance imaging studies of language.

    Science.gov (United States)

    Small, Steven L; Burton, Martha W

    2002-11-01

    Functional neuroimaging of language builds on almost 150 years of study in neurology, psychology, linguistics, anatomy, and physiology. In recent years, there has been an explosion of research using functional imaging technology, especially positron emission tomography (PET) and functional magnetic resonance imaging (fMRI), to understand the relationship between brain mechanisms and language processing. These methods combine high-resolution anatomic images with measures of language-specific brain activity to reveal neural correlates of language processing. This article reviews some of what has been learned about the neuroanatomy of language from these imaging techniques. We first discuss the normal case, organizing the presentation according to the levels of language, encompassing words (lexicon), sound structure (phonemes), and sentences (syntax and semantics). Next, we delve into some unusual language processing circumstances, including second languages and sign languages. Finally, we discuss abnormal language processing, including developmental and acquired dyslexia and aphasia.

  17. Magnetic resonance perfusion imaging without contrast media

    Energy Technology Data Exchange (ETDEWEB)

    Martirosian, Petros; Graf, Hansjoerg; Schick, Fritz [University Hospital of Tuebingen, Section on Experimental Radiology, Tuebingen (Germany); Boss, Andreas; Schraml, Christina; Schwenzer, Nina F.; Claussen, Claus D. [University Hospital of Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany)

    2010-08-15

    Principles of magnetic resonance imaging techniques providing perfusion-related contrast weighting without administration of contrast media are reported and analysed systematically. Especially common approaches to arterial spin labelling (ASL) perfusion imaging allowing quantitative assessment of specific perfusion rates are described in detail. The potential of ASL for perfusion imaging was tested in several types of tissue. After a systematic comparison of technical aspects of continuous and pulsed ASL techniques the standard kinetic model and tissue properties of influence to quantitative measurements of perfusion are reported. For the applications demonstrated in this paper a flow-sensitive alternating inversion recovery (FAIR) ASL perfusion preparation approach followed by true fast imaging with steady precession (true FISP) data recording was developed and implemented on whole-body scanners operating at 0.2, 1.5 and 3 T for quantitative perfusion measurement in various types of tissue. ASL imaging provides a non-invasive tool for assessment of tissue perfusion rates in vivo. Images recorded from kidney, lung, brain, salivary gland and thyroid gland provide a spatial resolution of a few millimetres and sufficient signal to noise ratio in perfusion maps after 2-5 min of examination time. Newly developed ASL techniques provide especially high image quality and quantitative perfusion maps in tissues with relatively high perfusion rates (as also present in many tumours). Averaging of acquisitions and image subtraction procedures are mandatory, leading to the necessity of synchronization of data recording to breathing in abdominal and thoracic organs. (orig.)

  18. Magnetic resonance imaging in neurologic diseases

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Kee Hyun; Han, Man Chung; Wan, Chu Wan; Myung, Ho Jin; Choi, Kil Soo [Seoul National University College of Medicine, Seoul (Korea, Republic of); Ahn, Chang Beom; Oh, Chang Hyun; Cho, Zang Hee [Koear Advanced Institute of Science, Seoul (Korea, Republic of)

    1985-02-15

    Magnetic resonance (MR) imaging with 0.15 Tesla resistive magnet developed by Korea Advanced Institute of Science were performed in 27 patients with various neurologic diseases and compared with x-ray computed tomography (CT). The purpose of the paper is to evaluate the image quality, the diagnostic value and limitation, and the optimal pulse sequence of MR imagings with a resistive magnet. The MR images were obtained by using a variety of pulse sequence with spin echo technique including saturation recovery. T2-weighted spin echo, and/or inversion recovery with various pulse repetition (TR) and echo delay (TE) times. The MR imaging demonstrated the capability of detecting the lesions shown on CT in al cases and also detected an additional finding in one case (multiple sclerosis) which was not seen on CT. The MR imaging appeared to be more useful than CT in the evaluation of syringomyelia of spinal cord and white matter disease, while it failed to demonstrated small calcific lesion or inflammatory nodule (less than 1 cm) shown on CT and has shown somewhat poor contrast resolution in the case of meingloma. The spatial resolution of saturation recovery images was similar or superior to CT, whereas the contrast resolution of saturation recovery was inferior to CT. While the saturation recovery images have shown false negative findings in 5 patients (19%), the inversion recovery and T2-weighted spin echo have shown consistently positive findings. The inversive recovery and T2-weighted spin echo images demonstrated better contrast discrimination between normal and pathologic conditions than the saturation recovery images, but somewhat poorer spatial resolution. Authors suggest that the MR images of both the saturation recovery with 300/30 and T2-weighted spin echo with 1000/90 be used as a routine procedure and additional inversion recovery of 1300/300/30 sequence as a option if white matter disease is suspected.

  19. 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 benefit. Three strategies can be applied for the monitoring of water contents and dynamics in natural porous media: i) Dedicated high-field scanners (with vertical bore) allowing stronger gradients and faster switching so that shorter echo times can be realized. ii) Special measurement sequences using ultrashort rf- and gradient-pulses like single point imaging derivates (SPI, SPRITE)(1) and multi-echo methods, which monitor series of echoes and allow for extrapolation to zero time(2). Hence, the loss of signal during the first echo period may be compensated to determine the initial magnetization (= water content) as well as relaxation time maps simultaneously. iii) Finally low field( strategies will be given. References 1) Pohlmeier et al. Vadose Zone J. 7, 1010-1017 (2008) 2) Edzes et al., Magn. Res. Imag. 16, 185-196 (1998) 3) 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)

  20. 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.

  1. Lossless coding using predictors and VLCs optimized for each image

    Science.gov (United States)

    Matsuda, Ichiro; Shirai, Noriyuki; Itoh, Susumu

    2003-06-01

    This paper proposes an efficient lossless coding scheme for still images. The scheme utilizes an adaptive prediction technique where a set of linear predictors are designed for a given image and an appropriate predictor is selected from the set block-by-block. The resulting prediction errors are encoded using context-adaptive variable-length codes (VLCs). Context modeling, or adaptive selection of VLCs, is carried out pel-by-pel and the VLC assigned to each context is designed on a probability distribution model of the prediction errors. In order to improve coding efficiency, a generalized Gaussian function is used as the model for each context. Moreover, not only the predictors but also parameters of the probability distribution models are iteratively optimized for each image so that a coding rate of the prediction errors can have a minimum. Experimental results show that the proposed coding scheme attains comparable coding performance to the state-of-the-art TMW scheme with much lower complexity in the decoding process.

  2. Early neurological deterioration after thrombolysis: Clinical and imaging predictors

    DEFF Research Database (Denmark)

    Simonsen, Claus Z; Schmitz, Marie Louise; Hjørringgaard Madsen, Mette;

    2016-01-01

    BACKGROUND: National Institutes of Health Stroke Scale is the most common scale used in stroke patients. An increase of four points or more within 24 h signifies early neurological deterioration. We aimed to establish how often early neurological deterioration occurs in a cohort selected...... by magnetic resonance imaging and which factors predicted early neurological deterioration. METHODS: In this single-center study, we collected epidemiological, imaging and outcome data on 569 consecutive patients undergoing reperfusion therapy after magnetic resonance imaging selection. RESULTS: Of these, 33...... (5.8%) experienced early neurological deterioration. Seven were due to a symptomatic intracerebral hemorrhage, 23 were caused by extension of ischemia on follow-up imaging and three were due to progression on the basis of small vessel disease. Early neurological deterioration was predicted...

  3. Achilles Impingement Tendinopathy on Magnetic Resonance Imaging.

    Science.gov (United States)

    Bullock, Mark J; Mourelatos, Jan; Mar, Alice

    2017-02-28

    Haglund's syndrome is impingement of the retrocalcaneal bursa and Achilles tendon caused by a prominence of the posterosuperior calcaneus. Radiographic measurements are not sensitive or specific for diagnosing Haglund's deformity. Localization of a bone deformity and tendinopathy in the same sagittal section of a magnetic resonance imaging scan can assist with the diagnosis in equivocal cases. The aim of the present cross-sectional study was to determine the prevalence of Haglund's syndrome in patients presenting with Achilles tendinopathy and note any associated findings to determine the criteria for a diagnosis of Haglund's syndrome. We reviewed 40 magnetic resonance imaging scans with Achilles tendinopathy and 19 magnetic resonance imaging scans with Achilles high-grade tears and/or ruptures. Achilles tendinopathy was often in close proximity to the superior aspect of the calcaneal tuberosity, consistent with impingement (67.5%). Patients with Achilles impingement tendinopathy were more often female (p < .04) and were significantly heavier than patients presenting with noninsertional Achilles tendinopathy (p = .014) or Achilles tendon rupture (p = .010). Impingement tendinopathy occurred medially (8 of 20) and centrally (10 of 20) more often than laterally (2 of 20) and was associated with a posterior prominence or hyperconvexity with a loss of calcaneal recess more often than a superior projection (22 of 27 versus 8 of 27; p < .001). Haglund's deformity should be reserved for defining a posterior prominence or hyperconvexity with loss of calcaneal recess because this corresponds with impingement. Achilles impingement tendinopathy might be more appropriate terminology for Haglund's syndrome, because the bone deformity is often subtle. Of the 27 images with Achilles impingement tendinopathy, 10 (37.0%) extended to a location prone to Achilles tendon rupture. Given these findings, insertional and noninsertional Achilles tendinopathy are not mutually

  4. Surface Coil for Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Beatriz Taimy Ricardo Ferro

    2015-01-01

    Full Text Available Currently Magnetic Resonance Imaging (MRI, has become a vital tool for the clinical diagnosis of various diseases, especially in the Nervisos Central System and the Musculos keletal System. Coils(RF are an essential component in the generation of these images, are responsible for exciting thespins of nuclei in a sample and/or detect the resultant signal coming from them. The use of surface RF coils has increased considerably, because they have a high signal to noise ratio, a parameter that defines the quality of the image. In the present work, there was realized the theoretical design and practical implementation of a circular surface RF coil. The experimental prototype was optimized to be used in the tomograph Giroimag03  built in Medical Biophysics Center

  5. Ultrafast Imaging using Spectral Resonance Modulation.

    Science.gov (United States)

    Huang, Eric; Ma, Qian; Liu, Zhaowei

    2016-04-28

    CCD cameras are ubiquitous in research labs, industry, and hospitals for a huge variety of applications, but there are many dynamic processes in nature that unfold too quickly to be captured. Although tradeoffs can be made between exposure time, sensitivity, and area of interest, ultimately the speed limit of a CCD camera is constrained by the electronic readout rate of the sensors. One potential way to improve the imaging speed is with compressive sensing (CS), a technique that allows for a reduction in the number of measurements needed to record an image. However, most CS imaging methods require spatial light modulators (SLMs), which are subject to mechanical speed limitations. Here, we demonstrate an etalon array based SLM without any moving elements that is unconstrained by either mechanical or electronic speed limitations. This novel spectral resonance modulator (SRM) shows great potential in an ultrafast compressive single pixel camera.

  6. Magnetic resonance imaging of the small bowel

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-15

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

  7. Magnetic resonance imaging of the adrenal

    Energy Technology Data Exchange (ETDEWEB)

    Reinig, J.W.; Doppmann, J.L.

    1986-04-01

    Magnetic resonance imaging (MRI) of the adrenals was performed on 50 subjects: 5 normal volunteers, 6 Cushing patients with bilateral adrenal hyperplasia, 14 patients with adrenal adenomas, 3 with adrenal carcinomas, 15 with pheochromocytomas and 7 with metastatic disease to the adrenal. The normal and hyperplastic adrenal glands were imaged in all cases. Using the signal intensity of the adrenals on a T2 weighted image, various forms of adrenal pathology could be differentiated. A ratio of signal intensity of the adrenal mass to the liver was utilized and allowed the differentitaion of adrenal adenomas from adrenal carcinomas, pheochromocytomas and metastases. Using the same ratio, metastases could be distinguished from pheochromocytomas as well. MRI appears to be particularly valuable in distinguishing clinically silent adrenal metastases from nonfunctioning adrenal adenomas.

  8. 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.

  9. Magnetic resonance imaging of optic nerve

    Directory of Open Access Journals (Sweden)

    Foram Gala

    2015-01-01

    Full Text Available Optic nerves are the second pair of cranial nerves and are unique as they represent an extension of the central nervous system. Apart from clinical and ophthalmoscopic evaluation, imaging, especially magnetic resonance imaging (MRI, plays an important role in the complete evaluation of optic nerve and the entire visual pathway. In this pictorial essay, the authors describe segmental anatomy of the optic nerve and review the imaging findings of various conditions affecting the optic nerves. MRI allows excellent depiction of the intricate anatomy of optic nerves due to its excellent soft tissue contrast without exposure to ionizing radiation, better delineation of the entire visual pathway, and accurate evaluation of associated intracranial pathologies.

  10. Magnetic resonance imaging of septic sacroiliitis

    Energy Technology Data Exchange (ETDEWEB)

    Sandrasegaran, K. (MRI Unit, Dept. of Radiology, St. James' s Univ. Hospital, Leeds (United Kingdom)); Saifuddin, A. (MRI Unit, Dept. of Radiology, St. James' s Univ. Hospital, Leeds (United Kingdom)); Coral, A. (MRI Unit, Dept. of Radiology, St. James' s Univ. Hospital, Leeds (United Kingdom)); Butt, W.P. (MRI Unit, Dept. of Radiology, St. James' s Univ. Hospital, Leeds (United Kingdom))

    1994-05-01

    Five cases of septic sacroiliitis diagnosed by magnetic resonance imaging (MRI) are presented. Imaging was performed between 2 and 14 days after onset of symptoms and consisted of varying combinations of coronal short tau inversion recovery (STIR), axial T2-weighted spin echo (SE), and coronal and axial pre- and postcontrast T1-weighted SE scans. Abnormalities included demonstration of sacroiliac joint effusions, bone oedema and adjacent inflammation as high signal on STIR and T2-weighted SE scans, and identification of abscesses in two cases as rim-enhancing lesions anterior to the joint on gadolinium-enhanced T1-weighted SE scans. The role of MRI and other forms of imaging in septic sacroiliitis is discussed. (orig.)

  11. Magnetic resonance imaging at ultrahigh fields.

    Science.gov (United States)

    Ugurbil, Kamil

    2014-05-01

    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, ultrahigh 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.

  12. Quantitative Pulmonary Imaging Using Computed Tomography and Magnetic Resonance Imaging

    Science.gov (United States)

    Washko, George R.; Parraga, Grace; Coxson, Harvey O.

    2011-01-01

    Measurements of lung function, including spirometry and body plethesmography, are easy to perform and are the current clinical standard for assessing disease severity. However, these lung functional techniques do not adequately explain the observed variability in clinical manifestations of disease and offer little insight into the relationship of lung structure and function. Lung imaging and the image based assessment of lung disease has matured to the extent that it is common for clinical, epidemiologic, and genetic investigation to have a component dedicated to image analysis. There are several exciting imaging modalities currently being used for the non-invasive study of lung anatomy and function. In this review we will focus on two of them, x-ray computed tomography and magnetic resonance imaging. Following a brief introduction of each method we detail some of the most recent work being done to characterize smoking-related lung disease and the clinical applications of such knowledge. PMID:22142490

  13. Evaluation of image uniformity in diagnostic magnetic resonance images

    Energy Technology Data Exchange (ETDEWEB)

    Ogura, Akio [Kyoto City Hospital (Japan); Inoue, Hiroshi; Higashida, Mitsuji; Yamazaki, Masaru; Uto, Tomoyuki

    1997-12-01

    Image uniformity refers to the ability of the MR imaging system to produce a constant signal response throughout the scanned volume when the object being imaged has homogeneous MR characteristics. To facilitate the determination of image uniformity in diagnostic magnetic resonance images, reports such as the NEMA Standard and AAPM report have been issued. However, these methods of evaluation are impractical in cases such as the day-to-day quality control of the machine or comparisons between the different MR systems, because these methods affect the signal-to-noise ratio (SNR) and create problems by displaying nonuniformity locations. Therefore, we present a new method for evaluating uniformity, called the test segment method. The influence of SNR on the NEMA test and the segment method were examined. In addition, the results of the two methods were compared for certain nonuniformity conditions. Results showed that the segment method did not affect SNR and provided good display of nonuniformity. (author)

  14. 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)

  15. 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.

  16. Magnetic Resonance Imaging Evaluation of Cardiac Masses

    Energy Technology Data Exchange (ETDEWEB)

    Braggion-Santos, Maria Fernanda, E-mail: ferbraggion@yahoo.com.br [Divisão de Cardiologia do Departamento de Clínica Médica - Hospital das Clínicas - Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Hospital Universitário - Universidade de Heidelberg, Heidelberg (Germany); Koenigkam-Santos, Marcel [Centro de Ciências das Imagens e Física Médica - Hospital das Clínicas - Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Hospital Universitário - Universidade de Heidelberg, Heidelberg (Germany); Teixeira, Sara Reis [Centro de Ciências das Imagens e Física Médica - Hospital das Clínicas - Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Volpe, Gustavo Jardim [Divisão de Cardiologia do Departamento de Clínica Médica - Hospital das Clínicas - Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Divisão de Cardiologia - Universidade Johns Hopkins, Baltimore (United States); Trad, Henrique Simão [Centro de Ciências das Imagens e Física Médica - Hospital das Clínicas - Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Schmidt, André [Divisão de Cardiologia do Departamento de Clínica Médica - Hospital das Clínicas - Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2013-09-15

    Cardiac tumors are extremely rare; however, when there is clinical suspicion, proper diagnostic evaluation is necessary to plan the most appropriate treatment. In this context, cardiovascular magnetic resonance imaging (CMRI) plays an important role, allowing a comprehensive characterization of such lesions. To review cases referred to a CMRI Department for investigation of cardiac and paracardiac masses. To describe the positive case series with a brief review of the literature for each type of lesion and the role of cardiovascular magnetic resonance imaging in evaluation. Between August 2008 and December 2011, all cases referred for CMRI with suspicion of tumor involving the heart were reviewed. Cases with positive histopathological diagnosis, clinical evolution or therapeutic response compatible with the clinical suspicion and imaging findings were selected. Among the 13 cases included in our study, eight (62%) had histopathological confirmation. We describe five benign tumors (myxomas, rhabdomyoma and fibromas), five malignancies (sarcoma, lymphoma, Richter syndrome involving the heart and metastatic disease) and three non-neoplastic lesions (pericardial cyst, intracardiac thrombus and infectious vegetation). CMRI plays an important role in the evaluation of cardiac masses of non-neoplastic and neoplastic origin, contributing to a more accurate diagnosis in a noninvasive manner and assisting in treatment planning, allowing safe clinical follow-up with good reproducibility.

  17. 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.)

  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 imaging of musculoaponeurotic fibromatosis

    Energy Technology Data Exchange (ETDEWEB)

    Hawnaur, J.M.; Jenkins, J.P.R.; Isherwood, I. (Manchester Univ. (UK). Dept. of Diagnostic Radiology)

    1990-10-01

    Musculoaponeurotic fibromatosis can be mistaken for soft-tissue sarcoma both clinically and on X-ray computed tomography. Magnetic resonance imaging (MRI) in three patients with this condition enabled the correct diagnosis to be made prospectively in two. The appearance on MRI of a heterogeneous mass with well-defined, predominantly peripheral areas of very low signal intensity due to dense fibrous tissue and areas of medium to high signal intensity corresponding to a more cellular stroma should raise the suspicion of musculoaponeurotic fibromatosis. Cellular areas within the tumour showed moderate enhancement after gadolinium diethylene triamine pentaacetic acid administration. (orig.).

  20. Fetal magnetic resonance imaging and human genetics

    Energy Technology Data Exchange (ETDEWEB)

    Hengstschlaeger, Markus [Medical Genetics, Obstetrics and Gynecology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna (Austria)]. E-mail: markus.hengstschlaeger@meduniwien.ac.at

    2006-02-15

    The use of fetal magnetic resonance imaging (MRI), in addition to prenatal genetic testing and sonography, has the potential to improve prenatal diagnosis of genetic disorders. MRI plays an important role in the evaluation of fetal abnormalities and malformations. Fetal MRI often enables a differential diagnosis, a determination of the extent of the disorder, the prognosis, and an improvement in therapeutic management. For counseling of parents, as well as to basically understand how genetic aberrations affect fetal development, it is of great importance to correlate different genotypes with fetal MRI data.

  1. Sensorineural Hearing Loss after Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Abolfazl Mollasadeghi

    2013-01-01

    Full Text Available 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. In this report, a case of bilateral sensorineural hearing loss in an otherwise healthy patient underwent brain MRI was described. The patient’s hearing loss was accompanied with tinnitus and was not improved after 3 months of followup.

  2. 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.

  3. Magnetic resonance imaging of the cervical region

    Energy Technology Data Exchange (ETDEWEB)

    Tjoerstad, K.; Kaass, B.; Svihus, R.

    1987-11-01

    Magnetic resonance imaging (MRI) of the cervical region was carried out on 139 patients in a ten-month period. 64 patients came from Rogaland Central Hospital and 75 from the rest of Norway. A retrospective questionnaire was filled in by the referring physicians. MRI seems to be of great value in the diagnosis of cervical vertebrogenic myelopathy, multiple sclerosis, syringomyelia, and intraspinal tumors. Besides its diagnostic superiority, at least in patients with cervical myelopathy, MRI has definite economic advantages compared to CT and myelography.

  4. Magnetic resonance imaging of unicornuate uterus

    Energy Technology Data Exchange (ETDEWEB)

    Fedele, L.; Dorta, M.; Brioschi, D.; Giudici, M.N.; Villa, L. (1st Dept. of Obstetrics and Gynecology, Univ. of Milan (Italy))

    1990-01-01

    Five patient with a hysterosalpingographic diagnosis of unicornuate uterus underwent resonance imaging (MRI) and subsequently laparoscopy/laparotomy to evaluate the ability of MRI to identify the various subclasses of this malformation. The method was demonstrated to be valid, since in all 5 cases (one subclass A1b, two subclass B) were correctly diagnosed. Compared with laparoscopy, MRI is less expensive, less invasive, and can be performed in women in whom laparoscopic examination is risky. However, unlike laparoscopy, MRI can not detect the presence of minimal and mild endometriosis and does not allow assessment of the tubal conditions. (au).

  5. Magnetic resonance imaging of cystic periventricular leukomalacia

    Energy Technology Data Exchange (ETDEWEB)

    Kadoi, Nobuaki; Nomura, Junko; Nowatari, Masahiko; Ohta, Takeo; Kamohara, Takashi; Yashiro, Kimio (Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine)

    1990-08-01

    A study was performed to assess the values of magnetic resonance (MR) imaging in evaluation and the follow up of patients with cystic periventricular leukomalacia. Ten patients selected for MR imaging were diagnosed as having periventricular cystic lesions based on US scans. The range of gestational ages was 27 to 32 weeks, and the range of birth weights was 927 to 2,046 g. Twenty MR examinations were carried out using a 0.5 T superconducting system (Resona; Yokogawa). On the first MR examinations, taken by 6 months of age, low signal intensity lesions within the periventricular white matter, moderate ventriculomegaly with irregularity of the ventricular wall and delayed myelination were observed. These were the MR findings observed in the subacute stage of PVL. On the second or the third MR examinations, taken after 12 months of age, increased signal intensity in periventricular white matter on T{sub 2} weighted images decreased volume of periventricular white matter and centrum semiovale and the ventriculomagaly with irregularity of ventricular wall were observed. However, progressions of myelination were proved to be not delayed in comparison with age matched controls. These were thought to be the MR findings of late stage of PVL. As the US findings of PVL have good correlation with pathologic changes revealed at autopsy, MR imaging can depict myelination and detect PVL lesion beyond the neonatal period. These observations demonstrate the value of the MR imaging for the follow up of the patients with PVL beyond the time of fontanel closure. (author).

  6. Magnetic resonance imaging (MRI) in parasinus mucocele

    Energy Technology Data Exchange (ETDEWEB)

    Kakisu, Yonetsugu; Watanabe, Yoshihiro (Chiba Univ. (Japan). School of Medicine)

    1989-07-01

    We evaluated the clinical value of magnetic resonance imaging (MRI) in 9 cases of parasinus mucocele. The series included frontal mucocele 1 case, frontal and anterior ethmoidal mucocele 3 cases, anterior mucocele 2 cases, posterior ethmoidal mucocele 2 cases, and maxillary mucocele 1 case. MRI was performed with proton density P (300), inversion recovery IR (1000, 350), and spin echo SE (1000, 60/90) with 0.1 tesla resistive conducting system, or with T/sub 1/-weighted SE (440, 40), IR (1500, 500) and T/sub 2/-weighted SE (1500, 500) with 0.5 tesla superconducting system. We obtained images of variable intensities when employing P, IR and T/sub 1/-weighted SE imaging. It was possible to differentiate mucocele from normal orbital tissue by comparison with T/sub 2/-weighted imaging. All the 9 cases manifested a high intensity of T/sub 2/-weighted images. The findings were suggestive of a possibility to verify the content to parasinus cysts by MRI findings. (author).

  7. Epidural fat image in lumbar magnetic resonance image

    Energy Technology Data Exchange (ETDEWEB)

    Nishijima, Yuichiro; Yamasaki, Yasuo; Higashida, Norihiko; Okada, Masato (Kanazawa Medical School, Ishikawa (Japan))

    1993-12-01

    To examine epidural fat images, lumbar magnetic resonance (MR) images were retrospectively reviewed in a total of 103 patients with surgically proven lumbar disc herniation (DH, n=57) and lumbar canal stenosis (LCS, n=46). Epidural fat images consisted of middorsal epidural fat (MDF), paramedian ventral fat (PVF) and intervertebral foraminal fat (IFF) ones. In the group of DH, the thickness of MDF image did not correlate with that of subcutaneous fat, suggesting that epidural fat was not affected by body fat. From the pathophysiological point of view, decrease and disappearance of MDF images correlated with compression of the epidural canal. Decrease and disappearance of PVF images lead to suspicious compression of the traversing root. In addition, asymmetrical PVF images were useful for the bilateral diagnosis of herniation. Abnormal findings of IFF images were suggestive of compression of the exiting nerve root at the intervertebral foramen. This was also seen frequently at the non-responsible level in patients over the age of 50. Degenerative and sequentrated spondylolistheses in the group of LCS were more frequently associated with a higher incidence of abnormal findings of IFF images, suggesting the presence of existing nerve root compression. (N.K.).

  8. 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)

  9. Penetrating power of resonant electromagnetic induction imaging

    Science.gov (United States)

    Guilizzoni, Roberta; Watson, Joseph C.; Bartlett, Paul; Renzoni, Ferruccio

    2016-09-01

    The possibility of revealing the presence and identifying the nature of conductive targets is of central interest in many fields, including security, medicine, industry, archaeology and geophysics. In many applications, these targets are shielded by external materials and thus cannot be directly accessed. Hence, interrogation techniques are required that allow penetration through the shielding materials, in order for the target to be identified. Electromagnetic interrogation techniques represent a powerful solution to this challenge, as they enable penetration through conductive shields. In this work, we demonstrate the power of resonant electromagnetic induction imaging to penetrate through metallic shields (1.5-mm-thick) and image targets (having conductivities σ ranging from 0.54 to 59.77 MSm-1) concealed behind them.

  10. Penetrating power of resonant electromagnetic induction imaging

    Directory of Open Access Journals (Sweden)

    Roberta Guilizzoni

    2016-09-01

    Full Text Available The possibility of revealing the presence and identifying the nature of conductive targets is of central interest in many fields, including security, medicine, industry, archaeology and geophysics. In many applications, these targets are shielded by external materials and thus cannot be directly accessed. Hence, interrogation techniques are required that allow penetration through the shielding materials, in order for the target to be identified. Electromagnetic interrogation techniques represent a powerful solution to this challenge, as they enable penetration through conductive shields. In this work, we demonstrate the power of resonant electromagnetic induction imaging to penetrate through metallic shields (1.5-mm-thick and image targets (having conductivities σ ranging from 0.54 to 59.77 MSm−1 concealed behind them.

  11. Magnetic resonance imaging of brain death

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D.H.; Nathanson, J.A.; Fox, A.J.; Pelz, D.M.; Lownie, S.P.

    1995-06-01

    In order to demonstrate the magnetic resonance imaging (MRI) appearance of the brain in patients with clinical brain death, high-field MRI was performed on 5 patients using conventional T1-weighted and T2-weighted imaging. The study showed MRI exhibited similar features for all of the patients, features which were not found in MRI of comatose patients who were not clinically brain dead. It was stated that up to now the most important limitation in MRI of patients with suspected brain death has been the extreme difficulty of moving them out of the intensive care setting. If this problem can be overcome, and it appears possible with with the advent of MRI-compatible ventilators and noninvasive monitoring, MRI could become an excellent alternative for confirming clinical diagnosis of brain death for such patients. 15 refs., 3 figs.

  12. Nuclear magnetic resonance imaging of the spine

    Energy Technology Data Exchange (ETDEWEB)

    Modic, M.T.; Weinstein, M.A.; Pavlicek, W.; Starnes, D.L.; Duchesneau, P.M.; Boumphrey, F.; Hardy, R.J. Jr.

    1984-01-01

    Forty subjects were examined to determine the accuracy and clinical usefulness of nuclear magnetic resonance (NMR) examination of the spine. The NMR images were compared with plain radiographs, high-resolution computed tomograms, and myelograms. The study included 15 patients with normal spinal cord anatomy and 25 patients whose pathological conditions included canal stenosis, herniated discs, metastatic tumors, primary cord tumor, trauma, Chiari malformations, syringomyelia, and developmental disorders. Saturation recovery images were best in differentiating between soft tissue and cerebrospinal fluid. NMR was excellent for the evaluation of the foramen magnum region and is presently the modality of choice for the diagnosis of syringomyelia and Chiari malformation. NMR was accurate in diagnosing spinal cord trauma and spinal canal block.

  13. Prostate magnetic resonance imaging: challenges of implementation.

    Science.gov (United States)

    Loch, Ronald; Fowler, Kathryn; Schmidt, Ryan; Ippolito, Joseph; Siegel, Cary; Narra, Vamsi

    2015-01-01

    Prostate cancer is among the most common causes of cancer and cancer deaths in men. Screening methods and optimal treatments have become controversial in recent years. Prostate magnetic resonance imaging (MRI) is gaining popularity as a tool to assist diagnosis, risk assessment, and staging. However, implementation into clinical practice can be difficult, with many challenges associated with image acquisition, postprocessing, interpretation, reporting, and radiologic-pathologic correlation. Although state-of-the-art technology is available at select sites for targeting tissue biopsy and interpreting multiparametric prostate MRI, many institutions struggle with adapting this new technology into an efficient multidisciplinary model of patient care. This article reviews several of the challenges that radiologists should be aware of when integrating prostate MRI into their clinical practice.

  14. Magnetic resonance imaging of spinal cord syndromes

    Energy Technology Data Exchange (ETDEWEB)

    Einsiedel, H. von; Stepan, R.

    1985-05-01

    Thirty-four patients with intramedullary space-occupying lesions or cord compression syndromes were examined with a resistive and two different superconductive magnetic resonance (MR) imaging units. Studies were done primarily by the spin-echo (SE) technique and in the majority of patients different pulse sequences were used. Images with short echo-time (TE) and short recovery-time (TR) were best for demonstration of spinal cord anatomy, for depicting cystic portions in intramedullary tumours and for showing syringomyelia. Solid intramedullary tumours showed normal cord signal intensity. Images with prolonged TE and TR predominantly enhanced CSF signal intensity and, to a more considerable extent, solid intramedullary tumours. Thus, the diameter of the subarachnoid space and the presence of a solid intramedullary tumour, not concomittant with a significant enlargement of the spinal cord, could only be recognized on these prolonged SE images. Major advantages of MR in comparison to CT are that the spinal cord can be imaged in the sagittal plane and that beam hardening artifacts do not occur; in comparison to myelography the cord can be imaged directly by MR. Partial volume is a major limitation of MR, not only in the preferably applied sagittal plane. The choice of slice thickness adequate to the diameter of the lesion and straight positioning of the patient for sagittal single slice midline images are fundamental for reliable MR investigations. Another limitation to MR is that cortical bone gives no signal. The actual diameter of the spinal canal therefore cannot be correctly appreciated and consequently it was difficult or impossible to assess spinal stenosis.

  15. 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 ...

  16. Neurological images and the predictors for neurological sequelae of epidemic herpangina/hand-foot-mouth disease with encephalomyelitis.

    Science.gov (United States)

    Tsai, Jeng-Dau; Kuo, Hung-Tsung; Chen, Shan-Ming; Lue, Ko-Huang; Sheu, Ji-Nan

    2014-04-01

    Since 1998 in Taiwan, enterovirus (EV) 71 epidemics have caused encephalomyelitis and placed a significant burden on parents and physicians. In this study, we present clinical manifestations, magnetic resonance (MR) imaging findings, and neurological sequelae on epidemic EV-infected patients with encephalomyelitis. Of the 46 patients, 14 patients presented with neurological sequelae; of them, 3 patients suffered from complications of mental regression. Predictors of unfavorable neurological sequelae were myoclonic jerks (> 4 times/night) and pleocytosis (167/μL) of the cerebrospinal fluid (CSF). Results from viral culture and MR imaging indicated that positive identification of EV71 infection was associated significantly with lesions on MR imaging. Our results show that hand-foot-mouth disease carries a higher risk of encephalomyelitis and that frequent myoclonic jerks and pleocytosis of the CSF are risk factors for subsequent neurological sequelae. Positive identification of EV71 might be useful as a predictor of lesions in MR imaging.

  17. Magnetic resonance imaging in complex partial seizures

    Energy Technology Data Exchange (ETDEWEB)

    Furune, Sunao; Negoro, Tamiko; Maehara, Mitsuo; Nomura, Kazushi; Miura, Kiyokuni; Takahashi, Izumi; Watanabe, Kazuyoshi (Nagoya Univ. (Japan). Faculty of Medicine)

    1989-09-01

    Magnetic resonance imaging (MRI) and computed tomography (CT) were performed on 45 patients with intractable complex partial seizures. MRI was performed with a superconducting whole-body scanner operating at 0.5 tesla (T) and 1.5 T. In patients with temporal lobe epilepsy, 8 of 24 patients had abnormal CT, but 16 or 24 patients showed abnormal MRI. 1.5 T MRI detected more abnormality than 0.5 T MRI when CT was normal. In patients with frontal lobe epilepsy, 5 of 7 patients had normal CT and MRI. In 2 other patients, MRI demonstrated an arachnoid cyst and increased signal intensity area on the T2-weighted images which were not detected by CT. In patients with occipital lobe epilepsy, 5 of 6 patients show abnormal CT and MRI. In patients with tuberous sclerosis, MRI revealed some increased signal intensity areas on the T2-weighted images in the occipital and temporal lobe, which were not detected by CT. Most surface EEG foci corresponded with the side of MRI abnormality. These data indicate that MRI is more informative than CT in complex partial seizures. MRI is the imaging technique of choice in the diagnosis of complex partial seizures. (author).

  18. Magnetic resonance imaging in glenohumeral instability

    Science.gov (United States)

    Jana, Manisha; Gamanagatti, Shivanand

    2011-01-01

    The glenohumeral joint is the most commonly dislocated joint of the body and anterior instability is the most common type of shoulder instability. Magnetic resonance (MR) imaging, and more recently, MR arthrography, have become the essential investigation modalities of glenohumeral instability, especially for pre-procedure evaluation before arthroscopic surgery. Injuries associated with glenohumeral instability are variable, and can involve the bones, the labor-ligamentous components, or the rotator cuff. Anterior instability is associated with injuries of the anterior labrum and the anterior band of the inferior glenohumeral ligament, in the form of Bankart lesion and its variants; whereas posterior instability is associated with reverse Bankart and reverse Hill-Sachs lesion. Multidirectional instability often has no labral pathology on imaging but shows specific osseous changes such as increased chondrolabral retroversion. This article reviews the relevant anatomy in brief, the MR imaging technique and the arthrographic technique, and describes the MR findings in each type of instability as well as common imaging pitfalls. PMID:22007285

  19. Magnetic resonance imaging and its applicability in veterinary cardiology

    OpenAIRE

    Ferreira, José Manuel de Seiça

    2016-01-01

    Magnetic Resonance Imaging (MRI) is a technique whereby images are created by the manipulation of hydrogen atoms in magnetic fields; it is based on the principle of nuclear magnetic resonance (MR), which is non-invasive and non-ionising (Constantine, Shan, Flamm, & Sivananthan, 2004). Cardiac Magnetic Resonance Imaging (CMRI) uses the same principle: application of magnetic-field gradients that are adjusted to highlight desired tissue characteristics, producing a variety of sequences that all...

  20. Research progress of magnetic resonance imaging contrast agents

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Magnetic resonance imaging (MRI) is a clinical diagnostic modality, which has become popular in hospitals around the world. Approximately 30% of MRI exams include the use of contrast agents. The research progress of the paramagnetic resonance imaging contrast agents was described briefly. Three important approaches in the soluble paramagnetic resonance imaging contrast agents design including nonionic, tissue-specific and macromolecular contrast agents were investigated. In addition, the problems in the research and development in future were discussed.

  1. Image fusion for dynamic contrast enhanced magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Leach Martin O

    2004-10-01

    Full Text Available Abstract Background Multivariate imaging techniques such as dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI have been shown to provide valuable information for medical diagnosis. Even though these techniques provide new information, integrating and evaluating the much wider range of information is a challenging task for the human observer. This task may be assisted with the use of image fusion algorithms. Methods In this paper, image fusion based on Kernel Principal Component Analysis (KPCA is proposed for the first time. It is demonstrated that a priori knowledge about the data domain can be easily incorporated into the parametrisation of the KPCA, leading to task-oriented visualisations of the multivariate data. The results of the fusion process are compared with those of the well-known and established standard linear Principal Component Analysis (PCA by means of temporal sequences of 3D MRI volumes from six patients who took part in a breast cancer screening study. Results The PCA and KPCA algorithms are able to integrate information from a sequence of MRI volumes into informative gray value or colour images. By incorporating a priori knowledge, the fusion process can be automated and optimised in order to visualise suspicious lesions with high contrast to normal tissue. Conclusion Our machine learning based image fusion approach maps the full signal space of a temporal DCE-MRI sequence to a single meaningful visualisation with good tissue/lesion contrast and thus supports the radiologist during manual image evaluation.

  2. Pancreatitis: computed tomography and magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, P.J.A.; Sheridan, M.B. [Dept. of Clinical Radiology, St. James' s University Hospital, Leeds (United Kingdom)

    2000-03-01

    The value of CT in management of severe acute pancreatitis is well established. Some, but not all, experimental studies suggest a detrimental effect of intravenous iodinated contrast agents in acute pancreatitis, but although initial clinical data tends to support this, the positive advantages of enhanced CT outweigh the possible risks. Magnetic resonance imaging has been shown to be as effective as CT in demonstrating the presence and extent of pancreatic necrosis and fluid collections, and probably superior in indicating the suitability of such collections for percutaneous drainage. Image-guided intervention remains a key approach in the management of severely ill patients, and the indications, techniques and results of radiological intervention are reviewed herein. Both CT and MRI can be used to diagnose advanced chronic pancreatitis, with the recent addition of MRCP as a viable alternative to diagnostic endoscopic retrograde cholangiopancreatography (ERCP). Both MRCP and CT/MR imaging of the pancreatic parenchyma still have limitations in the recognition of the earliest changes of chronic pancreatitis - for which ERCP and tests of pancreatic function remain more sensitive - but the clinical significance of these minor changes remains contentious. (orig.)

  3. 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.

  4. 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.

  5. Segmentation of neuroanatomy in magnetic resonance images

    Science.gov (United States)

    Simmons, Andrew; Arridge, Simon R.; Barker, G. J.; Tofts, Paul S.

    1992-06-01

    Segmentation in neurological magnetic resonance imaging (MRI) is necessary for feature extraction, volume measurement and for the three-dimensional display of neuroanatomy. Automated and semi-automated methods offer considerable advantages over manual methods because of their lack of subjectivity, their data reduction capabilities, and the time savings they give. We have used dual echo multi-slice spin-echo data sets which take advantage of the intrinsically multispectral nature of MRI. As a pre-processing step, a rf non-uniformity correction is applied and if the data is noisy the images are smoothed using a non-isotropic blurring method. Edge-based processing is used to identify the skin (the major outer contour) and the eyes. Edge-focusing has been used to significantly simplify edge images and thus allow simple postprocessing to pick out the brain contour in each slice of the data set. Edge- focusing is a technique which locates significant edges using a high degree of smoothing at a coarse level and tracks these edges to a fine level where the edges can be determined with high positional accuracy. Both 2-D and 3-D edge-detection methods have been compared. Once isolated, the brain is further processed to identify CSF, and, depending upon the MR pulse sequence used, the brain itself may be sub-divided into gray matter and white matter using semi-automatic contrast enhancement and clustering methods.

  6. Suspected invasive placenta: evaluation with magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bour, Laurence; Place, Vinciane; Bendavid, Sandra; Fargeaudou, Yann [Hopital Lariboisiere-AP-HP, Department of Abdominal and Interventional Imaging, Paris cedex 10 (France); Portal, Jean-Jacques [Hopital Lariboisiere-AP-HP, Department of Biostatistics and Clinical Research, Paris cedex 10 (France); Ricbourg, Aude [Hopital Lariboisiere-AP-HP, Department of Obstetrics and Gynecology, Paris cedex 10 (France); Sebbag, Delphine; Dohan, Anthony; Soyer, Philippe [Hopital Lariboisiere-AP-HP, Department of Abdominal and Interventional Imaging, Paris cedex 10 (France); Diderot-Paris 7 University-Sorbonne Paris-Cite, Paris (France); Vicaut, Eric [Hopital Lariboisiere-AP-HP, Department of Biostatistics and Clinical Research, Paris cedex 10 (France); Diderot-Paris 7 University-Sorbonne Paris-Cite, Paris (France)

    2014-12-15

    To determine the utility of magnetic resonance imaging (MRI) in diagnosing invasive placenta (IP). MRI findings in 32 women with suspected IP were evaluated independently by four readers. Interobserver agreement was calculated with kappa (κ) statistics. Associations between MRI findings and IP were assessed by univariate and multivariate analyses. Sensitivity, specificity and accuracy of MRI for the diagnosis of IP were estimated. Sixteen women (16/32; 50 %) had confirmed IP. Interobserver correlation for the diagnosis of IP was fair (κ = 0.40). Univariate analysis revealed that thinning or focal defect of the uteroplacental interface (P < 0.0001) was the most discriminating MRI variable in the differentiation between normal and IP. Overall sensitivity and specificity of MRI for the diagnosis of IP were 84 % [95 % CI: 75-94 %] and 80 % [95 % CI: 66-93 %], respectively. Thinning or focal defect of the uteroplacental interface was the most accurate finding (88 %) in the diagnosis of IP. Multivariate analysis revealed that thinning or focal defect of the uteroplacental interface was the single independent predictor of IP (P = 0.0006; OR = 64.99). MR imaging has 84 % sensitivity [95 % CI: 75-94 %] and 80 % specificity [95 % CI: 66-93 %] for the diagnosis of IP. Thinning or focal defect of the uteroplacental interface is the most discriminating independent MR variable in differentiating between normal placenta and IP. (orig.)

  7. Cardiac magnetic resonance imaging: patient safety considerations.

    Science.gov (United States)

    Giroletti, Elio; Corbucci, Giorgio

    Magnetic Resonance Imaging (MRI) is widely used in medicine. In cardiology, it is used to assess congenital or acquired diseases of the heat: and large vessels. Unless proper precautions are taken, it is generally advisable to avoid using this technique in patients with implanted electronic stimulators, such as pacemakers and defibrillators, on account of the potential risk of inducing electrical currents on the endocardial catheters, since these currents might stimulate the heart at a high frequency, thereby triggering dangerous arrhythmias. In addition to providing some basic information on pacemakers, defibrillators and MRI, and on the possible physical phenomena that may produce harmful effects, the present review examines the indications given in the literature, with particular reference to coronary stents, artificial heart valves and implantable cardiac stimulators.

  8. Breast conserving therapy and magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Seki, Tsuneaki; Masuda, Yu; Hachiya, Junichi; Nitatori, Toshiaki; Fukushima, Hisayoshi; Uchigasaki, Shinya [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine

    1996-12-01

    Recently, breast conserving therapy has been widely accepted in our country. The extensive intraductal component (EIC) is a serious problem in breast conserving therapy, because it is well-known that EIC frequently causes locoregional recurrence in preserved breast parenchyma. Magnetic resonance imaging (MRI) is a useful method for detecting breast masses due to its excellent contrast resolution. We studied the application of MRI to detection of intraductal spread in twenty-two patients. All cases were revealed invasive cancer with intraductal spread by histopathological examination. MRI findings of intraductal spread can be divided into two major groups. One is daugter nodules or strand-like enhancement and the other is bridging enhancement. We also reffered to the preliminary study of MR-guiding transcutaneous aspiration biopsy of mammographically and clinically occult breast masses. (author)

  9. Magnetic resonance imaging of the heart.

    Science.gov (United States)

    Tscholakoff, D; Higgins, C B

    1985-01-01

    Magnetic resonance imaging (MRI) is a completely noninvasive technique for the evaluation of the cardiovascular system. With a multi-section technique and the spin echo pulse sequence the entire heart can be examined within six to ten minutes. All our cardiac MR studies were performed with electrocardiographic (ECG) gating, to obtain adequate resolution of the cardiac structures. With this technique, patients and animals with a variety of cardiac abnormalities were studied. The examined pathologic conditions included acute and chronic myocardial infarctions and their complications, hypertrophic and congestive cardiomyopathies, congenital heart diseases and pericardial diseases. MRI offers an enormous potential for cardiovascular diagnosis, even beyond the demonstration of pathoanatomy, because of the capability for direct tissue characterization and blood flow measurements.

  10. Magnetic resonance imaging of traumatic cervical injury

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-04-15

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

  11. Magnetic resonance imaging of the normal placenta.

    Science.gov (United States)

    Blaicher, Wibke; Brugger, Peter C; Mittermayer, Christoph; Schwindt, Jens; Deutinger, Josef; Bernaschek, Gerhard; Prayer, Daniela

    2006-02-01

    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.

  12. 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.

  13. Antepartum pelvimetry by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Koshiba, Hisato; Kikuchi, Noriko; Ogino, Yoshio [Kyoto Second Red Cross Hospital (Japan)] (and others)

    2001-09-01

    Evaluation of the pelvis by pelvimetry plays an important role in selecting patients for possible vaginal delivery. However, x-ray pelvimetry involves the disadvantage of fetal exposure to ionizing radiation. The clear advantage of magnetic resonance imaging (MRI) pelvimetry is that this procedure is free from ionizing radiation. Measurements with MRI are as reliable as those with x-ray pelvimetry and the contrast of MRI is even better. MRI shows soft-tissue structures as well as bone. The use of this scanning technique is contraindicated for patients with pacemakers. But, pacemakers are rarely encountered in young pregnant women. In our department, 203 patients underwent antepartum pelvimetry with MRI during the last 5 years. T1-weighted mediosagittal images were used for measurement of the obstetric conjugate (OC) and to determine whether a straight sacrum can be recognized. Data were compared between patients who had undergone cesarean section due to cephalopelvic disproportion (CPD) and patients who experienced vaginal delivery. OC and OC-biparietal diameter were significantly different between the two groups. MRI can be further used for the diagnosis of CPD and to select patients for whom planned vaginal delivery is appropriate. (author)

  14. Magnetic resonance imaging of pelvic endometriosis.

    Science.gov (United States)

    Méndez Fernández, R; Barrera Ortega, J

    Endometriosis is common in women of reproductive age; it can cause pelvic pain and infertility. It is important to diagnose endometriosis and to thoroughly evaluate its extension, especially when surgical treatment is being considered. Magnetic resonance imaging (MRI) with careful examination technique and interpretation enables more accurate and complete diagnosis and staging than ultrasonography, especially in cases of deep pelvic endometriosis. Furthermore, MRI can identify implants in sites that can be difficult to access in endoscopic or laparoscopic explorations. In this article, we describe the appropriate MRI protocol for the study of pelvic endometriosis and the MRI signs of pelvic organ involvement. It is necessary to know the subtle findings and to look for them so we can ensure that they are not overlooked. We describe clinical grading systems for endometriosis and review the diagnostic efficacy of MRI in comparison with other imaging techniques and surgery. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Magnetic resonance imaging of cerebellopontine angle lesions

    Directory of Open Access Journals (Sweden)

    Pratiksha Yadav

    2015-01-01

    Full Text Available Background: Cerebellopontine angle (CPA tumors are usually benign, and they are divided into extra-axial, intra-axial, extradural, and petrous axis tumors. CPA pathologies can be asymptomatic or it may present with vertigo, tinnitus, or unilateral hearing loss depending upon the site of tumor origin and displacement of the neurovascular structure. Aim and Objectives: To evaluate the role of magnetic resonance imaging (MRI aided with contrast-enhanced MRI as an imaging modality for diagnosis of CPA lesions. Materials and Methods: Analysis of 36 patients of CPA lesions over a period of 2 years was done. MRI was performed on Siemens 1.5 Tesla MAGNETOM Avanto Machine. Conclusion: There are spectrums of pathologies, which can present with these symptoms, which includes tumors, vascular malformations, and vascular loop compressing vestibulocochlear nerve or mastoid pathology so it is important to investigate the patient by MRI. Contrast-enhanced MRI is the most sensitive investigation in the evaluation of the CPA lesions, its characteristic, and its extent.

  16. 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...

  17. Real-time magnetic resonance imaging investigation of resonance tuning in soprano singing

    OpenAIRE

    Bresch, Erik; Narayanan, Shrikanth

    2010-01-01

    This article investigates using real-time magnetic resonance imaging the vocal tract shaping of 5 soprano singers during the production of two-octave scales of sung vowels. A systematic shift of the first vocal tract resonance frequency with respect to the fundamental is shown to exist for high vowels across all subjects. No consistent systematic effect on the vocal tract resonance could be shown across all of the subjects for other vowels or for the second vocal tract resonance.

  18. 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.)

  19. Correlation of computed tomography, magnetic resonance imaging and clinical outcome in acute carbon monoxide poisoning.

    Science.gov (United States)

    Ozcan, Namik; Ozcam, Giray; Kosar, Pinar; Ozcan, Ayse; Basar, Hulya; Kaymak, Cetin

    2016-01-01

    Carbon monoxide is a toxic gas for humans and is still a silent killer in both developed and developing countries. The aim of this case series was to evaluate early radiological images as a predictor of subsequent neuropsychological sequelae, following carbon monoxide poisoning. After carbon monoxide exposure, early computed tomography scans and magnetic resonance imaging findings of a 52-year-old woman showed bilateral lesions in the globus pallidus. This patient was discharged and followed for 90 days. The patient recovered without any neurological sequela. In a 58-year-old woman exposed to carbon monoxide, computed tomography showed lesions in bilateral globus pallidus and periventricular white matter. Early magnetic resonance imaging revealed changes similar to that like in early tomography images. The patient recovered and was discharged from hospital. On the 27th day of exposure, the patient developed disorientation and memory impairment. Late magnetic resonance imaging showed diffuse hyperintensity in the cerebral white matter. White matter lesions which progress to demyelination and end up in neuropsychological sequelae cannot always be diagnosed by early computed tomography and magnetic resonance imaging in carbon monoxide poisoning. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  20. Correlation of computed tomography, magnetic resonance imaging and clinical outcome in acute carbon monoxide poisoning

    Directory of Open Access Journals (Sweden)

    Namik Ozcan

    Full Text Available Abstract Background and objectives: Carbon monoxide is a toxic gas for humans and is still a silent killer in both developed and developing countries. The aim of this case series was to evaluate early radiological images as a predictor of subsequent neuropsychological sequelae, following carbon monoxide poisoning. Case 1: After carbon monoxide exposure, early computed tomography scans and magnetic resonance imaging findings of a 52-year-old woman showed bilateral lesions in the globus pallidus. This patient was discharged and followed for 90 days. The patient recovered without any neurological sequela. Case 2: In a 58-year-old woman exposed to carbon monoxide, computed tomography showed lesions in bilateral globus pallidus and periventricular white matter. Early magnetic resonance imaging revealed changes similar to that like in early tomography images. The patient recovered and was discharged from hospital. On the 27th day of exposure, the patient developed disorientation and memory impairment. Late magnetic resonance imaging showed diffuse hyperintensity in the cerebral white matter. Conclusion: White matter lesions which progress to demyelination and end up in neuropsychological sequelae cannot always be diagnosed by early computed tomography and magnetic resonance imaging in carbon monoxide poisoning.

  1. Far-field super-resolution imaging of resonant multiples

    KAUST Repository

    Guo, Bowen

    2016-05-20

    We demonstrate for the first time that seismic resonant multiples, usually considered as noise, can be used for super-resolution imaging in the far-field region of sources and receivers. Tests with both synthetic data and field data show that resonant multiples can image reflector boundaries with resolutions more than twice the classical resolution limit. Resolution increases with the order of the resonant multiples. This procedure has important applications in earthquake and exploration seismology, radar, sonar, LIDAR (light detection and ranging), and ultrasound imaging, where the multiples can be used to make high-resolution images.

  2. Diagnostic imaging of psoriatic arthritis. Part II: magnetic resonance imaging and ultrasonography.

    Science.gov (United States)

    Sudoł-Szopińska, Iwona; Pracoń, Grzegorz

    2016-06-01

    Plain radiography reveals specific, yet late changes of advanced psoriatic arthritis. Early inflammatory changes are seen both on magnetic resonance imaging and ultrasound within peripheral joints (arthritis, synovitis), tendons sheaths (tenosynovitis, tendovaginitis) and entheses (enthesitis, enthesopathy). In addition, magnetic resonance imaging enables the assessment of inflammatory features in the sacroiliac joints (sacroiliitis), and the spine (spondylitis). In this article, we review current opinions on the diagnostics of some selective, and distinctive features of psoriatic arthritis concerning magnetic resonance imaging and ultrasound and present some hypotheses on psoriatic arthritis etiopathogenesis, which have been studied with the use of magnetic resonance imaging. The following elements of the psoriatic arthritis are discussed: enthesitis, extracapsular inflammation, dactylitis, distal interphalangeal joint and nail disease, and the ability of magnetic resonance imaging to differentiate undifferentiated arthritis, the value of whole-body magnetic resonance imaging and dynamic contrast-enhanced magnetic resonance imaging.

  3. Diagnostic imaging of psoriatic arthritis. Part II: magnetic resonance imaging and ultrasonography

    Directory of Open Access Journals (Sweden)

    Iwona Sudoł-Szopińska

    2016-06-01

    Full Text Available Plain radiography reveals specific, yet late changes of advanced psoriatic arthritis. Early inflammatory changes are seen both on magnetic resonance imaging and ultrasound within peripheral joints (arthritis, synovitis, tendons sheaths (tenosynovitis, tendovaginitis and entheses (enthesitis, enthesopathy. In addition, magnetic resonance imaging enables the assessment of inflammatory features in the sacroiliac joints (sacroiliitis, and the spine (spondylitis. In this article, we review current opinions on the diagnostics of some selective, and distinctive features of psoriatic arthritis concerning magnetic resonance imaging and ultrasound and present some hypotheses on psoriatic arthritis etiopathogenesis, which have been studied with the use of magnetic resonance imaging. The following elements of the psoriatic arthritis are discussed: enthesitis, extracapsular inflammation, dactylitis, distal interphalangeal joint and nail disease, and the ability of magnetic resonance imaging to differentiate undifferentiated arthritis, the value of whole-body magnetic resonance imaging and dynamic contrast-enhanced magnetic resonance imaging.

  4. Valid MR imaging predictors of prior knee arthroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Discepola, Federico; Le, Huy B.Q. [McGill University Health Center, Jewsih General Hospital, Division of Musculoskeletal Radiology, Montreal, Quebec (Canada); Park, John S. [Annapolis Radiology Associates, Division of Musculoskeletal Radiology, Annapolis, MD (United States); Clopton, Paul; Knoll, Andrew N.; Austin, Matthew J.; Resnick, Donald L. [University of California San Diego (UCSD), Division of Musculoskeletal Radiology, San Diego, CA (United States)

    2012-01-15

    To determine whether fibrosis of the medial patellar reticulum (MPR), lateral patellar reticulum (LPR), deep medial aspect of Hoffa's fat pad (MDH), or deep lateral aspect of Hoffa's fat pad (LDH) is a valid predictor of prior knee arthroscopy. Institutional review board approval and waiver of informed consent were obtained for this HIPPA-compliant study. Initially, fibrosis of the MPR, LPR, MDH, or LDH in MR imaging studies of 50 patients with prior knee arthroscopy and 100 patients without was recorded. Subsequently, two additional radiologists, blinded to clinical data, retrospectively and independently recorded the presence of fibrosis of the MPR in 50 patients with prior knee arthroscopy and 50 without. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for detecting the presence of fibrosis in the MPR were calculated. {kappa} statistics were used to analyze inter-observer agreement. Fibrosis of each of the regions examined during the first portion of the study showed a significant association with prior knee arthroscopy (p < 0.005 for each). A patient with fibrosis of the MPR, LDH, or LPR was 45.5, 9, or 3.7 times more likely, respectively, to have had a prior knee arthroscopy. Logistic regression analysis indicated that fibrosis of the MPR supplanted the diagnostic utility of identifying fibrosis of the LPR, LDH, or MDH, or combinations of these (p {>=} 0.09 for all combinations). In the second portion of the study, fibrosis of the MPR demonstrated a mean sensitivity of 82%, specificity of 72%, PPV of 75%, NPV of 81%, and accuracy of 77% for predicting prior knee arthroscopy. Analysis of MR images can be used to determine if a patient has had prior knee arthroscopy by identifying fibrosis of the MPR, LPR, MDH, or LDH. Fibrosis of the MPR was the strongest predictor of prior knee arthroscopy. (orig.)

  5. Nonpolitical images evoke neural predictors of political ideology.

    Science.gov (United States)

    Ahn, Woo-Young; Kishida, Kenneth T; Gu, Xiaosi; Lohrenz, Terry; Harvey, Ann; Alford, John R; Smith, Kevin B; Yaffe, Gideon; Hibbing, John R; Dayan, Peter; Montague, P Read

    2014-11-17

    Political ideologies summarize dimensions of life that define how a person organizes their public and private behavior, including their attitudes associated with sex, family, education, and personal autonomy. Despite the abstract nature of such sensibilities, fundamental features of political ideology have been found to be deeply connected to basic biological mechanisms that may serve to defend against environmental challenges like contamination and physical threat. These results invite the provocative claim that neural responses to nonpolitical stimuli (like contaminated food or physical threats) should be highly predictive of abstract political opinions (like attitudes toward gun control and abortion). We applied a machine-learning method to fMRI data to test the hypotheses that brain responses to emotionally evocative images predict individual scores on a standard political ideology assay. Disgusting images, especially those related to animal-reminder disgust (e.g., mutilated body), generate neural responses that are highly predictive of political orientation even though these neural predictors do not agree with participants' conscious rating of the stimuli. Images from other affective categories do not support such predictions. Remarkably, brain responses to a single disgusting stimulus were sufficient to make accurate predictions about an individual subject's political ideology. These results provide strong support for the idea that fundamental neural processing differences that emerge under the challenge of emotionally evocative stimuli may serve to structure political beliefs in ways formerly unappreciated. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  6. 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

  7. Voxelwise multivariate analysis of multimodality magnetic resonance imaging.

    Science.gov (United States)

    Naylor, Melissa G; Cardenas, Valerie A; Tosun, Duygu; Schuff, Norbert; Weiner, Michael; Schwartzman, Armin

    2014-03-01

    Most brain magnetic resonance imaging (MRI) studies concentrate on a single MRI contrast or modality, frequently structural MRI. By performing an integrated analysis of several modalities, such as structural, perfusion-weighted, and diffusion-weighted MRI, new insights may be attained to better understand the underlying processes of brain diseases. We compare two voxelwise approaches: (1) fitting multiple univariate models, one for each outcome and then adjusting for multiple comparisons among the outcomes and (2) fitting a multivariate model. In both cases, adjustment for multiple comparisons is performed over all voxels jointly to account for the search over the brain. The multivariate model is able to account for the multiple comparisons over outcomes without assuming independence because the covariance structure between modalities is estimated. Simulations show that the multivariate approach is more powerful when the outcomes are correlated and, even when the outcomes are independent, the multivariate approach is just as powerful or more powerful when at least two outcomes are dependent on predictors in the model. However, multiple univariate regressions with Bonferroni correction remain a desirable alternative in some circumstances. To illustrate the power of each approach, we analyze a case control study of Alzheimer's disease, in which data from three MRI modalities are available. Copyright © 2013 Wiley Periodicals, Inc.

  8. 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.

  9. 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.

  10. Magnetic Resonance Imaging in Pediatric Elbow Fractures

    Energy Technology Data Exchange (ETDEWEB)

    Pudas, T.; Hurme, T.; Mattila, K.; Svedstroem, E. [Univ. of Turku, (Finland). Depts. of Radiology and Pediatric Surgery

    2005-10-01

    Purpose: Magnetic resonance imaging (MRI) evaluation of pediatric elbow trauma with or without a visible fracture on radiography. Material and Methods: MRI was performed in the acute phase in 25 children with an elbow injury. Nine patients with an elbow effusion only on radiographs and 16 with a fracture or luxation seen on radiographs underwent subsequent MRI. No sedation was used. Results: MRI revealed eight occult fractures (89%) in seven out of nine patients who had only an effusion on radiographs. Based on MRI findings, septic arthritis was suspected in one patient. Two patients out of five with a supracondylar fracture on the radiograph had a cartilage lesion in the humerus. MRI depicted a 3-mm gap on the articular surface in two patients with a lateral condyle fracture, a more accurate fracture location in two patients than the radiographs, and an additional occult fracture in two patients. MRI showed a fracture not seen on radiographs in two of three patients with prior luxation. Conclusion: MRI is a sensitive and accurate method in the diagnosis of pediatric elbow injuries, especially when only an effusion is present on radiographs. Occult fractures are more common in pediatric patients with elbow injury than reported earlier.

  11. Endorectal magnetic resonance imaging in persistent hemospermia

    Directory of Open Access Journals (Sweden)

    Adilson Prando

    2008-03-01

    Full Text Available OBJECTIVE: To present the spectrum of abnormalities found at endorectal magnetic resonance imaging (E-MRI, in patients with persistent hemospermia. MATERIALS AND METHODS: A review of E-MRI findings observed in 86 patients with persistent hemospermia was performed and results compared with those reported in the literature. Follow-up was possible in 37 of 86 (43% patients with hemospermia. RESULTS: E-MRI showed abnormal findings in 52 of 86 (60% patients with hemospermia. These findings were: a hemorrhagic seminal vesicle and ejaculatory duct, isolated (n = 11 or 21% or associated with complicated midline prostatic cyst (n = 10 or 19.0%; b hemorrhagic chronic seminal vesiculitis, isolated (n = 14 or 27% or associated with calculi within dilated ejaculatory ducts (n = 2 or 4 %; c hemorrhagic seminal vesicle associated with calculi within dilated ejaculatory duct (n = 4 or 7.7% or within seminal vesicle (n = 4 or 7.7%; d non-complicated midline prostatic cyst (n = 6 or 11.5%; and e prostate cancer (n = 1 or 2%. Successful treatment was more frequent in patients with chronic inflammatory and/or obstructive abnormalities. CONCLUSION: E-MRI should be considered the modality of choice, for the evaluation of patients with persistent hemospermia.

  12. Endorectal magnetic resonance imaging in persistent hemospermia

    Energy Technology Data Exchange (ETDEWEB)

    Prando, Adilson [Vera Cruz Hospital, Campinas, SP (Brazil). Dept. of Radiology and Diagnostic Imaging

    2008-03-15

    Objective: To present the spectrum of abnormalities found at endorectal magnetic resonance imaging (E-MRI), in patients with persistent hemospermia. Materials and methods: A review of E-MRI findings observed in 86 patients with persistent hemospermia was performed and results compared with those reported in the literature. Follow-up was possible in 37 of 86 (43%) patients with hemospermia. Results: E-MRI showed abnormal findings in 52 of 86 (60%) patients with hemospermia. These findings were: a) hemorrhagic seminal vesicle and ejaculatory duct, isolated (n = 11 or 21%) or associated with complicated midline prostatic cyst (n = 10 or 19.0%); b) hemorrhagic chronic seminal vesiculitis, isolated (n = 14 or 27%) or associated with calculi within dilated ejaculatory ducts (n = 2 or 4 %); c) hemorrhagic seminal vesicle associated with calculi within dilated ejaculatory duct (n = 4 or 7.7%) or within seminal vesicle (n = 4 or 7.7%); d) non-complicated midline prostatic cyst (n = 6 or 11.5%); and e) prostate cancer (n = 1 or 2%). Successful treatment was more frequent in patients with chronic inflammatory and/or obstructive abnormalities. Conclusion: E-MRI should be considered the modality of choice, for the evaluation of patients with persistent hemospermia. (author)

  13. Potts disease: Diagnosis with magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pursey, Jacqueline [MRI Department, Gartnavel General Hospitial, 1053 Great Western road, Glasgow G12 0YN (United Kingdom)], E-mail: Jacqueline.pursey@ggc.scot.nhs.uk; Stewart, Sharon [School of Health and Social Care, Caledonian University, Glasgow (United Kingdom)

    2010-02-15

    The eponymously named Potts disease is a relatively rare form of Tuberculosis (TB) which affects the spine. TB of the spine is one of the earliest diseases known to man and in the 20th century was thought to be a disease which had been defeated by the advent of antitubercular drugs. Over the last two decades there have been several reports which indicate a revival of TB in both the developing and developed world. Factors which may be contributing to this are the spread of the HIV virus, increased immigration and the emergence of drug resistant strains of the TB bacteria. Potts disease has an insidious onset and often the radiographic findings are far advanced when a diagnosis is finally reached. MRI is able to detect changes to the vertebrae in Potts disease earlier than radiographs. This case report outlines the clinical presentation of a young male with Potts disease who was HIV negative, and the important role that MRI plays in diagnosis and therefore in appropriate and timely intervention. The typical magnetic resonance (MR) imaging features and the radiographic hallmarks of the disease will also be discussed.

  14. 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

  15. Technical aspects of magnetic resonance imaging in parathyroid gland lesions

    Energy Technology Data Exchange (ETDEWEB)

    Hemmingsson, A.; Ericsson, A.; Ljunghall, S.; Juhlin, C.; Jung, B.; Rastad, J.; Thuomas, K.A.; Akerstroem, G.

    Two patients with primary hyperparathyroidism were examined before parathyroid surgery with magnetic resonance imaging at 0.35 telsa in order to analyse optimal methods of visualization. Two large parathyroid glands in the neck had long transverse relaxation times which rendered them clearly visible in T2-weighted images as structures of a signal intensity higher than that of the surrounding. Large parathyroid lesions may thus be easily detected by magnetic resonance imaging provided proper examination parameters are employed.

  16. Prostate Cancer: The Role of Multiparametric Magnetic Resonance Imaging.

    Science.gov (United States)

    Dias, João Lopes; Pina, João Magalhães; João, Raquel; Fialho, Joana; Carmo, Sandra; Leal, Cecília; Bilhim, Tiago; Marques, Rui Mateus; Pinheiro, Luís Campos

    2015-01-01

    Multiparametric magnetic resonance imaging has been increasingly used for detection, localization and staging of prostate cancer over the last years. It combines high-resolution T2 weighted-imaging and at least two functional techniques, which include dynamic contrast-enhanced magnetic resonance imaging, diffusion-weighted imaging, and magnetic resonance imaging spectroscopy. Although the combined use of a pelvic phased-array and an endorectal coil is considered the state-of-the-art for magnetic resonance imaging evaluation of prostate cancer, endorectal coil is only absolute mandatory for magnetic resonance imaging spectroscopy at 1.5 T. Sensitivity and specificity levels in cancer detection and localization have been improving with functional technique implementation, compared to T2 weighted-imaging alone. It has been particularly useful to evaluate patients with abnormal PSA and negative biopsy. Moreover, the information added by the functional techniques may correlate to cancer aggressiveness and therefore be useful to select patients for focal radiotherapy, prostate sparing surgery, focal ablative therapy and active surveillance. However, more studies are needed to compare the functional techniques and understand the advantages and disadvantages of each one. This article reviews the basic principles of prostatic mp-magnetic resonance imaging, emphasizing its role on detection, staging and active surveillance of prostate cancer.

  17. 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

  18. NMRI: nuclear magnetic resonance imaging; IRM: imagerie par resonance magnetique

    Energy Technology Data Exchange (ETDEWEB)

    Doyon, D.; Cabanis, E.A.; Iba-Zizen, M.Th

    2001-07-01

    The harmlessness of NMR imaging make it the best examination technique for the brain, marrow, bones, joints, heart, vessels, liver, pelvis etc.. The improvement of images and their preciseness enlarges the field of investigation of interventional and functional NMRs. The basic principles, semiology in 3-D NMR, contra-indications, risks and cardiac pathology are analyzed. (J.S.)

  19. Imaging prostate cancer: an update on positron emission tomography and magnetic resonance imaging

    DEFF Research Database (Denmark)

    Bouchelouche, Kirsten; Turkbey, Baris; Choyke, Peter

    2010-01-01

    , and molecular imaging information. Developments in imaging technologies, specifically magnetic resonance imaging (MRI) and positron emission tomography (PET)/computed tomography (CT), have improved the detection rate of prostate cancer. MRI has improved lesion detection and local staging. Furthermore, MRI...

  20. Anaesthesia for magnetic resonance imaging/computed tomography.

    Science.gov (United States)

    Funk, W; Taeger, K

    2000-08-01

    The need for general anaesthesia for magnetic resonance imaging/computed tomography investigations can be reduced by the implementation of structured sedation programmes supervised by anaesthetists. Despite its side-effects, chloral hydrate is still the drug most widely used. Rectal thiopental or intravenous propofol are suggested anaesthetic agents for pre-school children and uncooperative or claustrophobic individuals. Spiral computed tomography scans and ultrafast magnetic resonance imaging shorten immobilization times further. However, functional magnetic resonance imaging and intervention techniques in neuroradiology depend on a motionless patient. A useful strategy for testing anaesthesia equipment has been outlined.

  1. Whole-body magnetic resonance imaging: assessment of skeletal metastases.

    Science.gov (United States)

    Moynagh, Michael R; Colleran, Gabrielle C; Tavernaraki, Katarina; Eustace, Stephen J; Kavanagh, Eoin C

    2010-03-01

    The concept of a rapid whole-body imaging technique with high resolution and the absence of ionizing radiation for the assessment of osseous metastatic disease is a desirable tool. This review article outlines the current perspective of whole-body magnetic resonance imaging in the assessment of skeletal metastatic disease, with comparisons made to alternative whole-body imaging modalities.

  2. 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...

  3. Benefits and limitations of imaging multiples: Interferometric and resonant migration

    KAUST Repository

    Guo, Bowen

    2015-07-01

    The benefits and limitations of imaging multiples are reviewed for interferometric migration and resonant migration. Synthetic and field data examples are used to characterize the effectiveness of the methods.

  4. Biological effects of exposure to magnetic resonance imaging: an overview

    OpenAIRE

    Formica Domenico; Silvestri Sergio

    2004-01-01

    Abstract The literature on biological effects of magnetic and electromagnetic fields commonly utilized in magnetic resonance imaging systems is surveyed here. After an introduction on the basic principles of magnetic resonance imaging and the electric and magnetic properties of biological tissues, the basic phenomena to understand the bio-effects are described in classical terms. Values of field strengths and frequencies commonly utilized in these diagnostic systems are reported in order to a...

  5. 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)

  6. 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)

  7. 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.

  8. 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.

    2017-01-01

    Purpose 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. Materials and Methods 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 cm3) was assessed by ROC analysis. The same analysis was also conducted for the 1.15 shrinkage factor corrected histopathology data set. Results There was a positive correlation between histopathology tumor volume and magnetic resonance tumor volume (Pearson coefficient 0.633, p <0.0001), but a weak correlation between prostate specific antigen and histopathology tumor volume (Pearson coefficient 0.237, p=0.003). On linear regression analysis histopathology tumor volume and magnetic resonance tumor volume were correlated (r2=0.401, p <0.00001). On ROC analysis AUC values for magnetic resonance tumor volume, prostate specific antigen and age in estimating tumors larger than 0.5 cm3 at histopathology were 0.949 (p <0.0000001), 0.685 (p=0.001) and 0.627 (p=0

  9. 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.)

  10. Slotted cage resonator for high-field magnetic resonance imaging of rodents

    Energy Technology Data Exchange (ETDEWEB)

    Marrufo, O; Vasquez, F; Solis, S E; Rodriguez, A O, E-mail: arog@xanum.uam.mx [Departamento de Ingenieria Electrica, Universidad Autonoma Metropolitana Iztapalapa, Mexico, DF 09340 (Mexico)

    2011-04-20

    A variation of the high-frequency cavity resonator coil was experimentally developed according to the theoretical frame proposed by Mansfield in 1990. Circular slots were used instead of cavities to form the coil endplates and it was called the slotted cage resonator coil. The theoretical principles were validated via a coil equivalent circuit and also experimentally with a coil prototype. The radio frequency magnetic field, B1, produced by several coil configurations was numerically simulated using the finite-element approach to investigate their performances. A transceiver coil, 8 cm long and 7.6 cm in diameter, and composed of 4 circular slots with a 15 mm diameter on both endplates, was built to operate at 300 MHz and quadrature driven. Experimental results obtained with the slotted cage resonator coil were presented and showed very good agreement with the theoretical expectations for the resonant frequency as a function of the coil dimensions and slots. A standard birdcage coil was also built for performance comparison purposes. Phantom images were then acquired to compute the signal-to-noise ratio of both coils showing an important improvement of the slotted cage coil over the birdcage coil. The whole-body images of the mouse were also obtained showing high-quality images. Volume resonator coils can be reliably built following the physical principles of the cavity resonator design for high-field magnetic resonance imaging applications of rodents.

  11. 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....

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

    Science.gov (United States)

    ... being imaged, send and receive radio waves, producing signals that are detected by the coils. The electric current does not come in contact with the patient. A computer then processes the signals and generates a series of images, each of ...

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

    CERN Document Server

    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, perfusion weighted imaging uses tracers to exploit hemodynamic status, which enables researchers and clinicians to consider this imaging modality as an early biomarker of certain brain diseases. In this review, the fundamentals of physics for diffusion and perfusion MR imaging both of which are highly sensitive to microenvironmental alterations at the cellular level as well as their application in the treatment of aging, Alzheimer's disease, brain tumors and cerebral ischemic injury were discussed.

  14. Fast abdominal magnetic resonance imaging; Schnelle Abdomenbildgebung in der Magnetresonanztomografie

    Energy Technology Data Exchange (ETDEWEB)

    Budjan, J.; Schoenberg, S.O.; Riffel, P. [University Medical Center Mannheim (Germany). Dept. of Clinical Radiology and Nuclear Medicine

    2016-06-15

    Abdominal imaging is the driving force that necessitates the development of numerous techniques for accelerated image acquisition in magnetic resonance imaging (MRI). Today, numerous techniques are available that enable rapid, high spatial resolution acquisition for both T1 and T2 weighted images. These techniques open new opportunities in the detection and classification of numerous pathologies in the abdomen. However, there is still ongoing progress in the development of fast and ultrafast sequences and promising techniques are currently close to clinical application. With these 4D-technologies, MRI is becoming the central imaging modality for dynamic, motion-compensated imaging of the parenchymal abdominal organs such as liver, pancreas and kidney.

  15. Imaging of the hip joint. Computed tomography versus magnetic resonance imaging

    Science.gov (United States)

    Lang, P.; Genant, H. K.; Jergesen, H. E.; Murray, W. R.

    1992-01-01

    The authors reviewed the applications and limitations of computed tomography (CT) and magnetic resonance (MR) imaging in the assessment of the most common hip disorders. Magnetic resonance imaging is the most sensitive technique in detecting osteonecrosis of the femoral head. Magnetic resonance reflects the histologic changes associated with osteonecrosis very well, which may ultimately help to improve staging. Computed tomography can more accurately identify subchondral fractures than MR imaging and thus remains important for staging. In congenital dysplasia of the hip, the position of the nonossified femoral head in children less than six months of age can only be inferred by indirect signs on CT. Magnetic resonance imaging demonstrates the cartilaginous femoral head directly without ionizing radiation. Computed tomography remains the imaging modality of choice for evaluating fractures of the hip joint. In some patients, MR imaging demonstrates the fracture even when it is not apparent on radiography. In neoplasm, CT provides better assessment of calcification, ossification, and periosteal reaction than MR imaging. Magnetic resonance imaging, however, represents the most accurate imaging modality for evaluating intramedullary and soft-tissue extent of the tumor and identifying involvement of neurovascular bundles. Magnetic resonance imaging can also be used to monitor response to chemotherapy. In osteoarthrosis and rheumatoid arthritis of the hip, both CT and MR provide more detailed assessment of the severity of disease than conventional radiography because of their tomographic nature. Magnetic resonance imaging is unique in evaluating cartilage degeneration and loss, and in demonstrating soft-tissue alterations such as inflammatory synovial proliferation.

  16. Imaging of the hip joint. Computed tomography versus magnetic resonance imaging

    Science.gov (United States)

    Lang, P.; Genant, H. K.; Jergesen, H. E.; Murray, W. R.

    1992-01-01

    The authors reviewed the applications and limitations of computed tomography (CT) and magnetic resonance (MR) imaging in the assessment of the most common hip disorders. Magnetic resonance imaging is the most sensitive technique in detecting osteonecrosis of the femoral head. Magnetic resonance reflects the histologic changes associated with osteonecrosis very well, which may ultimately help to improve staging. Computed tomography can more accurately identify subchondral fractures than MR imaging and thus remains important for staging. In congenital dysplasia of the hip, the position of the nonossified femoral head in children less than six months of age can only be inferred by indirect signs on CT. Magnetic resonance imaging demonstrates the cartilaginous femoral head directly without ionizing radiation. Computed tomography remains the imaging modality of choice for evaluating fractures of the hip joint. In some patients, MR imaging demonstrates the fracture even when it is not apparent on radiography. In neoplasm, CT provides better assessment of calcification, ossification, and periosteal reaction than MR imaging. Magnetic resonance imaging, however, represents the most accurate imaging modality for evaluating intramedullary and soft-tissue extent of the tumor and identifying involvement of neurovascular bundles. Magnetic resonance imaging can also be used to monitor response to chemotherapy. In osteoarthrosis and rheumatoid arthritis of the hip, both CT and MR provide more detailed assessment of the severity of disease than conventional radiography because of their tomographic nature. Magnetic resonance imaging is unique in evaluating cartilage degeneration and loss, and in demonstrating soft-tissue alterations such as inflammatory synovial proliferation.

  17. Ocular pursuit movement assessment by magnetic resonance imaging.

    Science.gov (United States)

    Cadera, W; Karlik, S J; Viirre, E; Bloom, J N

    1994-01-01

    We describe a new technique for generating cinematic magnetic resonance images. This method produces more physiological imaging of extraocular muscles than our previous method. In addition, this technique provides more comfort for the study subject and results in less head movement artifact.

  18. Magnetic Resonance Perfusion Imaging in the Study of Language

    Science.gov (United States)

    Hillis, Argye E.

    2007-01-01

    This paper provides a brief review of various uses of magnetic resonance perfusion imaging in the investigation of brain/language relationships. The reviewed studies illustrate how perfusion imaging can reveal areas of brain where dysfunction due to low blood flow is associated with specific language deficits, and where restoration of blood flow…

  19. Voriconazole-related periostitis presenting on magnetic resonance imaging.

    Science.gov (United States)

    Davis, Derik L

    2015-01-01

    Painful periostitis is a complication of long-term antifungal therapy with voriconazole. A high clinical suspicion coupled with imaging and laboratory assessment is useful to establish the diagnosis. Prompt discontinuance of voriconazole typically results in the resolution of symptoms and signs. This report describes the presentation of voriconazole-related periostitis on magnetic resonance imaging.

  20. Voriconazole-related periostitis presenting on magnetic resonance imaging

    OpenAIRE

    Davis, Derik L

    2015-01-01

    Painful periostitis is a complication of long-term antifungal therapy with voriconazole. A high clinical suspicion coupled with imaging and laboratory assessment is useful to establish the diagnosis. Prompt discontinuance of voriconazole typically results in the resolution of symptoms and signs. This report describes the presentation of voriconazole-related periostitis on magnetic resonance imaging.

  1. Analysis and exploitation of field imperfections in magnetic resonance imaging

    NARCIS (Netherlands)

    Peeters, Johannes Martinus

    2006-01-01

    Field imperfections are normally undesirable in magnetic resonance imaging. They degrade the quality of the images by wrong depiction of the anatomy and decrease of the signal-to-noise ratio. Furthermore, for velocity, flow and diffusion quantification, measurement errors related to these imperfecti

  2. 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...

  3. Artifacts and pitfalls in shoulder magnetic resonance imaging.

    Science.gov (United States)

    Marcon, Gustavo Felix; Macedo, Tulio Augusto Alves

    2015-01-01

    Magnetic resonance imaging has revolutionized the diagnosis of shoulder lesions, in many cases becoming the method of choice. However, anatomical variations, artifacts and the particularity of the method may be a source of pitfalls, especially for less experienced radiologists. In order to avoid false-positive and false-negative results, the authors carried out a compilation of imaging findings that may simulate injury. It is the authors' intention to provide a useful, consistent and comprehensive reference for both beginner residents and skilled radiologists who work with musculoskeletal magnetic resonance imaging, allowing for them to develop more precise reports and helping them to avoid making mistakes.

  4. Magnetic resonance imaging of tumor oxygenation and metabolic profile

    DEFF Research Database (Denmark)

    Krishna, Murali C.; Matsumoto, Shingo; Saito, Keita

    2013-01-01

    The tumor microenvironment is distinct from normal tissue as a result of abnormal vascular network characterized by hypoxia, low pH, high interstitial fluid pressure and elevated glycolytic activity. This poses a barrier to treatments including radiation therapy and chemotherapy. Imaging methods...... which can characterize such features non-invasively and repeatedly will be of significant value in planning treatment as well as monitoring response to treatment. The three techniques based on magnetic resonance imaging (MRI) are reviewed here. Tumor pO2 can be measured by two MRI methods requiring...... an exogenous contrast agent: electron paramagnetic resonance imaging (EPRI) and Overhauser magnetic resonance imaging (OMRI). Tumor metabolic profile can be assessed by a third method, hyperpolarized metabolic MR, based on injection of hyperpolarized biological molecules labeled with 13C or 15N and MR...

  5. Clinical software VIII for magnetic resonance imaging systems

    Energy Technology Data Exchange (ETDEWEB)

    Kohno, Satoru; Takeo, Kazuhiro [Medical Applications Department, Medical Systems Division, Shimadzu Corporation, Kyoto (Japan)

    2001-02-01

    This report describes the latest techniques of MRA (magnetic resonance angiography) and the brain attack diagnosis protocol which are now effectively utilized in the Shimadzu-Marconi MAGNEX ECLIPSE MRI (magnetic resonance imaging) system (1.5 tesla type) and the MAGNEX POLARIS MRI system (1.0 tesla type). As for the latest techniques for MRA, this report refers to the SLINKY (sliding interleaved ky) technique, which provides high-resolution images over a wide range in the direction of slice, without using contrast agent, and to the iPass technique which enables highly reliable CE-MRA (contrast-enhanced magnetic resonance angiography), through easy and simple operation. Also reported are the techniques of diffusion imaging and perfusion imaging, utilized for stroke assessment. (author)

  6. An Evolutionary Algorithm for Enhanced Magnetic Resonance Imaging Classification

    Directory of Open Access Journals (Sweden)

    T.S. Murunya

    2014-11-01

    Full Text Available 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. Image processing techniques are required to analyze medical images and retrieve it from database. The proposed framework extracts features using Moment Invariants (MI and Wavelet Packet Tree (WPT. Extracted features are reduced using Correlation based Feature Selection (CFS and a CFS with cuckoo search algorithm is proposed. Naïve Bayes and K-Nearest Neighbor (KNN classify the selected features. National Biomedical Imaging Archive (NBIA dataset including colon, brain and chest is used to evaluate the framework.

  7. Texture analysis of torn rotator cuff on preoperative magnetic resonance arthrography as a predictor of postoperative tendon status

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Yeon Ah; Lee, Guen Young; Lee, Joon Woo; Lee, Eugene; Kim, Boh Young; Kim, Su Jin; Ahn, Joong Mo; Kang, Heung Sik [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2017-08-01

    To evaluate texture data of the torn supraspinatus tendon (SST) on preoperative T2-weighted magnetic resonance arthrography (MRA) using the gray-level co-occurrence matrix (GLCM) for prediction of post-operative tendon state. Fifty patients who underwent arthroscopic rotator cuff repair for full-thickness tears of the SST were included in this retrospective study. Based on 1-year follow-up, magnetic resonance imaging showed that 30 patients had intact SSTs, and 20 had rotator cuff retears. Using GLCM, two radiologists measured independently the highest signal intensity area of the distal end of the torn SST on preoperative T2-weighted MRA, which were compared between two groups.The relationships with other well-known prognostic factors, including age, tear size (anteroposterior dimension), retraction size (mediolateral tear length), grade of fatty degeneration of the SST and infraspinatus tendon, and arthroscopic fixation technique (single or double row), also were evaluated. Of all the GLCM features, the retear group showed significantly higher entropy (p < 0.001 and p = 0.001), variance (p = 0.030 and 0.011), and contrast (p = 0.033 and 0.012), but lower angular second moment (p < 0.001 and p = 0.002) and inverse difference moment (p = 0.027 and 0.027), as well as larger tear size (p = 0.001) and retraction size (p = 0.002) than the intact group. Retraction size (odds ratio [OR] = 3.053) and entropy (OR = 17.095) were significant predictors. Texture analysis of torn SSTs on preoperative T2-weighted MRA using the GLCM may be helpful to predict postoperative tendon state after rotator cuff repair.

  8. Magnetic resonance imaging of brain angiogenesis after stroke

    OpenAIRE

    Seevinck, Peter R.; Deddens, Lisette H; Dijkhuizen, Rick M.

    2010-01-01

    Stroke is a major cause of mortality and long-term disability worldwide. The initial changes in local perfusion and tissue status underlying loss of brain function are increasingly investigated with noninvasive imaging methods. In addition, there is a growing interest in imaging of processes that contribute to post-stroke recovery. In this review, we discuss the application of magnetic resonance imaging (MRI) to assess the formation of new vessels by angiogenesis, which is hypothesized to par...

  9. Ultrasound versus high field magnetic resonance imaging in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Tan, York Kiat; Østergaard, Mikkel; Bird, Paul;

    2014-01-01

    Over the past decade there have been significant advances in the field of musculoskeletal imaging, especially in the application of ultrasound (US) and magnetic resonance imaging (MRI) to the management of rheumatoid arthritis (RA). Both modalities offer significant advantages over the previous...... standards of clinical examination and radiography, and allow direct visualisation of both joint inflammation and structural damage. Although measuring similar pathology, each of these imaging tools has its own benefits and limitations; understanding these will help researchers and clinicians to determine...

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

    Science.gov (United States)

    Mantle, M D

    2011-09-30

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

  11. Magnetic resonance imaging (MRI) of diastematomyelia

    Energy Technology Data Exchange (ETDEWEB)

    Thron, A.; Schroth, G.

    1986-07-01

    The MRI-features of diastematomyelia in a patient with unusually late onset of symptoms are reported. Direct visualization of the split cord and low conus on frontal MR-images was facilitated by three-dimensional Fourier transform (3-DFT) image acquisition.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-11-15

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

  13. Thresholding magnetic resonance images of human brain

    Institute of Scientific and Technical Information of China (English)

    Qing-mao HU; Wieslaw L NOWINSKI

    2005-01-01

    In this paper, methods are proposed and validated to determine low and high thresholds to segment out gray matter and white matter for MR images of different pulse sequences of human brain. First, a two-dimensional reference image is determined to represent the intensity characteristics of the original three-dimensional data. Then a region of interest of the reference image is determined where brain tissues are present. The non-supervised fuzzy c-means clustering is employed to determine: the threshold for obtaining head mask, the low threshold for T2-weighted and PD-weighted images, and the high threshold for T1-weighted, SPGR and FLAIR images. Supervised range-constrained thresholding is employed to determine the low threshold for T1-weighted, SPGR and FLAIR images. Thresholding based on pairs of boundary pixels is proposed to determine the high threshold for T2- and PD-weighted images. Quantification against public data sets with various noise and inhomogeneity levels shows that the proposed methods can yield segmentation robust to noise and intensity inhomogeneity. Qualitatively the proposed methods work well with real clinical data.

  14. 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.

  15. Medical Therapies for Stricturing Crohn's Disease: Efficacy and Cross-Sectional Imaging Predictors of Therapeutic Failure.

    Science.gov (United States)

    Campos, Cécile; Perrey, Antoine; Lambert, Céline; Pereira, Bruno; Goutte, Marion; Dubois, Anne; Goutorbe, Felix; Dapoigny, Michel; Bommelaer, Gilles; Hordonneau, Constance; Buisson, Anthony

    2017-06-01

    Medical therapy efficacy remains controversial in stricturing Crohn's disease. Cross-sectional imaging, especially magnetic resonance imaging, has been suggested as very helpful to guide therapeutic decision making. To assess efficacy and predictors of therapeutic failure in patients receiving medical treatments for stricturing Crohn's disease. In this retrospective study, therapeutic failure was defined as symptomatic stricture leading to surgical or endoscopic therapeutics, hospitalization, treatment discontinuation or additional therapy and short-term clinical response as clinical improvement assessed by two physicians. The 55 cross-sectional imaging examinations (33 magnetic resonance imaging and 22 CT scan) before starting medical therapy were analyzed independently by two radiologists. Results were expressed as hazard ratio (HR) or odds ratio (OR) with 95% confidence intervals (95% CI). Among 84 patients, therapeutic failure rate within 60 months was 66.6%. In multivariate analysis, Crohn's disease diagnosis after 40 years old (HR 3.9, 95% CI [1.37-11.2], p = 0.011), small stricture luminal diameter (HR 1.34, 95% CI [1.01-1.80], p = 0.046), increased stricture wall thickness (HR 1.23, 95% CI [1.04-1.46], p = 0.013) and fistula with abscess (HR 5.63, 95% CI [1.64-19.35], p = 0.006) were associated with therapeutic failure, while anti-TNF combotherapy (HR 0.17, 95% CI [0.40-0.71], p = 0.015) prevented it. Considering 108 therapeutic sequences, the short-term clinical response rate was 65.7%. In multivariate analysis, male gender (OR 0.15, 95% CI [0.03-0.64], p = 0.011), fistula with abscess (OR 0.09, 95% CI [0.01-0.77], p = 0.028) and comb sign (OR 0.23, 95% CI [0.005-0.97], p = 0.047) were associated with short-term clinical failure. Anti-TNF combotherapy seemed to prevent therapeutic failure, and cross-sectional imaging should be systematically performed to help medical management in stricturing Crohn's disease.

  16. Familial Essential Tremor Studied With Functional Magnetic Resonance Imaging

    Science.gov (United States)

    Hernandez, A.; Salgado, P.; Gil, A.; Barrios, F. A.

    2003-09-01

    Functional Magnetic Resonance Imaging has become an important analytical tool to study neurodegenerative diseases. We applied the EPI-BOLD functional Magnetic Resonance Imaging technique to acquire functional images of patients with familial essential tremor (FET) disorder and healthy control volunteers, during a motor task activity. Functional and anatomic images were used to produce the brain activation maps of the patients and volunteers. These functional maps of the primary somatosensorial and motor cortexes of patients and control subjects were compared for functional differences per subject. The averaged functional brain images of eight of each case were acquired were, it can be clearly observed the differences in active zones. The results presented in this work show that there are differences in the functional maps during motor task activation between control subjects and FET patients suggesting a cerebral functional reorganization that can be mapped with BOLD-fMRI.

  17. Evaluation of the Relationship Between Relative Signal Intensity of Magnetic Resonance Images of Retrodiscal Tissue and Lateral Ptrygoid Muscle and Magnetic Resonance Imaging Findings

    Directory of Open Access Journals (Sweden)

    Hoda Banihashemi

    2012-09-01

    Full Text Available Background and Aims: Disc displacement is the most common temporomandibular joint disorder and magnetic resonance imaging (MRI is the gold standard in its diagnosis. This disorder can lead to changes in signal intensity of magnetic resonance (MR. The purpose of this study was evaluation of correlation between relative signal intensity of MR images of retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle with type of anterior disk displacement and condylar head flattening in patients with temporomandibular disorder (TMD. Materials and Methods: In this retrospective study, 31 MR images of patients who had anterior disc displacement were evaluated. After relative signal intensity measurement for retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle, the correlation between relative signal intensity and type of anterior disc displacement was evaluated with repeated measure ANOVA test. In each of these 3 areas, t-test was used to compare the groups with and without condylar head flattening. Results: The correlation between relative signal intensity of MR images and type of anterior disc displacement in retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle was not significant. There was also no statistically significant correlation between relative signal intensity of MR images and flattening of condylar head in retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle (P>0.05. Conclusion: According to findings of this study, relative signal intensity of MR images in retrodiscal tissue, superior and inferior head of ptrygoid muscle is not a good predictor for type of anterior disc displacement and flattening of condylar head. It seems that this cannot be used as a diagnostic marker for TMD progression.

  18. Subcutaneous Tissue Thickness is an Independent Predictor of Image Noise in Cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Staniak, Henrique Lane; Sharovsky, Rodolfo [Hospital Universitário - Universidade de São Paulo, São Paulo, SP (Brazil); Pereira, Alexandre Costa [Hospital das Clínicas - Universidade de São Paulo, São Paulo, SP (Brazil); Castro, Cláudio Campi de; Benseñor, Isabela M.; Lotufo, Paulo A. [Hospital Universitário - Universidade de São Paulo, São Paulo, SP (Brazil); Faculdade de Medicina - Universidade de São Paulo, São Paulo, SP (Brazil); Bittencourt, Márcio Sommer, E-mail: msbittencourt@mail.harvard.edu [Hospital Universitário - Universidade de São Paulo, São Paulo, SP (Brazil)

    2014-01-15

    Few data on the definition of simple robust parameters to predict image noise in cardiac computed tomography (CT) exist. To evaluate the value of a simple measure of subcutaneous tissue as a predictor of image noise in cardiac CT. 86 patients underwent prospective ECG-gated coronary computed tomographic angiography (CTA) and coronary calcium scoring (CAC) with 120 kV and 150 mA. The image quality was objectively measured by the image noise in the aorta in the cardiac CTA, and low noise was defined as noise < 30HU. The chest anteroposterior diameter and lateral width, the image noise in the aorta and the skin-sternum (SS) thickness were measured as predictors of cardiac CTA noise. The association of the predictors and image noise was performed by using Pearson correlation. The mean radiation dose was 3.5 ± 1.5 mSv. The mean image noise in CT was 36.3 ± 8.5 HU, and the mean image noise in non-contrast scan was 17.7 ± 4.4 HU. All predictors were independently associated with cardiac CTA noise. The best predictors were SS thickness, with a correlation of 0.70 (p < 0.001), and noise in the non-contrast images, with a correlation of 0.73 (p < 0.001). When evaluating the ability to predict low image noise, the areas under the ROC curve for the non-contrast noise and for the SS thickness were 0.837 and 0.864, respectively. Both SS thickness and CAC noise are simple accurate predictors of cardiac CTA image noise. Those parameters can be incorporated in standard CT protocols to adequately adjust radiation exposure.

  19. Predictors of Toxicity After Image-guided High-dose-rate Interstitial Brachytherapy for Gynecologic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Larissa J. [Department of Radiation Oncology, Brigham and Women' s Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (United States); Viswanathan, Akila N., E-mail: aviswanathan@lroc.harvard.edu [Department of Radiation Oncology, Brigham and Women' s Hospital and Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts (United States)

    2012-12-01

    Purpose: To identify predictors of grade 3-4 complications and grade 2-4 rectal toxicity after three-dimensional image-guided high-dose-rate (HDR) interstitial brachytherapy for gynecologic cancer. Methods and Materials: Records were reviewed for 51 women (22 with primary disease and 29 with recurrence) treated with HDR interstitial brachytherapy. A single interstitial insertion was performed with image guidance by computed tomography (n = 43) or magnetic resonance imaging (n = 8). The median delivered dose in equivalent 2-Gy fractions was 72.0 Gy (45 Gy for external-beam radiation therapy and 24 Gy for brachytherapy). Toxicity was reported according to the Common Toxicity Criteria for Adverse Events. Actuarial toxicity estimates were calculated by the Kaplan-Meier method. Results: At diagnosis, the median patient age was 62 years and the median tumor size was 3.8 cm. The median D90 and V100 were 71.4 Gy and 89.5%; the median D2cc for the bladder, rectum, and sigmoid were 64.6 Gy, 61.0 Gy, and 52.7 Gy, respectively. The actuarial rates of all grade 3-4 complications at 2 years were 20% gastrointestinal, 9% vaginal, 6% skin, 3% musculoskeletal, and 2% lymphatic. There were no grade 3-4 genitourinary complications and no grade 5 toxicities. Grade 2-4 rectal toxicity was observed in 10 patients, and grade 3-4 complications in 4; all cases were proctitis with the exception of 1 rectal fistula. D2cc for rectum was higher for patients with grade 2-4 (68 Gy vs 57 Gy for grade 0-1, P=.03) and grade 3-4 (73 Gy vs 58 Gy for grade 0-2, P=.02) rectal toxicity. The estimated dose that resulted in a 10% risk of grade 2-4 rectal toxicity was 61.8 Gy (95% confidence interval, 51.5-72.2 Gy). Discussion: Image-guided HDR interstitial brachytherapy results in acceptable toxicity for women with primary or recurrent gynecologic cancer. D2cc for the rectum is a reliable predictor of late rectal complications. Three-dimensional-based treatment planning should be performed to ensure

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

    Science.gov (United States)

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

    2015-01-01

    Malformation of cortical development (MCD) is a term representing an inhomogeneous group of central nervous system abnormalities, referring particularly to embriyological aspect as a consequence of any of the three developmental stages, i.e., cell proliferation, cell migration and cortical organization. These include cotical dysgenesis, microcephaly, polymicrogyria, schizencephaly, lissencephaly, hemimegalencephaly, heterotopia and focal cortical dysplasia. Since magnetic resonance imaging is the modality of choice that best identifies the structural anomalies of the brain cortex, we aimed to provide a mini review of MCD by using 3T magnetic resonance scanner images. PMID:26516429

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

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

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

  2. 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. The brea......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...

  3. Correlating hemodynamic magnetic resonance imaging with high-field intracranial vessel wall imaging in stroke.

    Science.gov (United States)

    Langdon, Weston; Donahue, Manus J; van der Kolk, Anja G; Rane, Swati; Strother, Megan K

    2014-06-01

    Vessel wall magnetic resonance imaging at ultra-high field (7 Tesla) can be used to visualize vascular lesions noninvasively and holds potential for improving stroke-risk assessment in patients with ischemic cerebrovascular disease. We present the first multi-modal comparison of such high-field vessel wall imaging with more conventional (i) 3 Tesla hemodynamic magnetic resonance imaging and (ii) digital subtraction angiography in a 69-year-old male with a left temporal ischemic infarct.

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

    Science.gov (United States)

    Baskan, Ozdil; Erol, Cengiz; Sahingoz, Yusuf

    2016-01-01

    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. PMID:25216728

  5. Open magnetic resonance imaging (MRI) scanners.

    Science.gov (United States)

    Hailey, D

    2006-11-01

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

  6. Random forest regression for magnetic resonance image synthesis.

    Science.gov (United States)

    Jog, Amod; Carass, Aaron; Roy, Snehashis; Pham, Dzung L; Prince, Jerry L

    2017-01-01

    By choosing different pulse sequences and their parameters, magnetic resonance imaging (MRI) can generate a large variety of tissue contrasts. This very flexibility, however, can yield inconsistencies with MRI acquisitions across datasets or scanning sessions that can in turn cause inconsistent automated image analysis. Although image synthesis of MR images has been shown to be helpful in addressing this problem, an inability to synthesize both T2-weighted brain images that include the skull and FLuid Attenuated Inversion Recovery (FLAIR) images has been reported. The method described herein, called REPLICA, addresses these limitations. REPLICA is a supervised random forest image synthesis approach that learns a nonlinear regression to predict intensities of alternate tissue contrasts given specific input tissue contrasts. Experimental results include direct image comparisons between synthetic and real images, results from image analysis tasks on both synthetic and real images, and comparison against other state-of-the-art image synthesis methods. REPLICA is computationally fast, and is shown to be comparable to other methods on tasks they are able to perform. Additionally REPLICA has the capability to synthesize both T2-weighted images of the full head and FLAIR images, and perform intensity standardization between different imaging datasets.

  7. The challenges of neonatal magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Arthurs, Owen J.; Graves, Martin J.; Lomas, David J. [Addenbrooke' s Hospital, Cambridge University Hospitals NHS Foundation Trust, Department of Radiology, Cambridge (United Kingdom); Edwards, Andrea [Addenbrooke' s Hospital, Cambridge University Hospitals NHS Foundation Trust, Department of Radiology, Cambridge (United Kingdom); Addenbrooke' s Hospital, Department of Neonatology, Cambridge (United Kingdom); Austin, Topun [Addenbrooke' s Hospital, Department of Neonatology, Cambridge (United Kingdom)

    2012-10-15

    Improved neonatal survival rates and antenatal diagnostic imaging is generating a growing demand for postnatal MRI examinations. Neonatal brain MRI is now becoming standard clinical care in many settings, but with the exception of some research centres, the technique has not been optimised for imaging neonates and small children. Here, we review some of the challenges involved in neonatal MRI, including recent advances in overall MR practicality and nursing practice, to address some of the ways in which the MR experience could be made more neonate-friendly. (orig.)

  8. Travelling Wave Magnetic Resonance Imaging at 3 Tesla

    CERN Document Server

    Vazquez, F; Marrufo, O; Rodriguez, A O

    2013-01-01

    Waveguides have been successfully used to generate magnetic resonance images at 7 T with whole-body systems. The bore limits the magnetic resonance signal transmitted because its specific cut-off frequency is greater than the majority of resonant frequencies. This restriction can be overcome by using a parallel-plate waveguide whose cut-off frequency is zero for the transversal electric modes and it can propagate any frequency. To investigate the potential benefits for whole-body imaging at 3 T, we compare numerical simulations at 1.5 T, 3 T, 7 T, and 9 T via the propagation of the parallel-plate waveguide principal mode filled with a cylindrical phantom and two surface coils. B1 mapping was computed to investigate the feasibility of this approach at 3T. The point spread function method was used to measure the imager performance for the traveling-wave magnetic resonance imaging experiment. Human leg images were acquired to experimentally validate this approach. The principal mode shows very little field magni...

  9. Molecular aspects of magnetic resonance imaging and spectroscopy.

    Science.gov (United States)

    Boesch, C

    1999-01-01

    Magnetic resonance imaging (MRI) is a well known diagnostic tool in radiology that produces unsurpassed images of the human body, in particular of soft tissue. However, the medical community is often not aware that MRI is an important yet limited segment of magnetic resonance (MR) or nuclear magnetic resonance (NMR) as this method is called in basic science. The tremendous morphological information of MR images sometimes conceal the fact that MR signals in general contain much more information, especially on processes on the molecular level. NMR is successfully used in physics, chemistry, and biology to explore and characterize chemical reactions, molecular conformations, biochemical pathways, solid state material, and many other applications that elucidate invisible characteristics of matter and tissue. In medical applications, knowledge of the molecular background of MRI and in particular MR spectroscopy (MRS) is an inevitable basis to understand molecular phenomenon leading to macroscopic effects visible in diagnostic images or spectra. This review shall provide the necessary background to comprehend molecular aspects of magnetic resonance applications in medicine. An introduction into the physical basics aims at an understanding of some of the molecular mechanisms without extended mathematical treatment. The MR typical terminology is explained such that reading of original MR publications could be facilitated for non-MR experts. Applications in MRI and MRS are intended to illustrate the consequences of molecular effects on images and spectra.

  10. Magnetic resonance imaging in patients with panhypopituitarism

    Energy Technology Data Exchange (ETDEWEB)

    Pozzi Mucelli, R.S. [Ist. di Radiologia, Univ. di Trieste, Ospedale di Cattinara (Italy); Frezza, F. [Ist. di Radiologia, Univ. di Trieste, Ospedale di Cattinara (Italy); Magnaldi, S. [Ist. di Radiologia, Univ. di Trieste, Ospedale di Cattinara (Italy); Proto, G. [Servizio di Endocrinologia, Ospedale Civile di Udine (Italy)

    1992-02-01

    Primary panhypopituitarism consists of functional deficiency of the anterior pituitary lobe, which appears during infancy or adolescence. The magnetic resonance findings in 10 patients with a history of primary hypopituitarism are presented. The findings include: reduced pituitary size in all cases; partially (8 cases) or totally (2 cases) empty sella; thin (4 cases), partially visible (3 cases) or absent (2 cases) pituitary stalk; absence of the posterior lobe in 9 cases; bright spot corresponding to an ectopic posterior lobe in 8 cases. These findings are similar to those already reported in pituitary dwarfism and may help understanding of the pathogenesis of the disease, which seems to be related to a pituitary stalk lesion. (orig.)

  11. Image-processing pipelines: applications in magnetic resonance histology

    Science.gov (United States)

    Johnson, G. Allan; Anderson, Robert J.; Cook, James J.; Long, Christopher; Badea, Alexandra

    2016-03-01

    Image processing has become ubiquitous in imaging research—so ubiquitous that it is easy to loose track of how diverse this processing has become. The Duke Center for In Vivo Microscopy has pioneered the development of Magnetic Resonance Histology (MRH), which generates large multidimensional data sets that can easily reach into the tens of gigabytes. A series of dedicated image-processing workstations and associated software have been assembled to optimize each step of acquisition, reconstruction, post-processing, registration, visualization, and dissemination. This talk will describe the image-processing pipelines from acquisition to dissemination that have become critical to our everyday work.

  12. Automated image analysis techniques for cardiovascular magnetic resonance imaging

    NARCIS (Netherlands)

    Geest, Robertus Jacobus van der

    2011-01-01

    The introductory chapter provides an overview of various aspects related to quantitative analysis of cardiovascular MR (CMR) imaging studies. Subsequently, the thesis describes several automated methods for quantitative assessment of left ventricular function from CMR imaging studies. Several novel

  13. Diffusion weighted magnetic resonance imaging in

    Directory of Open Access Journals (Sweden)

    A.H. Afifi

    2016-03-01

    Conclusions: MRI DWI offers quick and non-invasive technique to distinct between viable and necrotic tumor areas and helps the diagnosis of residual tumor. Potential effect of treatment can be detected as increase in the diffusion coefficient. We recommend that optimal follow-up after image guided trans-catheter tumor therapy should include DWI and contrast-enhanced MRI.

  14. Magnetic Resonance Imaging of the Prostate

    NARCIS (Netherlands)

    L. Wang (Liang)

    2007-01-01

    textabstractThe high incidence of prostate cancer, combined with downstaging at diagnosis and the slow natural progression of the disease, has made its management a complex and controversial issue. Endorectal MRI is emerging as the most accurate imaging modality for the local anatomic assess

  15. Magnetic resonance imaging assessment of labyrinthine pathology

    Energy Technology Data Exchange (ETDEWEB)

    Marsot-Dupuch, K. [Hopital Saint-Antoine, Service de Radiologie, 75 - Paris (France); Vignaud, J. [Val de Grace, Hopital d`Instruction du Service de Sante des Armees, 75 - Paris (France); Mehdi, M. [Hopital Saint-Antoine, Service de Radiologie, 75 - Paris (France); Pharaboz, C. [Hopital Begin, Hopital d`Instruction des Armees, 94 - Saint-Mande (France); Meyer, B. [Hopital Saint-Antoine, Service d`ORL, 75 - Paris (France)

    1996-10-01

    Membranous labyrinth pathologies are quite rare. They were until recently difficult to demonstrate by imaging technics, CT being the modality of choice. Our purpose was to stress the interest of MR examination for investigating patients complaining of vertigo, tinnitus, and profound sensorineural hearing loss. Normal anatomy as well as the main pathologically encountered changes are illustrated. (orig.)

  16. Endoluminal magnetic resonance imaging in fecal incontinence

    NARCIS (Netherlands)

    E. Rociu (Elena)

    2000-01-01

    textabstractFecal incontinence is a chronic disability, has serious emotional impact and increased risk for social isolation. Imaging has become important in the diagnostic work-up of fecal incontinence. The research described in this thesis continues the line of efforts to improve the quality and t

  17. Magnetic Resonance Imaging of the Prostate

    NARCIS (Netherlands)

    L. Wang (Liang)

    2007-01-01

    textabstractThe high incidence of prostate cancer, combined with downstaging at diagnosis and the slow natural progression of the disease, has made its management a complex and controversial issue. Endorectal MRI is emerging as the most accurate imaging modality for the local anatomic

  18. Magnetic resonance imaging for prostate cancer clinical application

    Institute of Scientific and Technical Information of China (English)

    Bing Li; Yong Du; Hanfeng Yang; Yayong Huang; Jun Meng; Dongmei Xiao

    2013-01-01

    As prostate cancer is a biologically heterogeneous disease for which a variety of treatment options are available,the major objective of prostate cancer imaging is to achieve more precise disease characterization.In clinical practice,magnetic resonance imaging (MRI) is one of the imaging tools for the evaluation of prostate cancer,the fusion of MRI or dynamic contrast-enhanced MRI (DCE-MRI) with magnetic resonance spectroscopic imaging (MRSI) is improving the evaluation of cancer location,size,and extent,while providing an indication of tumor aggressiveness.This review summarizes the role of MRI in the application of prostate cancer and describes molecular MRI techniques (including MRSI and DCE-MRI)for aiding prostate cancer management.

  19. Magnetic Resonance Image Segmentation and its Volumetric Measurement

    Directory of Open Access Journals (Sweden)

    Rahul R. Ambalkar

    2013-02-01

    Full Text Available Image processing techniques make it possible to extract meaningful information from medical images. Magnetic resonance (MR imaging has been widely applied in biological research and diagnostics because of its excellent soft tissue contrast, non-invasive character, high spatial resolution and easy slice selection at any orientation. The MRI-based brain volumetric is concerned with the analysis of volumes and shapes of the structural components of the human brain. It also provides a criterion, by which we recognize the presence of degenerative diseases and characterize their rates of progression to make the diagnosis and treatments as a easy task. In this paper we have proposed an automated method for volumetric measurement of Magnetic Resonance Imaging and used Self Organized Map (SOM clustering method for their segmentations. We have used the MRI data set of 61 slices of 256×256 pixels in DICOM standard format

  20. Caroli's disease: magnetic resonance imaging features

    Energy Technology Data Exchange (ETDEWEB)

    Guy, France; Cognet, Francois; Dranssart, Marie; Cercueil, Jean-Pierre; Conciatori, Laurent; Krause, Denis [Department of Radiology and Imaging, Dijon Le Bocage University Hospital, 2 Blvd. Marechal de Lattre de Tassigny, BP 1542, 21034 Dijon Cedex (France)

    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. (orig.)

  1. Integrated imaging of neuromagnetic reconstructions and morphological magnetic resonance data.

    Science.gov (United States)

    Kullmann, W H; Fuchs, M

    1991-01-01

    New neuromagnetic imaging methods provide spatial information about the functional electrical properties of complex current distributions in the human brain. For practical use in medical diagnosis a combination of the abstract neuromagnetic imaging results with magnetic resonance (MR) or computed tomography (CT) images of the morphology is required. The biomagnetic images can be overlayed onto three-dimensional morphological images with spatially arbitrary selectable slices, calculated from conventional 2D data. For the current reconstruction the 3D images furthermore provide a priori information about the conductor geometry. A combination of current source density calculations and linear estimation methods for handling the inverse magnetic problem allows quick imaging of impressed current source density in arbitrary volume conductors.

  2. Pattern recognition on brain magnetic resonance imaging in alpha dystroglycanopathies

    Directory of Open Access Journals (Sweden)

    Bindu Parayil

    2010-01-01

    Full Text Available Alpha dystroglycanopathies are heterogeneous group of disorders both phenotypically and genetically. A subgroup of these patients has characteristic brain imaging findings. Four patients with typical imaging findings of alpha dystroglycanopathy are reported. Phenotypic features included: global developmental delay, contractures, hypotonia and oculomotor abnormalities in all. Other manifestations were consanguinity (3, seizures (3, macrocephaly (1, microcephaly (3, retinal changes (2 and hypogenitalism (2. Magnetic resonance imaging (MRI of the brain revealed polymicrogyria, white matter changes, pontine hypoplasia, and subcortical cerebellar cysts in all the patients, ventriculomegaly, callosal abnormalities, and absent septum pellucidum in two and Dandy -Walker variant malformation in three. Magnetic resonace imaging of the first cousin of one the patient had the same characteristic imaging features. Brain imaging findings were almost identical despite heterogeneity in clinical presentation and histopathological features. Pattern recognition of MR imaging features may serve as a clue to the diagnosis of alpha dystroglycanopathy.

  3. Magnetic resonance imaging of plantar aponeurosis lesions

    Energy Technology Data Exchange (ETDEWEB)

    Roger, B. and others

    1987-12-01

    Exploration of sporting injuries to plantar aponeurosis (PA) has up to now been based mainly on clinical examination, from which the diagnosis was established. Imaging technics such as standard radiography and ultrasound scanning have limitations allowing diagnosis to be made usually only by elimination, the lesion being very rarely visualized directly. Ten patients with hyperalgic lesion of plantar arch and functional impotence were explored by MR imaging, and in all cases this examination provided superior data confirmed at operation. The examination is painless and little invasive and can be carried out during the acute phase. The plantar aponeurosis is visualized directly between the muscle mass of the plantar arch and the fatty cushion. All three spatial planes can be investigated, most interesting data being obtained from the sagittal (in the PA axis) and frontal (comparative) planes.

  4. Magnetic resonance imaging of pituitary adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Bonneville, Jean-Francois; Bonneville, Fabrice; Cattin, Francoise [University Hospital, Department of Neuroradiology, Besancon (France)

    2005-03-01

    Today, MR is the only method needed for the morphological investigation of endocrine-active pituitary adenomas. In acromegaly and Cushing's syndrome, the therapeutic attitude is directly dictated by MR data. We present the MR aspect of pituitary adenomas according to size, sex, age, endocrine activity and a few particular conditions such as hemorrhagic pituitary adenomas, pituitary adenomas during pregnancy, cavernous sinus invasion and postsurgical changes. When an intrasellar mass extending out of the sella turcica is detected, the goal of the MR examination is to indicate precisely the origin of the tumor, its extension in relation to the various surrounding structures, its structure and its enhancement in order to help in the differential diagnosis. Demonstration of very small pituitary adenomas remains a challenge. When SE T1- and Turbo SE T2-weighted sequences are non-diagnostic, enhanced imaging becomes mandatory; half-dose gadolinium injection, delayed sequence, dynamic imaging can be of some help. (orig.)

  5. Temporomandibular joint disk adhesion: evidence from magnetic resonance images

    OpenAIRE

    MELO,Daniela Pita de; Oliveira, Luciana Soares de Andrade Freitas; Carvalho, Ana Clara Alves de; Oenning,Anne Caroline Costa; Gonzaga,Amanda Katarinny Goes; Campos,Paulo Sérgio Flores

    2014-01-01

    This case report has the aim to present an adhesion of the temporomadibular disc to the articular eminence, diagnosed on magnetic resonance imaging images. A 37-year-old female patient with TMJ (temporomandibular joint) disk adhesion on the left side and complaining of bilateral otalgia over the last 2 years is reported in the present article. The patient did not complain of articular pain or clicking, or any other noises of any nature. Clinical observation showed that the patient had restric...

  6. Magnetic resonance imaging spectrum of medulloblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Fruehwald-Pallamar, Julia; Puchner, Stefan B.; Koelblinger, Claus [Medical University of Vienna, Department of Radiology, Vienna (Austria); Rossi, Andrea [G. Gaslini Children' s Hospital, Department of Pediatric Neuroradiology, Genova (Italy); Garre, Maria L. [G. Gaslini Children' s Research Hospital (IRCCS), Neurooncology Unit, Genova (Italy); Cama, Armando [G. Gaslini Children' s Hospital, Neurosurgery Department, Genova (Italy); Osborn, Anne G. [University of Utah, Department of Radiology, Salt Lake City, UT (United States); Thurnher, Majda M. [Medical University of Vienna, Department of Radiology, Vienna (Austria); Medical University of Vienna, Division of Neuro- and Musculoskeletal Radiology, Vienna (Austria)

    2011-06-15

    Two medulloblastoma variants were recently added to the WHO classification of CNS tumours. We retrospectively analysed the imaging findings of 37 classic and 27 cases of variant medulloblastomas to identify imaging characteristics that might suggest a particular MB subtype. Sixty-four patients from three institutions were included. Location, tumour margins, signal intensities on conventional MRI, enhancement pattern, the presence of haemorrhage, calcifications and hydrocephalus were recorded and analysed. Signal characteristics on diffusion-weighted MR images and MR spectra were evaluated when available. Thirty-seven classic type of MB (CMB), twelve cases of desmoplastic/nodular medulloblastoma (DMB), nine medulloblastomas with extensive nodularity (MB-EN), five cases of anaplastic and one of large-cell medulloblastoma were included. Fifty of 64 tumours were located in the 4th ventricle region. On T2WI, CMB were all hyperintense, whereas DMB and MB-EN showed isointensity in up to 66%. One third of the classic MB showed only subtle marginal or linear enhancement. All medulloblastoma variants showed marked enhancement. The results of our study suggest: (a) an age-dependent distribution of MB variants, with DMB and MB-EN more common in younger children; (b) a female predominance in DMB; (c) a more common off-midline location in DMB (50%) and MB-EN (33%) variants. (orig.)

  7. Cardiac magnetic resonance imaging in children

    Energy Technology Data Exchange (ETDEWEB)

    Helbing, Willem A. [Erasmus Medical Centre - Sophia Children' s Hospital, Department of Radiology, Rotterdam (Netherlands); Department of Paediatrics (Division of Cardiology), Sp-2.429, P.O. Box 2060, CB, Rotterdam (Netherlands); Ouhlous, Mohamed [Erasmus Medical Centre - Sophia Children' s Hospital, Department of Radiology, Rotterdam (Netherlands)

    2015-01-01

    MRI is an important additional tool in the diagnostic work-up of children with congenital heart disease. This review aims to summarise the role MRI has in this patient population. Echocardiography remains the main diagnostic tool in congenital heart disease. In specific situations, MRI is used for anatomical imaging of congenital heart disease. This includes detailed assessment of intracardiac anatomy with 2-D and 3-D sequences. MRI is particularly useful for assessment of retrosternal structures in the heart and for imaging large vessel anatomy. Functional assessment includes assessment of ventricular function using 2-D cine techniques. Of particular interest in congenital heart disease is assessment of right and single ventricular function. Two-dimensional and newer 3-D techniques to quantify flow in these patients are or will soon become an integral part of quantification of shunt size, valve function and complex flow patterns in large vessels. More advanced uses of MRI include imaging of cardiovascular function during stress and tissue characterisation of the myocardium. Techniques used for this purpose need further validation before they can become part of the daily routine of MRI assessment of congenital heart disease. (orig.)

  8. Diagnosis of carotid artery atheroma by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Katsuhiro; Watanabe, Shigeru; Daimon, Yumiko; Sakurada, Hideki; Urano, Miharu; Sun, Kezhu; Hijikata, Yasuyoshi; Inoue, Toshihisa; Masuda, Yoshiaki [Chiba Univ. (Japan). School of Medicine

    2001-03-01

    Atheroma appears as a very low signal intensity area on 2-dimensional time-of-flight (TOF) magnetic resonance (MR) images, and its components have various signal intensities on spin-echo (SE) images. The present study investigated atheroma of the carotid arteries in 37 subjects with risk factors (63{+-}10 years of age; 19 men) by magnetic resonance imaging (MRI). On 2-dimensional (2D) TOF images, the carotid arteries were clearly demonstrated in all cases and atheroma was detected in 23 patients. The most common location of atheroma was at the origin of the internal carotid artery. There was vascular remodeling in all patients with atheroma. 2D-TOF images showed 97% agreement with ultrasonography. SE images clearly demonstrated atheroma in all 23 patients with atheroma. All patients with atheroma showing high signal intensity on T1-weighted images had hyperlipidemia. These findings indicate that the 2D-TOF imaging method is useful for detecting atheroma and SE-images are useful for its characterization. (author)

  9. Imaging Prostate Cancer: An Update on Positron Emission Tomography and Magnetic Resonance Imaging

    OpenAIRE

    Bouchelouche, Kirsten; Turkbey, Baris; Choyke, Peter; Capala, Jacek

    2010-01-01

    Prostate cancer is a common cancer in men and continues to be a major health problem. Imaging plays an essential role in the clinical management of patients. An important goal for prostate cancer imaging is more accurate disease characterization through the synthesis of anatomic, functional, and molecular imaging information. Developments in imaging technologies, specifically magnetic resonance imaging (MRI) and positron emission tomography (PET)/computed tomography (CT), have improved the de...

  10. Nuclear magnetic resonance imaging of water motion in plants

    NARCIS (Netherlands)

    Scheenen, T.W.J.

    2001-01-01

    This Thesis treats one of the new techniques in plant science i.e. nuclear magnetic resonance imaging (NMRi) applied to water motion in plants. It is a challenge, however, to measure this motion in intact plants quantitatively, because plants impose specific problems when studied using

  11. 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...

  12. Functional Connectivity Magnetic Resonance Imaging Classification of Autism

    Science.gov (United States)

    Anderson, Jeffrey S.; Nielsen, Jared A.; Froehlich, Alyson L.; DuBray, Molly B.; Druzgal, T. Jason; Cariello, Annahir N.; Cooperrider, Jason R.; Zielinski, Brandon A.; Ravichandran, Caitlin; Fletcher, P. Thomas; Alexander, Andrew L.; Bigler, Erin D.; Lange, Nicholas; Lainhart, Janet E.

    2011-01-01

    Group differences in resting state functional magnetic resonance imaging connectivity between individuals with autism and typically developing controls have been widely replicated for a small number of discrete brain regions, yet the whole-brain distribution of connectivity abnormalities in autism is not well characterized. It is also unclear…

  13. Magnetic resonance imaging of atherosclerosis : studies in visceral obesity

    NARCIS (Netherlands)

    Alizadeh Dehnavi, Reza

    2009-01-01

    The aim of this thesis was to explore the relation between visceral obesity and the accompanying metabolic disturbances, systemic inflammation and the atherosclerotic process. A newly developed magnetic resonance vessel wall imaging technique was implemented in phenotyping patients and as a

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

    NARCIS (Netherlands)

    Driessen, Mieke M P; Breur, Johannes M. P. J.; Budde, Ricardo P J; van Oorschot, Joep W M; van Kimmenade, Roland R J; Sieswerda, Gertjan Tj.; Meijboom, Folkert J; Leiner, Tim

    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 advan

  15. A Quantum Mechanical Review of Magnetic Resonance Imaging

    CERN Document Server

    Odaibo, Stephen G

    2012-01-01

    In this paper, we review the quantum mechanics of magnetic resonance imaging (MRI). We traverse its hierarchy of scales from the spin and orbital angular momentum of subatomic particles to the ensemble magnetization of tissue. And we review a number of modalities used in the assessment of acute ischemic stroke and traumatic brain injury.

  16. Magnetic resonance imaging criteria for thrombolysis in acute cerebral infarct

    NARCIS (Netherlands)

    Hjort, N; Butcher, K; Davis, SM; Kidwell, CS; Koroshetz, WJ; Rother, J; Schellinger, PD; Warach, S; Ostergaard, L

    2005-01-01

    Background and Purpose - Magnetic resonance imaging (MRI) selection of stroke patients eligible for thrombolytic therapy is an emerging application. Although the efficacy of therapy within 3 hours after onset of symptoms with intravenous (IV) tissue plasminogen activator (tPA) has been proven for pa

  17. 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...

  18. Increased cerebral blood flow in preeclampsia with magnetic resonance imaging

    NARCIS (Netherlands)

    Zeeman, GG; Hatab, MR; Twickler, DM

    2004-01-01

    Objective: The purpose of this study was to compare third trimester and nonpregnant cerebral blood flow of women with preeclampsia to normotensive control subjects with the use of magnetic resonance imaging techniques. Study design: Nine normotensive pregnant women and 12 untreated women with preecl

  19. Functional Connectivity Magnetic Resonance Imaging Classification of Autism

    Science.gov (United States)

    Anderson, Jeffrey S.; Nielsen, Jared A.; Froehlich, Alyson L.; DuBray, Molly B.; Druzgal, T. Jason; Cariello, Annahir N.; Cooperrider, Jason R.; Zielinski, Brandon A.; Ravichandran, Caitlin; Fletcher, P. Thomas; Alexander, Andrew L.; Bigler, Erin D.; Lange, Nicholas; Lainhart, Janet E.

    2011-01-01

    Group differences in resting state functional magnetic resonance imaging connectivity between individuals with autism and typically developing controls have been widely replicated for a small number of discrete brain regions, yet the whole-brain distribution of connectivity abnormalities in autism is not well characterized. It is also unclear…

  20. 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...

  1. Three-Dimensional Magnetic Resonance Imaging of Velopharyngeal Structures

    Science.gov (United States)

    Bae, Youkyung; Kuehn, David P.; Sutton, Bradley P.; Conway, Charles A.; Perry, Jamie L.

    2011-01-01

    Purpose: To report the feasibility of using a 3-dimensional (3D) magnetic resonance imaging (MRI) protocol for examining velopharyngeal structures. Using collected 3D MRI data, the authors investigated the effect of sex on the midsagittal velopharyngeal structures and the levator veli palatini (levator) muscle configurations. Method: Ten Caucasian…

  2. Does magnetic resonance imaging predict future low back pain?

    DEFF Research Database (Denmark)

    Steffens, D; Hancock, M J; Maher, C G;

    2014-01-01

    Magnetic resonance imaging (MRI) has the potential to identify pathology responsible for low back pain (LBP). However, the importance of findings on MRI remains controversial. We aimed to systematically review whether MRI findings of the lumbar spine predict future LBP in different samples...

  3. Magnetic Resonance Imaging in Follow-up Assessment of Sciatica

    NARCIS (Netherlands)

    el Barzouhi, Abdelilah; Vleggeert-Lankamp, Carmen L. A. M.; Nijeholt, Geert J. Lycklama A.; Van der Kallen, Bas F.; van den Hout, Wilbert B.; Jacobs, Wilco C. H.; Koes, Bart W.; Peul, Wilco C.

    2013-01-01

    BACKGROUND Magnetic resonance imaging (MRI) is frequently performed during follow-up in patients with known lumbar-disk herniation and persistent symptoms of sciatica. The association between findings on MRI and clinical outcome is controversial. METHODS We studied 283 patients in a randomized trial

  4. Magnetic resonance imaging of the breast: A clinicial perspective

    Directory of Open Access Journals (Sweden)

    Jenny Edge

    2012-06-01

    Full Text Available The role of magnetic resonance imaging (MRI in screening for breast cancer and its use after the diagnosis of breast cancer is discussed. The topic is enormous, with over 5 000 papers published in the last 10 years. In this précis, we focused on articles that examine its clinical relevance. We did not look at economic factors.

  5. Magnetic resonance imaging criteria for thrombolysis in acute cerebral infarct

    NARCIS (Netherlands)

    Hjort, N; Butcher, K; Davis, SM; Kidwell, CS; Koroshetz, WJ; Rother, J; Schellinger, PD; Warach, S; Ostergaard, L

    Background and Purpose - Magnetic resonance imaging (MRI) selection of stroke patients eligible for thrombolytic therapy is an emerging application. Although the efficacy of therapy within 3 hours after onset of symptoms with intravenous (IV) tissue plasminogen activator (tPA) has been proven for

  6. Magnetic resonance imaging features of chloroma of the shoulder

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, N. [Department of Radiology, Hospital de la Princesa, Madrid (Spain)]|[Department of Radiology, Hospital de la Princesa, Madrid (Spain); Ocon, E. [Department of Radiology, Hospital de la Princesa, Madrid (Spain); Friera, A. [Department of Radiology, Hospital de la Princesa, Madrid (Spain); Penarrubia, M.J. [Department of Hematology, Hospital de la Princesa, Madrid (Spain); Acevedo, A. [Department of Pathology, Hospital de la Princesa, Madrid (Spain)

    1997-01-01

    A patient with a history of essential thrombocytosis presented with diffuse skeletal pain and restricted motion of the left shoulder. Magnetic resonance imaging (MRI) of the left glenohumeral joint showed a soft tissue mass that displaced the rotator cuff. Biopsy of the mass revealed chloroma. MRI is the method that best characterizes this lesion. (orig.). With 5 figs.

  7. The Nobel Prize in Medicine for Magnetic Resonance Imaging

    Science.gov (United States)

    Fry, Charles G.

    2004-01-01

    Nobel Prize in Medicine awarded in December 2003 to chemist Paul C. Lauterbur and physicist Peter Mansfield for the development of magnetic resonance imaging (MRI), a long overdue recognition of the huge impact MRI has had in medical diagnostics and research is mentioned. MRI was derived, and remains an extension of nuclear magnetic resonance…

  8. Nuclear magnetic resonance imaging of water motion in plants

    NARCIS (Netherlands)

    Scheenen, T.W.J.

    2001-01-01

    This Thesis treats one of the new techniques in plant science i.e. nuclear magnetic resonance imaging (NMRi) applied to water motion in plants. It is a challenge, however, to measure this motion in intact plants quantitatively, because plants impose specific problems when studied using NMRi. At high

  9. OMERACT Rheumatoid Arthritis Magnetic Resonance Imaging Studies. Summary of OMERACT 6 MR Imaging Module

    DEFF Research Database (Denmark)

    McQueen, F; Lassere, M; Edmonds, J;

    2003-01-01

    Magnetic resonance image (MRI) scanning is a new method for imaging and quantifying joint inflammation and damage in rheumatoid arthritis (RA). Over the past 4 years, the OMERACT MR Imaging Group has been developing and testing the RA-MRI scoring system (RAMRIS) for use in RA. The OMERACT filter...

  10. Improvement in dynamic magnetic resonance imaging thermometry

    Science.gov (United States)

    Guo, Jun-Yu

    This dissertation is focused on improving MRI Thermometry (MRIT) techniques. The application of the spin-lattice relaxation constant is investigated in which T1 is used as indicator to measure the temperature of flowing fluid such as blood. Problems associated with this technique are evaluated, and a new method to improve the consistency and repeatability of T1 measurements is presented. The new method combines curve fitting with a measure of the curve null point to acquire more accurate and consistent T1 values. A novel method called K-space Inherited Parallel Acquisition (KIPA) is developed to achieve faster dynamic temperature measurements. Localized reconstruction coefficients are used to achieve higher reduction factors, and lower noise and artifact levels compared to that of GeneRalized Autocalibrating Partially Parallel Acquisition (GRAPPA) reconstruction. Artifacts in KIPA images are significantly reduced, and SNR is largely improved in comparison with that in GRAPPA images. The Root-Mean-Square (RMS) error of temperature for GRAPPA is 2 to 5 times larger than that for KIPA. Finally, the accuracy and comparison of the effects of motion on three parallel imaging methods: SENSE (SENSitivity Encoding), VSENSE (Variable-density SENSE) and KIPA are estimated. According to the investigation, KIPA is the most accurate and robust method among all three methods for studies with or without motion. The ratio of the normalized RMS (NRMS) error for SENSE to that for KIPA is within the range from 1 to 3.7. The ratio of the NRMS error for VSENSE to that for KIPA is about 1 to 2. These factors change with the reduction factor, motion and subject. In summary, the new strategy and method for the fast noninvasive measurement of T1 of flowing blood are proposed to improve stability and precision. The novel parallel reconstruction algorithm, KIPA, is developed to improve the temporal and spatial resolution for the PRF method. The motion effects on the KIPA method are also

  11. Magnetic resonance imaging in preterm infants

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, Rosemary [Leeds General Infirmary, Radiology Department, Leeds (United Kingdom)

    2006-07-15

    MR imaging of the premature infant poses a number of challenges with regard to safety, sequence optimization and recognition of the normal appearances of the developing brain. In this paper we discuss these challenges, and review the common intracerebral abnormalities associated with premature birth. Although the outcome for very-low-birth-weight babies has improved over the last decade, there remains a significant risk of subsequent development of neurological disability. The relationship between MRI abnormalities and long-term outcome is considered. (orig.)

  12. Coronary magnetic resonance vein imaging: imaging contrast, sequence, and timing.

    Science.gov (United States)

    Nezafat, Reza; Han, Yuchi; Peters, Dana C; Herzka, Daniel A; Wylie, John V; Goddu, Beth; Kissinger, Kraig K; Yeon, Susan B; Zimetbaum, Peter J; Manning, Warren J

    2007-12-01

    Recently, there has been increased interest in imaging the coronary vein anatomy to guide interventional cardiovascular procedures such as cardiac resynchronization therapy (CRT), a device therapy for congestive heart failure (CHF). With CRT the lateral wall of the left ventricle is electrically paced using a transvenous coronary sinus lead or surgically placed epicardial lead. Proper transvenous lead placement is facilitated by the knowledge of the coronary vein anatomy. Cardiovascular MR (CMR) has the potential to image the coronary veins. In this study we propose and test CMR techniques and protocols for imaging the coronary venous anatomy. Three aspects of design of imaging sequence were studied: magnetization preparation schemes (T(2) preparation and magnetization transfer), imaging sequences (gradient-echo (GRE) and steady-state free precession (SSFP)), and imaging time during the cardiac cycle. Numerical and in vivo studies both in healthy and CHF subjects were performed to optimize and demonstrate the utility of CMR for coronary vein imaging. Magnetization transfer was superior to T(2) preparation for contrast enhancement. Both GRE and SSFP were viable imaging sequences, although GRE provided more robust results with better contrast. Imaging during the end-systolic quiescent period was preferable as it coincided with the maximum size of the coronary veins.

  13. Contrast Agent in Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Vu-Quang, Hieu

    2015-01-01

    formulated in order to suppress inflamed cytokine expression by siRNA transfection as well as following the migration of macrophage using MRI and NIR bio-imaging. The nano-complexes could inhibit 50 % mRNA expression and 39 % protein expression. In the in vivo cell tracking NIR bio-imaging and MRI...... for chemotherapy. The nanoparticles were 150 nm in size with spherical shape, which contained PFOB in the inner core and Dox and ICG in the polymeric shell. More importantly, they could target folate receptor expressing cancer cells, which provide positive in vitro and in vivo NIR and 19F MRI results. In project...... stem cells and Raw 264.7 macrophages were chitosan-to-particles weight ratios of w0.1 and w0.01, respectively. In vivo 19F MRI results showed the possibility of capturing labeled cells indicating the potential use of PLGA PFOB in future research involving such as cell migration. . In regard of magnetic...

  14. Infantile encephalitic beriberi: magnetic resonance imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Wani, Nisar A. [Government Medical College Srinagar, Department of Pediatric Radiology, Jammu and Kashmir, Pin (India); Qureshi, Umar A.; Ahmad, Kaiser; Ahmad, Waseem [Government Medical College Srinagar, Department of Pediatrics, Jammu and Kashmir (India); Jehangir, Majid [Government Medical College Srinagar, Department of Radiology, Jammu and Kashmir (India)

    2016-01-15

    Thiamine deficiency in infants is still encountered in developing countries. It may present with acute neurological manifestations of infantile encephalitic beriberi. To review brain MRI findings in infantile encephalitic beriberi from a single institution. A retrospective review of MRI scans in 22 infants with acute-onset beriberi encephalopathy was carried out. Hyperintense lesions on T2-weighted images were seen symmetrically in the putamen in all patients, in the caudate nuclei in 16/22 (73%), the thalami in 7/22 (32%) and the globi pallidi in 3/22 (14%) of the infants. Altered signal intensity lesions in the cerebral cortex were seen in 7/22 (32%). The mammillary bodies were seen in one infant and the periaqueductal gray matter in two. There was restricted diffusion in 14/22 (64%), and 6/8 children with no evidence of restriction had been imaged ≥10 days after presentation. MR spectroscopy showed increased lactate peak in 6/8 infants (75%). Recognition of symmetrical T2-W hyperintense lesions in the basal ganglia with restricted diffusion and prominent lactate peak may allow early diagnosis of encephalitic beriberi in at-risk infants. (orig.)

  15. Seven topics in functional magnetic resonance imaging.

    Science.gov (United States)

    Bandettini, Peter A

    2009-09-01

    Functional MRI (fMRI) is a non-invasive brain imaging methodology that started in 1991 and allows human brain activation to be imaged at high resolution within only a few minutes. Because it has extremely high sensitivity, is relatively easy to implement, and can be performed on most standard clinical MRI scanners. It continues to grow at an explosive rate throughout the world. Over the years, at any given time, fMRI has been defined by only a handful of major topics that have been the focus of researchers using and developing the methodology. In this review, I attempt to take a snapshot of the field of fMRI as it is in mid-2009 by discussing the seven topics that I feel are most on the minds of fMRI researchers. The topics are, in no particular order or grouping: (1) Clinical impact, (2) Utilization of individual functional maps, (3) fMRI signal interpretation, (4) Pattern effect mapping and decoding, (5) Endogenous oscillations, (6) MRI technology, and (7) Alternative functional contrast mechanisms. Most of these topics are highly interdependent, each advancing as the others advance. While most fMRI involves applications towards clinical or neuroscience questions, all applications are fundamentally dependent on advances in basic methodology as well as advances in our understanding of the relationship between neuronal activity and fMRI signal changes. This review neglects almost completely an in-depth discussion of applications. Rather the discussions are on the methods and interpretation.

  16. Appearance of the canine meninges in subtraction magnetic resonance images.

    Science.gov (United States)

    Lamb, Christopher R; Lam, Richard; Keenihan, Erin K; Frean, Stephen

    2014-01-01

    The canine meninges are not visible as discrete structures in noncontrast magnetic resonance (MR) images, and are incompletely visualized in T1-weighted, postgadolinium images, reportedly appearing as short, thin curvilinear segments with minimal enhancement. Subtraction imaging facilitates detection of enhancement of tissues, hence may increase the conspicuity of meninges. The aim of the present study was to describe qualitatively the appearance of canine meninges in subtraction MR images obtained using a dynamic technique. Images were reviewed of 10 consecutive dogs that had dynamic pre- and postgadolinium T1W imaging of the brain that was interpreted as normal, and had normal cerebrospinal fluid. Image-anatomic correlation was facilitated by dissection and histologic examination of two canine cadavers. Meningeal enhancement was relatively inconspicuous in postgadolinium T1-weighted images, but was clearly visible in subtraction images of all dogs. Enhancement was visible as faint, small-rounded foci compatible with vessels seen end on within the sulci, a series of larger rounded foci compatible with vessels of variable caliber on the dorsal aspect of the cerebral cortex, and a continuous thin zone of moderate enhancement around the brain. Superimposition of color-encoded subtraction images on pregadolinium T1- and T2-weighted images facilitated localization of the origin of enhancement, which appeared to be predominantly dural, with relatively few leptomeningeal structures visible. Dynamic subtraction MR imaging should be considered for inclusion in clinical brain MR protocols because of the possibility that its use may increase sensitivity for lesions affecting the meninges.

  17. Magnetic Resonance Imaging as a Biomarker for Renal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Yan Wu

    2015-01-01

    Full Text Available As the most common neoplasm arising from the kidney, renal cell carcinoma (RCC continues to have a significant impact on global health. Conventional cross-sectional imaging has always served an important role in the staging of RCC. However, with recent advances in imaging techniques and postprocessing analysis, magnetic resonance imaging (MRI now has the capability to function as a diagnostic, therapeutic, and prognostic biomarker for RCC. For this narrative literature review, a PubMed search was conducted to collect the most relevant and impactful studies from our perspectives as urologic oncologists, radiologists, and computational imaging specialists. We seek to cover advanced MR imaging and image analysis techniques that may improve the management of patients with small renal mass or metastatic renal cell carcinoma.

  18. Gated magnetic resonance imaging of the normal and diseased heart

    Energy Technology Data Exchange (ETDEWEB)

    Lieberman, J.M.; Alfidi, R.J.; Nelson, A.D.; Botti, R.E.; Moir, T.W.; Haaga, J.R.; Kopiwoda, S.; Miraldi, F.D.; Cohen, A.M.; Butler, H.E.

    1984-08-01

    Gated cardiac magnetic resonance (MR) images were obtained in two normal volunteers and 21 adults with a variety of cardiovascular abnormalities. The images were correlated with data from clinical examination, electrocardiograms, and cardiac catheterization. Gated cardiac images were superior to nongated images. Combined cardiac and respiratory gated images were superior to images obtained with cardiac gating only, but acquisition time was longer. Portions of the coronary arteries were visualized in seven of 23 examinations (30%), and subacute and old myocardial infarcts were seen in five of nine patients (55%) as areas of thinned myocardium. Normal cardiac anatomy (chambers, valves, and papillary muscles) was well visualized. Examples of aortic stenosis and atherosclerosis of the abdominal aorta are shown.

  19. Magnetic resonance imaging of the cirrhotic liver: Anupdate

    Institute of Scientific and Technical Information of China (English)

    Agnes Watanabe; Miguel Ramalho; Mamdoh AlObaidy; Hye Jin Kim; Fernanda G Velloni; Richard C Semelka

    2015-01-01

    Noninvasive imaging has become the standard forhepatocellular carcinoma (HCC) diagnosis in cirrhoticlivers. In this review paper, we go over the basics ofMR imaging in cirrhotic livers and describe the imagingappearance of a spectrum of hepatic nodules markingthe progression from regenerative nodules to low- andhigh-grade dysplastic nodules, and ultimately to HCCs.We detail and illustrate the typical imaging appearancesof different types of HCC including focal, multifocal,massive, diffuse/infiltrative, and intra-hepaticmetastases; with emphasis on the diagnostic value ofMR in imaging these lesions. We also shed some lighton liver imaging reporting and data system, and therole of different magnetic resonance imaging (MRI)contrast agents and future MRI techniques includingthe use of advanced MR pulse sequences and utilizationof hepatocyte-specific MRI contrast agents, and howthey might contribute to improving the diagnosticperformance of MRI in early stage HCC diagnosis.

  20. Modelling Brain Tissue using Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Dyrby, Tim Bjørn

    2008-01-01

    Diffusion MRI, or diffusion weighted imaging (DWI), is a technique that measures the restricted diffusion of water molecules within brain tissue. Different reconstruction methods quantify water-diffusion anisotropy in the intra- and extra-cellular spaces of the neural environment. Fibre tracking...... models then use the directions of greatest diffusion as estimates of white matter fibre orientation. Several fibre tracking algorithms have emerged in the last few years that provide reproducible visualizations of three-dimensional fibre bundles. One class of these algorithms is probabilistic...... be used. Within a two year period, no statistical inter- or intra-brain difference in the diffusion coefficient was found in perfusion fixated minipig brains. However, a decreasing tendency in the diffusion coefficient was found at the last time points about 24 months post mortem and might be explained...

  1. Interactive Real-time Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Brix, Lau

    seeks to implement and assess existing reconstruction algorithms using multi-processors of modern graphics cards and many-core computer processors and to cover some of the potential clinical applications which might benefit from using an interactive real-time MRI system. First an off......-line, but interactive, slice alignment tool was used to support the notion that 3D blood flow quantification in the heart possesses the ability to obtain curves and volumes which are not statistical different from standard 2D flow. Secondly, the feasibility of an interactive real-time MRI system was exploited...... 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...

  2. [Magnetic resonance imaging of tibial periostitis].

    Science.gov (United States)

    Meyer, X; Boscagli, G; Tavernier, T; Aczel, F; Weber, F; Legros, R; Charlopain, P; Martin, J P

    1998-01-01

    Tibial periostitis frequently occurs in athletes. We present our experience with MRI in a series of 7 patients (11 legs) with this condition. The clinical presentation and scintigraphic scanning suggested the diagnosis. MRI exploration of 11 legs demonstrated a high band-like juxta-osseous signal enhancement of SE and IR T2 weighted sequences in 6 cases, a signal enhancement after i.v. contrast administration in 4. Tibial periostitis is a clinical diagnosis and MRI and scintigraphic findings can be used to assure the differential diagnosis in difficult cases with stress fracture. MRI can visualize juxta-osseous edematous and inflammatory reactions and an increased signal would appear to be characteristic when the band-like image is fixed to the periosteum.

  3. Imaging oxygen metabolism with hyperpolarized magnetic resonance

    DEFF Research Database (Denmark)

    Schroeder, Marie; Laustsen, Christoffer

    2017-01-01

    Every tissue in the body critically depends on meeting its energetic demands with sufficient oxygen supply. Oxygen supply/demand imbalances underlie the diseases that inflict the greatest socioeconomic burden globally. The purpose of this review is to examine how hyperpolarized contrast media, used...... in combination with MR data acquisition methods, may advance our ability to assess oxygen metabolism non-invasively and thus improve management of clinical disease. We first introduce the concept of hyperpolarization and how hyperpolarized contrast media have been practically implemented to achieve translational...... and clinical research. We will then analyze how incorporating hyperpolarized contrast media could enable realization of unmet technical needs in clinical practice. We will focus on imaging cardiac and renal oxygen metabolism, as both organs have unique physiological demands to satisfy their requirements...

  4. Magnetic resonance imaging of patellofemoral relationships

    Energy Technology Data Exchange (ETDEWEB)

    Koskinen, S.K. (Dept. of Diagnostic Radiology, Turku Univ. Hospital (Finland)); Taimela, S. (Helsinki Research Inst. for Sports and Exercise Medicine (Finland)); Nelimarkka, O. (Dept. of Surgery, Turku Univ. Hospital (Finland)); Komu, M. (Dept. of Diagnostic Radiology, Turku Univ. Hospital (Finland)); Kujala, U.M. (Helsinki Research Inst. for Sports and Exercise Medicine (Finland))

    1993-08-01

    Patellofemoral relationships were analyzed in 11 patients (13 knees) with patellar dislocation and 15 asymptomatic subjects (15 knees) at 0 and 20 of flexion. The measurements were made from five consecutive axial images through the patellofemoral joint. The six indices measured were lateral patellar tilt (LPT), lateral patellofemoral angle (LPA), lateral patellar displacement (LPD), patella-lateral condyle index (L/PW), congruence angle (CA), and sulcus angle (SA). The reproducibility of the method was evaluated. The difference between the two study groups was more evident at 0 than at 20 of knee flexion. Significant differences were noted between measurements made at different levels of the joint, particularly in the controls. Isometric contraction of the quadriceps muscle lateralized and tilted the patella slightly in both groups. L/PW with and without quadriceps muscle contraction, and LPA with reference to the anterior condyles differentiated between the two study groups most clearly. LPT and LPA with reference to the anterior condyles differentiated the study groups better than LPT and LPA with reference to the posterior condyles. The reproducibility was good except for interobserver comparison of CA and SA. The use of an imaging plane selected at the midpoint of the patellar articular cartilage increases the sensitivity of the measurements, since it takes into account both the height of the patella and the tendency towards lateralization. These results indicate that patellar tilt is best measured with the LPA index and patellar lateralization with the L/PW index at 0 knee flexion. This study should always include isometric contraction of the quadriceps muscle. (orig.)

  5. Magnetic resonance imaging of the skeletal musculature

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Marc-Andre (ed.) [Univ. Hospital Heidelberg (Germany). Diagnostic and Intverventional Radiology

    2014-07-01

    Comprehensive overview of the value of cutting-edge MRI for the assessment of normal and diseased skeletal muscle. Presents research findings in respect of the role of modern morphological and functional MRI techniques. Provides examples of the added value provided by these techniques when evaluating muscular diseases. Although muscular diseases are a huge and heterogeneous group, in most cases of progressive disease the result is focal or general muscular weakness that presents as an unspecific symptom. Imaging techniques that offer differential diagnostic clues are therefore urgently needed. Despite this, MRI has to date often been assigned a subsidiary role in the diagnostic work-up of these diseases owing to the frequent inability of routine MRI protocols to detect pathognomonic findings. This situation is changing with the advent of modern MRI techniques that offer deeper insights into surrogate pathophysiologic parameters, such as muscular microcirculation, sodium homeostasis, energy and lipid metabolism, and muscle fiber architecture. Much higher levels of acceptance and demand by clinicians can be anticipated for these new techniques in the near future, and radiologists will have to face up to the increasing value of MRI of the skeletal musculature. In this book, recognized experts from around the world provide a comprehensive overview of the value of cutting-edge MRI for the assessment of normal and diseased skeletal muscle. A range of aspects are covered, from the general role of MRI in imaging the skeletal musculature, including in comparison with ultrasonography, through to the current value of MRI in the diagnostic work-up of different diseases. In addition, several chapters present research findings in respect of modern morphological and functional MRI techniques for assessment of the skeletal musculature and provide examples of the added value provided by these techniques when evaluating muscular diseases.

  6. Magnetic resonance imaging in the staging of cervical cancer

    Energy Technology Data Exchange (ETDEWEB)

    Camisao, Claudia C. [Hospital Sao Lucas, Rio de Janeiro, RJ (Brazil)]. E-mail: ccamisao@inca.gov.br; Brenna, Sylvia M.F. [Hospital Maternidade Leonor Mendes de Barros, Sao Paulo, SP (Brazil); Lombardelli, Karen V.P. [Hospital do Cancer (HCII), Rio de Janeiro, RJ (Brazil); Djahjah, Maria Celia R. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Faculdade de Medicina. Dept. de Radiologia; Zeferino, Luiz Carlos [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Faculdade de Ciencias Medicas. Dept. de Ginecologia

    2007-05-15

    Cervical cancer is the worldwide leading cause of cancer-related death of women, especially in developing countries. The International Federation of Gynecology and Obstetrics recommends staging during surgery, however, surgical-pathologic staging would not be feasible in cases of more advanced cancers. Generally, in these cases, the staging is performed by means of clinical and gynecological examination and basic imaging studies. However, such an approach fails to demonstrate the actual extent of the disease, and does not include significant prognostic factors such as tumor volume, stromal invasion and lymph node involvement. Magnetic resonance imaging has increasingly been utilized in cervical cancer staging, since at early stages of the disease its performance may be compared to intraoperative findings and, at advanced stages, it shows to be superior to the clinical evaluation. Additionally, magnetic resonance imaging presents an excellent imaging resolution for the different densities of pelvic structures, does not require ionizing radiation, is comfortable for the patient, improves de staging, allowing the early detection of recurrence and the identification of reliable prognostic factors which contribute to the therapeutic decision making process and results prediction with an excellent cost-effectiveness. The present article is aimed at reviewing the most significant aspects of magnetic resonance imaging in the cervical cancer staging. (author)

  7. Magnetic resonance imaging characteristics of posterior scleritis mimicking choroidal mass

    Energy Technology Data Exchange (ETDEWEB)

    Osman Saatci, A.; Saatci, Isil E-mail: cekirgesaatci@superonline.com; Kocak, Niluefer; Durak, Ismet

    2001-08-01

    We present imaging findings in a case of posterior scleritis, which may mimic tumoral mass lesion resulting in unnecessary enucleation. Magnetic resonance imaging was remarkable for a subretinal mass hypointense on T2 and hyperintense on T1 weighted images. A peripheral rim of hypointensity was noteworthy, suggestive of sclerouveal thickening. There was an ill-defined area of increased T2 signal intensity adjacent to globe at the site of nodular lesion implying an inflammatory process. A linear contrast enhancement was seen within the bulbus oculi which may represent detached retina by exudation or displaced retina due to thickened sclera and choroidal layers. The CSF space around the optic nerve was enlarged.

  8. Dental magnetic resonance imaging; MRT der Zaehne und des Zahnhalteapparats

    Energy Technology Data Exchange (ETDEWEB)

    Hilgenfeld, Tim; Bendszus, Martin; Haehnel, Stefan [Universitaetsklinikum Heidelberg (Germany). Abt. fuer Neuroradiologie

    2016-03-15

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

  9. Myxoid Adrenocortical Adenoma: Magnetic resonance imaging and pathology correlation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Un [Dept. of Radiology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan (Korea, Republic of); Kim, Suk; Lee, Jun Woo; Lee, Nam Kyung; Ha, Hong Koo; Park, Won Young [Biomedical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine, Busan (Korea, Republic of)

    2014-04-15

    We report a case of a 74-year-old female with myxoid adrenocortical adenoma which showed different magnetic resonance imaging findings compared to those of a typical adrenocortical adenoma. The myxoid change in the adrenocortical adenoma is a rare form of degeneration. It presents a considerable diagnostic challenge to both radiologists and clinicians because it can mimic other adrenal tumor types on imaging. The MRI findings of the presented case included a high signal intensity on T2-weighted images similar to that of fluid and delayed progressive enhancement.

  10. Muscle magnetic resonance imaging in congenital myasthenic syndromes

    OpenAIRE

    Finlayson, Sarah; Morrow, Jasper M.; Rodriguez Cruz, Pedro M.; Sinclair, Christopher D. J.; Fischmann, Arne; Thornton, John S.; Knight, Steve; Norbury, Ray; White, Mel; Al‐hajjar, Michal; Carboni, Nicola; Jayawant, Sandeep; Robb, Stephanie A.; Yousry, Tarek A; Beeson, David

    2016-01-01

    ABSTRACT Introduction In this study we investigated muscle magnetic resonance imaging in congenital myasthenic syndromes (CMS). Methods Twenty‐six patients with 9 CMS subtypes and 10 controls were imaged. T1‐weighted (T1w) and short‐tau inversion recovery (STIR) 3‐Tesla MRI images obtained at thigh and calf levels were scored for severity. Results Overall mean the T1w score was increased in GFPT1 and DPAGT1 CMS. T1w scans of the AChR‐deficiency, COLQ, and CHAT subjects were indistinguishable ...

  11. Pictorial review: magnetic resonance imaging of colonic diverticulitis

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, Orla; Geoghegan, Tony; McAuley, Grainne; Persaud, Thara; Khosa, Faisal; Torreggiani, William C. [The Adelaide and Meath Hospital, Department of Radiology, Tallaght, Dublin 24 (Ireland)

    2007-01-15

    Magnetic resonance imaging (MRI) is rapidly emerging as a useful imaging modality for the evaluation of the gastrointestinal tract. Increasingly rapid sequences and improving hardware have significantly improved the visualisation of diseases of the colon. MRI has a major advantage over CT in that there is no ionising radiation. In our institution, MRI has increasingly been used as a complimentary imaging modality to CT in the diagnosis and evaluation of diverticulitis and its complications. In this review article, we illustrate the emerging role of MRI in the diagnosis and evaluation of colonic diverticulitis. (orig.)

  12. Surface plasmon resonance imaging for parallelized detection of protein biomarkers

    Science.gov (United States)

    Piliarik, Marek; Párová, Lucie; Vaisocherová, Hana; Homola, Jiří

    2009-05-01

    We report a novel high-throughput surface plasmon resonance (SPR) biosensor for rapid and parallelized detection of protein biomarkers. The biosensor is based on a high-performance SPR imaging sensor with polarization contrast and internal referencing which yields a considerably higher sensitivity and resolution than conventional SPR imaging systems (refractive index resolution 2 × 10-7 RIU). We combined the SPR imaging biosensor with microspotting to create an array of antibodies. DNA-directed protein immobilization was utilized for the spatially resolved attachment of antibodies. Using Human Chorionic Gonadotropin (hCG) as model protein biomarker, we demonstrated the potential for simultaneous detection of proteins in up to 100 channels.

  13. Demonstration of coarctation of the aorta by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Amparo, E.; Higgins, C.B.; Shafton, E.P.

    1984-12-01

    The physical findings in coarctation of the aorta are sufficiently characteristic to allow a reasonably accurate clinical diagnosis. The preoperative evaluation has been accomplished by catheterization, aortography, intravenous digital subtraction angiography, computed tomography (CT), and two-dimensional (2D) echocardiography. The authors report a case of coarctation of the aorta clinically suspected in a 29-year-old man. Magnetic resonance imaging (MRI) was the initial preoperative imaging technique. In retrospect, it provided sufficient information for preoperative evaluation so that other imaging techniques would not have been required.

  14. Magnetic resonance imaging and histopathology in the femoral head

    Energy Technology Data Exchange (ETDEWEB)

    Takatori, Yoshio; Kamogawa, Morihide; Nakamura, Toshitaka; Ninomiya, Setsuo; Kokubo, Takashi

    1989-05-01

    To correlate the magnetic resonance (MR) images with the histopathological findings in the femoral head, the histopathology of 24 femoral heads, 15 with osteonecrosis, five with osteoarthritis and four with other hip disorders were subjected to preoperative MR imaging which demonstrated low intensity areas due to long T1 relaxation time in the femoral head. The MR signal was low where fibrovascular tissue, disintegrated fibrovascular tissue, amorphous necrotic material, bone, or cartilagenous tissue occupied the medullary space. From this study, it seems possible to predict the histopathologic changes in the femoral head using MR images. (author).

  15. Magnetic resonance imaging of traumatic transection of the optic chiasm

    Energy Technology Data Exchange (ETDEWEB)

    De Nunzio, M.; McAuliffe, W.; Chakera, T.M.H. [Royal Perth Hospital, Perth, WA (Australia). Department of Diagnostic Radiology

    1997-05-01

    Traumatic lesions of the visual pathways are an uncommon, but well recognized complication of head injury. Optimal visualization of such lesions is probably best achieved using multiplanar magnetic resonance (MR) imaging. A case of complete sagittal transection of the optic chiasm using MR imaging is reported. This has been rarely documented in the literature. Computerized tomography demonstrated a basal skull fracture extending through the sphenoid sinus and into the floor of the pituitary fossa. However, MRI is advocated as the optimal imaging modality for the diagnosis of traumatic lesions of suprasellar structures, perhaps obviating the need for future investigations. 7 refs., 1 fig.

  16. Normal feline brain: clinical anatomy using magnetic resonance imaging.

    Science.gov (United States)

    Mogicato, G; Conchou, F; Layssol-Lamour, C; Raharison, F; Sautet, J

    2012-04-01

    The purpose of this study was to provide a clinical anatomy atlas of the feline brain using magnetic resonance imaging (MRI). Brains of twelve normal cats were imaged using a 1.5 T magnetic resonance unit and an inversion/recovery sequence (T1). Fourteen relevant MRI sections were chosen in transverse, dorsal, median and sagittal planes. Anatomic structures were identified and labelled using anatomical texts and Nomina Anatomica Veterinaria, sectioned specimen heads, and previously published articles. The MRI sections were stained according to the major embryological and anatomical subdivisions of the brain. The relevant anatomical structures seen on MRI will assist clinicians to better understand MR images and to relate this neuro-anatomy to clinical signs. © 2011 Blackwell Verlag GmbH.

  17. Functional magnetic resonance imaging in oncology: state of the art*

    Science.gov (United States)

    Guimaraes, Marcos Duarte; Schuch, Alice; Hochhegger, Bruno; Gross, Jefferson Luiz; Chojniak, Rubens; Marchiori, Edson

    2014-01-01

    In the investigation of tumors with conventional magnetic resonance imaging, both quantitative characteristics, such as size, edema, necrosis, and presence of metastases, and qualitative characteristics, such as contrast enhancement degree, are taken into consideration. However, changes in cell metabolism and tissue physiology which precede morphological changes cannot be detected by the conventional technique. The development of new magnetic resonance imaging techniques has enabled the functional assessment of the structures in order to obtain information on the different physiological processes of the tumor microenvironment, such as oxygenation levels, cellularity and vascularity. The detailed morphological study in association with the new functional imaging techniques allows for an appropriate approach to cancer patients, including the phases of diagnosis, staging, response evaluation and follow-up, with a positive impact on their quality of life and survival rate. PMID:25741058

  18. Ferromagnetic particles as magnetic resonance imaging temperature sensors.

    Science.gov (United States)

    Hankiewicz, J H; Celinski, Z; Stupic, K F; Anderson, N R; Camley, R E

    2016-08-09

    Magnetic resonance imaging is an important technique for identifying different types of tissues in a body or spatial information about composite materials. Because temperature is a fundamental parameter reflecting the biological status of the body and individual tissues, it would be helpful to have temperature maps superimposed on spatial maps. Here we show that small ferromagnetic particles with a strong temperature-dependent magnetization, can be used to produce temperature-dependent images in magnetic resonance imaging with an accuracy of about 1 °C. This technique, when further developed, could be used to identify inflammation or tumours, or to obtain spatial maps of temperature in various medical interventional procedures such as hyperthermia and thermal ablation. This method could also be used to determine temperature profiles inside nonmetallic composite materials.

  19. Magnetic Resonance Imaging in Chronic Achilles Tendinopathy

    Energy Technology Data Exchange (ETDEWEB)

    Shalabi, A. [Karolinska Institutet, Stockholm (Sweden). Center for Surgical Sciences Divisions of Radiology and Orthopedics

    2004-09-01

    The main objective of this thesis was to evaluate and monitor the morphological response following treatment interventions in patients with chronic Achilles tendinopathy by using different MRI techniques. For this purpose, we investigated different types of sequences, including gadolinium contrast medium-enhanced T1-WI images (CME T1-WI), and developed a precise method to measure tendon volume and mean intratendinous signal of the Achilles tendon. Study I aimed at evaluating 15 patients with chronic, painful Achilles tendinosis, before and 2 years after surgical treatment. There was marked regression of the intratendinous signal postoperatively. The most sensitive sequence for depicting an intratendinous lesion in this study was CME T1-WI images. They showed a regression of the intratendinous signal abnormality from 13/15 patients preoperatively to 4/15 postoperatively. The clinical outcome was excellent in eight, good in five, fair in one and poor in one patient. In study II, the early contrast agent enhancement in the dynamically enhanced MRI signal (DEMRI) was correlated with the histopathologic findings in 15 patients with chronic Achilles tendinopathy. Early contrast enhancement (within the first 72 s) was seen in DEMRI in the symptomatic Achilles tendons, with a significant difference compared to the asymptomatic contralateral tendons. Increased severity of tendon changes, including fiber structure abnormality, increased vascularity, rounding of nuclei, and increased amount of glycosaminoglycans, correlated to CME. In study III, we developed a computerized 3-D seed-growing MRI technique to measure tendon volume and mean intratendinous signal. This technique showed an excellent inter- and intra-observer reliability. The technique was also used to follow up prospectively the tendon adaptation and healing described in studies IV-VI. In study IV, using serial MRI during a period of 1 year, we evaluated the biological effect of tendon repair following iatrogenic

  20. Resonant Mode Reduction in Radiofrequency Volume Coils for Ultrahigh Field Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Xiaoliang Zhang

    2011-07-01

    Full Text Available In a multimodal volume coil, only one mode can generate homogeneous Radiofrequency (RF field for Magnetic Resonance Imaging. The existence of other modes may increase the volume coil design difficulties and potentially decreases coil performance. In this study, we introduce common-mode resonator technique to high and ultrahigh field volume coil designs to reduce the resonant mode while maintain the homogeneity of the RF field. To investigate the design method, the common-mode resonator was realized by using a microstrip line which was split along the central to become a pair of parallel transmission lines within which common-mode currents exist. Eight common-mode resonators were placed equidistantly along the circumference of a low loss dielectric cylinder to form a volume coil. Theoretical analysis and comparison between the 16-strut common-mode volume coil and a conventional 16-strut volume coil in terms of RF field homogeneity and efficiency was performed using Finite-Difference Time-Domain (FDTD method at 298.2 MHz. MR imaging experiments were performed by using a prototype of the common-mode volume coil on a whole body 7 Tesla scanner. FDTD simulation results showed the reduced number of resonant modes of the common-mode volume coil over the conventional volume coil, while the RF field homogeneity of the two type volume coils was kept at the same level. MR imaging of a water phantom and a kiwi fruit showing the feasibility of the proposed method for simplifying the volume coil design is also presented.

  1. Reproducibility of magnetic resonance perfusion imaging.

    Directory of Open Access Journals (Sweden)

    Xiaomeng Zhang

    Full Text Available Dynamic MR biomarkers (T2*-weighted or susceptibility-based and T1-weighted or relaxivity-enhanced have been applied to assess tumor perfusion and its response to therapies. A significant challenge in the development of reliable biomarkers is a rigorous assessment and optimization of reproducibility. The purpose of this study was to determine the measurement reproducibility of T1-weighted dynamic contrast-enhanced (DCE-MRI and T2*-weighted dynamic susceptibility contrast (DSC-MRI with two contrast agents (CA of different molecular weight (MW: gadopentetate (Gd-DTPA, 0.5 kDa and Gadomelitol (P792, 6.5 kDa. Each contrast agent was tested with eight mice that had subcutaneous MDA-MB-231 breast xenograft tumors. Each mouse was imaged with a combined DSC-DCE protocol three times within one week to achieve measures of reproducibility. DSC-MRI results were evaluated with a contrast to noise ratio (CNR efficiency threshold. There was a clear signal drop (>95% probability threshold in the DSC of normal tissue, while signal changes were minimal or non-existent (<95% probability threshold in tumors. Mean within-subject coefficient of variation (wCV of relative blood volume (rBV in normal tissue was 11.78% for Gd-DTPA and 6.64% for P792. The intra-class correlation coefficient (ICC of rBV in normal tissue was 0.940 for Gd-DTPA and 0.978 for P792. The inter-subject correlation coefficient was 0.092. Calculated K(trans from DCE-MRI showed comparable reproducibility (mean wCV, 5.13% for Gd-DTPA, 8.06% for P792. ICC of K(trans showed high intra-subject reproducibility (ICC = 0.999/0.995 and inter-subject heterogeneity (ICC = 0.774. Histograms of K(trans distributions for three measurements had high degrees of overlap (sum of difference of the normalized histograms <0.01. These results represent homogeneous intra-subject measurement and heterogeneous inter-subject character of biological population, suggesting that perfusion MRI could be an imaging biomarker to

  2. Oxygen challenge magnetic resonance imaging in healthy human volunteers.

    Science.gov (United States)

    Dani, Krishna A; Moreton, Fiona C; Santosh, Celestine; Lopez, Rosario; Brennan, David; Schwarzbauer, Christian; Goutcher, Colin; O'Hare, Kevin; Macrae, I Mhairi; Muir, Keith W

    2017-01-01

    Oxygen challenge imaging involves transient hyperoxia applied during deoxyhaemoglobin sensitive (T2*-weighted) magnetic resonance imaging and has the potential to detect changes in brain oxygen extraction. In order to develop optimal practical protocols for oxygen challenge imaging, we investigated the influence of oxygen concentration, cerebral blood flow change, pattern of oxygen administration and field strength on T2*-weighted signal. Eight healthy volunteers underwent multi-parametric magnetic resonance imaging including oxygen challenge imaging and arterial spin labelling using two oxygen concentrations (target FiO2 of 100 and 60%) administered consecutively (two-stage challenge) at both 1.5T and 3T. There was a greater signal increase in grey matter compared to white matter during oxygen challenge (p challenge imaging. Reductions in cerebral blood flow did not obscure the T2*-weighted signal increases. In conclusion, the optimal protocol for further study should utilise target FiO2 = 100% during a single oxygen challenge. Imaging at both 1.5T and 3T is clinically feasible.

  3. Liver magnetic resonance imaging: State of the art

    Institute of Scientific and Technical Information of China (English)

    Paul; E; Sijens

    2010-01-01

    Magnetic resonance imaging (MRI) has now been used for about three decades to characterize the human liver in a non-invasive way, that is without the need of using ionizing radiation or removing tissue samples. During the past few years, technical progress has been considerable and novel applications of MRI have been implemented in the clinic. The beginning of a new decade offers an excellent opportunity for having fi ve experts to present their view on the current status of MRI (and magnetic resonance spec...

  4. Elastomeric actuator devices for magnetic resonance imaging

    Science.gov (United States)

    Dubowsky, Steven (Inventor); Hafez, Moustapha (Inventor); Jolesz, Ferenc A. (Inventor); Kacher, Daniel F. (Inventor); Lichter, Matthew (Inventor); Weiss, Peter (Inventor); Wingert, Andreas (Inventor)

    2008-01-01

    The present invention is directed to devices and systems used in magnetic imaging environments that include an actuator device having an elastomeric dielectric film with at least two electrodes, and a frame attached to the actuator device. The frame can have a plurality of configurations including, such as, for example, at least two members that can be, but not limited to, curved beams, rods, plates, or parallel beams. These rigid members can be coupled to flexible members such as, for example, links wherein the frame provides an elastic restoring force. The frame preferably provides a linear actuation force characteristic over a displacement range. The linear actuation force characteristic is defined as .+-.20% and preferably 10% over a displacement range. The actuator further includes a passive element disposed between the flexible members to tune a stiffness characteristic of the actuator. The passive element can be a bi-stable element. The preferred embodiment actuator includes one or more layers of the elastomeric film integrated into the frame. The elastomeric film can be made of many elastomeric materials such as, for example, but not limited to, acrylic, silicone and latex.

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

    Science.gov (United States)

    Seedhouse, Steven J.; Hoffmann, Markus M.

    2008-01-01

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

  6. Protease-specific nanosensors for magnetic resonance imaging.

    Science.gov (United States)

    Schellenberger, Eyk; Rudloff, Franziska; Warmuth, Carsten; Taupitz, Matthias; Hamm, Bernd; Schnorr, Jörg

    2008-12-01

    Imaging of enzyme activity is a central goal of molecular imaging. With the introduction of fluorescent smart probes, optical imaging has become the modality of choice for experimental in vivo detection of enzyme activity. Here, we present a novel high-relaxivity nanosensor that is suitable for in vivo imaging of protease activity by magnetic resonance imaging. Upon specific protease cleavage, the nanoparticles rapidly switch from a stable low-relaxivity stealth state to become adhesive, aggregating high-relaxivity particles. To demonstrate the principle, we chose a cleavage motif of matrix metalloproteinase 9 (MMP-9), an enzyme important in inflammation, atherosclerosis, tumor progression, and many other diseases with alterations of the extracellular matrix. On the basis of clinically tested very small iron oxide particles (VSOP), the MMP-9-activatable protease-specific iron oxide particles (PSOP) have a hydrodynamic diameter of only 25 nm. PSOP are rapidly activated, resulting in aggregation and increased T2*-relaxivity.

  7. Prostate cancer - the role of magnetic resonance imaging.

    Science.gov (United States)

    Mocikova, Ingrid; Babela, Jozef; Balaz, Vladimir

    2012-06-01

    This article reviews the potential of magnetic resonance imaging (MRI) in prostate cancer diagnosis. Systematic scan of Pubmed, Ovid, Medline, Elsevier search engines was used, additional information was found through bibliographic review of relevant articles. Results. Substantial progress has been made in the imaging of prostate cancer in MR imaging, as well as in advanced MR spectroscopy. MRI is a non-invasive and direct imaging modality useful for cancer staging, therapy response, detection of recurrence and guided biopsy in previous negative biopsies. MRI with 3.0T system, whole-body MRI, dynamic contrast enhanced MRI, diffusion-weighted imaging (DWI) and MR spectroscopy (MRS) have improved tumor staging, assessment of tumor volume, aggressiveness or recurrence. Implementation of endorectal/phased array superficial MRI findings on 1.5 or 3.0T systems into nomograms for prostate pretreatment prediction is warranted. Surface phasedarray coil MRI accurately defines prostate cancer with elevated risk of extraprostatic disease.

  8. Application of magnetic resonance techniques for imaging tumour physiology

    Energy Technology Data Exchange (ETDEWEB)

    Stubbs, M. [Saint George' s Hospital Medical School, London (United Kingdom). Dept. of Biochemistry

    1999-07-01

    Magnetic resonance (MR) techniques have the unique ability to measure in vivo the biochemical content of living tissue in the body in a dynamic, non-invasive and non-destructive manner. MR also permits serial investigations of steady-state tumour physiology and biochemistry, as well as the response of a tumour to treatment. Magnetic resonance imaging (MRI), Magnetic resonance spectroscopy (MRS) and a mixture of the two techniques (spectroscopic imaging) allow some physiological parameters, for example pH, to be 'imaged'. Using these methods, information on tissue bioenergetics and phospolipid membrane turnover, pH, hypoxia, oxygenation, and various aspects of vascularity including blood flow, angiogenesis, permeability and vascular volume can be obtained. In addition, MRS methods can be used for monitoring anticancer drugs (e.g. 5FU, ifosfamide) and their metabolites at their sites of action. The role of these state-of-the-art MR methods in imaging tumour physiology and their potential role in the clinic are discussed. (orig.)

  9. Hybrid Method for 3D Segmentation of Magnetic Resonance Images

    Institute of Scientific and Technical Information of China (English)

    ZHANGXiang; ZHANGDazhi; TIANJinwen; LIUJian

    2003-01-01

    Segmentation of some complex images, especially in magnetic resonance brain images, is often difficult to perform satisfactory results using only single approach of image segmentation. An approach towards the integration of several techniques seems to be the best solution. In this paper a new hybrid method for 3-dimension segmentation of the whole brain is introduced, based on fuzzy region growing, edge detection and mathematical morphology, The gray-level threshold, controlling the process of region growing, is determined by fuzzy technique. The image gradient feature is obtained by the 3-dimension sobel operator considering a 3×3×3 data block with the voxel to be evaluated at the center, while the gradient magnitude threshold is defined by the gradient magnitude histogram of brain magnetic resonance volume. By the combined methods of edge detection and region growing, the white matter volume of human brain is segmented perfectly. By the post-processing using mathematical morphological techniques, the whole brain region is obtained. In order to investigate the validity of the hybrid method, two comparative experiments, the region growing method using only gray-level feature and the thresholding method by combining gray-level and gradient features, are carried out. Experimental results indicate that the proposed method provides much better results than the traditional method using a single technique in the 3-dimension segmentation of human brain magnetic resonance data sets.

  10. Gastrointestinal imaging-practical magnetic resonance imaging approach

    Institute of Scientific and Technical Information of China (English)

    Baodong; Liu; Miguel; Ramalho; Mamdoh; AlObaidy; Kiran; K; Busireddy; Ersan; Altun; Janaka; Kalubowila; Richard; C; Semelka

    2014-01-01

    Over the past two decades, advances in cross-sectionalimaging such as computed tomography and magneticresonance imaging(MRI) have dramatically changed theconcept of gastrointestinal imaging. MR is playing anincreasing role in the evaluation of gastrointestinal disorders. MRI combines the advantages of excellent soft-tissue contrast, noninvasiveness, functional informationand lack of ionizing radiation. Furthermore, recent developments of MRI have led to improved spatial and temporal resolution as well as decreased motion artifacts. Inthis article we describe the technical aspects of gastroin-testinal MRI and present a practical approach for a well-known spectrum of gastrointestinal disease processes.

  11. Breast imaging and reporting data system (BIRADS): magnetic resonance imaging.

    Science.gov (United States)

    Tardivon, Anne A; Athanasiou, Alexandra; Thibault, Fabienne; El Khoury, Carl

    2007-02-01

    This article reviews the technical aspects and interpretation criteria in breast MR imaging based on the first edition of breast imaging and reporting data system (BIRADS) published by the American College of Radiology (ACR) in 2003. In a second article, practical cases will be proposed for training the readers. The major aims of using this lexicon are: first to use a logical and standardized description of MR lesions, secondly to obtain a structured MR report with a clear final impression (BIRADS assessment categories), and thirdly to help comparison between different clinical studies based on similar breast MRI terminology.

  12. Breast imaging and reporting data system (BIRADS): Magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tardivon, Anne A. [Department of Radiology, Institut Curie, 26 rue d' Ulm, 75248 Paris Cedex 05 (France)]. E-mail: anne.tardivon@curie.net; Athanasiou, Alexandra [Department of Radiology, Institut Curie, 26 rue d' Ulm, 75248 Paris Cedex 05 (France); Thibault, Fabienne [Department of Radiology, Institut Curie, 26 rue d' Ulm, 75248 Paris Cedex 05 (France); El Khoury, Carl [Department of Radiology, Institut Curie, 26 rue d' Ulm, 75248 Paris Cedex 05 (France)

    2007-02-15

    This article reviews the technical aspects and interpretation criteria in breast MR imaging based on the first edition of breast imaging and reporting data system (BIRADS) published by the American College of Radiology (ACR) in 2003. In a second article, practical cases will be proposed for training the readers. The major aims of using this lexicon are: first to use a logical and standardized description of MR lesions, secondly to obtain a structured MR report with a clear final impression (BIRADS assessment categories), and thirdly to help comparison between different clinical studies based on similar breast MRI terminology.

  13. Intraoperative magnetic resonance imaging-conditional robotic devices for therapy and diagnosis.

    Science.gov (United States)

    Fisher, Taylor; Hamed, Abbi; Vartholomeos, Panagiotis; Masamune, Ken; Tang, Guoyi; Ren, Hongliang; Tse, Zion T H

    2014-03-01

    Magnetic resonance imaging presents high-resolution preoperative scans of target tissue and allows for the availability of intraoperative real-time images without the exposure of patients to ionizing radiation. This has motivated scientists and engineers to integrate medical robotics with the magnetic resonance imaging modality to allow robot-assisted, image-guided diagnosis and therapy. This article provides a review of the state-of-the-art medical robotic systems available for use in conjunction with intraoperative magnetic resonance imaging. The robot functionalities and mechanical designs for a wide range of magnetic resonance imaging interventions are presented, including their magnetic resonance imaging compatibility, actuation, kinematics and the mechanical and electrical designs of the robots. Classification and comparative study of various intraoperative magnetic resonance image guided robotic systems are provided. The robotic systems reviewed are summarized in a table in detail. Current technologies for magnetic resonance imaging-conditional robotics are reviewed and their potential future directions are sketched.

  14. 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.

  15. Resonant plasmonic nanoparticles for multicolor second harmonic imaging

    Science.gov (United States)

    Accanto, Nicolò; Piatkowski, Lukasz; Hancu, Ion M.; Renger, Jan; van Hulst, Niek F.

    2016-02-01

    Nanoparticles capable of efficiently generating nonlinear optical signals, like second harmonic generation, are attracting a lot of attention as potential background-free and stable nano-probes for biological imaging. However, second harmonic nanoparticles of different species do not produce readily distinguishable optical signals, as the excitation laser mainly defines their second harmonic spectrum. This is in marked contrast to other fluorescent nano-probes like quantum dots that emit light at different colors depending on their sizes and materials. Here, we present the use of resonant plasmonic nanoparticles, combined with broadband phase-controlled laser pulses, as tunable sources of multicolor second harmonic generation. The resonant plasmonic nanoparticles strongly interact with the electromagnetic field of the incident light, enhancing the efficiency of nonlinear optical processes. Because the plasmon resonance in these structures is spectrally narrower than the laser bandwidth, the plasmonic nanoparticles imprint their fingerprints on the second harmonic spectrum. We show how nanoparticles of different sizes produce different colors in the second harmonic spectra even when excited with the same laser pulse. Using these resonant plasmonic nanoparticles as nano-probes is promising for multicolor second harmonic imaging while keeping all the advantages of nonlinear optical microscopy.

  16. [Safety of magnetic resonance imaging after coronary stenting].

    Science.gov (United States)

    Sinitsyn, V E; Stukalova, O V; Kupriianova, O M; Ternovoĭ, S K

    2007-01-01

    Magnetic resonance imaging (MRI) is contraindicated to some patients with certain types of metallic devices and implants (e.g. cerebral surgical clips, defibrillators). There are some controversies concerning safety of MRI in patients with metallic coronary stents in cases when MRI examination is performed earlier then one month after stent implantation. Analysis of published data has shown that MRI performed with systems having field strength up to 3 Tesla does not cause migration and heating of both bare and coated stent and is not associated with increased risk of coronary artery thrombosis. MRI can be performed safely in first days after coronary stent implantation. Small local artifacts on MRI images do not influence interpretation of the data (except for cases of coronary magnetic resonance angiography).

  17. Far-field superresolution by imaging of resonance scattering

    KAUST Repository

    Schuster, Gerard T.

    2014-10-31

    We show that superresolution imaging in the far-field region of the sources and receivers is theoretically and practically possible if migration of resonant multiples is employed. A resonant multiple is one that bounces back and forth between two scattering points; it can also be the multiple between two smoothly varying interfaces as long as the reflection wave paths partially overlap and reflect from the same Fresnel zone. For a source with frequency f, compared to a one-way trip, N round trips in propagating between two scatterers increase the effective frequency by 2N × f and decrease the effective wavelength by λ/(2N). Thus, multiples can, in principle, be used as high-frequency probes to estimate detailed properties of layers. Tests with both synthetic and field data validate this claim. Improved resolution by multiple imaging is not only feasible for crustal reflections, but might be applicable to mantle and core reverberations recorded by earthquake seismologists.

  18. Magnetic resonance imaging in deep pelvic endometriosis: iconographic essay

    Energy Technology Data Exchange (ETDEWEB)

    Coutinho Junior, Antonio Carlos; Coutinho, Elisa Pompeu Dias; Lima, Claudio Marcio Amaral de Oliveira; Ribeiro, Erica Barreiros; Aidar, Marisa Nassar [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil); Clinica Multi-Imagem, Rio de Janeiro, RJ (Brazil); E-mail: cmaol@br.inter.net; Gasparetto, Emerson Leandro [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. de Radiologia

    2008-03-15

    Endometriosis is characterized by the presence of normal endometrial tissue outside the uterine cavity. In patients with deep pelvic endometriosis, uterosacral ligaments, rectum, rectovaginal septum, vagina or bladder may be involved. Clinical manifestations may be variable, including pelvic pain, dysmenorrhea, dyspareunia, urinary symptoms and infertility. Complete surgical excision is the gold standard for treating this disease, and hence the importance of the preoperative work-up that usually is limited to an evaluation of sonographic and clinical data. Magnetic resonance imaging is of paramount importance in the diagnosis of endometriosis, considering its high accuracy in the identification of lesions intermingled with adhesions, and in the determination of peritoneal lesions extent. The present pictorial review describes the main magnetic resonance imaging findings in deep pelvic endometriosis. (author)

  19. When should magnetic resonance imaging be considered with neck pain?

    Science.gov (United States)

    Howard, Patricia Kunz; Shapiro, Susan E

    2012-01-01

    Review of recent evidence with translation to practice for the advanced practice nurse role is presented using a case study module for "Cervical Spine Magnetic Resonance Imaging in Alert, Neurologically Intact Trauma Patients With Persistent Midline Tenderness and Negative Computed Tomography Results." The study was designed to identify factors predictive of clinically significant spinal injury in neurologically intact trauma patients with persistent midline cervical tenderness, despite negative computed tomography and plain film findings. The authors reported a lack of guidelines to help emergency care providers identify which of these patients should undergo magnetic resonance imaging studies. The authors highlight the need to develop a clinical prediction rule, or clinical decision rule, to help providers caring for patients such as those with persistent neck pain. The implications and clinical relevance of these findings for advanced practice nurses are discussed highlighting best evidence.

  20. Subtraction gadolinium enhanced magnetic resonance for head and neck imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lloyd, G.A.S.; Barker, P.G.; Phelps, P.D. (Royal National Throat, Nose and Ear Hospital, London (United Kingdom))

    1993-01-01

    The subtraction method of Des Plantes was applied to gadolinium enhanced magnetic resonance imaging (GdMR). Using short acquisition times, T[sub 1] weighted spin echo pulse sequences are made immediately before and after intravenous administration of gadolinium DTPA. The needle is placed in the vein prior to putting the patient into the scanner and is irrigated with saline while the control series is obtained. 42 patients with naso-sinus or skull base tumours have been successfully investigated by this technique and satisfactory subtraction studies are now obtained on all patients other than the claustrophobic. Subtraction GdMR provides the best demonstration of the effects of gadolinium DTPA on the magnetic resonance signal for both normal and abnormal tissues. Tbe signal recorded on the subtraction image is dependent on tissue blood supply and provides a more accurate record of tumour extent than that shown by unsubtracted GdMR scans. (author).

  1. Evaluation of congenital heart disease by magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Roos, A. de; Roest, A.A.W. [Department of Radiology, Leiden University Medical Center (Netherlands)

    2000-01-01

    Magnetic resonance imaging has proven to be useful in the assessment of patients with complex congenital heart disease and in the post-surgical follow-up of patients with corrected congenital heart disease. A thorough understanding of the congenital cardiac malformations that can be encountered is needed and the use of the sequential segmental analysis helps to standardize the evaluation and diagnosis of (complex) congenital heart disease. After surgical correction of congenital heart defects, patients must be followed over extended periods of time, because morphological and functional abnormalities may still be present or may develop. The use of echocardiography may be hampered in these patients as scar tissue and thorax deformities limit the acoustic window. Magnetic resonance imaging has proven to be advantageous in the follow-up of these post-surgical patients and with the use of several different techniques the morphological as well as functional abnormalities can be evaluated and followed over time. (orig.)

  2. Various diffusion magnetic resonance imaging techniques for pancreatic cancer

    Institute of Scientific and Technical Information of China (English)

    Meng-Yue Tang; Xiao-Ming Zhang; Tian-Wu Chen; Xiao-Hua Huang

    2015-01-01

    Pancreatic cancer is one of the most common malignanttumors and remains a treatment-refractory cancer with a poor prognosis. Currently, the diagnosis of pancreatic neoplasm depends mainly on imaging and which methods are conducive to detecting small lesions. Compared to the other techniques, magnetic resonance imaging(MRI) has irreplaceable advantages and can provide valuable information unattainable with other noninvasive or minimally invasive imaging techniques. Advances in MR hardware and pulse sequence design have particularly improved the quality and robustness of MRI of the pancreas. Diffusion MR imaging serves as one of the common functional MRI techniques and is the only technique that can be used to reflect the diffusion movement of water molecules in vivo. It is generally known that diffusion properties depend on the characterization of intrinsic features of tissue microdynamics and microstructure. With the improvement of the diffusion models, diffusion MR imaging techniques are increasingly varied, from the simplest and most commonly used technique to the more complex. In this review, the various diffusion MRI techniques for pancreatic cancer are discussed, including conventional diffusion weighted imaging(DWI), multi-b DWI based on intra-voxel incoherent motion theory, diffusion tensor imaging and diffusion kurtosis imaging. The principles, main parameters, advantages and limitations of these techniques, as well as future directions for pancreatic diffusion imaging are also discussed.

  3. Sedation of Pediatric Patients in Magnetic Resonance Imaging

    Science.gov (United States)

    2000-01-03

    midazolam, and atropine with a propofol infusion is used for pediatric sedation for magnetic resonance imaging (Worrell & McCune, 1993). First used as an...after the infusion is discontinued (Stoelting & Miller, 1994). Propofol is frequently used alone 7 Pediatric Sedation 8 during MRI examinations...drugs used in pediatrics , such as midazolam, ketamine and propofol , will be discussed. The primary focus will be the drug affect on the patient’s

  4. Magnetic resonance imaging of the ductus arteriosus - case report

    Energy Technology Data Exchange (ETDEWEB)

    Yousry, T.; Bacherler, B.; Tiling, R.; Fink, U.; Werdan, K.

    1989-03-01

    In a female patient suffering from renal insufficiency in whom angiography could not be performed, it was possible to confirm the diagnosis of a ductus arteriosus (ductus of Botalli) by magnetic resonance imaging. The present case report shows that it is possible to visualise this congenital heart disease by MRI. This can be of importance especially if angiography cannot be performed (as in this case) because of renal insufficiency or because of contrast medium allergy.

  5. Giant right atrial myxoma: characterization with cardiac magnetic resonance imaging.

    LENUS (Irish Health Repository)

    Ridge, Carole A

    2012-02-01

    A 53-year-old woman presented to the emergency department with a 2-week history of dyspnoea and chest pain. Computed tomography pulmonary angiography was performed to exclude acute pulmonary embolism (PE). This demonstrated a large right atrial mass and no evidence of PE. Transthoracic echocardiography followed by cardiac magnetic resonance imaging confirmed a mobile right atrial mass. Surgical resection was then performed confirming a giant right atrial myxoma. We describe the typical clinical, radiologic, and pathologic features of right atrial myxoma.

  6. Using magnetic resonance imaging to assess visual deficits

    OpenAIRE

    Brown, Holly Diane; Woodall, Rachel Louise; Kitching, Rebecca Elizabeth; Baseler, Heidi A.; Morland, Antony B.

    2016-01-01

    Abstract PURPOSE: Over the last two decades, magnetic resonance imaging (MRI) has been widely used in neuroscience research to assess both structure and function in the brain in health and disease. With regard to vision research, prior to the advent of MRI, researchers relied on animal physiology and human post-mortem work to assess the impact of eye disease on visual cortex and connecting structures. Using MRI, researchers can non-invasively examine the effects of eye disease on the whole vi...

  7. Advanced and Conventional Magnetic Resonance Imaging in Neuropsychiatric Lupus.

    Science.gov (United States)

    Sarbu, Nicolae; Bargalló, Núria; Cervera, Ricard

    2015-01-01

    Neuropsychiatric lupus is a major diagnostic challenge, and a main cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). Magnetic resonance imaging (MRI) is, by far, the main tool for assessing the brain in this disease. Conventional and advanced MRI techniques are used to help establishing the diagnosis, to rule out alternative diagnoses, and recently, to monitor the evolution of the disease. This review explores the neuroimaging findings in SLE, including the recent advances in new MRI methods.

  8. Metabolic Syndrome, Brain Magnetic Resonance Imaging, and Cognition

    OpenAIRE

    2010-01-01

    OBJECTIVE We explored cognitive impairment in metabolic syndrome in relation to brain magnetic resonance imaging (MRI) findings. RESEARCH DESIGN AND METHODS We studied 819 participants free of clinical stroke and dementia of the population-based Austrian Stroke Prevention Study who had undergone brain MRI, neuropsychological testing, and a risk factor assessment relevant to National Cholesterol Education Program Adult Treatment Panel III criteria–defined metabolic syndrome. High-sensitivity C...

  9. 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...... of radiographical outcome in RA. Similarly, there is solid evidence for MRI synovitis representing true synovial inflammation and being of considerable practical, clinical and radiological significance in RA. Describing the encouraging current knowledge regarding MRI for diagnosis, monitoring and prognosis...

  10. Liver iron content determination by magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    Konstantinos; Tziomalos; Vassilios; Perifanis

    2010-01-01

    Accurate evaluation of iron overload is necessary to establish the diagnosis of hemochromatosis and guide chelation treatment in transfusion-dependent anemia. The liver is the primary site for iron storage in patients with hemochromatosis or transfusion-dependent anemia, therefore, liver iron concentration (LIC) accurately re? ects total body iron stores. In the past 20 years, magnetic resonance imaging (MRI) has emerged as a promising method for measuring LIC in a variety of diseases. We review the potenti...

  11. Tuberous sclerosis complex: Diagnostic role of magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Virendra N Sehgal

    2015-01-01

    Full Text Available Tuberous sclerosis complex (TSC is a well-known clinical entity, characterized by facial angio-fibroma, shagreen patch, and hypo-melanotic, and confetti-like skin lesions. An exquisite fresh case is being narrated, emphasizing its microscopic pathology. The role of magnetic resonance imaging of the brain, in particular, is highlighted to define the large variety of neurological abrasions for determining its future progression.

  12. Magnetic resonance imaging of epiploic appendagitis in children.

    Science.gov (United States)

    Boscarelli, Alessandro; Frediani, Simone; Ceccanti, Silvia; Falconi, Ilaria; Masselli, Gabriele; Casciani, Emanuele; Cozzi, Denis A

    2016-12-01

    In children, epiploic appendagitis has been seldom reported. We describe two children with clinical presentations mimicking appendicitis. A correct diagnosis was eventually achieved by magnetic resonance imaging (MRI) and confirmed at laparoscopy in the initial case. Our preliminary experience suggests that MRI is a valid and non-invasive alternative to computed tomography for characterization of unusual causes of pediatric abdominal pain in the acute hospital care setting. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. A review of functional magnetic resonance imaging for Brainnetome

    Institute of Scientific and Technical Information of China (English)

    Ming Song; Tianzi Jiang

    2012-01-01

    The functional brain network using blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) has revealed the potentials for probing brain architecture,as well as for identifying clinical biomarkers for brain diseases.In the general context of Brainnetome,this review focuses on the development of approaches for modeling and analyzing functional brain networks with BOLD fMRI.The prospects for these approaches are also discussed.

  14. Primate comparative neuroscience using magnetic resonance imaging: promises and challenges

    OpenAIRE

    Mars, Rogier B.; Neubert, Franz-Xaver; Verhagen, Lennart; Sallet, Jérôme; Karla L. Miller; Robin I. M. Dunbar; Barton, Robert A.

    2014-01-01

    Primate comparative anatomy is an established field that has made rich and substantial contributions to neuroscience. However, the labor-intensive techniques employed mean that most comparisons are often based on a small number of species, which limits the conclusions that can be drawn. In this review we explore how new developments in magnetic resonance imaging have the potential to apply comparative neuroscience to a much wider range of species, allowing it to realize an even...

  15. Cranial magnetic resonance imaging in chronic demyelinating polyneuropathy.

    OpenAIRE

    Hawke, S H; Hallinan, J M; McLeod, J G

    1990-01-01

    Twenty one patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and five patients with chronic demyelinating polyneuropathy associated with benign monoclonal paraproteinaemia none of whom had signs or symptoms of central nervous system disease, had cranial magnetic resonance imaging (MRI) on a 1.5 Tesla unit. Areas of increased white matter signal intensity were seen in one of 10 patients aged less than 50 years and in five of 16 patients aged more than 50 years. In ...

  16. Towards T1-limited magnetic resonance imaging using Rabi beats

    CERN Document Server

    Fedder, H; Rempp, F; Wolf, T; Hemmer, P; Jelezko, F; Wrachtrup, J

    2010-01-01

    Two proof-of-principle experiments towards T1-limited magnetic resonance imaging with NV centers in diamond are demonstrated. First, a large number of Rabi oscillations is measured and it is demonstrated that the hyperfine interaction due to the NV's 14N can be extracted from the beating oscillations. Second, the Rabi beats under V-type microwave excitation of the three hyperfine manifolds is studied experimentally and described theoretically.

  17. Towards T 1-limited magnetic resonance imaging using Rabi beats

    Science.gov (United States)

    Fedder, H.; Dolde, F.; Rempp, F.; Wolf, T.; Hemmer, P.; Jelezko, F.; Wrachtrup, J.

    2011-03-01

    Two proof-of-principle experiments toward T 1-limited magnetic resonance imaging with NV centers in diamond are demonstrated. First, a large number of Rabi oscillations is measured and it is demonstrated that the hyperfine interaction due to the NV's 14N can be extracted from the beating oscillations. Second, the Rabi beats under V-type microwave excitation of the three hyperfine manifolds is studied experimentally and described theoretically.

  18. Medical Imaging Field of Magnetic Resonance Imaging: Identification of Specialties within the Field

    Science.gov (United States)

    Grey, Michael L.

    2009-01-01

    This study was conducted to determine if specialty areas are emerging in the magnetic resonance imaging (MRI) profession due to advancements made in the medical sciences, imaging technology, and clinical applications used in MRI that would require new developments in education/training programs and national registry examinations. In this…

  19. Medical Imaging Field of Magnetic Resonance Imaging: Identification of Specialties within the Field

    Science.gov (United States)

    Grey, Michael L.

    2009-01-01

    This study was conducted to determine if specialty areas are emerging in the magnetic resonance imaging (MRI) profession due to advancements made in the medical sciences, imaging technology, and clinical applications used in MRI that would require new developments in education/training programs and national registry examinations. In this…

  20. Application of magnetic resonance imaging in cervical spondylotic myelopathy

    Institute of Scientific and Technical Information of China (English)

    Chuan; Zhang; Sushant; K; Das; Dong-Jun; Yang; Han-Feng; Yang

    2014-01-01

    Cervical spondylotic myelopathy(CSM) is the most common cause of spinal cord dysfunction and is caused by static or dynamic repeated compression of the spinal cord resulting from degenerative arthritis of the cervical spine and some biological injuries to the cervical spine. The T2 signal change on conventional magnetic resonance imaging(MRI) is most commonly associated with neurological deficits. Diffusion tensor imaging and MR spectroscopy show altered microstructure and biochemistry that reflect patient-specific pathogenesis and can be used to predict neurological outcome and response to intervention. Functional MRI can help to assess the neurological functional recovery after decompression surgery for CSM.

  1. Reversible Myelopathy on Magnetic Resonance Imaging Due to Cobalamin Deficiency

    Directory of Open Access Journals (Sweden)

    Wei-Ju Lee

    2008-07-01

    Full Text Available Subacute combined degeneration (SCD is known as myelopathy due to vitamin B12 deficiency. SCD always involves the posterior and lateral columns of the spinal cord, with the neuropathologic change showing vacuolation of the white matter. We describe 2 patients who presented with ataxic gait, impaired proprioception over limbs, and even mental change due to vitamin B12 deficiency. Magnetic resonance imaging (MRI of the cervical spine showed increased signal intensity on T2-weighted imaging, and laboratory data showed low serum vitamin B12 level. The 2 patients were treated with vitamin B12 injection intramuscularly. There was clinical improvement after treatment along with normalization of the MRI.

  2. [Appropriateness of referrals for magnetic resonance imaging in Latium, Italy].

    Science.gov (United States)

    Prota, Federica; Rosano, Aldo; San Martini, Elena; Cau, Norberto; Guasticchi, Gabriella

    2012-01-01

    Long wait times for access to Nuclear Magnetic resonance imaging (MRI) examinations are a concern and for this reason the project "Appropriateness of referrals for MRI examinations" has been launched in Latium (Italy). The aim of this preliminary study was to describe the main characteristics of MRI referrals in the region. Findings highlight a large variation in referral rates across the region, with 80% of MRI referrals being ordered by general practitioners and family pediatricians. The latter points to the possibility of inappropriate referrals for MRI imaging in Latium.

  3. Magnetic Resonance Imaging of Gel-cast Ceramic Composites

    Science.gov (United States)

    Dieckman, S. L.; Balss, K. M.; Waterfield, L. G.; Jendrzejczyk, J. A.; Raptis, A. C.

    1997-01-16

    Magnetic resonance imaging (MRI) techniques are being employed to aid in the development of advanced near-net-shape gel-cast ceramic composites. MRI is a unique nondestructive evaluation tool that provides information on both the chemical and physical properties of materials. In this effort, MRI imaging was performed to monitor the drying of porous green-state alumina - methacrylamide-N.N`-methylene bisacrylamide (MAM-MBAM) polymerized composite specimens. Studies were performed on several specimens as a function of humidity and time. The mass and shrinkage of the specimens were also monitored and correlated with the water content.

  4. Magnetic Resonance Imaging Guided Vacuum Assisted and Core Needle Biopsies.

    Science.gov (United States)

    Kılıç, Fahrettin; Eren, Abdulkadir; Tunç, Necmettin; Velidedeoğlu, Mehmet; Bakan, Selim; Aydoğan, Fatih; Çelik, Varol; Gazioğlu, Ertuğrul; Yılmaz, Mehmet Halit

    2016-01-01

    The purpose of this study to present the results of Magnetic resonance imaging (MRI) guided cutting needle biopsy procedures of suspicious breast lesions that can be solely detected on Magnetic resonance (MR) examination. The study included 48 patients with 48 lesions which were solely be observed in breast MRI, indistinguishable in ultrasonography and mammography, for MR guided vacuum-assisted cutting needle biopsy and 42 patients with 42 lesions for MR guided cutting needle biopsy for the lesions of the same nature. MR imaging was performed using a 1.5-Tesla MRI device. Acquired MR images were determined and biopsy protocol was performed using computer-aided diagnosis system on the workstation. Vacuum biopsies were performed using 10 G or 12 G automatic biopsy systems, cutting needle biopsy procedures were performed using fully automated 12 G biopsy needle. All biopsy procedures were finalized successfully without major complications. The lesions were 54 mass (60%), 28 were non-mass contrast enhancement (31%) and 8 were foci (9%) in the MR examination. Histopathological evaluation revealed 18 malignant (invasive, in-situ ductal carcinoma and lobular carcinoma), 66 benign (apocrine metaplasia, fibrosis, fibroadenomatoid lesion, sclerosing adenosis, fibrocystic disease and mild-to-severe epithelial proliferation) and 6 high-risk (atypical ductal hyperplasia, intraductal papilloma, radial scar) lesions. Magnetic resonance guided vacuum and cutting needle biopsy methods are successful methods fort he evaluation of solely MRI detected suspicious breast lesions. There are several advantages relative to each other in both methods.

  5. High Performance Nuclear Magnetic Resonance Imaging Using Magnetic Resonance Force Microscopy

    Science.gov (United States)

    2013-12-12

    Moler. Direct imaging of the coexistence of ferromagnetism and superconductivity at the LaAlO3/SrTiO3 interface. Nature Physics, 7(10) 767771...2011) [35] S. M. M. Yee, D. A. Crandles and L. V. Gon- charova. Ferromagnetism on the unpolished sur- faces of single crystal metal oxide substrates. J. App. Phys., 110(3) (2011) ...International Workshop on Spin Mechanics, Tokai,Japan, 24–26 February 2013, “Nanoscale scanning probe ferromagnetic resonance imaging using localized

  6. Poor quality of early evaluations of magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, L.S.; Chalmers, T.C.; McCally, M.; Berrier, J.; Sacks, H.S.

    1988-06-10

    To study the quality of early research on the clinical efficacy of diagnostic imaging with magnetic resonance, they assessed 54 evaluations published in the first four years after introduction of this modality using ten commonly accepted criteria of research methodology. The terms sensitivity, specificity, false-positive or false-negative, accuracy, and predictive values were used infrequently. 19% of the evaluations used three terms appropriately, 48% used one or two terms, and 33% used none. Data were presented appropriately for one or more of the five terms in 59% of evaluations. A gold standard comparison with the results of an independent procedure, such as surgical or autopsy findings, was presented in 22% of evaluations. Results of another imaging procedure were described in 63% of evaluations. Only one evaluation clearly described a prospective study design, although 11 evaluations apparently were planned in advance. Not one evaluation contained an appropriate statistical analysis of the distributions of quantitative readings, blinded image readers to diagnosis or other test results, measured observer error, or randomized the order of magnetic resonance imaging and other imaging procedures. The authors concludes that health care professionals paying for expensive innovative diagnostic technology should demand better research on diagnostic efficacy.

  7. Recent advances in magnetic resonance imaging for stroke diagnosis

    Directory of Open Access Journals (Sweden)

    Radhika Rastogi

    2015-01-01

    Full Text Available In stroke, diagnosis and identification of the infarct core and the penumbra is integral to therapeutic determination. With advances in magnetic resonance imaging (MRI technology, stroke visualization has been radically altered. MRI allows for better visualization of factors such as cerebral microbleeds (CMBs, lesion and penumbra size and location, and thrombus identification; these factors help determine which treatments, ranging from tissue plasminogen activator (tPA, anti-platelet therapy, or even surgery, are appropriate. Current stroke diagnosis standards use several MRI modalities in conjunction, with T2- or T2FNx01- weighted MRI to rule out intracerebral hemorrhage (ICH, magnetic resonance angiography (MRA for thrombus identification, and the diffusion-weighted imaging (DWI and perfusion-weighted imaging (PWI mismatch for penumbral identification and therapeutic determination. However, to better clarify the neurological environment, susceptibility-weighted imaging (SWI for assessing oxygen saturation and the presence of CMBs as well as additional modalities, such as amide proton transfer (APT imaging for pH mapping, have emerged to offer more insight into anatomical and biological conditions during stroke. Further research has unveiled potential for alternative contrasts to gadolinium for PWI as well, as the contrast has contraindications for patients with renal disease. Superparamagnetic iron oxide nanoparticles (SPIONs as an exogenous contrast and arterial spin labeling (ASL as an endogenous contrast offer innovative alternatives. Thus, emerging MRI modalities are enhancing the diagnostic capabilities of MRI in stroke and provide more guidance for patient outcome by offering increased accessibility, accuracy, and information.

  8. Signal Improvement and Contrast Enhancement in Magnetic Resonance Imaging

    CERN Document Server

    Han, Yi

    2015-01-01

    This thesis reports advances in magnetic resonance imaging (MRI), with the ultimate goal of improving signal and contrast in biomedical applications. More specifically, novel MRI pulse sequences have been designed to characterize microstructure, enhance signal and contrast in tissue, and image functional processes. In this thesis, rat brain and red bone marrow images are acquired using iMQCs (intermolecular multiple quantum coherences) between intermediate separated spins. As an important application, iMQCs images in different directions can be used for anisotropy mapping and tissue microstructure analysis. At the same time, the simulations prove that the dipolar field from the overall shape only has small contributions to the experimental iMQC signal. Besides magnitude of iMQCs, phase of iMQCs should be studied as well. The phase anisotropy maps built by our method can clearly show susceptibility information in rat brain. It may provide meaningful diagnostic information. To deeply study susceptibility, the m...

  9. Central nervous system lymphoma: magnetic resonance imaging features at presentation.

    Science.gov (United States)

    Schwingel, Ricardo; Reis, Fabiano; Zanardi, Veronica A; Queiroz, Luciano S; França, Marcondes C

    2012-02-01

    This paper aimed at studying presentations of the central nervous system (CNS) lymphoma using structural images obtained by magnetic resonance imaging (MRI). The MRI features at presentation of 15 patients diagnosed with CNS lymphoma in a university hospital, between January 1999 and March 2011, were analyzed by frequency and cross tabulation. All patients had supratentorial lesions; and four had infra- and supratentorial lesions. The signal intensity on T1 and T2 weighted images was predominantly hypo- or isointense. In the T2 weighted images, single lesions were associated with a hypointense signal component. Six patients presented necrosis, all of them showed perilesional abnormal white matter, nine had meningeal involvement, and five had subependymal spread. Subependymal spread and meningeal involvement tended to occur in younger patients. Presentations of lymphoma are very pleomorphic, but some of them should point to this diagnostic possibility.

  10. Advances in Magnetic Resonance Imaging Contrast Agents for Biomarker Detection

    Science.gov (United States)

    Sinharay, Sanhita; Pagel, Mark D.

    2016-06-01

    Recent advances in magnetic resonance imaging (MRI) contrast agents have provided new capabilities for biomarker detection through molecular imaging. MRI contrast agents based on the T2 exchange mechanism have more recently expanded the armamentarium of agents for molecular imaging. Compared with T1 and T2* agents, T2 exchange agents have a slower chemical exchange rate, which improves the ability to design these MRI contrast agents with greater specificity for detecting the intended biomarker. MRI contrast agents that are detected through chemical exchange saturation transfer (CEST) have even slower chemical exchange rates. Another emerging class of MRI contrast agents uses hyperpolarized 13C to detect the agent with outstanding sensitivity. These hyperpolarized 13C agents can be used to track metabolism and monitor characteristics of the tissue microenvironment. Together, these various MRI contrast agents provide excellent opportunities to develop molecular imaging for biomarker detection.

  11. Magnetic resonance imaging in the evaluation of cognitive function.

    Science.gov (United States)

    Bigler, Erin D

    2014-10-01

    Image quality of magnetic resonance imaging (MRI) scans of the brain currently approximate gross anatomy as would be viewed at autopsy. During the first decade of the 21st Century incredible advances in image processing and quantification have occurred permitting more refined methods for studying brain-behavior-cognitive functioning. The current presentation overviews the current status of MRI methods for routine clinical assessment of brain pathology, how these techniques identify neuropathology and how pathological findings are quantified. Diffusion tensor imaging (DTI), functional MRI (fMRI), and resting state fMRI are all reviewed, emphasizing how these techniques permit an examination of brain function and connectivity. General regional relationships of brain function associated with cognitive control will be highlighted.

  12. Magnetic resonance imaging of the elbow. Part II: Abnormalities of the ligaments, tendons, and nerves

    Energy Technology Data Exchange (ETDEWEB)

    Kijowski, Richard; Tuite, Michael; Sanford, Matthew [University of Wisconsin Hospital, Department of Radiology, Madison, WI (United States)

    2005-01-01

    Part II of this comprehensive review on magnetic resonance imaging of the elbow discusses the role of magnetic resonance imaging in evaluating patients with abnormalities of the ligaments, tendons, and nerves of the elbow. Magnetic resonance imaging can yield high-quality multiplanar images which are useful in evaluating the soft tissue structures of the elbow. Magnetic resonance imaging can detect tears of the ulnar collateral ligament and lateral collateral ligament of the elbow with high sensitivity and specificity. Magnetic resonance imaging can determine the extent of tendon pathology in patients with medial epicondylitis and lateral epicondylitis. Magnetic resonance imaging can detect tears of the biceps tendon and triceps tendon and can distinguishing between partial and complete tendon rupture. Magnetic resonance imaging is also helpful in evaluating patients with nerve disorders at the elbow. (orig.)

  13. Magnetic resonance imaging of small bowel Crohn's disease.

    Science.gov (United States)

    Ramalho, Miguel; Herédia, Vasco; Cardoso, Cláudia; Matos, António P; Palas, João; De Freitas, João; Semelka, Richard C

    2012-01-01

    Crohn's disease (CD) is a chronic relapsing inflammatory disease of the gastrointestinal tract, which mostly affects young patients. Imaging techniques form a very important part for the evaluation of CD and for monitoring disease progression or response to therapy. Currently, imaging of CD is increasingly being performed by cross-sectional modalities, i.e. multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI), since these techniques allow for simultaneous visualization of luminal, mural and extraintestinal disease extension. MR enterography has the potential to safely and noninvasively accomplish the imaging needs of patients with Crohn disease without exposing them to ionizing radiation. The new imaging paradigm should contemplate patient safety as a very important aspect when assessing the role of an imaging modality in comparison with others. For this reason, MRI may be the preferred modality for evaluation of small bowel disease, especially in young patients in the setting of CD, considering that the majority will undergo frequent repeat studies. Also, the information on disease activity is not matched by any other imaging method. In this review article, the authors discuss the essential aspects of MR evaluation of CD, including protocol and imaging findings, also referring the advantages over other radiological studies, concerning safety, accuracy and potential importance for therapeutic approach.

  14. Aortic dimensions in girls and young women with turner syndrome: a magnetic resonance imaging study

    DEFF Research Database (Denmark)

    Mortensen, Kristian H; Skouby, Sven O; Leffers, Anne-Mette

    2010-01-01

    This study aimed to determine the dimensions of the thoracic aorta and the predictors of aortic dimensions in girls and young women with Turner syndrome (TS). A cross-sectional study was performed at a secondary care center. The study compared 41 TS patients with 50 healthy age-matched control...... subjects. The mean age of the patients was 17 +/- 3.3 years. Magnetic resonance imaging was performed for all the patients. The thoracic aortic diameters of the patients were measured at nine positions. Adjustment for body surface area (BSA) was performed. The outcome for the patients was measured in terms...... and in five TS patients after BSA-adjustment. The aortic diameters correlated with height, weight, body mass index (BMI), and BSA at all positions (R = 0.34-0.60; all p aorta correlated with a history of aortic coarctation (R = 0.35-0.52; p

  15. Predictors and Health-Related Outcomes of Positive Body Image in Adolescent Girls: A Prospective Study

    Science.gov (United States)

    Andrew, Rachel; Tiggemann, Marika; Clark, Levina

    2016-01-01

    This study aimed to investigate prospective predictors and health-related outcomes of positive body image in adolescent girls. In so doing, the modified acceptance model of intuitive eating was also examined longitudinally. A sample of 298 girls aged 12 to 16 years completed a questionnaire containing measures of body appreciation, potential…

  16. Sociocultural and Individual Psychological Predictors of Body Image in Young Girls: A Prospective Study

    Science.gov (United States)

    Clark, Levina; Tiggemann, Marika

    2008-01-01

    This study investigated the prospective predictors of body image in 9- to 12-year-old girls. Participants were 150 girls in Grades 4-6 with a mean age of 10.3 years. Girls completed questionnaire measures of media and peer influences (television/magazine exposure, peer appearance conversations), individual psychological variables (appearance…

  17. Sociocultural and Individual Psychological Predictors of Body Image in Young Girls: A Prospective Study

    Science.gov (United States)

    Clark, Levina; Tiggemann, Marika

    2008-01-01

    This study investigated the prospective predictors of body image in 9- to 12-year-old girls. Participants were 150 girls in Grades 4-6 with a mean age of 10.3 years. Girls completed questionnaire measures of media and peer influences (television/magazine exposure, peer appearance conversations), individual psychological variables (appearance…

  18. Navigation concepts for magnetic resonance imaging-guided musculoskeletal interventions.

    Science.gov (United States)

    Busse, Harald; Kahn, Thomas; Moche, Michael

    2011-08-01

    Image-guided musculoskeletal (MSK) interventions are a widely used alternative to open surgical procedures for various pathological findings in different body regions. They traditionally involve one of the established x-ray imaging techniques (radiography, fluoroscopy, computed tomography) or ultrasound scanning. Over the last decades, magnetic resonance imaging (MRI) has evolved into one of the most powerful diagnostic tools for nearly the whole body and has therefore been increasingly considered for interventional guidance as well.The strength of MRI for MSK applications is a combination of well-known general advantages, such as multiplanar and functional imaging capabilities, wide choice of tissue contrasts, and absence of ionizing radiation, as well as a number of MSK-specific factors, for example, the excellent depiction of soft-tissue tumors, nonosteolytic bone changes, and bone marrow lesions. On the downside, the magnetic resonance-compatible equipment needed, restricted space in the magnet, longer imaging times, and the more complex workflow have so far limited the number of MSK procedures under MRI guidance.Navigation solutions are generally a natural extension of any interventional imaging system, in particular, because powerful hardware and software for image processing have become routinely available. They help to identify proper access paths, provide accurate feedback on the instrument positions, facilitate the workflow in an MRI environment, and ultimately contribute to procedural safety and success.The purposes of this work were to describe some basic concepts and devices for MRI guidance of MSK procedures and to discuss technical and clinical achievements and challenges for some selected implementations.

  19. Quantitative analysis of brain magnetic resonance imaging for hepatic encephalopathy

    Science.gov (United States)

    Syh, Hon-Wei; Chu, Wei-Kom; Ong, Chin-Sing

    1992-06-01

    High intensity lesions around ventricles have recently been observed in T1-weighted brain magnetic resonance images for patients suffering hepatic encephalopathy. The exact etiology that causes magnetic resonance imaging (MRI) gray scale changes has not been totally understood. The objective of our study was to investigate, through quantitative means, (1) the amount of changes to brain white matter due to the disease process, and (2) the extent and distribution of these high intensity lesions, since it is believed that the abnormality may not be entirely limited to the white matter only. Eleven patients with proven haptic encephalopathy and three normal persons without any evidence of liver abnormality constituted our current data base. Trans-axial, sagittal, and coronal brain MRI were obtained on a 1.5 Tesla scanner. All processing was carried out on a microcomputer-based image analysis system in an off-line manner. Histograms were decomposed into regular brain tissues and lesions. Gray scale ranges coded as lesion were then brought back to original images to identify distribution of abnormality. Our results indicated the disease process involved pallidus, mesencephalon, and subthalamic regions.

  20. Magnetic resonance imaging of trilucent TM breast implants

    Energy Technology Data Exchange (ETDEWEB)

    Elson, Elspeth M.; Jones, Annette; King, Rebecca; Chapman, P.; Stanek, Jan; Irvine, Allan T.; Bingham, John B

    2002-04-01

    AIM: To demonstrate the magnetic resonance imaging (MRI) appearances of intact and ruptured Trilucent TM implants with imaging and surgical correlation. The appearances of the implant transponder artefact are also described MATERIALS AND METHODS: A retrospective review of the MRI findings in 34 patients with bilateral subpectoral Trilucent TM breast implants (Lipomatrix, Inc./Collagen Aesthetics International Inc., Neuchatel, Switzerland) was performed. Patients under implant surveillance and those with suspected implant rupture formed the study group. Imaging findings were correlated with surgical appearances. RESULTS: Surgical correlation was available in 53% of patients. Fifty per cent (18/36) of implants were intact at surgery, 50% (18/36) of implants were ruptured. Of the 18 ruptured implants, 17 were intracapsular ruptures and one an extracapsular rupture. The sensitivity of MRI for detection of intracapsular rupture in Trilucent TM breast implants was 82% specificity 76%, positive predictive value 78%, negative predictive value 81% and accuracy 79% in this study group. No case of implant rupture was obscured by the transponder artefact. Four implants were found to have 'pseudocapsules' at surgery (5{center_dot}9%), the implants were intact with fluid present between the implant and capsule. Only one pseudocapsule was demonstrated on MRI. CONCLUSION: Magnetic resonance imaging is currently the most accurate technique for diagnosis of implant rupture in Trilucent TM breast implants. Transponder artefact does not appear to interfere with the assessment of implant rupture. Elson, E. M. et al. (2002)