WorldWideScience

Sample records for 3d-dynamic mri initial

  1. Estimation of Pulmonary Motion in Healthy Subjects and Patients with Intrathoracic Tumors Using 3D-Dynamic MRI: Initial Results

    Energy Technology Data Exchange (ETDEWEB)

    Plathow, Christian; Schoebinger, Max; Meinzer, Heinz Peter [German Cancer Research Center, Heidelberg (Germany); Herth, Felix; Tuengerthal, Siegfried [Clinic of Thoracic Disease, Heidelberg (Germany); Kauczor, Hans Ulrich [University of Heidelberg, Heidelberg (Germany)

    2009-12-15

    To estimate a new technique for quantifying regional lung motion using 3D-MRI in healthy volunteers and to apply the technique in patients with intra- or extrapulmonary tumors. Intraparenchymal lung motion during a whole breathing cycle was quantified in 30 healthy volunteers using 3D-dynamic MRI (FLASH [fast low angle shot] 3D, TRICKS [time-resolved interpolated contrast kinetics]). Qualitative and quantitative vector color maps and cumulative histograms were performed using an introduced semiautomatic algorithm. An analysis of lung motion was performed and correlated with an established 2D-MRI technique for verification. As a proof of concept, the technique was applied in five patients with non-small cell lung cancer (NSCLC) and 5 patients with malignant pleural mesothelioma (MPM). The correlation between intraparenchymal lung motion of the basal lung parts and the 2D-MRI technique was significant (r = 0.89, p < 0.05). Also, the vector color maps quantitatively illustrated regional lung motion in all healthy volunteers. No differences were observed between both hemithoraces, which was verified by cumulative histograms. The patients with NSCLC showed a local lack of lung motion in the area of the tumor. In the patients with MPM, there was global diminished motion of the tumor bearing hemithorax, which improved significantly after chemotherapy (CHT) (assessed by the 2D- and 3D-techniques) (p < 0.01). Using global spirometry, an improvement could also be shown (vital capacity 2.9 {+-} 0.5 versus 3.4 L {+-} 0.6, FEV1 0.9 {+-} 0.2 versus 1.4 {+-} 0.2 L) after CHT, but this improvement was not significant. A 3D-dynamic MRI is able to quantify intraparenchymal lung motion. Local and global parenchymal pathologies can be precisely located and might be a new tool used to quantify even slight changes in lung motion (e.g. in therapy monitoring, follow-up studies or even benign lung diseases)

  2. Estimation of Pulmonary Motion in Healthy Subjects and Patients with Intrathoracic Tumors Using 3D-Dynamic MRI: Initial Results

    International Nuclear Information System (INIS)

    To estimate a new technique for quantifying regional lung motion using 3D-MRI in healthy volunteers and to apply the technique in patients with intra- or extrapulmonary tumors. Intraparenchymal lung motion during a whole breathing cycle was quantified in 30 healthy volunteers using 3D-dynamic MRI (FLASH [fast low angle shot] 3D, TRICKS [time-resolved interpolated contrast kinetics]). Qualitative and quantitative vector color maps and cumulative histograms were performed using an introduced semiautomatic algorithm. An analysis of lung motion was performed and correlated with an established 2D-MRI technique for verification. As a proof of concept, the technique was applied in five patients with non-small cell lung cancer (NSCLC) and 5 patients with malignant pleural mesothelioma (MPM). The correlation between intraparenchymal lung motion of the basal lung parts and the 2D-MRI technique was significant (r = 0.89, p < 0.05). Also, the vector color maps quantitatively illustrated regional lung motion in all healthy volunteers. No differences were observed between both hemithoraces, which was verified by cumulative histograms. The patients with NSCLC showed a local lack of lung motion in the area of the tumor. In the patients with MPM, there was global diminished motion of the tumor bearing hemithorax, which improved significantly after chemotherapy (CHT) (assessed by the 2D- and 3D-techniques) (p < 0.01). Using global spirometry, an improvement could also be shown (vital capacity 2.9 ± 0.5 versus 3.4 L ± 0.6, FEV1 0.9 ± 0.2 versus 1.4 ± 0.2 L) after CHT, but this improvement was not significant. A 3D-dynamic MRI is able to quantify intraparenchymal lung motion. Local and global parenchymal pathologies can be precisely located and might be a new tool used to quantify even slight changes in lung motion (e.g. in therapy monitoring, follow-up studies or even benign lung diseases)

  3. Scaling in Gravitational Clustering, 2D and 3D Dynamics

    CERN Document Server

    Munshi, D; Melott, A L; Schäffer, R

    1999-01-01

    Perturbation Theory (PT) applied to a cosmological density field with Gaussian initial fluctuations suggests a specific hierarchy for the correlation functions when the variance is small. In particular quantitative predictions have been made for the moments and the shape of the one-point probability distribution function (PDF) of the top-hat smoothed density. In this paper we perform a series of systematic checks of these predictions against N-body computations both in 2D and 3D with a wide range of featureless power spectra. In agreement with previous studies, we found that the reconstructed PDF-s work remarkably well down to very low probabilities, even when the variance approaches unity. Our results for 2D reproduce the features for the 3D dynamics. In particular we found that the PT predictions are more accurate for spectra with less power on small scales. The nonlinear regime has been explored with various tools, PDF-s, moments and Void Probability Function (VPF). These studies have been done with unprec...

  4. 3D Dynamic Earthquake Fracture Simulation (Test Case)

    Science.gov (United States)

    Korkusuz Öztürk, Yasemin; Meral Özel, Nurcan; Ando, Ryosuke

    2016-04-01

    A 3D dynamic earthquake fracture simulation is being developed for the fault structures which are non-planar to understand heterogeneous stress states in the Marmara Sea. Locating in a seismic gap, a large earthquake is expected in the center of the Sea of Marmara. Concerning the fact that more than 14 million inhabitants of İstanbul, located very closely to the Marmara Sea, the importance of the analysis of the Central Marmara Sea is extremely high. A few 3D dynamic earthquake fracture studies have been already done in the Sea of Marmara for pure right lateral strike-slip stress regimes (Oglesby and Mai, 2012; Aochi and Ulrich, 2015). In this study, a 3D dynamic earthquake fracture model with heterogeneous stress patches from the TPV5, a SCEC code validation case, is adapted. In this test model, the fault and the ground surfaces are gridded by a scalene triangulation technique using GMSH program. For a grid size changing between 0.616 km and 1.050 km the number of elements for the fault surface is 1984 and for the ground surface is 1216. When these results are compared with Kaneko's results for TPV5 from SPECFEM3D, reliable findings could be observed for the first 6.5 seconds (stations on the fault) although a stability problem is encountered after this time threshold. To solve this problem grid sizes are made smaller, so the number of elements increase 7986 for the fault surface and 4867 for the ground surface. On the other hand, computational problems arise in that case, since the computation time is directly proportional to the number of total elements and the required memory also increases with the square of that. Therefore, it is expected that this method can be adapted for less coarse grid cases, regarding the main difficulty coming from the necessity of an effective supercomputer and run time limitations. The main objective of this research is to obtain 3D dynamic earthquake rupture scenarios, concerning not only planar and non-planar faults but also

  5. 3-D DYNAMIC RESPONSE OF TRANSVERSELY ISOTROPIC SATURATED SOILS

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-gang; HUANG Yi

    2005-01-01

    A study on dynamic response of transversely isotropic saturated poroelastic media under a circular non-axisymmetrical harmonic source has been presented by Huang Yi et al.using the technique of Fourier expansion and Hankel transform. However, the method may not always be valid. The work is extended to the general case being in the rectangular coordinate. The purpose is to study the 3-d dynamic response of transversely isotropic saturated soils under a general source distributing in arbitrary rectangular zoon on the medium surface. Based on Biot's theory for fluid-saturated porous media, the 3-d wave motion equations in rectangular coordinate for transversely isotropic saturated poroelastic media were transformed into the two uncoupling governing differential equations of 6-order and 2-order respectively by means of the displacement functions. Then, using the technique of double Fourier transform, the governing differential equations were easily solved. Integral solutions of soil skeleton displacements and pore pressure as well as the total stresses for poroelastic media were obtained. Furthermore, a systematic study on half-space problem in saturated soils was performed. Integral solutions for surface displacements under the general harmonic source distributing on arbitrary surface zone,considering both case of drained surface and undrained surface,were presented.

  6. Simulation of Missing Pellet Surface thermal behavior with 3D dynamic gap element

    International Nuclear Information System (INIS)

    Most of the fuel performance codes that are able to simulate a multidimensional analysis are used to calculate the radial temperature distribution and perform a multidimensional mechanical analysis based on a one-dimensional (1D) temperature result. The FRAPCON-FRAPTRAN code system incorporates a 1D thermal module and two-dimensional (2D) mechanical module when FEM option is activated. In this method, the multidimensional gap conductance model is not required because one-dimensional thermal analysis is carried out. On the other hand, a gap conductance model for a multi-dimension should be developed in the code to perform a multidimensional thermal analysis. ALCYONE developed by CEA introduces an equivalent heat convection coefficient that represents the multidimensional gap conductance. However, the code does not employ dynamic gap conductance which is a function of gap thickness and gap characteristics in direct. The BISON code, which has been developed by INL (Idaho National Laboratory), employed a thermo-mechanical contact method that is specifically designed for tightly-coupled implicit solutions that employ Jacobian-free solution methods. Owing to tightly-coupled implicit solutions, the BISON code solves gap conductance and gap thickness simultaneously with given boundary conditions. In this paper, 3D dynamic gap element has been proposed to resolve convergence issue and nonlinear characteristic of multidimensional gap conductance. To evaluate 3D dynamic gap element module, 3D thermomechanical module using FORTRAN77 has been implemented incorporating 3D dynamic gap element. To demonstrate effect of 3D dynamic gap element, thermal behavior of missing pellet surface (MPS) has been simulated by the developed module. LWR fuel performance codes should incorporate thermo-mechanical loop to solve gap conductance problem, iteratively. However, gap conductance in multidimensional model is difficult issue owing to its nonlinearity and convergence characteristics. In

  7. Assessment of pulmonary parenchyma perfusion with FAIR in comparison with DCE-MRI-Initial results

    Energy Technology Data Exchange (ETDEWEB)

    Fan Li [Department of Radiology, ChangZheng Hospital Affiliated to Second Military Medical University, No. 415 Fengyang Road, Shanghai 200003 (China)], E-mail: fanli0930@163.com; Liu Shiyuan [Department of Radiology, ChangZheng Hospital Affiliated to Second Military Medical University, No. 415 Fengyang Road, Shanghai 200003 (China); Sun Fei [GE Healthcare China (China)], E-mail: Fei.sun@med.ge.com; Xiao Xiangsheng [Department of Radiology, ChangZheng Hospital Affiliated to Second Military Medical University, No. 415 Fengyang Road, Shanghai 200003 (China)], E-mail: lizhaobin79@163.com

    2009-04-15

    Objective: The aim of this study was to assess pulmonary parenchyma perfusion with flow-sensitive alternating inversion recovery (FAIR) in comparison with 3D dynamic contrast-enhanced (DCE) imaging in healthy volunteers and in patients with pulmonary embolism or lung cancer. Materials and methods: Sixteen healthy volunteers and 16 patients with pulmonary embolism (5 cases) or lung cancer (11 cases) were included in this study. Firstly, the optimized inversion time of FAIR (TI) was determined in 12 healthy volunteers. Then, FAIR imaging with the optimized TI was performed followed by DCE-MRI on the other 4 healthy volunteers and 16 patients. Tagging efficiency of lung and SNR of perfusion images were calculated with different TI values. In the comparison of FAIR with DCE-MRI, the homogeneity of FAIR and DCE-MRI perfusion was assessed. In the cases of perfusion abnormality, the contrast between normal lung and perfusion defects was quantified by calculating a normalized signal intensity ratio. Results: One thousand milliseconds was the optimal TI, which generated the highest lung tagging efficiency and second highest PBF SNR. In the volunteers, the signal intensity of perfusion images acquired with both FAIR and DCE-MRI was homogeneous. Wedged-shaped or triangle perfusion defects were visualized in five pulmonary embolisms and three lung cancer cases. There was no significant statistical difference in signal intensity ratio between FAIR and DCE-MRI (P > 0.05). In the rest of eight lung cancers, all the lesions showed low perfusion against the higher perfused pulmonary parenchyma in both FAIR and DCE-MRI. Conclusion: Pulmonary parenchyma perfusion imaging with FAIR was feasible, consistent and could obtain similar functional information to that from DCE-MRI.

  8. 3D Dynamic Representation for Urban Sprawl Modelling: Example of India’s Delhi-Mumbai corridor

    OpenAIRE

    Gadal, Sébastien; Fournier, Stéphane; Prouteau, Emeric

    2010-01-01

    3D dynamic geo-visualisation models reflect changes in urban land areas and make a new contribution to the spatiotemporal representation of land use processes and the production of geographic knowledge. They facilitate understanding of the process of urbanisation and the resulting transformations of land use. The 3D dynamic visualisation model of the Delhi-Mumbai corridor in India illustrates how it is now possible to integrate the temporal, spatial dynamic and geographic dimensions of a proc...

  9. Hand Gesture Spotting Based on 3D Dynamic Features Using Hidden Markov Models

    Science.gov (United States)

    Elmezain, Mahmoud; Al-Hamadi, Ayoub; Michaelis, Bernd

    In this paper, we propose an automatic system that handles hand gesture spotting and recognition simultaneously in stereo color image sequences without any time delay based on Hidden Markov Models (HMMs). Color and 3D depth map are used to segment hand regions. The hand trajectory will determine in further step using Mean-shift algorithm and Kalman filter to generate 3D dynamic features. Furthermore, k-means clustering algorithm is employed for the HMMs codewords. To spot meaningful gestures accurately, a non-gesture model is proposed, which provides confidence limit for the calculated likelihood by other gesture models. The confidence measures are used as an adaptive threshold for spotting meaningful gestures. Experimental results show that the proposed system can successfully recognize isolated gestures with 98.33% and meaningful gestures with 94.35% reliability for numbers (0-9).

  10. A 3D dynamical model of the colliding winds in binary systems

    CERN Document Server

    Parkin, E R

    2008-01-01

    We present a 3D dynamical model of the orbital induced curvature of the wind-wind collision region in binary star systems. Momentum balance equations are used to determine the position and shape of the contact discontinuity between the stars, while further downstream the gas is assumed to behave ballistically. An archimedean spiral structure is formed by the motion of the stars, with clear resemblance to high resolution images of the so-called ``pinwheel nebulae''. A key advantage of this approach over grid or smoothed particle hydrodynamic models is its significantly reduced computational cost, while it also allows the study of the structure obtained in an eccentric orbit. The model is relevant to symbiotic systems and Gamma-ray binaries, as well as systems with O-type and Wolf-Rayet stars. As an example application, we simulate the X-ray emission from hypothetical O+O and WR+O star binaries, and describe a method of ray tracing through the 3D spiral structure to account for absorption by the circumstellar m...

  11. Trans-rectal interventional MRI: initial prostate biopsy experience

    Science.gov (United States)

    Greenwood, Bernadette M.; Behluli, Meliha R.; Feller, John F.; May, Stuart T.; Princenthal, Robert; Winkel, Alex; Kaminsky, David B.

    2010-02-01

    Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) of the prostate gland when evaluated along with T2-weighted images, diffusion-weighted images (DWI) and their corresponding apparent diffusion coefficient (ADC) maps can yield valuable information in patients with rising or elevated serum prostate-specific antigen (PSA) levels1. In some cases, patients present with multiple negative trans-rectal ultrasound (TRUS) biopsies, often placing the patient into a cycle of active surveillance. Recently, more patients are undergoing TRIM for targeted biopsy of suspicious findings with a cancer yield of ~59% compared to 15% for second TRUS biopsy2 to solve this diagnostic dilemma and plan treatment. Patients were imaged in two separate sessions on a 1.5T magnet using a cardiac phased array parallel imaging coil. Automated CAD software was used to identify areas of wash-out. If a suspicious finding was identified on all sequences it was followed by a second imaging session. Under MRI-guidance, cores were acquired from each target region3. In one case the microscopic diagnosis was prostatic intraepithelial neoplasia (PIN), in the other it was invasive adenocarcinoma. Patient 1 had two negative TRUS biopsies and a PSA level of 9ng/mL. Patient 2 had a PSA of 7.2ng/mL. He underwent TRUS biopsy which was negative for malignancy. He was able to go on to treatment for his prostate carcinoma (PCa)4. MRI may have an important role in a subset of patients with multiple negative TRUS biopsies and elevated or rising PSA.

  12. Initial Incidence of White Matter Hyperintensities on MRI in Astronauts

    Science.gov (United States)

    Norcross, Jason; Sherman, Paul; McGuire, Steve; Kochunov, Peter

    2016-01-01

    Introduction: Previous literature has described the increase in white matter hyperintensity (WMH) burden associated with hypobaric exposure in the U-2 and altitude chamber operating personnel. Although astronauts have similar hypobaric exposure pressures to the U2 pilot population, astronauts have far fewer exposures and each exposure would be associated with a much lower level of decompression stress due to rigorous countermeasures to prevent decompression sickness. Therefore, we postulated that the WMH burden in the astronaut population would be less than in U2 pilots. Methods: Twenty-one post-flight de-identified astronaut MRIs (5 mm slice thickness FLAIR sequences) were evaluated for WMH count and volume. The only additional data provided was an age range of the astronauts (43-57) and if they had ever performed an EVA (13 yes, 8 no). Results: WMH count in these 21 astronaut MRI was 21.0 +/- 24.8 (mean+/- SD) and volume was 0.382 +/- 0.602 ml, which was significantly higher than previously published results for the U2 pilots. No significant differences between EVA and no EVA groups existed. Age range of astronaut population is not directly comparable to the U2 population. Discussion: With significantly less frequent (sometimes none) and less stressful hypobaric exposures, yet a much higher incidence of increased WMH, this indicates the possibility of additional mechanisms beyond hypobaric exposure. This increase unlikely to be attributable just to the differences in age between astronauts and U2 pilots. Forward work includes continuing review of post-flight MRI and evaluation of pre to post flight MRI changes if available. Data mining for potential WMH risk factors includes collection of age, sex, spaceflight experience, EVA hours, other hypobaric exposures, hyperoxic exposures, radiation, high performance aircraft experience and past medical history. Finally, neurocognitive and vision/eye results will be evaluated for any evidence of impairment linked to

  13. Imaging of tumor viability in lung cancer. Initial results using {sup 23}Na-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Henzler, T.; Apfaltrer, P.; Haneder, S.; Schoenberg, S.O.; Fink, C. [University Medical Center Mannheim Heidelberg Univ., Mannheim (Germany). Inst. of Clinical Radiology and Nuclear Medicine; Konstandin, S.; Schad, L. [University Medical Center Mannheim Heidelberg Univ., Mannheim (Germany). Computer Assisted Clinical Medicine; Schmid-Bindert, G.; Manegold, C. [University Medical Center Mannheim Heidelberg Univ., Mannheim (Germany). Interdisciplinary Thoracic Oncology; Wenz, F. [University Medical Center Mannheim Heidelberg Univ., Mannheim (Germany). Dept. of Radiation Oncology

    2012-04-15

    {sup 23}Na-MRI has been proposed as a potential imaging biomarker for the assessment of tumor viability and the evaluation of therapy response but has not yet been evaluated in patients with lung cancer. We aimed to assess the feasibility of {sup 23}Na-MRI in patients with lung cancer. Three patients with stage IV adenocarcinoma of the lung were examined on a clinical 3 Tesla MRI system (Magnetom TimTrio, Siemens Healthcare, Erlangen, Germany). Feasibility of {sup 23}Na-MRI images was proven by comparison and fusion of {sup 23}Na-MRI with {sup 1}H-MR, CT and FDG-PET-CT images. {sup 23}Na signal intensities (SI) of tumor and cerebrospinal fluid (CSF) of the spinal canal were measured and the SI ratio in tumor and CSF was calculated. One chemonaive patient was examined before and after the initiation of combination therapy (Carboplatin, Gemcitabin, Cetuximab). All {sup 23}Na-MRI examinations were successfully completed and were of diagnostic quality. Fusion of {sup 23}Na-MRI images with {sup 1}H-MRI, CT and FDG-PET-CT was feasible in all patients and showed differences in solid and necrotic tumor areas. The mean tumor SI and the tumor/CSF SI ratio were 13.3 {+-} 1.8 x 103 and 0.83 {+-} 0.14, respectively. In necrotic tumors, as suggested by central non-FDG-avid areas, the mean tumor SI and the tumor/CSF ratio were 19.4 x 103 and 1.10, respectively. {sup 23}Na-MRI is feasible in patients with lung cancer and could provide valuable functional molecular information regarding tumor viability, and potentially treatment response. (orig.)

  14. Posture-Dependent Human 3He Lung Imaging in an Open Access MRI System: Initial Results

    CERN Document Server

    Tsai, L L; Li, C -H; Rosen, M S; Patz, S; Walsworth, R L

    2007-01-01

    The human lung and its functions are extremely sensitive to orientation and posture, and debate continues as to the role of gravity and the surrounding anatomy in determining lung function and heterogeneity of perfusion and ventilation. However, study of these effects is difficult. The conventional high-field magnets used for most hyperpolarized 3He MRI of the human lung, and most other common radiological imaging modalities including PET and CT, restrict subjects to lying horizontally, minimizing most gravitational effects. In this paper, we briefly review the motivation for posture-dependent studies of human lung function, and present initial imaging results of human lungs in the supine and vertical body orientations using inhaled hyperpolarized 3He gas and an open-access MRI instrument. The open geometry of this MRI system features a "walk-in" capability that permits subjects to be imaged in vertical and horizontal positions, and potentially allows for complete rotation of the orientation of the imaging su...

  15. 3D-dynamic visualization of complex molecular cell biology processes : 1-year university students' understanding of visualizations of signal transduction

    OpenAIRE

    Jacobsson, Johan Lars Henrik

    2008-01-01

    This study deals with the use of 3D-dynamic visualizations for teaching complex molecular cell biology concepts. The focus is on signal transduction, which is a concept that constitutes an important part of biological systems. 3D-dynamic visualizations (animations) were produced and shown for a total of 24 students attending a course in molecular cell biology at Karlstad University, Sweden. Data were collected by questionnaires and interviews which were structured around the understandability...

  16. Negative predictive value of multiparametric MRI for prostate cancer detection: Outcome of 5-year follow-up in men with negative findings on initial MRI studies

    Energy Technology Data Exchange (ETDEWEB)

    Itatani, R., E-mail: banguliao@gmail.com [Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto 860-8556 (Japan); Department of Radiology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Kumamoto 862-0965 (Japan); Namimoto, T. [Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto 860-8556 (Japan); Atsuji, S.; Katahira, K.; Morishita, S. [Department of Radiology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Kumamoto 862-0965 (Japan); Kitani, K.; Hamada, Y. [Department of Urology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Kumamoto 862-0965 (Japan); Kitaoka, M. [Department of Pathology, Kumamoto Chuo Hospital, 1-5-1, Tainoshima, Kumamoto 862-0965 (Japan); Nakaura, T. [Department of Diagnostic Radiology, Amakusa Medical Center, Kameba 854-1, Amakusa, Kumamoto 863-0046 (Japan); Yamashita, Y. [Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto 860-8556 (Japan)

    2014-10-15

    Highlights: • We assess the negative predictive value of multiparametric MRI for prostate cancer. • Patients with positive prostate biopsy findings were defined as false-negative. • Patients with negative initial prostate biopsy findings were followed up for 5 years. • The negative predictive value was 89.6% for significant prostate cancer. • MRI is a useful tool to rule out significant prostate cancer before biopsy. - Abstract: Objective: To assess the clinical negative predictive value (NPV) of multiparametric MRI (mp-MRI) for prostate cancer in a 5-year follow-up. Materials and methods: One hundred ninety-three men suspected of harboring prostate cancer with negative MRI findings were included. Patients with positive transrectal ultrasound (TRUS)-guided biopsy findings were defined as false-negative. Patients with negative initial TRUS-guided biopsy findings were followed up and only patients with negative findings by digital rectal examination, MRI, and repeat biopsy and no increase in PSA at 5-year follow-up were defined as “clinically negative”. The clinical NPV of mp-MRI was calculated. For quantitative analysis, mean signal intensity on T2-weighted images and the mean apparent diffusion coefficient value on ADC maps of the initial MRI studies were compared between peripheral-zone (PZ) cancer and the normal PZ based on pathologic maps of patients who had undergone radical prostatectomy. Results: The clinical NPV of mp-MRI was 89.6% for significant prostate cancer. Small cancers, prostatitis, and benign prostatic hypertrophy masking prostate cancer returned false-negative results. Quantitative analysis showed that there was no significant difference between PZ cancer and the normal PZ. Conclusion: The mp-MRI revealed a high clinical NPV and is a useful tool to rule out clinically significant prostate cancer before biopsy.

  17. 3D Dynamic Finite Element Analysis of the Nonuniform Residual Stress in Ultrasonic Impact Treatment Process

    Science.gov (United States)

    Hu, Shengsun; Guo, Chaobo; Wang, Dongpo; Wang, Zhijiang

    2016-09-01

    The nonuniform distributions of the residual stress were simulated by a 3D finite element model to analyze the elastic-plastic dynamic ultrasonic impact treatment (UIT) process of multiple impacts on the 2024 aluminum alloy. The evolution of the stress during the impact process was discussed. The successive impacts during the UIT process improve the uniformity of the plastic deformation and decrease the maximum compressive residual stress beneath the former impact indentations. The influences of different controlled parameters, including the initial impact velocity, pin diameter, pin tip, device moving, and offset distances, on the residual stress distributions were analyzed. The influences of the controlled parameters on the residual stress distributions are apparent in the offset direction due to the different surface coverage in different directions. The influences can be used to understand the UIT process and to obtain the desired residual stress by optimizing the controlled parameters.

  18. 3D Dynamic Modeling of the Head-Neck Complex for Fast Eye and Head Orientation Movements Research

    Directory of Open Access Journals (Sweden)

    Daniel A. Sierra

    2011-01-01

    Full Text Available A 3D dynamic computer model for the movement of the head-neck complex is presented. It incorporates anatomically correct information about the diverse elements forming the system. The skeleton is considered as a set of interconnected rigid 3D bodies following the Newton-Euler laws of movement. The muscles are modeled using Enderle's linear model, which shows equivalent dynamic characteristics to Loeb's virtual muscle model. The soft tissues, namely, the ligaments, intervertebral disks, and facet joints, are modeled considering their physiological roles and dynamics. In contrast with other head and neck models developed for safety research, the model is aimed to study the neural control of the complex during fast eye and head movements, such as saccades and gaze shifts. In particular, the time-optimal hypothesis and the feedback control ones are discussed.

  19. MRI-guided percutaneous laser ablation of small renal cell carcinoma: Initial clinical experience

    Energy Technology Data Exchange (ETDEWEB)

    Kariniemi, Juho; Ojala, Risto; Hellstroem, Pekka; Sequeiros, Roberto Blanco (Dept. of Radiology, Dept. of Surgery, Oulu Univ. Hospital, Oulu (Finland)), e-mail: juho.kariniemi@oulu.fi

    2010-05-15

    Background: The number of detected small renal cell carcinomas (RCCs) has been rising, largely due to advances in imaging. Open surgical resection is the standard management of small RCCs; however, imaging-guided percutaneous ablative therapies have emerged as a minimally invasive treatment alternative, especially for patients who are poor candidates for surgery. Purpose: To evaluate the initial clinical experience of magnetic resonance imaging (MRI)-guided percutaneous laser ablation of small RCCs. Material and Methods: Eight patients with 10 tumors were treated with percutaneous MRI-guided laser ablation. All tumors (diameter range 1.5-3.8 cm, mean 2.7 cm) were biopsy-proven RCCs. By using a 0.23 T open MRI system and general anesthesia in patients, one to four (mean 2.6) laser fibers were placed and the tumors were ablated under near real-time MRI control by observing the signal void caused by the temperature change in the heated tissue. The treatment was considered successful if the tumor showed no contrast enhancement at follow-up imaging. Results: All except one tumor were successfully ablated in one session. The first patient treated showed enhancing residual tumor in post-procedural MRI; she has thus far declined retreatment. One complication, a myocardial infarction, occurred; all other patients tolerated the procedure well. No local recurrence was discovered during the follow-up (range 12-30 months, mean 20 months). Conclusion: In this small group of patients with relatively short follow-up period, MRI-guided percutaneous laser ablation proved to be a promising treatment option for small RCCs

  20. Diagnosis of breast cancer extent and enhancement patterns using 3D-dynamic MR imaging. Correlation with intraductal component

    International Nuclear Information System (INIS)

    The usefulness of 3D-dynamic MR imaging with fat suppression and magnetization transfer contrast for assessing breast cancer extent and tumor profile was evaluated in 74 breasts with 67 malignant and 7 benign lesions. We classified breast cancer by the intraductal component of the main tumor. Five histological types were assigned: type 1 (DS 0) invasive carcinoma without intraductal component, type 2 (DS 1): intraductal component is less than 50% of whole tumor, type 3 (DS 2): intraductal component is nearly equal to 50%, type 4 (DS 3): intraductal component is more than 50%, type 5 (DS 4): pure DSIC or DCIS associated with microinvasive foci. Histologic results and preoperative MR imaging were analyzed regarding tumor size and enhancement pattern for the various tumor types (DS 0, 1, 2, 3 and 4). The three tumors occult to MR imaging were two DCIS and one Paget's disease. The other 64 breast cancers were detected on MR imaging. Tumor size measured with MR imaging correlated closely with histologic measurement in DS 0, 1 and 2, whereas less accuracy was noted in DS 3 and 4. Rapid enhancement was frequently seen in DS 0, 1, 2 and 3. Peripheral enhancement was highly specific for breast cancer. However, peripheral enhancement was not found in all cases of DS 4. Linear and nodular enhancement was frequently seen in DS 3 and 4. MR imaging was useful in predicting the intraductal component. (author)

  1. 3D Dynamics of the Near-Surface Layer of the Ocean in the Presence of Freshwater Influx

    Science.gov (United States)

    Dean, C.; Soloviev, A.

    2015-12-01

    Freshwater inflow due to convective rains or river runoff produces lenses of freshened water in the near surface layer of the ocean. These lenses are localized in space and typically involve both salinity and temperature anomalies. Due to significant density anomalies, strong pressure gradients develop, which result in lateral spreading of freshwater lenses in a form resembling gravity currents. Gravity currents inherently involve three-dimensional dynamics. The gravity current head can include the Kelvin-Helmholtz billows with vertical density inversions. In this work, we have conducted a series of numerical experiments using computational fluid dynamics tools. These numerical simulations were designed to elucidate the relationship between vertical mixing and horizontal advection of salinity under various environmental conditions and potential impact on the pollution transport including oil spills. The near-surface data from the field experiments in the Gulf of Mexico during the SCOPE experiment were available for validation of numerical simulations. In particular, we observed a freshwater layer within a few-meter depth range and, in some cases, a density inversion at the edge of the freshwater lens, which is consistent with the results of numerical simulations. In conclusion, we discuss applicability of these results to the interpretation of Aquarius and SMOS sea surface salinity satellite measurements. The results of this study indicate that 3D dynamics of the near-surface layer of the ocean are essential in the presence of freshwater inflow.

  2. Constraining the Absolute Orientation of Eta Carinae's Binary Orbit: A 3-D Dynamical Model for the Broad [Fe III] Emission

    CERN Document Server

    Madura, Thomas I; Owocki, Stanley P; Groh, Jose H; Okazaki, Atsuo T; Russell, Christopher M P

    2011-01-01

    We present a three-dimensional (3-D) dynamical model for the broad [Fe III] emission observed in Eta Carinae using the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS). This model is based on full 3-D Smoothed Particle Hydrodynamics (SPH) simulations of Eta Car's binary colliding winds. Radiative transfer codes are used to generate synthetic spectro-images of [Fe III] emission line structures at various observed orbital phases and STIS slit position angles (PAs). Through a parameter study that varies the orbital inclination i, the PA {\\theta} that the orbital plane projection of the line-of-sight makes with the apastron side of the semi-major axis, and the PA on the sky of the orbital axis, we are able, for the first time, to tightly constrain the absolute 3-D orientation of the binary orbit. To simultaneously reproduce the blue-shifted emission arcs observed at orbital phase 0.976, STIS slit PA = +38 degrees, and the temporal variations in emission seen at negative slit PAs, the binary ...

  3. Aquilion ONE / ViSION Edition CT scanner realizing 3D dynamic observation with low-dose scanning

    International Nuclear Information System (INIS)

    Computed tomography (CT) scanners have been continuously advancing as essential diagnostic imaging equipment for the diagnosis and treatment of a variety of diseases, including the three major disease classes of cerebrovascular disease, cardiovascular disease, and cancer. Through the development of helical CT scanners and multislice CT scanners, Toshiba Medical Systems Corporation has developed the Aquilion ONE, a CT scanner with a scanning range of up to 160 mm per rotation that can obtain three-dimensional (3D) images of the brain, heart, and other organs in a single rotation. We have now developed the Aquilion ONE / ViSION Edition, a next-generation 320-row multislice CT scanner incorporating the latest technologies that achieves a shorter scanning time and significant reduction in dose compared with conventional products. This product with its low-dose scanning technology will contribute to the practical realization of new diagnosis and treatment modalities employing four-dimensional (4D) data based on 3D dynamic observations through continuous rotations. (author)

  4. Usefulness of 3-D dynamic pulmonary xenon-133 SPECT for thoracoscopic lung volume reduction surgery in patients with pulmonary emphysema

    International Nuclear Information System (INIS)

    Six patients with pulmonary emphysema scheduled to undergo thoracoscopic lung volume reduction surgery (TLVRS) were evaluated by three-dimensional (3-D) dynamic pulmonary xenon-133 SPECT. Serial 30-second dynamic SPECT data for equilibrium and washout (for 5 min) were acquired using a continuous repetitive rotating acquisition mode with a triple-detector SPECT system. SPECT data were reconstructed to 3-D images with a color, surface-rendering technique, and a 3-D fusion image of the 3-min washout image over the equilibrium image was obtained. Regional ventilation was visually assessed on the fusion 3-D images and quantified by xenon-133 half-washout time (T1/2) and mean transit time (MTT). The 3-D fusion image localized and lateralized the worst diseased sites with xenon-133 retention. Xenon-133 retention, T1/2 and MTT were reduced on these images in five patients with improved pulmonary function tests following TLVRS. However, xenon-133 retention was greater in one with asynchronous diaphragm movement after TLVRS. This modality will assist TLVRS in determining the lung-resection target and in evaluating the treatment effect. (author)

  5. Radionuclide Transport and Uptake in Coastal Aquatic Ecosystems: A Comparison of a 3D Dynamic Model and a Compartment Model

    Energy Technology Data Exchange (ETDEWEB)

    Erichsen, Anders Christian; Moehlenberg, Flemming; Closter, Rikke Margrethe [Ecological and Environmental Dept., DHI, Hoersholm (Denmark)], E-mail: aer@dhigroup.com; Konovalenko, Lena; Bradshaw, Clare [The Dept. of Ecology, Environment and Plant Sciences, Stockholm Univ., Stockholm (Sweden); Kautsky, Ulrik [Swedish Nuclear Fuel and Waste Management Co. (SKB), Stockholm (Sweden); Aquilonius, Karin [Studsvik Nuclear AB, Nykoeping (Sweden)

    2013-05-15

    In safety assessments of underground radioactive waste repositories, understanding radionuclide fate in ecosystems is necessary to determine the impacts of potential releases. Here, the reliability of two mechanistic models (the compartmental K-model and the 3D dynamic D-model) in describing the fate of radionuclides released into a Baltic Sea bay is tested. Both are based on ecosystem models that simulate the cycling of organic matter (carbon). Radionuclide transfer is linked to adsorption and flows of carbon in food chains. Accumulation of Th-230, Cs-135, and Ni-59 in biological compartments was comparable between the models and site measurements despite differences in temporal resolution, biological state variables, and partition coefficients. Both models provided confidence limits for their modeled concentration ratios, an improvement over models that only estimate means. The D-model enables estimates at high spatio-temporal resolution. The K-model, being coarser but faster, allows estimates centuries ahead. Future developments could integrate the two models to take advantage of their respective strengths.

  6. Real-time magnetic resonance imaging (MRI during active wrist motion--initial observations.

    Directory of Open Access Journals (Sweden)

    Robert D Boutin

    Full Text Available BACKGROUND: Non-invasive imaging techniques such as magnetic resonance imaging (MRI provide the ability to evaluate the complex anatomy of bone and soft tissues of the wrist without the use of ionizing radiation. Dynamic instability of wrist--occurring during joint motion--is a complex condition that has assumed increased importance in musculoskeletal medicine. The objective of this study was to develop an MRI protocol for evaluating the wrist during continuous active motion, to show that dynamic imaging of the wrist is realizable, and to demonstrate that the resulting anatomical images enable the measurement of metrics commonly evaluated for dynamic wrist instability. METHODS: A 3-Tesla "active-MRI" protocol was developed using a bSSFP sequence with 475 ms temporal resolution for continuous imaging of the moving wrist. Fifteen wrists of 10 asymptomatic volunteers were scanned during active supination/pronation, radial/ulnar deviation, "clenched-fist", and volarflexion/dorsiflexion maneuvers. Two physicians evaluated distal radioulnar joint (DRUJ congruity, extensor carpi ulnaris (ECU tendon translation, the scapholunate (SL interval, and the SL, radiolunate (RL and capitolunate (CL angles from the resulting images. RESULTS: The mean DRUJ subluxation ratio was 0.04 in supination, 0.10 in neutral, and 0.14 in pronation. The ECU tendon was subluxated or translated out of its groove in 3 wrists in pronation, 9 wrists in neutral, and 11 wrists in supination. The mean SL interval was 1.43 mm for neutral, ulnar deviation, radial deviation positions, and increased to 1.64 mm during the clenched-fist maneuver. Measurement of SL, RL and CL angles in neutral and dorsiflexion was also accomplished. CONCLUSION: This study demonstrates the initial performance of active-MRI, which may be useful in the investigation of dynamic wrist instability in vivo.

  7. FEM modeling for 3D dynamic analysis of deep-ocean mining pipeline and its experimental verification

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    3D dynamic analysis models of 1000 m deep-ocean mining pipeline, including steel lift pipe, pump, buffer and flexible hose, were established by finite element method (FEM). The coupling effect of steel lift pipe and flexible hose, and main external loads of pipeline were considered in the models, such as gravity, buoyancy, hydrodynamic forces, internal and external fluid pressures, concentrated suspension buoyancy on the flexible hose, torsional moment and axial force induced by pump working.Some relevant FEM models and solution techniques were developed, according to various 3D transient behaviors of integrated deep-ocean mining pipeline, including towing motions of track-keeping operation and launch process of pipeline. Meanwhile, an experimental verification system in towing water tank that had similar characteristics of designed mining pipeline was developed to verify the accuracy of the FEM models and dynamic simulation. The experiment results show that the experimental records and simulation results of stress of pipe are coincided. Based on the further simulations of 1 000 m deep-ocean mining pipeline, the simulation results show that, to form configuration of a saddle shape, the total concentrated suspension buoyancy of flexible hose should be 95%-105% of the gravity of flexible hose in water, the first suspension point occupies 1/3 of the total buoyancy, and the second suspension point occupies 2/3 of the total buoyancy. When towing velocity of mining system is less than 0.5 m/s, the towing track of buffer is coincided with the setting route of ship on the whole and the configuration of flexible hose is also kept well.

  8. Efficiency of Non-Contrast-Enhanced Liver Imaging Sequences Added to Initial Rectal MRI in Rectal Cancer Patients.

    Directory of Open Access Journals (Sweden)

    Gene-hyuk Kwon

    Full Text Available The purpose of this study was to estimate the value of addition of liver imaging to initial rectal magnetic resonance imaging (MRI for detection of liver metastasis and evaluate imaging predictors of a high risk of liver metastasis on rectal MRI.We enrolled 144 patients who from October 2010 to May 2013 underwent rectal MRI with T2-weighted imaging (T2WI and diffusion-weighted imaging (DWI (b values = 50, 500, and 900 s/mm2 of the liver and abdominopelvic computed tomography (APCT for the initial staging of rectal cancer. Two reviewers scored the possibility of liver metastasis on different sets of liver images (T2WI, DWI, and combined T2WI and DWI and APCT and reached a conclusion by consensus for different analytic results. Imaging features from rectal MRI were also analyzed. The diagnostic performances of CT and an additional liver scan to detect liver metastasis were compared. Multivariate logistic regression to determine independent predictors of liver metastasis among rectal MRI features and tumor markers was performed. This retrospective study was approved by the Institutional Review Board, and the requirement for informed consent was waived.All sets of liver images were more effective than APCT for detecting liver metastasis, and DWI was the most effective. Perivascular stranding and anal sphincter invasion were statistically significant for liver metastasis (p = 0.0077 and p = 0.0471, while extramural vascular invasion based on MRI (mrEMVI was marginally significant (p = 0.0534.The addition of non-contrast-enhanced liver imaging, particularly DWI, to initial rectal MRI in rectal cancer patients could facilitate detection of liver metastasis without APCT. Perivascular stranding, anal sphincter invasion, and mrEMVI detected on rectal MRI were important imaging predictors of liver metastasis.

  9. Contrast-enhanced spectral mammography versus MRI: Initial results in the detection of breast cancer and assessment of tumour size

    Energy Technology Data Exchange (ETDEWEB)

    Fallenberg, E.M.; Renz, D.M. [Charite - Universitaetsmedizin Berlin, Clinic of Radiology, Berlin (Germany); Dromain, C. [Institut Gustave Roussy, Department of Radiology, Villejuif cedex (France); Diekmann, F. [St. Joseph-Stift Bremen, Department of Medical Imaging, Bremen (Germany); Engelken, F.; Krohn, M.; Singh, J.M.; Bick, U. [Charite - Universitaetsmedizin Berlin, Department of Radiology, Berlin (Germany); Ingold-Heppner, B. [Charite - Universitaetsmedizin Berlin, Institute of Pathology, Berlin (Germany); Winzer, K.J. [Charite - Universitaetsmedizin Berlin, Breast Center, Department of Gynecology, Berlin (Germany)

    2014-01-15

    To compare mammography (MG), contrast-enhanced spectral mammography (CESM), and magnetic resonance imaging (MRI) in the detection and size estimation of histologically proven breast cancers using postoperative histology as the gold standard. After ethical approval, 80 women with newly diagnosed breast cancer underwent MG, CESM, and MRI examinations. CESM was reviewed by an independent experienced radiologist, and the maximum dimension of suspicious lesions was measured. For MG and MRI, routine clinical reports of breast specialists, with judgment based on the BI-RADS lexicon, were used. Results of each imaging technique were correlated to define the index cancer. Fifty-nine cases could be compared to postoperative histology for size estimation. Breast cancer was visible in 66/80 MG, 80/80 CESM, and 77/79 MRI examinations. Average lesion largest dimension was 27.31 mm (SD 22.18) in MG, 31.62 mm (SD 24.41) in CESM, and 27.72 mm (SD 21.51) in MRI versus 32.51 mm (SD 29.03) in postoperative histology. No significant difference was found between lesion size measurement on MRI and CESM compared with histopathology. Our initial results show a better sensitivity of CESM and MRI in breast cancer detection than MG and a good correlation with postoperative histology in size assessment. (orig.)

  10. MRI for the initial evaluation of acute wrist, knee, and ankle trauma

    NARCIS (Netherlands)

    J.J. Nikken (Jeroen)

    2003-01-01

    textabstractIn this thesis we study the application of MRI in acute trauma of wrist, knee, and ankle, evaluating its potentials, its effects, and its costs. Our aim was to use MRI in all patients with acute trauma of wrist, knee, and ankle, without increasing the overall costs to society, potentiall

  11. An MRI system for imaging neonates in the NICU: initial feasibility study

    International Nuclear Information System (INIS)

    Transporting premature infants from a neonatal intensive care unit (NICU) to a radiology department for MRI has medical risks and logistical challenges. To develop a small 1.5-T MRI system for neonatal imaging that can be easily installed in the NICU and to evaluate its performance using a sheep model of human prematurity. A 1.5-T MRI system designed for orthopedic use was adapted for neonatal imaging. The system was used for MRI examinations of the brain, chest and abdomen in 12 premature lambs during the first hours of life. Spin-echo, fast spin-echo and gradient-echo MR images were evaluated by two pediatric radiologists. All animals remained physiologically stable throughout the imaging sessions. Animals were imaged at two or three time points. Seven brain MRI examinations were performed in seven different animals, 23 chest examinations in 12 animals and 19 abdominal examinations in 11 animals. At each anatomical location, high-quality images demonstrating good spatial resolution, signal-to-noise ratio and tissue contrast were routinely obtained within 30 min using standard clinical protocols. Our preliminary experience demonstrates the feasibility and potential of the neonatal MRI system to provide state-of-the-art MRI capabilities within the NICU. Advantages include overall reduced cost and site demands, lower acoustic noise, improved ease of access and reduced medical risk to the neonate. (orig.)

  12. An MRI system for imaging neonates in the NICU: initial feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Tkach, Jean A.; Loew, Wolfgang; Pratt, Ron G.; Daniels, Barret R.; Giaquinto, Randy O.; Winter, Patrick M.; Li, Yu; Dumoulin, Charles L. [Cincinnati Children' s Hospital Medical Center, Imaging Research Center, Department of Radiology, Cincinnati, OH (United States); Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Hillman, Noah H.; Jobe, Alan H.; Kallapur, Suhas G.; Merhar, Stephanie L.; Ikegami, Machiko; Whitsett, Jeffrey A. [Perinatal Institute, Cincinnati Children' s Hospital Medical Center, Division of Neonatology and Pulmonary Biology, Cincinnati, OH (United States); Kline-Fath, Beth M. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2012-11-15

    Transporting premature infants from a neonatal intensive care unit (NICU) to a radiology department for MRI has medical risks and logistical challenges. To develop a small 1.5-T MRI system for neonatal imaging that can be easily installed in the NICU and to evaluate its performance using a sheep model of human prematurity. A 1.5-T MRI system designed for orthopedic use was adapted for neonatal imaging. The system was used for MRI examinations of the brain, chest and abdomen in 12 premature lambs during the first hours of life. Spin-echo, fast spin-echo and gradient-echo MR images were evaluated by two pediatric radiologists. All animals remained physiologically stable throughout the imaging sessions. Animals were imaged at two or three time points. Seven brain MRI examinations were performed in seven different animals, 23 chest examinations in 12 animals and 19 abdominal examinations in 11 animals. At each anatomical location, high-quality images demonstrating good spatial resolution, signal-to-noise ratio and tissue contrast were routinely obtained within 30 min using standard clinical protocols. Our preliminary experience demonstrates the feasibility and potential of the neonatal MRI system to provide state-of-the-art MRI capabilities within the NICU. Advantages include overall reduced cost and site demands, lower acoustic noise, improved ease of access and reduced medical risk to the neonate. (orig.)

  13. PET/MRI and PET/CT in advanced gynaecological tumours: initial experience and comparison

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Marcelo A.; Schulthess, Gustav von; Veit-Haibach, Patrick [University Hospital Zurich, Department Medical Radiology, Nuclear Medicine, Zurich (Switzerland); University Hospital Zurich, Department Medical Radiology, Diagnostic and Interventional Radiology, Zurich (Switzerland); University of Zurich, Zurich (Switzerland); Kubik-Huch, Rahel A.; Freiwald-Chilla, Bianka [Kantonsspital Baden AG, Department of Radiology, Baden (Switzerland); Hauser, Nik [Kantonsspital Baden AG, Department of Gynaecology, Baden (Switzerland); Froehlich, Johannes M. [Guerbet AG, Zurich (Switzerland)

    2015-08-15

    To compare the diagnostic accuracy of PET/MRI and PET/CT for staging and re-staging advanced gynaecological cancer patients as well as identify the potential benefits of each method in such a population. Twenty-six patients with suspicious or proven advanced gynaecological cancer (12 ovarian, seven cervical, one vulvar and four endometrial tumours, one uterine metastasis, and one primary peritoneal cancer) underwent whole-body imaging with a sequential trimodality PET/CT/MR system. Images were analysed regarding primary tumour detection and delineation, loco-regional lymph node staging, and abdominal/extra-abdominal distant metastasis detection (last only by PET/CT). Eighteen (69.2 %) patients underwent PET/MRI for primary staging and eight patients (30.8 %) for re-staging their gynaecological malignancies. For primary tumour delineation, PET/MRI accuracy was statistically superior to PET/CT (p < 0.001). Among the different types of cancer, PET/MRI presented better tumour delineation mainly for cervical (6/7) and endometrial (2/3) cancers. PET/MRI for local evaluation as well as PET/CT for extra-abdominal metastases had therapeutic consequences in three and one patients, respectively. PET/CT detected 12 extra-abdominal distant metastases in 26 patients. PET/MRI is superior to PET/CT for primary tumour delineation. No differences were found in detection of regional lymph node involvement and abdominal metastases detection. (orig.)

  14. 3D dynamic simulations of spontaneous rupture propagation governed by different constitutive laws with rake rotation allowed

    Directory of Open Access Journals (Sweden)

    M. Cocco

    2005-06-01

    Full Text Available In this work we present a 3D Finite Difference numerical method to model the dynamic spontaneous propagation of an earthquake rupture on planar faults in an elastic half-space. We implement the Traction-at-Split-Nodes fault boundary condition for a system of faults, either vertical or oblique, using different constitutive laws. We can adopt both a slip-weakening law to prescribe the traction evolution within the breakdown zone or rate- and state-dependent friction laws, which involve the choice of an evolution relation for the state variable. Our numerical procedure allows the use of oblique and heterogeneous distribution of initial stress and allows the rake rotation. This implies that the two components of slip velocity and total dynamic traction are coupled together to satisfy, in norm, the adopted constitutive law. The simulations presented in this study show that the rupture acceleration to super-shear crack speeds occurs along the direction of the imposed initial stress; the rupture front velocity along the perpendicular direction is slower than that along the pre-stress direction. Depending on the position on the fault plane the orientation of instantaneous total dynamic traction can change with time with respect to the imposed initial stress direction. These temporal rake rotations depend on the amplitude of initial stress and on its distribution on the fault plane. They also depend on the curvature and direction of the rupture front with respect to the imposed initial stress direction: this explains why rake rotations are mostly located near the rupture front and within the cohesive zone.

  15. Brain MRI findings in patients with initial cerebral thrombosis and the relationship between incidental findings, aging and dementia

    International Nuclear Information System (INIS)

    To estimate the relationship between aging, dementia and changes observed on magnetic resonance imaging (MRI) seen in elderly patients with cerebral thrombosis, MRI findings in 103 patients with an initial stroke event (thrombosis group) were compared with those of 37 patients with hypertension/diabetes (high risk group) and 78 patients without those disorders (low risk group). In addition to the causative lesions in the thrombosis group, periventricular hyperintensities (PVH), spotty lesions (SL), silent infarctions (SI), ventricular dilatation (VD), and cortical atrophy (CA) were analyzed in these groups. Infarctions located in the internal capsule/corona radiata were the most frequent causative lesion. Compared to the low risk group, a high incidence of patchy/diffuse PVH, SI, and severe CA was seen in both the thrombosis group and the high risk group. Widespread PVH and multiple SL increased with age in the thrombosis group, while severe CA was seen in each group. SI and VD tended to increase after age 60, though they were not significant. Dementia, diagnosed in 40 out of 78 patients, increased with age. Multivariate analysis revealed the degree of the effects of MRI findings on dementia to be marked in PVH, brain atrophy, causative lesions, and SL, in that order. These results indicated that diffuse PVH and brain atrophy, developing with age, promoted dementia in the elderly with vascular lesions. Moreover, they suggested that a variety of silent brain lesions recognized on MRI other than infarction can affect symptoms in the elderly. (author)

  16. MRI findings associated with development of incident knee pain over 48 months: data from the osteoarthritis initiative

    International Nuclear Information System (INIS)

    The purpose of this nested case-control study was to identify baseline, incident, and progressive MRI findings visible on standard MRI clinical sequences that were associated with development of incident knee pain in subjects at risk for OA over a period of 48 months. We analyzed 60 case knees developing incident pain (WOMACpain = 0 at baseline and WOMACpain ≥ 5 at 48 months) and 60 control knees (WOMACpain = 0 at baseline and WOMACpain = 0 at 48 months) from the Osteoarthritis Initiative. 3 T knee MRIs were analyzed using a modified WORMS score (cartilage, meniscus, bone marrow) at baseline and after 48 months. Baseline and longitudinal findings were grouped into logistic regression models and compared using likelihood-ratio tests. For each model that was significant, a stepwise elimination was used to isolate significant MRI findings. One baseline MRI finding and three findings that changed from baseline to 48 months were associated with the development of pain: at baseline, the severity of a cartilage lesion in the medial tibia was associated with incident pain - (odds ratio (OR) for incident pain = 3.05; P = 0.030). Longitudinally, an incident effusion (OR = 9.78; P = 0.005), a progressive cartilage lesion of the patella (OR = 4.59; P = 0.009), and an incident medial meniscus tear (OR = 4.91; P = 0.028) were associated with the development of pain. Our results demonstrate that baseline abnormalities of the medial tibia cartilage as well as an incident joint effusion, progressive patella cartilage defects, and an incident medial meniscus tear over 48 months may be associated with incident knee pain. Clinically, this study helps identify MRI findings that are associated with the development of knee pain. (orig.)

  17. MRI findings associated with development of incident knee pain over 48 months: data from the osteoarthritis initiative

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, Gabby B.; Hou, Stephanie W.; Nardo, Lorenzo; Heilmeier, Ursula; Link, Thomas M. [University of California, San Francisco, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Nevitt, Michael C.; McCulloch, Charles E. [University of California, San Francisco, Department of Epidemiology and Biostatistics, San Francisco, CA (United States)

    2016-05-15

    The purpose of this nested case-control study was to identify baseline, incident, and progressive MRI findings visible on standard MRI clinical sequences that were associated with development of incident knee pain in subjects at risk for OA over a period of 48 months. We analyzed 60 case knees developing incident pain (WOMAC{sub pain} = 0 at baseline and WOMAC{sub pain} ≥ 5 at 48 months) and 60 control knees (WOMAC{sub pain} = 0 at baseline and WOMAC{sub pain} = 0 at 48 months) from the Osteoarthritis Initiative. 3 T knee MRIs were analyzed using a modified WORMS score (cartilage, meniscus, bone marrow) at baseline and after 48 months. Baseline and longitudinal findings were grouped into logistic regression models and compared using likelihood-ratio tests. For each model that was significant, a stepwise elimination was used to isolate significant MRI findings. One baseline MRI finding and three findings that changed from baseline to 48 months were associated with the development of pain: at baseline, the severity of a cartilage lesion in the medial tibia was associated with incident pain - (odds ratio (OR) for incident pain = 3.05; P = 0.030). Longitudinally, an incident effusion (OR = 9.78; P = 0.005), a progressive cartilage lesion of the patella (OR = 4.59; P = 0.009), and an incident medial meniscus tear (OR = 4.91; P = 0.028) were associated with the development of pain. Our results demonstrate that baseline abnormalities of the medial tibia cartilage as well as an incident joint effusion, progressive patella cartilage defects, and an incident medial meniscus tear over 48 months may be associated with incident knee pain. Clinically, this study helps identify MRI findings that are associated with the development of knee pain. (orig.)

  18. High temporal resolution parametric MRI monitoring of the initial ischemia/reperfusion phase in experimental acute kidney injury.

    Directory of Open Access Journals (Sweden)

    Andreas Pohlmann

    Full Text Available Ischemia/reperfusion (I/R injury, a consequence of kidney hypoperfusion or temporary interruption of blood flow is a common cause of acute kidney injury (AKI. There is an unmet need to better understand the mechanisms operative during the initial phase of ischemic AKI. Non-invasive in vivo parametric magnetic resonance imaging (MRI may elucidate spatio-temporal pathophysiological changes in the kidney by monitoring the MR relaxation parameters T2* and T2, which are known to be sensitive to blood oxygenation. The aim of our study was to establish the technical feasibility of fast continuous T2*/T2 mapping throughout renal I/R. MRI was combined with a remotely controlled I/R model and a segmentation model based semi-automated quantitative analysis. This technique enabled the detailed assessment of in vivo changes in all kidney regions during ischemia and early reperfusion. Significant changes in T2* and T2 were observed shortly after induction of renal ischemia and during the initial reperfusion phase. Our study demonstrated for the first time that continuous and high temporal resolution parametric MRI is feasible for in-vivo monitoring and characterization of I/R induced AKI in rats. This technique may help in the identification of the timeline of key events responsible for development of renal damage in hypoperfusion-induced AKI.

  19. 3D Dynamic Rupture Simulation Across a Complex Fault System: the Mw7.0, 2010, Haiti Earthquake

    Science.gov (United States)

    Douilly, R.; Aochi, H.; Calais, E.; Freed, A. M.

    2013-12-01

    Earthquakes ruptures sometimes take place on a secondary fault and surprisingly do not activate an adjacent major one. The 1989 Loma Prieta earthquake is a classic case where rupture occurred on a blind thrust while the adjacent San Andreas Fault was not triggered during the process. Similar to Loma Prieta, the Mw7.0, January 12 2010, Haiti earthquake also ruptured a secondary blind thrust, the Léogâne fault, adjacent to the main plate boundary, the Enriquillo Plantain Garden Fault, which did not rupture during this event. Aftershock relocalizations delineate the Léogâne rupture with two north dipping segments with slightly different dip, where the easternmost segment had mostly dip-slip motion and the westernmost one had mostly strike-slip motion. In addition, an offshore south dipping structure inferred from the aftershocks to the west of the rupture zone coincides with the offshore Trois Baies reverse fault, a region of increase in Coulomb stress increase. In this study, we investigate the rupture dynamics of the Haiti earthquake in a complex fault system of multiple segments identified by the aftershock relocations. We suppose a background stress regime that is consistent with the type of motion of each fault and with the regional tectonic regime. We initiate a nucleation on the east segment of the Léogâne fault by defining a circular region with a 2 km radius where shear stress is slightly greater than the yield stress. By varying friction on faults and background stress, we find a range of plausible scenarios. In the absence of near-field seismic records of the event, we score the different models against the static deformation field derived from GPS and InSAR at the surface. All the plausible simulations show that the rupture propagates from the eastern to the western segment along the Léogâne fault, but not on the Enriquillo fault nor on the Trois Baies fault. The best-fit simulation shows a significant increase of shear stresses on the Trois Baies

  20. Contrast-enhanced 3D MRI of lung perfusion in children with cystic fibrosis - initial results

    International Nuclear Information System (INIS)

    This paper is a feasibility study of magnetic resonance imaging (MRI) of lung perfusion in children with cystic fibrosis (CF) using contrast-enhanced 3D MRI. Correlation assessment of perfusion changes with structural abnormalities. Eleven CF patients (9 f, 2 m; median age 16 years) were examined at 1.5 T. Morphology: HASTE coronal, transversal (TR/TE/α/ST: 600 ms/28 ms/180 /6 mm), breath-hold 18 s. Perfusion: Time-resolved 3D GRE pulse sequence (FLASH, TE/TR/α: 0.8/1.9 ms/40 ), parallel imaging (GRAPPA, PAT 2). Twenty-five data sets were acquired after intravenous injection of 0.1 mmol/kg body weight of gadodiamide, 3-5 ml/s. A total of 198 lung segments were analyzed by two radiologists in consensus and scored for morphological and perfusion changes. Statistical analysis was performed by Mantel-Haenszel chi-square test. Results showed that perfusion defects were observed in all patients and present in 80% of upper, and 39% of lower lobes. Normal lung parenchyma showed homogeneous perfusion (86%, P<0.0001). Severe morphological changes led to perfusion defects (97%, P<0.0001). Segments with moderate morphological changes showed normal (53%) or impaired perfusion (47%). In conclusion, pulmonary perfusion is easy to judge in segments with normal parenchyma or severe changes. In moderately damaged segments, MRI of lung perfusion may help to better assess actual functional impairment. Contrast-enhanced 3D MRI of lung perfusion has the potential for early vascular functional assessment and therapy control in CF patients. (orig.)

  1. Myocardial delayed contrast enhancement in patients with arterial hypertension: Initial results of cardiac MRI

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Kjel [Institute of Diagnostic Radiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: kjel_andersen@web.de; Hennersdorf, Marcus [Department of Cardiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: hennersdorf@med.uni-duesseldorf.de; Cohnen, Mathias [Institute of Diagnostic Radiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: cohnen@med.uni-duesseldorf.de; Blondin, Dirk [Institute of Diagnostic Radiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: blondin@med.uni-duesseldorf.de; Moedder, Ulrich [Institute of Diagnostic Radiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: moedder@uni-duesseldorf.de; Poll, Ludger W. [Institute of Diagnostic Radiology, University Hospital Duesseldorf, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: poll@gmx.de

    2009-07-15

    Purpose: In arterial hypertension left ventricular hypertrophy comprises myocyte hypertrophy, interstitial fibrosis and structural alterations of the coronary microcirculation. MRI enables the detection of myocardial fibrosis, infarction and scar tissue by delayed enhancement (DE) after contrast media application. Aim of this study was to investigate patients with arterial hypertension but without known coronary disease or previous myocardial infarction to detect areas of DE. Methods and material: Twenty patients with arterial hypertension with clinical symptoms of myocardial ischemia, but without history of myocardial infarction and normal coronary arteries during coronary angiography were investigated on a 1.0 T superconducting magnet (Gyroscan T10-NT, Intera Release 8.0, Philips). Fast gradient-echo cine sequences and T2-weighted STIR-sequences were acquired. Fifteen minutes after injection of Gadobenate dimeglumine inversion recovery gradient-echo sequences were performed for detection of myocardial DE. Presence or absence of DE on MRI was correlated with clinical data and the results of echocardiography and electrocardiography, respectively. Results: Nine of 20 patients showed DE in the interventricular septum and the anteroseptal left ventricular wall. In 6 patients, DE was localized intramurally and in 3 patients subendocardially. There was a significant correlation between myocardial DE and ST-segment depressions during exercise and between DE and left-ventricular enddiastolic pressure. Patients with intermittent atrial fibrillation showed a myocardial DE more often than patients without atrial fibrillation. Conclusion: In our series, 45% of patients with arterial hypertension showed DE on cardiac MRI. In this clinical setting, delayed enhancement may be due to coronary microangiopathy. The more intramurally localization of DE, however, rather indicates myocardial interstitial fibrosis.

  2. 7-T MRI in Cerebrovascular Diseases: Challenges to Overcome and Initial Results.

    Science.gov (United States)

    Harteveld, Anita A; van der Kolk, Anja G; Zwanenburg, Jaco J M; Luijten, Peter R; Hendrikse, Jeroen

    2016-04-01

    Magnetic resonance imaging (MRI) plays a key role in the investigation of cerebrovascular diseases. Compared with computed tomography (CT) and digital subtraction angiography (DSA), its advantages in diagnosing cerebrovascular pathology include its superior tissue contrast, its ability to visualize blood vessels without the use of a contrast agent, and its use of magnetic fields and radiofrequency pulses instead of ionizing radiation. In recent years, ultrahigh field MRI at 7 tesla (7 T) has shown promise in the diagnosis of many cerebrovascular diseases. The increased signal-to-noise ratio (SNR; 2.3x and 4.7x increase compared with 3 and 1.5 T, respectively) and contrast-to-noise ratio (CNR) at this higher field strength can be exploited to obtain a higher spatial resolution and higher lesion conspicuousness, enabling assessment of smaller brain structures and lesions. Cerebrovascular diseases can be assessed at different tissue levels; for instance, changes of the arteries feeding the brain can be visualized to determine the cause of ischemic stroke, regional changes in brain perfusion can be mapped to predict outcome after revascularization, and tissue damage, including old and recent ischemic infarcts, can be evaluated as a marker of ischemic burden. For the purpose of this review, we will discriminate 3 levels of assessment of cerebrovascular diseases using MRI: Pipes, Perfusion, and Parenchyma (3 Ps). The term Pipes refers to the brain-feeding arteries from the heart and aortic arch, upwards to the carotid arteries, vertebral arteries, circle of Willis, and smaller intracranial arterial branches. Perfusion is the amount of blood arriving at the brain tissue level, and includes the vascular reserve and perfusion territories. Parenchyma refers to the acute and chronic burden of brain tissue damage, which includes larger infarcts, smaller microinfarcts, and small vessel disease manifestations such as white matter lesions, lacunar infarcts, and microbleeds

  3. MR guidance and thermometry of percutaneous laser disc decompression in open MRI: an initial clinical investigation

    Energy Technology Data Exchange (ETDEWEB)

    Streitparth, Florian; Walter, Thula; Bucourt, Maximilian de; Freyhardt, Patrick; Maurer, Martin; Renz, Diane; Gebauer, Bernhard; Hamm, Bernd; Teichgraeber, Ulf K.M. [Charite, Humboldt-University Medical School, Department of Radiology, Berlin (Germany); Hartwig, Tony; Putzier, Michael; Strube, Patrick [Charite, Humboldt-University, Center for Musculoskeletal Surgery, Berlin (Germany); Bretschneider, Tina [University of Magdeburg, Department of Radiology, Magdeburg (Germany)

    2013-10-15

    To assess the feasibility, safety and efficacy of real-time MR guidance and thermometry of percutaneous laser disc decompression (PLDD). Twenty-four discs in 22 patients with chronic low-back and radicular pain were treated by PLDD using open 1.0-T magnetic-resonance imaging (MRI). A fluoroscopic proton-density-weighted turbo spin-echo (PDw TSE) sequence was used to position the laser fibre. Non-spoiled gradient-echo (GRE) sequences were employed for real-time thermal monitoring based on proton resonance frequency (PRF). Radicular pain was assessed over 6 months with a numerical rating scale (NRS). PLDD was technically successful in all cases, with adequate image quality for laser positioning. The PRF-based real-time temperature monitoring was found to be feasible in practice. After 6 months, 21 % reported complete remission of radicular pain, 63 % at least great pain relief and 74 % at least mild relief. We found a significant decrease in the NRS score between the pre-intervention and the 6-month follow-up assessment (P < 0.001). No major complications occurred; the single adverse event recorded, moderate motor impairment, resolved. Real-time MR guidance and PRF-based thermometry of PLDD in the lumbar spine under open 1.0-T MRI appears feasible, safe and effective and may pave the way to more precise operating procedures. (orig.)

  4. Noninvasive measurement of liver iron concentration at MRI in children with acute leukemia: initial results

    Energy Technology Data Exchange (ETDEWEB)

    Vag, Tibor; Krumbein, Ines; Reichenbach, Juergen R.; Lopatta, Eric; Stenzel, Martin; Kaiser, Werner A.; Mentzel, Hans-Joachim [Friedrich Schiller University Jena, Institute of Diagnostic and Interventional Radiology, Jena (Germany); Kentouche, Karim; Beck, James [Friedrich Schiller University Jena, Department of Pediatrics, Jena (Germany); Renz, Diane M. [Charite University Medicine Berlin, Department of Radiology, Campus Virchow Clinic, Berlin (Germany)

    2011-08-15

    Routine assessment of body iron load in patients with acute leukemia is usually done by serum ferritin (SF) assay; however, its sensitivity is impaired by different conditions including inflammation and malignancy. To estimate, using MRI, the extent of liver iron overload in children with acute leukemia and receiving blood transfusions, and to examine the association between the degree of hepatic iron overload and clinical parameters including SF and the transfusion iron load (TIL). A total of 25 MRI measurements of the liver were performed in 15 children with acute leukemia (mean age 9.75 years) using gradient-echo sequences. Signal intensity ratios between the liver and the vertebral muscle (L/M ratio) were calculated and compared with SF-levels. TIL was estimated from the cumulative blood volume received, assuming an amount of 200 mg iron per transfused red blood cell unit. Statistical analysis revealed good correlation between the L/M SI ratio and TIL (r = -0.67, P = 0.002, 95% confidence interval CI = -0.83 to -0.34) in patients with acute leukemia as well as between L/M SI ratio and SF (r = -0.76, P = 0.0003, 95% CI = -0.89 to -0.52). SF may reliably reflect liver iron stores as a routine marker in patients suffering from acute leukemia. (orig.)

  5. RM de cuerpo entero, experiencia inicial Whole body MRI, initial experience

    Directory of Open Access Journals (Sweden)

    Ezequiel Rombolá

    2008-09-01

    Full Text Available Objetivo: Exponer y compartir nuestra experiencia en resonancia magnética de cuerpo entero (RMCE. Material y métodos: Se realizó estudio prospectivo entre octubre de 2005 y mayo de 2007 sobre 165 RMCE. Edad de los pacientes: 21 y 85 años, media de 51,64. Se utilizó equipo de 1,5 Tesla de campo magnético y tabla deslizable. El protocolo de estudio estuvo integrado por cortes coronales multicontraste (T1, T2 y STIR, axiales y sagitales en T2. Resultados: Se obtuvieron 140 (84,84 % estudios con hallazgos relevantes y 25 (15,15 % sin alteraciones. Se halló predominancia de enfermedades degenerativas articulares del esqueleto axial en 94 pacientes (56,96% sin diferencias significativas entre sexos. Trece pacientes realizaron controles oncológicos demostrándose diseminación a distancia en 6 estudios. En 1 examen se registró la distribución de polimiositis. Conclusiones: La RMCE no representa solamente una innovadora herramienta diagnóstica, sino también ostenta el potencial de competir con metodologías preexistentes en aplicaciones oncológicas y no oncológicas. La sensibilidad y especificidad del método están probadas, pero su aplicación se encuentra limitada por el alto costo y la falta de inclusión en protocolos diagnósticos de estadificación tumoral.Objective: To expose and share our experience in whole-body MRI. Material and methods: A prospective study of 165 whole-body MRI was made from october 2005 to may 2007. The age range was between 21 to 85 years old, with a mean age of 51, 64. A 1.5 Tesla MRI scan was utilized with a table-top movement. Multicontrast coronal scans (T1, T2 and STIR, sagittal and axial T2 compose the study protocol. Results: 140 (84,84 % scans with relevant results and 25 (15,15 % without abnormalities were found. The axial skeletal articular degenerative disease prevalence on 94 (56,96 % cases, without significant difference. Six MRI scans showed secondary dissemination of the oncology disease in a

  6. MRI-based motion correction of thoracic PET: initial comparison of acquisition protocols and correction strategies suitable for simultaneous PET/MRI systems

    Energy Technology Data Exchange (ETDEWEB)

    Dikaios, Nikolaos; Fryer, Tim D. [University of Cambridge, Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, Cambridge (United Kingdom); Izquierdo-Garcia, David; Mani, Venkatesh; Fayad, Zahi A. [Mount Sinai School of Medicine, Imaging Science Laboratories, Translational and Molecular Imaging Institute, Department of Radiology, New York, NY (United States); Graves, Martin J. [University of Cambridge, Department of Radiology, Cambridge (United Kingdom)

    2012-02-15

    Magnetic resonance imaging (MRI) acquired on equipment capable of simultaneous MRI and positron emission tomography (PET) could potentially provide the gold standard method for motion correction of PET. To assess the latter, in this study we compared fast 2D and 3D MRI of the torso and used deformation parameters from real MRI data to correct simulated PET data for respiratory motion. PET sinogram data were simulated using SimSET from a 4D pseudo-PET image series created by segmenting MR images acquired over a respiratory cycle. Motion-corrected PET images were produced using post-reconstruction registration (PRR) and motion-compensated image reconstruction (MCIR). MRI-based motion correction improved PET image quality at the lung-liver and lung-spleen boundaries and in the heart but little improvement was obtained where MRI contrast was low. The root mean square error in SUV units per voxel compared to a motion-free image was reduced from 0.0271 (no motion correction) to 0.0264 (PRR) and 0.0250 (MCIR). Motion correction using MRI can improve thoracic PET images but there are limitations due to the quality of fast MRI. (orig.)

  7. GEM/POPs: a global 3-D dynamic model for semi-volatile persistent organic pollutants – Part 2: Global transports and budgets of PCBs

    Directory of Open Access Journals (Sweden)

    L. A. Barrie

    2007-03-01

    Full Text Available Global transports and budgets of three PCBs were investigated with a 3-D dynamic model for semi-volatile persistent organic pollutants – GEM/POPs. Dominant pathways were identified for PCB transports in the atmosphere with a peak transport flux below 8 km and 14 km for gaseous and particulate PCB28, 4 km and 6 km for gaseous and particulate PCB180. The inter-continental transports of PCBs in the Northern Hemisphere (NH are dominated in the zonal direction with their route changes seasonally regulated by the variation of westerly jet. The transport pathways from Europe and North Atlantic to the Arctic contributed the most PCBs over there. Inter-hemispheric transports of PCBs originated from the regions of Europe, Asia and North America in three different flow-paths, accompanying with easterly jet, Asian monsoon winds and trade winds. PCBs from the Southern Hemisphere (SH could export into the NH. According to the PCB emissions of year 2000, Europe, North America and Asia are the three largest sources of the three PCBs, contributing to the global background concentrations in the atmosphere and soil and water. Globally, PCB28 in soil and water has become a comparable source to the anthropogenic emissions while heavier PCBs such as PCB153 and 180 are still transporting into soil and water. It is found that lighter PCBs have more long range transport potentials than their heavier counter-parts in the atmosphere.

  8. Imaging of brain metastases of bronchial carcinomas with 7 T MRI. Initial results

    Energy Technology Data Exchange (ETDEWEB)

    Moenninghoff, C. [Universitaetsklinikum Essen (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie und Neuroradiologie; Maderwald, S.; Theysohn, J.M.; Kraff, O.; Ladd, S.C.; Wanke, I. [Universitaetsklinikum Essen (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie und Neuroradiologie; Duisburg-Essen Univ. (Germany). Erwin L. Hahn Inst. fuer Magnetresonanztomographie; Schuett, P.; Gauler, T. [Universitaetsklinikum Essen (Germany). Klinik fuer Innere Medizin, Konservative Onkologie; Ladd, M.E. [Duisburg-Essen Univ. (Germany). Erwin L. Hahn Inst. fuer Magnetresonanztomographie

    2010-09-15

    Purpose: To compare the depiction of brain metastases of bronchial carcinomas on susceptibility-weighted and contrast-enhanced images with 7 T and at 1.5 T MRI. Materials and Methods: Twelve patients with brain metastases of bronchial carcinomas underwent 7 T and 1.5 T MRI. Minimum intensity projections (MinIP) of a 1.5 T SWI sequence (voxel size = 0.9 x 0.9 x 2.0 mm{sup 3}) were compared to 7 T SWI MinIPs (voxel size = 0.4 x 0.4 x 1.5 mm{sup 3}). A T 1-w 3D MPRAGE at 1.5 T (voxel size = 1 x 1 x 1 mm{sup 3} after double-dose (DD) gadoterate meglumine, Gd-DOTA) was compared to a 7 T MPRAGE sequence (voxel size = 0.7 x 0.7 x x 0.7 mm{sup 3}, single dose (SD) Gd-DOTA) in all patients, and to DD Gd-DOTA in 6 patients after a 10 minute delay. The number of intracranial microhemorrhages in SWI MinIPs and the number of contrast-enhancing metastases in MPRAGE images were compared in each patient grouped into three size ranges ({<=} 2 mm, > 2 mm and < 6 mm, {>=} 6 mm) by two radiologists in consensus. Results: In all 12 patients the 7 T SWI with spatially higher resolution allowed the identification of 87 versus 67 cerebral microhemorrhages at 1.5 T. 7 T T 1-w images after SD Gd-DOTA depicted 198 brain metastases versus 238 at 1.5 T after DD Gd-DOTA. After doubling the contrast dose in six patients, 4 additional brain metastases were identified at 7 T. Conclusion: Our preliminary results indicate that despite the higher spatial resolution the detection of brain metastases on 7 T MPRAGE images is almost equal to 1.5 T MPRAGE images. The 7 T SWI sequence with spatially higher resolution allowed the detection of 20 % more microhemorrhages in brain metastases compared to the 1.5 T SWI sequence. (orig.)

  9. A comparison of non-contrast and contrast-enhanced MRI in the initial stage of Legg-Calve-Perthes disease

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Harry K.W. [Texas Scottish Rite Hospital for Children, Center of Excellence in Hip Disorders, Dallas, TX (United States); University of Texas Southwestern, Department of Orthopedic Surgery, Dallas, TX (United States); Kaste, Sue [St. Jude Children' s Research Hospital, Department of Radiological Sciences, Memphis, TN (United States); St. Jude Children' s Research Hospital, Department of Oncology, Memphis, TN (United States); University of Tennessee School of Health Sciences, Department of Radiology, Memphis, TN (United States); Dempsey, Molly; Wilkes, David [Texas Scottish Rite Hospital for Children, Department of Radiology, Dallas, TX (United States)

    2013-09-15

    A prognostic indicator of outcome for Legg-Calve-Perthes disease (LCP) is needed to guide treatment decisions during the initial stage of the disease (stage 1), before deformity occurs. Radiographic prognosticators are applicable only after fragmentation (stage II). We investigated pre- and postcontrast MRI in depicting stage I femoral head involvement. Thirty children with stage I LCP underwent non-contrast coronal T1 fast spin-echo (FSE) and corresponding postcontrast fat-suppressed T1-weighted fast spin-echo (FSE) sequences to quantify the extent of femoral head involvement. Three pediatric radiologists and one pediatric orthopedic surgeon independently measured central head involvement. Interobserver reliability of percent head involvement using non-contrasted MR images had intraclass correlation coefficient (ICC) of 0.72. Postcontrast MRI improved interobserver reliability (ICC 0.82). Qualitatively, the area of involvement was more clearly visible on contrast-enhanced MRI. A comparison of results obtained by each observer using the two MRI techniques showed no correlation. ICC ranged from -0.08 to 0.03 for each observer. Generally, greater head involvement was depicted by contrast compared with non-contrast MRI (Pearson r = -0.37, P = 0.04). Pre- and postcontrast MRI assess two different components of stage I LCP. However, contrast-enhanced MRI more clearly depicts the area of involvement. (orig.)

  10. MRI-controlled interstitial ultrasound brain therapy: An initial in-vivo study

    Science.gov (United States)

    N'Djin, W. Apoutou; Burtnyk, Mathieu; Lipsman, Nir; Bronskill, Michael; Schwartz, Michael; Kucharczyk, Walter; Chopra, Rajiv

    2012-11-01

    The recent emergence at the clinical level of minimally-invasive focal therapy such as laser-induced thermal therapy (LITT) has demonstrated promise in the management of brain metastasis [1], although control over the spatial pattern of heating is limited. Delivery of HIFU from minimally-invasive applicators enables high spatial control of the heat deposition in biological tissues, large treatment volumes and high treatment rate in well chosen conditions [2,3]. In this study, the feasibility of MRI-guided interstitial ultrasound therapy in brain was studies in-vivo in a porcine model. A prototype system originally developed for transurethral ultrasound therapy [4,5,6] was used in this study. Two burr holes of 12 mm in diameter were created in the animal's skull to allow the insertion of the therapeutic ultrasound applicator (probe) into the brain at two locations (right and left frontal lobe). A 4-element linear ultrasound transducer (f = 8 MHz) was mounted at the tip of a 25-cm linear probe (6 mm in diameter). The target boundary was traced to cover in 2D a surface compatible with the treatment of a 2 cm brain tumor. Acoustic power of each element and rotation rate of the device were adjusted in real-time based on MR-thermometry feedback control to optimize heat deposition at the target boundary [2,4,5]. Two MRT-controlled ultrasound brain treatments per animal have been performed using a maximal surface acoustic power of 10W.cm-2. In all cases, it was possible to increase accurately the temperature of the brain tissues in the targeted region over the 55°C threshold necessary for the creation of irreversible thermal lesion. Tissue changes were visible on T1w contrast-enhanced images immediately after treatment. These changes were also evident on T2w FSE images taken 2 hours after the 1st treatment and correlated well with the temperature image. On average, the targeted volume was 4.7 ± 2.3 cm3 and the 55°C treated volume was 6.7 ± 4.4 cm3. The volumetric

  11. Study of 3-D Dynamic Roughness Effects on Flow Over a NACA 0012 Airfoil Using Large Eddy Simulations at Low Reynolds Numbers

    Science.gov (United States)

    Guda, Venkata Subba Sai Satish

    There have been several advancements in the aerospace industry in areas of design such as aerodynamics, designs, controls and propulsion; all aimed at one common goal i.e. increasing efficiency --range and scope of operation with lesser fuel consumption. Several methods of flow control have been tried. Some were successful, some failed and many were termed as impractical. The low Reynolds number regime of 104 - 105 is a very interesting range. Flow physics in this range are quite different than those of higher Reynolds number range. Mid and high altitude UAV's, MAV's, sailplanes, jet engine fan blades, inboard helicopter rotor blades and wind turbine rotors are some of the aerodynamic applications that fall in this range. The current study deals with using dynamic roughness as a means of flow control over a NACA 0012 airfoil at low Reynolds numbers. Dynamic 3-D surface roughness elements on an airfoil placed near the leading edge aim at increasing the efficiency by suppressing the effects of leading edge separation like leading edge stall by delaying or totally eliminating flow separation. A numerical study of the above method has been carried out by means of a Large Eddy Simulation, a mathematical model for turbulence in Computational Fluid Dynamics, owing to the highly unsteady nature of the flow. A user defined function has been developed for the 3-D dynamic roughness element motion. Results from simulations have been compared to those from experimental PIV data. Large eddy simulations have relatively well captured the leading edge stall. For the clean cases, i.e. with the DR not actuated, the LES was able to reproduce experimental results in a reasonable fashion. However DR simulation results show that it fails to reattach the flow and suppress flow separation compared to experiments. Several novel techniques of grid design and hump creation are introduced through this study.

  12. Breast MRI for Evaluating Patients with Metastatic Axillary Lymph Node and Initially Negative Mammography and Sonography

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Eun Young; Han, Boo Kyung; Shin, Jung Hee; Kang, Seok Seon [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2007-10-15

    We wanted to investigate the ability of breast MR imaging to identify the primary malignancy in patients with axillary lymph node metastases and initially negative mammography and sonography, and we correlated those results with the conventional imaging. From September 2001 to April 2006, 12 patients with axillary lymph node metastases and initially negative mammography and sonography underwent breast MR imaging to identify occult breast carcinoma. We analyzed the findings of the MR imaging, the MR-correlated mammography and the second-look sonography. We followed up both the MR-positive and MR-negative patients. MR imaging detected occult breast carcinoma in 10 of 12 (83%) patients. Two MR-negative patients were free of carcinoma in the ipsilateral breast during their follow-up period (39 and 44 months, respectively). In nine out of 10 patients, the MR-correlated mammography and second-look sonography localized lesions that were not detected on the initial exam. All the non-MR-correlated sonographic abnormalities were benign. Breast MR imaging can identify otherwise occult breast cancer in patients with metastatic axillary lymph nodes. Localization of the lesions through MR-correlated mammography and second-look sonography is practically feasible in most cases.

  13. Predictive value of semi-quantitative MRI-based scoring systems for future knee replacement: data from the osteoarthritis initiative

    Energy Technology Data Exchange (ETDEWEB)

    Hafezi-Nejad, Nima; Eng, John; Demehri, Shadpour [Johns Hopkins University School of Medicine, Musculoskeletal Radiology, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Zikria, Bashir [Johns Hopkins University, Department of Orthopedic Surgery, Baltimore, MD (United States); Carrino, John A. [Hospital for Special Surgery, Department of Radiology and Imaging, New York, NY (United States)

    2015-11-15

    To evaluate, in a confirmatory fashion, whether baseline and change from baseline to 24-month follow-up in cartilage damage, bone marrow lesions and meniscal damage are predictors of knee replacement (KR) in subjects with a high risk of osteoarthritis (OA), independent of the level of physical activity, symptom severity and radiographic abnormalities. Data from the Osteoarthritis Initiative's (OAI) baseline and 24-month follow-up knee MRIs of 115 patients (age range: 45-78 years; 48 % female; BMI: 20.9-48.7) were analyzed. Cartilage, bone marrow and menisci were semi-quantitatively scored according to the Whole-Organ Magnetic Resonance Imaging Score (WORMS) and Boston-Leeds Osteoarthritis Knee Score (BLOKS) systems in all compartments. Baseline and 24-month interval changes in structural tissue damage assessed by BLOKS and WORMS were used as predictors of KR independent of clinical and radiographic parameters using Cox hazard analysis. Adjustments were performed for age, gender, BMI and physical activity (Physical Activity Scale for the Elderly: PASE), Western Ontario and McMaster Questionnaire (WOMAC) total score and radiographic Kellgren-Lawrence (KL) score. BLOKS and WORMS baseline cartilage scores were predictors of KR independent of the PASE, WOMAC and KL score. One score increase in the average baseline BLOKS full-thickness cartilage defect score was associated with a [hazard ratio (95 % CI)] 13.55 (3.61-50.89) times greater risk of KR independent of the PASE, WOMAC and KL score. Net reclassification improvements (NRIs) of the additional evaluation of 24-month follow-up MRI scores and assessment of changes were not significant for prediction of KR (NRI range: - 7.23 - 24.8 %). The BLOKS cartilage score for full-thickness cartilage defects had the highest hazard for KR. Follow-up MRI changes in structural tissue damage, detected by BLOKS and WORMS cartilage, bone marrow or meniscus scores (up to 24 months) had no significant predictive value in addition

  14. 3-D Dynamic Simulation System of Nuclear Power Plants%核电站三维动态仿真系统

    Institute of Scientific and Technical Information of China (English)

    阎光伟; 王瑞华

    2012-01-01

    为提高核电站仿真培训系统的真实感,设计了基于虚拟现实技术的核电站三维动态仿真系统。系统采用三维建模技术构建核电站的主要厂房和设备,通过三维场景交互技术实现对核电站虚拟场景的自主和固定路径漫游,采用三维动画技术对设备拆装、冷却系统和堆芯工作原理进行模拟。提出了基于参数关联的时序动画生成方法,用以实现设备的虚拟拆装;利用纹理法实现了冷却系统中的水流效果;提出了模型叠加法,用以表现反应堆内部的反应速率。利用该系统,受培训人员能够在核电站虚拟场景中直观了解核电站的构造和工作原理,从而增强了培训的效果。%To improve the sense of reality for the nuclear power station simulation training system,a 3-D dynamic simulation system based on virtual reality technology is designed.The main powerhouses and equipments of nuclear power plants are modeled by means of 3-D modeling technology.Roaming in nuclear power station virtual scene is realized by 3-D interaction technology.Equipments dismounting,cooling system and working principles of the reactor core are simulated using 3-D animation technology.A sequence animation generating method based on parameter-correlation is proposed to realize virtual equipments dismounting.The effectiveness of running water in the cooling system is simulated by means of the texture method.A model-superposition method is proposed to simulate the reaction rate within the reactor.Through this system,trainees can grasp the structure and working principles of the nuclear power station in a visual mode,thus improving the training effects.

  15. Ischemic Stroke of the Artery of Percheron with Normal Initial MRI: A Case Report

    Directory of Open Access Journals (Sweden)

    Guillaume Cassourret

    2010-01-01

    Full Text Available The artery of Percheron is a solitary trunk representing an uncommon anatomic variant that provides bilateral arterial supply to the paramedian thalami and the rostral midbrain. Occlusion of this artery results in bilateral thalamic and mesencephalic infarctions. The clinical diagnosis is difficult because the complex anatomy causes large clinical variability. We report a case of a comatose patient with normal early head-computed tomography and magnetic resonance imaging. A bilateral paramedian thalamic infarct due to an occlusion of the artery of Percheron was revealed two days later by a new head computed tomography. To our knowledge, this is the first report in the literature of a symptomatic patient presenting an acute Percheron stroke with normal early brain magnetic resonance imaging. Our case indicates that a normal initial magnetic resonance imaging cannot formally eliminate the diagnosis of acute stroke of the artery of Percheron. We discuss the causes of noncontributive brain magnetic resonance imaging at the onset of this acute Percheron stroke and the alternative diagnosis and therapy methods.

  16. {sup 18}F-FDG PET and MRS of the early stages of subacute sclerosing panencephalitis in a child with a normal initial MRI

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Yeong-Seon; Jung, Da-Eun [Ajou University School of Medicine, Department of Pediatrics, Suwon, Kyungki-do (Korea, Republic of); Kim, Ho-Sung [Ajou University School of Medicine, Department of Radiology, Suwon, Kyungki-do (Korea, Republic of)

    2010-11-15

    In subacute sclerosing panencephalitis (SSPE), conventional MRI findings have been reported. However, in the early clinical stages, imaging studies can appear normal. Moreover, with no history of infant measles infection, the diagnosis of SSPE can only be arrived at after extensive investigation that must eliminate a number of neurodegenerative diseases. We report here on {sup 18} F-fluorodeoxyglucose positron emission tomography ({sup 18}F-FDG PET) and magnetic resonance spectroscopy (MRS) findings in a 14-year-old girl with a normal initial MRI who had not contracted measles. Although {sup 18} F-FDG PET and MRS are not specific or diagnostic for SSPE, these techniques can demonstrate substantial metabolic impairments when MRI findings show no obvious abnormalities, as is often the case in the early stages of this disease. (orig.)

  17. Heart MRI

    Science.gov (United States)

    Magnetic resonance imaging - cardiac; Magnetic resonance imaging - heart; Nuclear magnetic resonance - cardiac; NMR - cardiac; MRI of the heart; Cardiomyopathy - MRI; Heart failure - MRI; Congenital heart disease - MRI

  18. Evaluation of kinetic entropy of breast masses initially found on MRI using whole-lesion curve distribution data: Comparison with the standard kinetic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Shimauchi, Akiko [University of Chicago, Department of Radiology, Chicago, IL (United States); Tohoku University, Department of Diagnostic Radiology, Graduate School of Medicine, Sendai, Miyagi (Japan); Abe, Hiroyuki; Schacht, David V.; Yulei, Jian; Pineda, Federico D.; Jansen, Sanaz A.; Ganesh, Rajiv; Newstead, Gillian M. [University of Chicago, Department of Radiology, Chicago, IL (United States)

    2015-08-15

    To quantify kinetic heterogeneity of breast masses that were initially detected with dynamic contrast-enhanced MRI, using whole-lesion kinetic distribution data obtained from computer-aided evaluation (CAE), and to compare that with standard kinetic curve analysis. Clinical MR images from 2006 to 2011 with breast masses initially detected with MRI were evaluated with CAE. The relative frequencies of six kinetic patterns (medium-persistent, medium-plateau, medium-washout, rapid-persistent, rapid-plateau, rapid-washout) within the entire lesion were used to calculate kinetic entropy (KE), a quantitative measure of enhancement pattern heterogeneity. Initial uptake (IU) and signal enhancement ratio (SER) were obtained from the most-suspicious kinetic curve. Mann-Whitney U test and ROC analysis were conducted for differentiation of malignant and benign masses. Forty benign and 37 malignant masses comprised the case set. IU and SER were not significantly different between malignant and benign masses, whereas KE was significantly greater for malignant than benign masses (p = 0.748, p = 0.083, and p < 0.0001, respectively). Areas under ROC curve for IU, SER, and KE were 0.479, 0.615, and 0.662, respectively. Quantification of kinetic heterogeneity of whole-lesion time-curve data with KE has the potential to improve differentiation of malignant from benign breast masses on breast MRI. (orig.)

  19. Evaluation of kinetic entropy of breast masses initially found on MRI using whole-lesion curve distribution data: Comparison with the standard kinetic analysis

    International Nuclear Information System (INIS)

    To quantify kinetic heterogeneity of breast masses that were initially detected with dynamic contrast-enhanced MRI, using whole-lesion kinetic distribution data obtained from computer-aided evaluation (CAE), and to compare that with standard kinetic curve analysis. Clinical MR images from 2006 to 2011 with breast masses initially detected with MRI were evaluated with CAE. The relative frequencies of six kinetic patterns (medium-persistent, medium-plateau, medium-washout, rapid-persistent, rapid-plateau, rapid-washout) within the entire lesion were used to calculate kinetic entropy (KE), a quantitative measure of enhancement pattern heterogeneity. Initial uptake (IU) and signal enhancement ratio (SER) were obtained from the most-suspicious kinetic curve. Mann-Whitney U test and ROC analysis were conducted for differentiation of malignant and benign masses. Forty benign and 37 malignant masses comprised the case set. IU and SER were not significantly different between malignant and benign masses, whereas KE was significantly greater for malignant than benign masses (p = 0.748, p = 0.083, and p < 0.0001, respectively). Areas under ROC curve for IU, SER, and KE were 0.479, 0.615, and 0.662, respectively. Quantification of kinetic heterogeneity of whole-lesion time-curve data with KE has the potential to improve differentiation of malignant from benign breast masses on breast MRI. (orig.)

  20. MRI-guided breast biopsy at 3T using a dedicated large core biopsy set: Feasibility and initial results

    Energy Technology Data Exchange (ETDEWEB)

    Meeuwis, Carla, E-mail: cmeeuwis@alysis.nl [Department of Radiology, Radboud University Nijmegen Medical Centre, Geert Grooteplein-Zuid 10, 6525GA Nijmegen (Netherlands); Department of Radiology, Rijnstate Hospital, Alysis Zorggroep, Wagnerlaan 55, 6815 AD Arnhem (Netherlands); Mann, Ritse M., E-mail: r.mann@rad.umcn.nl [Department of Radiology, Radboud University Nijmegen Medical Centre, Geert Grooteplein-Zuid 10, 6525GA Nijmegen (Netherlands); Mus, Roel D.M., E-mail: r.mus@rad.umcn.nl [Department of Radiology, Radboud University Nijmegen Medical Centre, Geert Grooteplein-Zuid 10, 6525GA Nijmegen (Netherlands); Winkel, Axel, E-mail: awinkel@invivocorp.de [Interventional Instruments, INVIVO Germany GMBH, Schwerin (Germany); Boetes, Carla, E-mail: c.boetes@mumc.nl [Department of Radiology, Radboud University Nijmegen Medical Centre, Geert Grooteplein-Zuid 10, 6525GA Nijmegen (Netherlands); Department of Radiology, Maastricht University Medical Center (Netherlands); Barentsz, Jelle O., E-mail: j.barentsz@rad.umcn.nl [Department of Radiology, Radboud University Nijmegen Medical Centre, Geert Grooteplein-Zuid 10, 6525GA Nijmegen (Netherlands); Veltman, Jeroen, E-mail: veltman@rad.umcn.nl [Department of Radiology, Radboud University Nijmegen Medical Centre, Geert Grooteplein-Zuid 10, 6525GA Nijmegen (Netherlands)

    2011-08-15

    Objective: The increasing importance of breast MRI in the diagnostic processes concerning breast cancer yield often lesions that are visible on MRI only. To assess the nature of these lesions, pathologic analysis is necessary. Therefore, MR-guided biopsy should be available. Breast MRI at 3T has shown advantage over 1.5T. Unfortunately, current equipment for MR-guided biopsy is better suited for intervention at 1.5T due to the danger of heating titanium co-axial sleeves and large susceptibility artifacts. We evaluated a dedicated 3T breast biopsy set that uses plastic coaxial needles to overcome these problems. Materials and methods: We performed MRI-guided breast biopsy in 23 women with 24 MRI-only visible breast lesions at 3T. Biopsy procedures were performed with plastic coaxial needles in a closed bore 3T clinical MR system on a dedicated phased array breast coil with a commercially available add-on stereotactic biopsy device. Results: Width of the needle artifact was 2 mm in all 24 cases. Biopsy procedure was completed between 35 and 67 min. The procedure was judged moderately easy in 12 and normal in 10 cases. One procedure was judged difficult and there was one technical failure. Conclusion: MRI-guided breast biopsy at 3T is a fast and accurate procedure. The plastic coaxial needles reduce the susceptibility artifact largely and do not increase the difficulty of the procedure. The diagnostic yield is at least equal to the diagnostic yield of the same procedure at 1.5T. Therefore, this technique can be safely used for lesions only visible at 3T MRI.

  1. Simultaneous measurement of kidney function by dynamic contrast enhanced MRI and FITC-sinistrin clearance in rats at 3 tesla: initial results.

    Directory of Open Access Journals (Sweden)

    Frank G Zöllner

    Full Text Available Glomerular filtration rate (GFR is an essential parameter of kidney function which can be measured by dynamic contrast enhanced magnetic resonance imaging (MRI-GFR and transcutaneous approaches based on fluorescent tracer molecules (optical-GFR. In an initial study comparing both techniques in separate measurements on the same animal, the correlation of the obtained GFR was poor. The goal of this study was to investigate if a simultaneous measurement was feasible and if thereby, the discrepancies in MRI-GFR and optical-GFR could be reduced. For the experiments healthy and unilateral nephrectomised (UNX Sprague Dawley (SD rats were used. The miniaturized fluorescent sensor was fixed on the depilated back of an anesthetized rat. A bolus of 5 mg/100 g b.w. of FITC-sinistrin was intravenously injected. For dynamic contrast enhanced perfusion imaging (DCE-MRI a 3D time-resolved angiography with stochastic trajectories (TWIST sequence was used. By means of a one compartment model the excretion half-life (t1/2 of FITC-sinistrin was calculated and converted into GFR. GFR from DCE-MRI was calculated by fitting pixel-wise a two compartment renal filtration model. Mean cortical GFR and GFR by FITC-sinistrin were compared by Bland-Altman plots and pair-wise t-test. Results show that a simultaneous GFR measurement using both techniques is feasible. Mean optical-GFR was 4.34 ± 2.22 ml/min (healthy SD rats and 2.34 ± 0.90 ml/min (UNX rats whereas MRI-GFR was 2.10 ± 0.64 ml/min (SD rats and 1.17 ± 0.38 ml/min (UNX rats. Differences between healthy and UNX rats were significant (p<0.05 and almost equal percentage difference (46.1% and 44.3% in mean GFR were assessed with both techniques. Overall mean optical-GFR values were approximately twice as high compared to MRI-GFR values. However, compared to a previous study, our results showed a higher agreement. In conclusion, the possibility to use the transcutaneous method in MRI may have a huge impact in

  2. Performance of gadofosveset-enhanced MRI for staging rectal cancer nodes: can the initial promising results be reproduced?

    Energy Technology Data Exchange (ETDEWEB)

    Heijnen, Luc A.; Martens, Milou H. [Maastricht University Medical Center, Department of Radiology, P.O. Box 5800, Maastricht (Netherlands); Maastricht University Medical Center, Department of Surgery, Maastricht (Netherlands); GROW School for Oncology and Developmental Biology, Maastricht (Netherlands); Lambregts, Doenja M.J.; Maas, Monique; Bakers, Frans C.H. [Maastricht University Medical Center, Department of Radiology, P.O. Box 5800, Maastricht (Netherlands); Cappendijk, Vincent C. [Jeroen Bosch Ziekenhuis, Department of Radiology, ' s Hertogenbosch (Netherlands); Oliveira, Pedro [Instituto Portugues de Oncologia do Porto Francisco Gentil, Department of Radiology, Porto (Portugal); Lammering, Guido [Maastro Clinic, Radiation Oncology, Maastricht (Netherlands); GROW School for Oncology and Developmental Biology, Maastricht (Netherlands); Riedl, Robert G. [Maastricht University Medical Center, Department of Pathology, Maastricht (Netherlands); Beets, Geerard L. [Maastricht University Medical Center, Department of Surgery, Maastricht (Netherlands); GROW School for Oncology and Developmental Biology, Maastricht (Netherlands); Beets-Tan, Regina G.H. [Maastricht University Medical Center, Department of Radiology, P.O. Box 5800, Maastricht (Netherlands); GROW School for Oncology and Developmental Biology, Maastricht (Netherlands)

    2014-02-15

    A previous study showed promising results for gadofosveset-trisodium as a lymph node magnetic resonance imaging (MRI) contrast agent in rectal cancer. The aim of this study was to prospectively confirm the diagnostic performance of gadofosveset MRI for nodal (re)staging in rectal cancer in a second patient cohort. Seventy-one rectal cancer patients were prospectively included, of whom 13 (group I) underwent a primary staging gadofosveset MRI (1.5-T) followed by surgery (± preoperative 5 x 5 Gy) and 58 (group II) underwent both primary staging and restaging gadofosveset MRI after a long course of chemoradiotherapy followed by surgery. Nodal status was scored as (y)cN0 or (y)cN+ by two independent readers (R1, R2) with different experience levels. Results were correlated with histology on a node-by-node basis. Sensitivity, specificity and area under the receiver operating characteristics curve (AUC) were 94 %, 79 % and 0.89 for the more experienced R1 and 50 %, 83 % and 0.74 for the non-experienced R2. R2's performance improved considerably after a learning curve, to an AUC of 0.83. Misinterpretations mainly occurred in nodes located in the superior mesorectum, nodes located in between vessels and nodes containing micrometastases. This prospective study confirms the good diagnostic performance of gadofosveset MRI for nodal (re)staging in rectal cancer. (orig.)

  3. Predicting response before initiation of neoadjuvant chemotherapy in breast cancer using new methods for the analysis of dynamic contrast enhanced MRI (DCE MRI) data

    Science.gov (United States)

    DeGrandchamp, Joseph B.; Whisenant, Jennifer G.; Arlinghaus, Lori R.; Abramson, V. G.; Yankeelov, Thomas E.; Cárdenas-Rodríguez, Julio

    2016-03-01

    The pharmacokinetic parameters derived from dynamic contrast enhanced (DCE) MRI have shown promise as biomarkers for tumor response to therapy. However, standard methods of analyzing DCE MRI data (Tofts model) require high temporal resolution, high signal-to-noise ratio (SNR), and the Arterial Input Function (AIF). Such models produce reliable biomarkers of response only when a therapy has a large effect on the parameters. We recently reported a method that solves the limitations, the Linear Reference Region Model (LRRM). Similar to other reference region models, the LRRM needs no AIF. Additionally, the LRRM is more accurate and precise than standard methods at low SNR and slow temporal resolution, suggesting LRRM-derived biomarkers could be better predictors. Here, the LRRM, Non-linear Reference Region Model (NRRM), Linear Tofts model (LTM), and Non-linear Tofts Model (NLTM) were used to estimate the RKtrans between muscle and tumor (or the Ktrans for Tofts) and the tumor kep,TOI for 39 breast cancer patients who received neoadjuvant chemotherapy (NAC). These parameters and the receptor statuses of each patient were used to construct cross-validated predictive models to classify patients as complete pathological responders (pCR) or non-complete pathological responders (non-pCR) to NAC. Model performance was evaluated using area under the ROC curve (AUC). The AUC for receptor status alone was 0.62, while the best performance using predictors from the LRRM, NRRM, LTM, and NLTM were AUCs of 0.79, 0.55, 0.60, and 0.59 respectively. This suggests that the LRRM can be used to predict response to NAC in breast cancer.

  4. Diffusion-weighted MRI of bone marrow oedema, soft tissue oedema and synovitis in paediatric patients: feasibility and initial experience

    Directory of Open Access Journals (Sweden)

    Neubauer Henning

    2012-07-01

    Full Text Available Abstract Background MRI has become the mainstay of diagnostic imaging in paediatric rheumatology for lesion detection, differential diagnosis and therapy surveillance. MR imaging of synovitis, in particular, is indispensable for early diagnosis and follow-up in arthritis patients. We used diffusion-weighted MRI (DWI as a new imaging modality in comparison to standard MRI sequences to study bone marrow oedema, soft-tissue oedema and synovitis in paediatric patients. Methods A total of 52 patients (mean age 11 ± 5 years with bone marrow oedema (n = 31, soft-tissue oedema (n = 20 and synovitis (n = 15 were examined with transversal diffusion-weighted single-shot echoplanar imaging in addition to standard MR sequences (T2W TIRM, T1W pre- and post-contrast. Diffusion-weighted images were used for lesion detection and apparent diffusion coefficient (ADC, unit × 10-3 mm2/s values were measured with ROI technique on ADC maps. Results In 50 of 52 patients, DWI delineated the lesion of interest corresponding to pathological signal increase on standard sequences. Mean ADC was 1.60 ± 0.14 (range 1.38 - 1.99 in osseous lesions, 1.72 ± 0.31 (range 1.43 - 2.56 in soft tissue oedema and 2.82 ± 0.24 (range 2.47 - 3.18 for joint effusion (ANOVA p  Conclusions Diffusion-weighted MRI reliably visualises osseous and soft tissue oedema, as compared to standard sequences. DWI of synovitis is feasible in large joints and presents a novel approach to contrast-free imaging of synovitis. Whole-body DWI for chronic non-bacterial osteomyelitis should be evaluated in future studies.

  5. Dynamic Contrast-Enhanced MRI Assessment of Hyperemic Fractional Microvascular Blood Plasma Volume in Peripheral Arterial Disease: Initial Findings

    OpenAIRE

    Bas Versluis; Marjolein H G Dremmen; Nelemans, Patty J; Wildberger, Joachim E.; Geert-Willem Schurink; Tim Leiner; Walter H Backes

    2012-01-01

    OBJECTIVES: The aim of the current study was to describe a method that assesses the hyperemic microvascular blood plasma volume of the calf musculature. The reversibly albumin binding contrast agent gadofosveset was used in dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) to assess the microvascular status in patients with peripheral arterial disease (PAD) and healthy controls. In addition, the reproducibility of this method in healthy controls was determined. MATERIALS AND METH...

  6. SU-D-18C-06: Initial Experience with Implementing MRI Safety Guidelines for Patients with Pacemakers - Medical Physicist Perspective

    Energy Technology Data Exchange (ETDEWEB)

    James, J; Place, V; Panda, A [Mayo Clinic, Scottsdale, AZ (United States); Edmonson, H [Mayo Clinic College of Medicine, Rochester, MN (United States); Felmlee, J [Mayo Clinic, Rochester, MN (United States); Pooley, R [Mayo Clinic, Jacksonville, FL (United States)

    2014-06-01

    Purpose: Several institutions have developed MRI guidelines for patients with MR-unsafe or MR-conditional pacemakers. Here we highlight the role of a medical physicist in implementing these guidelines for non-pacemaker dependent patients. Guidelines: Implementing these guidelines requires involvement from several medical specialties and a strong collaboration with the site MRI supervisor to develop a structured workflow. A medical physicist is required to be present during the scan to supervise the MR scanning and to maintain a safety checklist that ensures: 1) uninterrupted patient communication with the technologist, 2) continuous patient physiologic monitoring (e.g. blood pressure and electrocardiography) by a trained nurse, 3) redundant patient vitals monitoring (e.g. pulse oximetry) due to the possibility of in vivo electrocardiography reading fluctuations during image acquisition. A radiologist is strongly recommended to be available to review the images before patients are discharged from the scanner. Pacemaker MRI should be restricted to 1.5T field strength. The MRI sequences should be optimized by the physicist with regards to: a) SAR: limited to <1.5 W/Kg for MR-unsafe pacemakers in normal operating mode, b) RF exposure time: <30 min, c) Coils: use T/R coils but not restricted to such, d) Artifacts: further optimization of sequences whenever image quality is compromised due to the pacemaker. In particular, cardiac, breast and left-shoulder MRIs are most susceptible to these artifacts. Possible strategies to lower the SAR include: a) BW reduction, 2) echo-train-length reduction, 3) increase TR, 4) decrease number of averages, 5) decrease flip angle, 6) reduce slices and/or a combination of all the options. Conclusion: A medical physicist in collaboration with the MR supervisor plays an important role in the supervision/implementation of safe MR scanning of pacemaker patients. Developing and establishing a workflow has enabled our institution to scan over

  7. A dimensionless dynamic contrast enhanced MRI parameter for intra-prostatic tumour target volume delineation: initial comparison with histology

    Science.gov (United States)

    Hrinivich, W. Thomas; Gibson, Eli; Gaed, Mena; Gomez, Jose A.; Moussa, Madeleine; McKenzie, Charles A.; Bauman, Glenn S.; Ward, Aaron D.; Fenster, Aaron; Wong, Eugene

    2014-03-01

    Purpose: T2 weighted and diffusion weighted magnetic resonance imaging (MRI) show promise in isolating prostate tumours. Dynamic contrast enhanced (DCE)-MRI has also been employed as a component in multi-parametric tumour detection schemes. Model-based parameters such as Ktrans are conventionally used to characterize DCE images and require arterial contrast agent (CR) concentration. A robust parameter map that does not depend on arterial input may be more useful for target volume delineation. We present a dimensionless parameter (Wio) that characterizes CR wash-in and washout rates without requiring arterial CR concentration. Wio is compared to Ktrans in terms of ability to discriminate cancer in the prostate, as demonstrated via comparison with histology. Methods: Three subjects underwent DCE-MRI using gadolinium contrast and 7 s imaging temporal resolution. A pathologist identified cancer on whole-mount histology specimens, and slides were deformably registered to MR images. The ability of Wio maps to discriminate cancer was determined through receiver operating characteristic curve (ROC) analysis. Results: There is a trend that Wio shows greater area under the ROC curve (AUC) than Ktrans with median AUC values of 0.74 and 0.69 respectively, but the difference was not statistically significant based on a Wilcoxon signed-rank test (p = 0.13). Conclusions: Preliminary results indicate that Wio shows potential as a tool for Ktrans QA, showing similar ability to discriminate cancer in the prostate as Ktrans without requiring arterial CR concentration.

  8. Dynamic contrast-enhanced MRI assessment of hyperemic fractional microvascular blood plasma volume in peripheral arterial disease: initial findings.

    Directory of Open Access Journals (Sweden)

    Bas Versluis

    Full Text Available OBJECTIVES: The aim of the current study was to describe a method that assesses the hyperemic microvascular blood plasma volume of the calf musculature. The reversibly albumin binding contrast agent gadofosveset was used in dynamic contrast-enhanced magnetic resonance imaging (DCE MRI to assess the microvascular status in patients with peripheral arterial disease (PAD and healthy controls. In addition, the reproducibility of this method in healthy controls was determined. MATERIALS AND METHODS: Ten PAD patients with intermittent claudication and 10 healthy control subjects were included. Patients underwent contrast-enhanced MR angiography of the peripheral arteries, followed by one DCE MRI examination of the musculature of the calf. Healthy control subjects were examined twice on different days to determine normative values and the interreader and interscan reproducibility of the technique. The MRI protocol comprised dynamic imaging of contrast agent wash-in under reactive hyperemia conditions of the calf musculature. Using pharmacokinetic modeling the hyperemic fractional microvascular blood plasma volume (V(p, unit: % of the anterior tibial, gastrocnemius and soleus muscles was calculated. RESULTS: V(p was significantly lower for all muscle groups in PAD patients (4.3±1.6%, 5.0±3.3% and 6.1±3.6% for anterior tibial, gastrocnemius and soleus muscles, respectively compared to healthy control subjects (9.1±2.0%, 8.9±1.9% and 9.3±2.1%. Differences in V(p between muscle groups were not significant. The coefficient of variation of V(p varied from 10-14% and 11-16% at interscan and interreader level, respectively. CONCLUSIONS: Using DCE MRI after contrast-enhanced MR angiography with gadofosveset enables reproducible assessment of hyperemic fractional microvascular blood plasma volume of the calf musculature. V(p was lower in PAD patients than in healthy controls, which reflects a promising functional (hemodynamic biomarker for the

  9. Altered baseline brain activity with 72 h of simulated microgravity--initial evidence from resting-state fMRI.

    Science.gov (United States)

    Liao, Yang; Zhang, Jinsong; Huang, Zhiping; Xi, Yibin; Zhang, Qianru; Zhu, Tianli; Liu, Xufeng

    2012-01-01

    To provide the basis and reference to further insights into the neural activity of the human brain in a microgravity environment, we discuss the amplitude changes of low-frequency brain activity fluctuations using a simulated microgravity model. Twelve male participants between 24 and 31 years old received resting-state fMRI scans in both a normal condition and after 72 hours in a -6° head down tilt (HDT). A paired sample t-test was used to test the amplitude differences of low-frequency brain activity fluctuations between these two conditions. With 72 hours in a -6° HDT, the participants showed a decreased amplitude of low-frequency fluctuations in the left thalamus compared with the normal condition (a combined threshold of Pmicrogravity environment. PMID:23285086

  10. Semi-automatic lung segmentation of DCE-MRI data sets of 2-year old children after congenital diaphragmatic hernia repair: Initial results.

    Science.gov (United States)

    Zöllner, Frank G; Daab, Markus; Weidner, Meike; Sommer, Verena; Zahn, Katrin; Schaible, Thomas; Weisser, Gerald; Schoenberg, Stefan O; Neff, K Wolfgang; Schad, Lothar R

    2015-12-01

    In congenital diaphragmatic hernia (CDH), lung hypoplasia and secondary pulmonary hypertension are the major causes of death and severe disability. Based on new therapeutic strategies survival rates could be improved to up to 80%. However, after surgical repair of CDH, long-term follow-up of these pediatric patients is necessary. In this, dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) provides insights into the pulmonary microcirculation and might become a tool within the routine follow-up program of CDH patients. However, whole lung segmentation from DCE-MRI scans is tedious and automated procedures are warranted. Therefore, in this study, an approach to semi-automated lung segmentation is presented. Segmentation of the lung is obtained by calculating the cross correlation and the area under curve between all voxels in the data set and a reference region-of-interest (ROI), here the arterial input function (AIF). By applying an upper and lower threshold to the obtained maps and intersecting these, a final segmentation is reached. This approach was tested on twelve DCE-MRI data sets of 2-year old children after CDH repair. Segmentation accuracy was evaluated by comparing obtained automatic segmentations to manual delineations using the Dice overlap measure. Optimal thresholds for the cross correlation were 0.5/0.95 and 0.1/0.5 for the area under curve, respectively. The ipsilateral (left) lung showed reduced segmentation accuracy compared to the contralateral (right) lung. Average processing time was about 1.4s per data set. Average Dice score was 0.7±0.1 for the whole lung. In conclusion, initial results are promising. By our approach, whole lung segmentation is possible and a rapid evaluation of whole lung perfusion becomes possible. This might allow for a more detailed analysis of lung hypoplasia of children after CDH.

  11. Fetal MRI

    International Nuclear Information System (INIS)

    Ultrasonography is the method of choice for prenatal malformation screening, but it does not always provide sufficient information for correct diagnosis or adequate abnormality evaluation. Fetal MRI is increasingly being used to complete sonographic findings. It was initially used for evaluation of cerebral abnormalities but is increasingly being applied to other fetal areas. In vivo investigation of fetal brain maturation has been enhanced by MRI. An adequate analysis of fetal chest and abdomen can be achieved with fast T2-, T1-weighted and diffusion-weighted imaging (DWI). The advantages include the great field of view and the excellent soft tissue contrast. This allows correct diagnosis of congenital diaphragmatic hernia and evaluation of the consequences on pulmonary growth. Other pulmonary malformations, such as cystic adenomatoid malformation, sequestration and brochogenic cysts, can also be easily identified. Renal position can be quickly determined using DWI sequences and renal agenesia can be easily diagnosed with only one sequence. Prenatal MRI is virtually as effective as postnatal examination, dispenses with transport of a potentially very ill newborn, and provides logistic advantages. Therefore, prenatal MRI is useful for adequate postnatal treatment of newborns with malformations. (orig.)

  12. Altered baseline brain activity with 72 h of simulated microgravity--initial evidence from resting-state fMRI.

    Directory of Open Access Journals (Sweden)

    Yang Liao

    Full Text Available To provide the basis and reference to further insights into the neural activity of the human brain in a microgravity environment, we discuss the amplitude changes of low-frequency brain activity fluctuations using a simulated microgravity model. Twelve male participants between 24 and 31 years old received resting-state fMRI scans in both a normal condition and after 72 hours in a -6° head down tilt (HDT. A paired sample t-test was used to test the amplitude differences of low-frequency brain activity fluctuations between these two conditions. With 72 hours in a -6° HDT, the participants showed a decreased amplitude of low-frequency fluctuations in the left thalamus compared with the normal condition (a combined threshold of P<0.005 and a minimum cluster size of 351 mm(3 (13 voxels, which corresponded with the corrected threshold of P<0.05 determined by AlphaSim. Our findings indicate that a gravity change-induced redistribution of body fluid may disrupt the function of the left thalamus in the resting state, which may contribute to reduced motor control abilities and multiple executive functions in astronauts in a microgravity environment.

  13. Initial PET Performance Evaluation of a Preclinical Insert for PET/MRI with Digital SiPM Technology

    CERN Document Server

    Schug, David; Weissler, Bjoern; Gebhardt, Pierre; Goldschmidt, Benjamin; Wehner, Jakob; Dueppenbecker, Peter Michael; Salomon, Andre; Hallen, Patrick; Kiessling, Fabian; Schulz, Volkmar

    2015-01-01

    Hyperion-IID is a positron emission tomography (PET) insert which allows simultaneous operation in a clinical magnetic resonance imaging (MRI) scanner. To read out the scintillation light of the employed LYSO crystal arrays with a pitch of 1 mm pitch and 12 mm in height, digital silicon photomultipliers (DPC 3200-22, Philips Digital Photon Counting) (DPC) are used. The basic PET performance in terms of energy resolution, coincidence resolution time (CRT) and sensitivity as a function of operating parameters, such as the operating temperature, the applied overvoltage, activity and configuration parameters of the DPCs, were evaluated on system level. The measured energy resolution did not show a large dependency on the selected parameters and is in the range of 12.4-12.9% for low activities and degrades to ~13.6% at activities of ~100 MBq. The CRT strongly depends on the selected trigger scheme (trig) of the DPCs. We measured approximately 260 ps, 440 ps, 540 ps and 1300 ps for trig 1-4, respectively. The trues...

  14. Rendering of 3D Dynamic Virtual Environments

    CERN Document Server

    Catanese, Salvatore; Fiumara, Giacomo; Pagano, Francesco

    2011-01-01

    In this paper we present a framework for the rendering of dynamic 3D virtual environments which can be integrated in the development of videogames. It includes methods to manage sounds and particle effects, paged static geometries, the support of a physics engine and various input systems. It has been designed with a modular structure to allow future expansions. We exploited some open-source state-of-the-art components such as OGRE, PhysX, ParticleUniverse, etc.; all of them have been properly integrated to obtain peculiar physical and environmental effects. The stand-alone version of the application is fully compatible with Direct3D and OpenGL APIs and adopts OpenAL APIs to manage audio cards. Concluding, we devised a showcase demo which reproduces a dynamic 3D environment, including some particular effects: the alternation of day and night infuencing the lighting of the scene, the rendering of terrain, water and vegetation, the reproduction of sounds and atmospheric agents.

  15. Initial PET performance evaluation of a preclinical insert for PET/MRI with digital SiPM technology

    Science.gov (United States)

    Schug, David; Lerche, Christoph; Weissler, Bjoern; Gebhardt, Pierre; Goldschmidt, Benjamin; Wehner, Jakob; Dueppenbecker, Peter Michael; Salomon, Andre; Hallen, Patrick; Kiessling, Fabian; Schulz, Volkmar

    2016-04-01

    Hyperion-IID is a positron emission tomography (PET) insert which allows simultaneous operation in a clinical magnetic resonance imaging (MRI) scanner. To read out the scintillation light of the employed lutetium yttrium orthosilicate crystal arrays with a pitch of 1 mm and 12 mm in height, digital silicon photomultipliers (DPC 3200-22, Philips Digital Photon Counting) (DPC) are used. The basic PET performance in terms of energy resolution, coincidence resolution time (CRT) and sensitivity as a function of the operating parameters, such as the operating temperature, the applied overvoltage, activity and configuration parameters of the DPCs, has been evaluated at system level. The measured energy resolution did not show a large dependency on the selected parameters and is in the range of 12.4%-12.9% for low activity, degrading to  ˜13.6% at an activity of  ˜100 MBq. The CRT strongly depends on the selected trigger scheme (trig) of the DPCs, and we measured approximately 260 ps, 440 ps, 550 ps and 1300 ps for trig 1-4, respectively. The trues sensitivity for a NEMA NU 4 mouse-sized scatter phantom with a 70 mm long tube of activity was dependent on the operating parameters and was determined to be 0.4%-1.4% at low activity. The random fraction stayed below 5% at activity up to 100 MBq and the scatter fraction was evaluated as  ˜6% for an energy window of 411 keV-561 keV and  ˜16% for 250 keV-625 keV. Furthermore, we performed imaging experiments using a mouse-sized hot-rod phantom and a large rabbit-sized phantom. In 2D slices of the reconstructed mouse-sized hot-rod phantom (∅ = 28 mm), the rods were distinguishable from each other down to a rod size of 0.8 mm. There was no benefit from the better CRT of trig 1 over trig 3, where in the larger rabbit-sized phantom (∅ = 114 mm) we were able to show a clear improvement in image quality using the time-of-flight information. The findings will allow system architects—aiming at a similar

  16. Chest MRI

    Science.gov (United States)

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

  17. Obesity increases the prevalence and severity of focal knee abnormalities diagnosed using 3T MRI in middle-aged subjects - data from the osteoarthritis initiative

    Energy Technology Data Exchange (ETDEWEB)

    Laberge, Marc A.; Baum, Thomas; Virayavanich, Warapat; Nardo, Lorenzo; Link, Thomas M. [University of California San Francisco, Musculoskeletal and Quantitative Imaging Research, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Nevitt, M.C.; Lynch, J.; McCulloch, C.E. [University of California San Francisco, Department of Epidemiology and Biostatistics, San Francisco, CA (United States)

    2012-06-15

    To study the effect of BMI on the prevalence, severity, and 36-month progression of early degenerative changes in the knee by using 3T MRI in middle-aged subjects without radiographic osteoarthritis (OA). We examined baseline and 36-month follow-up MR studies from 137 middle-aged individuals (45-55 years old) with risk factors for knee OA but no radiographic OA from the Osteoarthritis Initiative. Subjects were grouped into three categories: normal BMI (BMI < 25 kg/m{sup 2}, n = 38), overweight (BMI 25-29.9 kg/m{sup 2}, n = 37), and obese (BMI {>=} 30 kg/m{sup 2}, n = 62). Using 3T MRI, cartilage, meniscus, and bone marrow abnormalities were graded using the OA Whole-organ MR Imaging Score (WORMS). The statistical analysis was corrected as necessary for differences in age, sex, and OA risk factors other than BMI. The overall prevalence of lesions was 64% for meniscus and 79% for cartilage (including low grade lesions). At baseline, the prevalence and severity of knee lesions was positively associated with BMI, with a nearly fourfold increase in meniscal tears and more than twofold increase in high-grade cartilage defects in obese individuals relative to normal-weight subjects. Over the 36-month follow-up period, the number of new or worsening cartilage lesions of any grade was significantly higher in obese subjects (p = 0.039), while there was no significant difference in meniscal lesion progression. Obesity was associated with both higher prevalence and severity of early degenerative changes in the knee in middle-aged individuals without radiographic OA and with significantly increased cartilage lesion progression (of any grade) over 36 months. (orig.)

  18. Obesity increases the prevalence and severity of focal knee abnormalities diagnosed using 3T MRI in middle-aged subjects - data from the osteoarthritis initiative

    International Nuclear Information System (INIS)

    To study the effect of BMI on the prevalence, severity, and 36-month progression of early degenerative changes in the knee by using 3T MRI in middle-aged subjects without radiographic osteoarthritis (OA). We examined baseline and 36-month follow-up MR studies from 137 middle-aged individuals (45-55 years old) with risk factors for knee OA but no radiographic OA from the Osteoarthritis Initiative. Subjects were grouped into three categories: normal BMI (BMI 2, n = 38), overweight (BMI 25-29.9 kg/m2, n = 37), and obese (BMI ≥ 30 kg/m2, n = 62). Using 3T MRI, cartilage, meniscus, and bone marrow abnormalities were graded using the OA Whole-organ MR Imaging Score (WORMS). The statistical analysis was corrected as necessary for differences in age, sex, and OA risk factors other than BMI. The overall prevalence of lesions was 64% for meniscus and 79% for cartilage (including low grade lesions). At baseline, the prevalence and severity of knee lesions was positively associated with BMI, with a nearly fourfold increase in meniscal tears and more than twofold increase in high-grade cartilage defects in obese individuals relative to normal-weight subjects. Over the 36-month follow-up period, the number of new or worsening cartilage lesions of any grade was significantly higher in obese subjects (p = 0.039), while there was no significant difference in meniscal lesion progression. Obesity was associated with both higher prevalence and severity of early degenerative changes in the knee in middle-aged individuals without radiographic OA and with significantly increased cartilage lesion progression (of any grade) over 36 months. (orig.)

  19. MRI and low back pain

    Science.gov (United States)

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

  20. Whole-body MRI for initial staging of paediatric lymphoma: prospective comparison to an FDG-PET/CT-based reference standard

    Energy Technology Data Exchange (ETDEWEB)

    Littooij, Annemieke S. [University Medical Centre Utrecht/Wilhelmina Children' s Hospital, Department of Radiology and Nuclear Medicine, Utrecht (Netherlands); KK Women' s and Children' s Hospital, Department of Diagnostic and Interventional Imaging, Singapore (Singapore); Kwee, Thomas C.; Vermoolen, Malou A.; Keizer, Bart de; Beek, Frederik J.A.; Hobbelink, Monique G.; Nievelstein, Rutger A.J. [University Medical Centre Utrecht/Wilhelmina Children' s Hospital, Department of Radiology and Nuclear Medicine, Utrecht (Netherlands); Barber, Ignasi; Enriquez, Goya [Hospital Materno-Infantil Vall d' Hebron, Department of Paediatric Radiology, Barcelona (Spain); Granata, Claudio [IRCCS Giannina Gaslini Hospital, Department of Radiology, Genoa (Italy); Zsiros, Jozsef [University of Amsterdam, Department of Paediatric Oncology, Emma Children' s Hospital, Academic Medical Centre, Amsterdam (Netherlands); Soh, Shui Yen [KK Women' s and Children' s Hospital, Haematology and Oncology service, Department of Paediatric Subspecialities, Singapore (Singapore); Bierings, Marc B. [University Medical Centre Utrecht/Wilhelmina Children' s Hospital, Department of Paediatric Haematology-Oncology, Utrecht (Netherlands); Stoker, Jaap [University of Amsterdam, Department of Radiology, Academic Medical Centre, Amsterdam (Netherlands)

    2014-05-15

    To compare whole-body MRI, including diffusion-weighted imaging (whole-body MRI-DWI), with FDG-PET/CT for staging newly diagnosed paediatric lymphoma. A total of 36 children with newly diagnosed lymphoma prospectively underwent both whole-body MRI-DWI and FDG-PET/CT. Whole-body MRI-DWI was successfully performed in 33 patients (mean age 13.9 years). Whole-body MRI-DWI was independently evaluated by two blinded observers. After consensus reading, an unblinded expert panel evaluated the discrepant findings between whole-body MRI-DWI and FDG-PET/CT and used bone marrow biopsy, other imaging data and clinical information to derive an FDG-PET/CT-based reference standard. Interobserver agreement of whole-body MRI-DWI was good [all nodal sites together (κ = 0.79); all extranodal sites together (κ = 0.69)]. There was very good agreement between the consensus whole-body MRI-DWI- and FDG-PET/CT-based reference standard for nodal (κ = 0.91) and extranodal (κ = 0.94) staging. The sensitivity and specificity of consensus whole-body MRI-DWI were 93 % and 98 % for nodal staging and 89 % and 100 % for extranodal staging, respectively. Following removal of MRI reader errors, the disease stage according to whole-body MRI-DWI agreed with the reference standard in 28 of 33 patients. Our results indicate that whole-body MRI-DWI is feasible for staging paediatric lymphoma and could potentially serve as a good radiation-free alternative to FDG-PET/CT. (orig.)

  1. A 3D dynamic teaching system of data structure based on virtual reality%基于虚拟现实的数据结构三维动态教学系统

    Institute of Scientific and Technical Information of China (English)

    杨程; 刘涛; 范勇; 陈念年

    2012-01-01

    Focusing on shortcomings of traditional writing on the blackboard teaching and configuration of educational software in intuitiveness and interesting, a 3D dynamic teaching system of data structure was designed and then realized based on virtual reality technology. By using a hybrid software development method based on VC/MFC and OpenGL, practical teaching software which is simple to use and more intuitiveness was developed. Also, multi-thread technology was used to synchronize the current line of code and the steps of the algorithm. After applying the virtual reality technology to the teaching process, the purpose of improving the teaching of data structure and arising students' inspiration of this primary course was achieved.%针对传统板书式教学和组态式教学软件在直观性和趣味性方面的不足,设计并实现了一种基于虚拟现实技术的数据结构三维动态教学系统.系统以VC/MFC+ OpenGL的混合软件开发方式实现,具备简单、直观、易用并且交互性良好的特点,还利用Windows多线程技术实现了算法演示步骤与代码当前执行行的同步关联运行.课堂教学应用表明,达到了改进数据结构课程教学、提高学生学习该课程积极性的目的.

  2. Simultaneous evaluation of brain tumour metabolism, structure and blood volume using [{sup 18}F]-fluoroethyltyrosine (FET) PET/MRI: feasibility, agreement and initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Henriksen, Otto M.; Hansen, Adam E.; Law, Ian [Copenhagen University Hospital Rigshospitalet Blegdamsvej, Department of Clinical Physiology Nuclear Medicine and PET, Copenhagen (Denmark); Larsen, Vibeke A. [Copenhagen University Hospital Rigshospitalet Blegdamsvej, Department of Radiology, Copenhagen (Denmark); Muhic, Aida; Poulsen, Hans S. [Copenhagen University Hospital Rigshospitalet Blegdamsvej, Department of Oncology, Copenhagen (Denmark); Larsson, Henrik B.W. [Copenhagen University Hospital Rigshospitalet Glostrup, Functional Imaging Unit, Department of Clinical Physiology Nuclear Medicine and PET, Glostrup (Denmark)

    2016-01-15

    Both [{sup 18}F]-fluoroethyltyrosine (FET) PET and blood volume (BV) MRI supplement routine T1-weighted contrast-enhanced MRI in gliomas, but whether the two modalities provide identical or complementary information is unresolved. The aims of the study were to investigate the feasibility of simultaneous structural MRI, BV MRI and FET PET of gliomas using an integrated PET/MRI scanner and to assess the spatial and quantitative agreement in tumour imaging between BV MRI and FET PET. A total of 32 glioma patients underwent a 20-min static simultaneous PET/MRI acquisition on a Siemens mMR system 20 min after injection of 200 MBq FET. The MRI protocol included standard structural MRI and dynamic susceptibility contrast (DSC) imaging for BV measurements. Maximal relative tumour FET uptake (TBR{sub max}) and BV (rBV{sub max}), and Dice coefficients were calculated to assess the quantitative and spatial congruence in the tumour volumes determined by FET PET, BV MRI and contrast-enhanced MRI. FET volume and TBR{sub max} were higher in BV-positive than in BV-negative scans, and both VOL{sub BV} and rBV{sub max} were higher in FET-positive than in FET-negative scans. TBR{sub max} and rBV{sub max} were positively correlated (R{sup 2} = 0.59, p < 0.001). FET and BV positivity were in agreement in only 26 of the 32 patients and in 42 of 63 lesions, and spatial congruence in the tumour volumes as assessed by the Dice coefficients was generally poor with median Dice coefficients exceeding 0.1 in less than half the patients positive on at least one modality for any pair of modalities. In 56 % of the patients susceptibility artefacts in DSC BV maps overlapped the tumour on MRI. The study demonstrated that although tumour volumes determined by BV MRI and FET PET were quantitatively correlated, their spatial congruence in a mixed population of treated glioma patients was generally poor, and the modalities did not provide the same information in this population of patients. Combined

  3. Simultaneous evaluation of brain tumour metabolism, structure and blood volume using [18F]-fluoroethyltyrosine (FET) PET/MRI: feasibility, agreement and initial experience

    International Nuclear Information System (INIS)

    Both [18F]-fluoroethyltyrosine (FET) PET and blood volume (BV) MRI supplement routine T1-weighted contrast-enhanced MRI in gliomas, but whether the two modalities provide identical or complementary information is unresolved. The aims of the study were to investigate the feasibility of simultaneous structural MRI, BV MRI and FET PET of gliomas using an integrated PET/MRI scanner and to assess the spatial and quantitative agreement in tumour imaging between BV MRI and FET PET. A total of 32 glioma patients underwent a 20-min static simultaneous PET/MRI acquisition on a Siemens mMR system 20 min after injection of 200 MBq FET. The MRI protocol included standard structural MRI and dynamic susceptibility contrast (DSC) imaging for BV measurements. Maximal relative tumour FET uptake (TBRmax) and BV (rBVmax), and Dice coefficients were calculated to assess the quantitative and spatial congruence in the tumour volumes determined by FET PET, BV MRI and contrast-enhanced MRI. FET volume and TBRmax were higher in BV-positive than in BV-negative scans, and both VOLBV and rBVmax were higher in FET-positive than in FET-negative scans. TBRmax and rBVmax were positively correlated (R2 = 0.59, p < 0.001). FET and BV positivity were in agreement in only 26 of the 32 patients and in 42 of 63 lesions, and spatial congruence in the tumour volumes as assessed by the Dice coefficients was generally poor with median Dice coefficients exceeding 0.1 in less than half the patients positive on at least one modality for any pair of modalities. In 56 % of the patients susceptibility artefacts in DSC BV maps overlapped the tumour on MRI. The study demonstrated that although tumour volumes determined by BV MRI and FET PET were quantitatively correlated, their spatial congruence in a mixed population of treated glioma patients was generally poor, and the modalities did not provide the same information in this population of patients. Combined imaging of brain tumour metabolism and perfusion using

  4. 3 Tesla proton MRI for the diagnosis of pneumonia/lung infiltrates in neutropenic patients with acute myeloid leukemia: Initial results in comparison to HRCT

    International Nuclear Information System (INIS)

    Purpose: To evaluate the diagnostic accuracy of 3 Tesla proton MRI for the assessment of pneumonia/lung infiltrates in neutropenic patients with acute myeloid leukemia. Material and methods: In a prospective study, 3 Tesla MRI was performed in 19 febrile neutropenic patients (5 women, 14 men; mean age 61 years ± 14.2; range 23–77 years). All patients underwent high-resolution CT less than 24 h prior to MRI. The MRI protocol (Magnetom Tim Trio, Siemens) included a T2-weighted HASTE sequence (TE/TR: 49 ms/∞, slice thickness 6 mm) and a high-resolution 3D VIBE sequence with an ultra-short TE < 1 ms (TE/TR 0.8/2.9 ms, slice thickness 2 mm). The VIBE sequence was examined before and after intravenous injection of 0.1 mmol/kg gadoterate meglumine (Dotarem, Guerbet). The presence of pulmonary abnormalities, their location within the lung, and lesion type (nodules, consolidations, glass opacity areas) were analyzed by one reader and compared to the findings of HRCT, which was evaluated by a second independent radiologist who served as the reference standard. The findings were compared per lobe in each patient and rated as true positive (TP) findings if all three characteristics (presence, location, and lesion type) listed above were concordant to HRCT. Results: Pulmonary abnormalities were characterized by 3 Tesla MRI with a sensitivity of 82.3% and a specificity of 78.6%, resulting in an overall accuracy of 88% (NPV/PPV 66.7%/89.5%). In 51 lobes (19 of 19 patients), pulmonary abnormalities visualized by MR were judged to be concordant in their location and in the lesion type identified by both readers. In 22 lobes (11 of 19 patients), no abnormalities were present on either MR or HRCT (true negative). In 6 lobes (5 of 19 patients), ground glass opacity areas were detected on MRI but were not visible on HRCT (false positives). In 11 lobes (7 of 19 patients), MRI failed to detect ground glass opacity areas identified by HRCT. However, since the abnormalities were

  5. 3 Tesla proton MRI for the diagnosis of pneumonia/lung infiltrates in neutropenic patients with acute myeloid leukemia: Initial results in comparison to HRCT

    Energy Technology Data Exchange (ETDEWEB)

    Attenberger, U.I., E-mail: ulrike.attenberger@umm.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim (Germany); Morelli, J.N. [Scott and White Hospital, Texas A and M Health Sciences Center, Temple (United States); Henzler, T. [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim (Germany); Buchheidt, D. [Department of Hematology and Oncology, University Medical Center Mannheim (Germany); Fink, C. [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim (Germany); Department of Radiology, AKH Celle, Celle (Germany); Schoenberg, S.O.; Reichert, M. [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim (Germany)

    2014-01-15

    Purpose: To evaluate the diagnostic accuracy of 3 Tesla proton MRI for the assessment of pneumonia/lung infiltrates in neutropenic patients with acute myeloid leukemia. Material and methods: In a prospective study, 3 Tesla MRI was performed in 19 febrile neutropenic patients (5 women, 14 men; mean age 61 years ± 14.2; range 23–77 years). All patients underwent high-resolution CT less than 24 h prior to MRI. The MRI protocol (Magnetom Tim Trio, Siemens) included a T2-weighted HASTE sequence (TE/TR: 49 ms/∞, slice thickness 6 mm) and a high-resolution 3D VIBE sequence with an ultra-short TE < 1 ms (TE/TR 0.8/2.9 ms, slice thickness 2 mm). The VIBE sequence was examined before and after intravenous injection of 0.1 mmol/kg gadoterate meglumine (Dotarem, Guerbet). The presence of pulmonary abnormalities, their location within the lung, and lesion type (nodules, consolidations, glass opacity areas) were analyzed by one reader and compared to the findings of HRCT, which was evaluated by a second independent radiologist who served as the reference standard. The findings were compared per lobe in each patient and rated as true positive (TP) findings if all three characteristics (presence, location, and lesion type) listed above were concordant to HRCT. Results: Pulmonary abnormalities were characterized by 3 Tesla MRI with a sensitivity of 82.3% and a specificity of 78.6%, resulting in an overall accuracy of 88% (NPV/PPV 66.7%/89.5%). In 51 lobes (19 of 19 patients), pulmonary abnormalities visualized by MR were judged to be concordant in their location and in the lesion type identified by both readers. In 22 lobes (11 of 19 patients), no abnormalities were present on either MR or HRCT (true negative). In 6 lobes (5 of 19 patients), ground glass opacity areas were detected on MRI but were not visible on HRCT (false positives). In 11 lobes (7 of 19 patients), MRI failed to detect ground glass opacity areas identified by HRCT. However, since the abnormalities were

  6. MRI Scans

    Science.gov (United States)

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

  7. Quantification of left ventricular function and mass in heart transplant recipients using dual-source CT and MRI: initial clinical experience

    Energy Technology Data Exchange (ETDEWEB)

    Bastarrika, Gorka; Arraiza, Maria; Cecco, Carlo N. de; Mastrobuoni, Stefano; Ubilla, Matias; Rabago, Gregorio [Clinica Universitaria, Universidad de Navarra, Department of Radiology, Pamplona (Spain); Universita' di Roma ' ' Sapienza' ' -Ospedale Sant' Andrea, Department of Radiology, Rome (Italy); Clinica Universitaria, Universidad de Navarra, Department of Cardiovascular Surgery, Pamplona (Spain)

    2008-09-15

    The purpose of this study was to compare LV function and mass quantification derived from cardiac dual-source CT (DSCT) exams with those obtained by MRI in heart transplant recipients. Twelve heart transplant recipients who underwent cardiac DSCT and MRI examination were included. Double-oblique short-axis 8-mm slice thickness images were evaluated. Left ventricular ejection fraction, end-diastolic volume, end-systolic volume, stroke volume, cardiac output and myocardial mass were manually assessed for each patient by two blinded readers. A systematic overestimation of all left ventricular volumes by DSCT when compared with MRI was observed. Mean difference was 16.58{+-}18.61 ml for EDV, 4.94{+-}6.84 ml for ESV, 11.64{+-}13.58 ml for SV and 5.73{+-}1.14 l/min for CO. Slightly lower values for left ventricular ejection fraction with DSCT compared with MRI were observed (mean difference 0.34{+-}3.18%, p=0.754). Correlation between DSCT and MRI for left ventricular mass was excellent (rho = 0.972). Bland and Altman plots and CCC indicated good agreement between DSCT and MRI left ventricular function and mass measurements. The interobserver correlation was good. In conclusion, DSCT accurately estimates left ventricular ejection fraction, volumes and mass in heart transplant recipients. (orig.)

  8. Whole-body [{sup 18}F]FDG PET/MRI vs. PET/CT in the assessment of bone lesions in oncological patients: initial results

    Energy Technology Data Exchange (ETDEWEB)

    Beiderwellen, Karsten; Huebner, Michael; Grueneisen, Johannes; Nensa, Felix; Kuehl, Hilmar; Umutlu, Lale; Lauenstein, Thomas C. [University of Duisburg-Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Essen, Essen (Germany); Heusch, Philipp [University of Duesseldorf, Department of Diagnostic and Interventional Radiology, Medical Faculty, Duesseldorf (Germany); Ruhlmann, Verena; Rosenbaum-Krumme, Sandra [University of Duisburg-Essen, Department of Nuclear Medicine, University Hospital Essen, Essen (Germany)

    2014-08-15

    To compare [{sup 18} F]FDG PET/MRI with PET/CT for the assessment of bone lesions in oncologic patients. This prospective study included 67 patients with solid tumours scheduled for PET/CT with [{sup 18} F]FDG who also underwent a whole-body PET/MRI scan. The datasets (PET/CT, PET/MRI) were rated by two readers regarding lesion conspicuity (four-point scale) and diagnostic confidence (five-point scale). Median scores were compared using the Wilcoxon test. Bone metastases were present in ten patients (15 %), and benign bone lesions in 15 patients (22 %). Bone metastases were predominantly localized in the pelvis (18 lesions, 38 %) and the spine (14 lesions, 29 %). Benign bone lesions were exclusively osteosclerotic and smaller than the metastases (mean size 6 mm vs. 23 mm). While PET/CT allowed identification of 45 of 48 bone metastases (94 %), PET/MRI allowed identification of all bone metastases (100 %). Conspicuity of metastases was high for both modalities with significantly better results using PET/MRI (p < 0.05). Diagnostic confidence in lesion detection was high for both modalities without a significant difference. In benign lesions, conspicuity and diagnostic confidence were significantly higher with PET/CT (p < 0.05). [{sup 18} F]FDG PET/MRI shows high potential for the assessment of bone metastases by offering superior lesion conspicuity when compared to PET/CT. In hypersclerotic, benign bone lesions PET/CT still sets the reference. (orig.)

  9. [{sup 18}F]FDG PET/MRI vs. PET/CT for whole-body staging in patients with recurrent malignancies of the female pelvis: initial results

    Energy Technology Data Exchange (ETDEWEB)

    Beiderwellen, Karsten; Grueneisen, Johannes; Forsting, Michael; Lauenstein, Thomas C.; Umutlu, Lale [University Hospital Essen, University of Duisburg-Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Ruhlmann, Verena [University Hospital Essen, University of Duisburg-Essen, Clinic for Nuclear Medicine, Essen (Germany); Buderath, Paul; Aktas, Bahriye [University Hospital Essen, University of Duisburg-Essen, Clinic for Obstetrics and Gynecology, Essen (Germany); Heusch, Philipp [University of Dusseldorf, Department of Diagnostic and Interventional Radiology, Dusseldorf (Germany); Kraff, Oliver [University of Duisburg-Essen, Erwin L. Hahn Institute for Magnetic Resonance Imaging, Essen (Germany)

    2015-01-15

    To evaluate the diagnostic potential of PET/MRI with [{sup 18}F]FDG in recurrent ovarian and cervical cancer in comparison to PET/CT. A group of 19 patients with suspected recurrence of pelvic malignancies (ovarian cancer, 11 patients; cervical cancer, 8 patients) scheduled for an [{sup 18}F]FDG PET/CT were subsequently enrolled for a PET/MRI. The scan protocol comprised: (1) a T1-W axial VIBE after contrast agent adminstration, (2) an axial T2-W HASTE, (3) a coronal TIRM, (4) an axial DWI, and dedicated MR sequences of the female pelvis including (5) a T1-W VIBE before contrast agent adminstration, (6) a sagittal T2-W TSE, and (7) a sagittal T1-W dynamic VIBE. The datasets (PET/CT, PET/MRI) were rated separately by two readers regarding lesion count, lesion localization, lesion conspicuity (four-point scale), lesion characterization (benign/malignant/indeterminate) and diagnostic confidence (three-point scale). All available data (histology, prior examinations, PET/CT, PET/MRI, follow-up examinations) served as standard of reference. Median values were compared using the Wilcoxon rank sum test. Metastatic lesions were present in 16 of the 19 patients. A total of 78 lesions (malignant, 58; benign, 20) were described. Both PET/CT and PET/MRI allowed correct identification of all malignant lesions and provided equivalent conspicuity (3.86 ± 0.35 for PET/CT, 3.91 ± 0.28 for PET/MRI; p > 0.05). Diagnostic confidence was significantly higher for PET/MRI in malignant (p < 0.01) and benign lesions (p < 0.05). Both PET/CT and PET/MRI offer an equivalently high diagnostic value for recurrent pelvic malignancies. PET/MRI offers higher diagnostic confidence in the discrimination of benign and malignant lesions. Considering the reduced radiation dose and superior lesion discrimination, PET/MRI may serve as a powerful alternative to PET/CT in the future. (orig.)

  10. Initial experience with lung-MRI at 3.0 T: Comparison with CT and clinical data in the evaluation of interstitial lung disease activity

    Energy Technology Data Exchange (ETDEWEB)

    Lutterbey, G. [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn (Germany)]. E-mail: goetz.lutterbey@ukb.uni-bonn.de; Grohe, C. [Department of Internal Medicine, University of Bonn (Germany); Gieseke, J. [PHILIPS Medical Systems, Best (Netherlands); Falkenhausen, M. von [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn (Germany); Morakkabati, N. [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn (Germany); Wattjes, M.P. [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn (Germany); Manka, R. [Department of Internal Medicine, University of Bonn (Germany); Trog, D. [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn (Germany); Schild, H.H. [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn (Germany)

    2007-02-15

    Objectives: We evaluated the feasibility of highfield lung-MRI at 3.0 T. A comparison with Computed Tomography (CT) and clinical data regarding the assessment of inflammatory activity in patients with diffuse lung disease was performed. Material and methods: Prospective evaluation of 21 patients (15 males, 6 females, 43-80 y) with diffuse lung diseases who underwent clinical work-up inclusive laboratory tests, lung-function tests and transbronchial biopsy. After routine helical CT (additional 12 HRCT) a lung-MRI (3.0 Intera, Philips Medical Systems, Best, The Netherlands) using a T2-weighted, cardiac and respiratory triggered Fast-Spinecho-Sequence (TE/TR = 80/1500-2500 ms, 22 transverse slices, 7/2 mm slice-thickness/-gap) was performed. A pneumologist classified the cases into two groups: A = temporary acute interstitial disease or chronic interstitial lung disease with acute episode or superimposed infection/B = burned out interstitial lung disease without activity. Two blinded CT-radiologists graded the cases in active/inactive disease on the basis of nine morphological criteria each. A third radiologist rated the MRI-cases as active/inactive, depending on the signal-intensities of lung tissues. Results: The pneumologist classified 14 patients into group A and 7 patients into group B. Using CT, 6 cases were classified as active, 15 cases as inactive disease. With MRI 12 cases were classified as active and 9 cases as inactive. In the complete group of 21 patients MRI decisions and CT decisions respectively were false positive/false negative/correct in 2/4/15 respectively 0/8/13 cases. Correct diagnoses were obtained in 72% (MRI) respectively 62% (CT). In the subgroup of 12 cases including HRCT, MRI respectively CT were false positive/false negative/correct in 2/1/9 respectively 0/5/7 cases. Correct diagnoses were obtained in 75% (MRI) respectively 58% (CT). Conclusion: Highfield MRI of the lung is feasible and performed slightly better compared to CT in the

  11. Influence of heavy truck dynamic parameters on ride comfort using 3D dynamic model%基于三维动力学模型的重型卡车动态参数对平顺性的影响

    Institute of Scientific and Technical Information of China (English)

    Le Van Quynh; 张建润; 王园; 孙小娟; Nguyen Van Liem

    2013-01-01

    In order to study the influence of heavy vehicle dynamic parameters on ride comfort with random road excitation,a 3D dynamic model with 13-DOF(degree of freedom) is established for simulation,and the weighted r.m.s acceleration responses of the vertical driver's seat,pitch and roll angle of the cab are chosen as objective functions which uses Matlab/Simulink software to simulate and calculate the objective functions.The influence of the different vehicle dynamics system parameters on the vertical vibration of driver's seat,pitch and roll of the cab which include the stiffness and damping of vehicle suspension,tires,cab suspension and the driver's seat suspension are analyzed in this paper.The results show that the influence of the stiffness and damping parameters in the suspension systems on the vehicle ride comfort is very obvious.The vehicle ride comfort is going to be worse with the increase of the stiffness of the suspension systems and tires.And the vehicle ride comfort is improved with the increase of the damping of the suspension systems.This study can provide a theoretical basis for the suspension system design of heavy trucks.%为了研究重型卡车动态参数对驾驶员舒适性的影响,以路面随机不平度为激扰,以驾驶室座椅垂向、驾驶室的俯仰角和侧倾角的加权加速度均方根值为目标函数,建立了13自由度的三维动力学模型.采用Matlab/Simulink软件对整车模型进行仿真计算,分析了不同系统参数,如悬架、轮胎、驾驶室悬架和驾驶员座椅悬架的参数对驾驶员座椅垂向振动、驾驶室前后和左右晃动的影响.研究结果表明:悬架系统中刚度和阻尼参数的最佳匹配对车辆平顺性的影响非常明显;随着悬架系统和轮胎刚度的增加,车辆平顺性从优向劣转变,而随着悬架系统阻尼的增加,车辆平顺性呈现从劣转优现象.该研究为重型卡车悬架系统设计提供相应的理论依据.

  12. In Vivo Correlation of Glucose Metabolism, Cell Density and Microcirculatory Parameters in Patients with Head and Neck Cancer: Initial Results Using Simultaneous PET/MRI.

    Directory of Open Access Journals (Sweden)

    Matthias Gawlitza

    Full Text Available To demonstrate the feasibility of simultaneous acquisition of 18F-FDG-PET, diffusion-weighted imaging (DWI and T1-weighted dynamic contrast-enhanced MRI (T1w-DCE in an integrated simultaneous PET/MRI in patients with head and neck squamous cell cancer (HNSCC and to investigate possible correlations between these parameters.17 patients that had given informed consent (15 male, 2 female with biopsy-proven HNSCC underwent simultaneous 18F-FDG-PET/MRI including DWI and T1w-DCE. SUVmax, SUVmean, ADCmean, ADCmin and Ktrans, kep and ve were measured for each tumour and correlated using Spearman's ρ.Significant correlations were observed between SUVmean and Ktrans (ρ = 0.43; p ≤ 0.05; SUVmean and kep (ρ = 0.44; p ≤ 0.05; Ktrans and kep (ρ = 0.53; p ≤ 0.05; and between kep and ve (ρ = -0.74; p ≤ 0.01. There was a trend towards statistical significance when correlating SUVmax and ADCmin (ρ = -0.35; p = 0.08; SUVmax and Ktrans (ρ = 0.37; p = 0.07; SUVmax and kep (ρ = 0.39; p = 0.06; and ADCmean and ve (ρ = 0.4; p = 0.06.Simultaneous 18F-FDG-PET/MRI including DWI and T1w-DCE in patients with HNSCC is feasible and allows depiction of complex interactions between glucose metabolism, microcirculatory parameters and cellular density.

  13. Utility of Postmortem Autopsy via Whole-Body Imaging: Initial Observations Comparing MDCT and 3.0T MRI Findings with Autopsy Findings

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Jang Gyu; Kim, Dong Hun; Paik, Sang Hyun [National Institute of Scientific Investigation, Seoul (Korea, Republic of)

    2010-08-15

    We prospectively compared whole-body multidetector computed tomography (MDCT) and 3.0T magnetic resonance (MR) images with autopsy findings. Five cadavers were subjected to whole-body, 16- channel MDCT and 3.0T MR imaging within two hours before an autopsy. A radiologist classified the MDCT and 3.0T MRI findings into major and minor findings, which were compared with autopsy findings. Most of the imaging findings, pertaining to head and neck, heart and vascular, chest, abdomen, spine, and musculoskeletal lesions, corresponded to autopsy findings. The causes of death that were determined on the bases of MDCT and 3.0T MRI findings were consistent with the autopsy findings in four of five cases. CT was useful in diagnosing fatal hemorrhage and pneumothorax, as well as determining the shapes and characteristics of the fractures and the direction of external force. MRI was effective in evaluating and tracing the route of a metallic object, soft tissue lesions, chronicity of hemorrhage, and bone bruises. A postmortem MDCT combined with MRI is a potentially powerful tool, providing noninvasive and objective measurements for forensic investigations

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

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

  16. Multi-modal MRI analysis with disease-specific spatial filtering: initial testing to predict mild cognitive impairment patients who convert to Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Kenichi eOishi

    2011-08-01

    Full Text Available Background: Alterations of the gray and white matter have been identified in Alzheimer’s disease (AD by structural MRI and diffusion tensor imaging (DTI. However, whether the combination of these modalities could increase the diagnostic performance is unknown.Methods: Participants included 19 AD patients, 22 amnestic mild cognitive impairment (aMCI patients, and 22 cognitively normal elderly (NC. The aMCI group was further divided into an aMCI-converter group (converted to AD dementia within three years, and an aMCI-stable group who did not convert in this time period. A T1-weighted image, a T2 map, and a DTI of each participant were normalized, and voxel-based comparisons between AD and NC groups were performed. Regions-of-interest, which defined the areas with significant differences between AD and NC, were created for each modality and named disease-specific spatial filters (DSF. Linear discriminant analysis was used to optimize the combination of multiple MRI measurements extracted by DSF to effectively differentiate AD from NC. The resultant DSF and the discriminant function were applied to the aMCI group to investigate the power to differentiate the aMCI-converters from the aMCI-stable patients. Results: The multi-modal approach with AD-specific filters led to a predictive model with an area under the receiver operating characteristic curve (AUC of 0.93, in differentiating aMCI-converters from aMCI-stable patients. This AUC was better than that of a single-contrast-based approach, such as T1-based morphometry or diffusion anisotropy analysis. Conclusion: The multi-modal approach has the potential to increase the value of MRI in predicting conversion from aMCI to AD.

  17. Pediatric MRI

    Data.gov (United States)

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

  18. The use of high-pressure injector and its nursing care during 3 D dynamic enhanced MR portography%三维动态增强磁共振门静脉造影中高压注射器的使用及护理配合

    Institute of Scientific and Technical Information of China (English)

    刘翠莲

    2010-01-01

    @@ 本文拟通过对120例使用专用的防磁双筒高压注射器行三维动态增强磁共振门静脉造影(3 D dynamic congtrast-enhanced MR portography,3 D DCE-MRP)患者的结果分析,探讨磁共振高压注射器在门静脉造影血管成像中的应用及护理配合,并对其使用过程中的要点和护理进行讨论.

  19. Portable MRI

    Energy Technology Data Exchange (ETDEWEB)

    Espy, Michelle A. [Los Alamos National Laboratory

    2012-06-29

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

  20. MRI Artifacts

    Directory of Open Access Journals (Sweden)

    Abed Al Nasser Assi

    2009-12-01

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

  1. Diffusion tensor imaging of normal-appearing temporal white matter on conventional MRI in patients with nasopharyngeal carcinoma after irradiation therapy: initial experience

    International Nuclear Information System (INIS)

    Objective: To detect radiation-induced changes of temporal lobe normal-appearing white matter on conventional MRI following radiation therapy (RT) for nasopharyngeal carcinoma (NPC). Methods: The clinical and imaging features of 75 patients with nasopharyngeal carcinoma were retrospectively analyzed, all patients were confirmed by biopsy. All patients performed conventional MRI and Diffusion-tensor imaging (DTI) examinations, and there was no abnormal finding on conventional MRI. Eighteen patients without radiotherapy were selected as the control group and fifty-seven patients with radiotherapy were as the experimental group. We divided the experimental group into five subgroups based on completion time of RT: group 1 (less than 3 months, n=16), group 2 (3 to 6 months, n=12), group 3 (6 to 9 months; n=10), group 4 (9 to 12 months, n=8), and group 5 (more than 12 months, n=11). The mean diffusivity (MD), apparent diffusion coefficient (ADC), fractional anisotropy (FA), radial diffusivity (λ⊥) and axial diffusivity (k ‖) were calculated in bilateral temporal lobe.One-way analysis of variance (one-way ANOVA) test was used for comparison among groups. Results: The mean λ⊥ values of the control group and experimental groups (group 1-5) after radiotherapy were (6.075 ± 0.341) × 10-4 (6.700±0.379) × 10-4,(6.976 ±0.527) ×10-4,(6.621 ±0.388) ×10-4,(6.751 ±0.460) ×10-4,(6.222 ±0.256) × 10-4 mm2/s, respectively. The mean λ ‖ values of the control group and experimental groups were (12.524±0.713) ×10-4, (11.764 ±0.574) ×l0-4, (11.842±0.471) ×10-4, (11.569 ± 0.552) × 10-4, (12.050 ±0.614) × 10-4, (12.100 ±0.529) × 10-4 mm2/s, respectively. The mean FA values of the control group and experimental groups were 0.452 ± 0.030, 0.379 ± 0.028, 0.382 ± 0.028, 0.389 ± 0.032, 0.388 ± 0.022, 0.423 ± 0.232, respectively. The three indicators were significantly different among groups (F=10.485, 4.625, 16.539, respectively, P<0.05). Multiple

  2. MRI of congenital urethroperineal fistula

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-15

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

  3. MRI Safety during Pregnancy

    Science.gov (United States)

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

  4. Fetal MRI

    Energy Technology Data Exchange (ETDEWEB)

    Prayer, D.; Brugger, P.C. [University Hospital of Vienna (Austria). Division of Neuroradiology

    2004-07-01

    New, ultrafast sequences have made it possible to obtain MR images of the fetus without maternal sedation or immobilization of the fetus itself. While fetal MRI began as an adjunct to ultrasound, it has now been shown that MRI can provide additional information that may change prognosis, the management of pregnancy, or the treatment of the newborn child. It is of particular value in the assessment of malformations of the central nervous system. The steady development and adaptation of MR-sequences to the needs of fetal imaging has led to new indications that can support prognostic and therapeutic decisions. (orig.)

  5. MRI zoo

    DEFF Research Database (Denmark)

    Laustsen, Christoffer

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

  6. Fetal MRI; Fetales MRT

    Energy Technology Data Exchange (ETDEWEB)

    Blondin, D. [Inst. fuer Diagn. Radiologie, Uniklinikum Duesseldorf (Germany); Turowski, B. [Inst. fuer Diagn. Radiologie, Neuroradiologie, Uniklinikum Duesseldorf (Germany); Schaper, J. [Inst. fuer Diagn. Radiologie, Kinderradiologie, Uniklinikum Duesseldorf (Germany)

    2007-02-15

    Ultrasonography is the method of choice for prenatal malformation screening, but it does not always provide sufficient information for correct diagnosis or adequate abnormality evaluation. Fetal MRI is increasingly being used to complete sonographic findings. It was initially used for evaluation of cerebral abnormalities but is increasingly being applied to other fetal areas. In vivo investigation of fetal brain maturation has been enhanced by MRI. An adequate analysis of fetal chest and abdomen can be achieved with fast T2-, T1-weighted and diffusion-weighted imaging (DWI). The advantages include the great field of view and the excellent soft tissue contrast. This allows correct diagnosis of congenital diaphragmatic hernia and evaluation of the consequences on pulmonary growth. Other pulmonary malformations, such as cystic adenomatoid malformation, sequestration and brochogenic cysts, can also be easily identified. Renal position can be quickly determined using DWI sequences and renal agenesia can be easily diagnosed with only one sequence. Prenatal MRI is virtually as effective as postnatal examination, dispenses with transport of a potentially very ill newborn, and provides logistic advantages. Therefore, prenatal MRI is useful for adequate postnatal treatment of newborns with malformations. (orig.)

  7. Analysis on Wearable Lower Extremity Exoskeleton Gait Based on 3 D Dynamic Capture System and Matlab%基于三维动态捕捉系统和Matlab的穿戴式下肢外骨骼步态分析

    Institute of Scientific and Technical Information of China (English)

    孟庆鑫; 李志瑶

    2013-01-01

    This paper obtains the trajectory and 3D datum of human lower limb key points by 3D dynamic capture system, uses Matlab software to analyze the datum, draws the time-coordinate graphics and establishes a 3D model of wearable lower limb exoskeleton, which lays a foundation for further study on wearable lower limb exoskeleton.%使用三维动态捕捉系统获取人体下肢关键点的运动轨迹和三维数据,用Matlab软件分析数据,绘制时间-坐标图形,建立穿戴式下肢外骨骼的三维模型,为进一步研究穿戴式下肢外骨骼奠定基础。

  8. Battlefield MRI

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-01

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

  9. Situs anomalies on prenatal MRI

    International Nuclear Information System (INIS)

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

  10. Breast MRI used as a problem-solving tool reliably excludes malignancy

    Energy Technology Data Exchange (ETDEWEB)

    Spick, Claudio, E-mail: claudio.spick@meduniwien.ac.at [Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna (AKH), Waehringer-Guertel 18-20, 1090 Vienna (Austria); Szolar, Dieter H.M.; Preidler, Klaus W.; Tillich, Manfred; Reittner, Pia [Diagnostikum Graz-Südwest, Weblinger Guertel 25, 8054 Graz (Austria); Baltzer, Pascal A., E-mail: pascal.baltzer@meduniwien.ac.at [Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna (AKH), Waehringer-Guertel 18-20, 1090 Vienna (Austria)

    2015-01-15

    Highlights: • Breast MRI reliably excludes malignancy in conventional BI-RADS 0 cases (NPV: 100%). • Malignancy rate in the BI-RADS 0 population is substantial with 13.5%. • Breast MRI used as a problem-solving tool reliably excludes malignancy. - Abstract: Purpose: To evaluate the diagnostic performance of breast MRI if used as a problem-solving tool in BI-RADS 0 cases. Material and methods: In this IRB-approved, single-center study, 687 women underwent high-resolution-3D, dynamic contrast-enhanced breast magnetic resonance imaging (MRI) between January 2012 and December 2012. Of these, we analyzed 111 consecutive patients (mean age, 51 ± 12 years; range, 20–83 years) categorized as BI-RADS 0. Breast MRI findings were stratified by clinical presentations, conventional imaging findings, and breast density. MRI results were compared to the reference standard, defined as histopathology or an imaging follow-up of at least 1 year. Results: One hundred eleven patients with BI-RADS 0 conventional imaging findings revealed 30 (27%) mammographic masses, 57 (51.4%) mammographic architectural distortions, five (4.5%) mammographic microcalcifications, 17 (15.3%) ultrasound-only findings, and two palpable findings without imaging correlates. There were 15 true-positive, 85 true-negative, 11 false-positive, and zero false-negative breast MRI findings, resulting in a sensitivity, specificity, PPV, and NPV of 100% (15/15), 88.5% (85/96), 57.7% (15/26), and 100% (85/85), respectively. Breast density and reasons for referral had no significant influence on the diagnostic performance of breast MRI (p > 0.05). Conclusion: Breast MRI reliably excludes malignancy in conventional BI-RADS 0 cases resulting in a NPV of 100% (85/85) and a PPV of 57.7% (15/26)

  11. What Is Chest MRI?

    Science.gov (United States)

    ... from the NHLBI on Twitter. What Is Chest MRI? Chest MRI (magnetic resonance imaging) is a safe, noninvasive test. "Noninvasive" means that ... your chest wall, heart, and blood vessels. Chest MRI uses radio waves, magnets, and a computer to ...

  12. Breast MRI scan

    Science.gov (United States)

    MRI - breast; Magnetic resonance imaging - breast; Breast cancer - MRI; Breast cancer screening - MRI ... your stomach on a narrow table with your breasts hanging down into cushioned openings. The table slides ...

  13. MRI (Magnetic Resonance Imaging)

    Science.gov (United States)

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

  14. Hepatocellular carcinoma: perfusion quantification with dynamic contrast-enhanced MRI

    NARCIS (Netherlands)

    Taouli, B.; Johnson, R.S.; Hajdu, C.H.; Oei, M.T.H.; Merad, M.; Yee, H.; Rusinek, H.

    2013-01-01

    The objective of our study was to report our initial experience with dynamic contrast-enhanced MRI (DCE-MRI) for perfusion quantification of hepatocellular carcinoma (HCC) and surrounding liver.DCE-MRI of the liver was prospectively performed on 31 patients with HCC (male-female ratio, 26:5; mean ag

  15. MRI assessment of local acute radiation syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Weber-Donat, G.; Potet, J.; Baccialone, J.; Teriitehau, C. [Military Hospital Percy, Radiology Department, Clamart (France); Amabile, J.C.; Laroche, P. [Military Hospital Percy, Army Institute of Radioprotection, Clamart (France); Lahutte-Auboin, M. [Military Hospital Val-de-Grace, Radiology Department, Paris (France); Bey, E. [Military Hospital Percy, Plastic and Reconstructive Surgery Department, Clamart (France)

    2012-12-15

    To describe local acute radiation syndrome and its radiological imaging characteristics. We performed a retrospective study of patients who had suffered skin and deeper radiation damage who were investigated by magnetic resonance imaging (MRI). We compared the clinical findings, C-reactive protein (CRP) levels and MRI results. A total of 22 MRI examinations were performed between 2005 and 2010 in 7 patients; 6 patients had increased CRP levels and MRI abnormalities. They were treated by surgery and local cellular therapy. One patient had no CRP or MRI abnormalities, and had a spontaneous good outcome. Eighteen abnormal MR examinations demonstrated high STIR signal and/or abnormal enhancement in the dermis and muscle tissues. Three MRI examinations demonstrated skeletal abnormalities, consistent with radionecrosis. The four normal MRI examinations were associated only with minor clinical manifestations such as pain and pigmentation disorders. MRI seems to be a useful and promising imaging investigation in radiation burns management i.e. initial lesion evaluation, treatment evaluation and complication diagnosis. MRI findings correlated perfectly with clinical stage and no false negative examinations were obtained. In particular, the association between normal MRI and low CRP level seems to be related to good outcome without specific treatment. (orig.)

  16. Lagrangian structures, integrability and chaos for 3D dynamical equations

    International Nuclear Information System (INIS)

    In this paper, we consider the general setting for constructing action principles for three-dimensional first-order autonomous equations. We present the results for some integrable and non-integrable cases of the Lotka-Volterra equation, and show Lagrangian descriptions which are valid for systems satisfying Shil'nikov criteria on the existence of strange attractors, though chaotic behaviour has not been verified up to now. The Euler-Lagrange equations we get for these systems usually present 'time reparametrization' invariance, though other kinds of invariance may be found according to the kernel of the associated symplectic 2-form. The formulation of a Hamiltonian structure (Poisson brackets and Hamiltonians) for these systems from the Lagrangian viewpoint leads to a method of finding new constants of the motion starting from known ones, which is applied to some systems found in the literature known to possess a constant of the motion, to find the other and thus showing their integrability. In particular, we show that the so-called ABC system is completely integrable if it possesses one constant of the motion

  17. Lagrangian structures, integrability and chaos for 3D dynamical equations

    CERN Document Server

    Bustamante, M D; Bustamante, Miguel D.; Hojman, Sergio A.

    2003-01-01

    In this paper we consider the general setting for constructing Action Principles for three-dimensional first order autonomous equations. We present the results for some integrable and non-integrable cases of the Lotka-Volterra equation, and we show Lagrangian descriptions which are valid for systems satisfying Shil'nikov criteria on the existence of strange attractors, though chaotic behavior or homoclinic orbits have not been verified up to now. The Euler-Lagrange equations we get for these systems usually present "time reparameterization" symmetry, though other kinds of invariance may be found according to the kernel of the associated symplectic 2-form. The formulation of a Hamiltonian structure (Poisson brackets and Hamiltonians) for these systems from the Lagrangian viewpoint leads to a method of finding new constants of the motion starting from known ones, which is applied to some systems found in the literature known to possess a constant of the motion, to find the other and thus showing their integrabi...

  18. Magnetic Resonance Imaging (MRI)

    Science.gov (United States)

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

  19. Competitive advantage of PET/MRI.

    Science.gov (United States)

    Jadvar, Hossein; Colletti, Patrick M

    2014-01-01

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

  20. MRI of car occupants with whiplash injury

    International Nuclear Information System (INIS)

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

  1. Initial clinical results of simultaneous {sup 18}F-FDG PET/MRI in comparison to {sup 18}F-FDG PET/CT in patients with head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kubiessa, K.; Gawlitza, M.; Kuehn, A.; Fuchs, J.; Kahn, T.; Stumpp, P. [University Hospital of Leipzig, Department of Diagnostic and Interventional Radiology, Leipzig (Germany); Purz, S.; Steinhoff, K.G.; Sabri, O.; Kluge, R. [University Hospital of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Boehm, A. [University Hospital of Leipzig, ENT Department, Leipzig (Germany)

    2014-04-15

    The aim of this study was to evaluate the diagnostic capability of simultaneous {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/MRI compared to {sup 18}F-FDG PET/CT as well as their single components in head and neck cancer patients. In a prospective study 17 patients underwent {sup 18}F-FDG PET/CT for staging or follow-up and an additional {sup 18}F-FDG PET/MRI scan with whole-body imaging and dedicated examination of the neck. MRI, CT and PET images as well as PET/MRI and PET/CT examinations were evaluated independently and in a blinded fashion by two reader groups. Results were compared with the reference standard (final diagnosis determined in consensus using all available data including histology and follow-up). Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated. A total of 23 malignant tumours were found with the reference standard. PET/CT showed a sensitivity of 82.7 %, a specificity of 87.3 %, a PPV of 73.2 % and a NPV of 92.4 %. Corresponding values for PET/MRI were 80.5, 88.2, 75.6 and 92.5 %. No statistically significant difference in diagnostic capability could be found between PET/CT and PET/MRI. Evaluation of the PET part from PET/CT revealed highest sensitivity of 95.7 %, and MRI showed best specificity of 96.4 %. There was a high inter-rater agreement in all modalities (Cohen's kappa 0.61-0.82). PET/MRI of patients with head and neck cancer yielded good diagnostic capability, similar to PET/CT. Further studies on larger cohorts to prove these first results seem justified. (orig.)

  2. Validation of Continuously Tagged MRI for the Measurement of Dynamic 3D Skeletal Muscle Tissue Deformation

    CERN Document Server

    Moerman, Kevin M; Simms, Ciaran K; Lamerichs, Rolf M; Stoker, Jaap; Nederveen, Aart J

    2016-01-01

    A SPAMM tagged MRI methodology is presented allowing continuous (3.3-3.6 Hz) sampling of 3D dynamic soft tissue deformation using non-segmented 3D acquisitions. The 3D deformation is reconstructed by the combination of 3 mutually orthogonal tagging directions, thus requiring only 3 repeated motion cycles. In addition a fully automatic post-processing framework is presented employing Gabor scale-space and filter-bank analysis for tag extrema segmentation and triangulated surface fitting aided by Gabor filter bank derived surface normals. Deformation is derived following tracking of tag surface triplet triangle intersections. The dynamic deformation measurements were validated using indentation tests (~20 mm deep at 12 mm/s) on a silicone gel soft tissue phantom containing contrasting markers which provide a reference measure of deformation. In addition, the techniques were evaluated in-vivo for dynamic skeletal muscle tissue deformation measurement during indentation of the biceps region of the upper arm in a ...

  3. Improved visualization of delayed perfusion in lung MRI

    Energy Technology Data Exchange (ETDEWEB)

    Risse, Frank [Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg (Germany); Eichinger, Monika [Department of Radiology, German Cancer Research Center, Heidelberg (Germany); Kauczor, Hans-Ulrich [Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg (Germany); Semmler, Wolfhard [Department of Medical Physics in Radiology, German Cancer Research Center, Heidelberg (Germany); Puderbach, Michael, E-mail: m.puderbach@dkfz.de [Department of Radiology, German Cancer Research Center, Heidelberg (Germany)

    2011-01-15

    Introduction: The investigation of pulmonary perfusion by three-dimensional (3D) dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was proposed recently. Subtraction images are generated for clinical evaluation, but temporal information is lost and perfusion defects might therefore be masked in this process. The aim of this study is to demonstrate a simple analysis strategy and classification for 3D-DCE-MRI perfusion datasets in the lung without omitting the temporal information. Materials and methods: Pulmonary perfusion measurements were performed in patients with different lung diseases using a 1.5 T MR-scanner with a time-resolved 3D-GRE pulse sequence. 25 3D-volumes were acquired after iv-injection of 0.1 mmol/kg KG Gadolinium-DTPA. Three parameters were determined for each pixel: (1) peak enhancement S{sub n,max} normalized to the arterial input function to detect regions of reduced perfusion; (2) time between arterial peak enhancement in the large pulmonary artery and tissue peak enhancement {tau} to visualize regions with delayed bolus onset; and (3) ratio R = S{sub n,max}/{tau} was calculated to visualize impaired perfusion, irrespectively of whether related to reduced or delayed perfusion. Results: A manual selection of peak perfusion images is not required. Five different types of perfusion can be found: (1) normal perfusion; (2) delayed non-reduced perfusion; (3) reduced non-delayed perfusion; (4) reduced and delayed perfusion; and (5) no perfusion. Types II and IV could not be seen in subtraction images since the temporal information is necessary for this purpose. Conclusions: The analysis strategy in this study allows for a simple and observer-independent visualization and classification of impaired perfusion in dynamic contrast-enhanced pulmonary perfusion MRI by using the temporal information of the datasets.

  4. Magnetic Resonance Imaging (MRI) Safety

    Science.gov (United States)

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

  5. Abdominal MRI scan

    Science.gov (United States)

    Nuclear magnetic resonance - abdomen; NMR - abdomen; Magnetic resonance imaging - abdomen; MRI of the abdomen ... spread. This is called staging. MRI avoids the dangers of angiography , such as too much radiation exposure ...

  6. MRI of the Chest

    Science.gov (United States)

    ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... over time. top of page What are the benefits vs. risks? Benefits MRI is a noninvasive imaging ...

  7. Interventional MRI: update

    Energy Technology Data Exchange (ETDEWEB)

    Lufkin, R.B. [Department of Radiology, University of California Los Angeles, School of Medicine, 10 833 Le Comte Avenue, Los Angeles, CA 90024-1721 (United States); Gronemeyer, D.H.W.; Seibel, R.M.M. [Institute of Diagnostic and Interventional Radiology, Medical Computerscience, University Witten/Herdecke (Germany)

    1997-12-31

    Interventional MRI is in its early stages of development. Nevertheless, the design of new interventional MRI scanners that allow maximum direct access to the patient combined with the development of new interventional MRI pulse sequences and localization systems, means that the archetypal operating rooms of the 21st century may well contain dedicated interventional MRI units for combined radiological and surgical procedures. The present article looks at the state of interventional MRI today and looks ahead to what may be forthcoming in the not-too-distant future. After briefly discussing the instrumentation necessary for practical interventional MRI, the article will go on to describe a number of different approaches to, and clinical applications for, interventional MRI. The use of MRI in guiding and controlling tumor ablation, aspiration cytology and surgical biopsy of different body parts is described. (orig.) With 13 figs., 1 tab., 114 refs.

  8. Neurosarcoidosis with unusual MRI findings

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-02-01

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

  9. MRI of radiographically occult ischial apophyseal avulsions

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-11-15

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

  10. Getting an MRI

    Medline Plus

    Full Text Available ... Skating Crushes What's a Booger? Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) Print A A A Text Size en español Obtención de una resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed ...

  11. Getting an MRI

    Science.gov (United States)

    ... Snowboarding, Skating Crushes What's a Booger? Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) Print A A A Text Size en ... Obtención de una resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed pictures of ...

  12. Getting an MRI

    Medline Plus

    Full Text Available ... Snowboarding, Skating Crushes What's a Booger? Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) Print A A A Text Size en ... Obtención de una resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed pictures of ...

  13. MRI in acute poliomyelitis

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-05-01

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

  14. fMRI Neuroinformatics

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  15. Leptomeningeal metastasis: a CT and MRI study

    Energy Technology Data Exchange (ETDEWEB)

    Oschmann, P. [Dept. of Neurology, Univ. of Giessen (Germany); Bauer, T. [Dept. of Radiology, Univ. of Giessen (Germany); Kaps, M. [Dept. of Neurology, Univ. of Giessen (Germany); Trittmacher, S. [Dept. of Radiology, Univ. of Giessen (Germany); Dorndorf, W. [Dept. of Neurology, Univ. of Giessen (Germany)

    1994-08-01

    We evaluated 35 patients with leptomeningeal metastasis (LM) that was proved by repeated positive cytology (33 patients) and/or autopsy (10 patients) with T1-weighted Gadolinium-DTPA-enhanced MRI and contrast-enhanced CT. The patients (20 women and 15 men) ranged in age from 5-77 years (mean 56 years). Tumour histology included 26 carcinomas, 1 sarcoma, 6 leucaemias, 1 medulloblastoma and 1 primary CNS lymphoma. Intracranial abnormalities were noted in 58% of cases by CT and 88% by MRI, and included hydrocephalus, meningeal or ependymal enhancement, subarachnoidal or intraparenchymal nodules. Leptomeningeal metastasis was detected by MRI in 13 of 17 examined patients, including the three cases with a positive CT. It was proved that MRI is equal or superior to CT in demonstrating meningeal or ependymal enhancement and quantifying enhanced subarachnoidal or parenchymal nodules. However, in the evaluation of leptomeningeal metastasis both modalities had a high incidence of false-negative studies, 89% (31 of 35) by CT and 24% (4 of 17) by MRI. In contrast, two patients with initially negative cytology had pathological MRI findings. Our data indicate that Gadolinium-enhanced MRI is the preferred imaging modality in leptomeningeal metastasis, and suggest that CT does not add significant additional information. However, LM is primarily a histological diagnosis by detecting tumour cells in the cerebrospinal fluid. (orig.)

  16. MRI diagnosis of multiple sclerosis

    International Nuclear Information System (INIS)

    Objective: It's a study of MRI diagnosis and differential diagnosis of multiple sclerosis (MS) in 49 cases. Methods: 49 patients were diagnosed as MS of brain or/and spinal cord in the year of 1995 to 2002. All cases had clinical informations, including evoked potential. MR brain scan was done in 49 patients, and spinal cord scan was performed in 10 cases out of 49. Enhanced scan were done in 29 cases. A follow-up examination was done in 17 patients within 30 days after the initial study. Results: Multiple brain lesions, located in peri-ventricular region, semi-elliptical center, cerebellum and brain stem, were revealed in 47 patients, MS plaques were speckle or patchy and the largest one was 2.2 x 5.0 cm. Simple spinal Cord lesions involving at least 2 sections were revealed in 2 patients. Two cases were initially misdiagnosed as encephalitis. Another case was defined as tumor because of the brainstem swelling and enhanced plaques. Optic nerve impairment was found in a case besides the brain lesions. Complicated brain and spinal Cord lesions were shown in 4 cases. Enhanced MRI scan was performed in 29 cases: non-enhanced lesions were revealed in 7 cases and lesions were enhanced in the rest 22. Mottling or plaque enhancement was presented in 20 cases, while ring enhancement was presented in 2. Follow-up study showed the improvement in 17 cases. Conclusion: Brain and spinal cord MS plaques can be demonstrated on MRI, while clinical manifestation is necessary for MRI diagnosis in atypical lesions. Serial study is helpful for differential diagnosis

  17. MRI in psychiatry

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

  18. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  19. MRI brain imaging.

    Science.gov (United States)

    Skinner, Sarah

    2013-11-01

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

  20. MRI assessment program

    International Nuclear Information System (INIS)

    Usage, cost and efficacy data from the MRI Assessment Program to 30 March 1988 is presented, as a continuation of an earlier analysis. Analysis has been performed on data from 8565 examinations relating to 7997 patients at 4 hospitals. MRI was used mainly for examination of the head and spine. Some details of the follow up studies being conducted on selected patients and disease categories are given. A consensus statement is included which summaries the view of the Technical Committee on the potential applications of MRI in Australia. The MRI unit quench incident at Royal Adelaide Hospital is described. Refs., 10 figs., tabs

  1. 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 ... medically necessary. MRI may not always distinguish between cancer tissue and fluid, known as edema . MRI typically ...

  2. The Management of Benign Concordant MRI-guided Brest Biopsies: Lessons Learned.

    Science.gov (United States)

    Lee, Su-Ju; Mahoney, Mary C; Redus, Zachary

    2015-01-01

    After benign concordant magnetic resonance imaging (MRI)-guided breast biopsy, initial follow-up MRI at 6 months is often recommended for confirmation. This study was undertaken to determine the proper management of stable lesions on initial follow-up MRI and whether such follow-up can be safely deferred to 12 months. Retrospective review of 240 MRI-guided biopsies identified 156 benign concordant lesions. 85 eligible cases received follow-up MRI and constitute the study population. On initial follow-up MRI, 72 of 85 lesions appeared adequately sampled, 12 were stable and underwent further MRI follow-up, and 1 was benign on subsequent surgery. No cancers were diagnosed at the biopsy sites on either 6- or 12-month follow-up MRI. Among the 12 stable lesions, four were masses and eight were nonmass enhancements. One of the stable masses enlarged on 24-month follow-up MRI and proved malignant. All stable nonmass lesions were benign on long-term follow-up. After benign concordant MRI-guided breast biopsy, a stable mass has a 25% probability of malignancy in our series. Re-biopsy of such masses should be strongly considered. Stable nonmass lesions may be followed with subsequent MRI without rebiopsy. Deferral of initial follow-up MRI to 12 months may be acceptable.

  3. MRI of Listeria rhombencephalitis

    International Nuclear Information System (INIS)

    A case of Listeria rhombencephalitis in a patient, who was evaluated by MRI, is reported. MRI shows areas of high signal intensity on T2-weighted images in the rhombencephalon and confirmed the clinical diagnosis of a brainstem affection by Listeria monocytogenes. (orig.)

  4. Getting an MRI

    Medline Plus

    Full Text Available ... School Butterflies? Read This Chloe & Nurb Meet The Brain (Movie) Quiz: Do You Need a Flu Shot? Got Homework? Here's Help White House Lunch Recipes Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) ...

  5. Getting an MRI

    Medline Plus

    Full Text Available ... Dictionary of Medical Words En Español What Other Kids Are Reading Movie: Digestive System Winter Sports: Sledding, ... a Booger? Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) Print A A A ...

  6. Play the MRI Game

    Science.gov (United States)

    ... Play MRI the Magnetic Miracle Game About the game In the MRI imaging technique, strong magnets and radio waves are used for getting images of inner organs made of soft tissue, compared to X-ray imaging where you get images of hard tissue, ...

  7. MRI of atherosclerose

    NARCIS (Netherlands)

    te Boekhorst, B.C.M.

    2010-01-01

    This thesis is aimed at visualization of atherosclerotic plaques with MRI. Noninvasive screening for subclinical atherosclerosis as well as detection of high-risk atherosclerotic plaque in an established population of cardiovascular patients is important for patient management. Anatomical MRI utiliz

  8. High Dimensional Classification of Structural MRI Alzheimer’s Disease Data Based on Large Scale Regularization

    OpenAIRE

    Ramon Casanova; Whitlow, Christopher T.; Williamson, Jeff D.; Shumaker, Sally A.

    2011-01-01

    In this work we use a large scale regularization approach based on penalized logistic regression to automatically classify structural MRI images (sMRI) according to cognitive status. Its performance is illustrated using sMRI data from the Alzheimer Disease Neuroimaging Initiative (ADNI) clinical database. We downloaded sMRI data from 98 subjects (49 cognitive normal and 49 patients) matched by age and sex from the ADNI website. Images were segmented and normalized using SPM8 and ANTS software...

  9. New method for 3D parametric visualization of contrast-enhanced pulmonary perfusion MRI data

    Energy Technology Data Exchange (ETDEWEB)

    Kuder, Tristan A.; Eichinger, Monika; Ley, Sebastian; Puderbach, Michael; Kauczor, Hans-Ulrich [Deutsches Krebsforschungszentrum, Department of Radiology, E010, Heidelberg (Germany); Risse, Frank [Deutsches Krebsforschungszentrum, Department of Medical Physics in Radiology, Heidelberg (Germany); Fink, Christian [Deutsches Krebsforschungszentrum, Department of Radiology, E010, Heidelberg (Germany); Medical Faculty Mannheim - University of Heidelberg, Department of Clinical Radiology, University Hospital Mannheim, Mannheim (Germany)

    2008-02-15

    Three-dimensional (3D) dynamic contrast-enhanced magnetic resonance imaging (3D DCE-MRI) has been proposed for the assessment of regional perfusion. The aim of this work was the implementation of an algorithm for a 3D parametric visualization of lung perfusion using different cutting planes and volume rendering. Our implementation was based on 3D DCE-MRI data of the lungs of five patients and five healthy volunteers. Using the indicator dilution theory, the regional perfusion parameters, tissue blood flow, blood volume and mean transit time were calculated. Due to the required temporal resolution, the volume elements of dynamic MR data sets show a reduced spatial resolution in the z-direction. Therefore, perfusion parameter volumes were interpolated. Linear interpolation and a combination of linear and nearest-neighbor interpolation were evaluated. Additionally, ray tracing was applied for 3D visualization. The linear interpolation algorithm caused interpolation errors at the lung borders. Using the combined interpolation, visualization of perfusion information in arbitrary cutting planes and in 3D using volume rendering was possible. This facilitated the localization of perfusion deficits compared with the coronal orientated source data. The 3D visualization of perfusion parameters using a combined interpolation algorithm is feasible. Further studies are required to evaluate the additional benefit from the 3D visualization. (orig.)

  10. Fetal Brain MRI

    Directory of Open Access Journals (Sweden)

    Ahmad Tahmasebpour

    2010-05-01

    Full Text Available MRI is a useful supplement to ultrasonography for the assessment of fetal brain malformations. Superior soft tissue contrast and the ability to depict sulcation and myelination are the strengths of MRI. Subtle or inconclusive ultrasonography abnormalities can be confirmed or ruled out by MRI. In some cases, additional findings detected with MRI often help in arriving at a definitive diagnosis, which is necessary for parental counseling and for guiding management. Fast T2W sequences form the basis of fetal MRI. There have been no reports of deleterious effects of MRI on the fetus. A few case examples are presented to illustrate the advantages of MRI. "nThe database comprises MR images of a total of 26 fetuses (gestational age 22-23 weeks reformed be-cause of suspected abnormalities due to ultrasonic findings, family history or maternal illness and scanned on a 1.5T MR system using single-shot fast spin echo "SSFSE, HASTE" T2 sequence, slice thick-ness 3mm, no gap. "HASTE=fourier acquisition single shotturbospinecho". In the normal fetus the ventricular size or volume did not vary with the gestational age but cerebral and cerebellar volumes increase during the same period "Grossman et al." Diagnostic accuracy is about 48%. "OB/GYN news, Chicago". Today it is not necessary to use sedatives or muscle relaxants to control fetal movement "ultra-fast MRI techniques". Modified technique for 50% reduction in the time necessary to take MRI images of the fetal brain is dedicated by Kianosh Hosseinzadeh, by using a line of reference through the eyes "AJR 2005"."nOur fetuses are 22-23 weeks in gestational age, 26 in number and we found agenesis of corpus callosum, hydrocephaly, holoprosencephaly, mega-cisterna magna, occipital meningocele, Arnold Chiari malformation type 1, Dandy Walker syndrome and lissencephaly

  11. Explaining MRI examinations DVD

    International Nuclear Information System (INIS)

    When conducting MRI examinations, there are various things to be careful of. There is often stress related to the MRI examinations, so in order to perform an examination safely and smoothly, sufficient explanation must be given. An explanation of what to do and what not to do during an examination should be outlined in a brochure given to patients before the examination. There may be many patients who have misgivings about their MRI examinations, so to reduce their anxiousness and deepen their understanding of MRI examinations and to improve the safety and effiency of MRI examinations,; we created a DVD about MRI examinations. We gathered MRI-related safety information and instructions, and assessed the effect that the information might have on patients. We started a workgroup for a project to plan and record a video according to the Storyboard. When editing, we reviewed the length of each segment, the amount of information on screen, and the overall length of the DVD. We discussed the issue within the workgroup and had hospital approval. It was possible for us to complete it without depending on the supplier and the cost was kept to a minimum. Finally, we decided on a viewing location. We asked a hospital volunteers to see a complete DVD and we evaluated their responses by questionnaires. As the result, their understanding and anxieties related to MRI examinations were alleviated, as expected. Their anxiety seemed to be eased. Patients also seemed to have a deeper understanding of MRI examinations having seen an examination being conducted. (author)

  12. MRI in perianal fistulae

    International Nuclear Information System (INIS)

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

  13. MRI of brachial plexopathies

    Energy Technology Data Exchange (ETDEWEB)

    Sureka, J. [Department of Radiology, Christian Medical College, Vellore (India)], E-mail: drjyoticmch@rediffmail.com; Cherian, R.A.; Alexander, M.; Thomas, B.P. [Department of Radiology, Christian Medical College, Vellore (India)

    2009-02-15

    Magnetic resonance imaging (MRI) has become the primary imaging technique in the evaluation of brachial plexus pathology, and plays an important role in the identification, localization, and characterization of the cause. Improvements in MRI technique have helped in detecting changes in the signal intensity of nerves, subtle enhancement, and in detecting perineural pathology, thereby refining the differential diagnosis. The present review of the visualization of brachial plexus abnormalities using MRI is based on a review of 26 cases. The causes include trauma and a spectrum of non-traumatic causes, such as acute idiopathic/viral plexitis, metastases, immune-mediated plexitis, and mass lesions compressing the brachial plexus.

  14. MRI in perianal fistulae

    Directory of Open Access Journals (Sweden)

    Khera Pushpinder

    2010-01-01

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

  15. Brain MRI in Parkinson's disease

    NARCIS (Netherlands)

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

    2014-01-01

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

  16. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  17. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  18. Quality assurance in functional MRI

    DEFF Research Database (Denmark)

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

    2015-01-01

    Over the past 20 years, functional magnetic resonance imaging (fMRI) has ben- efited greatly from improvements in MRI hardware and software. At the same time, fMRI researchers have pushed the technical limits of MRI systems and greatly in- fluenced the development of state-of-the-art systems. Min...

  19. MRI of myelitis

    OpenAIRE

    Hodel, J.; Outteryck, O; Jissendi, P; Zins, M.; Leclerc, X; Pruvo, J P

    2012-01-01

    The diagnosis of myelitis relies on MRI. The purpose of this review is to describe the imaging findings in patients with myelitis through clinical cases. MR findings in Multiple Sclerosis, Neuromyelitis Optica and others Transverse Myelitis are highlighted.

  20. MRI of the shoulder

    International Nuclear Information System (INIS)

    Magnetic resonance imaging has become available at a time in which shoulder pathology is more frequently seen. It is a noninvasive procedure that does not use ionizing radiation. It provides detailed visualization of soft-tissue structures that is not possible with other imaging modalities. Though not as widely available as conventional radiographs or computed tomography scanning, the number of MRI units worldwide is increasing steadily. The main features of the present book are as follows: The physical basis of Magnetic Resonance Imaging (MRI), normal shoulder anatomy and MRI, diagnosis of shoulder disorders, MRI of patients with shoulder pain or instability, case studies as well as treatment of shoulder disorders. (orig./MG) With 145 figs

  1. MRI of intracranial calcifications

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jin Wha; Chang, Kee Hyun; Park, Jung Mi; Han, Moon Hee; Han, Man Chung; Kim, Chu Wan [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1988-12-15

    Recently computed tomography(CT) has been rapidly replaced by magnetic resonance imaging (MRI) in diagnosis of majority of intracranial diseases. But MRI still has some limitation, one of which is its inferiority in detecting calcification. MRI of intracranial calcification has been known to be variable in signal intensity. We retrospectively analyzed the MRI of 26 patients with intracranial calcified lesions in order to evaluate the MR intensity of calcification and to assess the capability of MRI in detecting calcification in various intracranial lesions. All the MRI were obtained using routine T1-and T2-weighted spin eco pulse sequences on 2.0T superconducting system. The 26 patients consisted of 13 brain tumors (4 oligodendrogliomas, 2 craniopharyngiomas, 2 astrocytomas, 1 gem cell tumor, 1 medulloblastoma, 1 ependympma, and pathologically unconfirmed 2 cases), 11 infectious diseases (1 paragonimiasis, 1 sparganosis, 2 cysticercosis, 3 tuberculosis, and 4 unknown cases), and 2 undetermined pathologies. Eighty-two percent (9/11) of infections disease, and 50% (1/2) of undetermined group showed signal diminution or signal void on both T1-and T2-weighted image (T1W1, T2W1). Twenty-four percent (3/13) of brain tumors showed signal diminution on both T1W1 and T2W1. In 46% (6/13) and 61% (8/13) of brain tumors the signal intensities were isointense on T1W1 and T1W1, respectively. Unexpectedly, 3 oligodendrogliomas showed high signal intensity on T1W1, two of which showed com plexed signal intensity mixed with high, iso, and low signal intensities on T2W1. In remained cases (18% (2/11) of infectious diseases and 50% (1/2) of undetermined group) the signal intensities were mixed. With simultaneous review of CT and MRI in each case, the calcification (at least one in cases showing multiple ones) was identifiable on MRI in 62% (8/13) of rumors, 82% (9/11) of infectious diseases, and 100% (2/2) in undetermined group. In 36% (4/11) of infectious diseases, fewer number of

  2. MRI of plantar fasciitis

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-01

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

  3. MRI of the penis

    OpenAIRE

    Kirkham, A

    2012-01-01

    MRI of the penis is an expensive test that is not always superior to clinical examination or ultrasound. However, it shows many of the important structures, and in particular the combination of tumescence from intracavernosal alprostadil, and high-resolution T2 sequences show the glans, corpora and the tunica albuginea well. In this paper we summarise the radiological anatomy and discuss the indications for MRI. For penile cancer, it may be useful in cases where the local stage is not apparen...

  4. Posttraumatic pseudolipoma: MRI appearances

    International Nuclear Information System (INIS)

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

  5. Posttraumatic pseudolipoma: MRI appearances

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-09-01

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

  6. Fetal MRI in experimental tracheal occlusion

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-02-15

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

  7. Fetal MRI in experimental tracheal occlusion

    International Nuclear Information System (INIS)

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

  8. Contrast Enhanced MRI in the Diagnosis of HCC

    Directory of Open Access Journals (Sweden)

    Eric Niendorf

    2015-09-01

    Full Text Available Hepatocellular carcinoma (HCC is the 6th most common cancer worldwide. Imaging plays a critical role in HCC screening and diagnosis. Initial screening of patients at risk for HCC is performed with ultrasound. Confirmation of HCC can then be obtained by Computed Tomography (CT or Magnetic Resonance Imaging (MRI, due to the relatively high specificity of both techniques. This article will focus on reviewing MRI techniques for imaging HCC, felt by many to be the exam of choice for HCC diagnosis. MRI relies heavily upon the use of gadolinium-based contrast agents and while primarily extracellular gadolinium-based contrast agents are used, there is an emerging role of hepatobiliary contrast agents in HCC imaging. The use of other non-contrast enhanced MRI techniques for assessing HCC will also be discussed and these MRI strategies will be reviewed in the context of the pathophysiology of HCC to help understand the MR imaging appearance of HCC.

  9. Applications of arterial spin labeled MRI in the brain.

    Science.gov (United States)

    Detre, John A; Rao, Hengyi; Wang, Danny J J; Chen, Yu Fen; Wang, Ze

    2012-05-01

    Perfusion provides oxygen and nutrients to tissues and is closely tied to tissue function while disorders of perfusion are major sources of medical morbidity and mortality. It has been almost two decades since the use of arterial spin labeling (ASL) for noninvasive perfusion imaging was first reported. While initial ASL magnetic resonance imaging (MRI) studies focused primarily on technological development and validation, a number of robust ASL implementations have emerged, and ASL MRI is now also available commercially on several platforms. As a result, basic science and clinical applications of ASL MRI have begun to proliferate. Although ASL MRI can be carried out in any organ, most studies to date have focused on the brain. This review covers selected research and clinical applications of ASL MRI in the brain to illustrate its potential in both neuroscience research and clinical care.

  10. MRI of anterior cruciate ligament healing

    Energy Technology Data Exchange (ETDEWEB)

    Ihara, Hidetoshi; Miwa, Megumi; Deya, Keizo; Torisu, Kenji [Kyushu Rosai Hospital, Kitakyushu (Japan)

    1996-03-01

    The purpose of this study was to evaluate using MRI the natural healing of the anterior cruciate ligament (ACL) when treated conservatively by early protective motion. Consecutive acute complete intraligamentous ruptures of the ACL in 50 cases that were allowed to heal without surgery were evaluated before and after 3 month treatment by MRI, arthroscopy, and stress radiographs. Twenty-nine of the 50 patients were also reevaluated 11 months from the initial injury, of which 7 were reevaluated again 24 months from the initial injury by MRI. The MR appearance of the treated ACL was categorized into four grades depending on homogeneity, straight band, and size. MR assessment of the ACL after 3 month treatment demonstrated a well defined normal-sized straight band in 37 cases (74%). There was a significant relationship between the 3 and 11 month MR evaluations (r. = 0.801, p < 0.0001). There were also significant relationships between the MR and arthroscopic evaluations (r, = 0.455, p < 0.005) and between the MR and stress radiographic evaluations (r, = 0.348, p < 0.025) after the 3 month treatment. MRI can demonstrate ACL healing when treated conservatively with early protective mobilization. 40 refs., 3 figs., 2 tabs.

  11. No erosive progression revealed by MRI in rheumatoid arthritis patients treated with etanercept, even in patients with persistent MRI and clinical signs of joint inflammation

    DEFF Research Database (Denmark)

    Døhn, Uffe Møller; Skjødt, Henrik; Hetland, Merete Lund;

    2007-01-01

    The aim of this study is to investigate the course of magnetic resonance imaging (MRI) signs of inflammatory and destructive changes in rheumatoid arthritis (RA) wrist and metacarpophalangeal (MCP) joints during etanercept treatment. MRI of the non-dominant wrist and second to fifth MCP joints...... was performed in five clinical active RA patients before and 4 and 16 weeks after initiation of etanercept treatment. MRI was evaluated according to the EULAR-OMERACT RA MRI reference image atlas. The median 28-joint count disease activity score (DAS28; erythrocyte sedimentation rate based) was 5.6 (range 5...... patient showed erosive regression, while no patient showed erosive progression on MRI during 16 weeks of etanercept therapy; even though clinical and MRI signs of joint inflammation remained. This small study supports that erosive progression judged by MRI is minimal in RA patients treated with etanercept...

  12. Parametric T2 and T2* mapping techniques to visualize intervertebral disc degeneration in patients with low back pain: initial results on the clinical use of 3.0 Tesla MRI

    International Nuclear Information System (INIS)

    To assess, compare and correlate quantitative T2 and T2* relaxation time measurements of intervertebral discs (IVDs) in patients suffering from low back pain, with respect to the IVD degeneration as assessed by the morphological Pfirrmann Score. Special focus was on the spatial variation of T2 and T2* between the annulus fibrosus (AF) and the nucleus pulposus (NP). Thirty patients (mean age: 38.1 ± 9.1 years; 20 female, 10 male) suffering from low back pain were included. Morphological (sagittal T1-FSE, sagittal and axial T2-FSE) and biochemical (sagittal T2- and T2* mapping) MRI was performed at 3 Tesla covering IVDs L1-L2 to L5-S1. All IVDs were morphologically classified using the Pfirrmann score. Region-of-interest (ROI) analysis was performed on midsagittal T2 and T2* maps at five ROIs from anterior to posterior to obtain information on spatial variation between the AF and the NP. Statistical analysis-of-variance and Pearson correlation was performed. The spatial variation as an increase in T2 and T2* values from the AF to the NP was highest at Pfirmann grade I and declined at higher Pfirmann grades II-IV (p < 0.05). With increased IVD degeneration, T2 and T2* revealed a clear differences in the NP, whereas T2* was additionally able to depict changes in the posterior AF. Correlation between T2 and T2* showed a medium Pearson's correlation (0.210 to 0.356 [p < 0.001]). The clear differentiation of IVD degeneration and the possible quantification by means of T2 and fast T2* mapping may provide a new tool for follow-up therapy protocols in patients with low back pain. (orig.)

  13. Parametric T2 and T2* mapping techniques to visualize intervertebral disc degeneration in patients with low back pain: initial results on the clinical use of 3.0 Tesla MRI

    Energy Technology Data Exchange (ETDEWEB)

    Welsch, Goetz Hannes [Medical University of Vienna, MR Center - High Field MR, Department of Radiology, Vienna (Austria); University of Erlangen, Department of Trauma Surgery, Erlangen (Germany); Trattnig, Siegfried; Goed, Sabine; Stelzeneder, David [Medical University of Vienna, MR Center - High Field MR, Department of Radiology, Vienna (Austria); Paternostro-Sluga, Tatjana [Medical University of Vienna, Department of Physical Therapy, Vienna (Austria); Bohndorf, Klaus [Klinikum Augsburg, Department of Radiology, Augsburg (Germany); Mamisch, Tallal Charles [Medical University of Vienna, MR Center - High Field MR, Department of Radiology, Vienna (Austria); University of Berne, Department of Orthopedic Surgery, Berne (Switzerland)

    2011-05-15

    To assess, compare and correlate quantitative T2 and T2* relaxation time measurements of intervertebral discs (IVDs) in patients suffering from low back pain, with respect to the IVD degeneration as assessed by the morphological Pfirrmann Score. Special focus was on the spatial variation of T2 and T2* between the annulus fibrosus (AF) and the nucleus pulposus (NP). Thirty patients (mean age: 38.1 {+-} 9.1 years; 20 female, 10 male) suffering from low back pain were included. Morphological (sagittal T1-FSE, sagittal and axial T2-FSE) and biochemical (sagittal T2- and T2* mapping) MRI was performed at 3 Tesla covering IVDs L1-L2 to L5-S1. All IVDs were morphologically classified using the Pfirrmann score. Region-of-interest (ROI) analysis was performed on midsagittal T2 and T2* maps at five ROIs from anterior to posterior to obtain information on spatial variation between the AF and the NP. Statistical analysis-of-variance and Pearson correlation was performed. The spatial variation as an increase in T2 and T2* values from the AF to the NP was highest at Pfirmann grade I and declined at higher Pfirmann grades II-IV (p < 0.05). With increased IVD degeneration, T2 and T2* revealed a clear differences in the NP, whereas T2* was additionally able to depict changes in the posterior AF. Correlation between T2 and T2* showed a medium Pearson's correlation (0.210 to 0.356 [p < 0.001]). The clear differentiation of IVD degeneration and the possible quantification by means of T2 and fast T2* mapping may provide a new tool for follow-up therapy protocols in patients with low back pain. (orig.)

  14. MRI of the lung

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  15. MRI in Japanese encephalitis

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-03-01

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

  16. MRI of the lung

    International Nuclear Information System (INIS)

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

  17. MRI of oriental cholangiohepatitis

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-15

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

  18. Optimised, low cost, low field dedicated extremity MRI is highly specific and sensitive for synovitis and bone erosions in rheumatoid arthritis wrist and finger joints: comparison with conventional high field MRI and radiography

    DEFF Research Database (Denmark)

    Ejbjerg, B.J; Narvestad, E; Jacobsen, S;

    2005-01-01

    were performed. In an initial low field MRI 'sequence selection phase', based on a subset of 10 patients and 10 controls, sequences for comparison with high field MRI were selected. RESULTS: With high field, spin echo MRI considered as the reference method, the sensitivity, specificity, and accuracy of......OBJECTIVE: To evaluate a low field dedicated extremity MRI unit for detection of bone erosions, synovitis, and bone marrow oedema in wrist and metacarpophalangeal (MCP) joints, with a high field MRI unit as the standard reference. METHODS: In 37 patients with RA and 28 healthy controls MRI of the...... wrist and 2nd-5th MCP joints was performed on a low field MRI unit (0.2 T Esaote Artoscan) and a high field MRI unit (1.0 T Siemens Impact) on 2 subsequent days. MRI was performed and evaluated according to OMERACT recommendations. Additionally, conventional x ray, clinical, and biochemical examinations...

  19. Reprint of "Hypomyelinating disorders: An MRI approach.

    Science.gov (United States)

    Barkovich, A James; Deon, Sean

    2016-08-01

    In recent years, the concept of hypomyelinating disorders has been proposed as a group of disorders with varying systemic manifestations that are identified by MR findings of absence or near absence of the T2 hypointensity that develops in white matter as a result of myelination. Initially proposed as a separate group because they were the largest single category of undiagnosed leukodystrophies, their separation as a distinct group that can be recognized by looking for a specific MRI feature has resulted in a marked increase in their diagnosis and a better understanding of the different causes of hypomyelination. This review will discuss the clinical presentations, imaging findings on standard MRI, and new MRI-related techniques that allow a better understanding of these disorders and proposed methods for quantifying the myelination as a potential means of assessing disease course and the effects of proposed treatments. Disorders with hypomyelination of white matter, or hypomyelinating disorders (HMDs), represent the single largest category among undiagnosed genetic leukoencephalopathies (Schiffmann and van der Knaap, 2009; Steenweg et al., 2010). This group of inborn errors of metabolism is characterized by a magnetic resonance imaging (MRI) appearance of reduced or absent myelin development: delay in the development of T2 hypointensity and, often, T1 hyperintensity in the white matter of the brain. The concept of hypomyelination was first conceptualized by (Schiffmann and van der Knaap, 2009; Steenweg et al., 2010; Schiffmann et al., 1994) in a series of papers that showed that these MRI characteristics were easily recognized, were different from the MRI characteristics of dysmyelinating and demyelinating disorders, and that the combination of these imaging findings with specific other clinical and imaging features could be used to make diagnoses with some confidence. In this manuscript, we will discuss the physiologic and genetic bases of hypomyelinating

  20. MRI findings of treated bacterial septic arthritis

    International Nuclear Information System (INIS)

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

  1. MRI findings of treated bacterial septic arthritis

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-12-15

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

  2. Background and Mathematical Analysis of Diffusion MRI Methods.

    Science.gov (United States)

    Ozcan, Alpay; Wong, Kenneth H; Larson-Prior, Linda; Cho, Zang-Hee; Mun, Seong K

    2012-03-01

    The addition of a pair of magnetic field gradient pulses had initially provided the measurement of spin motion with nuclear magnetic resonance (NMR) techniques. In the adaptation of DW-NMR techniques to magnetic resonance imaging (MRI), the taxonomy of mathematical models is divided in two categories: model matching and spectral methods. In this review, the methods are summarized starting from early diffusion weighted (DW) NMR models followed up with their adaptation to DW MRI. Finally, a newly introduced Fourier analysis based unifying theory, so-called Complete Fourier Direct MRI, is included to explain the mechanisms of existing methods.

  3. Ultrasound- and MRI-Guided Prostate Biopsy

    Science.gov (United States)

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

  4. Introduction to Interventional MRI

    Institute of Scientific and Technical Information of China (English)

    Jarmo Ruohonen; William G.Bradley; Jr.MD

    2002-01-01

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

  5. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  6. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  7. 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 ...

  8. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI an invaluable tool in early diagnosis and evaluation of many conditions, including tumors. MRI enables the ... physicians with expertise in several radiologic areas. Outside links: For the convenience of our users, RadiologyInfo .org ...

  9. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  10. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  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 ... over time. top of page What are the benefits vs. risks? Benefits MRI is a noninvasive imaging ...

  12. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  13. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... 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 ...

  14. Less Confusion in Diffusion MRI

    NARCIS (Netherlands)

    Tax, C.M.W.

    2016-01-01

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

  15. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... of page What are the benefits vs. risks? Benefits MRI is a noninvasive 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 selected cases. MR images of ...

  16. In vitro MRI of brain development

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-02-15

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

  17. MRI of intact plants

    NARCIS (Netherlands)

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

    2009-01-01

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

  18. MRI of intact plants.

    NARCIS (Netherlands)

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

    2009-01-01

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

  19. MRI and interventions

    Institute of Scientific and Technical Information of China (English)

    Roberto Blanco Sequeiros

    2002-01-01

    @@ Interventional radiology was started not long after the discovery of X - rays. Interventions started as image guided biopsies and angiographies early this century, later emerged computed tomography (CT) and ultrasound-guided interventions in the 1970s and ultimately the magnetic resonance imaging(MRI) guided interventions at the 1980s.

  20. Combined PET/MRI

    DEFF Research Database (Denmark)

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

    2015-01-01

    February 23 to 27, 2015. Specifically, we summarise the three days of invited presentations from active researchers in this and associated fields augmented by round table discussions and dialogue boards with specific topics. These include the use of PET/MRI in cardiovascular disease, paediatrics, oncology......, the conclusion of last year's meeting "the real work has just started" still holds true....

  1. MRI Findings in Patients with TMJ Click

    Directory of Open Access Journals (Sweden)

    Mahrokh Imanimoghaddam

    2013-12-01

    Full Text Available Introduction: It has been shown that joint click, an initial and common finding in internal derangement (ID, respond to neither conservative treatment nor surgical intervention. This raises the question as to whether it must be treated in the absence of other pertinent signs and symptoms, so the aim of this study was to investigate and compare the MRI findings of TMJ in both normal subjects and patients with click, in order to determine the importance of click in predicting TMJ pathological changes. Methods: A total of 26 patients with clinical symptoms of disk displacement with reduction (DDwR according to RDC/TMD were compared to 14 normal subjects in terms of their MRI findings, including disk displacement, effusion, condylar osteoarthritic changes and disk deformities. Results: Out of 80 joints in total (52 affected joints in 26 patients and 28 joints in control group, 48 were shown with normal disk position in MRI whereas 28 (35% and 4 (5% were categorised as DDwR and (disk displacement without reduction DDwoR, respectively. Statistically significant correlations were established between the following pairs of variables in order: Click and disk displacement, effusion and disk displacement, disk displacement and effusion with disk deformity. Conclusion: The correlation between the presence of click and disk displacement, disk deformity and effusion emphasizes the importance of MRI for an accurate diagnosis and development of an appropriate treatment plan in these cases and shows that clinical examination is not sufficient for these purposes.

  2. Postinterventional MRI findings following MRI-guided laser ablation of osteoid osteoma

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, S., E-mail: simon.fuchs@charite.de [Department of Radiology, Charité, Humboldt University, Berlin (Germany); Gebauer, B.; Stelter, L.; Schäfer, M.L.; Renz, D.M. [Department of Radiology, Charité, Humboldt University, Berlin (Germany); Melcher, I.; Schaser, K. [Center for Musculoskeletal Surgery, Charité, Humboldt University, Berlin (Germany); Hamm, B.; Streitparth, F. [Department of Radiology, Charité, Humboldt University, Berlin (Germany)

    2014-04-15

    Objective: To evaluate postinterventional magnetic resonance imaging (MRI) characteristics following MRI-guided laser ablation of osteoid osteoma (OO). Materials and methods: 35 patients treated with MRI-guided laser ablation underwent follow-up MRI immediately after the procedure, after 3, 6, 12, 24, 36, and up to 48 months. The imaging protocol included multiplanar fat-saturated T2w TSE, unenhanced and contrast-enhanced T1w SE, and subtraction images. MR images were reviewed regarding the appearance and size of treated areas, and presence of periablation bone and soft tissue changes. Imaging was correlated with clinical status. Results: Mean follow-up time was 13.6 months. 28/35 patients (80%) showed a postinterventional “target-sign” appearance consisting of a fibrovascular rim zone and a necrotic core area. After an initial increase in total lesion diameter after 3 months, a subsequent progressive inward remodeling process of the zonal compartments was observed for up to 24 months. Periablation bone and soft tissue changes showed a constant decrease over time. MR findings correlated well with the clinical status. Clinical success was achieved in 32/35 (91%). Conclusions: Evaluation of long-term follow-up MRI after laser ablation of OO identified typical postinterventional changes and thus may contribute to the interpretation of therapeutic success and residual or recurrent OO in suspected cases.

  3. High-quality breast MRI.

    Science.gov (United States)

    Hendrick, R Edward

    2014-05-01

    Breast magnetic resonance imaging (MRI) demands the competing factors of high spatial resolution, good temporal resolution, high signal-to-noise ratios, and complete bilateral breast coverage. Achieving these competing factors requires modern MRI equipment with high magnetic field strength and homogeneity, high maximum gradient strength with short rise times, dedicated multichannel bilateral breast coils with prone patient positioning, and 3D (volume) gradient-echo MRI pulse sequences with short TR, short TE, high spatial resolution, and reasonably short acquisition times. This article discusses the equipment and pulse sequences needed to achieve high-quality breast MRI and summarizes requirements of the ACR Breast MRI Accreditation Program. PMID:24792656

  4. Clinical impact of MRI in acute wrist fractures

    Energy Technology Data Exchange (ETDEWEB)

    Mack, Martin G.; Keim, Sabine; Balzer, Joern O.; Schwarz, Wolfram; Hochmuth, Kathrin; Vogl, Thomas J. [Department of Diagnostic and Interventional Radiology, Universitaetsklinikum Frankfurt/Main, Theodor-Stern-Kai 7, 60590 Frankfurt/Main (Germany); Windolf, Joachim [Department of Traumatology and Reconstructive Surgery, University of Hamburg, Martinistrasse 52, 20246 Hamburg (Germany)

    2003-03-01

    The purpose of this study was to evaluate the clinical impact of MRI in the early diagnosis of wrist trauma. High-resolution MR imaging was performed on a 1.5-T unit (Symphony Quantum, Siemens, Erlangen, Germany) using coronal and axial T1- and T2-weighted fat-saturated turbo-spin-echo sequence via a dedicated wrist coil within a mean of 6.6 days after initial radiographs in 54 patients (56 wrists) with clinical suspicion of wrist fractures and normal plain or indistinct radiographs. Initial radiographs were evaluated independently by two senior radiologists and the hand surgeon without knowledge of the MRI findings. The initial treatment protocol was based on evaluation of plain films and clinical findings by the hand surgeon. Treatment protocol was changed after MRI examination if necessary. In 31 of 56 wrists MRI findings resulted in a change of diagnosis. There were false-positive diagnoses on plain radiographs in nearly one half (n=25) of the patients. False-negative diagnoses on plain radiographs resulted in 6 cases. Magnetic resonance imaging detected additional injuries of soft tissue in more than one third (n=20). In 22 of 56 wrists the period of immobilization could be shortened or ended, in 12 of 56 it was prolonged, and in 3 of 56 a surgical intervention was necessary. In 19 wrists MRI had no therapeutic consequences. Our data demonstrate the high clinical impact of MRI in the detection of acute wrist fractures. We recommend MRI of the wrist immediately on the day of trauma if there is clinical suspicion and normal plain radiographs. Accurate diagnosis by MRI examination within the first days following trauma may reduce economic costs due to shortened immobilization time in cases with a suspected fracture but plain radiographs. (orig.)

  5. Three-Dimensional Expansion of a Dynamic Programming Method for Boundary Detection and Its Application to Sequential Magnetic Resonance Imaging (MRI

    Directory of Open Access Journals (Sweden)

    Da-Chuan Cheng

    2012-04-01

    Full Text Available This study proposes a fast 3D dynamic programming expansion to find a shortest surface in a 3D matrix. This algorithm can detect boundaries in an image sequence. Using phantom image studies with added uniform distributed noise from different SNRs, the unsigned error of this proposed method is investigated. Comparing the automated results to the gold standard, the best averaged relative unsigned error of the proposed method is 0.77% (SNR = 20 dB, and its corresponding parameter values are reported. We further apply this method to detect the boundary of the real superficial femoral artery (SFA in MRI sequences without a contrast injection. The manual tracings on the SFA boundaries are performed by well-trained experts to be the gold standard. The comparisons between the manual tracings and automated results are made on 16 MRI sequences (800 total images. The average unsigned error rate is 2.4% (SD = 2.0%. The results demonstrate that the proposed method can perform qualitatively better than the 2D dynamic programming for vessel boundary detection on MRI sequences.

  6. The impact of MRI on the treatment of DCIS.

    Science.gov (United States)

    Chung, Alice; Saouaf, Rola; Scharre, Karen; Phillips, Edward

    2005-09-01

    Magnetic resonance imaging (MRI) has been shown to detect occult invasive breast cancers with a sensitivity of 97 per cent to 100 per cent. Mammography and ultrasonography does not accurately assess the extent of ductal carcinoma in situ (DCIS), which results in a high reoperation rate. Breast MRI can improve the surgical planning in women with DCIS, improving the adequacy of initial treatment while reducing reoperation. We examined 54 patients with predominantly DCIS (> 50%) who underwent breast MRI from January 2003 to November 2004. MRI altered the surgical management in 14 (26%) patients: unilateral changed to bilateral mastectomy (5); lumpectomy or reexcision to mastectomy (3); unilateral lumpectomy or mastectomy had additional biopsies for lesions detected by MRI in the ipsilateral or contralateral breast (6). There were 8 true-positives and 7 false-positives: sensitivity 86 per cent, positive predictive value 84 per cent. MRI changed the surgical management to more appropriate therapy in 15 per cent of patients avoiding additional surgery, while 11 per cent underwent negative surgical interventions. Breast MRI is a sensitive diagnostic imaging tool in patients with DCIS. However, any suspicious finding should be biopsied before a definitive operation is planned. PMID:16468502

  7. The MRI appearances of early vertebral osteomyelitis and discitis

    Energy Technology Data Exchange (ETDEWEB)

    Dunbar, J.A.T.; Sandoe, J.A.T. [Department of Microbiology, Leeds General Infirmary, Leeds LS1 3EX (United Kingdom); Rao, A.S. [Department of Orthopaedics, Leeds General Infirmary, Leeds LS1 3EX (United Kingdom); Crimmins, D.W. [Department of Neurosurgery, Leeds General Infirmary, Leeds LS1 3EX (United Kingdom); Baig, W. [Department of Cardiology, Leeds General Infirmary, Leeds LS1 3EX (United Kingdom); Rankine, J.J., E-mail: james.rankine@leedsth.nhs.u [Department of Radiology, Leeds General Infirmary, Leeds LS1 3EX (United Kingdom); Leeds Musculoskeletal Biomedical Research Unit, Leeds (United Kingdom)

    2010-12-15

    Aim: To describe the magnetic resonance imaging (MRI) appearances in patients with a clinical history suggestive of vertebral osteomyelitis and discitis who underwent MRI very early in their clinical course. Materials and methods: A retrospective review of the database of spinal infections from a spinal microbiological liaison team was performed over a 2 year period to identify cases with clinical features suggestive of spinal infection and an MRI that did not show features typical of vertebral osteomyelitis and discitis. All patients had positive microbiology and a follow up MRI showing typical features of spinal infection. Results: In four cases the features typical of spinal infection were not evident at the initial MRI. In three cases there was very subtle endplate oedema associated with disc degeneration, which was interpreted as Modic type I degenerative endplate change. Intravenous antibiotic therapy was continued prior to repeat MRI examinations. The mean time to the repeat examination was 17 days with a range of 8-22 days. The second examinations clearly demonstrated vertebral osteomyelitis and discitis. Conclusion: Although MRI is the imaging method of choice for vertebral osteomyelitis and discitis in the early stages, it may show subtle, non-specific endplate subchondral changes; a repeat examination may be required to show the typical features.

  8. MRI of the posttraumatic shoulder

    International Nuclear Information System (INIS)

    functional discomfort during the joint loading. Compression on the rotator cuff from the overlying acromion and the subsequent tissue reaction in the subacromial bursa causes suffering tendons of these muscles. Unrated its diagnostic leads to deepen the ‘subacromial conflict’ and reach rotator cuff initially partial and later progressed. The shoulder stiffness is a condition in which the passive motion restriction is combined with pain in their final phase as well as during sleep. This also affects the active movements which are also reduced. ‘The shoulder hardening’ is at the organic component expense and it must be distinguished from the functional disorders such as muscle contracture and ‘subacromial conflict’. Restoration of work capacity in patients with idiopathic ‘frozen shoulder’ is faster than in post-traumatic shoulder. Diagnostic estimated joint capsule fibrosis more quickly gives a way to the treatment, which shortens the patient’s suffering. MRI imaging is a method of choice for the diagnosis of these conditions. MRI shows not only broken integrity of the rotator cuff tendons, but also the fluid in the subacromial bursa, which means that, must have a lesion. MRI provides information about fatty degeneration of the tendon. MRI registers the distance of the torn tendon retraction, the rupture size, may advise the surgeon on its mobility, and hence the expected forecast. However in the impingement indicative are only local areas with increased signal on T 2 images and data about severe osteophytosis in the area of the acromioclavicular joint. Outlined are the areas of present calcification in the subacromial bursa and, what is more important for the process of treatment, - their density. In shoulder instability MRI demonstrates the presence of lesions type Bankart, partial rotator cuff lesions, lesions of the ligament apparatus in combination with SLAP lesions, lesions of the posterior labrum and refers to the type of instability and the choice of

  9. Clinical evaluation of 3D/3D MRI-CBCT automatching on brain tumors for online patient setup verification - A step towards MRI-based treatment planning

    DEFF Research Database (Denmark)

    Buhl, Sune K.; Duun-Christensen, Anne Katrine; Kristensen, Brian H.;

    2010-01-01

    Background. Magnetic Resonance Imaging (MRI) is often used in modern day radiotherapy (RT) due to superior soft tissue contrast. However, treatment planning based solely on MRI is restricted due to e. g. the limitations of conducting online patient setup verification using MRI as reference....... In this study 3D/3D MRI-Cone Beam CT (CBCT) automatching for online patient setup verification was investigated. Material and methods. Initially, a multi-modality phantom was constructed and used for a quantitative comparison of CT-CBCT and MRI-CBCT automatching. Following the phantom experiment three patients...... undergoing postoperative radiotherapy for malignant brain tumors received a weekly CBCT. In total 18 scans was matched with both CT and MRI as reference. The CBCT scans were acquired using a Clinac iX 2300 linear accelerator (Varian Medical Systems) with an On-Board Imager (OBI). Results. For the phantom...

  10. Clinical evaluation of 3D/3D MRI-CBCT automatching on brain tumors for online patient setup verification - A step towards MRI-based treatment planning

    DEFF Research Database (Denmark)

    Buhl, S.K.; Duun-Christensen, Anne Katrine; Kristensen, B.H.;

    2010-01-01

    undergoing postoperative radiotherapy for malignant brain tumors received a weekly CBCT. In total 18 scans was matched with both CT and MRI as reference. The CBCT scans were acquired using a Clinac iX 2300 linear accelerator (Varian Medical Systems) with an On-Board Imager (OBI). Results. For the phantom......Background. Magnetic Resonance Imaging (MRI) is often used in modern day radiotherapy (RT) due to superior soft tissue contrast. However, treatment planning based solely on MRI is restricted due to e. g. the limitations of conducting online patient setup verification using MRI as reference....... In this study 3D/3D MRI-Cone Beam CT (CBCT) automatching for online patient setup verification was investigated. Material and methods. Initially, a multi-modality phantom was constructed and used for a quantitative comparison of CT-CBCT and MRI-CBCT automatching. Following the phantom experiment three patients...

  11. {sup 3}He-MRI in follow-up of lung transplant recipients

    Energy Technology Data Exchange (ETDEWEB)

    Gast, Klaus Kurt; Zaporozhan, Julia; Ley, Sebastian; Biedermann, Alexander; Knitz, Frank; Eberle, Balthasar; Schmiedeskamp, Joerg; Heussel, Claus-Peter; Mayer, Eckhard; Schreiber, Wolfgang Guenter; Thelen, Manfred; Kauczor, Hans-Ulrich [Department of Radiology, Johannes Gutenberg University Hospital, Langenbeckstrasse 1, 55131, Mainz (Germany)

    2004-01-01

    The aim of this study was to evaluate the possible contribution of {sup 3}He-MRI to detect obliterative bronchiolitis (OB) in the follow-up of lung transplant recipients. Nine single- and double-lung transplanted patients were studied by an initial and a follow-up {sup 3}He-MRI study. Images were evaluated subjectively by estimation of ventilation defect area and quantitatively by individually adapted threshold segmentation and subsequent calculation of ventilated lung volume. Bronchiolitis obliterans syndrome (BOS) was diagnosed using pulmonary function tests. At {sup 3}He-MRI, OB was suspected if ventilated lung volume had decreased by 10% or more at the follow-up MRI study compared with the initial study. General accordance between pulmonary function testing and {sup 3}He-MRI was good, although subjective evaluation of {sup 3}He-MRI underestimated improvement in ventilation as obtained by pulmonary function tests. The {sup 3}He-MRI indicated OB in 6 cases. According to pulmonary function tests, BOS was diagnosed in 5 cases. All diagnoses of BOS were also detected by {sup 3}He-MRI. In 2 of these 5 cases, {sup 3}He-MRI indicated OB earlier than pulmonary function tests. The results support the hypothesis that {sup 3}He-MRI may be sensitive for early detection of OB and emphasize the need for larger prospective follow-up studies. (orig.)

  12. 腕关节3D LAVA动态增强在判断类风湿性关节炎疾病进程的价值研究%The value of 3D dynamic contrast enhanced LAVA in evaluating the progression of rheumatoid arthritis of the wrist

    Institute of Scientific and Technical Information of China (English)

    傅丽晖; 李晖; 王波; 胡斌; 王莹莹; 梁良

    2014-01-01

    目的:探讨3.0T MRI LAVA动态增强检查在判断类风湿性关节炎(RA)疾病进程的价值.方法:收集临床确诊的RA患者35例,其中关节炎活动期20例,缓解期15例,进行碗关节MRI平扫加动态增强扫描,并将采集的动态增强图像进行后处理,每位患者选取碗关节周围滑膜异常强化6个感兴趣区,获得动态增强时间信号曲线,分别计算每个感兴趣区的滑膜强化率并取平均值,同时测量6个感兴趣区的滑膜厚度并取平均值.将活动期和缓解期患者的滑膜强化率、滑膜厚度差异进行统计学比较,将所有患者的滑膜强化率及滑膜厚度与血沉(ESR)、C反应蛋白(CRP)的相关性进行统计学研究.结果:活动期的时间信号曲线为快速上升平台型,缓解期的时间信号曲线为缓慢上升型.活动期患者的平均滑膜强化率(2.27±0.56)与缓解期患者的平均滑膜强化率(1.04 ±0.42)差别有统汁学意义,P<0.01;活动期平均滑膜厚度((5.9±0.4)mm)与缓解期滑膜平均厚度((2.9±0.6)mm)差别具有统计学意义,P<0.01..患者的滑膜强化率分别与ESR及CRP呈正相关(相关系数R值分别为0.778和0.816,P值分别为0.02和0.01),滑膜厚度与ESR及CRP具有一定相关性(相关系数R值分别为0.506和0.402,P值均为0.05).结论:动态增强MRI时间信号曲线形状、滑膜强化率及滑膜厚度对判断RA的活动性具有较高价值.

  13. MRI of the shoulder

    Energy Technology Data Exchange (ETDEWEB)

    Vahlensieck, M.

    2000-02-01

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

  14. MRI of cardiovascular malformations

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

  15. X-Ray and MRI Correlation of Bone Tumours

    Directory of Open Access Journals (Sweden)

    Mitesh D. Ghadiali

    2015-12-01

    Full Text Available Introduction: The evaluation of all skeletal lesions should begin with plain radiographic imaging. These images give basic information about its site, its location,its morphology, its aggressiveness. After the initial plain radiographic evaluation, the next imaging modality of choice is MRI. its clinical applications in the form of diagnostic and therapeutic monitoring has reached a new height in musculoskeletal imaging1. Method: Correlating x-ray findings with mri findings to know the sensitivity and specificity of each diagnostic modality and to know role of each in planning management 30 patients were studied,The plain film included at least 2 projection depending on location and then patients underwent MRI. Result: MRI is useful for information regarding soft tissue component, periosteal reaction where as XRAY is useful for information regarding bone and tumour calcification [Natl J Med Res 2015; 5(4.000: 309-311

  16. Measuring MRI noise

    OpenAIRE

    Hoiting, Gerke Jan

    2005-01-01

    De MRI-scanner wordt tegenwoordig veel gebruikt voor medisch onderzoek. Het lawaai dat het apparaat produceert (110 dB en meer), is echter een storende factor die lastig te beteugelen is. Weliswaar kan het geluiddruk vooraf berekend worden, maar de tot nu gehanteerde methode geeft een foute voorspelling wanneer het over een lage geluidsdruk gaat. Gerke Hoiting stelt in zijn proefschrift een nieuwe methode voor, die bij lage geluidsdruk wel een correcte voorspelling doet. Het proefschrift beva...

  17. Edge-oriented dual-dictionary guided enrichment (EDGE) for MRI-CT image reconstruction.

    Science.gov (United States)

    Li, Liang; Wang, Bigong; Wang, Ge

    2016-01-01

    In this paper, we formulate the joint/simultaneous X-ray CT and MRI image reconstruction. In particular, a novel algorithm is proposed for MRI image reconstruction from highly under-sampled MRI data and CT images. It consists of two steps. First, a training dataset is generated from a series of well-registered MRI and CT images on the same patients. Then, an initial MRI image of a patient can be reconstructed via edge-oriented dual-dictionary guided enrichment (EDGE) based on the training dataset and a CT image of the patient. Second, an MRI image is reconstructed using the dictionary learning (DL) algorithm from highly under-sampled k-space data and the initial MRI image. Our algorithm can establish a one-to-one correspondence between the two imaging modalities, and obtain a good initial MRI estimation. Both noise-free and noisy simulation studies were performed to evaluate and validate the proposed algorithm. The results with different under-sampling factors show that the proposed algorithm performed significantly better than those reconstructed using the DL algorithm from MRI data alone.

  18. MRI assessment of cervical cancer for adaptive radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Dimopoulos, Johannes C.A.; Schirl, Gertrude; Baldinger, Anja; Poetter, Richard [Medical Univ. of Vienna (Austria). Dept. of Radiotherapy; Helbich, Thomas H. [Medical Univ. of Vienna (Austria). Dept of Radiology

    2009-05-15

    Purpose: To assess the importance of the information obtained from MRI for adaptive cervix cancer radiotherapy. Patients and methods: 49 patients with cervix cancer, treated by external-beam radiotherapy (EBRT) and MRI-assisted high-dose-rate brachytherapy {+-} concomitant cisplatin, underwent MRI at diagnosis and at the time of brachytherapy fractions. 190 MRI examinations were performed. Pretreatment scans were correlated with clinical examination (CE) findings. Measurements in 3-D of the tumor extension and also of the distance from the tumor to the pelvic side wall were performed using both MRI and CE. The tumor volume regression induced initially by EBRT and the subsequent regression after each brachytherapy fraction were assessed. Results: MRI and CE showed 92% agreement in overall parametrial staging and 73% agreement in terms of vaginal involvement. There was, however, disagreement in parametrial side (right/left) classification in 25% of the parametria examined. These were patients with unilateral displacement of the cervix and contralateral invasion of the parametrium. The mean tumor volume on the pretreatment MRI scan (GTVD) was 61 cm{sup 3}. At the time of the four brachytherapy fractions the mean was 16 cm{sup 3}, 10 cm{sup 3}, 9 cm{sup 3}, and 8 cm{sup 3}, defined as the GTVBT plus the gray zones in the parametria. Conclusion: CE and MRI findings agree well in terms of overall staging. The clinical assessment of side-specific parametrial invasion improved when having access to the additional knowledge obtained from MRI. The greatest decrease in tumor volume occurs during EBRT, whereas tumor regression between the first and subsequent brachytherapy fractions is minor. (orig.)

  19. Functional MRI in human motor control studies and clinical applications

    International Nuclear Information System (INIS)

    Functional magnetic resonance imaging (fMRI) has been a useful tool for the noninvasive mapping of brain function associated with various motor and cognitive tasks. Because fMRI is based on the blood oxygenation level dependent (BOLD) effect, it does not directly record neural activity. With the fMRI technique, distinguishing BOLD signals creased by cortical projection neurons from those created by intracortical neurons appears to be difficult. Two major experimental designs are used in fMRI studies: block designs and event-related designs. Block-designed fMRI presupposes the steady state of regional cerebral blood flow and has been applied to examinations of brain activation caused by tasks requiring sustained or repetitive movements. By contrast, the more recently developed event-related fMRI with time resolution of a few seconds allows the mapping of brain activation associated with a single movement according to the transient aspects of the hemodynamic response. Increasing evidence suggests that multiple motor areas are engaged in a networked manner to execute various motor acts. In order to understand functional brain maps, it is important that one understands sequential and parallel organizations of anatomical connections between multiple motor areas. In fMRI studies of complex motor tasks, elementary parameters such as movement length, force, velocity, acceleration and frequency should be controlled, because inconsistency in those parameters may alter the extent and intensity of motor cortical activation, confounding interpretation of the findings obtained. In addition to initiation of movements, termination of movements plays an important role in the successful achievement of complex movements. Brain areas exclusively related to the termination of movements have been, for the first time, uncovered with an event-related fMRI technique. We propose the application of fMRI to the elucidation of the pathophysiology of movement disorders, particularly dystonia

  20. Pediatric elbow fractures: MRI evaluation

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-05-01

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

  1. MRI follow-up of conservatively treated meniscal knee lesions in general practice

    Energy Technology Data Exchange (ETDEWEB)

    Oei, Edwin H.G.; Hunink, M.G.M. [University Medical Center Rotterdam, Program for the Assessment of Radiological Technology (ART Program), Erasmus MC, Rotterdam (Netherlands); University Medical Center Rotterdam, Department of Radiology, Erasmus MC, Rotterdam (Netherlands); University Medical Center Rotterdam, Department of Epidemiology, Erasmus MC, Rotterdam (Netherlands); Koster, Ingrid M. [University Medical Center Rotterdam, Department of Radiology, Erasmus MC, Rotterdam (Netherlands); Maasstad Ziekenhuis, Department of Radiology, Rotterdam (Netherlands); Hensen, Jan-Hein J.; Vroegindeweij, Dammis [Maasstad Ziekenhuis, Department of Radiology, Rotterdam (Netherlands); Boks, Simone S. [University Medical Center Rotterdam, Department of General Practice, Erasmus MC, Rotterdam (Netherlands); Maasstad Ziekenhuis, Department of Radiology, Rotterdam (Netherlands); Diaconessenhuis Meppel, Department of Radiology, Meppel (Netherlands); Wagemakers, Harry P.A.; Koes, Bart W.; Bierma-Zeinstra, Sita M.A. [University Medical Center Rotterdam, Department of General Practice, Erasmus MC, Rotterdam (Netherlands)

    2010-05-15

    To evaluate meniscal status change on follow-up MRI after 1 year, prognostic factors and association with clinical outcome in patients with conservatively treated knee injury. We analysed 403 meniscal horns in 101 conservatively treated patients (59 male; mean age 40 years) in general practice who underwent initial knee MRI within 5 weeks of trauma. We performed ordinal logistic regression analysis to analyse prognostic factors for meniscal change on follow-up MRI after 1 year, and we assessed the association with clinical outcome. On follow-up MRI 49 meniscal horns had deteriorated and 18 had improved. Age (odds ratio [OR] 1.3/decade), body weight (OR 1.2/10 kg), total anterior cruciate ligament (ACL) rupture on initial MRI (OR 2.4), location in the posterior horn of the medial meniscus (OR 3.0) and an initial meniscal lesion (OR 0.3) were statistically significant predictors of meniscal MRI appearance change after 1 year, which was not associated with clinical outcome. In conservatively treated patients, meniscal deterioration on follow-up MRI 1 year after trauma is predicted by higher age and body weight, initial total ACL rupture, and location in the medial posterior horn. Change in MRI appearance is not associated with clinical outcome. (orig.)

  2. The OMERACT MRI inflammatory arthritis group: advances and future research priorities

    DEFF Research Database (Denmark)

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

    2009-01-01

    The OMERACT magnetic resonance imaging (MRI) in inflammatory arthritis group previously developed the rheumatoid arthritis MRI score (RAMRIS) for use in clinical studies, evaluated the use of extremity MRI, and initiated development of a psoriatic arthritis MRI score (PsAMRIS). At OMERACT 9...... the group looked at clarifications of applying the RAMRIS, and presented data from a study examining how the contrast agent gadolinium affects RAMRIS outcomes. Much of the group's effort has been aimed at the iterative development of its PsA score, and reported exercises examining this score demonstrated...

  3. MRI finding of hemangioblastomas

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seung Cheol; Oh, Min Cheol; Chung, Hwan Hoon; Seol, Hye Young; Lee, Nam Joon; Kim, Jung Hyuk [Korea University College of Medicine, Seoul (Korea, Republic of)

    1994-05-15

    The purpose of this study is to evaluate the findings of magnetic resonance imaging (MRI) of posterior fossa hemanangioblastoma and usefulness of contrast enhancement with Gd-DTPA. Seven patients with posterior fossa hemangioblastoma were studied with both pre- and post-enhanced MRI. The MR images were reviewed regarding the location, size, signal intensities of cysts and mural nodules, and their contrast enhancement pattern. Five tumors were located in cerebellar hemisphere, one in vermis, and one in posterior part of medulla. One patient with von Hippel-Lindau disease had a medullary hemangioblastoma with multiple pancreatic cysts. In 6 cases, the major portion of the tumor was cysts and had small mulkal nodules. The solid portion was relatively lange in one cases, cemprising half of the tumor cysts were oval shaped and their sized were 3-6.7 cm in diameter. In five cases(71%), septations were noted within the cysts. Cysts were isointense or slightly hyperintense on T1-weighted image and hyperintense on T2- weighted image compared with cerebrospinal fluid. Mural nodules were oval or rounded radiotherapy had better prognosis than those treated with radiotherapy alwas 0.5-2.5 cm in diameter. Mural nodules were isointense to gray matter. They were detected in five cases on T1-weighted images and one case on T2-weighted images. In two cases, vascular signal void area was noted in mural nodules. On contrast-enhanced T1-weighted images, all mural nodules were intensely enhanced. MRI provide to be a good diagnostic method to detect and characterize posterior fossa hemangioblastoma. The most common finding is Cystic posterior fossa lesion with enhancing mural nodule. Contrast enhancement is essential for specific diagnosis.

  4. MRI quantification of rheumatoid arthritis: Current knowledge and future perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Boesen, Mikael [Parker Institute, Frederiksberg University Hospital, Copenhagen (Denmark)], E-mail: parker@frh.regionh.dk; Ostergaard, Mikkel [Department of Rheumatology, Hvidovre and Herlev University Hospitals, Copenhagen (Denmark); Cimmino, Marco A. [Department of Rheumatology, University of Genoa, Genoa (Italy); Kubassova, Olga [Image Analysis LTD, Leeds (United Kingdom); Jensen, Karl Erik [Department of Radiology, MR section, Rigshospitalet, Copenhagen (Denmark); Bliddal, Henning [Parker Institute, Frederiksberg University Hospital, Copenhagen (Denmark)

    2009-08-15

    The international consensus on treatment of rheumatoid arthritis (RA) involves early initiation of disease modifying anti-rheumatic drugs (DMARDs) for which a reliable identification of early disease is mandatory. Conventional radiography of the joints is considered the standard method for detecting and quantifying joint damage in RA. However, radiographs only show late disease manifestations as joint space narrowing and bone erosions, whereas it cannot detect synovitis and bone marrow oedema, i.e., inflammation in the synovium or the bone, which may be visualized by magnetic resonance imaging (MRI) months to years before erosions develop. Furthermore, MRI allows earlier visualization of bone erosions than radiography. In order to allow early treatment initiation and optimal guidance of the therapeutic strategy, there is a need for methods which are capable of early detection of inflammatory joint changes. In this review, we will discuss available data, advantages, limitations and potential future of MRI in RA.

  5. Whole-body MRI (WB-MRI) versus axial skeleton MRI (AS-MRI) to detect and measure bone metastases in prostate cancer (PCa)

    International Nuclear Information System (INIS)

    To compare whole-body MRI (WB-MRI) and axial skeleton MRI (AS-MRI) in detecting and measuring bone metastases in patients with prostate cancer (PCa). WB-MRI and AS-MRI examinations were performed in 60 patients with PCa at high risk of metastases. Two radiologists separately categorised the AS-MRI and WB-MRI as negative or positive for metastases, and measured focal metastases using the ''Response evaluation criteria in solid tumours'' (RECIST) criteria transposed to bone. One radiologist reviewed all examinations 2 months later. Inter- and intraobserver agreements in establishing the presence/absence of metastases were calculated. Bland-Altman plots were used to assess measurement agreement between AS-MRI and WB-MRI. Strong to perfect inter- and intraobserver agreements were found between AS-MRI and WB-MRI in defining the presence/absence of bone metastases. There were no patients with isolated ''peripheral'' metastases at WB-MRI, missed at AS-MRI. There was no difference in lesion count between the two radiologists. AS-MRI and WB-MRI provided statistically equivalent RECIST values for one radiologist and slightly lower values at AS-MRI for the other. In our series of PCa patients, AS-MRI and WB-MRI were equivalent in determining the presence/absence of bone metastases and provided similar evaluation of the metastatic burden. (orig.)

  6. Whole-body MRI (WB-MRI) versus axial skeleton MRI (AS-MRI) to detect and measure bone metastases in prostate cancer (PCa)

    Energy Technology Data Exchange (ETDEWEB)

    Lecouvet, F.E.; Simon, M.; Berg, B.C.V.; Simoni, P. [Universite Catholique de Louvain, Cliniques Universitaires St Luc, Department of Radiology and Medical Imaging, Brussels (Belgium); Tombal, B. [Universite Catholique de Louvain, Cliniques Universitaires St Luc, Department of Urology, Brussels (Belgium); Jamart, J. [Universite Catholique de Louvain, Clinique Universitaire de Mont-Godinne, Center of Biostatistics and Medical Documentation, Yvoir (Belgium)

    2010-12-15

    To compare whole-body MRI (WB-MRI) and axial skeleton MRI (AS-MRI) in detecting and measuring bone metastases in patients with prostate cancer (PCa). WB-MRI and AS-MRI examinations were performed in 60 patients with PCa at high risk of metastases. Two radiologists separately categorised the AS-MRI and WB-MRI as negative or positive for metastases, and measured focal metastases using the ''Response evaluation criteria in solid tumours'' (RECIST) criteria transposed to bone. One radiologist reviewed all examinations 2 months later. Inter- and intraobserver agreements in establishing the presence/absence of metastases were calculated. Bland-Altman plots were used to assess measurement agreement between AS-MRI and WB-MRI. Strong to perfect inter- and intraobserver agreements were found between AS-MRI and WB-MRI in defining the presence/absence of bone metastases. There were no patients with isolated ''peripheral'' metastases at WB-MRI, missed at AS-MRI. There was no difference in lesion count between the two radiologists. AS-MRI and WB-MRI provided statistically equivalent RECIST values for one radiologist and slightly lower values at AS-MRI for the other. In our series of PCa patients, AS-MRI and WB-MRI were equivalent in determining the presence/absence of bone metastases and provided similar evaluation of the metastatic burden. (orig.)

  7. MRI of intact plants

    OpenAIRE

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

    2009-01-01

    Nuclear magnetic resonance imaging (MRI) is a non-destructive and non-invasive technique that can be used to acquire two- or even three-dimensional images of intact plants. The information within the images can be manipulated and used to study the dynamics of plant water relations and water transport in the stem, e.g., as a function of environmental (stress) conditions. Non-spatially resolved portable NMR is becoming available to study leaf water content and distribution of water in different...

  8. Ovarian cysts on prenatal MRI

    International Nuclear Information System (INIS)

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

  9. Ovarian cysts on prenatal MRI

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-08-15

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

  10. Juvenile osteochondritis dissecans: a 5-year review of the natural history using clinical and MRI evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Jacqueline A.; Cook, Jane V.; Warren, Mary E. [Radiology Department, Queen Mary' s Hospital for Children, Epsom and St Helier NHS Trust, Carshalton, Surrey SM5 1AA (United Kingdom); Churchill, Mark A. [Orthopaedic Department, Queen Mary' s Hospital for Children, Epsom and St Helier NHS Trust, Carshalton (United Kingdom)

    2003-06-01

    Although MRI prognostic features for juvenile osteochondritis dissecans (JOCD) have been determined, the natural history of JOCD on serial MRI has not been fully documented. To document the natural history of JOCD on serial MRI and to correlate this with arthroscopy and clinical outcome over a 5-year follow-up. Twenty-one knees in 19 patients (15 boys, 4 girls; age range 5-15 years) with JOCD underwent MRI and clinical follow-up over 5 years. Lesions were classified as stable or unstable on MRI and compared with clinical and arthroscopic data. On 5-year follow-up, 17 of 19 patients were asymptomatic and 2 of 19 had minimal pain. Fourteen arthroscopies were performed on 11/21 knees. One of twenty-one had fragment fixation. On initial MRI, eight knees had marked fragmentation, high signal at the fragment/bone interface and incomplete defects in the hyaline cartilage (MRI stage III-stable), but no tear. Of these, five had arthroscopy, all confirming intact cartilage. One of twenty-one knees was unstable (MRI stage IVb) with a detached osteochondral fragment, requiring surgery. Despite extensive subchondral bone changes on MRI, all cases with intact cartilage (95%) improved with conservative treatment. Early MRI allows prompt diagnosis and institution of conservative treatment. This results in healing and avoidance of surgery in most patients. (orig.)

  11. Cardiovascular MRI with ferumoxytol.

    Science.gov (United States)

    Finn, J P; Nguyen, K-L; Han, F; Zhou, Z; Salusky, I; Ayad, I; Hu, P

    2016-08-01

    The practice of contrast-enhanced magnetic resonance angiography (CEMRA) has changed significantly in the span of a decade. Concerns regarding gadolinium (Gd)-associated nephrogenic systemic fibrosis in those with severely impaired renal function spurred developments in low-dose CEMRA and non-contrast MRA as well as efforts to seek alternative MR contrast agents. Originally developed for MR imaging use, ferumoxytol (an ultra-small superparamagnetic iron oxide nanoparticle), is currently approved by the US Food and Drug Administration for the treatment of iron deficiency anaemia in adults with renal disease. Since its clinical availability in 2009, there has been rising interest in the scientific and clinical use of ferumoxytol as an MR contrast agent. The unique physicochemical and pharmacokinetic properties of ferumoxytol, including its long intravascular half-life and high r1 relaxivity, support a spectrum of MRI applications beyond the scope of Gd-based contrast agents. Moreover, whereas Gd is not found in biological systems, iron is essential for normal metabolism, and nutritional iron deficiency poses major public health challenges worldwide. Once the carbohydrate shell of ferumoxytol is degraded, the elemental iron at its core is incorporated into the reticuloendothelial system. These considerations position ferumoxytol as a potential game changer in the field of CEMRA and MRI. In this paper, we aim to summarise our experience with the cardiovascular applications of ferumoxytol and provide a brief synopsis of ongoing investigations on ferumoxytol-enhanced MR applications. PMID:27221526

  12. Hyperoxia and Functional MRI.

    Science.gov (United States)

    Bulte, Daniel

    2016-01-01

    Oxygen plays a fundamental role in functional magnetic resonance imaging (FMRI). Blood oxygenation level-dependent (BOLD) imaging is the foundation stone of all FMRI and is still the essential workhorse of the vast majority of FMRI procedures. Hemoglobin may provide the magnetic properties that allow the technique to work, but it is oxygen that allows the contrast to effectively be switched on or off, and it is oxygen that we are interested in tracking in order to observe the oxygen metabolism changes. In general the changes in venous oxygen saturation are observed in order to infer changes in the correlated mechanisms, which can include changes in cerebral blood flow, metabolism, and the fraction of inspired oxygen. By independently manipulating the fraction of inspired oxygen it is possible to alter the amount of dissolved oxygen in the plasma, the venous saturation, or even the blood flow. The effects that these changes have on the observed MRI signal can be either a help or a hindrance depending on how well the changes induced are understood. The administration of supplemental inspired oxygen is in a unique position to provide a flexible, noninvasive, inexpensive, patient-friendly addition to the MRI toolkit to enable investigations to look beyond statistics and regions of interest, and actually produce calibrated, targeted measurements of blood flow, metabolism or pathology. PMID:27343097

  13. Tailgut cysts: MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Aflalo-Hazan, V.; Rousset, P.; Lewin, M.; Azizi, L. [Hopital Saint Antoine, Department of Radiology, PARIS Cedex 12 (France); Mourra, N. [Hopital Saint Antoine, Department of Pathology, PARIS Cedex 12 (France); Hoeffel, C. [Hopital Robert Debre, Department of Radiology, Reims Cedex (France)

    2008-11-15

    Magnetic resonance imaging (MRI) features of 11 surgically resected pelvic tailgut cysts were analyzed with reference to histopathologic and clinical data. Homogeneity, size, location, signal intensity, appearance and presence of septa and/or nodules and/or peripheral rim and involvement of surrounding structures were studied. Histological examination demonstrated 11 tailgut cysts (TGC), including one infected TGC and one TGC with a component of adenocarcinoma. Lesions (3-8 cm in diameter) were exclusively or partly retrorectal in all cases but one, with an extension down the anal canal in five cases. Lesions were multicystic in all patients but one. On T1-weighted MR images, all cystic lesions contained at least one hyperintense cyst. The peripheral rim of the cystic lesion was regular and non or moderately enhancing in all cases but the two complicated TGC. Nodular peripheral rim and irregular septa were seen in the degenerated TGC. Marked enhancement of the peripheral structures was noted in the two complicated TGC. Pelvic MRI is a valuable tool in the preoperative evaluation of TGC. (orig.)

  14. Tailgut cysts: MRI findings.

    Science.gov (United States)

    Aflalo-Hazan, V; Rousset, P; Mourra, N; Lewin, M; Azizi, L; Hoeffel, C

    2008-11-01

    Magnetic resonance imaging (MRI) features of 11 surgically resected pelvic tailgut cysts were analyzed with reference to histopathologic and clinical data. Homogeneity, size, location, signal intensity, appearance and presence of septa and/or nodules and/or peripheral rim and involvement of surrounding structures were studied. Histological examination demonstrated 11 tailgut cysts (TGC), including one infected TGC and one TGC with a component of adenocarcinoma. Lesions (3-8 cm in diameter) were exclusively or partly retrorectal in all cases but one, with an extension down the anal canal in five cases. Lesions were multicystic in all patients but one. On T1-weighted MR images, all cystic lesions contained at least one hyperintense cyst. The peripheral rim of the cystic lesion was regular and non or moderately enhancing in all cases but the two complicated TGC. Nodular peripheral rim and irregular septa were seen in the degenerated TGC. Marked enhancement of the peripheral structures was noted in the two complicated TGC. Pelvic MRI is a valuable tool in the preoperative evaluation of TGC. PMID:18566821

  15. MRI in intraspinal tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-01-01

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

  16. Postmortem MRI of bladder agenesis

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-01-15

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

  17. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... cases. MR images of the brain and other cranial structures are clearer and more detailed than with other imaging methods. This detail makes MRI an invaluable tool in early diagnosis and evaluation of many conditions, including tumors. MRI enables the discovery of ...

  18. Molecular MRI of Atherosclerotic lesions

    NARCIS (Netherlands)

    Adel, Brigit den

    2013-01-01

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

  19. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  20. 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 ...

  1. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI exam is assumed to outweigh the potential risks. Pregnant women should not receive injections of gadolinium contrast ... top of page What are the benefits vs. risks? Benefits ... (fMRI) in selected cases. MR images of the brain and other cranial structures ...

  2. MRI Findings In Dengue Encephalitis

    Directory of Open Access Journals (Sweden)

    Ashraf V.V

    2004-01-01

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

  3. Threats to ultra-high-field MRI

    Science.gov (United States)

    Le Bihan, Denis

    2009-08-01

    In 2004 the European Commission (EC) adopted a directive restricting occupational exposure to electromagnetic fields. This directive (2004/40/CE), which examines the possible health risks of the electromagnetic fields from mobile phones, Wi-Fi, Bluetooth and other devices, concluded that upper limits on radiation and applied electromagnetic fields are necessary to prevent workers from suffering any undue acute health effects. But although not initially intended, the biggest impact of the directive could be on magnetic resonance imaging (MRI), which is used in hospitals worldwide to produce images of unrivalled quality of the brain and other soft tissues.

  4. MRI in the assessment of congenital vaginal anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Humphries, P.D. [Department of Radiology, University College Hospital, London (United Kingdom); Simpson, J.C.; Creighton, S.M. [Department of Obstetrics and Gynaecology, University College Hospital, London (United Kingdom); Hall-Craggs, M.A. [Department of Radiology, University College Hospital, London (United Kingdom)], E-mail: margaret.hall-craggs@uclh.nhs.uk

    2008-04-15

    Aim: To assess accuracy of magnetic resonance imaging (MRI) for the delineation of morphological abnormalities of the vagina in patients with congenital anomalies of the genito-urinary tract. Materials and methods: Fifty-one patients (median age 19 years; range 12-40 years) were studied. All were consecutively referred for MRI to assess genital tract anatomy, between 1996 and 2004, from a clinic specializing in congenital abnormalities of the urogenital tract. All patients were assessed clinically and underwent MRI. Images were reviewed retrospectively by an experienced radiologist. Where there was discordance between clinical and radiological findings a consensus diagnosis was achieved by the gynaecologists and radiologists reviewing all of the clinical and radiological evidence together, including assessment of vaginal length. Results: The clinical data were incomplete for five women and the images non-diagnostic in two cases; consequently, 44 of 51 women had complete datasets and could be evaluated. Vaginas were abnormal in 30 of the 44 patients. There was discordance between the clinical and imaging findings at the initial review in three of the 44 cases (6.8%). After consensus review, and with the inclusion of measurement of the vaginal length on MRI, the MRI and clinical findings were concordant in all cases. The initial discordance was due to two vaginal dimples not being appreciated on MRI and one case in which presence of vaginal tissue proximal to a mid-segment obstruction was not appreciated clinically. Conclusion: MRI is an accurate method of imaging vaginal anomalies. However, to achieve reliable results the radiologist requires details of previous surgery and the vaginal length must be measured.

  5. MRI quantification of rheumatoid arthritis: current knowledge and future perspectives

    DEFF Research Database (Denmark)

    Boesen, Mikael; Østergaard, Mikkel; Cimmino, Marco A;

    2009-01-01

    The international consensus on treatment of rheumatoid arthritis (RA) involves early initiation of disease modifying anti-rheumatic drugs (DMARDs) for which a reliable identification of early disease is mandatory. Conventional radiography of the joints is considered the standard method for detect...... of inflammatory joint changes. In this review, we will discuss available data, advantages, limitations and potential future of MRI in RA....

  6. Visualizing electromagnetic vacuum by MRI

    CERN Document Server

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

    2016-01-01

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

  7. Fast Reference-Based MRI

    CERN Document Server

    Weizman, Lior; Ben-Basaht, Dafna

    2015-01-01

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

  8. MRI appearances of inflammatory vertebral osteitis in early ankylosing spondylitis

    Energy Technology Data Exchange (ETDEWEB)

    Kurugoglu, Sebuh; Kanberoglu, Kaya; Mihmanli, Ismail; Cokyuksel, Oktay [Department of Radiology, Cerrahpasa Medical Faculty, Istanbul University (Turkey); Kanberoglu, Ayfer [Department of Physical Medicine, SSK Istanbul Hospital, Istanbul (Turkey)

    2002-03-01

    Background: Undiagnosed and early ankylosing spondylitis (AS), especially in adolescent patients suffering from back pain, may present with the finding of vertebral osteitis on MRI. Aims: To identify the early MRI changes of vertebral osteitis in AS. Patients and methods: Five patients (three boys, two girls) aged 11-20 years (mean 15.4 years) suffering from back pain underwent MRI of the thoracolumbar spine. There was no initial diagnosis of AS. After clinical and radiological suspicion of AS, MRI of the sacroiliac (SI) joints was performed. Results: During the course of AS, destructive and reactive changes affect the discovertebral junctions that are initially seen in the thoracolumbar area. At this stage plain radiography of the spinal column may be normal. On MR images, inflammatory osteitis of the vertebrae is seen as hypointense areas on T1-weighted images and hyperintense areas on T2-W images. The lesions enhance homogenously with contrast material. Conclusions: Awareness of the MRI appearances of vertebral osteitis is helpful in suspecting AS. Radiological examination of the SI facilitates the diagnosis and unnecessary further imaging can be avoided. (orig.)

  9. MRI diagnosis of osteomyelitis of the cuboid bone in two infants

    International Nuclear Information System (INIS)

    We describe two infants in whom MRI diagnosed osteomyelitis of the cuboid bone when conventional X-rays were negative. Neoplastic, traumatic and ischaemic aetiologies could be excluded with the initial MR examinations. (orig.)

  10. MRI findings in Hirayama disease

    Directory of Open Access Journals (Sweden)

    Raval Monali

    2010-01-01

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

  11. MRI findings in Hirayama disease

    International Nuclear Information System (INIS)

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

  12. MRI findings in bipartite patella

    Energy Technology Data Exchange (ETDEWEB)

    Kavanagh, Eoin C. [University of Pittsburgh Medical Centre, Department of Radiology, Pittsburgh, PA (United States); Zoga, Adam; Omar, Imran [Thomas Jefferson University Hospital, Department of Radiology, Philadelphia, PA (United States); Ford, Stephanie; Eustace, Stephen [Cappagh National Orthopaedic Hospital, Department of Radiology, Dublin (Ireland); Schweitzer, Mark [Hospital for Joint Disease, Orthopedic Institute, Department of Radiology, New York, NY (United States)

    2007-03-15

    Bipartite patella is a known cause of anterior knee pain. Our purpose was to detail the magnetic resonance imaging (MRI) features of bipartite patella in a retrospective cohort of patients imaged at our institution. MRI exams from 53 patients with findings of bipartite patella were evaluated to assess for the presence of bone marrow edema within the bipartite fragment and for the presence of abnormal signal across the synchondrosis or pseudarthrosis. Any other significant knee pathology seen at MRI was also recorded. We also reviewed 400 consecutive knee MRI studies to determine the MRI prevalence of bipartite patella. Of the 53 patients with bipartite patella 40 (75%) were male; 35 (66%) had edema within the bipartite fragment. Of the 18 with no edema an alternative explanation for knee pain was found in 13 (72%). Edema within the bipartite fragment was the sole finding in 26 of 53 (49%) patients. Bipartite patella was seen in 3 (0.7%) of 400 patients. In patients with bipartite patella at knee MRI, bone marrow edema within the bipartite fragment was the sole finding on knee MRI in almost half of the patients in our series. (orig.)

  13. fMRI adaptation revisited.

    Science.gov (United States)

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

    2016-07-01

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

  14. Pediatric Burkitt lymphoma presenting as acute pancreatitis: MRI characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Amodio, John; Brodsky, Jennie E. [SUNY Downstate Medical Center, Department of Radiology, Brooklyn, NY (United States)

    2010-05-15

    Acute pancreatitis is a rare initial presentation of non-Hodgkin lymphoma with few reported cases described in older adults and even fewer in children. MRI features of Burkitt lymphoma of the pancreas are sparse in the radiologic literature. We present a 6-year-old boy who presented with pancreatitis and obstructive jaundice, which was the result of Burkitt lymphoma of the pancreas. The imaging findings of pancreatic involvement of Burkitt lymphoma on MRI are discussed and the contributory role of the radiologist in guiding the appropriate clinical work-up of this disease is highlighted. (orig.)

  15. MRI findings of neuro-Behcet's disease.

    Science.gov (United States)

    Borhani Haghighi, Afshin; Sarhadi, Sirous; Farahangiz, Siamak

    2011-06-01

    Neurological manifestations present in 5% to 30% of patients with Behçet's disease. We studied consecutive patients with relapsing--remitting or progressive neuro-Behcet's disease who referred from January 2002 to January 2009 to Nemazee Hospital, Shiraz, southern Iran. Sequential MRIs were performed during clinical relapses in patients with relapsing--remitting course or during relentless progression after first referral of patients with progressive course. We reviewed 55 MRIs of 17 patients (ten men and seven women) with age of 36.4 ± 8.1 years at the time of first MRI. Nine (53%) patients had a relapsing-remitting course and eight (47%) had a progressive course. The initial and last follow-up studies had a mean interval of 29.2 months (range, 24 to 84). Of the patients with progressive neuro-Behcet's disease, 50% had brainstem atrophy and 75% had black holes in their last follow-up MRIs. The respective prevalence rates for those with relapsing--remitting neuro-Behcet's disease were 0% and 11%. In the total population of patients with neuro-Behcet's disease, the number of lesions (p = 0.002) and MRI burden (p = 0.016) had a significant increase in the last follow-up studies in comparison to the initial studies. Incremental pattern in the number of lesions and MRI burdens in patients with parenchymal neuro-Behcet's disease in our longitudinal study may imply an ongoing pathologic process. PMID:21165752

  16. 3D Dynamic Response of Layered Unsaturated Soils to Harmonic Loads

    Institute of Scientific and Technical Information of China (English)

    XU Ming-jiang; WEI De-min

    2010-01-01

    Considering compression of solid grain and pore fluids,viscous-coupling interactions and inertial force of fluids,dynamic governing equations for unsaturated soils are established by adopting an exact constitutive formula of saturation.These equations are highly versatile and completely compatible with Biot's wave equations for the special case of fully saturated soils.The governing equations in Cartesian coordinates are firstly transformed into a group of state differential equations by introducing the state vector.Then the transfer matrix for layered media are derived by means of a double Fourier transform.Using the transfer matrix followed by boundary and continuity conditions between strata,solutions of steady-state dynamic response for multi-layered unsaturated soils are obtained.Numerical examples show that the echoes generated by boundary and stratum interfaces make the displacement amplitude of the ground surface fluctuate with distance;the relative position of soft and hard strata has a significant influence on displacement.

  17. KMOS^3D: Dynamical constraints on the mass budget in early star-forming disks

    CERN Document Server

    Wuyts, S; Wisnioski, E; Genzel, R; Burkert, A; Bandara, K; Beifiori, A; Belli, S; Bender, R; Brammer, G B; Chan, J; Davies, R; Fossati, M; Galametz, A; Kulkarni, S K; Lang, P; Lutz, D; Mendel, J T; Momcheva, I G; Naab, T; Nelson, E J; Saglia, R P; Seitz, S; Tacconi, L J; Tadaki, K; Übler, H; van Dokkum, P G; Wilman, D J; Wuyts, E

    2016-01-01

    We exploit deep integral-field spectroscopic observations with KMOS/VLT of 240 star-forming disks at 0.6 2 being strongly baryon-dominated within $R_e$. Substantial object-to-object variations in both stellar and baryonic mass fractions are observed among the galaxies in our sample, larger than what can be accounted for by the formal uncertainties in their respective measurements. In both cases, the mass fractions correlate most strongly with measures of surface density. High $\\Sigma_{star}$ galaxies feature stellar mass fractions closer to unity, and systems with high inferred gas or baryonic surface densities leave less room for additional mass components other than stars and molecular gas. Our findings can be interpreted as more extended disks probing further (and more compact disks probing less far) into the dark matter halos that host them. However, a non-negligible tail of the derived baryonic mass fraction distribution reaching into the unphysical $f_{bar} > 1$ regime may in addition hint at more effi...

  18. A Novel Flow-Perfusion Bioreactor Supports 3D Dynamic Cell Culture

    Directory of Open Access Journals (Sweden)

    Alexander M. Sailon

    2009-01-01

    Full Text Available Background. Bone engineering requires thicker three-dimensional constructs than the maximum thickness supported by standard cell-culture techniques (2 mm. A flow-perfusion bioreactor was developed to provide chemotransportation to thick (6 mm scaffolds. Methods. Polyurethane scaffolds, seeded with murine preosteoblasts, were loaded into a novel bioreactor. Control scaffolds remained in static culture. Samples were harvested at days 2, 4, 6, and 8 and analyzed for cellular distribution, viability, metabolic activity, and density at the periphery and core. Results. By day 8, static scaffolds had a periphery cell density of 67%±5.0%, while in the core it was 0.3%±0.3%. Flow-perfused scaffolds demonstrated peripheral cell density of 94%±8.3% and core density of 76%±3.1% at day 8. Conclusions. Flow perfusion provides chemotransportation to thick scaffolds. This system may permit high throughput study of 3D tissues in vitro and enable prefabrication of biological constructs large enough to solve clinical problems.

  19. A 3D dynamical biomechanical tongue model to study speech motor control

    CERN Document Server

    Gérard, J M; Perrier, P; Payan, Y; Gerard, Jean-Michel; Wilhelms-Tricarico, Reiner; Perrier, Pascal; Payan, Yohan

    2003-01-01

    A 3D biomechanical dynamical model of human tongue is presented, that is elaborated in the aim to test hypotheses about speech motor control. Tissue elastic properties are accounted for in Finite Element Modeling (FEM). The FEM mesh was designed in order to facilitate the implementation of muscle arrangement within the tongue. Therefore, its structure was determined on the basis of accurate anatomical data about the tongue. Mechanically, the hypothesis of hyperelasticity was adopted with the Mooney-Rivlin formulation of the strain energy function. Muscles are modeled as general force generators that act on anatomically specified sets of nodes of the FEM structure. The 8 muscles that are known to be largely involved in the production of basic speech movements are modeled. The model and the solving of the Lagrangian equations of movement are implemented using the ANSYSTM software. Simulations of the influence of muscle activations onto the tongue shape are presented and analyzed.

  20. The 3-D dynamics of slab break-off and implications for continental collision zones

    Science.gov (United States)

    van Hunen, Jeroen; Allen, Mark

    2010-05-01

    Some of the world best studied mountain ranges are a result of continental collision, such as the Himalayas, Zagros mountains, and the Alps. Continental collision forms the last stage of the closure of an oceanic basin, and leads to the slow-down or complete cessation of the subduction process. Previously subducted slab material will experience a period of thermal warming (Gerya et al., 2004) and/or a larger tensile stress, and will eventually weaken, yield and sink into the mantle. This process has potentially important implications for the thermal and stress regime of the overlying convergence zone, and has been held responsible for various phenomena such as late-stage magmatism (Davies and von Blanckenburg, 1995) and surface uplift or depression (van der Meulen et al., 1998, Buiter et al., 2002). Even though the collision process itself is relatively short-lived compared to the preceding oceanic subduction, its remnants are often preserved, and probably provide a valuable window into the plate tectonic process during the Proterozoic and perhaps the Archaean (e.g. Calvert et al., 1995). The three-dimensional nature of this break-off process has previously been discussed with conceptual models. E.g. slab break-off has been suggested to propagate laterally through an advancing tear (Wortel and Spakman, 2000). In this study we present 3D numerical results of the evolution of slab break-off. We focus on the development and evolution of a laterally migrating slab tear, and present results on the sensitivity of this process to the geometry of the closing oceanic basin, the tensile stresses in and the rheological properties of the slab, and the thermal state of the surrounding mantle. By comparing our numerical results to previously published analogue results (Regard et al., 2004) and various tomographic, structural, and magmatic observations of well-studied subduction collision systems, we are able to extract valuable insights in to the dynamics and strength of subducting oceanic and continental lithosphere.

  1. Solid friction at high sliding velocities: an explicit 3D dynamical SPH approach

    OpenAIRE

    Maveyraud, C.; Benz, W.; Ouillon, G.; Sornette, A.; Sornette, D.

    1998-01-01

    We present realistic 3D numerical simulations of elastic bodies sliding on top of each other in a regime of velocities ranging from meters to tens of meters per second using the so-called Smoothed Particle Hydrodynamics (SPH) method. Our investigations are restricted to regimes of pressure and roughness where only elastic deformations occur between asperities at the contact surface between the slider block and the substrate. In this regime, solid friction is due to the generation of vibration...

  2. 3D Dynamics of Magnetopause Reconnection Using Hall-MHD Global Simulations

    Science.gov (United States)

    Maynard, K.; Germaschewski, K.; Raeder, J.; Bhattacharjee, A.

    2011-12-01

    Magnetic reconnection at Earth's magnetopause and in the magnetotail is of crucial importance for the dynamics of the global magnetosphere and space weather. Even though the plasma conditions in the magnetosphere are largely in the collisionless regime, most of the existing research using global computational models employ single-fluid magnetohydrodynamics (MHD) with artificial resistivity. Studies of reconnection in simplified, two-dimensional geometries have established that two-fluid and kinetic effects can dramatically alter dynamics and reconnection rates when compared with single-fluid models. These enhanced models also introduce particular signatures, for example a quadrupolar out-of-plane magnetic field component that has already been observed in space by satellite measurements. However, results from simplified geometries cannot be translated directly to the dynamics of three-dimensional magnetospheric reconnection. For instance, magnetic flux originating from the solar wind and arriving at the magnetopause can either reconnect or be advected around the magnetosphere. In this study, we use a new version of the OpenGGCM code that incorporates the Hall term in a Generalized Ohm's Law to study magnetopause reconnection under synthetic solar wind conditions and investigate how reconnection rates and dynamics of flux transfer events depend on the strength of the Hall term. The OpenGGCM, a global model of Earth's magnetosphere, has recently been ported to exploit modern computing architectures like the Cell processor and SIMD capabilities of conventional processors using an automatic code generator. These enhancements provide us with the performance needed to include the computationally expensive Hall physics.

  3. Tailored RF Pulse Modulation for RF Refocussed Variable Flip Angle MRI

    Science.gov (United States)

    Shah, Ajit S.; Ortendahl, Douglas A.; Carlson, Joseph W.; Kramer, David M.; Crooks, Larry E.

    1989-05-01

    Advances in Magnetice Resonance Imaging (MRI) techniques have recently made MRI the imaging modality of choice for many applications of clinical imaging. MRI provides the diagnosing clinician a non-invasive method for obtaining soft tissue differentiation with sub-millimeter resolution. Clinical MRI techniques include 3-dimensional imaging, spectroscopic imaging, arterial angiography and cardiac imaging. One MRI technique which has recently gained popularity is a class of protocols known as variable/partial flip angle MRI. Partial flip angle MRI techniques are useful because of their ability to vary contrast between tissues and/or maintain a particular level of contrast with a reduction in acquisition time [1]. Variable flip angle techniques differ from conventional MRI protocols in that the initial RF excitation/rotation pulse is not constrained to a 90 degree rotation of the longitudinal magnetization. Instead, the initial excitation flip angle is calculated to provide improved contrast between two tissues and/or maximize the intensity of a particular tissue. For tissues with reduced TR/T1 ratios, variable flip angle techniques may also be used to increase the image signal to noise within a localized region.

  4. Pictorial essay: MRI of the fetal brain

    International Nuclear Information System (INIS)

    MRI is a useful supplement to USG for the assessment of fetal brain malformations. Superior soft tissue contrast and the ability to depict sulcation and myelination are the strengths of MRI. Subtle or inconclusive USG abnormalities can be confirmed or ruled out by MRI. In some cases, additional findings detected with MRI often help in arriving at a definitive diagnosis, which is necessary for parental counseling and for guiding management. Fast T2W sequences form the basis of fetal MRI. There have been no reports of deleterious effects of MRI on the fetus. A few case examples are presented to illustrate the advantages of MRI

  5. Early detection of Alzheimer's disease using MRI hippocampal texture

    DEFF Research Database (Denmark)

    Sørensen, Lauge; Igel, Christian; Hansen, Naja Liv;

    2016-01-01

    Cognitive impairment in patients with Alzheimer's disease (AD) is associated with reduction in hippocampal volume in magnetic resonance imaging (MRI). However, it is unknown whether hippocampal texture changes in persons with mild cognitive impairment (MCI) that does not have a change in hippocam......Cognitive impairment in patients with Alzheimer's disease (AD) is associated with reduction in hippocampal volume in magnetic resonance imaging (MRI). However, it is unknown whether hippocampal texture changes in persons with mild cognitive impairment (MCI) that does not have a change...... in hippocampal volume. We tested the hypothesis that hippocampal texture has association to early cognitive loss beyond that of volumetric changes. The texture marker was trained and evaluated using T1-weighted MRI scans from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database, and subsequently...

  6. Real-time functional MR imaging (fMRI) for presurgical evaluation of paediatric epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Kesavadas, Chandrasekharan; Thomas, Bejoy; Kumar Gupta, Arun [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Department of Imaging Sciences and Interventional Radiology, Trivandrum (India); Sujesh, Sreedharan [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Biomedical Technology Wing, Trivandrum (India); Ashalata, Radhakrishnan; Radhakrishnan, Kurupath [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Department of Neurology, Trivandrum (India); Abraham, Mathew [Sree Chitra Tirunal Institute for Medical Sciences and Technology, Department of Neurosurgery, Trivandrum (India)

    2007-10-15

    The role of fMRI in the presurgical evaluation of children with intractable epilepsy is being increasingly recognized. Real-time fMRI allows the clinician to visualize functional brain activation in real time. Since there is no off-line data analysis as in conventional fMRI, the overall time for the procedure is reduced, making it clinically feasible in a busy clinical sitting. (1) To study the accuracy of real-time fMRI in comparison to conventional fMRI with off-line processing; (2) to determine its effectiveness in mapping the eloquent cortex and language lateralization in comparison to invasive procedures such as intraoperative cortical stimulation and Wada testing; and (3) to evaluate the role of fMRI in presurgical decision making in children with epilepsy. A total of 23 patients (age range 6-18 years) underwent fMRI with sensorimotor, visual and language paradigms. Data processing was done in real time using in-line BOLD. The results of real-time fMRI matched those of off-line processing done using the well-accepted standard technique of statistical parametric mapping (SPM) in all the initial ten patients in whom the two techniques were compared. Coregistration of the fMRI data on a 3-D FLAIR sequence rather than a T1-weighted image gave better information regarding the relationship of the lesion to the area of activation. The results of intraoperative cortical stimulation and fMRI matched in six out of six patients, while the Wada test and fMRI had similar results in four out of five patients in whom these techniques were performed. In the majority of patients in this series the technique influenced patient management. Real-time fMRI is an easily performed and reliable technique in the presurgical workup of children with epilepsy. (orig.)

  7. Real-time functional MR imaging (fMRI) for presurgical evaluation of paediatric epilepsy

    International Nuclear Information System (INIS)

    The role of fMRI in the presurgical evaluation of children with intractable epilepsy is being increasingly recognized. Real-time fMRI allows the clinician to visualize functional brain activation in real time. Since there is no off-line data analysis as in conventional fMRI, the overall time for the procedure is reduced, making it clinically feasible in a busy clinical sitting. (1) To study the accuracy of real-time fMRI in comparison to conventional fMRI with off-line processing; (2) to determine its effectiveness in mapping the eloquent cortex and language lateralization in comparison to invasive procedures such as intraoperative cortical stimulation and Wada testing; and (3) to evaluate the role of fMRI in presurgical decision making in children with epilepsy. A total of 23 patients (age range 6-18 years) underwent fMRI with sensorimotor, visual and language paradigms. Data processing was done in real time using in-line BOLD. The results of real-time fMRI matched those of off-line processing done using the well-accepted standard technique of statistical parametric mapping (SPM) in all the initial ten patients in whom the two techniques were compared. Coregistration of the fMRI data on a 3-D FLAIR sequence rather than a T1-weighted image gave better information regarding the relationship of the lesion to the area of activation. The results of intraoperative cortical stimulation and fMRI matched in six out of six patients, while the Wada test and fMRI had similar results in four out of five patients in whom these techniques were performed. In the majority of patients in this series the technique influenced patient management. Real-time fMRI is an easily performed and reliable technique in the presurgical workup of children with epilepsy. (orig.)

  8. Intracranial tuberculoma: CT and MRI

    International Nuclear Information System (INIS)

    The appearances of intracranial tuberculoma on CT and MRI are described. Eight patients (6 males and 2 females) with intracranial tuberculomas studied over the past 4 years are presented. Four patients had AIDS and among the four non-AIDS patients 1 had undergone hepatic transplantation. All the cases were studied with CT and 6 underwent MRI. Five lesions were infratentorial, and 2 patients had double lesions. In 2 patients obstructive triventricular hydrocephalus was present. No patient had meningeal involvement. The stage of evolution was cerebritis in 1 case, incipient tuberculoma in 3 cases, mature tuberculoma in 1 case and tuberculous abscess in 5 cases. Diagnosis of intracranial tuberculoma was determined histologically in 5 patients and by good response to specific therapy in the remaining patients. Although CT allows differentiation between incipient and mature tuberculoma, MRI allows a better determination of the evolutonary stage. In most cases combined CT and MRI examinations provide an accurate diagnosis of intracranial tuberculoma. (orig.)

  9. Intracranial tuberculoma: CT and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Bargallo, N. [Dept. of Radiology, Hospital Clinic i Provincial de Barcelona (Spain); Berenguer, J. [Dept. of Radiology, Hospital Clinic i Provincial de Barcelona (Spain); Tomas, X. [Dept. of Radiology, Hospital Clinic i Provincial de Barcelona (Spain); Nicolau, C. [Dept. of Radiology, Hospital Clinic i Provincial de Barcelona (Spain); Cardenal, C. [Dept. of Radiology, Hospital Clinic i Provincial de Barcelona (Spain); Mercader, J.M. [Dept. of Radiology, Hospital Clinic i Provincial de Barcelona (Spain)

    1993-04-01

    The appearances of intracranial tuberculoma on CT and MRI are described. Eight patients (6 males and 2 females) with intracranial tuberculomas studied over the past 4 years are presented. Four patients had AIDS and among the four non-AIDS patients 1 had undergone hepatic transplantation. All the cases were studied with CT and 6 underwent MRI. Five lesions were infratentorial, and 2 patients had double lesions. In 2 patients obstructive triventricular hydrocephalus was present. No patient had meningeal involvement. The stage of evolution was cerebritis in 1 case, incipient tuberculoma in 3 cases, mature tuberculoma in 1 case and tuberculous abscess in 5 cases. Diagnosis of intracranial tuberculoma was determined histologically in 5 patients and by good response to specific therapy in the remaining patients. Although CT allows differentiation between incipient and mature tuberculoma, MRI allows a better determination of the evolutonary stage. In most cases combined CT and MRI examinations provide an accurate diagnosis of intracranial tuberculoma. (orig.)

  10. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... want to ask your doctor for a mild sedative prior to the exam. What is MRI of ... your physician for a prescription for a mild sedative prior to your scheduled examination. Jewelry and other ...

  11. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... may have. top of page What does the equipment look like? The traditional MRI unit is a ... traction devices and many types of life support equipment must be kept away from the area to ...

  12. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  13. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  14. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... the 1980s with no reports of any ill effects on pregnant women or their unborn babies. However, ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ...

  15. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... contrast for an MRI. If you have a history of kidney disease or liver transplant, it will ... you are in the scanner without causing any chemical changes in the tissues. As the hydrogen atoms ...

  16. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... so the radiologist should be aware of them. Parents or family members who accompany patients into the ... intercom. Many MRI centers allow a friend or parent to stay in the room as long as ...

  17. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  18. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... contrast for an MRI. If you have a history of kidney disease or liver transplant, it will ... data suggest that it is safe to continue breastfeeding after receiving intravenous contrast. For further information please ...

  19. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  20. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  1. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... to produce detailed pictures of organs, soft tissues, bone and virtually all other internal body structures. MRI ... discovery of abnormalities that might be obscured by bone with other imaging methods. The contrast material used ...

  2. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... MRI scanners are air-conditioned and well-lit. Music may be played through the headphones to help ... from the contrast material, including nausea and local pain. Similarly, patients are very rarely allergic to the ...

  3. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  4. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  5. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  6. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  7. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  8. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... within a vein) top of page How should I prepare? You may be asked to wear a ... total exam time. top of page What will I experience during and after the procedure? Most MRI ...

  9. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  10. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... page What does the equipment look like? The traditional MRI unit is a large cylinder-shaped tube ... page Additional Information and Resources RTAnswers.org : Radiation Therapy for Brain Tumors Radiation Therapy for Head and ...

  11. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (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 ... page Additional Information and Resources RTAnswers.org : Radiation Therapy for Brain Tumors Radiation Therapy for Head and ...

  13. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits MRI is a noninvasive imaging technique that does ... the possible charges you will incur. Web page review process: This Web page is reviewed regularly by ...

  14. Metalloprotein-based MRI probes.

    Science.gov (United States)

    Matsumoto, Yuri; Jasanoff, Alan

    2013-04-17

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

  15. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... take food and medications as usual. Some MRI examinations may require you to receive an injection of ... for a mild sedative prior to your scheduled examination. Jewelry and other accessories should be left at ...

  16. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... in patients with very poor kidney function. Careful assessment of kidney function before considering a contrast injection ... the limitations of MRI of the Head? High-quality images are assured only if you are able ...

  17. 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 ... the possible charges you will incur. Web page review process: This Web page is reviewed regularly by ...

  18. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... a computer to produce detailed pictures of organs, soft tissues, bone and virtually all other internal body structures. MRI does not use ionizing radiation (x-rays). Detailed MR images allow physicians to evaluate various ...

  19. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  20. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... contrast for an MRI. If you have a history of kidney disease or liver transplant, it will ... gadolinium contrast material except when absolutely necessary for medical treatment. See the Safety page for more information ...

  1. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    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, ...

  2. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

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

  3. Dynamic MRI CSF imaging

    International Nuclear Information System (INIS)

    Full text: Understanding of the cerebrospinal fluid (CSF) flow physiological and anatomical substrate underwent the revolutionary process during the last one hundred years, resulting with the theory of what we call today the 'bulk' flow. Due to almost incredible technological advance we experienced a prominent clinical and experimental advance in the field of CSF creation, flow, and absorption that have brought the 'bulk' flow theory partly under question. There are still a large number of uncertainties in our truly understanding of basic CSF flow physiology, but also pathology, that are persistently present, requesting further and ever more advanced investigation in order to provide the most adequate diagnosis for the benefit of the patient. It is my strong believe that the diagnostic reality nowadays is that we are still facing the major lack of understanding how is CSF actually created, what are the CSF pathways trough the intracranial and extracranial spaces, and finally where and how does CSF got absorbed. This certainly opens the space for numerous different theories pretending to give correct explanation of CSF physiological behavior. On the other hand, a proper and valuable technique which would provide us with the wanted information may still not be available at the present time. Therefore, as the radiologists examining the patients with CSF flow disorders, we are constantly challenged by the number of questions in an attempt to achieve the relevant and overall, accurate diagnostic information on the type of the CSF flow disorder, in order to facilitate the planning of the better individually optimized neurosurgical treatment. Though MRI, with mostly used phase-contrast but also technically older maximum dephasing techniques allows dynamic CSF flow visualization introducing us into the field of CSF hydrodynamics disorder diagnostics, we should face the fact that in the routine radiological examination with currently available and most dedicated

  4. Pictorial essay: MRI of the fetal brain

    OpenAIRE

    B, Ganesh Rao; Ramamurthy, BS

    2009-01-01

    MRI is a useful supplement to USG for the assessment of fetal brain malformations. Superior soft tissue contrast and the ability to depict sulcation and myelination are the strengths of MRI. Subtle or inconclusive USG abnormalities can be confirmed or ruled out by MRI. In some cases, additional findings detected with MRI often help in arriving at a definitive diagnosis, which is necessary for parental counseling and for guiding management. Fast T2W sequences form the basis of fetal MRI. There...

  5. Clinical application of functional MRI

    International Nuclear Information System (INIS)

    Described is the present state of clinical application of fMRI in the preoperative assessment of brain tumors, and plasticity in and pathophysiology of central diseases. For the tumor resection, fMRI is useful for risk assessment of postoperative nerve dysfunction, for selection of the patient rather suitable for brain mapping at the invasive surgery than at the pre-operation and for guidance of the operation itself. Preoperative fMRI alone can neither distinguish the regions of the primary and secondary functions nor exhibit the relation between the tumor and white matter fibers but there are compensatory means for these drawbacks. Benefit of preoperative fMRI has not yet been based on the evidence on double blind trials. Combination of fMRI imaging and electroencephalography (EEG) finding has shown that, in generalized epilepsy, extensive and stimulated activation occurs in both frontal/occipital regions and in thalamus area, respectively, and that the concomitant lowered activities are conceivably the reflection of burst discharge in normal brain functions. Plasticity in the human brain has been demonstrated by fMRI in cerebral vascular diseases, multiple sclerosis and amyotrophic lateral sclerosis. Pathogenesis of Parkinson disease and depression has been better understood by fMRI investigations revealing regions with elevated and reduced activities. Studies of attention deficit hyperactivity disorder have shown similar change of activities with functional reductions of the right dorsolateral frontal anterior area and of dorsal frontal cingulate gyrus, together with stimulated wider regions to given tasks. As above, fMRI has greatly contributed to our understanding of diseases of central nervous system and is to be expected to expand wider in this field. (T.T.)

  6. MRI findings of Intracranial hemangioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Deok; Cho, Mee Young [College of Medicine, Inje University, Busan (Korea, Republic of); Baik, Seung Kug [Wallace Memorial Hospital, Busan (Korea, Republic of); Choi, Sun Sub [College of Medicine Dong-A University, Busan (Korea, Republic of); Kim, Chang Soo; Chung, Chun Phil [Maryknoll Hospital, Busan (Korea, Republic of)

    1995-10-15

    Complete resection of the tumor nodule (mural nodule or solid portion of the tumor) is the essential goal of surgical treatment for hemangioblastoma. The purpose of this study was to classify the morphologic types of intracranial hemangioblastoma on MRI and to compare the location and contour of tumor nodule on MRI with those on angiography. The MRI findings of 34 lesions (38 lesions if 4 spinal cord lesions were included) in 26 patients (17 males and 9 females, range of age, 18-67 years, mean, 39 years) with surgically and histopathologically proved intracranial hemangioblastomas were reviewed. Seventeen patients underwent CT scanning in a short interval. Contrast-enahnced T1-weighted imaging patterns of hemangioblastoma were classified according to Ho's morphologic types. The location and contour of tumor nodule were compared between MRI and angiography in 15 patients (24 lesions). By location, cerebellar hemisphere predominated (55%), followed by cerebellar vermis (26%), supratentorial region (5%), and medulla oblongata (3%). Spinal cord lesions (11%) were seen in 3 patients of 5 von Hippel-Lindau diseases. The frequency of morphologic types was as follows; Type 1 (purely cystic), 3%, Type 2 (mural nodule), 50%, Type 3 (cyst with wall enhancement), 3%, Type 4 (cystic nodule), 15%, Type 5 (solid with internal cyst), 9%, and Type 6 (solid), 20%. All tumor nodules (33 lesions) enhanced intensely with intravenous contrast material on MRI, of which 24 lesions (in 15 patients) revealed hypervascular masses fed by pial arteries on angiography. They were superficial and abutted pia mater partially or in large portion on both MRI and angiography. Over 70% of intracranial hemangioblastomas had a surrounding cyst, and superficial, pial-based location and number of the tumor nodules on MRI was correlated well with those on angiography. MRI is the examination of choice for preoperative evaluation of intracranial hemangioblastoma.

  7. MRI evaluation of vascular dementia

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

  8. High resolution pituitary gland MRI at 7.0 tesla: a clinical evaluation in Cushing's disease

    Energy Technology Data Exchange (ETDEWEB)

    Rotte, Alexandra A.J. de; Groenewegen, Amy; Rutgers, Dik R.; Witkamp, Theo; Luijten, Peter R.; Hendrikse, Jeroen [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Zelissen, Pierre M.J. [University Medical Center Utrecht, Department of Internal Medicine (Section of Endocrinology), Utrecht (Netherlands); Meijer, F.J.A. [Radboud University Medical Center, Department of Radiology and Nuclear Medicine, Nijmegen (Netherlands); Lindert, Erik J. van [Radboud University Medical Center, Department of Neurosurgery, Nijmegen (Netherlands); Hermus, Ad [Radboud University Medical Center, Department of Internal Medicine (Section of Endocrinology), Nijmegen (Netherlands)

    2016-01-15

    To evaluate the detection of pituitary lesions at 7.0 T compared to 1.5 T MRI in 16 patients with clinically and biochemically proven Cushing's disease. In seven patients, no lesion was detected on the initial 1.5 T MRI, and in nine patients it was uncertain whether there was a lesion. Firstly, two readers assessed both 1.5 T and 7.0 T MRI examinations unpaired in a random order for the presence of lesions. Consensus reading with a third neuroradiologist was used to define final lesions in all MRIs. Secondly, surgical outcome was evaluated. A comparison was made between the lesions visualized with MRI and the lesions found during surgery in 9/16 patients. The interobserver agreement for lesion detection was good at 1.5 T MRI (κ = 0.69) and 7.0 T MRI (κ = 0.62). In five patients, both the 1.5 T and 7.0 T MRI enabled visualization of a lesion on the correct side of the pituitary gland. In three patients, 7.0 T MRI detected a lesion on the correct side of the pituitary gland, while no lesion was visible at 1.5 T MRI. The interobserver agreement of image assessment for 7.0 T MRI in patients with Cushing's disease was good, and lesions were detected more accurately with 7.0 T MRI. (orig.)

  9. High resolution pituitary gland MRI at 7.0 tesla: a clinical evaluation in Cushing's disease

    International Nuclear Information System (INIS)

    To evaluate the detection of pituitary lesions at 7.0 T compared to 1.5 T MRI in 16 patients with clinically and biochemically proven Cushing's disease. In seven patients, no lesion was detected on the initial 1.5 T MRI, and in nine patients it was uncertain whether there was a lesion. Firstly, two readers assessed both 1.5 T and 7.0 T MRI examinations unpaired in a random order for the presence of lesions. Consensus reading with a third neuroradiologist was used to define final lesions in all MRIs. Secondly, surgical outcome was evaluated. A comparison was made between the lesions visualized with MRI and the lesions found during surgery in 9/16 patients. The interobserver agreement for lesion detection was good at 1.5 T MRI (κ = 0.69) and 7.0 T MRI (κ = 0.62). In five patients, both the 1.5 T and 7.0 T MRI enabled visualization of a lesion on the correct side of the pituitary gland. In three patients, 7.0 T MRI detected a lesion on the correct side of the pituitary gland, while no lesion was visible at 1.5 T MRI. The interobserver agreement of image assessment for 7.0 T MRI in patients with Cushing's disease was good, and lesions were detected more accurately with 7.0 T MRI. (orig.)

  10. Imaging the fetus: when does MRI really help?

    Energy Technology Data Exchange (ETDEWEB)

    Garel, Catherine [Hopital d' Enfants Armand-Trousseau, Service de Radiologie Pediatrique, Paris Cedex 12 (France)

    2008-06-15

    It is widely accepted that fetal MRI should be used to complement rather than to replace US, which remains the primary screening modality. Under certain circumstances where US is limited, such as maternal obesity, fetal MRI may be useful as a primary screening tool. It is well known that maternal obesity is increasing worldwide and is more common in certain countries. It certainly contributes to a shift from US to MRI as a prenatal diagnostic imaging modality. Inadequacies of US may also be directly related to the sonographer's level of experience. Use and development of fetal US are not comparable in different countries. Some countries prioritise the development of fetal US and increase the experience of sonographers by political initiatives such as reimbursement of US by social insurance, thus raising people's expectations. In other countries, fetal US is considered of secondary importance and is not exploited as much as it could be. Consequently, in those countries, the place occupied by fetal MRI and the expectations regarding its diagnostic accuracy are much more prominent. This is undoubtedly the reason why there are so many discrepancies regarding the relative contributions of fetal MRI and fetal US in the prenatal literature. (orig.)

  11. MRI and ultrasound in children with juvenile chronic arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Lamer, S.; Sebag, G.H

    2000-02-01

    In this era of advancing imaging technology, a knowledge of the relative values of available imaging techniques is necessary to optimize the management of children with juvenile chronic arthritis (JCA). After clinical examination, plain films remain the initial investigation. The need for radiation protection must be a priority in children with JCA. Conventional radiographs allow grouping of the various arthritides (on the base of the distribution and pattern of joint space changes) and staging of disease progression. Ultrasound (US) is very sensitive in the detection of joint effusions, especially in the hip, and guides fluid aspiration. US and Doppler can be used for the evaluation of synovial hypertrophy and activity. Arthrography and to a certain extent nuclear studies have been replaced by magnetic resonance imaging (MRI). MRI can demonstrate articular cartilage, joint effusion, synovial hypertrophy, cortical and medullary bone, cartilage and bone perfusion, and fibrocartilaginous structures (menisci and ligaments). Contrast enhanced MRI is the most sensitive modality to determine whether an arthritic condition is present. However, it does not assist in establishing a specific diagnosis. MRI determines accurately the activity and the extent of the disease and is particularly useful in the early detection of articular damage. Finally, MRI is of major importance in the evaluation of response to local therapy (especially steroids) and the detection of complications.

  12. Dynamic MRI of the liver with parallel acquisition technique. Characterization of focal liver lesions and analysis of the hepatic vasculature in a single MRI session

    International Nuclear Information System (INIS)

    Purpose: to retrospectively evaluate the performance of breath-hold contrast-enhanced 3D dynamic parallel gradient echo MRI (pMRT) for the characterization of focal liver lesions (standard of reference: histology) and for the analysis of hepatic vasculature (standard of reference: contrast-enhanced 64-detector row computed tomography; MSCT) in a single MRI session. Materials and method: two blinded readers independently analyzed preoperative pMRT data sets (1.5T-MRT) of 45 patients (23 men, 22 women; 28 - 77 years, average age, 48 years) with a total of 68 focal liver lesions with regard to image quality of hepatic arteries, portal and hepatic veins, presence of variant anatomy of the hepatic vasculature, as well as presence of portal vein thrombosis and hemodynamically significant arterial stenosis. In addition, both readers were asked to identify and characterize focal liver lesions. Imaging parameters of pMRT were: TR/TE/matrix/slice thickness/acquisition time: 3.1 ms/1.4 ms/384 x 224/4 mm/15 - 17 s. MSCT was performed with a pitch of 1.2, an effective slice thickness of 1 mm and a matrix of 512 x 512. Results: based on histology, the 68 liver lesions were found to be 42 hepatocellular carcinomas (HCC), 20 metastases, 3 cholangiocellular carcinomas (CCC) as well as 1 dysplastic nodule, 1 focal nodular hyperplasia (FNH) and 1 atypical hemangioma. Overall, the diagnostic accuracy was high for both readers (91 - 100%) in the characterization of these focal liver lesions with an excellent interobserver agreement (κ-values of 0.89 [metastases], 0.97 [HCC] and 1 [CCC]). On average, the image quality of all vessels under consideration was rated good or excellent in 89% (reader 1) and 90% (reader 2). Anatomical variants of the hepatic arteries, hepatic veins and portal vein as well as thrombosis of the portal vein were reliably detected by pMRT. Significant arterial stenosis was found with a sensitivity between 86% and 100% and an excellent interobserver agreement (κ

  13. Semicircular canal dehiscence: comparison of T2-weighted turbo spin-echo MRI and CT

    Energy Technology Data Exchange (ETDEWEB)

    Krombach, G.A.; Schmitz-Rode, T.; Haage, P.; Guenther, R.W. [Department of Diagnostic Radiology, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany); DiMartino, E. [Department of Otorhinolaryngology, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany); Prescher, A. [Department of Anatomy, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany); Kinzel, S. [Department of Experimental Veterinary Medicine, University of Technology, Pauwelstrasse 30, 52057, Aachen (Germany)

    2004-04-01

    We assessed the value of MRI for delineation of dehiscence of the superior or posterior semicircular canal, as compared with CT, the current standard study for this entity. We reviewed heavily T2-weighted fast spin-echo images and high-resolution CT of the temporal bones of 185 patients independently semicircular canal dehiscence and its extent. In 30 patients (19 men, 11 women) we identified dehiscence of the bone over the superior and/or posterior semicircular canal on MRI. In 27 of these cases CT also showed circumscribed bone defects. In one patient dehiscence of the superior semicircular canal was initially overlooked on MRI, but seen on CT. MRI imaging thus had a sensitivity of 96% and specificity of 98%. Knowledge of the appearances of this entity on MRI may contribute to early diagnosis in patients with vertigo due to semicircular canal dehiscence. (orig.)

  14. Spondyloarthritis-related and degenerative MRI changes in the axial skeleton--an inter- and intra-observer agreement study

    DEFF Research Database (Denmark)

    Arnbak, Bodil; Jensen, Tue Secher; Manniche, Claus;

    2013-01-01

    The Back Pain Cohort of Southern Denmark (BaPa Cohort) was initiated with the aim of evaluating the clinical relevance of magnetic resonance imaging (MRI) in the diagnosis of early spondyloarthritis (SpA). In order to facilitate the collection of MRI data for this study, an electronic evaluation ...

  15. Dementia: role of MRI

    International Nuclear Information System (INIS)

    Full text: This presentation will focus on the role of MRI in the diagnosis of dementia and related diseases. We will discuss the following subjects: 1. Systematic assessment of MR in dementia 2. MR protocol for dementia 3. Typical findings in the most common dementia syndrome Alzheimer's disease (AD), Vascular Dementia (VaD), Frontotemporal lobe dementia (FTLD) 4. Short overview of neurodegenerative disorders which may be associated with dementia. The role of neuroimaging in dementia nowadays extends to support the diagnosis of specific neurodegenerative disorders. It is a challenge to the early diagnosis of neurodegenerative diseases such as Alzheimer's disease. Early diagnosis includes recognition of predementia conditions, such as mild cognitive impairment (MCI). Neuroimaging may also be used to assess disease progression and is adopted in current trials investigating MCI and AD. An MR-study of a patient suspected of having dementia must be assessed in a standardized way. First of all, treatable diseases like subdural hematomas, tumors and hydrocephalus need to be excluded. Next we should look for signs of specific dementias such as: Alzheimer's disease (AD): medial temporal lobe atrophy (MTA) and parietal atrophy. Frontotemporal Lobar Degeneration (FTLD): (asymmetric) frontal lobe atrophy and atrophy of the temporal pole. Vascular Dementia (VaD): global atrophy, diffuse white matter lesions, lacunas and 'strategic infarcts' (infarcts in regions that are involved in cognitive function). Dementia with Lewy bodies (DLB): in contrast to other forms of dementia usually no specific abnormalities. So when we study the MR images we should score in a systematic way for global atrophy, focal atrophy and for vascular disease (i.e. infarcts, white matter lesions, lacunas)

  16. [MRI-guided musculoskeletal biopsy].

    Science.gov (United States)

    Daecke, W; Libicher, M; Mädler, U; Rumpf, C; Bernd, L

    2003-02-01

    MRI-guided musculoskeletal biopsy has been mentioned to be a minimally invasive method to obtain specimens for diagnostic purposes in bone tumors. To evaluate the viability, to assess the accuracy, and to record possible complications of this method, clinical data of 19 MRI-guided biopsies were analyzed. Interventions were performed on 18 patients (1-78 years) as an outpatient procedure: 15 skeletal and 4 soft tissue biopsies were taken from the pelvis, upper limb,or lower limb. We used T1-weighted gradient echoes (GE) for locating the puncture site and T2-weighted turbo spin echoes (TSE) for visualization of needle position. In 14 of 18 MRI-guided biopsies, a definite histological diagnosis was obtained. According to the pathologist, the inadequate size of the specimen was the main reason for missing the diagnoses in four cases.Long intervention time and inappropriate biopsy tools proved to be the main disadvantages of MRI-guided biopsy, but technical improvement might solve these technical problems in future.A postbiopsy hematoma was the only complication observed. Once technically improved, MRI-guided biopsy could be a precise alternative routine method for musculoskeletal biopsies in future. PMID:12607083

  17. Whole-body MRI screening

    Energy Technology Data Exchange (ETDEWEB)

    Puls, Ralf [HELIOS Klinikum Erfurt (Germany). Inst. of Diagnostic and Interventional Radiology and Neuroradiology; Hosten, Norbert (ed.) [Universitaetsklinikum Greifswald (Germany). Diagnostic Radiology and Neuroradiology

    2014-07-01

    The advent of dedicated whole-body MRI scanners has made it possible to image the human body from head to toe with excellent spatial resolution and with the sensitivity and specificity of conventional MR systems. A comprehensive screening examination by MRI relies on fast image acquisition, and this is now feasible owing to several very recent developments, including multichannel techniques, new surface coil systems, and automatic table movement. The daily analysis of whole-body MRI datasets uncovers many incidental findings, which are discussed by an interdisciplinary advisory board of physicians from all specialties. This book provides a systematic overview of these incidental findings with the aid of approximately 240 high-quality images. The radiologists involved in the project have written chapters on each organ system, presenting a structured compilation of the most common findings, their morphologic appearances on whole-body MRI, and guidance on their clinical management. Chapters on technical and ethical issues are also included. It is hoped that this book will assist other diagnosticians in deciding how to handle the most common incidental findings encountered when performing whole-body MRI.

  18. Whole-body MRI screening

    International Nuclear Information System (INIS)

    The advent of dedicated whole-body MRI scanners has made it possible to image the human body from head to toe with excellent spatial resolution and with the sensitivity and specificity of conventional MR systems. A comprehensive screening examination by MRI relies on fast image acquisition, and this is now feasible owing to several very recent developments, including multichannel techniques, new surface coil systems, and automatic table movement. The daily analysis of whole-body MRI datasets uncovers many incidental findings, which are discussed by an interdisciplinary advisory board of physicians from all specialties. This book provides a systematic overview of these incidental findings with the aid of approximately 240 high-quality images. The radiologists involved in the project have written chapters on each organ system, presenting a structured compilation of the most common findings, their morphologic appearances on whole-body MRI, and guidance on their clinical management. Chapters on technical and ethical issues are also included. It is hoped that this book will assist other diagnosticians in deciding how to handle the most common incidental findings encountered when performing whole-body MRI.

  19. Automated planning of MRI neuro scans

    Science.gov (United States)

    Young, Stewart; Bystrov, Daniel; Netsch, Thomas; Bergmans, Rene; van Muiswinkel, Arianne; Visser, Fredy; Sprigorum, Rudolf; Gieseke, Jürgen

    2006-03-01

    In clinical MRI examinations, the geometry of diagnostic scans is defined in an initial planning phase. The operator plans the scan volumes (off-centre, angulation, field-of-view) with respect to patient anatomy in 'scout' images. Often multiple plans are required within a single examination, distracting attention from the patient waiting in the scanner. A novel and robust method is described for automated planning of neurological MRI scans, capable of handling strong shape deviations from healthy anatomy. The expert knowledge required to position scan geometries is learned from previous example plans, allowing site-specific styles to be readily taken into account. The proposed method first fits an anatomical model to the scout data, and then new scan geometries are positioned with respect to extracted landmarks. The accuracy of landmark extraction was measured to be comparable to the inter-observer variability, and automated plans are shown to be highly consistent with those created by expert operators using clinical data. The results of the presented evaluation demonstrate the robustness and applicability of the proposed approach, which has the potential to significantly improve clinical workflow.

  20. Prostate contouring in MRI guided biopsy.

    Science.gov (United States)

    Vikal, Siddharth; Haker, Steven; Tempany, Clare; Fichtinger, Gabor

    2009-03-27

    With MRI possibly becoming a modality of choice for detection and staging of prostate cancer, fast and accurate outlining of the prostate is required in the volume of clinical interest. We present a semi-automatic algorithm that uses a priori knowledge of prostate shape to arrive at the final prostate contour. The contour of one slice is then used as initial estimate in the neighboring slices. Thus we propagate the contour in 3D through steps of refinement in each slice. The algorithm makes only minimum assumptions about the prostate shape. A statistical shape model of prostate contour in polar transform space is employed to narrow search space. Further, shape guidance is implicitly imposed by allowing only plausible edge orientations using template matching. The algorithm does not require region-homogeneity, discriminative edge force, or any particular edge profile. Likewise, it makes no assumption on the imaging coils and pulse sequences used and it is robust to the patient's pose (supine, prone, etc.). The contour method was validated using expert segmentation on clinical MRI data. We recorded a mean absolute distance of 2.0 ± 0.6 mm and dice similarity coefficient of 0.93 ± 0.3 in midsection. The algorithm takes about 1 second per slice. PMID:21132083

  1. MRI of the Brachial Plexus

    Directory of Open Access Journals (Sweden)

    Seyed Hassan Mostafavi

    2010-05-01

    Full Text Available Evaluation of the brachial plexus is a clinical chal-lenge. Physical examination has traditionally been a mainstay in evaluating and localizing pathology involving the brachial plexus. Physical examination is especially difficult in patients with scarring and fibrosis secondary to surgery or irradiation. Electrophysiologic studies may be used to detect abnormalities in nerve conduction, but are poor for localizing a lesion. "nMRI has become increasingly important in the evaluation of brachial plexus pathology, as the technology and resolution has improved. Correlation of imaging results with electrophysiologic findings increases the overall specificity and sensitivity. CT has increased sensitivity for depicting extrinsic masses that com-press the nerves; however, it offers poor soft tissue contrast to directly evaluate the nerves."nWith the advent of MRI, nerves that compose the brachial plexus can now be directly evaluated. Intrinsic and extrinsic pathology may be evaluated. Exact anatomic components of the brachial plexus, such as the roots, trunks, divisions, and cords may be identified. MRI has the additional benefit of multiplanar imaging and increased soft tissue contrast. The tissue resolution of MRI is constantly improving with new pulse sequences and coil designs."nWith radiography and CT, changes in the shape or position of the brachial plexus were used to assess the pathology. With MRI, the nerve can be directly visualized and evaluated for pathology. MRI sequences such as fat-saturated T2-weighted spin-echo, short-tau inversion recovery (STIR, and gadolinium-enhanced T1-weighted spin-echo sequences help in depicting subtle changes in the signal intensity of the nerves or enhancement and aid in refining the differential diagnosis. In addition, maximum intensity projections can make localization and visualization of the pathology most understandable for referring clinicians and surgeons.

  2. Interstitial pregnancy: role of MRI

    International Nuclear Information System (INIS)

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

  3. MRI changes in the central nervous system in a child with lupus erythematosus

    Energy Technology Data Exchange (ETDEWEB)

    Gieron, M.A. [Dept. of Pediatrics, Univ. of South Florida, Coll. of Medicine, Tampa, FL (United States); Khoromi, S. [Dept. of Neurology, Univ. of South Florida, Coll. of Medicine, Tampa, FL (United States); Campos, A. [Dept. of Pediatrics, Univ. of South Florida, Coll. of Medicine, Tampa, FL (United States)

    1995-05-01

    We report on a 10-year-old girl with systemic lupus erythematosus who presented in status epilepticus as the only manifestation of central nervous system involvement. MRI of the brain showed diffuse gray and white matter lesions which almost completely resolved after treatment with methylprednisolone. MRI findings in this child are similar to those in adults with diffuse clinical manifestations. The study is essential in the initial evaluation of patients suspected of central nervous system lupus. (orig.)

  4. Modification of Angular Velocity by Inhomogeneous MRI Growth in Protoplanetary Disks

    OpenAIRE

    Kato, M T; Nakamura, K.; Tandokoro, R.; Fujimoto, M.; Ida, S.

    2008-01-01

    We have investigated evolution of magneto-rotational instability (MRI) in protoplanetary disks that have radially non-uniform magnetic field such that stable and unstable regions coexist initially, and found that a zone in which the disk gas rotates with a super-Keplerian velocity emerges as a result of the non-uniformly growing MRI turbulence. We have carried out two-dimensional resistive MHD simulations with a shearing box model. We found that if the spatially averaged magnetic Reynolds num...

  5. Clinical applications of functional MRI in epilepsy

    International Nuclear Information System (INIS)

    The role of functional MRI (fMRI) in the presurgical evaluation of patients with intractable epilepsy is being increasingly recognized. Real-time fMRI is an easily performable diagnostic technique in the clinical setting. It has become a noninvasive alternative to intraoperative cortical stimulation and the Wada test for eloquent cortex mapping and language lateralization, respectively. Its role in predicting postsurgical memory outcome and in localizing the ictal activity is being recognized. This review article describes the biophysical basis of blood-oxygen-level-dependent (BOLD) fMRI and the methodology adopted, including the design, paradigms, the fMRI setup, and data analysis. Illustrative cases have been discussed, wherein the fMRI results influenced the seizure team's decisions with regard to diagnosis and therapy. Finally, the special issues involved in fMRI of epilepsy patients and the various challenges of clinical fMRI are detailed

  6. mritc: A Package for MRI Tissue Classification

    Directory of Open Access Journals (Sweden)

    Luke Tierney

    2011-10-01

    Full Text Available This paper presents an R package for magnetic resonance imaging (MRI tissue classification. The methods include using normal mixture models, hidden Markov normal mixture models, and a higher resolution hidden Markov normal mixture model fitted by various optimization algorithms and by a Bayesian Markov chain Monte Carlo (MCMC method. Functions to obtain initial values of parameters of normal mixture models and spatial parameters are provided. Supported input formats are ANALYZE, NIfTI, and a raw byte format. The function slices3d in misc3d is used for visualizing data and results. Various performance evaluation indices are provided to evaluate classification results. To improve performance, table lookup methods are used in several places, and vectorized computation taking advantage of conditional independence properties are used. Some computations are performed by C code, and OpenMP is used to parallelize key loops in the C code.

  7. Directed evolution of protein-based neurotransmitter sensors for MRI

    OpenAIRE

    Romero, Philip A.; Shapiro, Mikhail G.; Frances H Arnold; Jasanoff, Alan

    2013-01-01

    The production of contrast agents sensitive to neuronal signaling events is a rate- limiting step in the development of molecular-level functional magnetic resonance imaging (molecular fMRI) approaches for studying the brain. High throughput generation and evaluation of potential probes is possible using techniques for macromolecular engineering of protein-based contrast agents. In an initial exploration of this strategy, we used the method of directed evolution to identify mutants of a bacte...

  8. Value of retrospective image fusion of {sup 18}F-FDG PET and MRI for preoperative staging of head and neck cancer: Comparison with PET/CT and contrast-enhanced neck MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kanda, Tomonori [Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Department of Radiology, Hyogo Cancer Center, Hyogo (Japan); Kitajima, Kazuhiro, E-mail: kitajima@med.kobe-u.ac.jp [Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Suenaga, Yuko; Konishi, Jyunya [Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Sasaki, Ryohei [Division of Radiation Oncology, Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan); Morimoto, Koichi; Saito, Miki; Otsuki, Naoki; Nibu, Ken-ichi [Department of Otolaryngology-Head and Neck Surgery, Kobe University Graduate School of Medicine, Kobe (Japan); Sugimura, Kazuro [Department of Radiology, Kobe University Graduate School of Medicine, Kobe (Japan)

    2013-11-01

    Purpose: To assess the clinical value of retrospective image fusion of neck MRI and {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) PET for locoregional extension and nodal staging of neck cancer. Materials and methods: Thirty patients with carcinoma of the oral cavity or hypopharynx underwent PET/CT and contrast-enhanced neck MRI for initial staging before surgery including primary tumor resection and neck dissection. Diagnostic performance of PET/CT, MRI, and retrospective image fusion of PET and MRI (fused PET/MRI) for assessment of the extent of the primary tumor (T stage) and metastasis to regional lymph nodes (N stage) was evaluated. Results: Accuracy for T status was 87% for fused PET/MRI and 90% for MRI, thus proving significantly superior to PET/CT, which had an accuracy of 67% (p = 0.041 and p = 0.023, respectively). Accuracy for N status was 77% for both fused PET/MRI and PET/CT, being superior to MRI, which had an accuracy of 63%, although the difference was not significant (p = 0.13). On a per-level basis, the sensitivity, specificity and accuracy for detection of nodal metastasis were 77%, 96% and 93% for both fused PET/MRI and PET/CT, compared with 49%, 99% and 91% for MRI, respectively. The differences for sensitivity (p = 0.0026) and accuracy (p = 0.041) were significant. Conclusion: Fused PET/MRI combining the individual advantages of MRI and PET is a valuable technique for assessment of staging neck cancer.

  9. MRI and neurological findings in patients with spinal metastases

    Energy Technology Data Exchange (ETDEWEB)

    Switlyk, M.D.; Hole, K.H.; Knutstad, K. [Department of Radiology and Nuclear Medicine, Oslo University Hospital, Norwegian Radium Hospital, Oslo (Norway)], E-mail: marta.switlyk@radiumhospitalet.no; Skjeldal, S.; Zaikova, O. [Department of Orthopedics, Oslo University Hospital, Norwegian Radium Hospital, Oslo (Norway); Hald, J.K. [Department of Radiology and Nuclear Medicine, Oslo University Hospital, Rikshospitalet, Oslo (Norway); Seierstad, T. [Department of Radiology and Nuclear Medicine, Oslo University Hospital, Norwegian Radium Hospital, Oslo (Norway); Faculty of Health Sciences, Buskerud University College, Drammen (Norway)

    2012-12-15

    Background. Magnetic resonance imaging (MRI) is the recommended primary investigation method for metastatic spinal cord compression (MSCC). Initiating treatment before the development of motor deficits is essential to preserve neurological function. However, the relationship between MRI-assessed grades of spinal metastatic disease and neurological status has not been widely investigated. Purpose. To analyze the association between neurological function and MRI-based assessment of the extent of spinal metastases using two different grading systems. Material and Methods. A total of 284 patients admitted to our institution for initial radiotherapy or surgery for symptomatic spinal metastases were included in the study. Motor and sensory deficits were categorized according to the Frankel classification system. Pre-treatment MRI evaluations of the entire spine were scored for the extent of spinal metastases, presence and severity of spinal cord compression, and nerve root compression. Two MRI-based scales were used to evaluate the degree of cord compression and spinal canal narrowing and relate these findings to neurological function. Results. Of the patients included in the study, 28 were non-ambulatory, 49 were ambulatory with minor motor deficits, and 207 had normal motor function. Spinal cord compression was present in all patients with Frankel scores of B or C, 23 of 35 patients with a Frankel score of D (66%), and 48 of 152 patients with a Frankel score of E (32%). The percentage of patients with severe spinal canal narrowing increased with increasing Frankel grades. The grading according to the scales showed a significant association with the symptoms according to the Frankel scale (P < 0.001). Conclusion. In patients with neurological dysfunction, the presence and severity of impairment was associated with the epidural tumor burden. A significant number of patients had radiological spinal cord compression and normal motor function (occult MSCC)

  10. Contribution of plexus MRI in the diagnosis of atypical chronic inflammatory demyelinating polyneuropathies.

    Science.gov (United States)

    Lozeron, Pierre; Lacour, Marie-Christine; Vandendries, Christophe; Théaudin, Marie; Cauquil, Cécile; Denier, Christian; Lacroix, Catherine; Adams, David

    2016-01-15

    Nerve enlargement has early been recognized in CIDP and plexus MRI hypertrophy has been reported in typical CIDP cases. Our aim is to determine plexus MRI value in the diagnosis of CIDP with an initial atypical presentation, which, up to now, has not been demonstrated. Retrospective study of 33 consecutive patients suspected of CIDP. Plexus MRI was performed on the most affected territory (brachial or lumbar). Were assessed: plexus trophicity, T2-STIR signal intensity and gadolinium enhancement. Final CIDP diagnosis was made after comprehensive workup. A histo-radiological correlation was performed. Final CIDP diagnosis was made in 25 (76%) including 21 with initial atypical clinical presentation. Eleven CIDP patients (52%) with initial atypical clinical presentation had abnormal plexus MRI including 9 suggestive of CIDP (43%) and none of the patients with an alternative diagnosis. Hypertrophy of the proximal plexus and/or extraforaminal roots was found in 8 cases and Gadolinium enhancement in 2 cases. Abnormalities were more frequent on brachial (86%) than lumbosacral MRIs (29%) and asymmetrical (72%) and most often associated with histological signs of demyelination. The nerve biopsy was suggestive of CIDP in 9/13 patients with normal MRI. Plexus MRI seems useful in the diagnostic strategy of patients with suspicion of CIDP with atypical presentation. Nerve biopsy remains important when other investigations are inconclusive. PMID:26723995

  11. Breast MRI in high risk patients

    NARCIS (Netherlands)

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

    2015-01-01

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

  12. Navicular bone position determined by positional MRI

    DEFF Research Database (Denmark)

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

    2016-01-01

    OBJECTIVE: To examine intraobserver, interobserver and between-day reproducibility of positional MRI for evaluation of navicular bone height (NVH) and medial navicular position (MNP). MATERIALS AND METHODS: Positional MRI (pMRI) of the foot was performed on ten healthy participants (0.25 T G-scan...

  13. MRI of plants and foods

    NARCIS (Netherlands)

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

    2013-01-01

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

  14. 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 ... information please consult the ACR Manual on Contrast Media and its references. top of page What are the limitations of MRI of the Head? High-quality images are assured only if you are able to ...

  15. MRI of rectal stromal tumour

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  16. MRI of the pulmonary parenchyma

    International Nuclear Information System (INIS)

    Imaging of the pulmonary parenchyma represents a unique challenge for MRI. Limited signal is caused by low proton density, susceptibility artifacts, and physiological motion (cardiac pulsation, respiration). Recently, further improvements in MRI techniques have widened the potential for investigations of pulmonary parenchymal disease. These include very short echo times, ultrafast turbo-spin-echo acquisitions, projection reconstruction technique, breathhold imaging, ECG triggering, contrast agents (perfusion imaging, aerosols), sodium imaging, hyperpolarized noble gas imaging, and oxygen enhancement. By using widely available techniques, MRI is helpful in the assessment of (a) acute alveolitic processes in chronic infiltrative lung disease, (b) detection and characterization of pulmonary nodules, (c) detection, characterization, and follow-up of pneumonia, (d) differentiation of obstructive atelectasis from non-obstructive atelectasis and infarctions, and (e) measurements of lung water content. Chronic bronchitis, bronchiectasis, and emphysema are not readily assessable by routine MRI techniques. More sophisticated techniques are under investigation for MR imaging of pulmonary ventilation and perfusion. They represent the beginning of functional MR imaging of the lung which will be established in the future. (orig.)

  17. MRI of the pulmonary parenchyma

    Energy Technology Data Exchange (ETDEWEB)

    Kauczor, H.U.; Kreitner, K.F. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie

    1999-07-01

    Imaging of the pulmonary parenchyma represents a unique challenge for MRI. Limited signal is caused by low proton density, susceptibility artifacts, and physiological motion (cardiac pulsation, respiration). Recently, further improvements in MRI techniques have widened the potential for investigations of pulmonary parenchymal disease. These include very short echo times, ultrafast turbo-spin-echo acquisitions, projection reconstruction technique, breathhold imaging, ECG triggering, contrast agents (perfusion imaging, aerosols), sodium imaging, hyperpolarized noble gas imaging, and oxygen enhancement. By using widely available techniques, MRI is helpful in the assessment of (a) acute alveolitic processes in chronic infiltrative lung disease, (b) detection and characterization of pulmonary nodules, (c) detection, characterization, and follow-up of pneumonia, (d) differentiation of obstructive atelectasis from non-obstructive atelectasis and infarctions, and (e) measurements of lung water content. Chronic bronchitis, bronchiectasis, and emphysema are not readily assessable by routine MRI techniques. More sophisticated techniques are under investigation for MR imaging of pulmonary ventilation and perfusion. They represent the beginning of functional MR imaging of the lung which will be established in the future. (orig.)

  18. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician ... when absolutely necessary for medical treatment. See the Safety page for more information about pregnancy and MRI. ...

  19. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician ... may follow your regular daily routine and take food and medications as usual. Some MRI examinations may ...

  20. MRI of medulloblastoma in adults

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

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

  1. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... have allergies of any kind, such as an allergy to iodine or x-ray contrast material, drugs, food, or the environment, or if you have asthma. The contrast material most commonly used for an MRI exam contains a metal called ... with iodine contrast allergy, but may require pre-medication. It is far ...

  2. MRI of closed spinal dysraphisms

    Energy Technology Data Exchange (ETDEWEB)

    Badve, Chaitra A.; Khanna, Paritosh C.; Phillips, Grace S.; Thapa, Mahesh M.; Ishak, Gisele E. [Seattle Children' s Hospital and University of Washington Medical Center, Department of Radiology, Seattle, WA (United States)

    2011-10-15

    We present a pictorial review of MRI features of various closed spinal dysraphisms based on previously described clinicoradiological classification of spinal dysraphisms proposed. The defining imaging features of each dysraphism type are highlighted and a diagnostic algorithm for closed spinal dysraphisms is suggested. (orig.)

  3. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... types of clips used for brain aneurysms some types of metal coils placed within blood vessels nearly all cardiac defibrillators and pacemakers You ... called MR angiography (MRA) provides detailed images of blood vessels in the ... the opening of certain types of MRI machines. The presence of an implant ...

  4. Brain MRI of diabetes Mellitus

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-11-01

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

  5. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... entire examination is usually completed within 45 minutes. MR spectroscopy, which provides additional information on the chemicals present in the body's cells, may also be performed during the MRI exam and may add approximately ... to remain still during MR imaging. Others experience a sense of being closed- ...

  6. Brain MRI of diabetes Mellitus

    International Nuclear Information System (INIS)

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

  7. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... body structures. MRI does not use ionizing radiation (x-rays). Detailed MR images allow physicians to evaluate various ... kind, such as an allergy to iodine or x-ray contrast material, drugs, food, or the environment, or ...

  8. Sequential changes in the femoral head after intracapsular fracture of the femoral neck. MRI findings

    International Nuclear Information System (INIS)

    Authors obtained T1-weighted MRI images of the femoral head after fracture of the femoral neck and classified the signals into four patterns to investigate the sequential changes of the femoral head. The T1-weighted MRI images obtained initially after femoral neck fracture showed a normal pattern in 10 of the 15 hip joints studied. MRI images obtained subsequently still showed the normal signal pattern in eight of the 10 hip joints which had shown the normal pattern in the first MRI, while two of the 10 joints subsequently showed a band pattern. The joint with the homogeneous pattern in the first MRI subsequently showed a band pattern. Of the three joints with an inhomogeneous pattern in the first MRI, two joints showed a subsequent band pattern, and the other a normal pattern. The joints which showed a band pattern continued to show a similar band pattern. Eventually, all hip joints studied showed a normal or band pattern within six months after intracapsular fracture of the femoral neck. The joints which showed a band pattern in the first MRI continued to show a similar band pattern in the subsequent MRI, without any change. Collapse occurred in one hip joint which showed an extensive band pattern. Plain X-rays showed collapse of one of the joints with a band pattern in the MRI image. It was therefore suggested that necrosis may be present histologically in the femoral head after fracture of the femoral neck even when no abnormalities are present in plain X-rays. Based on the above results, it is considered necessary to follow-up patients with femoral neck fracture with MRI for at least six months until the normal or band pattern is observed. (K.H.)

  9. Surveillance imaging in children with malignant CNS tumors: low yield of spine MRI.

    Science.gov (United States)

    Perreault, Sébastien; Lober, Robert M; Carret, Anne-Sophie; Zhang, Guohua; Hershon, Linda; Décarie, Jean-Claude; Vogel, Hannes; Yeom, Kristen W; Fisher, Paul G; Partap, Sonia

    2014-02-01

    Magnetic resonance imaging (MRI) is routinely obtained in patients with central nervous system (CNS) tumors, but few studies have been conducted to evaluate this practice. We assessed the benefits of surveillance MRI and more specifically spine MRI in a contemporary cohort. We evaluated MRI results of children diagnosed with CNS tumors from January 2000 to December 2011. Children with at least one surveillance MRI following the diagnosis of medulloblastoma (MB), atypical teratoid rhabdoid tumor (ATRT), pineoblastoma (PB), supratentorial primitive neuroectodermal tumor, supratentorial high-grade glioma (World Health Organization grade III-IV), CNS germ cell tumors or ependymoma were included. A total of 2,707 brain and 1,280 spine MRI scans were obtained in 258 patients. 97% of all relapses occurred in the brain and 3% were isolated to the spine. Relapse was identified in 226 (8%) brain and 48 (4%) spine MRI scans. The overall rate of detecting isolated spinal relapse was 9/1,000 and 7/1,000 for MB patients. MRI performed for PB showed the highest rate for detecting isolated spinal recurrence with 49/1,000. No initial isolated spinal relapse was identified in patients with glioma, supratentorial primitive neuroectodermal tumor and ATRT. Isolated spinal recurrences are infrequent in children with malignant CNS tumors and the yield of spine MRI is very low. Tailoring surveillance spine MRI to patients with higher spinal relapse risk such as PB, MB with metastatic disease and within 3 years of diagnosis could improve allocation of resources without compromising patient care. PMID:24401959

  10. Temporal and spatial MRI responses to subsecond visual activation.

    Science.gov (United States)

    Fransson, P; Krüger, G; Merboldt, K D; Frahm, J

    1999-01-01

    The temporal and spatial characteristics of oxygenation-sensitive MRI responses to very brief visual stimuli (five Hz reversing black and white checkerboard pattern versus darkness) were investigated (nine subjects) by means of serial single-shot gradient-echo echo-planar imaging (2.0 T, TR=400 ms, mean TE=54 ms, flip angle 30 degrees). The use of a 0.2-s stimulus and a 90-s control phase resulted in an initial latency phase (about 2 s, no signal change), a positive MRI response (2.5% signal increase peaking at 5 s after stimulus onset), and a post-stimulus undershoot (1% signal decrease peaking at 15 s after stimulus onset) lasting for about 50-60 s. The finding that a subsecond visual stimulus elicits both a strong positive MRI response and a long-lasting undershoot provides further evidence for the neuronal origin of slow signal fluctuations seen in the absence of functional challenge and their utility for mapping functional connectivity. The additional observation that a reduction of the inter-stimulus control phase from 90 s to 9.8 s does not seem to affect the spatial extent of cortical activation in pertinent maps is of major relevance for the design and analysis of "event-related" MRI studies. PMID:9888393

  11. High-temporospatial-resolution dynamic contrast-enhanced (DCE) wrist MRI with variable-density pseudo-random circular Cartesian undersampling (CIRCUS) acquisition: evaluation of perfusion in rheumatoid arthritis patients.

    Science.gov (United States)

    Liu, Jing; Pedoia, Valentina; Heilmeier, Ursula; Ku, Eric; Su, Favian; Khanna, Sameer; Imboden, John; Graf, Jonathan; Link, Thomas; Li, Xiaojuan

    2016-01-01

    This study is to evaluate highly accelerated three-dimensional (3D) dynamic contrast-enhanced (DCE) wrist MRI for assessment of perfusion in rheumatoid arthritis (RA) patients. A pseudo-random variable-density undersampling strategy, circular Cartesian undersampling (CIRCUS), was combined with k-t SPARSE-SENSE reconstruction to achieve a highly accelerated 3D DCE wrist MRI. Two healthy volunteers and 10 RA patients were studied. Two patients were on methotrexate (MTX) only (Group I) and the other eight were treated with a combination therapy of MTX and anti-tumor necrosis factor (TNF) therapy (Group II). Patients were scanned at baseline and 3 month follow-up. DCE MR images were used to evaluate perfusion in synovitis and bone marrow edema pattern in the RA wrist joints. A series of perfusion parameters was derived and compared with clinical disease activity scores of 28 joints (DAS28). 3D DCE wrist MR images were obtained with a spatial resolution of 0.3 × 0.3 × 1.5 mm(3) and temporal resolution of 5 s (with an acceleration factor of 20). The derived perfusion parameters, most notably transition time (dT) of synovitis, showed significant negative correlations with DAS28-ESR (r = -0.80, p perfusion in RA joints, showing promise as a potential tool for evaluating treatment responses.

  12. Usefulness of Integrated PET/MRI in Head and Neck Cancer: A Preliminary Study

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Soo Jin; Seo, Hyo Jung; Cheon, Gi Jeong; Kim, Ji Hoon; Kim, E. Edmund; Kang, Keon Wook; Paeng, Jin Chul; Chung, Junekey; Lee, Dong Soo [Seoul National Univ., Seoul (Korea, Republic of)

    2014-06-15

    The new modality of an integrated positron emission tomography/magnetic resonance imaging (PET/MRI) has recently been introduced but not validated. Our objective was to evaluate clinical performance of {sup 18}F-fluoro-2-deoxyglucose ({sup 18}F-FDG) PET/MRI in patients with head and neck cancer. This retrospective study was conducted between January 2013 and February 2013. Ten patients (eight men, two women; mean age, 61.4±13.4 years) with histologically proven head and neck tumors were enrolled.Whole-body PET/MRI and regional positron emission tomography (PET) with dedicated MRI were sequentially obtained. Maximum standardized uptake value (SUVmax), SUVmean, metabolic tumor volume, total lesion glycolysis and contrast enhancement were analyzed. A total of ten whole-body positron emission tomography (PET), ten regional positron emission tomography (PET), ten dedicated MRI and ten regional PET/gadolinium-enhanced T1-weighted (Gd)-MRI images were analyzed for initial staging. Two nuclear medicine physicians analyzed positron emission tomography (PET) and PET/MRI with a consensus. One radiologist analyzed dedicated MRI. The primary lesions and number of metastatic lymph nodes analyzed from each image were compared. Eight patients were diagnosed with head and neck cancer (one tongue cancer, four tonsillar cancers, one nasopharyngeal cancer and two hypopharyngeal cancers) by histological diagnosis. Two benign tumors (pleomorphic adenoma and Warthin tumor) were diagnosed with surgical operation. Whole-body positron emission tomography (PET) and regional positron emission tomography (PET) attenuated by MRI showed good image quality for the lesion detection. Whole-body positron emission tomography (PET) and regional positron emission tomography (PET) detected ten primary sites and compensated for a missed lesion on dedicated MRI. A discordant number of suspicious lymph node metastases was noted according to the different images; 22, 16, 39 and 40 in the whole

  13. MRI diagnosis of aggressive fibromatosis

    International Nuclear Information System (INIS)

    Objective: To analyze the MRI features of aggressive fibromatosis (AF) in order to improve its diagnostic accuracy. Method: The clinical files and MRI appearances of 66 AF patients (primary 19 cases, recurrent 47 cases) were reviewed and compared with the postoperative pathological findings. Results: The median age of all patients was 31 years (-range, 11-60 years) with a male-to-female sex ratio of 1 : 3.4. Eighty tumors were discovered. There were 5 superficial fibromatosis and 75 deep fibromatosis in which 2 lesions were intraabdominal, 6 lesions in the abdominal wall and 67 lesions extraabdominal. The average long diameter of all lesions was (8.7±5.4) cm, of superficial lesions (5.7± 2.8)cm, of deep lesions (8.9±5.5) cm. Of the 80 tumors, 79 were displayed as space-occupying intramuscular lesions, 47 (58.8%) were ovoid or lobulated and 22 (27.5%) were infiltrative in shape; 48 (60%) lesions had a well-defined margin, of which 4 formed a pseudocapsule as they enlarged by compressing normal tissue. To compare with the muscle signal intensity on MRI, 75 lesions demonstrated isointensity, mild hyperintensity or hypointensity on T1WI , heterogeneous high intensity on T2WI, and avid heterogeneous enhancement after contrast administration. There was no necrosis or surrounding edema in all lesions. Tumors destroyed bone in 2, cases. Conclusion: Aggressive fibromatosis has characteristic features on MRI, and MRI is valuable in diagnosing AF and evaluating the extend of lesion and involvement of adjacent structures. (authors)

  14. Initial Study

    DEFF Research Database (Denmark)

    Torp, Kristian

    2009-01-01

    Congestion is a major problem in most cities and the problem is growing (Quiroga, 2000) (Faghri & Hamad, 2002). When the congestion level is increased the drivers notice this as delays in the traffic (Taylor, Woolley, & Zito, 2000), i.e., the travel time for the individual driver is simply...... increased. In the initial study presented here, the time it takes to pass an intersection is studied in details. Two major signal-controlled four-way intersections in the center of the city Aalborg are studied in details to estimate the congestion levels in these intersections, based on the time it takes...

  15. Rill Initiation

    OpenAIRE

    Ottosen, Thor-Bjørn

    2008-01-01

    This project is about rill erosion. The aim is to test whether rill initiation can be predicted from the shear strength of the soil as measured with a torvane on saturated soil. This approach was set forward by Rauws and Govers 1988. Rainfall simulation experiments are conducted at a plot size 2x1m, performed in May on the Marbjerg experimental field. The results are evaluated using a chain set to measure alterations of the surface roughness as a result of the erosion, visual evaluation of ph...

  16. fMRI-BCI: a Review

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  17. Clinical presentations and MRI findings of angiographically occult vascular malformations

    International Nuclear Information System (INIS)

    Various clinical features as well as MRI findings of AOVM (angiographically occult vascular malformation) were studied. Amongst out patients, since January 1988, there have been 30 cases of symptomatic AOVM (20 males, 10 females) including 4 cases with multiple lesions. The age ranged from 3 to 60 years of age, with a mean of 33.4 years. The locations of symptomatic lesions were in the cerebral hemisphere (15), the thalamus (4), the brain stem (8) and in the cerebellum (3). The initial presentations of these 30 cases were either by hemorrhage (18), convulsive seizure (9) or by progressive neurological deficits (3). The initial presentation was not related to the patient's age and the size of the lesion, but apparently related to the location of AOVM. Most of the lesions in the cerebral hemisphere presented seizures, but all of the lesions in the thalamus, the brain stem and the cerebellum disclosed hemorrhage as an initial presentation. In fact it was noticed that brain stem lesions tend to cause repetitive hemorrhage in a relatively short period. AOVM lesions were clearly visualized with T2-weighted MRI images, consisting of high intensity cores with surrounding low intensity rims. Most of the symptomatic lesions were partially enhanced by Gd-DTPA with varied intensity. Dynamic changes in size and enhancement pattern on MRI were occasionally seen, usually accompanied with episodes such as hemorrhage or neurological deterioration. Although AOVMs were angiographically negative some strands indicating draining veins were observed on MRI in several cases. In contrast, none of the nonsymptomatic lesions (22 lesions) demonstrated enhancement effects with Gd-DTPA. (author)

  18. Lumbosacral epidural lipomatosis: MRI grading

    Energy Technology Data Exchange (ETDEWEB)

    Borre, Daniel G. [Department of MRI, RM-Hastings, Clinica Monte Grande, Monte Grande, Buenos Aires (Argentina); Department of MRI, Oncologic Center of Excellence, Gonnet, Buenos Aires (Argentina); Sociedad Argentina de Radiologia, Arenales 1985 P.B., Ciudad Autonoma de Buenos Aires C1124AAC (Argentina); Borre, Guillermo E. [Department of MRI, RM-Hastings, Clinica Monte Grande, Monte Grande, Buenos Aires (Argentina); Department of MRI, Oncologic Center of Excellence, Gonnet, Buenos Aires (Argentina); Aude, Flavio [Department of MRI, Oncologic Center of Excellence, Gonnet, Buenos Aires (Argentina); Palmieri, Gladys N. [Department of MRI, RM-Hastings, Clinica Monte Grande, Monte Grande, Buenos Aires (Argentina)

    2003-07-01

    Lumbosacral epidural lipomatosis (LEL) is characterized by excessive deposition of epidural fat (EF). The purpose of our retrospective study was to quantify normal and pathologic amounts of EF in order to develop a reproducible MRI grading of LEL. In this study of 2528 patients (1095 men and 1433 women; age range 18-84 years, mean age 47.3 years) we performed a retrospective analysis of MRI exams. We obtained four linear measurements at the axial plane parallel and tangent to the superior end plate of S1 vertebral body: antero-posterior diameter of dural sac (A-Pd DuS), A-Pd of EF, located ventrally and dorsally to the DuS, and A-Pd of the spinal canal (Spi C). We calculated (a) DuS/EF index and (b) EF/Spi C index. We developed the following MRI grading of LEL: normal, grade 0: DuS/EF index {>=}1.5, EF/Spi C index {<=}40%; LEL grade I: DuS/EF index 1.49-1, EF/Spi C index 41-50% (mild EF overgrowth); LEL grade II: DuS/EF index 0.99-0.34, EF/Spi C index 51-74% (moderate EF overgrowth); LEL grade III: DuS/EF index {<=}0.33, EF/Spi C index {>=}75% (severe EF overgrowth). The MRI exams were evaluated independently by three readers. Intra- and interobserver reliabilities were obtained by calculating Kappa statistics. The MRI grading showed the following distribution: grade 0, 2003 patients (79.2%); LEL grade I, 308 patients (12.2%); LEL grade II, 165 patients (6.5%); and LEL grade III, 52 patients (2.1%). The kappa coefficients for intra- and interobserver agreement in a four-grade classification system were substantial to excellent: intraobserver, kappa range 0.79 [95% confidence interval (CI), 0.65-0.93] to 0.82 (95% CI, 0.70-0.95); interobserver, kappa range 0.76 (95% CI, 0.62-0.91) to 0.85 (95% CI, 0.73-0.97). In LEL grade I, there were no symptomatic cases due to fat hypertrophy. LEL grade II was symptomatic in only 24 cases (14.5%). In LEL grade III, all cases were symptomatic. A subgroup of 22 patients (42.3%) showed other substantial spinal pathologies (e

  19. [Progress of clinical application of functional MRI in the localization of brain language area].

    Science.gov (United States)

    Zhang, Nan; Lu, Junfeng; Wu, Jinsong

    2016-02-01

    For surgical operation in the functional area in the brain, it's commonly demanded to resect the lesion to the maximal extent on the basis of preserve the normal neural function, thus the precise localization of functional area is extremely important. As for the advantages of being widely available, easy to grasp and non-invasive, the functional MRI (fMRI) has come into wide use, while the application of language fMRI is still in the initial stage. It's important to choose appropriate fMRI task according to the individual condition of the subject, the commonly-adopted tasks include verb generation, picture naming, word recognition, word generation, etc. However, the effectiveness of using fMRI to localize language area is not totally satisfactory, adopting multiple task is an effective approach to improve the sensitivity of this technique. The application of resting state fMRI in the localization of language area and the further research of the role of fMRI in localizing the Chinese language area are the important future directions.

  20. IMAGING OF ROTATOR CUFF PATHOLOGY- IS ULTRASOUND AS GOOD AS MRI

    Directory of Open Access Journals (Sweden)

    Vinot

    2015-12-01

    Full Text Available Aim of this study is to compare the diagnostic accuracy of ultrasound versus MRI in detecting rotator cuff pathology. Rotator cuff pathology involves group of disorder, which progresses from bursitis to tendinitis to partial tear and full thickenss tear. The most commonly affected tendon is the supraspinatus tendon. In our prospective study of 35 patients as initial ultrasound was followed by MRI sensitivity, specificity and accuracy for diagnosis of full thickness tear of supraspinatus when USG was compared to MRI was 100%, whereas sensitivity, specificity and accuracy of diagnosing partial thickness tear using ultrasound compared to MRI are 100%, 78% and 84%. There is no significant p value difference on comparing ultrasound with MRI on detecting tears. Ultrasound and MRI showed almost similar diagnostic accuracy in associated findings like tendon retraction, muscle atrophy, bursal effusion. Ultrasound also has additional value of dynamic evaluation, which is useful in evaluating subacromial and subcoracoid impingement. Modality choice for the evaluation of rotator cuff pathology should be based on several factors like availability, patient preference and clinical information being sought. The high resolution sonography is an attractive screening modality for rotator cuff in patients presenting with painful shoulder. A well performed ultrasound examination in most cases obviates the need for more invasive diagnostic tests like arthrography and cumbersome and expensive MRI examinations.

  1. [Simultaneous whole-body PET-MRI in pediatric oncology : More than just reducing radiation?].

    Science.gov (United States)

    Gatidis, S; Gückel, B; la Fougère, C; Schmitt, J; Schäfer, J F

    2016-07-01

    Diagnostic imaging plays an essential role in pediatric oncology with regard to diagnosis, therapy-planning, and the follow-up of solid tumors. The current imaging standard in pediatric oncology includes a variety of radiological and nuclear medicine imaging modalities depending on the specific tumor entity. The introduction of combined simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) has opened up new diagnostic options in pediatric oncology. This novel modality combines the excellent anatomical accuracy of MRI with the metabolic information of PET. In initial clinical studies, the technical feasibility and possible diagnostic advantages of combined PET-MRI have been in comparison with alternative imaging techniques. It was shown that a reduction in radiation exposure of up to 70 % is achievable compared with PET-CT. Furthermore, it has been shown that the number of imaging studies necessary can be markedly reduced using combined PET-MRI. Owing to its limited availability, combined PET-MRI is currently not used as a routine procedure. However, this new modality has the potential to become the imaging reference standard in pediatric oncology in the future. This review article summarizes the central aspects of pediatric oncological PET-MRI based on existing literature. Typical pediatric oncological PET-MRI cases are also presented.

  2. MRI findings of serous atrophy of bone marrow and associated complications

    International Nuclear Information System (INIS)

    To report the MRI appearance of serous atrophy of bone marrow (SABM) and analyse clinical findings and complications of SABM. A retrospective search of MRI examinations of SABM was performed. Symptoms, underlying conditions, MRI findings, delay in diagnosis and associated complications were recorded. We identified 30 patients (15 male, 15 female; mean age: 46 ± 21 years) with MRI findings of SABM. Underlying conditions included anorexia nervosa (n = 10), cachexia from malignant (n = 5) and non-malignant (n = 7) causes, massive weight loss after bariatric surgery (n = 1), biliary atresia (n = 1), AIDS (n = 3), endocrine disorders (n = 2) and scurvy (n = 1). MRI showed mildly hypointense signal on T1- weighted and hyperintense signal on fat-suppressed fluid-sensitive images of affected bone marrow in all cases and similar signal abnormalities of the adjacent subcutaneous fat in 29/30 cases. Seven patients underwent repeat MRI due to initial misinterpretation of bone marrow signal as technical error. Superimposed fractures of the hips and lower extremities were common (n = 14). SABM occurs most commonly in anorexia nervosa and cachexia. MRI findings of SABM are often misinterpreted as technical error requiring unnecessary repeat imaging. SABM is frequently associated with fractures of the lower extremities. (orig.)

  3. EEG-fMRI integration for the study of human brain function.

    Science.gov (United States)

    Jorge, João; van der Zwaag, Wietske; Figueiredo, Patrícia

    2014-11-15

    Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) have proved to be extremely valuable tools for the non-invasive study of human brain function. Moreover, due to a notable degree of complementarity between the two modalities, the combination of EEG and fMRI data has been actively sought in the last two decades. Although initially focused on epilepsy, EEG-fMRI applications were rapidly extended to the study of healthy brain function, yielding new insights into its underlying mechanisms and pathways. Nevertheless, EEG and fMRI have markedly different spatial and temporal resolutions, and probe neuronal activity through distinct biophysical processes, many aspects of which are still poorly understood. The remarkable conceptual and methodological challenges associated with EEG-fMRI integration have motivated the development of a wide range of analysis approaches over the years, each relying on more or less restrictive assumptions, and aiming to shed further light on the mechanisms of brain function along with those of the EEG-fMRI coupling itself. Here, we present a review of the most relevant EEG-fMRI integration approaches yet proposed for the study of brain function, supported by a general overview of our current understanding of the biophysical mechanisms coupling the signals obtained from the two modalities.

  4. Spinal cord involvement in chronic inflammatory demyelinating polyradiculoneuropathy: a clinical and MRI study.

    Science.gov (United States)

    Ioannidis, Panagiotis; Parissis, Dimitris; Karapanayiotides, Theodoros; Maiovis, Pantelis; Karacostas, Dimitris; Grigoriadis, Nikolaos

    2015-06-01

    Concomitant central nervous system (CNS) involvement in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is rare. Although the spinal nerve roots may present MRI abnormalities in CIDP, hitherto, the spinal cord has been investigated in a single study. We retrospectively investigated clinically and with MRI a cohort of patients with definite CIDP diagnosis (EFNS/PNS criteria) for evidence of brain and spinal cord involvement, who were initially admitted in our department during the last 4 years. Among 12 patients with CIDP (men: 8, mean age: 59.3 years, mean disease duration: 3.8 years), nine patients had their MRI scan during a clinical relapse and three during remission. Brain MRI did not document typical multiple sclerosis lesions in any patient. We did not identify any MRI abnormalities in ten patients without clinical evidence of spinal cord involvement. Conversely, MRI disclosed extensive lesions of the thoracic cord in two patients with an overt spinal cord syndrome, whom we describe. This represents the biggest MRI study of CIDP patients who have been investigated for spinal cord involvement. Our data support earlier observations that a minority of CIDP patients may additionally develop CNS involvement of variable degree.

  5. MRI findings of serous atrophy of bone marrow and associated complications

    Energy Technology Data Exchange (ETDEWEB)

    Boutin, Robert D. [Department of Radiology, Sacramento, CA (United States); White, Lawrence M. [University of Toronto, Joint Department of Medical Imaging, Toronto General Hospital, Toronto, ON (Canada); Laor, Tal [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Spitz, Damon J. [New England Baptist Hospital, Department of Radiology, Boston, MA (United States); Lopez-Ben, Robert R. [Carolinas HealthCare System, Charlotte Radiology, Diagnostic Radiology, Charlotte, NC (United States); Stevens, Kathryn J. [Stanford University, Department of Radiology, Stanford, CA (United States); Bredella, Miriam A. [Massachusetts General Hospital and Harvard Medical School, Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States)

    2015-09-15

    To report the MRI appearance of serous atrophy of bone marrow (SABM) and analyse clinical findings and complications of SABM. A retrospective search of MRI examinations of SABM was performed. Symptoms, underlying conditions, MRI findings, delay in diagnosis and associated complications were recorded. We identified 30 patients (15 male, 15 female; mean age: 46 ± 21 years) with MRI findings of SABM. Underlying conditions included anorexia nervosa (n = 10), cachexia from malignant (n = 5) and non-malignant (n = 7) causes, massive weight loss after bariatric surgery (n = 1), biliary atresia (n = 1), AIDS (n = 3), endocrine disorders (n = 2) and scurvy (n = 1). MRI showed mildly hypointense signal on T1- weighted and hyperintense signal on fat-suppressed fluid-sensitive images of affected bone marrow in all cases and similar signal abnormalities of the adjacent subcutaneous fat in 29/30 cases. Seven patients underwent repeat MRI due to initial misinterpretation of bone marrow signal as technical error. Superimposed fractures of the hips and lower extremities were common (n = 14). SABM occurs most commonly in anorexia nervosa and cachexia. MRI findings of SABM are often misinterpreted as technical error requiring unnecessary repeat imaging. SABM is frequently associated with fractures of the lower extremities. (orig.)

  6. MRI in the management of scaphoid fractures in skeletally immature patients

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, K.J.; Haigh, S.F. [Birmingham Children' s Hospital NHS Trust (United Kingdom). Radiology Dept.; Symonds, K.E. [Diana Princess of Wales Children' s Hospital, Birmingham (United Kingdom). Accident and Emergengency

    2000-10-01

    Background. The scaphoid is the commonest fractured carpal bone, but excluding a scaphoid fracture with plain radiographs is difficult. Other imaging modalities are being increasingly evaluated in the management of scaphoid injuries. MRI has been shown to be of considerable value in the adult population but there have been limited studies of its use in children. Purpose. To evaluate the role of MRI in the acute management of suspected scaphoid injuries in children. Methods and materials. Fifty-six children (57 injuries) who had a suspected scaphoid injury underwent MRI within 10 days of their initial trauma. The results of MRI were used to dictate management of the injury. Results. In 33 (58 %) of the 57 injuries, MRI was normal and the patient was discharged from care. In 16 cases (28 %), a fractured scaphoid was diagnosed and appropriate treatment started early. Additionally, other fractures around the wrist joint and ganglion cysts were demonstrated on MRI. Conclusions. MRI of acute scaphoid injuries in children significantly alters management. Those children with normal scans are discharged earlier. Scaphoid fractures are confirmed earlier and other pathological conditions are also detected. (orig.)

  7. Equilibrium disks, MRI mode excitation, and steady state turbulence in global accretion disk simulations

    CERN Document Server

    Parkin, E R

    2012-01-01

    Global three dimensional magnetohydrodynamic (MHD) simulations of turbulent accretion disks are presented which start from fully equilibrium initial conditions in which the magnetic forces are accounted for and the induction equation is satisfied. The local linear theory of the magnetorotational instability (MRI) is used as a predictor of the growth of magnetic field perturbations in the global simulations. The linear growth estimates and global simulations diverge when non-linear motions - perhaps triggered by the onset of turbulence - upset the velocity perturbations used to excite the MRI. The saturated state is found to be independent of the initially excited MRI mode, showing that once the disk has expelled the initially net flux field and settled into quasi-periodic oscillations in the toroidal magnetic flux, the dynamo cycle regulates the global saturation stress level. Furthermore, time-averaged measures of converged turbulence, such as the ratio of magnetic energies, are found to be in agreement with...

  8. Magnetic resonance imaging (MRI) of liver and brain in haematologic-organic patients with fever of unknown origin

    International Nuclear Information System (INIS)

    To examine the advantage of liver and brain MRI in clinically anomalous haematological patients with fever of unknown origin. Material and Methods: Twenty liver MRI (T2-TSE, T2-HASTE, T1-FLASH±Gd dynamic) and 16 brain MRI (T2-TSE, FLAIR, T1-TSE±Gd) were performed searching for a focus of fever with a suspected organ system. Comparison with clinical follow-up. Results: suspected organ system. Comparison with clinical follow-up. Results: A focus was detected in 11/20 liver MRI. Candidiasis (n=3), mycobacteriosis (n=2), relapse of haematological disease (n=3), graft versus host disease (n=1), non-clarified (n=2). The remaining 9 cases with normal MRI were not suspicious of infectious hepatic disease during follo-wup. In brain MRI, 3/16 showed a focus (toxoplasmosis, aspergillosis, mastoiditis). Clinical indication for an infectious involvement of the brain was found in 4/16 cases 2--5 months after initially normal brain MRI. No suspicion of an infectious involvement of brain was present in the remaining 9/16 cases. Conclusion: In case of fever of unknown origin and suspicion of liver involvement, MRI of the liver should be performed due to data given in literature and its sensitivity of 100%. Because of the delayed detectability of cerebral manifestations, in cases of persisting suspicion even a previously normal MRI of the brain should be repeated. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Roberta Fusco

    2015-01-01

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

  10. Feasibility of carotid artery PET/MRI in psoriasis patients.

    Science.gov (United States)

    Rajiah, Prabhakar; Hojjati, Mojgan; Lu, Ziang; Kosaraju, Vijaya; Partovi, Sasan; O'Donnell, James K; Longenecker, Christopher; McComsey, Grace A; Golden, Jackelyn B; Muakkassa, Fuad; Santilli, Scott; McCormick, Thomas S; Cooper, Kevin D; Korman, Neil J

    2016-01-01

    We report our initial experience of performing integrated PET/MR imaging of the carotid arteries in psoriatic patients. Eleven patients with psoriasis and ten controls underwent carotid PET/MRI. Following injection of the FDG tracer, 3d T1w gradient echo sequence (atMR) was obtained for attenuation correction of PET data. High resolution images of carotid artery were then obtained, including pre-and post-contrast T1-w, T2-w and proton-density images as well as TOF images followed by PET imaging of the torso. From the fused axial PET/MRI, the arterial wall SUVmax and TBRmax was quantified in each slice. MRI images were also evaluated for vessel wall volume, plaque and internal composition. SUVmax and TBRmax were respectively, 1.72 ± 0.38 & 1.17 ± 0.27 in L- CCA, 1.75 ± 0.39 & 1.24 ± 0.19 in R-CCA, 1.59 ± 0.24 & 1.08 ± 0.14 in L-ICA and 1.62 ± 0.27 & 1.15 ± 0.17 in R-ICA in psoriatic patients and 1.74 ± 0.22 & 1.28 ± 0.44 in L- CCA, 1.74 ± 0.33 & 1.07 ± 0.28 in R-CCA, 1.78 ± 0.32 & 1.29 ± 0.39 in L-ICA and 1.60 ± 0.29 & 0.98 ± 0.25 in R-ICA in the controls. No discrete plaques were identified in any of the vessel segments in MRI. PET/MRI is feasible in evaluation of carotid arteries in psoriatic patients. PMID:27648374

  11. MRI of Wolfram syndrome (DIDMOAD)

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-10-01

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

  12. MRI morphometry in Alzheimer's disease.

    Science.gov (United States)

    Matsuda, Hiroshi

    2016-09-01

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

  13. MRI in subacute sclerosing panencephalitis

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-10-01

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

  14. MRI in mucoviscidosis (cystic fibrosis)

    International Nuclear Information System (INIS)

    Cystic fibrosis (CF) is a multi-systemic disease with major impact on the lungs. Pulmonary manifestation is crucial for the prognosis and life expectancy of patients. Imaging modalities and lung function tests reflect the pulmonary status in these patients. The standard imaging modality for diagnosis and follow-up of pulmonary changes is chest x-ray. The gold standard for the detection of parenchymal lung changes remains high resolution computed tomography (HRCT), but this is not used routinely for CF-patients due to radiation exposure. Magnetic resonance imaging (MRI) used to be of no importance in monitoring cystic fibrosis lung disease, as shown in studies from the 1980s and early 1990s. The continuing improvement of MRI techniques, however, has allowed for an adequate application of this non-radiation method in diagnosing the major pulmonary findings in CF, in addition to the assessment of lung function. (orig.)

  15. MRI of Wolfram syndrome (DIDMOAD)

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Roberta Fusco; Mario Sansone; Salvatore Filice; Vincenza Granata; Orlando Catalano; Daniela Maria Amato; Maurizio Di Bonito; Massimiliano D’Aiuto; Immacolata Capasso; Massimo Rinaldo; Antonella Petrillo

    2015-01-01

    Objective. The purpose of our study was to evaluate the diagnostic value of an imaging protocol combining dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted MRI (DW-MRI) in patients with suspicious breast lesions. Materials and Methods. A total of 31 breast lesions (15 malignant and 16 benign proved by histological examination) in 26 female patients were included in this study. For both DCE-MRI and DW-MRI model free and model based parameters were computed pixel by pixel on manual...

  17. Importance of MRI in the diagnosis of vertebral involvement in generalized cystic lymphangiomatosis

    Energy Technology Data Exchange (ETDEWEB)

    Renjen, Pooja; Kovanlikaya, Arzu; Brill, Paula W. [New York Presbyterian Hospital/Weill Cornell Medical Center, Department of Radiology, New York, NY (United States); Narula, Navneet [New York Presbyterian Hospital/Weill Cornell Medical Center, Department of Pathology, New York, NY (United States)

    2014-11-15

    A 9-year-old boy presented with the sudden onset of pleuritic chest pain and on CT was found to have a large pleural effusion, mediastinal fluid, splenic lesions and multiple apparently sclerotic vertebral bodies. Subsequent MRI showed that those vertebral bodies that appeared sclerotic were in fact normal, and the vertebral bodies initially interpreted as normal had an abnormal T1 and T2 hyperintense signal on MRI and were relatively lucent on CT. MRI also demonstrated abnormal heterogeneous T2 hyperintense paraspinal tissue and several multicystic soft tissue masses. Biopsy of two adjacent vertebral bodies, one relatively sclerotic and one lucent, demonstrated findings of bony remodeling without a specific diagnosis. Biopsy of an infiltrative mediastinal mass confirmed the diagnosis of generalized cystic lymphangiomatosis. MRI should be included in the assessment of vertebral involvement in this condition because CT and biopsy findings may be nonspecific. (orig.)

  18. Fetal MRI Characteristics of Exencephaly: A Case Report and Literature Review

    Directory of Open Access Journals (Sweden)

    Ali Sharif

    2016-01-01

    Full Text Available We present the fetal MRI characteristics of exencephaly, a rare malformation of the cranium. The fetus was initially misdiagnosed as anencephaly at 14 weeks of estimated gestational age (EGA and later mislabeled as acrania at 20 weeks of EGA by ultrasound. A confirmatory magnetic resonance imaging (MRI at 29 weeks of EGA demonstrated findings consistent with exencephaly, which was confirmed after birth. To our knowledge, no full fetal MRI characteristics have been described. We hope to use this case to review the key MRI findings in differentiating exencephaly from other cranial vault defects and to help early diagnosis of exencephaly as the appropriate use of correct nomenclature allows better research while giving parents the most accurate and appropriate counseling.

  19. Fetal MRI Characteristics of Exencephaly: A Case Report and Literature Review.

    Science.gov (United States)

    Sharif, Ali; Zhou, Yihua

    2016-01-01

    We present the fetal MRI characteristics of exencephaly, a rare malformation of the cranium. The fetus was initially misdiagnosed as anencephaly at 14 weeks of estimated gestational age (EGA) and later mislabeled as acrania at 20 weeks of EGA by ultrasound. A confirmatory magnetic resonance imaging (MRI) at 29 weeks of EGA demonstrated findings consistent with exencephaly, which was confirmed after birth. To our knowledge, no full fetal MRI characteristics have been described. We hope to use this case to review the key MRI findings in differentiating exencephaly from other cranial vault defects and to help early diagnosis of exencephaly as the appropriate use of correct nomenclature allows better research while giving parents the most accurate and appropriate counseling. PMID:26955498

  20. Imaging in rheumatoid arthritis--why MRI and ultrasonography can no longer be ignored

    DEFF Research Database (Denmark)

    Østergaard, Mikkel; Szkudlarek, Marcin

    2003-01-01

    knowledge on conventional radiography, computed tomography, MRI and US for assessment of peripheral joints in RA. The rationale is provided for MRI being the new gold standard for assessment of RA joints and US becoming a routine bedside tool for improved joint assessments and injections by rheumatologists......Implementing the modern treatment strategy in rheumatoid arthritis (RA), i.e. early initiation and optimal adjustments of aggressive therapies, requires methods for early diagnosis and sensitive monitoring of the disease process. In rheumatoid arthritis clinical trials and routine management...... imaging (MRI) offers assessment of bone damage with improved sensitivities to early pathology and to change. In addition, detailed assessment of soft tissue changes, including synovitis and tenosynovitis, is possible and MRI findings are of prognostic value for the long-term radiological outcome...

  1. Multiparametric prostate MRI for follow-up monitoring after radiation therapy

    International Nuclear Information System (INIS)

    Radiation therapy is a therapeutic option with curative intent for patients with prostate cancer. Monitoring of prostate-specific antigen (PSA) values is the current standard of care in the follow-up. Imaging is recommended only for symptomatic patients and/or for further therapeutic options. For detection of local recurrence magnetic resonance imaging (MRI) of the prostate is acknowledged as the method of choice. Good results for primary diagnosis were found especially in combination with functional techniques, whereas in recurrent prostate cancer only few studies with heterogeneous study design are available for prostate MRI. Furthermore, changes in different MRI modalities due to radiation therapy have been insufficiently investigated to date. As the initial results were promising prostate MRI and available therapeutic options for detection of local recurrence should be considered in patients with increased PSA. (orig.)

  2. Identifying biological pathways in the MRI findings of people with low back pain

    DEFF Research Database (Denmark)

    Jensen, Rikke Krüger; Jensen, Tue Secher; Kjær, Per;

    Title Identifying biological pathways in the MRI findings of people with low back pain Authors and affiliations Rikke K Jensen1, Tue Secher Jensen1, Per Kjaer1,2, Peter Kent1 1Research Department, Spine Centre of Southern Denmark, Hospital Lillebaelt, Institute of Regional Health Services Research...... Investigations into the association between lumbar MRI findings and low back pain (LBP) are complicated by multiple MRI findings being present at the same time. Findings such as lumbar intervertebral disc protrusions or endplate changes almost always co-exist with other degenerative disc findings...... such as the reduction of disc height and signal intensity. Despite this, the majority of previous research has focused solely on the associations between single imaging findings and pain or other clinical outcomes. Only recently have researchers started to engage with this complexity of MRI findings. An initial...

  3. Slow-growing labyrinthine masses: contribution of MRI to diagnosis, follow-up and treatment

    Energy Technology Data Exchange (ETDEWEB)

    Deux, J.F.; Marsot-Dupuch, K.; Tubiana, J.M. [Hopital Saint-Antoine, Paris (France). Service de Radiology; Ouayoun, M.; Meyer, B. [Service d`ORL, Hopital Saint-Antoine, 184 rue du Faubourg Saint-Antoine, F-75012 Paris (France); Tran Ba Huy, P. [Service d`ORL, Hopital Lariboisiere, 2 rue Ambroise Pare, F-75010 Paris (France); Sterkers, J.M.

    1998-10-01

    We report the use of MRI in the diagnosis, follow-up and therapeutic management of three cases of intralabyrinthine Schwannoma. The diagnosis was based on the history and initial and follow-up MRI findings. The main feature suggesting the diagnosis was a nodular intralabyrinthine mass of low signal intensity on T2-weighted images, and high or isointense signal on T1-weighted images (relative to cerebrospinal fluid), which showed contrast enhancement. Follow-up imaging showed growth of the tumour in one patient. One patient underwent surgery for severe tinnitus. To detect these lesions, MRI should be focussed on the inner ear, using thin-section T2-weighted and T1-weighted images before and after contrast medium. MRI allowed informed surgical planning. (orig.) (orig.) With 3 figs., 1 tab., 21 refs.

  4. Current status and future role of brain PET/MRI in clinical and research settings

    Energy Technology Data Exchange (ETDEWEB)

    Werner, P.; Barthel, H.; Sabri, O. [University Hospital Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Drzezga, A. [University Hospital Cologne, Department of Nuclear Medicine, Koeln (Germany)

    2015-01-09

    Hybrid PET/MRI systematically offers a complementary combination of two modalities that has often proven itself superior to the single modality approach in the diagnostic work-up of many neurological and psychiatric diseases. Emerging PET tracers, technical advances in multiparametric MRI and obvious workflow advantages may lead to a significant improvement in the diagnosis of dementia disorders, neurooncological diseases, epilepsy and neurovascular diseases using PET/MRI. Moreover, simultaneous PET/MRI is well suited to complex studies of brain function in which fast fluctuations of brain signals (e.g. related to task processing or in response to pharmacological interventions) need to be monitored on multiple levels. Initial simultaneous studies have already demonstrated that these complementary measures of brain function can provide new insights into the functional and structural organization of the brain. (orig.)

  5. MRI-induced retrocalcaneal bursitis

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-10-01

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

  6. Retroperitoneal Bronchogenic Cyst: MRI Findings

    OpenAIRE

    Castro, R.; Oliveira, M. I.; Fernandes, T; Madureira, A. J.

    2013-01-01

    The authors describe a case of a retroperitoneal bronchogenic cyst in a 36-year-old female. She presented with abdominal pain, nausea, and vomiting. An MRI scan revealed an 8 cm cystic lesion in the left upper retroperitoneum, with intermediate signal on T2-weighted images, high signal on T1 weighted images, and lack of internal enhancement after gadolinium. After laparoscopic excision, the histology findings were compatible with a bronchogenic cyst, which is extremely uncommon in the retrope...

  7. MRI in cerebral toxocaral disease.

    OpenAIRE

    Rüttinger, P; Hadidi, H

    1991-01-01

    Toxocara canis, the common roundworm in the dog, can cause "visceral larva migrans" syndrome in humans, which may include generalised illness, eosinophilia, and symptoms arising from larval invasion of different organs. Of these, the clinically most important are liver, lungs, eyes and CNS. Involvement of the different parts of the CNS in human toxocaral disease has been described, but not the CT or MRI appearances of the cerebral lesions. In one case with a single focal epileptic fit, CT was...

  8. Retroperitoneal bronchogenic cyst: MRI findings.

    Science.gov (United States)

    Castro, R; Oliveira, M I; Fernandes, T; Madureira, A J

    2013-01-01

    The authors describe a case of a retroperitoneal bronchogenic cyst in a 36-year-old female. She presented with abdominal pain, nausea, and vomiting. An MRI scan revealed an 8 cm cystic lesion in the left upper retroperitoneum, with intermediate signal on T2-weighted images, high signal on T1 weighted images, and lack of internal enhancement after gadolinium. After laparoscopic excision, the histology findings were compatible with a bronchogenic cyst, which is extremely uncommon in the retroperitoneum.

  9. MRI findings of extramedullary haemopoiesis

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-09-01

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

  10. MRI in insulinomas; Preliminary findings

    Energy Technology Data Exchange (ETDEWEB)

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

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

  11. Openness initiative

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, S.S. [Los Alamos National Lab., NM (United States)

    1995-12-31

    Although antinuclear campaigns seem to be effective, public communication and education efforts on low-level radioactive waste have mixed results. Attempts at public information programs on low-level radioactive waste still focus on influencing public opinion. A question then is: {open_quotes}Is it preferable to have a program focus on public education that will empower individuals to make informed decisions rather than trying to influence them in their decisions?{close_quotes} To address this question, a case study with both quantitative and qualitative data will be used. The Ohio Low-Level Radioactive Waste Education Program has a goal to provide people with information they want/need to make their own decisions. The program initiated its efforts by conducting a statewide survey to determine information needed by people and where they turned for that information. This presentation reports data from the survey and then explores the program development process in which programs were designed and presented using the information. Pre and post data from the programs reveal attitude and knowledge shifts.

  12. Intracranical calcification in siblings with nephrogenic diabetes insipidus: CT and MRI

    International Nuclear Information System (INIS)

    Computed tomography and magnetic resonance imaging (MRI) were used to examine three male siblings with nephrogenic diabetes insipidus (NDI). The two elder brothers had varying degrees of unusual intracranial calcification; the eldest also showed involvement of the cerebral white matter on MRI. The severity of intracranial calcification was related to the time before initiation of treatment and inversely to mental ability. Brain damage and mental retardation in NDI may be caused by a delay in initiating treatment; early detection and treatment are important to prevent brain damage. (orig.)

  13. MRI findings of juvenile psoriatic arthritis

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-11-15

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

  14. Decision forests for learning prostate cancer probability maps from multiparametric MRI

    Science.gov (United States)

    Ehrenberg, Henry R.; Cornfeld, Daniel; Nawaf, Cayce B.; Sprenkle, Preston C.; Duncan, James S.

    2016-03-01

    Objectives: Advances in multiparametric magnetic resonance imaging (mpMRI) and ultrasound/MRI fusion imaging offer a powerful alternative to the typical undirected approach to diagnosing prostate cancer. However, these methods require the time and expertise needed to interpret mpMRI image scenes. In this paper, a machine learning framework for automatically detecting and localizing cancerous lesions within the prostate is developed and evaluated. Methods: Two studies were performed to gather MRI and pathology data. The 12 patients in the first study underwent an MRI session to obtain structural, diffusion-weighted, and dynamic contrast enhanced image vol- umes of the prostate, and regions suspected of being cancerous from the MRI data were manually contoured by radiologists. Whole-mount slices of the prostate were obtained for the patients in the second study, in addition to structural and diffusion-weighted MRI data, for pathology verification. A 3-D feature set for voxel-wise appear- ance description combining intensity data, textural operators, and zonal approximations was generated. Voxels in a test set were classified as normal or cancer using a decision forest-based model initialized using Gaussian discriminant analysis. A leave-one-patient-out cross-validation scheme was used to assess the predictions against the expert manual segmentations confirmed as cancer by biopsy. Results: We achieved an area under the average receiver-operator characteristic curve of 0.923 for the first study, and visual assessment of the probability maps showed 21 out of 22 tumors were identified while a high level of specificity was maintained. In addition to evaluating the model against related approaches, the effects of the individual MRI parameter types were explored, and pathological verification using whole-mount slices from the second study was performed. Conclusions: The results of this paper show that the combination of mpMRI and machine learning is a powerful tool for

  15. T2 weighted MRI for assessing renal lesions in transgenic mouse models of tuberous sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Kalogerou, Maria; Zhang, Yadan; Yang, Jian; Garrahan, Nigel [Institute of Medical Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN (United Kingdom); Paisey, Stephen; Tokarczuk, Paweł; Stewart, Andrew [School of Bioscience, Cardiff University, Museum Avenue, Cardiff CF10 3AX (United Kingdom); Gallacher, John [Department of Primary Care and Public Health, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4YS (United Kingdom); Sampson, Julian R. [Institute of Medical Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN (United Kingdom); Shen, Ming Hong, E-mail: shenmh@cf.ac.uk [Institute of Medical Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN (United Kingdom)

    2012-09-15

    Objective: Transgenic mouse models of tuberous sclerosis (TSC) develop renal cysts, cystadenomas, solid adenomas and carcinomas. Identification and characterisation of these lesions in vivo may help in TSC pre-clinical trials. This study was to evaluate T2 weighted MRI for assessment of renal lesions in two Tsc mouse models. Materials and Methods: Tsc1{sup +/−}, Tsc2{sup +/−} and wild type mice were subjected to a first MRI scan at 12 months of age and a second scan 2 months later. One Tsc2{sup +/−} mouse was treated with rapamycin for two months after the initial scan. Immediately following the second scan, mice were sacrificed and MRI images were compared to renal histological findings. Results: MRI identified all types of Tsc-associated renal lesions in both Tsc1{sup +/−} and Tsc2{sup +/−} mice. The smallest detectable lesions were <0.1 mm{sup 3}. Eighty three percent of all renal lesions detected in the first scan were re-identified in the second scan. By MRI, these lesions demonstrated significant growth in the 9 untreated Tsc1{sup +/−} and Tsc2{sup +/−} mice but shrinkage in the rapamycin treated Tsc2{sup +/−} mouse. Between the two scans, MRI also revealed significant increase in both the total number and volume of lesions in untreated mice and decrease in the rapamycin treated mouse, respectively. In comparison to histological analysis MRI detected most cysts and cystadenomas (66%) but only a minority of solid tumours (29%). Conclusion: These results suggest that T2 weighted MRI may be a useful tool for assessing some renal lesions in pre-clinical studies using Tsc mouse models. However, improved sensitivity for T2 weighted MRI is required, particularly for solid renal lesions.

  16. Comparison of foetal US and MRI in the characterisation of congenital lung anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Alamo, Leonor, E-mail: leonor.alamo@chuv.ch [Unit of Pediatric Radiology, Department of Diagnostic and Interventional Radiology, Centre Hospitalière Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1011 Lausanne (Switzerland); Reinberg, Olivier, E-mail: Olivier.reinberg@chuv.ch [Department of Pediatric Surgery, Centre Hospitalière Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1011 Lausanne (Switzerland); Vial, Yvan, E-mail: Yvan.vial@chuv.ch [Unit of Prenatal Obstetric Diagnosis, Department of Gynecology and Obstetrics, Centre Hospitalière Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1011 Lausanne (Switzerland); Gudinchet, François, E-mail: Francois.Gudinchet@chuv.ch [Unit of Pediatric Radiology, Department of Diagnostic and Interventional Radiology, Centre Hospitalière Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1011 Lausanne (Switzerland); Meuli, Reto, E-mail: Reto.Meuli@chuv.ch [Unit of Pediatric Radiology, Department of Diagnostic and Interventional Radiology, Centre Hospitalière Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1011 Lausanne (Switzerland)

    2013-12-01

    Objectives: To compare the accuracy of prenatal ultrasonography (US) to magnetic resonance imaging (MRI) in the characterisation of congenital lung anomalies, and to assess their agreement with final diagnosis. To evaluate the influence of additional MRI information on therapeutic management. Methods: 26 prenatal congenital lung anomalies detected consecutively between 2006 and 2012 were retrospectively evaluated. Lesions were initially observed at prenatal US and further investigated with MRI. Prenatal US and MRI imaging findings, and suggested diagnosis were compared with the final diagnosis, obtained from autopsies (4), pathological evaluation following surgical resection (15) and postnatal imaging studies (7). Results: Postnatal diagnoses included 7 congenital pulmonary airway malformations, 8 complex lesions, 7 overinflations, 1 sequestration, 1 bronchogenic cyst, 1 blastoma and 1 bilateral lymphangioma. Suggested prenatal US and MRI diagnosis was correct in 34.6% and 46.2% of patients, respectively, mainly isolated lung lesions with typical imaging findings. Nonspecific imaging findings at US and MRI studies were observed in 38.4% of cases. In 42% of the operated anomalies, pathological dissection revealed the presence of complex anomalies. MRI changed the US diagnosis, but not the further management in 9.7% of the lesions. Conclusions: Prenatal US and MRI showed a high accuracy in the diagnosis of isolated congenital lung lesions with typical imaging findings. However, overall characterisation rates were low, because of both a high percentage of complex lesions and of lesions with nonspecific imaging findings. MRI was better than US in characterising complex lesions, but its additional information did not influence therapy decisions.

  17. Bladder cancer: utility of MRI in detection of occult muscle-invasive disease

    Energy Technology Data Exchange (ETDEWEB)

    Rosenkrantz, Andrew B. [Dept. of Radiology, NYU Langone Medical Center, New York (United States)], E-mail: Andrew.rosenkrantz@nyumc.org; Mussi, Thais C. [Dept. of Radiology, NYU Langone Medical Center, New York (United States); Hospital Israelita Albert Einstein, Sao Paulo (Brazil); Melamed, Jonathan [Dept. of Pathology, NYU Langone Medical Center, New York (United States); Taneja, Samir S.; Huang, William C. [Dept. of Urology, Div. of Urologic Oncology, NYU Langone Medical Center, New York (United States)

    2012-07-15

    Background. The presence of muscularis propria invasion by bladder cancer is a key factor in prognosis and treatment decisions, although may be missed by biopsy due to sampling error. MRI has shown potential for detection of muscle invasion but has not specifically been evaluated for this purpose in the setting of bladder cancer patients without evidence of muscle invasion on initial biopsy. Purpose. To evaluate the role of MRI in detection of muscularis propria invasion by bladder cancer following a pathologic diagnosis of non-invasive tumor. Material and Methods. This retrospective study included 23 patients who underwent pelvic MRI following a pathologic diagnosis of bladder cancer without muscularis propria invasion and in whom additional histologic evaluation was performed following MRI. Two radiologists in consensus reviewed T2-weighted images to identify those cases suspicious for muscle invasion on MRI. The radiologists identified whether cases suspicious for invasion demonstrated disruption of the T2-hypointense muscularis layer of the bladder wall, peri-vesical fat stranding, and peri-vesical soft tissue nodularity. Findings were compared with pathologic results obtained after MRI. Results. Suspicion was raised for muscle invasion in eight of 23 cases, four of which exhibited invasion on follow-up pathology. No case without suspicion on MRI exhibited invasion on follow-up pathology. Therefore, sensitivity and specificity were 100% and 79%, respectively. Among individual findings, muscularis disruption on T2WI exhibited sensitivity of 100% and specificity of 79%, peri-vesical fat stranding exhibited sensitivity and specificity of 50% and 84%, and peri-vesical soft tissue nodularity exhibited sensitivity and specificity of 25% and 100%. Conclusion. MRI demonstrated high sensitivity for detection of muscle invasion in cases of bladder cancer without invasion on initial histologic assessment. Muscularis disruption on T2WI appeared to exhibit a better

  18. Whole-body MRI for primary evaluation of malignant disease in children

    Energy Technology Data Exchange (ETDEWEB)

    Krohmer, S. [Universitaetsklinikum Leipzig AoeR, Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Abteilung Paediatrische Radiologie, Liebigstr. 20, 04103 Leipzig (Germany)], E-mail: Swetlana.Krohmer@medizin.uni-leipzig.de; Sorge, I. [Universitaetsklinikum Leipzig AoeR, Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Abteilung Paediatrische Radiologie, Liebigstr. 20, 04103 Leipzig (Germany); Krausse, A.; Kluge, R. [Universitaetsklinikum Leipzig AoeR, Klinik und Poliklinik fuer Nuklearmedizin (Germany); Bierbach, U. [Universitaetsklinikum Leipzig AoeR, Klinik und Poliklinik fuer Kinder und Jugendliche (Germany); Marwede, D.; Kahn, T.; Hirsch, W. [Universitaetsklinikum Leipzig AoeR, Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Abteilung Paediatrische Radiologie, Liebigstr. 20, 04103 Leipzig (Germany)

    2010-04-15

    Objective: The aim of this study was to compare diagnostic accuracy of whole-body (WB) MRI to a combined reference standard of conventional cross-sectional imaging methods and FDG-PET in the detection of malignant disease spread in children. Materials and methods: 24 children (age between 5 and 18 years) with malignant diseases (mainly Hodgkin's lymphoma and different types of sarcoma) initially examined with conventional cross-sectional imaging methods (ultrasound, computed tomography, or magnetic resonance imaging) were examined prospectively with whole-body MRI (1.5 T) and FDG-PET. Studies were read by two nuclear medicine physicians (FDG-PET) and two radiologists (WB-MRI) independently in a blinded manner and each study type was evaluated in consensus. The reference standard was defined as pathological lesions detected in the same location both in FDG-PET and another conventional cross-sectional imaging method. Results: Overall 190 lesions were detected by WB-MRI and 155 lesion were found by FDG-PET. 106 lesions fulfilled the criteria of the reference standard (42 osseous and 64 extraosseous lesions) from which 102 were detected by WB-MRI (sensitivity of 96%). All bone lesions were detected and extra-skeletal lesions were identified with a sensitivity of 93.8%. Overall 88 lesions detected by WB-MRI were not part of the reference standard from which 33 were lesions of the peripheral skeleton not imaged by conventional cross-sectional imaging studies. 4 lesions of the reference standard were not identified by WB-MRI which were all lymph nodes. Conclusion: WB-MRI is a radiation free imaging technique with high sensitivity for the detection of malignant disease spread in particular beneficial for children. In patients with suspected bone lesions it should be considered for initial disease evaluation prior to specific and regional imaging methods to reduce the overall number of imaging examinations and radiation exposure.

  19. Future perspectives for intraoperative MRI.

    Science.gov (United States)

    Jolesz, Ferenc A

    2005-01-01

    MRI-guided neurosurgery not only represents a technical challenge but a transformation from conventional hand-eye coordination to interactive navigational operations. In the future, multimodality-based images will be merged into a single model, in which anatomy and pathologic changes are at once distinguished and integrated into the same intuitive framework. The long-term goals of improving surgical procedures and attendant outcomes, reducing costs, and achieving broad use can be achieved with a three-pronged approach: 1. Improving the presentation of preoperative and real-time intraoperative image information 2. Integrating imaging and treatment-related technology into therapy delivery systems 3. Testing the clinical utility of image guidance in surgery The recent focus in technology development is on improving our ability to understand and apply medical images and imaging systems. Areas of active research include image processing, model-based image analysis, model deformation, real-time registration, real-time 3D (so-called "four-dimensional") imaging, and the integration and presentation of image and sensing information in the operating room. Key elements of the technical matrix also include visualization and display platforms and related software for information and display, model-based image understanding, the use of computing clusters to speed computation (ie, algorithms with partitioned computation to optimize performance), and advanced devices and systems for 3D device tracking (navigation). Current clinical applications are successfully incorporating real-time and/or continuously up-dated image-based information for direct intra-operative visualization. In addition to using traditional imaging systems during surgery, we foresee optimized use of molecular marker technology, direct measures of tissue characterization (ie, optical measurements and/or imaging), and integration of the next generation of surgical and therapy devices (including image

  20. How to scan polymer gels with MRI?

    Science.gov (United States)

    De Deene, Y.

    2013-06-01

    The absorbed radiation dose fixated in a polymer gel dosimeter can be read out by several methods such as magnetic resonance imaging (MRI), optical CT, X-ray CT and ultrasound with MRI being the first method that was explored. Although MRI was considered as an elegant scanning technique, readily available in most hospitals, it was later found that using a non-optimized imaging protocol may result in unacceptable deviations in the obtained dose distribution. Although most medical physicists have an understanding of the basic principles of magnetic resonance imaging (MRI), the optimization of quantitative imaging sequences and protocols is often perceived as the work of MRI experts. In this paper, we aim at providing the reader with some easy guidelines in how to obtain reliable quantitative MRI maps.

  1. MRI patterns in recurrence of primary CNS lymphoma in immunocompetent patients

    Energy Technology Data Exchange (ETDEWEB)

    Schulte-Altedorneburg, Gernot, E-mail: Gernot.Schulte-Altedorneburg@klinikum-muenchen.de [Institute of Radiology, Neuroradiology and Nuclear Medicine, University of Bochum, Knappschaftskrankenhaus, In der Schornau 23-25, 44892 Bochum (Germany); Heuser, Lothar [Institute of Radiology, Neuroradiology and Nuclear Medicine, University of Bochum, Knappschaftskrankenhaus, In der Schornau 23-25, 44892 Bochum (Germany); Pels, Hendrik [Department of Neurology, Knappschaftskrankenhaus, University of Bochum, In der Schornau 23-25, 44892 Bochum (Germany)

    2012-09-15

    Highlights: ► PCNSL are rare but highly malignant brain tumors. ► PCNSL recur in different anatomic sites compared with initial presentation. ► Non-parenchymal contrast enhancement is a frequent finding at initialdiagnosis and at relapse. -- Abstract: Purpose: Primary CNS lymphomas (PCNSL) are highly malignant non-Hodgkin's B-cell lymphoma restricted to the CNS. While MRI features of PCNSL at initial presentation have been comprehensively described, literature on MRI-characteristics at relapse is sparse. The purpose of this study was to investigate anatomic location and contrast enhancement patterns at PCNSL recurrence by cranial MRI. Methods: Sixteen immunocompetent patients (9 men, 7 women, median age 65 years) with histologically proven PCNSL and initial response to a standardized polychemotherapy, but suffering from a relapse were consecutively recorded. Native and contrast-enhanced MRI examinations carried out at initial presentation and at time of relapse were compared. Anatomical site of parenchymal enhancement, frequency and presence of non-parenchymal contrast enhancement (i.e. ventricular, superficial, subependymal) patterns at initial presentation and at relapse were recorded and compared. Results: Local recurrence was found at the site of the initial tumor presentation in four of the 16 cases. Six of 11 patients presenting a unilateral PCNSL at initial presentation had a bilateral involvement at relapse. In two cases, recurrence appeared solely on the contralateral side without involvement of the hemisphere initially affected. At both dates, subependymal enhancement was the most often found non-parenchymal pattern (six at initial presentation, and five at relapse). The number of patients with a ventricular contrast enhancement increased from one at initial presentation to four at relapse. Conclusions: PCNSL tend to recur in different parenchymal anatomic sites as compared with the site of the initial tumor presentation. Contrast-enhancing non

  2. MRI of sequela of transverse myelitis

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-09-01

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

  3. MRI of sequela of transverse myelitis

    International Nuclear Information System (INIS)

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

  4. Post-processing speech recordings during MRI

    OpenAIRE

    Kuortti, Juha; Malinen, Jarmo; Ojalammi, Antti

    2015-01-01

    We discuss post-processing of speech that has been recorded during Magnetic Resonance Imaging (MRI) of the vocal tract. Such speech recordings are contaminated by high levels of acoustic noise from the MRI scanner. Also, the frequency response of the sound signal path is not flat as a result of severe restrictions on recording instrumentation due to MRI technology. The post-processing algorithm for noise reduction is based on adaptive spectral filtering. The speech material consists of sample...

  5. [Marketing of MRI in the world].

    Science.gov (United States)

    Lavayssière, R; Cabée, A E

    1990-01-01

    The authors are recalling the main tendancies of the medical imaging world market before studying MRI diffusion in the 3 great sectors, USA, Europe and Japan. MRI diffusion is highly regulated in Europe but in the 2 other areas the growth of MRI was slower than the CT growth for the same period of time for medical, technological and financial reasons. The market evolution with the uprising of the mid-field niche and industrial offers will be presented. PMID:2254867

  6. MRI of central nervous system anomalies

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-05-01

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

  7. MRI of central nervous system anomalies

    International Nuclear Information System (INIS)

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

  8. Research progress of functional MRI in depression

    International Nuclear Information System (INIS)

    The mood disorders of depression are associated with abnormalities of brain structure and function, and exploring their pathological mechanism has important significance for the choice of treatment and the curative effect evaluation. In recent years, the research of MRI on brain structure and function of depression has made great progress, especially in functional magnetic resonance imaging (fMRI). fMRI can detect the functional change in real time, and also can display the activity of brain and changes in the nerve pathways in patients with depression. This article summarizes the present research situation and progress of MRI in the diagnosis of depression. (authors)

  9. MRI in knee osteoarthritis. Application in diet intervention.

    Science.gov (United States)

    Gudbergsen, Henrik

    2013-03-01

    This thesis examines two main hypotheses: 1. Obese knee osteoarthritis (KOA) patients can achieve symptomatic improvements following diet intervention regardless of their level of structural damage and overall joint malfunctioning: 2. Rapid weight-loss in obese patients with KOA will lead to improvements in KOA related pathology that can be assessed and evaluated by MRI. Data for the studies were obtained from obese KOA patients who were recruited for a 16 week diet intervention trial, the CAROT-trial (ClinicalTrials.gov identification no.: NCT00655941). Inclusion criteria were age ≥ 50 years, BMI ≥ 30 kg/square metro plus symptomatic and verified KOA. Patients underwent a 16 weeks dietary programme with formula products and counselling. Baseline and week 16 assessments included clinical examinations, MRI and CR of the most symptomatic knee, muscle strength tests, gait analyses, blood samples and collection of patient-reported outcomes with a variety of generic and specific health status questionnaires. MRI scans were graded by the BLOKS and CR was analysed by measuring the mJSW and grading the knee as described by KL. 388 possible subjects were pre-screened, 192 were enrolled. Following the 16 weeks diet intervention 175 patients remained in the study. 187 (97%) MRI scans were completed at baseline, 172 (98 %) MRI scans obtained at week 16 and this left the study with 169 (97%) patients with complete MRI datasets at week 16. No statistical significant differences were detected between baseline characteristics of all the initially included patients (n = 192) and the 169 patients included in the per protocol analyses performed in study III (p CAROT-trial were graded as expected. In study II we investigated the impact of diet intervention on KOA symptoms whatever the patient's individual level of joint damage and malfunctioning, and the explanatory variables included high-field MRI, radiographs, and muscle strength in m. quadriceps as well as measurements of the

  10. MRI features of placenta accreta

    International Nuclear Information System (INIS)

    Objective: To investigate the MRI features of placenta accreta. Methods: From Apr 2009 to Jun 2011, 15 patients with placenta accrete received MRI examination. In them, placenta accreta was diagnosed based on clinical manifestations or postoperative histopathology. The MR features of placenta accreta in them (study group) were retrospectively analyzed and compared with those in 15 pregnant women without placenta accreta (control group) with Fisher exact test. Results: In the 15 patients with placenta accreta,uterine bulging and (or) a focal outward contour bulge was detected in 14 patients; heterogeneous signal intensity in the placenta was detected in 15 patients; dark intraplacental bands on T2-weighted images was detected in 15 patients; and increased subplacental vascularity was detected in 11 patients on T1- weighted images. In the study group, 14 patients showed at least three of the above four features, and in all of them uterine bulging and (or) a focal outward contour bulge, heterogeneous signal intensity in the placenta and dark intraplacental bands on T2-weighted images were detected; one patient showed heterogeneous signal intensity in the placenta, dark intraplacental bands on T2-weighted images and increased subplacental vascularity. In the control group,none patient had three of the above features.Uterine bulging and (or) a focal outward contour bulge, heterogeneous signal intensity in the placenta, dark intraplacental bands on T2-weighted images and increased subplacental vascularity were detected in 3, 6, 3 and 4 patients (P=0.000, 0.001, 0.000 and 0.027), respectively. Conclusions: The main MRI features of placenta accreta are uterine bulging and (or) a focal outward contour bulge, heterogeneous signal intensity in the placenta and dark intraplacental bands on T2-weighted images Besides, increased subplacental vascularity also could provide useful information for the diagnosis of placenta accreta. (authors)

  11. Multiparametric MRI in Prostate Cancer

    OpenAIRE

    Tarık Esen; Barıs Turkbey; Anup Patel; Jurgen Futterer

    2014-01-01

    Editorial Multiparametric MRI in Prostate Cancer TarJk Esen,1 BarJs Turkbey,2 Anup Patel,3 and Jurgen Futterer4 1 Department of Urology, School of Medicine, Koc University, 34450 Istanbul, Turkey 2Molecular Imaging Program, NCI, NIH, Bethesda, MD 20892, USA 3Royal London Hospital, Barts Health NHS Trust, London E1 1BB,UK 4Department of Radiology, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen, The Netherlands Correspondence should be addressed to Tarık Esen;...

  12. Retroperitoneal Bronchogenic Cyst: MRI Findings

    Directory of Open Access Journals (Sweden)

    R. Castro

    2013-01-01

    Full Text Available The authors describe a case of a retroperitoneal bronchogenic cyst in a 36-year-old female. She presented with abdominal pain, nausea, and vomiting. An MRI scan revealed an 8 cm cystic lesion in the left upper retroperitoneum, with intermediate signal on T2-weighted images, high signal on T1 weighted images, and lack of internal enhancement after gadolinium. After laparoscopic excision, the histology findings were compatible with a bronchogenic cyst, which is extremely uncommon in the retroperitoneum.

  13. Compressive myelopathy in fluorosis: MRI

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-05-01

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

  14. Imaging of posterior tibial tendon dysfunction—Comparison of high-resolution ultrasound and 3 T MRI

    International Nuclear Information System (INIS)

    Highlights: • 18 MHz high-resolution ultrasound appears to be slightly more accurate than 3 T MRI in the diagnosis of PTTD. • High-resolution ultrasound is recommended as an initial diagnostic tool. • Long-lasting PTT discomfort may require MRI. • Other pathologies can mimic PTTD. - Abstract: Purpose: Posterior tibial tendon dysfunction is the most common cause of acquired asymmetric flatfoot deformity. The purpose of this study was to determine and compare the diagnostic value of MRI and high-resolution ultrasound (HR-US) in posterior tibial tendon dysfunction (PTTD), and assess their correlation with intraoperative findings. Materials and methods: We reviewed 23 posterior tibial tendons in 23 patients with clinical findings of PTTD (13 females, 10 males; mean age, 50 years) with 18 MHz HR-US and 3 T MRI. Surgical intervention was performed in nine patients. Results: HR-US findings included 2 complete tears, 6 partial tears, 10 tendons with tendinosis, and 5 unremarkable tendons. MRI demonstrated 2 complete tears, 7 partial tears, 10 tendons with tendinosis, and 4 unremarkable tendons. HR-US and MRI were concordant in 20/23 cases (87%). Image findings for HR-US were confirmed in six of nine patients (66.7%) by intraoperative inspection, whereas imaging findings for MRI were concordant with five of nine cases (55.6%). Conclusion: Our results indicate that HR-US can be considered slightly more accurate than MRI in the detection of PTTD

  15. Imaging of posterior tibial tendon dysfunction—Comparison of high-resolution ultrasound and 3 T MRI

    Energy Technology Data Exchange (ETDEWEB)

    Arnoldner, Michael A., E-mail: michael.arnoldner@meduniwien.ac.at [Medical University of Vienna, Vienna General Hospital, Department of Biomedical Imaging and Image-guided Therapy, Währinger Gürtel 18-20, 1090 Vienna (Austria); Gruber, Michael [Medical University of Vienna, Vienna General Hospital, Department of Biomedical Imaging and Image-guided Therapy, Währinger Gürtel 18-20, 1090 Vienna (Austria); Syré, Stefanie [Medical University of Vienna, Vienna General Hospital, Department of Trauma-Surgery, Währinger Gürtel 18-20, 1090 Vienna (Austria); Kristen, Karl-Heinz [Foot & Ankle Centre Vienna, Alser Straße 43/8, 1080 Vienna (Austria); Trnka, Hans-Jörg [Foot & Ankle Centre Vienna, Alser Straße 43/8, 1080 Vienna (Austria); Orthopaedic Hospital Vienna, Speisinger Straße 109, 1130 Vienna (Austria); Kainberger, Franz; Bodner, Gerd [Medical University of Vienna, Vienna General Hospital, Department of Biomedical Imaging and Image-guided Therapy, Währinger Gürtel 18-20, 1090 Vienna (Austria)

    2015-09-15

    Highlights: • 18 MHz high-resolution ultrasound appears to be slightly more accurate than 3 T MRI in the diagnosis of PTTD. • High-resolution ultrasound is recommended as an initial diagnostic tool. • Long-lasting PTT discomfort may require MRI. • Other pathologies can mimic PTTD. - Abstract: Purpose: Posterior tibial tendon dysfunction is the most common cause of acquired asymmetric flatfoot deformity. The purpose of this study was to determine and compare the diagnostic value of MRI and high-resolution ultrasound (HR-US) in posterior tibial tendon dysfunction (PTTD), and assess their correlation with intraoperative findings. Materials and methods: We reviewed 23 posterior tibial tendons in 23 patients with clinical findings of PTTD (13 females, 10 males; mean age, 50 years) with 18 MHz HR-US and 3 T MRI. Surgical intervention was performed in nine patients. Results: HR-US findings included 2 complete tears, 6 partial tears, 10 tendons with tendinosis, and 5 unremarkable tendons. MRI demonstrated 2 complete tears, 7 partial tears, 10 tendons with tendinosis, and 4 unremarkable tendons. HR-US and MRI were concordant in 20/23 cases (87%). Image findings for HR-US were confirmed in six of nine patients (66.7%) by intraoperative inspection, whereas imaging findings for MRI were concordant with five of nine cases (55.6%). Conclusion: Our results indicate that HR-US can be considered slightly more accurate than MRI in the detection of PTTD.

  16. Inexperienced clinicians can extract pathoanatomic information from MRI narrative reports with high reproducability for use in research/quality assurance

    DEFF Research Database (Denmark)

    Kent, Peter; Briggs, Andrew M; Albert, Hanne Birgit;

    2011-01-01

    pathoanatomic information from radiologist-generated MRI narrative reports. Methods Twenty MRI narrative reports were randomly extracted from an institutional database. A group of three physiotherapy students independently reviewed the reports and coded the presence of 14 common pathoanatomic findings using...... a categorical electronic coding matrix. Decision rules were developed after initial coding in an effort to resolve ambiguities in narrative reports. This process was repeated a further three times using separate samples of 20 MRI reports until no further ambiguities were identified (total n=80). Reproducibility...... not participated in the production of the decision rules, using another sample of 20 MRI reports. Results The mean percentage agreement for paired comparisons between the initial trainee clinicians improved over the four coding rounds (97.9-99.4%), although the greatest improvement was observed after the first...

  17. Neuroradiological findings in primary progressive aphasia: CT, MRI and cerebral perfusion SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Sinnatamby, R. [Dept. of Radiology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Antoun, N.A. [Dept. of Radiology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Freer, C.E.L. [Dept. of Radiology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Miles, K.A. [Dept. of Nuclear Medicine, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom); Hodges, J.R. [Dept. of Neurology, Addenbrooke`s Hospital NHS Trust, Cambridge (United Kingdom)

    1996-04-01

    Primary progressive aphasia (PPA) is defined as progressive decline in language for 2 or more years with preservation of activities of daily living and general cognitive functions. Whereas the clinical features of this syndrome have been well documented, the neuroradiological findings have not been studied systematically. We studied 13 patients with PPA retrospectively: 10 underwent CT, 12 MRI and 12 cerebral perfusion studies using {sup 99m}Tc-HMPAO SPECT. CT and MR images were scored for focal atrophy by two independent assessors. Initial qualitative assessment of SPECT images was confirmed by quantitative analysis. CY was normal in 5 patients. Focal atrophy, affecting predominantly the left temporal lobe, was seen in 4 of 10 patients on CT, and 10 of 12 on MRI. Atrophy was localised primarily to the superior and middle temporal gyri on MRI. All 12 patients who underwent SPECT had unilateral temporal lobe perfusion defects, in 2 patients of whom MRI was normal. CT is relatively insensitive to focal abnormalities in PPA; MRI and SPECT are the imaging modalities of choice. MRI allows accurate, specific localisation of atrophy with the temporal neocortex. SPECT may reveal a functional decrease in cerebral perfusion prior to establishment of structural change. (orig.)

  18. Correlation of MRI Biomarkers with Tumor Necrosis in Hras5 Tumor Xenograft in Athymic Rats

    Directory of Open Access Journals (Sweden)

    Daniel P. Bradley

    2007-05-01

    Full Text Available Magnetic resonance imaging (MRI can measure the effects of therapies targeting the tumor vasculature and has demonstrated that vascular-damaging agents (VDA induce acute vascular shutdown in tumors in human and animal models. However, at subtherapeutic doses, blood flow may recover before the induction of significant levels of necrosis. We present the relationship between changes in MRI biomarkers and tumor necrosis. Multiple MRI measurements were taken at 4.7 T in athymic rats (n = 24 bearing 1.94 ± 0.2-cm3 subcutaneous Hras5 tumors (ATCC 41000 before and 24 hours after clinically relevant doses of the VDA, ZD6126 (0-10 mg/kg, i.v.. We measured effective transverse relaxation rate (R2*, initial area under the gadolinium concentration-time curve (IAUGC60/150, equivalent enhancing fractions (EHF60/150, time constant (Ktrans, proportion of hypoperfused voxels as estimated from fit failures in Ktrans analysis, and signal intensity (SI in T2-weighted MRI (T2W. ZD6126 treatment induced < 90% dose-dependent tumor necrosis at 10 mg/kg; correspondingly, SI changes were evident from T2W MRI. Although R2* did not correlate, other MRI biomarkers significantly correlated with necrosis at doses of ≥ 5 mg/kg ZD6126. These data on Hras5 tumors suggest that the quantification of hypoperfused voxels might provide a useful biomarker of tumor necrosis.

  19. Statistical shape model-based segmentation of brain MRI images.

    Science.gov (United States)

    Bailleul, Jonathan; Ruan, Su; Constans, Jean-Marc

    2007-01-01

    We propose a segmentation method that automatically delineates structures contours from 3D brain MRI images using a statistical shape model. We automatically build this 3D Point Distribution Model (PDM) in applying a Minimum Description Length (MDL) annotation to a training set of shapes, obtained by registration of a 3D anatomical atlas over a set of patients brain MRIs. Delineation of any structure from a new MRI image is first initialized by such registration. Then, delineation is achieved in iterating two consecutive steps until the 3D contour reaches idempotence. The first step consists in applying an intensity model to the latest shape position so as to formulate a closer guess: our model requires far less priors than standard model in aiming at direct interpretation rather than compliance to learned contexts. The second step consists in enforcing shape constraints onto previous guess so as to remove all bias induced by artifacts or low contrast on current MRI. For this, we infer the closest shape instance from the PDM shape space using a new estimation method which accuracy is significantly improved by a huge increase in the model resolution and by a depth-search in the parameter space. The delineation results we obtained are very encouraging and show the interest of the proposed framework. PMID:18003193

  20. Imaging of prostate cancer: a platform for 3D co-registration of in-vivo MRI ex-vivo MRI and pathology

    Science.gov (United States)

    Orczyk, Clément; Mikheev, Artem; Rosenkrantz, Andrew; Melamed, Jonathan; Taneja, Samir S.; Rusinek, Henry

    2012-02-01

    Objectives: Multi-parametric MRI is emerging as a promising method for prostate cancer diagnosis. prognosis and treatment planning. However, the localization of in-vivo detected lesions and pathologic sites of cancer remains a significant challenge. To overcome this limitation we have developed and tested a system for co-registration of in-vivo MRI, ex-vivo MRI and histology. Materials and Methods: Three men diagnosed with localized prostate cancer (ages 54-72, PSA levels 5.1-7.7 ng/ml) were prospectively enrolled in this study. All patients underwent 3T multi-parametric MRI that included T2W, DCEMRI, and DWI prior to robotic-assisted prostatectomy. Ex-vivo multi-parametric MRI was performed on fresh prostate specimen. Excised prostates were then sliced at regular intervals and photographed both before and after fixation. Slices were perpendicular to the main axis of the posterior capsule, i.e., along the direction of the rectal wall. Guided by the location of the urethra, 2D digital images were assembled into 3D models. Cancer foci, extra-capsular extensions and zonal margins were delineated by the pathologist and included in 3D histology data. A locally-developed software was applied to register in-vivo, ex-vivo and histology using an over-determined set of anatomical landmarks placed in anterior fibro-muscular stroma, central. transition and peripheral zones. The mean root square distance across corresponding control points was used to assess co-registration error. Results: Two specimens were pT3a and one pT2b (negative margin) at pathology. The software successfully fused invivo MRI. ex-vivo MRI fresh specimen and histology using appropriate (rigid and affine) transformation models with mean square error of 1.59 mm. Coregistration accuracy was confirmed by multi-modality viewing using operator-guided variable transparency. Conclusion: The method enables successful co-registration of pre-operative MRI, ex-vivo MRI and pathology and it provides initial evidence

  1. Demonstration of the reproducibility of free-breathing diffusion-weighted MRI and dynamic contrast enhanced MRI in children with solid tumours: a pilot study

    International Nuclear Information System (INIS)

    The objectives are to examine the reproducibility of functional MR imaging in children with solid tumours using quantitative parameters derived from diffusion-weighted (DW-) and dynamic contrast enhanced (DCE-) MRI. Patients under 16-years-of age with confirmed diagnosis of solid tumours (n = 17) underwent free-breathing DW-MRI and DCE-MRI on a 1.5 T system, repeated 24 hours later. DW-MRI (6 b-values, 0-1000 sec/mm2) enabled monoexponential apparent diffusion coefficient estimation using all (ADC0-1000) and only ≥100 sec/mm2 (ADC100-1000) b-values. DCE-MRI was used to derive the transfer constant (Ktrans), the efflux constant (kep), the extracellular extravascular volume (ve), and the plasma fraction (vp), using a study cohort arterial input function (AIF) and the extended Tofts model. Initial area under the gadolinium enhancement curve and pre-contrast T1 were also calculated. Percentage coefficients of variation (CV) of all parameters were calculated. The most reproducible cohort parameters were ADC100-1000 (CV = 3.26 %), pre-contrast T1 (CV = 6.21 %), and Ktrans (CV = 15.23 %). The ADC100-1000 was more reproducible than ADC0-1000, especially extracranially (CV = 2.40 % vs. 2.78 %). The AIF (n = 9) derived from this paediatric population exhibited sharper and earlier first-pass and recirculation peaks compared with the literature's adult population average. Free-breathing functional imaging protocols including DW-MRI and DCE-MRI are well-tolerated in children aged 6 - 15 with good to moderate measurement reproducibility. (orig.)

  2. Demonstration of the reproducibility of free-breathing diffusion-weighted MRI and dynamic contrast enhanced MRI in children with solid tumours: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, Keiko; Jerome, Neil P.; Collins, David J.; Orton, Matthew R.; D' Arcy, James A.; Leach, Martin O. [Cancer Research UK Cancer Imaging Centre at The Institute of Cancer Research, London (United Kingdom); Wallace, Toni; Koh, Dow-Mu [Royal Marsden Hospital, Department of Radiology, London, England (United Kingdom); Moreno, Lucas [The Institute of Cancer Research, Paediatric Drug Development Team, Divisions of Cancer Therapeutics and Clinical Studies, London (United Kingdom); Spanish National Cancer Research Centre (CNIO), Clinical Research Programme, Madrid (Spain); The Royal Marsden NHS Foundation Trust, Paediatric Drug Development Unit, Children and Young People' s Unit, Sutton (United Kingdom); Pearson, Andrew D.J.; Marshall, Lynley V.; Carceller, Fernando; Zacharoulis, Stergios [The Institute of Cancer Research, Paediatric Drug Development Team, Divisions of Cancer Therapeutics and Clinical Studies, London (United Kingdom); The Royal Marsden NHS Foundation Trust, Paediatric Drug Development Unit, Children and Young People' s Unit, Sutton (United Kingdom)

    2015-09-15

    The objectives are to examine the reproducibility of functional MR imaging in children with solid tumours using quantitative parameters derived from diffusion-weighted (DW-) and dynamic contrast enhanced (DCE-) MRI. Patients under 16-years-of age with confirmed diagnosis of solid tumours (n = 17) underwent free-breathing DW-MRI and DCE-MRI on a 1.5 T system, repeated 24 hours later. DW-MRI (6 b-values, 0-1000 sec/mm{sup 2}) enabled monoexponential apparent diffusion coefficient estimation using all (ADC{sub 0-1000}) and only ≥100 sec/mm{sup 2} (ADC{sub 100-1000}) b-values. DCE-MRI was used to derive the transfer constant (K{sup trans}), the efflux constant (k{sub ep}), the extracellular extravascular volume (v{sub e}), and the plasma fraction (v{sub p}), using a study cohort arterial input function (AIF) and the extended Tofts model. Initial area under the gadolinium enhancement curve and pre-contrast T{sub 1} were also calculated. Percentage coefficients of variation (CV) of all parameters were calculated. The most reproducible cohort parameters were ADC{sub 100-1000} (CV = 3.26 %), pre-contrast T{sub 1} (CV = 6.21 %), and K{sup trans} (CV = 15.23 %). The ADC{sub 100-1000} was more reproducible than ADC{sub 0-1000}, especially extracranially (CV = 2.40 % vs. 2.78 %). The AIF (n = 9) derived from this paediatric population exhibited sharper and earlier first-pass and recirculation peaks compared with the literature's adult population average. Free-breathing functional imaging protocols including DW-MRI and DCE-MRI are well-tolerated in children aged 6 - 15 with good to moderate measurement reproducibility. (orig.)

  3. Morton neuroma: MRI diagnostic value

    International Nuclear Information System (INIS)

    Objective: To evaluate the diagnostic value of MRI in Morton's Neuroma (MN). Material and methods: 23 patients with clinical diagnosis of MN were examined under two different protocols, with a 1.5 T Magnet. 1) T1, FSET2, FIR, T1 with contrast enhancement and fat suppression; 2) T1, FSET2, FIR without contrast enhancement (i.v. Gadolinium). Results: In the first group MN was found in 7 patients. In the second group 14 patients were studied, 7 with positive MR for neuroma, and 9 with negative MR. 6 were true-negative and 3 were false-negative. The Fisher Test between both groups was p < 0.05. Conclusion: MRI is effective for the diagnosis of Morton neuroma. The use of gadolinium and fat suppression significantly improved the detection of Morton neuroma, allowing better measurements of the lesion. These findings do not correlate with previous papers that do not encourage the use of i.v. Gadolinium. (author)

  4. MRI in acute transverse myelopathy

    Energy Technology Data Exchange (ETDEWEB)

    Holtaas, S. (Dept. of Diagnostic Radiology, Univ. Hospital Lund (Sweden)); Basibueyuek, N. (Dept. of Diagnostic Radiology, Univ. Hospital Lund (Sweden)); Fredriksson, K. (Dept. of Neurology, Univ. Hospital Lund (Sweden))

    1993-03-01

    The MRI examinations of seven patients with acute transverse myelopathy (ATM) were analysed. The patients were examined 2-5 times during the course of their disease with short and long TR/TE spin-echo sequences in the sagittal projection. A previous history of autoimmune disorder and/or signs of infection at the onset of ATM were present in all cases. Cerebrospinal fluid analysis showed local synthesis of immunoglobulin in the nervours system in three cases and signs of infectious myelitis in one. During the acute phase four patients had local enlargement of the cord and all had increased signal on long TR/TE sequences. The outcome was grave in the majority of patients and there seemed to be a correlation between the degree of cord enlargement, persistence of increased signal intensity and limited recovery. Atrophy and remaining high signal intensity were noted on late MRI patients with poor outcome. In one patient with probable anterior spinal artery occlusion, cavitation of the cord was seen. (orig.)

  5. MRI in acute transverse myelopathy

    International Nuclear Information System (INIS)

    The MRI examinations of seven patients with acute transverse myelopathy (ATM) were analysed. The patients were examined 2-5 times during the course of their disease with short and long TR/TE spin-echo sequences in the sagittal projection. A previous history of autoimmune disorder and/or signs of infection at the onset of ATM were present in all cases. Cerebrospinal fluid analysis showed local synthesis of immunoglobulin in the nervours system in three cases and signs of infectious myelitis in one. During the acute phase four patients had local enlargement of the cord and all had increased signal on long TR/TE sequences. The outcome was grave in the majority of patients and there seemed to be a correlation between the degree of cord enlargement, persistence of increased signal intensity and limited recovery. Atrophy and remaining high signal intensity were noted on late MRI patients with poor outcome. In one patient with probable anterior spinal artery occlusion, cavitation of the cord was seen. (orig.)

  6. Central nervous system tuberculosis: MRI

    International Nuclear Information System (INIS)

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

  7. Physics of MRI: a primer.

    Science.gov (United States)

    Plewes, Donald B; Kucharczyk, Walter

    2012-05-01

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

  8. The diagnostic utility of MRI in spondyloarthritis

    DEFF Research Database (Denmark)

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

    2012-01-01

    and fat infiltrations, and recent studies suggest that assessment of both inflammatory and structural changes of the sacroiliac joints may improve the diagnostic utility of MRI. The present article reviews the evidence for the use of sacroiliac joint and spinal MRI to assess patients with axial...

  9. MRI of cardiac rhabdomyoma in the fetus

    Energy Technology Data Exchange (ETDEWEB)

    Kivelitz, Dietmar E.; Muehler, Matthias [Institut fuer Radiologie, Medizinische Fakultaet, Humboldt-Universitaet zu Berlin, Charite, Schumannstrasse 20/21, 10098, Berlin (Germany); Rake, Annett; Chaoui, Rabih [Klinik fuer Gynaekologie und Geburtshilfe, Medizinische Fakultaet, Humboldt-Universitaet zu Berlin, Charite, Schumannstrasse 20/21, 10098, Berlin (Germany); Scheer, Ianina [Klinik fuer Strahlenheilkunde, Abteilung Paediatrische Radiologie, Medizinische Fakultaet, Humboldt-Universitaet zu Berlin, Charite, Schumannstrasse 20/21, 10098, Berlin (Germany)

    2004-08-01

    Primary cardiac tumors are rarely diagnosed in utero and are usually seen on prenatal echocardiography. Cardiac rhabdomyomata can be associated with tuberous sclerosis. Prenatal MRI can be performed to assess associated malformations. This case report illustrates the ability of fetal MRI to image cardiac rhabdomyata and compares it with prenatal and postnatal echocardiography. (orig.)

  10. Cardiac MRI of the athlete's heart

    NARCIS (Netherlands)

    Prakken, N.H.J.

    2010-01-01

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

  11. Anencephaly: MRI findings and pathogenetic theories

    International Nuclear Information System (INIS)

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

  12. Paradigm shift in MRI for sciatica

    NARCIS (Netherlands)

    Barzouhi, Abdelilah el

    2013-01-01

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

  13. Pathologic Findings in MRI-Guided Needle Core Biopsies of the Breast in Patients with Newly Diagnosed Breast Cancer

    OpenAIRE

    M. Cobleigh; Jokich, P.; Siziopikou, K. P.

    2011-01-01

    The role of MRI in the management of breast carcinoma is rapidly evolving from its initial use for specific indications only to a more widespread use on all women with newly diagnosed early stage breast cancer. However, there are many concerns that such widespread use is premature since detailed correlation of MRI findings with the underlying histopathology of the breast lesions is still evolving and clear evidence for improvements in management and overall prognosis of breast cancer patients...

  14. Whole-body MRI of neuroblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo, E-mail: hwgoo@amc.seoul.k [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Asanbyeongwon-gil 86, Songpa-gu, Seoul 138-736 (Korea, Republic of)

    2010-09-15

    Whole-body MRI (WBMRI) is an emerging imaging method that has a great potential in pediatric oncologic imaging. It appears useful in staging and monitoring neuroblastoma although its clinical impact has not been thoroughly evaluated. Among various imaging techniques currently available for WBMRI, coronal and sagittal STIR imaging with a quadrature body coil at 1.5T MR system is recommended for a standard protocol. Nevertheless, further technical improvements are anticipated at 3.0T MR system and multi-channel surface coil system. Scan time of WBMRI is reasonably short ranging from 20 min to 60 min. In localized neuroblatoma, WBMRI may help in predicting surgical risks by evaluating image-defined risk factors accurately. In addition, WBMRI is quite useful in detecting distant metastasis, assessing initial treatment responses, and identifying tumor recurrence of neuroblastoma. We should understand limitations of WBMRI in the evaluation of lymph node involvement, in the differentiation between viable tumor and non-viable residual lesion, and in the detection of calcified lesion. Diffusion-weighted imaging may improve diagnostic accuracy of WBMRI. Complementary use of WBMRI and other metabolic imaging method such as MIBG scintigraphy or PET probably increases diagnostic accuracy and, subsequently, improves clinical outcome of children with neuroblastoma.

  15. Whole-body MRI of neuroblastoma

    International Nuclear Information System (INIS)

    Whole-body MRI (WBMRI) is an emerging imaging method that has a great potential in pediatric oncologic imaging. It appears useful in staging and monitoring neuroblastoma although its clinical impact has not been thoroughly evaluated. Among various imaging techniques currently available for WBMRI, coronal and sagittal STIR imaging with a quadrature body coil at 1.5T MR system is recommended for a standard protocol. Nevertheless, further technical improvements are anticipated at 3.0T MR system and multi-channel surface coil system. Scan time of WBMRI is reasonably short ranging from 20 min to 60 min. In localized neuroblatoma, WBMRI may help in predicting surgical risks by evaluating image-defined risk factors accurately. In addition, WBMRI is quite useful in detecting distant metastasis, assessing initial treatment responses, and identifying tumor recurrence of neuroblastoma. We should understand limitations of WBMRI in the evaluation of lymph node involvement, in the differentiation between viable tumor and non-viable residual lesion, and in the detection of calcified lesion. Diffusion-weighted imaging may improve diagnostic accuracy of WBMRI. Complementary use of WBMRI and other metabolic imaging method such as MIBG scintigraphy or PET probably increases diagnostic accuracy and, subsequently, improves clinical outcome of children with neuroblastoma.

  16. Prenatal diagnosis of horseshoe lung: contribution of MRI

    Energy Technology Data Exchange (ETDEWEB)

    Tilea, Bogdana; Garel, Catherine; Sebag, Guy [Hopital Robert Debre, Department of Paediatric Imaging, Paris (France); Delezoide, Anne-Lise [Hopital Robert Debre, Department of Developmental Biology, Paris (France); Vuillard, Edith; Oury, Jean-Francois [Hopital Robert Debre, Department of Obstetrics and Gynaecology, Paris (France); Azancot, Annabelle [Hopital Robert Debre, Department of Fetal Cardiology, Paris (France)

    2005-10-01

    Horseshoe lung is a very rare pulmonary anomaly that is characterized by an isthmus of lung parenchyma bridging the right and left lungs and extending through the mediastinum. We report on the prenatal diagnosis of such a malformation in a 33-week-gestation fetus. The diagnosis was initially suspected on antenatal ultrasonography performed at 33 weeks and confirmed by fetal MRI and subsequent pathological examination after termination of pregnancy. To our knowledge, this is the first reported case of antenatal diagnosis of horseshoe lung. (orig.)

  17. Unexpected Coexisting Myocardial Infarction Detected by Delayed Enhancement MRI

    Directory of Open Access Journals (Sweden)

    Edouard Gerbaud

    2009-01-01

    Full Text Available We report a case of an unexpected coexisting anterior myocardial infarction detected by delayed enhancement MRI in a 41-year-old man following a presentation with a first episode of chest pain during inferior acute myocardial infarction. This second necrotic area was not initially suspected because there were no ECG changes in the anterior leads and the left descending coronary artery did not present any significant stenoses on emergency coronary angiography. Unrecognised myocardial infarction may carry important prognostic implications. CMR is currently the best imaging technique to detect unexpected infarcts.

  18. MRI diagnosis of osteomyelitis of the cuboid bone in two infants

    Energy Technology Data Exchange (ETDEWEB)

    Peene, P.; Celis, I.; Bijnens, E.; Thywissen, C.; Vervloesem, R. [Department of Radiology, Virga Jesse Ziekenhuis, Hasselt (Belgium); Raes, M.; Alliet, P. [Department of Paediatrics, Virga Jesse Ziekenhuis, Hasselt (Belgium)

    1998-09-01

    We describe two infants in whom MRI diagnosed osteomyelitis of the cuboid bone when conventional X-rays were negative. Neoplastic, traumatic and ischaemic aetiologies could be excluded with the initial MR examinations. (orig.) With 2 figs., 1 tab., 8 refs.

  19. Conventional MRI and magnetisation transfer imaging of tumour-like multiple sclerosis in a child

    International Nuclear Information System (INIS)

    Tumefactive multiple sclerosis is a rare entity in children. Differential diagnosis includes other mass lesions such as neoplasm and abscess. A case of tumefactive multiple sclerosis in a child is presented. The open-ring pattern of enhancement on conventional MRI and magnetisation transfer imaging was important for the initial diagnosis and the evaluation of the course of the disease. (orig.)

  20. MRI and CT patterns of neurocysticercosis

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-05-01

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

  1. Clinical functional MRI. Presurgical functional neuroimaging

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

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

  2. MRI findings in 100 epileptic children

    International Nuclear Information System (INIS)

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

  3. MRI of mediastinal tumor in children

    Energy Technology Data Exchange (ETDEWEB)

    Inuzuka, Michiko; Aida, Noriko; Nishi, Toshiji; Nishihira, Hirokazu; Odagiri, Kunio (Kanagawa Children' s Medical Center, Yokohama (Japan)); Katsumata, Yasushi

    1994-05-01

    We reviewed MRI findings in 15 children with mediastinal tumors before operation or biopsy. Their pathological diagnosis were: 4 neuroblastomas, 3 bronchogenic cysts, 2 mature teratomas, 2 malignant lymphomas, an immature teratoma, a PNET, a BPFM and a ganglioneuroblastoma. We evaluated the usefulness and the limits of MRI. MRI was not more useful than CT for the pathological differential diagnosis of tumors with the exception of cystic lesion. MRI was useful in distinguishing the interface between tumor and spine, and the vascular system. Therefore, it was very efficient before treatment including surgery. Two cases were followed up after operation, chemotherapy and radiation. We believe that MRI will replace invasive imaging modalities such as angiography and myelography. (author).

  4. MRI findings in 100 epileptic children

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-02-01

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

  5. No erosive progression revealed by MRI in rheumatoid arthritis patients treated with etanercept, even in patients with persistent MRI and clinical signs of joint inflammation

    DEFF Research Database (Denmark)

    Døhn, Uffe Møller; Skjødt, Henrik; Hetland, Merete;

    2007-01-01

    The aim of this study is to investigate the course of magnetic resonance imaging (MRI) signs of inflammatory and destructive changes in rheumatoid arthritis (RA) wrist and metacarpophalangeal (MCP) joints during etanercept treatment. MRI of the non-dominant wrist and second to fifth MCP joints was...... performed in five clinical active RA patients before and 4 and 16 weeks after initiation of etanercept treatment. MRI was evaluated according to the EULAR-OMERACT RA MRI reference image atlas. The median 28-joint count disease activity score (DAS28; erythrocyte sedimentation rate based) was 5.6 (range 5.......0-6.8) at baseline and 3.5 (1.5-4.1) at week 16 (decreased in all patients compared to baseline, Wilcoxon-Pratt, p < 0.05). The median MRI synovitis score was 18 (14-21), 18 (10-20) and 16 (10-20) at baseline, week 4 and 16, respectively (decreased in all patients compared to baseline, Wilcoxon-Pratt, p < 0...

  6. MRI evaluation of aseptic osteonecrosis in children over the course of hyperbaric oxygen therapy

    International Nuclear Information System (INIS)

    Purpose: The study aimed at MRI evaluation of aseptic osteonecrosis (AON) in children over the course of hyperbaric oxygen (HBO) therapy. Material and methods: Retrospective analysis of 72 MRI studies in 20 children presenting with AON during chemotherapy. Two groups were differentiated: Gr. I (n=8) was treated exclusively with relief of weightbearing structures, Gr. II (n=12) was additionally treated with HBO therapy. The MRI examinations were evaluated by a point-score system (1-6 points) by two radiologists. Results: Gr. II initially showed more severe findings (average score: 3.4) in comparison to Gr. I (average score: 2.65). During the follow-up time period the average scores rose to 3.2 score-points in Gr. I and 4.1 points in Gr. II. No statistically significant difference was evident between the two groups in the course of AON. Conclusion: The majority of chemotherapy associated AON which initially present with advanced findings show a progression in MRI over their further course. HBO therapy in addition to the relief of affected weightbearing structures statistically shows no significant improvement in MRI morphology during the course of the treatment. (orig.)

  7. MRI evaluation of aseptic osteonecrosis in children over the course of hyperbaric oxygen therapy

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, A.; Engelbrecht, V.; May, P.; Moedder, U. [Duesseldorf Univ. (Germany). Inst. fuer Diagnostische Radiologie; Bernbeck, B.; Goebel, U. [Duesseldorf Univ. (Germany). Dept. of Pediatric Hematology and Oncology; Willers, R. [Duesseldorf Univ. (Germany). Inst. of Statistics

    2000-10-01

    Purpose: The study aimed at MRI evaluation of aseptic osteonecrosis (AON) in children over the course of hyperbaric oxygen (HBO) therapy. Material and methods: Retrospective analysis of 72 MRI studies in 20 children presenting with AON during chemotherapy. Two groups were differentiated: Gr. I (n=8) was treated exclusively with relief of weightbearing structures, Gr. II (n=12) was additionally treated with HBO therapy. The MRI examinations were evaluated by a point-score system (1-6 points) by two radiologists. Results: Gr. II initially showed more severe findings (average score: 3.4) in comparison to Gr. I (average score: 2.65). During the follow-up time period the average scores rose to 3.2 score-points in Gr. I and 4.1 points in Gr. II. No statistically significant difference was evident between the two groups in the course of AON. Conclusion: The majority of chemotherapy associated AON which initially present with advanced findings show a progression in MRI over their further course. HBO therapy in addition to the relief of affected weightbearing structures statistically shows no significant improvement in MRI morphology during the course of the treatment. (orig.)

  8. MRI-conditional pacemakers: current perspectives

    Directory of Open Access Journals (Sweden)

    Ferreira AM

    2014-05-01

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

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

    Science.gov (United States)

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

    2013-12-24

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

  10. Magnet discolation - An increasing and serious complication following MRI in patients with chochlear implants; Magnetdiskolation - eine zunehmende und folgenreiche Komplikation nach MRT bei Patienten mit Cochlea Implantat

    Energy Technology Data Exchange (ETDEWEB)

    Hassepass, F.; Staubenau, V.; Arndt, S.; Beck, R.; Grauvogel, T.; Aschendorff, A. [Univ. Medical Center Freiburg (Germany). Dept. of Otorhinolaryngology-Head and Neck Surgery; Bulla, S. [Univ. Medical Center Freiburg (Germany). Dept. of Diagnostic Radiology

    2014-07-15

    Cochlear implantation (CI) represents the gold standard in the treatment of children born deaf and postlingually deafened adults. Initial magnetic resonance imaging (MRI) was contraindicated in CI users. Meanwhile, there are specific recommendations concerning MRI compatibility depending on the type of CI system and the device manufacturer. Some CI systems are even approved for MRI with the internal magnet left in place. The aim of this study was to analyze all magnet revision surgeries in CI patients at one CI center and the relationship to MRI scans over time. Between 2000 and 2013, a total of 2027 CIs were implanted. The number of magnet dislocation (MD) surgeries and their causes was assessed retrospectively. In total 12 cases of MD resulting from an MRI scan (0.59 %) were observed, accounting for 52.2 % of all magnetic revision surgeries. As per the labeling, it was considered safe to leave the internal magnet in place during MRI while following specific manufacturer recommendations: MRI intensity of 1.5 Tesla (T) and compression head bandage during examination. A compression head bandage in a 1.5 T MRI unit does not safely prevent MD and the related serious complications in CI recipients. We recommend a Stenvers view radiograph after MRI with the internal magnet in place for early identification of MD, at least in the case of pain during or after MRI examination. MRI in CI patients should be indicated with restraint and patients should be explicitly informed about the possible risks. Recommendations regarding MRI compatibility and the handling of CI patients issued with MRI for the most common CI systems are summarized.

  11. Imaging of atherosclerosis with MRI

    International Nuclear Information System (INIS)

    Vascular delineation with Magnetic Resonance Imaging (MRI) suffers from severe artifacts caused by the motion of flowing blood. With recent developments these artifacts are reduced significantly. Using special sequences and processing algorithms the resulting images have an angiographic-like character (MR-Angiography, MRA). While MRA-signals derive from moving spins, the vessel wall itself is suppressed like it is in conventional angiography also. Prerequisites for the assessment of the arterial wall are increased spatial resolution and the discrimination of blood signals. This study demonstrates the clinical value of MRA with respect to arteriosclerosis. Moreover, a pilot study to visualize the arterial wall and atheroma is presented. (author). 11 refs.; 3 figs.; 2 tabs

  12. Fetal MRI: techniques and protocols

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-09-01

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

  13. Combined PET/MRI scanner

    Science.gov (United States)

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

    2007-10-23

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

  14. MRI-compatible micromanipulator; design and implementation and MRI-compatibility tests.

    Science.gov (United States)

    Koseki, Yoshihiko; Tanikawa, Tamio; Chinzei, Kiyoyuki

    2007-01-01

    In this paper, we present a magnetic resonance imaging (MRI)-compatible micromanipulator, which can be employed to provide medical and biological scientists with the ability to concurrently manipulate and observe micron-scale objects inside an MRI gantry. The micromanipulator formed a two-finger micro hand, and it could handle a micron-scale object using a chopstick motion. For performing operations inside the MRI gantry in a manner such that the MRI is not disturbed, the system was designed to be nonmagnetic and electromagnetically compatible with the MRI. The micro-manipulator was implemented with piezoelectric transducers (PZT) as actuators for micro-motion, strain gauges as sensors for closed-loop control, and a flexure parallel mechanism made of acrylic plastic. Its compatibility with a 2-Tesla MRI was preliminarily tested by checking if the MRI obtained with the micromanipulator were similar to those obtained without the micromanipulator. The tests concluded that the micromanipulator caused no distortion but small artifacts on the MRI. The signal-to-noise ratio (SNR) of the MRI significantly deteriorated mainly due to the wiring of the micromanipulator. The MRI caused noise of the order of ones of volts in the strain amplifier. PMID:18001990

  15. Evaluating organ delineation, dose calculation and daily localization in an open-MRI simulation workflow for prostate cancer patients

    International Nuclear Information System (INIS)

    This study describes initial testing and evaluation of a vertical-field open Magnetic Resonance Imaging (MRI) scanner for the purpose of simulation in radiation therapy for prostate cancer. We have evaluated the clinical workflow of using open MRI as a sole modality for simulation and planning. Relevant results related to MRI alignment (vs. CT) reference dataset with Cone-Beam CT (CBCT) for daily localization are presented. Ten patients participated in an IRB approved study utilizing MRI along with CT simulation with the intent of evaluating the MRI-simulation process. Differences in prostate gland volume, seminal vesicles, and penile bulb were assessed with MRI and compared to CT. To evaluate dose calculation accuracy, bulk-density-assignments were mapped onto respective MRI datasets and treated IMRT plans were re-calculated. For image localization purposes, 400 CBCTs were re-evaluated with MRI as the reference dataset and daily shifts compared against CBCT-to-CT registration. Planning margins based on MRI/CBCT shifts were computed using the van Herk formalism. Significant organ contour differences were noted between MRI and CT. Prostate volumes were on average 39.7% (p = 0.002) larger on CT than MRI. No significant difference was found in seminal vesicle volumes (p = 0.454). Penile bulb volumes were 61.1% higher on CT, without statistical significance (p = 0.074). MRI-based dose calculations with assigned bulk densities produced agreement within 1% with heterogeneity corrected CT calculations. The differences in shift positions for the cohort between CBCT-to-CT registration and CBCT-to-MRI registration are −0.15 ± 0.25 cm (anterior-posterior), 0.05 ± 0.19 cm (superior-inferior), and −0.01 ± 0.14 cm (left-right). This study confirms the potential of using an open-field MRI scanner as primary imaging modality for prostate cancer treatment planning simulation, dose calculations and daily image localization

  16. Intra voxel analysis in MRI

    Science.gov (United States)

    Ambrosanio, Michele; Baselice, Fabio; Ferraioli, Giampaolo; Pascazio, Vito

    2014-03-01

    A new application of Compressive Sensing (CS) in Magnetic Resonance Imaging (MRI) field is presented. In particular, first results of the Intra Voxel Analysis (IVA) technique are reported. The idea is to exploit CS peculiarities in order to distinguish different contributions inside the same resolution cell, instead of reconstructing images from not fully sampled k-space acquisition. Applied to MRI field, this means the possibility of estimating the presence of different tissues inside the same voxel, i.e. in one pixel of the obtained image. In other words, the method is the first attempt, as far as we know, of achieving Spectroscopy-like results starting from each pixel of MR images. In particular, tissues are distinguished each others by evaluating their spin-spin relaxation times. Within this manuscript, first results on clinical dataset, in particular a phantom made by aqueous solution and oil and an occipital brain lesion corresponding to a metastatic breast cancer nodule, are reported. Considering the phantom dataset, in particular focusing on the slice where the separation between water and oil occurs, the methodology is able to distinguish the two components with different spin-spin relaxation times. With respect to clinical dataset,focusing on a voxel of the lesion area, the approach is able to detect the presence of two tissues, namely the healthy and the cancer related ones, while in other location outside the lesion only the healthy tissue is detected. Of course, these are the first results of the proposed methodology, further studies on different types of clinical datasets are required in order to widely validate the approach. Although few datasets have been considered, results seem both interesting and promising.

  17. Recommendations for real-time speech MRI.

    Science.gov (United States)

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

    2016-01-01

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

  18. MRI visualisation by digitally reconstructed radiographs

    Science.gov (United States)

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

    2015-03-01

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

  19. Application of functional MRI in epilepsy

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

  20. Fetal MRI of clubfoot associated with myelomeningocele

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-15

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

  1. Low-Cost High-Performance MRI

    Science.gov (United States)

    Sarracanie, Mathieu; Lapierre, Cristen D.; Salameh, Najat; Waddington, David E. J.; Witzel, Thomas; Rosen, Matthew S.

    2015-10-01

    Magnetic Resonance Imaging (MRI) is unparalleled in its ability to visualize anatomical structure and function non-invasively with high spatial and temporal resolution. Yet to overcome the low sensitivity inherent in inductive detection of weakly polarized nuclear spins, the vast majority of clinical MRI scanners employ superconducting magnets producing very high magnetic fields. Commonly found at 1.5-3 tesla (T), these powerful magnets are massive and have very strict infrastructure demands that preclude operation in many environments. MRI scanners are costly to purchase, site, and maintain, with the purchase price approaching $1 M per tesla (T) of magnetic field. We present here a remarkably simple, non-cryogenic approach to high-performance human MRI at ultra-low magnetic field, whereby modern under-sampling strategies are combined with fully-refocused dynamic spin control using steady-state free precession techniques. At 6.5 mT (more than 450 times lower than clinical MRI scanners) we demonstrate (2.5 × 3.5 × 8.5) mm3 imaging resolution in the living human brain using a simple, open-geometry electromagnet, with 3D image acquisition over the entire brain in 6 minutes. We contend that these practical ultra-low magnetic field implementations of MRI (MRI, providing clinically relevant images and setting new standards for affordable (<$50,000) and robust portable devices.

  2. Low-Cost High-Performance MRI.

    Science.gov (United States)

    Sarracanie, Mathieu; LaPierre, Cristen D; Salameh, Najat; Waddington, David E J; Witzel, Thomas; Rosen, Matthew S

    2015-01-01

    Magnetic Resonance Imaging (MRI) is unparalleled in its ability to visualize anatomical structure and function non-invasively with high spatial and temporal resolution. Yet to overcome the low sensitivity inherent in inductive detection of weakly polarized nuclear spins, the vast majority of clinical MRI scanners employ superconducting magnets producing very high magnetic fields. Commonly found at 1.5-3 tesla (T), these powerful magnets are massive and have very strict infrastructure demands that preclude operation in many environments. MRI scanners are costly to purchase, site, and maintain, with the purchase price approaching $1 M per tesla (T) of magnetic field. We present here a remarkably simple, non-cryogenic approach to high-performance human MRI at ultra-low magnetic field, whereby modern under-sampling strategies are combined with fully-refocused dynamic spin control using steady-state free precession techniques. At 6.5 mT (more than 450 times lower than clinical MRI scanners) we demonstrate (2.5 × 3.5 × 8.5) mm(3) imaging resolution in the living human brain using a simple, open-geometry electromagnet, with 3D image acquisition over the entire brain in 6 minutes. We contend that these practical ultra-low magnetic field implementations of MRI (<10 mT) will complement traditional MRI, providing clinically relevant images and setting new standards for affordable (<$50,000) and robust portable devices. PMID:26469756

  3. MRI of anterior cruciate ligament autografts

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-09-01

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

  4. Recommendations for Real-Time Speech MRI

    Science.gov (United States)

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

    2016-01-01

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

  5. MRI findings in acute Hendra virus meningoencephalitis

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-05-15

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

  6. Acute verbal dyspraxia, a rare presentation in multiple sclerosis: a case report with MRI localization.

    Science.gov (United States)

    Jaffe, Stephen L; Glabus, Michael F; Kelley, Roger E; Minagar, Alireza

    2003-12-01

    Cortical speech disorders rarely occur in multiple sclerosis (MS). We report a patient with relapsing-remitting MS, who presented with acute verbal dyspraxia. Magnetic resonance imaging (MRI) demonstrated an acute T2/Flair hyperintense, primarily white matter lesion underlying the middle third of the inferior frontal gyrus. The verbal dyspraxia cleared beginning 48 hours after the initiation of iv dexamethasone. Follow-up MRI demonstrated qualitative and quantitative diminution of the hyperintensity. This is the first report of a clinically definite MS patient with acute verbal dyspraxia. Moreover, there was a suggestive localization of verbal praxis to Brodmann areas 44/45. PMID:14664479

  7. Automatic probe artifact detection in MRI-guided cryoablation

    Science.gov (United States)

    Liu, Xinyang; Tuncali, Kemal; Wells, William M.; Zientara, Gary P.

    2013-03-01

    Probe or needle artifact detection in 3D scans gives an approximate location for the tools inserted, and is thus crucial in assisting many image-guided procedures. Conventional needle localization algorithms often start with cropped images, where unwanted parts of raw scans are cropped either manually or by applying pre-defined masks. In cryoablation, however, the number of probes used, the placement and direction of probe insertion, and the portions of abdomen scanned differs significantly from case to case, and probes are often constantly being adjusted during the Probe Placement Phase. These features greatly reduce the practicality of approaches based on image cropping. In this work, we present a fully Automatic Probe Artifact Detection method, APAD, that works directly on uncropped raw MRI images, taken during the Probe Placement Phase in 3Tesla MRI-guided cryoablation. The key idea of our method is to first locate an initial 2D line strip within a slice of the MR image which approximates the position and direction of the 3D probes bundle, noting that cryoprobes or biopsy needles create a signal void (black) artifact in MRI with a bright cylindrical border. With the initial 2D line, standard approaches to detect line structures such as the 3D Hough Transform can be applied to quickly detect each probe's axis. By comparing with manually labeled probes, the analysis of 5 patient treatment cases of kidney cryoablation with varying probe placements demonstrates that our algorithm combined with standard 3D line detection is an accurate and robust method to detect probe artifacts.

  8. 6{sup th} interventional MRI symposium. Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

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

  9. MRI differential diagnosis of suspected multiple sclerosis.

    Science.gov (United States)

    Chen, J J; Carletti, F; Young, V; Mckean, D; Quaghebeur, G

    2016-09-01

    Diagnosing multiple sclerosis (MS) can be very challenging owing to its variable clinical features and lack of a definitive test. Magnetic resonance imaging (MRI) is a core diagnostic tool in the detection of MS lesions and demonstration of spatial and temporal distribution of disease. Moreover, MRI plays a crucial role in the exclusion of alternative diagnoses of MS. The aim of this review is to describe the typical MRI features of MS and to present a series of common mimics of MS with emphasis on their distinguishing features from MS. PMID:27349475

  10. 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.

  11. Multidetector CT and MRI in pancreatic diseases

    International Nuclear Information System (INIS)

    Multidetector CT and MRI are the most efficient non invasive techniques in the assessment of pancreatic diseases. As with MRI, multidetector CT has now become an all in one examination using 2 D and 3 D multiplanar reformations with the ability to perform with high accuracy: a) vascular assessment using MIP reconstruction and b) biliary and pancreatic ducts assessment using minIP reconstruction. This review compares and illustrates the respective advantages of MRI and multidetector CT in the assessment of pancreatic diseases. (authors)

  12. MRI findings in little leaguer's shoulder

    International Nuclear Information System (INIS)

    Little leaguer's shoulder, a stress injury of the proximal humeral physis, should be considered in the differential diagnosis for an adolescent baseball player with shoulder pain, especially if the player is pitching regularly in a competitive environment. While roentgenographs may or may not be helpful, depending on the duration and severity of the injury, we report the MRI appearance of a case of little leaguer's shoulder. We found MRI helpful in diagnosing injury to the growth plate that was radiographically occult; furthermore, we were able to document the patient's progress with a follow-up MRI examination, which showed improvement with treatment. (orig.)

  13. MRI findings in pediatric patients with scurvy.

    Science.gov (United States)

    Gulko, Edwin; Collins, Lee K; Murphy, Robyn C; Thornhill, Beverly A; Taragin, Benjamin H

    2015-02-01

    In modern times scurvy is a rarely encountered disease caused by ascorbic acid (vitamin C) deficiency. However, sporadic cases of scurvy persist, particularly within the pediatric population. Recent individual case reports highlight an increased incidence of scurvy among patients with autism or developmental delay, with isolated case reports detailing the magnetic resonance imaging (MRI) findings of scurvy in these pediatric populations. We present the MRI findings of scurvy in four patients with autism or developmental delay, and review the literature on MRI findings in pediatric patients with scurvy. Despite its rarity, the radiologist must consider scurvy in a pediatric patient with a restricted diet presenting with arthralgia or myalgia. PMID:25109378

  14. Fetal MRI as complement to US in the diagnosis and characterization of anomalies of the genito-urinary tract

    Energy Technology Data Exchange (ETDEWEB)

    Alamo, Leonor, E-mail: leonor.alamo@chuv.ch [Unit of Pediatric Radiology, Department of diagnostic and interventional Radiology, Centre Hospitaliere Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1011 Lausanne (Switzerland); Laswad, Tarek, E-mail: Tarek.laswad@chuv.ch [Unit of Pediatric Radiology, Department of diagnostic and interventional Radiology, Centre Hospitaliere Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1011 Lausanne (Switzerland); Schnyder, Pierre, E-mail: Pierre.Schnyder@chuv.ch [Unit of Pediatric Radiology, Department of diagnostic and interventional Radiology, Centre Hospitaliere Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1011 Lausanne (Switzerland); Meuli, Reto, E-mail: Meuli.Reto@chuv.ch [Unit of Pediatric Radiology, Department of diagnostic and interventional Radiology, Centre Hospitaliere Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1011 Lausanne (Switzerland); Vial, Yvan, E-mail: Yvan.Vial@chuv.ch [Department of Obstetrics and Gynecology, Centre Hospitaliere Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1011 Lausanne (Switzerland); Osterheld, Maria-Chiara, E-mail: Maria-Chiara.Osterheld@chuv.ch [Department of Pathology, Centre Hospitaliere Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1011 Lausanne (Switzerland); Gudinchet, Francois, E-mail: Francois.Gudinchet@chuv.ch [Unit of Pediatric Radiology, Department of diagnostic and interventional Radiology, Centre Hospitaliere Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1011 Lausanne (Switzerland)

    2010-11-15

    The purpose of this study is to compare the accuracy of prenatal ultrasound (US) and prenatal magnetic resonance imaging (MRI) in the diagnosis and characterization of congenital abnormalities of the genito-urinary tract and to determine if the additional information obtained by MRI may influence the management of the fetus. We retrospectively evaluate 15 cases of congenital genito-urinary tract anomalies detected by prenatal US and with echographic inconclusive diagnosis. We compare the MRI findings with the US findings and the final diagnosis, obtained from neonatal outcomes, imaging studies and pathology records. Fetal US diagnosis was correct in 9 cases (60%) and MRI in 13 cases (86.7%). Prenatal MRI revealed additional information to US in 9 cases (60%), which modified the initial US diagnosis in 5 cases (33.3%) and changed the therapeutic approach in 5 fetuses (33.3%). Fetal MRI was better than US in cases of oligoamnios and in fetuses with genito-urinary pathology concerning the pelvic and perineum region. We believe that MRI should be considered as a complementary diagnostic method in cases of echographic suspicion of congenital pathology of the genito-urinary tract and inconclusive prenatal US.

  15. Enhanced MRI and MRI-Guided Interventional Procedures in Women with Asymptomatic Silicone-Injected Breasts

    OpenAIRE

    Yun-Chung Cheung; Shin-Chih Chen; Yung-Feng Lo

    2012-01-01

    Asymptomatic women who have received silicone injection for breast augmentation have a risk of underestimating breast cancer by palpation, mammography, or breast sonography. Enhanced breast MRI is sensitive to display certain nonspecific enhanced lesions or suspicious lesions. Such nonspecific MRI-detected lesions could be managed by American College Radiology BI-RADS lexicon and selectively with MRI-guided techniques biopsy to prevent unnecessary surgery.

  16. Application Of Fuzzy System In Segmentation Of MRI Brain Tumor

    CERN Document Server

    Rajya, Mrigank; Sheoran, Swati

    2010-01-01

    Segmentation of images holds an important position in the area of image processing. It becomes more important whi le typically dealing with medical images where presurgery and post surgery decisions are required for the purpose of initiating and speeding up the recovery process. Segmentation of 3-D tumor structures from magnetic resonance images (MRI) is a very challenging problem due to the variability of tumor geometry and intensity patterns. Level set evolution combining global smoothness with the flexibility of topology changes offers significant advantages over the conventional statistical classification followed by mathematical morphology. Level set evolution with constant propagation needs to be initialized either completely inside or outside the tumor and can leak through weak or missing boundary parts. Replacing the constant propagation term by a statistical force overcomes these limitations and results in a convergence to a stable solution. Using MR images presenting tumors, probabilities for backgr...

  17. Statistical analysis of MRI-only based dose planning

    DEFF Research Database (Denmark)

    Korsholm, M. E.; Waring, L. W.; Paulsen, Rasmus Reinhold;

    2012-01-01

    . MRIonly based RT eliminates these errors and reduce the time and costs of a CT scan. The aim of this study is to investigate the dosimetric differences of a treatment plan when the dose calculation is based on MRI as compared to CT. Materials and Methods: Four diagnostic groups are investigated; 12...... as a clinically approved treatment plan. The treatment planning software is Eclipse v.10.0 (Varian Medical Systems). The dose calculation based on MRI data is evaluated in two different ways; a homogeneous density assigned MRI (MRI unit), where the entire body is assigned an HU equal to water and a heterogeneous...... density assigned MRI (MRI bulk) where in addition the CT segmented bone is transferred to the MRI and assigned an age dependent HU based on ICRU report 46. The CT based clinical treatment plan and structure set are registered to the corresponding MRI unit and MRI bulk. The body is outlined on both the MRI...

  18. SISCOM imaging : an initial South African experience

    International Nuclear Information System (INIS)

    Full text: Subtraction ictal SPECT co-registered with MRI (SISCOM) is a new technique utilized for the detection and localization of epileptogenic foci in patients with refractory focal epilepsy who are candidates for surgical resection. The technique requires many challenges to be overcome, in particular in relation to the administration of the radiopharmaceutical, acquisition of brain SPECT and the conversion, co-registration and fusion of brain SPECT and MRI studies. Furthermore the interpretation of the studies is complex and is ideally performed in a multidisciplinary context in cooperation with disciplines such as neurology, radiology, psychiatry and neurosurgery. Materials and methods: Two brain SPECT studies are performed using 99mTc-ethylene cystinate dimer (ECD). An ictal study is performed after the administration of the 99mTc-ECD during a seizure. An interictal SPECT, performed between seizures is then subtracted from the ictal SPECT, and the difference image fused with an MRI study to optimise localization of the epileptogenic focus. Image conversion, co-registration and fusion was performed using MRlcro and SPM software. Results: To date the Departments of Neurology and Nuclear Medicine have completed over 10 SISCOM studies. Conclusion: During this presentation this initial work will be presented. The methodology as well as the challenges involved in performing and interpreting these studies will be discussed. Individual cases will be used to illustrate the impact of this powerful technique on future patient management. (author)

  19. Simultaneous PET/MRI: Impact on cancer management-A comprehensive review of cases

    Directory of Open Access Journals (Sweden)

    Amarnath Jena

    2014-01-01

    Full Text Available The metabolic mapping of malignancy in whole body in a single examination by PET/CT has gained widespread acceptance where the CT provides an anatomical correlate for the PET. MRI offers advantage over CT in providing better anatomical information owing to its high soft tissue resolution especially in brain, liver, neck, pelvis and bone marrow. Simultaneous PET/MRI is a new multimodal imaging modality that is expected to improve the diagnostic performance of imaging wherein better anatomical and metabolic information can be acquired at the same time and space during a single examination time. Also, MR attributes like diffusion, perfusion and spectroscopy may further add to its diagnostic potential. In this article, we present our initial experience in illustrated cases done with simultaneous PET/MRI and outline its potential for several clinical applications in oncology.

  20. Detection and Demarcation of Tumor using Vector Quantization in MRI images

    CERN Document Server

    Kekre, H B; Gharge, Saylee M

    2010-01-01

    Segmenting a MRI images into homogeneous texture regions representing disparate tissue types is often a useful preprocessing step in the computer-assisted detection of breast cancer. That is why we proposed new algorithm to detect cancer in mammogram breast cancer images. In this paper we proposed segmentation using vector quantization technique. Here we used Linde Buzo-Gray algorithm (LBG) for segmentation of MRI images. Initially a codebook of size 128 was generated for MRI images. These code vectors were further clustered in 8 clusters using same LBG algorithm. These 8 images were displayed as a result. This approach does not leads to over segmentation or under segmentation. For the comparison purpose we displayed results of watershed segmentation and Entropy using Gray Level Co-occurrence Matrix along with this method.

  1. Post-traumatic upper cervical subluxation visualized by MRI: a case report

    Directory of Open Access Journals (Sweden)

    Demetrious James

    2007-12-01

    Full Text Available Abstract Background This paper describes MRI findings of upper cervical subluxation due to alar ligament disruption following a vehicular collision. Incidental findings included the presence of a myodural bridge and a spinal cord syrinx. Chiropractic management of the patient is discussed. Case presentation A 21-year old female presented with complaints of acute, debilitating upper neck pain with unremitting sub-occipital headache and dizziness following a vehicular collision. Initial emergency department and neurologic investigations included x-ray and CT evaluation of the head and neck. Due to persistent pain, the patient sought chiropractic care. MRI of the upper cervical spine revealed previously unrecognized clinical entities. Conclusion This case highlights the identification of upper cervical ligamentous injury that produced vertebral subluxation following a traumatic incident. MRI evaluation provided visualization of previously undetected injury. The patient experienced improvement through chiropractic care.

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

    Directory of Open Access Journals (Sweden)

    Dalia Z. Zidan

    2014-06-01

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

  3. Relationship between diffusion parameters derived from intravoxel incoherent motion MRI and perfusion measured by dynamic contrast-enhanced MRI of soft tissue tumors.

    Science.gov (United States)

    Marzi, Simona; Stefanetti, Linda; Sperati, Francesca; Anelli, Vincenzo

    2016-01-01

    Our aim was to evaluate the link between diffusion parameters measured by intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) and the perfusion metrics obtained with dynamic contrast-enhanced (DCE) MRI in soft tissue tumors (STTs). Twenty-eight patients affected by histopathologically confirmed STT were included in a prospective study. All patients underwent both DCE MRI and IVIM DWI. The perfusion fraction f, diffusion coefficient D and perfusion-related diffusion coefficient D* were estimated using a bi-exponential function to fit the DWI data. DCE MRI was acquired with a temporal resolution of 3-5 s. Maps of the initial area under the gadolinium concentration curve (IAUGC), time to peak (TTP) and maximum slope of increase (MSI) were derived using commercial software. The relationships between the DCE MRI and IVIM DWI measurements were assessed by Spearman's test. To exclude false positive results under multiple testing, the false discovery rate (FDR) procedure was applied. The Mann-Whitney test was used to evaluate the differences between all variables in patients with non-myxoid and myxoid STT. No significant relationship was found between IVIM parameters and any DCE MRI parameters. Higher f and D*f values were found in non-myxoid tumors compared with myxoid tumors (p = 0.004 and p = 0.003, respectively). MSI was significantly higher in non-myxoid tumors than in myxoid tumors (p = 0.029). From the visual assessments of single clinical cases, both f and D*f maps were in satisfactory agreement with DCE maps in the extreme cases of an avascular mass and a highly vascularized mass, whereas, for tumors with slight vascularity or with a highly heterogeneous perfusion pattern, this association was not straightforward. Although IVIM DWI was demonstrated to be feasible in STT, our data did not support evident relationships between perfusion-related IVIM parameters and perfusion measured by DCE MRI.

  4. MRI manifestations of enlarged superior ophthalmic vein

    Institute of Scientific and Technical Information of China (English)

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

    2002-01-01

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

  5. MRI findings of Guillain-Barre syndrome

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-04-01

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

  6. PET/MRI in cancer patients

    DEFF Research Database (Denmark)

    Kjær, Andreas; Loft, Annika; Law, Ian;

    2013-01-01

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

  7. PET/MRI in cancer patients

    DEFF Research Database (Denmark)

    Kjær, Andreas; Loft, Annika; Law, Ian;

    2013-01-01

    described include brain tumors, pediatric oncology as well as lung, abdominal and pelvic cancer. In general the cases show that PET/MRI performs well in all these types of cancer when compared to PET/CT. However, future large-scale clinical studies are needed to establish when to use PET/MRI. We envision......Combined PET/MRI systems are now commercially available and are expected to change the medical imaging field by providing combined anato-metabolic image information. We believe this will be of particular relevance in imaging of cancer patients. At the Department of Clinical Physiology, Nuclear...... Medicine & PET at Rigshospitalet in Copenhagen we installed an integrated PET/MRI in December 2011. Here, we describe our first clinical PET/MR cases and discuss some of the areas within oncology where we envision promising future application of integrated PET/MR imaging in clinical routine. Cases...

  8. Upright positional MRI of the lumbar spine

    Energy Technology Data Exchange (ETDEWEB)

    Alyas, F.; Connell, D. [London Upright MRI Centre, London (United Kingdom); Department of Radiology, Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex (United Kingdom); Saifuddin, A. [London Upright MRI Centre, London (United Kingdom); Department of Radiology, Royal National Orthopaedic Hospital NHS Trust, Stanmore, Middlesex (United Kingdom)], E-mail: asif.saifuddin@rnoh.nhs.uk

    2008-09-15

    Supine magnetic resonance imaging (MRI) is routinely used in the assessment of low back pain and radiculopathy. However, imaging findings often correlate poorly with clinical findings. This is partly related to the positional dependence of spinal stenosis, which reflects dynamic changes in soft-tissue structures (ligaments, disc, dural sac, epidural fat, and nerve roots). Upright MRI in the flexed, extended, rotated, standing, and bending positions, allows patients to reproduce the positions that bring about their symptoms and may uncover MRI findings that were not visible with routine supine imaging. Assessment of the degree of spinal stability in the degenerate and postoperative lumbar spine is also possible. The aim of this review was to present the current literature concerning both the normal and symptomatic spine as imaged using upright MRI and to illustrate the above findings using clinical examples.

  9. Multichannel Compressive Sensing MRI Using Noiselet Encoding

    CERN Document Server

    Pawar, Kamlesh; Zhang, Jingxin

    2014-01-01

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

  10. Value of MRI in female stress incontinence

    International Nuclear Information System (INIS)

    Twenty women with stress incontinence were examined using conventional and dynamic MRI before and after reconstructive surgery. The results thus obtained were compared with those recorded in a control group of 15 asymptomatic women and in three patients with urogenital prolapse but without incontinence. MRI does not offer specific criteria for estimation of stress incontinence. However, it provides for preoperative evaluation of pelvic muscle condition as well as of grade and type of bladder and urethral prolapse. The displacement of the bladder and urethra in the sagittal plane is evaluated by means of a reference line, drawn between the lower border of the symphysis and the sacrococcygeal joint. The postoperative MRI examination enables visualization and estimation of the newly formed muscle sling and of the changes in the ventral urethrosymphyseal fixation. MRI is suitable for diagnosis of periurethral causes of stress incontinence and, generally, is a reliable method for verification of surgical succes. (orig.)

  11. Brain MRI Findings in Congenital Muscular Dystrophy

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2006-03-01

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

  12. MRI Reporter Genes for Noninvasive Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Caixia Yang

    2016-05-01

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

  13. MRI for the evaluation of gastric physiology

    Energy Technology Data Exchange (ETDEWEB)

    Zwart, Ingrid M. de; Roos, Albert de [C2-S Leiden University Medical Center, Department of Radiology, Leiden (Netherlands)

    2010-11-15

    Evaluation of gastric physiology (gastric emptying and motility) is important for the diagnosis of disturbances such as functional dyspepsia. MRI is a non-invasive technique that allows simultaneous registration of gastric emptying and motility. To provide an overview of the literature of studies that used MRI as a tool for evaluation of gastric function in both research and clinical settings. A MEDLINE search was performed (1990-2008) directed at the radiology and gastroenterology literature on gastric physiology. Key words that were used included: functional tests, gastric emptying, gastric motility, gastric physiology and MRI. Twenty-five articles fulfilled the inclusion criteria and were included in the analysis. Over the last decade, MRI has developed as a reliable, non-invasive method for detailed evaluation of gastric emptying and motility without the disadvantages of ionizing radiation and without the use of intragastric catheters that influence gastric physiology. (orig.)

  14. 2015 MICCAI Workshop on Computational Diffusion MRI

    CERN Document Server

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

    2016-01-01

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

  15. Wrist injuries in young adults: The diagnostic impact of CT and MRI

    International Nuclear Information System (INIS)

    Purpose: To evaluate the diagnostic impact of MRI or/and multidetector CT in young patients with wrist injury and inconclusive or negative clinical examination and X-rays and to analyze variations in imaging strategies between a district general hospital (GH) and a university hospital (UH). Materials and methods: A retrospective analysis of 34 young patients (mean age 23 years) with wrist trauma who underwent CT or/and MRI was performed. The injury was acute in 24, and chronic in 10 patients. Twenty-two patients were from a GH and 12 from a UH. Two experienced musculoskeletal radiologists blindly reviewed the imaging studies. The effect of cross-sectional imaging on patient care and treatment plan was evaluated. Results: In 9 of 34 patients one or more fractures were diagnosed on cross-sectional imaging. The scaphoid was fractured in four patients, the lunate and/or the trapezium in three patients, the scaphoid together with the lunate in one patient, and finally the distal radius in one patient. Ligamentous trauma was identified solely on MRI in 11 patients (involving the TFCC in eight cases). In four patients with both imaging methods, CT revealed one fracture of the trapezium not seen on MRI, and one scapholunate fracture with MRI findings of distal radial fracture only. In two patients with normal CT, MRI revealed bone marrow oedema of the scaphoid in one and of the distal radius, lunate and triquetrum in the other. Conclusion: Both CT and MRI might be considered in patients with acute or chronic wrist injury, clinical dilemma and normal initial radiographs, depending on the availability and the individual institution policies.

  16. Wrist injuries in young adults: The diagnostic impact of CT and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Fotiadou, Anastasia [Department of Radiology, Hinchingbrooke Hospital, Huntingdon, PE29 6NT, Cambridgeshire (United Kingdom); Patel, Arpit [Orthopaedic Surgery, Hinchingbrooke Hospital, Huntingdon, PE29 6NT, Cambridgeshire (United Kingdom); Morgan, Tony [Department of Radiology, Hinchingbrooke Hospital, Huntingdon, PE29 6NT, Cambridgeshire (United Kingdom); Karantanas, Apostolos H., E-mail: karantanas@med.uoc.gr [Department of Radiology, University of Crete, Heraklion (Greece)

    2011-02-15

    Purpose: To evaluate the diagnostic impact of MRI or/and multidetector CT in young patients with wrist injury and inconclusive or negative clinical examination and X-rays and to analyze variations in imaging strategies between a district general hospital (GH) and a university hospital (UH). Materials and methods: A retrospective analysis of 34 young patients (mean age 23 years) with wrist trauma who underwent CT or/and MRI was performed. The injury was acute in 24, and chronic in 10 patients. Twenty-two patients were from a GH and 12 from a UH. Two experienced musculoskeletal radiologists blindly reviewed the imaging studies. The effect of cross-sectional imaging on patient care and treatment plan was evaluated. Results: In 9 of 34 patients one or more fractures were diagnosed on cross-sectional imaging. The scaphoid was fractured in four patients, the lunate and/or the trapezium in three patients, the scaphoid together with the lunate in one patient, and finally the distal radius in one patient. Ligamentous trauma was identified solely on MRI in 11 patients (involving the TFCC in eight cases). In four patients with both imaging methods, CT revealed one fracture of the trapezium not seen on MRI, and one scapholunate fracture with MRI findings of distal radial fracture only. In two patients with normal CT, MRI revealed bone marrow oedema of the scaphoid in one and of the distal radius, lunate and triquetrum in the other. Conclusion: Both CT and MRI might be considered in patients with acute or chronic wrist injury, clinical dilemma and normal initial radiographs, depending on the availability and the individual institution policies.

  17. Effect of acupuncture in mild cognitive impairment and Alzheimer disease: a functional MRI study.

    Directory of Open Access Journals (Sweden)

    Zhiqun Wang

    Full Text Available We aim to clarify the mechanisms of acupuncture in treating mild cognitive impairment (MCI and Alzheimer disease (AD by using functional magnetic resonance imaging (fMRI. Thirty-six right-handed subjects (8 MCI patients, 14 AD patients, and 14 healthy elders participated in this study. Clinical and neuropsychological examinations were performed on all the subjects. MRI data acquisition was performed on a SIEMENS verio 3-Tesla scanner. The fMRI study used a single block experimental design. We first acquired the baseline resting state data in the initial 3 minutes; we then acquired the fMRI data during the procession of acupuncture stimulation on the acupoints of Tai chong and Hegu for the following 3 minutes. Last, we acquired fMRI data for another 10 minutes after the needle was withdrawn. The preprocessing and data analysis were performed using the statistical parametric mapping (SPM8 software. Then the two-sample t-tests were performed between each two groups of different states. We found that during the resting state, brain activities in AD and MCI patients were different from those of control subjects. During the acupuncture and the second resting state after acupuncture, when comparing to resting state, there are several regions showing increased or decreased activities in MCI, AD subjects compared to normal subjects. Most of the regions were involved in the temporal lobe and the frontal lobe, which were closely related to the memory and cognition. In conclusion, we investigated the effect of acupuncture in AD and MCI patients by combing fMRI and traditional acupuncture. Our fMRI study confirmed that acupuncture at Tai chong (Liv3 and He gu (LI4 can activate certain cognitive-related regions in AD and MCI patients.

  18. Infantile Refsum disease: serial evaluation with MRI.

    Science.gov (United States)

    Cakirer, Sinan; Savas, Mahmut R

    2005-02-01

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

  19. Infantile Refsum disease: serial evaluation with MRI

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-02-01

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

  20. Diffusion MRI Registration Using Orientation Distribution Functions

    OpenAIRE

    Geng, Xiujuan; Ross, Thomas J.; Zhan, Wang; Gu, Hong; Chao, Yi-Ping; Lin, Ching-Po; Christensen, Gary E.; Schuff, Norbert; Yang, Yihong

    2009-01-01

    We propose a linear-elastic registration method to register diffusion-weighted MRI (DW-MRI) data sets by mapping their diffusion orientation distribution functions (ODFs). The ODFs were reconstructed using a q-ball imaging (QBI) technique to resolve intravoxel fiber crossing. The registration method is based on mapping the ODF maps represented by spherical harmonics which yield analytic solutions and reduce the computational complexity. ODF reorientation is required to maintain the consistenc...