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Sample records for 3-dimensional cardiovascular magnetic

  1. Solar energetic particle propagation in 3-dimensional heliospheric magnetic field

    Science.gov (United States)

    Zhang, M.; Qin, G.; Rassoul, H.

    2008-05-01

    We present the first model calculation of solar energetic particle propagation in realistic 3-dimensional heliopsheric magnetic field. The model includes essentially all the particle transport mechanisms: streaming along magnetic fields, convection with the solar wind, pitch-angle diffusion, focusing, perpendicular diffusion, and pitch-angle dependent adiabatic cooling. We solve the Fokker-Planck transport equation with simulation of backward stochastic processes in a fixed reference frame. Here we focus on high-energy E > ~ 10 MeV solar energetic particles that are accelerated and injected near the Sun. The source of solar energetic particles can be either solar flares or coronal mass ejections, both having limited coverage of latitude and longitude on the solar surface. We compute the particle flux and anisotropy profiles at various observation locations in interplanetary space up to 5 AU from the ecliptic to the solar poles. We found that solar energetic particles are observed no matter whether an observer is directly connected to solar source by the magnetic field. Our model calculation results can explain why we often see solar energetic particles reach an almost uniform reservoir in the inner heliosphere a few days after the onset of a solar energetic particle event and then the intensities of particles in a broad range of energies decay uniformly everywhere. This phenomenon can happen without a need of particle diffusion barrier in the outer heliosphere. We will discuss what mechanism is responsible for the formation of such a reservoir and what role the perpendicular diffusion plays in the transport of solar energetic particles.

  2. Heat pulse propagation in chaotic 3-dimensional magnetic fields

    CERN Document Server

    del-Castillo-Negrete, D

    2014-01-01

    Heat pulse propagation in $3$-D chaotic magnetic fields is studied by solving the parallel heat transport equation using a Lagrangian-Green's function (LG) method. The LG method provides an efficient and accurate technique that circumvents limitations of finite elements and finite difference methods. The main two problems addressed are: (i) The dependence of the radial transport on the magnetic field stochasticity (controlled by the amplitude of the perturbation, $\\epsilon$); and (ii) The role of reversed shear configurations on pulse propagation. In all the cases considered there are no magnetic flux surfaces. However, radial transport is observed to depend strongly on $\\epsilon$ due to the presence of high-order magnetic islands and Cantori that act as quasi-transport barriers that preclude the radial penetration of heat pulses within physically relevant time scale. The dependence of the magnetic field connection length, $\\ell_B$, on $\\epsilon$ is studied in detail. The decay rate of the temperature maximum...

  3. 3-dimensional modeling of transcranial magnetic stimulation: Design and application

    Science.gov (United States)

    Salinas, Felipe Santiago

    Over the past three decades, transcranial magnetic stimulation (TMS) has emerged as an effective tool for many research, diagnostic and therapeutic applications in humans. TMS delivers highly localized brain stimulations via non-invasive externally applied magnetic fields. This non-invasive, painless technique provides researchers and clinicians a unique tool capable of stimulating both the central and peripheral nervous systems. However, a complete analysis of the macroscopic electric fields produced by TMS has not yet been performed. In this dissertation, we present a thorough examination of the total electric field induced by TMS in air and a realistic head model with clinically relevant coil poses. In the first chapter, a detailed account of TMS coil wiring geometry was shown to provide significant improvements in the accuracy of primary E-field calculations. Three-dimensional models which accounted for the TMS coil's wire width, height, shape and number of turns clearly improved the fit of calculated-to-measured E-fields near the coil body. Detailed primary E-field models were accurate up to the surface of the coil body (within 0.5% of measured values) whereas simple models were often inadequate (up to 32% different from measured). In the second chapter, we addressed the importance of the secondary E-field created by surface charge accumulation during TMS using the boundary element method (BEM). 3-D models were developed using simple head geometries in order to test the model and compare it with measured values. The effects of tissue geometry, size and conductivity were also investigated. Finally, a realistic head model was used to assess the effect of multiple surfaces on the total E-field. We found that secondary E-fields have the greatest impact at areas in close proximity to each tissue layer. Throughout the head, the secondary E-field magnitudes were predominantly between 25% and 45% of the primary E-fields magnitude. The direction of the secondary E

  4. Preoperative 3-dimensional Magnetic Resonance Imaging of Uterine Myoma and Endometrium Before Myomectomy.

    Science.gov (United States)

    Kim, Young Jae; Kim, Kwang Gi; Lee, Sa Ra; Lee, Seung Hyun; Kang, Byung Chul

    2017-02-01

    Uterine myomas are the most common gynecologic benign tumor affecting women of childbearing age, and myomectomy is the main surgical option to preserve the uterus and fertility. During myomectomy for women with multiple myomas, it is advisable to identify and remove as many as possible to decrease the risk of future myomectomies. With deficient preoperative imaging, gynecologists are challenged to identify the location and size of myomas and the endometrium, which, in turn, can lead to uterine rupture during future pregnancies. Current conventional 2-dimensional imaging has limitations in identifying precise locations of multiple myomas and the endometrium. In our experience, we preferred to use 3-dimensional imaging to delineate the myomas, endometrium, or blood vessels, which we were able to successfully reconstruct by using the following imaging method. To achieve 3-dimensional imaging, we matched T2 turbo spin echo images to detect uterine myomas and endometria with T1 high-resolution isotropic volume excitation-post images used to detect blood vessels by using an algorithm based on the 3-dimensional region growing method. Then, we produced images of the uterine myomas, endometria, and blood vessels using a 3-dimensional surface rendering method and successfully reconstructed selective 3-dimensional imaging for uterine myomas, endometria, and adjacent blood vessels. A Web-based survey was sent to 66 gynecologists concerning imaging techniques used before myomectomy. Twenty-eight of 36 responding gynecologists answered that the 3-dimensional image produced in the current study is preferred to conventional 2-dimensional magnetic resonance imaging in identifying precise locations of uterine myomas and endometria. The proposed 3-dimensional magnetic resonance imaging method successfully reconstructed uterine myomas, endometria, and adjacent vessels. We propose that this will be a helpful adjunct to uterine myomectomy as a preoperative imaging technique in future

  5. Cardiovascular Magnetic Resonance Imaging

    Science.gov (United States)

    Pelc, Norbert

    2000-03-01

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

  6. Cardiovascular magnetic resonance: physics and terminology.

    Science.gov (United States)

    Rodgers, Christopher T; Robson, Matthew D

    2011-01-01

    Cardiovascular magnetic resonance (CMR) is the branch of magnetic resonance imaging (MRI) whose acquisition methods are adapted to surmount the particular challenges caused by motion of the heart and blood in vivo. Magnetic resonance imaging is supremely flexible; it can produce images showing the spatial distribution of diverse tissue characteristics, for example, proton density, T(1), T(2), T(2)(⁎), fat concentration, flow rate, and diffusion parameters. The image contrast may usefully be modified by intravenous infusion of contrast agents. Magnetic resonance imaging permits 2-dimensional or 3-dimensional acquisitions with arbitrary slice orientation. Unfortunately, MRI's flexibility is matched by a remarkable complexity not only in its fundamental principles but also in the optimization of applications in the clinic. This article attempts to demystify the basic principles of CMR and provides a primer on the terminology used in CMR. Complete confidence in the principles of CMR is not essential to use the technology. Nevertheless, knowledge of the principal terminology of MRI is a valuable first step when seeking to understand and apply modern methods in a clinical or research setting. Thus, the article closes with a glossary of terminology and references to high-quality educational resources. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Diagnosis of dental abnormalities in children using 3-dimensional magnetic resonance imaging.

    Science.gov (United States)

    Tymofiyeva, Olga; Proff, Peter C; Rottner, Kurt; Düring, Markus; Jakob, Peter M; Richter, Ernst-Jürgen

    2013-07-01

    To assess the feasibility of magnetic resonance imaging (MRI) of dental abnormalities in children. The study included 16 patients (mean age, 10.8 yr) prospectively selected from 1,500 orthodontic patients. The selected patients included 3 with a mesiodens, 9 with supernumerary teeth other than a mesiodens, 1 with gemination, 1 with dilacerations, 1 with transmigration, and 1 with transposition. Three-dimensional (3D) images were acquired on a 1.5-T MRI scanner using a 3D turbo spin echo pulse sequence with a voxel size of 0.8 × 0.8 × 1 mm. The measurement time was 4 to 5 minutes. Using natural MRI contrast, the teeth, dental pulp, mandibular canal, and cortical bone could be clearly delineated. The position and shape of malformed teeth could be assessed in all 3 spatial dimensions. MRI was found to be a well-tolerated imaging modality for the diagnosis of dental abnormalities in children and for orthodontic treatment and surgical planning. Compared with conventional radiography, dental MRI provides the advantage of 3-dimensionality and complete elimination of ionizing radiation, which is particularly relevant for repeated examinations in children. Copyright © 2013 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  8. 3-Dimensional modelling of chick embryo eye development and growth using high resolution magnetic resonance imaging.

    Science.gov (United States)

    Goodall, Nicola; Kisiswa, Lilian; Prashar, Ankush; Faulkner, Stuart; Tokarczuk, Paweł; Singh, Krish; Erichsen, Jonathan T; Guggenheim, Jez; Halfter, Willi; Wride, Michael A

    2009-10-01

    Magnetic resonance imaging (MRI) is a powerful tool for generating 3-dimensional structural and functional image data. MRI has already proven valuable in creating atlases of mouse and quail development. Here, we have exploited high resolution MRI to determine the parameters necessary to acquire images of the chick embryo eye. Using a 9.4 Tesla (400 MHz) high field ultra-shielded and refrigerated magnet (Bruker), MRI was carried out on paraformaldehyde-fixed chick embryos or heads at E4, E6, E8, and E10. Image data were processed using established and custom packages (MRICro, ImageJ, ParaVision, Bruker and mri3dX). Voxel dimensions ranged from 62.5 microm to 117.2 microm. We subsequently used the images obtained from the MRI data in order to make precise measurements of chick embryo eye surface area, volume and axial length from E4 to E10. MRI was validated for accurate sizing of ocular tissue features by direct comparison with previously published literature. Furthermore, we demonstrate the utility of high resolution MRI for making accurate measurements of morphological changes due to experimental manipulation of chick eye development, thereby facilitating a better understanding of the effects on chick embryo eye development and growth of such manipulations. Chondroitin sulphate or heparin were microinjected into the vitreous cavity of the right eyes of each of 3 embryos at E5. At E10, embryos were fixed and various eye parameters (volume, surface area, axial length and equatorial diameter) were determined using MRI and normalised with respect to the un-injected left eyes. Statistically significant alterations in eye volume (p < 0.05; increases with chondroitin sulphate and decreases with heparin) and changes in vitreous homogeneity were observed in embryos following microinjection of glycosaminoglycans. Furthermore, in the heparin-injected eyes, significant disturbances at the vitreo-retinal boundary were observed as well as retinal folding and detachment

  9. Editorial Commentary: Single-Image Slice Magnetic Resonance Imaging Assessments Do Not Predict 3-Dimensional Muscle Volume.

    Science.gov (United States)

    Brand, Jefferson C

    2016-01-01

    No single-image magnetic resonance imaging (MRI) assessment-Goutallier classification, Fuchs classification, or cross-sectional area-is predictive of whole-muscle volume or fatty atrophy of the supraspinatus or infraspinatus. Rather, 3-dimensional MRI measurement of whole-muscle volume and fat-free muscle volume is required and is associated with shoulder strength, which is clinically relevant. Three-dimensional MRI may represent a new gold standard for assessment of the rotator cuff musculature using imaging and may help to predict the feasibility of repair of a rotator cuff tear as well as the postoperative outcome. Unfortunately, 3-dimensional MRI assessment of muscle volume is labor intensive and is not widely available for clinical use.

  10. Metal organic framework derived magnetically separable 3-dimensional hierarchical Ni@C nanocomposites: Synthesis and adsorption properties

    Science.gov (United States)

    Song, Yixuan; Qiang, Tingting; Ye, Ming; Ma, Qiuyang; Fang, Zhen

    2015-12-01

    Design an effective absorbent that has high surface area, and perfect recyclable is imperative for pollution elimination. Herein, we report a facile two-step strategy to fabricate magnetically separable 3-dimensional (3D) hierarchical carbon-coated nickel (Ni@C) nanocomposites by calcinating nickel based metal organic framework (Ni3(OH)2(C8H4O4)2(H2O)4). SEM and TEM images illuminate that the nanocomposites were constructed by 8 nm nickel nanoparticle encapsulated in 3D flake like carbon. The specific surface area of the obtained nanocomposites is up to 120.38 m2 g-1. Room temperature magnetic measurement indicates the nanocomposites show soft magnetism property, which endows the nanocomposites with an ideal fast magnetic separable property. The maximum adsorption capacity of the nanocomposites for rhodamine B is 84.5 mg g-1. Furthermore, the nanocomposites also exhibit a high adsorption capacity for heavy metal ions. The adsorbent can be very easily separated from the solution by using a common magnet without exterior energy. The as-prepared Ni@C nanocomposites can apply in waste water treatment on a large-scale as a new adsorbent with high efficiency and excellent recyclability.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-12-15

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

  12. A complete model of solar energetic particle propagation in 3-dimensional interplanetary magnetic field

    Science.gov (United States)

    Zhang, Ming; Rassoul, Hamid; Qin, Gang

    We present a model calculation of solar energetic particle propagation in a realistic 3-d Interplanetary magnetic field. The model includes essentially all the particle transport mechanisms: streaming along magnetic fields, convection with the solar wind, pitch-angle diffusion, magnetic focusing, cross-field diffusion, and adiabatic cooling with pitch-angle dependence. We solve a Fokker-Planck transport equation with simulation of stochastic processes in a fixed reference frame, in which an observer on a spacecraft is roughly stationary. For simplicity, as the first model calculation of this sort, we focus on high-energy E > 10 MeV solar energetic particles that are accelerated near the Sun and then released into interplanetary space. The source of solar energetic particles can be either solar flares or coronal mass ejections, both having limited coverage of latitude and longitude on the solar surface. We compute the particle flux and anisotropy profiles for various observation locations in interplanetary space up to 5 AU from the ecliptic to the poles. Our model calculation results can explain why we often see solar energetic particles reach an almost uniform reservoir in the inner heliosphere a few days after onset of a solar energetic particle event and then the intensities of particles in a broad range of particle energies decay uniformly everywhere. This phenomenon can happen without a need of particle diffusion barrier in the outer heliosphere. We will discuss what mechanism is behind the formation of such a reservoir and what role the cross-field diffusion plays in the transport of solar energetic particles.

  13. The Kubo conductivity tensor for 2- and 3-dimensional magnetic nulls

    Science.gov (United States)

    St-Onge, Denis A.

    The complete set of Kubo conductivity tensors are computed in two- and three-dimensional linear magnetic null systems using collisionless single-particle simulations. Chaos regions are constructed for each case, along with the complete Lyapunov spectrum. It is found that stochastic frequency mixing of particle bounce motion, as well as gyromotion, contribute significantly to the conductivity. For many cases, the conductivity curve is well approximated by power-laws, resulting in a divergent value of the direct-current conductivity, while others can be described by a sum of Maxwellian curves. The energy dissipation of these systems is also briefly discussed.

  14. Society for Cardiovascular Magnetic Resonance guidelines for reporting cardiovascular magnetic resonance examinations

    Directory of Open Access Journals (Sweden)

    van Rossum Albert C

    2009-03-01

    Full Text Available Abstract These reporting guidelines are recommended by the Society for Cardiovascular Magnetic Resonance (SCMR to provide a framework for healthcare delivery systems to disseminate cardiac and vascular imaging findings related to the performance of cardiovascular magnetic resonance (CMR examinations.

  15. Cardiovascular magnetic resonance in systemic hypertension

    Directory of Open Access Journals (Sweden)

    Maceira Alicia M

    2012-06-01

    Full Text Available Abstract Systemic hypertension is a highly prevalent potentially modifiable cardiovascular risk factor. Imaging plays an important role in the diagnosis of underlying causes for hypertension, in assessing cardiovascular complications of hypertension, and in understanding the pathophysiology of the disease process. Cardiovascular magnetic resonance (CMR provides accurate and reproducible measures of ventricular volumes, mass, function and haemodynamics as well as uniquely allowing tissue characterization of diffuse and focal fibrosis. In addition, CMR is well suited for exclusion of common secondary causes for hypertension. We review the current and emerging clinical and research applications of CMR in hypertension.

  16. Cardiovascular magnetic resonance in systemic hypertension

    Science.gov (United States)

    2012-01-01

    Systemic hypertension is a highly prevalent potentially modifiable cardiovascular risk factor. Imaging plays an important role in the diagnosis of underlying causes for hypertension, in assessing cardiovascular complications of hypertension, and in understanding the pathophysiology of the disease process. Cardiovascular magnetic resonance (CMR) provides accurate and reproducible measures of ventricular volumes, mass, function and haemodynamics as well as uniquely allowing tissue characterization of diffuse and focal fibrosis. In addition, CMR is well suited for exclusion of common secondary causes for hypertension. We review the current and emerging clinical and research applications of CMR in hypertension. PMID:22559053

  17. Clinical applications of cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-10-15

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

  18. Image Quality of the 3 Dimensional Phase-Contrast Technique in an Intracranial Magnetic Resonance Angiography with Artifacts Caused by Orthodontic Devices: A Comparison with 3 Dimensional Time-of-Flight Technique

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Seong Jin; Kim, Young Soo; Hong, Hyun Sook [Dept. of Radiology, Soonchunhyang University College of Medicine, Bucheon (Korea, Republic of); Kim, Dong Hun [Dept. of Radiology, Chosun University School of Medicine, Kwangju (Korea, Republic of)

    2011-07-15

    To evaluate the degree of image distortion caused by orthodontic devices during a intracranial magnetic resonance angiography (MRA), and to determine the effectiveness of the 3 dimensional phase-contrast (3D PC). Subjects were divided into group A (n = 20) wearing a home-made orthodontic device, and group B (n = 10) with an actual orthodontic device. A 3.0T MR scanner was used, applying 3D time-of-flight (TOF) and 3D PC. Two board-certified radiologists evaluated images independently based on a four point scale classifying segments of the circle of Willis. Magnetic susceptibility variations and contrast-to-noise ratio (CNR) on maximum intensity projection images were measured. In group A, scores of the 3D TOF and 3D PC were 2.84 {+-} 0.1 vs. 2.88 {+-} 0.1 (before) and 1.8 {+-} 0.4 vs 2.83 {+-} 0.1 (after wearing device), respectively. In group B, the scores of 3D TOF and 3D PC were 1.86 {+-} 0.43 and 2.81 {+-} 0.15 (p = 0.005), respectively. Magnetic susceptibility variations showed meaningful results after wearing the device (p = 0.0001). CNRs of the 3D PC before and after wearing device were 142.9 {+-} 6.6 vs. 140.8 {+-} 7.2 (p = 0.7507), respectively. In the 3D TOF, CNRs were 324.8 {+-} 25.4 vs. 466.3 {+-} 41.7 (p = 0.0001). The 3D PC may be a solution method for distorted images by magnetic susceptibility in the intracranial MRA compared with 3D TOF.

  19. Cardiovascular magnetic resonance in carotid atherosclerotic disease

    Directory of Open Access Journals (Sweden)

    Chen Huijun

    2009-12-01

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

  20. 3-DIMENSIONAL MAGNETIC-RESONANCE-IMAGING OF THE INNER-EAR IN IDIOPATHIC SUDDEN SENSORINEURAL HEARING-LOSS

    NARCIS (Netherlands)

    ALBERS, FWJ; DEMUYNCK, KMNP; CASSELMAN, JW

    1994-01-01

    Five patients with idiopathic sudden sensorineural hearing loss (ISSHL) were examined by a combination of high-resolution computed tomography and special magnetic resonance imaging techniques. By three-dimensional constructive interference in steady state magnetic resonance imaging excellent

  1. 3-DIMENSIONAL MAGNETIC-RESONANCE-IMAGING OF THE INNER-EAR IN IDIOPATHIC SUDDEN SENSORINEURAL HEARING-LOSS

    NARCIS (Netherlands)

    ALBERS, FWJ; DEMUYNCK, KMNP; CASSELMAN, JW

    1994-01-01

    Five patients with idiopathic sudden sensorineural hearing loss (ISSHL) were examined by a combination of high-resolution computed tomography and special magnetic resonance imaging techniques. By three-dimensional constructive interference in steady state magnetic resonance imaging excellent visuali

  2. Cardiovascular magnetic resonance in hypertrophic cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-03-15

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

  3. Effect of zero magnetic field on cardiovascular system and microcirculation

    Science.gov (United States)

    Gurfinkel, Yu. I.; At'kov, O. Yu.; Vasin, A. L.; Breus, T. K.; Sasonko, M. L.; Pishchalnikov, R. Yu.

    2016-02-01

    The effects of zero magnetic field conditions on cardiovascular system of healthy adults have been studied. In order to generate zero magnetic field, the facility for magnetic fields modeling "ARFA" has been used. Parameters of the capillary blood flow, blood pressure, and the electrocardiogram (ECG) monitoring were measured during the study. All subjects were tested twice: in zero magnetic field and, for comparison, in sham condition. The obtained results during 60 minutes of zero magnetic field exposure demonstrate a clear effect on cardiovascular system and microcirculation. The results of our experiments can be used in studies of long-term stay in hypo-magnetic conditions during interplanetary missions.

  4. Cardiovascular magnetic resonance in pericardial diseases

    Directory of Open Access Journals (Sweden)

    Francone Marco

    2009-05-01

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

  5. Uterine volume and endometrial thickness in healthy girls evaluated by ultrasound (3-dimensional) and magnetic resonance imaging

    DEFF Research Database (Denmark)

    Hagen, Casper P; Mouritsen, Annette; Mieritz, Mikkel G

    2015-01-01

    OBJECTIVE: To report normative data on uterine volume and endometrial thickness in girls, according to pubertal stages; to evaluate factors that affect uterine volume; and to compare transabdominal ultrasound (TAUS) and magnetic resonance imaging (MRI). DESIGN: Cross-sectional study of a nested...... cohort of girls participating in The Copenhagen Mother-Child Cohort. SETTING: General community. PATIENT(S): One hundred twenty-one healthy girls, aged 9.8-14.7 years. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Clinical examination, including pubertal breast stage (Tanner classification: B1-B5...

  6. Exploration of the structural features and magnetic behaviour in a novel 3-dimensional interpenetrating Co(II)-based framework

    Indian Academy of Sciences (India)

    Soumyabrata Goswami; Amit Kumar Mondal; Sanjit Konar

    2015-02-01

    A new Co(II)-based three-dimensional (3D) framework having the molecular formula [Co(C4O4)(4-bpmh))H2O)2]n·2nH2O·2nMeOH·(1)(4-bpmh = N, N-bis-pyridin-4-ylmethylene-hydrazine) has been synthesized using a mixed ligand system and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, single crystal X-ray diffraction and variable temperature magnetic study. The framework is constructed by the bridging squarate (C4O2−4) and N, N-bis-pyridin-4-ylmethylene-hydrazine (4-bpmh) ligands and interpenetration of the 2D grid-like frameworks at definite angles gives rise to 2D→3D inclined polycatenation with sql/Shubnikov tetragonal plane net topology. Extensive non-covalent interactions (H-bonding as well as $\\cdots$ interactions) are also observed which stabilises the 3D arrangement. Additionally, complex 1 contains 1D channels of large dimensions (10.91 × 11.78 Å2) that runs along the b-axis. Variable temperature DC magnetic susceptibility study reveals dominant spin–orbit coupling effect typical of the 4T1g ground state of octahedral high-spin Co(II) ion at a higher temperature range.

  7. Fast 3-Breath-Hold 3-Dimensional Tagging Cardiac Magnetic Resonance in Patients with Hypertrophic Myocardial Diseases: A Feasibility Study

    Directory of Open Access Journals (Sweden)

    Yasuo Amano

    2016-01-01

    Full Text Available Tagging CMR has been established as the standard reference for measurement of myocardial strain. The current 2D tagging technique requires multiple breath-holds to cover the whole heart and cannot show the 3D motions of the left ventricle. We performed fast 3-breath-hold 3D tagging with localized tagging preparation and complementary spatial modulation of magnetization in 10 patients with hypertrophic myocardial diseases and 6 normal volunteers. The left wall motion was observed at any view angle, which allowed for the identification of regional and global hypokinesis using the fast 3D tagging. Although a decrease in the circumferential strain and LGE were observed at the basal septum in hypertrophic cardiomyopathy, they were not located together in each patient. In hypertensive heart disease, the decrease in circumferential strain was observed more widely than LGE, and the summed strain of all segments was significantly decreased. The decrease in strain and LGE were observed diffusely in cardiac amyloidosis. In conclusion, fast 3-breath-hold 3D tagging is feasible for the regional and global strain analysis. The location of reduced circumferential strain is not necessarily the same as that of LGE and is related to the global cardiac function in patients with hypertrophic myocardial diseases.

  8. Cardiovascular Applications of Magnetic Resonance Imaging

    NARCIS (Netherlands)

    Bovens, S.M.

    2012-01-01

    Cardiovascular diseases are the leading cause of death in the Netherlands. By the year 2030 it will be the leading cause of death in all parts of the world, including third world countries. Therefore, it is essential to improve diagnostic tools and continue research into the development of these

  9. Management implications of massive left ventricular hypertrophy in hypertrophic cardiomyopathy significantly underestimated by echocardiography but identified by cardiovascular magnetic resonance.

    Science.gov (United States)

    Maron, Martin S; Lesser, John R; Maron, Barry J

    2010-06-15

    Cardiovascular magnetic resonance (CMR) is a high spatial resolution, 3-dimensional tomographic imaging technique which may identify regions of massive left ventricular hypertrophy (particularly when confined to the anterolateral free wall) in which the extent of wall thickness is underestimated with traditional 2-dimensional echocardiography in patients with hypertrophic cardiomyopathy (HC). This observation may have potential implications on management strategies as extreme left ventricular hypertrophy is a primary risk factor for sudden death in HC and therefore supports an expanding role for CMR in the evaluation of HC patients.

  10. Focal Liver Lesions: Real-time 3-Dimensional Contrast-Enhanced Ultrasonography Compared With 2-Dimensional Contrast-Enhanced Ultrasonography and Magnetic Resonance Imaging.

    Science.gov (United States)

    Lee, Jung-Chieh; Yan, Kun; Lee, San-Kan; Yang, Wei; Chen, Min-Hua

    2017-06-24

    This study sought to evaluate the application of real-time 3-dimensional (3D) contrast-enhanced ultrasonography (US) to diagnose focal liver lesions and to compare these results with those from 2-dimensional (2D) contrast-enhanced US and contrast-enhanced magnetic resonance imaging (MRI). Patients with focal liver lesions were examined by 2D contrast-enhanced US, 3D contrast-enhanced US, and contrast-enhanced MRI for lesion characterization, and biopsies and comprehensive clinical diagnoses served as reference standards. The sensitivity, specificity, area under the receiver operating characteristic curve, and intermodality agreement were assessed. The number of contrast agent injections and lesions observed per injection were calculated for 3D and 2D contrast-enhanced US. The number and display quality of the feeding arteries observed with 3D and 2D contrast-enhanced US were assessed. A total of 117 patients with 151 focal liver lesions were enrolled, including 67 cases of hepatocellular carcinoma, 51 cases of liver metastasis, and 33 cases of benign liver lesions. No significant differences were found among the modalities. The sensitivity values for 3D contrast-enhanced US, 2D contrast-enhanced US, and contrast-enhanced MRI were 96%, 95%, and 93%, respectively; the specificity values were 87%, 84%, and 89%; and the area under the receiver operating characteristic curve values were 0.92, 0.90, and 0.92. The intermodality agreement was excellent (κ > 0.77). Fewer contrast agent injections were needed, and more lesions and feeding arteries were more clearly displayed on 3D than 2D contrast-enhanced US (P < .001). Real-time 3D contrast-enhanced US is useful for diagnosing focal liver lesions and for observing feeding arteries with fewer contrast agent injections. © 2017 by the American Institute of Ultrasound in Medicine.

  11. Quantitative assessment of fatty infiltration and muscle volume of the rotator cuff muscles using 3-dimensional 2-point Dixon magnetic resonance imaging.

    Science.gov (United States)

    Matsumura, Noboru; Oguro, Sota; Okuda, Shigeo; Jinzaki, Masahiro; Matsumoto, Morio; Nakamura, Masaya; Nagura, Takeo

    2017-10-01

    In patients with rotator cuff tears, muscle degeneration is known to be a predictor of irreparable tears and poor outcomes after surgical repair. Fatty infiltration and volume of the whole muscles constituting the rotator cuff were quantitatively assessed using 3-dimensional 2-point Dixon magnetic resonance imaging. Ten shoulders with a partial-thickness tear, 10 shoulders with an isolated supraspinatus tear, and 10 shoulders with a massive tear involving supraspinatus and infraspinatus were compared with 10 control shoulders after matching age and sex. With segmentation of muscle boundaries, the fat fraction value and the volume of the whole rotator cuff muscles were computed. After reliabilities were determined, differences in fat fraction, muscle volume, and fat-free muscle volume were evaluated. Intra-rater and inter-rater reliabilities were regarded as excellent for fat fraction and muscle volume. Tendon rupture adversely increased the fat fraction value of the respective rotator cuff muscle (P tear group, muscle volume was significantly decreased in the infraspinatus (P = .035) and increased in the teres minor (P = .039). With subtraction of fat volume, a significant decrease of fat-free volume of the supraspinatus muscle became apparent with a massive tear (P = .003). Three-dimensional measurement could evaluate fatty infiltration and muscular volume with excellent reliabilities. The present study showed that chronic rupture of the tendon adversely increases the fat fraction of the respective muscle and indicates that the residual capacity of the rotator cuff muscles might be overestimated in patients with severe fatty infiltration. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  12. High-Quality 3-Dimensional 1H Magnetic Resonance Spectroscopic Imaging of the Prostate Without Endorectal Receive Coil Using A Semi-LASER Sequence.

    Science.gov (United States)

    Tayari, Nassim; Steinseifer, Isabell K; Selnæs, Kirsten M; Bathen, Tone F; Maas, Marnix C; Heerschap, Arend

    2017-10-01

    Inclusion of 3-dimensional H magnetic resonance spectroscopic imaging (3D-H-MRSI) in routine multiparametric MRI of the prostate requires good quality spectra and easy interpretable metabolite maps of the whole organ obtained without endorectal coil in clinically feasible acquisition times. We evaluated if a semi-LASER pulse sequence with gradient offset independent adiabaticity refocusing pulses (GOIA-sLASER) for volume selection can meet these requirements. Thirteen patients with suspicion of prostate cancer and 1 patient known to have prostate cancer were examined at 3 T with a multichannel body-receive coil. A 3D-H-MRSI sequence with GOIA-sLASER volume selection (echo time, 88 milliseconds) was added to a routine clinical multiparametric MRI examination of these patients. Repetition times from 630 to 1000 milliseconds and effective voxel sizes of approximately 0.9 and 0.6 cm were tested. Spectral components were quantified by LCModel software for quality assessment and to construct choline and citrate maps. Three-dimensional MRSI of the prostate was successfully performed in all patients in measurement times of 5 to 10 minutes. Analysis of the multiparametric MRI examination or of biopsies did not reveal malignant tissue in the prostate of the 13 patients. In 1404 evaluated voxels acquired from 13 patients, the citrate resonance could be fitted with a high reliability (Cramér-Rao lower bound coil enabled the generation of whole organ metabolite maps, revealing choline and citrate variations between areas with normal prostate tissue, seminal vesicles, proliferative benign prostatic hyperplasia, and tumor. The good signal-to-noise ratio and low chemical shift artifacts of GOIA-sLASER at an echo time of 88 milliseconds enable acquisition of high-quality 3D-H-MRSI of the prostate without endorectal coil in less than 10 minutes. This facilitates reconstruction of easy interpretable, quantitative metabolite maps for routine clinical applications of prostate MRSI.

  13. Characterization of left and right atrial function in healthy volunteers by cardiovascular magnetic resonance.

    Science.gov (United States)

    Maceira, Alicia M; Cosin-Sales, Juan; Prasad, Sanjay K; Pennell, Dudley J

    2016-10-10

    Left and right atrial function show a different pattern in advanced age in order to maintain adequate ventricular filling. It has been shown that left atrial (LA) function has a prognostic value in a number of heart conditions. Cardiovascular magnetic resonance (CMR) provides high quality images of the left and right atria using high temporal resolution steady state free precession (SSFP) cine sequences. We used SSFP cines to characterize atrial function in healthy, normotensive, volunteers. We measured maximum, preatrial contraction and minimum left and right atrial volumes in 120 healthy subjects after careful exclusion of cardiovascular abnormality (60 men, 60 women; 20 subjects per age decile from 20 to 80 years). Data were generated from 3-dimensional modeling, including tracking of the atrioventricular ring motion and time-volume curves analysis. With those measurements, all the usual parameters for left and right atrial function were calculated. Gender had significant influence on some parameters of left and right atrial conduit and booster pump function. Age significantly influenced the majority of parameters of both left and right atrial function, with typically lower reservoir and conduit functions and higher booster pump function, both in males and females belonging to older age groups. CMR normal ranges were modelled for clinical use with normalization, where appropriate, for body surface area and gender, displaying parameters with respect to age. CMR normal reference ranges for components of left and right atrial function are provided for males and females for a wide age range.

  14. Technical competence in cardiovascular magnetic resonance and computed tomography; Competencia tecnica em ressonancia e tomografia cardiovascular

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Juliano Lara; Shiozaki, Afonso Akio; Azevedo Filho, Clerio Francisco de; Rochitte, Carlos Eduardo; Pinto, Ibraim Marciarelli Francisco; Lopes, Marly Maria Uellendahl; Schvartzman, Paulo Roberto, E-mail: jlaraf@fcm.unicamp.br [Universidade de Campinas (UNICAMP/GERT) SP (Brazil). Grupo de Estudo em Ressonancia e Tomografia Cardiovascular

    2009-10-15

    Cardiovascular magnetic resonance and computed tomography have evolved as very practical and useful techniques applied in clinical cardiology. Due to their rapid acceptance in the cardiology community and widespread use, training of both cardiologists and radiologists on this subspecialty has not been homogeneous so far. This in part explains significant differences observed in the diverse background found in today’s practicing physicians who execute these exams. In order to guide training facilities as well as both payers, contractors and general cardiologists ordering the exam, this document provides a minimum standard that should be accomplished by all physicians who pursue education in the field and for those who already practice in it. The clinical competences listed in this statement are by no means thorough but should be required by all those involved in cardiovascular magnetic resonance and computed tomography as the customary requirements for current and future practitioners. (author)

  15. 3-Dimensional Magnetic Resonance Spectroscopic Imaging at 3 Tesla for Early Response Assessment of Glioblastoma Patients During External Beam Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Muruganandham, Manickam; Clerkin, Patrick P. [Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa (United States); Smith, Brian J. [Department of Biostatistics, University of Iowa Hospitals and Clinics, Iowa City, Iowa (United States); Anderson, Carryn M.; Morris, Ann [Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa (United States); Capizzano, Aristides A.; Magnotta, Vincent [Department of Radiology, University of Iowa Hospitals and Clinics, Iowa City, Iowa (United States); McGuire, Sarah M.; Smith, Mark C.; Bayouth, John E. [Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa (United States); Buatti, John M., E-mail: john-buatti@uiowa.edu [Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa (United States)

    2014-09-01

    Purpose: To evaluate the utility of 3-dimensional magnetic resonance (3D-MR) proton spectroscopic imaging for treatment planning and its implications for early response assessment in glioblastoma multiforme. Methods and Materials: Eighteen patients with newly diagnosed, histologically confirmed glioblastoma had 3D-MR proton spectroscopic imaging (MRSI) along with T2 and T1 gadolinium-enhanced MR images at simulation and at boost treatment planning after 17 to 20 fractions of radiation therapy. All patients received standard radiation therapy (RT) with concurrent temozolomide followed by adjuvant temozolomide. Imaging for response assessment consisted of MR scans every 2 months. Progression-free survival was defined by the criteria of MacDonald et al. MRSI images obtained at initial simulation were analyzed for choline/N-acetylaspartate ratios (Cho/NAA) on a voxel-by-voxel basis with abnormal activity defined as Cho/NAA ≥2. These images were compared on anatomically matched MRSI data collected after 3 weeks of RT. Changes in Cho/NAA between pretherapy and third-week RT scans were tested using Wilcoxon matched-pairs signed rank tests and correlated with progression-free survival, radiation dose and location of recurrence using Cox proportional hazards regression. Results: After a median follow-up time of 8.6 months, 50% of patients had experienced progression based on imaging. Patients with a decreased or stable mean or median Cho/NAA values had less risk of progression (P<.01). Patients with an increase in mean or median Cho/NAA values at the third-week RT scan had a significantly greater chance of early progression (P<.01). An increased Cho/NAA at the third-week MRSI scan carried a hazard ratio of 2.72 (95% confidence interval, 1.10-6.71; P=.03). Most patients received the prescription dose of RT to the Cho/NAA ≥2 volume, where recurrence most often occurred. Conclusion: Change in mean and median Cho/NAA detected at 3 weeks was a significant predictor of

  16. 3 - Dimensional Body Measurement Technology

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xu-dong; LI Yan-mei

    2002-01-01

    3 - dimensional body measurement technology, the basis of developing high technology in industry, accelerates digital development of aplparel industry. This paper briefly introduces the history of 3 - dimensional body measurement technology, and recounts the principle and primary structure of some types of 3 - dimensional automatic body measurement system. With this understanding, it discusses prospect of 3- dimensional CAD and virtual technology used in apparel industry.

  17. Multidirectional flow analysis by cardiovascular magnetic resonance in aneurysm development following repair of aortic coarctation

    Directory of Open Access Journals (Sweden)

    Stalder Aurelien F

    2008-06-01

    Full Text Available Abstract Aneurysm formation is a life-threatening complication after operative therapy in coarctation. The identification of patients at risk for the development of such secondary pathologies is of high interest and requires a detailed understanding of the link between vascular malformation and altered hemodynamics. The routine morphometric follow-up by magnetic resonance angiography is a well-established technique. However, the intrinsic sensitivity of magnetic resonance (MR towards motion offers the possibility to additionally investigate hemodynamic consequences of morphological changes of the aorta. We demonstrate two cases of aneurysm formation 13 and 35 years after coarctation surgery based on a Waldhausen repair with a subclavian patch and a Vosschulte repair with a Dacron patch, respectively. Comprehensive flow visualization by cardiovascular MR (CMR was performed using a flow-sensitive, 3-dimensional, and 3-directional time-resolved gradient echo sequence at 3T. Subsequent analysis included the calculation of a phase contrast MR angiography and color-coded streamline and particle trace 3D visualization. Additional quantitative evaluation provided regional physiological information on blood flow and derived vessel wall parameters such as wall shear stress and oscillatory shear index. The results highlight the individual 3D blood-flow patterns associated with the different vascular pathologies following repair of aortic coarctation. In addition to known factors predisposing for aneurysm formation after surgical repair of coarctation these findings indicate the importance of flow sensitive CMR to follow up hemodynamic changes with respect to the development of vascular disease.

  18. Cardiothoracic Applications of 3-dimensional Printing.

    Science.gov (United States)

    Giannopoulos, Andreas A; Steigner, Michael L; George, Elizabeth; Barile, Maria; Hunsaker, Andetta R; Rybicki, Frank J; Mitsouras, Dimitris

    2016-09-01

    Medical 3-dimensional (3D) printing is emerging as a clinically relevant imaging tool in directing preoperative and intraoperative planning in many surgical specialties and will therefore likely lead to interdisciplinary collaboration between engineers, radiologists, and surgeons. Data from standard imaging modalities such as computed tomography, magnetic resonance imaging, echocardiography, and rotational angiography can be used to fabricate life-sized models of human anatomy and pathology, as well as patient-specific implants and surgical guides. Cardiovascular 3D-printed models can improve diagnosis and allow for advanced preoperative planning. The majority of applications reported involve congenital heart diseases and valvular and great vessels pathologies. Printed models are suitable for planning both surgical and minimally invasive procedures. Added value has been reported toward improving outcomes, minimizing perioperative risk, and developing new procedures such as transcatheter mitral valve replacements. Similarly, thoracic surgeons are using 3D printing to assess invasion of vital structures by tumors and to assist in diagnosis and treatment of upper and lower airway diseases. Anatomic models enable surgeons to assimilate information more quickly than image review, choose the optimal surgical approach, and achieve surgery in a shorter time. Patient-specific 3D-printed implants are beginning to appear and may have significant impact on cosmetic and life-saving procedures in the future. In summary, cardiothoracic 3D printing is rapidly evolving and may be a potential game-changer for surgeons. The imager who is equipped with the tools to apply this new imaging science to cardiothoracic care is thus ideally positioned to innovate in this new emerging imaging modality.

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

    Directory of Open Access Journals (Sweden)

    Dargie Henry J

    2011-10-01

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

  20. Cutting edge clinical applications in cardiovascular magnetic resonance

    Science.gov (United States)

    De Cecco, Carlo N; Muscogiuri, Giuseppe; Varga-Szemes, Akos; Schoepf, U Joseph

    2017-01-01

    Today, the use of cardiovascular magnetic resonance (CMR) is widespread in clinical practice. The increased need to evaluate of subtle myocardial changes, coronary artery anatomy, and hemodynamic assessment has prompted the development of novel CMR techniques including T1 and T2 mapping, non-contrast angiography and four dimensional (4D) flow. T1 mapping is suitable for diagnosing pathologies affecting extracellular volume such as myocarditis, diffuse myocardial fibrosis and amyloidosis, and is a promising diagnostic tool for patients with iron overload and Fabry disease. T2 mapping is useful in depicting acute myocardial edema and estimating the amount of salvageable myocardium following an ischemic event. Novel angiography techniques, such as the self-navigated whole-heart or the quiescent-interval single-shot sequence, enable the visualization of the great vessels and coronary artery anatomy without the use of contrast material. The 4D flow technique overcomes the limitations of standard phase-contrast imaging and allows for the assessment of cardiovascular hemodynamics in the great arteries and flow patterns in the cardiac chambers. In conclusion, the future of CMR is heading toward a more reliable quantitative assessment of the myocardium, an improved non-contrast visualization of the coronary artery anatomy, and a more accurate evaluation of the cardiac hemodynamics. PMID:28144400

  1. Cardiac resynchronization therapy guided by cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Leyva Francisco

    2010-11-01

    Full Text Available Abstract Cardiac resynchronization therapy (CRT is an established treatment for patients with symptomatic heart failure, severely impaired left ventricular (LV systolic dysfunction and a wide (> 120 ms complex. As with any other treatment, the response to CRT is variable. The degree of pre-implant mechanical dyssynchrony, scar burden and scar localization to the vicinity of the LV pacing stimulus are known to influence response and outcome. In addition to its recognized role in the assessment of LV structure and function as well as myocardial scar, cardiovascular magnetic resonance (CMR can be used to quantify global and regional LV dyssynchrony. This review focuses on the role of CMR in the assessment of patients undergoing CRT, with emphasis on risk stratification and LV lead deployment.

  2. Update of the European Association of Cardiovascular Imaging (EACVI) Core Syllabus for the European Cardiovascular Magnetic Resonance Certification Exam.

    Science.gov (United States)

    Petersen, Steffen E; Almeida, Ana G; Alpendurada, Francisco; Boubertakh, Redha; Bucciarelli-Ducci, Chiara; Cosyns, Bernard; Greil, Gerald F; Karamitsos, Theodoros D; Lancellotti, Patrizio; Stefanidis, Alexandros S; Tann, Oliver; Westwood, Mark; Plein, Sven

    2014-07-01

    An updated version of the European Association of Cardiovascular Imaging (EACVI) Core Syllabus for the European Cardiovascular Magnetic Resonance (CMR) Certification Exam is now available online. The syllabus lists key elements of knowledge in CMR. It represents a framework for the development of training curricula and provides expected knowledge-based learning outcomes to the CMR trainees, in particular those intending to demonstrate CMR knowledge in the European CMR exam, a core requirement in the CMR certification process.

  3. Quantitative characterization of myocardial infarction by cardiovascular magnetic resonance predicts future cardiovascular events in patients with ischemic cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Pauly John M

    2008-04-01

    Full Text Available Abstract Background Cardiovascular magnetic resonance (CMR can provide quantitative data of the myocardial tissue utilizing high spatial and temporal resolution along with exquisite tissue contrast. Previous studies have correlated myocardial scar tissue with the occurrence of ventricular arrhythmia. This study was conducted to evaluate whether characterization of myocardial infarction by CMR can predict cardiovascular events in patients with ischemic cardiomyopathy (ICM. Results We consecutively studied 86 patients with ICM (LVEF Conclusion Quantification of the scar volume and scar percentage by CMR is superior to LVEDV, LVESV, and LVEF in prognosticating the future likelihood of the development of cardiovascular events in patients with ICM.

  4. A calculation of Eliashberg equations for superconducting phase under the ultra-high magnetic field of strong coupling cases in 2 and 3 dimensional systems

    Energy Technology Data Exchange (ETDEWEB)

    Goto, H. [Dept. of Mathematics and Physical Science, Graduate School of Science and Technology, Chiba Univ. (Japan); Natsume, Y. [Chiba Univ. (Japan). Dept. of Physics

    1995-04-01

    The estimation of Tc for the superconducting phase under the ultra-high magnetic feild is discussed on the basis of numerical calculation by the use of the expression of Eliashberg equations for strong coupling theory. The essenthial effect of the retardation of the interaction by phonons on making the gap is pointed out in comparison between 2 and 3 dimensinal systems. (orig.)

  5. Non-cardiovascular findings in clinical cardiovascular magnetic resonance imaging in children

    Energy Technology Data Exchange (ETDEWEB)

    Ghadimi Mahani, Maryam [University of Michigan Health System, C.S. Mott Children' s Hospital, Department of Radiology, Section of Pediatric Radiology, Ann Arbor, MI (United States); Morani, Ajaykumar C. [The University of Texas MD Anderson Cancer Center, Department of Diagnostic Radiology, Houston, TX (United States); Lu, Jimmy C.; Dorfman, Adam L. [University of Michigan Health System, C.S. Mott Children' s Hospital, Department of Pediatrics and Communicable Diseases, Division of Pediatric Cardiology, Ann Arbor, MI (United States); Fazeli Dehkordy, Soudabeh [University of Michigan Health System, C.S. Mott Children' s Hospital, Department of Radiology, Section of Pediatric Radiology, Ann Arbor, MI (United States); Providence Hospital and Medical Centers, Department of Graduate Medical Education, Southfield, MI (United States); Jeph, Sunil [The University of Texas MD Anderson Cancer Center, Department of Diagnostic Radiology, Houston, TX (United States); Geisinger Medical Center, Department of Radiology, Danville, PA (United States); Agarwal, Prachi P. [University of Michigan Health System, Department of Radiology, Division of Cardiothoracic Radiology, Ann Arbor, MI (United States)

    2016-04-15

    With increasing use of pediatric cardiovascular MRI, it is important for all imagers to become familiar with the spectrum of non-cardiovascular imaging findings that can be encountered. This study aims to ascertain the prevalence and nature of these findings in pediatric cardiovascular MRIs performed at our institution. We retrospectively evaluated reports of all cardiovascular MRI studies performed at our institute from January 2008 to October 2012 in patients younger than18 years. Most studies (98%) were jointly interpreted by a pediatric cardiologist and a radiologist. We reviewed the electronic medical records of all cases with non-cardiovascular findings, defined as any imaging finding outside the cardiovascular system. Non-cardiovascular findings were classified into significant and non-significant, based on whether they were known at the time of imaging or they required additional workup or a change in management. In 849 consecutive studies (mean age 9.7 ± 6.3 years), 145 non-cardiovascular findings were found in 140 studies (16.5% of total studies). Overall, 51.0% (74/145) of non-cardiovascular findings were in the abdomen, 30.3% (44/145) were in the chest, and 18.6% (27/145) were in the spine. A total of 19 significant non-cardiovascular findings were observed in 19 studies in individual patients (2.2% of total studies, 47% male, mean age 5.9 ± 6.7 years). Significant non-cardiovascular findings included hepatic adenoma, arterially enhancing focal liver lesions, asplenia, solitary kidney, pelvicaliectasis, renal cystic diseases, gastric distention, adrenal hemorrhage, lung hypoplasia, air space disease, bronchial narrowing, pneumomediastinum and retained surgical sponge. Non-cardiovascular findings were seen in 16.5% of cardiovascular MRI studies in children, of which 2.2% were clinically significant findings. Prevalence and nature of these non-cardiovascular findings are different from those reported in adults. Attention to these findings is important

  6. Review of Journal of Cardiovascular Magnetic Resonance 2013.

    Science.gov (United States)

    Pennell, Dudley John; Baksi, Arun John; Kilner, Philip John; Mohiaddin, Raad Hashem; Prasad, Sanjay Kumar; Alpendurada, Francisco; Babu-Narayan, Sonya Vidya; Neubauer, Stefan; Firmin, David Nigel

    2014-12-05

    There were 109 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2013, which is a 21% increase on the 90 articles published in 2012. The quality of the submissions continues to increase. The editors are delighted to report that the 2012 JCMR Impact Factor (which is published in June 2013) has risen to 5.11, up from 4.44 for 2011 (as published in June 2012), a 15% increase and taking us through the 5 threshold for the first time. The 2012 impact factor means that the JCMR papers that were published in 2010 and 2011 were cited on average 5.11 times in 2012. The impact factor undergoes natural variation according to citation rates of papers in the 2 years following publication, and is significantly influenced by highly cited papers such as official reports. However, the progress of the journal's impact over the last 5 years has been impressive. Our acceptance rate is journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality manuscripts to JCMR for publication.

  7. Value of black blood T2* cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Carpenter John Paul

    2011-03-01

    Full Text Available Abstract Purpose To assess whether black blood T2* cardiovascular magnetic resonance is superior to conventional white blood imaging of cardiac iron in patients with thalassaemia major (TM. Materials and methods We performed both conventional white blood and black blood T2* CMR sequences in 100 TM patients to determine intra and inter-observer variability and presence of artefacts. In 23 patients, 2 separate studies of both techniques were performed to assess interstudy reproducibility. Results Cardiac T2* values ranged from 4.5 to 43.8 ms. The mean T2* values were not different between black blood and white blood acquisitions (20.5 vs 21.6 ms, p = 0.26. Compared with the conventional white blood diastolic acquisition, the coefficient of variance of the black blood CMR technique was superior for intra-observer reproducibility (1.47% vs 4.23%, p Conclusions Black blood T2* CMR has superior reproducibility and reduced imaging artefacts for the assessment of cardiac iron, in comparison with the conventional white blood technique, which make it the preferred technique for clinical practice.

  8. Inflammation in takotsubo cardiomyopathy: insights from cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Eitel, Ingo; Sareban, Mahdi; Schuler, Gerhard; Thiele, Holger [University of Leipzig - Heart Centre, Department of Internal Medicine/Cardiology, Leipzig (Germany); Luecke, Christian; Grothoff, Matthias; Gutberlet, Matthias [University of Leipzig - Heart Centre, Department of Diagnostic and Interventional Radiology, Leipzig (Germany)

    2010-02-15

    Takotsubo cardiomyopathy (TTC) is an increasingly recognised acute cardiac syndrome, whose underlying pathophysiological mechanisms remain unknown. Inflammation might play a role as this has been shown in endomyocardial biopsies. The aim of this study was to assess inflammatory parameters in patients with TTC using a comprehensive cardiovascular magnetic resonance imaging (CMR) approach. Thirty-seven patients with the suspected diagnosis of TTC underwent CMR. T2-weighted imaging to calculate the oedema ratio, T1-weighted imaging before and after contrast agent administration to calculate the global relative enhancement (gRE), and late gadolinium enhancement (LGE) imaging were performed. In 11 patients CMR revealed the diagnosis of myocardial infarction (n = 7; 19%) or myocarditis (n = 4; 11%) with typical patterns of LGE. In all other patients (n = 26; 70%), no LGE was detected consistent with the diagnosis of TTC. Of these, in 16 patients (62%) both inflammatory markers (oedema ratio and gRE) were elevated with concomitant pericardial effusion, indicating acute inflammation. Follow-up CMR after 3 months showed complete normalisation of left ventricular function and inflammatory parameters in the absence of LGE and pericardial effusion. This CMR study provides further insights into the pathophysiological mechanisms in TTC, supporting the contribution of an inflammatory process in the acute setting. (orig.)

  9. Fractal frontiers in cardiovascular magnetic resonance: towards clinical implementation.

    Science.gov (United States)

    Captur, Gabriella; Karperien, Audrey L; Li, Chunming; Zemrak, Filip; Tobon-Gomez, Catalina; Gao, Xuexin; Bluemke, David A; Elliott, Perry M; Petersen, Steffen E; Moon, James C

    2015-09-07

    Many of the structures and parameters that are detected, measured and reported in cardiovascular magnetic resonance (CMR) have at least some properties that are fractal, meaning complex and self-similar at different scales. To date however, there has been little use of fractal geometry in CMR; by comparison, many more applications of fractal analysis have been published in MR imaging of the brain.This review explains the fundamental principles of fractal geometry, places the fractal dimension into a meaningful context within the realms of Euclidean and topological space, and defines its role in digital image processing. It summarises the basic mathematics, highlights strengths and potential limitations of its application to biomedical imaging, shows key current examples and suggests a simple route for its successful clinical implementation by the CMR community.By simplifying some of the more abstract concepts of deterministic fractals, this review invites CMR scientists (clinicians, technologists, physicists) to experiment with fractal analysis as a means of developing the next generation of intelligent quantitative cardiac imaging tools.

  10. MRXCAT: Realistic numerical phantoms for cardiovascular magnetic resonance.

    Science.gov (United States)

    Wissmann, Lukas; Santelli, Claudio; Segars, William P; Kozerke, Sebastian

    2014-08-20

    Computer simulations are important for validating novel image acquisition and reconstruction strategies. In cardiovascular magnetic resonance (CMR), numerical simulations need to combine anatomical information and the effects of cardiac and/or respiratory motion. To this end, a framework for realistic CMR simulations is proposed and its use for image reconstruction from undersampled data is demonstrated. The extended Cardiac-Torso (XCAT) anatomical phantom framework with various motion options was used as a basis for the numerical phantoms. Different tissue, dynamic contrast and signal models, multiple receiver coils and noise are simulated. Arbitrary trajectories and undersampled acquisition can be selected. The utility of the framework is demonstrated for accelerated cine and first-pass myocardial perfusion imaging using k-t PCA and k-t SPARSE. MRXCAT phantoms allow for realistic simulation of CMR including optional cardiac and respiratory motion. Example reconstructions from simulated undersampled k-t parallel imaging demonstrate the feasibility of simulated acquisition and reconstruction using the presented framework. Myocardial blood flow assessment from simulated myocardial perfusion images highlights the suitability of MRXCAT for quantitative post-processing simulation. The proposed MRXCAT phantom framework enables versatile and realistic simulations of CMR including breathhold and free-breathing acquisitions.

  11. Feasibility of perfusion cardiovascular magnetic resonance in paediatric patients

    Directory of Open Access Journals (Sweden)

    Kellenberger Christian

    2009-01-01

    Full Text Available Abstract Aims As coronary artery disease may also occur during childhood in some specific conditions, we sought to assess the feasibility and accuracy of perfusion cardiovascular magnetic resonance (CMR in paediatric patients. Methods and results First-pass perfusion CMR studies were performed under pharmacological stress with adenosine and by using a hybrid echo-planar pulse sequence with slice-selective saturation recovery preparation. Fifty-six perfusion CMR examinations were performed in 47 patients. The median age was 12 years (1 month-18 years, and weight 42.8 kg (2.6-82 kg. General anaesthesia was required in 18 patients. Mean examination time was 67 ± 19 min. Diagnostic image quality was obtained in 54/56 examinations. In 23 cases the acquisition parameters were adapted to patient's size. Perfusion CMR was abnormal in 16 examinations. The perfusion defects affected the territory of the left anterior descending coronary artery in 11, of the right coronary artery in 3, and of the circumflex coronary artery in 2 cases. Compared to coronary angiography, perfusion CMR showed a sensitivity of 87% (CI 52-97% and a specificity of 95% (CI 79-99%. Conclusion In children, perfusion CMR is feasible and accurate. In very young children (less than 1 year old, diagnostic image quality may be limited.

  12. Cardiovascular magnetic resonance in rheumatology: Current status and recommendations for use

    NARCIS (Netherlands)

    Mavrogeni, S.I.; Kitas, G.D.; Dimitroulas, T.; Sfikakis, P.P.; Seo, P.; Gabriel, S.; Patel, A.R.; Gargani, L.; Bombardieri, S.; Matucci-Cerinic, M.; Lombardi, M.; Pepe, A.; Aletras, A.H.; Kolovou, G.; Miszalski, T.; Riel, P. van; Semb, A.; Gonzalez-Gay, M.A.; Dessein, P.; Karpouzas, G.; Puntmann, V.; Nagel, E.; Bratis, K.; Karabela, G.; Stavropoulos, E.; Katsifis, G.; Koutsogeorgopoulou, L.; Rossum, A. van; Rademakers, F.; Pohost, G.; Lima, J.A.

    2016-01-01

    Targeted therapies in connective tissue diseases (CTDs) have led to improvements of disease-associated outcomes, but life expectancy remains lower compared to general population due to emerging co-morbidities, particularly due to excess cardiovascular risk. Cardiovascular magnetic resonance (CMR) is

  13. Evaluating the systemic right ventricle by cardiovascular magnetic resonance: short axis or axial slices?

    NARCIS (Netherlands)

    Bom, T. van der; Romeih, S.; Groenink, M.; Pieper, P.G.; Dijk, A.P.J. van; Helbing, W.A.; Zwinderman, A.H.; Mulder, B.J.; Bouma, B.J.

    2015-01-01

    OBJECTIVE: To evaluate differences in functional parameters and reproducibility between short axis and axial slice orientation in the quantitative evaluation of the systemic right ventricle by cardiovascular magnetic resonance. DESIGN: Cross-sectional evaluation comparing two methods (Bland-Altman).

  14. The 3-dimensional radio mapping experiment /SBH/ on ISEE-C. [interplanetary magnetic field structure for solar wind flow studies using type 3 bursts

    Science.gov (United States)

    Knoll, R.; Epstein, G.; Hoang, S.; Huntzinger, G.; Steinberg, J. L.; Fainberg, J.; Grena, F.; Stone, R. G.; Mosier, S. R.

    1978-01-01

    The SBH experiment on ISEE-C will provide maps of the large scale structure of the interplanetary magnetic field from ten solar radii altitude to the earth orbit, in and out of the ecliptic. The SBH instrument will track type III solar radio bursts at 24 frequencies in the range 30 kHz-2 MHz thus providing the positions of 24 points along the line of force which guides the electrons producing the radio radiation. The antennas are two dipoles: one (90 m long) in the spin plane, the other (15 m long) along the spin axis. The receiver was designed for high sensitivity (0.3 microV in 3 kHz BW), high intermodulation rejection (80 dB/1 microV input for order 2 products), large dynamic range (70 dB), high selectivity (-30-dB response 6.5 kHz away from the center frequency of 10.7 MHz for the 3 kHz BW channels), and high reliability (expected orbital life: 3 years).

  15. Highlights of the 16th annual scientific sessions of the Society for Cardiovascular Magnetic Resonance.

    Science.gov (United States)

    Carpenter, John-Paul; Patel, Amit R; Fernandes, Juliano Lara

    2013-07-19

    The 16th Annual Scientific Sessions of the Society for Cardiovascular Magnetic Resonance (SCMR) took place in San Francisco, USA at the end of January 2013. With a faculty of experts from across the world, this congress provided a wealth of insight into cutting-edge research and technological development. This review article intends to provide a highlight of what represented the most significant advances in the field of cardiovascular magnetic resonance (CMR) during this year's meeting.

  16. Review of Journal of Cardiovascular Magnetic Resonance 2012.

    Science.gov (United States)

    Pennell, Dudley J; Baksi, A John; Carpenter, John Paul; Firmin, David N; Kilner, Philip J; Mohiaddin, Raad H; Prasad, Sanjay K

    2013-09-04

    There were 90 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2012, which is an 8% increase in the number of articles since 2011. The quality of the submissions continues to increase. The editors are delighted to report that the 2011 JCMR Impact Factor (which is published in June 2012) has risen to 4.44, up from 3.72 for 2010 (as published in June 2011), a 20% increase. The 2011 impact factor means that the JCMR papers that were published in 2009 and 2010 were cited on average 4.44 times in 2011. The impact factor undergoes natural variation according to citation rates of papers in the 2 years following publication, and is significantly influenced by highly cited papers such as official reports. However, the progress of the journal's impact over the last 5 years has been impressive. Our acceptance rate is approximately 25%, and has been falling as the number of articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. For this reason, the Editors have felt that it is useful once per calendar year to summarize the papers for the readership into broad areas of interest or theme, so that areas of interest can be reviewed in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality manuscripts to JCMR for publication.

  17. Cardiovascular Magnetic Resonance and prognosis in cardiac amyloidosis

    Directory of Open Access Journals (Sweden)

    Roughton Michael

    2008-11-01

    Full Text Available Abstract Background Cardiac involvement is common in amyloidosis and associated with a variably adverse outcome. We have previously shown that cardiovascular magnetic resonance (CMR can assess deposition of amyloid protein in the myocardial interstitium. In this study we assessed the prognostic value of late gadolinium enhancement (LGE and gadolinium kinetics in cardiac amyloidosis in a prospective longitudinal study. Materials and methods The pre-defined study end point was all-cause mortality. We prospectively followed a cohort of 29 patients with proven cardiac amyloidosis. All patients underwent biopsy, 2D-echocardiography and Doppler studies, 123I-SAP scintigraphy, serum NT pro BNP assay, and CMR with a T1 mapping method and late gadolinium enhancement (LGE. Results Patients with were followed for a median of 623 days (IQ range 221, 1436, during which 17 (58% patients died. The presence of myocardial LGE by itself was not a significant predictor of mortality. However, death was predicted by gadolinium kinetics, with the 2 minute post-gadolinium intramyocardial T1 difference between subepicardium and subendocardium predicting mortality with 85% accuracy at a threshold value of 23 ms (the lower the difference the worse the prognosis. Intramyocardial T1 gradient was a better predictor of survival than FLC response to chemotherapy (Kaplan Meier analysis P = 0.049 or diastolic function (Kaplan-Meier analysis P = 0.205. Conclusion In cardiac amyloidosis, CMR provides unique information relating to risk of mortality based on gadolinium kinetics which reflects the severity of the cardiac amyloid burden.

  18. Review of Journal of Cardiovascular Magnetic Resonance 2011.

    Science.gov (United States)

    Pennell, Dudley J; Carpenter, John Paul; Firmin, David N; Kilner, Philip J; Mohiaddin, Raad H; Prasad, Sanjay K

    2012-11-18

    There were 83 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2011, which is an 11% increase in the number of articles since 2010. The quality of the submissions continues to increase. The editors had been delighted with the 2010 JCMR Impact Factor of 4.33, although this fell modestly to 3.72 for 2011. The impact factor undergoes natural variation according to citation rates of papers in the 2 years following publication, and is significantly influenced by highly cited papers such as official reports. However, we remain very pleased with the progress of the journal's impact over the last 5 years. Our acceptance rate is approximately 25%, and has been falling as the number of articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. For this reason, the Editors feel it is useful to summarize the papers for the readership into broad areas of interest or theme, which we feel would be useful, so that areas of interest from the previous year can be reviewed in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality manuscripts to JCMR for publication.

  19. Review of Journal of Cardiovascular Magnetic Resonance 2015.

    Science.gov (United States)

    Pennell, D J; Baksi, A J; Prasad, S K; Mohiaddin, R H; Alpendurada, F; Babu-Narayan, S V; Schneider, J E; Firmin, D N

    2016-11-15

    There were 116 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2015, which is a 14 % increase on the 102 articles published in 2014. The quality of the submissions continues to increase. The 2015 JCMR Impact Factor (which is published in June 2016) rose to 5.75 from 4.72 for 2014 (as published in June 2015), which is the highest impact factor ever recorded for JCMR. The 2015 impact factor means that the JCMR papers that were published in 2013 and 2014 were cited on average 5.75 times in 2015. The impact factor undergoes natural variation according to citation rates of papers in the 2 years following publication, and is significantly influenced by highly cited papers such as official reports. However, the progress of the journal's impact over the last 5 years has been impressive. Our acceptance rate is articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. For this reason, the Editors have felt that it is useful once per calendar year to summarize the papers for the readership into broad areas of interest or theme, so that areas of interest can be reviewed in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality papers to JCMR for publication.

  20. Heart valve disease: investigation by cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Myerson Saul G

    2012-01-01

    Full Text Available Abstract Cardiovascular magnetic resonance (CMR has become a valuable investigative tool in many areas of cardiac medicine. Its value in heart valve disease is less well appreciated however, particularly as echocardiography is a powerful and widely available technique in valve disease. This review highlights the added value that CMR can bring in valve disease, complementing echocardiography in many areas, but it has also become the first-line investigation in some, such as pulmonary valve disease and assessing the right ventricle. CMR has many advantages, including the ability to image in any plane, which allows full visualisation of valves and their inflow/outflow tracts, direct measurement of valve area (particularly for stenotic valves, and characterisation of the associated great vessel anatomy (e.g. the aortic root and arch in aortic valve disease. A particular strength is the ability to quantify flow, which allows accurate measurement of regurgitation, cardiac shunt volumes/ratios and differential flow volumes (e.g. left and right pulmonary arteries. Quantification of ventricular volumes and mass is vital for determining the impact of valve disease on the heart, and CMR is the 'Gold standard' for this. Limitations of the technique include partial volume effects due to image slice thickness, and a low ability to identify small, highly mobile objects (such as vegetations due to the need to acquire images over several cardiac cycles. The review examines the advantages and disadvantages of each imaging aspect in detail, and considers how CMR can be used optimally for each valve lesion.

  1. Cardiovascular magnetic resonance physics for clinicians: Part II.

    Science.gov (United States)

    Biglands, John D; Radjenovic, Aleksandra; Ridgway, John P

    2012-09-20

    This is the second of two reviews that is intended to cover the essential aspects of cardiovascular magnetic resonance (CMR) physics in a way that is understandable and relevant to clinicians using CMR in their daily practice. Starting with the basic pulse sequences and contrast mechanisms described in part I, it briefly discusses further approaches to accelerate image acquisition. It then continues by showing in detail how the contrast behaviour of black blood fast spin echo and bright blood cine gradient echo techniques can be modified by adding rf preparation pulses to derive a number of more specialised pulse sequences. The simplest examples described include T2-weighted oedema imaging, fat suppression and myocardial tagging cine pulse sequences. Two further important derivatives of the gradient echo pulse sequence, obtained by adding preparation pulses, are used in combination with the administration of a gadolinium-based contrast agent for myocardial perfusion imaging and the assessment of myocardial tissue viability using a late gadolinium enhancement (LGE) technique. These two imaging techniques are discussed in more detail, outlining the basic principles of each pulse sequence, the practical steps required to achieve the best results in a clinical setting and, in the case of perfusion, explaining some of the factors that influence current approaches to perfusion image analysis. The key principles of contrast-enhanced magnetic resonance angiography (CE-MRA) are also explained in detail, especially focusing on timing of the acquisition following contrast agent bolus administration, and current approaches to achieving time resolved MRA. Alternative MRA techniques that do not require the use of an endogenous contrast agent are summarised, and the specialised pulse sequence used to image the coronary arteries, using respiratory navigator gating, is described in detail. The article concludes by explaining the principle behind phase contrast imaging techniques

  2. Cardiovascular magnetic resonance physics for clinicians: part II

    Directory of Open Access Journals (Sweden)

    Biglands John D

    2012-09-01

    Full Text Available Abstract This is the second of two reviews that is intended to cover the essential aspects of cardiovascular magnetic resonance (CMR physics in a way that is understandable and relevant to clinicians using CMR in their daily practice. Starting with the basic pulse sequences and contrast mechanisms described in part I, it briefly discusses further approaches to accelerate image acquisition. It then continues by showing in detail how the contrast behaviour of black blood fast spin echo and bright blood cine gradient echo techniques can be modified by adding rf preparation pulses to derive a number of more specialised pulse sequences. The simplest examples described include T2-weighted oedema imaging, fat suppression and myocardial tagging cine pulse sequences. Two further important derivatives of the gradient echo pulse sequence, obtained by adding preparation pulses, are used in combination with the administration of a gadolinium-based contrast agent for myocardial perfusion imaging and the assessment of myocardial tissue viability using a late gadolinium enhancement (LGE technique. These two imaging techniques are discussed in more detail, outlining the basic principles of each pulse sequence, the practical steps required to achieve the best results in a clinical setting and, in the case of perfusion, explaining some of the factors that influence current approaches to perfusion image analysis. The key principles of contrast-enhanced magnetic resonance angiography (CE-MRA are also explained in detail, especially focusing on timing of the acquisition following contrast agent bolus administration, and current approaches to achieving time resolved MRA. Alternative MRA techniques that do not require the use of an endogenous contrast agent are summarised, and the specialised pulse sequence used to image the coronary arteries, using respiratory navigator gating, is described in detail. The article concludes by explaining the principle behind phase

  3. 3-Dimensional Response of Composites

    Science.gov (United States)

    1989-01-01

    AFWAL-TR-88-4242 3-DIMENSIONAL RESPONSE OF COMPOSITES S.R. Soni S. Chandrashekara G.P. Tandon U. Santhosh Ten-Lu Hsiao CADTECH SYSTEMS RESEARCH INC...Composites 12. PERSONAL AUTHOR(S) S. R. Soni, S. Chandrashekara, G. P. Tandon, U. Santhosh , T. Isiao 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPRT...Chandrashekara, G.P. Tandon; Mr. U. Santhosh and Mr. Ten-Lu Hsiao. Accesion For NTIS CRAWI DTIC TAB 13 Unaonou,)ced 0 JustfCdtf)In ...._ By .... Di~t ibut;01 I

  4. Automated image analysis techniques for cardiovascular magnetic resonance imaging

    NARCIS (Netherlands)

    Geest, Robertus Jacobus van der

    2011-01-01

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

  5. Cardiovascular magnetic resonance imaging findings in children with myocarditis

    Institute of Scientific and Technical Information of China (English)

    Liu Guiying; Yang Xi; Su Ying; Xu Jimin; Wen Zhaoying

    2014-01-01

    Background Myocarditis is a common,potentially life-threatening disease that presents a wide rang of symptoms in children,as an important underlying etiology of other myocardial diseases such as dilated and arrhythmogenic right ventricular cardiomyopathy.The incidence of nonfatal myocarditis is probably greater than that of the one actually diagnosed,which is the result of the challenges of establishing the diagnosis in standard clinical settings.Currently,no single clinical or imaging finding confirms the diagnosis of myocarditis with absolute certainty.Historically,clinical exam,electrocardiogram (ECG),serology and echocardiography had an unsatisfactory diagnostic accuracy in myocarditis.Endomyocardial biopsy remains as a widely accepted standard,but may not be suitable for every patient,especially for those with less severe disease.Our aim was to find the changes in cardiovascular magnetic resonance (CMR) imaging of children with myocarditis diagnosed by clinical criteria.Methods We studied 25 children (18 male,7 female; aged from 5-17 years) with diagnosed myocarditis by clinical criteria.CMR included function analyses,T2-weighted imaging,T1-weighted imaging before and after i.v.gadolinium injection (early gadolinium enhancement (EGE) and late gadolinium enhancement (LGE)).Results The T2 ratio was elevated in 21 children (84%,11 in anterolateral (44%),5 in inferolateral (20%),and 5 in septum (20%)),EGE was present in 9 children (36%,3 in anterolateral (12%),4 in inferolateral (20%),and 2 in septum (8%)),and LGE was present in 5 children (20%,2 in anterolateral (8%),1 in inferolateral (4%),1 in septum (4%),and 1 in midwall of left ventricular (LV) wall).In 9 children (36%),two (or more) out of three sequences (T2,EGE,LGE) were abnormal.Conclusions The CMR findings in children with clinically diagnosed myocarditis vary within the groups,including regional or global myocardial signal increase in T2-weighted images,EGE and LGE in T1

  6. Clinical Utility of Cardiovascular Magnetic Resonance in Hypertrophic Cardiomyopathy

    Science.gov (United States)

    2012-01-01

    Hypertrophic cardiomyopathy (HCM) is characterized by substantial genetic and phenotypic heterogeneity, leading to considerable diversity in clinical course including the most common cause of sudden death in young people and a determinant of heart failure symptoms in patients of any age. Traditionally, two-dimensional echocardiography has been the most reliable method for establishing a clinical diagnosis of HCM. However, cardiovascular magnetic resonance (CMR), with its high spatial resolution and tomographic imaging capability, has emerged as a technique particularly well suited to characterize the diverse phenotypic expression of this complex disease. For example, CMR is often superior to echocardiography for HCM diagnosis, by identifying areas of segmental hypertrophy (ie., anterolateral wall or apex) not reliably visualized by echocardiography (or underestimated in terms of extent). High-risk HCM patient subgroups identified with CMR include those with thin-walled scarred LV apical aneurysms (which prior to CMR imaging in HCM remained largely undetected), end-stage systolic dysfunction, and massive LV hypertrophy. CMR observations also suggest that the cardiomyopathic process in HCM is more diffuse than previously regarded, extending beyond the LV myocardium to include thickening of the right ventricular wall as well as substantial morphologic diversity with regard to papillary muscles and mitral valve. These findings have implications for management strategies in patients undergoing invasive septal reduction therapy. Among HCM family members, CMR has identified unique phenotypic markers of affected genetic status in the absence of LV hypertrophy including: myocardial crypts, elongated mitral valve leaflets and late gadolinium enhancement. The unique capability of contrast-enhanced CMR with late gadolinium enhancement to identify myocardial fibrosis has raised the expectation that this may represent a novel marker, which may enhance risk stratification. At

  7. Clinical Utility of Cardiovascular Magnetic Resonance in Hypertrophic Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Maron Martin S

    2012-02-01

    Full Text Available Abstract Hypertrophic cardiomyopathy (HCM is characterized by substantial genetic and phenotypic heterogeneity, leading to considerable diversity in clinical course including the most common cause of sudden death in young people and a determinant of heart failure symptoms in patients of any age. Traditionally, two-dimensional echocardiography has been the most reliable method for establishing a clinical diagnosis of HCM. However, cardiovascular magnetic resonance (CMR, with its high spatial resolution and tomographic imaging capability, has emerged as a technique particularly well suited to characterize the diverse phenotypic expression of this complex disease. For example, CMR is often superior to echocardiography for HCM diagnosis, by identifying areas of segmental hypertrophy (ie., anterolateral wall or apex not reliably visualized by echocardiography (or underestimated in terms of extent. High-risk HCM patient subgroups identified with CMR include those with thin-walled scarred LV apical aneurysms (which prior to CMR imaging in HCM remained largely undetected, end-stage systolic dysfunction, and massive LV hypertrophy. CMR observations also suggest that the cardiomyopathic process in HCM is more diffuse than previously regarded, extending beyond the LV myocardium to include thickening of the right ventricular wall as well as substantial morphologic diversity with regard to papillary muscles and mitral valve. These findings have implications for management strategies in patients undergoing invasive septal reduction therapy. Among HCM family members, CMR has identified unique phenotypic markers of affected genetic status in the absence of LV hypertrophy including: myocardial crypts, elongated mitral valve leaflets and late gadolinium enhancement. The unique capability of contrast-enhanced CMR with late gadolinium enhancement to identify myocardial fibrosis has raised the expectation that this may represent a novel marker, which may enhance

  8. [Is stress cardiovascular magnetic resonance really useful to detect ischemia and predict events in patients with different cardiovascular risk profile?

    Science.gov (United States)

    Esteban-Fernández, Alberto; Coma-Canella, Isabel; Bastarrika, Gorka; Barba-Cosials, Joaquín; Azcárate-Agüero, Pedro M

    The aim of this study was to evaluate the diagnostic and prognostic usefulness of stress cardiovascular magnetic resonance (stress CMR) in patients with different cardiovascular risk profile and to assess if the degree of hypoperfusion is important to guide clinical decisions. We included patients submitted to adenosine stress CMR to rule out myocardial ischemia. We evaluated its diagnostic accuracy with likelihood ratio (LR) and its prognostic value with survival curves and a Cox regression model. 295 patients were studied. The positive LR was 3.40 and the negative one 0.47. The maximal usefulness of the test was found in patients without previous ischemic cardiomyopathy (positive LR 4.85), patients with atypical chest pain (positive LR 8.56), patients with low or intermediate cardiovascular risk (positive LR 3.87) and those with moderate or severe hypoperfusion (positive LR 8.63). Sixty cardiovascular major events were registered. The best survival prognosis was found in patients with a negative result (p=0.001) or mild hypoperfusion (p=0.038). In the multivariate analysis, a moderate or severe hypoperfusion increased cardiovascular event probability (HR=2.2; IC 95% 1.26-3.92), with no differences between a mild positive and a negative result (HR=0.93; IC 95% 0.38-2.28). Stress CMR was specially useful in patients with low or intermediate cardiovascular risk, patients with atypical chest pain, patients without previous ischemic cardiomyopathy and those with moderate or severe hypoperfusion. Hypoperfusion degree was the main issue factor to guide clinical decisions. Copyright © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

  9. Dobutamine stress cardiovascular magnetic resonance at 3 Tesla

    Directory of Open Access Journals (Sweden)

    Klein C

    2008-10-01

    Full Text Available Abstract Purpose The assessment of inducible wall motion abnormalities during high-dose dobutamine-stress cardiovascular magnetic resonance (DCMR is well established for the identification of myocardial ischemia at 1.5 Tesla. Its feasibility at higher field strengths has not been reported. The present study was performed to prospectively determine the feasibility and diagnostic accuracy of DCMR at 3 Tesla for depicting hemodynamically significant coronary artery stenosis (≥ 50% diameter stenosis in patients with suspected or known coronary artery disease (CAD. Materials and methods Thirty consecutive patients (6 women (66 ± 9.3 years were scheduled for DCMR between January and May 2007 for detection of coronary artery disease. Patients were examined with a Philips Achieva 3 Tesla system (Philips Healthcare, Best, The Netherlands, using a spoiled gradient echo cine sequence. Technical parameters were: spatial resolution 2 × 2 × 8 mm3, 30 heart phases, spoiled gradient echo TR/TE: 4.5/2.6 msec, flip angle 15°. Images were acquired at rest and stress in accordance with a standardized high-dose dobutamine-atropine protocol during short breath-holds in three short and three long-axis views. Dobutamine was administered using a standard protocol (10 μg increments every 3 minutes up to 40 μg dobutamine/kg body weight/minute plus atropine if required to reach target heart rate. The study protocol included administration of 0.1 mmol/kg/body weight Gd-DTPA before the cine images at rest were acquired to improve the image quality. The examination was terminated if new or worsening wall-motion abnormalities or chest pain occurred or when > 85% of age-predicted maximum heart rate was reached. Myocardial ischemia was defined as new onset of wall-motion abnormality in at least one segment. In addition, late gadolinium enhancement (LGE was performed. Images were evaluated by two blinded readers. Diagnostic accuracy was determined with coronary

  10. Cardiovascular Magnetic Resonance in Cardiology Practice: A Concise Guide to Image Acquisition and Clinical Interpretation.

    Science.gov (United States)

    Valbuena-López, Silvia; Hinojar, Rocío; Puntmann, Valentina O

    2016-02-01

    Cardiovascular magnetic resonance plays an increasingly important role in routine cardiology clinical practice. It is a versatile imaging modality that allows highly accurate, broad and in-depth assessment of cardiac function and structure and provides information on pertinent clinical questions in diseases such as ischemic heart disease, nonischemic cardiomyopathies, and heart failure, as well as allowing unique indications, such as the assessment and quantification of myocardial iron overload or infiltration. Increasing evidence for the role of cardiovascular magnetic resonance, together with the spread of knowledge and skill outside expert centers, has afforded greater access for patients and wider clinical experience. This review provides a snapshot of cardiovascular magnetic resonance in modern clinical practice by linking image acquisition and postprocessing with effective delivery of the clinical meaning. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  11. Heating of cardiovascular stents in intense radiofrequency magnetic fields.

    Science.gov (United States)

    Foster, K R; Goldberg, R; Bonsignore, C

    1999-01-01

    We consider the heating of a metal stent in an alternating magnetic field from an induction heating furnace. An approximate theoretical analysis is conducted to estimate the magnetic field strength needed to produce substantial temperature increases. Experiments of stent heating in industrial furnaces are reported, which confirm the model. The results show that magnetic fields inside inductance furnaces are capable of significantly heating stents. However, the fields fall off very quickly with distance and in most locations outside the heating coil, field levels are far too small to produce significant heating. The ANSI/IEEE C95.1-1992 limits for human exposure to alternating magnetic fields provide adequate protection against potential excessive heating of the stents.

  12. Isometric stress in cardiovascular magnetic resonance - a simple and easily replicable method of assessing cardiovascular differences not apparent at rest

    Energy Technology Data Exchange (ETDEWEB)

    Mortensen, Kristian H.; Jones, Alexander; Steeden, Jennifer A.; Taylor, Andrew M.; Muthurangu, Vivek [UCL Centre for Cardiovascular MR, UCL Institute of Cardiovascular Science, Level 6 Old Nurses Home, Cardiorespiratory Unit, Great Ormond Street Hospital for Children, London (United Kingdom)

    2016-04-15

    Isometric exercise may unmask cardiovascular disease not evident at rest, and cardiovascular magnetic resonance (CMR) imaging is proven for comprehensive resting assessment. This study devised a simple isometric exercise CMR methodology and assessed the hemodynamic response evoked by isometric exercise. A biceps isometric exercise technique was devised for CMR, and 75 healthy volunteers were assessed at rest, after 3-minute biceps exercise, and 5-minute of recovery using: (1) blood pressure (BP) and (2) CMR measured aortic flow and left ventricular function. Total peripheral resistance (SVR) and arterial compliance (TAC), cardiac output (CO), left ventricular volumes and function (ejection fraction, stroke volume, power output), blood pressure (BP), heart rate (HR), and rate pressure product were assessed at all time points. Image quality was preserved during stress. During exercise there were increases in CO (+14.9 %), HR (+17.0 %), SVR (+9.8 %), systolic BP (+22.4 %), diastolic BP (+25.4 %) and mean BP (+23.2 %). In addition, there were decreases in TAC (-22.0 %) and left ventricular ejection fraction (-6.3 %). Age and body mass index modified the evoked response, even when resting measures were similar. Isometric exercise technique evokes a significant cardiovascular response in CMR, unmasking physiological differences that are not apparent at rest. (orig.)

  13. Cardiovascular Magnetic Resonance Imaging for Structural and Valvular Heart Disease Interventions.

    Science.gov (United States)

    Cavalcante, João L; Lalude, Omosalewa O; Schoenhagen, Paul; Lerakis, Stamatios

    2016-03-14

    The field of percutaneous interventions for the treatment of structural and valvular heart diseases has been expanding rapidly in the last 5 years. Noninvasive cardiac imaging has been a critical part of the planning, procedural guidance, and follow-up of these procedures. Although echocardiography and cardiovascular computed tomography are the most commonly used and studied imaging techniques in this field today, advances in cardiovascular magnetic resonance imaging continue to provide important contributions in the comprehensive assessment and management of these patients. In this comprehensive paper, we will review and demonstrate how cardiovascular magnetic resonance imaging can be used to assist in diagnosis, treatment planning, and follow-up of patients who are being considered for and/or who have undergone interventions for structural and valvular heart diseases.

  14. Evaluating the Systemic Right Ventricle by Cardiovascular Magnetic Resonance : Short Axis or Axial Slices?

    NARCIS (Netherlands)

    van der Bom, Teun; Romeih, Soha; Groenink, Maarten; Pieper, Petronella G.; van Dijk, Arie P. J.; Helbing, Willem A.; Zwinderman, Aeilko H.; Mulder, Barbara J. M.; Bouma, Berto J.

    2015-01-01

    ObjectiveTo evaluate differences in functional parameters and reproducibility between short axis and axial slice orientation in the quantitative evaluation of the systemic right ventricle by cardiovascular magnetic resonance. DesignCross-sectional evaluation comparing two methods (Bland-Altman).

  15. Cardiovascular magnetic resonance myocardial feature tracking detects quantitative wall motion during dobutamine stress.

    NARCIS (Netherlands)

    Schuster, A.; Kutty, S.; Padiyath, A.; Parish, V.; Gribben, P.; Danford, D.A.; Makowski, M.R.; Bigalke, B.; Beerbaum, P.B.J.; Nagel, E.

    2011-01-01

    BACKGROUND: Dobutamine stress cardiovascular magnetic resonance (DS-CMR) is an established tool to assess hibernating myocardium and ischemia. Analysis is typically based on visual assessment with considerable operator dependency. CMR myocardial feature tracking (CMR-FT) is a recently introduced tec

  16. Cardiovascular magnetics resonance diagnosis of cystic tumor of the atrioventricular node

    Directory of Open Access Journals (Sweden)

    Wang Xuedong

    2009-04-01

    Full Text Available Abstract Late gadolinium enhanced (LGE cardiovascular magnetic resonance (CMR has proven to be the gold standard for viability assessment. LGE CMR is also useful for identifying the nature of cardiac masses or lesions. We report a case of a rare primary cystic tumor of the atrioventricular node, in which CMR proved to be valuable.

  17. Magnetic Resonance Cardiorhythmography as a Method of Study of Human's Cardiovascular System Condition

    Science.gov (United States)

    Protasov, E. A.; Ryzhkova, A. V.

    In this article a highly sensitive method for graphic recording of cardiogram by detecting the signal of nuclear magnetic resonance (NMR) of human finger has been developed and signals directly related to movement of blood ejected by the heart into the vessels have been studied. Changes in the behavior of signals depending on the condition of the cardiovascular system of person have been discovered.

  18. Cardiovascular magnetic resonance in the evaluation of heart failure: a luxury or a need?

    Science.gov (United States)

    D'Andrea, Antonello; Fontana, Marianna; Cocchia, Rosangela; Scarafile, Raffaella; Calabrò, Raffaele; Moon, James C

    2012-01-01

    Heart failure is a common syndrome with multiple causes. Cardiovascular magnetic resonance (CMR), using the available range of technique, is establishing itself as the gold standard noninvasive test for determining the underlying causes, and adding prognostic value, guiding therapy. Progress is continuing and rapid with promising new techniques such as diffuse fibrosis assessment. This article discusses the diverse roles of CMR in heart failure.

  19. Ultrahigh Resolution 3-Dimensional Imaging Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Southwest Sciences proposes to develop innovative instrumentation for the rapid, 3-dimensional imaging of biological tissues with cellular resolution. Our approach...

  20. Current variables, definitions and endpoints of the European Cardiovascular Magnetic Resonance Registry

    Directory of Open Access Journals (Sweden)

    Schwitter Juerg

    2009-11-01

    Full Text Available Abstract Background Cardiovascular Magnetic Resonance (CMR is increasingly used in daily clinical practice. However, little is known about its clinical utility such as image quality, safety and impact on patient management. In addition, there is limited information about the potential of CMR to acquire prognostic information. Methods The European Cardiovascular Magnetic Resonance Registry (EuroCMR Registry will consist of two parts: 1 Multicenter registry with consecutive enrolment of patients scanned in all participating European CMR centres using web based online case record forms. 2 Prospective clinical follow up of patients with suspected coronary artery disease (CAD and hypertrophic cardiomyopathy (HCM every 12 months after enrolment to assess prognostic data. Conclusion The EuroCMR Registry offers an opportunity to provide information about the clinical utility of routine CMR in a large number of cases and a diverse population. Furthermore it has the potential to gather information about the prognostic value of CMR in specific patient populations.

  1. cardiovasculares

    Directory of Open Access Journals (Sweden)

    Cristina Guerrero

    2006-01-01

    Full Text Available Uno de los aspectos que más discusión ha suscitado en los últimos tiempos entre quienes nos dedicamos al estudio de la emoción tiene que ver con la eventual asociación entre percepción, valoración y respuesta fisiológica. Esto es, siguiendo la máxima aristotélica, cabría cuestionar si las cosas son como son o son como cada quien las percibe. El objetivo de este experimento ha sido establecer la existencia de una conexión entre percepción de control y responsividad cardiovascular. La muestra estudiada ha estado conformada por estudiantes de la Universidad de Castellón; todos ellos han participado de forma voluntaria. La prueba de estrés ha consistido en un examen real de una asignatura troncal de la titulación que cursaban los participantes. Así pues, utilizando una situación de estrés real, hipotetizamos que las respuestas cardiovasculares (medidas a través de la tasa cardiaca, la presión sanguínea sistólica y la presión sanguínea diastólica dependen de la percepción de control que el individuo tiene, o cree tener, sobre la situación.

  2. Multimodality 3-Dimensional Image Integration for Congenital Cardiac Catheterization

    Science.gov (United States)

    2014-01-01

    Cardiac catheterization procedures for patients with congenital and structural heart disease are becoming more complex. New imaging strategies involving integration of 3-dimensional images from rotational angiography, magnetic resonance imaging (MRI), computerized tomography (CT), and transesophageal echocardiography (TEE) are employed to facilitate these procedures. We discuss the current use of these new 3D imaging technologies and their advantages and challenges when used to guide complex diagnostic and interventional catheterization procedures in patients with congenital heart disease. PMID:25114757

  3. Cardiovascular Magnetic Resonance Relaxometry Predicts Regional Functional Outcome After Experimental Myocardial Infarction.

    Science.gov (United States)

    Haberkorn, Sebastian M; Jacoby, Christoph; Ding, Zhaoping; Keul, Petra; Bönner, Florian; Polzin, Amin; Levkau, Bodo; Schrader, Jürgen; Kelm, Malte; Flögel, Ulrich

    2017-08-01

    Cardiovascular magnetic resonance with gadolinium-based contrast agents has established as gold standard for tissue characterization after myocardial infarction (MI). Beyond accurate diagnosis, the value of cardiovascular magnetic resonance to predict the outcome after MI has yet to be substantiated. Recent cardiovascular magnetic resonance approaches were systematically compared for quantification of tissue injury and functional impairment after MI using murine models with permanent left anterior descending coronary artery ligation (n=14) or 50 minutes ischemia/reperfusion (n=13). Cardiovascular magnetic resonance included native/postcontrast T1 maps, T2 maps, and late gadolinium enhancement at days 1 and 21 post-MI. For regional correlation of parametric and functional measures, the left ventricle was analyzed over 200 sectors. For T1 mapping, we used retrospective triggering with variable flip angle analysis. Sectoral analysis of native T1 maps already revealed in the acute phase after MI substantial discrepancies in myocardial tissue texture between the 2 MI models (native T1 day 1: permanent ligation, 1280.0±162.6 ms; ischemia/reperfusion, 1115.0±140.5 ms; Pfunctional outcome (left ventricular ejection fraction day 21: permanent ligation, 24.5±7.0%; ischemia/reperfusion, 33.7±11.6%; Pfunction in corresponding areas at day 21 demonstrated for early native T1 values the best correlation with the later functional impairment (R(2) =0.94). The present T1 mapping approach permits accurate characterization of local tissue injury and holds the potential for sensitive and graduated prognosis of the functional outcome after MI without gadolinium-based contrast agents. © 2017 American Heart Association, Inc.

  4. Age-dependent heterogeneity of familiar hypertrophic cardiomyopathy phenotype: a role of cardiovascular magnetic resonance.

    Science.gov (United States)

    Glaveckaitė, Sigita; Rudys, Alfredas; Mikštienė, Violeta; Valevičienė, Nomeda; Palionis, Darius; Laucevičius, Aleksandras

    2013-01-01

    In this case report, we present familiar hypertrophic cardiomyopathy with age-dependent heterogeneity of the disease phenotype among the members of one family who carry the same mutation of the myosin-binding protein C gene. Phenotypic heterogeneity is common in patients with familial forms of hypertrophic cardiomyopathy, both in clinical expression and outcome. Compared with other noninvasive cardiac imaging modalities, cardiovascular magnetic resonance provides an opportunity to more accurately characterize the varying phenotypic presentations of hypertrophic cardiomyopathy.

  5. Minimizing Risk of Nephrogenic systemic fibrosis in Cardiovascular Magnetic Resonance

    Directory of Open Access Journals (Sweden)

    Reiter Theresa

    2012-05-01

    Full Text Available Abstract Nephrogenic Systemic Fibrosis is a rare condition appearing only in patients with severe renal impairment or failure and presents with dermal lesions and involvement of internal organs. Although many cases are mild, an estimated 5 % have a progressive debilitating course. To date, there is no known effective treatment thus stressing the necessity of ample prevention measures. An association with the use of Gadolinium based contrast agents (GBCA makes Nephrogenic Systemic Fibrosis a potential side effect of contrast enhanced magnetic resonance imaging and offers the opportunity for prevention by limiting use of gadolinium based contrast agents in renal failure patients. In itself toxic, Gadolinium is embedded into chelates that allow its safe use as a contrast agent. One NSF theory is that Gadolinium chelates distribute into the extracellular fluid compartment and set Gadolinium ions free, depending on multiple factors among which the duration of chelates exposure is directly related to the renal function. Major medical societies both in Europe and in North America have developed guidelines for the usage of GBCA. Since the establishment of these guidelines and the increased general awareness of this condition, the occurrence of NSF has been nearly eliminated. Giving an overview over the current knowledge of NSF pathobiochemistry, pathogenesis and treatment options this review focuses on the guidelines of the European Medicines Agency, the European Society of Urogenital Radiology, the FDA and the American College of Radiology from 2008 up to 2011 and the transfer of this knowledge into every day practice.

  6. Cardiovascular assessment of patients with Ullrich-Turner's Syndrome on Doppler echocardiography and magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Castro Ana Valéria Barros de

    2002-01-01

    Full Text Available OBJECTIVE: To assess the cardiovascular features of Ullrich-Turner's syndrome using echocardiography and magnetic resonance imaging, and to correlate them with the phenotype and karyotype of the patients. The diagnostic concordance between the 2 methods was also assessed. METHODS: Fifteen patients with the syndrome were assessed by echocardiography and magnetic resonance imaging (cardiac chambers, valves, and aorta. Their ages ranged from 10 to 28 (mean of 16.7 years. The karyotype was analyzed in 11 or 25 metaphases of peripheral blood lymphocytes, or both. RESULTS: The most common phenotypic changes were short stature and spontaneous absence of puberal development (100%; 1 patient had a cardiac murmur. The karyotypes detected were as follows: 45,X (n=7, mosaics (n=5, and deletions (n=3. No echocardiographic changes were observed. In regard to magnetic resonance imaging, coarctation and dilation of the aorta were found in 1 patient, and isolated dilation of the aorta was found in 4 patients. CONCLUSION: The frequencies of coarctation and dilation of the aorta detected on magnetic resonance imaging were similar to those reported in the literature (5.5% to 20%, and 6.3% to 29%, respectively. This confirmed the adjuvant role of magnetic resonance imaging to Doppler echocardiography for diagnosing cardiovascular alterations in patients with Ullrich-Turner's syndrome.

  7. Cardiovascular magnetic resonance as a reliable alternative to cardiovascular computed tomography and transesophageal echocardiography for aortic annulus valve sizing.

    Science.gov (United States)

    Faletti, Riccardo; Gatti, Marco; Salizzoni, Stefano; Bergamasco, Laura; Bonamini, Rodolfo; Garabello, Domenica; Marra, Walter Grosso; La Torre, Michele; Morello, Mara; Veglia, Simona; Fonio, Paolo; Rinaldi, Mauro

    2016-08-01

    To assess the accuracy and reproducibly of cardiovascular magnetic resonance (CMR) in the measurement of the aortic annulus and in process of valve sizing as compared to intra-operative sizing, cardiovascular computed tomography (CCT) and transesophageal echocardiography (TEE). Retrospective study on 42 patients who underwent aortic valve replacement from September 2010 to September 2015, with available records of pre surgery annulus assessment by CMR, CCT and TEE and of peri-operative assessment. In CCT and CMR, the annular plane was considered a virtual ring formed by the lowest hinge points of the valvular attachments to the aorta. In TEE the annulus was measured at the base of leaflet insertion in the mid-esophageal long-axis view using the X-plane technique. Two double-blinded operators performed the assessments for each imaging technique. Intra-operative evaluation was performed using Hegar dilators. Continuous variables were studied with within-subject ANOVA, Bland-Altman (BA) plots, Wilcoxon's and Friedman's tests; trends were explored with scatter plots. Categorical variables were studied with Fisher's exact test. The intra- and inter-operator reliability was satisfying. There were no significant differences between the annulus dimensions measured by CMR and either one of the three references. Valve sizing for CoreValve by CMR had the same good agreement with CCT and TEE, with a 78 % match rate; for SAPIEN XT the agreement was slightly better (82 %) for CCT than for TEE (66 %). MR performs well when compared to the surgical reference of intra-operative sizing and stands up to the level of the most used imaging references (CCT and TEE).

  8. Standardized cardiovascular magnetic resonance imaging (CMR protocols, society for cardiovascular magnetic resonance: board of trustees task force on standardized protocols

    Directory of Open Access Journals (Sweden)

    Kim Raymond J

    2008-07-01

    Full Text Available Index 1. General techniques 1.1. Stress and safety equipment 1.2. Left ventricular (LV structure and function module 1.3. Right ventricular (RV structure and function module 1.4. Gadolinium dosing module. 1.5. First pass perfusion 1.6. Late gadolinium enhancement (LGE 2. Disease specific protocols 2.1. Ischemic heart disease 2.1.1. Acute myocardial infarction (MI 2.1.2. Chronic ischemic heart disease and viability 2.1.3. Dobutamine stress 2.1.4. Adenosine stress perfusion 2.2. Angiography: 2.2.1. Peripheral magnetic resonance angiography (MRA 2.2.2. Thoracic MRA 2.2.3. Anomalous coronary arteries 2.2.4. Pulmonary vein evaluation 2.3. Other 2.3.1. Non-ischemic cardiomyopathy 2.3.2. Arrhythmogenic right ventricular cardiomyopathy (ARVC 2.3.3. Congenital heart disease 2.3.4. Valvular heart disease 2.3.5. Pericardial disease 2.3.6. Masses

  9. Cardiovascular magnetic resonance at 3.0T: Current state of the art

    Directory of Open Access Journals (Sweden)

    Gharib Ahmed M

    2010-10-01

    Full Text Available Abstract There are advantages to conducting cardiovascular magnetic resonance (CMR studies at a field strength of 3.0 Telsa, including the increase in bulk magnetization, the increase in frequency separation of off-resonance spins, and the increase in T1 of many tissues. However, there are significant challenges to routinely performing CMR at 3.0T, including the reduction in main magnetic field homogeneity, the increase in RF power deposition, and the increase in susceptibility-based artifacts. In this review, we outline the underlying physical effects that occur when imaging at higher fields, examine the practical results these effects have on the CMR applications, and examine methods used to compensate for these effects. Specifically, we will review cine imaging, MR coronary angiography, myocardial perfusion imaging, late gadolinium enhancement, and vascular wall imaging.

  10. Effect of rosiglitazone on progression of atherosclerosis: insights using 3D carotid cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Chan Cheuk F

    2009-07-01

    Full Text Available Abstract Background There is recent evidence suggesting that rosiglitazone increases death from cardiovascular causes. We investigated the direct effect of this drug on atheroma using 3D carotid cardiovascular magnetic resonance. Results A randomized, placebo-controlled, double-blind study was performed to evaluate the effect of rosiglitazone treatment on carotid atherosclerosis in subjects with type 2 diabetes and coexisting vascular disease or hypertension. The primary endpoint of the study was the change from baseline to 52 weeks of carotid arterial wall volume, reflecting plaque burden, as measured by carotid cardiovascular magnetic resonance. Rosiglitazone or placebo was allocated to 28 and 29 patients respectively. Patients were managed to have equivalent glycemic control over the study period, but in fact the rosiglitazone group lowered their HbA1c by 0.88% relative to placebo (P 3 and in the rosiglitazone group was 1354 ± 532 mm3. After 52 weeks, the respective volumes were 1134 ± 523 mm3 and 1348 ± 531 mm3. These changes (-12.1 mm3 and -5.7 mm3 in the placebo and rosiglitazone groups, respectively were not statistically significant between groups (P = 0.57. Conclusion Treatment with rosiglitazone over 1 year had no effect on progression of carotid atheroma in patients with type 2 diabetes mellitus compared to placebo.

  11. Cardiac resynchronization therapy guided by late gadolinium-enhancement cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Smith Russell EA

    2011-06-01

    Full Text Available Abstract Background Myocardial scarring at the LV pacing site leads to incomplete resynchronization and a suboptimal symptomatic response to CRT. We sought to determine whether the use of late gadolinium cardiovascular magnetic resonance (LGE-CMR to guide left ventricular (LV lead deployment influences the long-term outcome of cardiac resynchronization therapy (CRT. Methods 559 patients with heart failure (age 70.4 ± 10.7 yrs [mean ± SD] due to ischemic or non-ischemic cardiomyopathy underwent CRT. Implantations were either guided (+CMR or not guided (-CMR by LGE-CMR prior to implantation. Fluoroscopy and LGE-CMR were used to localize the LV lead tip and and myocardial scarring retrospectively. Clinical events were assessed in three groups: +CMR and pacing scar (+CMR+S; CMR and not pacing scar (+CMR-S, and; LV pacing not guided by CMR (-CMR. Results Over a maximum follow-up of 9.1 yrs, +CMR+S had the highest risk of cardiovascular death (HR: 6.34, cardiovascular death or hospitalizations for heart failure (HR: 5.57 and death from any cause or hospitalizations for major adverse cardiovascular events (HR: 4.74 (all P Conclusions Compared with a conventional implantation approach, the use of LGE-CMR to guide LV lead deployment away from scarred myocardium results in a better clinical outcome after CRT. Pacing scarred myocardium was associated with the worst outcome, in terms of both pump failure and sudden cardiac death.

  12. Vascular function assessed with cardiovascular magnetic resonance predicts survival in patients with advanced chronic kidney disease

    Directory of Open Access Journals (Sweden)

    Steedman Tracey

    2008-08-01

    Full Text Available Abstract Background Increased arterial stiffness is associated with mortality in patients with chronic kidney disease. Cardiovascular magnetic resonance (CMR permits assessment of the central arteries to measure aortic function. Methods We studied the relationship between central haemodynamics and outcome using CMR in 144 chronic kidney disease patients with estimated glomerular filtration rate Results Median follow up after the scan was 24 months. There were no significant differences in aortic distensibilty or aortic volumetric arterial strain between pre-dialysis and dialysis patients. Aortic distensibilty and volumetric arterial strain negatively correlated with age. Aortic distensibilty and volumetric arterial strain were lower in diabetics, patients with ischaemic heart disease and peripheral vascular disease. During follow up there were 20 deaths. Patients who died had lower aortic distensibilty than survivors. In a survival analysis, diabetes, systolic blood pressure and aortic distensibilty were independent predictors of mortality. There were 12 non-fatal cardiovascular events during follow up. Analysing the combined end point of death or a vascular event, diabetes, aortic distensibilty and volumetric arterial strain were predictors of events. Conclusion Deranged vascular function measured with CMR correlates with cardiovascular risk factors and predicts outcome. CMR measures of vascular function are potential targets for interventions to reduce cardiovascular risk.

  13. 3-Dimensional Topographic Models for the Classroom

    Science.gov (United States)

    Keller, J. W.; Roark, J. H.; Sakimoto, S. E. H.; Stockman, S.; Frey, H. V.

    2003-01-01

    We have recently undertaken a program to develop educational tools using 3-dimensional solid models of digital elevation data acquired by the Mars Orbital Laser Altimeter (MOLA) for Mars as well as a variety of sources for elevation data of the Earth. This work is made possible by the use of rapid prototyping technology to construct solid 3-Dimensional models of science data. We recently acquired rapid prototyping machine that builds 3-dimensional models in extruded plastic. While the machine was acquired to assist in the design and development of scientific instruments and hardware, it is also fully capable of producing models of spacecraft remote sensing data. We have demonstrated this by using Mars Orbiter Laser Altimeter (MOLA) topographic data and Earth based topographic data to produce extruded plastic topographic models which are visually appealing and instantly engage those who handle them.

  14. Primary 3-dimensional culture of mouse hepatocytes

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Complex 3-dimensional structures with good functions have been obtained under the primary mixcoculture of mouse hepatocytes with mouse liver fibroblasts without serum. Albumin secretion is kept above 10 μg/106 cells and urea synthesis reaches 25 μg/106 on the 7th day of culture. Avoiding serum affection, liver fibroblasts' effects on hepatocytes' viability, functions and 3-dimensional structure forming in primary serum-free culture have been studied. Important effects of the mesenchyma, especially the direct adherence of fibroblasts to hepatocytes, are shown.

  15. Assessment of Ischemic Cardiomyopathy Using Cardiovascular Magnetic Resonance Imaging: A Pictorial Review.

    Science.gov (United States)

    Olivas-Chacon, Cristina Ivette; Mullins, Carola; Solberg, Agnieszka; Akle, Nassim; Calleros, Jesus E; Ramos-Duran, Luis R

    2015-01-01

    Ischemic heart disease is the leading cause of death worldwide. In the last two decades, cardiovascular magnetic resonance imaging (CMRI) has emerged as the primary imaging tool in the detection and prognostic assessment of ischemic heart disease. In a single study, CMRI allows evaluation of not only myocardial wall perfusion, but also the presence, acuity, and extent of myocardial ischemia and infarction complications. Also, rest and stress perfusion imaging can accurately depict inducible ischemia secondary to significant coronary artery stenosis. We present a pictorial review of the assessment of ischemic cardiomyopathy with an emphasis on CMRI features.

  16. Assessment of Ischemic Cardiomyopathy Using Cardiovascular Magnetic Resonance Imaging: A Pictorial Review

    Directory of Open Access Journals (Sweden)

    Cristina Ivette Olivas-Chacon

    2015-01-01

    Full Text Available Ischemic heart disease is the leading cause of death worldwide. In the last two decades, cardiovascular magnetic resonance imaging (CMRI has emerged as the primary imaging tool in the detection and prognostic assessment of ischemic heart disease. In a single study, CMRI allows evaluation of not only myocardial wall perfusion, but also the presence, acuity, and extent of myocardial ischemia and infarction complications. Also, rest and stress perfusion imaging can accurately depict inducible ischemia secondary to significant coronary artery stenosis. We present a pictorial review of the assessment of ischemic cardiomyopathy with an emphasis on CMRI features.

  17. The role of cardiovascular magnetic resonance in the evaluation of valve disease.

    Science.gov (United States)

    Karamitsos, Theodoros D; Myerson, Saul G

    2011-01-01

    Echocardiography is the primary imaging modality for initial assessment and longitudinal evaluation of patients with valvular heart disease. Cardiovascular magnetic resonance (CMR) has emerged as an additional or alternative modality in these patients providing clinically useful information not only about the valve lesion itself but also about the consequences for the relevant ventricle. Other unique capabilities of CMR include the assessment of surrounding anatomy (eg, great vessels) and the evaluation of myocardial scar or fibrosis. This review will highlight the role of CMR in the assessment of patients with valve disease with particular emphasis on the advantages of this imaging modality in key areas. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Cardiovascular magnetic resonance imaging assessment of outcomes in acute myocardial infarction

    Science.gov (United States)

    Khan, Jamal N; McCann, Gerry P

    2017-01-01

    Cardiovascular magnetic resonance (CMR) imaging uniquely characterizes myocardial and microvascular injury in acute myocardial infarction (AMI), providing powerful surrogate markers of outcomes. The last 10 years have seen an exponential increase in AMI studies utilizing CMR based endpoints. This article provides a contemporary, comprehensive review of the powerful role of CMR imaging in the assessment of outcomes in AMI. The theory, assessment techniques, chronology, importance in predicting left ventricular function and remodelling, and prognostic value of each CMR surrogate marker is described in detail. Major studies illustrating the importance of the markers are summarized, providing an up to date review of the literature base in CMR imaging in AMI. PMID:28289525

  19. ECG-based gating in ultra high field cardiovascular magnetic resonance using an independent component analysis approach

    OpenAIRE

    Krug, Johannes W; Rose, Georg; Clifford, Gari D.; Oster, Julien

    2013-01-01

    Background In Cardiovascular Magnetic Resonance (CMR), the synchronization of image acquisition with heart motion is performed in clinical practice by processing the electrocardiogram (ECG). The ECG-based synchronization is well established for MR scanners with magnetic fields up to 3 T. However, this technique is prone to errors in ultra high field environments, e.g. in 7 T MR scanners as used in research applications. The high magnetic fields cause severe magnetohydrodynamic (MHD) effects w...

  20. 3-Dimensional Right Ventricular Volume Assessment

    NARCIS (Netherlands)

    Jainandunsing, Jayant S.; Matyal, Robina; Shahul, Sajid S.; Wang, Angela; Woltersom, Bozena; Mahmood, Feroze

    Purpose: The purpose of this review was to evaluate new computer software available for 3-dimensional right ventricular (RV) volume estimation. Description: Based on 2-dimensional echocardiography, various algorithms have been used for RV volume estimation. These are complex, time-consuming

  1. 3-dimensional imaging at nanometer resolutions

    Science.gov (United States)

    Werner, James H.; Goodwin, Peter M.; Shreve, Andrew P.

    2010-03-09

    An apparatus and method for enabling precise, 3-dimensional, photoactivation localization microscopy (PALM) using selective, two-photon activation of fluorophores in a single z-slice of a sample in cooperation with time-gated imaging for reducing the background radiation from other image planes to levels suitable for single-molecule detection and spatial location, are described.

  2. On 3-Dimensional Stability of Reshaping Breakwaters

    DEFF Research Database (Denmark)

    Burcharth, Hans F.; Frigaard, Peter

    1989-01-01

    The paper deals with the 3-dimensional stability of the type of rubble mound breakwaters where reshaping of the mound due to wave action is foreseen in the design. Such breakwaters are commonly named sacrificial types and berm types. The latter is due to the relatively large volume of armour stones...

  3. Properties of 3-dimensional line location models

    DEFF Research Database (Denmark)

    Brimberg, Jack; Juel, Henrik; Schöbel, Anita

    2002-01-01

    We consider the problem of locating a line with respect to some existing facilities in 3-dimensional space, such that the sum of weighted distances between the line and the facilities is minimized. Measuring distance using the l\\_p norm is discussed, along with the special cases of Euclidean...

  4. Properties of 3-dimensional line location models

    DEFF Research Database (Denmark)

    Brimberg, Jack; Juel, Henrik; Schöbel, Anita

    2002-01-01

    We consider the problem of locating a line with respect to some existing facilities in 3-dimensional space, such that the sum of weighted distances between the line and the facilities is minimized. Measuring distance using the l\\_p norm is discussed, along with the special cases of Euclidean...

  5. Cardiovascular magnetic resonance imaging of scar development following pulmonary vein isolation: a prospective study.

    Directory of Open Access Journals (Sweden)

    Jeff Hsing

    Full Text Available AIMS: Cardiovascular magnetic resonance (MR provides non-invasive assessment of early (24-hour edema and injury following pulmonary vein isolation (by ablation and subsequent scar formation. We hypothesize that 24-hours after ablation, cardiovascular MR would demonstrate a pattern of edema and injury due to ablation and the severity would correlate with subsequent scar. METHODS: Fifteen atrial fibrillation patients underwent cardiovascular MR prior to pulmonary vein isolation, 24-hours post (N = 11 and 30-days post (N = 7 ablation, with T2-weighted (T2W and late gadolinium enhancement (LGE imaging. Left atrial wall thickness, edema enhancement ratio and LGE enhancement were assessed at each time point. Volumes of LGE and edema enhancement were measured, and the circumferential presence of injury was assessed at 24-hours, including comparison with LGE enhancement at 30 days. RESULTS: Left atrial wall thickness was increased 24-hours post-ablation (10.7 ± 4.1 mm vs. 7.0 ± 1.8 mm pre-PVI, p<0.05. T2W enhancement at 24-hours showed increased edema enhancement ratio (1.5 ± 0.4 for post-ablation, vs. 0.9 ± 0.2 pre-ablation, p < 0.001. Edema and LGE volumes at 24-hours were correlated with 30-day LGE volume (R = 0.76, p = 0.04, and R = 0.74, p = 0.09, respectively. Using a 16 segment model for assessment, 24-hour T2W had sensitivity, specificity, and accuracy of 82%, 63%, and 79% respectively, for predicting 30-day LGE. 24-hour LGE had sensitivity, specificity, and accuracy of 91%, 47%, and 84%. CONCLUSIONS: Increased left atrial wall thickening and edema were characterized on cardiovascular MR early post-ablation, and found to correlate with 30-day LGE scar.

  6. Pulmonary Arterial Hypertension: Use of Delayed Contrast-Enhanced Cardiovascular Magnetic Resonance in Risk Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Bessa, Luiz Gustavo Pignataro, E-mail: lgpignataro@ig.com.br; Junqueira, Flávia Pegado; Bandeira, Marcelo Luiz da Silva; Garcia, Marcelo Iorio; Xavier, Sérgio Salles; Lavall, Guilherme; Torres, Diego; Waetge, Daniel [Hospital Universitário Clementino Fraga Filho, Ilha do Fundão, RJ (Brazil)

    2013-10-15

    Pulmonary arterial hypertension is a severe and progressive disease. Its early diagnosis is the greatest clinical challenge. To evaluate the presence and extension of the delayed myocardial contrast-enhanced cardiovascular magnetic resonance, as well as to verify if the percentage of the myocardial fibrosis mass is a severity predictor. Cross-sectional study with 30 patients with pulmonary arterial hypertension of groups I and IV, subjected to clinical, functional and hemodynamic evaluation, and to cardiac magnetic resonance. The mean age of patients was 52 years old, with female predominance (77%). Among the patients, 53% had right ventricular failure at diagnosis, and 90% were in functional class II/III. The mean of the 6-minute walk test was 395m. In hemodynamic study with right catheterism, the mean average pulmonary arterial pressure was 53.3mmHg, of the cardiac index of 2.1L/ min.m{sup 2}, and median right atrial pressure was 13.5 mmHg. Delayed myocardial contrast enhanced cardiovascular magnetic resonance was found in 28 patients. The mean fibrosis mass was 9.9 g and the median percentage of fibrosis mass was 6.17%. The presence of functional class IV, right ventricular failure at diagnosis, 6-minute walk test < 300 meters and right atrial pressure ≥ 15 mmHg, with cardiac index < 2.0 L/ min.m{sup 2}, there was a relevant association with the increased percentage of myocardial fibrosis. The percentage of the myocardial fibrosis mass indicates a non-invasive marker with promising perspectives in identifying patients with high risk factors for pulmonary hypertension.

  7. Pulmonary Arterial Hypertension: Use of Delayed Contrast-Enhanced Cardiovascular Magnetic Resonance in Risk Assessment

    Science.gov (United States)

    Bessa, Luiz Gustavo Pignataro; Junqueira, Flávia Pegado; Bandeira, Marcelo Luiz da Silva; Garcia, Marcelo Iorio; Xavier, Sérgio Salles; Lavall, Guilherme; Torres, Diego; Waetge, Daniel

    2013-01-01

    Background Pulmonary arterial hypertension is a severe and progressive disease. Its early diagnosis is the greatest clinical challenge. Objective To evaluate the presence and extension of the delayed myocardial contrast-enhanced cardiovascular magnetic resonance, as well as to verify if the percentage of the myocardial fibrosis mass is a severity predictor. Methods Cross-sectional study with 30 patients with pulmonary arterial hypertension of groups I and IV, subjected to clinical, functional and hemodynamic evaluation, and to cardiac magnetic resonance. Results The mean age of patients was 52 years old, with female predominance (77%). Among the patients, 53% had right ventricular failure at diagnosis, and 90% were in functional class II/III. The mean of the 6-minute walk test was 395m. In hemodynamic study with right catheterism, the mean average pulmonary arterial pressure was 53.3mmHg, of the cardiac index of 2.1L/ min.m2, and median right atrial pressure was 13.5 mmHg. Delayed myocardial contrast enhanced cardiovascular magnetic resonance was found in 28 patients. The mean fibrosis mass was 9.9 g and the median percentage of fibrosis mass was 6.17%. The presence of functional class IV, right ventricular failure at diagnosis, 6-minute walk test < 300 meters and right atrial pressure ≥ 15 mmHg, with cardiac index < 2.0 L/ min.m2, there was a relevant association with the increased percentage of myocardial fibrosis. Conclusion The percentage of the myocardial fibrosis mass indicates a non-invasive marker with promising perspectives in identifying patients with high risk factors for pulmonary hypertension. PMID:23979779

  8. Effects of 50-Hz magnetic field on the cardiovascular system in rats

    Institute of Scientific and Technical Information of China (English)

    LAI Jin-sheng; WAN Bao-quan; LIU Xing-fa; ZHANG Ye-mao; RUAN Guo-ran; HE Meng-ying; CHEN Chen; WANG Dao-wen

    2016-01-01

    AIM:The 50-Hz magnetic field (MF) is a potential health-risk factor.Its effects on the cardiovascular system have not been fully investigated .This study was conducted to explore the effects of long-term exposure to 50-Hz MF on the cardiovascular system . METHODS:In the study , an exposure system was constructed and the distribution of 50-Hz MF was detected .Sixty-four Sprague-Dawley (SD) rats were exposed to 50-Hz MF at 100 μT for 24 weeks, 20 hours per day, while another 64 rats were sham exposed. During the exposure, blood pressure was measured every 4 weeks, and 24 weeks later, echocardiography, cardiac catheterisation and electrocardiography were performed .Moreover , heart and body weight were recorded , while haematoxylin-eosin staining and real-time PCR were conducted .RESULTS:The results showed that compared with the sham group , exposure to 50-Hz MF did not exert any effect on blood pressure, pulse rate, heart rate and cardiac rhythm.Further, echocardiography and cardiac catheterisation showed that there were no significant differences in the cardiac morphology and haemodynamics .In addition , histopathological examination showed that 50-Hz MF exposure had no effect on the structure of hearts .Finally, the expression of the cardiac hypertrophic relative genes did not show any significant differences between 50-Hz MF exposure group and the sham group .CONCLUSION: Taken together , in SD rats, exposure to 50-Hz/100-μT MF for 24 weeks did not show any obvious effects on the cardiovascular system .

  9. On the evaluation of vorticity using cardiovascular magnetic resonance velocity measurements.

    Science.gov (United States)

    Garcia, J; Larose, E; Pibarot, P; Kadem, L

    2013-12-01

    Vorticity and vortical structures play a fundamental role affecting the evaluation of energetic aspects (mainly left ventricle work) of cardiovascular function. Vorticity can be derived from cardiovascular magnetic resonance (CMR) imaging velocity measurements. However, several numerical schemes can be used to evaluate the vorticity field. The main objective of this work is to assess different numerical schemes used to evaluate the vorticity field derived from CMR velocity measurements. We compared the vorticity field obtained using direct differentiation schemes (eight-point circulation and Chapra) and derivate differentiation schemes (Richardson 4* and compact Richardson 4*) from a theoretical velocity field and in vivo CMR velocity measurements. In all cases, the effect of artificial spatial resolution up-sampling and signal-to-noise ratio (SNR) on vorticity computation was evaluated. Theoretical and in vivo results showed that the eight-point circulation method underestimated vorticity. Up-sampling evaluation showed that the artificial improvement of spatial resolution had no effect on mean absolute vorticity estimation but it affected SNR for all methods. The Richardson 4* method and its compact version were the most accurate and stable methods for vorticity magnitude evaluation. Vorticity field determination using the eight-point circulation method, the most common method used in CMR, has reduced accuracy compared to other vorticity schemes. Richardson 4* and its compact version showed stable SNR using both theoretical and in vivo data.

  10. Safety of magnetic resonance imaging in patients with implanted cardiac prostheses and metallic cardiovascular electronic devices.

    Science.gov (United States)

    Baikoussis, Nikolaos G; Apostolakis, Efstratios; Papakonstantinou, Nikolaos A; Sarantitis, Ioannis; Dougenis, Dimitrios

    2011-06-01

    Magnetic resonance imaging (MRI) in patients with implanted cardiac prostheses and metallic cardiovascular electronic devices is sometimes a risky procedure. Thus MRI in these patients should be performed when it is the only examination able to help with the diagnosis. Moreover the diagnostic benefit must outweigh the risks. Coronary artery stents, prosthetic cardiac valves, metal sternal sutures, mediastinal vascular clips, and epicardial pacing wires are not contraindications for MRI, in contrast to pacemakers and implantable cardioverter-defibrillators. Appropriate patient selection and precautions ensure MRI safety. However it is commonly accepted that although hundreds of patients with pacemakers or implantable cardioverter-defibrillators have undergone safe MRI scanning, it is not a safe procedure. Currently, heating of the pacemaker lead is the major problem undermining MRI safety. According to the US Food and Drug Administration (FDA), there are currently neither "MRI-safe" nor "MRI-compatible" pacemakers and implantable cardioverter-defibrillators. In this article we review the international literature in regard to safety during MRI of patients with implanted cardiac prostheses and metallic cardiovascular electronic devices.

  11. Alterations in vascular function in primary aldosteronism: a cardiovascular magnetic resonance imaging study.

    Science.gov (United States)

    Mark, P B; Boyle, S; Zimmerli, L U; McQuarrie, E P; Delles, C; Freel, E M

    2014-02-01

    Excess aldosterone is associated with increased cardiovascular risk. Aldosterone has a permissive effect on vascular fibrosis. Cardiovascular magnetic resonance imaging (CMR) allows study of vascular function by measuring aortic distensibility. We compared aortic distensibility in primary aldosteronism (PA), essential hypertension (EH) and normal controls and explored the relationship between aortic distensibility and pulse wave velocity (PWV). We studied PA (n=14) and EH (n=33) subjects and age-matched healthy controls (n=17) with CMR, including measurement of aortic distensibility, and measured PWV using applanation tonometry. At recruitment, PA and EH patients had similar blood pressure and left ventricular mass. Subjects with PA had significantly lower aortic distensibility and higher PWV compared with EH and healthy controls. These changes were independent of other factors associated with reduced aortic distensibility, including ageing. There was a significant relationship between increasing aortic stiffness and age in keeping with physical and vascular ageing. As expected, aortic distensibility and PWV were closely correlated. These results demonstrate that PA patients display increased arterial stiffness compared with EH, independent of vascular ageing. The implication is that aldosterone invokes functional impairment of arterial function. The long-term implications of arterial stiffening in aldosterone excess require further study.

  12. Magnetic Resonance Imaging-derived Flow Parameters for the Analysis of Cardiovascular Diseases and Drug Development.

    Science.gov (United States)

    Michael, Dada O; Bamidele, Awojoyogbe O; Adewale, Adesola O; Karem, Boubaker

    2013-01-01

    Nuclear magnetic resonance (NMR) allows for fast, accurate and noninvasive measurement of fluid flow in restricted and non-restricted media. The results of such measurements may be possible for a very small B 0 field and can be enhanced through detailed examination of generating functions that may arise from polynomial solutions of NMR flow equations in terms of Legendre polynomials and Boubaker polynomials. The generating functions of these polynomials can present an array of interesting possibilities that may be useful for understanding the basic physics of extracting relevant NMR flow information from which various hemodynamic problems can be carefully studied. Specifically, these results may be used to develop effective drugs for cardiovascular-related diseases.

  13. Remote magnetic targeting of iron oxide nanoparticles for cardiovascular diagnosis and therapeutic drug delivery: where are we now?

    Science.gov (United States)

    Bietenbeck, Michael; Florian, Anca; Faber, Cornelius; Sechtem, Udo; Yilmaz, Ali

    2016-01-01

    Magnetic resonance imaging (MRI) allows for an accurate assessment of both functional and structural cardiac parameters, and thereby appropriate diagnosis and validation of cardiovascular diseases. The diagnostic yield of cardiovascular MRI examinations is often increased by the use of contrast agents that are almost exclusively based on gadolinium compounds. Another clinically approved contrast medium is composed of superparamagnetic iron oxide nanoparticles (IONs). These particles may expand the field of contrast-enhanced cardiovascular MRI as recently shown in clinical studies focusing on acute myocardial infarction (AMI) and atherosclerosis. Furthermore, IONs open up new research opportunities such as remote magnetic drug targeting (MDT). The approach of MDT relies on the coupling of bioactive molecules and magnetic nanoparticles to form an injectable complex. This complex, in turn, can be attracted to and retained at a desired target inside the body with the help of applied magnetic fields. In comparison to common systemic drug applications, MDT techniques promise both higher concentrations at the target site and lower concentrations elsewhere in the body. Moreover, concurrent or subsequent MRI can be used for noninvasive monitoring of drug distribution and successful delivery to the desired organ in vivo. This review does not only illustrate the basic conceptual and biophysical principles of IONs, but also focuses on new research activities and achievements in the cardiovascular field, mainly in the management of AMI. Based on the presentation of successful MDT applications in preclinical models of AMI, novel approaches and the translational potential of MDT are discussed.

  14. Coronary artery calcification score by multislice computed tomography predicts the outcome of dobutamine cardiovascular magnetic resonance imaging

    NARCIS (Netherlands)

    Janssen, CHC; Kuijpers, D; Vliegenthart, R; Overbosch, J; van Dijkman, PRM; Zijlstra, F; Oudkerk, M

    The aim of this study was to determine whether a coronary artery calcium (CAC) score of less than 11 can reliably rule out myocardial ischemia detected by dobutamine cardiovascular magnetic resonance imaging (CMR) in patients suspected of having myocardial ischemia. In 114 of 136 consecutive

  15. Non Hodgkin lymphoma metastasis to the heart detected by cardiovascular magnetic resonance; Metastasis cardiaca secundaria al linfoma de Hodgkin detectada por la resonancia magnetica cardiovascular

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Florange; Morales, Marisela; Pedreanez, Norma, E-mail: martinez.florangel@gmail.com [Hospital Cardiologico Infantil Latinoamericano Dr Gilberto Rodriguez Ochoa, Carcacas (Venezuela, Bolivarian Republic of); Pabon, Luz; Carrillo, Milton [Universidad Central de Venezuela (UCV/HUC), Caracas (Venezuela, Bolivarian Republic of). Instituto de Hematoncologia. Hospital Universitario; Fernandes, Juliano Lara [Universidade de Campinas (UNICAMP), SP (Brazil)

    2009-10-15

    Primary and secondary heart tumors are relatively rare occurrences but usually imply significant treatment decisions. The differential diagnosis among these tumors and other masses can sometimes be difficult and require the use of different imaging modalities to establish a confident verdict. Cardiovascular magnetic resonance CMR imaging is a very useful tool in these cases by allowing for the application of different strategies to better delineate masses, heart structures and adjacent tissues. In this case description, we present a woman with shortness of breath and a paracardiac mass showing how CMR can be applied. (author)

  16. Cardiovascular magnetic resonance and computed tomography imaging for the assessment of cardiovascular complications of type 2 diabetes mellitus

    OpenAIRE

    Graça, Bruno Miguel Silva Rosa da

    2015-01-01

    Tese de doutoramento em Ciências da Saúde, no ramo de Medicina, na especialidade de Medicina Interna (Radiologia e Imagiologia), apresentada à Faculdade de Medicina da Universidade de Coimbra Diabetes mellitus is responsible for diverse cardiovascular complications such as increased atherosclerosis in large arteries (carotids, aorta, and femoral arteries) and increased coronary atherosclerosis. A number of noninvasive tests are now available to detect coronary atherosclerotic disease, ...

  17. Insights into cardiac involvement in ankylosing spondylitis from cardiovascular magnetic resonance.

    Science.gov (United States)

    Biesbroek, P Stefan; Heslinga, Sjoerd C; Konings, Thelma C; van der Horst-Bruinsma, Irene E; Hofman, Mark B M; van de Ven, Peter M; Kamp, Otto; van Halm, Vokko P; Peters, Mike J L; Smulders, Yvo M; van Rossum, Albert C; Nurmohamed, Mike T; Nijveldt, Robin

    2017-05-01

    To evaluate cardiac involvement in patients with ankylosing spondylitis using cardiac magnetic resonance (CMR). Patients with ankylosing spondylitis without cardiovascular symptoms or known cardiovascular disease were screened by transthoracic echocardiography (TTE) for participation in this exploratory CMR study. We prospectively enrolled 15 ankylosing spondylitis patients with an abnormal TTE for further tissue characterisation using late gadolinium enhancement (LGE) and T1 mapping. T1 mapping was used to calculate myocardial extracellular volume (ECV). Disease activity was assessed by C reactive protein (CRP) and erythrocyte sedimentation rate (ESR) measurements. In the total of 15 included patients, 14 had a complete CMR exam (mean age 62 years, 93% male and mean disease duration 21 years). Left ventricular (LV) diastolic dysfunction was the most common finding on TTE (79%), followed by aortic root dilatation (14%), right ventricular (RV) dilatation (7%) and RV dysfunction (7%). CMR revealed focal hyperenhancement in three patients (21%), all with a particular pattern of enhancement. LV dysfunction, as defined by a LV ejection fraction below 55%, was observed in five patients (36%). Myocardial ECV was correlated with the CRP concentration (R=0.78, pankylosing spondylitis, CMR with cine imaging and LGE identified global LV dysfunction and focal areas of hyperenhancement. Myocardial ECV, quantified by CMR T1 mapping, was associated with the degree of disease activity. These results may suggest the presence of cardiac involvement in ankylosing spondylitis and may show the potential of ECV as a marker for disease monitoring. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  18. A systematic review of the diagnostic accuracy of cardiovascular magnetic resonance for pulmonary hypertension.

    Science.gov (United States)

    Wang, Ning; Hu, Xiaolan; Liu, Chenjing; Ali, Bihi; Guo, Xiaojuan; Liu, Min; Peng, Xiaoxia; Yang, Yuanhua

    2014-04-01

    The diagnostic accuracy of cardiovascular magnetic resonance (CMR) for pulmonary hypertension (PH) compared with right heart catheterization were assessed. The purpose of this systematic review was to comprehensively evaluate the diagnostic accuracy of CMR in evaluating PH. Published literature was obtained from PUBMED, Web of Knowledge, Cochrane library, Embase, Biosis Preview, China National Knowledge Infrastructure, and Chongqing VIP databases, and all studies were inclusive until December 2012. Studies relevant to PH and its imaging in CMR and right heart catheterization were included if correlation coefficient was elucidated clearly. Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) score was used to assess the quality of studies. Sensitivity and specificity were pooled separately and compared with overall accuracy measures: diagnostic odds ratio and symmetric summary receiver operating characteristic. Sixteen studies were included in the systematic review. Of all the studies, the most widely used index was ventricular mass index (VMI) of CMR. We performed a meta-analysis for VMI among 429 patients in 5 individual studies, which showed a modest diagnostic accuracy of VMI for PH with a summary sensitivity and specificity of 84% (95% confidence interval, 79%-87%) and 82% (95% confidence interval, 73%-89%), respectively. In addition, the summary positive likelihood ratio was 4.894, indicating that VMI of CMR allows a modest ability to distinguish PH patients from healthy subjects with a cutoff point of 0.45 using functional and structural measures. This systematic review and meta-analysis indicates that VMI seems to have a moderate sensitivity and specificity for detection of PH. The application values of other parameters still need further investigation. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  19. A dilogarithmic 3-dimensional Ising tetrahedron

    CERN Document Server

    Broadhurst, D J

    1999-01-01

    In 3 dimensions, the Ising model is in the same universality class as unknown analytical nature. In contrast, all single-scale 4-dimensional tetrahedra were reduced, in hep-th/9803091, to special values of exponentially convergent polylogarithms. Combining dispersion relations with the integer-relation finder PSLQ, we find that $C^{Tet}/2^{5/2} = Cl_2(4\\alpha) - Cl_2(2\\alpha)$, with $Cl_2(\\theta):=\\sum_{n>0}\\sin(n\\theta)/n^2$ and 1,000-digit precision and readily yields 50,000 digits of $C^{Tet}$, after transformation to an exponentially convergent sum, akin to those studied in math.CA/9803067. It appears that this 3-dimensional result entails a polylogarithmic ladder beginning with the classical formula for $\\pi/\\sqrt2$, in the manner that 4-dimensional results build on that for $\\pi/\\sqrt3$.

  20. Remote magnetic targeting of iron oxide nanoparticles for cardiovascular diagnosis and therapeutic drug delivery: where are we now?

    Directory of Open Access Journals (Sweden)

    Bietenbeck M

    2016-07-01

    Full Text Available Michael Bietenbeck,1 Anca Florian,1 Cornelius Faber,2 Udo Sechtem,3 Ali Yilmaz11Department of Cardiology and Angiology, 2Department of Clinical Radiology, University Hospital Münster, Münster, 3Division of Cardiology, Robert-Bosch-Krankenhaus, Stuttgart, Germany Abstract: Magnetic resonance imaging (MRI allows for an accurate assessment of both functional and structural cardiac parameters, and thereby appropriate diagnosis and validation of cardiovascular diseases. The diagnostic yield of cardiovascular MRI examinations is often increased by the use of contrast agents that are almost exclusively based on gadolinium compounds. Another clinically approved contrast medium is composed of superparamagnetic iron oxide nanoparticles (IONs. These particles may expand the field of contrast-enhanced cardiovascular MRI as recently shown in clinical studies focusing on acute myocardial infarction (AMI and atherosclerosis. Furthermore, IONs open up new research opportunities such as remote magnetic drug targeting (MDT. The approach of MDT relies on the coupling of bioactive molecules and magnetic nanoparticles to form an injectable complex. This complex, in turn, can be attracted to and retained at a desired target inside the body with the help of applied magnetic fields. In comparison to common systemic drug applications, MDT techniques promise both higher concentrations at the target site and lower concentrations elsewhere in the body. Moreover, concurrent or subsequent MRI can be used for noninvasive monitoring of drug distribution and successful delivery to the desired organ in vivo. This review does not only illustrate the basic conceptual and biophysical principles of IONs, but also focuses on new research activities and achievements in the cardiovascular field, mainly in the management of AMI. Based on the presentation of successful MDT applications in preclinical models of AMI, novel approaches and the translational potential of MDT are discussed

  1. Feasibility and Diagnostic Value of Cardiovascular Magnetic Resonance Imaging After Acute Ischemic Stroke of Undetermined Origin.

    Science.gov (United States)

    Haeusler, Karl Georg; Wollboldt, Christian; Bentheim, Laura Zu; Herm, Juliane; Jäger, Sebastian; Kunze, Claudia; Eberle, Holger-Carsten; Deluigi, Claudia Christina; Bruder, Oliver; Malsch, Carolin; Heuschmann, Peter U; Endres, Matthias; Audebert, Heinrich J; Morguet, Andreas J; Jensen, Christoph; Fiebach, Jochen B

    2017-05-01

    Etiology of acute ischemic stroke remains undetermined (cryptogenic) in about 25% of patients after state-of-the-art diagnostic work-up. One-hundred and three patients with magnetic resonance imaging (MRI)-proven acute ischemic stroke of undetermined origin were prospectively enrolled and underwent 3-T cardiac MRI and magnetic resonance angiography of the aortic arch in addition to state-of-the-art diagnostic work-up, including transesophageal echocardiography (TEE). We analyzed the feasibility, diagnostic accuracy, and added value of cardiovascular MRI (cvMRI) compared with TEE for detecting sources of stroke. Overall, 102 (99.0%) ischemic stroke patients (median 63 years [interquartile range, 53-72], 24% female, median NIHSS (National Institutes of Health Stroke Scale) score on admission 2 [interquartile range, 1-4]) underwent cvMRI and TEE in hospital; 89 (86.4%) patients completed the cvMRI examination. In 93 cryptogenic stroke patients, a high-risk embolic source was found in 9 (8.7%) patients by cvMRI and in 11 (11.8%) patients by echocardiography, respectively. cvMRI and echocardiography findings were consistent in 80 (86.0%) patients, resulting in a degree of agreement of κ=0.24. In 82 patients with cryptogenic stroke according to routine work-up, including TEE, cvMRI identified stroke etiology in additional 5 (6.1%) patients. Late gadolinium enhancement consistent with previous myocardial infarction was found in 13 (14.6%) out of 89 stroke patients completing cvMRI. Only 2 of these 13 patients had known coronary artery disease. Our study demonstrated that cvMRI was feasible in the vast majority of included patients with acute ischemic stroke. The diagnostic information of cvMRI seems to be complementary to TEE but is not replacing echocardiography after acute ischemic stroke. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01917955. © 2017 American Heart Association, Inc.

  2. Left ventricular non-compaction: clinical features and cardiovascular magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Sandman Harald

    2009-08-01

    Full Text Available Abstract Background It is apparent that despite lack of family history, patients with the morphological characteristics of left ventricular non-compaction develop arrhythmias, thrombo-embolism and left ventricular dysfunction. Methods Forty two patients, aged 48.7 ± 2.3 yrs (mean ± SEM underwent cardiovascular magnetic resonance (CMR for the quantification of left ventricular volumes and extent of non-compacted (NC myocardium. The latter was quantified using planimetry on the two-chamber long axis LV view (NC area. The patients included those referred specifically for CMR to investigate suspected cardiomyopathy, and as such is represents a selected group of patients. Results At presentation, 50% had dyspnoea, 19% chest pain, 14% palpitations and 5% stroke. Pulmonary embolism had occurred in 7% and brachial artery embolism in 2%. The ECG was abnormal in 81% and atrial fibrillation occurred in 29%. Transthoracic echocardiograms showed features of NC in only 10%. On CMR, patients who presented with dyspnoea had greater left ventricular volumes (both p Conclusion Left ventricular non-compaction is associated with dysrrhythmias, thromboembolic events, chest pain and LV dysfunction. The inverse correlation between NC area and EF suggests that NC contributes to left ventricular dysfunction.

  3. Advancing Cardiovascular, Neurovascular, and Renal Magnetic Resonance Imaging in Small Rodents Using Cryogenic Radiofrequency Coil Technology.

    Science.gov (United States)

    Niendorf, Thoralf; Pohlmann, Andreas; Reimann, Henning M; Waiczies, Helmar; Peper, Eva; Huelnhagen, Till; Seeliger, Erdmann; Schreiber, Adrian; Kettritz, Ralph; Strobel, Klaus; Ku, Min-Chi; Waiczies, Sonia

    2015-01-01

    Research in pathologies of the brain, heart and kidney have gained immensely from the plethora of studies that have helped shape new methods in magnetic resonance (MR) for characterizing preclinical disease models. Methodical probing into preclinical animal models by MR is invaluable since it allows a careful interpretation and extrapolation of data derived from these models to human disease. In this review we will focus on the applications of cryogenic radiofrequency (RF) coils in small animal MR as a means of boosting image quality (e.g., by supporting MR microscopy) and making data acquisition more efficient (e.g., by reducing measuring time); both being important constituents for thorough investigational studies on animal models of disease. This review attempts to make the (bio)medical imaging, molecular medicine, and pharmaceutical communities aware of this productive ferment and its outstanding significance for anatomical and functional MR in small rodents. The goal is to inspire a more intense interdisciplinary collaboration across the fields to further advance and progress non-invasive MR methods that ultimately support thorough (patho)physiological characterization of animal disease models. In this review, current and potential future applications for the RF coil technology in cardiovascular, neurovascular, and renal disease will be discussed.

  4. Diagnosis and management of ischemic cardiomyopathy: Role of cardiovascular magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    Christina; Doesch; Theano; Papavassiliu

    2014-01-01

    Coronary artery disease(CAD) represents an important cause of mortality. Cardiovascular magnetic resonance(CMR) imaging evolved as an imaging modality that allows the assessment of myocardial function, perfusion, contractile reserve and extent of fibrosis in a single comprehensive exam. This review highlights the role of CMR in the differential diagnosis of acute chest pain by detecting the location of obstructive CAD or necrosis and identifying other conditions like stress cardiomyopathy or myocarditis that can present with acute chest pain. Besides, it underlines the prognostic implication of perfusion abnormalities in the setting of acute chest pain. Furthermore, the review addresses the role of CMR to detect significant CAD in patients with stable CAD. It elucidates the accuracy and clinical utility of CMR with respect to other imaging modalitieslike single-photon emission computed tomography and positron emission tomography. Besides, the prognostic value of CMR stress testing is discussed. Additionally, it summarizes the available CMR techniques to assess myocardial viability and describes algorithm to identify those patient who might profit from revascularization those who should be treated medically. Finally, future promising imaging techniques that will provide further insights into the fundamental disease processes in ischemic cardiomyopathy are discussed.

  5. Dilation of the ascending aorta in Turner syndrome - a prospective cardiovascular magnetic resonance study

    Directory of Open Access Journals (Sweden)

    Pedersen Erik M

    2011-04-01

    Full Text Available Abstract Background The risk of aortic dissection is 100-fold increased in Turner syndrome (TS. Unfortunately, risk stratification is inadequate due to a lack of insight into the natural course of the syndrome-associated aortopathy. Therefore, this study aimed to prospectively assess aortic dimensions in TS. Methods Eighty adult TS patients were examined twice with a mean follow-up of 2.4 ± 0.4 years, and 67 healthy age and gender-matched controls were examined once. Aortic dimensions were measured at nine predefined positions using 3D, non-contrast and free-breathing cardiovascular magnetic resonance. Transthoracic echocardiography and 24-hour ambulatory blood pressure were also performed. Results At baseline, aortic diameters (body surface area indexed were larger at all positions in TS. Aortic dilation was more prevalent at all positions excluding the distal transverse aortic arch. Aortic diameter increased in the aortic sinus, at the sinotubular junction and in the mid-ascending aorta with growth rates of 0.1 - 0.4 mm/year. Aortic diameters at all other positions were unchanged. The bicuspid aortic valve conferred higher aortic sinus growth rates (p Conclusion A general aortopathy is present in TS with enlargement of the ascending aorta, which is accelerated in the presence of a bicuspid aortic valve.

  6. Cardiovascular magnetic resonance imaging to assess myocardial fibrosis in valvular heart disease.

    Science.gov (United States)

    Podlesnikar, Tomaz; Delgado, Victoria; Bax, Jeroen J

    2017-06-22

    The left ventricular (LV) remodeling process associated with significant valvular heart disease (VHD) is characterized by an increase of myocardial interstitial space with deposition of collagen and loss of myofibers. These changes occur before LV systolic function deteriorates or the patient develops symptoms. Cardiovascular magnetic resonance (CMR) permits assessment of reactive fibrosis, with the use of T1 mapping techniques, and replacement fibrosis, with the use of late gadolinium contrast enhancement. In addition, functional consequences of these structural changes can be evaluated with myocardial tagging and feature tracking CMR, which assess the active deformation (strain) of the LV myocardium. Several studies have demonstrated that CMR techniques may be more sensitive than the conventional measures (LV ejection fraction or LV dimensions) to detect these structural and functional changes in patients with severe left-sided VHD and have shown that myocardial fibrosis may not be reversible after valve surgery. More important, the presence of myocardial fibrosis has been associated with lesser improvement in clinical symptoms and recovery of LV systolic function. Whether assessment of myocardial fibrosis may better select the patients with severe left-sided VHD who may benefit from surgery in terms of LV function and clinical symptoms improvement needs to be demonstrated in prospective studies. The present review article summarizes the current status of CMR techniques to assess myocardial fibrosis and appraises the current evidence on the use of these techniques for risk stratification of patients with severe aortic stenosis or regurgitation and mitral regurgitation.

  7. Cardiovascular magnetic resonance of pulmonary artery growth and ventricular function after Norwood procedure with Sano modification

    Directory of Open Access Journals (Sweden)

    Matherne G Paul

    2008-07-01

    Full Text Available Abstract For hypoplastic left heart syndrome (HLHS, there have been concerns regarding pulmonary artery growth and ventricular dysfunction after first stage surgery consisting of the Norwood procedure modified with a right ventricle-to-pulmonary artery conduit. We report our experience using cardiovascular magnetic resonance (CMR to determine and follow pulmonary arterial growth and ventricular function in this cohort. Following first stage palliation, serial CMR was performed at 1 and 10 weeks post-operatively, followed by cardiac catheterization at 4 – 6 months. Thirty-four of 47 consecutive patients with HLHS (or its variations underwent first stage palliation. Serial CMR was performed in 20 patients. Between studies, ejection fraction decreased (58 ± 9% vs. 50 ± 5%, p In this cohort, reasonable growth of pulmonary arteries occurred following first stage palliation with this modification, although that growth was preferential to the left. Serial studies demonstrate worsening of ventricular function for the cohort. CMR was instrumental for detecting pulmonary artery stenosis and right ventricular dysfunction.

  8. Routine evaluation of left ventricular diastolic function by cardiovascular magnetic resonance: A practical approach

    Directory of Open Access Journals (Sweden)

    Vido Diane

    2008-07-01

    Full Text Available Abstract Background Cardiovascular magnetic resonance (CMR has excellent capabilities to assess ventricular systolic function. Current clinical scenarios warrant routine evaluation of ventricular diastolic function for complete evaluation, especially in congestive heart failure patients. To our knowledge, no systematic assessment of diastolic function over a range of lusitropy has been performed using CMR. Methods and Results Left ventricular diastolic function was assessed in 31 subjects (10 controls who underwent CMR and compared with Transthoracic echocardiogram (TTE evaluation of mitral valve (MV and pulmonary vein (PV blood flow. Blood flow in the MV and PV were successfully imaged by CMR for all cases (31/31,100% while TTE evaluated flow in all MV (31/31,100% but only 21/31 PV (68% cases. Velocities of MV flow (E and A measured by CMR correlated well with TTE (r = 0.81, p Conclusion We have shown that there is homology between CMR and TTE for the assessment of diastolic inflow over a wide range of conditions, including normal, impaired relaxation and restrictive. There is excellent agreement of quantitative velocity measurements between CMR and TTE. Diastolic blood flow assessment by CMR can be performed in a single scan, with times ranging from 20 sec to 3 min, and we show that there is good indication for applying CMR to assess diastolic conditions, either as an adjunctive test when evaluating systolic function, or even as a primary test when TTE data cannot be obtained.

  9. Feature tracking measurement of dyssynchrony from cardiovascular magnetic resonance cine acquisitions: comparison with echocardiographic speckle tracking.

    Science.gov (United States)

    Onishi, Toshinari; Saha, Samir K; Ludwig, Daniel R; Onishi, Tetsuari; Marek, Josef J; Cavalcante, João L; Schelbert, Erik B; Schwartzman, David; Gorcsan, John

    2013-10-17

    Analysis of left ventricular (LV) mechanical dyssynchrony may provide incremental prognostic information regarding cardiac resynchronization therapy (CRT) response in addition to QRS width alone. Our objective was to quantify LV dyssynchrony using feature tracking post processing of routine cardiovascular magnetic resonance (CMR) cine acquisitions (FT-CMR) in comparison to speckle tracking echocardiography. We studied 72 consecutive patients who had both steady-state free precession CMR and echocardiography. Mid-LV short axis CMR cines were analyzed using FT-CMR software and compared with echocardiographic speckle tracking radial dyssynchrony (time difference between the anteroseptal and posterior wall peak strain). Radial dyssynchrony analysis was possible by FT-CMR in all patients, and in 67 (93%) by echocardiography. Dyssynchrony by FT-CMR and speckle tracking showed limits of agreement of strain delays of ± 84 ms. These were large (up to 100% or more) relative to the small mean delays measured in more synchronous patients, but acceptable (mainly 200 ms. Radial dyssynchrony was significantly greater in wide QRS patients than narrow QRS patients by both FT-CMR (radial strain delay 230 ± 94 vs. 77 ± 92* ms) and speckle tracking (radial strain delay 242 ± 101 vs. 75 ± 88* ms, all *p speckle tracking echocardiography. The clinical usefulness of the method, for example in predicting prognosis in CRT patients, remains to be investigated.

  10. Velocity encoded cardiovascular magnetic resonance to assess left atrial appendage emptying

    Directory of Open Access Journals (Sweden)

    Muellerleile Kai

    2012-06-01

    Full Text Available Abstract Background The presence of impaired left atrial appendage (LAA function identifies patients who are prone to thrombus formation in the LAA and therefore being at high risk for subsequent cardioembolic stroke. LAA function is typically assessed by measurements of LAA emptying velocities using transesophageal echocardiography (TEE in clinical routine. This study aimed at evaluating the feasibility of assessing LAA emptying by velocity encoded (VENC cardiovascular magnetic resonance (CMR. Methods This study included 30 patients with sinus rhythm (n = 18 or atrial fibrillation (n = 12. VENC-CMR velocity measurements were performed perpendicular to the orifice of the LAA. Peak velocities were measured of passive diastolic LAA emptying (e-wave in all patients. Peak velocities of active, late-diastolic LAA emptying (a-wave were assessed in patients with sinus rhythm. Correlation and agreement was analyzed between VENC-CMR and TEE measurements of e- and a-wave peak velocities. Results A significant correlation and good agreement was found between VENC-CMR and TEE measurements of maximal e-wave velocities (r = 0.61, P  Conclusions The assessment of active and passive LAA emptying by VENC-CMR is feasible. Further evaluation is required of potential future clinical applications such as risk stratification for cardioembolic stroke.

  11. Late gadolinium enhanced cardiovascular magnetic resonance of lamin A/C gene mutation related dilated cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Peuhkurinen Keijo

    2011-06-01

    Full Text Available Abstract Background The purpose of this study was to identify early features of lamin A/C gene mutation related dilated cardiomyopathy (DCM with cardiovascular magnetic resonance (CMR. We characterise myocardial and functional findings in carriers of lamin A/C mutation to facilitate the recognition of these patients using this method. We also investigated the connection between myocardial fibrosis and conduction abnormalities. Methods Seventeen lamin A/C mutation carriers underwent CMR. Late gadolinium enhancement (LGE and cine images were performed to evaluate myocardial fibrosis, regional wall motion, longitudinal myocardial function, global function and volumetry of both ventricles. The location, pattern and extent of enhancement in the left ventricle (LV myocardium were visually estimated. Results Patients had LV myocardial fibrosis in 88% of cases. Segmental wall motion abnormalities correlated strongly with the degree of enhancement. Myocardial enhancement was associated with conduction abnormalities. Sixty-nine percent of our asymptomatic or mildly symptomatic patients showed mild ventricular dilatation, systolic failure or both in global ventricular analysis. Decreased longitudinal systolic LV function was observed in 53% of patients. Conclusions Cardiac conduction abnormalities, mildly dilated LV and depressed systolic dysfunction are common in DCM caused by a lamin A/C gene mutation. However, other cardiac diseases may produce similar symptoms. CMR is an accurate tool to determine the typical cardiac involvement in lamin A/C cardiomyopathy and may help to initiate early treatment in this malignant familiar form of DCM.

  12. Cardiovascular magnetic resonance in patients with pectus excavatum compared with normal controls

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    Abrazado Marlon

    2010-12-01

    Full Text Available Abstract Purpose To assess cardiothoracic structure and function in patients with pectus excavatum compared with control subjects using cardiovascular magnetic resonance imaging (CMR. Method Thirty patients with pectus excavatum deformity (23 men, 7 women, age range: 14-67 years underwent CMR using 1.5-Tesla scanner (Siemens and were compared to 25 healthy controls (18 men, 7 women, age range 18-50 years. The CMR protocol included cardiac cine images, pulmonary artery flow quantification, time resolved 3D contrast enhanced MR angiography (CEMRA and high spatial resolution CEMRA. Chest wall indices including maximum transverse diameter, pectus index (PI, and chest-flatness were measured in all subjects. Left and right ventricular ejection fractions (LVEF, RVEF, ventricular long and short dimensions (LD, SD, mid-ventricle myocardial shortening, pulmonary-systemic circulation time, and pulmonary artery flow were quantified. Results In patients with pectus excavatum, the pectus index was 9.3 ± 5.0 versus 2.8 ± 0.4 in controls (P Conclusion Depression of the sternum in pectus excavatum patients distorts RV geometry. Resting RVEF was reduced by 6% of the control value, suggesting that these geometrical changes may influence myocardial performance. Resting LV function, pulmonary circulation times and pulmonary vascular anatomy and perfusion indices were no different to controls.

  13. Advancing Cardiovascular, Neurovascular and Renal Magnetic Resonance Imaging in Small Rodents Using Cryogenic Radiofrequency Coil Technology

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    Thoralf eNiendorf

    2015-11-01

    Full Text Available Research in pathologies of the brain, heart and kidney have gained immensely from the plethora of studies that have helped shape new methods in magnetic resonance (MR for characterizing preclinical disease models. Methodical probing into preclinical animal models by MR is invaluable since it allows a careful interpretation and extrapolation of data derived from these models to human disease. In this review we will focus on the applications of cryogenic radiofrequency (RF coils in small animal MR as a means of boosting image quality (e.g. by supporting MR microscopy and making data acquisition more efficient (e.g. by reducing measuring time; both being important constituents for thorough investigational studies on animal models of disease. This review attempts to make the (biomedical imaging, molecular medicine and pharmaceutical communities aware of this productive ferment and its outstanding significance for anatomical and functional MR in small rodents. The goal is to inspire a more intense interdisciplinary collaboration across the fields to further advance and progress non-invasive MR methods that ultimately support thorough (pathophysiological characterization of animal disease models. In this review, current and potential future applications for the RF coil technology in cardiovascular, neurovascular and renal disease will be discussed.

  14. Advancing Cardiovascular, Neurovascular, and Renal Magnetic Resonance Imaging in Small Rodents Using Cryogenic Radiofrequency Coil Technology

    Science.gov (United States)

    Niendorf, Thoralf; Pohlmann, Andreas; Reimann, Henning M.; Waiczies, Helmar; Peper, Eva; Huelnhagen, Till; Seeliger, Erdmann; Schreiber, Adrian; Kettritz, Ralph; Strobel, Klaus; Ku, Min-Chi; Waiczies, Sonia

    2015-01-01

    Research in pathologies of the brain, heart and kidney have gained immensely from the plethora of studies that have helped shape new methods in magnetic resonance (MR) for characterizing preclinical disease models. Methodical probing into preclinical animal models by MR is invaluable since it allows a careful interpretation and extrapolation of data derived from these models to human disease. In this review we will focus on the applications of cryogenic radiofrequency (RF) coils in small animal MR as a means of boosting image quality (e.g., by supporting MR microscopy) and making data acquisition more efficient (e.g., by reducing measuring time); both being important constituents for thorough investigational studies on animal models of disease. This review attempts to make the (bio)medical imaging, molecular medicine, and pharmaceutical communities aware of this productive ferment and its outstanding significance for anatomical and functional MR in small rodents. The goal is to inspire a more intense interdisciplinary collaboration across the fields to further advance and progress non-invasive MR methods that ultimately support thorough (patho)physiological characterization of animal disease models. In this review, current and potential future applications for the RF coil technology in cardiovascular, neurovascular, and renal disease will be discussed. PMID:26617515

  15. Myocardial late gadolinium enhancement in specific cardiomyopathies by cardiovascular magnetic resonance: a preliminary experience.

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    Silva, Caterina; Moon, James C; Elkington, Andrew G; John, Anna S; Mohiaddin, Raad H; Pennell, Dudley J

    2007-12-01

    Late gadolinium enhancement cardiovascular magnetic resonance (CMR) can visualize myocardial interstitial abnormalities. The aim of this study was to assess whether regions of abnormal myocardium can also be visualized by late enhancement gadolinium CMR in the specific cardiomyopathies. A retrospective review of all referrals for gadolinium CMR with specific cardiomyopathy over 20 months. Nine patients with different specific cardiomyopathies were identified. Late enhancement was demonstrated in all patients, with a mean signal intensity of 390 +/- 220% compared with normal regions. The distribution pattern of late enhancement was unlike the subendocardial late enhancement related to coronary territories found in myocardial infarction. The affected areas included papillary muscles (sarcoid), the mid-myocardium (Anderson-Fabry disease, glycogen storage disease, myocarditis, Becker muscular dystrophy) and the global sub-endocardium (systemic sclerosis, Loeffler's endocarditis, amyloid, Churg-Strauss). Focal myocardial late gadolinium enhancement is found in the specific cardiomyopathies, and the pattern is distinct from that seen in infarction. Further systematic studies are warranted to assess whether the pattern and extent of late enhancement may aid diagnosis and prognostic assessment.

  16. Structural and functional cardiac changes in myotonic dystrophy type 1: a cardiovascular magnetic resonance study

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    Hermans Mieke CE

    2012-07-01

    Full Text Available Abstract Background Myotonic dystrophy type 1 (MD1 is a neuromuscular disorder with potential involvement of the heart and increased risk of sudden death. Considering the importance of cardiomyopathy as a predictor of prognosis, we aimed to systematically evaluate and describe structural and functional cardiac alterations in patients with MD1. Methods Eighty MD1 patients underwent physical examination, electrocardiography (ECG, echocardiography and cardiovascular magnetic resonance (CMR. Blood samples were taken for determination of NT-proBNP plasma levels and CTG repeat length. Results Functional and structural abnormalities were detected in 35 patients (44%. Left ventricular systolic dysfunction was found in 20 cases, left ventricular dilatation in 7 patients, and left ventricular hypertrophy in 6 patients. Myocardial fibrosis was seen in 10 patients (12.5%. In general, patients had low left ventricular mass indexes. Right ventricular involvement was uncommon and only seen together with left ventricular abnormalities. Functional or structural cardiac involvement was associated with age (p = 0.04, male gender (p Conclusions CMR can be useful to detect early structural and functional myocardial abnormalities in patients with MD1. Myocardial involvement is strongly associated with conduction abnormalities, but a normal ECG does not exclude myocardial alterations. These findings lend support to the hypothesis that MD1 patients have a complex cardiac phenotype, including both myocardial and conduction system alteration.

  17. Cardiac magnetic resonance: Impact on diagnosis and management of patients with congenital cardiovascular disease

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    Secchi, F., E-mail: francescosecchimd@gmail.com [Scuola di Specializzazione in Radiodiagnostica, Universita degli Studi di Milano, Milan (Italy); Di Leo, G. [S.C. di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese, Milan (Italy); Papini, G.D.E. [Scuola di Specializzazione in Radiodiagnostica, Universita degli Studi di Milano, Milan (Italy); Nardella, V.G. [Facolta di Medicina e Chirurgia, Universita degli Studi di Milano, Milan (Italy); Negura, D.; Carminati, M. [S.C. di Cardiologia Pediatrica, IRCCS Policlinico San Donato, San Donato Milanese, Milan (Italy); Sardanelli, F. [S.C. di Radiologia, IRCCS Policlinico San Donato, San Donato Milanese, Milan (Italy); Dipartimento di Scienze Medico-Chirurgiche, Universita degli Studi di Milano, Milan (Italy)

    2011-08-15

    Aim: To estimate the clinical impact of cardiac magnetic resonance (CMR) in patients with congenital cardiovascular disease (CCD). Materials and methods: Since 2003, 1.5 T CMR was used at our university hospital to evaluate morphology, cardiac kinetics, aortic and pulmonary flow, and vascular anatomy in patients with CCD. The present study considered a consecutive series of these patients from 2003 to 2006. A paediatric cardiologist judged our reports as expected or unexpected and, secondarily, as not reliable (level 0), describing findings already known (level 1), not changing therapy/suggested lifestyle (level 2), changing therapy/suggested lifestyle (level 3) or changing diagnosis (level 4). Results: CMR reports were judged to be expected in 187/214 (87%) and unexpected in 27/214 (13%). Less than 2% of CMRs were judged as levels 0 or 1, 66% as level 2, and 5% as level 4. During 2005-2006 the clinical impact improved toward higher impact levels (p < 0.001, chi-square test). Conclusions: In patients with CCD, more than one in 10 CMR reports were unexpected to cardiologists and over seven in 10 prompted a change of diagnosis or therapy.

  18. Myocardial edema in Takotsubo syndrome mimicking apical hypertrophic cardiomyopathy: An insight into diagnosis by cardiovascular magnetic resonance.

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    Izgi, Cemil; Ray, Sanjoy; Nyktari, Evangelia; Alpendurada, Francisco; Lyon, Alexander R; Rathore, Sudhir; Baksi, Arun John

    2015-01-01

    Myocardial edema is one of the characteristic features in the pathogenesis of Takotsubo syndrome. We report a middle aged man who presented with typical clinical and echocardiographic features of apical variant of Takotsubo syndrome. However, a cardiovascular magnetic resonance study performed 10 days after presentation did not show any apical 'ballooning' but revealed features of an apical hypertrophic cardiomyopathy on cine images. Tissue characterization with T2 weighted images proved severe edema as the cause of significantly increased apical wall thickness. A follow-up cardiovascular magnetic resonance study was performed 5 months later which showed that edema, wall thickening and the appearance of apical hypertrophic cardiomyopathy all resolved, confirming Takotsubo syndrome as the cause of the initial appearance. As the affected myocardium most commonly involves the apical segments, an edema induced increase in apical wall thickness may lead to appearances of an apical hypertrophic cardiomyopathy rather than apical ballooning in the acute to subacute phase of Takotsubo syndrome.

  19. Myocardial tagging by cardiovascular magnetic resonance: evolution of techniques--pulse sequences, analysis algorithms, and applications.

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    Ibrahim, El-Sayed H

    2011-07-28

    Cardiovascular magnetic resonance (CMR) tagging has been established as an essential technique for measuring regional myocardial function. It allows quantification of local intramyocardial motion measures, e.g. strain and strain rate. The invention of CMR tagging came in the late eighties, where the technique allowed for the first time for visualizing transmural myocardial movement without having to implant physical markers. This new idea opened the door for a series of developments and improvements that continue up to the present time. Different tagging techniques are currently available that are more extensive, improved, and sophisticated than they were twenty years ago. Each of these techniques has different versions for improved resolution, signal-to-noise ratio (SNR), scan time, anatomical coverage, three-dimensional capability, and image quality. The tagging techniques covered in this article can be broadly divided into two main categories: 1) Basic techniques, which include magnetization saturation, spatial modulation of magnetization (SPAMM), delay alternating with nutations for tailored excitation (DANTE), and complementary SPAMM (CSPAMM); and 2) Advanced techniques, which include harmonic phase (HARP), displacement encoding with stimulated echoes (DENSE), and strain encoding (SENC). Although most of these techniques were developed by separate groups and evolved from different backgrounds, they are in fact closely related to each other, and they can be interpreted from more than one perspective. Some of these techniques even followed parallel paths of developments, as illustrated in the article. As each technique has its own advantages, some efforts have been made to combine different techniques together for improved image quality or composite information acquisition. In this review, different developments in pulse sequences and related image processing techniques are described along with the necessities that led to their invention, which makes this

  20. Myocardial tagging by Cardiovascular Magnetic Resonance: evolution of techniques--pulse sequences, analysis algorithms, and applications

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    Ibrahim El-Sayed H

    2011-07-01

    Full Text Available Abstract Cardiovascular magnetic resonance (CMR tagging has been established as an essential technique for measuring regional myocardial function. It allows quantification of local intramyocardial motion measures, e.g. strain and strain rate. The invention of CMR tagging came in the late eighties, where the technique allowed for the first time for visualizing transmural myocardial movement without having to implant physical markers. This new idea opened the door for a series of developments and improvements that continue up to the present time. Different tagging techniques are currently available that are more extensive, improved, and sophisticated than they were twenty years ago. Each of these techniques has different versions for improved resolution, signal-to-noise ratio (SNR, scan time, anatomical coverage, three-dimensional capability, and image quality. The tagging techniques covered in this article can be broadly divided into two main categories: 1 Basic techniques, which include magnetization saturation, spatial modulation of magnetization (SPAMM, delay alternating with nutations for tailored excitation (DANTE, and complementary SPAMM (CSPAMM; and 2 Advanced techniques, which include harmonic phase (HARP, displacement encoding with stimulated echoes (DENSE, and strain encoding (SENC. Although most of these techniques were developed by separate groups and evolved from different backgrounds, they are in fact closely related to each other, and they can be interpreted from more than one perspective. Some of these techniques even followed parallel paths of developments, as illustrated in the article. As each technique has its own advantages, some efforts have been made to combine different techniques together for improved image quality or composite information acquisition. In this review, different developments in pulse sequences and related image processing techniques are described along with the necessities that led to their invention

  1. On the subjective acceptance during cardiovascular magnetic resonance imaging at 7.0 Tesla.

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    Sabrina Klix

    Full Text Available This study examines the subjective acceptance during UHF-CMR in a cohort of healthy volunteers who underwent a cardiac MR examination at 7.0T.Within a period of two-and-a-half years (January 2012 to June 2014 a total of 165 healthy volunteers (41 female, 124 male without any known history of cardiac disease underwent UHF-CMR. For the assessment of the subjective acceptance a questionnaire was used to examine the participants experience prior, during and after the UHF-CMR examination. For this purpose, subjects were asked to respond to the questionnaire in an exit interview held immediately after the completion of the UHF-CMR examination under supervision of a study nurse to ensure accurate understanding of the questions. All questions were answered with "yes" or "no" including space for additional comments.Transient muscular contraction was documented in 12.7% of the questionnaires. Muscular contraction was reported to occur only during periods of scanning with the magnetic field gradients being rapidly switched. Dizziness during the study was reported by 12.7% of the subjects. Taste of metal was reported by 10.1% of the study population. Light flashes were reported by 3.6% of the entire cohort. 13% of the subjects reported side effects/observations which were not explicitly listed in the questionnaire but covered by the question about other side effects. No severe side effects as vomiting or syncope after scanning occurred. No increase in heart rate was observed during the UHF-CMR exam versus the baseline clinical examination.This study adds to the literature by detailing the subjective acceptance of cardiovascular magnetic resonance imaging examinations at a magnetic field strength of 7.0T. Cardiac MR examinations at 7.0T are well tolerated by healthy subjects. Broader observational and multi-center studies including patient cohorts with cardiac diseases are required to gain further insights into the subjective acceptance of UHF

  2. Performance Analysis of 3-Dimensional Turbo Codes

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    Rosnes, Eirik

    2011-01-01

    In this work, we consider the minimum distance properties and convergence thresholds of 3-dimensional turbo codes (3D-TCs), recently introduced by Berrou et al.. Here, we consider binary 3D-TCs while the original work of Berrou et al. considered double-binary codes. In the first part of the paper, the minimum distance properties are analyzed from an ensemble perspective, both in the finite-length regime and in the asymptotic case of large block lengths. In particular, we analyze the asymptotic weight distribution of 3D-TCs and show numerically that their typical minimum distance dmin may, depending on the specific parameters, asymptotically grow linearly with the block length, i.e., the 3D-TC ensemble is asymptotically good for some parameters. In the second part of the paper, we derive some useful upper bounds on the dmin when using quadratic permutation polynomial (QPP) interleavers with a quadratic inverse. Furthermore, we give examples of interleaver lengths where an upper bound appears to be tight. The b...

  3. Measurements of Pulmonary Artery Size for Assessment of Pulmonary Hypertension by Cardiovascular Magnetic Resonance and Clinical Application

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    Fan YANG

    2017-02-01

    Full Text Available Background and objective Pulmonary hypertension (PH often leads to dilatation of main pulmonary artery (MPA. MPA measurements can be used to predict PH. This aim of this study is to investigate power of MPA vessel indices, which are acquired from cardiovascular magnetic resonance, to evaluate PH. Methods Cardiovascular-magnetic-resonance-determined parameters of MPA were acquired and calculated in 83 PH patients, whose diagnosis were confirmed with right heart catheterization and 49 healthy volunteers; these parameters included MPA diameter (DPA, ratio of DPA and ascending aorta diameter (DPA/DAo, max mean diameter (MDmax, min mean diameter (MDmin, fraction transverse diameter (fTD, fraction longitudinal diameter (fLD, and distensibility. Results Compared with control group, DPA, DPA/DAo, MDmax, and MDmin were significantly higher in patients with PH (P28.4 mm, and MDmax>32.4 mm (area under the curve, AUC=0.979, 0.981 showed best performance in predicting PH, yielding highest specificity at 100%. Conclusion Noninvasive cardiovascular-magnetic-resonance-derived MPA measurements provide excellent and practical reference in clinical settings for detecting PH.

  4. Measuring aortic pulse wave velocity using high-field cardiovascular magnetic resonance: comparison of techniques

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    Shaffer Jean M

    2010-05-01

    Full Text Available Abstract Background The assessment of arterial stiffness is increasingly used for evaluating patients with different cardiovascular diseases as the mechanical properties of major arteries are often altered. Aortic stiffness can be noninvasively estimated by measuring pulse wave velocity (PWV. Several methods have been proposed for measuring PWV using velocity-encoded cardiovascular magnetic resonance (CMR, including transit-time (TT, flow-area (QA, and cross-correlation (XC methods. However, assessment and comparison of these techniques at high field strength has not yet been performed. In this work, the TT, QA, and XC techniques were clinically tested at 3 Tesla and compared to each other. Methods Fifty cardiovascular patients and six volunteers were scanned to acquire the necessary images. The six volunteer scans were performed twice to test inter-scan reproducibility. Patient images were analyzed using the TT, XC, and QA methods to determine PWV. Two observers analyzed the images to determine inter-observer and intra-observer variabilities. The PWV measurements by the three methods were compared to each other to test inter-method variability. To illustrate the importance of PWV using CMR, the degree of aortic stiffness was assessed using PWV and related to LV dysfunction in five patients with diastolic heart failure patients and five matched volunteers. Results The inter-observer and intra-observer variability results showed no bias between the different techniques. The TT and XC results were more reproducible than the QA; the mean (SD inter-observer/intra-observer PWV differences were -0.12(1.3/-0.04(0.4 for TT, 0.2(1.3/0.09(0.9 for XC, and 0.6(1.6/0.2(1.4 m/s for QA methods, respectively. The correlation coefficients (r for the inter-observer/intra-observer comparisons were 0.94/0.99, 0.88/0.94, and 0.83/0.92 for the TT, XC, and QA methods, respectively. The inter-scan reproducibility results showed low variability between the repeated

  5. Prognostic value of adenosine stress cardiovascular magnetic resonance in patients with low-risk chest pain

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    Oshinski John N

    2009-09-01

    Full Text Available Abstract Background Approximately 5% of patients with an acute coronary syndrome are discharged from the emergency room with an erroneous diagnosis of non-cardiac chest pain. Highly accurate non-invasive stress imaging is valuable for assessment of low-risk chest pain patients to prevent these errors. Adenosine stress cardiovascular magnetic resonance (AS-CMR is an imaging modality with increasing application. The goal of this study was to evaluate the negative prognostic value of AS-CMR among low-risk acute chest pain patients. Methods We studied 103 patients, mean 56.7 ± 12.3 years of age, with chest pain and no electrocardiographic evidence of ischemia and negative cardiac biomarkers of necrosis, who were admitted to the Cardiac Decision Unit of our institution. All patients underwent AS-CMR. A negative AS-CMR was defined as absence of all the following: regional wall motion abnormalities at rest; perfusion defects during stress (adenosine and rest; and myocardial scar on late gadolinium enhancement images. The patients were followed for a mean of 277 (range 161-462 days. The primary end point was defined as the combination of cardiac death, nonfatal acute myocardial infarction, re-hospitalization for chest pain, obstructive coronary artery disease (>50% coronary stenosis on invasive angiography and coronary revascularization. Results In 14 patients (13.6%, AS-CMR was positive. The remaining 89 patients (86.4%, who had negative AS-CMR, were discharged. No patient with negative AS-CMR reached the primary end-point during follow-up. The negative predictive value of AS-CMR was 100%. Conclusion AS-CMR holds promise as a useful tool to rule out significant coronary artery disease in patients with low-risk chest pain. Patients with negative AS-CMR have an excellent short and mid-term prognosis.

  6. Troponin release following endurance exercise: is inflammation the cause? a cardiovascular magnetic resonance study

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    O'Hanlon Rory

    2010-07-01

    Full Text Available Abstract Background The aetiology and clinical significance of troponin release following endurance exercise is unclear but may be due to transient myocardial inflammation. Cardiovascular magnetic resonance (CMR affords us the opportunity to evaluate the presence of myocardial inflammation and focal fibrosis and is the ideal imaging modality to study this hypothesis. We sought to correlate the relationship between acute bouts of ultra endurance exercise leading to cardiac biomarkers elevation and the presence of myocardial inflammation and fibrosis using CMR. Methods 17 recreation athletes (33.5 +/- 6.5 years were studied before and after a marathon run with troponin, NTproBNP, and CMR. Specific imaging parameters to look for inflammation included T2 weighted images, and T1 weighted spin-echo images before and after an intravenous gadolinium-DTPA to detect myocardial hyperemia secondary to inflammation. Late gadolinium imaging was performed (LGE to detect any focal regions of replacement fibrosis. Results Eleven of the 17 participant had elevations of TnI above levels of cut off for myocardial infarction 6 hrs after the marathon (0.075 +/- 0.02, p = 0.007. Left ventricular volumes were reduced post marathon and a small increase in ejection fraction was noted (64+/- 1% pre, 67+/- 1.2% post, P = 0.014. Right ventricular volumes, stroke volume, and ejection fraction were unchanged post marathon. No athlete fulfilled criteria for myocardial inflammation based on current criteria. No regions of focal fibrosis were seen in any of the participants. Conclusion Exercise induced cardiac biomarker release is not associated with any functional changes by CMR or any detectable myocardial inflammation or fibrosis.

  7. Left ventricular thrombus formation after acute myocardial infarction as assessed by cardiovascular magnetic resonance imaging

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    Delewi, Ronak [Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Interuniversity Cardiology Institute of the Netherlands (Netherlands); Nijveldt, Robin [Department of Cardiology, VU University Medical Center, Amsterdam (Netherlands); Hirsch, Alexander [Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Marcu, Constantin B.; Robbers, Lourens [Department of Cardiology, VU University Medical Center, Amsterdam (Netherlands); Hassell, Marriela E.C.J.; Bruin, Rianne H.A. de; Vleugels, Jim; Laan, Anja M. van der; Bouma, Berto J. [Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Tio, René A. [Thorax Center, University Medical Center Groningen, Groningen (Netherlands); Tijssen, Jan G.P. [Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Rossum, Albert C. van [Department of Cardiology, VU University Medical Center, Amsterdam (Netherlands); Zijlstra, Felix [Thorax Center, Department of Cardiology, Erasmus University Medical Center, Rotterdam (Netherlands); Piek, Jan J., E-mail: j.j.piek@amc.uva.nl [Department of Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands)

    2012-12-15

    Introduction: Left ventricular (LV) thrombus formation is a feared complication of myocardial infarction (MI). We assessed the prevalence of LV thrombus in ST-segment elevated MI patients treated with percutaneous coronary intervention (PCI) and compared the diagnostic accuracy of transthoracic echocardiography (TTE) to cardiovascular magnetic resonance imaging (CMR). Also, we evaluated the course of LV thrombi in the modern era of primary PCI. Methods: 200 patients with primary PCI underwent TTE and CMR, at baseline and at 4 months follow-up. Studies were analyzed by two blinded examiners. Patients were seen at 1, 4, 12, and 24 months for assessment of clinical status and adverse events. Results: On CMR at baseline, a thrombus was found in 17 of 194 (8.8%) patients. LV thrombus resolution occurred in 15 patients. Two patients had persistence of LV thrombus on follow-up CMR. On CMR at four months, a thrombus was found in an additional 12 patients. In multivariate analysis, thrombus formation on baseline CMR was independently associated with, baseline infarct size (g) (B = 0.02, SE = 0.02, p < 0.001). Routine TTE had a sensitivity of 21–24% and a specificity of 95–98% compared to CMR for the detection of LV thrombi. Intra- and interobserver variation for detection of LV thrombus were lower for CMR (κ = 0.91 and κ = 0.96) compared to TTE (κ = 0.74 and κ = 0.53). Conclusion: LV thrombus still occurs in a substantial amount of patients after PCI-treated MI, especially in larger infarct sizes. Routine TTE had a low sensitivity for the detection of LV thrombi and the interobserver variation of TTE was large.

  8. Left ventricular remodeling and hypertrophy in patients with aortic stenosis: insights from cardiovascular magnetic resonance

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    Dweck Marc R

    2012-07-01

    Full Text Available Abstract Background Cardiovascular magnetic resonance (CMR is the gold standard non-invasive method for determining left ventricular (LV mass and volume but has not been used previously to characterise the LV remodeling response in aortic stenosis. We sought to investigate the degree and patterns of hypertrophy in aortic stenosis using CMR. Methods Patients with moderate or severe aortic stenosis, normal coronary arteries and no other significant valve lesions or cardiomyopathy were scanned by CMR with valve severity assessed by planimetry and velocity mapping. The extent and patterns of hypertrophy were investigated using measurements of the LV mass index, indexed LV volumes and the LV mass/volume ratio. Asymmetric forms of remodeling and hypertrophy were defined by a regional wall thickening ≥13 mm and >1.5-fold the thickness of the opposing myocardial segment. Results Ninety-one patients (61±21 years; 57 male with aortic stenosis (aortic valve area 0.93±0.32cm2 were recruited. The severity of aortic stenosis was unrelated to the degree (r2=0.012, P=0.43 and pattern (P=0.22 of hypertrophy. By univariate analysis, only male sex demonstrated an association with LV mass index (P=0.02. Six patterns of LV adaption were observed: normal ventricular geometry (n=11, concentric remodeling (n=11, asymmetric remodeling (n=11, concentric hypertrophy (n=34, asymmetric hypertrophy (n=14 and LV decompensation (n=10. Asymmetric patterns displayed considerable overlap in appearances (wall thickness 17±2mm with hypertrophic cardiomyopathy. Conclusions We have demonstrated that in patients with moderate and severe aortic stenosis, the pattern of LV adaption and degree of hypertrophy do not closely correlate with the severity of valve narrowing and that asymmetric patterns of wall thickening are common. Trial registration ClinicalTrials.gov Reference Number: NCT00930735

  9. Gender difference in ventricular response to aortic stenosis: insight from cardiovascular magnetic resonance.

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    Joo Myung Lee

    Full Text Available Although left ventricular hypertrophy (LVH and remodeling is associated with cardiac mortality and morbidity, little is known about the impact of gender on the ventricular response in aortic stenosis (AS patients. This study aimed to analyze the differential effect of gender on ventricular remodeling in moderate to severe AS patients.A total of 118 consecutive patients (67±9 years; 63 males with moderate or severe AS (severe 81.4% underwent transthoracic echocardiography and cardiovascular magnetic resonance (CMR within a 1-month period in this two-center prospective registry. The pattern of LV remodeling was assessed using the LV mass index (LVMI and LV remodeling index (LVRI; LV mass/LV end-diastolic volume by CMR. Although there were no differences in AS severity parameters nor baseline characteristics between genders, males showed a significantly higher LVMI (102.6±29.1 g/m2 vs. 86.1±29.2 g/m2, p=0.003 and LVRI (1.1±0.2 vs. 1.0±0.3, p=0.018, regardless of AS severity. The LVMI was significantly associated with aortic valve area (AVA index and valvuloarterial impedance in females, whereas it was not in males, resulting in significant interaction between genders (PInteraction=0.007/0.014 for AVA index/valvuloarterial impedance, respectively. Similarly, the LVRI also showed a significantly different association between male and female subjects with the change in AS severity parameters (PInteraction=0.033/<0.001/0.029 for AVA index/transaortic mean pressure gradient/valvuloarterial impedance, respectively.Males are associated with greater degree of LVH and higher LVRI compared to females at moderate to severe AS. However, females showed a more exaggerated LV remodeling response, with increased severity of AS and hemodynamic loads, than males.

  10. Assessment of atrial septal defects in adults comparing cardiovascular magnetic resonance with transoesophageal echocardiography

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    Brown Michael A

    2010-07-01

    Full Text Available Abstract Background Many adult patients with secundum-type atrial septal defects (ASDs are able to have these defects fixed percutaneously. Traditionally, this has involved an assessment of ASD size, geometry and atrial septal margins by transoesophageal echocardiography (TOE prior to percutaneous closure. This is a semi-invasive technique, and all of the information obtained could potentially be obtained by non-invasive cardiovascular magnetic resonance (CMR. We compared the assessment of ASDs in consecutive patients being considered for percutaneous ASD closure using CMR and TOE. Methods Consecutive patients with ASDs diagnosed on transthoracic echocardiography (TTE were invited to undergo both CMR and TOE. Assessment of atrial septal margins, maximal and minimal defect dimensions was performed with both techniques. Analyses between CMR and TOE were made using simple linear regression and Bland Altman Analyses. Results Total CMR scan time was 20 minutes, and comparable to the TOE examination time. A total of 20 patients (M:F = 5:15, mean age 42.8 years ± 15.7 were included in the analyses. There was an excellent agreement between CMR and TOE for estimation of maximum defect size (R = 0.87. The anterior inferior, anterior superior and posterior inferior margins could be assessed in all patients with CMR. The posterior superior margin could not be assessed in only one patient. Furthermore, in 1 patient in whom TOE was unable to be performed, CMR was used to successfully direct percutaneous ASD closure. Conclusions CMR agrees with TOE assessment of ASDs in the work-up for percutaneous closure. Potentially CMR could be used instead of TOE for this purpose.

  11. Hemodynamic predictors of aortic dilatation in bicuspid aortic valve by velocity-encoded cardiovascular magnetic resonance

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    Ramamurthy Senthil

    2010-01-01

    Full Text Available Abstract Background Congenital Bicuspid Aortic Valve (BAV is a significant risk factor for serious complications including valve dysfunction, aortic dilatation, dissection, and sudden death. Clinical tools for identification and monitoring of BAV patients at high risk for development of aortic dilatation, an early complication, are not available. Methods This paper reports an investigation in 18 pediatric BAV patients and 10 normal controls of links between abnormal blood flow patterns in the ascending aorta and aortic dilatation using velocity-encoded cardiovascular magnetic resonance. Blood flow patterns were quantitatively expressed in the angle between systolic left ventricular outflow and the aortic root channel axis, and also correlated with known biochemical markers of vessel wall disease. Results The data confirm larger ascending aortas in BAV patients than in controls, and show more angled LV outflow in BAV (17.54 ± 0.87 degrees than controls (10.01 ± 1.29 (p = 0.01. Significant correlation of systolic LV outflow jet angles with dilatation was found at different levels of the aorta in BAV patients STJ: r = 0.386 (N = 18, p = 0.048, AAO: r = 0.536 (N = 18, p = 0.022, and stronger correlation was found with patients and controls combined into one population: SOV: r = 0.405 (N = 28, p = 0.033, STJ: r = 0.562 (N = 28, p = 0.002, and AAO r = 0.645 (N = 28, p Conclusions The results of this study provide new insights into the pathophysiological processes underlying aortic dilatation in BAV patients. These results show a possible path towards the development of clinical risk stratification protocols in order to reduce morbidity and mortality for this common congenital heart defect.

  12. Contribution of cardiovascular magnetic resonance in the evaluation of coronary arteries

    Institute of Scientific and Technical Information of China (English)

    Sophie; Mavrogeni; George; Markousis-Mavrogenis; Genovefa; Kolovou

    2014-01-01

    Cardiovascular magnetic resonance(CMR) allows the nonradiating assessment of coronary arteries; to achieve better image quality cardiorespiratory artefacts should be corrected. Coronary MRA(CMRA) at the mo-ment is indicated only for the detection of abnormal coronary origin, coronary artery ectasia and/or aneu-rysms(class Ⅰ indication) and coronary bypass grafts(class Ⅱ indication). CMRA utilisation for coronary ar-tery disease is not yet part of clinical routine. However, the lack of radiation is of special value for the coronary artery evaluation in children and women. CMRA can assess the proximal part of coronary arteries in almost all cases. The best results have been observed in the evaluation of the left anterior descending and the right coronary artery, while the left circumflex, which is lo-cated far away from the coil elements, is frequently im-aged with reduced quality, compared to the other two. Different studies detected an increase in wall thickness of the coronaries in patients with type Ⅰ diabetes and abnormal renal function. Additionally, the non-contrast enhanced T1-weighed images detected the presence of thrombus in acute myocardial infarction. New tech-niques using delayed gadolinium enhanced imaging promise the direct visualization of inflamed plaques in the coronary arteries. The major advantage of CMRis the potential of an integrated protocol offering as-sessment of coronary artery anatomy, cardiac function, inflammation and stress perfusion-fibrosis in the same study, providing an individualized clinical profile of pa-tients with heart disease.

  13. The role of cardiovascular magnetic resonance in candidates for Fontan operation: Proposal of a new Algorithm

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    Ait-Ali Lamia

    2011-11-01

    Full Text Available Abstract Background To propose a new diagnostic algorithm for candidates for Fontan and identify those who can skip cardiac catheterization (CC. Methods Forty-four candidates for Fontan (median age 4.8 years, range: 2-29 years were prospectively evaluated by trans-thoracic echocardiography (TTE, Cardiovascular magnetic resonance (CMR and CC. Before CC, according to clinical, echo and CMR findings, patients were divided in two groups: Group I comprised 18 patients deemed suitable for Fontan without requiring CC; group II comprised 26 patients indicated for CC either in order to detect more details, or for interventional procedures. Results In Group I ("CC not required" no unexpected new information affecting surgical planning was provided by CC. Conversely, in Group II new information was provided by CC in three patients (0 vs 11.5%, p = 0.35 and in six an interventional procedure was performed. During CC, minor complications occurred in one patient from Group I and in three from Group II (6 vs 14%, p = 0.7. Radiation Dose-Area product was similar in the two groups (Median 20 Gycm2, range: 5-40 vs 26.5 Gycm2, range: 9-270 p = 0.37. All 18 Group I patients and 19 Group II patients underwent a total cavo-pulmonary anastomosis; in the remaining seven group II patients, four were excluded from Fontan; two are awaiting Fontan; one refused the intervention. Conclusion In this paper we propose a new diagnostic algorithm in a pre-Fontan setting. An accurate non-invasive evaluation comprising TTE and CMR could select patients who can skip CC.

  14. Low prevalence of fibrosis in thalassemia major assessed by late gadolinium enhancement cardiovascular magnetic resonance

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    Tanner Mark A

    2011-01-01

    Full Text Available Abstract Background Heart failure remains a major cause of mortality in thalassaemia major. The possible role of cardiac fibrosis in thalassemia major in the genesis of heart failure is not clear. It is also unclear whether cardiac fibrosis might arise as a result of heart failure. Methods We studied 45 patients with thalassaemia major who had a wide range of current cardiac iron loading and included patients with prior and current heart failure. Myocardial iron was measured using T2* cardiovascular magnetic resonance (CMR, and following this, late gadolinium enhancement (LGE was used to determine the presence of macroscopic myocardial fibrosis. Results The median myocardial T2* in all patients was 22.6 ms (range 5.3-58.8 ms. Fibrosis was detected in only one patient, whose myocardial T2* was 20.1 ms and left ventricular ejection fraction 57%. No fibrosis was identified in 5 patients with a history of heart failure with full recovery, in 3 patients with current left ventricular dysfunction undergoing treatment, or in 18 patients with myocardial iron loading with cardiacT2* Conclusion This study shows that macroscopic myocardial fibrosis is uncommon in thalassemia major across a broad spectrum of myocardial iron loading. Importantly, there was no macroscopic fibrosis in patients with current or prior heart failure, or in patients with myocardial iron loading without heart failure. Therefore if myocardial fibrosis indeed contributes to myocardial dysfunction in thalassemia, our data combined with the knowledge that the myocardial dysfunction of iron overload can be reversed, indicates that any such fibrosis would need to be both microscopic and reversible.

  15. Cardiac remodeling following percutaneous mitral valve repair. Initial results assessed by cardiovascular magnetic resonance imaging

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    Radunski, U.K [University Heart Center, Hamburg (Germany). Cardiology; Franzen, O. [Rigshospitalet, Copenhagen (Denmark). Cardiology; Barmeyer, A. [Klinikum Dortmund (Germany). Kardiologie; and others

    2014-10-15

    Percutaneous mitral valve repair with the MitraClip device (Abbott Vascular, Redwood City, California, USA) is a novel therapeutic option in patients with mitral regurgitation. This study evaluated the feasibility of cardiac volume measurements by cardiovascular magnetic resonance imaging (CMR) to assess reverse myocardial remodeling in patients after MitraClip implantation. 12 patients underwent CMR at baseline (BL) before and at 6 months follow-up (FU) after MitraClip implantation. Cine-CMR was performed in short- and long-axes for the assessment of left ventricular (LV), right ventricular (RV) and left atrial (LA) volumes. Assessment of endocardial contours was not compromised by the device-related artifact. No significant differences in observer variances were observed for LV, RV and LA volume measurements between BL and FU. LV end-diastolic (median 127 [IQR 96-150] vs. 112 [86-150] ml/m{sup 2}; p=0.03) and LV end-systolic (82 [54-91] vs. 69 [48-99] ml/m{sup 2}; p=0.03) volume indices decreased significantly from BL to FU. No significant differences were found for RV end-diastolic (94 [75-103] vs. 99 [77-123] ml/m{sup 2}; p=0.91), RV end-systolic (48 [42-80] vs. 51 [40-81] ml/m{sup 2}; p=0.48), and LA (87 [55-124] vs. 92 [48-137]R ml/m{sup 2}; p=0.20) volume indices between BL and FU. CMR enables the assessment of cardiac volumes in patients after MitraClip implantation. Our CMR findings indicate that percutaneous mitral valve repair results in reverse LV but not in RV or LA remodeling.

  16. Regional quantification of myocardial mechanics in rat using 3D cine DENSE cardiovascular magnetic resonance.

    Science.gov (United States)

    Zhang, Xiaoyan; Liu, Zhan-Qiu; Singh, Dara; Wehner, Gregory J; Powell, David K; Campbell, Kenneth S; Fornwalt, Brandon K; Wenk, Jonathan F

    2017-08-01

    Rat models have assumed an increasingly important role in cardiac research. However, a detailed profile of regional cardiac mechanics, such as strains and torsion, is lacking for rats. We hypothesized that healthy rat left ventricles (LVs) exhibit regional differences in cardiac mechanics, which are part of normal function. In this study, images of the LV were obtained with 3D cine displacement encoding with stimulated echoes (DENSE) cardiovascular magnetic resonance in 10 healthy rats. To evaluate regional cardiac mechanics, the LV was divided into basal, mid-ventricular, and apical regions. The myocardium at the mid-LV was further partitioned into four wall segments (i.e. septal, inferior, lateral, and anterior) and three transmural layers (i.e. sub-endocardium, mid-myocardium, and sub-epicardium). The six Lagrangian strain components (i.e. Err , Ecc , Ell , Ecl , Erl , and Ecr ) were computed from the 3D displacement field and averaged within each region of interest. Torsion was quantified using the circumferential-longitudinal shear angle. While peak systolic Ecl differed between the mid-ventricle and apex, the other five components of peak systolic strain were similar across the base, mid-ventricle, and apex. In the mid-LV myocardium, Ecc decreased gradually from the sub-endocardial to the sub-epicardial layer. Ell demonstrated significant differences between the four wall segments, with the largest magnitude in the inferior segment. Err was uniform among the four wall segments. Ecl varied along the transmural direction and among wall segments, whereas Erl differed only among the wall segments. Erc was not associated with significant variations. Torsion also varied along the transmural direction and among wall segments. These results provide fundamental insights into the regional contractile function of healthy rat hearts, and form the foundation for future studies on regional changes induced by disease or treatments. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Cardiovascular magnetic resonance of cardiomyopathy in limb girdle muscular dystrophy 2B and 2I

    Directory of Open Access Journals (Sweden)

    Habib Philip

    2011-08-01

    Full Text Available Abstract Background Limb girdle muscular dystrophies (LGMD are inclusive of 7 autosomal dominant and 14 autosomal recessive disorders featuring progressive muscle weakness and atrophy. Studies of cardiac function have not yet been well-defined in deficiencies of dysferlin (LGMD2B and fukutin related protein (LGMD2I. In this study of patients with these two forms of limb girdle muscular dystrophy, cardiovascular magnetic resonance (CMR was used to more specifically define markers of cardiomyopathy including systolic dysfunction, myocardial fibrosis, and diastolic dysfunction. Methods Consecutive patients with genetically-proven LGMD types 2I (n = 7 and 2B (n = 9 and 8 control subjects were enrolled. All subjects underwent cardiac magnetic resonance (CMR on a standard 1.5 Tesla clinical scanner with cine imaging for left ventricular (LV volume and ejection fraction (EF measurement, vector velocity analysis of cine data to calculate myocardial strain, and late post-gadolinium enhancement imaging (LGE to assess for myocardial fibrosis. Results Sixteen LGMD patients (7 LGMD2I, 9 LGMD2B, and 8 control subjects completed CMR. All but one patient had normal LV size and systolic function; one (type 2I had severe dilated cardiomyopathy. Of 15 LGMD patients with normal systolic function, LGE imaging revealed focal myocardial fibrosis in 7 (47%. Peak systolic circumferential strain rates were similar in patients vs. controls: εendo was -23.8 ± 8.5vs. -23.9 ± 4.2%, εepi was -11.5 ± 1.7% vs. -10.1 ± 4.2% (p = NS for all. Five of 7 LGE-positive patients had grade I diastolic dysfunction [2I (n = 2, 2B (n = 3]. that was not present in any LGE-negative patients or controls. Conclusions LGMD2I and LGMD2B generally result in mild structural and functional cardiac abnormalities, though severe dilated cardiomyopathy may occur. Long-term studies are warranted to evaluate the prognostic significance of subclinical fibrosis detected by CMR in these patients.

  18. Incorporating 3-dimensional models in online articles

    Science.gov (United States)

    Cevidanes, Lucia H. S.; Ruellasa, Antonio C. O.; Jomier, Julien; Nguyen, Tung; Pieper, Steve; Budin, Francois; Styner, Martin; Paniagua, Beatriz

    2015-01-01

    Introduction The aims of this article were to introduce the capability to view and interact with 3-dimensional (3D) surface models in online publications, and to describe how to prepare surface models for such online 3D visualizations. Methods Three-dimensional image analysis methods include image acquisition, construction of surface models, registration in a common coordinate system, visualization of overlays, and quantification of changes. Cone-beam computed tomography scans were acquired as volumetric images that can be visualized as 3D projected images or used to construct polygonal meshes or surfaces of specific anatomic structures of interest. The anatomic structures of interest in the scans can be labeled with color (3D volumetric label maps), and then the scans are registered in a common coordinate system using a target region as the reference. The registered 3D volumetric label maps can be saved in .obj, .ply, .stl, or .vtk file formats and used for overlays, quantification of differences in each of the 3 planes of space, or color-coded graphic displays of 3D surface distances. Results All registered 3D surface models in this study were saved in .vtk file format and loaded in the Elsevier 3D viewer. In this study, we describe possible ways to visualize the surface models constructed from cone-beam computed tomography images using 2D and 3D figures. The 3D surface models are available in the article’s online version for viewing and downloading using the reader’s software of choice. These 3D graphic displays are represented in the print version as 2D snapshots. Overlays and color-coded distance maps can be displayed using the reader’s software of choice, allowing graphic assessment of the location and direction of changes or morphologic differences relative to the structure of reference. The interpretation of 3D overlays and quantitative color-coded maps requires basic knowledge of 3D image analysis. Conclusions When submitting manuscripts, authors can

  19. Sudden cardiac death from structural heart diseases in adults: imaging findings with cardiovascular computed tomography and magnetic resonance.

    Science.gov (United States)

    Kim, Song Soo; Ko, Sung Min; Choi, Sang Il; Choi, Bo Hwa; Stillman, Arthur E

    2016-06-01

    Sudden cardiac death (SCD) is defined as the unexpected natural death from a cardiac cause within an hour of the onset of symptoms in the absence of any other cause. Although such a rapid course of death is mainly attributed to a cardiac arrhythmia, identification of structural heart disease by cardiovascular computed tomography (CCT) and cardiovascular magnetic resonance (CMR) imaging is important to predict the long-term risk of SCD. In adults, SCD most commonly results from coronary artery diseases, coronary artery anomalies, inherited cardiomyopathies, valvular heart diseases, myocarditis, and aortic dissection with coronary artery involvement or acute aortic regurgitation. This review describes the CCT and CMR findings of structural heart diseases related to SCD, which are essential for radiologists to diagnose or predict.

  20. Feasibility and safety of high-dose adenosine perfusion cardiovascular magnetic resonance

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    Holloway Cameron J

    2010-11-01

    Full Text Available Abstract Introduction Adenosine is the most widely used vasodilator stress agent for Cardiovascular Magnetic Resonance (CMR perfusion studies. With the standard dose of 140 mcg/kg/min some patients fail to demonstrate characteristic haemodynamic changes: a significant increase in heart rate (HR and mild decrease in systolic blood pressure (SBP. Whether an increase in the rate of adenosine infusion would improve peripheral and, likely, coronary vasodilatation in those patients is unknown. The aim of the present study was to assess the tolerance and safety of a high-dose adenosine protocol in patients with inadequate haemodynamic response to the standard adenosine protocol when undergoing CMR perfusion imaging. Methods 98 consecutive patients with known or suspected coronary artery disease (CAD underwent CMR perfusion imaging at 1.5 Tesla. Subjects were screened for contraindications to adenosine, and an electrocardiogram was performed prior to the scan. All patients initially received the standard adenosine protocol (140 mcg/kg/min for at least 3 minutes. If the haemodynamic response was inadequate (HR increase Results All patients successfully completed the CMR scan. Of a total of 98 patients, 18 (18% did not demonstrate evidence of a significant increase in HR or decrease in SBP under the standard adenosine infusion rate. Following the increase in the rate of infusion, 16 out of those 18 patients showed an adequate haemodynamic response. One patient of the standard infusion group and two patients of the high-dose group developed transient advanced AV block. Significantly more patients complained of chest pain in the high-dose group (61% vs. 29%, p = 0.009. On multivariate analysis, age > 65 years and ejection fraction Conclusions A substantial number of patients do not show adequate peripheral haemodynamic response to standard-dose adenosine stress during perfusion CMR imaging. Age and reduced ejection fraction are predictors of inadequate

  1. Semi-automatic segmentation of myocardium at risk in T2-weighted cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Sjögren Jane

    2012-01-01

    Full Text Available Abstract Background T2-weighted cardiovascular magnetic resonance (CMR has been shown to be a promising technique for determination of ischemic myocardium, referred to as myocardium at risk (MaR, after an acute coronary event. Quantification of MaR in T2-weighted CMR has been proposed to be performed by manual delineation or the threshold methods of two standard deviations from remote (2SD, full width half maximum intensity (FWHM or Otsu. However, manual delineation is subjective and threshold methods have inherent limitations related to threshold definition and lack of a priori information about cardiac anatomy and physiology. Therefore, the aim of this study was to develop an automatic segmentation algorithm for quantification of MaR using anatomical a priori information. Methods Forty-seven patients with first-time acute ST-elevation myocardial infarction underwent T2-weighted CMR within 1 week after admission. Endocardial and epicardial borders of the left ventricle, as well as the hyper enhanced MaR regions were manually delineated by experienced observers and used as reference method. A new automatic segmentation algorithm, called Segment MaR, defines the MaR region as the continuous region most probable of being MaR, by estimating the intensities of normal myocardium and MaR with an expectation maximization algorithm and restricting the MaR region by an a priori model of the maximal extent for the user defined culprit artery. The segmentation by Segment MaR was compared against inter observer variability of manual delineation and the threshold methods of 2SD, FWHM and Otsu. Results MaR was 32.9 ± 10.9% of left ventricular mass (LVM when assessed by the reference observer and 31.0 ± 8.8% of LVM assessed by Segment MaR. The bias and correlation was, -1.9 ± 6.4% of LVM, R = 0.81 (p Conclusions There is a good agreement between automatic Segment MaR and manually assessed MaR in T2-weighted CMR. Thus, the proposed algorithm seems to be a

  2. Real-time cardiovascular magnetic resonance at high temporal resolution: radial FLASH with nonlinear inverse reconstruction

    Directory of Open Access Journals (Sweden)

    Merboldt Klaus-Dietmar

    2010-07-01

    Full Text Available Abstract Background Functional assessments of the heart by dynamic cardiovascular magnetic resonance (CMR commonly rely on (i electrocardiographic (ECG gating yielding pseudo real-time cine representations, (ii balanced gradient-echo sequences referred to as steady-state free precession (SSFP, and (iii breath holding or respiratory gating. Problems may therefore be due to the need for a robust ECG signal, the occurrence of arrhythmia and beat to beat variations, technical instabilities (e.g., SSFP "banding" artefacts, and limited patient compliance and comfort. Here we describe a new approach providing true real-time CMR with image acquisition times as short as 20 to 30 ms or rates of 30 to 50 frames per second. Methods The approach relies on a previously developed real-time MR method, which combines a strongly undersampled radial FLASH CMR sequence with image reconstruction by regularized nonlinear inversion. While iterative reconstructions are currently performed offline due to limited computer speed, online monitoring during scanning is accomplished using gridding reconstructions with a sliding window at the same frame rate but with lower image quality. Results Scans of healthy young subjects were performed at 3 T without ECG gating and during free breathing. The resulting images yield T1 contrast (depending on flip angle with an opposed-phase or in-phase condition for water and fat signals (depending on echo time. They completely avoid (i susceptibility-induced artefacts due to the very short echo times, (ii radiofrequency power limitations due to excitations with flip angles of 10° or less, and (iii the risk of peripheral nerve stimulation due to the use of normal gradient switching modes. For a section thickness of 8 mm, real-time images offer a spatial resolution and total acquisition time of 1.5 mm at 30 ms and 2.0 mm at 22 ms, respectively. Conclusions Though awaiting thorough clinical evaluation, this work describes a robust and

  3. Inter-study reproducibility of cardiovascular magnetic resonance myocardial feature tracking

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    Morton Geraint

    2012-06-01

    Full Text Available Abstract Background Cardiovascular magnetic resonance myocardial feature tracking (CMR-FT is a recently described method of post processing routine cine acquisitions which aims to provide quantitative measurements of circumferentially and radially directed ventricular wall strain. Inter-study reproducibility is important for serial assessments however has not been defined for CMR-FT. Methods 16 healthy volunteers were imaged 3 times within a single day. The first examination was performed at 0900 after fasting and was immediately followed by the second. The third, non-fasting scan, was performed at 1400. CMR-FT measures of segmental and global strain parameters were calculated. Left ventricular (LV circumferential and radial strain were determined in the short axis orientation (EccSAX and ErrSAX respectively. LV and right ventricular longitudinal strain and LV radial strain were determined from the 4-chamber orientation (EllLV, EllRV, and ErrLAX respectively. LV volumes and function were also analysed. Inter-study reproducibility and study sample sizes required to demonstrate 5% changes in absolute strain were determined by comparison of the first and second exams. The third exam was used to determine whether diurnal variation affected reproducibility. Results CMR-FT strain analysis inter-study reproducibility was variable. Global strain assessment was more reproducible than segmental analysis. Overall EccSAX was the most reproducible measure of strain: coefficient of variation (CV 38% and 20.3% and intraclass correlation coefficient (ICC 0.68 (0.55-0.78 and 0.7 (0.32-0.89 for segmental and global analysis respectively. The least reproducible segmental measure was EllRV: CV 60% and ICC 0.56 (0.41-0.69 whilst the least reproducible global measure was ErrLAX: CV 33.3% and ICC 0.44 (0–0.77. Variable reproducibility was also reflected in the calculated sample sizes, which ranged from 11 (global EccSAX to 156 subjects (segmental EllRV. The

  4. Natural history of spontaneous aortic intramural hematoma progression: Six years follow-up with cardiovascular magnetic resonance

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    Zhao Lei

    2010-05-01

    Full Text Available Abstract We described a 6 years follow-up of a spontaneous aortic intramural hematoma (IMH with cardiovascular magnetic resonance (CMR examination. Since multiple factors may play roles in the natural history of IMH, the patient experienced the course of progression, which included hematoma absorption, ulcer-like lesion, aneurysm and limited dissection. The initial and follow-up CMR examination included 3D CE MRA and non-enhanced "bright blood" pulse sequence. The inherent advantage of outstanding contrast with plain scan, which shorten the scan time and avoid potential risk of contrast agent, might make the fast gradient echo sequence as an alternative method when following stable IMH.

  5. The usefulness of 3-dimensional endoscope systems in endoscopic surgery.

    Science.gov (United States)

    Egi, Hiroyuki; Hattori, Minoru; Suzuki, Takahisa; Sawada, Hiroyuki; Kurita, Yuichi; Ohdan, Hideki

    2016-10-01

    The image quality and performance of 3-dimensional video image systems has improved along with improvements in technology. However, objective evaluation on the usefulness of 3-dimensional video image systems is insufficient. Therefore, we decided to investigate the usefulness of 3-dimensional video image systems using the objective endoscopic surgery technology evaluating apparatus that we have developed, the Hiroshima University Endoscopic Surgical Assessment Device (HUESAD). The participants were 28 student volunteers enrolled in Hiroshima University (17 men and 11 women, age: median 22.5, range 20-25), with no one having experienced endoscopic surgery training. Testing was carried out by dividing the subjects into two groups to initially carry out HUESAD with 2-dimensional video imaging (N = 14) and with 3-dimensional video imaging (N = 14). Questionnaires were carried out along with the investigation regarding both 2-dimensional and 3-dimensional video imaging. The task was carried out for approximately 15 min regarding both 2-dimensional and 3-dimensional video imaging. Lastly, the Mental Rotation Test, which is a standard space perception ability test, was used to evaluate the space perception ability. No difference was observed in the nauseous and uncomfortable feeling of practitioners between the two groups. Regarding smoothness, no difference was observed between 2-dimensional and 3-dimensional video imaging (p = 0.8665). Deviation (space perception ability) and approaching time (accuracy) were significantly lower with 3-dimensional video imaging compared to 2-dimensional video imaging. Moreover, the approaching time (accuracy) significantly improved in 3-dimensional video imaging compared to 2-dimensional video imaging in the group with low space perception ability (p = 0.0085). Objective evaluation using HUESAD and subjective evaluation by questionnaire revealed that endoscopic surgery techniques significantly improved in 3-dimensional video

  6. Optimization of 3-dimensional imaging of the breast region with 3-dimensional laser scanners.

    Science.gov (United States)

    Kovacs, Laszlo; Yassouridis, Alexander; Zimmermann, Alexander; Brockmann, Gernot; Wöhnl, Antonia; Blaschke, Matthias; Eder, Maximilian; Schwenzer-Zimmerer, Katja; Rosenberg, Robert; Papadopulos, Nikolaos A; Biemer, Edgar

    2006-03-01

    The anatomic conditions of the female breast require imaging the breast region 3-dimensionally in a normal standing position for quality assurance and for surgery planning or surgery simulation. The goal of this work was to optimize the imaging technology for the mammary region with a 3-dimensional (3D) laser scanner, to evaluate the precision and accuracy of the method, and to allow optimum data reproducibility. Avoiding the influence of biotic factors, such as mobility, we tested the most favorable imaging technology on dummy models for scanner-related factors such as the scanner position in comparison with the torso and the number of scanners and single shots. The influence of different factors of the breast region, such as different breast shapes or premarking of anatomic landmarks, was also first investigated on dummies. The findings from the dummy models were then compared with investigations on test persons, and the accuracy of measurements on the virtual models was compared with a coincidence analysis of the manually measured values. The best precision and accuracy of breast region measurements were achieved when landmarks were marked before taking the shots and when shots at 30 degrees left and 30 degrees right, relative to the sagittal line, were taken with 2 connected scanners mounted with a +10-degree upward angle. However, the precision of the measurements on test persons was significantly lower than those measured on dummies. Our findings show that the correct settings for 3D imaging of the breast region with a laser scanner can achieve an acceptable degree of accuracy and reproducibility.

  7. Zeeman-Tomography of the Solar Photosphere -- 3-Dimensional Surface Structures Retrieved from Hinode Observations

    CERN Document Server

    Carroll, T A

    2008-01-01

    AIMS :The thermodynamic and magnetic field structure of the solar photosphere is analyzed by means of a novel 3-dimensional spectropolarimetric inversion and reconstruction technique. METHODS : On the basis of high-resolution, mixed-polarity magnetoconvection simulations, we used an artificial neural network (ANN) model to approximate the nonlinear inverse mapping between synthesized Stokes spectra and the underlying stratification of atmospheric parameters like temperature, line-of-sight (LOS) velocity and LOS magnetic field. This approach not only allows us to incorporate more reliable physics into the inversion process, it also enables the inversion on an absolute geometrical height scale, which allows the subsequent combination of individual line-of-sight stratifications to obtain a complete 3-dimensional reconstruction (tomography) of the observed area. RESULTS : The magnetoconvection simulation data, as well as the ANN inversion, have been properly processed to be applicable to spectropolarimetric obser...

  8. Left ventricular long axis function assessed during cine-cardiovascular magnetic resonance is an independent predictor of adverse cardiac events.

    Science.gov (United States)

    Rangarajan, Vibhav; Chacko, Satish Jacob; Romano, Simone; Jue, Jennifer; Jariwala, Nikhil; Chung, Jaehoon; Farzaneh-Far, Afshin

    2016-06-07

    Left ventricular pump function requires a complex interplay involving myocardial fibers orientated in the longitudinal, oblique and circumferential directions. Long axis dysfunction appears to be an early marker for a number of pathological states. We hypothesized that mitral annular plane systolic excursion (MAPSE) measured during cine-cardiovascular magnetic resonance (CMR) reflects changes in long axis function and may be an early marker for adverse cardiovascular outcomes. The aims of this study were therefore: 1) To assess the feasibility and reproducibility of MAPSE measurements during routine cine-CMR; and 2) To assess whether MAPSE, as a surrogate for long axis function, is a predictor of major adverse cardiovascular events (MACE). Four hundred consecutive patients undergoing CMR were prospectively enrolled. MAPSE was measured in the 4-chamber cine view. Patients were prospectively followed for major adverse cardiac events (MACE) - death, non-fatal myocardial infarction, hospitalization for heart failure or unstable angina, and late revascularization. Cox proportional hazards regression modeling was used to identify factors independently associated with MACE. Net reclassification improvement (NRI) was calculated to assess whether addition of MAPSE resulted in improved risk reclassification of MACE. Seventy-two MACE occurred during a median follow-up of 14.5 months. By Kaplan-Meier analysis, patients with lateral MAPSE cine-CMR is an independent predictor of MACE.

  9. Using a respiratory navigator significantly reduces variability when quantifying left ventricular torsion with cardiovascular magnetic resonance.

    Science.gov (United States)

    Hamlet, Sean M; Haggerty, Christopher M; Suever, Jonathan D; Wehner, Gregory J; Andres, Kristin N; Powell, David K; Charnigo, Richard J; Fornwalt, Brandon K

    2017-03-01

    Left ventricular (LV) torsion is an important indicator of cardiac function that is limited by high inter-test variability (50% of the mean value). We hypothesized that this high inter-test variability is partly due to inconsistent breath-hold positions during serial image acquisitions, which could be significantly improved by using a respiratory navigator for cardiovascular magnetic resonance (CMR) based quantification of LV torsion. We assessed respiratory-related variability in measured LV torsion with two distinct experimental protocols. First, 17 volunteers were recruited for CMR with cine displacement encoding with stimulated echoes (DENSE) in which a respiratory navigator was used to measure and then enforce variability in end-expiratory position between all LV basal and apical acquisitions. From these data, we quantified the inter-test variability of torsion in the absence and presence of enforced end-expiratory position variability, which established an upper bound for the expected torsion variability. For the second experiment (in 20 new, healthy volunteers), 10 pairs of cine DENSE basal and apical images were each acquired from consecutive breath-holds and consecutive navigator-gated scans (with a single acceptance position). Inter-test variability of torsion was compared between the breath-hold and navigator-gated scans to quantify the variability due to natural breath-hold variation. To demonstrate the importance of these variability reductions, we quantified the reduction in sample size required to detect a clinically meaningful change in LV torsion with the use of a respiratory navigator. The mean torsion was 3.4 ± 0.2°/cm. From the first experiment, enforced variability in end-expiratory position translated to considerable variability in measured torsion (0.56 ± 0.34°/cm), whereas inter-test variability with consistent end-expiratory position was 57% lower (0.24 ± 0.16°/cm, p < 0.001). From the second experiment, natural

  10. 3-Dimensional quantitative detection of nanoparticle content in biological tissue samples after local cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

    Rahn, Helene, E-mail: helene.rahn@gmail.com [Institute of Fluid Mechanics, Chair of Magnetofluiddynamics, Technische Universitaet Dresden, Dresden 01069 (Germany); Alexiou, Christoph [ENT-Department, Section for Experimental Oncology and Nanomedicine (Else Kröner-Fresenius-Stiftungsprofessur), University Hospital Erlangen, Waldstraße 1, Erlangen 91054 (Germany); Trahms, Lutz [Physikalisch-Technische Bundesanstalt, Abbestraße 2-12, Berlin 10587 (Germany); Odenbach, Stefan [Institute of Fluid Mechanics, Chair of Magnetofluiddynamics, Technische Universitaet Dresden, Dresden 01069 (Germany)

    2014-06-01

    X-ray computed tomography is nowadays used for a wide range of applications in medicine, science and technology. X-ray microcomputed tomography (XµCT) follows the same principles used for conventional medical CT scanners, but improves the spatial resolution to a few micrometers. We present an example of an application of X-ray microtomography, a study of 3-dimensional biodistribution, as along with the quantification of nanoparticle content in tumoral tissue after minimally invasive cancer therapy. One of these minimal invasive cancer treatments is magnetic drug targeting, where the magnetic nanoparticles are used as controllable drug carriers. The quantification is based on a calibration of the XµCT-equipment. The developed calibration procedure of the X-ray-µCT-equipment is based on a phantom system which allows the discrimination between the various gray values of the data set. These phantoms consist of a biological tissue substitute and magnetic nanoparticles. The phantoms have been studied with XµCT and have been examined magnetically. The obtained gray values and nanoparticle concentration lead to a calibration curve. This curve can be applied to tomographic data sets. Accordingly, this calibration enables a voxel-wise assignment of gray values in the digital tomographic data set to nanoparticle content. Thus, the calibration procedure enables a 3-dimensional study of nanoparticle distribution as well as concentration. - Highlights: • Local cancer treatments are promising in reducing negative side effects occurring during conventional chemotherapy. • The nanoparticles play an important role in delivering drugs to the designated area during local cancer treatments as magnetic drug targeting. • We study the nanoparticles distribution in tumor tissue after magnetic drug targeting with X-ray computed tomography. • We achieved a 3-dimensional quantification of the nanoparticles content in tumor tissue out of digital tomographic data.

  11. Brain tumor surgery with 3-dimensional surface navigation.

    Science.gov (United States)

    Mert, Ayguel; Buehler, Katja; Sutherland, Garnette R; Tomanek, Boguslaw; Widhalm, Georg; Kasprian, Gregor; Knosp, Engelbert; Wolfsberger, Stefan

    2012-12-01

    Precise lesion localization is necessary for neurosurgical procedures not only during the operative approach, but also during the preoperative planning phase. To evaluate the advantages of 3-dimensional (3-D) brain surface visualization over conventional 2-dimensional (2-D) magnetic resonance images for surgical planning and intraoperative guidance in brain tumor surgery. Preoperative 3-D brain surface visualization was performed with neurosurgical planning software in 77 cases (58 gliomas, 7 cavernomas, 6 meningiomas, and 6 metastasis). Direct intraoperative navigation on the 3-D brain surface was additionally performed in the last 20 cases with a neurosurgical navigation system. For brain surface reconstruction, patient-specific anatomy was obtained from MR imaging and brain volume was extracted with skull stripping or watershed algorithms, respectively. Three-dimensional visualization was performed by direct volume rendering in both systems. To assess the value of 3-D brain surface visualization for topographic lesion localization, a multiple-choice test was developed. To assess accuracy and reliability of 3-D brain surface visualization for intraoperative orientation, we topographically correlated superficial vessels and gyral anatomy on 3-D brain models with intraoperative images. The rate of correct lesion localization with 3-D was significantly higher (P = .001, χ), while being significantly less time consuming (P < .001, χ) compared with 2-D images. Intraoperatively, visual correlation was found between the 3-D images, superficial vessels, and gyral anatomy. The proposed method of 3-D brain surface visualization is fast, clinically reliable for preoperative anatomic lesion localization and patient-specific planning, and, together with navigation, improves intraoperative orientation in brain tumor surgery and is relatively independent of brain shift.

  12. Relation between cardiovascular disease risk markers and brain infarcts detected by magnetic resonance imaging in an elderly population.

    Science.gov (United States)

    Nylander, Ruta; Lind, Lars; Wikström, Johan; Lindahl, Bertil; Venge, Per; Larsson, Anders; Ärnlöv, Johan; Berglund, Lars; Ahlström, Håkan; Johansson, Lars; Larsson, Elna-Marie

    2015-02-01

    Established cardiovascular risk markers, such as hypertension, are associated with increased risk of brain infarcts. The newer markers N-terminal pro-brain natriuretic peptide, troponin I, C-reactive protein, and cystatin C may affect the risk of cardiovascular events and potentially, thereby, also stroke. We investigated the association between established and new risk markers for cardiovascular disease and brain infarcts detected by magnetic resonance imaging (MRI) at age 75. Four hundred six randomly selected subjects from the Prospective Investigation of the Vasculature in Uppsala Seniors study were examined with MRI of the brain at age 75. Blood samples, measurements, and dedicated questionnaires at age 70 were used for analysis of risk markers. A history of diseases had been obtained at age 70 and 75. MRI was evaluated regarding lacunar and cortical infarcts. Univariate associations between outcomes and risk markers were assessed with logistic regression models. One or more infarcts were seen in 23% of the subjects (20% had only lacunar infarcts, 1% had only cortical infarcts, and 2% had both). Hypertension (odds ratio [OR] 2.6, 95% confidence interval [CI] 1.4, 4.7) and obesity (OR 1.3; CI 1.0, 1.8) were significantly associated with increased risk of brain infarction. The newer risk markers were not significantly associated with the brain infarcts. The new markers were not associated with the predominantly lacunar infarcts in our 75-year-old population, why troponin I and NT-proBNP may be associated mainly with cardioembolic infarcts as shown recently. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  13. Early detection of cardiac involvement in Miyoshi myopathy: 2D strain echocardiography and late gadolinium enhancement cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Kim Byoung

    2010-05-01

    Full Text Available Abstract Background Miyoshi myopathy (MM is an autosomal recessive distal myopathy characterized by early adult onset. Cardiomyopathy is a major clinical manifestation in other muscular dystrophies and an important prognostic factor. Although dysferlin is highly expressed in cardiac muscle, the effect of dysferlin deficiency in cardiac muscle has not been studied. We hypothesized that early myocardial dysfunction could be detected by 2D strain echocardiography and late gadolinium enhancement (LGE cardiovascular magnetic resonance (CMR. Method Five consecutive MM patients (3 male in whom we detected the DYSF gene mutation and age-matched healthy control subjects were included. None of the patients had history of cardiac disease or signs and symptoms of overt heart failure. Patients were studied using 2D strain echocardiography and CMR, with 2D strain being obtained using the Automated Function Imaging technique. Results All patients had preserved left ventricular systolic function. However, segmental Peak Systolic Longitudinal Strain (PSLS was decreased in 3 patients. Global PSLS was significantly lower in patients with MM than in control subjects (p = 0.005. Basal anterior septum, basal inferior septum, mid anterior, and mid inferior septum PSLS were significantly lower in patients with MM than in control subjects (P Conclusions Patients with MM showed subclinical involvement of the heart. 2D strain and LGE are sensitive methods for detecting myocardial dysfunction prior to the development of cardiovascular symptoms. The prognostic significance of these findings warrants further longitudinal follow-up.

  14. Cardiovascular magnetic resonance imaging assessment of diastolic dysfunction in a population without heart disease: a gender-based study

    Energy Technology Data Exchange (ETDEWEB)

    Graca, Bruno; Donato, Paulo; Caseiro-Alves, Filipe [University of Coimbra, Medical Imaging Department, University Centre Hospitals of Coimbra, Faculty of Medicine, Coimbra (Portugal); Ferreira, Maria Joao [University of Coimbra, Cardiology Department, University Centre Hospitals of Coimbra, Faculty of Medicine, Coimbra (Portugal); Castelo-Branco, Miguel [University of Coimbra, Institute for Biomedical Imaging and Life Sciences, Faculty of Medicine, Coimbra (Portugal)

    2014-01-15

    Asymptomatic left ventricular (LV) diastolic dysfunction is increasingly recognised as an important diagnosis. Our goal was to study the prevalence and gender differences in subclinical LV diastolic dysfunction, using cardiovascular magnetic resonance imaging (CMR) at 3 T. We prospectively studied 48 volunteers (19 male and 29 female, mean age 49 ± 7 years) with no evidence of cardiovascular disease. We used CMR to measure left atrium (LA) and LV volumes, LV peak filling rate and transmitral flow. The overall prevalence of LV diastolic dysfunction in our cohort varied between 20 % (based on evaluation of LV filing profiles) and 24 % (based on the evaluation of the transmitral flow). The prevalence of diastolic dysfunction was higher in men than in women, independently of the criteria used (P between 0.004 and 0.022). Indexed LV end-diastolic volume, indexed LV stroke volume, indexed LV mass, indexed LA minimum volume and indexed LA maximum volume were significantly greater in men than in women (P < 0.05). All the subjects had LV ejection fractions within the normal range. It is clinically feasible to study diastolic flow and LV filling with CMR. CMR detected diastolic dysfunction in asymptomatic men and women. (orig.)

  15. Imaging focal and interstitial fibrosis with cardiovascular magnetic resonance in athletes with left ventricular hypertrophy: implications for sporting participation.

    LENUS (Irish Health Repository)

    Waterhouse, Deirdre F

    2012-11-01

    Long-term high-intensity physical activity is associated with morphological changes, termed as the \\'athlete\\'s heart\\'. The differentiation of physiological cardiac adaptive changes in response to high-level exercise from pathological changes consistent with an inherited cardiomyopathy is imperative. Cardiovascular magnetic resonance (CMR) imaging allows definition of abnormal processes occurring at the tissue level, including, importantly, myocardial fibrosis. It is therefore vital in accurately making this differentiation. In this review, we will review the role of CMR imaging of fibrosis, and detail CMR characterisation of myocardial fibrosis in various cardiomyopathies, and the implications of fibrosis. Additionally, we will outline advances in imaging fibrosis, in particular T1 mapping. Finally we will address the role of CMR in pre-participation screening.

  16. Cardiovascular magnetic resonance for evaluation of heart involvement in ANCA-associated vasculitis. A luxury or a valuable diagnostic tool?

    Science.gov (United States)

    Mavrogeni, Sophie; Markousis-Mavrogenis, George; Kolovou, Genovefa

    2014-01-01

    Antineutrophil cytoplasmic antibody (ANCA)-related vasculitis is a systemic small-vessel vasculitis, including 3 clinical syndromes: granulomatosis with polyangiitis, known as Wegener's granulomatosis (WG), microscopic polyangiitis (MPA) and the Churg-Strauss syndrome (CSS). ANCA-related vasculitis usually presents with severe kidney or pulmonary disease, has a mortality of 28% at 5 years, and also contributes to increased morbidity in vasculitis patients. Cardiac involvement in this entity may have different forms, including coronary vessels, pericarditis, myocarditis, endocarditis, myocardial infarction and subendocardial vasculitis that can contribute to reduced life expectancy. Cardiovascular magnetic resonance using oedema and fibrosis imaging can early reveal, noninvasively and without radiation, heart involvement during vasculitis, undetected by other imaging techniques and guide further risk stratification and treatment of these patients.

  17. 3 dimensional volume MR imaging of intratemporal facial nerve

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jeong Jin; Kang, Heoung Keun; Kim, Hyun Ju; Kim, Jae Kyu; Jung, Hyun Ung; Moon, Woong Jae [Chonnam University Medical School, Kwangju (Korea, Republic of)

    1994-10-15

    To evaluate the usefulness of 3 dimensional volume MR imaging technique for demonstrating the facial nerves and to describe MR findings in facial palsy patients and evaluate the significance of facial nerve enhancement. We reviewed the MR images of facial nerves obtained with 3 dimensional volume imaging technique before and after intravenous administration of Gadopentetate dimeglumine in 13 cases who had facial paralysis and 33 cases who had no facial palsy. And we analyzed the detectability of ananatomical segments of intratemporal facial nerves and facial nerve enhancement. When the 3 dimensional volume MR images of 46 nerves were analyzed subjectively, the nerve courses of 43(93%) of 46 nerves were effectively demonstrated on 3 dimensional volume MR images. Internal acoustic canal portions and geniculate ganglion of facial nerve were well visualized on axial images and tympanic and mastoid segments were well depicted on oblique sagittal images. 10 of 13 patients(77%) were visibly enhanced along at least one segment of the facial nerve with swelling or thickening, and nerves of 8 of normal 33 cases(24%) were enhanced without thickening or swelling. MR findings of facial nerve parelysis is asymmetrical thickening of facial nerve with contrast enhancement. The 3 dimensional volume MR imaging technique should be a useful study for the evaluation of intratemporal facial nerve disease.

  18. Myocardial area at risk and salvage measured by T2-weighted cardiovascular magnetic resonance: reproducibility and comparison of two T2-weighted protocols

    DEFF Research Database (Denmark)

    Lønborg, Jacob; Vejlstrup, Niels; Mathiasen, Anders B

    2011-01-01

    Late gadolinium enhancement (LGE) and T2-weighted cardiovascular magnetic resonance (CMR) provides a means to measure myocardial area at risk (AAR) and salvage. Several T2-weighted CMR sequences are in use, but there is no consensus in terms of which sequence to be the preferred. Therefore, the aim...

  19. Myocardial infarct heterogeneity assessment by late gadolinium enhancement cardiovascular magnetic resonance imaging shows predictive value for ventricular arrhythmia development after acute myocardial infarction

    NARCIS (Netherlands)

    Robbers, Lourens F. H. J.; Delewi, Ronak; Nijveldt, Robin; Hirsch, Alexander; Beek, Aernout M.; Kemme, Michiel J. B.; van Beurden, Yvette; van der Laan, Anja M.; van der Vleuten, Pieter A.; Tio, Rene A.; Zijlstra, Felix; Piek, Jan J.; van Rossum, Albert C.

    2013-01-01

    The aim of this study was to assess the association between the proportions of penumbrauvisualized by late gadolinium enhanced cardiovascular magnetic resonance imaging (LGE-CMR)uafter acute myocardial infarction (AMI) and the prevalence of ventricular tachycardia (VT). One-hundred and sixty-two AMI

  20. Semi-quantitative assessment of right ventricular function in comparison to a 3D volumetric approach: A cardiovascular magnetic resonance study

    NARCIS (Netherlands)

    Nijveldt, Robin; Germans, Tjeerd; McCann, Gerald; Beek, Aernout; Rossum, van Albert

    2008-01-01

    Right ventricular (RV) volume measurements with cardiovascular magnetic resonance (CMR) is considered the gold standard, but acquisition and analysis remain timeconsuming. The aim of our study was therefore to investigate the accuracy and performance of a semi-quantitative assessment of RV function

  1. Myocardial infarct heterogeneity assessment by late gadolinium enhancement cardiovascular magnetic resonance imaging shows predictive value for ventricular arrhythmia development after acute myocardial infarction

    NARCIS (Netherlands)

    Robbers, Lourens F. H. J.; Delewi, Ronak; Nijveldt, Robin; Hirsch, Alexander; Beek, Aernout M.; Kemme, Michiel J. B.; van Beurden, Yvette; van der Laan, Anja M.; van der Vleuten, Pieter A.; Tio, Rene A.; Zijlstra, Felix; Piek, Jan J.; van Rossum, Albert C.

    2013-01-01

    The aim of this study was to assess the association between the proportions of penumbrauvisualized by late gadolinium enhanced cardiovascular magnetic resonance imaging (LGE-CMR)uafter acute myocardial infarction (AMI) and the prevalence of ventricular tachycardia (VT). One-hundred and sixty-two AMI

  2. Quantification of myocardial deformation in children by cardiovascular magnetic resonance feature tracking: determination of reference values for left ventricular strain and strain rate

    NARCIS (Netherlands)

    André, F. (Florian); D. Robbers-Visser (Daniëlle); Helling-Bakki, A. (Astrid); Föll, A. (Angela); Voss, A. (Andreas); H.A. Katus (Hugo); W.A. Helbing (Willem); Buss, S.J. (Sebastian J.); J. Eichhorn

    2016-01-01

    textabstractBackground: The objective assessment of global and regional cardiac function in children has shown to be clinically relevant but is challenging to conduct. Cardiovascular magnetic resonance (CMR) has emerged as a valuable diagnostic modality especially in patients with cardiomyopathy or

  3. Semi-quantitative assessment of right ventricular function in comparison to a 3D volumetric approach: A cardiovascular magnetic resonance study

    NARCIS (Netherlands)

    Nijveldt, Robin; Germans, Tjeerd; McCann, Gerald; Beek, Aernout; Rossum, van Albert

    2008-01-01

    Right ventricular (RV) volume measurements with cardiovascular magnetic resonance (CMR) is considered the gold standard, but acquisition and analysis remain timeconsuming. The aim of our study was therefore to investigate the accuracy and performance of a semi-quantitative assessment of RV function

  4. Mannheim Curves in Nonflat 3-Dimensional Space Forms

    Directory of Open Access Journals (Sweden)

    Wenjing Zhao

    2015-01-01

    Full Text Available We consider the Mannheim curves in nonflat 3-dimensional space forms (Riemannian or Lorentzian and we give the concept of Mannheim curves. In addition, we investigate the properties of nonnull Mannheim curves and their partner curves. We come to the conclusion that a necessary and sufficient condition is that a linear relationship with constant coefficients will exist between the curvature and the torsion of the given original curves. In the case of null curve, we reveal that there are no null Mannheim curves in the 3-dimensional de Sitter space.

  5. Meta-analysis of the diagnostic performance of stress perfusion cardiovascular magnetic resonance for detection of coronary artery disease

    Directory of Open Access Journals (Sweden)

    Ehtisham Javed

    2010-05-01

    Full Text Available Abstract Aim Evaluation of the diagnostic accuracy of stress perfusion cardiovascular magnetic resonance for the diagnosis of significant obstructive coronary artery disease (CAD through meta-analysis of the available data. Methodology Original articles in any language published before July 2009 were selected from available databases (MEDLINE, Cochrane Library and BioMedCentral using the combined search terms of magnetic resonance, perfusion, and coronary angiography; with the exploded term coronary artery disease. Statistical analysis was only performed on studies that: (1 used a [greater than or equal to] 1.5 Tesla MR scanner; (2 employed invasive coronary angiography as the reference standard for diagnosing significant obstructive CAD, defined as a [greater than or equal to] 50% diameter stenosis; and (3 provided sufficient data to permit analysis. Results From the 263 citations identified, 55 relevant original articles were selected. Only 35 fulfilled all of the inclusion criteria, and of these 26 presented data on patient-based analysis. The overall patient-based analysis demonstrated a sensitivity of 89% (95% CI: 88-91%, and a specificity of 80% (95% CI: 78-83%. Adenosine stress perfusion CMR had better sensitivity than with dipyridamole (90% (88-92% versus 86% (80-90%, P = 0.022, and a tendency to a better specificity (81% (78-84% versus 77% (71-82%, P = 0.065. Conclusion Stress perfusion CMR is highly sensitive for detection of CAD but its specificity remains moderate.

  6. T1 mapping in myocarditis - headway to a new era for cardiovascular magnetic resonance.

    Science.gov (United States)

    Hinojar, Rocio; Nagel, Eike; Puntmann, Valentina O

    2015-01-01

    Myocarditis is a major cause of cardiac morbidity and mortality, particularly in young patients. A spectrum of challenges besets this condition, from establishing the diagnosis to effective treatment. Endomyocardial biopsy remains the diagnostic gold standard, despite its invasiveness, low diagnostic yield and a paucity of consequential management pathways. Cardiac magnetic resonance by Lake Louise criteria has contested to become the non-invasive diagnostic alternative by providing confirmation of disease. The advent of T1 mapping now allows a high diagnostic accuracy in confirmation and exclusion of disease, discrimination of stages and activity of disease. Alongside the research into the mechanisms and potential therapeutic targets, cardiac magnetic resonance confidently claims a prime role within a modern diagnostic pathway in clinically stable patients with suspected myocarditis.

  7. Interexaminer and intraexaminer reliabilities of 3-dimensional orthodontic digital setups

    NARCIS (Netherlands)

    Fabels, L.N.J.; Nijkamp, P.G.

    2014-01-01

    Introduction The use of digital orthodontic setups has grown quickly. The purpose of this study was to test the interexaminer and intraexaminer reliabilities of 3-dimensional orthodontic digital setups in OrthoCAD (Align Technology, San Jose, Calif). Methods Six clinicians made digital orthodontic s

  8. Interexaminer and intraexaminer reliabilities of 3-dimensional orthodontic digital setups

    NARCIS (Netherlands)

    Fabels, L.N.J.; Nijkamp, P.G.

    2014-01-01

    Introduction The use of digital orthodontic setups has grown quickly. The purpose of this study was to test the interexaminer and intraexaminer reliabilities of 3-dimensional orthodontic digital setups in OrthoCAD (Align Technology, San Jose, Calif). Methods Six clinicians made digital orthodontic

  9. Differential Cross Section Kinematics for 3-dimensional Transport Codes

    Science.gov (United States)

    Norbury, John W.; Dick, Frank

    2008-01-01

    In support of the development of 3-dimensional transport codes, this paper derives the relevant relativistic particle kinematic theory. Formulas are given for invariant, spectral and angular distributions in both the lab (spacecraft) and center of momentum frames, for collisions involving 2, 3 and n - body final states.

  10. In vitro study on the feasibility of magnetic stent hyperthermia for the treatment of cardiovascular restenosis

    OpenAIRE

    Li, Li; Wang, Rui; Shi, Huan-Huan; Xie, Le; LI, JING-DING-SHA; KONG, WEI-CHAO; Tang, Jin-Tian; KE, DA-NIAN; ZHAO, LING-YUN

    2013-01-01

    Thermal treatment or hyperthermia has received considerable attention in recent years due to its high efficiency, safety and relatively few side-effects. In this study, we investigated whether it was possible to utilize targeted thermal or instent thermal treatments for the treatment of restenosis following percutaneous transluminal coronary angioplasty (PTCA) through magnetic stent hyperthermia (MSH). A 316L stainless steel stent and rabbit vascular smooth muscle cells (VSMCs) were used in t...

  11. Ultra-Wideband Sensors for Improved Magnetic Resonance Imaging, Cardiovascular Monitoring and Tumour Diagnostics

    Directory of Open Access Journals (Sweden)

    Frank Seifert

    2010-12-01

    Full Text Available The specific advantages of ultra-wideband electromagnetic remote sensing (UWB radar make it a particularly attractive technique for biomedical applications. We partially review our activities in utilizing this novel approach for the benefit of high and ultra-high field magnetic resonance imaging (MRI and other applications, e.g., for intensive care medicine and biomedical research. We could show that our approach is beneficial for applications like motion tracking for high resolution brain imaging due to the non-contact acquisition of involuntary head motions with high spatial resolution, navigation for cardiac MRI due to our interpretation of the detected physiological mechanical contraction of the heart muscle and for MR safety, since we have investigated the influence of high static magnetic fields on myocardial mechanics. From our findings we could conclude, that UWB radar can serve as a navigator technique for high and ultra-high field magnetic resonance imaging and can be beneficial preserving the high resolution capability of this imaging modality. Furthermore it can potentially be used to support standard ECG analysis by complementary information where sole ECG analysis fails. Further analytical investigations have proven the feasibility of this method for intracranial displacements detection and the rendition of a tumour’s contrast agent based perfusion dynamic. Beside these analytical approaches we have carried out FDTD simulations of a complex arrangement mimicking the illumination of a human torso model incorporating the geometry of the antennas applied.

  12. Strain measurement by cardiovascular magnetic resonance in pediatric cancer survivors: validation of feature tracking against harmonic phase imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jimmy C. [C.S. Mott Children' s Hospital, University of Michigan Congenital Heart Center, Ann Arbor, MI (United States); University of Michigan, Department of Pediatrics and Communicable Diseases, Division of Pediatric Cardiology, Ann Arbor, MI (United States); University of Michigan, Department of Radiology, Section of Pediatric Radiology, Ann Arbor, MI (United States); Connelly, James A. [University of Michigan, Department of Pediatrics and Communicable Diseases, Division of Hematology-Oncology, Ann Arbor, MI (United States); Zhao, Lili [University of Michigan, Department of Biostatistics, Ann Arbor, MI (United States); Agarwal, Prachi P. [University of Michigan, Department of Radiology, Division of Cardiothoracic Radiology, Ann Arbor, MI (United States); Dorfman, Adam L. [University of Michigan, Department of Pediatrics and Communicable Diseases, Division of Pediatric Cardiology, Ann Arbor, MI (United States); University of Michigan, Department of Radiology, Section of Pediatric Radiology, Ann Arbor, MI (United States)

    2014-09-15

    Left ventricular strain may be a more sensitive marker of left ventricular dysfunction than ejection fraction in pediatric cancer survivors after anthracycline therapy, but there is limited validation of strain measurement by feature tracking on cardiovascular magnetic resonance (MR) images. To compare left ventricular circumferential and radial strain by feature tracking vs. harmonic phase imaging analysis (HARP) in pediatric cancer survivors. Twenty-six patients (20.2 ± 5.6 years old) underwent cardiovascular MR at least 5 years after completing anthracycline therapy. Circumferential and radial strain were measured at the base, midventricle and apex from short-axis myocardial tagged images by HARP, and from steady-state free precession images by feature tracking. Left ventricular ejection fraction more closely correlated with global circumferential strain by feature tracking (r = -0.63, P = 0.0005) than by HARP (r = -0.39, P = 0.05). Midventricular circumferential strain did not significantly differ by feature tracking or HARP (-20.8 ± 3.4 vs. -19.5 ± 2.5, P = 0.07), with acceptable limits of agreement. Midventricular circumferential strain by feature tracking strongly correlated with global circumferential strain by feature tracking (r = 0.87, P < 0.0001). Radial strain by feature tracking had poor agreement with HARP, particularly at higher values of radial strain. Intraobserver and interobserver reproducibility was excellent for feature tracking circumferential strain, but reproducibility was poor for feature tracking radial strain. Midventricular circumferential strain by feature tracking is a reliable and reproducible measure of myocardial deformation in patients status post anthracycline therapy, while radial strain measurements are unreliable. Further studies are necessary to evaluate potential relation to long-term outcomes. (orig.)

  13. Relationship between coronary flow reserve evaluated by phase-contrast cine cardiovascular magnetic resonance and serum eicosapentaenoic acid

    Science.gov (United States)

    2013-01-01

    Background Long-term intake of long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs), especially eicosapentaenoic acid (EPA) is associated with a low risk for cardiovascular disease. Phase-contrast cine cardiovascular magnetic resonance (PC cine CMR) can assess coronary flow reserve (CFR). The present study investigates the relationship between CFR evaluated by PC cine CMR and the serum EPA. Methods We studied 127 patients (male, 116 (91%); mean age, 72.2 ± 7.4 years) with known or suspected coronary artery disease (CAD). X-ray coronary angiography revealed no significant coronary arterial stenoses (defined as luminal diameter reduction ≥50% on quantitative coronary angiogram (QCA) analysis) in all study participants. Breath-hold PC cine CMR images of the coronary sinus (CS) were acquired to assess blood flow of the CS both at rest and during adenosine triphosphate (ATP) infusion. We calculated CFR as CS blood flow during ATP infusion divided by that at rest. Patients were allocated to groups according to whether they had high (n = 64, EPA ≥ 75.8 μg/mL) or low (n = 63, EPA  2.5, which is the previously reported lower limit of normal flow reserve without obstructive CAD. Multivariate analysis revealed that EPA is an independent predictor of CFR > 2.5 (odds ratio, 1.01; 95% confidence interval, 1.00 – 1.02, p = 0.008). Conclusions The serum EPA is significantly correlated with CFR in CAD patients without significant coronary artery stenosis. PMID:24359564

  14. The deleterious effects of arteriovenous fistula-creation on the cardiovascular system: a longitudinal magnetic resonance imaging study

    Directory of Open Access Journals (Sweden)

    Dundon BK

    2014-09-01

    Full Text Available Benjamin K Dundon,1–3 Kim Torpey,3 Adam J Nelson,1 Dennis TL Wong,1,2 Rae F Duncan,1 Ian T Meredith,2 Randall J Faull,1,3 Stephen G Worthley,1,4 Matthew I Worthley1,4 1Cardiology Department, Royal Adelaide Hospital, Central Adelaide Local Health Network, Discipline of Medicine, University of Adelaide, Adelaide, SA, Australia; 2Monash Cardiovascular Research Centre, MonashHEART, Monash Health, Melbourne, Vic, Australia; 3Central Northern Renal and Transplantation Service, Royal Adelaide Hospital, Central Adelaide Local Health Network, Adelaide, SA, Australia; 4South Australian Health and Medical Research Institute, Adelaide, SA, Australia Aim: Arteriovenous fistula-formation remains critical for the provision of hemodialysis in end-stage renal failure patients. Its creation results in a significant increase in cardiac output, with resultant alterations in cardiac stroke volume, systemic blood flow, and vascular resistance. The impact of fistula-formation on cardiac and vascular structure and function has not yet been evaluated via "gold standard" imaging techniques in the modern era of end-stage renal failure care. Methods: A total of 24 patients with stage 5 chronic kidney disease undergoing fistula-creation were studied in a single-arm pilot study. Cardiovascular magnetic resonance imaging was undertaken at baseline, and prior to and 6 months following fistula-creation. This gold standard imaging modality was used to evaluate, via standard brachial flow-mediated techniques, cardiac structure and function, aortic distensibility, and endothelial function. Results: At follow up, left ventricular ejection fraction remained unchanged, while mean cardiac output increased by 25.0% (P<0.0001. Significant increases in left and right ventricular end-systolic volumes (21% [P=0.014] and 18% [P<0.01], left and right atrial area (11% [P<0.01] and 9% [P<0.01], and left ventricular mass were observed (12.7% increase (P<0.01. Endothelial

  15. Principios básicos de resonancia magnética cardiovascular (RMC: secuencias, planos de adquisición y protocolo de estudio Basic principles of cardiovascular magnetic resonance (CMR: sequences, acquisition planes and study protocol

    Directory of Open Access Journals (Sweden)

    C. Hernández

    2007-12-01

    Full Text Available El estudio de la patología del sistema cardiovascular por resonancia magnética (RMC es una de las aplicaciones más actuales de esta técnica diagnóstica, ya que permite estudiar la anatomía y función del corazón y grandes vasos de forma exacta y reproducible. La complejidad de la técnica viene dada por la localización y orientación anatómica de las estructuras cardiovasculares, las secuencias específicas que se deben emplear y la ausencia de familiarización por parte de los radiólogos con la patología cardiovascular. En este trabajo se describen los principios básicos de la RMC. Se exponen la utilidad clínica de las secuencias anatómicas, funcionales y secuencias de flujo, se describen los planos de adquisición en un estudio de RMC convencional y se propone un protocolo de estudio sencillo.Evaluation of the cardiovascular system with magnetic resonance (CMR has become one of the most relevant and up-to-the-minute clinical applications of this diagnostic technique, as CMR makes possible an exact and reproducible study of the anatomy and function of the heart and great vessels. The complexity of this technique is mainly due to the anatomical location and orientation of the cardiovascular structures, the specific CMR sequences that have to be used and a lack of familiarity amongst radiologists regarding cardiovascular pathology. In this report the most basic principles of CMR are described. The clinical usefulness of anatomical, functional, and flow quantification sequences are discussed, conventional CMR acquisition planes are described, and an easy CMR study protocol is proposed.

  16. In vitro study on the feasibility of magnetic stent hyperthermia for the treatment of cardiovascular restenosis.

    Science.gov (United States)

    Li, Li; Wang, Rui; Shi, Huan-Huan; Xie, LE; Li, Jing-Ding-Sha; Kong, Wei-Chao; Tang, Jin-Tian; Ke, DA-Nian; Zhao, Ling-Yun

    2013-08-01

    Thermal treatment or hyperthermia has received considerable attention in recent years due to its high efficiency, safety and relatively few side-effects. In this study, we investigated whether it was possible to utilize targeted thermal or instent thermal treatments for the treatment of restenosis following percutaneous transluminal coronary angioplasty (PTCA) through magnetic stent hyperthermia (MSH). A 316L stainless steel stent and rabbit vascular smooth muscle cells (VSMCs) were used in the present study, in which the inductive heating characteristics of the stent under alternative magnetic field (AMF) exposure, as well as the effect of MSH on the proliferation, apoptosis, cell cycle and proliferating cell nuclear antigen (PCNA) expression of the rabbit VSMCs, were evaluated. The results demonstrated that 316L stainless steel coronary stents possess ideal inductive heating characteristics under 300 kHz AMF exposure. The heating properties were shown to be affected by the field intensity of the AMF, as well as the orientation the stent axis. MSH had a significant effect on the proliferation and apoptosis of VSMCs, and the effect was temperature-dependent. While a mild temperature of 43°C demonstrated negligible effects on the growth of VSMCs, MSH treatment above 47°C effectively inhibited the VSMC proliferation and induced apoptosis. Furthermore, a 47°C treatment exhibited a significant and long-term inhibitory effect on VSMC migration. The results strongly suggested that MSH may be potentially applied in the clinic as an alternative approach for the prevention and treatment of restenosis.

  17. Assessment of Cardiovascular Apoptosis in the Isolated Rat Heart by Magnetic Resonance Molecular Imaging

    Directory of Open Access Journals (Sweden)

    Karl-Heinz Hiller

    2006-04-01

    Full Text Available Apoptosis, an active process of cell self-destruction, is associated with myocardial ischemia. The redistribution of phosphatidylserine (PS from the inner to the outer leaflet of the cell membrane is an early event in apoptosis. Annexin V, a protein with high specificity and tight binding to PS, was used to identify and localize apoptosis in the ischemic heart. Fluorescein-labeled annexin V has been used routinely for the assessment of apoptosis in vitro. For the detection of apoptosis in vivo, positron emission tomography and single-photon emission computed tomography have been shown to be suitable tools. In view of the relatively low spatial resolution of nuclear imaging techniques, we developed a high-resolution contrast-enhanced magnetic resonance imaging (MRI method that allows rapid and noninvasive monitoring of apoptosis in intact organs. Instead of employing superparamagnetic iron oxide particles linked to annexin V, a new T1 contrast agent was used. To this effect, annexin V was linked to gadolinium diethylenetriamine pentaacetate (Gd-DTPA-coated liposomes. The left coronary artery of perfused isolated rat hearts was ligated for 30 min followed by reperfusion. T1 and T2* images were acquired by using an 11.7-T magnet before and after intracoronary injection of Gd-DTP-labeled annexin V to visualize apoptotic cells. A significant increase in signal intensity was visible in those regions containing cardiomyocytes in the early stage of apoptosis. Because labeling of early apoptotic cell death in intact organs by histological and immunohistochemical methods remains challenging, the use of Gd-DTPA-labeled annexin V in MRI is clearly an improvement in rapid targeting of apoptotic cells in the ischemic and reperfused myocardium.

  18. 3-Dimensional reconstruction of fluorescent structures in tardigrades

    Directory of Open Access Journals (Sweden)

    Franz BRÜMMER

    2007-09-01

    Full Text Available Tardigrades are microscopic animals, thus brightfield microscopy is a well established method for tardigrade observation. Modern techniques in functional genetics like fluorescence in situ hybridisation or fluorescently labelled expression markers demand high resolution fluorescence microscopy. Nevertheless tardigrades are still considered to be difficult objects for fluorescence techniques as they are covered by an opaque and diffracting cuticle. We show a modern technique of structured light illumination that enables us to acquire thin optical sections and consequently to reconstruct 3-dimensional structures in tardigrades with a high spatial resolution in all 3 dimensions. This technique is evaluated on taxonomically valuable internal as well as external structures of eutardigrades: the bucco-pharyngeal apparatus and the claws. The 3-dimensional reconstructions allow the measurement of distances in all 3 dimensions.

  19. Wetting characteristics of 3-dimensional nanostructured fractal surfaces

    Science.gov (United States)

    Davis, Ethan; Liu, Ying; Jiang, Lijia; Lu, Yongfeng; Ndao, Sidy

    2017-01-01

    This article reports the fabrication and wetting characteristics of 3-dimensional nanostructured fractal surfaces (3DNFS). Three distinct 3DNFS surfaces, namely cubic, Romanesco broccoli, and sphereflake were fabricated using two-photon direct laser writing. Contact angle measurements were performed on the multiscale fractal surfaces to characterize their wetting properties. Average contact angles ranged from 66.8° for the smooth control surface to 0° for one of the fractal surfaces. The change in wetting behavior was attributed to modification of the interfacial surface properties due to the inclusion of 3-dimensional hierarchical fractal nanostructures. However, this behavior does not exactly obey existing surface wetting models in the literature. Potential applications for these types of surfaces in physical and biological sciences are also discussed.

  20. Acute effect of static exercise in patients with aortic regurgitation assessed by cardiovascular magnetic resonance: role of left ventricular remodelling.

    Science.gov (United States)

    Alegret, Josep M; Martinez-Micaelo, Neus; La Gerche, Andre; Franco-Bonafonte, Luis; Rubio-Pérez, Francisco; Calvo, Nahum; Montero, Manuel

    2017-04-01

    In patients with aortic regurgitation (AR), the effect of static exercise (SE) on global ventricular function and AR severity has not been previously studied. Resting and SE cardiovascular magnetic resonance (CMR) were prospectively performed in 23 asymptomatic patients with AR. During SE, we observed a decrease in regurgitant volume in both end-diastolic (EDV) and end-systolic (ESV) volume in both ventricles, as well as a slight decrease in LV ejection fraction (EF). Interestingly, responses varied depending on the degree of LV remodelling. Among patients with a greater degree of LV remodelling, we observed a decrease in LVEF (56 ± 4 % at rest vs 48 ± 7 % during SE, p = 0.001) as a result of a lower decrease in LVESV (with respect to LVEDV. Among patients with a lower degree of LV remodelling, LVEF remained unchanged. RVEF remained unchanged in both groups. In patients with AR, SE provoked a reduction in preload, LV stroke volume, and regurgitant volume. In those patients with higher LV remodelling, we observed a decrease in LVEF, suggesting a lower LV contractile reserve. • In patients with aortic regurgitation, static exercise reduced preload volume. • In patients with aortic regurgitation, static exercise reduced stroke volume. • In patients with aortic regurgitation, static exercise reduced regurgitant volume. • In patients with greater remodelling, static exercise unmasked a lower contractile reserve. • Effect of static exercise on aortic regurgitation was assessed by cardiac MR.

  1. Assessment of distribution and evolution of Mechanical dyssynchrony in a porcine model of myocardial infarction by cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Abd-Elmoniem Khaled Z

    2012-01-01

    Full Text Available Abstract Background We sought to investigate the relationship between infarct and dyssynchrony post- myocardial infarct (MI, in a porcine model. Mechanical dyssynchrony post-MI is associated with left ventricular (LV remodeling and increased mortality. Methods Cine, gadolinium-contrast, and tagged cardiovascular magnetic resonance (CMR were performed pre-MI, 9 ± 2 days (early post-MI, and 33 ± 10 days (late post-MI post-MI in 6 pigs to characterize cardiac morphology, location and extent of MI, and regional mechanics. LV mechanics were assessed by circumferential strain (eC. Electro-anatomic mapping (EAM was performed within 24 hrs of CMR and prior to sacrifice. Results Mean infarct size was 21 ± 4% of LV volume with evidence of post-MI remodeling. Global eC significantly decreased post MI (-27 ± 1.6% vs. -18 ± 2.5% (early and -17 ± 2.7% (late, p Conclusions Mechanical dyssynchrony occurs early after MI and is the result of delayed electrical and mechanical activation in the infarct.

  2. The role of preoperative cerebral magnetic resonance angiography in the prevention of cerebral complications following cardiovascular surgery

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Masakazu; Sakai, Akira; Kodera, Koujirou; Sudo, Kyouichi; Oosawa, Mikio [Seirei Hamamatsu General Hospital, Shizuoka (Japan)

    1997-11-01

    Screening of carotid and intracranial artery diseases by magnetic resonance angiography (MRA) was performed in forty-one adult patients prior to elective cardiovascular surgery. In twenty patients (48.8%), MRA demonstrated significant cerebrovascular lesions: carotid or main cerebral artery stenosis in 7, diffuse cerebral arteriosclerotic change in 6, vertebral artery lesion in 5 and berry aneurysm in 2. Advanced age (over 70 years) and previous cerebrovascular events increased the incidence of cerebrovascular lesions on MRA. Forty patients underwent scheduled surgery under cardiopulmonary bypass, and pulsatile flow perfusion was used in patients in whom significant cerebrovascular lesions were demonstrated on MRA. One patient with aortic arch aneurysm was judged to be an unacceptable candidate for surgery in light of his marked diffuse arteriosclerotic lesions on MRA. In five patients, staged operation was performed from 10 to 30 days after cerebrovascular surgery (bypass surgery for internal carotid occlusion in 2, aneurysm clipping in 2, carotid endarterectomy in 1). Postoperative neurological complications occurred in one patient (2.5%). In conclusion, screening of carotid and intracranial artery diseases by MRA is a safe and useful method for evaluation of cerebrovascular lesions in patients with advanced age, previous cerebrovascular events and/or arteriosclerotic diseases. (author)

  3. Clinical implications of microvascular obstruction and intramyocardial haemorrhage in acute myocardial infarction using cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bekkers, Sebastiaan C.A.M.; Smulders, Martijn W.; Waltenberger, Johannes; Gorgels, Anton P.M.; Schalla, Simon [Maastricht University Medical Center, Department of Cardiology, Maastricht (Netherlands); Passos, Valeria Lima [Maastricht University Medical Center, Department of Methodology and Statistics, Maastricht (Netherlands); Leiner, Tim [Maastricht University Medical Center, Department of Radiology, Maastricht (Netherlands)

    2010-11-15

    To investigate the clinical implications of microvascular obstruction (MVO) and intramyocardial haemorrhage (IMH) in acute myocardial infarction (AMI). Ninety patients with a first AMI undergoing primary percutaneous coronary intervention (PCI) were studied. T2-weighted, cine and late gadolinium-enhanced cardiovascular magnetic resonance imaging was performed at 5 {+-} 2 and 103 {+-} 11 days. Patients were categorised into three groups based on the presence or absence of MVO and IMH. MVO was observed in 54% and IMH in 43% of patients, and correlated significantly (r = 0.8, p < 0.001). Pre-PCI thrombolysis in myocardial infarction 3 flow was only observed in MVO(-)/IMH(-) patients. Infarct size and impairment of systolic function were largest in MVO(+)/IMH(+) patients (n = 39, 23 {+-} 9% and 47 {+-} 7%), smallest in MVO(-)/IMH(-) patients (n = 41, 8 {+-} 8% and 55 {+-} 8%) and intermediate in MVO(+)/IMH(-) patients (n = 10, 16 {+-} 7% and 51 {+-} 6%, p < 0.001). LVEF increased in all three subgroups at follow-up, but remained intermediate in MVO(+)/IMH(-) and was lowest in MVO(+)/IMH(+) patients. Using random intercept model analysis, only infarct size was an independent predictor for adverse LV remodelling. Intramyocardial haemorrhage and microvascular obstruction are strongly related. Pre-PCI TIMI 3 flow is less frequently observed in patients with MVO and IMH. Only infarct size was an independent predictor of LV remodelling. (orig.)

  4. Pulmonary artery diameters, cross sectional areas and area changes measured by cine cardiovascular magnetic resonance in healthy volunteers.

    Science.gov (United States)

    Burman, Elisabeth D; Keegan, Jennifer; Kilner, Philip J

    2016-03-03

    We measured by cine cardiovascular magnetic resonance (CMR) main and branch pulmonary artery diameters and cross sectional areas in diastole and systole in order to establish normal ranges and the effects on them of age, gender and body surface area (BSA). Documentation of normal ranges provides a reference for research and clinical investigation in the fields of congenital heart disease, pulmonary hypertension and connective tissue disorders. We recruited 120 healthy volunteers: ten males (M) and ten females (F) in each decile between 20 and 79 years, imaging them in a 1.5 Tesla CMR system. Scout acquisitions guided the placement of steady state free precession cine acquisitions transecting the main, right and left pulmonary arteries (MPA, RPA and LPA). Cross sections were rarely quite circular. From all subjects, the means of the greater and lesser orthogonal diastolic diameters in mm were: MPA, 22.9 ± 2.4 (M) and 21.2 ± 2.1 (F), RPA 16.6 ± 2.8 (M) and 14.7 ± 2.2 (F), and LPA 17.3 ± 2.5 (M) and 15.9 ± 2.0 (F), p cine CMR are provided for reference, with documentation of their changes with age and BSA.

  5. Cohomological rigidity of manifolds defined by 3-dimensional polytopes

    Science.gov (United States)

    Buchstaber, V. M.; Erokhovets, N. Yu.; Masuda, M.; Panov, T. E.; Park, S.

    2017-04-01

    A family of closed manifolds is said to be cohomologically rigid if a cohomology ring isomorphism implies a diffeomorphism for any two manifolds in the family. Cohomological rigidity is established here for large families of 3-dimensional and 6-dimensional manifolds defined by 3-dimensional polytopes. The class \\mathscr{P} of 3-dimensional combinatorial simple polytopes P different from tetrahedra and without facets forming 3- and 4-belts is studied. This class includes mathematical fullerenes, that is, simple 3- polytopes with only 5-gonal and 6-gonal facets. By a theorem of Pogorelov, any polytope in \\mathscr{P} admits in Lobachevsky 3-space a right-angled realisation which is unique up to isometry. Our families of smooth manifolds are associated with polytopes in the class \\mathscr{P}. The first family consists of 3-dimensional small covers of polytopes in \\mathscr{P}, or equivalently, hyperbolic 3-manifolds of Löbell type. The second family consists of 6-dimensional quasitoric manifolds over polytopes in \\mathscr{P}. Our main result is that both families are cohomologically rigid, that is, two manifolds M and M' from either family are diffeomorphic if and only if their cohomology rings are isomorphic. It is also proved that if M and M' are diffeomorphic, then their corresponding polytopes P and P' are combinatorially equivalent. These results are intertwined with classical subjects in geometry and topology such as the combinatorics of 3-polytopes, the Four Colour Theorem, aspherical manifolds, a diffeomorphism classification of 6-manifolds, and invariance of Pontryagin classes. The proofs use techniques of toric topology. Bibliography: 69 titles.

  6. Circuit-Switched Gossiping in the 3-Dimensional Torus Networks

    OpenAIRE

    Delmas, Olivier; Pérennes, Stéphane

    1996-01-01

    In this paper we describe, in the case of short messages, an efficient gossiping algorithm for 3-dimensional torus networks (wrap-around or toroidal meshes) that uses synchronous circuit-switched routing. The algorithm is based on a recursive decomposition of a torus. The algorithm requires an optimal number of rounds and a quasi-optimal number of intermediate switch settings to gossip in an $7^i \\times 7^i \\times 7^i$ torus.

  7. Review of cardiovascular imaging in the journal of nuclear cardiology in 2015. Part 1 of 2: Plaque imaging, positron emission tomography, computed tomography, and magnetic resonance.

    Science.gov (United States)

    AlJaroudi, Wael A; Hage, Fadi G

    2016-02-01

    In 2015, many original articles pertaining to cardiovascular imaging with impressive quality were published in the Journal of Nuclear Cardiology. In a set of 2 articles, we provide an overview of these contributions to facilitate for the interested reader a quick review of the advancements that occurred in the field over this year. In this first article, we focus on arterial plaque imaging, cardiac positron emission tomography, computed tomography, and magnetic resonance imaging.

  8. Cardiac pathologies in female carriers of Duchenne muscular dystrophy assessed by cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Schelhorn, Juliane; Schemuth, Haemi; Nensa, Felix; Nassenstein, Kai; Forsting, Michael; Schlosser, Thomas [University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Schoenecker, Anne; Neudorf, Ulrich [University Hospital Essen, Department of Pediatric Cardiology, Essen (Germany); Schara, Ulrike [University Hospital Essen, Department of Pediatric Neurology, Essen (Germany)

    2015-10-15

    Duchenne muscular dystrophy (DMD) is the most common and severe dystrophinopathy. DMD carriers rarely present with clinical symptoms, but may suffer from cardiac involvement. Because echocardiographic findings are inconsistent and cardiac magnetic resonance imaging (CMRI) data are limited, this study sought to investigate asymptomatic carriers for cardiac abnormalities using CMRI. Fifteen genetically confirmed DMD carriers (age, 32.3 ± 10.2 years) were prospectively examined on a 1.5T MR system. Cine, T2, and late-gadolinium-enhanced (LGE) images were acquired, and were evaluated in consensus by two experienced readers. Left ventricular (LV) parameters were analysed semiautomatically, normalized to BSA. Normalized LV end-diastolic volume was increased in 7 % (73.7 ± 16.8 ml/m{sup 2}; range, 48-116 ml/m{sup 2}) and normalized LV end-systolic volume in 20 % (31.5 ± 13.3 ml/m{sup 2}; range, 15-74 ml/m{sup 2}). EF was reduced in 33 % (58.4 ± 7.6 %; range, 37-69 %) and normalized LV myocardial mass in 80 % (40.5 ± 6.8 g/m{sup 2}; range, 31-55 g/m{sup 2}). In 80 %, regional myocardial thinning was detected in more than one segment. In 13 % and 40 %, apical-lateral accentuation of LV non-compaction was present. LGE was found in 60 % (midmyocardial inferolateral accentuation). Given the high frequency of cardiac pathologies detected by CMRI, regular cardiac risk assessment is advisable for DMD carriers. Besides clinical examination, CMRI is an excellent tool for this purpose. (orig.)

  9. Combined blood pool and extracellular contrast agents for pediatric and young adult cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Joyce T. [Ann and Robert Lurie Children' s Hospital of Chicago, Division of Pediatric Cardiology, 225 E. Chicago Ave., Box 21, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Robinson, Joshua D. [Ann and Robert Lurie Children' s Hospital of Chicago, Division of Pediatric Cardiology, 225 E. Chicago Ave., Box 21, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Deng, Jie [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States); Rigsby, Cynthia K. [Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States)

    2016-12-15

    A comprehensive cardiac magnetic resonance (cardiac MR) study including both late gadolinium enhancement (LGE) and MR angiography may be indicated for patients with a history of acquired or congenital heart disease. To study the novel use of an extracellular agent for assessment of LGE combined with a blood pool contrast agent for detailed MR angiography evaluation to yield a comprehensive cardiac MR study in these patients. We reviewed clinical cardiac MR studies utilizing extracellular and blood pool contrast agents and noted demographics, clinical data and adverse events. We rated LGE image quality and MR angiography image quality for each vascular segment and calculated inter-rater variability. We also quantified contrast-to-noise ratio (CNR). Thirty-three patients (mean age 13.9 ± 3 years) received an extracellular contrast agent (10 gadobenate dimeglumine, 23 gadopentetate dimeglumine) and blood pool contrast agent (33 gadofosveset trisodium). No adverse events were reported. MRI indications included Kawasaki disease (8), cardiomyopathy and coronary anatomy (15), repaired congenital heart disease (8), and other (2). Mean LGE quality was 2.6 ± 0.6 with 97% diagnostic imaging. LGE quality did not vary by type of contrast agent given (P = 0.07). Mean MR angiography quality score was 4.7 ± 0.6, with high inter-rater agreement (k = 0.6-0.8, P < 0.002). MR angiography quality did not vary by type of contrast agent used (P = 0.6). Cardiac MR studies utilizing both extracellular and blood pool contrast agents are feasible and safe and provide excellent-quality LGE and MR angiography images. The use of two contrast agents allows for a comprehensive assessment of both myocardial viability and vascular anatomy during the same exam. (orig.)

  10. Cost evaluation of cardiovascular magnetic resonance versus coronary angiography for the diagnostic work-up of coronary artery disease: Application of the European Cardiovascular Magnetic Resonance registry data to the German, United Kingdom, Swiss, and United States health care systems

    Directory of Open Access Journals (Sweden)

    Moschetti Karine

    2012-06-01

    Full Text Available Abstract Background Cardiovascular magnetic resonance (CMR has favorable characteristics for diagnostic evaluation and risk stratification of patients with known or suspected CAD. CMR utilization in CAD detection is growing fast. However, data on its cost-effectiveness are scarce. The goal of this study is to compare the costs of two strategies for detection of significant coronary artery stenoses in patients with suspected coronary artery disease (CAD: 1 Performing CMR first to assess myocardial ischemia and/or infarct scar before referring positive patients (defined as presence of ischemia and/or infarct scar to coronary angiography (CXA versus 2 a hypothetical CXA performed in all patients as a single test to detect CAD. Methods A subgroup of the European CMR pilot registry was used including 2,717 consecutive patients who underwent stress-CMR. From these patients, 21% were positive for CAD (ischemia and/or infarct scar, 73% negative, and 6% uncertain and underwent additional testing. The diagnostic costs were evaluated using invoicing costs of each test performed. Costs analysis was performed from a health care payer perspective in German, United Kingdom, Swiss, and United States health care settings. Results In the public sectors of the German, United Kingdom, and Swiss health care systems, cost savings from the CMR-driven strategy were 50%, 25% and 23%, respectively, versus outpatient CXA. If CXA was carried out as an inpatient procedure, cost savings were 46%, 50% and 48%, respectively. In the United States context, cost savings were 51% when compared with inpatient CXA, but higher for CMR by 8% versus outpatient CXA. Conclusion This analysis suggests that from an economic perspective, the use of CMR should be encouraged as a management option for patients with suspected CAD.

  11. Dobutamine Stress Cardiovascular Magnetic Resonance Imaging in Patients after Invasive Coronary Revascularization with Stent Placement

    Energy Technology Data Exchange (ETDEWEB)

    Heilmaier, C.; Meier, F.; Forsting, M.; Schlosser, T.W. (Dept. of Diagnostic and Interventional Radiology and Neuroradiology, Univ. Hospital Essen, Essen (Germany)). e-mail: christina.heilmaier@uni-due.de; Bruder, O.; Jochims, M.; Sabin, G.V. (Dept. of Cardiology and Angiology, Elisabeth Hospital, Essen (Germany)); Barkhausen, J. (Dept. of Radiology and Nuclear Medicine, Univ. Hospital Schleswig-Holstein, Campus Luebeck, Luebeck (Germany))

    2009-12-15

    Background: High-dose dobutamine stress magnetic resonance (DSMR) is a well-established imaging technique for the detection of coronary artery disease (CAD). Purpose: To investigate the value of DSMR for the detection of in-stent restenoses (ISR) in patients with prior coronary stenting, using invasive coronary angiography (ICA) as the standard of reference. Material and Methods: 50 patients with 74 stents and without wall motion abnormalities at rest were examined on a 1.5T MR scanner and underwent ICA for clinical reasons within 14 days after DSMR examination. A dobutamine/atropine stress protocol was employed until age-predicted heart rate was achieved, and imaging was performed in at least three long- and three short-axis views using a segmented steady-state free precession sequence (repetition/echo time [TR/TE] 3/1.5 ms, flip angle 60 deg). All examinations were read by an experienced cardiologist and radiologist in consensus, with myocardial ischemia being defined as a new stress-induced wall motion abnormality in at least one myocardial segment. Statistical analysis was performed on a per-vessel (left circumflex artery [LCX], left anterior descending artery [LAD], and right coronary artery [RCA]) basis and with regard to the number of affected vessels (one-, two- or three-vessel disease). Results: ICA yielded seven ISR, of which one was missed by DSMR (sensitivity 86%, 95% confidence interval [CI] 0.42-0.99). Sixty-seven coronary arteries showed no ISR in ICA; however, due to new wall motion abnormalities, seven ISR were suspected in DSMR (2xRCA, 3xLCX, and 2xLAD; sensitivity 86%, specificity 90%, positive predictive value 46%, negative predictive value 98%, and diagnostic accuracy 89%). The per-vessel analysis of the three main coronary arteries revealed highest sensitivity (100%), specificity (93%), and diagnostic accuracy (94%) for the LAD. Conclusion: High-dose DSMR is an accurate, noninvasive technique for the detection of ISR and reliably allows

  12. Cleft posterior mitral valve leaflet in an adult with Turner syndrome diagnosed with the use of 3-dimensional transesophageal echocardiography.

    Science.gov (United States)

    Negrea, Stefania Luminita; Alexandrescu, Clara; Sabatier, Michel; Dreyfus, Gilles D

    2012-01-01

    Turner syndrome is a monosomy (45,X karyotype) in which the prevalence of cardiovascular anomalies is high. However, this aspect of Turner syndrome has received little attention outside of the pediatric medical literature, and the entire spectrum of cardiovascular conditions in adults remains unknown. We present the case of a 34-year-old woman who had Turner syndrome. When she was a teenager, her native bicuspid aortic valve was replaced with a mechanical prosthesis. Fifteen years later, during preoperative examination for prosthesis-patient mismatch, severe mitral regurgitation was detected, and a congenital cleft in the posterior leaflet of the mitral valve was diagnosed with use of 3-dimensional transesophageal echocardiography. The patient underwent concurrent mitral valve repair and aortic valve replacement. To our knowledge, this is the first report of a cleft in the posterior mitral valve leaflet as a cardiovascular defect observed in Turner syndrome, and the first such instance to have been diagnosed with the use of 3-dimensional echocardiography.

  13. Cellular Changes of Stem Cells in 3-Dimensional Culture.

    Science.gov (United States)

    Green, Matthew P; Hou, Bo

    2017-06-12

    During various operations and procedures, such as distraction osteogenesis and orthodontics, skeletal tissues use mechanotransduction. Mechanotransduction is important for maintaining bone health and converting mechanical forces into biochemical signals. We hypothesized that cells put under mechanical stress would adapt and change morphologically and respond with a decrease in cellular proliferation to accommodate the stress differences. These differences will be measured at the molecular and genetic level. We also wanted to test the practicality of an in vitro 3-dimensional gel model system. We implemented a 3-dimensional cell culture model. The sample was composed of isolated mouse mesenchymal prefibroblast bone marrow cells from the femurs and tibias of 6- to 8-week-old wild-type C57BL6 mice. The cells were seeded on fibronectin-coated hydrogels along with fibrin and nodulin growth factors. The variables tested were a no-force model (control) and a force model. The force model required two 0.1-mm suture pins put through one 0.25-cm length of cell-gel matrix. After the experiments were run to completion, the samples were fixed with 4% paraformaldehyde and embedded in paraffin. Serial sections were cut at a thickness of 5 μm along the long axis for the force construct and encompassing the entire circular area of the control construct. Descriptive and bivariate statistics were computed, and the P value was set at 5%. There was a statistically significant difference between the 2 models. The force model had longer and straighter primary cilia, less apoptosis, and an increase in cell proliferation. In addition, the shape of the cells was markedly different after the experiment. The results of the study suggest cells put under tensile stress have the ability to mechanically sense the environment to provide improved adaptation. Our work also confirms the usefulness of the in vitro 3-dimensional gel model system to mimic in vivo applications. Published by Elsevier

  14. Effect of Papillary Muscles and Trabeculae on Left Ventricular Measurement Using Cardiovascular Magnetic Resonance Imaging in Patients with Hypertrophic Cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Park, Eun-Ah; Lee, Whal [Department of Radiology, Cardiovascular Division, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of); Kim, Hyung-Kwan [Department of Internal Medicine, Cardiovascular Division, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of); Chung, Jin Wook [Department of Radiology, Cardiovascular Division, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of)

    2015-11-01

    To evaluate the influence of papillary muscles and trabeculae on left ventricular (LV) cardiovascular magnetic resonance (CMR) analysis using three methods of cavity delineation (classic or modified inclusion methods, and the exclusion method) in patients with hypertrophic cardiomyopathy (HCM). This retrospective study included 20 consecutive HCM patients who underwent 1.5-T CMR imaging with short-axis cine stacks of the entire LV. LV measurements were performed using three different methods of manual cavity delineation of the endocardial and epicardial contours: method A, presumed endocardial boundary as seen on short-axis cine images; method B, including solely the cavity and closely adjacent trabeculae; or method C, excluding papillary muscles and trabeculae. Ascending aorta forward flow was measured as reference for LV-stroke volume (SV). Interobserver reproducibility was assessed using intraclass correlation coefficients. Method A showed larger end-diastole and end-systole volumes (largest percentage differences of 25% and 68%, respectively, p < 0.05), compared with method C. The ejection fraction was 55.7 ± 6.9% for method A, 68.6 ± 8.4% for B, and 71.7 ± 7.0% for C (p < 0.001). Mean mass was also significantly different: 164.6 ± 47.4 g for A, 176.5 ± 50.5 g for B, and 199.6 ± 53.2 g for C (p < 0.001). LV-SV error was largest with method B (p < 0.001). No difference in interobserver agreement was observed (p > 0.05). In HCM patients, LV measurements are strikingly different dependent on whether papillary muscles and trabeculae are included or excluded. Therefore, a consistent method of LV cavity delineation may be crucial during longitudinal follow-up to avoid misinterpretation and erroneous clinical decision-making.

  15. Role of Perfusion at Rest in the Diagnosis of Myocardial Infarction Using Vasodilator Stress Cardiovascular Magnetic Resonance.

    Science.gov (United States)

    Patel, Mita B; Mor-Avi, Victor; Kawaji, Keigo; Nathan, Sandeep; Kramer, Christopher M; Lang, Roberto M; Patel, Amit R

    2016-04-01

    In clinical practice, perfusion at rest in vasodilator stress single-photon emission computed tomography is commonly used to confirm myocardial infarction (MI) and ischemia and to rule out artifacts. It is unclear whether perfusion at rest carries similar information in cardiovascular magnetic resonance (CMR). We sought to determine whether chronic MI is associated with abnormal perfusion at rest on CMR. We compared areas of infarct and remote myocardium in 31 patients who underwent vasodilator stress CMR (1.5 T), had MI confirmed by late gadolinium enhancement (LGE scar), and coronary angiography within 6 months. Stress perfusion imaging during gadolinium first pass was followed by reversal with aminophylline (75 to 125 mg), rest perfusion, and LGE imaging. Resting and peak-stress time-intensity curves were used to obtain maximal upslopes (normalized by blood pool upslopes), which were compared between infarcted and remote myocardial regions of interest. At rest, there was no significant difference between the slopes in the regions of interest supplied by arteries with and without stenosis >70% (0.31 ± 0.16 vs 0.26 ± 0.15 1/s), irrespective of LGE scar. However, at peak stress, we found significant differences (0.20 ± 0.11 vs 0.30 ± 0.22 1/s; p rest, there was no difference between infarcted and remote myocardium (0.27 ± 0.14 vs 0.30 ± 0.17 1/s), irrespective of stenosis, but significant differences were seen during stress (0.21 ± 0.16 vs 0.28 ± 0.18 1/s; p rest associated with chronic MI are not reliably detectable on CMR images. Accordingly, unlike single-photon emission computed tomography, normal CMR perfusion at rest should not be used to rule out chronic MI.

  16. The clinical impact of late gadolinium enhancement in Takotsubo cardiomyopathy: serial analysis of cardiovascular magnetic resonance images

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    Katoh Hideki

    2011-10-01

    Full Text Available Abstract Background Our study aimed to investigate both the clinical implications of late gadolinium enhancement (LGE by cardiovascular magnetic resonance (CMR and the relation of LGE to clinical findings in patients with Takotsubo cardiomyopathy (TTC. Methods We evaluated 20 consecutive patients (2 men, 18 women; median age, 77 years; interquartile range [IQR] 67-82 years who were admitted to our hospital with the diagnosis of TTC. CMR was performed within 1 week after admission, and follow-up studies were conducted 1.5 and 6 months later. Results In 8 patients, CMR imaging during the sub-acute phase revealed LGE in the area matched with wall motion impairment. Cardiogenic shock was more frequently observed in patients with LGE than in those without LGE (38% vs 0%, p = 0.049. The patients with LGE needed a longer duration for ECG normalization and recovery of wall motion than did those without LGE (median 205 days, IQR [152-363] vs 68 days, [43-145], p = 0.005; 15 days, [10-185] vs 7 days, [4-13], p = 0.030, respectively. In 5 of these 8 patients, LGE disappeared within 45-180 days (170, IQR [56-180] of onset. The patients with LGE remaining in the chronic phase had higher peak creatine kinase levels than did those without LGE (median 307 IU/L, IQR [264-460] vs 202 IU/L, [120-218], p = 0.017. Conclusion LGE by CMR in the sub-acute phase may be associated with the severity and prolonged recovery to normal of clinical findings in TTC.

  17. Potential clinical impact of cardiovascular magnetic resonance assessment of ejection fraction on eligibility for cardioverter defibrillator implantation

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    Joshi Subodh B

    2012-10-01

    Full Text Available Abstract Background For the primary prevention of sudden cardiac death, guidelines provide left ventricular ejection fraction (EF criteria for implantable cardioverter defibrillator (ICD placement without specifying the technique by which it should be measured. We sought to investigate the potential impact of performing cardiovascular magnetic resonance (CMR for EF on ICD eligibility. Methods The study population consisted of patients being considered for ICD implantation who were referred for EF assessment by CMR. Patients who underwent CMR within 30 days of echocardiography were included. Echocardiographic EF was determined by Simpson’s biplane method and CMR EF was measured by Simpson’s summation of discs method. Results Fifty-two patients (age 62±15 years, 81% male had a mean EF of 38 ± 14% by echocardiography and 35 ± 14% by CMR. CMR had greater reproducibility than echocardiography for both intra-observer (ICC, 0.98 vs 0.94 and inter-observer comparisons (ICC 0.99 vs 0.93. The limits of agreement comparing CMR and echocardiographic EF were – 16 to +10 percentage points. CMR resulted in 11 of 52 (21% and 5 of 52 (10% of patients being reclassified regarding ICD eligibility at the EF thresholds of 35 and 30% respectively. Among patients with an echocardiographic EF of between 25 and 40%, 9 of 22 (41% were reclassified by CMR at either the 35 or 30% threshold. Echocardiography identified only 1 of the 6 patients with left ventricular thrombus noted incidentally on CMR. Conclusions CMR resulted in 21% of patients being reclassified regarding ICD eligibility when strict EF criteria were used. In addition, CMR detected unexpected left ventricular thrombus in almost 10% of patients. Our findings suggest that the use of CMR for EF assessment may have a substantial impact on management in patients being considered for ICD implantation.

  18. Prognostic value at 5 years of microvascular obstruction after acute myocardial infarction assessed by cardiovascular magnetic resonance

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    Klug Gert

    2012-07-01

    Full Text Available Abstract Background Early and late microvascular obstruction (MVO assessed by cardiovascular magnetic resonance (CMR are prognostic markers for short-term clinical endpoints after acute ST-elevation myocardial infarction (STEMI. However, there is a lack of studies with long-term follow-up periods (>24 months. Methods STEMI patients reperfused by primary angioplasty (n = 129 underwent MRI at a median of 2 days after the index event. Early MVO was determined on dynamic Gd first-pass images directly after the administration of 0.1 mmol/kg bodyweight Gd-based contrast agent. Furthermore, ejection fraction (EF, %, left ventricular myocardial mass (LVMM and total infarct size (% of LVMM were determined with CMR. Clinical follow-up was conducted after a median of 52 months. The primary endpoint was defined as a composite of death, myocardial re-infarction, stroke, repeat revascularization, recurrence of ischemic symptoms, atrial fibrillation, congestive heart failure and hospitalization. Results Follow-up was completed by 107 patients. 63 pre-defined events occurred during follow-up. Initially, 74 patients showed early MVO. Patients with early MVO had larger infarcts (mean: 24.9 g vs. 15.5 g, p = 0.002 and a lower EF (mean: 39% vs. 46%, p = 0.006. The primary endpoint occurred in 66.2% of patients with MVO and in 42.4% of patients without MVO (p  Conclusion Early MVO, as assessed by first-pass CMR, is an independent long-term prognosticator for morbidity after AMI.

  19. Breathing Maneuvers as a Vasoactive Stimulus for Detecting Inducible Myocardial Ischemia – An Experimental Cardiovascular Magnetic Resonance Study

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    Fischer, Kady; Guensch, Dominik P; Shie, Nancy; Lebel, Julie; Friedrich, Matthias G

    2016-01-01

    Background Breathing maneuvers can elicit a similar vascular response as vasodilatory agents like adenosine; yet, their potential diagnostic utility in the presence of coronary artery stenosis is unknown. The objective of the study is to investigate if breathing maneuvers can non-invasively detect inducible ischemia in an experimental animal model when the myocardium is imaged with oxygenation-sensitive cardiovascular magnetic resonance (OS-CMR). Methods and Findings In 11 anesthetised swine with experimentally induced significant stenosis (fractional flow reserve coronary artery (LAD) and 9 control animals, OS-CMR at 3T was performed during two different breathing maneuvers, a long breath-hold; and a combined maneuver of 60s of hyperventilation followed by a long breath-hold. The resulting change of myocardial oxygenation was compared to the invasive measurements of coronary blood flow, blood gases, and oxygen extraction. In control animals, all breathing maneuvers could significantly alter coronary blood flow as hyperventilation decreased coronary blood flow by 34±23%. A long breath-hold alone led to an increase of 97±88%, while the increase was 346±327% (pcoronary blood flow response was attenuated after both hyperventilation and the following breath-hold. This was matched by the observed oxygenation response as breath-holds following hyperventilation consistently yielded a significant difference in the signal of the MRI images between the perfusion territory of the stenosis LAD and remote myocardium. There was no difference between the coronary territories during the other breathing maneuvers or in the control group at any point. Conclusion In an experimental animal model, the response to a combined breathing maneuver of hyperventilation with subsequent breath-holding is blunted in myocardium subject to significant coronary artery stenosis. This maneuver may allow for detecting severe coronary artery stenosis and have a significant clinical potential as a

  20. Noninvasive assessment of coronary vasodilation using cardiovascular magnetic resonance in patients at high risk for coronary artery disease

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    Yang Phillip

    2008-05-01

    Full Text Available Abstract Background Impaired coronary vasodilation to both endothelial-dependent and endothelial-independent stimuli have been associated with atherosclerosis. Direct measurement of coronary vasodilation using x-ray angiography or intravascular ultrasound is invasive and, thus, not appropriate for asymptomatic patients or for serial follow-up. In this study, high-resolution coronary cardiovascular magnetic resonance (CMR was used to investigate the vasodilatory response to nitroglycerine (NTG of asymptomatic patients at high risk for CAD. Methods A total of 46 asymptomatic subjects were studied: 13 high-risk patients [8 with diabetes mellitus (DM, 5 with end stage renal disease (ESRD] and 33 age-matched controls. Long-axis and cross-sectional coronary artery images were acquired pre- and 5 minutes post-sublingual NTG using a sub-mm-resolution multi-slice spiral coronary CMR sequence. Coronary cross sectional area (CSA was measured on pre- and post-NTG images and % coronary vasodilation was calculated. Results Patients with DM and ESRD had impaired coronary vasodilation to NTG compared to age-matched controls (17.8 ± 7.3% vs. 25.6 ± 7.1%, p = 0.002. This remained significant for ESRD patients alone (14.8 ± 7.7% vs. 25.6 ± 7.1%; p = 0.003 and for DM patients alone (19.8 ± 6.3% vs. 25.6 ± 7.1%; p = 0.049, with a non-significant trend toward greater impairment in the ESRD vs. DM patients (14.8 ± 7.7% vs. 19.8 ± 6.3%; p = 0.23. Conclusion Noninvasive coronary CMR demonstrates impairment of coronary vasodilation to NTG in high-risk patients with DM and ESRD. This may provide a functional indicator of subclinical atherosclerosis and warrants clinical follow up to determine prognostic significance.

  1. Regional myocardial function after intracoronary bone marrow cell injection in reperfused anterior wall infarction - a cardiovascular magnetic resonance tagging study

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    Arnesen Harald

    2011-03-01

    Full Text Available Abstract Background Trials have brought diverse results of bone marrow stem cell treatment in necrotic myocardium. This substudy from the Autologous Stem Cell Transplantation in Acute Myocardial Infarction trial (ASTAMI explored global and regional myocardial function after intracoronary injection of autologous mononuclear bone marrow cells (mBMC in acute anterior wall myocardial infarction treated with percutaneous coronary intervention. Methods Cardiovascular magnetic resonance (CMR tagging was performed 2-3 weeks and 6 months after revascularization in 15 patients treated with intracoronary stem cell injection (mBMC group and in 13 controls without sham injection. Global and regional left ventricular (LV strain and LV twist were correlated to cine CMR and late gadolinium enhancement (LGE. Results In the control group myocardial function as measured by strain improved for the global LV (6 months: -13.1 ± 2.4 versus 2-3 weeks: -11.9 ± 3.4%, p = 0.014 and for the infarct zone (-11.8 ± 3.0 versus -9.3 ± 4.1%, p = 0.001, and significantly more than in the mBMC group (inter-group p = 0.027 for global strain, respectively p = 0.009 for infarct zone strain. LV infarct mass decreased (35.7 ± 20.4 versus 45.7 ± 29.5 g, p = 0.024, also significantly more pronounced than the mBMC group (inter-group p = 0.034. LV twist was initially low and remained unchanged irrespective of therapy. Conclusions LGE and strain findings quite similarly demonstrate subtle differences between the mBMC and control groups. Intracoronary injection of autologous mBMC did not strengthen regional or global myocardial function in this substudy. Trial registration ClinicalTrials.gov: NCT00199823

  2. How do hypertrophic cardiomyopathy mutations affect myocardial function in carriers with normal wall thickness? Assessment with cardiovascular magnetic resonance

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    Pinto Yigal M

    2010-03-01

    Full Text Available Abstract Background Clinical data on myocardial function in HCM mutation carriers (carriers is sparse but suggests that subtle functional abnormalities can be measured with tissue Doppler imaging before the development of overt hypertrophy. We aimed to confirm the presence of functional abnormalities using cardiovascular magnetic resonance (CMR, and to investigate if sensitive functional assessment could be employed to identify carriers. Results 28 carriers and 28 controls were studied. Global left atrial (LA and left ventricular (LV dimensions, segmental peak systolic circumferential strain (SCS and peak diastolic circumferential strain rate (DCSR, as well as the presence of late Gadolinium enhancement (LGE were determined with CMR. Septal and lateral myocardial velocities were measured with echocardiographic tissue Doppler imaging. lv mass and volumes were comparable between groups. Maximal septal to lateral wall thickness ratio (SL ratio was larger in carriers than in controls (1.3 ± 0.2 versus 1.1 ± 0.1, p 1.2 and a peak DCSR -1 was present in 45% of carriers and in none of the controls, yielding a positive predictive value of 100%. Two carriers and 18 controls had a SL ratio 105%.s-1, yielding a negative predictive value of 90%. With multivariate analysis, HCM mutation carriership was an independent determinant of reduced peak SCS and peak DCSR. Conclusions HCM mutation carriership is an independent determinant of reduced peak SCS and peak DCSR when LV wall thickness is within normal limits, and is associated with increased LA volumes and SL ratio. Using SL ratio and peak DCSR has a high accuracy to identify carriers. However, since carriers also display structural abnormalities and focal LGE, we advocate to also evaluate morphology and presence of LGE when screening for carriers.

  3. Mapping of mitral regurgitant defects by cardiovascular magnetic resonance in moderate or severe mitral regurgitation secondary to mitral valve prolapse

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    Raffel Owen C

    2008-04-01

    Full Text Available Abstract Purpose In mitral valve prolapse, determining whether the valve is suitable for surgical repair depends on the location and mechanism of regurgitation. We assessed whether cardiovascular magnetic resonance (CMR could accurately identify prolapsing or flail mitral valve leaflets and regurgitant jet direction in patients with known moderate or severe mitral regurgitation. Methods CMR of the mitral valve was compared with trans-thoracic echocardiography (TTE in 27 patients with chronic moderate to severe mitral regurgitation due to mitral valve prolapse. Contiguous long-axis high temporal resolution CMR cines perpendicular to the valve commissures were obtained across the mitral valve from the medial to lateral annulus. This technique allowed systematic valve inspection and mapping of leaflet prolapse using a 6 segment model. CMR mapping was compared with trans-oesophageal echocardiography (TOE or surgical inspection in 10 patients. Results CMR and TTE agreed on the presence/absence of leaflet abnormality in 53 of 54 (98% leaflets. Prolapse or flail was seen in 36 of 54 mitral valve leaflets examined on TTE. CMR and TTE agreed on the discrimination of prolapse from flail in 33 of 36 (92% leaflets and on the predominant regurgitant jet direction in 26 of the 27 (96% patients. In the 10 patients with TOE or surgical operative findings available, CMR correctly classified presence/absence of segmental abnormality in 49 of 60 (82% leaflet segments. Conclusion Systematic mitral valve assessment using a simple protocol is feasible and could easily be incorporated into CMR studies in patients with mitral regurgitation due to mitral valve prolapse.

  4. Cardiovascular magnetic resonance by non contrast T1-mapping allows assessment of severity of injury in acute myocardial infarction

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    2012-01-01

    Background Current cardiovascular magnetic resonance (CMR) methods, such as late gadolinium enhancement (LGE) and oedema imaging (T2W) used to depict myocardial ischemia, have limitations. Novel quantitative T1-mapping techniques have the potential to further characterize the components of ischemic injury. In patients with myocardial infarction (MI) we sought to investigate whether state-of the art pre-contrast T1-mapping (1) detects acute myocardial injury, (2) allows for quantification of the severity of damage when compared to standard techniques such as LGE and T2W, and (3) has the ability to predict long term functional recovery. Methods 3T CMR including T2W, T1-mapping and LGE was performed in 41 patients [of these, 78% were ST elevation MI (STEMI)] with acute MI at 12-48 hour after chest pain onset and at 6 months (6M). Patients with STEMI underwent primary PCI prior to CMR. Assessment of acute regional wall motion abnormalities, acute segmental damaged fraction by T2W and LGE and mean segmental T1 values was performed on matching short axis slices. LGE and improvement in regional wall motion at 6M were also obtained. Results We found that the variability of T1 measurements was significantly lower compared to T2W and that, while the diagnostic performance of acute T1-mapping for detecting myocardial injury was at least as good as that of T2W-CMR in STEMI patients, it was superior to T2W imaging in NSTEMI. There was a significant relationship between the segmental damaged fraction assessed by either by LGE or T2W, and mean segmental T1 values (P myocardial damage. T1-mapping might become an important complementary technique to LGE and T2W for identification of reversible myocardial injury and prediction of functional recovery in acute MI. PMID:22309452

  5. Three-Directional Evaluation of Mitral Flow in the Rat Heart by Phase-Contrast Cardiovascular Magnetic Resonance.

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    Kristine Skårdal

    Full Text Available Determination of mitral flow is an important aspect in assessment of cardiac function. Traditionally, mitral flow is measured by Doppler echocardiography which suffers from several challenges, particularly related to the direction and the spatial inhomogeneity of flow. These challenges are especially prominent in rodents. The purpose of this study was to establish a cardiovascular magnetic resonance (CMR protocol for evaluation of three-directional mitral flow in a rodent model of cardiac disease.Three-directional mitral flow were evaluated by phase contrast CMR (PC-CMR in rats with aortic banding (AB (N = 7 and sham-operated controls (N = 7. Peak mitral flow and deceleration rate from PC-CMR was compared to conventional Doppler echocardiography. The accuracy of PC-CMR was investigated by comparison of spatiotemporally integrated mitral flow with left ventricular stroke volume assessed by cine CMR.PC-CMR portrayed the spatial distribution of mitral flow and flow direction in the atrioventricular plane throughout diastole. Both PC-CMR and echocardiography demonstrated increased peak mitral flow velocity and higher deceleration rate in AB compared to sham. Comparison with cine CMR revealed that PC-CMR measured mitral flow with excellent accuracy. Echocardiography presented significantly lower values of flow compared to PC-CMR.For the first time, we show that PC-CMR offers accurate evaluation of three-directional mitral blood flow in rodents. The method successfully detects alterations in the mitral flow pattern in response to cardiac disease and provides novel insight into the characteristics of mitral flow.

  6. Cardiovascular magnetic resonance of scar and ischemia burden early after acute ST elevation and non-ST elevation myocardial infarction

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    Sparrow Patrick

    2008-10-01

    Full Text Available Abstract Background The acute coronary syndrome diagnosis includes different classifications of myocardial infarction, which have been shown to differ in their pathology, as well as their early and late prognosis. These differences may relate to the underlying extent of infarction and/or residual myocardial ischemia. The study aim was to compare scar and ischemia mass between acute non-ST elevation myocardial infarction (NSTEMI, ST-elevation MI with Q-wave formation (Q-STEMI and ST-elevation MI without Q-wave formation (Non-Q STEMI in-vivo, using cardiovascular magnetic resonance (CMR. Methods and results This was a prospective cohort study of twenty five consecutive patients with NSTEMI, 25 patients with thrombolysed Q-STEMI and 25 patients with thrombolysed Non-Q STEMI. Myocardial function (cine imaging, ischemia (adenosine stress first pass myocardial perfusion and scar (late gadolinium enhancement were assessed by CMR 2–6 days after presentation and before any invasive revascularisation procedure. All subjects gave written informed consent and ethical committee approval was obtained. Scar mass was highest in Q-STEMI, followed by Non-Q STEMI and NSTEMI (24.1%, 15.2% and 3.8% of LV mass, respectively; p Conclusion Prior to revascularisation, the ratio of scar to ischemia differs between NSTEMI, Non-Q STEMI and Q-STEMI, whilst the combined scar and ischemia mass is similar between these three types of MI. These results provide in-vivo confirmation of the diverse pathophysiology of different types of acute myocardial infarction and may explain their divergent early and late prognosis.

  7. Towards real-time cardiovascular magnetic resonance guided transarterial CoreValve implantation: in vivo evaluation in swine

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    Kahlert Philipp

    2012-03-01

    Full Text Available Abstract Background Real-time cardiovascular magnetic resonance (rtCMR is considered attractive for guiding TAVI. Owing to an unlimited scan plane orientation and an unsurpassed soft-tissue contrast with simultaneous device visualization, rtCMR is presumed to allow safe device navigation and to offer optimal orientation for precise axial positioning. We sought to evaluate the preclinical feasibility of rtCMR-guided transarterial aortic valve implatation (TAVI using the nitinol-based Medtronic CoreValve bioprosthesis. Methods rtCMR-guided transfemoral (n = 2 and transsubclavian (n = 6 TAVI was performed in 8 swine using the original CoreValve prosthesis and a modified, CMR-compatible delivery catheter without ferromagnetic components. Results rtCMR using TrueFISP sequences provided reliable imaging guidance during TAVI, which was successful in 6 swine. One transfemoral attempt failed due to unsuccessful aortic arch passage and one pericardial tamponade with subsequent death occurred as a result of ventricular perforation by the device tip due to an operating error, this complication being detected without delay by rtCMR. rtCMR allowed for a detailed, simultaneous visualization of the delivery system with the mounted stent-valve and the surrounding anatomy, resulting in improved visualization during navigation through the vasculature, passage of the aortic valve, and during placement and deployment of the stent-valve. Post-interventional success could be confirmed using ECG-triggered time-resolved cine-TrueFISP and flow-sensitive phase-contrast sequences. Intended valve position was confirmed by ex-vivo histology. Conclusions Our study shows that rtCMR-guided TAVI using the commercial CoreValve prosthesis in conjunction with a modified delivery system is feasible in swine, allowing improved procedural guidance including immediate detection of complications and direct functional assessment with reduction of radiation and omission of contrast media.

  8. Quantitative assessment of left ventricular mechanical dyssynchrony using cine cardiovascular magnetic resonance imaging: Inter-study reproducibility.

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    Kowallick, Johannes T; Morton, Geraint; Lamata, Pablo; Jogiya, Roy; Kutty, Shelby; Hasenfuß, Gerd; Lotz, Joachim; Chiribiri, Amedeo; Nagel, Eike; Schuster, Andreas

    2017-01-01

    To determine the inter-study reproducibility of left ventricular (LV) mechanical dyssynchrony measures based on standard cardiovascular magnetic resonance (CMR) cine images. Steady-state free precession (SSFP) LV short-axis stacks and three long-axes were acquired on the same day at three time points. Circumferential strain systolic dyssynchrony indexes (SDI), area-SDI as well as circumferential and radial uniformity ratio estimates (CURE and RURE, respectively) were derived from CMR myocardial feature-tracking (CMR-FT) based on the tracking of three SSFP short-axis planes. Furthermore, 4D-LV-analysis based on SSFP short-axis stacks and longitudinal planes was performed to quantify 4D-volume-SDI. A single-centre London teaching hospital. 16 healthy volunteers. Inter-study reproducibility between the repeated exams. CURE and RURE as well as 4D-volume-SDI showed good inter-study reproducibility (coefficient of variation [CoV] 6.4%-12.9%). Circumferential strain and area-SDI showed higher variability between the repeated measurements (CoV 24.9%-37.5%). Uniformity ratio estimates showed the lowest inter-study variability (CoV 6.4%-8.5%). Derivation of LV mechanical dyssynchrony measures from standard cine images is feasible using CMR-FT and 4D-LV-analysis tools. Uniformity ratio estimates and 4D-volume-SDI showed good inter-study reproducibility. Their clinical value should next be explored in patients who potentially benefit from cardiac resynchronization therapy.

  9. An isolated perfused pig heart model for the development, validation and translation of novel cardiovascular magnetic resonance techniques

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    Perera Divaka

    2010-09-01

    Full Text Available Abstract Background Novel cardiovascular magnetic resonance (CMR techniques and imaging biomarkers are often validated in small animal models or empirically in patients. Direct translation of small animal CMR protocols to humans is rarely possible, while validation in humans is often difficult, slow and occasionally not possible due to ethical considerations. The aim of this study is to overcome these limitations by introducing an MR-compatible, free beating, blood-perfused, isolated pig heart model for the development of novel CMR methodology. Methods 6 hearts were perfused outside of the MR environment to establish preparation stability. Coronary perfusion pressure (CPP, coronary blood flow (CBF, left ventricular pressure (LVP, arterial blood gas and electrolyte composition were monitored over 4 hours. Further hearts were perfused within 3T (n = 3 and 1.5T (n = 3 clinical MR scanners, and characterised using functional (CINE, perfusion and late gadolinium enhancement (LGE imaging. Perfusion imaging was performed globally and selectively for the right (RCA and left coronary artery (LCA. In one heart the RCA perfusion territory was determined and compared to infarct size after coronary occlusion. Results All physiological parameters measured remained stable and within normal ranges. The model proved amenable to CMR at both field strengths using typical clinical acquisitions. There was good agreement between the RCA perfusion territory measured by selective first pass perfusion and LGE after coronary occlusion (37% versus 36% of the LV respectively. Conclusions This flexible model allows imaging of cardiac function in a controllable, beating, human-sized heart using clinical MR systems. It should aid further development, validation and clinical translation of novel CMR methodologies, and imaging sequences.

  10. The intra-observer reproducibility of cardiovascular magnetic resonance myocardial feature tracking strain assessment is independent of field strength

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    Schuster, Andreas, E-mail: andreas_schuster@gmx.net [Division of Imaging Sciences and Biomedical Engineering, King' s College London British Heart Foundation BHF Centre of Excellence, National Institute of Health Research NIHR Biomedical Research Centre at Guy' s and St. Thomas' NHS Foundation Trust, Wellcome Trust and Engineering and Physical Sciences Research Council EPSRC Medical Engineering Centre, The Rayne Institute, St. Thomas' Hospital, London (United Kingdom); Department of Cardiology and Pulmonology and Heart Research Centre, Georg-August-University, Göttingen (Germany); Morton, Geraint, E-mail: geraint.morton@kcl.ac.uk [Division of Imaging Sciences and Biomedical Engineering, King' s College London British Heart Foundation BHF Centre of Excellence, National Institute of Health Research NIHR Biomedical Research Centre at Guy' s and St. Thomas' NHS Foundation Trust, Wellcome Trust and Engineering and Physical Sciences Research Council EPSRC Medical Engineering Centre, The Rayne Institute, St. Thomas' Hospital, London (United Kingdom); Hussain, Shazia T., E-mail: shazia.1.hussain@kcl.ac.uk [Division of Imaging Sciences and Biomedical Engineering, King' s College London British Heart Foundation BHF Centre of Excellence, National Institute of Health Research NIHR Biomedical Research Centre at Guy' s and St. Thomas' NHS Foundation Trust, Wellcome Trust and Engineering and Physical Sciences Research Council EPSRC Medical Engineering Centre, The Rayne Institute, St. Thomas' Hospital, London (United Kingdom); and others

    2013-02-15

    Background: Cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) is a promising novel method for quantification of myocardial wall mechanics from standard steady-state free precession (SSFP) images. We sought to determine whether magnetic field strength affects the intra-observer reproducibility of CMR-FT strain analysis. Methods: We studied 2 groups, each consisting of 10 healthy subjects, at 1.5 T or 3 T Analysis was performed at baseline and after 4 weeks using dedicated CMR-FT prototype software (Tomtec, Germany) to analyze standard SSFP cine images. Right ventricular (RV) and left ventricular (LV) longitudinal strain (Ell{sub RV} and Ell{sub LV}) and LV long-axis radial strain (Err{sub LAX}) were derived from the 4-chamber cine, and LV short-axis circumferential and radial strains (Ecc{sub SAX}, Err{sub SAX}) from the short-axis orientation. Strain parameters were assessed together with LV ejection fraction (EF) and volumes. Intra-observer reproducibility was determined by comparing the first and the second analysis in both groups. Results: In all volunteers resting strain parameters were successfully derived from the SSFP images. There was no difference in strain parameters, volumes and EF between field strengths (p > 0.05). In general Ecc{sub SAX} was the most reproducible strain parameter as determined by the coefficient of variation (CV) at 1.5 T (CV 13.3% and 46% global and segmental respectively) and 3 T (CV 17.2% and 31.1% global and segmental respectively). The least reproducible parameter was Ell{sub RV} (CV 1.5 T 28.7% and 53.2%; 3 T 43.5% and 63.3% global and segmental respectively). Conclusions: CMR-FT results are similar with reasonable intra-observer reproducibility in different groups of volunteers at 1.5 T and 3 T. CMR-FT is a promising novel technique and our data indicate that results might be transferable between field strengths. However there is a considerable amount of segmental variability indicating that further

  11. Acoustic cardiac triggering: a practical solution for synchronization and gating of cardiovascular magnetic resonance at 7 Tesla

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    von Knobelsdorff-Brenkenhoff Florian

    2010-11-01

    Full Text Available Abstract Background To demonstrate the applicability of acoustic cardiac triggering (ACT for imaging of the heart at ultrahigh magnetic fields (7.0 T by comparing phonocardiogram, conventional vector electrocardiogram (ECG and traditional pulse oximetry (POX triggered 2D CINE acquisitions together with (i a qualitative image quality analysis, (ii an assessment of the left ventricular function parameter and (iii an examination of trigger reliability and trigger detection variance derived from the signal waveforms. Results ECG was susceptible to severe distortions at 7.0 T. POX and ACT provided waveforms free of interferences from electromagnetic fields or from magneto-hydrodynamic effects. Frequent R-wave mis-registration occurred in ECG-triggered acquisitions with a failure rate of up to 30% resulting in cardiac motion induced artifacts. ACT and POX triggering produced images free of cardiac motion artefacts. ECG showed a severe jitter in the R-wave detection. POX also showed a trigger jitter of approximately Δt = 72 ms which is equivalent to two cardiac phases. ACT showed a jitter of approximately Δt = 5 ms only. ECG waveforms revealed a standard deviation for the cardiac trigger offset larger than that observed for ACT or POX waveforms. Image quality assessment showed that ACT substantially improved image quality as compared to ECG (image quality score at end-diastole: ECG = 1.7 ± 0.5, ACT = 2.4 ± 0.5, p = 0.04 while the comparison between ECG vs. POX gated acquisitions showed no significant differences in image quality (image quality score: ECG = 1.7 ± 0.5, POX = 2.0 ± 0.5, p = 0.34. Conclusions The applicability of acoustic triggering for cardiac CINE imaging at 7.0 T was demonstrated. ACT's trigger reliability and fidelity are superior to that of ECG and POX. ACT promises to be beneficial for cardiovascular magnetic resonance at ultra-high field strengths including 7.0 T.

  12. Individual component analysis of the multi-parametric cardiovascular magnetic resonance protocol in the CE-MARC trial.

    Science.gov (United States)

    Ripley, David P; Motwani, Manish; Brown, Julia M; Nixon, Jane; Everett, Colin C; Bijsterveld, Petra; Maredia, Neil; Plein, Sven; Greenwood, John P

    2015-07-15

    The CE-MARC study assessed the diagnostic performance investigated the use of cardiovascular magnetic resonance (CMR) in patients with suspected coronary artery disease (CAD). The study used a multi-parametric CMR protocol assessing 4 components: i) left ventricular function; ii) myocardial perfusion; iii) viability (late gadolinium enhancement (LGE)) and iv) coronary magnetic resonance angiography (MRA). In this pre-specified CE-MARC sub-study we assessed the diagnostic accuracy of the individual CMR components and their combinations. All patients from the CE-MARC population (n = 752) were included using data from the original blinded-read. The four individual core components of the CMR protocol was determined separately and then in paired and triplet combinations. Results were then compared to the full multi-parametric protocol. CMR and X-ray angiography results were available in 676 patients. The maximum sensitivity for the detection of significant CAD by CMR was achieved when all four components were used (86.5%). Specificity of perfusion (91.8%), function (93.7%) and LGE (95.8%) on its own was significantly better than specificity of the multi-parametric protocol (83.4%) (all P parametric protocol was the optimum to rule-out significant CAD (Likelihood Ratio negative (LR-) 0.16) and the LGE component alone was the best to rue-in CAD (LR+ 9.81). Overall diagnostic accuracy was similar with the full multi-parametric protocol (85.9%) compared to paired and triplet combinations. The use of coronary MRA within the full multi-parametric protocol had no additional diagnostic benefit compared to the perfusion/function/LGE combination (overall accuracy 84.6% vs. 84.2% (P = 0.5316); LR- 0.16 vs. 0.21; LR+ 5.21 vs. 5.77). From this pre-specified sub-analysis of the CE-MARC study, the full multi-parametric protocol had the highest sensitivity and was the optimal approach to rule-out significant CAD. The LGE component alone was the optimal rule-in strategy

  13. Cardiac-respiratory self-gated cine ultra-short echo time (UTE) cardiovascular magnetic resonance for assessment of functional cardiac parameters at high magnetic fields.

    Science.gov (United States)

    Hoerr, Verena; Nagelmann, Nina; Nauerth, Arno; Kuhlmann, Michael T; Stypmann, Jörg; Faber, Cornelius

    2013-07-04

    To overcome flow and electrocardiogram-trigger artifacts in cardiovascular magnetic resonance (CMR), we have implemented a cardiac and respiratory self-gated cine ultra-short echo time (UTE) sequence. We have assessed its performance in healthy mice by comparing the results with those obtained with a self-gated cine fast low angle shot (FLASH) sequence and with echocardiography. 2D self-gated cine UTE (TE/TR = 314 μs/6.2 ms, resolution: 129 × 129 μm, scan time per slice: 5 min 5 sec) and self-gated cine FLASH (TE/TR = 3 ms/6.2 ms, resolution: 129 × 129 μm, scan time per slice: 4 min 49 sec) images were acquired at 9.4 T. Volume of the left and right ventricular (LV, RV) myocardium as well as the end-diastolic and -systolic volume was segmented manually in MR images and myocardial mass, stroke volume (SV), ejection fraction (EF) and cardiac output (CO) were determined. Statistical differences were analyzed by using Student t test and Bland-Altman analyses. Self-gated cine UTE provided high quality images with high contrast-to-noise ratio (CNR) also for the RV myocardium (CNRblood-myocardium = 25.5 ± 7.8). Compared to cine FLASH, susceptibility, motion, and flow artifacts were considerably reduced due to the short TE of 314 μs. The aortic valve was clearly discernible over the entire cardiac cycle. Myocardial mass, SV, EF and CO determined by self-gated UTE were identical to the values measured with self-gated FLASH and showed good agreement to the results obtained by echocardiography. Self-gated UTE allows for robust measurement of cardiac parameters of diagnostic interest. Image quality is superior to self-gated FLASH, rendering the method a powerful alternative for the assessment of cardiac function at high magnetic fields.

  14. Materials applications of an advanced 3-dimensional atom probe

    Energy Technology Data Exchange (ETDEWEB)

    Cerezo, A. [Oxford Univ. (United Kingdom). Dept. of Materials; Gibuoin, D. [Oxford Univ. (United Kingdom). Dept. of Materials; Kim, S. [Oxford Univ. (United Kingdom). Dept. of Materials; Sijbrandij, S.J. [Oxford Univ. (United Kingdom). Dept. of Materials; Venker, F.M. [Oxford Univ. (United Kingdom). Dept. of Materials]|[Rijksuniversiteit Groningen (Netherlands). Dept. of Applied Physics; Warren, P.J. [Oxford Univ. (United Kingdom). Dept. of Materials; Wilde, J. [Oxford Univ. (United Kingdom). Dept. of Materials; Smith, G.D.W. [Oxford Univ. (United Kingdom). Dept. of Materials

    1996-09-01

    An advanced 3-dimensional atom probe system has been constructed, based on an optical position-sensitive atom probe (OPoSAP) detector with energy compensation using a reflectron lens. The multi-hit detection capability of the OPoSAP leads to significant improvements in the efficiency of the instrument over the earlier serial position-sensing system. Further gains in efficiency are obtained by using a biassed grid in front of the detector to collect secondary electrons generated when ions strike the interchannel area. The improvement in detection efficiency gives enhanced performance in the studies of ordered materials and the determination of site occupation. Energy compensation leads to a much improved mass resolution (m/{Delta}m=500 full width at half maximum) making it possible to map out the 3-dimensional spatial distributions of all the elements in complex engineering alloys, even when elements lie close together in the mass spectrum. For example, in the analysis of a maraging steel, this allows separation between the {sup 61}Ni{sup 2+} and {sup 92}Mo{sup 3+} peaks, which are only 1/6 of a mass unit apart. (orig.).

  15. Automated feature extraction for 3-dimensional point clouds

    Science.gov (United States)

    Magruder, Lori A.; Leigh, Holly W.; Soderlund, Alexander; Clymer, Bradley; Baer, Jessica; Neuenschwander, Amy L.

    2016-05-01

    Light detection and ranging (LIDAR) technology offers the capability to rapidly capture high-resolution, 3-dimensional surface data with centimeter-level accuracy for a large variety of applications. Due to the foliage-penetrating properties of LIDAR systems, these geospatial data sets can detect ground surfaces beneath trees, enabling the production of highfidelity bare earth elevation models. Precise characterization of the ground surface allows for identification of terrain and non-terrain points within the point cloud, and facilitates further discernment between natural and man-made objects based solely on structural aspects and relative neighboring parameterizations. A framework is presented here for automated extraction of natural and man-made features that does not rely on coincident ortho-imagery or point RGB attributes. The TEXAS (Terrain EXtraction And Segmentation) algorithm is used first to generate a bare earth surface from a lidar survey, which is then used to classify points as terrain or non-terrain. Further classifications are assigned at the point level by leveraging local spatial information. Similarly classed points are then clustered together into regions to identify individual features. Descriptions of the spatial attributes of each region are generated, resulting in the identification of individual tree locations, forest extents, building footprints, and 3-dimensional building shapes, among others. Results of the fully-automated feature extraction algorithm are then compared to ground truth to assess completeness and accuracy of the methodology.

  16. The 3-dimensional architecture of the Upsilon Andromedae planetary system

    CERN Document Server

    Deitrick, Russell; McArthur, Barbara; Quinn, Thomas R; Luger, Rodrigo; Antonsen, Adrienne; Benedict, G Fritz

    2014-01-01

    The Upsilon Andromedae system is the first exoplanetary system to have the relative inclination of two planets' orbital planes directly measured, and therefore offers our first window into the 3-dimensional configurations of planetary systems. We present, for the first time, full 3-dimensional, dynamically stable configurations for the 3 planets of the system consistent with all observational constraints. While the outer 2 planets, c and d, are inclined by about 30 degrees, the inner planet's orbital plane has not been detected. We use N-body simulations to search for stable 3-planet configurations that are consistent with the combined radial velocity and astrometric solution. We find that only 10 trials out of 1000 are robustly stable on 100 Myr timescales, or about 8 billion orbits of planet b. Planet b's orbit must lie near the invariable plane of planets c and d, but can be either prograde or retrograde. These solutions predict b's mass is in the range 2 - 9 $M_{Jup}$ and has an inclination angle from the...

  17. Myocardial scarring on cardiovascular magnetic resonance in asymptomatic or minimally symptomatic patients with “pure” apical hypertrophic cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Kim Kyung-Hee

    2012-07-01

    Full Text Available Abstract Background Late gadolinium enhancement (LGE cardiovascular magnetic resonance (CMR enables state-of-the-art in vivo evaluations of myocardial fibrosis. Although LGE patterns have been well described in asymmetrical septal hypertrophy, conflicting results have been reported regarding the characteristics of LGE in apical hypertrophic cardiomyopathy (ApHCM. This study was undertaken to determine 1 the frequency and distribution of LGE and 2 its prognostic implication in ApHCM. Methods Forty patients with asymptomatic or minimally symptomatic pure ApHCM (age, 60.2 ± 10.4 years, 31 men were prospectively enrolled. LGE images were acquired using the inversion recovery segmented spoiled-gradient echo and phase-sensitive inversion recovery sequence, and analyzed using a 17-segment model. Summing the planimetered LGE areas in all short axis slices yielded the total volume of late enhancement, which was subsequently presented as a proportion of total LV myocardium (% LGE. Results Mean maximal apical wall thickness was 17.9±2.3mm, and mean left ventricular (LV ejection fraction was 67.7 ± 8.0%. All but one patient presented with electrocardiographic negative T wave inversion in anterolateral leads, with a mean maximum negative T wave of 7.2 ± 4.7mm. Nine patients (22.5% had giant negative T waves, defined as the amplitude of ≥10mm, in electrocardiogram. LGE was detected in 130 segments of 30 patients (75.0%, occupying 4.9 ± 5.5% of LV myocardium. LGE was mainly detected at the junction between left and right ventricles in 12 (30% and at the apex in 28 (70%, although LGE-positive areas were widely distributed, and not limited to the apex. Focal LGE at the non-hypertrophic LV segments was found in some ApHCM patients, even without LGE of hypertrophied apical segments. Over the 2-year follow-up, there was no one achieving the study end-point, defined as all-cause death, sudden cardiac death and hospitalization for heart failure

  18. Left ventricular fluid kinetic energy time curves in heart failure from cardiovascular magnetic resonance 4D flow data.

    Science.gov (United States)

    Kanski, Mikael; Arvidsson, Per M; Töger, Johannes; Borgquist, Rasmus; Heiberg, Einar; Carlsson, Marcus; Arheden, Håkan

    2015-12-20

    Measurement of intracardiac kinetic energy (KE) provides new insights into cardiac hemodynamics and may improve assessment and understanding of heart failure. We therefore aimed to investigate left ventricular (LV) KE time curves in patients with heart failure and in controls. Patients with heart failure (n = 29, NYHA class I-IV) and controls (n = 12) underwent cardiovascular magnetic resonance (CMR) including 4D flow. The vortex-ring boundary was computed using Lagrangian coherent structures. The LV endocardium and vortex-ring were manually delineated and KE was calculated as ½mv(2) of the blood within the whole LV and the vortex ring, respectively. The systolic average KE was higher in patients compared to controls (2.2 ± 1.4 mJ vs 1.6 ± 0.6 mJ, p = 0.048), but lower when indexing to EDV (6.3 ± 2.2 μJ/ml vs 8.0 ± 2.1 μJ/ml, p = 0.025). No difference was seen in diastolic average KE (3.2 ± 2.3 mJ vs 2.0 ± 0.8 mJ, p = 0.13) even when indexing to EDV (9.0 ± 4.4 μJ/ml vs 10.2 ± 3.3 μJ/ml, p = 0.41). In patients, a smaller fraction of diastolic average KE was observed inside the vortex ring compared to controls (72 ± 6% vs 54 ± 9%, p < 0.0001). Three distinctive KE time curves were seen in patients which were markedly different from findings in controls, and with a moderate agreement between KE time curve patterns and degree of diastolic dysfunction (Cohen's kappa = 0.49), but unrelated to NYHA classification (p = 0.12), or 6-minute walk test (p = 0.72). Patients with heart failure exhibit higher systolic average KE compared to controls, suggesting altered intracardiac blood flow. The different KE time curves seen in patients may represent a conceptually new approach for heart failure classification.

  19. Investigating Cardiac Motion Patterns Using Synthetic High-Resolution 3D Cardiovascular Magnetic Resonance Images and Statistical Shape Analysis

    Science.gov (United States)

    Biffi, Benedetta; Bruse, Jan L.; Zuluaga, Maria A.; Ntsinjana, Hopewell N.; Taylor, Andrew M.; Schievano, Silvia

    2017-01-01

    Diagnosis of ventricular dysfunction in congenital heart disease is more and more based on medical imaging, which allows investigation of abnormal cardiac morphology and correlated abnormal function. Although analysis of 2D images represents the clinical standard, novel tools performing automatic processing of 3D images are becoming available, providing more detailed and comprehensive information than simple 2D morphometry. Among these, statistical shape analysis (SSA) allows a consistent and quantitative description of a population of complex shapes, as a way to detect novel biomarkers, ultimately improving diagnosis and pathology understanding. The aim of this study is to describe the implementation of a SSA method for the investigation of 3D left ventricular shape and motion patterns and to test it on a small sample of 4 congenital repaired aortic stenosis patients and 4 age-matched healthy volunteers to demonstrate its potential. The advantage of this method is the capability of analyzing subject-specific motion patterns separately from the individual morphology, visually and quantitatively, as a way to identify functional abnormalities related to both dynamics and shape. Specifically, we combined 3D, high-resolution whole heart data with 2D, temporal information provided by cine cardiovascular magnetic resonance images, and we used an SSA approach to analyze 3D motion per se. Preliminary results of this pilot study showed that using this method, some differences in end-diastolic and end-systolic ventricular shapes could be captured, but it was not possible to clearly separate the two cohorts based on shape information alone. However, further analyses on ventricular motion allowed to qualitatively identify differences between the two populations. Moreover, by describing shape and motion with a small number of principal components, this method offers a fully automated process to obtain visually intuitive and numerical information on cardiac shape and motion

  20. Comparison between cardiovascular magnetic resonance and transthoracic doppler echocardiography for the estimation of effective orifice area in aortic stenosis

    Directory of Open Access Journals (Sweden)

    Larose Eric

    2011-04-01

    Full Text Available Abstract Background The effective orifice area (EOA estimated by transthoracic Doppler echocardiography (TTE via the continuity equation is commonly used to determine the severity of aortic stenosis (AS. However, there are often discrepancies between TTE-derived EOA and invasive indices of stenosis, thus raising uncertainty about actual definite severity. Cardiovascular magnetic resonance (CMR has emerged as an alternative method for non-invasive estimation of valve EOA. The objective of this study was to assess the concordance between TTE and CMR for the estimation of valve EOA. Methods and results 31 patients with mild to severe AS (EOA range: 0.72 to 1.73 cm2 and seven (7 healthy control subjects with normal transvalvular flow rate underwent TTE and velocity-encoded CMR. Valve EOA was calculated by the continuity equation. CMR revealed that the left ventricular outflow tract (LVOT cross-section is typically oval and not circular. As a consequence, TTE underestimated the LVOT cross-sectional area (ALVOT, 3.84 ± 0.80 cm2 compared to CMR (4.78 ± 1.05 cm2. On the other hand, TTE overestimated the LVOT velocity-time integral (VTILVOT: 21 ± 4 vs. 15 ± 4 cm. Good concordance was observed between TTE and CMR for estimation of aortic jet VTI (61 ± 22 vs. 57 ± 20 cm. Overall, there was a good correlation and concordance between TTE-derived and CMR-derived EOAs (1.53 ± 0.67 vs. 1.59 ± 0.73 cm2, r = 0.92, bias = 0.06 ± 0.29 cm2. The intra- and inter- observer variability of TTE-derived EOA was 5 ± 5% and 9 ± 5%, respectively, compared to 2 ± 1% and 7 ± 5% for CMR-derived EOA. Conclusion Underestimation of ALVOT by TTE is compensated by overestimation of VTILVOT, thereby resulting in a good concordance between TTE and CMR for estimation of aortic valve EOA. CMR was associated with less intra- and inter- observer measurement variability compared to TTE. CMR provides a non-invasive and reliable alternative to Doppler-echocardiography for the

  1. Use of cardiovascular magnetic resonance imaging for TAVR assessment in patients with bioprosthetic aortic valves: Comparison with computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Quail, Michael A., E-mail: m.quail@ucl.ac.uk [Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science and Great Ormond Street Hospital for Children, London (United Kingdom); Nordmeyer, Johannes [Department of Congenital Heart Disease and Paediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin (Germany); Schievano, Silvia [Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science and Great Ormond Street Hospital for Children, London (United Kingdom); Reinthaler, Markus; Mullen, Michael J. [The Heart Hospital, University College Hospital and Institute of Cardiovascular Sciences, UCL, 16-18 Westmoreland Street, London (United Kingdom); Taylor, Andrew M. [Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science and Great Ormond Street Hospital for Children, London (United Kingdom)

    2012-12-15

    Purpose: Transcatheter aortic valve replacement (TAVR) has been successfully used to treat patients with failing aortic bioprostheses. Computed tomography (CT) is the usual method of pre-procedural imaging for TAVR in the native position; however, the optimal modality for valve-in-valve procedures has not been established. CT can assess intracardiac anatomy and is superior to cardiovascular magnetic resonance (CMR) in the assessment of coronary artery disease. However, CMR can provide superior haemodynamic information, does not carry the risk of ionising radiation, and may be performed without contrast in patients with renal insufficiency. In this study, we compared CT and CMR for the evaluation of TAVR in a small cohort of patients with existing aortic bioprostheses. Materials and methods: 21 patients with aortic bioprostheses were prospectively evaluated by CT and CMR, as pre-assessment for TAVR; agreement between measurements of aortic geometries was assessed. Results: 16/21 patients had aortic bioprostheses constructed with a metal ring, and 5/21 patients had a metal strut construction. Patients with metal struts had significant metal-artefact on CMR, which compromised image quality in this region. There was good agreement between CT and CMR measurements of aortic geometry. The mean difference (d) in annulus area-derived diameter was 0.5 mm (95% limits of agreement [L.A] 4.2 mm). There was good agreement between modalities for the cross-sectional area of the sinuses of valsalva (d 0.5 cm{sup 2}, L.A 1.4 cm{sup 2}), sinotubular junction (d 0.9 cm{sup 2}, L.A 1.5 cm{sup 2}), and ascending aorta (d 0.6 cm{sup 2}, L.A 1.4 cm{sup 2}). In patients without metal struts, the left coronary artery height d was 0.7 mm and L.A 2.8 mm. Conclusions: Our analysis shows that CMR and CT measurements of aortic geometry show good agreement, including measurement of annulus size and coronary artery location, and thus provide the necessary anatomical information for valve

  2. Preliminary assessment of cardiac short term safety and efficacy of manganese chloride for cardiovascular magnetic resonance in humans

    Directory of Open Access Journals (Sweden)

    Kalaf Jose M

    2011-01-01

    Full Text Available Abstract Background Manganese based agents are intracellular and accumulate inside myocytes allowing for different imaging strategies compared to gadolinium contrasts. While previous agents release manganese very slowly in the circulation, MnCl2 allows for rapid Mn2+ uptake in myocytes, creating a memory effect that can be potentially explored. Data on animal models are very encouraging but the safety and efficacy of this approach in humans has not yet been investigated. Therefore, our objectives were to study the safety and efficacy of a rapid infusion of manganese chloride (MnCl2 for cardiovascular magnetic resonance (CMR in humans. Methods Fifteen healthy volunteers underwent a CMR scan on a 1.5 T scanner. Before the infusion, cardiac function was calculated and images of a short axis mid-ventricular slice were obtained using a 2D and 3D gradient-echo inversion recovery (GRE-IR sequence, a phase-sensitive IR sequence and a single breath-hold segmented IR prepared steady-state precession acquisition for T1 calculations. MnCl2 was infused over three minutes at a total dose of 5 μMol/kg. Immediately after the infusion, and at 15 and 30 minutes later, new images were obtained and cardiac function re-evaluated. Results There was a significant decrease in T1 values compared to baseline, sustained up to 30 minutes after the MnCl2 infusion (pre,839 ± 281 ms; 0 min, 684 ± 99; 15 min, 714 ± 168; 30 min, 706 ± 172, P = 0.003. The 2D and 3D GRE-IR sequence showed the greatest increase in signal-to-noise ratio compared to the other sequences (baseline 6.6 ± 4.2 and 9.7 ± 5.3; 0 min, 11.3 ± 4.1 and 15.0 ± 8.7; 15 min, 10.8 ± 4.0 and 16.9 ± 10.2; 30 min, 10.6 ± 5.2 and 16.5 ± 8.3, P 2 with no major adverse events, despite all reporting transient facial flush. Conclusions In the short term, MnCl2 appears safe for human use. It effectively decreases myocardium T1, maintaining this effect for a relatively long period of time and allowing for the

  3. Use of self-gated radial cardiovascular magnetic resonance to detect and classify arrhythmias (atrial fibrillation and premature ventricular contraction).

    Science.gov (United States)

    Piekarski, Eve; Chitiboi, Teodora; Ramb, Rebecca; Feng, Li; Axel, Leon

    2016-11-25

    Arrhythmia can significantly alter the image quality of cardiovascular magnetic resonance (CMR); automatic detection and sorting of the most frequent types of arrhythmias during the CMR acquisition could potentially improve image quality. New CMR techniques, such as non-Cartesian CMR, can allow self-gating: from cardiac motion-related signal changes, we can detect cardiac cycles without an electrocardiogram. We can further use this data to obtain a surrogate for RR intervals (valley intervals: VV). Our purpose was to evaluate the feasibility of an automated method for classification of non-arrhythmic (NA) (regular cycles) and arrhythmic patients (A) (irregular cycles), and for sorting of common arrhythmia patterns between atrial fibrillation (AF) and premature ventricular contraction (PVC), using the cardiac motion-related signal obtained during self-gated free-breathing radial cardiac cine CMR with compressed sensing reconstruction (XD-GRASP). One hundred eleven patients underwent cardiac XD-GRASP CMR between October 2015 and February 2016; 33 were included for retrospective analysis with the proposed method (6 AF, 8 PVC, 19 NA; by recent ECG). We analyzed the VV, using pooled statistics (histograms) and sequential analysis (Poincaré plots), including the median (medVV), the weighted mean (meanVV), the total number of VV values (VVval), and the total range (VVTR) and half range (VVHR) of the cumulative frequency distribution of VV, including the median to half range (medVV/VVHR) and the half range to total range (VVHR/VVTR) ratios. We designed a simple algorithm for using the VV results to differentiate A from NA, and AF from PVC. Between NA and A, meanVV, VVval, VVTR, VVHR, medVV/VVHR and VVHR/VVTR ratios were significantly different (p values = 0.00014, 0.0027, 0.000028, 5×10(-9), 0.002, respectively). Between AF and PVC, meanVV, VVval and medVV/VVHR ratio were significantly different (p values = 0.018, 0.007, 0.044, respectively). Using our algorithm

  4. Hexad Preons and Emergent Gravity in 3-dimensional Complex Spacetime

    CERN Document Server

    Wang, Shun-Zhi

    2010-01-01

    We suggest that at high energy each space dimension has their own time dimension, forming a 3-dimensional complex spacetime. Based on this hypothesis, we propose that the primordial universe is made of six fundamental fermions and their complex conjugate states. These fermions are called Hexad Preons which carry hypercolor degree of freedom transforming under $U(3,3)$ gauge group. The Hermitian metric emerges upon the breakdown of the gauge group from $U(3,3)$ to its maximal compact subgroup $U(3)\\otimes U(3)$. Leptons, quarks, as well as other matter states may be formed from the subsequent condensate of Hexad Preons. Strong and electroweak forces are manifestations of the hypercolor interaction in the corresponding cases. Our framework sheds light on many problems in cosmology and particle physics.

  5. Hamiltonian Formulation of Jackiw-Pi 3-Dimensional Gauge Theories

    CERN Document Server

    Dayi, O F

    1998-01-01

    A 3-dimensional non-abelian gauge theory was proposed by Jackiw and Pi to create mass for the gauge fields. However, the set of gauge invariances of the quadratic action obtained by switching off the non-abelian interactions is larger than the original one. This inconsistency in the gauge invariances causes some problems in quantization. Jackiw and Pi proposed another action by enlarging the space of states whose gauge invariances are consistent with the quadratic part. It is shown that all of these theories yield the same number of physical degrees of freedom in the hamiltonian framework. Hence, as far as the physical states are considered there is no inconsistency. Nevertheless, perturbation expansion is still problamatic.

  6. Review of 3-Dimensional Printing on Cranial Neurosurgery Simulation Training.

    Science.gov (United States)

    Vakharia, Vejay N; Vakharia, Nilesh N; Hill, Ciaran S

    2016-04-01

    Shorter working times, reduced operative exposure to complex procedures, and increased subspecialization have resulted in training constraints within most surgical fields. Simulation has been suggested as a possible means of acquiring new surgical skills without exposing patients to the surgeon's operative "learning curve." Here we review the potential impact of 3-dimensional printing on simulation and training within cranial neurosurgery and its implications for the future. In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, a comprehensive search of PubMed, OVID MEDLINE, Embase, and the Cochrane Database of Systematic Reviews was performed. In total, 31 studies relating to the use of 3-dimensional (3D) printing within neurosurgery, of which 16 were specifically related to simulation and training, were identified. The main impact of 3D printing on neurosurgical simulation training was within vascular surgery, where patient-specific replication of vascular anatomy and pathologies can aid surgeons in operative planning and clip placement for reconstruction of vascular anatomy. Models containing replicas of brain tumors have also been reconstructed and used for training purposes, with some providing realistic representations of skin, subcutaneous tissue, bone, dura, normal brain, and tumor tissue. 3D printing provides a unique means of directly replicating patient-specific pathologies. It can identify anatomic variation and provide a medium in which training models can be generated rapidly, allowing the trainee and experienced neurosurgeon to practice parts of operations preoperatively. Future studies are required to validate this technology in comparison with current simulators and show improved patient outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. 3-dimensional analysis of regenerative endodontic treatment outcome.

    Science.gov (United States)

    EzEldeen, Mostafa; Van Gorp, Gertrude; Van Dessel, Jeroen; Vandermeulen, Dirk; Jacobs, Reinhilde

    2015-03-01

    A growing body of evidence supports the regeneration potential of dental tissues after regenerative endodontic treatment (RET). Nevertheless, a standard method for the evaluation of RET outcome is lacking. The aim of this study was to develop a standardized quantitative method for RET outcome analysis based on cone-beam computed tomographic (CBCT) volumetric measurements. Five human teeth embedded in mandibular bone samples were scanned using both an Accuitomo 170 CBCT machine (Morita, Kyoto, Japan) and a SkyScan 1174 micro-computed tomographic (μCT) system (SkyScan, Antwerp, Belgium). For subsequent clinical application, clinical data and low-dose CBCT scans (preoperatively and follow-up) from 5 immature permanent teeth treated with RET were retrieved. In vitro and clinical 3-dimensional image data sets were imported into a dedicated software tool. Two segmentation steps were applied to extract the teeth of interest from the surrounding tissue (livewire) and to separate tooth hard tissue and root canal space (level set methods). In vitro and clinical volumetric measurements were assessed separately for differences using Wilcoxon matched pairs test. Pearson correlation analysis and Bland-Altman plots were used to evaluate the relation and agreement between the segmented CBCT and μCT volumes. The results showed no statistical differences and strong agreement between CBCT and μCT volumetric measurements. Volumetric comparison of the root hard tissue showed significant hard tissue formation. (The mean volume of newly formed hard tissue was 27.9 [±10.5] mm(3) [P < .05]). Analysis of 3-dimensional data for teeth treated with RET offers valuable insights into the treatment outcome and patterns of hard tissue formation. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. Comprehensive assessment of a post-coronary bypass graft patient with cardiovascular magnetic resonance imaging and multi-detector computed tomography

    Institute of Scientific and Technical Information of China (English)

    Pairoj Rerkpattanapipat; Patcharee Paijitprapaporn; Suthipong Jongjirasiri; Jiraporn Laothamatas; Nithi Mahanonda

    2007-01-01

    Coronary bypass graft surgery (CABG) is a revascularization procedure which reduces myocardial ischemia and cardiovascular morbidity and mortality in selected patients; however, up to 40% of saphanous vein grafts may degenerate over 10 years. Although coronary angiography is the gold standard to detect graft patency and native vessel disease, sometimes it is difficult to locate the grafts resulting in increased exposure to radiation and contrast administration. This case highlights the utility of cardiac computerized tomography and magnetic resonance imaging to provide comprehensive noninvasive assessment in a patient post CABG.

  9. First-trimester detection of surface abnormalities: A comparison of 2- and 3-dimensional ultrasound and 3-dimensional virtual reality ultrasound

    NARCIS (Netherlands)

    L. Baken (Leonie); M. Rousian (Melek); A.H.J. Koning (Anton); G.J. Bonsel (Gouke); A.J. Eggink (Alex); J.M.J. Cornette (Jérôme); E.M. Schoonderwaldt (Ernst); M. Husen-Ebbinge (Margreet); K. Teunissen (Katinka); P.J. van der Spek (Peter); E.A.P. Steegers (Eric); N. Exalto (Niek)

    2014-01-01

    textabstractThe aim was to determine the diagnostic performance of 3-dimensional virtual reality ultrasound (3D-VR-US) and conventional 2- and 3-dimensional ultrasound (2D/3D-US) for first-trimester detection of structural abnormalities. Forty-eight first trimester cases (gold standard available, 22

  10. Hypertensive heart disease versus hypertrophic cardiomyopathy: multi-parametric cardiovascular magnetic resonance discriminators when end-diastolic wall thickness ≥ 15 mm.

    Science.gov (United States)

    Rodrigues, Jonathan C L; Rohan, Stephen; Ghosh Dastidar, Amardeep; Harries, Iwan; Lawton, Christopher B; Ratcliffe, Laura E; Burchell, Amy E; Hart, Emma C; Hamilton, Mark C K; Paton, Julian F R; Nightingale, Angus K; Manghat, Nathan E

    2017-03-01

    European guidelines state left ventricular (LV) end-diastolic wall thickness (EDWT) ≥15mm suggests hypertrophic cardiomyopathy (HCM), but distinguishing from hypertensive heart disease (HHD) is challenging. We identify cardiovascular magnetic resonance (CMR) predictors of HHD over HCM when EDWT ≥15mm. 2481 consecutive clinical CMRs between 2014 and 2015 were reviewed. 464 segments from 29 HCM subjects with EDWT ≥15mm but without other cardiac abnormality, hypertension or renal impairment were analyzed. 432 segments from 27 HHD subjects with EDWT ≥15mm but without concomitant cardiac pathology were analyzed. Magnitude and location of maximal EDWT, presence of late gadolinium enhancement (LGE), LV asymmetry (>1.5-fold opposing segment) and systolic anterior motion of the mitral valve (SAM) were measured. Multivariate logistic regression was performed. Significance was defined as pheart disease (HHD) can be difficult to distinguish from HCM. • Retrospective case-control study showed that location and magnitude of EDWT are poor discriminators. • Increased left ventricular mass and midwall fibrosis are independent predictors of HHD. • Cardiovascular magnetic resonance parameters facilitate a better discrimination between HHD and HCM.

  11. A 3-Dimensional Atlas of Human Tongue Muscles

    Science.gov (United States)

    SANDERS, IRA; MU, LIANCAI

    2013-01-01

    The human tongue is one of the most important yet least understood structures of the body. One reason for the relative lack of research on the human tongue is its complex anatomy. This is a real barrier to investigators as there are few anatomical resources in the literature that show this complex anatomy clearly. As a result, the diagnosis and treatment of tongue disorders lags behind that for other structures of the head and neck. This report intended to fill this gap by displaying the tongue’s anatomy in multiple ways. The primary material used in this study was serial axial images of the male and female human tongue from the Visible Human (VH) Project of the National Library of Medicine. In addition, thick serial coronal sections of three human tongues were rendered translucent. The VH axial images were computer reconstructed into serial coronal sections and each tongue muscle was outlined. These outlines were used to construct a 3-dimensional computer model of the tongue that allows each muscle to be seen in its in vivo anatomical position. The thick coronal sections supplement the 3-D model by showing details of the complex interweaving of tongue muscles throughout the tongue. The graphics are perhaps the clearest guide to date to aid clinical or basic science investigators in identifying each tongue muscle in any part of the human tongue. PMID:23650264

  12. Thermal crosstalk in 3-dimensional RRAM crossbar array.

    Science.gov (United States)

    Sun, Pengxiao; Lu, Nianduan; Li, Ling; Li, Yingtao; Wang, Hong; Lv, Hangbing; Liu, Qi; Long, Shibing; Liu, Su; Liu, Ming

    2015-08-27

    High density 3-dimensional (3D) crossbar resistive random access memory (RRAM) is one of the major focus of the new age technologies. To compete with the ultra-high density NAND and NOR memories, understanding of reliability mechanisms and scaling potential of 3D RRAM crossbar array is needed. Thermal crosstalk is one of the most critical effects that should be considered in 3D crossbar array application. The Joule heat generated inside the RRAM device will determine the switching behavior itself, and for dense memory arrays, the temperature surrounding may lead to a consequent resistance degradation of neighboring devices. In this work, thermal crosstalk effect and scaling potential under thermal effect in 3D RRAM crossbar array are systematically investigated. It is revealed that the reset process is dominated by transient thermal effect in 3D RRAM array. More importantly, thermal crosstalk phenomena could deteriorate device retention performance and even lead to data storage state failure from LRS (low resistance state) to HRS (high resistance state) of the disturbed RRAM cell. In addition, the resistance state degradation will be more serious with continuously scaling down the feature size. Possible methods for alleviating thermal crosstalk effect while further advancing the scaling potential are also provided and verified by numerical simulation.

  13. Mandibular reconstruction using stereolithographic 3-dimensional printing modeling technology.

    Science.gov (United States)

    Cohen, Adir; Laviv, Amir; Berman, Phillip; Nashef, Rizan; Abu-Tair, Jawad

    2009-11-01

    Mandibular reconstruction can be challenging for the surgeon wishing to restore its unique geometry. Reconstruction can be achieved with titanium bone plates followed by autogenous bone grafting. Incorporation of the bone graft into the mandible provides continuity and strength required for proper esthetics and function and permitting dental implant rehabilitation at a later stage. Precious time in the operating room is invested in plate contouring to reconstruct the mandible. Rapid prototyping technologies can construct physical models from computer-aided design via 3-dimensional (3D) printers. A prefabricated 3D model is achieved, which assists in accurate contouring of plates and/or planning of bone graft harvest geometry before surgery. The 2 most commonly used rapid prototyping technologies are stereolithography and 3D printing (3DP). Three-dimensional printing is advantageous to stereolithography for better accuracy, quicker printing time, and lower cost. We present 3 clinical cases based on 3DP modeling technology. Models were fabricated before the resection of mandibular ameloblastoma and were used to prepare bridging plates before the first stage of reconstruction. In 1 case, another model was fabricated and used as a template for iliac crest bone graft in the second stage of reconstruction. The 3DP technology provided a precise, fast, and cheap mandibular reconstruction, which aids in shortened operation time (and therefore decreased exposure time to general anesthesia, decreased blood loss, and shorter wound exposure time) and easier surgical procedure.

  14. 3-dimensional analysis of scaphoid fracture angle morphology.

    Science.gov (United States)

    Luria, Shai; Schwarcz, Yonatan; Wollstein, Ronit; Emelife, Patrick; Zinger, Gershon; Peleg, Eran

    2015-03-01

    Scaphoid fractures are classified according to their 2-dimensional radiographic appearance, and transverse waist fractures are considered the most common. Our hypothesis was that most scaphoid fractures are not perpendicular to the longitudinal axis of the scaphoid (ie, not transverse). Computerized 3-dimensional analyses were performed on 124 computed tomography scans of acute scaphoid fractures. Thirty of the fractures were displaced and virtually reduced. The angle between the scaphoid's first principal axis (longitudinal axis) and the fracture plane was analyzed for location and displacement. The distal radius articular surface was used to depict the volar-dorsal vector of the wrist. There were 86 fractures of the waist, 13 of the distal third, and 25 of the proximal third. The average angle between the scaphoid longitudinal axis and the fracture plane was 53° for all fractures and 56° for waist fractures, both differing significantly from a 90°, transverse fracture. The majority of fracture planes were found to have a volar distal to dorsal proximal (horizontal oblique) inclination relative to the volar-dorsal vector. Most waist fractures were horizontal oblique and not transverse. According to these findings, fixation of all fractures along the longitudinal axis of the scaphoid may not be the optimal mode of fixation for most. A different approach may be needed in accordance with the fracture plane. Diagnostic II. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  15. High spatial and temporal resolution retrospective cine cardiovascular magnetic resonance from shortened free breathing real-time acquisitions.

    Science.gov (United States)

    Xue, Hui; Kellman, Peter; Larocca, Gina; Arai, Andrew E; Hansen, Michael S

    2013-11-14

    Cine cardiovascular magnetic resonance (CMR) is challenging in patients who cannot perform repeated breath holds. Real-time, free-breathing acquisition is an alternative, but image quality is typically inferior. There is a clinical need for techniques that achieve similar image quality to the segmented cine using a free breathing acquisition. Previously, high quality retrospectively gated cine images have been reconstructed from real-time acquisitions using parallel imaging and motion correction. These methods had limited clinical applicability due to lengthy acquisitions and volumetric measurements obtained with such methods have not previously been evaluated systematically. This study introduces a new retrospective reconstruction scheme for real-time cine imaging which aims to shorten the required acquisition. A real-time acquisition of 16-20s per acquired slice was inputted into a retrospective cine reconstruction algorithm, which employed non-rigid registration to remove respiratory motion and SPIRiT non-linear reconstruction with temporal regularization to fill in missing data. The algorithm was used to reconstruct cine loops with high spatial (1.3-1.8 × 1.8-2.1 mm²) and temporal resolution (retrospectively gated, 30 cardiac phases, temporal resolution 34.3 ± 9.1 ms). Validation was performed in 15 healthy volunteers using two different acquisition resolutions (256 × 144/192 × 128 matrix sizes). For each subject, 9 to 12 short axis and 3 long axis slices were imaged with both segmented and real-time acquisitions. The retrospectively reconstructed real-time cine images were compared to a traditional segmented breath-held acquisition in terms of image quality scores. Image quality scoring was performed by two experts using a scale between 1 and 5 (poor to good). For every subject, LAX and three SAX slices were selected and reviewed in the random order. The reviewers were blinded to the reconstruction approach and acquisition protocols and

  16. Aortic valve stenotic area calculation from phase contrast cardiovascular magnetic resonance: the importance of short echo time

    Directory of Open Access Journals (Sweden)

    Cowan Brett R

    2009-11-01

    Full Text Available Abstract Background Cardiovascular magnetic resonance (CMR can potentially quantify aortic valve area (AVA in aortic stenosis (AS using a single-slice phase contrast (PC acquisition at valve level: AVA = aortic flow/aortic velocity-time integral (VTI. However, CMR has been shown to underestimate aortic flow in turbulent high velocity jets, due to intra-voxel dephasing. This study investigated the effect of decreasing intra-voxel dephasing by reducing the echo time (TE on AVA estimates in patients with AS. Method 15 patients with moderate or severe AS, were studied with three different TEs (2.8 ms/2.0 ms/1.5 ms, in the main pulmonary artery (MPA, left ventricular outflow tract (LVOT and 0 cm/1 cm/2.5 cm above the aortic valve (AoV. PC estimates of stroke volume (SV were compared with CMR left ventricular SV measurements and PC peak velocity, VTI and AVA were compared with Doppler echocardiography. CMR estimates of AVA obtained by direct planimetry from cine acquisitions were also compared with the echoAVA. Results With a TE of 2.8 ms, the mean PC SV was similar to the ventricular SV at the MPA, LVOT and AoV0 cm (by Bland-Altman analysis bias ± 1.96 SD, 1.3 ± 20.2 mL/-6.8 ± 21.9 mL/6.5 ± 50.7 mL respectively, but was significantly lower at AoV1 and AoV2.5 (-29.3 ± 31.2 mL/-21.1 ± 35.7 mL. PC peak velocity and VTI underestimated Doppler echo estimates by approximately 10% with only moderate agreement. Shortening the TE from 2.8 to 1.5 msec improved the agreement between ventricular SV and PC SV at AoV0 cm (6.5 ± 50.7 mL vs 1.5 ± 37.9 mL respectively but did not satisfactorily improve the PC SV estimate at AoV1 cm and AoV2.5 cm. Agreement of CMR AVA with echoAVA was improved at TE 1.5 ms (0.00 ± 0.39 cm2 versus TE 2.8 (0.11 ± 0.81 cm2. The CMR method which agreed best with echoAVA was direct planimetry (-0.03 cm2 ± 0.24 cm2. Conclusion Agreement of CMR AVA at the aortic valve level with echo AVA improves with a reduced TE of 1.5 ms

  17. Distance stereotest using a 3-dimensional monitor for adult subjects.

    Science.gov (United States)

    Kim, Jongshin; Yang, Hee Kyung; Kim, Youngmin; Lee, Byoungho; Hwang, Jeong-Min

    2011-06-01

    To evaluate the validity and test-retest reliability of a contour-based 3-dimensional (3-D) monitor distance stereotest (distance 3-D stereotest) and to measure the maximum horizontal disparity that can be fused with disparity vergence for determining the largest measurable disparity of true stereopsis. Observational case series. Sixty-four normal adult subjects (age range, 23 to 39 years) were recruited. Contour-based circles (crossed disparity, 5000 to 20 seconds of arc; Microsoft Visual Studio C(++) 6.0; Microsoft, Inc, Seattle, Washington, USA) were generated on a 3-D monitor (46-inch stereoscopic display) using polarization glasses and were presented to subjects with normal binocularity at 3 m. While the position of the stimulus changed among 4 possible locations, the subjects were instructed to press the corresponding position of the stimulus on a keypad. The results with the new distance 3-D stereotest were compared with those from the distance Randot stereotest. The results of the distance 3-D stereotest and the distance Randot stereotests were identical in 64% and within 1 disparity level in 97% of normal adults. Scores obtained with the 2 tests showed a statistically significant correlation (r = 0.324, P = .009). The half-width of the 95% limit of agreement was 0.47 log seconds of arc (1.55 octaves) using the distance 3-D stereotest--similar to or better than that obtained with conventional distance stereotests. The maximum binocular disparity that can be fused with vergence was 1828 ± 794 seconds of arc (range, 4000 to 500). The distance 3-D stereotest showed good concordance with the distance Randot stereotest and relatively good test-retest reliability, supporting the validity of the distance 3-D stereotest. The normative data set obtained from the present study can serve as a useful reference for quantitative assessment of a wide range of binocular sensory abnormalities. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. A 3-Dimensional Anatomic Study of the Distal Biceps Tendon

    Science.gov (United States)

    Walton, Christine; Li, Zhi; Pennings, Amanda; Agur, Anne; Elmaraghy, Amr

    2015-01-01

    Background Complete rupture of the distal biceps tendon from its osseous attachment is most often treated with operative intervention. Knowledge of the overall tendon morphology as well as the orientation of the collagenous fibers throughout the musculotendinous junction are key to intraoperative decision making and surgical technique in both the acute and chronic setting. Unfortunately, there is little information available in the literature. Purpose To comprehensively describe the morphology of the distal biceps tendon. Study Design Descriptive laboratory study. Methods The distal biceps terminal musculature, musculotendinous junction, and tendon were digitized in 10 cadaveric specimens and data reconstructed using 3-dimensional modeling. Results The average length, width, and thickness of the external distal biceps tendon were found to be 63.0, 6.0, and 3.0 mm, respectively. A unique expansion of the tendon fibers within the distal muscle was characterized, creating a thick collagenous network along the central component between the long and short heads. Conclusion This study documents the morphologic parameters of the native distal biceps tendon. Reconstruction may be necessary, especially in chronic distal biceps tendon ruptures, if the remaining tendon morphology is significantly compromised compared with the native distal biceps tendon. Knowledge of normal anatomical distal biceps tendon parameters may also guide the selection of a substitute graft with similar morphological characteristics. Clinical Relevance A thorough description of distal biceps tendon morphology is important to guide intraoperative decision making between primary repair and reconstruction and to better select the most appropriate graft. The detailed description of the tendinous expansion into the muscle may provide insight into better graft-weaving and suture-grasping techniques to maximize proximal graft incorporation. PMID:26665092

  19. The 3-dimensional construction of the Rae craton, central Canada

    Science.gov (United States)

    Snyder, David B.; Craven, James A.; Pilkington, Mark; Hillier, Michael J.

    2015-10-01

    Reconstruction of the 3-dimensional tectonic assembly of early continents, first as Archean cratons and then Proterozoic shields, remains poorly understood. In this paper, all readily available geophysical and geochemical data are assembled in a 3-D model with the most accurate bedrock geology in order to understand better the geometry of major structures within the Rae craton of central Canada. Analysis of geophysical observations of gravity and seismic wave speed variations revealed several lithospheric-scale discontinuities in physical properties. Where these discontinuities project upward to correlate with mapped upper crustal geological structures, the discontinuities can be interpreted as shear zones. Radiometric dating of xenoliths provides estimates of rock types and ages at depth beneath sparse kimberlite occurrences. These ages can also be correlated to surface rocks. The 3.6-2.6 Ga Rae craton comprises at least three smaller continental terranes, which "cratonized" during a granitic bloom. Cratonization probably represents final differentiation of early crust into a relatively homogeneous, uniformly thin (35-42 km), tonalite-trondhjemite-granodiorite crust with pyroxenite layers near the Moho. The peak thermotectonic event at 1.86-1.7 Ga was associated with the Hudsonian orogeny that assembled several cratons and lesser continental blocks into the Canadian Shield using a number of southeast-dipping megathrusts. This orogeny metasomatized, mineralized, and recrystallized mantle and lower crustal rocks, apparently making them more conductive by introducing or concentrating sulfides or graphite. Little evidence exists of thin slabs similar to modern oceanic lithosphere in this Precambrian construction history whereas underthrusting and wedging of continental lithosphere is inferred from multiple dipping discontinuities.

  20. A new preclinical 3-dimensional agarose colony formation assay.

    Science.gov (United States)

    Kajiwara, Yoshinori; Panchabhai, Sonali; Levin, Victor A

    2008-08-01

    The evaluation of new drug treatments and combination treatments for gliomas and other cancers requires a robust means to interrogate wide dose ranges and varying times of drug exposure without stain-inactivation of the cells (colonies). To this end, we developed a 3-dimensional (3D) colony formation assay that makes use of GelCount technology, a new cell colony counter for gels and soft agars. We used U251MG, SNB19, and LNZ308 glioma cell lines and MiaPaCa pancreas adenocarcinoma and SW480 colon adenocarcinoma cell lines. Colonies were grown in a two-tiered agarose that had 0.7% agarose on the bottom and 0.3% agarose on top. We then studied the effects of DFMO, carboplatin, and SAHA over a 3-log dose range and over multiple days of drug exposure. Using GelCount we approximated the area under the curve (AUC) of colony volumes as the sum of colony volumes (microm2xOD) in each plate to calculate IC50 values. Adenocarcinoma colonies were recognized by GelCount scanning at 3-4 days, while it took 6-7 days to detect glioma colonies. The growth rate of MiaPaCa and SW480 cells was rapid, with 100 colonies counted in 5-6 days; glioma cells grew more slowly, with 100 colonies counted in 9-10 days. Reliable log dose versus AUC curves were observed for all drugs studied. In conclusion, the GelCount method that we describe is more quantitative than traditional colony assays and allows precise study of drug effects with respect to both dose and time of exposure using fewer culture plates.

  1. Magnetism of outdoor and indoor settled dust and its utilization as a tool for revealing the effect of elevated particulate air pollution on cardiovascular mortality

    Science.gov (United States)

    Jordanova, Diana; Jordanova, Neli; Lanos, Philippe; Petrov, Petar; Tsacheva, Tsenka

    2012-08-01

    Settled indoor and outdoor dusts in urban environment represent an important source of secondary pollution. Magnetic characteristics of the settled dust from six cities in Bulgaria are explored, allowing comparison on a national (country) scale. Monthly variations of the mass-specific magnetic susceptibilities (χindoor) and (χoutdoor) and calculated dust loading rates for a period of 17 months do not show seasonal variability, probably due to the dominant role of traffic-related emissions and soil-derived particles in the settled dust. The main magnetic mineral is magnetite, present as spherules and irregular particles of pseudo-single-domain grain sizes. Systematically lower remanence coercivities are obtained for outdoor dusts when compared with the corresponding indoor samples, implying that penetration of smaller particles of ambient origin indoors is the main source of the indoor dust. Mean yearly values of the ratio (χindoor/χoutdoor) for each city show statistically significant correlation with mortality due to cardiovascular diseases. This ratio reveals the source- and site-specific importance of the anthropogenically derived toxicogenic fraction. Heavy metal content of the settled dust is related to the contribution from several pollution sources (soil-derived, combustion and industrial), discriminated through analysis of principal components. SEM/EDX analyses reveal abundant presence of anthopogenic Fe-containing spherules, irregular particles and diesel exhaust conglomerates. High molecular weight polyaromatic hydrocarbons (PAH) dominate the total PAH content of the outdoor dust samples. The observed linear correlation between total PAH content, coercivity of remanence and the ratio Mrs/χ suggest either adsorption of PAHs on iron oxide particles and especially magnetite, or emission related increase in total PAH concentration along with a decrease of effective magnetic grain size of the accompanying magnetic fraction.

  2. Monte Carlo Simulation of 3-dimensional Ising Model%三维Ising模型的蒙特卡罗模拟

    Institute of Scientific and Technical Information of China (English)

    黄纯青; 邓绍军

    2009-01-01

    采用蒙特卡罗(Monte Cado)重点抽样法对三维Ising模型进行计算机模拟,测量无外磁场时三维Ising模型中自旋键链的能量、磁化强度、比热及磁化率的统计平均值与标准误差(不确定度).结果表明,三维Ising模型在无外磁场时存在自发磁化现象,铁磁→非铁磁相变临界点在J/(kBTc=0.222 0,或居里温度Tc=4.500 0处.并研究存在外磁场时上述物理量随温度与外磁场的变化规律,给出物理解释.%A 3-dimensional Ising model is simulated with Monte Carlo importance sampling method. Statistical values of energy, strength of magnetization, specific heat and rate of magnetization of spin links as well as their standard errors (uncertainties) are measured. 3-dimensional Ising model shows spontaneous magnetization with no exterior magnetic field. Critical point of phase transformation is at J/( k_BT_c ) = 0.222 0 or T_c = 4.500 0. Phase transformation at high temperature disappears with exterior magnetic field. Relationship between physical quantities, temperature and exterior magnetic field is investigated and analyzed.

  3. Rail Shear and Short Beam Shear Properties of Various 3-Dimensional (3-D) Woven Composites

    Science.gov (United States)

    2016-01-01

    ARL-TR-7576 ● JAN 2016 US Army Research Laboratory Rail Shear and Short Beam Shear Properties of Various 3 - Dimensional ( 3 -D...2016 US Army Research Laboratory Rail Shear and Short Beam Shear Properties of Various 3 - Dimensional ( 3 -D) Woven Composites by Mark...Properties of Various 3 - Dimensional Woven Composites 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Mark Pankow

  4. Assessment by cardiovascular magnetic resonance, electron beam computed tomography, and carotid ultrasonography of the distribution of subclinical atherosclerosis across Framingham risk strata.

    Science.gov (United States)

    Kathiresan, Sekar; Larson, Martin G; Keyes, Michelle J; Polak, Joseph F; Wolf, Philip A; D'Agostino, Ralph B; Jaffer, Farouc A; Clouse, Melvin E; Levy, Daniel; Manning, Warren J; O'Donnell, Christopher J

    2007-02-01

    Screening for subclinical atherosclerosis has been advocated for individuals at intermediate global risk for coronary heart disease (CHD). However, the distribution of subclinical atherosclerosis test values across CHD risk strata is unknown. We studied a stratified random sample of 292 participants (mean age 59.5 years, 50% women) from the offspring cohort of the Framingham Heart Study who were free of clinically apparent cardiovascular disease. We assessed abdominal and thoracic aortic plaque burden by cardiovascular magnetic resonance (CMR), coronary artery calcification (CAC) and thoracic aortic calcification (TAC) by electron beam computed tomography, and common carotid intima-media thickness (C-IMT) by ultrasonography. We categorized the upper 20% of each measurement as a high level of atherosclerosis and evaluated these variables across clinically relevant Framingham CHD risk score strata (low, intermediate, and high risk). In age-adjusted analyses in men and women, correlations across CMR aortic plaque, CAC, TAC, and C-IMT were low (maximum r = 0.30 for CAC:TAC in women, p or=2 measurements. However, different participants were identified as having high atherosclerosis by each modality. For example, in a comparison of the overlap across CMR aortic plaque, CAC, and C-IMT, only 4% of men and 16% of women were classified as having high atherosclerosis on all 3 measurements. In conclusion, in a community-based sample, correlations among subclinical atherosclerosis test results are low, and a substantial proportion has high levels of subclinical atherosclerosis detected on >or=2 imaging tests.

  5. 2014 Korean guidelines for appropriate utilization of cardiovascular magnetic resonance imaging: A joint report of the Korean Society of Cardiology and the Korean Society of Radiology

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Yeon Yee E. [Dept. of Cardiology, Cardiovascular Center, Seoul National University Bundang Hospital, Seoul (Korea, Republic of); Hong, Yoo Jin; Choi, Eui Young [Dept. of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul (Korea, Republic of); and others

    2015-04-15

    The use of cardiac magnetic resonance (CMR) imaging is increasing for the assessment of certain cardiovascular diseases, due to recent technical developments. CMR can give physicians information that cannot be found with other imaging modalities. However, there has been no guideline for the use of CMR in Korean people. Therefore, we have prepared a Korean guideline for the appropriate utilization of CMR to guide Korean physicians, imaging specialists, medical associates, and patients to improve the overall performances in medical system. By addressing CMR usage and creating these guidelines, we hope to contribute to the promotion of public health. This guideline is a joint report of the Korean Society of Cardiology and the Korean Society of Radiology.

  6. 2014 Korean Guidelines for Appropriate Utilization of Cardiovascular Magnetic Resonance Imaging: A Joint Report of the Korean Society of Cardiology and the Korean Society of Radiology

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Yeonyee E. [Department of Cardiology, Cardiovascular Center, Seoul National University Bundang Hospital, Seongnam 463-707 (Korea, Republic of); Hong, Yoo Jin [Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Kim, Hyung-Kwan [Division of Cardiology, Department of Internal Medicine, Cardiovascular Center, Seoul National University College of Medicine, Seoul National University Hospital, Seoul 110-744 (Korea, Republic of); Kim, Jeong A [Department of Radiology, Ilsan Paik Hospital, Inje University College of Medicine, Goyang 411-706 (Korea, Republic of); Na, Jin Oh [Cardiovascular Center, Korea University Guro Hospital, Korea University College of Medicine, Seoul 152-703 (Korea, Republic of); Yang, Dong Hyun [Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 138-736 (Korea, Republic of); Kim, Young Jin [Department of Radiology, Severance Hospital, Yonsei University College of Medicine, Seoul 120-752 (Korea, Republic of); Choi, Eui-Young [Division of Cardiology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 135-720 (Korea, Republic of)

    2014-07-01

    Cardiac magnetic resonance (CMR) imaging is now widely used in several fields of cardiovascular disease assessment due to recent technical developments. CMR can give physicians information that cannot be found with other imaging modalities. However, there is no guideline which is suitable for Korean people for the use of CMR. Therefore, we have prepared a Korean guideline for the appropriate utilization of CMR to guide Korean physicians, imaging specialists, medical associates and patients to improve the overall medical system performances. By addressing CMR usage and creating these guidelines we hope to contribute towards the promotion of public health. This guideline is a joint report of the Korean Society of Cardiology and the Korean Society of Radiology.

  7. Final infarct size measured by cardiovascular magnetic resonance in patients with ST elevation myocardial infarction predicts long-term clinical outcome

    DEFF Research Database (Denmark)

    Lønborg, Jacob Thomsen; Vejlstrup, Niels Grove; Kelbæk, Henning Skov

    2013-01-01

    AIMS: Tailored heart failure treatment and risk assessment in patients following ST-segment elevation myocardial infarction (STEMI) is mainly based on the assessment of the left ventricular (LV) ejection fraction (EF). Assessment of the final infarct size in addition to the LVEF may improve...... the prognostic evaluation. To evaluate the prognostic importance of the final infarct size measured by cardiovascular magnetic resonance (CMR) in patients with STEMI. METHODS AND RESULTS: In an observational study the final infarct size was measured by late gadolinium enhancement CMR 3 months after initial...... admission in 309 patients with STEMI. The clinical endpoint was a composite of all-cause mortality and admission for heart failure. During the follow-up period of median 807 days (IQR: 669-1117) 35 events (5 non-cardiac deaths, 3 cardiac deaths, and 27 admissions for heart failure) were recorded. Patients...

  8. Myocardial adaptation to high-intensity (interval) training in previously untrained men with a longitudinal cardiovascular magnetic resonance imaging study (Running Study and Heart Trial).

    Science.gov (United States)

    Scharf, Michael; Schmid, Axel; Kemmler, Wolfgang; von Stengel, Simon; May, Matthias S; Wuest, Wolfgang; Achenbach, Stephan; Uder, Michael; Lell, Michael M

    2015-04-01

    To prospectively evaluate whether short-term high-intensity (interval) training (HI(I)T) induces detectable morphological cardiac changes in previously untrained men in cardiovascular magnetic resonance imaging. Eighty-four untrained volunteers were randomly assigned to a HI(I)T group (n=42; 44.1±4.7 years) or an inactive control group (n=42; 42.3±5.6 years). HI(I)T focused on interval runs (intensity: 95%-105% of individually calculated heart rate at the anaerobic threshold). Before and after 16 weeks, all subjects underwent physiological examination, stepwise treadmill test with blood lactate analysis, and contrast-enhanced cardiovascular magnetic resonance imaging (cine, tagging, and delayed enhancement). Indexed left ventricular (LV) and right ventricular (RV) volume (LV, 77.1±8.5-83.9±8.6; RV, 80.5±8.5-86.6±8.1) and mass (LV, 58.2±6.4-63.4±8.1; RV, 14.8±1.7-16.1±2.1) significantly increased with HI(I)T. Changes in LV and RV morphological parameters with HI(I)T were highly correlated with an increase in maximal aerobic capacity (VO2max) and a decrease in blood lactate concentration at the anaerobic threshold. Mean LV and RV remodeling index of HI(I)T group did not alter with training (0.76 ±0.09 and 0.24±0.10 g/mL, respectively [P=0.97 and P=0.72]), indicating balanced cardiac adaptation. Myocardial circumferential strain decreased after HI(I)T within all 6 basal segments (anteroseptal, P=0.01 and anterolateral, PHeart Association, Inc.

  9. A medical device-grade T1 and ECV phantom for global T1 mapping quality assurance—the T1 Mapping and ECV Standardization in cardiovascular magnetic resonance (T1MES) program

    NARCIS (Netherlands)

    Captur, Gabriella; Gatehouse, Peter; Keenan, Kathryn; Heslinga, Friso Gerben; Bruehl, Ruediger; Prothmann, Marcel; Graves, Martin J.; Eames, Richard J.; Torlasco, Camilla; Benedetti, Giulia; Donovan, Jacqueline; Itterman, Bernd; Boubertakh, Redha; Bathgate, Andrew; Royet, Celine; Pang, Wenjie; Nezafat, Reza; Salerno, Michael; Kellman, Peter; Moon, James C.

    2016-01-01

    Background T1 mapping and extracellular volume (ECV) have the potential to guide patient care and serve as surrogate end-points in clinical trials, but measurements differ between cardiovascular magnetic resonance (CMR) scanners and pulse sequences. To help deliver T1 mapping to global clinical

  10. Impact of early, late, and no ST-segment resolution measured by continuous ST Holter monitoring on left ventricular ejection fraction and infarct size as determined by cardiovascular magnetic resonance imaging

    NARCIS (Netherlands)

    J.D.E. Haeck; N.J.W. Verouden; W.J. Kuijt; K.T. Koch; M. Majidi; A. Hirsch; J.G.P. Tijssen; M.W. Krucoff; R.J. de Winter

    2011-01-01

    Background: The goal of this study is to determine the predictive value of ST-segment resolution (STR) early after percutaneous coronary intervention (PCI), late STR, and no STR for left ventricular ejection fraction (LVEF) and infarct size (IS) by cardiovascular magnetic resonance (CMR) at follow-u

  11. A medical device-grade T1 and ECV phantom for global T1 mapping quality assurance—the T1 Mapping and ECV Standardization in cardiovascular magnetic resonance (T1MES) program

    NARCIS (Netherlands)

    Captur, Gabriella; Gatehouse, Peter; Keenan, Kathryn; Heslinga, Friso Gerben; Bruehl, Ruediger; Prothmann, Marcel; Graves, Martin J.; Eames, Richard J.; Torlasco, Camilla; Benedetti, Giulia; Donovan, Jacqueline; Itterman, Bernd; Boubertakh, Redha; Bathgate, Andrew; Royet, Celine; Pang, Wenjie; Nezafat, Reza; Salerno, Michael; Kellman, Peter; Moon, James C.

    2016-01-01

    Background T1 mapping and extracellular volume (ECV) have the potential to guide patient care and serve as surrogate end-points in clinical trials, but measurements differ between cardiovascular magnetic resonance (CMR) scanners and pulse sequences. To help deliver T1 mapping to global clinical care

  12. Quantitative comparison of operative skill using 2- and 3-dimensional monitors during laparoscopic phantom tasks.

    Science.gov (United States)

    Nishi, Masayasu; Kanaji, Shingo; Otake, Yoshito; Harada, Hitoshi; Yamamoto, Masashi; Oshikiri, Taro; Nakamura, Tetsu; Suzuki, Satoshi; Suzuki, Yuki; Hiasa, Yuta; Sato, Yoshinobu; Kakeji, Yoshihiro

    2017-05-01

    The recent development of stereoscopic images using 3-dimensional monitors is expected to improve techniques for laparoscopic operation. Several studies have reported technical advantages in using 3-dimensional monitors with regard to operative accuracy and working speed, but there are few reports that analyze forceps motions by 3-dimensional optical tracking systems during standardized laparoscopic phantom tasks. We attempted to develop a 3-dimensional motion analysis system for assessing laparoscopic tasks and to clarify the efficacy of using stereoscopic images from a 3-dimensional monitor to track forceps movement during laparoscopy. Twenty surgeons performed 3 tasks (Task 1: a simple operation by the dominant hand, Task 2: a simple operation using both hands, Task 3: a complicated operation using both hands) under 2-dimensional and 3-dimensional systems. We tracked and recorded the motion of forceps tips with an optical marker captured by a 3-dimensional position tracker. We analyzed factors such as forceps path lengths, operation times, and technical errors for each task and compared the results of 2-dimensional and 3-dimensional monitors. Mean operation times and technical errors were improved significantly for all tasks performed under the 3-dimensional system compared with the 2-dimensional system; in addition, mean path lengths for the forceps tips were shorter for all tasks performed under the 3-dimensional system. We found that stereoscopic images using a 3-dimensional monitor improved operative techniques with regard to increased accuracy and shorter path lengths for forceps movement, which resulted in a shorter operation time for basic phantom laparoscopic tasks. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Monolithically integrated Helmholtz coils by 3-dimensional printing

    Energy Technology Data Exchange (ETDEWEB)

    Li, Longguang [Department of Electrical Engineering, University of Michigan–Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai 200240 (China); Abedini-Nassab, Roozbeh; Yellen, Benjamin B., E-mail: yellen@duke.edu [Department of Electrical Engineering, University of Michigan–Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai 200240 (China); Department of Mechanical Engineering and Materials Science, Duke University, P.O. Box 90300, Hudson Hall, Durham, North Carolina 27708 (United States)

    2014-06-23

    3D printing technology is of great interest for the monolithic fabrication of integrated systems; however, it is a challenge to introduce metallic components into 3D printed molds to enable broader device functionality. Here, we develop a technique for constructing a multi-axial Helmholtz coil by injecting a eutectic liquid metal Gallium Indium alloy (EGaIn) into helically shaped orthogonal cavities constructed in a 3D printed block. The tri-axial solenoids each carry up to 3.6 A of electrical current and produce magnetic field up to 70 G. Within the central section of the coil, the field variation is less than 1% and is in agreement with theory. The flow rates and critical pressures required to fill the 3D cavities with liquid metal also agree with theoretical predictions and provide scaling trends for filling the 3D printed parts. These monolithically integrated solenoids may find future applications in electronic cell culture platforms, atomic traps, and miniaturized chemical analysis systems based on nuclear magnetic resonance.

  14. Feasibility of 3-dimensional sampling perfection with application optimized contrast sequence in the evaluation of patients with hydrocephalus.

    Science.gov (United States)

    Kartal, Merve Gulbiz; Ocakoglu, Gokhan; Algin, Oktay

    2015-01-01

    This study aimed to investigate the effectiveness and additive value of T2W 3-dimensional sampling perfection with application optimized contrast (3D-SPACE) with variant flip-angle mode in imaging of all types of hydrocephalus. Our secondary objective was to assess the reliability of 3D-SPACE sequence and correspondence of the results with phase-contrast magnetic resonance imaging (PC-MRI)-based data. Forty-one patients with hydrocephalus have undergone 3-T MRI. T2W 3D-SPACE sequence has been obtained in addition to routine hydrocephalus protocol. Cerebrospinal fluid circulation, presence/type/etiology of hydrocephalus, obstruction level scores, and diagnostic levels of confidence were evaluated separately by 2 radiologists. In the first session, routine sequences with PC-MRI were evaluated, and in another session, only 3D-SPACE and 3-dimensional magnetization prepared rapid acquisition gradient echo sequences were evaluated. Results obtained in these sessions were compared with each other and those obtained in consensus session. Agreement values were very good for both 3D-SPACE and PC-MRI sequences (P technique providing extensive multiplanar reformatted images with a lower specific absorption rate. These advantages over PC-MRI make 3D-SPACE sequence a promising tool in management of patients with hydrocephalus.

  15. Reliability and measurement error of 3-dimensional regional lumbar motion measures

    DEFF Research Database (Denmark)

    Mieritz, Rune M; Bronfort, Gert; Kawchuk, Greg

    2012-01-01

    The purpose of this study was to systematically review the literature on reproducibility (reliability and/or measurement error) of 3-dimensional (3D) regional lumbar motion measurement systems.......The purpose of this study was to systematically review the literature on reproducibility (reliability and/or measurement error) of 3-dimensional (3D) regional lumbar motion measurement systems....

  16. Occupational exposure to extremely low-frequency magnetic fields and cardiovascular disease mortality in a prospective cohort study

    NARCIS (Netherlands)

    Slottje, Pauline; Kromhout, Hans; Schouten, Leo J.; Goldbohm, R. Alexandra; van den Brandt, Piet A.; Vermeulen, Roel; Koeman, T.

    2013-01-01

    Objectives Although a study among utility workers found an increased risk for acute myocardial infarction and arrhythmia-related deaths associated with occupational extremely low-frequency magnetic fields (ELF-MF) exposure, later studies largely failed to replicate these findings. This study investi

  17. Topological Entropy and Renormalization group flow in 3-dimensional spherical spaces

    CERN Document Server

    Asorey, M; Cavero-Peláez, I; D'Ascanio, D; Santangelo, E M

    2015-01-01

    We analyze the renormalization group flow of the temperature independent term of the entropy in the high temperature limit \\beta/a S^IR_top between the topological entropies of the conformal field theories connected by such flow. From a 3-dimensional viewpoint the same term arises in the 3-dimensional Euclidean effective action and has the same monotone behavior under the RG group flow. We conjecture that such monotonic behavior is generic, which would give rise to a 3-dimensional generalization of the c-theorem, along the lines of the 2-dimensional c-theorem and the 4-dimensional a-theorem.

  18. Control of Grasp and Manipulation by Soft Fingers with 3-Dimensional Deformation

    Science.gov (United States)

    Nakashima, Akira; Shibata, Takeshi; Hayakawa, Yoshikazu

    In this paper, we consider control of grasp and manipulation of an object in a 3-dimensional space by a 3-fingered hand robot with soft finger tips. We firstly propose a 3-dimensional deformation model of a hemispherical soft finger tip and verify its relevance by experimental data. Second, we consider the contact kinematics and derive the dynamical equations of the fingers and the object where the 3-dimensional deformation is considered. For the system, we thirdly propose a method to regulate the object and the internal force with the information of the hand, the object and the deformation. A simulation result is presented to show the effectiveness of the control method.

  19. SOME PROBLEMS ON JUMP CONDITIONS OF SHOCK WAVES IN 3-DIMENSIONAL SOLIDS

    Institute of Scientific and Technical Information of China (English)

    LI Yong-chi; YAO Lei; HU Xiu-zhang; CAO Jie-dong; DONG Jie

    2006-01-01

    Based on the general conservation laws in continuum mechanics, the Eulerian and Lagrangian descriptions of the jump conditions of shock waves in 3-dimensional solids were presented respectively. The implication of the jump conditions and their relations between each other, particularly the relation between the mass conservation and the displacement continuity, were discussed. Meanwhile the shock wave response curves in 3-dimensional solids, i.e. the Hugoniot curves were analysed, which provide the foundation for studying the coupling effects of shock waves in 3-dimensional solids.

  20. Myocardial triglyceride content at 3 T cardiovascular magnetic resonance and left ventricular systolic function: a cross-sectional study in patients hospitalized with acute heart failure.

    Science.gov (United States)

    Liao, Pen-An; Lin, Gigin; Tsai, Shang-Yueh; Wang, Chao-Hung; Juan, Yu-Hsiang; Lin, Yu-Ching; Wu, Ming-Ting; Yang, Lan-Yan; Liu, Min-Hui; Chang, Tsun-Ching; Lin, Yu-Chun; Huang, Yu-Chieh; Huang, Pei-Ching; Wang, Jiun-Jie; Ng, Shu-Hang; Ng, Koon-Kwan

    2016-02-05

    Increased myocardial triglyceride (TG) content has been recognized as a risk factor for cardiovascular disease. However, its relation with cardiac function in patients on recovery from acute heart failure (HF) remains unclear. In this cross-sectional study, we sought to investigate the association between myocardial TG content measured on magnetic resonance spectroscopy ((1)H-MRS) and left ventricular (LV) function assessed on cardiovascular magnetic resonance (CMR) in patients who were hospitalized with HF. A total of 50 patients who were discharged after hospitalization for acute HF and 21 age- and sex-matched controls were included in the study. Myocardial TG content and LV parameters (function and mass) were measured on a 3.0 T MR scanner. Fatty acid (FA) and unsaturated fatty acid (UFA) content was normalized against water (W) using the LC-Model algorithm. The patient population was dichotomized according to the left ventricular ejection fraction (LVEF, <50% or ≥ 50%). H-MRS data were available for 48 patients and 21 controls. Of the 48 patients, 25 had a LVEF <50% (mean, 31.2%), whereas the remaining 23 had a normal LVEF (mean, 60.2%). Myocardial UFA/W ratio was found to differ significantly in patients with low LVEF, normal LVEF, and controls (0.79% vs. 0.21% vs. 0.14%, respectively, p = 0.02). The myocardial UFA/TG ratio was associated with LV mass (r = 0.39, p < 0.001) and modestly related to LV end-diastolic volume (LVEDV; r = 0.24, p = 0.039). We also identified negative correlations of the myocardial FA/TG ratio with both LV mass (r = -0.39, p < 0.001) and LVEDV (r = -0.24, p = 0.039). As compared with controls, patients who were discharged after hospitalization for acute HF had increased myocardial UFA content; furthermore, UFA was inversely related with LVEF, LV mass and, to a lesser extent, LVEDV. Our study may stimulate further research on the measure of myocardial UFA content by (1)H-MRS for outcome

  1. Various approaches to the modelling of large scale 3-dimensional circulation in the Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Shaji, C.; Bahulayan, N.; Rao, A.D.; Dube, S.K.

    In this paper, the three different approaches to the modelling of large scale 3-dimensional flow in the ocean such as the diagnostic, semi-diagnostic (adaptation) and the prognostic are discussed in detail. Three-dimensional solutions are obtained...

  2. COMPUTER SIMULATION OF 3-DIMENSIONAL DYNAMIC ASSEMBLY PROCESS OF MECHANICAL ROTATIONAL BODY

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Focusing on the study of the components of mechanical rotational body,the data structure and algorithm of component model generation are discussed.Some problems in assembly process of 3-dimensional graph of components are studied in great detail.

  3. On an asymptotic distribution of dependent random variables on a 3-dimensional lattice.

    Science.gov (United States)

    Harvey, Danielle J; Weng, Qian; Beckett, Laurel A

    2010-06-15

    We define conditions under which sums of dependent spatial data will be approximately normally distributed. A theorem on the asymptotic distribution of a sum of dependent random variables defined on a 3-dimensional lattice is presented. Examples are also presented.

  4. Stress distribution in the temporomandibular joint after mandibular protraction: a 3-dimensional finite element method study. Part 1.

    Science.gov (United States)

    Gupta, Anurag; Kohli, Virender S; Hazarey, Pushpa V; Kharbanda, Om P; Gunjal, Amit

    2009-06-01

    This study was designed to evaluate patterns of stress generation in the temporomandibular joint after mandibular protraction, by using a 3-dimensional finite element method. The results of the initial investigation are reported here in Part 1. The effects of varying the construction bite are reported in Part 2. A 3-dimensional computer-aided design model was developed from the magnetic resonance images of a growing boy (age, 12 years), by using I-DEAS NX (version 11.0, Siemens PLM Software, Plano, Tex). The model simulated mandibular protraction, with 5 mm of sagittal advancement and 4 mm of vertical opening. Stress distributions on the condylar neck, the glenoid fossa, and the articular disc in the anteroposterior and mediolateral directions were assessed. Tensile stresses were located on the posterosuperior aspects and compressive stresses on the anterior and anterosuperior aspects of the condylar head. Tensile stresses were found in the posterior region of the glenoid fossa near the attachment of the posterior connective tissues. These results suggest that, on mandibular protraction, the mandibular condyle experiences tensile stresses in the posterosuperior aspect that might help explain condylar growth in this direction. Similarly, on the glenoid fossa, tensile stresses are created in the region of posterior connective tissues; this might be correlated with the increased cellular activity in this region. Further study with variable vertical heights of the construction bites is needed.

  5. Longitudinal monitoring of cardiac siderosis using cardiovascular magnetic resonance T2* in patients with thalassemia major on various chelation regimens: a 6-year study.

    Science.gov (United States)

    Ambati, Srikanth R; Randolph, Rachel E; Mennitt, Kevin; Kleinert, Dorothy A; Weinsaft, Jonathan W; Giardina, Patricia J

    2013-08-01

    Cardiovascular magnetic resonance (CMR) and hepatic magnetic resonance imaging (MRI) have become reliable noninvasive tools to monitor iron excess in thalassemia major (TM) patients. However, long-term studies are lacking. We reviewed CMR and hepatic MRI T2* imaging on 54 TM patients who had three or more annual measurements. They were managed on various chelation regimens. Patients were grouped according to their degree of cardiac siderosis: severe (T2*, cardiac siderosis (T2*, >20 msec). We looked at the change in cardiac T2*, liver iron concentration (LIC) and left ventricular ejection fraction (LVEF) at years 3 and 5. In patients with severe cardiac siderosis, cardiac T2* (mean ± SD) improved from 6.9 ± 1.6 at baseline to 13.6 ± 10.0 by year 5, mean ΔT2* = 6.7 (P = 0.04). Change in cardiac T2* at year 3 was not significant in the severe group. Patients with mild to moderate cardiac siderosis had mean cardiac T2* of 14.6 ± 2.9 at baseline which improved to 26.3 ± 9.5 by year 3, mean ΔT2* =  1.7 (P = 0.01). At baseline, median LICs (mg/g dry weight) in patients with severe, mild-moderate, and no cardiac siderosis were 3.6, 2.8, and 3.3, whereas LVEFs (mean ± SD) (%) were 56.3 ± 10.1, 60 ± 5, and 66 ± 7.6, respectively. No significant correlation was noted between Δ cardiac T2* and Δ LIC, Δ cardiac T2*, and Δ LVEF at years 3 and 5. Throughout the observation period, patients with no cardiac siderosis maintained their cardiac T2* above 20 msec. The majority of patients with cardiac siderosis improve cardiac T2* over time with optimal chelation.

  6. Cardiac Sarcoidosis or Giant Cell Myocarditis? On Treatment Improvement of Fulminant Myocarditis as Demonstrated by Cardiovascular Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Hari Bogabathina

    2012-01-01

    Full Text Available Giant cell myocarditis, but not cardiac sarcoidosis, is known to cause fulminant myocarditis resulting in severe heart failure. However, giant cell myocarditis and cardiac sarcoidosis are pathologically similar, and attempts at pathological differentiation between the two remain difficult. We are presenting a case of fulminant myocarditis that has pathological features suggestive of cardiac sarcoidosis, but clinically mimicking giant cell myocarditis. This patient was treated with cyclosporine and prednisone and recovered well. This case we believe challenges our current understanding of these intertwined conditions. By obtaining a sense of severity of cardiac involvement via delayed hyperenhancement of cardiac magnetic resonance imaging, we were more inclined to treat this patient as giant cell myocarditis with cyclosporine. This resulted in excellent improvement of patient’s cardiac function as shown by delayed hyperenhancement images, early perfusion images, and SSFP videos.

  7. 3-DIMENSIONAL RECONSTRUCTION OF THE HIP MUSCLES ON THE BASIS OF MAGNETIC-RESONANCE IMAGES

    NARCIS (Netherlands)

    JAEGERS, SMHJ; DEJONGH, HJ; Dantuma, R.

    1992-01-01

    MRI in combination with three-dimensional reconstruction is pre-eminently suitable for the study of the human musculoskeletal system in vivo in an accurate and detailed way. MRI provides the possibility of studying superficial as well as deep muscles under tension in the living state. Bones, muscles

  8. Automated 3-dimensional segmentation of pelvic lymph nodes in magnetic resonance images

    NARCIS (Netherlands)

    Debats, O.A.; Litjens, G.J.S.; Barentsz, J.O.; Karssemeijer, N.; Huisman, H.J.

    2011-01-01

    Purpose: Computer aided diagnosis (CAD) of lymph node metastases may help reduce reading time and improve interpretation of the large amount of image data in a 3-D pelvic MRI exam. The purpose of this study was to develop an algorithm for automated segmentation of pelvic lymph nodes from a single

  9. Improvement of myocardial perfusion reserve detected by cardiovascular magnetic resonance after direct endomyocardial implantation of autologous bone marrow cells in patients with severe coronary artery disease

    Directory of Open Access Journals (Sweden)

    Lau Chu-Pak

    2010-01-01

    Full Text Available Abstract Background Recent studies suggested that bone marrow (BM cell implantation in patients with severe chronic coronary artery disease (CAD resulted in modest improvement in symptoms and cardiac function. This study sought to investigate the functional changes that occur within the chronic human ischaemic myocardium after direct endomyocardial BM cells implantation by cardiovascular magnetic resonance (CMR. Methods and Results We compared the interval changes of left ventricular ejection fraction (LVEF, myocardial perfusion reserve and the extent of myocardial scar by using late gadolinium enhancement CMR in 12 patients with severe CAD. CMR was performed at baseline and at 6 months after catheter-based direct endomyocardial autologous BM cell (n = 12 injection to viable ischaemic myocardium as guided by electromechanical mapping. In patients randomized to receive BM cell injection, there was significant decrease in percentage area of peri-infarct regions (-23.6%, P = 0.04 and increase in global LVEF (+9.0%, P = 0.02, the percentage of regional wall thickening (+13.1%, P= 0.04 and MPR (+0.25%, P = 0.03 over the target area at 6-months compared with baseline. Conclusions Direct endomyocardial implantation of autologous BM cells significantly improved global LVEF, regional wall thickening and myocardial perfusion reserve, and reduced percentage area of peri-infarct regions in patients with severe CAD.

  10. Age determination of vessel wall hematoma in spontaneous cervical artery dissection: A multi-sequence 3T Cardiovascular Magnetic resonance study

    Directory of Open Access Journals (Sweden)

    Habs Maximilian

    2011-11-01

    Full Text Available Abstract Background Previously proposed classifications for carotid plaque and cerebral parenchymal hemorrhages are used to estimate the age of hematoma according to its signal intensities on T1w and T2w MR images. Using these classifications, we systematically investigated the value of cardiovascular magnetic resonance (CMR in determining the age of vessel wall hematoma (VWH in patients with spontaneous cervical artery dissection (sCAD. Methods 35 consecutive patients (mean age 43.6 ± 9.8 years with sCAD received a cervical multi-sequence 3T CMR with fat-saturated black-blood T1w-, T2w- and TOF images. Age of sCAD was defined as time between onset of symptoms (stroke, TIA or Horner's syndrome and the CMR scan. VWH were categorized into hyperacute, acute, early subacute, late subacute and chronic based on their signal intensities on T1w- and T2w images. Results The mean age of sCAD was 2.0, 5.8, 15.7 and 58.7 days in patients with acute, early subacute, late subacute and chronic VWH as classified by CMR (p Conclusions Signal intensities of VWH in sCAD vary over time and multi-sequence CMR can help to determine the age of an arterial dissection. Furthermore, findings of this study suggest that the time course of carotid hematomas differs from that of cerebral hematomas.

  11. Impact of diastolic dysfunction severity on global left ventricular volumetric filling - assessment by automated segmentation of routine cine cardiovascular magnetic resonance

    Science.gov (United States)

    2010-01-01

    Objectives To examine relationships between severity of echocardiography (echo) -evidenced diastolic dysfunction (DD) and volumetric filling by automated processing of routine cine cardiovascular magnetic resonance (CMR). Background Cine-CMR provides high-resolution assessment of left ventricular (LV) chamber volumes. Automated segmentation (LV-METRIC) yields LV filling curves by segmenting all short-axis images across all temporal phases. This study used cine-CMR to assess filling changes that occur with progressive DD. Methods 115 post-MI patients underwent CMR and echo within 1 day. LV-METRIC yielded multiple diastolic indices - E:A ratio, peak filling rate (PFR), time to peak filling rate (TPFR), and diastolic volume recovery (DVR80 - proportion of diastole required to recover 80% stroke volume). Echo was the reference for DD. Results LV-METRIC successfully generated LV filling curves in all patients. CMR indices were reproducible (≤ 1% inter-reader differences) and required minimal processing time (175 ± 34 images/exam, 2:09 ± 0:51 minutes). CMR E:A ratio decreased with grade 1 and increased with grades 2-3 DD. Diastolic filling intervals, measured by DVR80 or TPFR, prolonged with grade 1 and shortened with grade 3 DD, paralleling echo deceleration time (p cine-CMR segmentation can discern LV filling changes that occur with increasing severity of echo-evidenced DD. Impaired relaxation is associated with prolonged filling intervals whereas restrictive filling is characterized by increased filling rates. PMID:20673372

  12. Multimodal cardiovascular magnetic resonance quantifies regional variation in vascular structure and function in patients with coronary artery disease: Relationships with coronary disease severity

    Directory of Open Access Journals (Sweden)

    Kylintireas Ilias

    2011-10-01

    Full Text Available Abstract Background Cardiovascular magnetic resonance (CMR of the vessel wall is highly reproducible and can evaluate both changes in plaque burden and composition. It can also measure aortic compliance and endothelial function in a single integrated examination. Previous studies have focused on patients with pre-identified carotid atheroma. We define these vascular parameters in patients presenting with coronary artery disease and test their relations to its extent and severity. Methods and Results 100 patients with CAD [single-vessel (16%; two-vessel (39%; and three-vessel (42% non-obstructed coronary arteries (3%] were studied. CAD severity and extent was expressed as modified Gensini score (mean modified score 12.38 ± 5.3. A majority of carotid plaque was located in the carotid bulb (CB. Atherosclerosis in this most diseased segment correlated modestly with the severity and extent of CAD, as expressed by the modified Gensini score (R = 0.251, P Conclusions Multimodal vascular CMR shows regional abnormalities of vascular structure and function that correlate modestly with the degree and extent of CAD.

  13. Comparison of cardiovascular magnetic resonance of late gadolinium enhancement and diastolic wall thickness to predict recovery of left ventricular function after coronary artery bypass surgery

    Directory of Open Access Journals (Sweden)

    Udompunturak Suthipol

    2008-09-01

    Full Text Available Abstract Background The objective was to compare the value of late gadolinium enhancement (LGE and end-diastolic wall thickness (EDWT assessed by cardiovascular magnetic resonance (CMR in predicting recovery of left ventricular function after coronary artery bypass surgery (CABG. Methods We enrolled patients with coronary artery disease and left ventricular ejection fraction Results We studied 46 men and 4 women with an average age of 61 years. Baseline left ventricular ejection fraction was 37 ± 13%. A total of 2,020 myocardial segments were analyzed. Abnormal wall motion and the LGE area were detected in 1,446 segments (71.6% and 1,196 segments (59.2% respectively. Wall motion improvement was demonstrated in 481 of 1,227 segments (39.2% that initially had wall motion abnormalities at baseline. Logistic regression analysis showed that the LGE area, EDWT and resting wall motion grade predicted wall motion improvement. Comparison of Receiver-Operator-Characteristic (ROC curves demonstrated that the LGE area was the most important predictor (p Conclusion LGE and EDWT are independent predictors for functional recovery after revascularization. However, LGE appears to be a more important factor and independent of EDWT.

  14. Knowledge-based reconstruction for measurement of right ventricular volumes on cardiovascular magnetic resonance images in a mixed population.

    Science.gov (United States)

    Pieterman, Elise D; Budde, Ricardo P J; Robbers-Visser, Daniëlle; van Domburg, Ron T; Helbing, Willem A

    2017-06-05

    Follow-up of right ventricular performance is important for patients with congenital heart disease. Cardiac magnetic resonance imaging is optimal for this purpose. However, observer-dependency of manual analysis of right ventricular volumes limit its use. Knowledge-based reconstruction is a new semiautomatic analysis tool that uses a database including knowledge of right ventricular shape in various congenital heart diseases. We evaluated whether knowledge-based reconstruction is a good alternative for conventional analysis. To assess the inter- and intra-observer variability and agreement of knowledge-based versus conventional analysis of magnetic resonance right ventricular volumes, analysis was done by two observers in a mixed group of 22 patients with congenital heart disease affecting right ventricular loading conditions (dextro-transposition of the great arteries and right ventricle to pulmonary artery conduit) and a group of 17 healthy children. We used Bland-Altman analysis and coefficient of variation. Comparison between the conventional method and the knowledge-based method showed a systematically higher volume for the latter group. We found an overestimation for end-diastolic volume (bias -40 ± 24 mL, r = .956), end-systolic volume (bias -34 ± 24 mL, r = .943), stroke volume (bias -6 ± 17 mL, r = .735) and an underestimation of ejection fraction (bias 7 ± 7%, r = .671) by knowledge-based reconstruction. The intra-observer variability of knowledge-based reconstruction varied with a coefficient of variation of 9% for end-diastolic volume and 22% for stroke volume. The same trend was noted for inter-observer variability. A systematic difference (overestimation) was noted for right ventricular size as assessed with knowledge-based reconstruction compared with conventional methods for analysis. Observer variability for the new method was comparable to what has been reported for the right ventricle in children and congenital

  15. Cardiovascular Deconditioning

    Science.gov (United States)

    Charles, John B.; Fritsch-Yelle, Janice M.; Whitson, Peggy A.; Wood, Margie L.; Brown, Troy E.; Fortner, G. William

    1999-01-01

    Spaceflight causes adaptive changes in cardiovascular function that may deleteriously affect crew health and safety. Over the last three decades, symptoms of cardiovascular changes have ranged from postflight orthostatic tachycardia and decreased exercise capacity to serious cardiac rhythm disturbances during extravehicular activities (EVA). The most documented symptom of cardiovascular dysfunction, postflight orthostatic intolerance, has affected a significant percentage of U.S. Space Shuttle astronauts. Problems of cardiovascular dysfunction associated with spaceflight are a concern to NASA. This has been particularly true during Shuttle flights where the primary concern is the crew's physical health, including the pilot's ability to land the Orbiter, and the crew's ability to quickly egress and move to safety should a dangerous condition arise. The study of astronauts during Shuttle activities is inherently more difficult than most human research. Consequently, sample sizes have been small and results have lacked consistency. Before the Extended Duration Orbiter Medical Project (EDOMP), there was a lack of normative data on changes in cardiovascular parameters during and after spaceflight. The EDOMP for the first time allowed studies on a large enough number of subjects to overcome some of these problems. There were three primary goals of the Cardiovascular EDOMP studies. The first was to establish, through descriptive studies, a normative data base of cardiovascular changes attributable to spaceflight. The second goal was to determine mechanisms of cardiovascular changes resulting from spaceflight (particularly orthostatic hypotension and cardiac rhythm disturbances). The third was to evaluate possible countermeasures. The Cardiovascular EDOMP studies involved parallel descriptive, mechanistic, and countermeasure evaluations.

  16. The emergence of proton nuclear magnetic resonance metabolomics in the cardiovascular arena as viewed from a clinical perspective.

    Science.gov (United States)

    Rankin, Naomi J; Preiss, David; Welsh, Paul; Burgess, Karl E V; Nelson, Scott M; Lawlor, Debbie A; Sattar, Naveed

    2014-11-01

    The ability to phenotype metabolic profiles in serum has increased substantially in recent years with the advent of metabolomics. Metabolomics is the study of the metabolome, defined as those molecules with an atomic mass less than 1.5 kDa. There are two main metabolomics methods: mass spectrometry (MS) and proton nuclear magnetic resonance ((1)H NMR) spectroscopy, each with its respective benefits and limitations. MS has greater sensitivity and so can detect many more metabolites. However, its cost (especially when heavy labelled internal standards are required for absolute quantitation) and quality control is sub-optimal for large cohorts. (1)H NMR is less sensitive but sample preparation is generally faster and analysis times shorter, resulting in markedly lower analysis costs. (1)H NMR is robust, reproducible and can provide absolute quantitation of many metabolites. Of particular relevance to cardio-metabolic disease is the ability of (1)H NMR to provide detailed quantitative data on amino acids, fatty acids and other metabolites as well as lipoprotein subparticle concentrations and size. Early epidemiological studies suggest promise, however, this is an emerging field and more data is required before we can determine the clinical utility of these measures to improve disease prediction and treatment. This review describes the theoretical basis of (1)H NMR; compares MS and (1)H NMR and provides a tabular overview of recent (1)H NMR-based research findings in the atherosclerosis field, describing the design and scope of studies conducted to date. (1)H NMR metabolomics-CVD related research is emerging, however further large, robustly conducted prospective, genetic and intervention studies are needed to advance research on CVD risk prediction and to identify causal pathways amenable to intervention. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  17. Drop-out from cardiovascular magnetic resonance in a randomized controlled trial of ST-elevation myocardial infarction does not cause selection bias on endpoints.

    Science.gov (United States)

    Laursen, Peter Nørkjær; Holmvang, L; Kelbæk, H; Vejlstrup, N; Engstrøm, T; Lønborg, J

    2017-07-01

    The extent of selection bias due to drop-out in clinical trials of ST-elevation myocardial infarction (STEMI) using cardiovascular magnetic resonance (CMR) as surrogate endpoints is unknown. We sought to interrogate the characteristics and prognosis of patients who dropped out before acute CMR assessment compared to CMR-participants in a previously published double-blinded, placebo-controlled all-comer trial with CMR outcome as the primary endpoint. Baseline characteristics and composite endpoint of all-cause mortality, heart failure and re-infarction after 30 days and 5 years of follow-up were assessed and compared between CMR-drop-outs and CMR-participants using the trial screening log and the Eastern Danish Heart Registry. The drop-out rate from acute CMR was 28% (n = 92). These patients had a significantly worse clinical risk profile upon admission as evaluated by the TIMI-risk score (3.7 (± 2.1) vs 4.0 (± 2.6), p = 0.043) and by left ventricular ejection fraction (43 (± 9) vs. 47 (± 10), p = 0.029). CMR drop-outs had a higher incidence of known hypertension (39% vs. 35%, p = 0.043), known diabetes (14% vs. 7%, p = 0.025), known cardiac disease (11% vs. 3%, p = 0.013) and known renal function disease (5% vs. 0%, p = 0.007). However, the 30-day and 5-years composite endpoint rate was not significantly higher among the CMR drop-out ((HR 1.43 (95%-CI 0.5; 3.97) (p = 0.5)) and (HR 1.31 (95%-CI 0.84; 2.05) (p = 0.24)). CMR-drop-outs had a higher incidence of cardiovascular risk factors at baseline, a worse clinical risk profile upon admission. However, no significant difference was observed in the clinical endpoints between the groups.

  18. Cardiovascular magnetic resonance imaging and transthoracic echocardiography in the assessment of stenotic aortic valve area: a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Dimitriou, Praxitelis; Kaehaeri, Anders [Dept. of Radiology, Oerebro Univ. Hospital, Oerebro (Sweden); Emilsson, Kent [Dept. of Clinical Physiology, Oerebro Univ. Hospital, Oerebro (Sweden); School of Health and Medical Sciences, Oerebro Univ., Oerebro (Sweden); Thunberg, Per [School of Health and Medical Sciences, Oerebro Univ., Oerebro (Sweden); Dept. of Medical Physics, Oerebro Univ. Hospital, Oerebro (Sweden)], E-mail: per.thunberg@orebroll.se

    2012-11-15

    Background Magnetic resonance (MR) imaging and echocardiography both allow assessment of aortic valve stenosis. In MR the aortic valve area (AvA) is measured using planimetry while in transthoracic echocardiography (TTE) AvA is usually calculated by applying the continuity equation. Purpose To compare the measured stenotic aortic valve areas using five different MR-acquisition alternatives with the corresponding area values calculated by TTE. Material and Methods The aortic valve was imaged in 14 patients, with diagnosed aortic valve stenosis, using balanced steady state free precession (bSSFP) gradient echo (GE) and phase contrast imaging (PC). Three adjacent slices were planned to encompass the aortic valve and the aortic valve area was measured using planimetry. The two sets of complex valued images generated by the PC sequence formed three kinds of images that could be used for aortic valve area measurements: the magnitude image (PC/Mag), the modulus (PCA/M), and phase difference (PCA/P) between the two complex images, respectively. The valve area from TTE was calculated using the continuity equation. A cut-off of <1.0 cm{sup 2} was used as a criteria for severe stenosis. Results The mean area differences between the different MR acquisitions and TTE method were -0.05 {+-} 0.37 cm{sup 2} (GE), -0.18 {+-} 0.46 cm{sup 2} (bSSFP), 0.27 {+-} 0.43 cm{sup 2} (PC/Mag), 0.15 {+-} 0.32 cm{sup 2} (PCA/P), and 0.26 {+-} 0.27 cm{sup 2} (PCA/M). The valve area was significantly overestimated using PCA/M that, in turn, implied a significant underestimation of the aortic valve stenosis severity compared to the assessments using TTE. Conclusion The smallest area valve difference between TTE and an MR-acquisition alternative is obtained with gradient echo images. The use of PCA/M leads to significant differences in planimetry measurements of the aortic valve orifice and the gradation of the stenosis severity compared to TTE.

  19. Absolute assessment of aortic valve stenosis by planimetry using cardiovascular magnetic resonance imaging: Comparison with transoesophageal echocardiography, transthoracic echocardiography, and cardiac catheterisation

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    Reant, Patricia [Department of Cardiology and Echocardiography, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France)]. E-mail: patreant@free.fr; Lederlin, Mathieu [Department of Radiology, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France); Lafitte, Stephane [Department of Cardiology and Echocardiography, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France); Serri, Karim [Department of Cardiology and Echocardiography, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France); Montaudon, Michel [Department of Radiology, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France); Inserm E356, F33076 Bordeaux (France); Corneloup, Olivier [Department of Radiology, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France); Roudaut, Raymond [Department of Cardiology and Echocardiography, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France); Laurent, Francois [Department of Radiology, Hopital Cardiologique Haut-Leveque, Bordeaux-Pessac (France); University of Victor Segalen, F33076 Bordeaux (France); Inserm E356, F33076 Bordeaux (France)

    2006-08-15

    Objective: The aims of this study were to investigate absolute assessment of aortic valve area (AVA), before surgery for aortic stenosis, using cardiovascular magnetic resonance (CMR) in comparison with transoesophageal echocardiography (TEE) and with effective AVA indirectly obtained by routine techniques i.e. transthoracic echocardiography (TTE) and cardiac catheterisation. Materials and methods: Absolute AVA planimetry was performed by TEE and CMR steady state free precession sequences obtained through the aortic valvular plane. Effective AVA was calculated by the continuity equation in TTE and by cardiac catheterisation (Gorlin formula). Results: Thirty-nine patients with aortic valve stenosis, mean age 71.7 {+-} 7.6 years, with a mean AVA of 0.93 {+-} 0.31 cm{sup 2} as measured by TEE, were enrolled in the study. Mean differences were: between CMR and TEE planimetry: d = 0.01 {+-} 0.14 cm{sup 2}, between CMR and cardiac catheterisation: d = 0.05 {+-} 0.13 cm{sup 2}, between CMR and TTE: d = 0.10 {+-} 0.17 cm{sup 2}, between TTE and TEE: d = 0.10 {+-} 0.18 cm{sup 2}, between TTE and cardiac catheterisation: d 0.06 {+-} 0.16 cm{sup 2}, and between TEE and cardiac catheterisation: d = 0.07 {+-} 0.13 cm{sup 2}. Mean intraobserver and interobserver differences of CMR planimetry were d = 0.02 {+-} 0.07 cm{sup 2} and d = 0.03 {+-} 0.14 cm{sup 2}, respectively. Conclusion: CMR planimetry of the AVA is a noninvasive and reproducible technique to evaluate stenotic aortic valves and can be used as an alternative to echocardiography or cardiac catheterisation.

  20. Quantitative cardiovascular magnetic resonance in pregnant women: cross-sectional analysis of physiological parameters throughout pregnancy and the impact of the supine position

    Directory of Open Access Journals (Sweden)

    Moelker Adriaan

    2011-06-01

    Full Text Available Abstract Background There are physiological reasons for the effects of positioning on hemodynamic variables and cardiac dimensions related to altered intra-abdominal and intra-thoracic pressures. This problem is especially evident in pregnant women due to the additional aorto-caval compression by the enlarged uterus. The purpose of this study was to investigate the effect of postural changes on cardiac dimensions and function during mid and late pregnancy using cardiovascular magnetic resonance (CMR. Methods Healthy non-pregnant women, pregnant women at 20th week of gestation and at 32nd week of gestation without history of cardiac disease were recruited to the study and underwent CMR in supine and left lateral positions. Cardiac hemodynamic parameters and dimensions were measured and compared between both positions. Results Five non-pregnant women, 6 healthy pregnant women at mid pregnancy and 8 healthy pregnant women at late pregnancy were enrolled in the study. In the group of non-pregnant women left ventricular (LV cardiac output (CO significantly decreased by 9% (p = 0.043 and right ventricular (RV end-diastolic volume (EDV significantly increased by 5% (p = 0.043 from the supine to the left lateral position. During mid pregnancy LV ejection fraction (EF, stroke volume (SV, left atrium lateral diameter and left atrial supero-inferior diameter increased significantly from the supine position to the left lateral position: 8%, 27%, 5% and 11%, respectively (p Conclusions During pregnancy positional changes affect significantly cardiac hemodynamic parameters and dimensions. Pregnant women who need serial studies by CMR should be imaged in a consistent position. From as early as 20 weeks the left lateral position should be preferred on the supine position because it positively affects venous return, SV and CO.

  1. Diagnostic accuracy of cardiovascular magnetic resonance imaging of right ventricular morphology and function in the assessment of suspected pulmonary hypertension results from the ASPIRE registry

    Directory of Open Access Journals (Sweden)

    Swift Andrew J

    2012-06-01

    Full Text Available Abstract Background Cardiovascular Magnetic Resonance (CMR imaging is accurate and reproducible for the assessment of right ventricular (RV morphology and function. However, the diagnostic accuracy of CMR derived RV measurements for the detection of pulmonary hypertension (PH in the assessment of patients with suspected PH in the clinic setting is not well described. Methods We retrospectively studied 233 consecutive treatment naïve patients with suspected PH including 39 patients with no PH who underwent CMR and right heart catheterisation (RHC within 48hours. The diagnostic accuracy of multiple CMR measurements for the detection of mPAP ≥ 25 mmHg was assessed using Fisher’s exact test and receiver operating characteristic (ROC analysis. Results Ventricular mass index (VMI was the CMR measurement with the strongest correlation with mPAP (r = 0.78 and the highest diagnostic accuracy for the detection of PH (area under the ROC curve of 0.91 compared to an ROC of 0.88 for echocardiography calculated mPAP. Late gadolinium enhancement, VMI ≥ 0.4, retrograde flow ≥ 0.3 L/min/m2 and PA relative area change ≤ 15% predicted the presence of PH with a high degree of diagnostic certainty with a positive predictive value of 98%, 97%, 95% and 94% respectively. No single CMR parameter could confidently exclude the presence of PH. Conclusion CMR is a useful alternative to echocardiography in the evaluation of suspected PH. This study supports a role for the routine measurement of ventricular mass index, late gadolinium enhancement and the use of phase contrast imaging in addition to right heart functional indices in patients undergoing diagnostic CMR evaluation for suspected pulmonary hypertension.

  2. T-wave inversions related to left ventricular basal hypertrophy and myocardial fibrosis in non-apical hypertrophic cardiomyopathy: A cardiovascular magnetic resonance imaging study

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    Chen, Xiuyu, E-mail: cxy0202@126.com [Department of Radiology, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037 (China); Zhao, Shihua, E-mail: zhaoshihua0202@126.com [Department of Radiology, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037 (China); Zhao, Tao, E-mail: taozhao0202@126.com [Department of Radiology, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037 (China); Lu, Minjie, E-mail: lmjkan@126.com [Department of Radiology, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037 (China); Yin, Gang, E-mail: gangyin0202@126.com [Department of Radiology, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037 (China); Jiang, Shiliang, E-mail: jiangsl-2011@163.com [Department of Radiology, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037 (China); Prasad, Sanjay, E-mail: s.prasad@rbht.nhs.uk [NIHR Biomedical Research Unit, Royal Brompton Hospital Sydney Street, London, SW3 6NP (United Kingdom)

    2014-02-15

    Objectives: To investigate the relationship between T-wave inversions and left ventricular (LV) segmental hypertrophy and myocardial fibrosis assessed by cardiovascular magnetic resonance (CMR) in patients with non-apical hypertrophic cardiomyopathy (HCM). Methods: 196 consecutive patients with non-apical HCM underwent late gadolinium enhancement (LGE) CMR and 12-lead electrocardiogram. The distribution and magnitude of LV segmental hypertrophy and LGE were assessed according to the AHA 17-segment model and analyzed in relation to T-wave inversions. Results: Of 196 HCM patients, 144 (73%) exhibited T-wave inversions. 144 (73%) patients had evidence of myocardial fibrosis as defined by LGE, and the prevalence of LGE was significantly higher in patients with T-wave inversions compared with those without T-wave inversions (78% vs. 59%, P = 0.008). T-wave inversions were related to basal anterior and basal anteroseptal LGE (20% vs. 10%, P = 0.04 and 68% vs. 46%, P = 0.005, respectively). In addition, T-wave inversions were associated with greater basal anteroseptal and basal inferior wall thickness (19.5 ± 4.7 mm vs. 16.7 ± 4.5 mm, P < 0.001 and 10.9 ± 3.3 mm vs. 9.6 ± 3.0 mm, P = 0.01, respectively). By logistic regression analysis, basal anteroseptal wall thickness and LGE were independent determinants of T-wave inversions (P = 0.005, P = 0.01, respectively). Conclusions: T-wave inversions in HCM are associated with LGE and wall thickness of the left ventricular basal segments. Moreover, basal anteroseptal wall thickness and LGE are independent determinants of T-wave inversions.

  3. Effect of lifestyle intervention plus rosiglitazone or placebo therapy on left ventricular mass assessed with cardiovascular magnetic resonance in the metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Tamsma Jouke T

    2011-10-01

    Full Text Available Abstract Background To evaluate the effect of lifestyle intervention in conjunction with rosiglitazone or placebo therapy on left ventricular (LV mass, using cardiovascular magnetic resonance (CMR in the metabolic syndrome. Methods The present study was a pre-specified substudy of a double-blind randomized controlled trial evaluating the effect of lifestyle intervention in conjunction with rosiglitazone or placebo therapy on carotid artery atherosclerosis in the metabolic syndrome. From this original study population, 10 subjects from the placebo group and 10 from the rosiglitazone group were randomly selected. At baseline and follow-up (52 weeks, clinical and laboratory measurements were assessed and a CMR-examination was performed to evaluate LV mass indexed for body surface area (LV mass-I. Subsequently, the effect of therapy (rosiglitazone vs. placebo and clinical and laboratory variables on LV mass-I was evaluated. Results In both groups, body mass index, waist circumference, systolic and diastolic blood pressure significantly decreased during follow-up. Interestingly, LV mass-I significantly decreased in the placebo group (48.9 ± 5.3 g/m2 vs. 44.3 ± 5.6 g/m2, p 2 vs. 53.7 ± 9.2 g/m2, p = 0.3. After correction for systolic and diastolic blood pressure and triglyceride, the kind of therapy (rosiglitazone vs. placebo remained the only significant predictor of LV mass-I reduction. Conclusions Lifestyle intervention resulted in a reduction of LV mass-I in the metabolic syndrome, indicating reverse remodeling. However, rosiglitazone therapy may have inhibited this positive reverse remodeling. Trial registration Current Controlled Trials ISRCTN54951661.

  4. Inter-observer agreement and diagnostic accuracy of myocardial perfusion reserve quantification by cardiovascular magnetic resonance at 3 Tesla in comparison to quantitative coronary angiography.

    Science.gov (United States)

    Ikuye, Katharina; Buckert, Dominik; Schaaf, Lisa; Walcher, Thomas; Rottbauer, Wolfgang; Bernhardt, Peter

    2013-03-27

    Quantification of cardiovascular magnetic resonance (CMR) myocardial perfusion reserve (MPR) at 1.5 Tesla has been shown to correlate to invasive evaluation of coronary artery disease (CAD) and to yield good inter-observer agreement. However, little is known about quantitative adenosine-perfusion CMR at 3 Tesla and no data about inter-observer agreement is available. Aim of our study was to evaluate inter-observer agreement and to assess the diagnostic accuracy in comparison to quantitative coronary angiography (QCA). Fifty-three patients referred for coronary x-ray angiography were previously examined in a 3 Tesla whole-body scanner. Adenosine and rest perfusion CMR were acquired for the quantification of MPR in all segments. Two blinded and independent readers analyzed all images. QCA was performed in case of coronary stenosis. QCA data was used to assess diagnostic accuracy of the MPR measurements. Inter-observer agreement was high for all myocardial perfusion territories (ρ = 0.92 for LAD, ρ = 0.93 for CX and RCA perfused segments). Compared to QCA receiver-operating characteristics yielded an area under the curve of 0.78 and 0.73 for RCA, 0.66 and 0.69 for LAD, and 0.52 and 0.53 for LCX perfused territories. Inter-observer agreement of MPR quantification at 3 Tesla CMR is very high for all myocardial segments. Diagnostic accuracy in comparison to QCA yields good values for the RCA and LAD perfused territories, but moderate values for the posterior LCX perfused myocardial segments.

  5. Pulmonary intravascular blood volume changes through the cardiac cycle in healthy volunteers studied by cardiovascular magnetic resonance measurements of arterial and venous flow

    Directory of Open Access Journals (Sweden)

    Arheden Hakan

    2009-10-01

    Full Text Available Abstract Background This study aims to present a novel method for using cardiovascular magnetic resonance (CMR to non-invasively quantify the variation in pulmonary blood volume throughout the cardiac cycle in humans. Methods 10 healthy volunteers (7 males, 3 female, age range 21-32 years were studied. The blood flow in the pulmonary artery and all pulmonary veins was quantified during free breathing using phase contrast velocity encoded CMR. The difference in flow between the pulmonary artery and the pulmonary veins was integrated to calculate the change in pulmonary blood volume throughout the cardiac cycle. Results The stroke volumes in the pulmonary artery and the sum of the pulmonary veins were (mean ± SEM 103 ± 6 ml and 95 ± 6 ml, respectively. The pulmonary blood volume variation (PBVV was 48 ± 5 ml, and the PBVV expressed as percent of the pulmonary artery stroke volume was 46 ± 3%. The maximum increase in pulmonary blood volume occurred 310 ± 12 ms after the R-wave from the ECG (32 ± 2% of the cardiac cycle. PBVV did not correlate to change in cross-sectional area in the pulmonary artery (R2 = 0.03, p = 0.66. Conclusion It is feasible to non-invasively quantify the change in pulmonary blood volume during the cardiac cycle in humans using CMR. The average pulmonary blood volume variation in healthy volunteers was approximately 50 ml and this was approximately 50% of the stroke volume. Further studies are needed to assess the utility of the pulmonary blood volume variation as a measure for identifying cardiac and pulmonary vascular disease.

  6. Assessment of circumferential endocardial extent of myocardial edema and infarction in patients with reperfused acute myocardial infarction: a cardiovascular magnetic resonance study.

    Science.gov (United States)

    Ota, Shingo; Tanimoto, Takashi; Hirata, Kumiko; Orii, Makoto; Shiono, Yasutsugu; Shimamura, Kunihiro; Ishibashi, Kohei; Yamano, Takashi; Ino, Yasushi; Kitabata, Hironori; Yamaguchi, Tomoyuki; Kubo, Takashi; Imanishi, Toshio; Akasaka, Takashi

    2014-01-01

    T2 weighted (T2W) images on cardiovascular magnetic resonance (CMR) visualizes myocardial edema, which reflects the myocardial area at risk (AAR) in reperfused acute myocardial infarction (AMI). Late gadolinium enhancement (LGE) demonstrates myocardial infarction. LGE images cover the whole left ventricle, but T2W images are obtained from a few slices of the left ventricle due to the long sequence time, so the quantification of AAR of the entire left ventricle is difficult. We hypothesize that we can quantify AAR with only LGE images if there is a strong correlation between the circumferential endocardial extent of myocardial edema and infarction. Thirty patients with first AMI were enrolled. All patients underwent successfully reperfusion therapy and CMR was performed within the first week after the event. We measured the circumferential extent of edema and infarction on short-axis views (T2 angle and LGE angle), respectively. A total of 82 short-axis slices showed transmural edema on T2W images. Corresponding LGE images were analyzed for the circumferential extent of infarction. The median [interquartile range] of T2 angle and DE angle were 147° [116°-219°] and 134° [104°-200°] in patients with LAD culprit lesion, 91° [87°-101°] and 85° [80°-90°] in LCX, and 110° [94°-123°] and 104° [89°-118°] in RCA, respectively. T2 angle was well correlated with LGE angle (r = 0.99, P infarction in reperfused AMI. Thus, T2 weighted imaging can be skipped to quantify the amount of AAR.

  7. Hypertensive heart disease versus hypertrophic cardiomyopathy: multi-parametric cardiovascular magnetic resonance discriminators when end-diastolic wall thickness ≥ 15 mm

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Jonathan C.L. [University Hospitals Bristol NHS Foundation Trust, NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute (United Kingdom); University of Bristol, School of Physiology, Pharmacology and Neuroscience, Faculty of Biomedical Sciences (United Kingdom); Rohan, Stephen [University of Bristol, Medical School, Faculty of Medicine and Dentistry (United Kingdom); Ghosh Dastidar, Amardeep; Harries, Iwan; Lawton, Christopher B. [University Hospitals Bristol NHS Foundation Trust, NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute (United Kingdom); Ratcliffe, Laura E.; Burchell, Amy E.; Nightingale, Angus K. [University Hospitals Bristol NHS Foundation Trust, CardioNomics Research Group, Clinical Research and Imaging Centre, Bristol Heart Institute (United Kingdom); Hart, Emma C.; Paton, Julian F.R. [University of Bristol, School of Physiology, Pharmacology and Neuroscience, Faculty of Biomedical Sciences (United Kingdom); University Hospitals Bristol NHS Foundation Trust, CardioNomics Research Group, Clinical Research and Imaging Centre, Bristol Heart Institute (United Kingdom); Hamilton, Mark C.K. [University Hospitals Bristol NHS Foundation Trust, Department of Radiology, Bristol Royal Infirmary (United Kingdom); Manghat, Nathan E. [University Hospitals Bristol NHS Foundation Trust, NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute (United Kingdom); University Hospitals Bristol NHS Foundation Trust, Department of Radiology, Bristol Royal Infirmary (United Kingdom)

    2017-03-15

    European guidelines state left ventricular (LV) end-diastolic wall thickness (EDWT) ≥15 mm suggests hypertrophic cardiomyopathy (HCM), but distinguishing from hypertensive heart disease (HHD) is challenging. We identify cardiovascular magnetic resonance (CMR) predictors of HHD over HCM when EDWT ≥15 mm. 2481 consecutive clinical CMRs between 2014 and 2015 were reviewed. 464 segments from 29 HCM subjects with EDWT ≥15 mm but without other cardiac abnormality, hypertension or renal impairment were analyzed. 432 segments from 27 HHD subjects with EDWT ≥15 mm but without concomitant cardiac pathology were analyzed. Magnitude and location of maximal EDWT, presence of late gadolinium enhancement (LGE), LV asymmetry (>1.5-fold opposing segment) and systolic anterior motion of the mitral valve (SAM) were measured. Multivariate logistic regression was performed. Significance was defined as p<0.05. HHD and HCM cohorts were age-/gender-matched. HHD had significantly increased indexed LV mass (110±27 g/m{sup 2} vs. 91±31 g/m{sup 2}, p=0.016) but no difference in site or magnitude of maximal EDWT. Mid-wall LGE was significantly more prevalent in HCM. Elevated indexed LVM, mid-wall LGE and absence of SAM were significant multivariate predictors of HHD, but LV asymmetry was not. Increased indexed LV mass, absence of mid-wall LGE and absence of SAM are better CMR discriminators of HHD from HCM than EDWT ≥15 mm. circle Hypertrophic cardiomyopathy (HCM) is often diagnosed with end-diastolic wall thickness ≥15 mm. (orig.)

  8. The Improvement of Torsion Assessed by Cardiovascular Magnetic Resonance Feature Tracking after Coronary Artery Bypass Grafting: A Sensitive Index of Cardiac Function.

    Science.gov (United States)

    Cheng, Nan; Cheng, Liuquan; Wang, Rong; Zhang, Lin; Gao, Changqing

    2017-02-28

    The aim of this study was to quantify left ventricular torsion by newly applied cardiovascular magnetic resonance feature tracking (CMR-FT), and to evaluate the clinical value of the ventricular torsion as a sensitive indicator of cardiac function by comparison of preoperative and postoperative torsion. A total of 54 volunteers and 36 patients with previous myocardial infarction (MI) and LV ejection fraction (EF) between 30%-50% were screened preoperatively or postoperatively by MRI. The patients' short axis views of the whole heart were acquired, and all patients had a scar area >75% in at least one of the anterior or inferior segments. Their apical and basal rotation values were analyzed by feature tracking, and the correlation analysis was performed for the improvement of LV torsion and ejection fraction after CABG. The intra- and inter-observer reliabilities of torsion measured by CMR-FT were assessed. In normal hearts, the apex rotated counterclockwise in the systolic period with the peak rotation as 10.2 ± 4.8°, and the base rotated clockwise as the peak value was 7.0 ± 3.3°. There was a timing hiatus between the apex and base untwisting, during which period the heart recoils and its suction sets the stage for the following rapid filling period. The postoperative torsion and rotation significantly improved compared with preoperative ones. However, the traditional indicator of cardiac function, ejection fraction, didn't show significant improvement. Left ventricular torsion derived from CMR-FT, which does not require specialized CMR sequences, was sensitive to patients with low ejection fraction whose cardiac function significantly improved after CABG. The rapid acquisition of this measurement has potential for the assessment of cardiac function in clinical practice.

  9. The added value of longitudinal black-blood cardiovascular magnetic resonance angiography in the cross sectional identification of carotid atherosclerotic ulceration

    Directory of Open Access Journals (Sweden)

    Hippe Daniel S

    2009-08-01

    Full Text Available Abstract Background Carotid atherosclerotic ulceration is a significant source of stroke. This study evaluates the efficacy of adding longitudinal black-blood (BB cardiovascular magnetic resonance (CMR angiography to cross-sectional CMR images in the identification of carotid atherosclerotic ulceration. Methods Thirty-two subjects (30 males and two females with ages between 48 and 83 years scheduled for carotid endarterectomy were imaged on a 1.5T GE Signa scanner using multisequence [3D time-of-flight, T1, proton density, T2, contrast enhanced T1], cross-sectional CMR images and longitudinal BB CMR angiography (0.625 × 0.625 mm/pixel. Two rounds of review (round 1: cross-sectional CMR images alone and round 2: cross-sectional CMR images plus longitudinal BB CMR angiography were conducted for the presence and volume measurements of ulceration. Ulceration was defined as a distinct depression into the plaque containing blood flow signal on cross-sectional CMR and longitudinal BB CMR angiography. Results Of the 32 plaques examined by histology, 17 contained 21 ulcers. Using the longitudinal BB CMR angiography sequence in addition to the cross-sectional CMR images in round 2, the sensitivity improved to 80% for ulcers of at least 6 mm3 in volume by histology and 52.4% for all ulcers, compared to 30% and 23.8% in round 1, respectively. There was a slight decline in specificity from 88.2% to 82.3%, though both the positive and negative predictive values increased modestly from 71.4% to 78.6% and from 48.4% to 58.3%, respectively. Conclusion The addition of longitudinal BB CMR angiography to multisequence cross-sectional CMR images increases accuracy in the identification of carotid atherosclerotic ulceration.

  10. Towards real-time cardiovascular magnetic resonance-guided transarterial aortic valve implantation: In vitro evaluation and modification of existing devices

    Directory of Open Access Journals (Sweden)

    Ladd Mark E

    2010-10-01

    Full Text Available Abstract Background Cardiovascular magnetic resonance (CMR is considered an attractive alternative for guiding transarterial aortic valve implantation (TAVI featuring unlimited scan plane orientation and unsurpassed soft-tissue contrast with simultaneous device visualization. We sought to evaluate the CMR characteristics of both currently commercially available transcatheter heart valves (Edwards SAPIEN™, Medtronic CoreValve® including their dedicated delivery devices and of a custom-built, CMR-compatible delivery device for the Medtronic CoreValve® prosthesis as an initial step towards real-time CMR-guided TAVI. Methods The devices were systematically examined in phantom models on a 1.5-Tesla scanner using high-resolution T1-weighted 3D FLASH, real-time TrueFISP and flow-sensitive phase-contrast sequences. Images were analyzed for device visualization quality, device-related susceptibility artifacts, and radiofrequency signal shielding. Results CMR revealed major susceptibility artifacts for the two commercial delivery devices caused by considerable metal braiding and precluding in vivo application. The stainless steel-based Edwards SAPIEN™ prosthesis was also regarded not suitable for CMR-guided TAVI due to susceptibility artifacts exceeding the valve's dimensions and hindering an exact placement. In contrast, the nitinol-based Medtronic CoreValve® prosthesis was excellently visualized with delineation even of small details and, thus, regarded suitable for CMR-guided TAVI, particularly since reengineering of its delivery device toward CMR-compatibility resulted in artifact elimination and excellent visualization during catheter movement and valve deployment on real-time TrueFISP imaging. Reliable flow measurements could be performed for both stent-valves after deployment using phase-contrast sequences. Conclusions The present study shows that the Medtronic CoreValve® prosthesis is potentially suited for real-time CMR-guided placement

  11. The 3-Dimensional q-Deformed Harmonic Oscillator and Magic Numbers of Alkali Metal Clusters

    CERN Document Server

    Bonatsos, Dennis; Raychev, P P; Roussev, R P; Terziev, P A; Bonatsos, Dennis

    1999-01-01

    Magic numbers predicted by a 3-dimensional q-deformed harmonic oscillator with Uq(3) > SOq(3) symmetry are compared to experimental data for alkali metal clusters, as well as to theoretical predictions of jellium models, Woods--Saxon and wine bottle potentials, and to the classification scheme using the 3n+l pseudo quantum number. The 3-dimensional q-deformed harmonic oscillator correctly predicts all experimentally observed magic numbers up to 1500 (which is the expected limit of validity for theories based on the filling of electronic shells), thus indicating that Uq(3), which is a nonlinear extension of the U(3) symmetry of the spherical (3-dimensional isotropic) harmonic oscillator, is a good candidate for being the symmetry of systems of alkali metal clusters.

  12. Application of 3-Dimensional Printing Technology to Kirschner Wire Fixation of Adolescent Condyle Fracture.

    Science.gov (United States)

    Dong, Zhiwei; Li, Qihong; Bai, Shizhu; Zhang, Li

    2015-10-01

    Condyle fractures are common in children and are increasingly treated with open reduction. Three-dimensional printing has developed into an important method of assisting surgical treatment. This report describes the case of a 14-year-old patient treated for a right condyle fracture at the authors' hospital. Preoperatively, the authors designed a surgical guide using 3-dimensional printing and virtual surgery. The 3-dimensional surgical guide allowed accurate alignment of the fracture using Kirschner wire without additional dissection and tissue injury. Kirschner wire fixation augmented by 3-dimensional printing technology produced a good outcome in this adolescent condyle fracture. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  13. Dual of 3-dimensional pure SU(2) Lattice Gauge Theory and the Ponzano-Regge Model

    CERN Document Server

    Anishetty, R; Sharatchandra, H S; Mathur, M; Anishetty, Ramesh; Cheluvaraja, Srinath; Mathur, Manu

    1993-01-01

    By carrying out character expansion and integration over all link variables, the partition function of 3-dimensional pure SU(2) lattice gauge theory is rewritten in terms of 6j symbols. The result is Ponzano-Regge model of 3-dimensional gravity with a term that explicitly breaks general coordinate invariance. Conversely, we show that dual of Ponzano-Regge model is an SU(2) lattice gauge theory where all plaquette variables are constrained to the identity matrix and therefore the model needs no further regularization. Our techniques are applicable to other models with non-abelian symmetries in any dimension and provide duality transform for the partition function.

  14. Regenerative material for aneurysm embolization A 3-dimensional culture system of fibroblasts and calcium alginate gel

    Institute of Scientific and Technical Information of China (English)

    Jingdong Zhang; Kan Xu; Jinlu Yu; Jun Wang; Qi Luo

    2011-01-01

    Calcium alginate gel (CAG) has been shown to successfully model aneurysm embolization within a short period of time. However, gradually degrading CAG potentially results in aneurysm recanalization.In the present study, a regenerative embolic material was designed by seeding rat fibroblasts in a CAG. The study investigated the feasibility of constructing a 3-dimensional culture system. The fibroblasts grew well and firmly attached to the CAG. CAG was conducive for fibroblast growth, and resulted in a 3-dimensional culture system. Results show that CAG can be used theoretically as a vascular, regenerative, embolic material.

  15. Comparison of 2-Dimensional and 3-Dimensional Metacarpal Fracture Plating Constructs Under Cyclic Loading.

    Science.gov (United States)

    Tannenbaum, Eric P; Burns, Geoffrey T; Oak, Nikhil R; Lawton, Jeffrey N

    2017-03-01

    Metacarpal fractures are commonly treated by a variety of means including casting or open reduction internal fixation when unacceptable alignment is present following attempted closed reduction. Dorsal plating with either single-row 2-dimensional or double-row 3-dimensional plates has been proposed. This study's purpose was to determine if there are any differences in fixation construct stability under cyclic loading and subsequent load to failure between the lower profile 3-dimensional and the larger 2-dimensional plates in a metacarpal fracture gap sawbone model. Thirty metacarpal cortico-cancellous synthetic bones were cut with a 1.75-mm gap between the 2 fragments simulating mid-diaphyseal fracture comminution. Half of the metacarpals were plated with 2.0-mm locking 2-dimensional plates and half with 1.5-mm locking 3-dimensional plates. The plated metacarpals were mounted into a materials testing apparatus and cyclically loaded under cantilever bending for 2,000 cycles at 70 N, then 2,000 cycles at 120 N, and finally monotonically loaded to failure. Throughout testing, fracture gap sizes were measured, failure modes were recorded, and construct strength and stiffness values were calculated. All 3-dimensional constructs survived both cyclic loading conditions. Ten (67%) 2-dimensional constructs survived both loading conditions, whereas 5 (33%) failed the 120-N loading at 1377 ± 363 cycles. When loaded to failure, the 3-dimensional constructs failed at 265 N ± 21 N, whereas the 2-dimensional constructs surviving cyclic loading failed at 190 N ± 17 N. The shorter, thinner 3-dimensional metacarpal plates demonstrated increased resistance to failure in a cyclic loading model and increased load to failure compared with the relatively longer, thicker 2-dimensional metacarpal plates. The lower-profile 3-dimensional metacarpal plate fixation demonstrated greater stability for early postoperative resistance than the thicker 2-dimensional fixation, whereas the smaller

  16. A customizable 3-dimensional digital atlas of the canary brain in multiple modalities

    DEFF Research Database (Denmark)

    Vellema, Michiel; Verschueren, Jacob; Van Meir, Vincent

    2011-01-01

    understanding of the brain anatomy is essential. Because traditional 2-dimensional brain atlases are limited in the information they can provide about the anatomy of the brain, here we present a 3-dimensional MRI-based atlas of the canary brain. Using multiple imaging protocols we were able to maximize...... the ideal orientation of the brain for stereotactic injections, electrophysiological recordings, and brain sectioning. The 3-dimensional canary brain atlas presented here is freely available and is easily adaptable to support many types of neurobiological studies, including anatomical, electrophysiological...

  17. 3-dimensional echocardiography and its role in preoperative mitral valve evaluation.

    Science.gov (United States)

    Andrawes, Michael N; Feinman, Jared W

    2013-05-01

    Echocardiography plays a key role in the preoperative evaluation of mitral valve disease. 3-dimensional echocardiography is a relatively new development that is being used more and more frequently in the evaluation of these patients. This article reviews the available literature comparing the use of this new technology to classic techniques in the assessment of mitral valve pathology. The authors also review some of the novel insights learned from 3-dimensional echocardiography and how they may be used in surgical decision making and planning.

  18. Fatigue behavior of carbon/epoxy composites reinforced with 3-Dimensional woven fabric

    Directory of Open Access Journals (Sweden)

    Mehmet Karahan

    2013-07-01

    Full Text Available This paper reports results of study of fatigue behavior of a non-crimp 3-dimensional woven carbon/epoxy composite in tension-tension fatigue. Infinite fatigue life limit corresponds to the load of 27.5 kN for fill direction. The damage under fatigue loading starts and develops from intersection of z-yarns and fill yarns. Since the z-yarns bonded the yarn layers, it is not seen the delaminastion damages. This indicate that for load carrying capacity and stiffness of 3-dimensional composites better than classic 2-dimensional textile composites.

  19. An application of the 3-dimensional q-deformed harmonic oscillator to the nuclear shell model

    CERN Document Server

    Raychev, P P; Lo-Iudice, N; Terziev, P A

    1998-01-01

    An analysis of the construction of a q-deformed version of the 3-dimensional harmonic oscillator, which is based on the application of q-deformed algebras, is presented. The results together with their applicability to the shell model are compared with the predictions of the modified harmonic oscillator.

  20. 3-Dimensional Cahn-Hilliard Equation with Concentration Dependent Mobility and Gradient Dependent Potential

    Institute of Scientific and Technical Information of China (English)

    Rui HUANG; Yang CAO

    2011-01-01

    In this paper we investigate the initial boundary value problem of Cahn-Hilliard equation with concentration dependent mobility and gradient dependent potential. By the energy method and the theory of Campanato spaces, we prove the existence and the uniqueness of classical solutions in 3-dimensional space.

  1. 3-dimensional orthodontics visualization system with dental study models and orthopantomograms

    Science.gov (United States)

    Zhang, Hua; Ong, S. H.; Foong, K. W. C.; Dhar, T.

    2005-04-01

    The aim of this study is to develop a system that provides 3-dimensional visualization of orthodontic treatments. Dental plaster models and corresponding orthopantomogram (dental panoramic tomogram) are first digitized and fed into the system. A semi-auto segmentation technique is applied to the plaster models to detect the dental arches, tooth interstices and gum margins, which are used to extract individual crown models. 3-dimensional representation of roots, generated by deforming generic tooth models with orthopantomogram using radial basis functions, is attached to corresponding crowns to enable visualization of complete teeth. An optional algorithm to close the gaps between deformed roots and actual crowns by using multi-quadratic radial basis functions is also presented, which is capable of generating smooth mesh representation of complete 3-dimensional teeth. User interface is carefully designed to achieve a flexible system with as much user friendliness as possible. Manual calibration and correction is possible throughout the data processing steps to compensate occasional misbehaviors of automatic procedures. By allowing the users to move and re-arrange individual teeth (with their roots) on a full dentition, this orthodontic visualization system provides an easy and accurate way of simulation and planning of orthodontic treatment. Its capability of presenting 3-dimensional root information with only study models and orthopantomogram is especially useful for patients who do not undergo CT scanning, which is not a routine procedure in most orthodontic cases.

  2. 3-dimensional root phenotyping with a novel imaging and software platform

    Science.gov (United States)

    A novel imaging and software platform was developed for the high-throughput phenotyping of 3-dimensional root traits during seedling development. To demonstrate the platform’s capacity, plants of two rice (Oryza sativa) genotypes, Azucena and IR64, were grown in a transparent gellan gum system and ...

  3. Generation and Active Absorption of 2- and 3-Dimensional Linear Water Waves in Physical Models

    DEFF Research Database (Denmark)

    Christensen, Morten

    Methods for mechanical generation of 2-dimensional (2-D) and 3-dimensional (3-D) linear water waves in physical models are presented. The results of a series of laboratory 3-D wave generation tests are presented and discussed. The tests preformed involve reproduction of wave fields characterised...

  4. Cueing for freezing of gait: a need for 3-dimensional cues?

    NARCIS (Netherlands)

    Snijders, A.H.; Jeene, P.; Nijkrake, M.J.; Abdo, W.F.; Bloem, B.R.

    2012-01-01

    Visual cues can ameliorate freezing of gait, an incapacitating symptom frequently seen in patients with parkinsonism. Here, we describe a patient with severe freezing of gait, who responded well to 3-dimensional cues, but not to 2-dimensional visual cues. We discuss the potential implications of

  5. Investigation of Measurement Condition for 3-Dimensional Spectroscopy by Scanning Transmission X-ray Microscopy

    Science.gov (United States)

    Ohigashi, T.; Inagaki, Y.; Ito, A.; Shinohara, K.; Kosugi, N.

    2017-06-01

    A sample cell for performing computed tomography (CT) was developed. The 3-dimensional (3D) structure of polystyrene spheres was observed and the fluctuation of reconstructed linear absorption coefficients (LAC) was 9.3%. To improve the quality of data in 3D spectro-microscopy, required measurement condition is discussed.

  6. Full 3-dimensional digital workflow for multicomponent dental appliances A proof of concept

    NARCIS (Netherlands)

    Meer, van der Joerd; Vissink, Arjan; Ren, Yijin

    Background. The authors used a 3-dimensional (3D) printer and a bending robot to produce a multicomponent dental appliance to assess whether 3D digital models of the dentition are applicable for a full digital workflow. Methods. The authors scanned a volunteer's dentition with an intraoral scanner

  7. Design of Biphasic Polymeric 3-Dimensional Fiber Deposited Scaffolds for Cartilage Tissue Engineering Applications

    NARCIS (Netherlands)

    Moroni, L.; Hendriks, J.A.A.; Schotel, R.; Wijn, de J.R.; Blitterswijk, van C.A.

    2007-01-01

    This report describes a novel system to create rapid prototyped 3-dimensional (3D) fibrous scaffolds with a shell-core fiber architecture in which the core polymer supplies the mechanical properties and the shell polymer acts as a coating providing the desired physicochemical surface properties. Pol

  8. Numerical Integration and Synchronization for the 3-Dimensional Metriplectic Volterra System

    Directory of Open Access Journals (Sweden)

    Gheorghe Ivan

    2011-01-01

    Full Text Available The main purpose of this paper is to study the metriplectic system associated to 3-dimensional Volterra model. For this system we investigate the stability problem and numerical integration via Kahan's integrator. Finally, the synchronization problem for two coupled metriplectic Volterra systems is discussed.

  9. Reproducibility of a 3-dimensional gyroscope in measuring shoulder anteflexion and abduction

    NARCIS (Netherlands)

    Penning, L.I.F.; Guldemond, N.A.; De Bie, R.A.; Walenkamp, G.H.I.M.

    2012-01-01

    Background: Few studies have investigated the use of a 3-dimensional gyroscope for measuring the range of motion (ROM) in the impaired shoulder. Reproducibility of digital inclinometer and visual estimation is poor. This study aims to investigate the reproducibility of a tri axial gyroscope in measu

  10. 3-Dimensional and Interactive Istanbul University Virtual Laboratory Based on Active Learning Methods

    Science.gov (United States)

    Ince, Elif; Kirbaslar, Fatma Gulay; Yolcu, Ergun; Aslan, Ayse Esra; Kayacan, Zeynep Cigdem; Alkan Olsson, Johanna; Akbasli, Ayse Ceylan; Aytekin, Mesut; Bauer, Thomas; Charalambis, Dimitris; Gunes, Zeliha Ozsoy; Kandemir, Ceyhan; Sari, Umit; Turkoglu, Suleyman; Yaman, Yavuz; Yolcu, Ozgu

    2014-01-01

    The purpose of this study is to develop a 3-dimensional interactive multi-user and multi-admin IUVIRLAB featuring active learning methods and techniques for university students and to introduce the Virtual Laboratory of Istanbul University and to show effects of IUVIRLAB on students' attitudes on communication skills and IUVIRLAB. Although…

  11. Full 3-dimensional digital workflow for multicomponent dental appliances A proof of concept

    NARCIS (Netherlands)

    Meer, van der Joerd; Vissink, Arjan; Ren, Yijin

    2016-01-01

    Background. The authors used a 3-dimensional (3D) printer and a bending robot to produce a multicomponent dental appliance to assess whether 3D digital models of the dentition are applicable for a full digital workflow. Methods. The authors scanned a volunteer's dentition with an intraoral scanner (

  12. On Maximal Surfaces in Certain Non-Flat 3-Dimensional Robertson-Walker Spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Romero, Alfonso, E-mail: aromero@ugr.es [Universidad de Granada, Departamento de Geometria y Topologia (Spain); Rubio, Rafael M., E-mail: rmrubio@uco.es [Universidad de Cordoba, Departamento de Matematicas, Campus de Rabanales (Spain)

    2012-09-15

    An upper bound for the integral, on a geodesic disc, of the squared length of the gradient of a distinguished function on any maximal surface in certain non-flat 3-dimensional Robertson-Walker spacetimes is obtained. As an application, a new proof of a known Calabi-Bernstein's theorem is given.

  13. On an asymptotic distribution of dependent random variables on a 3-dimensional lattice✩

    Science.gov (United States)

    Harvey, Danielle J.; Weng, Qian; Beckett, Laurel A.

    2010-01-01

    We define conditions under which sums of dependent spatial data will be approximately normally distributed. A theorem on the asymptotic distribution of a sum of dependent random variables defined on a 3-dimensional lattice is presented. Examples are also presented. PMID:20436940

  14. MAGNET

    CERN Multimedia

    by B. Curé

    2011-01-01

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

  15. Estimating 3-Dimensional Structure of Tropical Forests from Radar Interferometry / Estimativa da Estrutura 3-Dimensional das Florestas Tropicais Através de Interferometria de Radar

    Directory of Open Access Journals (Sweden)

    Robert Treuhaft

    2006-10-01

    Full Text Available This paper describes the retrieval of 3-dimensional vegetation density profiles from interferometric synthetic aperture radar (InSAR using physical models. InSAR’s sensitivity to vertical structure is generally regarded as less direct and more difficult to understand than that of lidar. But InSAR’s coverage is superior to that of lidar, suggesting InSAR is more promising as an important component of a global 3-dimensional forest monitoring technique. The goal of this paper is to introduce, simplify and demystify the use of simple physical models to understand InSAR. A general equation expressing the InSAR observation in terms of density is described heuristically, along with the approximations in its development. The information content of the equation leads to the estimation of density parameters. Preliminary results are shown from a multibaseline C-band (wavelength=0.056 m vertical-polarization interferometer, realized with AirSAR flown at multiple altitudes over primary, secondary, and selectively logged tropical forests, as well as abandoned pastures at La Selva Biological Station in Costa Rica.

  16. Topological entropy and renormalization group flow in 3-dimensional spherical spaces

    Energy Technology Data Exchange (ETDEWEB)

    Asorey, M. [Departamento de Física Teórica, Universidad de Zaragoza,E-50009 Zaragoza (Spain); Beneventano, C.G. [Departamento de Física, Universidad Nacional de La Plata,Instituto de Física de La Plata, CONICET-Universidad Nacional de La Plata,C.C. 67, 1900 La Plata (Argentina); Cavero-Peláez, I. [Departamento de Física Teórica, Universidad de Zaragoza,E-50009 Zaragoza (Spain); CUD,E-50090, Zaragoza (Spain); D’Ascanio, D.; Santangelo, E.M. [Departamento de Física, Universidad Nacional de La Plata,Instituto de Física de La Plata, CONICET-Universidad Nacional de La Plata,C.C. 67, 1900 La Plata (Argentina)

    2015-01-15

    We analyze the renormalization group (RG) flow of the temperature independent term of the entropy in the high temperature limit β/a≪1 of a massive field theory in 3-dimensional spherical spaces, M{sub 3}, with constant curvature 6/a{sup 2}. For masses lower than ((2π)/β), this term can be identified with the free energy of the same theory on M{sub 3} considered as a 3-dimensional Euclidean space-time. The non-extensive part of this free energy, S{sub hol}, is generated by the holonomy of the spatial metric connection. We show that for homogeneous spherical spaces the holonomy entropy S{sub hol} decreases monotonically when the RG scale flows to the infrared. At the conformal fixed points the values of the holonomy entropy do coincide with the genuine topological entropies recently introduced. The monotonic behavior of the RG flow leads to an inequality between the topological entropies of the conformal field theories connected by such flow, i.e. S{sub top}{sup UV}>S{sub top}{sup IR}. From a 3-dimensional viewpoint the same term arises in the 3-dimensional Euclidean effective action and has the same monotonic behavior under the RG group flow. We conjecture that such monotonic behavior is generic, which would give rise to a 3-dimensional generalization of the c-theorem, along the lines of the 2-dimensional c-theorem and the 4-dimensional a-theorem. The conjecture is related to recent formulations of the F-theorem. In particular, the holonomy entropy on lens spaces is directly related to the topological Rényi entanglement entropy on disks of 2-dimensional flat spaces.

  17. Topological entropy and renormalization group flow in 3-dimensional spherical spaces

    Science.gov (United States)

    Asorey, M.; Beneventano, C. G.; Cavero-Peláez, I.; D'Ascanio, D.; Santangelo, E. M.

    2015-01-01

    We analyze the renormalization group (RG) flow of the temperature independent term of the entropy in the high temperature limit β/a ≪ 1 of a massive field theory in 3-dimensional spherical spaces, M 3, with constant curvature 6 /a 2. For masses lower than , this term can be identified with the free energy of the same theory on M 3 considered as a 3-dimensional Euclidean space-time. The non-extensive part of this free energy, S hol, is generated by the holonomy of the spatial metric connection. We show that for homogeneous spherical spaces the holonomy entropy S hol decreases monotonically when the RG scale flows to the infrared. At the conformal fixed points the values of the holonomy entropy do coincide with the genuine topological entropies recently introduced. The monotonic behavior of the RG flow leads to an inequality between the topological entropies of the conformal field theories connected by such flow, i.e. S {top/ UV } > S {top/ IR }. From a 3-dimensional viewpoint the same term arises in the 3-dimensional Euclidean effective action and has the same monotonic behavior under the RG group flow. We conjecture that such monotonic behavior is generic, which would give rise to a 3-dimensional generalization of the c-theorem, along the lines of the 2-dimensional c-theorem and the 4-dimensional a-theorem. The conjecture is related to recent formulations of the F -theorem. In particular, the holonomy entropy on lens spaces is directly related to the topological Rényi entanglement entropy on disks of 2-dimensional flat spaces.

  18. Accelerated cardiovascular magnetic resonance of the mouse heart using self-gated parallel imaging strategies does not compromise accuracy of structural and functional measures

    Directory of Open Access Journals (Sweden)

    Dörries Carola

    2010-07-01

    Full Text Available Abstract Background Self-gated dynamic cardiovascular magnetic resonance (CMR enables non-invasive visualization of the heart and accurate assessment of cardiac function in mouse models of human disease. However, self-gated CMR requires the acquisition of large datasets to ensure accurate and artifact-free reconstruction of cardiac cines and is therefore hampered by long acquisition times putting high demands on the physiological stability of the animal. For this reason, we evaluated the feasibility of accelerating the data collection using the parallel imaging technique SENSE with respect to both anatomical definition and cardiac function quantification. Results Findings obtained from accelerated data sets were compared to fully sampled reference data. Our results revealed only minor differences in image quality of short- and long-axis cardiac cines: small anatomical structures (papillary muscles and the aortic valve and left-ventricular (LV remodeling after myocardial infarction (MI were accurately detected even for 3-fold accelerated data acquisition using a four-element phased array coil. Quantitative analysis of LV cardiac function (end-diastolic volume (EDV, end-systolic volume (ESV, stroke volume (SV, ejection fraction (EF and LV mass in healthy and infarcted animals revealed no substantial deviations from reference (fully sampled data for all investigated acceleration factors with deviations ranging from 2% to 6% in healthy animals and from 2% to 8% in infarcted mice for the highest acceleration factor of 3.0. CNR calculations performed between LV myocardial wall and LV cavity revealed a maximum CNR decrease of 50% for the 3-fold accelerated data acquisition when compared to the fully-sampled acquisition. Conclusions We have demonstrated the feasibility of accelerated self-gated retrospective CMR in mice using the parallel imaging technique SENSE. The proposed method led to considerably reduced acquisition times, while preserving high

  19. Impact of diastolic dysfunction severity on global left ventricular volumetric filling - assessment by automated segmentation of routine cine cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Mendoza Dorinna D

    2010-07-01

    Full Text Available Abstract Objectives To examine relationships between severity of echocardiography (echo -evidenced diastolic dysfunction (DD and volumetric filling by automated processing of routine cine cardiovascular magnetic resonance (CMR. Background Cine-CMR provides high-resolution assessment of left ventricular (LV chamber volumes. Automated segmentation (LV-METRIC yields LV filling curves by segmenting all short-axis images across all temporal phases. This study used cine-CMR to assess filling changes that occur with progressive DD. Methods 115 post-MI patients underwent CMR and echo within 1 day. LV-METRIC yielded multiple diastolic indices - E:A ratio, peak filling rate (PFR, time to peak filling rate (TPFR, and diastolic volume recovery (DVR80 - proportion of diastole required to recover 80% stroke volume. Echo was the reference for DD. Results LV-METRIC successfully generated LV filling curves in all patients. CMR indices were reproducible (≤ 1% inter-reader differences and required minimal processing time (175 ± 34 images/exam, 2:09 ± 0:51 minutes. CMR E:A ratio decreased with grade 1 and increased with grades 2-3 DD. Diastolic filling intervals, measured by DVR80 or TPFR, prolonged with grade 1 and shortened with grade 3 DD, paralleling echo deceleration time (p 80 identified 71% of patients with echo-evidenced grade 1 but no patients with grade 3 DD, and stroke-volume adjusted PFR identified 67% with grade 3 but none with grade 1 DD (matched specificity = 83%. The combination of DVR80 and PFR identified 53% of patients with grade 2 DD. Prolonged DVR80 was associated with grade 1 (OR 2.79, CI 1.65-4.05, p = 0.001 with a similar trend for grade 2 (OR 1.35, CI 0.98-1.74, p = 0.06, whereas high PFR was associated with grade 3 (OR 1.14, CI 1.02-1.25, p = 0.02 DD. Conclusions Automated cine-CMR segmentation can discern LV filling changes that occur with increasing severity of echo-evidenced DD. Impaired relaxation is associated with prolonged

  20. Comparison of long and short axis quantification of left ventricular volume parameters by cardiovascular magnetic resonance, with ex-vivo validation

    Directory of Open Access Journals (Sweden)

    Childs Helene

    2011-08-01

    Full Text Available Abstract Background The purpose of the study was to compare the accuracy and evaluation time of quantifying left ventricular (LV, left atrial (LA volume and LV mass using short axis (SAX and long axis (LAX methods when using cardiovascular magnetic resonance (CMR. Materials and methods We studied 12 explanted canine hearts and 46 patients referred for CMR (29 male, age 47 ± 18 years in a clinical 1.5 T CMR system, using standard cine sequences. In standard short axis stacks of various slice thickness values in dogs and 8 mm slice thickness (gap 2 mm in patients, we measured LV volumes using reference slices in a perpendicular, long axis orientation using certified software. Volumes and mass were also measured in six radial long axis (LAX views. LV parameters were also assessed for intra- and inter-observer variability. In 24 patients, we also analyzed reproducibility and evaluation time of two very experienced (> 10 years of CMR reading readers for SAX and LAX. Results In the explanted dog hearts, there was excellent agreement between ex vivo data and LV mass and volume data as measured by all methods for both, LAX (r2 = 0.98 and SAX (r2 = 0.88 to 0.98. LA volumes, however, were underestimated by 13% using the LAX views. In patients, there was a good correlation between all three assessed methods (r2 ≥ 0.95 for all. In experienced clinical readers, left-ventricular volumes and ejection fraction as measured in LAX views showed a better inter-observer reproducibility and a 27% shorter evaluation time. Conclusion When compared to an ex vivo standard, both, short axis and long axis techniques are highly accurate for the quantification of left ventricular volumes and mass. In clinical settings, however, the long axis approach may be more reproducible and more time-efficient. Therefore, the rotational long axis approach is a viable alternative for the clinical assessment of cardiac volumes, function and mass.

  1. Effects of slice orientation on reproducibility of sequential assessment of right ventricular volumes and ejection fraction: short-axis vs transverse SSFP cine cardiovascular magnetic resonance.

    Science.gov (United States)

    D'Errico, Luigia; Lamacie, Mariana M; Jimenez Juan, Laura; Deva, Djeven; Wald, Rachel M; Ley, Sebastian; Hanneman, Kate; Thavendiranathan, Paaladinesh; Wintersperger, Bernd J

    2016-09-22

    Test-retest reproducibility is of utmost importance in follow-up of right ventricular (RV) volumes and function; optimal slice orientation though is not yet known. We compared test-retest reproducibility and intra-/inter-observer variability of right ventricular (RV) volumes and function assessed with short-axis and transverse cardiovascular magnetic resonance (CMR). Eighteen volunteers underwent cine CMR for RV assessment obtaining ventricular coverage in short-axis and transverse slice orientation. Additional 2D phase contrast flow imaging of the main pulmonary artery (MPA) was performed. After complete repositioning repeat acquisitions were performed. Data sets were contoured by two blinded observers. Statistical analysis included Student's t-test, Bland-Altman plots, intra-class correlation coefficient (ICC) and 2-way ANOVA, SEM and minimal detectable difference calculations. Heart rates (65.0 ± 7.4 vs. 67.6 ± 9.9 bpm; P = 0.1) and MPA flow (89.8 ± 16.6 vs. 87.2 ± 14.9 mL; P = 0.1) did not differ between imaging sessions. EDV and ESV demonstrated an inter-study bias of 0.4 %[-9.5 %,10.3 %] and 2.1 %[-12.3 %,16.4 %] for short-axis and 1.1 %[-7.3 %,9.4 %] and 0.8 %[-16.0 %,17.6 %] for transverse orientation, respectively. There was no significant interaction between imaging orientation and interstudy reproducibility (p = 0.395-0.824), intra-observer variability (p = 0.726-0.862) or inter-observer variability (p = 0.447-0.706) by 2-way ANOVA. Inter-observer agreement by ICC was greater for short axis versus transverse orientation for all parameters (0.769-0.986 vs. 0.625-0.983, respectively). Minimal detectable differences for short axis and transverse orientations were 10.1 mL/11.5 mL for EDV, 8.3 mL/8.4 mL for ESV and 4.1 % vs. 4.7 % for EF, respectively. Short-axis and transverse orientation both provide reliable and reproducible measures for follow-up of RV volumes and global function. Therefore

  2. Cardiovascular pharmacogenetics.

    Science.gov (United States)

    Myburgh, Renier; Hochfeld, Warren E; Dodgen, Tyren M; Ker, James; Pepper, Michael S

    2012-03-01

    Human genetic variation in the form of single nucleotide polymorphisms as well as more complex structural variations such as insertions, deletions and copy number variants, is partially responsible for the clinical variation seen in response to pharmacotherapeutic drugs. This affects the likelihood of experiencing adverse drug reactions and also of achieving therapeutic success. In this paper, we review key studies in cardiovascular pharmacogenetics that reveal genetic variations underlying the outcomes of drug treatment in cardiovascular disease. Examples of genetic associations with drug efficacy and toxicity are described, including the roles of genetic variability in pharmacokinetics (e.g. drug metabolizing enzymes) and pharmacodynamics (e.g. drug targets). These findings have functional implications that could lead to the development of genetic tests aimed at minimizing drug toxicity and optimizing drug efficacy in cardiovascular medicine.

  3. Efficacy of 3-Dimensional Endorectal Ultrasound for Staging Early Extraperitoneal Rectal Neoplasms.

    Science.gov (United States)

    Pinto, Rodrigo Ambar; Corrêa Neto, Isaac José Felippe; Nahas, Sérgio Carlos; Rizkalah Nahas, Caio Sérgio; Sparapan Marques, Carlos Frederico; Ribeiro Junior, Ulysses; Kawaguti, Fábio Shiguehissa; Cecconello, Ivan

    2017-05-01

    Adequate oncologic staging of rectal neoplasia is important for treatment and prognostic evaluation of the disease. Diagnostic methods such as endorectal ultrasound can assess rectal wall invasion and lymph node involvement. The purpose of this study was to correlate findings of 3-dimensional endorectal ultrasound and pathologic diagnosis of extraperitoneal rectal tumors with regard to depth of rectal wall invasion, lymph node involvement, percentage of rectal circumference involvement, and tumor extension. Consecutive patients with extraperitoneal rectal tumors were prospectively assessed by 3-dimensional endorectal ultrasound blind to other staging methods and pathologic diagnosis. Patients who underwent endorectal ultrasound followed by surgery were included in the study. The study was conducted at a single academic institution. Sensitivity, specificity, positive and negative predictive values, area under curve, and κ coefficient between 3-dimensional endorectal ultrasound and pathologic diagnosis were determined. Intraclass correlation coefficient was calculated for tumor extension and percentage of rectal wall involvement. Forty-four patients (27 women; mean age = 63.5 years) were evaluated between September 2010 and June 2014. Most lesions were malignant (72.7%). For depth of submucosal invasion, 3-dimensional endorectal ultrasound showed sensitivity of 77.3%, specificity of 86.4%, positive predictive value of 85.0%, a negative predictive value of 79.2%, and an area under curve of 0.82. The weighted κ coefficient for depth of rectal wall invasion staging was 0.67, and there was no agreement between 3-dimensional endorectal ultrasound and pathologic diagnosis for lymph node involvement (κ = -0.164). Intraclass correlation coefficient for lesion extension and percentage of rectal circumference involvement were 0.45 and 0.66. A better correlation between 3-dimensional endorectal ultrasound and pathologic diagnosis was observed in tumors <5 cm and with <50

  4. 3-dimensional versus conventional laparoscopy for benign hysterectomy: protocol for a randomized clinical trial.

    Science.gov (United States)

    Hoffmann, Elise; Bennich, Gitte; Larsen, Christian Rifbjerg; Lindschou, Jannie; Jakobsen, Janus Christian; Lassen, Pernille Danneskiold

    2017-09-07

    Hysterectomy is one of the most common surgical procedures for women of reproductive age. Laparoscopy was introduced in the 1990es and is today one of the recommended routes of surgery. A recent observational study showed that operative time for hysterectomy was significantly lower for 3-dimensional compared to conventional laparoscopy. Complication rates were similar for the two groups. No other observational studies or randomized clinical trials have compared 3-dimensional to conventional laparoscopy in patients undergoing total hysterectomy for benign disease. The objective of the study is to determine if 3D laparoscopy gives better quality of life, less postoperative pain, less per- and postoperative complications, shorter operative time, or a shorter stay in hospital and a faster return to work or normal life, compared to conventional laparoscopy for benign hysterectomy. The design is a randomised multicentre clinical trial. Participants will be 400 women referred for laparoscopic hysterectomy for benign indications. Patients will be randomized to 3-dimensional or conventional laparoscopic hysterectomy. Operative procedures will follow the same principles and the same standard whether the surgeon's vision is 3-dimensional or conventional laparoscopy. Primary outcomes will be the impact of surgery on quality of life, assessed by the SF 36 questionnaire, and postoperative pain, assessed by a Visual Analogue scale for pain measurement. With a standard deviation of 12 points on SF 36 questionnaire, a risk of type I error of 3.3% and a risk of type II error of 10% a sample size of 190 patients in each arm of the trial is needed. Secondarily, we will investigate operative time, time to return to work, length of hospital stay, and - and postoperative complications. This trial will be the first randomized clinical trial investigating the potential clinical benefits and harms of 3-dimensional compared to conventional laparoscopy. The results may provide more evidence

  5. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

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

  6. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

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

  7. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

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

  8. Right Ventricular Volumes and Systolic Function by Cardiac Magnetic Resonance and the Impact of Sex, Age, and Obesity in a Longitudinally Followed Cohort Free of Pulmonary and Cardiovascular Disease: The Framingham Heart Study.

    Science.gov (United States)

    Foppa, Murilo; Arora, Garima; Gona, Philimon; Ashrafi, Arman; Salton, Carol J; Yeon, Susan B; Blease, Susan J; Levy, Daniel; O'Donnell, Christopher J; Manning, Warren J; Chuang, Michael L

    2016-03-01

    Cardiac magnetic resonance is uniquely well suited for noninvasive imaging of the right ventricle. We sought to define normal cardiac magnetic resonance reference values and to identify the main determinants of right ventricular (RV) volumes and systolic function using a modern imaging sequence in a community-dwelling, longitudinally followed cohort free of clinical cardiovascular and pulmonary disease. The Framingham Heart Study Offspring cohort has been followed since 1971. We scanned 1794 Offspring cohort members using steady-state free precession cardiac magnetic resonance and identified a reference group of 1336 adults (64±9 years, 576 men) free of prevalent cardiovascular and pulmonary disease. RV trabeculations and papillary muscles were considered cavity volume. Men had greater RV volumes and cardiac output before and after indexation to body size (all P<0.001). Women had higher RV ejection fraction than men (68±6% versus 64±7%; P<0.0001). RV volumes and cardiac output decreased with advancing age. There was an increase in raw and height-indexed RV measurements with increasing body mass index, but this trend was weakly inverted after indexation of RV volumes to body surface area. Sex, age, height, body mass index, and heart rate account for most of the variability in RV volumes and function in this community-dwelling population. We report sex-specific normative values for RV measurements among principally middle-aged and older adults. RV ejection fraction is greater in women. RV volumes increase with body size, are greater in men, and are smaller in older people. Body surface area seems to be appropriate for indexation of cardiac magnetic resonance-derived RV volumes. © 2016 American Heart Association, Inc.

  9. Construction of 3-Dimensional Printed Ultrasound Phantoms With Wall-less Vessels.

    Science.gov (United States)

    Nikitichev, Daniil I; Barburas, Anamaria; McPherson, Kirstie; Mari, Jean-Martial; West, Simeon J; Desjardins, Adrien E

    2016-06-01

    Ultrasound phantoms are invaluable as training tools for vascular access procedures. We developed ultrasound phantoms with wall-less vessels using 3-dimensional printed chambers. Agar was used as a soft tissue-mimicking material, and the wall-less vessels were created with rods that were retracted after the agar was set. The chambers had integrated luer connectors to allow for fluid injections with clinical syringes. Several variations on this design are presented, which include branched and stenotic vessels. The results show that 3-dimensional printing can be well suited to the construction of wall-less ultrasound phantoms, with designs that can be readily customized and shared electronically. © 2016 by the American Institute of Ultrasound in Medicine.

  10. A mathematical model of the discrete 3-disk for the 3-dimensional Universe

    CERN Document Server

    Yukawa, Tetsuyuki

    2015-01-01

    A mathematical model of the distribution function for the discrete 3-disk is proposed in order to utilize in the statistical evolution equation of the 3-dimensional Universe. The model distribution is constructed based on analyses in known exact solutions of recursion equations for the generating functions of the discrete 2-disk.The proposed distribution function is compared with numerical simulations of the dynamical triangulation with $ S^3 $, and $ D^3 $ topologies.The model distribution exhibits three types of phases characterized by geometrical nature of the disk with either 1, 2, or 3- dimensional structure.Transitions between those phases are either cross-over, 1st order, or 2nd order depending on the parameters, which reflect the type of discretization and matter fields coupled to space.

  11. Intraoperative 3-Dimensional Computed Tomography and Navigation in Foot and Ankle Surgery.

    Science.gov (United States)

    Chowdhary, Ashwin; Drittenbass, Lisca; Dubois-Ferrière, Victor; Stern, Richard; Assal, Mathieu

    2016-09-01

    Computer-assisted orthopedic surgery has developed dramatically during the past 2 decades. This article describes the use of intraoperative 3-dimensional computed tomography and navigation in foot and ankle surgery. Traditional imaging based on serial radiography or C-arm-based fluoroscopy does not provide simultaneous real-time 3-dimensional imaging, and thus leads to suboptimal visualization and guidance. Three-dimensional computed tomography allows for accurate intraoperative visualization of the position of bones and/or navigation implants. Such imaging and navigation helps to further reduce intraoperative complications, leads to improved surgical outcomes, and may become the gold standard in foot and ankle surgery. [Orthopedics.2016; 39(5):e1005-e1010.]. Copyright 2016, SLACK Incorporated.

  12. Born-Infeld determinantal gravity and the taming of the conical singularity in 3-dimensional spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Ferraro, Rafael, E-mail: ferraro@iafe.uba.a [Instituto de Astronomia y Fisica del Espacio, Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina); Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina); Fiorini, Franco, E-mail: franco@iafe.uba.a [Instituto de Astronomia y Fisica del Espacio, Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina)

    2010-08-30

    In the context of Born-Infeld determinantal gravity formulated in an n-dimensional spacetime with absolute parallelism, we found an exact 3-dimensional vacuum circular symmetric solution without cosmological constant consisting in a rotating spacetime with non-singular behavior. The space behaves at infinity as the conical geometry typical of 3-dimensional General Relativity without cosmological constant. However, the solution has no conical singularity because the space ends at a minimal circle that no freely falling particle can ever reach in a finite proper time. The space is curved, but no divergences happen since the curvature invariants vanish at both asymptotic limits. Remarkably, this very mechanism also forbids the existence of closed timelike curves in such a spacetime.

  13. 3-dimensional slope stability analyses using non-associative stress-strain relationships

    Institute of Scientific and Technical Information of China (English)

    CHEN ZuYu; SUN Ping; WANG YuJie; ZHANG HongTao

    2009-01-01

    The research work presented in this paper refers to a new slope stability analysis method used for landslide risk evaluations. It is an extension of the 3-dimensional upper-bound slope stability analysis method proposed by Chen et sl. in 2001, which employs the Mohr-Coulomb's associative flow rule. It has been found that in a 3-dimensional area, a prism may not be able to move at friction angles to all its surrounding interfaces, as required by this associative rule, and convergence problems may occa-sionally arise. The new method establishes two velocity fields: (i) The plastic one that represents a non-associative and the best representative dilation behavior, and (ii) the virtual one that permits the solution for factor of safety in the work and energy balance equation. The new method can then allow any input value of dilation angle and thus solve the convergence problem. A practical application to a concrete dam foundation is illustrated.

  14. DYNAMICAL CONSISTENCE IN 3-DIMENSIONAL TYPE-K COMPETITIVE LOTKA-VOLTERRA SYSTEM

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    A 3-dimensional type-K competitive Lotka-Volterra system is considered in this paper. Two discretization schemes are applied to the system with an positive interior fixed point, and two corresponding discrete systems are obtained. By analyzing the local dynamics of the corresponding discrete system near the interior fixed point, it is showed that this system is not dynamically consistent with the continuous counterpart system.

  15. Experimental evaluation of 3-dimensional kinematic behavior of the cruciate ligaments

    OpenAIRE

    2007-01-01

    PURPOSE: The purpose of this study was to evaluate a low-cost and easily reproducible technique for biomechanical studies in cadavers. In this kind of study, the natural effect of loading of the joint and shear forces are not taken into account. The objective is to describe the plastic deformation of the ligaments into 3-dimensional space. METHOD: For 18 intact human cadaver knees, the cruciate ligaments were divided into 3 fiber bundles, the tibial or femoral fixation points were marked, and...

  16. On the structure of 3-dimensional 2-body problem solutions in Wheeler-Feynman electrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Klimenko, S. [Institute for High Energy Physics, Protvino (Russian Federation); Nikitin, I. [National Research Center for Information Technology, St. Augustin (Germany)

    2001-09-01

    The problem of the relativistic 3-dimensional motion of 2 oppositely charged equally massive particles in classical electrodynamics with half-retarded/half-advanced interactions is investigated. It is shown that at a certain critical energy value the topological structure of phase space is changed, leading to bifurcation (splitting) of solutions, appearance of extra non-Newtonian degrees of freedom and break of reflectional symmetries.

  17. SOME EXACT SOLUTIONS OF 3-DIMENSIONAL ZERO-PRESSURE GAS DYNAMICS SYSTEM

    Institute of Scientific and Technical Information of China (English)

    K.T.Joseph; Manas R. Sahoo

    2011-01-01

    The 3-dimensional zero-pressure gas dynamics system appears in the modeling for the large scale structure formation in the universe.The aim of this paper is to construct spherically symmetric solutions to the system.The radial component of the velocity and density satisfy a simpler one dimensional problem.First we construct explicit solutions of this one dimensional case with initial and boundary conditions.Then we get special radial solutions with different behaviours at the origin.

  18. Energy Sources of the Dominant Frequency Dependent 3-dimensional Atmospheric Modes

    Science.gov (United States)

    Schubert, S.

    1985-01-01

    The energy sources and sinks associated with the zonally asymmetric winter mean flow are investigated as part of an on-going study of atmospheric variability. Distinctly different horizontal structures for the long, intermediate and short time scale atmospheric variations were noted. In previous observations, the 3-dimensional structure of the fluctuations is investigated and the relative roles of barotropic and baroclinic terms are assessed.

  19. 3-Dimensional analysis for class III malocclusion patients with facial asymmetry

    OpenAIRE

    2013-01-01

    Objectives The aim of this study is to investigate the correlation between 2-dimensional (2D) cephalometric measurement and 3-dimensional (3D) cone beam computed tomography (CBCT) measurement, and to evaluate the availability of 3D analysis for asymmetry patients. Materials and Methods A total of Twenty-seven patients were evaluated for facial asymmetry by photograph and cephalometric radiograph, and CBCT. The 14 measurements values were evaluated and those for 2D and 3D were compared. The pa...

  20. Analysis of 3-dimensional finite element after reconstruction of impaired ankle deltoid ligament

    OpenAIRE

    Ji, Yunhan; Tang, Xianzhong; Li, Yifan; Xu, Wei; Qiu, Wenjun

    2016-01-01

    We compared four repair techniques for impaired ankle ligament deltoideum, namely Wiltberger, Deland, Kitaoka and Hintermann using a 3-dimensional finite element. We built an ankle ligament deltoideum model, including six pieces of bone structures, gristles and main ligaments around the ankle. After testing the model, we built an impaired ligament deltoideum model plus four reconstruction models. Subsequently, different levels of force on ankles with different flexion were imposed and ankle b...

  1. The Preoperative Evaluation of Infective Endocarditis via 3-Dimensional Transesophageal Echocardiography.

    Science.gov (United States)

    Yong, Matthew S; Saxena, Pankaj; Killu, Ammar M; Coffey, Sean; Burkhart, Harold M; Wan, Siu-Hin; Malouf, Joseph F

    2015-08-01

    Transesophageal echocardiography continues to have a central role in the diagnosis of infective endocarditis and its sequelae. Recent technological advances offer the option of 3-dimensional imaging in the evaluation of patients with infective endocarditis. We present an illustrative case and review the literature regarding the potential advantages and limitations of 3-dimensional transesophageal echocardiography in the diagnosis of complicated infective endocarditis. A 51-year-old man, an intravenous drug user who had undergone bioprosthetic aortic valve replacement 5 months earlier, presented with prosthetic valve endocarditis. Preoperative transesophageal echocardiography with 3D rendition revealed a large abscess involving the mitral aortic intervalvular fibrosa, together with a mycotic aneurysm that had ruptured into the left atrium, resulting in a left ventricle-to-left atrium fistula. Three-dimensional transesophageal echocardiography enabled superior preoperative anatomic delineation and surgical planning. We conclude that 3-dimensional transesophageal echocardiography can be a useful adjunct to traditional 2-dimensional transesophageal echocardiography as a tool in the diagnosis of infective endocarditis.

  2. The Neural Representation of 3-Dimensional Objects in Rodent Memory Circuits

    Science.gov (United States)

    Burke, Sara N.; Barnes, Carol A.

    2014-01-01

    Three-dimensional objects are common stimuli that rodents and other animals encounter in the natural world that contribute to the associations that are the hallmark of explicit memory. Thus, the use of 3-dimensional objects for investigating the circuits that support associative and episodic memories has a long history. In rodents, the neural representation of these types of stimuli is a polymodal process and lesion data suggest that the perirhinal cortex, an area of the medial temporal lobe that receives afferent input from all sensory modalities, is particularly important for integrating sensory information across modalities to support object recognition. Not surprisingly, recent data from in vivo electrophysiological recordings have shown that principal cells within the perirhinal cortex are activated at locations of an environment that contain 3-dimensional objects. Interestingly, it appears that neural activity patterns related to object stimuli are ubiquitous across memory circuits and have now been observed in many medial temporal lobe structures as well as in the anterior cingulate cortex. This review summarizes behavioral and neurophysiological data that examine the representation of 3-dimensional objects across brain regions that are involved in memory. PMID:25205370

  3. Candidate gene analyses of 3-dimensional dentoalveolar phenotypes in subjects with malocclusion.

    Science.gov (United States)

    Weaver, Cole A; Miller, Steven F; da Fontoura, Clarissa S G; Wehby, George L; Amendt, Brad A; Holton, Nathan E; Allareddy, Veeratrishul; Southard, Thomas E; Moreno Uribe, Lina M

    2017-03-01

    Genetic studies of malocclusion etiology have identified 4 deleterious mutations in genes DUSP6,ARHGAP21, FGF23, and ADAMTS1 in familial Class III cases. Although these variants may have large impacts on Class III phenotypic expression, their low frequency (3-dimensional dentoalveolar phenotypes in patients with malocclusion. Pretreatment dental casts or cone-beam computed tomographic images from 300 healthy subjects were digitized with 48 landmarks. The 3-dimensional coordinate data were submitted to a geometric morphometric approach along with principal component analysis to generate continuous phenotypes including symmetric and asymmetric components of dentoalveolar shape variation, fluctuating asymmetry, and size. The subjects were genotyped for 222 single-nucleotide polymorphisms in 82 genes/loci, and phenotpye-genotype associations were tested via multivariate linear regression. Principal component analysis of symmetric variation identified 4 components that explained 68% of the total variance and depicted anteroposterior, vertical, and transverse dentoalveolar discrepancies. Suggestive associations (P 3-dimensional dentoalveolar phenotypic variation in malocclusions were identified. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  4. Association between 3-dimensional mandibular morphology and condylar movement in subjects with mandibular asymmetry.

    Science.gov (United States)

    Ikeda, Michiyo; Miyamoto, Jun J; Takada, Jun-Ichi; Moriyama, Keiji

    2017-02-01

    The purpose of this study was to evaluate the hypothesis that 3-dimensional mandibular morphology is correlated with condylar movement in patients with mandibular asymmetry. Subjects were classified into 2 groups (n = 25 each): mandibular asymmetry with a menton deviation greater than 4 mm and no mandibular asymmetry with a menton deviation less than 4 mm. Linear and volumetric measurements of 3-dimensional mandibular morphology were recorded using computed tomography. Mandibular functional movement was recorded by computerized axiography (CADIAX; Gamma Dental, Klosterneuburg, Austria), and condylar path length, sagittal condylar inclination, and transverse condylar inclination on protrusion were measured. We calculated side-to-side asymmetry (shifted side vs nonshifted side) in mandibular morphology and assessed condylar movement by using an asymmetry ratio (nonshifted side/shifted side). Significant differences in mandibular morphology and condylar movement were found between the 2 groups. In the group with menton deviation greater than 4 mm, significant correlations were found between the asymmetry ratio of mandibular morphology and condylar movement: ie, condylar path length and transverse condylar inclination. No significant correlations were found between any of these measurements in the group with menton deviation less than 4 mm. In support of our hypothesis, the results suggested that 3-dimensional mandibular morphologic asymmetry is associated with condylar movement in subjects with mandibular asymmetry. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  5. Reconstructing a 3-dimensional image of the results of antinuclear antibody testing by indirect immunofluorescence.

    Science.gov (United States)

    Murai, Ryosei; Yamada, Koji; Tanaka, Maki; Kuribayashi, Kageaki; Kobayashi, Daisuke; Tsuji, Naoki; Watanabe, Naoki

    2013-01-31

    Indirect immunofluorescence anti-nuclear antibody testing (IIF-ANAT) is an essential screening tool in the diagnosis of various autoimmune disorders. ANA titer quantification and interpretation of immunofluorescence patterns are determined subjectively, which is problematic. First, we determined the examination conditions under which IIF-ANAT fluorescence intensities are quantified. Next, IIF-ANAT was performed using homogeneous, discrete speckled, and mixed serum samples. Images were obtained using Bio Zero BZ-8000, and 3-dimensional images were reconstructed using the BZ analyzer software. In the 2-dimensional analysis, homogeneous ANAs hid the discrete speckled pattern, resulting in a diagnosis of homogeneous immunofluorescence. However, 3-dimensional analysis of the same sample showed discrete speckled-type ANA in the homogeneous background. This study strengthened the current IIF-ANAT method by providing a new approach to quantify the fluorescence intensity and enhance the resolution of IIF-ANAT fluorescence patterns. Reconstructed 3-dimensional imaging of IIF-ANAT can be a powerful tool for routine laboratory examination. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. MAGNET

    CERN Multimedia

    B. Curé

    2012-01-01

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

  7. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

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

  8. MAGNET

    CERN Multimedia

    B. Curé

    2013-01-01

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

  9. MAGNET

    CERN Multimedia

    B. Curé

    2011-01-01

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

  10. Systemic-to-pulmonary collateral flow in patients with palliated univentricular heart physiology: measurement using cardiovascular magnetic resonance 4D velocity acquisition

    Directory of Open Access Journals (Sweden)

    Valverde Israel

    2012-04-01

    Full Text Available Abstract Background Systemic-to-pulmonary collateral flow (SPCF may constitute a risk factor for increased morbidity and mortality in patients with single-ventricle physiology (SV. However, clinical research is limited by the complexity of multi-vessel two-dimensional (2D cardiovascular magnetic resonance (CMR flow measurements. We sought to validate four-dimensional (4D velocity acquisition sequence for concise quantification of SPCF and flow distribution in patients with SV. Methods 29 patients with SV physiology prospectively underwent CMR (1.5 T (n = 14 bidirectional cavopulmonary connection [BCPC], age 2.9 ± 1.3 years; and n = 15 Fontan, 14.4 ± 5.9 years and 20 healthy volunteers (age, 28.7 ± 13.1 years served as controls. A single whole-heart 4D velocity acquisition and five 2D flow acquisitions were performed in the aorta, superior/inferior caval veins, right/left pulmonary arteries to serve as gold-standard. The five 2D velocity acquisition measurements were compared with 4D velocity acquisition for validation of individual vessel flow quantification and time efficiency. The SPCF was calculated by evaluating the disparity between systemic (aortic minus caval vein flows and pulmonary flows (arterial and venour return. The pulmonary right to left and the systemic lower to upper body flow distribution were also calculated. Results The comparison between 4D velocity and 2D flow acquisitions showed good Bland-Altman agreement for all individual vessels (mean bias, 0.05±0.24 l/min/m2, calculated SPCF (−0.02±0.18 l/min/m2 and significantly shorter 4D velocity acquisition-time (12:34 min/17:28 min,p 2; Fontan 0.62±0.82 l/min/m2 and not in controls (0.01 + 0.16 l/min/m2, (3 inverse relation of right/left pulmonary artery perfusion and right/left SPCF (Pearson = −0.47,p = 0.01 and (4 upper to lower body flow distribution trend related to the weight (r = 0.742, p  Conclusions 4D

  11. Compressed sensing real-time cine cardiovascular magnetic resonance: accurate assessment of left ventricular function in a single-breath-hold.

    Science.gov (United States)

    Kido, Tomoyuki; Kido, Teruhito; Nakamura, Masashi; Watanabe, Kouki; Schmidt, Michaela; Forman, Christoph; Mochizuki, Teruhito

    2016-08-24

    Cardiovascular cine magnetic resonance (CMR) accelerated by compressed sensing (CS) is used to assess left ventricular (LV) function. However, it is difficult for prospective CS cine CMR to capture the complete end-diastolic phase, which can lead to underestimation of the end-diastolic volume (EDV), stroke volume (SV), and ejection fraction (EF), compared to retrospective standard cine CMR. This prospective study aimed to evaluate the diagnostic quality and accuracy of single-breath-hold full cardiac cycle CS cine CMR, acquired over two heart beats, to quantify LV volume in comparison to multi-breath-hold standard cine CMR. Eighty-one participants underwent standard segmented breath-hold cine and CS real-time cine CMR examinations to obtain a stack of eight contiguous short-axis images with same high spatial (1.7 × 1.7 mm(2)) and temporal resolution (41 ms). Two radiologists independently performed qualitative analysis of image quality (score, 1 [i.e., "nondiagnostic"] to 5 [i.e., "excellent"]) and quantitative analysis of the LV volume measurements. The total examination time was 113 ± 7 s for standard cine CMR and 24 ± 4 s for CS cine CMR (p cine image quality was slightly lower than standard cine (4.8 ± 0.5 for standard vs. 4.4 ± 0.5 for CS; p cine were above 4 (i.e., good). No significant differences existed between standard and CS cine MR for all quantitative LV measurements. The mean differences with 95 % confidence interval (CI), based on Bland-Altman analysis, were 1.3 mL (95 % CI, -14.6 - 17.2) for LV end-diastolic volume, 0.2 mL (95 % CI, -9.8 to10.3) for LV end-systolic volume, 1.1 mL (95 % CI, -10.5 to 12.7) for LV stroke volume, 1.0 g (95 % CI, -11.2 to 13.3) for LV mass, and 0.4 % (95 % CI, -4.8 - 5.6) for LV ejection fraction. The interobserver and intraobserver variability for CS cine MR ranged from -4.8 - 1.6 % and from -7.3 - 9.3 %, respectively, with slopes of the regressions ranging 0.88-1.0 and 0

  12. Single breath-hold 3D measurement of left atrial volume using compressed sensing cardiovascular magnetic resonance and a non-model-based reconstruction approach.

    Science.gov (United States)

    Vardoulis, Orestis; Monney, Pierre; Bermano, Amit; Vaxman, Amir; Gotsman, Craig; Schwitter, Janine; Stuber, Matthias; Stergiopulos, Nikolaos; Schwitter, Juerg

    2015-06-11

    Left atrial (LA) dilatation is associated with a large variety of cardiac diseases. Current cardiovascular magnetic resonance (CMR) strategies to measure LA volumes are based on multi-breath-hold multi-slice acquisitions, which are time-consuming and susceptible to misregistration. To develop a time-efficient single breath-hold 3D CMR acquisition and reconstruction method to precisely measure LA volumes and function. A highly accelerated compressed-sensing multi-slice cine sequence (CS-cineCMR) was combined with a non-model-based 3D reconstruction method to measure LA volumes with high temporal and spatial resolution during a single breath-hold. This approach was validated in LA phantoms of different shapes and applied in 3 patients. In addition, the influence of slice orientations on accuracy was evaluated in the LA phantoms for the new approach in comparison with a conventional model-based biplane area-length reconstruction. As a reference in patients, a self-navigated high-resolution whole-heart 3D dataset (3D-HR-CMR) was acquired during mid-diastole to yield accurate LA volumes. Phantom studies. LA volumes were accurately measured by CS-cineCMR with a mean difference of -4.73 ± 1.75 ml (-8.67 ± 3.54%, r2 = 0.94). For the new method the calculated volumes were not significantly different when different orientations of the CS-cineCMR slices were applied to cover the LA phantoms. Long-axis "aligned" vs "not aligned" with the phantom long-axis yielded similar differences vs the reference volume (-4.87 ± 1.73 ml vs. -4.45 ± 1.97 ml, p = 0.67) and short-axis "perpendicular" vs. "not-perpendicular" with the LA long-axis (-4.72 ± 1.66 ml vs. -4.75 ± 2.13 ml; p = 0.98). The conventional bi-plane area-length method was susceptible for slice orientations (p = 0.0085 for the interaction of "slice orientation" and "reconstruction technique", 2-way ANOVA for repeated measures). To use the 3D-HR-CMR as the reference for LA volumes

  13. MAGNETS

    Science.gov (United States)

    Hofacker, H.B.

    1958-09-23

    This patent relates to nmgnets used in a calutron and more particularly to means fur clamping an assembly of magnet coils and coil spacers into tightly assembled relation in a fluid-tight vessel. The magnet comprises windings made up of an assembly of alternate pan-cake type coils and spacers disposed in a fluid-tight vessel. At one end of the tank a plurality of clamping strips are held firmly against the assembly by adjustable bolts extending through the adjacent wall. The foregoing arrangement permits taking up any looseness which may develop in the assembly of coils and spacers.

  14. 3-dimensional resin casting and imaging of mouse portal vein or intrahepatic bile duct system.

    Science.gov (United States)

    Walter, Teagan J; Sparks, Erin E; Huppert, Stacey S

    2012-10-25

    In organs, the correct architecture of vascular and ductal structures is indispensable for proper physiological function, and the formation and maintenance of these structures is a highly regulated process. The analysis of these complex, 3-dimensional structures has greatly depended on either 2-dimensional examination in section or on dye injection studies. These techniques, however, are not able to provide a complete and quantifiable representation of the ductal or vascular structures they are intended to elucidate. Alternatively, the nature of 3-dimensional plastic resin casts generates a permanent snapshot of the system and is a novel and widely useful technique for visualizing and quantifying 3-dimensional structures and networks. A crucial advantage of the resin casting system is the ability to determine the intact and connected, or communicating, structure of a blood vessel or duct. The structure of vascular and ductal networks are crucial for organ function, and this technique has the potential to aid study of vascular and ductal networks in several ways. Resin casting may be used to analyze normal morphology and functional architecture of a luminal structure, identify developmental morphogenetic changes, and uncover morphological differences in tissue architecture between normal and disease states. Previous work has utilized resin casting to study, for example, architectural and functional defects within the mouse intrahepatic bile duct system that were not reflected in 2-dimensional analysis of the structure(1,2), alterations in brain vasculature of a Alzheimer's disease mouse model(3), portal vein abnormalities in portal hypertensive and cirrhotic mice(4), developmental steps in rat lymphatic maturation between immature and adult lungs(5), immediate microvascular changes in the rat liver, pancreas, and kidney in response in to chemical injury(6). Here we present a method of generating a 3-dimensional resin cast of a mouse vascular or ductal network

  15. MAGNET

    CERN Multimedia

    B. Curé

    2011-01-01

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

  16. MAGNET

    CERN Multimedia

    B. Curé

    2013-01-01

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

  17. MAGNET

    CERN Multimedia

    B. Curé

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

  18. MAGNET

    CERN Multimedia

    Benoit Curé

    2010-01-01

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

  19. MAGNET

    CERN Multimedia

    Benoit Curé.

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

  20. Laparoscopic Total Extraperitoneal (TEP) Inguinal Hernia Repair Using 3-dimensional Mesh Without Mesh Fixation.

    Science.gov (United States)

    Aliyazicioglu, Tolga; Yalti, Tunc; Kabaoglu, Burcak

    2017-08-01

    Approximately one fifth of patients suffer from inguinal pain after laparoscopic total extraperitoneal (TEP) inguinal hernia repair. There is existing literature suggesting that the staples used to fix the mesh can cause postoperative inguinal pain. In this study, we describe our experience with laparoscopic TEP inguinal hernia surgery using 3-dimensional mesh without mesh fixation, in our institution. A total of 300 patients who had undergone laparoscopic TEP inguinal hernia repair with 3-dimensional mesh in VKV American Hospital, Istanbul from November 2006 to November 2015 were studied retrospectively. Using the hospital's electronic archive, we studied patients' selected parameters, which are demographic features (age, sex), body mass index, hernia locations and types, duration of operations, preoperative and postoperative complications, duration of hospital stays, cost of surgery, need for analgesics, time elapsed until returning to daily activities and work. A total of 300 patients underwent laparoscopic TEP hernia repair of 437 inguinal hernias from November 2006 to November 2015. Of the 185 patients, 140 were symptomatic. Mean duration of follow-up was 48 months (range, 6 to 104 mo). The mean duration of surgery was 55 minutes for bilateral hernia repair, and 38 minutes for unilateral hernia repair. The mean duration of hospital stay was 0.9 day. There was no conversion to open surgery. In none of the cases the mesh was fixated with either staples or fibrin glue. Six patients (2%) developed seroma that were treated conservatively. One patient had inguinal hernia recurrence. One patient had preperitoneal hematoma. One patient operated due to indirect right-sided hernia developed right-sided hydrocele. One patient had wound dehiscence at the umbilical port entry site. Chronic pain developed postoperatively in 1 patient. Ileus developed in 1 patient. Laparoscopic TEP inguinal repair with 3-dimensional mesh without mesh fixation can be performed as safe as

  1. Dental implant customization using numerical optimization design and 3-dimensional printing fabrication of zirconia ceramic.

    Science.gov (United States)

    Cheng, Yung-Chang; Lin, Deng-Huei; Jiang, Cho-Pei; Lin, Yuan-Min

    2017-05-01

    This study proposes a new methodology for dental implant customization consisting of numerical geometric optimization and 3-dimensional printing fabrication of zirconia ceramic. In the numerical modeling, exogenous factors for implant shape include the thread pitch, thread depth, maximal diameter of implant neck, and body size. Endogenous factors are bone density, cortical bone thickness, and non-osseointegration. An integration procedure, including uniform design method, Kriging interpolation and genetic algorithm, is applied to optimize the geometry of dental implants. The threshold of minimal micromotion for optimization evaluation was 100 μm. The optimized model is imported to the 3-dimensional slurry printer to fabricate the zirconia green body (powder is bonded by polymer weakly) of the implant. The sintered implant is obtained using a 2-stage sintering process. Twelve models are constructed according to uniform design method and simulated the micromotion behavior using finite element modeling. The result of uniform design models yields a set of exogenous factors that can provide the minimal micromotion (30.61 μm), as a suitable model. Kriging interpolation and genetic algorithm modified the exogenous factor of the suitable model, resulting in 27.11 μm as an optimization model. Experimental results show that the 3-dimensional slurry printer successfully fabricated the green body of the optimization model, but the accuracy of sintered part still needs to be improved. In addition, the scanning electron microscopy morphology is a stabilized t-phase microstructure, and the average compressive strength of the sintered part is 632.1 MPa. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Incorporating a 3-dimensional printer into the management of early-stage cervical cancer.

    Science.gov (United States)

    Baek, Min-Hyun; Kim, Dae-Yeon; Kim, Namkug; Rhim, Chae Chun; Kim, Jong-Hyeok; Nam, Joo-Hyun

    2016-08-01

    We used a 3-dimensional (3D) printer to create anatomical replicas of real lesions and tested its application in cervical cancer. Our study patient decided to undergo radical hysterectomy after seeing her 3D model which was then used to plan and simulate this surgery. Using 3D printers to create patient-specific 3D tumor models may aid cervical cancer patients make treatment decisions. This technology will lead to better surgical and oncological outcomes for cervical cancer patients. J. Surg. Oncol. 2016;114:150-152. © 2016 Wiley Periodicals, Inc.

  3. A 3-dimensional finite-difference method for calculating the dynamic coefficients of seals

    Science.gov (United States)

    Dietzen, F. J.; Nordmann, R.

    1989-01-01

    A method to calculate the dynamic coefficients of seals with arbitrary geometry is presented. The Navier-Stokes equations are used in conjunction with the k-e turbulence model to describe the turbulent flow. These equations are solved by a full 3-dimensional finite-difference procedure instead of the normally used perturbation analysis. The time dependence of the equations is introduced by working with a coordinate system rotating with the precession frequency of the shaft. The results of this theory are compared with coefficients calculated by a perturbation analysis and with experimental results.

  4. Nano-yttria dispersed stainless steel composites composed by the 3 dimensional fiber deposition technique

    Energy Technology Data Exchange (ETDEWEB)

    Verhiest, K., E-mail: Katelijne.Verhiest@ArcelorMittal.com [ArcelorMittal Gent, Hot Strip Mill Department, J. Kennedylaan 51, 9042 Ghent (Belgium); Belgian Nuclear Research Centre, SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Ghent University, UGent, Department of Materials Science and Engineering (DMSE), Technologiepark 903, 9052 Ghent (Belgium); Mullens, S. [Flemish Institute for Technological Research, VITO, Materials Technology, Boeretang 200, 2400 Mol (Belgium); De Wispelaere, N.; Claessens, S. [ArcelorMittal Research Industry Gent, OCAS, J. Kennedylaan 3, 9060 Zelzate (Belgium); DeBremaecker, A. [Belgian Nuclear Research Centre, SCK-CEN, Boeretang 200, 2400 Mol (Belgium); Verbeken, K. [Ghent University, UGent, Department of Materials Science and Engineering (DMSE), Technologiepark 903, 9052 Ghent (Belgium)

    2012-09-15

    In this study, oxide dispersion strengthened (ODS) 316L steel samples were manufactured by the 3 dimensional fiber deposition (3DFD) technique. The performance of 3DFD as colloidal consolidation technique to obtain porous green bodies based on yttria (Y{sub 2}O{sub 3}) nano-slurries or paste, is discussed within this experimental work. The influence of the sintering temperature and time on sample densification and grain growth was investigated in this study. Hot consolidation was performed to obtain final product quality in terms of residual porosity reduction and final dispersion homogeneity.

  5. Towards a mathematical definition of Coulomb branches of $3$-dimensional $\\mathcal N=4$ gauge theories, II

    CERN Document Server

    Braverman, Alexander; Nakajima, Hiraku

    2016-01-01

    Consider the $3$-dimensional $\\mathcal N=4$ supersymmetric gauge theory associated with a compact Lie group $G_c$ and its quaternionic representation $\\mathbf M$. Physicists study its Coulomb branch, which is a noncompact hyper-K\\"ahler manifold with an $\\mathrm{SU}(2)$-action, possibly with singularities. We give a mathematical definition of the Coulomb branch as an affine algebraic variety with $\\mathbb C^\\times$-action when $\\mathbf M$ is of a form $\\mathbf N\\oplus\\mathbf N^*$, as the second step of the proposal given in arXiv:1503.03676.

  6. Hamiltonian Analysis of 3-Dimensional Connection Dynamics in Bondi-like Coordinates

    CERN Document Server

    Huang, Chao-Guang

    2016-01-01

    The Hamiltonian analysis for a 3-dimensional $SO(1,1)\\times T_+$-connection dynamics is conducted in a Bondi-like coordinate system.A null coframe with 5 independent variables and 9 connection coefficients are treated as basic configuration variables.All constraints and their consistency conditions, as well as the equations of motion,for the system are presented.There is no physical degree of freedom in the system as expected.The Ba\\~nados-Teitelboim-Zanelli spacetime as an example is used to check the analysis.

  7. Design of 3-dimensional complex airplane configurations with specified pressure distribution via optimization

    Science.gov (United States)

    Kubrynski, Krzysztof

    1991-01-01

    A subcritical panel method applied to flow analysis and aerodynamic design of complex aircraft configurations is presented. The analysis method is based on linearized, compressible, subsonic flow equations and indirect Dirichlet boundary conditions. Quadratic dipol and linear source distribution on flat panels are applied. In the case of aerodynamic design, the geometry which minimizes differences between design and actual pressure distribution is found iteratively, using numerical optimization technique. Geometry modifications are modeled by surface transpiration concept. Constraints in respect to resulting geometry can be specified. A number of complex 3-dimensional design examples are presented. The software is adopted to personal computers, and as result an unexpected low cost of computations is obtained.

  8. Patterned 3-dimensional metal grid electrodes as alternative electron collectors in dye-sensitized solar cells.

    Science.gov (United States)

    Chua, Julianto; Mathews, Nripan; Jennings, James R; Yang, Guangwu; Wang, Qing; Mhaisalkar, Subodh G

    2011-11-21

    We describe the application of 3-dimensional metal grid electrodes (3D-MGEs) as electron collectors in dye-sensitized solar cells (DSCs) as a replacement for fluorinated tin oxide (FTO) electrodes. Requirements, structure, advantages, and limitations of the metal grid electrodes are discussed. Solar conversion efficiencies of 6.2% have been achieved in 3D-MGE based solar cells, comparable to that fabricated on FTO (7.1%). The charge transport properties and collection efficiencies in these novel solar cells have been studied using electrochemical impedance spectroscopy.

  9. Computer modelling of the 3-dimensional structures of the cyanobacterial hepatotoxins microcystin-LR and nodularin.

    Science.gov (United States)

    Lanaras, T; Cook, C M; Eriksson, J E; Meriluoto, J A; Hotokka, M

    1991-01-01

    The 3-dimensional structures of two cyanobacterial hepatotoxins microcystin-LR, a cyclic heptapeptide and nodularin, a cyclic pentapeptide, and the novel amino acid ADDA (3-amino-9-methoxy-2,6,8-trimethyl-10-phenyl-4,6-decadienoic acid) were constructed, and optimized using the CHEM-X molecular mechanics program. The peptide rings were planar and of rectangular shape. Optimized ADDA formed a U-shape and a difference in the orientation of ADDA with respect to the peptide ring of the two hepatotoxins was observed.

  10. Brief communications: visualization of coronary arteries in rats by 3-dimensional real-time contrast echocardiography.

    Science.gov (United States)

    Ishikura, Fuminobu; Hirayama, Hideo; Iwata, Akiko; Toshida, Tsutomu; Masuda, Kasumi; Otani, Kentaro; Asanuma, Toshihiko; Beppu, Shintaro

    2008-05-01

    Angiogenesis is under intense investigation to advance the treatment of various ischemic diseases. Small animals, such as mice and rats, are often used for this purpose. However, evaluating the structure of coronary arteries in small animals in situ is not easy. We succeeded in visualizing the coronary artery in rats on 3-dimensional real-time contrast echocardiography using a high-frequency transducer. These methods will be applied for more convenient assessment in a new study, examining issues such as angiogenesis using rats in situ.

  11. Eikonal slant helices and eikonal Darboux helices in 3-dimensional pseudo-Riemannian manifolds

    OpenAIRE

    Önder, Mehmet; Ziplar, Evren

    2013-01-01

    In this study, we give definitions and characterizations of eikonal slant helices, eikonal Darboux helices and non-normed eikonal Darboux helices in 3-dimensional pseudo- Riemannian manifold M . We show that every eikonal slant helix is also an eikonal Darboux helix for timelike and spacelike curves. Furthermore, we obtain that if the non-null curve a is a non-normed eikonal Darboux helix, then a is an eikonal slant helix if and only if 2 2 e 3k +e1t = constant, where k and t are curvature an...

  12. Quantum Computing - A new Implementation of Simon Algorithm for 3-Dimensional Registers

    Directory of Open Access Journals (Sweden)

    Adina Bărîlă

    2015-03-01

    Full Text Available Quantum computing is a new field of science aiming to use quantum phenomena in order to perform operations on data. The Simon algorithm is one of the quantum algorithms which solves a certain problem exponentially faster than any classical algorithm solving the same problem. Simulating of quantum algorithms is very important since quantum hardware is not available outside of the research labs. QCL (Quantum Computation Language is the most advanced implemented quantum computer simulator and was conceived by Bernhard Ömer. The paper presents an implementation in QCL of the Simon algorithm in the case of 3-dimensional registers.

  13. A novel solar cell fabricated with spiral photo-electrode for capturing sunlight 3-dimensionally

    Institute of Scientific and Technical Information of China (English)

    LIU Yong; SHEN Hui; DENG Youjun

    2006-01-01

    A novel solar cell fabricated with spiral photo-electrode for capturing sunlight 3-dimensionally (3D-cell) is proposed in this paper. We studied its performance both in solar simulator and in nature sunlight. Spiral photo-electrode of 3D-cell can receive sunlight from all directions and therefore can track the sun passively. And it is much insensitive to solar azimuth angle and shade. In addition, it increases the area to obtain scattered sunlight and reflected light. Compared with the dye-sensitized solar cells using sandwich structure, it would be more advantageous in the sealing technique.

  14. The study of 3-dimensional structures of IgG with atomic force microscopy

    Institute of Scientific and Technical Information of China (English)

    YU Yi-gang; XU Ru-xiang; JIANG Xiao-dan; KE Yi-quan

    2005-01-01

    Objective: To detect 3-dimensional images of anti-N-methyl-D-aspartate receptor Nr1 (NMDAr1) polycolonal IgG affixed on mica in physiological environment. Methods: The images and data were obtained from a contact mode and commercial Si3N4 probed tip by using atomic force microscope (AFM). Conclusions: Using AFM to investigate biomacromolecule can make us deeply understand the structure of IgG, which will instruct us to detect the membrane receptor protein as a labelling agent.

  15. Crossover from 2-dimensional to 3-dimensional aggregations of clusters on square lattice substrates

    Science.gov (United States)

    Cheng, Yi; Zhu, Yu-Hong; Pan, Qi-Fa; Yang, Bo; Tao, Xiang-Ming; Ye, Gao-Xiang

    2015-11-01

    A Monte Carlo study on the crossover from 2-dimensional to 3-dimensional aggregations of clusters is presented. Based on the traditional cluster-cluster aggregation (CCA) simulation, a modified growth model is proposed. The clusters (including single particles and their aggregates) diffuse with diffusion step length l (1 ≤ l ≤ 7) and aggregate on a square lattice substrate. If the number of particles contained in a cluster is larger than a critical size sc, the particles at the edge of the cluster have a possibility to jump onto the upper layer, which results in the crossover from 2-dimensional to 3-dimensional aggregations. Our simulation results are in good agreement with the experimental findings. Project supported by the National Natural Science Foundation of China (Grant Nos. 11374082 and 11074215), the Science Foundation of Zhejiang Province Department of Education, China (Grant No. Y201018280), the Fundamental Research Funds for Central Universities, China (Grant No. 2012QNA3010), and the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20100101110005).

  16. Automated, non-linear registration between 3-dimensional brain map and medical head image

    Energy Technology Data Exchange (ETDEWEB)

    Mizuta, Shinobu; Urayama, Shin-ichi; Zoroofi, R.A.; Uyama, Chikao [National Cardiovascular Center, Suita, Osaka (Japan)

    1998-05-01

    In this paper, we propose an automated, non-linear registration method between 3-dimensional medical head image and brain map in order to efficiently extract the regions of interest. In our method, input 3-dimensional image is registered into a reference image extracted from a brain map. The problems to be solved are automated, non-linear image matching procedure, and cost function which represents the similarity between two images. Non-linear matching is carried out by dividing the input image into connected partial regions, transforming the partial regions preserving connectivity among the adjacent images, evaluating the image similarity between the transformed regions of the input image and the correspondent regions of the reference image, and iteratively searching the optimal transformation of the partial regions. In order to measure the voxelwise similarity of multi-modal images, a cost function is introduced, which is based on the mutual information. Some experiments using MR images presented the effectiveness of the proposed method. (author)

  17. Simple parameter estimation for complex models — Testing evolutionary techniques on 3-dimensional biogeochemical ocean models

    Science.gov (United States)

    Mattern, Jann Paul; Edwards, Christopher A.

    2017-01-01

    Parameter estimation is an important part of numerical modeling and often required when a coupled physical-biogeochemical ocean model is first deployed. However, 3-dimensional ocean model simulations are computationally expensive and models typically contain upwards of 10 parameters suitable for estimation. Hence, manual parameter tuning can be lengthy and cumbersome. Here, we present four easy to implement and flexible parameter estimation techniques and apply them to two 3-dimensional biogeochemical models of different complexities. Based on a Monte Carlo experiment, we first develop a cost function measuring the model-observation misfit based on multiple data types. The parameter estimation techniques are then applied and yield a substantial cost reduction over ∼ 100 simulations. Based on the outcome of multiple replicate experiments, they perform on average better than random, uninformed parameter search but performance declines when more than 40 parameters are estimated together. Our results emphasize the complex cost function structure for biogeochemical parameters and highlight dependencies between different parameters as well as different cost function formulations.

  18. An electro-dynamic 3-dimensional vibration test bed for engineering testing

    Science.gov (United States)

    Saadatzi, Mohammadsadegh; Saadatzi, Mohammad Nasser; Ahmed, Riaz; Banerjee, Sourav

    2017-04-01

    Primary objective of the work is to design, fabrication and testing of a 3-dimensional Mechanical vibration test bed. Vibration testing of engineering prototype devices in mechanical and industrial laboratories is essential to understand the response of the envisioned model under physical excitation conditions. Typically, two sorts of vibration sources are available in physical environment, acoustical and mechanical. Traditionally, test bed to simulate unidirectional acoustic or mechanical vibration is used in engineering laboratories. However, a device may encounter multiple uncoupled and/or coupled loading conditions. Hence, a comprehensive test bed in essential that can simulate all possible sorts of vibration conditions. In this article, an electrodynamic vibration exciter is presented which is capable of simulating 3-dimensional uncoupled (unidirectional) and coupled excitation, in mechanical environments. The proposed model consists of three electromagnetic shakers (for mechanical excitation). A robust electrical control circuit is designed to regulate the components of the test bed through a self-developed Graphical User Interface. Finally, performance of the test bed is tested and validated using commercially available piezoelectric sensors.

  19. High resolution 3-Dimensional imaging of the human cardiac conduction system from microanatomy to mathematical modeling.

    Science.gov (United States)

    Stephenson, Robert S; Atkinson, Andrew; Kottas, Petros; Perde, Filip; Jafarzadeh, Fatemeh; Bateman, Mike; Iaizzo, Paul A; Zhao, Jichao; Zhang, Henggui; Anderson, Robert H; Jarvis, Jonathan C; Dobrzynski, Halina

    2017-08-03

    Cardiac arrhythmias and conduction disturbances are accompanied by structural remodelling of the specialised cardiomyocytes known collectively as the cardiac conduction system. Here, using contrast enhanced micro-computed tomography, we present, in attitudinally appropriate fashion, the first 3-dimensional representations of the cardiac conduction system within the intact human heart. We show that cardiomyocyte orientation can be extracted from these datasets at spatial resolutions approaching the single cell. These data show that commonly accepted anatomical representations are oversimplified. We have incorporated the high-resolution anatomical data into mathematical simulations of cardiac electrical depolarisation. The data presented should have multidisciplinary impact. Since the rate of depolarisation is dictated by cardiac microstructure, and the precise orientation of the cardiomyocytes, our data should improve the fidelity of mathematical models. By showing the precise 3-dimensional relationships between the cardiac conduction system and surrounding structures, we provide new insights relevant to valvar replacement surgery and ablation therapies. We also offer a practical method for investigation of remodelling in disease, and thus, virtual pathology and archiving. Such data presented as 3D images or 3D printed models, will inform discussions between medical teams and their patients, and aid the education of medical and surgical trainees.

  20. Influence of different setups of the Frankfort horizontal plane on 3-dimensional cephalometric measurements.

    Science.gov (United States)

    Santos, Rodrigo Mologni Gonçalves Dos; De Martino, José Mario; Haiter Neto, Francisco; Passeri, Luis Augusto

    2017-08-01

    The Frankfort horizontal (FH) is a plane that intersects both porions and the left orbitale. However, other combinations of points have also been used to define this plane in 3-dimensional cephalometry. These variations are based on the hypothesis that they do not affect the cephalometric analysis. We investigated the validity of this hypothesis. The material included cone-beam computed tomography data sets of 82 adult subjects with Class I molar relationship. A third-party method of cone-beam computed tomography-based 3-dimensional cephalometry was performed using 7 setups of the FH plane. Six lateral cephalometric hard tissue measurements relative to the FH plane were carried out for each setup. Measurement differences were calculated for each pair of setups of the FH plane. The number of occurrences of differences greater than the limits of agreement was counted for each of the 6 measurements. Only 3 of 21 pairs of setups had no occurrences for the 6 measurements. No measurement had no occurrences for the 21 pairs of setups. Setups based on left or right porion and both orbitales had the greatest number of occurrences for the 6 measurements. This investigation showed that significant and undesirable measurement differences can be produced by varying the definition of the FH plane. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  1. Quantitative 3-Dimensional Imaging of Murine Neointimal and Atherosclerotic Lesions by Optical Projection Tomography

    Science.gov (United States)

    Kirkby, Nicholas S.; Low, Lucinda; Seckl, Jonathan R.; Walker, Brian R.; Webb, David J.; Hadoke, Patrick W. F.

    2011-01-01

    Objective Traditional methods for the analysis of vascular lesion formation are labour intensive to perform - restricting study to ‘snapshots’ within each vessel. This study was undertaken to determine the suitability of optical projection tomographic (OPT) imaging for the 3-dimensional representation and quantification of intimal lesions in mouse arteries. Methods and Results Vascular injury was induced by wire-insertion or ligation of the mouse femoral artery or administration of an atherogenic diet to apoE-deficient mice. Lesion formation was examined by OPT imaging of autofluorescent emission. Lesions could be clearly identified and distinguished from the underlying vascular wall. Planimetric measurements of lesion area correlated well with those made from histological sections subsequently produced from the same vessels (wire-injury: R2 = 0.92; ligation-injury: R2 = 0.89; atherosclerosis: R2 = 0.85), confirming both the accuracy of this methodology and its non-destructive nature. It was also possible to record volumetric measurements of lesion and lumen and these were highly reproducible between scans (coefficient of variation = 5.36%, 11.39% and 4.79% for wire- and ligation-injury and atherosclerosis, respectively). Conclusions These data demonstrate the eminent suitability of OPT for imaging of atherosclerotic and neointimal lesion formation, providing a much needed means for the routine 3-dimensional analysis of vascular morphology in studies of this type. PMID:21379578

  2. A New 3-Dimensional Dynamic Quantitative Analysis System of Facial Motion: An Establishment and Reliability Test

    Science.gov (United States)

    Feng, Guodong; Zhao, Yang; Tian, Xu; Gao, Zhiqiang

    2014-01-01

    This study aimed to establish a 3-dimensional dynamic quantitative facial motion analysis system, and then determine its accuracy and test-retest reliability. The system could automatically reconstruct the motion of the observational points. Standardized T-shaped rod and L-shaped rods were used to evaluate the static and dynamic accuracy of the system. Nineteen healthy volunteers were recruited to test the reliability of the system. The average static distance error measurement was 0.19 mm, and the average angular error was 0.29°. The measuring results decreased with the increase of distance between the cameras and objects, 80 cm of which was considered to be optimal. It took only 58 seconds to perform the full facial measurement process. The average intra-class correlation coefficient for distance measurement and angular measurement was 0.973 and 0.794 respectively. The results demonstrated that we successfully established a practical 3-dimensional dynamic quantitative analysis system that is accurate and reliable enough to meet both clinical and research needs. PMID:25390881

  3. A 3-dimensional model for inductively coupled plasma etching reactors: Coil generated plasma asymmetries

    Energy Technology Data Exchange (ETDEWEB)

    Kushner, M.J.; Collison, W.Z.; Grapperhaus, M.J. [Univ. of Illinois, Urbana, IL (United States). Dept. of Electrical and Computer Engineering

    1996-12-31

    Inductively Coupled Plasma (ICP) reactors are being developed as high plasma density, low gas pressure sources for etching and deposition of semiconductor materials. In this paper, the authors describe a 3-dimensional, time dependent model for ICP reactors whose intent is to provide an infrastructure to investigate asymmetries in plasma etching and deposition tools. The model is a 3-dimensional extension of a previously described 2-dimensional simulation called the Hybrid Plasma Equipment Model (HPEM). HPEM-3D consists of an electromagnetics module (EMM), a Boltzmann-electron energy module (BEM) and a fluid-chemical kinetics simulation (FKS). The inductively coupled electromagnetic fields are produced by the EMM. Results from HPEM-3D will be discussed for reactors using etching (Cl{sub 2}, BCl{sub 3}) and non-etching (Ar, Ar/N{sub 2}) gas mixtures, and which have geometrical asymmetries such as wafer clamps and load-lock bays. The authors show how details in the design of the coil, such as the value of the termination capacitance or number of turns, lead to azimuthal variations in the inductive electric field.

  4. Femtosecond laser assisted 3-dimensional freeform fabrication of metal microstructures in fused silica (Conference Presentation)

    Science.gov (United States)

    Ebrahim, Fatmah; Charvet, Raphaël.; Dénéréaz, Cyril; Mortensen, Andreas; Bellouard, Yves

    2017-03-01

    Femtosecond laser exposure of fused silica combined with chemical etching has opened up new opportunities for three-dimensional freeform processing of micro-structures that can form complex micro-devices of silica, integrating optical, mechanical and/or fluidic functionalities. Here, we demontrate an expansion of this process with an additional fabrication step that enables the integration of three-dimensional embedded metallic structures out of useful engineering metals such as silver, gold, copper as well as some of their alloys. This additional step is an adaptation of the pressure infiltration for the insertion of high conductivity, high melting point metals and alloys into topologically complex, femtosecond laser-machined cavities in fused silica. This produces truly 3-dimensional microstructures, including microcoils and needles, within the bulk of glass substrates. Combining this added capability with the existing possibilities of femtosecond laser micromachining (i.e. direct written waveguides, microchannels, resonators, etc.) opens up a host of potential applications for the contactless fabrication of highly integrated monolithic devices that include conductive element of all kind. We present preliminary results from this new fabrication process, including prototype devices that incorporate 3D electrodes with aspect ratios of 1:100 and a feature size resolution down to 2μm. We demonstrate the generation of high electric field gradients (of the order of 1013 Vm-2) in these devices due to the 3-dimensional topology of fabricated microstructures.

  5. Comparison of nonnavigated and 3-dimensional image-based computer navigated balloon kyphoplasty.

    Science.gov (United States)

    Sembrano, Jonathan N; Yson, Sharon C; Polly, David W; Ledonio, Charles Gerald T; Nuckley, David J; Santos, Edward R G

    2015-01-01

    Balloon kyphoplasty is a common treatment for osteoporotic and pathologic compression fractures. Advantages include minimal tissue disruption, quick recovery, pain relief, and in some cases prevention of progressive sagittal deformity. The benefit of image-based navigation in kyphoplasty has not been established. The goal of this study was to determine whether there is a difference between fluoroscopy-guided balloon kyphoplasty and 3-dimensional image-based navigation in terms of needle malposition rate, cement leakage rate, and radiation exposure time. The authors compared navigated and nonnavigated needle placement in 30 balloon kyphoplasty procedures (47 levels). Intraoperative 3-dimensional image-based navigation was used for needle placement in 21 cases (36 levels); conventional 2-dimensional fluoroscopy was used in the other 9 cases (11 levels). The 2 groups were compared for rates of needle malposition and cement leakage as well as radiation exposure time. Three of 11 (27%) nonnavigated cases were complicated by a malpositioned needle, and 2 of these had to be repositioned. The navigated group had a significantly lower malposition rate (1 of 36; 3%; P=.04). The overall rate of cement leakage was also similar in both groups (P=.29). Radiation exposure time was similar in both groups (navigated, 98 s/level; nonnavigated, 125 s/level; P=.10). Navigated kyphoplasty procedures did not differ significantly from nonnavigated procedures except in terms of needle malposition rate, where navigation may have decreased the need for needle repositioning.

  6. 3-dimensional slope stability analyses using non-associative stress-strain relationships

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The research work presented in this paper refers to a new slope stability analysis method used for landslide risk evaluations. It is an extension of the 3-dimensional upper-bound slope stability analysis method proposed by Chen et al. in 2001,which employs the Mohr-Coulomb’s associative flow rule. It has been found that in a 3-dimensional area,a prism may not be able to move at friction angles to all its surrounding interfaces,as required by this associative rule,and convergence problems may occasionally arise. The new method establishes two velocity fields:(i) The plastic one that represents a non-associative and the best representative dilation behavior,and (ii) the virtual one that permits the solution for factor of safety in the work and energy balance equation. The new method can then allow any input value of dilation angle and thus solve the convergence problem. A practical application to a concrete dam foundation is illustrated.

  7. MR imaging of the knee joint with 3-dimensional gradient echo

    Energy Technology Data Exchange (ETDEWEB)

    Shimagaki, Hajime; Matsubara, T.; Narisawa, Hiroko; Yamazaki, Yukio [Tsubame Rosai Hospital, Niigata (Japan)

    1996-11-01

    Authors considered and discussed whether various lesions of the knee joint can be diagnosed under the MR imaging condition with a pulse sequence of 3-dimensional fourier transformed gradient recalled acquisition in the steady state and what advantages the method has. The apparatus was 1.5T Signa (General Electric) equipped with surface coil for the knee. The consecutive 124 sagittal images of 0.8 mm thickness taken primarily for 3-dimensional reconstruction were processed to give any cross sections of coronary, horizontal, sagittal or further additional ones. Subjects were 243 knees (138 internal derangement and 105 osteoarthritis) whose lesions were confirmed by arthroscope or by arthrostomy after the MR imaging. Comparison of the MR imaging and surgical finding revealed that accuracy, specificity and sensitivity of the present MR imaging method were all >90% for diagnosis of internal derangement of anterior cruciate ligament and meniscus. For osteoarthritis, the method was thought useful for evaluation of the depth of cartilage deficit. (K.H.)

  8. Unobservable Problem of Target Tracking with Bearing-only Measurements in 3-dimensional Space

    Institute of Scientific and Technical Information of China (English)

    XU Zhi-gang; SHENG An-dong

    2008-01-01

    The bearings-only tracking (BOT) system is said to be observability if and only if the target motion parameters can be uniquely determined by noise-free bearing measurements. By utilizing the method of orthogonal vectors and characteristic of linear matrix equation, the problem of observability for BOT in noise-free bearings measurements from single observer is discussed based on the target and observer traveling in the 3-dimensional space. A proposition that BOT for target and observer traveling in the 3-dimensional space with constant acceleration remains unsolvable is presented and proved. By proving the proposition, it is also shown that some motion parameter ratios of target can be estimated under certain condition satisfied by measurements and time samples. The proposition is extended to arbitrary rank of manoeuvre for the observer and the target, which BOT remains unobservable property while the rank of target manoeuvre is higher than that of the observer manoeuvre. The theoretical analysis of this paper provides the guidelines for how the observer trajectory should be formulated to avoid unobservable state for BOT in practice application.

  9. Candidate gene analyses of 3-dimensional dentoalveolar phenotypes in subjects with malocclusion

    Science.gov (United States)

    Weaver, Cole A.; Miller, Steven F.; da Fontoura, Clarissa S. G.; Wehby, George L.; Amendt, Brad A.; Holton, Nathan E.; Allareddy, Veeratrishul; Southard, Thomas E.; Moreno Uribe, Lina M.

    2017-01-01

    Introduction Genetic studies of malocclusion etiology have identified 4 deleterious mutations in genes, DUSP6, ARHGAP21, FGF23, and ADAMTS1 in familial Class III cases. Although these variants may have large impacts on Class III phenotypic expression, their low frequency (subjects were digitized with 48 landmarks. The 3-dimensional coordinate data were submitted to a geometric morphometric approach along with principal component analysis to generate continuous phenotypes including symmetric and asymmetric components of dentoalveolar shape variation, fluctuating asymmetry, and size. The subjects were genotyped for 222 single-nucleotide polymorphisms in 82 genes/loci, and phenotpye-genotype associations were tested via multivariate linear regression. Results Principal component analysis of symmetric variation identified 4 components that explained 68% of the total variance and depicted anteroposterior, vertical, and transverse dentoalveolar discrepancies. Suggestive associations (P right discrepancies resulting in midline deviations, unilateral crossbites, and ectopic eruptions. Suggestive associations were found with TBX1 AJUBA, SNAI3 SATB2, TP63, and 1p22.1. Fluctuating asymmetry was associated with BMP3 and LATS1. Associations for SATB2 and BMP3 with asymmetric variations remained significant after the Bonferroni correction (P <0.00022). Suggestive associations were found for centroid size, a proxy for dentoalveolar size variation with 4p16.1 and SNAI1. Conclusions Specific genetic pathways associated with 3-dimensional dentoalveolar phenotypic variation in malocclusions were identified. PMID:28257739

  10. MAGNET

    CERN Multimedia

    Benoit Curé

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

  11. MAGNET

    CERN Multimedia

    B. Curé

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

  12. The value of preoperative 3-dimensional over 2-dimensional valve analysis in predicting recurrent ischemic mitral regurgitation after mitral annuloplasty

    NARCIS (Netherlands)

    Wijdh-den Hamer, Inez J.; Bouma, Wobbe; Lai, Eric K.; Levack, Melissa M.; Shang, Eric K.; Pouch, Alison M.; Eperjesi, Thomas J.; Plappert, Theodore J.; Yushkevich, Paul A.; Hung, Judy; Mariani, Massimo A.; Khabbaz, Kamal R.; Gleason, Thomas G.; Mahmood, Feroze; Acker, Michael A.; Woo, Y. Joseph; Cheung, Albert T.; Gillespie, Matthew J.; Jackson, Benjamin M.; Gorman, Joseph H.; Gorman, Robert C.

    2016-01-01

    Objectives: Repair for ischemic mitral regurgitation with undersized annuloplasty is characterized by high recurrence rates. We sought to determine the value of pre-repair 3-dimensional echocardiography over 2-dimensional echocardiography in predicting recurrence at 6 months. Methods: Intraoperative

  13. The value of preoperative 3-dimensional over 2-dimensional valve analysis in predicting recurrent ischemic mitral regurgitation after mitral annuloplasty

    NARCIS (Netherlands)

    Wijdh-den Hamer, Inez J.; Bouma, Wobbe; Lai, Eric K.; Levack, Melissa M.; Shang, Eric K.; Pouch, Alison M.; Eperjesi, Thomas J.; Plappert, Theodore J.; Yushkevich, Paul A.; Hung, Judy; Mariani, Massimo A.; Khabbaz, Kamal R.; Gleason, Thomas G.; Mahmood, Feroze; Acker, Michael A.; Woo, Y. Joseph; Cheung, Albert T.; Gillespie, Matthew J.; Jackson, Benjamin M.; Gorman, Joseph H.; Gorman, Robert C.

    Objectives: Repair for ischemic mitral regurgitation with undersized annuloplasty is characterized by high recurrence rates. We sought to determine the value of pre-repair 3-dimensional echocardiography over 2-dimensional echocardiography in predicting recurrence at 6 months. Methods: Intraoperative

  14. SECOND-ORDER OPTIMALITY CONDITIONS FOR OPTIMAL CONTROL PROBLEMS GOVERNED BY 3-DIMENSIONAL NEVIER-STOKES EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This article is concerned with second-order necessary and sufficient optimality conditions for optimal control problems governed by 3-dimensional Navier-Stokes equations. The periodic state constraint is considered.

  15. Fusion 3-Dimensional Angiography of Both Internal Carotid Arteries in the Evaluation of Anterior Communicating Artery Aneurysms.

    Science.gov (United States)

    Yang, Kuhyun; Koo, Hae-Won; Park, Wonhyoung; Kim, Jin Su; Choi, Choong Gon; Park, Jung Cheol; Ahn, Jae Sung; Kwon, Do Hoon; Kwun, Byung Duk; Lee, Deok Hee

    2017-02-01

    To determine whether fusion 3-dimensional (3D) angiography of both internal carotid arteries can better disclose vascular details in patients diagnosed with anterior communicating artery (ACoA) aneurysms by computed tomography angiography (CTA) or magnetic resonance angiography (MRA). Thirty-eight patients diagnosed with ACoA aneurysms by CTA or MRA were evaluated by the new postprocessing feature, fusion 3D angiography, with results individually interpreted by 4 experts. Those experts compared fusion 3D angiography with dominant A1 side single 3D angiography to define advantages and disadvantages for ACoA aneurysms. Patients with unilateral A1 aplasia or rudimentary A1 were excluded. Patients who showed any disadvantages with this additional feature were classified as group 1, those with no advantages were classified as group 2, those with 1 or 2 advantages were classified as group 3, and those with 3 or more advantages were classified as group 4. Radiologic and clinical results were also evaluated. Of the 38 patients, 33 (87%) benefited from fusion 3D angiography, including 17 in group 3 and 16 in group 4; of the remaining patients, 1 was classified as group 1 and 4 were classified as group 2. Representative 5 categories of advantage to fusion angiography were found and summarized by the 4 experts. All 33 patients showed defining the exact anatomy of the ACoA, and 22 (67%) showed full angiographic features of A2 or A3, including branches. Fusion 3D angiography can significantly contribute to a better understanding of the complex anatomy of the anterior cerebral artery-ACoA complex, which is essential for successful treatment planning for ACoA aneurysms. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. 儿童心肌炎MRI的诊断价值%Diagnostic value of cardiovascular magnetic resonance in children with myocarditis

    Institute of Scientific and Technical Information of China (English)

    陈冰华; 钟玉敏; 孙爱敏; 王谦; 朱铭; 王静蕾; 高伟; 黄美蓉; 王桂龙

    2015-01-01

    目的:探讨心脏磁共振(CMR)在儿童心肌炎诊断中的价值。方法搜集2013年5月至2014年6月41例进行CMR检查患儿,其中27例临床诊断为心肌炎(心肌炎组),急性期16例、慢性期11例;非心肌炎患儿14例(非心肌炎组)。41例患儿采用稳态自由进动(SSFP)序列进行心脏横断面、左心室二腔心、四腔心以及短轴面扫描以评估心脏功能,然后分别进行左心室短轴面三反转恢复序列T2WI、早期增强(EGE)和延迟强化(LGE)序列扫描,计算T2WI和EGE序列上心肌骨骼肌信号比值及LGE阳性例数。定量资料因不符合正态分布,数据描述使用中位数和上下四分位数范围表示,统计方法采用Mann⁃Whitney非参数检验以及χ2检验。计算T2WI、EGE、LGE及“综合序列诊断”诊断心肌炎的敏感度、特异度及准确性。结果心肌炎组射血分数为60.20%(44.40%,70.20%),T2WI上心肌骨骼肌信号比为2.50(2.04,3.79),延迟强化(LGE)例数为13例;非心肌炎组对应的数值分别为73.60%(65.40%,75.85%)、1.85(1.77,2.15)和1例,两组间差异具有统计学意义(Z值分别为-2.94、-2.52,χ2=5.19,P值均<0.05)。T2WI、EGE、LGE序列诊断心肌炎的敏感度分别为81.5%(22/27)、14.8%(4/27)、48.1%(13/27),特异度分别为57.1%(8/14)、100.0%(14/14)、92.9%(13/14),准确性分别为73.2%(30/41)、43.9%(18/41)和63.4%(26/41),综合序列诊断心肌炎的敏感度、特异度和准确性分别为51.9%(14/27)、92.9%(13/14)和65.9%(27/41)。结论心脏MRI是目前诊断儿童心肌炎重要的非创伤性检查方法,各扫描序列的综合评估可提高诊断的准确性。%Objective To determine the diagnostic value of cardiovascular magnetic resonance (CMR) in children with myocarditis. Methods A total of 27 children with myocarditis were examined with cardiac MRI, including 16 new⁃onset cases and 11 chronic cases, as well as 14

  17. DIEP Flap Breast Reconstruction Using 3-dimensional Surface Imaging and a Printed Mold

    Directory of Open Access Journals (Sweden)

    Koichi Tomita, MD, PhD

    2015-03-01

    Full Text Available Summary: Recent advances in 3-dimensional (3D surface imaging technologies allow for digital quantification of complex breast tissue. We performed 11 unilateral breast reconstructions with deep inferior epigastric artery perforator (DIEP flaps (5 immediate, 6 delayed using 3D surface imaging for easier surgery planning and 3D-printed molds for shaping the breast neoparenchyma. A single- or double-pedicle flap was preoperatively planned according to the estimated tissue volume required and estimated total flap volume. The DIEP flap was then intraoperatively shaped with a 3D-printed mold that was based on a horizontally inverted shape of the contralateral breast. Cosmetic outcomes were assessed as satisfactory, as confirmed by the postoperative 3D measurements of bilateral breasts. We believe that DIEP flap reconstruction assisted with 3D surface imaging and a 3D-printed mold is a simple and quick method for rebuilding a symmetric breast.

  18. Simple computer program to model 3-dimensional underground heat flow with realistic boundary conditions

    Science.gov (United States)

    Metz, P. D.

    A FORTRAN computer program called GROCS (GRound Coupled Systems) has been developed to study 3-dimensional underground heat flow. Features include the use of up to 30 finite elements or blocks of Earth which interact via finite difference heat flow equations and a subprogram which sets realistic time and depth dependent boundary conditions. No explicit consideration of mositure movement or freezing is given. GROCS has been used to model the thermal behavior of buried solar heat storage tanks (with and without insulation) and serpentine pipe fields for solar heat pump space conditioning systems. The program is available independently or in a form compatible with specially written TRNSYS component TYPE subroutines. The approach taken in the design of GROCS, the mathematics contained and the program architecture, are described. Then, the operation of the stand-alone version is explained. Finally, the validity of GROCS is discussed.

  19. Investigation of 3-dimensional structural morphology for enhancing light trapping with control of surface haze

    Science.gov (United States)

    Park, Hyeongsik; Shin, Myunghun; Kim, Hyeongseok; Kim, Sunbo; Le, Anh Huy Tuan; Kang, Junyoung; Kim, Yongjun; Pham, Duy Phong; Jung, Junhee; Yi, Junsin

    2017-04-01

    A comparative study of 3-dimensional textured glass morphologies with variable haze value and chemical texturing of the glass substrates was conducted to enhance light trapping in silicon (Si) thin film solar cells (TFSCs). The light trapping characteristics of periodic honeycomb structures show enhanced transmittance and haze ratio in numerical and experimental approaches. The periodic honeycomb structure of notched textures is better than a random or periodic carved structure. It has high transmittance of ∼95%, and haze ratio of ∼52.8%, and the haze property of the angular distribution function of transmittance shows wide scattering angles in the long wavelength region because of the wide spacing and aspect ratio of the texture. The numerical and experimental approaches of the 3-D texture structures in this work will be useful in developing high-performance Si TFSCs with light trapping.

  20. Large-eddy-simulation of 3-dimensional Rayleigh-Taylor instability in incompressible fluids

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The 3-dimensional incompressible Rayleigh-Taylor instability is numerically studied through the large-eddy-simulation (LES) approach based on the passive scalar transport model. Both the instantaneous velocity and the passive scalar fields excited by sinusoidal perturbation and random perturbation are simulated. A full treatment of the whole evolution process of the instability is addressed. To verify the reliability of the LES code, the averaged turbulent energy as well as the flux of passive scalar are calculated at both the resolved scale and the subgrid scale. Our results show good agreement with the experimental and other numerical work. The LES method has proved to be an effective approach to the Rayleigh-Taylor instability.

  1. The 3-dimensional numerical simulation of artificially altitude-triggered negative lightning

    Science.gov (United States)

    Zhang, Bo; Chen, Bin; Shi, Lihua; Chen, Qiang

    2013-03-01

    A 3-dimensional numerical model for artificially altitude-triggered negative lightning is developed based on an analytic thunderstorm model and the Dielectric Breakdown Model (DBM). Two major parameters are concerned, they are the thundercloud electric field and the length of the nylon wire which isolates the triggering wire from the ground. A few groups of contrast numerical experiments are done to study their effects on the success rates of altitude-triggered lightning. It is found that the success rates of altitude-triggered lightning increase when the thundercloud electric field enhances or the length of the nylon wire increases. Another interesting phenomenon is that the upward positive leader is always initiated earlier than the downward negative leader in either case.

  2. Design of a 3-dimensional visual illusion speed reduction marking scheme.

    Science.gov (United States)

    Liang, Guohua; Qian, Guomin; Wang, Ye; Yi, Zige; Ru, Xiaolei; Ye, Wei

    2017-03-01

    To determine which graphic and color combination for a 3-dimensional visual illusion speed reduction marking scheme presents the best visual stimulus, five parameters were designed. According to the Balanced Incomplete Blocks-Law of Comparative Judgment, three schemes, which produce strong stereoscopic impressions, were screened from the 25 initial design schemes of different combinations of graphics and colors. Three-dimensional experimental simulation scenes of the three screened schemes were created to evaluate four different effects according to a semantic analysis. The following conclusions were drawn: schemes with a red color are more effective than those without; the combination of red, yellow and blue produces the best visual stimulus; a larger area from the top surface and the front surface should be colored red; and a triangular prism should be painted as the graphic of the marking according to the stereoscopic impression and the coordination of graphics with the road.

  3. Reference Trajectory Generation for 3-Dimensional Walking of a Humanoid Robot

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Humanoid walking planning is a complicated task because of the high number of degrees of freedom (DOFs) and the variable mechanical structure during walking. In this paper, a planning method for 3-dimensional (3-D) walking movements was developed based on a model of a typical humanoid robot with 12 DOFs on the lower body. The planning process includes trajectory generation for the hip, ankle, and knee joints in the Cartesian space. The balance of the robot was ensured by adjusting the hip motion. The angles for each DOF were obtained from 3-D kinematics calculation. The calculation gave reference trajectories of all the DOFs on the humanoid robot which were used to control the real robot. The simulation results show that the method is effective.

  4. Using 3-dimensional printing to create presurgical models for endodontic surgery.

    Science.gov (United States)

    Bahcall, James K

    2014-09-01

    Advances in endodontic surgery--from both a technological and procedural perspective-have been significant over the last 18 years. Although these technologies and procedural enhancements have significantly improved endodontic surgical treatment outcomes, there is still an ongoing challenge of overcoming the limitations of interpreting preoperative 2-dimensional (2-D) radiographic representation of a 3-dimensional (3-D) in vivo surgical field. Cone-beam Computed Tomography (CBCT) has helped to address this issue by providing a 3-D enhancement of the 2-D radiograph. The next logical step to further improve a presurgical case 3-D assessment is to create a surgical model from the CBCT scan. The purpose of this article is to introduce 3-D printing of CBCT scans for creating presurgical models for endodontic surgery.

  5. A 3-Dimensional Cockpit Display with Traffic and Terrain Information for the Small Aircraft Transportation System

    Science.gov (United States)

    UijtdeHaag, Maarten; Thomas, Robert; Rankin, James R.

    2004-01-01

    The report discusses the architecture and the flight test results of a 3-Dimensional Cockpit Display of Traffic and terrain Information (3D-CDTI). The presented 3D-CDTI is a perspective display format that combines existing Synthetic Vision System (SVS) research and Automatic Dependent Surveillance-Broadcast (ADS-B) technology to improve the pilot's situational awareness. The goal of the 3D-CDTI is to contribute to the development of new display concepts for NASA's Small Aircraft Transportation System research program. Papers were presented at the PLANS 2002 meeting and the ION-GPS 2002 meeting. The contents of this report are derived from the results discussed in those papers.

  6. Relation between qualitative and quantitative 3-dimensional ultrasound and ki-67 expression in breast cancer.

    Science.gov (United States)

    Wang, Xiao-Yan; Zhang, Bing; He, Yan; Ning, Bing; Nong, Mei-Fen; Wei, Hai-Ming; Huang, Xiang-Hong

    2015-01-01

    To investigate the relation between quantitative blood flow parameters on 3-dimensional (3D) color histogram, 3D ultrasound characteristics and Ki-67 expression in breast cancer. Three-dimensional ultrasound characteristics and histological classifications of 76 breast tumors in 75 confirmed cases were analyzed. Relations of tumor volume (V), vascularization index (VI), flow index (FI) and vascularization-flow index (VFI) on 3D color histogram to Ki-67 expression were studied by statistical methods. VI and VFI measurements of tumors in positive Ki-67 expression group were obviously increased compared with the negative expression group (P0.05). Cases showing positive expression of Ki-67 were more likely to have lymph node metastases (P0.05). Qualitative and quantitative 3D ultrasound characteristics correlated with positive expression of Ki-67 in breast cancer. Quantitative analysis with 3D color histogram more accurately evaluates blood supply of breast tumors, providing references for predicting biological behaviors and prognosis of breast cancer.

  7. Towards a mathematical definition of Coulomb branches of $3$-dimensional $\\mathcal N=4$ gauge theories, I

    CERN Document Server

    Nakajima, Hiraku

    2015-01-01

    Consider the $3$-dimensional $\\mathcal N=4$ supersymmetric gauge theory associated with a compact Lie group $G$ and its quaternionic representation $\\mathbf M$. Physicists study its Coulomb branch, which is a noncompact hyper-K\\"ahler manifold, such as instanton moduli spaces on $\\mathbb R^4$, $SU(2)$-monopole moduli spaces on $\\mathbb R^3$, etc. In this paper and its sequel, we propose a mathematical definition of the coordinate ring of the Coulomb branch, using the vanishing cycle cohomology group of a certain moduli space for a gauged $\\sigma$-model on the $2$-sphere associated with $(G,\\mathbf M)$. In this first part, we check that the cohomology group has the correct graded dimensions expected from the monopole formula proposed by Cremonesi, Hanany and Zaffaroni arXiv:1309.2657. A ring structure (on the cohomology of a modified moduli space) will be introduced in the sequel of this paper.

  8. On Exact Controllability of Networks of Nonlinear Elastic Strings in 3-Dimensional Space

    Institute of Scientific and Technical Information of China (English)

    Günter R. LEUGERING; E. J. P. Georg SCHMIDT

    2012-01-01

    This paper concerns a system of nonlinear wave equations describing the vibrations of a 3-dimensional network of elastic strings.The authors derive the equations and appropriate nodal conditions,determine equilibrium solutions,and,by using the methods of quasilinear hyperbolic systems,prove that for tree networks the natural initial,bound-ary value problem has classical solutions existing in neighborhoods of the "stretched" equilibrium solutions.Then the local controllability of such networks near such equilibrium configurations in a certain specified time interval is proved.Finally,it is proved that,given two different equilibrium states satisfying certain conditions,it is possible to control the network from states in a small enough neighborhood of one equilibrium to any state in a suitable neighborhood of the second equilibrium over a sufficiently large time interval.

  9. Epigenetic and 3-dimensional regulation of V(D)J rearrangement of immunoglobulin genes.

    Science.gov (United States)

    Degner-Leisso, Stephanie C; Feeney, Ann J

    2010-12-01

    V(D)J recombination is a crucial component of the adaptive immune response, allowing for the production of a diverse antigen receptor repertoire (Ig and TCR). This review will focus on how epigenetic regulation and 3-dimensional (3D) interactions may control V(D)J recombination at Ig loci. The interplay between transcription factors and post-translational modifications at the Igh, Igκ, and Igλ loci will be highlighted. Furthermore, we propose that the spatial organization and epigenetic boundaries of each Ig loci before and during V(D)J recombination may be influenced in part by the CTCF/cohesin complex. Taken together, the many epigenetic and 3D layers of control ensure that Ig loci are only rearranged at appropriate stages of B cell development.

  10. Use of 3-Dimensional Printing for Preoperative Planning in the Treatment of Recurrent Anterior Shoulder Instability

    Science.gov (United States)

    Sheth, Ujash; Theodoropoulos, John; Abouali, Jihad

    2015-01-01

    Recurrent anterior shoulder instability often results from large bony Bankart or Hill-Sachs lesions. Preoperative imaging is essential in guiding our surgical management of patients with these conditions. However, we are often limited to making an attempt to interpret a 3-dimensional (3D) structure using conventional 2-dimensional imaging. In cases in which complex anatomy or bony defects are encountered, this type of imaging is often inadequate. We used 3D printing to produce a solid 3D model of a glenohumeral joint from a young patient with recurrent anterior shoulder instability and complex Bankart and Hill-Sachs lesions. The 3D model from our patient was used in the preoperative planning stages of an arthroscopic Bankart repair and remplissage to determine the depth of the Hill-Sachs lesion and the degree of abduction and external rotation at which the Hill-Sachs lesion engaged. PMID:26759768

  11. Vectors a Fortran 90 module for 3-dimensional vector and dyadic arithmetic

    Energy Technology Data Exchange (ETDEWEB)

    Brock, B.C.

    1998-02-01

    A major advance contained in the new Fortran 90 language standard is the ability to define new data types and the operators associated with them. Writing computer code to implement computations with real and complex three-dimensional vectors and dyadics is greatly simplified if the equations can be implemented directly, without the need to code the vector arithmetic explicitly. The Fortran 90 module described here defines new data types for real and complex 3-dimensional vectors and dyadics, along with the common operations needed to work with these objects. Routines to allow convenient initialization and output of the new types are also included. In keeping with the philosophy of data abstraction, the details of the implementation of the data types are maintained private, and the functions and operators are made generic to simplify the combining of real, complex, single- and double-precision vectors and dyadics.

  12. The distribution of particles in the plane dispersed by a simple 3-dimensional diffusion process

    DEFF Research Database (Denmark)

    Stockmarr, Anders

    2002-01-01

    Populations of particles dispersed in the 2-dimensional plane from a single pointsource may be grouped as focus expansion patterns, with an exponentially decreasing density, and more diffuse patterns with thicker tails. Exponentially decreasing distributions are often modelled as the result of 2......-dimensional diffusion processes acting to disperse the particles, while thick-tailed distributions tend to be modelled by purely descriptive distributions. Models based on the Cauchy distribution have been suggested, but these have not been related to diffusion modelling. However, the distribution...... of particles dispersed from a point source by a 3-dimensional Brownian motion that incorporates a constant drift, under the condition that the particle starts at a given height and is stopped when it reaches the xy plane (zero height) may be shown to result in both slim-tailed exponentially decreasing...

  13. Sonographic Parameters for Prediction of Miscarriage: Role of 3-Dimensional Volume Measurement.

    Science.gov (United States)

    Wie, Jeong Ha; Choe, Suyearn; Kim, Sa Jin; Shin, Jong Chul; Kwon, Ji Young; Park, In Yang

    2015-10-01

    To evaluate the value of volume measurement using 3-dimensional sonography for prediction of miscarriage. We prospectively enrolled 188 singleton pregnant women at 5 to 9 weeks' gestation. The 3-dimensional sonographic gestational sac volume and yolk sac volume were measured together with the fetal heart rate, gestational sac diameter, and yolk sac diameter. For each sonographic parameter, nomograms were created; z scores were calculated for each measurement, and the values were compared between miscarriage and ongoing pregnancy groups. Sonographic parameters for prediction of miscarriage were evaluated by multivariate analysis, and the screening performance was assessed by a receiver operating characteristic curve. Among the 188 pregnancies, 30 (16.0%) had miscarriage. Multivariate analysis showed that fetal heart rate below the 5th percentile (odds ratio, 6.43), gestational sac diameter below the 5th percentile (odds ratio, 4.87), gestational sac volume below the 5th percentile (odds ratio, 5.25), and yolk sac diameter below the 2.5th or above the 97.5th percentile (odds ratio, 15.86) were significant predictors of miscarriage (P = .018; P = .018; P = .033; and P < .001, respectively). At a false-positive rate of 30%, the detection rate for miscarriage in screening by a combination of fetal heart rate, gestational sac diameter, gestational sac volume, and yolk sac diameter was 77.8%. A small-for-gestational-age gestational sac volume is a significant sonographic predictor of miscarriage, as are fetal bradycardia, a small gestational sac diameter, and a small or large yolk sac diameter. © 2015 by the American Institute of Ultrasound in Medicine.

  14. Correlation Between Transperineal 3-Dimensional Ultrasound Measurements of Levator Hiatus and Female Sexual Function.

    Science.gov (United States)

    Aydin, Serdar; Bakar, Rabia Zehra; Arioğlu Aydin, Çağri; Ateş, Seda

    2017-03-09

    The aim of this study is to investigate the association of sexual functions with levator hiatus biometry measurements and levator ani muscle defect. In 62 heterosexual, sexually active premenopausal women without pelvic floor disorders or urinary incontinence, 3-dimensional transperineal ultrasound imaging was used. Two 3-dimensional volumes were recorded, one at rest and one on Valsalva maneuver. Levator biometry measurements and levator defect were evaluated in an axial plane. Sexual function was assessed by a validated questionnaire, Female Sexual Function Index (FSFI). The primary outcome measure was correlation of sexual functions with the levator hiatus area, transverse and anteroposterior diameters, levator ani muscle thickness, vaginal length, and changes in measurements with Valsalva and levator defect. Forty-two women (67.7%) had low total FSFI scores (<26.55). Levator defect rates were similar in female sexual dysfunction (7/42, 16.7%) and women without female sexual dysfunction (5/20, 25%). The FSFI was negatively and weakly correlated with Δhiatal anteroposterior diameter (r = -0.33, P < 0.009) in the study population. There was a weak and inverse correlation between Δhiatal anteroposterior diameter and arousal (r = -0.35, P < 0.002), desire (r = -0.38, P < 0.001), and orgasm (r = -0.33, P < 0.007). Pain and lubrication did not correlate with any measurement. Hiatal area and diameters at rest are not related to sexual functions. Changes in anteroposterior diameter of the levator hiatus during Valsalva, which may be a sign of pelvic floor laxity or levator muscle weakness, are weakly associated with sexual functions, particularly desire, arousal, and orgasm domains.

  15. Accuracy of 3-dimensional curvilinear measurements on digital models with intraoral scanners.

    Science.gov (United States)

    Mack, Spencer; Bonilla, Tammy; English, Jeryl D; Cozad, Benjamin; Akyalcin, Sercan

    2017-09-01

    Our objectives were to evaluate and compare the digital dental models generated from 2 commercial intraoral scanners with manual measurements when performing 3-dimensional surface measurements along a curved line (curvilinear). Dry mandibles (n = 61) with intact dentition were used. The mandibles were digitized using 2 chair-side intraoral scanners: Cadent iTero (Align Technology, San Jose, Calif) and Lythos Digital Impression system (Ormco, Orange, Calif). Digitized 3-dimensional models were converted to individual stereolithography files and used with commercial software to obtain the curvilinear measurements. Manual measurements were carried out directly on the mandibular teeth. Measurements were made on different locations on the dental arch in various directions. One-sample t tests and linear regression analyses were performed. To further graphically examine the accuracy between the different methods, Bland-Altman plots were computed. The level of significance was set at P 0.05). Bland-Altman analysis showed no fixed bias of 1 approach vs the other, and random errors were detected in all comparisons. Although the mean biases of the digital models obtained by the iTero and Lythos scanners, when compared with direct caliper measurements, were low, the comparison of the 2 intraoral scanners yielded the lowest mean bias. No comparison displayed statistical significance for the t scores; this indicated the absence of proportional bias in these comparisons. The intraoral scanners tested in this study produced digital dental models that were comparatively accurate when performing direct surface measurements along a curved line in 3 dimensions. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  16. Use of 3-Dimensional Printing to Create Patient-Specific Thoracic Spine Models as Task Trainers.

    Science.gov (United States)

    Jeganathan, Jelliffe; Baribeau, Yanick; Bortman, Jeffrey; Mahmood, Feroze; Shnider, Marc; Ahmed, Muneeb; Mashari, Azad; Amir, Rabia; Amador, Yannis; Matyal, Robina

    Thoracic epidural anesthesia is a technically challenging procedure with a high failure rate of 24% to 32% nationwide. Residents in anesthesiology have limited opportunities to practice this technique adequately, and there are no training tools available for this purpose. Our objective was to build a low-cost patient-specific thoracic epidural training model. We obtained thoracic computed tomography scan data from patients with normal and kyphotic spine. The thoracic spine was segmented from the scan, and a 3-dimensional model of the spine was generated and printed. It was then placed in a customized wooden box and filled with different types of silicone to mimic human tissues. Attending physicians in our institution then tested the final model. They were asked to fill out a brief questionnaire after the identification of the landmarks and epidural space using ultrasound and real-time performance for a thoracic epidural on the model (Supplemental Digital Content 1, http://links.lww.com/AAP/A197). Likert scoring system was used for scoring. The time to develop this simulator model took less than 4 days, and the materials cost approximately $400. Fourteen physicians tested the model for determining the realistic sensation while palpating the spinous process, needle entry through the silicone, the "pop" sensation and ultrasound fidelity of the model. Whereas the tactile fidelity scores were "neutral" (3.08, 3.06, and 3.0, respectively), the ultrasound guidance and overall suitability for residents were highly rated as being the most realistic (4.85 and 4.0, respectively). It is possible to develop homemade, low-cost, patient-specific, and high-fidelity ultrasound guidance simulators for resident training in thoracic epidurals using 3-dimensional printing technology.

  17. Effect of dental technician disparities on the 3-dimensional accuracy of definitive casts.

    Science.gov (United States)

    Emir, Faruk; Piskin, Bulent; Sipahi, Cumhur

    2017-03-01

    Studies that evaluated the effect of dental technician disparities on the accuracy of presectioned and postsectioned definitive casts are lacking. The purpose of this in vitro study was to evaluate the accuracy of presectioned and postsectioned definitive casts fabricated by different dental technicians by using a 3-dimensional computer-aided measurement method. An arch-shaped metal master model consisting of 5 abutments resembling prepared mandibular incisors, canines, and first molars and with a 6-degree total angle of convergence was designed and fabricated by computer-aided design and computer-aided manufacturing (CAD-CAM) technology. Complete arch impressions were made (N=110) from the master model, using polyvinyl siloxane (PVS) and delivered to 11 dental technicians. Each technician fabricated 10 definitive casts with dental stone, and the obtained casts were numbered. All casts were sectioned, and removable dies were obtained. The master model and the presectioned and postsectioned definitive casts were digitized with an extraoral scanner, and the virtual master model and virtual presectioned and postsectioned definitive casts were obtained. All definitive casts were compared with the master model by using computer-aided measurements, and the 3-dimensional accuracy of the definitive casts was determined with best fit alignment and represented in color-coded maps. Differences were analyzed using univariate analyses of variance, and the Tukey honest significant differences post hoc tests were used for multiple comparisons (α=.05). The accuracy of presectioned and postsectioned definitive casts was significantly affected by dental technician disparities (P<.001). The largest dimensional changes were detected in the anterior abutments of both of the definitive casts. The changes mostly occurred in the mesiodistal dimension (P<.001). Within the limitations of this in vitro study, the accuracy of presectioned and postsectioned definitive casts is susceptible

  18. The Effectiveness of an Interactive 3-Dimensional Computer Graphics Model for Medical Education

    Science.gov (United States)

    Konishi, Takeshi; Tamura, Yoko; Moriguchi, Hiroki

    2012-01-01

    Background Medical students often have difficulty achieving a conceptual understanding of 3-dimensional (3D) anatomy, such as bone alignment, muscles, and complex movements, from 2-dimensional (2D) images. To this end, animated and interactive 3-dimensional computer graphics (3DCG) can provide better visual information to users. In medical fields, research on the advantages of 3DCG in medical education is relatively new. Objective To determine the educational effectiveness of interactive 3DCG. Methods We divided 100 participants (27 men, mean (SD) age 17.9 (0.6) years, and 73 women, mean (SD) age 18.1 (1.1) years) from the Health Sciences University of Mongolia (HSUM) into 3DCG (n = 50) and textbook-only (control) (n = 50) groups. The control group used a textbook and 2D images, while the 3DCG group was trained to use the interactive 3DCG shoulder model in addition to a textbook. We conducted a questionnaire survey via an encrypted satellite network between HSUM and Tokushima University. The questionnaire was scored on a 5-point Likert scale from strongly disagree (score 1) to strongly agree (score 5). Results Interactive 3DCG was effective in undergraduate medical education. Specifically, there was a significant difference in mean (SD) scores between the 3DCG and control groups in their response to questionnaire items regarding content (4.26 (0.69) vs 3.85 (0.68), P = .001) and teaching methods (4.33 (0.65) vs 3.74 (0.79), P < .001), but no significant difference in the Web category. Participants also provided meaningful comments on the advantages of interactive 3DCG. Conclusions Interactive 3DCG materials have positive effects on medical education when properly integrated into conventional education. In particular, our results suggest that interactive 3DCG is more efficient than textbooks alone in medical education and can motivate students to understand complex anatomical structures. PMID:23611759

  19. MAGNET

    CERN Multimedia

    Benoit Curé

    2013-01-01

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

  20. MAGNET

    CERN Multimedia

    Benoit Curé

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

  1. MAGNET

    CERN Multimedia

    B. Curé

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

  2. Magnetic

    Science.gov (United States)

    Aboud, Essam; El-Masry, Nabil; Qaddah, Atef; Alqahtani, Faisal; Moufti, Mohammed R. H.

    2015-06-01

    The Rahat volcanic field represents one of the widely distributed Cenozoic volcanic fields across the western regions of the Arabian Peninsula. Its human significance stems from the fact that its northern fringes, where the historical eruption of 1256 A.D. took place, are very close to the holy city of Al-Madinah Al-Monawarah. In the present work, we analyzed aeromagnetic data from the northern part of Rahat volcanic field as well as carried out a ground gravity survey. A joint interpretation and inversion of gravity and magnetic data were used to estimate the thickness of the lava flows, delineate the subsurface structures of the study area, and estimate the depth to basement using various geophysical methods, such as Tilt Derivative, Euler Deconvolution and 2D modeling inversion. Results indicated that the thickness of the lava flows in the study area ranges between 100 m (above Sea Level) at the eastern and western boundaries of Rahat Volcanic field and getting deeper at the middle as 300-500 m. It also showed that, major structural trend is in the NW direction (Red Sea trend) with some minor trends in EW direction.

  3. Stress analysis in platform-switching implants: a 3-dimensional finite element study.

    Science.gov (United States)

    Pellizzer, Eduardo Piza; Verri, Fellippo Ramos; Falcón-Antenucci, Rosse Mary; Júnior, Joel Ferreira Santiago; de Carvalho, Paulo Sérgio Perri; de Moraes, Sandra Lúcia Dantas; Noritomi, Pedro Yoshito

    2012-10-01

    The aim of this study was to evaluate the influence of the platform-switching technique on stress distribution in implant, abutment, and peri-implant tissues, through a 3-dimensional finite element study. Three 3-dimensional mandibular models were fabricated using the SolidWorks 2006 and InVesalius software. Each model was composed of a bone block with one implant 10 mm long and of different diameters (3.75 and 5.00 mm). The UCLA abutments also ranged in diameter from 5.00 mm to 4.1 mm. After obtaining the geometries, the models were transferred to the software FEMAP 10.0 for pre- and postprocessing of finite elements to generate the mesh, loading, and boundary conditions. A total load of 200 N was applied in axial (0°), oblique (45°), and lateral (90°) directions. The models were solved by the software NeiNastran 9.0 and transferred to the software FEMAP 10.0 to obtain the results that were visualized through von Mises and maximum principal stress maps. Model A (implants with 3.75 mm/abutment with 4.1 mm) exhibited the highest area of stress concentration with all loadings (axial, oblique, and lateral) for the implant and the abutment. All models presented the stress areas at the abutment level and at the implant/abutment interface. Models B (implant with 5.0 mm/abutment with 5.0 mm) and C (implant with 5.0 mm/abutment with 4.1 mm) presented minor areas of stress concentration and similar distribution pattern. For the cortical bone, low stress concentration was observed in the peri-implant region for models B and C in comparison to model A. The trabecular bone exhibited low stress that was well distributed in models B and C. Model A presented the highest stress concentration. Model B exhibited better stress distribution. There was no significant difference between the large-diameter implants (models B and C).

  4. [Our experiences with the use of 3-dimensional meshes to prevent and to repair parastomal hernias].

    Science.gov (United States)

    Jánó, Zoltán; Mohos, Elemér; Réti, György; Kovács, Tamás; Mohay, József; Berki, Csaba; Horváth, Sándor; Bene, Krisztina; Horzov, Myroslav; Bognár, Gábor; Sándor, Gábor; Szenkovits, Péter; Mohos, Petra; Tornai, Gábor; Nagy, Attila

    2016-12-01

    Albeit there is decreasing tendency nowadays for stoma construction, if it still happens, parastomal herniation might occur in up to 50% of cases afterwards. One third of the cases requires surgical correction, not rarely as an emergency. The different methods of repair can be quite demanding and the complication rates are high. From 2003 we have started to use specially designed 3-dimensional meshes for the prevention and repair of parastomal hernias. From 1st of January 2012 to 1st of June 2016 we have used these devices within the framework of a prospective, controlled, randomized study enrolling the patients in preventive and repair arms. Until now mesh was implanted for prevention at the time of the index operation in 38 cases, (control group: 46 cases), and for repair in 14 cases (control group: 18 cases). Recruitment of the patients will end in 2017. The operations were performed by laparoscopic approach in 22 cases and by open approach in 62 cases in the preventive arm, and 6/26 cases in the repair arm respectively. Mean follow up period is 19.2 months in the mesh group and 22.6 months in the non mesh group in the preventive arm, and 25.9/20.4 months in the repair arm respectively. No statistical analysis was used to interpret these interim results in this paper, we intend to analyze our results at the end of the study. At this stage apparently there is no difference between the group of patients in terms of complications in both arms. Parastomal herniation was found in 18 cases (39.1%) in the non mesh group and in 3 cases (7.8%) in the mesh group in the preventive arm. Recurrency was noted in 8 cases (44%) in the non mesh group, and in 1 case (7.1%) in the mesh group in the repair arm. Our results correlate with other studies where mesh insertion was used to prevent and/or repair parastomal hernias. We attribute these results mainly to the special, 3-dimensional design of the meshes used by us. This construction was developed based on understanding the

  5. Duplication of complete dentures using general-purpose handheld optical scanner and 3-dimensional printer: Introduction and clinical considerations.

    Science.gov (United States)

    Kurahashi, Kosuke; Matsuda, Takashi; Goto, Takaharu; Ishida, Yuichi; Ito, Teruaki; Ichikawa, Tetsuo

    2017-01-01

    To introduce a new clinical procedure for fabricating duplicates of complete dentures by bite pressure impression using digital technology, and to discuss its clinical significance. The denture is placed on a rotary table and the 3-dimensional form of the denture is digitized using a general-purpose handheld optical scanner. The duplicate denture is made of polylactic acid by a 3-dimensional printer using the 3-dimensional data. This procedure has the advantages of wasting less material, employing less human power, decreasing treatment time at the chair side, lowering the rates of contamination, and being readily fabricated at the time of the treatment visit. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  6. A 3-Dimensional discrete fracture network generator to examine fracture-matrix interaction using TOUGH2

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Kazumasa; Yongkoo, Seol

    2003-04-09

    Water fluxes in unsaturated, fractured rock involve the physical processes occurring at fracture-matrix interfaces within fracture networks. Modeling these water fluxes using a discrete fracture network model is a complicated effort. Existing preprocessors for TOUGH2 are not suitable to generate grids for fracture networks with various orientations and inclinations. There are several 3-D discrete-fracture-network simulators for flow and transport, but most of them do not capture fracture-matrix interaction. We have developed a new 3-D discrete-fracture-network mesh generator, FRACMESH, to provide TOUGH2 with information about the fracture network configuration and fracture-matrix interactions. FRACMESH transforms a discrete fracture network into a 3 dimensional uniform mesh, in which fractures are considered as elements with unique rock material properties and connected to surrounding matrix elements. Using FRACMESH, individual fractures may have uniform or random aperture distributions to consider heterogeneity. Fracture element volumes and interfacial areas are calculated from fracture geometry within individual elements. By using FRACMESH and TOUGH2, fractures with various inclinations and orientations, and fracture-matrix interaction, can be incorporated. In this paper, results of flow and transport simulations in a fractured rock block utilizing FRACMESH are presented.

  7. The effect of stereoscopic anaglyphic 3-dimensional video didactics on learning neuroanatomy.

    Science.gov (United States)

    Goodarzi, Amir; EdM, Sara Monti; Lee, Darrin; Girgis, Fady

    2017-07-29

    The teaching of neuroanatomy in medical education has historically been based on didactic instruction, cadaveric dissections, and intra-operative experience for students. Multiple novel 3-Dimensional (3D) modalities have recently emerged. Among these, stereoscopic anaglyphic video is easily accessible and affordable, however, its effects have not yet formally been investigated. This study aimed to investigate if 3D stereoscopic anaglyphic video instruction in neuroanatomy could improve learning for content-naive students, as compared to 2D video instruction. A single-site controlled prospective case control study was conducted at the School of Education. Content knowledge was assessed at baseline, followed by the presentation of an instructional neuroanatomy video. Participants viewed the video in either 2D or 3D format, then completed a written test of skull base neuroanatomy. Pre-test and post-test performances were analyzed with independent t-tests and ANCOVA. 249 subjects completed the study. At baseline, the 2D (n=124, F=97) and 3D groups (n=125, F=96) were similar, although the 3D group was older by 1.7 years (p=.0355) and the curricula of participating classes differed (pvideo instruction into curricula without careful integration is insufficient to promote learning over 2D video. Published by Elsevier Inc.

  8. Research on the method of cavitations resistance in a piezoelectric pump with 3-dimensional mesh structure

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jian-hui; XIA Qi-xiao; Bai Heng-jun; NING Hong-gang; ONUKI Akiyoshi

    2006-01-01

    The volume valve piezoelectric pump has received increasing attention from many areas because of its different characteristics such as the absence of chemical pollution and electromagnetic pollution.However,when the pump is working,it produces cavitations and the air bubbles that originate from these will flow out of the pump.Cavitations occurring in the pump will bring out noise and shorten the life of the pump.Furthermore,air bubbles flowing out of the pump will hinder its application in areas such as medical treatment and health care where blood transfusion and infusion are concerned.As a solution to this disadvantage,the CR3DMS (cavitations resistance with 3-dimensional mesh structure) method is developed,which is tested and verified to be effective on not only reducing the occurrence of cavitations and eliminating cavitations' flowing out,but also restraining the emission of noise.In conclusion,the pump with CR3DMS,on the relationship between flow and driving frequency and the relationship between flow and the number of Resistant-Layers in both theory and test,are analyzed.

  9. Embedding and publishing interactive, 3-dimensional, scientific figures in Portable Document Format (PDF) files.

    Science.gov (United States)

    Barnes, David G; Vidiassov, Michail; Ruthensteiner, Bernhard; Fluke, Christopher J; Quayle, Michelle R; McHenry, Colin R

    2013-01-01

    With the latest release of the S2PLOT graphics library, embedding interactive, 3-dimensional (3-d) scientific figures in Adobe Portable Document Format (PDF) files is simple, and can be accomplished without commercial software. In this paper, we motivate the need for embedding 3-d figures in scholarly articles. We explain how 3-d figures can be created using the S2PLOT graphics library, exported to Product Representation Compact (PRC) format, and included as fully interactive, 3-d figures in PDF files using the movie15 LaTeX package. We present new examples of 3-d PDF figures, explain how they have been made, validate them, and comment on their advantages over traditional, static 2-dimensional (2-d) figures. With the judicious use of 3-d rather than 2-d figures, scientists can now publish, share and archive more useful, flexible and faithful representations of their study outcomes. The article you are reading does not have embedded 3-d figures. The full paper, with embedded 3-d figures, is recommended and is available as a supplementary download from PLoS ONE (File S2).

  10. The Usefulness of 3-Dimensional Virtual Simulation Using Haptics in Training Orotracheal Intubation

    Directory of Open Access Journals (Sweden)

    Dong Hoon Lee

    2013-01-01

    Full Text Available Objectives. Airway control is the most critical treatment. The most common and basic method of endotracheal intubation is orotracheal intubation. To perform accurate and rapid tracheal intubation, appropriate education and training are required. We developed the virtual simulation program utilizing the 3-dimensional display and haptic device to exercise orotracheal intubation, and the educational effect of this program was compared with that of the mannequin method. Method. The control group used airway mannequin and virtual intubation group was trained with new program. We videotaped both groups during objective structured clinical examination (OSCE with airway mannequin. The video was reviewed and scored, and the rate of success and time were calculated. Result. The success rate was 78.6% in virtual intubation group and 93.3% in control group (P=0.273. There was no difference in overall score of OSCE (21.14 ± 4.28 in virtual intubation group and 23.33 ± 4.45 in control group, P=0.188, the time spent in successful intubation (P=0.432, and the number of trials (P>0.101. Conclusion. The virtual simulation with haptics had a similar effect compared with mannequin, but it could be more cost effective and convenient than mannequin training in time and space.

  11. Optimal iodine dose for 3-dimensional multidetector-row CT angiography of the liver

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, Tomoaki, E-mail: ichikawa@yamanashi.ac.jp [Department of Radiology, University of Yamanashi, Yamanashi (Japan); Motosugi, Utaroh; Morisaka, Hiroyuki; Sou, Hironobu; Onohara, Kojiro; Sano, Katsuhiro; Araki, Tsutomu [Department of Radiology, University of Yamanashi, Yamanashi (Japan)

    2012-09-15

    Purpose: To clarify the optimal iodine dose of contrast material for 3-dimensional multidetector-row CT angiography (3D-MDCTA) of the venous vasculature of the liver using volume rendering technique. Materials and methods: This study included 103 patients who were randomly assigned to 5 contrast-enhanced MDCT protocol groups with different body-weight-tailored doses of contrast material: 500, 600, 630, 650, and 700 mgI/kg body weight. The arterial, portal, and hepatic parenchymal phases were obtained to evaluate enhancement values of the aorta, portal vein, and hepatic vein. Visualization of the portal and hepatic veins on the volume-rendering images of 3D-MDCTA was evaluated using a 5-point grade. Dunnett's test was used to compare the mean enhancement value and mean grades of image quality (700 mgI/kg dose group was control). Results: The mean enhancement values of portal and hepatic vein in the group with 500 and 600 mgI/kg were significantly lower than those of the control group. During visual assessment, a significantly lower mean grades were observed in 500 mgI/kg groups for the portal vein, and 500 and 600 mgI/kg groups for hepatic vein. There were no significant intergroup differences in mean enhancement values and visual assessment among the groups using 630 mgI/kg or more. Conclusion: Iodine doses of 630 mgI/kg was recommended for 3D-MDCTA.

  12. Assessment and Planning for a Pediatric Bilateral Hand Transplant Using 3-Dimensional Modeling: Case Report.

    Science.gov (United States)

    Gálvez, Jorge A; Gralewski, Kevin; McAndrew, Christine; Rehman, Mohamed A; Chang, Benjamin; Levin, L Scott

    2016-03-01

    Children are not typically considered for hand transplantation for various reasons, including the difficulty of finding an appropriate donor. Matching donor-recipient hands and forearms based on size is critically important. If the donor's hands are too large, the recipient may not be able to move the fingers effectively. Conversely, if the donor's hands are too small, the appearance may not be appropriate. We present an 8-year-old child evaluated for a bilateral hand transplant following bilateral amputation. The recipient forearms and model hands were modeled from computed tomography imaging studies and replicated as anatomic models with a 3-dimensional printer. We modified the scale of the printed hand to produce 3 proportions, 80%, 100% and 120%. The transplant team used the anatomical models during evaluation of a donor for appropriate match based on size. The donor's hand size matched the 100%-scale anatomical model hand and the transplant team was activated. In addition to assisting in appropriate donor selection by the transplant team, the 100%-scale anatomical model hand was used to create molds for prosthetic hands for the donor.

  13. Characterization of 3-dimensional superconductive thin film components for gravitational experiments in space

    Energy Technology Data Exchange (ETDEWEB)

    Hechler, S.; Nawrodt, R.; Nietzsche, S.; Vodel, W.; Seidel, P. [Friedrich-Schiller-Univ. Jena (Germany). Inst. fuer Festkoerperphysik; Dittus, H. [ZARM, Univ. Bremen (Germany); Loeffler, F. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)

    2007-07-01

    Superconducting quantum interference devices (SQUIDs) are used for high precise gravitational experiments. One of the most impressive experiments is the satellite test of the equivalence principle (STEP) of NASA/ESA. The STEP mission aims to prove a possible violation of Einstein's equivalence principle at an extreme level of accuracy of 1 part in 10{sup 18} in space. In this contribution we present an automatically working measurement equipment to characterize 3-dimensional superconducting thin film components like i.e. pick-up coils and test masses for STEP. The characterization is done by measurements of the transition temperature between the normal and the superconducting state using a special built anti-cryostat. Above all the setup was designed for use in normal LHe transport Dewars. The sample chamber has a volume of 150 cm{sup 3} and can be fully temperature controlled over a range from 4.2 K to 300 K with a resolution of better then 100 mK. (orig.)

  14. Guided Autotransplantation of Teeth: A Novel Method Using Virtually Planned 3-dimensional Templates.

    Science.gov (United States)

    Strbac, Georg D; Schnappauf, Albrecht; Giannis, Katharina; Bertl, Michael H; Moritz, Andreas; Ulm, Christian

    2016-12-01

    The aim of this study was to introduce an innovative method for autotransplantation of teeth using 3-dimensional (3D) surgical templates for guided osteotomy preparation and donor tooth placement. This report describes autotransplantation of immature premolars as treatment of an 11-year-old boy having suffered severe trauma with avulsion of permanent maxillary incisors. This approach uses modified methods from guided implant surgery by superimposition of Digital Imaging and Communications in Medicine files and 3D data sets of the jaws in order to predesign 3D printed templates with the aid of a fully digital workflow. The intervention in this complex case could successfully be accomplished by performing preplanned virtual transplantations with guided osteotomies to prevent bone loss and ensure accurate donor teeth placement in new recipient sites. Functional and esthetic restoration could be achieved by modifying methods used in guided implant surgery and prosthodontic rehabilitation. The 1-year follow-up showed vital natural teeth with physiological clinical and radiologic parameters. This innovative approach uses the latest diagnostic methods and techniques of guided implant surgery, enabling the planning and production of 3D printed surgical templates. These accurate virtually predesigned surgical templates could facilitate autotransplantation in the future by full implementation of recommended guidelines, ensuring an atraumatic surgical protocol. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. Pilot study of endoscopic retrograde 3-dimensional - computed tomography enteroclysis for the assessment of Crohn's disease.

    Science.gov (United States)

    Tanabe, Hiroki; Ito, Takahiro; Inaba, Yuhei; Ando, Katsuyoshi; Nomura, Yoshiki; Ueno, Nobuhiro; Kashima, Shin; Moriichi, Kentaro; Fujiya, Mikihiro; Okumura, Toshikatsu

    2017-01-01

    Endoscopic retrograde ileography (ERIG) is developed in our institute and applied clinically for the diagnosis and assessment of the Crohn's disease activity. We have further improved the technique using 3-dimensional - computed tomography enteroclysis (3D-CTE) and conducted a retrospective study to determine the feasibility and the diagnostic value of endoscopic retrograde 3D-CTE (ER 3D-CTE) in Crohn's disease patients in a state of remission. Thirteen Crohn's patients were included in this pilot study. CTE was performed after the infusion of air or CO2 through the balloon tube following conventional colonoscopy. The primary endpoint of this study was to assess the safety of this method. Secondarily, the specific findings of Crohn's disease and length of the visualized small intestine were assessed. The procedures were completed without any adverse events. Gas passed through the small intestine and enterographic images were obtained in 10 out of 13 cases, but, in the remaining patients, insertion of the balloon tubes into the terminal ileum failed. Various features specific to Crohn's disease were visualized using ER 3D-CTE. A cobble stone appearance or hammock-like malformation was specific and effective for diagnosing Crohn's disease and the features of anastomosis after the surgical operations were also well described. Therefore, this technique may be useful after surgery. In this study, ER 3D-CTE was performed safely in Crohn's disease patients and may be used for the diagnosis and follow-up of this disease.

  16. Tunneling currents between carbon nanotubes inside the 3-dimensional potential of a dielectric matrix

    Science.gov (United States)

    Tsagarakis, M. S.; Xanthakis, J. P.

    2017-07-01

    We have examined the tunneling currents between CNTs dispersed in a dielectric matrix as is normally the case in a tensile stress or toxic gas sensors. Due to the randomness of the immersion process the CNTs are at random angles and configurations between them, thus producing a 3-dimensional potential (3-D). We have produced a method that solves the Laplace equation for this type of problem and uses the WKB formulation to calculate the transmission coefficient between CNTs. We have then shown that the tunneling currents between a pair of CNTs depend critically on their relative angle and configuration. In particular we have shown that the tunneling currents do not occur only along a CNT tip to CNT tip configuration but other more efficient paths exist which give a current higher by two orders of magnitude from what a simple 1D theory would give. On the other hand the tunneling current between non-coplanar CNTs is negligible. We conclude that such phenomena cannot be analyzed by a simple 1-dimensional WKB theory and the percolation threshold necessary for conduction may be lower than the one such a theory would predict.

  17. Feasibility of 3-dimensional video-assisted thoracic surgery (3D-VATS) for pulmonary resection.

    Science.gov (United States)

    Dickhoff, Chris; Li, Wilson W; Symersky, Petr; Hartemink, Koen J

    2015-01-01

    Two-dimensional video-assisted thoracic surgery (2D-VATS) has gained its position in daily practise. Although very useful, its two-dimensional view has its drawbacks when performing pulmonary resections. We report our first experience with 3-dimensional video-assisted surgery (3D-VATS). Advantages and differences with 2D-VATS and robotic surgery (RS) are discussed. To evaluate feasibility, we scheduled patients for surgery by 3D-VATS who would normally be treated with 2D-VATS. The main difference of the equipment in 3D-VATS compared with former VATS equipment, is the flexible camera-tip (100-degrees) and the necessary 3D-glasses. Four patients were successfully operated for anatomic pulmonary resections. On-the-structure dissection was easily performed and with the flexible camera-tip, a perfect view can be obtained, with clear visualisation of important (hilar) structures. These features highly facilitate the surgeon in tissue preparation and recognition of the dissection planes. In our opinion, 3D-VATS is superior to 2D-VATS for performing anatomic pulmonary resection and we expect an improvement in terms of operation time and learning curve. Furthermore, it is a valuable alternative for RS at lower costs.

  18. Hamiltonian Analysis of 3-Dimensional Connection Dynamics in Bondi-like Coordinates

    Science.gov (United States)

    Huang, Chao-Guang; Kong, Shi-Bei

    2017-08-01

    The Hamiltonian analysis for a 3-dimensional connection dynamics of {s}{o}(1,2), spanned by {L-+, L-2, L+2 } instead of {L01, L02, L12 }, is first conducted in a Bondi-like coordinate system. The symmetry of the system is clearly presented. A null coframe with 3 independent variables and 9 connection coefficients are treated as basic configuration variables. All constraints and their consistency conditions, the solutions of Lagrange multipliers as well as the equations of motion are presented. There is no physical degree of freedom in the system. The Bañados-Teitelboim-Zanelli (BTZ) spacetime is discussed as an example to check the analysis. Unlike the ADM formalism, where only non-degenerate geometries on slices are dealt with and the Ashtekar formalism, where non-degenerate geometries on slices are mainly concerned though the degenerate geometries may be studied as well, in the present formalism the geometries on the slices are always degenerate though the geometries for the spacetime are not degenerate. Supported by National Natural Science Foundation of China under Grant Nos. 11275207 and 11690022

  19. Scaffold Free Bio-orthogonal Assembly of 3-Dimensional Cardiac Tissue via Cell Surface Engineering

    Science.gov (United States)

    Rogozhnikov, Dmitry; O’Brien, Paul J.; Elahipanah, Sina; Yousaf , Muhammad N.

    2016-01-01

    There has been tremendous interest in constructing in vitro cardiac tissue for a range of fundamental studies of cardiac development and disease and as a commercial system to evaluate therapeutic drug discovery prioritization and toxicity. Although there has been progress towards studying 2-dimensional cardiac function in vitro, there remain challenging obstacles to generate rapid and efficient scaffold-free 3-dimensional multiple cell type co-culture cardiac tissue models. Herein, we develop a programmed rapid self-assembly strategy to induce specific and stable cell-cell contacts among multiple cell types found in heart tissue to generate 3D tissues through cell-surface engineering based on liposome delivery and fusion to display bio-orthogonal functional groups from cell membranes. We generate, for the first time, a scaffold free and stable self assembled 3 cell line co-culture 3D cardiac tissue model by assembling cardiomyocytes, endothelial cells and cardiac fibroblast cells via a rapid inter-cell click ligation process. We compare and analyze the function of the 3D cardiac tissue chips with 2D co-culture monolayers by assessing cardiac specific markers, electromechanical cell coupling, beating rates and evaluating drug toxicity. PMID:28008983

  20. 3-DIMENSIONAL Numerical Modeling on the Combustion and Emission Characteristics of Biodiesel in Diesel Engines

    Science.gov (United States)

    Yang, Wenming; An, Hui; Amin, Maghbouli; Li, Jing

    2014-11-01

    A 3-dimensional computational fluid dynamics modeling is conducted on a direct injection diesel engine fueled by biodiesel using multi-dimensional software KIVA4 coupled with CHEMKIN. To accurately predict the oxidation of saturated and unsaturated agents of the biodiesel fuel, a multicomponent advanced combustion model consisting of 69 species and 204 reactions combined with detailed oxidation pathways of methyl decenoate (C11H22O2), methyl-9-decenoate (C11H20O2) and n-heptane (C7H16) is employed in this work. In order to better represent the real fuel properties, the detailed chemical and thermo-physical properties of biodiesel such as vapor pressure, latent heat of vaporization, liquid viscosity and surface tension were calculated and compiled into the KIVA4 fuel library. The nitrogen monoxide (NO) and carbon monoxide (CO) formation mechanisms were also embedded. After validating the numerical simulation model by comparing the in-cylinder pressure and heat release rate curves with experimental results, further studies have been carried out to investigate the effect of combustion chamber design on flow field, subsequently on the combustion process and performance of diesel engine fueled by biodiesel. Research has also been done to investigate the impact of fuel injector location on the performance and emissions formation of diesel engine.

  1. Systematic Review of the Use of 3-Dimensional Printing in Surgical Teaching and Assessment.

    Science.gov (United States)

    Langridge, Benjamin; Momin, Sheikh; Coumbe, Ben; Woin, Evelina; Griffin, Michelle; Butler, Peter

    2017-07-17

    The use of 3-dimensional (3D) printing in medicine has rapidly expanded in recent years as the technology has developed. The potential uses of 3D printing are manifold. This article provides a systematic review of the uses of 3D printing within surgical training and assessment. A structured literature search of the major literature databases was performed in adherence to PRISMA guidelines. Articles that met predefined inclusion and exclusion criteria were appraised with respect to the key objectives of the review and sources of bias were analysed. Overall, 49 studies were identified for inclusion in the qualitative analysis. Heterogeneity in study design and outcome measures used prohibited meaningful meta-analysis. 3D printing has been used in surgical training across a broad range of specialities but most commonly in neurosurgery and otorhinolaryngology. Both objective and subjective outcome measures have been studied, demonstrating the usage of 3D printed models in training and education. 3D printing has also been used in anatomical education and preoperative planning, demonstrating improved outcomes when compared to traditional educational methods and improved patient outcomes, respectively. 3D printing technology has a broad range of potential applications within surgical education and training. Although the field is still in its relative infancy, several studies have already demonstrated its usage both instead of and in addition to traditional educational methods. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  2. Current Status of 3-Dimensional Speckle Tracking Echocardiography: A Review from Our Experiences

    Science.gov (United States)

    Ishizu, Tomko; Aonuma, Kazutaka

    2014-01-01

    Cardiac function analysis is the main focus of echocardiography. Left ventricular ejection fraction (LVEF) has been the clinical standard, however, LVEF is not enough to investigate myocardial function. For the last decade, speckle tracking echocardiography (STE) has been the novel clinical tool for regional and global myocardial function analysis. However, 2-dimensional imaging methods have limitations in assessing 3-dimensional (3D) cardiac motion. In contrast, 3D echocardiography also has been widely used, in particular, to measure LV volume measurements and assess valvular diseases. Joining the technology bandwagon, 3D-STE was introduced in 2008. Experimental studies and clinical investigations revealed the reliability and feasibility of 3D-STE-derived data. In addition, 3D-STE provides a novel deformation parameter, area change ratio, which have the potential for more accurate assessment of overall and regional myocardial function. In this review, we introduced the features of the methodology, validation, and clinical application of 3D-STE based on our experiences for 7 years. PMID:25031794

  3. Dissection of the host-pathogen interaction in human tuberculosis using a bioengineered 3-dimensional model

    Science.gov (United States)

    Tezera, Liku B; Bielecka, Magdalena K; Chancellor, Andrew; Reichmann, Michaela T; Shammari, Basim Al; Brace, Patience; Batty, Alex; Tocheva, Annie; Jogai, Sanjay; Marshall, Ben G; Tebruegge, Marc; Jayasinghe, Suwan N; Mansour, Salah; Elkington, Paul T

    2017-01-01

    Cell biology differs between traditional cell culture and 3-dimensional (3-D) systems, and is modulated by the extracellular matrix. Experimentation in 3-D presents challenges, especially with virulent pathogens. Mycobacterium tuberculosis (Mtb) kills more humans than any other infection and is characterised by a spatially organised immune response and extracellular matrix remodelling. We developed a 3-D system incorporating virulent mycobacteria, primary human blood mononuclear cells and collagen–alginate matrix to dissect the host-pathogen interaction. Infection in 3-D led to greater cellular survival and permitted longitudinal analysis over 21 days. Key features of human tuberculosis develop, and extracellular matrix integrity favours the host over the pathogen. We optimised multiparameter readouts to study emerging therapeutic interventions: cytokine supplementation, host-directed therapy and immunoaugmentation. Each intervention modulates the host-pathogen interaction, but has both beneficial and harmful effects. This methodology has wide applicability to investigate infectious, inflammatory and neoplastic diseases and develop novel drug regimes and vaccination approaches. DOI: http://dx.doi.org/10.7554/eLife.21283.001 PMID:28063256

  4. Casting of 3-dimensional footwear prints in snow with foam blocks.

    Science.gov (United States)

    Petraco, Nicholas; Sherman, Hal; Dumitra, Aurora; Roberts, Marcel

    2016-06-01

    Commercially available foam blocks are presented as an alternative material for the casting and preservation of 3-dimensional footwear impressions located in snow. The method generates highly detailed foam casts of questioned footwear impressions. These casts can be compared to the known outsole standards made from the suspects' footwear. Modification of the commercially available foam casting blocks is simple and fast. The foam block is removed and a piece of cardboard is secured to one side of the block with painter's masking tape. The prepared foam block is then placed back into its original box, marked appropriately, closed and stored until needed. When required the foam block is carefully removed from its storage box and gently placed, foam side down, over the questioned footwear impression. Next, the crime scene technician's hands are placed on top of the cardboard and pressure is gently applied by firmly pressing down onto the impression. The foam cast is removed, dried and placed back into its original container and sealed. The resulting 3D impressions can be directly compared to the outsole of known suspected item(s) of footwear.

  5. Superimposition of 3-dimensional cone-beam computed tomography models of growing patients

    Science.gov (United States)

    Cevidanes, Lucia H. C.; Heymann, Gavin; Cornelis, Marie A.; DeClerck, Hugo J.; Tulloch, J. F. Camilla

    2009-01-01

    Introduction The objective of this study was to evaluate a new method for superimposition of 3-dimensional (3D) models of growing subjects. Methods Cone-beam computed tomography scans were taken before and after Class III malocclusion orthopedic treatment with miniplates. Three observers independently constructed 18 3D virtual surface models from cone-beam computed tomography scans of 3 patients. Separate 3D models were constructed for soft-tissue, cranial base, maxillary, and mandibular surfaces. The anterior cranial fossa was used to register the 3D models of before and after treatment (about 1 year of follow-up). Results Three-dimensional overlays of superimposed models and 3D color-coded displacement maps allowed visual and quantitative assessment of growth and treatment changes. The range of interobserver errors for each anatomic region was 0.4 mm for the zygomatic process of maxilla, chin, condyles, posterior border of the rami, and lower border of the mandible, and 0.5 mm for the anterior maxilla soft-tissue upper lip. Conclusions Our results suggest that this method is a valid and reproducible assessment of treatment outcomes for growing subjects. This technique can be used to identify maxillary and mandibular positional changes and bone remodeling relative to the anterior cranial fossa. PMID:19577154

  6. A Novel Method of Orbital Floor Reconstruction Using Virtual Planning, 3-Dimensional Printing, and Autologous Bone.

    Science.gov (United States)

    Vehmeijer, Maarten; van Eijnatten, Maureen; Liberton, Niels; Wolff, Jan

    2016-08-01

    Fractures of the orbital floor are often a result of traffic accidents or interpersonal violence. To date, numerous materials and methods have been used to reconstruct the orbital floor. However, simple and cost-effective 3-dimensional (3D) printing technologies for the treatment of orbital floor fractures are still sought. This study describes a simple, precise, cost-effective method of treating orbital fractures using 3D printing technologies in combination with autologous bone. Enophthalmos and diplopia developed in a 64-year-old female patient with an orbital floor fracture. A virtual 3D model of the fracture site was generated from computed tomography images of the patient. The fracture was virtually closed using spline interpolation. Furthermore, a virtual individualized mold of the defect site was created, which was manufactured using an inkjet printer. The tangible mold was subsequently used during surgery to sculpture an individualized autologous orbital floor implant. Virtual reconstruction of the orbital floor and the resulting mold enhanced the overall accuracy and efficiency of the surgical procedure. The sculptured autologous orbital floor implant showed an excellent fit in vivo. The combination of virtual planning and 3D printing offers an accurate and cost-effective treatment method for orbital floor fractures.

  7. A customized bolus produced using a 3-dimensional printer for radiotherapy.

    Science.gov (United States)

    Kim, Shin-Wook; Shin, Hun-Joo; Kay, Chul Seung; Son, Seok Hyun

    2014-01-01

    Boluses are used in high-energy radiotherapy in order to overcome the skin sparing effect. In practice though, commonly used flat boluses fail to make a perfect contact with the irregular surface of the patient's skin, resulting in air gaps. Hence, we fabricated a customized bolus using a 3-dimensional (3D) printer and evaluated its feasibility for radiotherapy. We designed two kinds of bolus for production on a 3D printer, one of which was the 3D printed flat bolus for the Blue water phantom and the other was a 3D printed customized bolus for the RANDO phantom. The 3D printed flat bolus was fabricated to verify its physical quality. The resulting 3D printed flat bolus was evaluated by assessing dosimetric parameters such as D1.5 cm, D5 cm, and D10 cm. The 3D printed customized bolus was then fabricated, and its quality and clinical feasibility were evaluated by visual inspection and by assessing dosimetric parameters such as Dmax, Dmin, Dmean, D90%, and V90%. The dosimetric parameters of the resulting 3D printed flat bolus showed that it was a useful dose escalating material, equivalent to a commercially available flat bolus. Analysis of the dosimetric parameters of the 3D printed customized bolus demonstrated that it is provided good dose escalation and good contact with the irregular surface of the RANDO phantom. A customized bolus produced using a 3D printer could potentially replace commercially available flat boluses.

  8. Ionizing radiation-induced adaptive response in fibroblasts under both monolayer and 3-dimensional conditions.

    Science.gov (United States)

    Zhao, Yinlong; Zhong, Rui; Sun, Liguang; Jia, Jie; Ma, Shumei; Liu, Xiaodong

    2015-01-01

    To observe the adaptive response (AR) induced by ionizing radiation in human fibroblasts under monolayer and 3-dimensional (3-D) condition. Three kinds of fibroblasts were cultured under both monolayer and 3-D condition. Immunofluorescent staining was used to detect the γ-H2AX foci and the morphological texture. Trypan blue staining was used to detect the cell death. Western blot was used to detect the expressions of γ-H2AX, p53 and CDKN1A/p21 (p21). We found that DNA damage increased in a dose-dependent and time-dependent manner after high doses of radiation. When cells were pretreated with a priming low dose of radiation followed by high dose radiation, DNA damage was attenuated under both monolayer and 3-D condition, and the adaptive response (AR) was induced. Additionally, the morphology of cells under monolayer and 3-D conditions were different, and radiation also induced AR according to morphological texture analysis. Priming low dose radiation induced AR both under monolayer and 3-D condition. Interestingly, 3-D microenvironment made cells more sensitive to radiation. The expression of p53 and p21 was changed and indicated that they might participate in the regulation of AR.

  9. Development of a 3-Dimensional Dosimetry System for Leksell Gamma Knife-Perfexion

    CERN Document Server

    Yoon, KyoungJun; Lee, DoHeui; Cho, ByungChul; Lee, SangWook; Ahn, SeungDo

    2015-01-01

    The purpose of our study is to develop a new, 3-dimensional dosimetry system to verify the accuracy of dose deliveries in Leksell Gamma Knife-Perfexion TM (LGKP) (Elekta, Norcross, GA, USA). The instrument consists of a moving head phantom, an embedded thin active layer and a CCD camera system and was designed to be mounted to LGKP. As an active material concentrically located in the hemispheric head phantom, we choose Gafchromic EBT3 films and Gd2O2S;Tb phosphor sheets for dosimetric measurements. Also, to compensate the lack of backscatter, we located a 1 cm thick PMMA plate downstream of the active layer. The PMMA plate was transparent for scintillation lights to reach the CCD with 1200x1200 pixels by a 5.2 um pitch. Using this system, three hundred images by a 0.2 mm slice gap were acquired under each of three collimator setups, i.e. 4 mm, 8 mm, and 16 mm, respectively. The 2D projected images taken by CCD camera were compared with the dose distributions measured by EBT3 films in the same conditions. All ...

  10. Scaffold Free Bio-orthogonal Assembly of 3-Dimensional Cardiac Tissue via Cell Surface Engineering

    Science.gov (United States)

    Rogozhnikov, Dmitry; O’Brien, Paul J.; Elahipanah, Sina; Yousaf, Muhammad N.

    2016-12-01

    There has been tremendous interest in constructing in vitro cardiac tissue for a range of fundamental studies of cardiac development and disease and as a commercial system to evaluate therapeutic drug discovery prioritization and toxicity. Although there has been progress towards studying 2-dimensional cardiac function in vitro, there remain challenging obstacles to generate rapid and efficient scaffold-free 3-dimensional multiple cell type co-culture cardiac tissue models. Herein, we develop a programmed rapid self-assembly strategy to induce specific and stable cell-cell contacts among multiple cell types found in heart tissue to generate 3D tissues through cell-surface engineering based on liposome delivery and fusion to display bio-orthogonal functional groups from cell membranes. We generate, for the first time, a scaffold free and stable self assembled 3 cell line co-culture 3D cardiac tissue model by assembling cardiomyocytes, endothelial cells and cardiac fibroblast cells via a rapid inter-cell click ligation process. We compare and analyze the function of the 3D cardiac tissue chips with 2D co-culture monolayers by assessing cardiac specific markers, electromechanical cell coupling, beating rates and evaluating drug toxicity.

  11. Automated image analysis reveals the dynamic 3-dimensional organization of multi-ciliary arrays.

    Science.gov (United States)

    Galati, Domenico F; Abuin, David S; Tauber, Gabriel A; Pham, Andrew T; Pearson, Chad G

    2015-12-23

    Multi-ciliated cells (MCCs) use polarized fields of undulating cilia (ciliary array) to produce fluid flow that is essential for many biological processes. Cilia are positioned by microtubule scaffolds called basal bodies (BBs) that are arranged within a spatially complex 3-dimensional geometry (3D). Here, we develop a robust and automated computational image analysis routine to quantify 3D BB organization in the ciliate, Tetrahymena thermophila. Using this routine, we generate the first morphologically constrained 3D reconstructions of Tetrahymena cells and elucidate rules that govern the kinetics of MCC organization. We demonstrate the interplay between BB duplication and cell size expansion through the cell cycle. In mutant cells, we identify a potential BB surveillance mechanism that balances large gaps in BB spacing by increasing the frequency of closely spaced BBs in other regions of the cell. Finally, by taking advantage of a mutant predisposed to BB disorganization, we locate the spatial domains that are most prone to disorganization by environmental stimuli. Collectively, our analyses reveal the importance of quantitative image analysis to understand the principles that guide the 3D organization of MCCs.

  12. PAMELA positron and electron spectra are reproduced by 3-dimensional cosmic-ray modeling

    CERN Document Server

    Gaggero, Daniele; Maccione, Luca; Di Bernardo, Giuseppe; Evoli, Carmelo

    2013-01-01

    The PAMELA collaboration recently released the $e^+$ absolute spectrum between 1 and 300 GeV in addition to the positron fraction and $e^-$ spectrum previously measured in the same time period. We use the newly developed 3-dimensional upgrade of the DRAGON code and the charge dependent solar modulation HelioProp code to consistently describe those data. We obtain very good fits of all data sets if a $e^+$ + $e^-$ hard extra-component peaked at 1 TeV is added to a softer $e^-$ background and the secondary $e^\\pm$ produced by the spallation of cosmic ray proton and helium nuclei. All sources are assumed to follow a realistic spiral arm spatial distribution. Remarkably, PAMELA data do not display any need of charge asymmetric extra-component. Finally, plain diffusion, or low re-acceleration, propagation models which are tuned against nuclear data, nicely describe PAMELA lepton data with no need to introduce a low energy break in the proton and Helium spectra.

  13. [Establishment of 3-dimensional finite element model of human knee joint and its biomechanics].

    Science.gov (United States)

    Yuan, Ping; Wang, Wanchun

    2010-01-01

    To establish a 3-dimensional (3-D) finite element knee model in healthy Chinese males, to verify the validity of the model, and to analyze the biomechanics of this model under axial load, flexion moment, varus/valgus torque, and internal/external axial torque. A set of consecutive transectional computerized tomography images of normal male knee joints in upright weight-bearing position was selected. With image processing and inversion technology, the 3-D finite element model of the normal knee joint was established through the software ABAQOUS/STANDARD Version-6.5.Biomechanical analysis of this model was processed under axial load, flexion moment, varus/valgus torque, and internal/external axial torque. A 3-D finite element model of healthy Chinese males was successfully established. The ranges of motion of varus and valgus were both small and the difference between them has no statistical significance (P>0.05). The motion of internal and external rotation of the knee took place only in flexion situation.The range of motion of external rotation was larger than that of internal rotation in the same knee (Pknee resembles the actual knee segments. It can imitate the knee response to different loads. This model could be used for further study on knee biomechanics.

  14. Using Interior Point Method Optimization Techniques to Improve 2- and 3-Dimensional Models of Earth Structures

    Science.gov (United States)

    Zamora, A.; Gutierrez, A. E.; Velasco, A. A.

    2014-12-01

    2- and 3-Dimensional models obtained from the inversion of geophysical data are widely used to represent the structural composition of the Earth and to constrain independent models obtained from other geological data (e.g. core samples, seismic surveys, etc.). However, inverse modeling of gravity data presents a very unstable and ill-posed mathematical problem, given that solutions are non-unique and small changes in parameters (position and density contrast of an anomalous body) can highly impact the resulting model. Through the implementation of an interior-point method constrained optimization technique, we improve the 2-D and 3-D models of Earth structures representing known density contrasts mapping anomalous bodies in uniform regions and boundaries between layers in layered environments. The proposed techniques are applied to synthetic data and gravitational data obtained from the Rio Grande Rift and the Cooper Flat Mine region located in Sierra County, New Mexico. Specifically, we improve the 2- and 3-D Earth models by getting rid of unacceptable solutions (those that do not satisfy the required constraints or are geologically unfeasible) given the reduction of the solution space.

  15. 3-dimensionally integrated photo-detector for neutrino physics and beyond

    Science.gov (United States)

    Retiere, Fabrice

    2016-09-01

    Silicon photo-multipliers (SiPMs) are a promising solution for the detection of scintillation light of liquid Xenon and Argon in applications requiring minimum radioactivity content such as neutrinoless double beta decay. The nEXO experiment in particular is planning to use SiPM planes covering 5 m2 for the detection of the light emitted within 5tons of liquid Xenon. The 3-dimensionally digital integrated SiPMs (3DdSiPMs) is an emerging technology that if successful would challenge the analog SiPM technology. Indeed, by combining separate photo-detector and electronics chips within a single package, 3DdSiPM achieve excellent performances for photon counting and time stamping, while dissipating minimum power. Being mostly based on high purity silicon chips, 3DdSiPMs are also expected to achieve excellent radiopurity.The development of 3DdSiPMs for applications in liquid Xenon is expected to progress rapidly by altering the design of the first successful chip assembly developed for medical imaging, focusing on minimizing power dissipation and large area (> cm2) scaling. In this talk we will describe the 3DdSiPM concept a solution for ``light to bit conversion'' within a single package and show how it may revolutionize light detection in noble-gas liquids and beyond.

  16. A 3-dimensional rigid cluster thorax model for kinematic measurements during gait.

    Science.gov (United States)

    Kiernan, D; Malone, A; O'Brien, T; Simms, C K

    2014-04-11

    The trunk has been shown to work as an active segment rather than a passenger unit during gait and it is felt that trunk kinematics should be given more consideration during gait assessment. While 3-dimensional assessment of the thorax with respect to the pelvis and laboratory can provide a comprehensive description of trunk movement, the majority of existing 3-D thorax models demonstrate shortcomings such as the need for multiple skin marker configurations, difficult landmark identification and practical issues for assessment on female subjects. A small number of studies have used rigid cluster models to quantify thorax movement, however the models and points of attachment are not well described and validation rarely considered. The aim of this study was to propose an alternative rigid cluster 3-D thorax model to quantify movement during gait and provide validation of this model. A rigid mount utilising active markers was developed and applied over the 3rd thoracic vertebra, previously reported as an area of least skin movement artefact on the trunk. The model was compared to two reference thorax models through simultaneous recording during gait on 15 healthy subjects. Excellent waveform similarity was demonstrated between the proposed model and the two reference models (CMC range 0.962-0.997). Agreement of discrete parameters was very-good to excellent. In addition, ensemble average graphs demonstrated almost identical curve displacement between models. The results suggest that the proposed model can be confidently used as an alternative to other thorax models in the clinical setting.

  17. An experimental study for qualitatively diagnosing stapes lesions by helical 3-dimensional CT

    Energy Technology Data Exchange (ETDEWEB)

    Kawaue, Akifumi; Kuki, Kiyonori; Yamanaka, Noboru [Wakayama Medical Univ., Wakayama (Japan); Nishimura, Michihiko

    2001-08-01

    To evaluate qualitative diagnosis of stapes lesions by 3-dimensional computed tomography (3D-CT) combined with superselective image processing (3D-SS) of stapes, we studied helical 3D-CT on a phantom model of the temporal bone. Two stapes models were used-1 made from the bone filler, Celatite, consistent in bone density but changing in cross sectional area, and the other made from an apacerum rod used in quantitative computed tomography (QCT), consistent in cross sectional area but changing in bone density. These stapes models were put into a skull phantom and analyzed by helical 3D-CT. The influence of the tympanic cavity conditions on CT images of stapes was evaluated by filling the phantom model with Vaseline following 3D selective reconstruction. In all stapes models, lowering the lower CT window width threshold resulted in an enlarged cross-sectional area of the model. The higher the bone density, the lower the increase in cross-sectional area in the image. The stapes model with lower density had greater influence on the imaging by tympanic cavity conditions and was likely to be misdiagnosed as showing higher bone density. Based on the experimental study, 3D-SS by helical 3D-CT appears to be a useful measure for qualitatively diagnosing stapes lesions. (author)

  18. Characterization of the 3-dimensional microstructure of a graphite negative electrode from a Li-ion battery

    DEFF Research Database (Denmark)

    Shearing, P.R.; Howard, L.E.; Jørgensen, Peter Stanley

    2010-01-01

    The 3-dimensional microstructure of a porous electrode from a lithium-ion battery has been characterized for the first time. We use X-ray tomography to reconstruct a 43 × 348 × 478 μm sample volume with voxel dimensions of 480 nm, subsequent division of the reconstructed volumes into sub-volumes ......The 3-dimensional microstructure of a porous electrode from a lithium-ion battery has been characterized for the first time. We use X-ray tomography to reconstruct a 43 × 348 × 478 μm sample volume with voxel dimensions of 480 nm, subsequent division of the reconstructed volumes into sub...

  19. The value of preoperative 3-dimensional over 2-dimensional valve analysis in predicting recurrent ischemic mitral regurgitation after mitral annuloplasty.

    Science.gov (United States)

    Wijdh-den Hamer, Inez J; Bouma, Wobbe; Lai, Eric K; Levack, Melissa M; Shang, Eric K; Pouch, Alison M; Eperjesi, Thomas J; Plappert, Theodore J; Yushkevich, Paul A; Hung, Judy; Mariani, Massimo A; Khabbaz, Kamal R; Gleason, Thomas G; Mahmood, Feroze; Acker, Michael A; Woo, Y Joseph; Cheung, Albert T; Gillespie, Matthew J; Jackson, Benjamin M; Gorman, Joseph H; Gorman, Robert C

    2016-09-01

    Repair for ischemic mitral regurgitation with undersized annuloplasty is characterized by high recurrence rates. We sought to determine the value of pre-repair 3-dimensional echocardiography over 2-dimensional echocardiography in predicting recurrence at 6 months. Intraoperative transesophageal 2-dimensional echocardiography and 3-dimensional echocardiography were performed in 50 patients undergoing undersized annuloplasty for ischemic mitral regurgitation. Two-dimensional echocardiography annular diameter and tethering parameters were measured in the apical 2- and 4-chamber views. A customized protocol was used to assess 3-dimensional annular geometry and regional leaflet tethering. Recurrence (grade ≥2) was assessed with 2-dimensional transthoracic echocardiography at 6 months. Preoperative 2- and 3-dimensional annular geometry were similar in all patients with ischemic mitral regurgitation. Preoperative 2- and 3-dimensional leaflet tethering were significantly higher in patients with recurrence (n = 13) when compared with patients without recurrence (n = 37). Multivariate logistic regression revealed preoperative 2-dimensional echocardiography posterior tethering angle as an independent predictor of recurrence with an optimal cutoff value of 32.0° (area under the curve, 0.81; 95% confidence interval, 0.68-0.95; P = .002) and preoperative 3-dimensional echocardiography P3 tethering angle as an independent predictor of recurrence with an optimal cutoff value of 29.9° (area under the curve, 0.92; 95% confidence interval, 0.84-1.00; P 3-dimensional geometric multivariate model can be augmented by adding basal aneurysm/dyskinesis (area under the curve, 0.94; 95% confidence interval, 0.87-1.00; P 3-dimensional echocardiography P3 tethering angle is a stronger predictor of ischemic mitral regurgitation recurrence after annuloplasty than preoperative 2-dimensional echocardiography posterior tethering angle, which is highly influenced by viewing plane. In

  20. Cardiovascular Magnetic Resonance to Predict Appropriate Implantable Cardioverter Defibrillator Therapy in Ischemic and Nonischemic Cardiomyopathy Patients Using Late Gadolinium Enhancement Border Zone: Comparison of Four Analysis Methods.

    Science.gov (United States)

    Jablonowski, Robert; Chaudhry, Uzma; van der Pals, Jesper; Engblom, Henrik; Arheden, Håkan; Heiberg, Einar; Wu, Katherine C; Borgquist, Rasmus; Carlsson, Marcus

    2017-09-01

    Late gadolinium enhancement (LGE) border zone on cardiac magnetic resonance imaging has been proposed as an independent predictor of ventricular arrhythmias. The purpose was to determine whether size and heterogeneity of LGE predict appropriate implantable cardioverter defibrillator (ICD) therapy in ischemic cardiomyopathy (ICM) and nonischemic cardiomyopathy (NI