WorldWideScience

Sample records for cardiac ionising imaging

  1. Cardiac hybrid imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gaemperli, Oliver [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); University Hospital Zurich, Nuclear Cardiology, Cardiovascular Center, Zurich (Switzerland); Kaufmann, Philipp A. [University Hospital Zurich, Cardiac Imaging, Zurich (Switzerland); Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland)

    2014-05-15

    Hybrid cardiac single photon emission computed tomography (SPECT)/CT imaging allows combined assessment of anatomical and functional aspects of cardiac disease. In coronary artery disease (CAD), hybrid SPECT/CT imaging allows detection of coronary artery stenosis and myocardial perfusion abnormalities. The clinical value of hybrid imaging has been documented in several subsets of patients. In selected groups of patients, hybrid imaging improves the diagnostic accuracy to detect CAD compared to the single imaging techniques. Additionally, this approach facilitates functional interrogation of coronary stenoses and guidance with regard to revascularization procedures. Moreover, the anatomical information obtained from CT coronary angiography or coronary artery calcium scores (CACS) adds prognostic information over perfusion data from SPECT. The use of cardiac hybrid imaging has been favoured by the dissemination of dedicated hybrid systems and the release of dedicated image fusion software, which allow simple patient throughput for hybrid SPECT/CT studies. Further technological improvements such as more efficient detector technology to allow for low-radiation protocols, ultra-fast image acquisition and improved low-noise image reconstruction algorithms will be instrumental to further promote hybrid SPECT/CT in research and clinical practice. (orig.)

  2. Cardiac imaging. A multimodality approach

    Energy Technology Data Exchange (ETDEWEB)

    Thelen, Manfred [Johannes Gutenberg University Hospital, Mainz (Germany); Erbel, Raimund [University Hospital Essen (Germany). Dept. of Cardiology; Kreitner, Karl-Friedrich [Johannes Gutenberg University Hospital, Mainz (Germany). Clinic and Polyclinic for Diagnostic and Interventional Radiology; Barkhausen, Joerg (eds.) [University Hospital Schleswig-Holstein, Luebeck (Germany). Dept. of Radiology and Nuclear Medicine

    2009-07-01

    An excellent atlas on modern diagnostic imaging of the heart Written by an interdisciplinary team of experts, Cardiac Imaging: A Multimodality Approach features an in-depth introduction to all current imaging modalities for the diagnostic assessment of the heart as well as a clinical overview of cardiac diseases and main indications for cardiac imaging. With a particular emphasis on CT and MRI, the first part of the atlas also covers conventional radiography, echocardiography, angiography and nuclear medicine imaging. Leading specialists demonstrate the latest advances in the field, and compare the strengths and weaknesses of each modality. The book's second part features clinical chapters on heart defects, endocarditis, coronary heart disease, cardiomyopathies, myocarditis, cardiac tumors, pericardial diseases, pulmonary vascular diseases, and diseases of the thoracic aorta. The authors address anatomy, pathophysiology, and clinical features, and evaluate the various diagnostic options. Key features: - Highly regarded experts in cardiology and radiology off er image-based teaching of the latest techniques - Readers learn how to decide which modality to use for which indication - Visually highlighted tables and essential points allow for easy navigation through the text - More than 600 outstanding images show up-to-date technology and current imaging protocols Cardiac Imaging: A Multimodality Approach is a must-have desk reference for cardiologists and radiologists in practice, as well as a study guide for residents in both fields. It will also appeal to cardiac surgeons, general practitioners, and medical physicists with a special interest in imaging of the heart. (orig.)

  3. An important step forward in continuous spectroscopic imaging of ionising radiations using ASICs

    CERN Document Server

    Fessler, P; Eberle, H; Raad-Iseli, C D; Hilt, B; Huss, D; Krummenacher, F; Lutz, Jean Robert; Prevot, G; Renouprez, Albert Jean; Sigward, M H; Schwaller, B; Voltolini, C

    1999-01-01

    Characterization results are given for an original ASIC allowing continuous acquisition of ionising radiation images in spectroscopic mode. Ionising radiation imaging in general and spectroscopic imaging in particular must primarily be guided by the attempt to decrease statistical noise, which requires detection systems designed to allow very high counting rates. Any source of dead time must therefore be avoided. Thus, the use of on-line corrections of the inevitable dispersion of characteristics between the large number of electronic channels of the detection system, shall be precluded. Without claiming to achieve ultimate noise levels, the work described is focused on how to prevent good individual acquisition channel noise performance from being totally destroyed by the dispersion between channels without introducing dead times. With this goal, we developed an automatic charge amplifier output voltage offset compensation system which operates regardless of the cause of the offset (detector or electronic). ...

  4. Confocal imaging of ionised calcium in living plant cells.

    Science.gov (United States)

    Williams, D A; Cody, S H; Gehring, C A; Parish, R W; Harris, P J

    1990-04-01

    Laser-scanning confocal microscopy has been used in conjunction with Fluo-3, a highly fluorescent visible wavelength probe for Ca2+, to visualize Ca2(+)-dynamics in the function of living plant cells. This combination has overcome many of the problems that have limited the use of fluorescence imaging techniques in the study of the role of cations (Ca2+ and H+) in plant cell physiology and enables these processes to be studied in single cells within intact plant tissue preparations. Maize coleoptiles respond to application of ionophores and plant growth hormones with elevations in cytosolic Ca2+ that can be resolved with a high degree of spatial resolution and can be interpreted quantitatively. PMID:2113832

  5. Cardiac imaging: does radiation matter?

    Science.gov (United States)

    Einstein, Andrew J.; Knuuti, Juhani

    2012-01-01

    The use of ionizing radiation in cardiovascular imaging has generated considerable discussion. Radiation should not be considered in isolation, but rather in the context of a careful examination of the benefits, risks, and costs of cardiovascular imaging. Such consideration requires an understanding of some fundamental aspects of the biology, physics, epidemiology, and terminology germane to radiation, as well as principles of radiological protection. This paper offers a concise, contemporary perspective on these areas by addressing pertinent questions relating to radiation and its application to cardiac imaging. PMID:21828062

  6. An important step forward in continuous spectroscopic imaging of ionising radiations using ASICs

    Energy Technology Data Exchange (ETDEWEB)

    Fessler, P. [11 rue Rabelais, 92170 Vanves (France); Coffin, J. [Institut de Recherches Subatomiques, B.P. 28, 67037 Strasbourg (France); Eberle, H. [Institut de Recherches Subatomiques, B.P. 28, 67037 Strasbourg (France); Raad Iseli, C. de [Smart Silicon Systems SA, Ch. de la Graviere 6, CH-1007 Lausanne (Switzerland); Hilt, B. [Universite de Haute-Alsace, GRPHE, 61, rue Albert Camus, 68093 Mulhouse (France); Huss, D. [Universite de Haute-Alsace, GRPHE, 61, rue Albert Camus, 68093 Mulhouse (France); Krummenacher, F. [Smart Silicon Systems SA, Ch. de la Graviere 6, CH-1007 Lausanne (Switzerland); Lutz, J.R. [Institut de Recherches Subatomiques, B.P. 28, 67037 Strasbourg (France); Prevot, G. [Institut de Recherches Subatomiques, B.P. 28, 67037 Strasbourg (France); Renouprez, A. [Institut de Recherche sur la Catalyse, 2 Avenue Albert Einstein, 69626 Villeurbanne (France); Sigward, M.H. [Institut de Recherches Subatomiques, B.P. 28, 67037 Strasbourg (France); Schwaller, B. [Universite de Haute-Alsace, GRPHE, 61, rue Albert Camus, 68093 Mulhouse (France); Voltolini, C. [Institut de Recherches Subatomiques, B.P. 28, 67037 Strasbourg (France)

    1999-01-21

    Characterization results are given for an original ASIC allowing continuous acquisition of ionising radiation images in spectroscopic mode. Ionising radiation imaging in general and spectroscopic imaging in particular must primarily be guided by the attempt to decrease statistical noise, which requires detection systems designed to allow very high counting rates. Any source of dead time must therefore be avoided. Thus, the use of on-line corrections of the inevitable dispersion of characteristics between the large number of electronic channels of the detection system, shall be precluded. Without claiming to achieve ultimate noise levels, the work described is focused on how to prevent good individual acquisition channel noise performance from being totally destroyed by the dispersion between channels without introducing dead times. With this goal, we developed an automatic charge amplifier output voltage offset compensation system which operates regardless of the cause of the offset (detector or electronic). The main performances of the system are the following: the input equivalent noise charge is 190 e rms (input non connected, peaking time 500 ns), the highest gain is 255 mV/fC, the peaking time is adjustable between 200 ns and 2 {mu}s and the power consumption is 10 mW per channel. The agreement between experimental data and theoretical simulation results is excellent.

  7. Follow-up of children exposed to ionising radiation from cardiac catheterisation: the Coccinelle study

    International Nuclear Information System (INIS)

    Cardiac catheterisation has become an essential tool in the diagnosis and treatment of children with a wide variety of congenital and acquired forms of cardiovascular disease. Despite the clear clinical benefit to the patient, radiation exposure from paediatric cardiac catheterisation procedures (CCPs) may be substantial. Given children's greater sensitivity to radiation and the longer life span during which radiation health effects can develop, an epidemiological cohort study, named Coccinelle or 'Ladybird' (French acronym for 'Cohorte sur le risque de cancer apres cardiologie interventionnelle pediatrique'), is carried out in France to evaluate the risks of leukaemia and solid cancers in this population. A total number of 8000 included children are expected. Individual CCP-related doses will be assessed for each child included in the cohort. For each CCP performed, dosimetric parameters (dose-area product, fluoroscopy time and total number of cine frames) are retrieved retrospectively. Organ doses, especially to the lung, the oesophagus and the thyroid, are calculated with PCXMC software. The cohort will be followed up through linkage with French paediatric cancer registries. (authors)

  8. Diagnosing cardiac disease during pregnancy: imaging modalities.

    Science.gov (United States)

    Ntusi, Ntobeko A; Samuels, Petronella; Moosa, Sulaiman; Mocumbi, Ana O

    2016-01-01

    Pregnant women with known or suspected cardiovascular disease (CVD) often require cardiovascular imaging during pregnancy. The accepted maximum limit of ionising radiation exposure to the foetus during pregnancy is a cumulative dose of 5 rad. Concerns related to imaging modalities that involve ionising radiation include teratogenesis, mutagenesis and childhood malignancy. Importantly, no single imaging study approaches this cautionary dose of 5 rad (50 mSv or 50 mGy). Diagnostic imaging procedures that may be used in pregnancy include chest radiography, fluoroscopy, echocardiography, invasive angiography, cardiovascular computed tomography, computed tomographic pulmonary angiography, cardiovascular magnetic resonance (CMR) and nuclear techniques. Echocardiography and CMR appear to be completely safe in pregnancy and are not associated with any adverse foetal effects, provided there are no general contra-indications to MR imaging. Concerns related to safety of imaging tests must be balanced against the importance of accurate diagnosis and thorough assessment of the pathological condition. Decisions about imaging in pregnancy are premised on understanding the physiology of pregnancy, understanding basic concepts of ionising radiation, the clinical manifestations of existent CVD in pregnancy and features of new CVD. The cardiologist/physician must understand the indications for and limitations of, and the potential harmful effects of each test during pregnancy. Current evidence suggests that a single cardiovascular radiological study during pregnancy is safe and should be undertaken at all times when clinically justified. In this article, the different imaging modalities are reviewed in terms of how they work, how safe they are and what their clinical utility in pregnancy is. Furthermore, the safety of contrast agents in pregnancy is also reviewed. PMID:27213857

  9. Ionising radiation induces persistent alterations in the cardiac mitochondrial function of C57BL/6 mice 40 weeks after local heart exposure

    International Nuclear Information System (INIS)

    Background and purpose: Radiotherapy of thoracic and chest-wall tumours increases the long-term risk of radiation-induced heart disease. The aim of this study was to investigate the long-term effect of local heart irradiation on cardiac mitochondria. Methods: C57BL/6 and atherosclerosis-prone ApoE−/− mice received local heart irradiation with a single X-ray dose of 2 Gy. To investigate the low-dose effect, C57BL/6 mice also received a single heart dose of 0.2 Gy. Functional and proteomic alterations of cardiac mitochondria were evaluated after 40 weeks, compared to age-matched controls. Results: The respiratory capacity of irradiated C57BL/6 cardiac mitochondria was significantly reduced at 40 weeks. In parallel, protein carbonylation was increased, suggesting enhanced oxidative stress. Considerable alterations were found in the levels of proteins of mitochondria-associated cytoskeleton, respiratory chain, ion transport and lipid metabolism. Radiation induced similar but less pronounced effects in the mitochondrial proteome of ApoE−/− mice. In ApoE−/−, no significant change was observed in mitochondrial respiration or protein carbonylation. The dose of 0.2 Gy had no significant effects on cardiac mitochondria. Conclusion: This study suggests that ionising radiation causes non-transient alterations in cardiac mitochondria, resulting in oxidative stress that may ultimately lead to malfunctioning of the heart muscle

  10. DNA double-strand breaks as potential indicators for the biological effects of ionising radiation exposure from cardiac CT and conventional coronary angiography: a randomised, controlled study

    Energy Technology Data Exchange (ETDEWEB)

    Geisel, Dominik; Zimmermann, Elke; Rief, Matthias; Greupner, Johannes; Hamm, Bernd [Charite Medical School, Department of Radiology, Berlin (Germany); Laule, Michael; Knebel, Fabian [Charite Medical School, Department of Cardiology, Berlin (Germany); Dewey, Marc [Charite Medical School, Department of Radiology, Berlin (Germany); Charite, Institut fuer Radiologie, Berlin (Germany)

    2012-08-15

    To prospectively compare induced DNA double-strand breaks by cardiac computed tomography (CT) and conventional coronary angiography (CCA). 56 patients with suspected coronary artery disease were randomised to undergo either CCA or cardiac CT. DNA double-strand breaks were assessed in fluorescence microscopy of blood lymphocytes as indicators of the biological effects of radiation exposure. Radiation doses were estimated using dose-length product (DLP) and dose-area product (DAP) with conversion factors for CT and CCA, respectively. On average there were 0.12 {+-} 0.06 induced double-strand breaks per lymphocyte for CT and 0.29 {+-} 0.18 for diagnostic CCA (P < 0.001). This relative biological effect of ionising radiation from CCA was 1.9 times higher (P < 0.001) than the effective dose estimated by conversion factors would have suggested. The correlation between the biological effects and the estimated radiation doses was excellent for CT (r = 0.951, P < 0.001) and moderate to good for CCA (r = 0.862, P < 0.001). One day after radiation, a complete repair of double-strand breaks to background levels was found in both groups. Conversion factors may underestimate the relative biological effects of ionising radiation from CCA. DNA double-strand break assessment may provide a strategy for individualised assessments of radiation. (orig.)

  11. DNA double-strand breaks as potential indicators for the biological effects of ionising radiation exposure from cardiac CT and conventional coronary angiography: a randomised, controlled study

    International Nuclear Information System (INIS)

    To prospectively compare induced DNA double-strand breaks by cardiac computed tomography (CT) and conventional coronary angiography (CCA). 56 patients with suspected coronary artery disease were randomised to undergo either CCA or cardiac CT. DNA double-strand breaks were assessed in fluorescence microscopy of blood lymphocytes as indicators of the biological effects of radiation exposure. Radiation doses were estimated using dose-length product (DLP) and dose-area product (DAP) with conversion factors for CT and CCA, respectively. On average there were 0.12 ± 0.06 induced double-strand breaks per lymphocyte for CT and 0.29 ± 0.18 for diagnostic CCA (P < 0.001). This relative biological effect of ionising radiation from CCA was 1.9 times higher (P < 0.001) than the effective dose estimated by conversion factors would have suggested. The correlation between the biological effects and the estimated radiation doses was excellent for CT (r = 0.951, P < 0.001) and moderate to good for CCA (r = 0.862, P < 0.001). One day after radiation, a complete repair of double-strand breaks to background levels was found in both groups. Conversion factors may underestimate the relative biological effects of ionising radiation from CCA. DNA double-strand break assessment may provide a strategy for individualised assessments of radiation. (orig.)

  12. Ultrasound Imaging in Teaching Cardiac Physiology

    Science.gov (United States)

    Johnson, Christopher D.; Montgomery, Laura E. A.; Quinn, Joe G.; Roe, Sean M.; Stewart, Michael T.; Tansey, Etain A.

    2016-01-01

    This laboratory session provides hands-on experience for students to visualize the beating human heart with ultrasound imaging. Simple views are obtained from which students can directly measure important cardiac dimensions in systole and diastole. This allows students to derive, from first principles, important measures of cardiac function, such…

  13. Cardiac sympathetic neuronal imaging using PET

    Energy Technology Data Exchange (ETDEWEB)

    Lautamaeki, Riikka; Tipre, Dnyanesh [Johns Hopkins University, Division of Nuclear Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Bengel, Frank M. [Johns Hopkins University, Division of Nuclear Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Cardiovascular Nuclear Medicine, Baltimore, MD (United States)

    2007-06-15

    Balance of the autonomic nervous system is essential for adequate cardiac performance, and alterations seem to play a key role in the development and progression of various cardiac diseases. PET imaging of the cardiac autonomic nervous system has advanced extensively in recent years, and multiple pre- and postsynaptic tracers have been introduced. The high spatial and temporal resolution of PET enables noninvasive quantification of neurophysiologic processes at the tissue level. Ligands for catecholamine receptors, along with radiolabeled catecholamines and catecholamine analogs, have been applied to determine involvement of sympathetic dysinnervation at different stages of heart diseases such as ischemia, heart failure, and arrhythmia. This review summarizes the recent findings in neurocardiological PET imaging. Experimental studies with several radioligands and clinical findings in cardiac dysautonomias are discussed. (orig.)

  14. Automated Segmentation of Cardiac Magnetic Resonance Images

    DEFF Research Database (Denmark)

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

    2001-01-01

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

  15. Dynamic NMR cardiac imaging in a piglet

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, M.; Rzedzian, R.; Mansfield, P. (Nottingham Univ. (UK). Dept. of Physics); Coupland, R.E. (Nottingham Univ. (UK). Queen' s Medical Centre)

    1983-12-01

    NMR echo-planar imaging (EPI) has been used in a real-time mode to visualise the thorax of a live piglet. Moving pictures are available on an immediate image display system which demonstrates dynamic cardiac function. Frame rates vary from one per cardiac cycle in a prospective stroboscopic mode with immediate visual output to a maximum of 10 frames per second yielding up to six looks in one piglet heart cycle, but using a visual playback mode. A completely new system has been used to obtain these images, features of which include a probe assembly with 22 cm access and an AP400 array processor for real-time data processing.

  16. Dynamic cardiac volume imaging using area detectors

    Science.gov (United States)

    Bruder, Herbert; Hoelzel, Arne; Stierstorfer, Karl; Rauscher, Annabella; Flohr, Thomas

    2003-05-01

    We present a reconstruction scheme for dynamic cardiac volume imaging using Area Detector Computed Tomography (CT) named Multi-Sector Cardiac Volume Reconstruction (MCVR) which is based on a 3D-backprojection of the Feldkamp-type. It is intended for circular scanning using area detectors covering the whole heart volume, but the method can easily be extended to cardiac spiral imaging using multi-slice CT. In cardiac imaging with multi-slice CT continuous data acquisition combined with the parallel recording of the patient's ECG enables retrospective gating of data segments for image reconstruction. Using consecutive heart cycles MCVR identifies complementary and time consistent projection data segments ECG. After a row by row parallel rebinning and temporal rebinning the projection data have to be filtered using conventional convolution kernels and finally reconstructed to image space using a 3D-backprojection. A dynamic anthropomorphic computer model of the human heart was developed in order to validate the MCVR approach. A 256-slice detector system with 0.5mm slice collimation was simulated operating in a circular scanning mode at a gantry rotation time of 330ms and compared to state-of-the-art 16-slice technology. At enddiastole the coronary anatomy can be visualized with excellent image quality. Although an area detector with large cone angling covering the entire heart volume was used no cone-artifacts could be observed. Using a 2-sector approach a nearly motion free 3D visualization of the heart chambers was obtained even at endsystole.

  17. Cardiac tumors: optimal cardiac MR sequences and spectrum of imaging appearances.

    LENUS (Irish Health Repository)

    O'Donnell, David H

    2012-02-01

    OBJECTIVE: This article reviews the optimal cardiac MRI sequences for and the spectrum of imaging appearances of cardiac tumors. CONCLUSION: Recent technologic advances in cardiac MRI have resulted in the rapid acquisition of images of the heart with high spatial and temporal resolution and excellent myocardial tissue characterization. Cardiac MRI provides optimal assessment of the location, functional characteristics, and soft-tissue features of cardiac tumors, allowing accurate differentiation of benign and malignant lesions.

  18. Cardiac nonrigid motion analysis from image sequences

    Institute of Scientific and Technical Information of China (English)

    LIU Huafeng

    2006-01-01

    Noninvasive estimation of the soft tissue kinematics properties from medical image sequences has many important clinical and physiological implications, such as the diagnosis of heart diseases and the understanding of cardiac mechanics. In this paper, we present a biomechanics based strategy, framed as a priori constraints for the ill-posed motion recovery problema, to realize estimation of the cardiac motion and deformation parameters. By constructing the heart dynamics system equations from biomechanics principles, we use the finite element method to generate smooth estimates.of heart kinematics throughout the cardiac cycle. We present the application of the strategy to the estimation of displacements and strains from in vivo left ventricular magnetic resonance image sequence.

  19. Myocardial wall motion imaging with cardiac magnetic resonance imaging

    NARCIS (Netherlands)

    Lubbers, Dani�l; Kuijpers, D.; Oudkerk, M.

    2006-01-01

    Wall motion imaging with cardiac magnetic resonance imaging (CMR) provides important functional information about global and regional myocardial function. This review will give an overview of the current state of myocardial wall motion imaging, especially focusing on the clinical role of dobutamine

  20. Postmortem cardiac imaging in fetuses and children

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Andrew M. [Great Ormond Street Hospital for Children NHS Foundation Trust, Cardiorespiratory Division, Level 7, Old Nurses Home, London (United Kingdom); UCL Institute of Cardiovascular Science, London (United Kingdom); Arthurs, Owen J. [Great Ormond Street Hospital for Children NHS Foundation Trust, Department of Radiology, London (United Kingdom); UCL Institute of Cardiovascular Science, London (United Kingdom); Sebire, Neil J. [UCL Institute of Cardiovascular Science, London (United Kingdom); Great Ormond Street Hospital for Children NHS Foundation Trust, Department of Histopathology, London (United Kingdom)

    2015-04-01

    Fetal and pediatric cardiac autopsies have a crucial role in the counseling of parents with regard to both the cause of death of their child and the implications of such findings for future pregnancies, as well as for quality assurance of antenatal screening programs and antemortem diagnostic procedures. Postmortem imaging allows an opportunity to investigate the heart in situ prior to dissection, and both postmortem CT and postmortem MRI have shown excellent accuracy in detecting the majority of clinically significant cardiac lesions in the perinatal and pediatric population. As less-invasive autopsy becomes increasingly popular, clinical guidelines for maximal diagnostic yield in specific circumstances can be developed. (orig.)

  1. Internet-based ICRP resource for healthcare providers on the risks and benefits of medical imaging that uses ionising radiation.

    Science.gov (United States)

    Demeter, S; Applegate, K E; Perez, M

    2016-06-01

    The purpose of the International Commission on Radiological Protection (ICRP) Committee 3 Working Party was to update the 2001 web-based module 'Radiation and your patient: a guide for medical practitioners' from ICRP. The key elements of this task were: to clearly identify the target audience (such as healthcare providers with an emphasis on primary care); to review other reputable sources of information; and to succinctly publish the contribution made by ICRP to the various topics. A 'question-and-answer' format addressing practical topics was adopted. These topics included benefits and risks of imaging using ionising radiation in common medical situations, as well as pertaining to specific populations such as pregnant, breast-feeding, and paediatric patients. In general, the benefits of medical imaging and related procedures far outweigh the potential risks associated with ionising radiation exposure. However, it is still important to ensure that the examinations are clinically justified, that the procedure is optimised to deliver the lowest dose commensurate with the medical purpose, and that consideration is given to diagnostic reference levels for particular classes of examinations. PMID:27012846

  2. Imaging of Cardiac Valves by Computed Tomography

    Directory of Open Access Journals (Sweden)

    Gudrun Feuchtner

    2013-01-01

    Full Text Available This paper describes “how to” examine cardiac valves with computed tomography, the normal, diseased valves, and prosthetic valves. A review of current scientific literature is provided. Firstly, technical basics, “how to” perform and optimize a multislice CT scan and “how to” interpret valves on CT images are outlined. Then, diagnostic imaging of the entire spectrum of specific valvular disease by CT, including prosthetic heart valves, is highlighted. The last part gives a guide “how to” use CT for planning of transcatheter aortic valve implantation (TAVI, an emerging effective treatment option for patients with severe aortic stenosis. A special focus is placed on clinical applications of cardiac CT in the context of valvular disease.

  3. Cardiac imaging in patients with chronic liver disease

    DEFF Research Database (Denmark)

    Wiese, Signe; Hove, Jens D; Møller, Søren

    2016-01-01

    dysfunction at rest by application of new myocardial strain techniques. Experience with other modalities such as cardiac magnetic resonance imaging and cardiac computed tomography is limited. Future studies exploring these imaging modalities are necessary to characterize and monitor the cardiac changes...

  4. Determination of agrochemical compounds in soya plants by imaging matrix-assisted laser desorption/ionisation mass spectrometry.

    Science.gov (United States)

    Mullen, Alexander K; Clench, Malcolm R; Crosland, Susan; Sharples, Kate R

    2005-01-01

    Detection and imaging of the herbicide mesotrione (2-(4-mesyl-2-nitrobenzoyl)cyclohexane-1,3-dione) and the fungicide azoxystrobin (methyl (E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate), on the surface of the soya leaf, and the detection and imaging of azoxystrobin inside the stem of the soya plant, have been achieved using matrix-assisted laser desorption/ionisation quadrupole time-of-flight mass spectrometry. In leaf analysis experiments, the two pesticides were deposited onto the surface of individual soya leaves on growing plants. The soya leaves were removed and prepared for direct and indirect (following blotting onto matrix-coated cellulose membranes) imaging analysis at different periods after initial pesticide application. In stem analysis experiments, azoxystrobin was added to the nutrient solution of a soya plant growing in a hydroponics system. The plant was left for 48 h, and then horizontal and vertical stem sections were prepared for direct imaging analysis. The images obtained demonstrate the applicability of MALDI imaging to the detection and imaging of small organic compounds in plant tissue and further extend the analytical repertoire of the versatile MALDI technique. PMID:16106343

  5. Magnetic Resonance Imaging Evaluation of Cardiac Masses

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-09-15

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

  6. Magnetic resonance imaging of congenital cardiac abnormalities

    International Nuclear Information System (INIS)

    Magnetic resonance imaging will not replace echocardiography as the simplest and most definitive method of establishing a noninvasive diagnosis in young patients with congenital cardiac malformations, nor will it replace radionuclide angiography for relatively noninvasive detection and quantitation of cardiac shunts. Magnetic resonance imaging is a complementary noninvasive imaging procedure that can answer some questions left in doubt by echocardiography (mainly extracardiac artery and vein assessments) or radionuclide angiography and used as a preferred follow-up imaging method in certain clinical circumstances. In addition, MRI can be a first-line modality for cardiovascular imaging in older patients in whom adequate echo windows are not available. Angiocardiography remains necessary to provide vital physiological data, i.e., chamber pressures, shunt volumes, oxygen saturations, and pulmonary vascular resistance; however, MRI could negate some follow-up catheterizations in appropriate clinical circumstances. High-resolution proton MRI tomography should ultimately permit the accurate evaluation of ventricular volumes, myocardial mass, and the assessment of regional wall motion and ejection fractions. Paramagnetic substances such as manganese ion may ultimately provide a basis for myocardial perfusion imaging. The potential for MRI evaluation of tissue characterization, noninvasive blood-flow measurements, and myocardial metabolism assessment in intriguing and awaits clinical evaluation

  7. Cardiac imaging in infectious endocarditis

    DEFF Research Database (Denmark)

    Bruun, Niels Eske; Habib, Gilbert; Thuny, Franck;

    2014-01-01

    Infectious endocarditis remains both a diagnostic and a treatment challenge. A positive outcome depends on a rapid diagnosis, accurate risk stratification, and a thorough follow-up. Imaging plays a key role in each of these steps and echocardiography remains the cornerstone of the methods in use....... The technique of both transthoracic echocardiography and transoesophageal echocardiography has been markedly improved across the last decades and most recently three-dimensional real-time echocardiography has been introduced in the management of endocarditis patients. Echocardiography depicts structural changes...... with conventional CT (SPECT/CT). Of these methods, (18)F-FDG PET-CT carries the best promise for a future role in endocarditis. But there are distinct limitations with both SPECT/CT and (18)F-FDG PET-CT which should not be neglected. MRI and spiral CT are methods primarily used in the search for extra cardial...

  8. Cardiac phase detection in intravascular ultrasound images

    Science.gov (United States)

    Matsumoto, Monica M. S.; Lemos, Pedro Alves; Yoneyama, Takashi; Furuie, Sergio Shiguemi

    2008-03-01

    Image gating is related to image modalities that involve quasi-periodic moving organs. Therefore, during intravascular ultrasound (IVUS) examination, there is cardiac movement interference. In this paper, we aim to obtain IVUS gated images based on the images themselves. This would allow the reconstruction of 3D coronaries with temporal accuracy for any cardiac phase, which is an advantage over the ECG-gated acquisition that shows a single one. It is also important for retrospective studies, as in existing IVUS databases there are no additional reference signals (ECG). From the images, we calculated signals based on average intensity (AI), and, from consecutive frames, average intensity difference (AID), cross-correlation coefficient (CC) and mutual information (MI). The process includes a wavelet-based filter step and ascendant zero-cross detection in order to obtain the phase information. Firstly, we tested 90 simulated sequences with 1025 frames each. Our method was able to achieve more than 95.0% of true positives and less than 2.3% of false positives ratio, for all signals. Afterwards, we tested in a real examination, with 897 frames and ECG as gold-standard. We achieved 97.4% of true positives (CC and MI), and 2.5% of false positives. For future works, methodology should be tested in wider range of IVUS examinations.

  9. Magnetic Resonance Imaging of Benign Cardiac Masses: A Pictorial Essay

    Directory of Open Access Journals (Sweden)

    Thomas J Ward

    2013-01-01

    Full Text Available The differential diagnosis for a cardiac mass includes primary and metastatic neoplasms. While primary cardiac tumors are rare, metastatic disease to the heart is a common finding in cancer patients. Several "tumor-like" processes can mimic a true cardiac neoplasm with accurate diagnosis critical at guiding appropriate management. We present a pictorial essay of the most common benign cardiac masses and "mass-like" lesions with an emphasis on magnetic resonance imaging features.

  10. Transthoracic Cardiac Acoustic Radiation Force Impulse Imaging

    Science.gov (United States)

    Bradway, David Pierson

    This dissertation investigates the feasibility of a real-time transthoracic Acoustic Radiation Force Impulse (ARFI) imaging system to measure myocardial function non-invasively in clinical setting. Heart failure is an important cardiovascular disease and contributes to the leading cause of death for developed countries. Patients exhibiting heart failure with a low left ventricular ejection fraction (LVEF) can often be identified by clinicians, but patients with preserved LVEF might be undetected if they do not exhibit other signs and symptoms of heart failure. These cases motivate development of transthoracic ARFI imaging to aid the early diagnosis of the structural and functional heart abnormalities leading to heart failure. M-Mode ARFI imaging utilizes ultrasonic radiation force to displace tissue several micrometers in the direction of wave propagation. Conventional ultrasound tracks the response of the tissue to the force. This measurement is repeated rapidly at a location through the cardiac cycle, measuring timing and relative changes in myocardial stiffness. ARFI imaging was previously shown capable of measuring myocardial properties and function via invasive open-chest and intracardiac approaches. The prototype imaging system described in this dissertation is capable of rapid acquisition, processing, and display of ARFI images and shear wave elasticity imaging (SWEI) movies. Also presented is a rigorous safety analysis, including finite element method (FEM) simulations of tissue heating, hydrophone intensity and mechanical index (MI) measurements, and thermocouple transducer face heating measurements. For the pulse sequences used in later animal and clinical studies, results from the safety analysis indicates that transthoracic ARFI imaging can be safely applied at rates and levels realizable on the prototype ARFI imaging system. Preliminary data are presented from in vivo trials studying changes in myocardial stiffness occurring under normal and abnormal

  11. Imaging spectrum of sudden athlete cardiac death.

    LENUS (Irish Health Repository)

    Arrigan, M T

    2012-02-01

    Sudden athlete death (SAD) is a widely publicized and increasingly reported phenomenon. For many, the athlete population epitomize human physical endeavour and achievement and their unexpected death comes with a significant emotional impact on the public. Sudden deaths within this group are often without prior warning. Preceding symptoms of exertional syncope and chest pain do, however, occur and warrant investigation. Similarly, a positive family history of sudden death in a young person or a known family history of a condition associated with SAD necessitates further tests. Screening programmes aimed at detecting those at risk individuals also exist with the aim of reducing fatalities. In this paper we review the topic of SAD and discuss the epidemiology, aetiology, and clinical presentations. We then proceed to discuss each underlying cause, in turn discussing the pathophysiology of each condition. This is followed by a discussion of useful imaging methods with an emphasis on cardiac magnetic resonance and cardiac computed tomography and how these address the various issues raised by the pathophysiology of each entity. We conclude by proposing imaging algorithms for the investigation of patients considered at risk for these conditions and discuss the various issues raised in screening.

  12. Cardiac stress MR imaging with dobutamine

    Energy Technology Data Exchange (ETDEWEB)

    Strach, K.; Meyer, C.; Schild, H.; Sommer, T. [University of Bonn, Department of Radiology, Bonn (Germany)

    2006-12-15

    Stress testing for detection of ischemia-induced wall-motion abnormalities has become a mainstay for noninvasive diagnosis and risk stratification of patients with suspected coronary artery disease (CAD). Recent technical developments in magnetic resonance imaging (MRI), including the adoption of balanced steady-state free precession (b-SSFP) sequences - preferentially in combination with parallel imaging techniques - have led to a significant reduction of imaging time and improved patient safety. The stress protocol includes application of high-dose dobutamine (up to 40 {mu}g/kg/min) combined with fractionated atropine (up to a maximal dose of 1.0 mg). High-dose dobutamine stress MRI revealed good sensitivity (83-96%) and specificity (80-100%) for detection of significant CAD. Myocardial tagging methods have been shown to further increase sensitivity for CAD detection. Severe complications (sustained tachycardia, ventricular fibrillation, myocardial infarction, cardiogenic shock) are rare but may be expected in 0.1-0.3% of patients. Dobutamine stress MRI has emerged as a reliable and safe clinical alternative for noninvasive assessment of CAD. New pulse sequences, such as real-time imaging, might obviate the need for breath holding and electrocardiogram (ECG) triggering in patients with severe dyspnoea and cardiac arrhythmias, which may further improve the clinical impact and acceptance of stress MRI in the future. (orig.)

  13. Functional cardiac imaging by random access microscopy

    Directory of Open Access Journals (Sweden)

    Claudia eCrocini

    2014-10-01

    Full Text Available Advances in the development of voltage sensitive dyes and Ca2+ sensors in combination with innovative microscopy techniques allowed researchers to perform functional measurements with an unprecedented spatial and temporal resolution. At the moment, one of the shortcomings of available technologies is their incapability of imaging multiple fast phenomena while controlling the biological determinants involved. In the near future, ultrafast deflectors can be used to rapidly scan laser beams across the sample, performing optical measurements of action potential and Ca2+ release from multiple sites within cardiac cells and tissues. The same scanning modality could also be used to control local Ca2+ release and membrane electrical activity by activation of caged compounds and light-gated ion channels. With this approach, local Ca2+ or voltage perturbations could be induced, simulating arrhythmogenic events, and their impact on physiological cell activity could be explored. The development of this optical methodology will provide fundamental insights in cardiac disease, boosting new therapeutic strategies, and, more generally, it will represent a new approach for the investigation of the physiology of excitable cells.

  14. Cardiac carcinoid: tricuspid delayed hyperenhancement on cardiac 64-slice multidetector CT and magnetic resonance imaging.

    LENUS (Irish Health Repository)

    Martos, R

    2012-02-01

    INTRODUCTION: Carcinoid heart disease is a rare condition in adults. Its diagnosis can be easily missed in a patient presenting to a primary care setting. We revised the advantages of using coronary multidetector computed tomography (MDCT) and cardiac magnetic resonance imaging (MRI) in diagnosing this condition. MATERIALS AND METHODS: We studied a 65-year-old patient with carcinoid heart disease and right heart failure using transthoracic Doppler-echocardiogram, cardiac MDCT and MRI. Cardiac echocardiogram revealed marked thickening and retraction of the tricuspid leaflets with dilated right atrium and ventricle. Cardiac MDCT and MRI demonstrated fixation and retraction of the tricuspid leaflets with delayed contrast hyperenhancement of the tricuspid annulus. CONCLUSION: This case demonstrates fascinating imaging findings of cardiac carcinoid disease and highlights the increasing utility of contrast-enhanced MRI and cardiac MDCT in the diagnosis of this interesting condition.

  15. The use of whole body magnetic resonance imaging in detecting bone marrow disorders - a valid alternative to imaging modalities that utilise ionising radiation

    International Nuclear Information System (INIS)

    Imaging modalities for investigation of bone marrow abnormalities have traditionally involved the use of ionising radiation. Now magnetic resonance imaging (MRI) offers an alternative to x-rays, computer tomography (CT), nuclear medicine bone scans and bone mineral densitometry. This study attempts to evaluate the sensitivity and specificity of whole body MRI in detecting bone marrow abnormalities, using Tl and short tau inversion recovery (STIR) weighted sequences. This was achieved by reviewing already acquired scan data to discover whether this method is more sensitive to marrow changes than conventional radiographic skeletal surveys and other imaging tests, involving ionising radiation. The study involved 10 adult participants all of whom suffered from heamatological malignancies, including multiple myeloma, plasma cell dyscrasia, non-Hodgkin's lymphoma and acute lymphocytic leukaemia. Most of the study group presented with multiple myeloma. Abnormal skeletal MRI findings were reported in nine out of the 10 participants, i.e., a positive detection rate of 90%, using whole body MRI. All participants in the study who suffered from multiple myeloma or plasma cell dyscrasia showed positive MRI findings regardless of the stage of their disease. Four already had a confirmed diagnosis prior to the MRI scan, which was either visible on x-ray or bone scintigraphy. Three participants had positive serum/urine tests, but negative radiographic findings. The study therefore established that, when investigating possible marrow disorders, MRI was more sensitive to changes in the bone-marrow producing part of the skeleton and that MRI therefore must be considered a more suitable imaging tool. Copyright (2005) Australian Institute of Radiography

  16. PET imaging of human cardiac opioid receptors

    International Nuclear Information System (INIS)

    The presence of opioid peptides and receptors and their role in the regulation of cardiovascular function has been previously demonstrated in the mammalian heart. The aim of this study was to image μ and δ opioid receptors in the human heart using positron emission tomography (PET). Five subjects (three females, two males, 65±8 years old) underwent PET scanning of the chest with [11C]carfentanil ([11C]CFN) and [11C]-N-methyl-naltrindole ([11C]MeNTI) and the images were analyzed for evidence of opioid receptor binding in the heart. Either [11C]CFN or [11C]MeNTI (20 mCi) was injected i.v. with subsequent dynamic acquisitions over 90 min. For the blocking studies, either 0.2 mg/kg or 1 mg/kg of naloxone was injected i.v. 5 min prior to the injection of [11C]CFN and [11C]MeNTI, respectively. Regions of interest were placed over the left ventricle, left ventricular chamber, lung and skeletal muscle. Graphical analysis demonstrated average baseline myocardial binding potentials (BP) of 4.37±0.91 with [11C]CFN and 3.86±0.60 with [11C]MeNTI. Administration of 0.2 mg/kg naloxone prior to [11C]CFN produced a 25% reduction in BP in one subject in comparison with baseline values, and a 19% decrease in myocardial distribution volume (DV). Administration of 1 mg/kg of naloxone before [11C]MeNTI in another subject produced a 14% decrease in BP and a 21% decrease in the myocardial DV. These results demonstrate the ability to image these receptors in vivo by PET. PET imaging of cardiac opioid receptors may help to better understand their role in cardiovascular pathophysiology and the effect of abuse of opioids and drugs on heart function. (orig.)

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

    NARCIS (Netherlands)

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

    2015-01-01

    Due to advances in cardiac surgery, survival of patients with congenital heart disease has increased considerably during the past decades. Many of these patients require repeated cardiovascular magnetic resonance imaging to assess cardiac anatomy and function. In the past decade, technological advan

  18. Quantitative image quality evaluation for cardiac CT reconstructions

    Science.gov (United States)

    Tseng, Hsin-Wu; Fan, Jiahua; Kupinski, Matthew A.; Balhorn, William; Okerlund, Darin R.

    2016-03-01

    Maintaining image quality in the presence of motion is always desirable and challenging in clinical Cardiac CT imaging. Different image-reconstruction algorithms are available on current commercial CT systems that attempt to achieve this goal. It is widely accepted that image-quality assessment should be task-based and involve specific tasks, observers, and associated figures of merits. In this work, we developed an observer model that performed the task of estimating the percentage of plaque in a vessel from CT images. We compared task performance of Cardiac CT image data reconstructed using a conventional FBP reconstruction algorithm and the SnapShot Freeze (SSF) algorithm, each at default and optimal reconstruction cardiac phases. The purpose of this work is to design an approach for quantitative image-quality evaluation of temporal resolution for Cardiac CT systems. To simulate heart motion, a moving coronary type phantom synchronized with an ECG signal was used. Three different percentage plaques embedded in a 3 mm vessel phantom were imaged multiple times under motion free, 60 bpm, and 80 bpm heart rates. Static (motion free) images of this phantom were taken as reference images for image template generation. Independent ROIs from the 60 bpm and 80 bpm images were generated by vessel tracking. The observer performed estimation tasks using these ROIs. Ensemble mean square error (EMSE) was used as the figure of merit. Results suggest that the quality of SSF images is superior to the quality of FBP images in higher heart-rate scans.

  19. PET imaging of human cardiac opioid receptors

    Energy Technology Data Exchange (ETDEWEB)

    Villemagne, Patricia S.R.; Dannals, Robert F. [Department of Radiology, The Johns Hopkins University School of Medicine, 605 N Caroline St., Baltimore, Maryland (United States); Department of Environmental Health Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Ravert, Hayden T. [Department of Radiology, The Johns Hopkins University School of Medicine, 605 N Caroline St., Baltimore, Maryland (United States); Frost, James J. [Department of Radiology, The Johns Hopkins University School of Medicine, 605 N Caroline St., Baltimore, Maryland (United States); Department of Environmental Health Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, Maryland (United States)

    2002-10-01

    The presence of opioid peptides and receptors and their role in the regulation of cardiovascular function has been previously demonstrated in the mammalian heart. The aim of this study was to image {mu} and {delta} opioid receptors in the human heart using positron emission tomography (PET). Five subjects (three females, two males, 65{+-}8 years old) underwent PET scanning of the chest with [{sup 11}C]carfentanil ([{sup 11}C]CFN) and [{sup 11}C]-N-methyl-naltrindole ([{sup 11}C]MeNTI) and the images were analyzed for evidence of opioid receptor binding in the heart. Either [{sup 11}C]CFN or [{sup 11}C]MeNTI (20 mCi) was injected i.v. with subsequent dynamic acquisitions over 90 min. For the blocking studies, either 0.2 mg/kg or 1 mg/kg of naloxone was injected i.v. 5 min prior to the injection of [{sup 11}C]CFN and [{sup 11}C]MeNTI, respectively. Regions of interest were placed over the left ventricle, left ventricular chamber, lung and skeletal muscle. Graphical analysis demonstrated average baseline myocardial binding potentials (BP) of 4.37{+-}0.91 with [{sup 11}C]CFN and 3.86{+-}0.60 with [{sup 11}C]MeNTI. Administration of 0.2 mg/kg naloxone prior to [{sup 11}C]CFN produced a 25% reduction in BP in one subject in comparison with baseline values, and a 19% decrease in myocardial distribution volume (DV). Administration of 1 mg/kg of naloxone before [{sup 11}C]MeNTI in another subject produced a 14% decrease in BP and a 21% decrease in the myocardial DV. These results demonstrate the ability to image these receptors in vivo by PET. PET imaging of cardiac opioid receptors may help to better understand their role in cardiovascular pathophysiology and the effect of abuse of opioids and drugs on heart function. (orig.)

  20. Accelerating Dynamic Cardiac MR Imaging Using Structured Sparse Representation

    Directory of Open Access Journals (Sweden)

    Nian Cai

    2013-01-01

    Full Text Available Compressed sensing (CS has produced promising results on dynamic cardiac MR imaging by exploiting the sparsity in image series. In this paper, we propose a new method to improve the CS reconstruction for dynamic cardiac MRI based on the theory of structured sparse representation. The proposed method user the PCA subdictionaries for adaptive sparse representation and suppresses the sparse coding noise to obtain good reconstructions. An accelerated iterative shrinkage algorithm is used to solve the optimization problem and achieve a fast convergence rate. Experimental results demonstrate that the proposed method improves the reconstruction quality of dynamic cardiac cine MRI over the state-of-the-art CS method.

  1. Incidental Cardiac Findings on Thoracic Imaging.

    LENUS (Irish Health Repository)

    Kok, Hong Kuan

    2013-02-07

    The cardiac structures are well seen on nongated thoracic computed tomography studies in the investigation and follow-up of cardiopulmonary disease. A wide variety of findings can be incidentally picked up on careful evaluation of the pericardium, cardiac chambers, valves, and great vessels. Some of these findings may represent benign variants, whereas others may have more profound clinical importance. Furthermore, the expansion of interventional and surgical practice has led to the development and placement of new cardiac stents, implantable pacemaker devices, and prosthetic valves with which the practicing radiologist should be familiar. We present a collection of common incidental cardiac findings that can be readily identified on thoracic computed tomography studies and briefly discuss their clinical relevance.

  2. Evaluation of respiratory and cardiac motion correction schemes in dual gated PET/CT cardiac imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lamare, F., E-mail: frederic.lamare@chu-bordeaux.fr; Fernandez, P. [Univ. Bordeaux, INCIA, UMR 5287, F-33400 Talence (France); CNRS, INCIA, UMR 5287, F-33400 Talence (France); Service de Médecine Nucléaire, Hôpital Pellegrin, CHU de Bordeaux, 33076 Bordeaux (France); Le Maitre, A.; Visvikis, D. [INSERM, UMR1101, LaTIM, Université de Bretagne Occidentale, 29609 Brest (France); Dawood, M.; Schäfers, K. P. [European Institute for Molecular Imaging, University of Münster, Mendelstr. 11, 48149 Münster (Germany); Rimoldi, O. E. [Vita-Salute University and Scientific Institute San Raffaele, Milan, Italy and CNR Istituto di Bioimmagini e Fisiologia Molecolare, Milan (Italy)

    2014-07-15

    Purpose: Cardiac imaging suffers from both respiratory and cardiac motion. One of the proposed solutions involves double gated acquisitions. Although such an approach may lead to both respiratory and cardiac motion compensation there are issues associated with (a) the combination of data from cardiac and respiratory motion bins, and (b) poor statistical quality images as a result of using only part of the acquired data. The main objective of this work was to evaluate different schemes of combining binned data in order to identify the best strategy to reconstruct motion free cardiac images from dual gated positron emission tomography (PET) acquisitions. Methods: A digital phantom study as well as seven human studies were used in this evaluation. PET data were acquired in list mode (LM). A real-time position management system and an electrocardiogram device were used to provide the respiratory and cardiac motion triggers registered within the LM file. Acquired data were subsequently binned considering four and six cardiac gates, or the diastole only in combination with eight respiratory amplitude gates. PET images were corrected for attenuation, but no randoms nor scatter corrections were included. Reconstructed images from each of the bins considered above were subsequently used in combination with an affine or an elastic registration algorithm to derive transformation parameters allowing the combination of all acquired data in a particular position in the cardiac and respiratory cycles. Images were assessed in terms of signal-to-noise ratio (SNR), contrast, image profile, coefficient-of-variation (COV), and relative difference of the recovered activity concentration. Results: Regardless of the considered motion compensation strategy, the nonrigid motion model performed better than the affine model, leading to higher SNR and contrast combined with a lower COV. Nevertheless, when compensating for respiration only, no statistically significant differences were

  3. Intraocular lymphoma after cardiac transplantation: Magnetic resonance imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yi Kyung; Kim, Hyung Jin; Woo, Kyung In; Kim, Yoon Duck [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2013-01-15

    We report a case of intraocular lymphoma in a 65-year-old man, 15 months after cardiac transplantation. On Magnetic Resonance (MR) images, the iris and the anterior chamber of the right eye were found to be involved with an enhancing soft-tissue lesion. To our knowledge, this is the first case of post-transplantation intraocular lymphoma evaluated with MR imaging.

  4. Characterisation of peripartum cardiomyopathy by cardiac magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mouquet, Frederic; Groote, Pascal de; Bouabdallaoui, Nadia; Dagorn, Joel; Lamblin, Nicolas; Bauters, Christophe [Pole de Cardiologie et Maladies Vasculaires, CHRU Lille et Universite Lille 2, Lille Cedex (France); Lions, Christophe; Willoteaux, Serge; Beregi, Jean Paul [Radiologie et Imagerie Cardiovasculaire, CHRU Lille et Universite Lille 2, Lille Cedex (France); Deruelle, Philippe [Gynecologie-Maternite, CHRU Lille et Universite Lille 2, Lille Cedex (France)

    2008-12-15

    Peripartum cardiomyopathy (PPCM) is a rare cause of heart failure. Only half of the patients recover normal cardiac function. We assessed the usefulness of magnetic resonance imaging (MRI) and late enhancement imaging to detect myocardial fibrosis in order to predict cardiac function recovery in patients with peripartum cardiomyopathy. Among a consecutive series of 1,037 patients referred for heart failure treatment or prognostic evaluation between 1999 and 2006, eight women had confirmed PPCM. They all underwent echocardiography and cardiac MRI for assessment of left ventricular anatomy, systolic function and detection of myocardial fibrosis through late enhancement imaging. Mean ({+-} SD) baseline left ventricular ejection fraction (LVEF) was 28 {+-} 4%. After a follow-up of 50 {+-} 9 months, half the patients recovered normal cardiac function (LVEF = 58 {+-} 4%) and four did not (LVEF = 35 {+-} 6%). None of the eight patients exhibited abnormal myocardial late enhancement. No difference in MRI characteristics was observed between the two groups. Patients with PPCM do not exhibit a specific cardiac MRI pattern and particularly no myocardial late enhancement. It suggests that myocardial fibrosis does not play a major role in the limitation of cardiac function recovery after PPCM. (orig.)

  5. Cardiac MR image segmentation using CHNN and level set method

    Institute of Scientific and Technical Information of China (English)

    王洪元; 周则明; 王平安; 夏德深

    2004-01-01

    Although cardiac magnetic resonance imaging (MRI) can provide high spatial resolution image, the area gray level inhomogenization, weak boundary and artifact often can be found in MR images. So, the MR images segmentation using the gradient-based methods is poor in quality and efficiency. An algorithm, based on the competitive hopfield neural network (CHNN) and the curve propagation, is proposed for cardiac MR images segmentation in this paper. The algorithm is composed of two phases. In first phase, a CHNN is used to classify the image objects, and to make gray level homogenization and to recognize weak boundaries in objects. In second phase, based on the classified results, the level set velocity function is created and the object boundaries are extracted with the curve propagation algorithm of the narrow band-based level set. The test results are promising and encouraging.

  6. Health Service use of ionising radiations: Guidance

    International Nuclear Information System (INIS)

    This booklet gives outline guidance on the use of ionising radiations in the Health Service in the United Kingdom. Extensive reference is made to documents where more detailed information may be found. The guidance covers general advice on the medical use of ionising radiations, statutory requirements, and guidance on selected Health Service issues such as patient identification procedures, information management systems, deviations from prescribed radiation dose, imaging and radiotherapy. (57 references) (U.K.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-01-01

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

  8. Cine MR imaging-current use in cardiac diagnosis

    International Nuclear Information System (INIS)

    This paper reviews the current status of cine MR imaging of the heart with special attention to the assessment of cardiac function. Cine MR provides tomographic sectional images with clear distinction between myocardium and flowing blood, and allows accurate volumetry of the cardiac chambers at specific points of the cardiac cycle. From these volume measurements parameters for the cardiac function, such as stroke volumem, ejection fraction, regurgitant fraction and shunt volum are calculated. While determination of chamber volumes can be done using any imaging plane, regional wall motion and wall thickening are evaluated with the short axis images. These images are readily obtained by orienting the slice selective gradient perpendicular to the long axis of the left ventricle. Left ventricular meridional wall stress is also calculated from cine MR images and noninvasive measurements of peak- and end-systolic pressure. Wall stress is an indicator of myocardial function in response to after load and can be used for monitoring patients with myocardial disease, regurgitant valvular disease and hypertension, and might be used to quantitatively assess the response of these diseases to therapy. Diseases causing hypertrophy of the ventricles, such as valvular stenosis, systemic or pulmonary hypertension and hypertrophic cardiomyopathy, can be monitored with cine MR by measuring the myocardial mass. A signal void from high velocity jets is caused by regurgitant or stenotic valvular lesion as well as flow across ventricular or atrial septal defects. Measurement of the dimension of the signal void have been correlated with the severity of regurgitation and can be used for semi-quantitation of these lesions. Due to the inherent contrast between blood and myocardium, high temporal resolution, and acquisition of tomographic images encompassing the entire heart, cine MR can serve as a comprehensive cardiac imaging modality that provides quantitative evaluation of anatomy and

  9. Double-oblique cine cardiac MR imaging

    International Nuclear Information System (INIS)

    A study has been performed analyzing the contrast between the blood pool and myocardium on double oblique long- and short-axis cine MR images using gradient echo fast imaging with steady precession and fast low-angle shot sequences. Inflow of unsaturated spins dominates the contrast behavior of short-axis images. With long-axis imaging, suboptimal contrast is seen in peak systole and early diastole due to partial saturation of spins in the imaging section and anatomic considerations at small ventricular volumes. The effects of echo time, flip angle, motion compensation, and spatial presaturation on the contrast between the blood pool and myocardium are discussed

  10. Cardiac CT for planning redo cardiac surgery: effect of knowledge-based iterative model reconstruction on image quality

    Energy Technology Data Exchange (ETDEWEB)

    Oda, Seitaro [MedStar Washington Hospital Center, Department of Cardiology, Washington, DC (United States); Kumamoto University, Department of Diagnostic Radiology, Faculty of Life Sciences, Kumamoto (Japan); Weissman, Gaby; Weigold, W. Guy [MedStar Washington Hospital Center, Department of Cardiology, Washington, DC (United States); Vembar, Mani [Philips Healthcare, CT Clinical Science, Cleveland, OH (United States)

    2015-01-15

    The purpose of this study was to investigate the effects of knowledge-based iterative model reconstruction (IMR) on image quality in cardiac CT performed for the planning of redo cardiac surgery by comparing IMR images with images reconstructed with filtered back-projection (FBP) and hybrid iterative reconstruction (HIR). We studied 31 patients (23 men, 8 women; mean age 65.1 ± 16.5 years) referred for redo cardiac surgery who underwent cardiac CT. Paired image sets were created using three types of reconstruction: FBP, HIR, and IMR. Quantitative parameters including CT attenuation, image noise, and contrast-to-noise ratio (CNR) of each cardiovascular structure were calculated. The visual image quality - graininess, streak artefact, margin sharpness of each cardiovascular structure, and overall image quality - was scored on a five-point scale. The mean image noise of FBP, HIR, and IMR images was 58.3 ± 26.7, 36.0 ± 12.5, and 14.2 ± 5.5 HU, respectively; there were significant differences in all comparison combinations among the three methods. The CNR of IMR images was better than that of FBP and HIR images in all evaluated structures. The visual scores were significantly higher for IMR than for the other images in all evaluated parameters. IMR can provide significantly improved qualitative and quantitative image quality at in cardiac CT for planning of reoperative cardiac surgery. (orig.)

  11. Cardiac Time Intervals by Tissue Doppler Imaging M-Mode

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Mogelvang, Rasmus; de Knegt, Martina Chantal;

    2016-01-01

    PURPOSE: To define normal values of the cardiac time intervals obtained by tissue Doppler imaging (TDI) M-mode through the mitral valve (MV). Furthermore, to evaluate the association of the myocardial performance index (MPI) obtained by TDI M-mode (MPITDI) and the conventional method of obtaining...... MPI (MPIConv), with established echocardiographic and invasive measures of systolic and diastolic function. METHODS: In a large community based population study (n = 974), where all are free of any cardiovascular disease and cardiovascular risk factors, cardiac time intervals, including isovolumic...... the MPITDI and MPIConv measured. RESULTS: IVRT, IVRT/ET and MPI all increased significantly with increasing age in both genders (pcardiac function. MPITDI...

  12. Variational Reconstruction of Left Cardiac Structure from CMR Images.

    Directory of Open Access Journals (Sweden)

    Min Wan

    Full Text Available Cardiovascular Disease (CVD, accounting for 17% of overall deaths in the USA, is the leading cause of death over the world. Advances in medical imaging techniques make the quantitative assessment of both the anatomy and function of heart possible. The cardiac modeling is an invariable prerequisite for quantitative analysis. In this study, a novel method is proposed to reconstruct the left cardiac structure from multi-planed cardiac magnetic resonance (CMR images and contours. Routine CMR examination was performed to acquire both long axis and short axis images. Trained technologists delineated the endocardial contours. Multiple sets of two dimensional contours were projected into the three dimensional patient-based coordinate system and registered to each other. The union of the registered point sets was applied a variational surface reconstruction algorithm based on Delaunay triangulation and graph-cuts. The resulting triangulated surfaces were further post-processed. Quantitative evaluation on our method was performed via computing the overlapping ratio between the reconstructed model and the manually delineated long axis contours, which validates our method. We envisage that this method could be used by radiographers and cardiologists to diagnose and assess cardiac function in patients with diverse heart diseases.

  13. Clinical application of l-123 MlBG cardiac imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Do Young [College of Medicine, Donga Univ., Busan (Korea, Republic of)

    2004-10-01

    Cardiac neurotransmission imaging allows in vivo assessment of presynaptic reuptake, neurotransmitter storage and postsynaptic receptors. Among the various neurotransmitter, I-123 MlBG is most available and relatively well-established. Metaiodobenzylguanidine (MIBG) is an analogue of the false neurotransmitter guanethidine. It is taken up to adrenergic neurons by uptake-1 mechanism as same as norepinephrine. As tagged with I-123, it can be used to image sympathetic function in various organs including heart with planar or SPECT techniques. I-123 MIBG imaging has a unique advantage to evaluate myocardial neuronal activity in which the heart has no significant structural abnormality or even no functional derangement measured with other conventional examination. In patients with cardiomyopathy and heart failure, this imaging has most sensitive technique to predict prognosis and treatment response of betablocker or ACE inhibitor. In diabetic patients, it allow very early detection of autonomic neuropathy. In patients with dangerous arrhythmia such as ventricular tachycardia or fibrillation, MIBG imaging may be only an abnormal result among various exams. In patients with ischemic heart disease, sympathetic derangement may be used as the method of risk stratification. In heart transplanted patients, sympathetic reinnervation is well evaluated. Adriamycin-induced cardiotoxicity is detected earlier than ventricular dysfunction with sympathetic dysfunction. Neurodegenerative disorder such as Parkinson's disease or dementia with Lewy bodies has also cardiac sympathetic dysfunction. Noninvasive assessment of cardiac sympathetic nerve activity with l-123 MlBG imaging may be improve understanding of the pathophysiology of cardiac disease and make a contribution to predict survival and therapy efficacy.

  14. Acupuncture Effects on Cardiac Functions Measured by Cardiac Magnetic Resonance Imaging in a Feline Model

    OpenAIRE

    Tzu-chi Lee; Jen-Hwey Chiu; Weng-Yih Tseng; Leang-Shin Wu; Krishna Kaphle; Jen-Hsou Lin; Chen-Haw Shih; Ying-Ling Wu

    2010-01-01

    The usefulness of acupuncture (AP) as a complementary and/or alternative therapy in animals is well established but more research is needed on its clinical efficacy relative to conventional therapy, and on the underlying mechanisms of the effects of AP. Cardiac magnetic resonance imaging (CMRI), an important tool in monitoring cardiovascular diseases, provides a reliable method to monitor the effects of AP on the cardiovascular system. This controlled experiment monitored the effect electro-a...

  15. Perceptual and statistical analysis of cardiac phase and amplitude images

    International Nuclear Information System (INIS)

    A perceptual experiment was conducted using cardiac phase and amplitude images. Estimates of statistical parameters were derived from the images and the diagnostic potential of human and statistical decisions compared. Five methods were used to generate the images from 75 gated cardiac studies, 39 of which were classified as pathological. The images were presented to 12 observers experienced in nuclear medicine. The observers rated the images using a five-category scale based on their confidence of an abnormality presenting. Circular and linear statistics were used to analyse phase and amplitude image data, respectively. Estimates of mean, standard deviation (SD), skewness, kurtosis and the first term of the spatial correlation function were evaluated in the region of the left ventricle. A receiver operating characteristic analysis was performed on both sets of data and the human and statistical decisions compared. For phase images, circular SD was shown to discriminate better between normal and abnormal than experienced observers, but no single statistic discriminated as well as the human observer for amplitude images. (orig.)

  16. Multimodality cardiac imaging in Turner syndrome.

    Science.gov (United States)

    Mortensen, Kristian H; Gopalan, Deepa; Nørgaard, Bjarne L; Andersen, Niels H; Gravholt, Claus H

    2016-06-01

    Congenital and acquired cardiovascular diseases contribute significantly to the threefold elevated risk of premature death in Turner syndrome. A multitude of cardiovascular anomalies and disorders, many of which deleteriously impact morbidity and mortality, is frequently left undetected and untreated because of poor adherence to screening programmes and complex clinical presentations. Imaging is essential for timely and effective primary and secondary disease prophylaxis that may alleviate the severe impact of cardiovascular disease in Turner syndrome. This review illustrates how cardiovascular disease in Turner syndrome manifests in a complex manner that ranges in severity from incidental findings to potentially fatal anomalies. Recommendations regarding the use of imaging for screening and surveillance of cardiovascular disease in Turner syndrome are made, emphasising the key role of non-invasive and invasive cardiovascular imaging to the management of all patients with Turner syndrome.

  17. Multimodality cardiac imaging in Turner syndrome.

    Science.gov (United States)

    Mortensen, Kristian H; Gopalan, Deepa; Nørgaard, Bjarne L; Andersen, Niels H; Gravholt, Claus H

    2016-06-01

    Congenital and acquired cardiovascular diseases contribute significantly to the threefold elevated risk of premature death in Turner syndrome. A multitude of cardiovascular anomalies and disorders, many of which deleteriously impact morbidity and mortality, is frequently left undetected and untreated because of poor adherence to screening programmes and complex clinical presentations. Imaging is essential for timely and effective primary and secondary disease prophylaxis that may alleviate the severe impact of cardiovascular disease in Turner syndrome. This review illustrates how cardiovascular disease in Turner syndrome manifests in a complex manner that ranges in severity from incidental findings to potentially fatal anomalies. Recommendations regarding the use of imaging for screening and surveillance of cardiovascular disease in Turner syndrome are made, emphasising the key role of non-invasive and invasive cardiovascular imaging to the management of all patients with Turner syndrome. PMID:26843123

  18. Cardiac magnetic resonance imaging in Alström syndrome

    Directory of Open Access Journals (Sweden)

    Carey Catherine M

    2009-06-01

    Full Text Available Abstract Background A case series of the cardiac magnetic resonance imaging findings in seven adult Alström patients. Methods Seven patients from the National Specialist Commissioning Group Centre for Alström Disease, Torbay, England, UK, completed the cardiac magnetic resonance imaging protocol to assess cardiac structure and function in Alström cardiomyopathy. Results All patients had some degree of left and right ventricular dysfunction. Patchy mid wall gadolinium delayed enhancement was demonstrated, suggesting an underlying fibrotic process. Some degree of cardiomyopathy was universal. No evidence of myocardial infarction or fatty infiltration was demonstrated, but coronary artery disease cannot be completely excluded. Repeat scanning after 18 months in one subject showed progression of fibrosis and decreased left ventricular function. Conclusion Adult Alström cardiomyopathy appears to be a fibrotic process causing impairment of both ventricles. Serial cardiac magnetic resonance scanning has helped clarify the underlying disease progression and responses to treatment. Confirmation of significant mutations in the ALMS1 gene should lead to advice to screen the subject for cardiomyopathy, and metabolic disorders.

  19. Acupuncture Effects on Cardiac Functions Measured by Cardiac Magnetic Resonance Imaging in a Feline Model

    Directory of Open Access Journals (Sweden)

    Jen-Hsou Lin

    2010-01-01

    Full Text Available The usefulness of acupuncture (AP as a complementary and/or alternative therapy in animals is well established but more research is needed on its clinical efficacy relative to conventional therapy, and on the underlying mechanisms of the effects of AP. Cardiac magnetic resonance imaging (CMRI, an important tool in monitoring cardiovascular diseases, provides a reliable method to monitor the effects of AP on the cardiovascular system. This controlled experiment monitored the effect electro-acupuncture (EA at bilateral acupoint Neiguan (PC6 on recovery time after ketamine/xylazine cocktail anesthesia in healthy cats. The CMRI data established the basic feline cardiac function index (CFI, including cardiac output and major vessel velocity. To evaluate the effect of EA on the functions of the autonomic nervous and cardiovascular systems, heart rate, respiration rate, electrocardiogram and pulse rate were also measured. Ketamine/xylazine cocktail anesthesia caused a transient hypertension in the cats; EA inhibited this anesthetic-induced hypertension and shortened the post-anesthesia recovery time. Our data support existing knowledge on the cardiovascular benefits of EA at PC6, and also provide strong evidence for the combination of anesthesia and EA to shorten post-anesthesia recovery time and counter the negative effects of anesthetics on cardiac physiology.

  20. Acupuncture effects on cardiac functions measured by cardiac magnetic resonance imaging in a feline model.

    Science.gov (United States)

    Lin, Jen-Hsou; Shih, Chen-Haw; Kaphle, Krishna; Wu, Leang-Shin; Tseng, Weng-Yih; Chiu, Jen-Hwey; Lee, Tzu-Chi; Wu, Ying-Ling

    2010-06-01

    The usefulness of acupuncture (AP) as a complementary and/or alternative therapy in animals is well established but more research is needed on its clinical efficacy relative to conventional therapy, and on the underlying mechanisms of the effects of AP. Cardiac magnetic resonance imaging (CMRI), an important tool in monitoring cardiovascular diseases, provides a reliable method to monitor the effects of AP on the cardiovascular system. This controlled experiment monitored the effect electro-acupuncture (EA) at bilateral acupoint Neiguan (PC6) on recovery time after ketamine/xylazine cocktail anesthesia in healthy cats. The CMRI data established the basic feline cardiac function index (CFI), including cardiac output and major vessel velocity. To evaluate the effect of EA on the functions of the autonomic nervous and cardiovascular systems, heart rate, respiration rate, electrocardiogram and pulse rate were also measured. Ketamine/xylazine cocktail anesthesia caused a transient hypertension in the cats; EA inhibited this anesthetic-induced hypertension and shortened the post-anesthesia recovery time. Our data support existing knowledge on the cardiovascular benefits of EA at PC6, and also provide strong evidence for the combination of anesthesia and EA to shorten post-anesthesia recovery time and counter the negative effects of anesthetics on cardiac physiology. PMID:18955311

  1. Automated Pointing of Cardiac Imaging Catheters.

    Science.gov (United States)

    Loschak, Paul M; Brattain, Laura J; Howe, Robert D

    2013-12-31

    Intracardiac echocardiography (ICE) catheters enable high-quality ultrasound imaging within the heart, but their use in guiding procedures is limited due to the difficulty of manually pointing them at structures of interest. This paper presents the design and testing of a catheter steering model for robotic control of commercial ICE catheters. The four actuated degrees of freedom (4-DOF) are two catheter handle knobs to produce bi-directional bending in combination with rotation and translation of the handle. An extra degree of freedom in the system allows the imaging plane (dependent on orientation) to be directed at an object of interest. A closed form solution for forward and inverse kinematics enables control of the catheter tip position and the imaging plane orientation. The proposed algorithms were validated with a robotic test bed using electromagnetic sensor tracking of the catheter tip. The ability to automatically acquire imaging targets in the heart may improve the efficiency and effectiveness of intracardiac catheter interventions by allowing visualization of soft tissue structures that are not visible using standard fluoroscopic guidance. Although the system has been developed and tested for manipulating ICE catheters, the methods described here are applicable to any long thin tendon-driven tool (with single or bi-directional bending) requiring accurate tip position and orientation control.

  2. An integrated platform for image-guided cardiac resynchronization therapy

    Science.gov (United States)

    Ma, Ying Liang; Shetty, Anoop K.; Duckett, Simon; Etyngier, Patrick; Gijsbers, Geert; Bullens, Roland; Schaeffter, Tobias; Razavi, Reza; Rinaldi, Christopher A.; Rhode, Kawal S.

    2012-05-01

    Cardiac resynchronization therapy (CRT) is an effective procedure for patients with heart failure but 30% of patients do not respond. This may be due to sub-optimal placement of the left ventricular (LV) lead. It is hypothesized that the use of cardiac anatomy, myocardial scar distribution and dyssynchrony information, derived from cardiac magnetic resonance imaging (MRI), may improve outcome by guiding the physician for optimal LV lead positioning. Whole heart MR data can be processed to yield detailed anatomical models including the coronary veins. Cine MR data can be used to measure the motion of the LV to determine which regions are late-activating. Finally, delayed Gadolinium enhancement imaging can be used to detect regions of scarring. This paper presents a complete platform for the guidance of CRT using pre-procedural MR data combined with live x-ray fluoroscopy. The platform was used for 21 patients undergoing CRT in a standard catheterization laboratory. The patients underwent cardiac MRI prior to their procedure. For each patient, a MRI-derived cardiac model, showing the LV lead targets, was registered to x-ray fluoroscopy using multiple views of a catheter looped in the right atrium. Registration was maintained throughout the procedure by a combination of C-arm/x-ray table tracking and respiratory motion compensation. Validation of the registration between the three-dimensional (3D) roadmap and the 2D x-ray images was performed using balloon occlusion coronary venograms. A 2D registration error of 1.2 ± 0.7 mm was achieved. In addition, a novel navigation technique was developed, called Cardiac Unfold, where an entire cardiac chamber is unfolded from 3D to 2D along with all relevant anatomical and functional information and coupled to real-time device detection. This allowed more intuitive navigation as the entire 3D scene was displayed simultaneously on a 2D plot. The accuracy of the unfold navigation was assessed off-line using 13 patient data sets

  3. Cardiac magnetic resonance imaging in children

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-01-01

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

  4. Imaging pitfalls, normal anatomy, and anatomical variants that can simulate disease on cardiac imaging as demonstrated on multidetector computed tomography

    International Nuclear Information System (INIS)

    Advances in computed tomography have led to continuous improvement in cardiac imaging. Dedicated postprocessing capabilities, faster scan times, and cardiac gating methods reveal details of normal cardiac anatomy and anatomic variants that can mimic pathologic conditions. This article will review normal cardiac anatomy and variants that can mimic disease. Radiologists should be familiar with normal cardiac anatomy and anatomic variants to avoid misinterpretation of normal findings for pathologic processes

  5. Bioluminescence imaging: a shining future for cardiac regeneration

    OpenAIRE

    Roura, Santiago; Gálvez-Montón, Carolina; Bayes-Genis, Antoni

    2013-01-01

    Advances in bioanalytical techniques have become crucial for both basic research and medical practice. One example, bioluminescence imaging (BLI), is based on the application of natural reactants with light-emitting capabilities (photoproteins and luciferases) isolated from a widespread group of organisms. The main challenges in cardiac regeneration remain unresolved, but a vast number of studies have harnessed BLI with the discovery of aequorin and green fluorescent proteins. First described...

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

    LENUS (Irish Health Repository)

    Ridge, Carole A

    2012-02-01

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

  7. Cardiac magnetic source imaging based on current multipole model

    Institute of Scientific and Technical Information of China (English)

    Tang Fa-Kuan; Wang Qian; Hua Ning; Lu Hong; Tang Xue-Zheng; Ma Ping

    2011-01-01

    It is widely accepted that the heart current source can be reduced into a current multipole. By adopting three linear inverse methods, the cardiac magnetic imaging is achieved in this article based on the current multipole model expanded to the first order terms. This magnetic imaging is realized in a reconstruction plane in the centre of human heart, where the current dipole array is employed to represent realistic cardiac current distribution. The current multipole as testing source generates magnetic fields in the measuring plane, serving as inputs of cardiac magnetic inverse problem. In the heart-torso model constructed by boundary element method, the current multipole magnetic field distribution is compared with that in the homogeneous infinite space, and also with the single current dipole magnetic field distribution.Then the minimum-norm least-squares (MNLS) method, the optimal weighted pseuDOInverse method (OWPIM), and the optimal constrained linear inverse method (OCLIM) are selected as the algorithms for inverse computation based on current multipole model innovatively, and the imaging effects of these three inverse methods are compared. Besides,two reconstructing parameters, residual and mean residual, are also discussed, and their trends under MNLS, OWPIM and OCLIM each as a function of SNR are obtained and compared.

  8. Autopsy imaging for cardiac tamponade in a Thoroughbred foal

    Science.gov (United States)

    YAMADA, Kazutaka; SATO, Fumio; HORIUCHI, Noriyuki; HIGUCHI, Tohru; KOBAYASHI, Yoshiyasu; SASAKI, Naoki; NAMBO, Yasuo

    2016-01-01

    ABSTRACT Autopsy imaging (Ai), postmortem imaging before necropsy, is used in human forensic medicine. Ai was performed using computed tomography (CT) for a 1-month-old Thoroughbred foal cadaver found in a pasture. CT revealed pericardial effusion, collapse of the aorta, bleeding in the lung lobe, gas in the ventricles and liver parenchyma, and distension of the digestive tract. Rupture in the left auricle was confirmed by necropsy; however, it was not depicted on CT. Therefore, Ai and conventional necropsy are considered to complement each other. The cause of death was determined to be traumatic cardiac tamponade. In conclusion, Ai is an additional option for determining cause of death. PMID:27703406

  9. Cardiac image modelling: Breadth and depth in heart disease.

    Science.gov (United States)

    Suinesiaputra, Avan; McCulloch, Andrew D; Nash, Martyn P; Pontre, Beau; Young, Alistair A

    2016-10-01

    With the advent of large-scale imaging studies and big health data, and the corresponding growth in analytics, machine learning and computational image analysis methods, there are now exciting opportunities for deepening our understanding of the mechanisms and characteristics of heart disease. Two emerging fields are computational analysis of cardiac remodelling (shape and motion changes due to disease) and computational analysis of physiology and mechanics to estimate biophysical properties from non-invasive imaging. Many large cohort studies now underway around the world have been specifically designed based on non-invasive imaging technologies in order to gain new information about the development of heart disease from asymptomatic to clinical manifestations. These give an unprecedented breadth to the quantification of population variation and disease development. Also, for the individual patient, it is now possible to determine biophysical properties of myocardial tissue in health and disease by interpreting detailed imaging data using computational modelling. For these population and patient-specific computational modelling methods to develop further, we need open benchmarks for algorithm comparison and validation, open sharing of data and algorithms, and demonstration of clinical efficacy in patient management and care. The combination of population and patient-specific modelling will give new insights into the mechanisms of cardiac disease, in particular the development of heart failure, congenital heart disease, myocardial infarction, contractile dysfunction and diastolic dysfunction. PMID:27349830

  10. MR image analysis: Longitudinal cardiac motion influences left ventricular measurements

    Energy Technology Data Exchange (ETDEWEB)

    Berkovic, Patrick [University Hospital Antwerp, Department of Cardiology (Belgium)], E-mail: pberko17@hotmail.com; Hemmink, Maarten [University Hospital Antwerp, Department of Cardiology (Belgium)], E-mail: maartenhemmink@gmail.com; Parizel, Paul M. [University Hospital Antwerp, Department of Radiology (Belgium)], E-mail: paul.parizel@uza.be; Vrints, Christiaan J. [University Hospital Antwerp, Department of Cardiology (Belgium)], E-mail: chris.vrints@uza.be; Paelinck, Bernard P. [University Hospital Antwerp, Department of Cardiology (Belgium)], E-mail: Bernard.paelinck@uza.be

    2010-02-15

    Background: Software for the analysis of left ventricular (LV) volumes and mass using border detection in short-axis images only, is hampered by through-plane cardiac motion. Therefore we aimed to evaluate software that involves longitudinal cardiac motion. Methods: Twenty-three consecutive patients underwent 1.5-Tesla cine magnetic resonance (MR) imaging of the entire heart in the long-axis and short-axis orientation with breath-hold steady-state free precession imaging. Offline analysis was performed using software that uses short-axis images (Medis MASS) and software that includes two-chamber and four-chamber images to involve longitudinal LV expansion and shortening (CAAS-MRV). Intraobserver and interobserver reproducibility was assessed by using Bland-Altman analysis. Results: Compared with MASS software, CAAS-MRV resulted in significantly smaller end-diastolic (156 {+-} 48 ml versus 167 {+-} 52 ml, p = 0.001) and end-systolic LV volumes (79 {+-} 48 ml versus 94 {+-} 52 ml, p < 0.001). In addition, CAAS-MRV resulted in higher LV ejection fraction (52 {+-} 14% versus 46 {+-} 13%, p < 0.001) and calculated LV mass (154 {+-} 52 g versus 142 {+-} 52 g, p = 0.004). Intraobserver and interobserver limits of agreement were similar for both methods. Conclusion: MR analysis of LV volumes and mass involving long-axis LV motion is a highly reproducible method, resulting in smaller LV volumes, higher ejection fraction and calculated LV mass.

  11. Radionuclide reporter gene imaging for cardiac gene therapy

    Energy Technology Data Exchange (ETDEWEB)

    Inubushi, Masayuki [Hokkaido University Graduate School of Medicine, Department of Molecular Imaging, Sapporo (Japan); Tamaki, Nagara [Hokkaido University Graduate School of Medicine, Department of Nuclear Medicine, Sapporo (Japan)

    2007-06-15

    In the field of cardiac gene therapy, angiogenic gene therapy has been most extensively investigated. The first clinical trial of cardiac angiogenic gene therapy was reported in 1998, and at the peak, more than 20 clinical trial protocols were under evaluation. However, most trials have ceased owing to the lack of decisive proof of therapeutic effects and the potential risks of viral vectors. In order to further advance cardiac angiogenic gene therapy, remaining open issues need to be resolved: there needs to be improvement of gene transfer methods, regulation of gene expression, development of much safer vectors and optimisation of therapeutic genes. For these purposes, imaging of gene expression in living organisms is of great importance. In radionuclide reporter gene imaging, ''reporter genes'' transferred into cell nuclei encode for a protein that retains a complementary ''reporter probe'' of a positron or single-photon emitter; thus expression of the reporter genes can be imaged with positron emission tomography or single-photon emission computed tomography. Accordingly, in the setting of gene therapy, the location, magnitude and duration of the therapeutic gene co-expression with the reporter genes can be monitored non-invasively. In the near future, gene therapy may evolve into combination therapy with stem/progenitor cell transplantation, so-called cell-based gene therapy or gene-modified cell therapy. Radionuclide reporter gene imaging is now expected to contribute in providing evidence on the usefulness of this novel therapeutic approach, as well as in investigating the molecular mechanisms underlying neovascularisation and safety issues relevant to further progress in conventional gene therapy. (orig.)

  12. SPECT imaging of cardiac reporter gene expression in living rabbits

    Institute of Scientific and Technical Information of China (English)

    LIU Ying; LAN Xiaoli; ZHANG Liang; WU Tao; JIANG Rifeng; ZHANG Yongxue

    2009-01-01

    This work is to demonstrate feasibility of imaging the expression of herpes simplex virus 1-thymidine ki-nase (HSV1-tk) reporter gene in rabbits myocardium by using the reporter probe 131I-2'-fluoro-2'-deoxy-1-β-D- arabi-nofuranosyl-5-iodouracil (131I-FIAU) and SPECT. Rabbits of the study group received intramyocardial injection of Ad5-tk and control group received aseptic saline injection. Two sets of experiments were performed on the study group. Rabbits of the 1st set were injected with 131I-FIAU 600 μCi at Day 2 after intramyocardial transfection of Ad5-tk in 1×109, 5×108, 1×108, 5×107 and 1×107 pfu, and heart SPECT imaging was done at different hours. Rabbits of the 2nd were transferred various titers of Ad5-tk (1×109, 5×108, 1×108, 5×107, 1×107 pfu) to determine the threshold and optimal viral titer needed for detection of gene expression. Two days later, 131I-FIAU was injected and heart SPECT imaging was performed at 6, 24 and 48 h, before killing them for gamma counting of the hearts. Reverse tran-scription-polymerase chain reaction (RT-PCR) was used to verify the transferred HSV1-tk gene expression. Semi-quantitative analysis derived of region of interest (ROI) of SPECT images and RT-PCR images was performed and the relationship of SPECT images with ex vivo gamma counting and mRNA level were evaluated. SPECT images conformed 131I-FIAU accumulation in rabbits injected with Ad5-tk in the anterolateral wall. The optimal images qual-ity was obtained at 24~48 h for different viral titers. The highest radioactivity in the focal myocardium was seen at 6 h, and then declined with time. The threshold was 5×107 pfu of virus titer. The result could be set better in 1~5×108 pfu by SPECT analysis and gamma counting. ROI-derived semi-quantitative study on SPECT images correlated well with ex vivo gamma counting and mRNA levels from RT-PCR analysis. The HSV1-tk/131I-FIAU reporter gene/reporter probe system is feasible for cardiac SPECT reporter gene imaging

  13. Rapid Circular Tomography System Suitable For Cardiac Imaging

    Science.gov (United States)

    Kruger, R. A.; Sorensor, J. A.; Boye, J. R.; Conrad, J.; Ric, S. P. D.; Yih, B. C.; Liu, P.

    1985-06-01

    Tomographic DSA (digital subtraction angiography) can be used to improve the image quality that results from intravenous angiographic studies of relatively stationary arterial anatomy. While DSA removes much of the non-opacified anatomy, tomographic blurring reduces both the severity of patient motion artefacts and the confusion introduced by overlapping vascular anatomy. For this purpose a conventional longitudinal tomography device to which an image intensifier and television has been added can be used. However, such an apparatus is inadequate for cardiac imaging due to the slow speed of the tomographic motion. A tomographic system consisting of a rotating focal spot x-ray tube and an image intensifier, modified to allow electronic image scanning, is proposed. After this device is constructed it will be possible to acquire tomographic images of the beating heart in as little as .005-.010 seconds. When combined with image subtraction it is anticipated that the quality of intravenous coronary angiograms will be improved in much the same way that tomographic DSA improves image quality in many of the other arteries of the body.

  14. Towards robust specularity detection and inpainting in cardiac images

    Science.gov (United States)

    Alsaleh, Samar M.; Aviles, Angelica I.; Sobrevilla, Pilar; Casals, Alicia; Hahn, James

    2016-03-01

    Computer-assisted cardiac surgeries had major advances throughout the years and are gaining more popularity over conventional cardiac procedures as they offer many benefits to both patients and surgeons. One obvious advantage is that they enable surgeons to perform delicate tasks on the heart while it is still beating, avoiding the risks associated with cardiac arrest. Consequently, the surgical system needs to accurately compensate the physiological motion of the heart which is a very challenging task in medical robotics since there exist different sources of disturbances. One of which is the bright light reflections, known as specular highlights, that appear on the glossy surface of the heart and partially occlude the field of view. This work is focused on developing a robust approach that accurately detects and removes those highlights to reduce their disturbance to the surgeon and the motion compensation algorithm. As a first step, we exploit both color attributes and Fuzzy edge detector to identify specular regions in each acquired image frame. These two techniques together work as restricted thresholding and are able to accurately identify specular regions. Then, in order to eliminate the specularity artifact and give the surgeon a better perception of the heart, the second part of our solution is dedicated to correct the detected regions using inpainting to propagate and smooth the results. Our experimental results, which we carry out in realistic datasets, reveal how efficient and precise the proposed solution is, as well as demonstrate its robustness and real-time performance.

  15. Wide coverage by volume CT: benefits for cardiac imaging

    Science.gov (United States)

    Sablayrolles, Jean-Louis; Cesmeli, Erdogan; Mintandjian, Laura; Adda, Olivier; Dessalles-Martin, Diane

    2005-04-01

    With the development of new technologies, computed tomography (CT) is becoming a strong candidate for non-invasive imaging based tool for cardiac disease assessment. One of the challenges of cardiac CT is that a typical scan involves a breath hold period consisting of several heartbeats, about 20 sec with scanners having a longitudinal coverage of 2 cm, and causing the image quality (IQ) to be negatively impacted since beat to beat variation is high likely to occur without any medication, e.g. beta blockers. Because of this and the preference for shorter breath hold durations, a CT scanner with a wide coverage without the compromise in the spatial and temporal resolution of great clinical value. In this study, we aimed at determining the optimum scan duration and the delay relative to beginning of breath hold, to achieve high IQ. We acquired EKG data from 91 consecutive patients (77 M, 14 F; Age: 57 +/- 14) undergoing cardiac CT exams with contrast, performed on LightSpeed 16 and LightSpeed Pro16. As an IQ metric, we adopted the standard deviation of "beat-to-beat variation" (stdBBV) within a virtual scan period. Two radiologists evaluated images by assigning a score of 1 (worst) to 4 best). We validated stdBBV with the radiologist scores, which resulted in a population distribution of 9.5, 9.5, 31, and 50% for the score groups 1, 2, 3, and 4, respectively. Based on the scores, we defined a threshold for stdBBV and identified an optimum combination of virtual scan period and a delay. With the assumption that the relationship between the stdBBV and diagnosable scan IQ holds, our analysis suggested that the success rate can be improved to 100% with scan durations equal or less than 5 sec with a delay of 1 - 2 sec. We confirmed the suggested conclusion with LightSpeed VCT (GE Healthcare Technologies, Waukesha, WI), which has a wide longitudinal coverage, fine isotropic spatial resolution, and high temporal resolution, e.g. 40 mm coverage per rotation of 0.35 sec

  16. Dose optimization in cardiac x-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gislason-Lee, Amber J.; McMillan, Catherine; Cowen, Arnold R.; Davies, Andrew G. [LXi Research, Division of Medical Physics, University of Leeds, Worsley Building, Clarendon Way, Leeds LS2 9JT (United Kingdom)

    2013-09-15

    Purpose: The aim of this research was to optimize x-ray image quality to dose ratios in the cardiac catheterization laboratory. This study examined independently the effects of peak x-ray tube voltage (kVp), copper (Cu), and gadolinium (Gd) x-ray beam filtration on the image quality to radiation dose balance for adult patient sizes.Methods: Image sequences of polymethyl methacrylate (PMMA) phantoms representing two adult patient sizes were captured using a modern flat panel detector based x-ray imaging system. Tin and copper test details were used to simulate iodine-based contrast medium and stents/guide wires respectively, which are used in clinical procedures. Noise measurement for a flat field image and test detail contrast were used to calculate the contrast to noise ratio (CNR). Entrance surface dose (ESD) and effective dose measurements were obtained to calculate the figure of merit (FOM), CNR{sup 2}/dose. This FOM determined the dose efficiency of x-ray spectra investigated. Images were captured with 0.0, 0.1, 0.25, 0.4, and 0.9 mm Cu filtration and with a range of gadolinium oxysulphide (Gd{sub 2}O{sub 2}S) filtration.Results: Optimum x-ray spectra were the same for the tin and copper test details. Lower peak tube voltages were generally favored. For the 20 cm phantom, using 2 Lanex Fast Back Gd{sub 2}O{sub 2}S screens as x-ray filtration at 65 kVp provided the highest FOM considering ESD and effective dose. Considering ESD, this FOM was only marginally larger than that from using 0.4 mm Cu at 65 kVp. For the 30 cm phantom, using 0.25 mm copper filtration at 80 kVp was most optimal; considering effective dose the FOM was highest with no filtration at 65 kVp.Conclusions: These settings, adjusted for x-ray tube loading limits and clinically acceptable image quality, should provide a useful option for optimizing patient dose to image quality in cardiac x-ray imaging. The same optimal x-ray beam spectra were found for both the tin and copper details, suggesting

  17. Constrain static target kinetic iterative image reconstruction for 4D cardiac CT imaging

    Science.gov (United States)

    Alessio, Adam M.; La Riviere, Patrick J.

    2011-03-01

    Iterative image reconstruction offers improved signal to noise properties for CT imaging. A primary challenge with iterative methods is the substantial computation time. This computation time is even more prohibitive in 4D imaging applications, such as cardiac gated or dynamic acquisition sequences. In this work, we propose only updating the time-varying elements of a 4D image sequence while constraining the static elements to be fixed or slowly varying in time. We test the method with simulations of 4D acquisitions based on measured cardiac patient data from a) a retrospective cardiac-gated CT acquisition and b) a dynamic perfusion CT acquisition. We target the kinetic elements with one of two methods: 1) position a circular ROI on the heart, assuming area outside ROI is essentially static throughout imaging time; and 2) select varying elements from the coefficient of variation image formed from fast analytic reconstruction of all time frames. Targeted kinetic elements are updated with each iteration, while static elements remain fixed at initial image values formed from the reconstruction of data from all time frames. Results confirm that the computation time is proportional to the number of targeted elements; our simulations suggest that 3 times reductions in reconstruction time. The images reconstructed with the proposed method have matched mean square error with full 4D reconstruction. The proposed method is amenable to most optimization algorithms and offers the potential for significant computation improvements, which could be traded off for more sophisticated system models or penalty terms.

  18. Korean Society of Cardiovascular Imaging Guidelines for Cardiac Computed Tomography

    International Nuclear Information System (INIS)

    The Korean Society of Cardiovascular Imaging (KOCSI) has issued a guideline for the use of cardiac CT imaging in order to assist clinicians and patients in providing adequate level of medical service. In order to establish a guideline founded on evidence based medicine, it was designed based on comprehensive data such as questionnaires conducted in international and domestic hospitals, intensive journal reviews, and with experts in cardiac radiology. The recommendations of this guideline should not be used as an absolute standard and medical professionals can always refer to methods non-adherent to this guideline when it is considered more reasonable and beneficial to an individual patient's medical situation. The guideline has its limitation and should be revised appropriately with the advancement medical equipment technology and public health care system. The guideline should not be served as a measure for standard of care. KOCSI strongly disapproves the use of the guideline to be used as the standard of expected practice in medical litigation processes.

  19. Imaging system for cardiac planar imaging using a dedicated dual-head gamma camera

    Science.gov (United States)

    Majewski, Stanislaw; Umeno, Marc M.

    2011-09-13

    A cardiac imaging system employing dual gamma imaging heads co-registered with one another to provide two dynamic simultaneous views of the heart sector of a patient torso. A first gamma imaging head is positioned in a first orientation with respect to the heart sector and a second gamma imaging head is positioned in a second orientation with respect to the heart sector. An adjustment arrangement is capable of adjusting the distance between the separate imaging heads and the angle between the heads. With the angle between the imaging heads set to 180 degrees and operating in a range of 140-159 keV and at a rate of up to 500kHz, the imaging heads are co-registered to produce simultaneous dynamic recording of two stereotactic views of the heart. The use of co-registered imaging heads maximizes the uniformity of detection sensitivity of blood flow in and around the heart over the whole heart volume and minimizes radiation absorption effects. A normalization/image fusion technique is implemented pixel-by-corresponding pixel to increase signal for any cardiac region viewed in two images obtained from the two opposed detector heads for the same time bin. The imaging system is capable of producing enhanced first pass studies, bloodpool studies including planar, gated and non-gated EKG studies, planar EKG perfusion studies, and planar hot spot imaging.

  20. Cell tracking in cardiac repair: What to image and how to image

    NARCIS (Netherlands)

    A. Ruggiero (Alessandro); D.L.J. Thorek (Daniel L.J.); J. Guenoun (Jamal); G.P. Krestin (Gabriel); M.R. Bernsen (Monique)

    2012-01-01

    textabstractStem cell therapies hold the great promise and interest for cardiac regeneration among scientists, clinicians and patients. However, advancement and distillation of a standard treatment regimen are not yet finalised. Into this breach step recent developments in the imaging biosciences. T

  1. Quantification in non-invasive cardiac imaging: CT and MR

    OpenAIRE

    Rossi, Alexia

    2013-01-01

    markdownabstract__Abstract__ The diagnosis and management of cardiac disease require a precise assessment of morphological and functional cardiac parameters. This thesis is divided in three parts. Part I emphasizes the role of cardiac computed tomography (CT) in the diagnosis of patients with ischemic heart disease. Part 2 describes the role of cardiac magnetic resonance (CMR) and cardiac CT in the diagnosis, interventional planning, and follow-up of patients with aortic valve stenosis. Part ...

  2. A unique pattern of delayed enhancement of a large cardiac fibroma on magnetic resonance imaging.

    Science.gov (United States)

    El Yaman, Malek M; Vos, Jeffrey A; Gustafson, Robert A

    2015-06-01

    MRI is a valuable noninvasive tool that helps in predicting the type of cardiac tumors and guiding management decisions. Several reports have described the appearance of cardiac fibromas on MRI, which typically show hyperenhancement on myocardial delayed enhancement (MDE) imaging, with or without a dark core. This report demonstrates the unique appearance of a large solitary ventricular septal cardiac fibroma in a 5-month-old patient on MDE imaging, with two discrete dark cores, each surrounded by a hyperenhancing pseudocapsule.

  3. Cardiac biplane strain imaging: initial in vivo experience

    Energy Technology Data Exchange (ETDEWEB)

    Lopata, R G P; Nillesen, M M; Thijssen, J M; De Korte, C L [Clinical Physics Laboratory, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Verrijp, C N; Lammens, M M Y; Van der Laak, J A W M [Department of Pathology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Singh, S K; Van Wetten, H B [Department of Cardiothoracic Surgery, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Kapusta, L [Pediatric Cardiology, Department of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)], E-mail: R.Lopata@cukz.umcn.nl

    2010-02-21

    In this study, first we propose a biplane strain imaging method using a commercial ultrasound system, yielding estimation of the strain in three orthogonal directions. Secondly, an animal model of a child's heart was introduced that is suitable to simulate congenital heart disease and was used to test the method in vivo. The proposed approach can serve as a framework to monitor the development of cardiac hypertrophy and fibrosis. A 2D strain estimation technique using radio frequency (RF) ultrasound data was applied. Biplane image acquisition was performed at a relatively low frame rate (<100 Hz) using a commercial platform with an RF interface. For testing the method in vivo, biplane image sequences of the heart were recorded during the cardiac cycle in four dogs with an aortic stenosis. Initial results reveal the feasibility of measuring large radial, circumferential and longitudinal cumulative strain (up to 70%) at a frame rate of 100 Hz. Mean radial strain curves of a manually segmented region-of-interest in the infero-lateral wall show excellent correlation between the measured strain curves acquired in two perpendicular planes. Furthermore, the results show the feasibility and reproducibility of assessing radial, circumferential and longitudinal strains simultaneously. In this preliminary study, three beagles developed an elevated pressure gradient over the aortic valve ({delta}p: 100-200 mmHg) and myocardial hypertrophy. One dog did not develop any sign of hypertrophy ({delta}p = 20 mmHg). Initial strain (rate) results showed that the maximum strain (rate) decreased with increasing valvular stenosis (-50%), which is in accordance with previous studies. Histological findings corroborated these results and showed an increase in fibrotic tissue for the hearts with larger pressure gradients (100, 200 mmHg), as well as lower strain and strain rate values.

  4. Prognostic value of coronary anatomy and myocardial innervation imaging in cardiac disease

    NARCIS (Netherlands)

    Veltman, Caroline Emma

    2016-01-01

    Over the last decade, there has been an exponential development in cardiac imaging technology. Currently, cardiac imaging plays a central role in clinical management and decision making in the diverse and growing population of patients encountered in daily cardiology practice. Important outcome-rela

  5. MR-Based Cardiac and Respiratory Motion-Compensation Techniques for PET-MR Imaging.

    Science.gov (United States)

    Munoz, Camila; Kolbitsch, Christoph; Reader, Andrew J; Marsden, Paul; Schaeffter, Tobias; Prieto, Claudia

    2016-04-01

    Cardiac and respiratory motion cause image quality degradation in PET imaging, affecting diagnostic accuracy of the images. Whole-body simultaneous PET-MR scanners allow for using motion information estimated from MR images to correct PET data and produce motion-compensated PET images. This article reviews methods that have been proposed to estimate motion from MR images and different techniques to include this information in PET reconstruction, in order to overcome the problem of cardiac and respiratory motion in PET-MR imaging. MR-based motion correction techniques significantly increase lesion detectability and contrast, and also improve accuracy of uptake values in PET images.

  6. Utility of Magnetic Resonance Imaging in Cardiac Venous Anatomic Variants

    International Nuclear Information System (INIS)

    The incidence of persistent left superior venacava (PLSVC) is approximately 0.5% in the general population; however,the coexistent absence of the right SVC has a reported incidence in tertiary centers of 0.1%. The vast majority of reports are limited to pediatric cardiology. Likewise, sinus of Valsalva aneurysm is a rare congenital anomaly, with a reported incidence of 0.1-3.5% of all congenital heart defects. We present a 71-year-old patient undergoing preoperative evaluation for incidental finding of aortic root aneurysm,and found to have all three in coexistence. Suggestive findings were demonstrated on cardiac catheterization and definitive diagnosis was made by magnetic resonance imaging. The use of MRI for the diagnosis of asymptomatic adult congenital heart disease will be reviewed

  7. New insights into peripartum cardiomyopathy using cardiac magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Renz, D.M.; Roettgen, R.; Wagner, M.; Elgeti, T. [Charite Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie; Habedank, D.; Dietz, R. [Charite Universitaetsmedizin Berlin (Germany). Medizinische Klinik mit Schwerpunkt Kardiologie; Boettcher, J. [SRH Wald-Klinikum Gera (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Pfeil, A. [Jena Univ. (Germany). Klinik fuer Innere Medizin III; Kivelitz, D. [Asklepios Klinik St. Georg, Hamburg (Germany). Albers-Schoenberg-Institut fuer Strahlendiagnostik

    2011-09-15

    Purpose: The aim of this study was to evaluate a comprehensive cardiac magnetic resonance (MR) imaging approach in patients with peripartum cardiomyopathy (PPCM). The focus was on inflammatory myocardial changes. Materials and Methods: Retrospective analysis of 12 cardiac MR examinations was performed in 6 patients with PPCM. The protocol comprised cine sequences for the determination of chamber sizes and function. T2-weighted sequences for determination of edema (T2 ratio), T1-weighted images for measurement of early gadolinium enhancement ratio (EGER), and late gadolinium enhancement (LGE) sequences were used for tissue characterization. 5 examinations were performed during the acute stage, and 7 examinations were performed during the course of the disease. Results: Initially, 3 of 5 patients presented with an elevated left ventricular end-diastolic volume (LVEDV); in one patient, the LVEDV was in the upper range. In 4 of 5 subjects, the left ventricular ejection fraction (LVEF) was decreased. The T2 ratio and EGER values were initially elevated in all women. No LGE was detected in initial scans. In follow-up examinations, the LVEDV decreased and the LVEF increased in all patients. Tissue-characterizing parameters decreased to normal in all but 1 patient. 2 patients showing LGE did not present a favorable clinical course. Conclusion: Myocardial inflammation was detected in the acute stage of PPCM, which was mostly transient. In our small group, patients showing LGE had a non-favorable clinical course. Future studies should include tissue-characterizing parameters, such as T2 ratio and EGER. Thus, further insights into pathophysiology can be gained and therapeutic effects can be measured in a more extensive manner. (orig.)

  8. Cardiac biplane strain imaging: initial in vivo experience

    Science.gov (United States)

    Lopata, R. G. P.; Nillesen, M. M.; Verrijp, C. N.; Singh, S. K.; Lammens, M. M. Y.; van der Laak, J. A. W. M.; van Wetten, H. B.; Thijssen, J. M.; Kapusta, L.; de Korte, C. L.

    2010-02-01

    In this study, first we propose a biplane strain imaging method using a commercial ultrasound system, yielding estimation of the strain in three orthogonal directions. Secondly, an animal model of a child's heart was introduced that is suitable to simulate congenital heart disease and was used to test the method in vivo. The proposed approach can serve as a framework to monitor the development of cardiac hypertrophy and fibrosis. A 2D strain estimation technique using radio frequency (RF) ultrasound data was applied. Biplane image acquisition was performed at a relatively low frame rate (cardiac cycle in four dogs with an aortic stenosis. Initial results reveal the feasibility of measuring large radial, circumferential and longitudinal cumulative strain (up to 70%) at a frame rate of 100 Hz. Mean radial strain curves of a manually segmented region-of-interest in the infero-lateral wall show excellent correlation between the measured strain curves acquired in two perpendicular planes. Furthermore, the results show the feasibility and reproducibility of assessing radial, circumferential and longitudinal strains simultaneously. In this preliminary study, three beagles developed an elevated pressure gradient over the aortic valve (Δp: 100-200 mmHg) and myocardial hypertrophy. One dog did not develop any sign of hypertrophy (Δp = 20 mmHg). Initial strain (rate) results showed that the maximum strain (rate) decreased with increasing valvular stenosis (-50%), which is in accordance with previous studies. Histological findings corroborated these results and showed an increase in fibrotic tissue for the hearts with larger pressure gradients (100, 200 mmHg), as well as lower strain and strain rate values.

  9. Clinical utility and cost effectiveness of a personal ultrasound imager for cardiac evaluation during consultation rounds in patients with suspected cardiac disease

    NARCIS (Netherlands)

    E.C. Vourvouri (Eleni); L.Y. Koroleva; F.J. ten Cate (Folkert); D. Poldermans (Don); A.F.L. Schinkel (Arend); W.B. Vletter (Wim); J.R.T.C. Roelandt (Jos); R.T. van Domburg (Ron)

    2003-01-01

    textabstractOBJECTIVE: To assess the clinical utility and cost effectiveness of a personal ultrasound imager (PUI) during consultation rounds for cardiac evaluation of patients with suspected cardiac disease. METHODS: 107 unselected patients from non-cardiac departments (55% men) w

  10. Accessory cardiac bronchus: Proposed imaging classification on multidetector CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kang Min; Kim, Young Tong; Han, Jong Kyu; Jou, Sung Shick [Dept. of Radiology, Soonchunhyang University College of Medicine, Cheonan Hospital, Cheonan (Korea, Republic of)

    2016-02-15

    To propose the classification of accessory cardiac bronchus (ACB) based on imaging using multidetector computed tomography (MDCT), and evaluate follow-up changes of ACB. This study included 58 patients diagnosed as ACB since 9 years, using MDCT. We analyzed the types, division locations and division directions of ACB, and also evaluated changes on follow-up. We identified two main types of ACB: blind-end (51.7%) and lobule (48.3%). The blind-end ACB was further classified into three subtypes: blunt (70%), pointy (23.3%) and saccular (6.7%). The lobule ACB was also further classified into three subtypes: complete (46.4%), incomplete (28.6%) and rudimentary (25%). Division location to the upper half bronchus intermedius (79.3%) and medial direction (60.3%) were the most common in all patients. The difference in division direction was statistically significant between the blind-end and lobule types (p = 0.019). Peribronchial soft tissue was found in five cases. One calcification case was identified in the lobule type. During follow-up, ACB had disappeared in two cases of the blind-end type and in one case of the rudimentary subtype. The proposed classification of ACB based on imaging, and the follow-up CT, helped us to understand the various imaging features of ACB.

  11. Quantification in non-invasive cardiac imaging: CT and MR

    NARCIS (Netherlands)

    A. Rossi (Alexia)

    2013-01-01

    markdownabstract__Abstract__ The diagnosis and management of cardiac disease require a precise assessment of morphological and functional cardiac parameters. This thesis is divided in three parts. Part I emphasizes the role of cardiac computed tomography (CT) in the diagnosis of patients with ische

  12. Computational chemical imaging for cardiovascular pathology: chemical microscopic imaging accurately determines cardiac transplant rejection.

    Directory of Open Access Journals (Sweden)

    Saumya Tiwari

    Full Text Available Rejection is a common problem after cardiac transplants leading to significant number of adverse events and deaths, particularly in the first year of transplantation. The gold standard to identify rejection is endomyocardial biopsy. This technique is complex, cumbersome and requires a lot of expertise in the correct interpretation of stained biopsy sections. Traditional histopathology cannot be used actively or quickly during cardiac interventions or surgery. Our objective was to develop a stain-less approach using an emerging technology, Fourier transform infrared (FT-IR spectroscopic imaging to identify different components of cardiac tissue by their chemical and molecular basis aided by computer recognition, rather than by visual examination using optical microscopy. We studied this technique in assessment of cardiac transplant rejection to evaluate efficacy in an example of complex cardiovascular pathology. We recorded data from human cardiac transplant patients' biopsies, used a Bayesian classification protocol and developed a visualization scheme to observe chemical differences without the need of stains or human supervision. Using receiver operating characteristic curves, we observed probabilities of detection greater than 95% for four out of five histological classes at 10% probability of false alarm at the cellular level while correctly identifying samples with the hallmarks of the immune response in all cases. The efficacy of manual examination can be significantly increased by observing the inherent biochemical changes in tissues, which enables us to achieve greater diagnostic confidence in an automated, label-free manner. We developed a computational pathology system that gives high contrast images and seems superior to traditional staining procedures. This study is a prelude to the development of real time in situ imaging systems, which can assist interventionists and surgeons actively during procedures.

  13. Dose optimization in pediatric cardiac x-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gislason, Amber J.; Davies, Andrew G.; Cowen, Arnold R. [LXi Research, Division of Medical Physics, University of Leeds, Worsley Building, Clarendon Way, Leeds LS2 9JT (United Kingdom)

    2010-10-15

    Purpose: The aim of this research was to explore x-ray beam parameters with intent to optimize pediatric x-ray settings in the cardiac catheterization laboratory. This study examined the effects of peak x-ray tube voltage (kVp) and of copper (Cu) x-ray beam filtration independently on the image quality to dose balance for pediatric patient sizes. The impact of antiscatter grid removal on the image quality to dose balance was also investigated. Methods: Image sequences of polymethyl methacrylate phantoms approximating chest sizes typical of pediatric patients were captured using a modern flat-panel receptor based x-ray imaging system. Tin was used to simulate iodine-based contrast medium used in clinical procedures. Measurements of tin detail contrast and flat field image noise provided the contrast to noise ratio. Entrance surface dose (ESD) and effective dose (E) measurements were obtained to calculate the figure of merit (FOM), CNR{sup 2}/dose, which evaluated the dose efficiency of the x-ray parameters investigated. The kVp, tube current (mA), and pulse duration were set manually by overriding the system's automatic dose control mechanisms. Images were captured with 0, 0.1, 0.25, 0.4, and 0.9 mm added Cu filtration, for 50, 55, 60, 65, and 70 kVp with the antiscatter grid in place, and then with it removed. Results: For a given phantom thickness, as the Cu filter thickness was increased, lower kVp was favored. Examining kVp alone, lower values were generally favored, more so for thinner phantoms. Considering ESD, the 8.5 cm phantom had the highest FOM at 50 kVp using 0.4 mm of Cu filtration. The 12 cm phantom had the highest FOM at 55 kVp using 0.9 mm Cu, and the 16 cm phantom had highest FOM at 55 kVp using 0.4 mm Cu. With regard to E, the 8.5 and 12 cm phantoms had the highest FOM at 50 kVp using 0.4 mm of Cu filtration, and the 16 cm phantom had the highest FOM at 50 kVp using 0.25 mm Cu. Antiscatter grid removal improved the FOM for a given set of x

  14. Multimodal Imaging after Sudden Cardiac Arrest in an 18-Year-Old Athlete

    Science.gov (United States)

    Rehman, Mobeen Ur; Atalay, Michael K.; Broderick, Ryan J.

    2015-01-01

    We report the case of a previously healthy 18-year-old male athlete who twice presented with sudden cardiac arrest. Our use of electrocardiography, echocardiography, cardiac magnetic resonance, coronary angiography, coronary computed tomographic angiography, and nuclear stress testing enabled the diagnoses of apical hypertrophic cardiomyopathy and anomalous origin of the right coronary artery. We discuss the patient's treatment and note the useful role of multiple cardiovascular imaging methods in cases of sudden cardiac arrest. PMID:26664308

  15. Quadricuspid aortic valve by cardiac magnetic resonance imaging: a case report and review of the literature.

    Science.gov (United States)

    Khan, Shamruz Khan Akerem; Tamin, Syahidah Syed; Araoz, Philip A

    2011-01-01

    Quadricuspid aortic valve (QAV) is a rare congenital cardiac entity. The recognition of QAV has clinical significance as it causes aortic valve dysfunction, commonly aortic regurgitation, and is often associated with other congenital cardiac abnormalities. We showed the important role played by cardiac magnetic resonance imaging in detecting QAV and review the available literature to explain its incidence, diagnosis, classifications, embryology, correlation between morphology of the QAV and its function, associated conditions, and management. PMID:21926862

  16. Filters in 2D and 3D Cardiac SPECT Image Processing

    Directory of Open Access Journals (Sweden)

    Maria Lyra

    2014-01-01

    Full Text Available Nuclear cardiac imaging is a noninvasive, sensitive method providing information on cardiac structure and physiology. Single photon emission tomography (SPECT evaluates myocardial perfusion, viability, and function and is widely used in clinical routine. The quality of the tomographic image is a key for accurate diagnosis. Image filtering, a mathematical processing, compensates for loss of detail in an image while reducing image noise, and it can improve the image resolution and limit the degradation of the image. SPECT images are then reconstructed, either by filter back projection (FBP analytical technique or iteratively, by algebraic methods. The aim of this study is to review filters in cardiac 2D, 3D, and 4D SPECT applications and how these affect the image quality mirroring the diagnostic accuracy of SPECT images. Several filters, including the Hanning, Butterworth, and Parzen filters, were evaluated in combination with the two reconstruction methods as well as with a specified MatLab program. Results showed that for both 3D and 4D cardiac SPECT the Butterworth filter, for different critical frequencies and orders, produced the best results. Between the two reconstruction methods, the iterative one might be more appropriate for cardiac SPECT, since it improves lesion detectability due to the significant improvement of image contrast.

  17. Imaging findings of multiple infantile hepatic hemangioma associated with cardiac insufficiency

    Institute of Scientific and Technical Information of China (English)

    Jing-Jing Ye; Yin-Can Shao; Qiang Shu

    2014-01-01

    Background: Infantile hepatic hemangioma (IHH) as a benign liver tumor in infancy and childhood is commonly associated with high output cardiac failure. The present study aims to describe the imaging findings in a patient who was diagnosed as having multiple IHH with congestive cardiac insuffi ciency. Methods: The imaging findings and clinical manifestations of the patient with multiple IHH associated with cardiac insuffi ciency were retrospectively reviewed. Results: Ultrasonography showed multiple intrahepatic lesions with mixed echoes and markedly expanded hepatic veins and the inferior vena cava of the patient. Echocardiography revealed right heart insufficiency and pulmonary hypertension. Contrast-enhanced MRI showed early mild enhancement of lesions and more obvious delayed enhancement. The patient died after combined therapy of surgery and hormone. Conclusions: The imaging findings of multiple IHH associated with cardiac insufficiency are typical and diagnostic. Early imaging assessment may facilitate the diagnosis and treatment of the disease.

  18. Non-cardiac findings on coronary computed tomography and magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Marc; Schnapauff, Dirk; Teige, Florian; Hamm, Bernd [Charite-Universitaetsmedizin Berlin, Humboldt-Universitaet zu Berlin, Department of Radiology, Chariteplatz 1, P.O. Box 10098, Berlin (Germany)

    2007-08-15

    Both multislice computed tomography (CT) and magnetic resonance imaging (MRI) are emerging as methods to detect coronary artery stenoses and assess cardiac function and morphology. Non-cardiac structures are also amenable to assessment by these non-invasive tests. We investigated the rate of significant and insignificant non-cardiac findings using CT and MRI. A total of 108 consecutive patients suspected of having coronary artery disease and without contraindications to CT and MRI were included in this study. Significant non-cardiac findings were defined as findings that required additional clinical or radiological follow-up. CT and MR images were read independently in a blinded fashion. CT yielded five significant non-cardiac findings in five patients (5%). These included a pulmonary embolism, large pleural effusions, sarcoid, a large hiatal hernia, and a pulmonary nodule (>1.0 cm). Two of these significant non-cardiac findings were also seen on MRI (pleural effusions and sarcoid, 2%). Insignificant non-cardiac findings were more frequent than significant findings on both CT (n = 11, 10%) and MRI (n = 7, 6%). Incidental non-cardiac findings on CT and MRI of the coronary arteries are common, which is why images should be analyzed by radiologists to ensure that important findings are not missed and unnecessary follow-up examinations are avoided. (orig.)

  19. Reduction of blooming artifacts in cardiac CT images by blind deconvolution and anisotropic diffusion filtering

    Science.gov (United States)

    Castillo-Amor, Angélica M.; Navarro-Navia, Cristian A.; Cadena-Bonfanti, Alberto J.; Contreras-Ortiz, Sonia H.

    2015-12-01

    Even though CT is an imaging technique that offers high quality images, limitations on its spatial resolution cause blurring in small objects with high contrast. This phenomenon is known as blooming artifact and affects cardiac images with small calcifications and stents. This paper describes an approach to reduce the blooming artifact and improve resolution in cardiac images using blind deconvolution and anisotropic diffusion filtering. Deconvolution increases resolution but reduces signal-to-noise ratio, and the anisotropic diffusion filter counteracts this effect without affecting the edges in the image.

  20. Effects of Radiation Exposure From Cardiac Imaging: How Good Are the Data?

    OpenAIRE

    Einstein, Andrew J.

    2012-01-01

    Concerns about medical exposure to ionizing radiation have become heightened in recent years due to rapid growth in procedure volumes and the high radiation doses incurred from some procedures. This article summarizes the evidence base undergirding concerns about radiation exposure in cardiac imaging. After classifying radiation effects, explaining terminology used to quantify the radiation received by patients, and describing typical doses from cardiac imaging procedures, I address the major...

  1. Echocardiography to magnetic resonance image registration for use in image-guided cardiac catheterization procedures

    Energy Technology Data Exchange (ETDEWEB)

    Ma Yingliang; Penney, Graeme P; Razavi, Reza; Rhode, Kawal S [Division of Imaging Sciences, King' s College, London SE1 7EH (United Kingdom); Rinaldi, C Aldo; Cooklin, Mike [Department of Cardiology, Guy' s and St Thomas' NHS Foundation Trust, London, SE1 7EH (United Kingdom)], E-mail: y.ma@kcl.ac.uk

    2009-08-21

    We present a robust method to register three-dimensional echocardiography (echo) images to magnetic resonance images (MRI) based on anatomical features, which is designed to be used in the registration pipeline for overlaying MRI-derived roadmaps onto two-dimensional live x-ray images during cardiac catheterization procedures. The features used in image registration are the endocardial surface of the left ventricle and the centre line of the descending aorta. The MR-derived left ventricle surface is generated using a fully automated algorithm, and the echo-derived left ventricle surface is produced using a semi-automatic segmentation method provided by the QLab software (Philips Healthcare) that it is routinely used in clinical practice. We test our method on data from six volunteers and four patients. We validated registration accuracy using two methods: the first calculated a root mean square distance error using expert identified anatomical landmarks, and the second method used catheters as landmarks in two clinical electrophysiology procedures. Results show a mean error of 4.1 mm, which is acceptable for our clinical application, and no failed registrations were observed. In addition, our algorithm works on clinical data, is fast and only requires a small amount of manual input, and so it is applicable for use during cardiac catheterization procedures.

  2. Coronary artery stent mimicking intracardiac thrombus on cardiac magnetic resonance imaging due to signal loss

    DEFF Research Database (Denmark)

    Qayyum, Abbas Ali; Vejlstrup, Niels Grove; Ahtarovski, Kiril Aleksov;

    2012-01-01

    Since the introduction of percutaneous coronary intervention for coronary artery disease, thousands of patients have been treated with the implantation of coronary stents. Moreover, several of the patients with coronary stent undergo cardiac magnetic resonance (CMR) imaging every year. This case...... report is of a 77-year-old man who was previously treated with the implantation of a coronary stent in the left circumflex artery. He underwent CMR imaging, which revealed a process 14×21 mm in the left atrium. Cardiac contrast computed tomography did not demonstrate any cardiac pathology. While the...

  3. An active contour framework based on the Hermite transform for shape segmentation of cardiac MR images

    Science.gov (United States)

    Barba-J, Leiner; Escalante-Ramírez, Boris

    2016-04-01

    Early detection of cardiac affections is fundamental to address a correct treatment that allows preserving the patient's life. Since heart disease is one of the main causes of death in most countries, analysis of cardiac images is of great value for cardiac assessment. Cardiac MR has become essential for heart evaluation. In this work we present a segmentation framework for shape analysis in cardiac magnetic resonance (MR) images. The method consists of an active contour model which is guided by the spectral coefficients obtained from the Hermite transform (HT) of the data. The HT is used as model to code image features of the analyzed images. Region and boundary based energies are coded using the zero and first order coefficients. An additional shape constraint based on an elliptical function is used for controlling the active contour deformations. The proposed framework is applied to the segmentation of the endocardial and epicardial boundaries of the left ventricle using MR images with short axis view. The segmentation is sequential for both regions: the endocardium is segmented followed by the epicardium. The algorithm is evaluated with several MR images at different phases of the cardiac cycle demonstrating the effectiveness of the proposed method. Several metrics are used for performance evaluation.

  4. Model-based segmentation of short-axis MR cardiac images

    NARCIS (Netherlands)

    Spreeuwers, L.J.; Breeuwer, M.

    2005-01-01

    Reliable automatic segmentation of MR cardiac images is still an important problem in medical image processing. Although image data quality has improved considerably during the last years, this segmentation is still considered a difficult problem. Manual segmentation is hardly an option as this is e

  5. Method for Automatic Tube Current Selection for Obtaining a Consistent Image Quality and Dose Optimization in a Cardiac Multidetector CT

    OpenAIRE

    Qi, Weiwei; Li, Jianying; Du, Xiangke

    2009-01-01

    Objective To evaluate a quantitative method for individually adjusting the tube current to obtain images with consistent noise in electrocardiogram (ECG)-gated CT cardiac scans. Materials and Methods The image noise from timing bolus and cardiac CT scans of 80 patients (Group A) who underwent a 64-row multidetector (MD) CT cardiac examination with patient-independent scan parameters were analyzed. A formula was established using the noise correlation between the timing bolus and cardiac scans...

  6. Matching the Clinical Question to the Appropriate Imaging Procedure: What a Cardiologist Wants from Cardiac Imaging

    Directory of Open Access Journals (Sweden)

    S. Wann

    2007-05-01

    Full Text Available In modern medicine, we too often become enamored with technology and lose focus on the reason for per-forming a diagnostic study. Cardiac imaging may have advanced to point of replacing the physical ex-amination, but there is still no substitute for thought-ful planning of a diagnostic approach based on a hier-archy of clinical data, an appreciation of the pre-test likelihood of disease, realistic expectation from vari-ous imaging procedures, and a rational plan for utiliz-ing the information gained. Team work is required to effectively utilize all the capabilities of the modern medical environment. Communication is essential if patients are to receive the best care. As the power and complexity of imag-ing has increase, so has its over-utilization. This lec-ture will focus on maximizing useful diagnostic yield, while minimizing redundancy and excessive costs. While evidence based medical practice is ideally based on controlled randomized trials to show im-proved patient outcomes. Medical imaging has his-torically developed by improving the quality of im-ages, comparing new to existing technologist. Exam-ples will be given of applications of various imaging techniques to common clinical problems, pointing out areas where true evidence is lacking. Appropriate imaging in these situations must be defined by con-sensus of expert opinion. A variety of clinical vi-gnettes will be presented.

  7. Patient management after noninvasive cardiac imaging results from SPARC (Study of myocardial perfusion and coronary anatomy imaging roles in coronary artery disease).

    NARCIS (Netherlands)

    Hachamovitch, R.; Nutter, B.; Hlatky, M.A.; Shaw, L.J.; Ridner, M.L.; Dorbala, S.; Beanlands, R.S.; Chow, B.J.; Branscomb, E.; Chareonthaitawee, P.; Weigold, W.G.; Voros, S.; Abbara, S.; Yasuda, T.; Jacobs, J.E.; Lesser, J.; Berman, D.S.; Thomson, L.E.; Raman, S.; Heller, G.V.; Schussheim, A.; Brunken, R.; Williams, K.A.; Farkas, S.; Delbeke, D.; Schoepf, U.J.; Reichek, N.; Rabinowitz, S.; Sigman, S.R.; Patterson, R.; Corn, C.R.; White, R.; Kazerooni, E.; Corbett, J.; Bokhari, S.; Machac, J.; Guarneri, E.; Borges-Neto, S.; Millstine, J.W.; Caldwell, J.; Arrighi, J.; Hoffmann, U.; Budoff, M.; Lima, J.; Johnson, J.R.; Johnson, B.; Gaber, M.; Williams, J.A.; Foster, C.; Hainer, J.; Carli, M.F. Di

    2012-01-01

    OBJECTIVES: This study examined short-term cardiac catheterization rates and medication changes after cardiac imaging. BACKGROUND: Noninvasive cardiac imaging is widely used in coronary artery disease, but its effects on subsequent patient management are unclear. METHODS: We assessed the 90-day post

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

    OpenAIRE

    Staniak, Henrique Lane; Sharovsky, Rodolfo; Pereira, Alexandre Costa; de Castro, Cláudio Campi; Isabela M. Benseñor; Paulo A Lotufo; Bittencourt, Márcio Sommer

    2014-01-01

    Background Few data on the definition of simple robust parameters to predict image noise in cardiac computed tomography (CT) exist. Objectives To evaluate the value of a simple measure of subcutaneous tissue as a predictor of image noise in cardiac CT. Methods 86 patients underwent prospective ECG-gated coronary computed tomographic angiography (CTA) and coronary calcium scoring (CAC) with 120 kV and 150 mA. The image quality was objectively measured by the image noise in the aorta in the car...

  9. Extracardiac findings detected by cardiac magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wyttenbach, Rolf; Medioni, Nathalie; Santini, Paolo [Ospedale San Giovanni Bellinzona (EOC), Department of Radiology, Bellinzona (Switzerland); Vock, Peter [University Hospital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); Szucs-Farkas, Zsolt [University Hospital Bern, Department of Diagnostic, Interventional and Paediatric Radiology, Bern (Switzerland); Spitalzentrum Biel AG, Department of Radiology, Biel (Switzerland)

    2012-06-15

    To determine the prevalence and importance of extracardiac findings (ECF) in patients undergoing clinical CMR and to test the hypothesis that the original CMR reading focusing on the heart may underestimate extracardiac abnormalities. 401 consecutive patients (mean age 53 years) underwent CMR at 1.5 T. Main indications were ischaemic heart disease (n = 183) and cardiomyopathy (n = 164). All CMR sequences, including scout images, were reviewed with specific attention to ECF in a second reading by the same radiologist who performed the first clinical reading. Potentially significant findings were defined as abnormalities requiring additional clinical or radiological follow-up. 250 incidental ECF were detected, of which 84 (34%) had potentially significant ECF including bronchial carcinoma (n = 1), lung consolidation (n = 7) and abdominal abnormalities. In 166 CMR studies (41%) non-significant ECF were detected. The number of ECF identified at second versus first reading was higher for significant (84 vs. 47) and non-significant (166 vs. 36) findings (P < 0.00001). About one fifth of patients undergoing CMR were found to have potentially significant ECF requiring additional work-up. The second dedicated reading detected significantly more ECF compared with the first clinical reading emphasising the importance of active search for extracardiac abnormalities when evaluating CMR studies. circle Many patients undergoing cardiac MR have significant extracardiac findings (ECF) circle These impact on management and require additional work-up. circle Wide review of scout and cine sequences will detect most ECFs. circle Education of radiologists is important to identify ECFs on CMR studies. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-15

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

  11. Clinical study on the adriamycin induced cardiomyopathy using the cardiac magnetic resonance imaging. Total dose and cardiac dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Kyoko; Teraoka, Kunihiko; Hirano, Masaharu [Tokyo Medical Coll. (Japan)

    2001-05-01

    We studied cardiac functional disorders caused by Adoriamycin using gadolinium (Gd) contrast cine MRI. Forty-eight patients were given ACT (31 men and 17 women; mean age, 52{+-}15 years). First, the relationship between dose and the left ventricular volume, cardiac function, left ventricular cardiac mass and localized wall motion were examined in all patients. Patients given a total dose of 300 mg/m{sup 2} or higher were assigned to the high dose group and those given doses under 300 mg/m{sup 2} to the low dose group. The same parameters were studied in both groups and compared. A 1.5-Tesla superconductive MRI was used for all studies. Cine images of the long and short axes at the papillary muscle level were obtained by ECG R-wave synchronized Gd contrast cine MRI. Left ventricular volume and cardiac function were analyzed using the long-axis cine images and the wall thickness in diastole and systole was measured at each site using the short-axis cine images. The percentage of wall thickness was calculated at each site. The mean ACT dose was 273.3{+-}218.2 mg/m{sup 2}. In all patients the total dose directly correlated with ESVI and inversely correlated with the ejection fraction (EF). In the high dose group, the total dose and EF were inversely correlated, but no significant differences were observed in the low dose group. In the high dose group, the ESVI was significantly greater and the SVI and EF were more significantly reduced than in the low dose group. In the high dose group, the thickness of the anterior, lateral and posterior walls, excluding the septum, was significantly lower than in the low dose group. However, changes in wall thickness were not significantly different between the groups. Gd contrast cine MRI was useful in examining cardiac functional disorders caused by anthracyclines. The total dose of anthracycline correlated directly with the ESVI, and inversely with the EF. A total dose of 300 mg/m{sup 2} appeared to be the borderline dose beyond

  12. Feasibility of using respiration-averaged MR images for attenuation correction of cardiac PET/MR imaging.

    Science.gov (United States)

    Ai, Hua; Pan, Tinsu

    2015-01-01

    Cardiac imaging is a promising application for combined PET/MR imaging. However, current MR imaging protocols for whole-body attenuation correction can produce spatial mismatch between PET and MR-derived attenuation data owing to a disparity between the two modalities' imaging speeds. We assessed the feasibility of using a respiration-averaged MR (AMR) method for attenuation correction of cardiac PET data in PET/MR images. First, to demonstrate the feasibility of motion imaging with MR, we used a 3T MR system and a two-dimensional fast spoiled gradient-recalled echo (SPGR) sequence to obtain AMR images ofa moving phantom. Then, we used the same sequence to obtain AMR images of a patient's thorax under free-breathing conditions. MR images were converted into PET attenuation maps using a three-class tissue segmentation method with two sets of predetermined CT numbers, one calculated from the patient-specific (PS) CT images and the other from a reference group (RG) containing 54 patient CT datasets. The MR-derived attenuation images were then used for attenuation correction of the cardiac PET data, which were compared to the PET data corrected with average CT (ACT) images. In the myocardium, the voxel-by-voxel differences and the differences in mean slice activity between the AMR-corrected PET data and the ACT-corrected PET data were found to be small (less than 7%). The use of AMR-derived attenuation images in place of ACT images for attenuation correction did not affect the summed stress score. These results demonstrate the feasibility of using the proposed SPGR-based MR imaging protocol to obtain patient AMR images and using those images for cardiac PET attenuation correction. Additional studies with more clinical data are warranted to further evaluate the method. PMID:26218995

  13. Optimising cardiac/angiographic digital images using a Butternut as the image quality phantom

    International Nuclear Information System (INIS)

    Full text: Digital images, whether produced by image intensifiers, flat panels or computed radiography imaging plates, have a broad dynamic range and, thus, there is a need to adjust the exposure parameters of the imaging protocols to obtain diagnostic images without over exposing patients. The default exposure techniques of protocols delivered with the imaging equipment are in general set to produce high quality images at the expense of high radiation doses to patients. Ideally, these protocols should be optimised for best possible image quality at the lowest possible patient dose, particularly for paediatric patients. Manufacturers of equipment do not generally supply paediatric protocols and, thus, the default settings of the adult protocols have to be adjusted for paediatric patients. Optimising imaging protocols is not a trivial matter and, without a suitable phantom, it is difficult and time consuming. Commercial phantoms are commonly used to optimise adult protocols, but these are made of dry materials such as perspex, Teflon, aluminium, dry bone as in dry skulls, or a combination of these materials. The problem with these phantoms is that the features on their images are artificial, not simulating any characteristics of patients' anatomic details. In optimising paediatric protocols for our new cardiac/angiographic Siemens Biplane Digital Imaging System, we searched for a paediatric phantom with moisture content, and found that the humble butternut pumpkin (cucurbita moschate) from the squash family makes a good paediatric phantom, particularly, when it is injected with contrast. The part of the butternut that is useful as a phantom is the pulp, i.e., the part that contains the seeds. This is also the part where the contrast is injected. The image of the pulp contains structures that are natural as the butternut is the fruit of a living plant. The image of the seeds is suitable for low-level contrast detectability while fine structures enhanced by the

  14. Comparison of magnetic resonance imaging and echocardiography in determination of cardiac dimensions in normal subjects.

    Science.gov (United States)

    Friedman, B J; Waters, J; Kwan, O L; DeMaria, A N

    1985-06-01

    No data exist regarding the ability of magnetic resonance imaging to assess cardiac size and performance in human beings. Therefore, measurements of cardiac dimensions by magnetic resonance imaging were compared with those obtained by two-dimensional echocardiography in 21 normal subjects. Magnetic resonance transverse cardiac sections were obtained during electrocardiographic gating using a spin echo pulse sequence. In normal subjects, magnetic resonance imaging yielded a range of values for cardiac dimensions having a similar standard deviation as that of two-dimensional echocardiography. Diastolic measurements of the aorta, left atrium, left ventricle and septum obtained by magnetic resonance imaging correlated well with those obtained by two-dimensional echocardiography (r = 0.82, 0.78, 0.81 and 0.75, respectively). The correlation coefficient of r = 0.35 observed for the posterior wall thickness was not surprising in view of the narrow range of normal values. Only a general correlation (r = 0.53) existed for the right ventricular diastolic dimension; this was probably related to the difficulty in obtaining representative measurements due to the complex geometry of this chamber. Failure of systolic dimension measurements by magnetic resonance imaging to correlate with those obtained by echocardiography is probably related to limitations of electrocardiographic gating, especially of determining the exact end-systolic frame. Although technically complex at present, magnetic resonance imaging does provide an additional noninvasive technique for measurement of cardiac size.

  15. SU-E-P-10: Imaging in the Cardiac Catheterization Lab - Technologies and Clinical Applications

    Energy Technology Data Exchange (ETDEWEB)

    Fetterly, K [Mayo Clinic, Rochester, MN (United States)

    2014-06-01

    Purpose: Diagnosis and treatment of cardiovascular disease in the cardiac catheterization laboratory is often aided by a multitude of imaging technologies. The purpose of this work is to highlight the contributions to patient care offered by the various imaging systems used during cardiovascular interventional procedures. Methods: Imaging technologies used in the cardiac catheterization lab were characterized by their fundamental technology and by the clinical applications for which they are used. Whether the modality is external to the patient, intravascular, or intracavity was specified. Specific clinical procedures for which multiple modalities are routinely used will be highlighted. Results: X-ray imaging modalities include fluoroscopy/angiography and angiography CT. Ultrasound imaging is performed with external, trans-esophageal echocardiography (TEE), and intravascular (IVUS) transducers. Intravascular infrared optical coherence tomography (IVOCT) is used to assess vessel endothelium. Relatively large (>0.5 mm) anatomical structures are imaged with x-ray and ultrasound. IVUS and IVOCT provide high resolution images of vessel walls. Cardiac CT and MRI images are used to plan complex cardiovascular interventions. Advanced applications are used to spatially and temporally merge images from different technologies. Diagnosis and treatment of coronary artery disease frequently utilizes angiography and intra-vascular imaging, and treatment of complex structural heart conditions routinely includes use of multiple imaging modalities. Conclusion: There are several imaging modalities which are routinely used in the cardiac catheterization laboratory to diagnose and treat both coronary artery and structural heart disease. Multiple modalities are frequently used to enhance the quality and safety of procedures. The cardiac catheterization laboratory includes many opportunities for medical physicists to contribute substantially toward advancing patient care.

  16. Radiation protection in newer medical imaging techniques: Cardiac CT

    International Nuclear Information System (INIS)

    Medical imaging has seen many developments as it has evolved since the mid-1890s. In the last 30-40 years, the pace of innovation has increased, starting with the introduction of computed tomography (CT) in the early 1970s. During the last decade, the rate of change has accelerated further, in terms of continuing innovation and its global application. Most patient exposure now arises from practices that barely existed two decades ago. These developments are evident in the technology on which this volume is based - multislice/detector CT scanning and its application in cardiac imaging. However, this advance is achieved at the cost of a radiation burden to the individual patient, and possibly to the community, if its screening potential is exploited. Much effort will be required to ensure that the undoubted benefit of this new practice will not pose an undue level of detriment to the individual in multiple examinations. For practitioners and regulators, it is evident that innovation has been driven by both the imaging industry and an increasing array of new applications generated and validated in the clinical environment. Regulation, industrial standardization, safety procedures and advice on best practices lag (inevitably) behind the industrial and clinical innovations. This series of Safety Reports (Nos 58, 60 and 61) is designed to help fill this growing vacuum, by bringing up to date and timely advice from experienced practitioners to bear on the problems involved. The advice in this report has been developed as part of the IAEA's statutory responsibility to establish standards for the protection of people against exposure to ionizing radiation and to provide for the worldwide application of these standards. The Fundamental Safety Principles and the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS) were issued by the IAEA and co-sponsored by organizations including the Food and Agriculture

  17. Integration of genomics, proteomics, and imaging for cardiac stem cell therapy

    International Nuclear Information System (INIS)

    Cardiac stem cell therapy is beginning to mature as a valid treatment for heart disease. As more clinical trials utilizing stem cells emerge, it is imperative to establish the mechanisms by which stem cells confer benefit in cardiac diseases. In this paper, we review three methods - molecular cellular imaging, gene expression profiling, and proteomic analysis - that can be integrated to provide further insights into the role of this emerging therapy. (orig.)

  18. Robust segmentation of 4D cardiac MRI-tagged images via spatio-temporal propagation

    Science.gov (United States)

    Qian, Zhen; Huang, Xiaolei; Metaxas, Dimitris N.; Axel, Leon

    2005-04-01

    In this paper we present a robust method for segmenting and tracking cardiac contours and tags in 4D cardiac MRI tagged images via spatio-temporal propagation. Our method is based on two main techniques: the Metamorphs Segmentation for robust boundary estimation, and the tunable Gabor filter bank for tagging lines enhancement, removal and myocardium tracking. We have developed a prototype system based on the integration of these two techniques, and achieved efficient, robust segmentation and tracking with minimal human interaction.

  19. Effects of Radiation Exposure From Cardiac Imaging: How Good Are the Data?

    Science.gov (United States)

    Einstein, Andrew J.

    2012-01-01

    Concerns about medical exposure to ionizing radiation have become heightened in recent years due to rapid growth in procedure volumes and the high radiation doses incurred from some procedures. This article summarizes the evidence base undergirding concerns about radiation exposure in cardiac imaging. After classifying radiation effects, explaining terminology used to quantify the radiation received by patients, and describing typical doses from cardiac imaging procedures, I address the major epidemiological studies having bearing on radiation effects at doses comparable to those received by patients undergoing cardiac imaging. These include studies of atomic bomb survivors, nuclear industry workers, and children exposed in utero to x-rays, all of which have evidenced increased cancer risks at low doses. Additional higher dose epidemiological studies of cohorts exposed to radiation in the context of medical treatment are described and found to be generally compatible with these cardiac-dose-level studies, albeit with exceptions. Using risk projection models developed by the US National Academies that incorporate these data and reflect several evidence-based assumptions, cancer risk from cardiac imaging can be estimated and compared to benefits from imaging. Several ongoing epidemiological studies will provide better understanding of radiation-associated cancer risks. PMID:22300689

  20. Incidental cardiac findings on computed tomography imaging of the thorax

    Directory of Open Access Journals (Sweden)

    El-Gendi Hossam

    2010-12-01

    Full Text Available Abstract Background Investigation of pulmonary pathology with computed tomography also allows visualisation of the heart and major vessels. We sought to explore whether clinically relevant cardiac pathology could be identified on computed tomography pulmonary angiograms (CTPA requested for the exclusion of pulmonary embolism (PE. 100 consecutive CT contrast-enhanced pulmonary angiograms carried out for exclusion of PE at a single centre were assessed retrospectively by two cardiologists. Findings Evidence of PE was reported in 5% of scans. Incidental cardiac findings included: aortic wall calcification (54%, coronary calcification (46%, cardiomegaly (41%, atrial dilatation (18%, mitral annulus calcification (15%, right ventricular dilatation (11%, aortic dilatation (8% and right ventricular thrombus (1%. Apart from 3 (3% reports describing cardiomegaly, no other cardiac findings were described in radiologists' reports. Other reported pulmonary abnormalities included: lung nodules (14%, lobar collapse/consolidation (8%, pleural effusion (2%, lobar collapse/consolidation (8%, emphysema (6% and pleural calcification (4%. Conclusions CTPAs requested for the exclusion of PE have a high yield of cardiac abnormalities. Although these abnormalities may not have implications for acute clinical management, they may, nevertheless, be important in long-term care.

  1. Intraoperative Cardiac Ultrasound Examination Using Vector Flow Imaging

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Lindskov; Pedersen, Mads Møller; Møller-Sørensen, Hasse;

    2013-01-01

    Conventional ultrasound (US) methods for blood velocity estimation only provide onedimensional and angle-dependent velocity estimates; thus, the complexity of cardiac flow has been difficult to measure. To circumvent these limitations, the Transverse Oscillation (TO) vector flow method has been p...

  2. Evaluation of apical subtype of hypertrophic cardiomyopathy using cardiac magnetic resonance imaging with gadolinium enhancement.

    Science.gov (United States)

    Kebed, Kalie Y; Al Adham, Raed I; Bishu, Kalkidan; Askew, J Wells; Klarich, Kyle W; Araoz, Philip A; Foley, Thomas A; Glockner, James F; Nishimura, Rick A; Anavekar, Nandan S

    2014-09-01

    Apical hypertrophic cardiomyopathy (HC) is an uncommon variant of HC. We sought to characterize cardiac magnetic resonance imaging (MRI) findings among apical HC patients. This was a retrospective review of consecutive patients with a diagnosis of apical HC who underwent cardiac MRI examinations at the Mayo Clinic (Rochester, MN) from August 1999 to October 2011. Clinical and demographic data at the time of cardiac MRI study were abstracted. Cardiac MRI study and 2-dimensional echocardiograms performed within 6 months of the cardiac MRI were reviewed; 96 patients with apical HC underwent cardiac MRI examinations. LV end-diastolic and end-systolic volumes were 130.7 ± 39.1 ml and 44.2 ± 20.9 ml, respectively. Maximum LV thickness was 19 ± 5 mm. Hypertrophy extended beyond the apex into other segments in 57 (59.4%) patients. Obstructive physiology was seen in 12 (12.5%) and was more common in the mixed apical phenotype than the pure apical (19.3 vs 2.6%, p = 0.02). Apical pouches were noted in 39 (40.6%) patients. Late gadolinium enhancement (LGE) was present in 70 (74.5%) patients. LGE was associated with severe symptoms and increased maximal LV wall thickness. In conclusion, cardiac MRI is well suited for studying the apical form of HC because of difficulty imaging the cardiac apex with standard echocardiography. Cardiac MRI is uniquely suited to delineate the presence or absence of an apical pouch and abnormal myocardial LGE that may have implications in the natural history of apical HM. In particular, the presence of abnormal LGE is associated with clinical symptoms and increased wall thickness. PMID:25037678

  3. Usefulness of Cardiac Sympathetic Nerve Imaging Using (123)Iodine-Metaiodobenzylguanidine Scintigraphy for Predicting Sudden Cardiac Death in Patients With Heart Failure.

    Science.gov (United States)

    Kasama, Shu; Toyama, Takuji; Kurabayashi, Masahiko

    2016-01-01

    The autonomic nervous system plays an important role in the human heart. Activation of the cardiac sympathetic nervous system is a cardinal pathophysiological abnormality associated with the failing human heart. Myocardial imaging using (123)I-metaiodobenzylguanidine (MIBG), an analog of norepinephrine, can be used to investigate the activity of norepinephrine, the predominant neurotransmitter of the sympathetic nervous system. Many clinical trials have demonstrated that (123)I-MIBG scintigraphic parameters predict cardiac adverse events, especially sudden cardiac death, in patients with heart failure. In this review, we summarize results from published studies that have focused on the use of cardiac sympathetic nerve imaging using (123)I-MIBG scintigraphy for risk stratification of sudden cardiac death in patients with heart failure.

  4. Food ionisation. Realities and perspectives

    International Nuclear Information System (INIS)

    The ionisation of food is a treatment using a certain type of energy. the radiations used in the industrial treatments are limited to three sources. The gamma radiations, the x radiations and the electrons beams emitted with accelerators. The physical treatments by ionizing radiations have for aim to cleanse and to increase the conservation time of food. Now, the applications in agriculture and food industry, are still marginal. The industrial using ionisation are these ones that did not find any alternative decontamination method. The barriers are more scientific or technical or economical than a question of regulation or behaviour. (N.C.)

  5. Virtual and augmented medical imaging environments: enabling technology for minimally invasive cardiac interventional guidance.

    Science.gov (United States)

    Linte, Cristian A; White, James; Eagleson, Roy; Guiraudon, Gérard M; Peters, Terry M

    2010-01-01

    Virtual and augmented reality environments have been adopted in medicine as a means to enhance the clinician's view of the anatomy and facilitate the performance of minimally invasive procedures. Their value is truly appreciated during interventions where the surgeon cannot directly visualize the targets to be treated, such as during cardiac procedures performed on the beating heart. These environments must accurately represent the real surgical field and require seamless integration of pre- and intra-operative imaging, surgical tracking, and visualization technology in a common framework centered around the patient. This review begins with an overview of minimally invasive cardiac interventions, describes the architecture of a typical surgical guidance platform including imaging, tracking, registration and visualization, highlights both clinical and engineering accuracy limitations in cardiac image guidance, and discusses the translation of the work from the laboratory into the operating room together with typically encountered challenges. PMID:22275200

  6. Unsupervised segmentation of cardiac PET transmission images for automatic heart volume extraction.

    Science.gov (United States)

    Juslin, Anu; Tohka, Jussi

    2006-01-01

    In this study, we propose an automatic method to extract the heart volume from the cardiac positron emission tomography (PET) transmission images. The method combines the automatic 3D segmentation of the transmission image using Markov random fields (MRFs) to surface extraction using deformable models. Deformable models were automatically initialized using the MRFs segmentation result. The extraction of the heart region is needed e.g. in independent component analysis (ICA). The volume of the heart can be used to mask the emission image corresponding to the transmission image, so that only the cardiac region is used for the analysis. The masking restricts the number of independent components and reduces the computation time. In addition, the MRF segmentation result could be used for attenuation correction. The method was tested with 25 patient images. The MRF segmentation results were of good quality in all cases and we were able to extract the heart volume from all the images. PMID:17946020

  7. Current development of cardiac imaging with multidetector-row CT

    International Nuclear Information System (INIS)

    Multidector-row CT (MDCT) with retrospective ECG gating allows scanning the entire heart with 1.25 mm slice thickness and 250 ms effective exposure time within 35 s investigation time. The resulting images allow for an accurate high-resolution assessment of morphological detail of both the coronary arteries and the cardiac chambers. Performing a contrast-enhanced MDCT angiography (MD-CTA) in addition to a non-enhanced scan for the detection and quantification of coronary calcifications may be indicated in patients with atypical chest pain and in young patients with high cardiovascular risk. This group of patients may show non-calcified plaques as the first sign of their coronary artery disease. As the proximal part of the coronary arteries is well displayed by MD-CTA it also helps to delineate the course in anomalous coronary vessels. Additional information is drawn from the preoperative use of MD-CTA do determine the distance of the left internal mammarian artery to the left anterior descending coronary artery prior to minimal invasive bypass grafting. Additional indications for MD-CTA are the non-invasive follow up after venous bypass grafting, PTCA, and coronary stent interventions. MD-CTA allows following the course of the coronary vessels to the level of third generation coronary segmental arteries. A definite diagnosis to rule out coronary artery disease can be reliably made in vessels with a diameter of 1.5 mm or greater. With MDCT a number of different atherosclerotic changes can be observed in diseased coronary arteries. Non-stenotic lesions may show tiny calcifications surrounded by large areas of irregularly distributed soft tissue. Calcifications in this type of atherosclerotic coronary artery wall changes appear as 'the tip of iceberg'. Heavy calcifications usually tend to be non-stenotic because of vessel remodelling resulting in a widening of the coronary vessel lumen. Therefore, heavy calcifications appear to act like an 'internal stent' for a

  8. Molecular imaging of macrophage enzyme activity in cardiac inflammation

    OpenAIRE

    Ali, Muhammad; Pulli, Benjamin; Chen, John W.

    2014-01-01

    Molecular imaging is highly advantageous as various insidious inflammatory events can be imaged in a serial and quantitative fashion. Combined with the conventional imaging modalities like computed tomography (CT), magnetic resonance (MR) and nuclear imaging, it helps us resolve the extent of ongoing pathology, quantify inflammation and predict outcome. Macrophages are increasingly gaining importance as an imaging biomarker in inflammatory cardiovascular diseases. Macrophages, recruited to th...

  9. A statistical method for retrospective cardiac and respiratory motion gating of interventional cardiac x-ray images

    Energy Technology Data Exchange (ETDEWEB)

    Panayiotou, Maria, E-mail: maria.panayiotou@kcl.ac.uk; King, Andrew P.; Housden, R. James; Ma, YingLiang; Rhode, Kawal S. [Division of Imaging Sciences and Biomedical Engineering, King' s College London, London SE1 7EH (United Kingdom); Cooklin, Michael; O' Neill, Mark; Gill, Jaswinder; Rinaldi, C. Aldo [Department of Cardiology, Guy' s and St. Thomas' Hospitals NHS Foundation Trust, London SE1 7EH (United Kingdom)

    2014-07-15

    Purpose: Image-guided cardiac interventions involve the use of fluoroscopic images to guide the insertion and movement of interventional devices. Cardiorespiratory gating can be useful for 3D reconstruction from multiple x-ray views and for reducing misalignments between 3D anatomical models overlaid onto fluoroscopy. Methods: The authors propose a novel and potentially clinically useful retrospective cardiorespiratory gating technique. The principal component analysis (PCA) statistical method is used in combination with other image processing operations to make our proposed masked-PCA technique suitable for cardiorespiratory gating. Unlike many previously proposed techniques, our technique is robust to varying image-content, thus it does not require specific catheters or any other optically opaque structures to be visible. Therefore, it works without any knowledge of catheter geometry. The authors demonstrate the application of our technique for the purposes of retrospective cardiorespiratory gating of normal and very low dose x-ray fluoroscopy images. Results: For normal dose x-ray images, the algorithm was validated using 28 clinical electrophysiology x-ray fluoroscopy sequences (2168 frames), from patients who underwent radiofrequency ablation (RFA) procedures for the treatment of atrial fibrillation and cardiac resynchronization therapy procedures for heart failure. The authors established end-systole, end-expiration, and end-inspiration success rates of 97.0%, 97.9%, and 97.0%, respectively. For very low dose applications, the technique was tested on ten x-ray sequences from the RFA procedures with added noise at signal to noise ratio (SNR) values of√(5)0, √(1)0, √(8), √(6), √(5), √(2), and √(1) to simulate the image quality of increasingly lower dose x-ray images. Even at the low SNR value of √(2), representing a dose reduction of more than 25 times, gating success rates of 89.1%, 88.8%, and 86.8% were established. Conclusions: The proposed

  10. A statistical method for retrospective cardiac and respiratory motion gating of interventional cardiac x-ray images

    International Nuclear Information System (INIS)

    Purpose: Image-guided cardiac interventions involve the use of fluoroscopic images to guide the insertion and movement of interventional devices. Cardiorespiratory gating can be useful for 3D reconstruction from multiple x-ray views and for reducing misalignments between 3D anatomical models overlaid onto fluoroscopy. Methods: The authors propose a novel and potentially clinically useful retrospective cardiorespiratory gating technique. The principal component analysis (PCA) statistical method is used in combination with other image processing operations to make our proposed masked-PCA technique suitable for cardiorespiratory gating. Unlike many previously proposed techniques, our technique is robust to varying image-content, thus it does not require specific catheters or any other optically opaque structures to be visible. Therefore, it works without any knowledge of catheter geometry. The authors demonstrate the application of our technique for the purposes of retrospective cardiorespiratory gating of normal and very low dose x-ray fluoroscopy images. Results: For normal dose x-ray images, the algorithm was validated using 28 clinical electrophysiology x-ray fluoroscopy sequences (2168 frames), from patients who underwent radiofrequency ablation (RFA) procedures for the treatment of atrial fibrillation and cardiac resynchronization therapy procedures for heart failure. The authors established end-systole, end-expiration, and end-inspiration success rates of 97.0%, 97.9%, and 97.0%, respectively. For very low dose applications, the technique was tested on ten x-ray sequences from the RFA procedures with added noise at signal to noise ratio (SNR) values of√(5)0, √(1)0, √(8), √(6), √(5), √(2), and √(1) to simulate the image quality of increasingly lower dose x-ray images. Even at the low SNR value of √(2), representing a dose reduction of more than 25 times, gating success rates of 89.1%, 88.8%, and 86.8% were established. Conclusions: The proposed

  11. Optimized protocols for cardiac magnetic resonance imaging in patients with thoracic metallic implants

    Energy Technology Data Exchange (ETDEWEB)

    Olivieri, Laura J.; Ratnayaka, Kanishka [Children' s National Health System, Division of Cardiology, Washington, DC (United States); National Institutes of Health, National Heart, Lung and Blood Institute, Bethesda, MD (United States); Cross, Russell R.; O' Brien, Kendall E. [Children' s National Health System, Division of Cardiology, Washington, DC (United States); Hansen, Michael S. [National Institutes of Health, National Heart, Lung and Blood Institute, Bethesda, MD (United States)

    2015-09-15

    Cardiac magnetic resonance (MR) imaging is a valuable tool in congenital heart disease; however patients frequently have metal devices in the chest from the treatment of their disease that complicate imaging. Methods are needed to improve imaging around metal implants near the heart. Basic sequence parameter manipulations have the potential to minimize artifact while limiting effects on image resolution and quality. Our objective was to design cine and static cardiac imaging sequences to minimize metal artifact while maintaining image quality. Using systematic variation of standard imaging parameters on a fluid-filled phantom containing commonly used metal cardiac devices, we developed optimized sequences for steady-state free precession (SSFP), gradient recalled echo (GRE) cine imaging, and turbo spin-echo (TSE) black-blood imaging. We imaged 17 consecutive patients undergoing routine cardiac MR with 25 metal implants of various origins using both standard and optimized imaging protocols for a given slice position. We rated images for quality and metal artifact size by measuring metal artifact in two orthogonal planes within the image. All metal artifacts were reduced with optimized imaging. The average metal artifact reduction for the optimized SSFP cine was 1.5+/-1.8 mm, and for the optimized GRE cine the reduction was 4.6+/-4.5 mm (P < 0.05). Quality ratings favored the optimized GRE cine. Similarly, the average metal artifact reduction for the optimized TSE images was 1.6+/-1.7 mm (P < 0.05), and quality ratings favored the optimized TSE imaging. Imaging sequences tailored to minimize metal artifact are easily created by modifying basic sequence parameters, and images are superior to standard imaging sequences in both quality and artifact size. Specifically, for optimized cine imaging a GRE sequence should be used with settings that favor short echo time, i.e. flow compensation off, weak asymmetrical echo and a relatively high receiver bandwidth. For static

  12. Noncardiac findings on cardiac CT. Part II: spectrum of imaging findings.

    LENUS (Irish Health Repository)

    Killeen, Ronan P

    2012-02-01

    Cardiac computed tomography (CT) has evolved into an effective imaging technique for the evaluation of coronary artery disease in selected patients. Two distinct advantages over other noninvasive cardiac imaging methods include its ability to directly evaluate the coronary arteries and to provide a unique opportunity to evaluate for alternative diagnoses by assessing the extracardiac structures, such as the lungs and mediastinum, particularly in patients presenting with the chief symptom of acute chest pain. Some centers reconstruct a small field of view (FOV) cropped around the heart but a full FOV (from skin to skin in the area irradiated) is obtainable in the raw data of every scan so that clinically relevant noncardiac findings are identifiable. Debate in the scientific community has centered on the necessity for this large FOV. A review of noncardiac structures provides the opportunity to make alternative diagnoses that may account for the patient\\'s presentation or to detect important but clinically silent problems such as lung cancer. Critics argue that the yield of biopsy-proven cancers is low and that the follow-up of incidental noncardiac findings is expensive, resulting in increased radiation exposure and possibly unnecessary further testing. In this 2-part review we outline the issues surrounding the concept of the noncardiac read, looking for noncardiac findings on cardiac CT. Part I focused on the pros and cons for and against the practice of identifying noncardiac findings on cardiac CT. Part II illustrates the imaging spectrum of cardiac CT appearances of benign and malignant noncardiac pathology.

  13. Cardiac evaluation using {sup 123}I-BMIPP imaging in children undergoing a stem cell transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Hiroyuki; Yoshihara, Takao; Nakauchi, Shohei; Tsunamoto, Kentaro [Matsushita Memorial Hospital, Moriguchi, Osaka (Japan); Morimoto, Akira; Hibi, Shigeyoshi; Todo, Shinjiro; Kamiya, Yasutaka [Kyoto Prefectural Univ. of Medicine (Japan); Imashuku, Shinsaku [Inst. of Kyoto Health and Environmental Sciences (Japan)

    2003-02-01

    Sixteen children with hematological disease who had undergone allogeneic stem cell transplantation (SCT) were evaluated to determine the adverse effect of anthracycline (ATC) and cyclophosphamide (CY) used as the conditioning regimen on pre- and post-transplant cardiac function. Methods employed were resting electrocardiogram (ECG), echocardiography and {sup 123}I-BMIPP (beta-methyl-iodophenyl-pentadecanoic acid) imaging. A cumulative ATC dose over 300 mg/m{sup 2}, especially over 400 mg/m{sup 2}, was predictable for pre-transplant abnormal findings by parameters such as uptake score (US) and heart mediastinum ratio (H/M). However, the cumulative ATC dose and pre-transplant mild abnormal cardiac findings did not correlate with post-transplant cardiac function. A 200 mg/kg dose of CY was predictable for decreased summated QRS amplitude (QRS sum) and left ventricular mass index (LVMI), however, there was no correlation between the CY dose and the values obtained through BMIPP imaging. Moreover, the CY dose was not a risk factor for worsening post-transplant fractional shortening (FS) as evaluated by echocardiography. In summary, {sup 123}I-BMIPP imaging was useful for evaluating subclinical cardiac damage due to ATC before transplant, but not for predicting cardiac damage during the course of SCT. (author)

  14. Iodine-123 metaiodobenzylguanidine imaging of the heart in idiopathic congestive cardiomyopathy and cardiac transplants

    Energy Technology Data Exchange (ETDEWEB)

    Glowniak, J.V.; Turner, F.E.; Gray, L.L.; Palac, R.T.; Lagunas-Solar, M.C.; Woodward, W.R.

    1989-07-01

    Iodine-123 metaiodobenzylguanidine ((/sup 123/I)MIBG) is a norepinephrine analog which can be used to image the sympathetic innervation of the heart. In this study, cardiac imaging with (/sup 123/I)MIBG was performed in patients with idiopathic congestive cardiomyopathy and compared to normal controls. Initial uptake, half-time of tracer within the heart, and heart to lung ratios were all significantly reduced in patients compared to normals. Uptake in lungs, liver, salivary glands, and spleen was similar in controls and patients with cardiomyopathy indicating that decreased MIBG uptake was not a generalized abnormality in these patients. Iodine-123 MIBG imaging was also performed in cardiac transplant patients to determine cardiac nonneuronal uptake. Uptake in transplants was less than 10% of normals in the first 2 hr and nearly undetectable after 16 hr. The decreased uptake of MIBG suggests cardiac sympathetic nerve dysfunction while the rapid washout of MIBG from the heart suggests increased cardiac sympathetic nerve activity in idiopathic congestive cardiomyopathy.

  15. Wild-Type Transthyretin Cardiac Amyloidosis: Novel Insights From Advanced Imaging.

    Science.gov (United States)

    Narotsky, David L; Castano, Adam; Weinsaft, Jonathan W; Bokhari, Sabahat; Maurer, Mathew S

    2016-09-01

    Amyloidosis is caused by extracellular deposition of abnormal protein fibrils, resulting in destruction of tissue architecture and impairment of organ function. The most common forms of systemic amyloidosis are light-chain and transthyretin-related (ATTR). ATTR can result from an autosomal dominant hereditary transmission of mutated genes in the transthyretin or from a wild-type form of disease (ATTRwt), previously known as senile cardiac amyloidosis. With the aging of the worldwide population, ATTRwt will emerge as the most common type of cardiac amyloidosis that clinicians encounter. Diagnosis of systemic amyloidosis is often delayed, either because of the false assumption that it is a rare disease, or because of misdiagnosis as a result of mistaking it with other conditions. Clinicians must integrate clinical clues from history, physical examination, and common diagnostic tests to raise suspicion for ATTRwt. The historical gold standard for diagnosis of cardiac amyloid is endomyocardial biopsy analysis with pathological distinction of precursor protein type, but this method often results in delayed diagnosis because of the limited availability of expertise to perform and interpret the endomyocardial biopsy specimen. Emerging noninvasive imaging modalities provide easier, accurate screening for ATTRwt. These modalities include advanced echocardiography, using strain imaging and the myocardial contraction fraction; nuclear scintigraphy, which can differentiate between ATTR and light-chain cardiac amyloid; and cardiac magnetic resonance imaging, using extracellular volume measurement, late gadolinium enhancement, and distinct T1 mapping. These novel approaches reveal insights into the prevalence, clinical course, morphological effects, and prognosis of ATTRwt. PMID:27568874

  16. A review of heart chamber segmentation for structural and functional analysis using cardiac magnetic resonance imaging.

    Science.gov (United States)

    Peng, Peng; Lekadir, Karim; Gooya, Ali; Shao, Ling; Petersen, Steffen E; Frangi, Alejandro F

    2016-04-01

    Cardiovascular magnetic resonance (CMR) has become a key imaging modality in clinical cardiology practice due to its unique capabilities for non-invasive imaging of the cardiac chambers and great vessels. A wide range of CMR sequences have been developed to assess various aspects of cardiac structure and function, and significant advances have also been made in terms of imaging quality and acquisition times. A lot of research has been dedicated to the development of global and regional quantitative CMR indices that help the distinction between health and pathology. The goal of this review paper is to discuss the structural and functional CMR indices that have been proposed thus far for clinical assessment of the cardiac chambers. We include indices definitions, the requirements for the calculations, exemplar applications in cardiovascular diseases, and the corresponding normal ranges. Furthermore, we review the most recent state-of-the art techniques for the automatic segmentation of the cardiac boundaries, which are necessary for the calculation of the CMR indices. Finally, we provide a detailed discussion of the existing literature and of the future challenges that need to be addressed to enable a more robust and comprehensive assessment of the cardiac chambers in clinical practice.

  17. Clinical usefulness of cardiac cine magnetic resonance imaging in patients with atrial fibrillation

    International Nuclear Information System (INIS)

    We studied the clinical usefulness of cine mode magnetic resonance (MR) imaging in patients with atrial fibrillation (AF) from aspects of image quality and cardiac function. The signal-to-noise (S/N) ratio in the myocardium was significantly (p<0.05) lower in patients with AF than those with normal sinus rhythm. Two radiologists who did not know any patient's information evaluated the image quality visually by marking method on a scale of 12 points. There was no difference of image quality between the two groups. The standard deviation of R-R interval was significantly (r=-0.92, p<0.001) correlated with the S/N ratio in myocardium. Consequently, it was not favorable to estimate visually cardiac cine MR image in patients with AF, when standard deviation of R-R interval was large. The left ventricular (LV) end diastolic, end systolic and stroke volumes and ejection fraction were closely (r=0.82∼0.95, p<0.05∼0.001) correlated between MR imaging and M-mode echocardiography, respectively. The ability to detect left side valvular regurgitation was almost equal in both MR imaging and color Doppler echocardiography. This result was coincided to previous papers in patients with normal sinus rhythm. In conclusion, cine mode MR imaging was also useful to analyze cardiac function and detect valvular regurgitation in patients with AF. (author)

  18. The role of cardiac magnetic resonance imaging following acute myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Dennis T.L.; Richardson, James D.; Puri, Rishi; Nelson, Adam J.; Teo, Karen S.L.; Worthley, Matthew I. [Royal Adelaide Hospital, Cardiovascular Research Centre, Adelaide (Australia); University of Adelaide, Department of Medicine, Adelaide (Australia); Bertaso, Angela G. [Royal Adelaide Hospital, Cardiovascular Research Centre, Adelaide (Australia); Worthley, Stephen G. [Royal Adelaide Hospital, Cardiovascular Research Centre, Adelaide (Australia); University of Adelaide, Department of Medicine, Adelaide (Australia); Cardiovascular Investigational Unit, Adelaide, SA (Australia)

    2012-08-15

    Advances in the management of myocardial infarction have resulted in substantial reductions in morbidity and mortality. However, after acute treatment a number of diagnostic and prognostic questions often remain to be answered, whereby cardiac imaging plays an essential role. For example, some patients will sustain early mechanical complications after infarction, while others may develop significant ventricular dysfunction. Furthermore, many individuals harbour a significant burden of residual coronary disease for which clarification of functional ischaemic status and/or viability of the suspected myocardial territory is required. Cardiac magnetic resonance (CMR) imaging is well positioned to fulfil these requirements given its unparalleled capability in evaluating cardiac function, stress ischaemia testing and myocardial tissue characterisation. This review will focus on the utility of CMR in resolving diagnostic uncertainty, evaluating early complications following myocardial infarction, assessing inducible ischaemia, myocardial viability, ventricular remodelling and the emerging role of CMR-derived measures as endpoints in clinical trials. (orig.)

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

    Science.gov (United States)

    Bogabathina, Hari; Olson, Peter; Rathi, Vikas K.; Biederman, Robert W. W.

    2012-01-01

    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. PMID:24826266

  20. 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.

  1. Automatic quantitative analysis of cardiac MR perfusion images

    NARCIS (Netherlands)

    Breeuwer, Marcel; Spreeuwers, Luuk; Quist, Marcel

    2001-01-01

    Magnetic Resonance Imaging (MRI) is a powerful technique for imaging cardiovascular diseases. The introduction of cardiovascular MRI into clinical practice is however hampered by the lack of efficient and accurate image analysis methods. This paper focuses on the evaluation of blood perfusion in the

  2. Towards automatic quantitative analysis of cardiac MR perfusion images

    NARCIS (Netherlands)

    Breeuwer, M.; Quist, M.; Spreeuwers, L.J.; Paetsch, I.; Al-Saadi, N.; Nagel, E.

    2001-01-01

    Magnetic Resonance Imaging (MRI) is a powerful technique for imaging cardiovascular diseases. The introduction of cardiovascular MRI into clinical practice is however hampered by the lack of efficient and reliable automatic image analysis methods. This paper focuses on the automatic evaluation of th

  3. Role of multimodality cardiac imaging in preoperative cardiovascular evaluation before noncardiac surgery

    Directory of Open Access Journals (Sweden)

    Fathala Ahmed

    2011-01-01

    Full Text Available The preoperative cardiac assessment of patients undergoing noncardiac surgery is common in the daily practice of medical consultants, anesthesiologists, and surgeons. The number of patients undergoing noncardiac surgery worldwide is increasing. Currently, there are several noninvasive diagnostic tests available for preoperative evaluation. Both nuclear cardiology with myocardial perfusion single photon emission computed tomography (SPECT and stress echocardiography are well-established techniques for preoperative cardiac evaluation. Recently, some studies demonstrated that both coronary angiography by gated multidetector computed tomography and stress cardiac magnetic resonance might potentially play a role in preoperative evaluation as well, but more studies are needed to assess the role of these new modalities in preoperative risk stratification. A common question that arises in preoperative evaluation is if further preoperative testing is needed, which preoperative test should be used. The preferred stress test is the exercise electrocardiogram (ECG. Stress imaging with exercise or pharmacologic stress agents is to be considered in patients with abnormal rest ECG or patients who are unable to exercise. After reviewing this article, the reader should develop an understanding of the following: (1 the magnitude of the cardiac preoperative morbidity and mortality, (2 how to select a patient for further preoperative testing, (3 currently available noninvasive cardiac testing for the detection of coronary artery disease and assessment of left ventricular function, and (4 an approach to select the most appropriate noninvasive cardiac test, if needed.

  4. Optimal Magnetic Sensor Vests for Cardiac Source Imaging.

    Science.gov (United States)

    Lau, Stephan; Petković, Bojana; Haueisen, Jens

    2016-01-01

    Magnetocardiography (MCG) non-invasively provides functional information about the heart. New room-temperature magnetic field sensors, specifically magnetoresistive and optically pumped magnetometers, have reached sensitivities in the ultra-low range of cardiac fields while allowing for free placement around the human torso. Our aim is to optimize positions and orientations of such magnetic sensors in a vest-like arrangement for robust reconstruction of the electric current distributions in the heart. We optimized a set of 32 sensors on the surface of a torso model with respect to a 13-dipole cardiac source model under noise-free conditions. The reconstruction robustness was estimated by the condition of the lead field matrix. Optimization improved the condition of the lead field matrix by approximately two orders of magnitude compared to a regular array at the front of the torso. Optimized setups exhibited distributions of sensors over the whole torso with denser sampling above the heart at the front and back of the torso. Sensors close to the heart were arranged predominantly tangential to the body surface. The optimized sensor setup could facilitate the definition of a standard for sensor placement in MCG and the development of a wearable MCG vest for clinical diagnostics. PMID:27231910

  5. Optimal Magnetic Sensor Vests for Cardiac Source Imaging

    Directory of Open Access Journals (Sweden)

    Stephan Lau

    2016-05-01

    Full Text Available Magnetocardiography (MCG non-invasively provides functional information about the heart. New room-temperature magnetic field sensors, specifically magnetoresistive and optically pumped magnetometers, have reached sensitivities in the ultra-low range of cardiac fields while allowing for free placement around the human torso. Our aim is to optimize positions and orientations of such magnetic sensors in a vest-like arrangement for robust reconstruction of the electric current distributions in the heart. We optimized a set of 32 sensors on the surface of a torso model with respect to a 13-dipole cardiac source model under noise-free conditions. The reconstruction robustness was estimated by the condition of the lead field matrix. Optimization improved the condition of the lead field matrix by approximately two orders of magnitude compared to a regular array at the front of the torso. Optimized setups exhibited distributions of sensors over the whole torso with denser sampling above the heart at the front and back of the torso. Sensors close to the heart were arranged predominantly tangential to the body surface. The optimized sensor setup could facilitate the definition of a standard for sensor placement in MCG and the development of a wearable MCG vest for clinical diagnostics.

  6. ICA based automatic segmentation of dynamic H(2)(15)O cardiac PET images.

    Science.gov (United States)

    Margadán-Méndez, Margarita; Juslin, Anu; Nesterov, Sergey V; Kalliokoski, Kari; Knuuti, Juhani; Ruotsalainen, Ulla

    2010-05-01

    In this study, we applied an iterative independent component analysis (ICA) method for the separation of cardiac tissue components (myocardium, right, and left ventricle) from dynamic positron emission tomography (PET) images. Previous phantom and animal studies have shown that ICA separation extracts the cardiac structures accurately. Our goal in this study was to investigate the methodology with human studies. The ICA separated cardiac structures were used to calculate the myocardial perfusion in two different cases: 1) the regions of interest were drawn manually on the ICA separated component images and 2) the volumes of interest (VOI) were automatically segmented from the component images. For the whole myocardium, the perfusion values of 25 rest and six drug-induced stress studies obtained with these methods were compared to the values from the manually drawn regions of interest on differential images. The separation of the rest and stress studies using ICA-based methods was successful in all cases. The visualization of the cardiac structures from H (2) (15) O PET studies was improved with the ICA separation. Also, the automatic segmentation of the VOI seemed to be feasible. PMID:19273031

  7. [Research of Left Ventricle Function Analysis Using Real-time Cardiac Magnetic Resonance Imaging].

    Science.gov (United States)

    Yang, Fan; He, Yan; Zhang, Jie; Wu, Yin

    2015-12-01

    Real-time free breathing cardiac cine imaging is a reproducible method with shorter acquisition time and without breath-hold for cardiac magnetic resonance imaging. However, the detection of end-diastole and end-systole frames of real-time free breathing cardiac cine imaging for left ventricle function analysis is commonly completed by visual identification, which is time-consuming and laborious. In order to save processing time, we propose a method for semi-automatic identification of end-diastole and end-systole frames. The method fits respiratory motion signal and acquires the expiration phase, end-diastole and end-systole frames by cross correlation coefficient. The procedure successfully worked on ten healthy volunteers and validated by the analysis of left ventricle function compared to the standard breath-hold steady-state free precession cardiac cine imaging without any significant statistical differences. The results demonstrated that the present method could correctly detect end-diastole and end-systole frames. In the future, this technique may be used for rapid left ventricle function analysis in clinic. PMID:27079101

  8. Cardiac magnetic resonance imaging and computed tomography in ischemic cardiomyopathy: an update

    Directory of Open Access Journals (Sweden)

    Fernanda Boldrini Assunção

    2016-02-01

    Full Text Available Abstract Ischemic cardiomyopathy is one of the major health problems worldwide, representing a significant part of mortality in the general population nowadays. Cardiac magnetic resonance imaging (CMRI and cardiac computed tomography (CCT are noninvasive imaging methods that serve as useful tools in the diagnosis of coronary artery disease and may also help in screening individuals with risk factors for developing this illness. Technological developments of CMRI and CCT have contributed to the rise of several clinical indications of these imaging methods complementarily to other investigation methods, particularly in cases where they are inconclusive. In terms of accuracy, CMRI and CCT are similar to the other imaging methods, with few absolute contraindications and minimal risks of adverse side-effects. This fact strengthens these methods as powerful and safe tools in the management of patients. The present study is aimed at describing the role played by CMRI and CCT in the diagnosis of ischemic cardiomyopathies.

  9. Cardiac magnetic resonance imaging and computed tomography in ischemic cardiomyopathy: an update.

    Science.gov (United States)

    Assunção, Fernanda Boldrini; de Oliveira, Diogo Costa Leandro; Souza, Vitor Frauches; Nacif, Marcelo Souto

    2016-01-01

    Ischemic cardiomyopathy is one of the major health problems worldwide, representing a significant part of mortality in the general population nowadays. Cardiac magnetic resonance imaging (CMRI) and cardiac computed tomography (CCT) are noninvasive imaging methods that serve as useful tools in the diagnosis of coronary artery disease and may also help in screening individuals with risk factors for developing this illness. Technological developments of CMRI and CCT have contributed to the rise of several clinical indications of these imaging methods complementarily to other investigation methods, particularly in cases where they are inconclusive. In terms of accuracy, CMRI and CCT are similar to the other imaging methods, with few absolute contraindications and minimal risks of adverse side-effects. This fact strengthens these methods as powerful and safe tools in the management of patients. The present study is aimed at describing the role played by CMRI and CCT in the diagnosis of ischemic cardiomyopathies.

  10. Cardiac magnetic resonance imaging and computed tomography in ischemic cardiomyopathy: an update

    International Nuclear Information System (INIS)

    Ischemic cardiomyopathy is one of the major health problems worldwide, representing a significant part of mortality in the general population nowadays. Cardiac magnetic resonance imaging (CMRI) and cardiac computed tomography (CCT) are noninvasive imaging methods that serve as useful tools in the diagnosis of coronary artery disease and may also help in screening individuals with risk factors for developing this illness. Technological developments of CMRI and CCT have contributed to the rise of several clinical indications of these imaging methods complimentarily to other investigation methods, particularly in cases where they are inconclusive. In terms of accuracy, CMRI and CCT are similar to the other imaging methods, with few absolute contraindications and minimal risks of adverse side-effects. This fact strengthens these methods as powerful and safe tools in the management of patients. The present study is aimed at describing the role played by CMRI and CCT in the diagnosis of ischemic cardiomyopathies. (author)

  11. Cardiac magnetic resonance imaging and computed tomography in ischemic cardiomyopathy: an update

    Energy Technology Data Exchange (ETDEWEB)

    Assuncao, Fernanda Boldrini; Oliveira, Diogo Costa Leandro de; Nacif, Marcelo Souto, E-mail: msnacif@gmail.com [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Escola de Medicina; Souza, Vitor Frauches [Complexo Hospitalar de Niteroi (CHN), Niteroi, RJ (Brazil)

    2016-01-15

    Ischemic cardiomyopathy is one of the major health problems worldwide, representing a significant part of mortality in the general population nowadays. Cardiac magnetic resonance imaging (CMRI) and cardiac computed tomography (CCT) are noninvasive imaging methods that serve as useful tools in the diagnosis of coronary artery disease and may also help in screening individuals with risk factors for developing this illness. Technological developments of CMRI and CCT have contributed to the rise of several clinical indications of these imaging methods complimentarily to other investigation methods, particularly in cases where they are inconclusive. In terms of accuracy, CMRI and CCT are similar to the other imaging methods, with few absolute contraindications and minimal risks of adverse side-effects. This fact strengthens these methods as powerful and safe tools in the management of patients. The present study is aimed at describing the role played by CMRI and CCT in the diagnosis of ischemic cardiomyopathies. (author)

  12. Image registration and analysis for quantitative myocardial perfusion: application to dynamic circular cardiac CT

    Science.gov (United States)

    Isola, A. A.; Schmitt, H.; van Stevendaal, U.; Begemann, P. G.; Coulon, P.; Boussel, L.; Grass, M.

    2011-09-01

    Large area detector computed tomography systems with fast rotating gantries enable volumetric dynamic cardiac perfusion studies. Prospectively, ECG-triggered acquisitions limit the data acquisition to a predefined cardiac phase and thereby reduce x-ray dose and limit motion artefacts. Even in the case of highly accurate prospective triggering and stable heart rate, spatial misalignment of the cardiac volumes acquired and reconstructed per cardiac cycle may occur due to small motion pattern variations from cycle to cycle. These misalignments reduce the accuracy of the quantitative analysis of myocardial perfusion parameters on a per voxel basis. An image-based solution to this problem is elastic 3D image registration of dynamic volume sequences with variable contrast, as it is introduced in this contribution. After circular cone-beam CT reconstruction of cardiac volumes covering large areas of the myocardial tissue, the complete series is aligned with respect to a chosen reference volume. The results of the registration process and the perfusion analysis with and without registration are evaluated quantitatively in this paper. The spatial alignment leads to improved quantification of myocardial perfusion for three different pig data sets.

  13. Cardiac Multidetector Computed Tomography: Basic Physics of Image Acquisition and Clinical Applications

    OpenAIRE

    Bardo, Dianna M.E; Brown, Paul

    2008-01-01

    Cardiac MDCT is here to stay. And, it is more than just imaging coronary arteries. Understanding the differences in and the benefits of one CT scanner from another will help you to optimize the capabilities of the scanner, but requires a basic understanding of the MDCT imaging physics. This review provides key information needed to understand the differences in the types of MDCT scanners, from 64 – 320 detectors, flat panels, single and dual source configurations, step and shoot prospective a...

  14. Assessment of Myocardial Infarction by Cardiac Magnetic Resonance Imaging and Long-Term Mortality

    Directory of Open Access Journals (Sweden)

    João Luiz Fernandes Petriz

    2015-02-01

    Full Text Available Background: Cardiac magnetic resonance imaging provides detailed anatomical information on infarction. However, few studies have investigated the association of these data with mortality after acute myocardial infarction. Objective: To study the association between data regarding infarct size and anatomy, as obtained from cardiac magnetic resonance imaging after acute myocardial infarction, and long-term mortality. Methods: A total of 1959 reports of “infarct size” were identified in 7119 cardiac magnetic resonance imaging studies, of which 420 had clinical and laboratory confirmation of previous myocardial infarction. The variables studied were the classic risk factors – left ventricular ejection fraction, categorized ventricular function, and location of acute myocardial infarction. Infarct size and acute myocardial infarction extent and transmurality were analyzed alone and together, using the variable named “MET-AMI”. The statistical analysis was carried out using the elastic net regularization, with the Cox model and survival trees. Results: The mean age was 62.3 ± 12 years, and 77.3% were males. During the mean follow-up of 6.4 ± 2.9 years, there were 76 deaths (18.1%. Serum creatinine, diabetes mellitus and previous myocardial infarction were independently associated with mortality. Age was the main explanatory factor. The cardiac magnetic resonance imaging variables independently associated with mortality were transmurality of acute myocardial infarction (p = 0.047, ventricular dysfunction (p = 0.0005 and infarcted size (p = 0.0005; the latter was the main explanatory variable for ischemic heart disease death. The MET-AMI variable was the most strongly associated with risk of ischemic heart disease death (HR: 16.04; 95%CI: 2.64-97.5; p = 0.003. Conclusion: The anatomical data of infarction, obtained from cardiac magnetic resonance imaging after acute myocardial infarction, were independently associated with long

  15. Assessment of Myocardial Infarction by Cardiac Magnetic Resonance Imaging and Long-Term Mortality

    Energy Technology Data Exchange (ETDEWEB)

    Petriz, João Luiz Fernandes, E-mail: jlpetriz@cardiol.br [Universidade Federal do Rio de Janeiro (UFRJ) / Instituto do Coração Edson Saad - Programa de Pós Graduação em Medicina (Cardiologia), Rio de Janeiro, RJ (Brazil); Hospital Barra D’Or, Rio de Janeiro, RJ (Brazil); Instituto D’Or de Pesquisa e Ensino, Rio de Janeiro, RJ (Brazil); Gomes, Bruno Ferraz de Oliveira; Rua, Braulio Santos [Hospital Barra D’Or, Rio de Janeiro, RJ (Brazil); Azevedo, Clério Francisco [Instituto D’Or de Pesquisa e Ensino, Rio de Janeiro, RJ (Brazil); Hadlich, Marcelo Souza [Universidade Federal do Rio de Janeiro (UFRJ) / Instituto do Coração Edson Saad - Programa de Pós Graduação em Medicina (Cardiologia), Rio de Janeiro, RJ (Brazil); Instituto D’Or de Pesquisa e Ensino, Rio de Janeiro, RJ (Brazil); Mussi, Henrique Thadeu Periard [Universidade Federal do Rio de Janeiro (UFRJ) / Instituto do Coração Edson Saad - Programa de Pós Graduação em Medicina (Cardiologia), Rio de Janeiro, RJ (Brazil); Hospital Barra D’Or, Rio de Janeiro, RJ (Brazil); Taets, Gunnar de Cunto [Instituto D’Or de Pesquisa e Ensino, Rio de Janeiro, RJ (Brazil); Nascimento, Emília Matos do; Pereira, Basílio de Bragança; Silva, Nelson Albuquerque de Souza e [Universidade Federal do Rio de Janeiro (UFRJ) / Instituto do Coração Edson Saad - Programa de Pós Graduação em Medicina (Cardiologia), Rio de Janeiro, RJ (Brazil)

    2015-02-15

    Cardiac magnetic resonance imaging provides detailed anatomical information on infarction. However, few studies have investigated the association of these data with mortality after acute myocardial infarction. To study the association between data regarding infarct size and anatomy, as obtained from cardiac magnetic resonance imaging after acute myocardial infarction, and long-term mortality. A total of 1959 reports of “infarct size” were identified in 7119 cardiac magnetic resonance imaging studies, of which 420 had clinical and laboratory confirmation of previous myocardial infarction. The variables studied were the classic risk factors – left ventricular ejection fraction, categorized ventricular function, and location of acute myocardial infarction. Infarct size and acute myocardial infarction extent and transmurality were analyzed alone and together, using the variable named “MET-AMI”. The statistical analysis was carried out using the elastic net regularization, with the Cox model and survival trees. The mean age was 62.3 ± 12 years, and 77.3% were males. During the mean follow-up of 6.4 ± 2.9 years, there were 76 deaths (18.1%). Serum creatinine, diabetes mellitus and previous myocardial infarction were independently associated with mortality. Age was the main explanatory factor. The cardiac magnetic resonance imaging variables independently associated with mortality were transmurality of acute myocardial infarction (p = 0.047), ventricular dysfunction (p = 0.0005) and infarcted size (p = 0.0005); the latter was the main explanatory variable for ischemic heart disease death. The MET-AMI variable was the most strongly associated with risk of ischemic heart disease death (HR: 16.04; 95%CI: 2.64-97.5; p = 0.003). The anatomical data of infarction, obtained from cardiac magnetic resonance imaging after acute myocardial infarction, were independently associated with long-term mortality, especially for ischemic heart disease death.

  16. Usefulness of true FISP cine MR imaging in patients with poor cardiac function

    Energy Technology Data Exchange (ETDEWEB)

    Sakuma, Toshiharu; Yamada, Naoaki; Motooka, Makoto; Enomoto, Naoyuki; Maeshima, Isamu; Matsuda, Kazuhide; Urayama, Shinichi; Ikeo, Miki [National Cardiovascular Center, Suita, Osaka (Japan)

    2002-01-01

    This study was done to assess the value of True FISP cine in patients with poor cardiac function. True FISP cine and FLASH cine imaging were performed on a 1.5 T machine. Both short axis and horizontal long axis imaging sections were used. The imaging sections used a Matrix (120 x 128), FOV (24 x 32 cm), and had a slice thickness of 8 mm. The imaging time for True FISP cine was 8 heart beats and 17 heart beats for FLASH cine. The contrast-to-noise ratio between the blood and myocardium (CNR) was measured at enddiastole and endsystole. The subjects in the study were 10 healty volunteers (average age 26.5{+-}3.2 years) and 12 patients with hypofunction (average age 53.9{+-}13.2 years). In the volunteers, the CNR of the short axis imaging was similar in both True FISP (24.6{+-}3.7) and FLASH (23.4{+-}5.9). In the patients with poor cardiac function however, the CNR of True FISP was larger than FLASH in both the short and long axis. In the short axis (22.7{+-}6.1 vs. 17.9{+-}5.3, P<0.01) and in the long axis (17.4{+-}4.3 vs. 9.3{+-}4.0, P<0.01). We conclude that True FISP cine has a higher contrast in a shorter imaging time than FLASH cine. True FISP cine is especially useful in patients with poor cardiac function. (author)

  17. Defining the mid-diastolic imaging period for cardiac CT – lessons from tissue Doppler echocardiography

    Directory of Open Access Journals (Sweden)

    Otton James M

    2013-02-01

    Full Text Available Abstract Background Aggressive dose reduction strategies for cardiac CT require the prospective selection of limited cardiac phases. At lower heart rates, the period of mid-diastole is typically selected for image acquisition. We aimed to identify the effect of heart rate on the optimal CT acquisition phase within the period of mid-diastole. Methods We utilized high temporal resolution tissue Doppler to precisely measure coronary motion within diastole. Tissue-Doppler waveforms of the myocardium corresponding to the location of the circumflex artery (100 patients and mid-right coronary arteries (50 patients and the duration and timing of coronary motion were measured. Using regression analysis an equation was derived for the timing of the period of minimal coronary motion within the RR interval. In a validation set of 50 clinical cardiac CT examinations, we assessed coronary motion artifact and the effect of using a mid-diastolic imaging target that was adjusted according to heart rate vs a fixed 75% phase target. Results Tissue Doppler analysis shows the period of minimal cardiac motion suitable for CT imaging decreases almost linearly as the RR interval decreases, becoming extinguished at an average heart rate of 91 bpm for the circumflex (LCX and 78 bpm for the right coronary artery (RCA. The optimal imaging phase has a strong linear relationship with RR duration (R2 = 0.92 LCX, 0.89 RCA. The optimal phase predicted by regression analysis of the tissue-Doppler waveforms increases from 74% at a heart rate of 55 bpm to 77% at 75 bpm. In the clinical CT validation set, the optimal CT acquisition phase similarly occurred later with increasing heart rate. When the selected cardiac phase was adjusted according to heart rate the result was closer to the optimal phase than using a fixed 75% phase. While this effect was statistically significant (p  Conclusion High temporal resolution imaging of coronary motion can be used to predict the optimal

  18. 18F-NaF PET/CT Images of Cardiac Metastasis From Osteosarcoma.

    Science.gov (United States)

    Chou, Yi-Hsien; Ko, Kuan-Yin; Cheng, Mei-Fang; Chen, Wei-Wu; Yen, Ruoh-Fang

    2016-09-01

    Osteosarcomas are aggressive with a high incidence of recurrence and metastasis. Cardiac osteosarcoma metastasis is rare. We described a 17-year-old boy who had right distal femoral osteosarcoma with lung metastases. During follow-up, right ventricular (RV) metastasis was noted and confirmed by histopathological examination of the surgical specimen. F-NaF PET/CT was then arranged 1 month after debulking surgery for residual tumor survey. The images showed intense F-NaF uptake at RV region, suggestive of residual cardiac metastases. PMID:27405028

  19. The Role of Imaging with Cardiac Computed Tomography in Cardio-Oncology Patients.

    Science.gov (United States)

    Pitekova, Barbora; Ravi, Sriram; Shah, Shimoli V; Mladosievicova, Beata; Heitner, Stephen; Ferencik, Maros

    2016-09-01

    Cardiovascular diseases and cancer represent the two most common causes of morbidity and mortality in industrialized countries. With the increase in long-term survival of cancer patients, cardiovascular diseases are the leading cause of mortality for many cancer survivors. In this article, we will review the most common cardiovascular toxicities of cancer therapies and will describe the role of cardiac CT in the detection and monitoring of cardiovascular disease. While there is limited evidence for the use of CT imaging in cancer patients, we will discuss the utility of cardiac CT in the detection and management of coronary artery disease, pericardial and valvular heart disease. PMID:27443383

  20. Radiative effects of tropospheric ionisation

    Directory of Open Access Journals (Sweden)

    K. L. Aplin

    2003-06-01

    Full Text Available Despite the increasing evidence that cosmic ray variations may influence clouds and climate, there has been little discussion of the direct radiative effects of atmospheric ionisation. Laboratory experiments show that hydrated molecular cluster-ions, formed in the atmosphere by cosmic rays, absorb in the infra-red continuum at wavelengths of 9–12 μm. The tropospheric magnitude of this effect is estimated: transmittance anomalies from clear sky ion concentrations peak at ~2% at 10 km in the mid-latitudes. A simple isothermal clear sky atmospheric model suggests the integrated effect of the absorption is ~2 Wm−2. The effect appears detectable in existing surface data sets; surface micrometeorological data shows a significant anticorrelation between downwelling infra-red radiation and atmospheric cosmic ray ionisation. This is consistent with the infra-red attenuation observed in laboratory studies of cluster-ion absorption. If atmospheric ionisation from cosmic rays has universally direct radiative effects, then reinterpretation of satellite cloud data may be necessary.

  1. Semi-automated scar detection in delayed enhanced cardiac magnetic resonance images

    Science.gov (United States)

    Morisi, Rita; Donini, Bruno; Lanconelli, Nico; Rosengarden, James; Morgan, John; Harden, Stephen; Curzen, Nick

    2015-06-01

    Late enhancement cardiac magnetic resonance images (MRI) has the ability to precisely delineate myocardial scars. We present a semi-automated method for detecting scars in cardiac MRI. This model has the potential to improve routine clinical practice since quantification is not currently offered due to time constraints. A first segmentation step was developed for extracting the target regions for potential scar and determining pre-candidate objects. Pattern recognition methods are then applied to the segmented images in order to detect the position of the myocardial scar. The database of late gadolinium enhancement (LE) cardiac MR images consists of 111 blocks of images acquired from 63 patients at the University Hospital Southampton NHS Foundation Trust (UK). At least one scar was present for each patient, and all the scars were manually annotated by an expert. A group of images (around one third of the entire set) was used for training the system which was subsequently tested on all the remaining images. Four different classifiers were trained (Support Vector Machine (SVM), k-nearest neighbor (KNN), Bayesian and feed-forward neural network) and their performance was evaluated by using Free response Receiver Operating Characteristic (FROC) analysis. Feature selection was implemented for analyzing the importance of the various features. The segmentation method proposed allowed the region affected by the scar to be extracted correctly in 96% of the blocks of images. The SVM was shown to be the best classifier for our task, and our system reached an overall sensitivity of 80% with less than 7 false positives per patient. The method we present provides an effective tool for detection of scars on cardiac MRI. This may be of value in clinical practice by permitting routine reporting of scar quantification.

  2. Coronary CT angiography: automatic cardiac-phase selection for image reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Ruzsics, Balazs; Brothers, Robin L.; Costello, Philip [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Gebregziabher, Mulugeta [Medical University of South Carolina, Department of Biostatistics, Bioinformatics, and Epidemiology, Charleston, SC (United States); Lee, Heon [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Seoul Medical Center, Department of Radiology, Seoul (Korea); Allmendinger, Thomas; Vogt, Sebastian [Siemens Medical Solutions, Division CT, Forchheim (Germany); Schoepf, U.J. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); Medical University of South Carolina, Division of Cardiology, Charleston, SC (United States)

    2009-08-15

    We evaluated an algorithm for automatic selection of the cardiac phase with the least motion for image reconstruction at coronary computed tomography (CT) angiography (CCTA). We analyzed data of 100 patients (49 female, mean age 59 years) who had undergone retrospectively ECG-gated CCTA. Two experienced observers visually identified the most suitable end-systolic and end-diastolic phases using a series of image reconstructions in 5% increments across the RR cycle. The same data were then reconstructed using an automatic phase finding algorithm based on a 4D weighting function of cardiac motion. On average, the algorithm determined the most suitable systolic reconstruction phase at 40.11{+-}6.29% RR compared with 40.07{+-}5.58% RR by the human observers (p=NS). The most suitable diastolic phase was found at 72.71{+-}7.37% RR by the automatic algorithm, compared with 76.43{+-}6.35% RR by the observers (p<0.05). No statistically significant difference was found between automatically and visually determined reconstruction phases regarding motion and stair-step artifacts in either systole or diastole (p>0.05). Thus, there appears to be no relevant difference between an automatic phase finding algorithm and visual selection by experienced observers for determining the phase with the least cardiac motion for CCTA image reconstruction. The use of automatic phase finding may therefore facilitate the performance of cardiac CT and reduce human error. (orig.)

  3. Measurements of pericardial adipose tissue using contrast enhanced cardiac multidetector computed tomography—comparison with cardiac magnetic resonance imaging

    DEFF Research Database (Denmark)

    Elming, Marie Bayer; Lønborg, Jacob; Rasmussen, Thomas;

    2013-01-01

    Recent studies have suggested that pericardial adipose tissue (PAT) located in close vicinity to the epicardial coronary arteries may play a role in the development of coronary artery disease. PAT has primarily been measured with cardiac magnetic resonance imaging (CMRI) or with non...... tested, and the smallest difference in PAT was noted when -30 to -190 HU were used in MDCT measures. The median difference between MDCT and CMRI for the assessment of PAT was 9 ml (SD 50) suggesting a reasonable robust method for the assessment of PAT in a large-scale study. Pericardial adipose tissue...... and CMRI scans were performed. The optimal fit for measuring PAT using contrast MDCT was developed and validated by the corresponding measures on CMRI. The median for PAT volume in patients was 175 ml (SD 68) and 153 ml (SD 60) measured by MDCT and CMRI respectively. Four different attenuation values were...

  4. Evaluation of cardiac structures and function in hypertrophic cardiomyopathy with magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective:To assess the capability of magnetic resonance imaging(MRI)in evaluating the cardiac structures and function in the hypertrophic cardiomyopathy(HCM).Methods:Fourteen healthy volunteers and eighteen cases with HCM verified by history,clinical presentation,electrocardiogram and echocardiography(ECG)were performed with MRI.The myocardial thickness of interventricular septum at the basal segment and that of posterolateral free wall of the left ventricle(LV)were measured.Some indexes for evaluating cardiac function were measured using ARGUS auto-quantitative program.Resuits:The myocardial thickness of septum at the basal segment had significant difference between the HCM patients and the healthy volunteers.There was no significant difference between MRI and ECG in examining end-diastolic volume,ejection fraction of the LV.Conclusion:MRI can fully provide more information on the abnormalities of cardiac anatomy and function;thus,it is of great value in clinical application.

  5. Calibration free beam hardening correction for cardiac CT perfusion imaging

    Science.gov (United States)

    Levi, Jacob; Fahmi, Rachid; Eck, Brendan L.; Fares, Anas; Wu, Hao; Vembar, Mani; Dhanantwari, Amar; Bezerra, Hiram G.; Wilson, David L.

    2016-03-01

    Myocardial perfusion imaging using CT (MPI-CT) and coronary CTA have the potential to make CT an ideal noninvasive gate-keeper for invasive coronary angiography. However, beam hardening artifacts (BHA) prevent accurate blood flow calculation in MPI-CT. BH Correction (BHC) methods require either energy-sensitive CT, not widely available, or typically a calibration-based method. We developed a calibration-free, automatic BHC (ABHC) method suitable for MPI-CT. The algorithm works with any BHC method and iteratively determines model parameters using proposed BHA-specific cost function. In this work, we use the polynomial BHC extended to three materials. The image is segmented into soft tissue, bone, and iodine images, based on mean HU and temporal enhancement. Forward projections of bone and iodine images are obtained, and in each iteration polynomial correction is applied. Corrections are then back projected and combined to obtain the current iteration's BHC image. This process is iterated until cost is minimized. We evaluate the algorithm on simulated and physical phantom images and on preclinical MPI-CT data. The scans were obtained on a prototype spectral detector CT (SDCT) scanner (Philips Healthcare). Mono-energetic reconstructed images were used as the reference. In the simulated phantom, BH streak artifacts were reduced from 12+/-2HU to 1+/-1HU and cupping was reduced by 81%. Similarly, in physical phantom, BH streak artifacts were reduced from 48+/-6HU to 1+/-5HU and cupping was reduced by 86%. In preclinical MPI-CT images, BHA was reduced from 28+/-6 HU to less than 4+/-4HU at peak enhancement. Results suggest that the algorithm can be used to reduce BHA in conventional CT and improve MPI-CT accuracy.

  6. Automatic quantitative analysis of cardiac MR perfusion images

    Science.gov (United States)

    Breeuwer, Marcel M.; Spreeuwers, Luuk J.; Quist, Marcel J.

    2001-07-01

    Magnetic Resonance Imaging (MRI) is a powerful technique for imaging cardiovascular diseases. The introduction of cardiovascular MRI into clinical practice is however hampered by the lack of efficient and accurate image analysis methods. This paper focuses on the evaluation of blood perfusion in the myocardium (the heart muscle) from MR images, using contrast-enhanced ECG-triggered MRI. We have developed an automatic quantitative analysis method, which works as follows. First, image registration is used to compensate for translation and rotation of the myocardium over time. Next, the boundaries of the myocardium are detected and for each position within the myocardium a time-intensity profile is constructed. The time interval during which the contrast agent passes for the first time through the left ventricle and the myocardium is detected and various parameters are measured from the time-intensity profiles in this interval. The measured parameters are visualized as color overlays on the original images. Analysis results are stored, so that they can later on be compared for different stress levels of the heart. The method is described in detail in this paper and preliminary validation results are presented.

  7. Prospective evaluation of stress myocardial perfusion imaging for pre-operative cardiac risk assessment

    International Nuclear Information System (INIS)

    Full text: A prospective evaluation of patients who underwent stress myocardial perfusion imaging (MPI) to assess preoperative cardiac risk was undertaken. At the time of the scan patients were classified into 4 Clinical Risk groups (CR) based on known clinical data. On completion of the scan, the patient was then categorised into 4 Scan based Risk groups (SR), incorporating size of perfusion deficit, single versus multi-vessel disease and ejection fraction. Surgery at Austin and Repatriation Medical Centre within 6 months of scan and complications were identified using the hospital medical database. Major early cardiac events coded were death (cardiac related), myocardial infarction, unstable angina, acute pulmonary oedema, cardiac arrest, and urgent revascularisation. 208 patients have reached 6 months post-MPI scan. Of these 119 (57%) were identified as having surgery. Of the Scan Risk groups, 63% of normal, 57% of increased, and 47% of high and very high groups have had surgery. An abnormal scan is associated with a three-fold risk of cardiac complication (3.5% vs 11.3%). This is lower than most previous reports and may be due to higher representation of low risk surgical procedures (14% in this series), improved peri-operative care and/or the test result influence on management (suggested by decreasing surgical rate as SR estimate rose). Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  8. A visible light imaging device for cardiac rate detection with reduced effect of body movement

    Science.gov (United States)

    Jiang, Xiaotian; Liu, Ming; Zhao, Yuejin

    2014-09-01

    A visible light imaging system to detect human cardiac rate is proposed in this paper. A color camera and several LEDs, acting as lighting source, were used to avoid the interference of ambient light. From people's forehead, the cardiac rate could be acquired based on photoplethysmography (PPG) theory. The template matching method was used after the capture of video. The video signal was discomposed into three signal channels (RGB) and the region of interest was chosen to take the average gray value. The green channel signal could provide an excellent waveform of pulse wave on the account of green lights' absorptive characteristics of blood. Through the fast Fourier transform, the cardiac rate was exactly achieved. But the research goal was not just to achieve the cardiac rate accurately. With the template matching method, the effects of body movement are reduced to a large extent, therefore the pulse wave can be detected even while people are in the moving state and the waveform is largely optimized. Several experiments are conducted on volunteers, and the results are compared with the ones gained by a finger clamped pulse oximeter. The contrast results between these two ways are exactly agreeable. This method to detect the cardiac rate and the pulse wave largely reduces the effects of body movement and can probably be widely used in the future.

  9. Cardiac sarcoidosis mimicking hypertrophic cardiomyopathy: clinical utility of radionuclide imaging for differential diagnosis.

    Science.gov (United States)

    Yazaki, Y; Isobe, M; Hayasaka, M; Tanaka, M; Fujii, T; Sekiguchi, M

    1998-06-01

    A 62-year-old woman with skin sarcoidosis was admitted to our hospital to ascertain whether she had cardiac involvement. Although she displayed no cardiac signs or symptoms, the electrocardiogram showed first-degree atrioventricular block, right bundle branch block with left anterior fascicular block, and giant negative T waves in the V3 lead. Echocardiography revealed marked hypertrophy localized in the basal portion of the interventricular septum (IVS) without systolic dysfunction, mimicking hypertrophic cardiomyopathy (HCM). Exercise thallium-201 myocardial imaging revealed redistribution in the anteroseptal region. Both gallium-67 (67Ga) and technetium-99m pyrophosphate (99mTc-PYP) scintigraphy revealed abnormal uptake in the myocardium. These findings disappeared after 2 months of steroid treatment. Reports of cardiac sarcoidosis mimicking HCM are rare. However, hypertrophy in the basal portion of the IVS is an important sign of early cardiac involvement in sarcoidosis. 67Ga and 99mTc-PYP scintigraphy were useful and necessary to differentiate this type of cardiac sarcoidosis from HCM.

  10. An event-driven distributed processing architecture for image-guided cardiac ablation therapy.

    Science.gov (United States)

    Rettmann, M E; Holmes, D R; Cameron, B M; Robb, R A

    2009-08-01

    Medical imaging data is becoming increasing valuable in interventional medicine, not only for preoperative planning, but also for real-time guidance during clinical procedures. Three key components necessary for image-guided intervention are real-time tracking of the surgical instrument, aligning the real-world patient space with image-space, and creating a meaningful display that integrates the tracked instrument and patient data. Issues to consider when developing image-guided intervention systems include the communication scheme, the ability to distribute CPU intensive tasks, and flexibility to allow for new technologies. In this work, we have designed a communication architecture for use in image-guided catheter ablation therapy. Communication between the system components is through a database which contains an event queue and auxiliary data tables. The communication scheme is unique in that each system component is responsible for querying and responding to relevant events from the centralized database queue. An advantage of the architecture is the flexibility to add new system components without affecting existing software code. In addition, the architecture is intrinsically distributed, in that components can run on different CPU boxes, and even different operating systems. We refer to this Framework for Image-Guided Navigation using a Distributed Event-Driven Database in Real-Time as the FINDER architecture. This architecture has been implemented for the specific application of image-guided cardiac ablation therapy. We describe our prototype image-guidance system and demonstrate its functionality by emulating a cardiac ablation procedure with a patient-specific phantom. The proposed architecture, designed to be modular, flexible, and intuitive, is a key step towards our goal of developing a complete system for visualization and targeting in image-guided cardiac ablation procedures.

  11. Development of an optical digital ionisation chamber

    International Nuclear Information System (INIS)

    We are developing a new device for optically detecting and imaging the track of a charged particle in a gas. The electrons in the particle track are made to oscillate rapidly by the application of an external, short duration, high voltage, RF electric field. The excited electrons produce additional ionisation and electronic excitation of the gas molecules in their immediate vicinity, leading to copious light emission (fluorescence) from the selected gas, allowing the location of the electrons along the track to be determined. Two digital cameras simultaneously scan the emitted light across two perpendicular planes outside the chamber containing the gas. The information thus obtained for a given track can be used to infer relevant quantities for microdosimetry and dosimetry, e.g. energy deposited, LET, and track structure in the gas. The design of such a device now being constructed and methods of obtaining the dosimetric data from the digital output will be described. (author)

  12. Improving best-phase image quality in cardiac CT by motion correction with MAM optimization

    International Nuclear Information System (INIS)

    Purpose: Research in image reconstruction for cardiac CT aims at using motion correction algorithms to improve the image quality of the coronary arteries. The key to those algorithms is motion estimation, which is currently based on 3-D/3-D registration to align the structures of interest in images acquired in multiple heart phases. The need for an extended scan data range covering several heart phases is critical in terms of radiation dose to the patient and limits the clinical potential of the method. Furthermore, literature reports only slight quality improvements of the motion corrected images when compared to the most quiet phase (best-phase) that was actually used for motion estimation. In this paper a motion estimation algorithm is proposed which does not require an extended scan range but works with a short scan data interval, and which markedly improves the best-phase image quality. Methods: Motion estimation is based on the definition of motion artifact metrics (MAM) to quantify motion artifacts in a 3-D reconstructed image volume. The authors use two different MAMs, entropy, and positivity. By adjusting the motion field parameters, the MAM of the resulting motion-compensated reconstruction is optimized using a gradient descent procedure. In this way motion artifacts are minimized. For a fast and practical implementation, only analytical methods are used for motion estimation and compensation. Both the MAM-optimization and a 3-D/3-D registration-based motion estimation algorithm were investigated by means of a computer-simulated vessel with a cardiac motion profile. Image quality was evaluated using normalized cross-correlation (NCC) with the ground truth template and root-mean-square deviation (RMSD). Four coronary CT angiography patient cases were reconstructed to evaluate the clinical performance of the proposed method. Results: For the MAM-approach, the best-phase image quality could be improved for all investigated heart phases, with a maximum

  13. Improving best-phase image quality in cardiac CT by motion correction with MAM optimization

    Energy Technology Data Exchange (ETDEWEB)

    Rohkohl, Christopher; Bruder, Herbert; Stierstorfer, Karl [Siemens AG, Healthcare Sector, Siemensstrasse 1, 91301 Forchheim (Germany); Flohr, Thomas [Siemens AG, Healthcare Sector, Siemensstrasse 1, 91301 Forchheim (Germany); Institute of Diagnostic Radiology, Eberhard Karls University, Hoppe-Seyler-Str. 3, 72076 Tuebingen (Germany)

    2013-03-15

    Purpose: Research in image reconstruction for cardiac CT aims at using motion correction algorithms to improve the image quality of the coronary arteries. The key to those algorithms is motion estimation, which is currently based on 3-D/3-D registration to align the structures of interest in images acquired in multiple heart phases. The need for an extended scan data range covering several heart phases is critical in terms of radiation dose to the patient and limits the clinical potential of the method. Furthermore, literature reports only slight quality improvements of the motion corrected images when compared to the most quiet phase (best-phase) that was actually used for motion estimation. In this paper a motion estimation algorithm is proposed which does not require an extended scan range but works with a short scan data interval, and which markedly improves the best-phase image quality. Methods: Motion estimation is based on the definition of motion artifact metrics (MAM) to quantify motion artifacts in a 3-D reconstructed image volume. The authors use two different MAMs, entropy, and positivity. By adjusting the motion field parameters, the MAM of the resulting motion-compensated reconstruction is optimized using a gradient descent procedure. In this way motion artifacts are minimized. For a fast and practical implementation, only analytical methods are used for motion estimation and compensation. Both the MAM-optimization and a 3-D/3-D registration-based motion estimation algorithm were investigated by means of a computer-simulated vessel with a cardiac motion profile. Image quality was evaluated using normalized cross-correlation (NCC) with the ground truth template and root-mean-square deviation (RMSD). Four coronary CT angiography patient cases were reconstructed to evaluate the clinical performance of the proposed method. Results: For the MAM-approach, the best-phase image quality could be improved for all investigated heart phases, with a maximum

  14. Do imaging studies performed in physician offices increase downstream utilization? An empiric analysis of cardiac stress testing with imaging

    Science.gov (United States)

    Chen, Jersey; Fazel, Reza; Ross, Joseph S.; McNamara, Robert L.; Einstein, Andrew J.; Al-Mallah, Mouaz; Krumholz, Harlan M.; Nallamothu, Brahmajee K.

    2012-01-01

    Objective To compare patterns of downstream testing and procedures after stress testing with imaging performed at physician offices versus at hospital-outpatient facilities. Background Stress testing with imaging has grown dramatically in recent years, but whether the location of where the test is performed correlates with different patterns for subsequent cardiac testing and procedures is unknown. Methods We identified 82,178 adults with private health insurance from 2005–2007 who underwent ambulatory myocardial perfusion imaging (MPI) or stress echocardiography (SE). Subsequent MPI, SE, cardiac catheterization or revascularization within 6 months were compared between physician office and hospital-outpatient settings. Results Overall, 84.5% of MPI and 84.9% of SE were performed in physician offices. The proportion of patients who underwent subsequent MPI, SE or cardiac catheterization was not statistically different between physician office and hospital-outpatient settings for MPI (14.2% v 14.1%, p=0.80) or SE (7.9% v 8.6%, p=0.21). However, patients with physician-office imaging had slightly higher rates of repeat MPI within 6 months compared with hospital-outpatient imaging for both index MPI (3.5% v 2.0%, p<0.001) and SE (3.4% v 2.1%, p<0.001), and slightly lower rates of cardiac catheterization after index MPI (11.5% v 12.3, p=0.01) and SE (4.5% v 7.0%, p<0.001). Differences in 6-month utilization were observed across the 5 healthcare markets after index MPI but not after index SE. Conclusions Physician office imaging is associated with slightly higher repeat MPI and fewer cardiac catheterizations than hospital outpatient imaging, but no overall difference in the proportion of patients undergoing additional further testing or procedures. While regional variation exists, especially for MPI, the relationship between physician-office location of stress testing with imaging and greater downstream resource utilization appears modest. PMID:21679898

  15. Four-dimensional modeling of the heart for image guidance of minimally invasive cardiac surgeries

    Science.gov (United States)

    Wierzbicki, Marcin; Drangova, Maria; Guiraudon, Gerard; Peters, Terry

    2004-05-01

    Minimally invasive surgery of the beating heart can be associated with two major limitations: selecting port locations for optimal target coverage from x-rays and angiograms, and navigating instruments in a dynamic and confined 3D environment using only an endoscope. To supplement the current surgery planning and guidance strategies, we continue developing VCSP - a virtual reality, patient-specific, thoracic cavity model derived from 3D pre-procedural images. In this work, we apply elastic image registration to 4D cardiac images to model the dynamic heart. Our method is validated on two image modalities, and for different parts of the cardiac anatomy. In a helical CT dataset of an excised heart phantom, we found that the artificial motion of the epicardial surface can be extracted to within 0.93 +/- 0.33 mm. For an MR dataset of a human volunteer, the error for different heart structures such as the myocardium, right and left atria, right ventricle, aorta, vena cava, and pulmonary artery, ranged from 1.08 +/- 0.18 mm to 1.14 +/- 0.22 mm. These results indicate that our method of modeling the motion of the heart is not only easily adaptable but also sufficiently accurate to meet the requirements for reliable cardiac surgery training, planning, and guidance.

  16. Comparison of simultaneous and sequential SPECT imaging for discrimination tasks in assessment of cardiac defects

    International Nuclear Information System (INIS)

    Simultaneous rest perfusion/fatty-acid metabolism studies have the potential to replace sequential rest/stress perfusion studies for the assessment of cardiac function. Simultaneous acquisition has the benefits of increased signal and lack of need for patient stress, but is complicated by cross-talk between the two radionuclide signals. We consider a simultaneous rest 99mTc-sestamibi/123I-BMIPP imaging protocol in place of the commonly used sequential rest/stress 99mTc-sestamibi protocol. The theoretical precision with which the severity of a cardiac defect and the transmural extent of infarct can be measured is computed for simultaneous and sequential SPECT imaging, and their performance is compared for discriminating (1) degrees of defect severity and (2) sub-endocardial from transmural defects. We consider cardiac infarcts for which reduced perfusion and metabolism are observed. From an information perspective, simultaneous imaging is found to yield comparable or improved performance compared with sequential imaging for discriminating both severity of defect and transmural extent of infarct, for three defects of differing location and size.

  17. Comparison of simultaneous and sequential SPECT imaging for discrimination tasks in assessment of cardiac defects

    Science.gov (United States)

    Trott, CM; Ouyang, J; El Fakhri, G

    2011-01-01

    Simultaneous rest perfusion/fatty-acid metabolism studies have the potential to replace sequential rest/stress perfusion studies for the assessment of cardiac function. Simultaneous acquisition has the benefits of increased signal and lack of need for patient stress, but is complicated by cross-talk between the two radionuclide signals. We consider a simultaneous rest 99mTc-sestamibi/123I-BMIPP imaging protocol in place of the commonly-used sequential rest/stress 99mTc-sestamibi protocol. The theoretical precision with which the severity of a cardiac defect and the transmural extent of infarct can be measured is computed for simultaneous and sequential SPECT imaging, and their performance is compared for discriminating (1) degrees of defect severity, and (2) sub-endocardial from transmural defects. We consider cardiac infarcts, for which reduced perfusion and metabolism are observed. From an information perspective, simultaneous imaging is found to yield comparable or improved performance compared with sequential imaging for discriminating both severity of defect and transmural extent of infarct, for three defects of differing location and size. PMID:21048290

  18. Imaging Techniques in Percutaneous Cardiac Structural Interventions: Atrial Septal Defect Closure and Left Atrial Appendage Occlusion.

    Science.gov (United States)

    Rodríguez Fernández, Antonio; Bethencourt González, Armando

    2016-08-01

    Because of advances in cardiac structural interventional procedures, imaging techniques are playing an increasingly important role. Imaging studies show sufficient anatomic detail of the heart structure to achieve an excellent outcome in interventional procedures. Up to 98% of atrial septal defects at the ostium secundum can be closed successfully with a percutaneous procedure. Candidates for this type of procedure can be identified through a systematic assessment of atrial septum anatomy, locating and measuring the size and shape of all defects, their rims, and the degree and direction of shunting. Three dimensional echocardiography has significantly improved anatomic assessments and the end result itself. In the future, when combined with other imaging techniques such as cardiac computed tomography and fluoroscopy, 3-dimensional echocardiography will be particularly useful for procedure guidance. Percutaneous closure of the left atrial appendage offers an alternative for treating patients with atrial fibrillation and contraindication for oral anticoagulants. In the future, the clinical focus may well turn to stroke prevention in selected patients. Percutaneous closure is effective and safe; device implantation is successful in 94% to 99% of procedures. However, the procedure requires an experienced cardiac structural interventional team. At present, 3-dimensional echocardiography is the most appropriate imaging technique to assess anatomy suitability, select device type and size, guide the procedure alongside fluoroscopy, and to follow-up the patient afterwards. PMID:27354151

  19. Comparison of simultaneous and sequential SPECT imaging for discrimination tasks in assessment of cardiac defects

    Energy Technology Data Exchange (ETDEWEB)

    Trott, C M; Ouyang, J; El Fakhri, G, E-mail: ctrott@pet.mgh.harvard.ed [Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St, Boston, MA 02114 (United States)

    2010-11-21

    Simultaneous rest perfusion/fatty-acid metabolism studies have the potential to replace sequential rest/stress perfusion studies for the assessment of cardiac function. Simultaneous acquisition has the benefits of increased signal and lack of need for patient stress, but is complicated by cross-talk between the two radionuclide signals. We consider a simultaneous rest {sup 99m}Tc-sestamibi/{sup 123}I-BMIPP imaging protocol in place of the commonly used sequential rest/stress {sup 99m}Tc-sestamibi protocol. The theoretical precision with which the severity of a cardiac defect and the transmural extent of infarct can be measured is computed for simultaneous and sequential SPECT imaging, and their performance is compared for discriminating (1) degrees of defect severity and (2) sub-endocardial from transmural defects. We consider cardiac infarcts for which reduced perfusion and metabolism are observed. From an information perspective, simultaneous imaging is found to yield comparable or improved performance compared with sequential imaging for discriminating both severity of defect and transmural extent of infarct, for three defects of differing location and size.

  20. Fully automated segmentation of left ventricle using dual dynamic programming in cardiac cine MR images

    Science.gov (United States)

    Jiang, Luan; Ling, Shan; Li, Qiang

    2016-03-01

    Cardiovascular diseases are becoming a leading cause of death all over the world. The cardiac function could be evaluated by global and regional parameters of left ventricle (LV) of the heart. The purpose of this study is to develop and evaluate a fully automated scheme for segmentation of LV in short axis cardiac cine MR images. Our fully automated method consists of three major steps, i.e., LV localization, LV segmentation at end-diastolic phase, and LV segmentation propagation to the other phases. First, the maximum intensity projection image along the time phases of the midventricular slice, located at the center of the image, was calculated to locate the region of interest of LV. Based on the mean intensity of the roughly segmented blood pool in the midventricular slice at each phase, end-diastolic (ED) and end-systolic (ES) phases were determined. Second, the endocardial and epicardial boundaries of LV of each slice at ED phase were synchronously delineated by use of a dual dynamic programming technique. The external costs of the endocardial and epicardial boundaries were defined with the gradient values obtained from the original and enhanced images, respectively. Finally, with the advantages of the continuity of the boundaries of LV across adjacent phases, we propagated the LV segmentation from the ED phase to the other phases by use of dual dynamic programming technique. The preliminary results on 9 clinical cardiac cine MR cases show that the proposed method can obtain accurate segmentation of LV based on subjective evaluation.

  1. SPECT-T1-201 cardiac imaging

    International Nuclear Information System (INIS)

    Topics of discussion include: limitations of planar thallium-201 imaging; tomographic acquisition protocol; quantitative analysis involving slice selection, circumferential profile generation, comparison to normal limits and polar display of results; sensitivity and specificity; sources of error involving patient motion and upward creep; and clinical applications

  2. The developing role of fetal magnetic resonance imaging in the diagnosis of congenital cardiac anomalies: A systematic review

    International Nuclear Information System (INIS)

    Advances in the fetal magnetic resonance imaging (MRI) over the last few years have resulted in the exploring the use of fetal MRI to detect congenital cardiac anomalies. Early detection of congenital cardiac anomalies can help more appropriately manage the infant's delivery and neonatal management. MRI offers anatomical and functional studies and is a safe adjunct that can help more fully understand a fetus' cardiac anatomy. It is important for the obstetricians and pediatric cardiologists to be aware of the recent advancements in fetal MRI and it's potential utility in diagnosing congenital cardiac anomalies

  3. The developing role of fetal magnetic resonance imaging in the diagnosis of congenital cardiac anomalies: A systematic review

    Directory of Open Access Journals (Sweden)

    Rohit S Loomba

    2011-01-01

    Full Text Available Advances in the fetal magnetic resonance imaging (MRI over the last few years have resulted in the exploring the use of fetal MRI to detect congenital cardiac anomalies. Early detection of congenital cardiac anomalies can help more appropriately manage the infant′s delivery and neonatal management. MRI offers anatomical and functional studies and is a safe adjunct that can help more fully understand a fetus′ cardiac anatomy. It is important for the obstetricians and pediatric cardiologists to be aware of the recent advancements in fetal MRI and it`s potential utility in diagnosing congenital cardiac anomalies.

  4. Self-gating MR imaging of the fetal heart: comparison with real cardiac triggering

    Energy Technology Data Exchange (ETDEWEB)

    Yamamura, Jin; Frisch, Michael; Ecker, Hannes; Adam, Gerhard; Wedegaertner, Ulrike [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Graessner, Joachim [Siemens AG, Healthcare, Hamburg (Germany); Hecher, Kurt [University Medical Center Hamburg-Eppendorf, Department of Obstetrics and Fetal Medicine, Hamburg (Germany)

    2011-01-15

    To investigate the self-gating technique for MR imaging of the fetal heart in a sheep model. MR images of 6 fetal sheep heart were obtained at 1.5T. For self-gating MRI of the fetal heart a cine SSFP in short axis, two and four chamber view was used. Self-gated images were compared with real cardiac triggered MR images (pulse-wave triggering). MRI of the fetal heart was performed using both techniques simultaneously. Image quality was assessed and the left ventricular volume and function were measured and compared. Compared with pulse-wave triggering, the self-gating technique produced slightly inferior images with artifacts. Especially the atrial septum could not be so clearly depicted. The contraction of the fetal heart was shown in cine sequences in both techniques. The average blood volumes could be measured with both techniques with no significant difference: at end-systole 3.1 ml (SD{+-} 0.2), at end-diastole 4.9 ml ({+-}0.2), with ejection fractions at 38.6%, respectively 39%. Both self-gating and pulse-wave triggered cardiac MRI of the fetal heart allowed the evaluation of anatomical structures and functional information. Images obtained by self-gating technique were slightly inferior than the pulse-wave triggered MRI. (orig.)

  5. Self-gating MR imaging of the fetal heart: comparison with real cardiac triggering

    International Nuclear Information System (INIS)

    To investigate the self-gating technique for MR imaging of the fetal heart in a sheep model. MR images of 6 fetal sheep heart were obtained at 1.5T. For self-gating MRI of the fetal heart a cine SSFP in short axis, two and four chamber view was used. Self-gated images were compared with real cardiac triggered MR images (pulse-wave triggering). MRI of the fetal heart was performed using both techniques simultaneously. Image quality was assessed and the left ventricular volume and function were measured and compared. Compared with pulse-wave triggering, the self-gating technique produced slightly inferior images with artifacts. Especially the atrial septum could not be so clearly depicted. The contraction of the fetal heart was shown in cine sequences in both techniques. The average blood volumes could be measured with both techniques with no significant difference: at end-systole 3.1 ml (SD± 0.2), at end-diastole 4.9 ml (±0.2), with ejection fractions at 38.6%, respectively 39%. Both self-gating and pulse-wave triggered cardiac MRI of the fetal heart allowed the evaluation of anatomical structures and functional information. Images obtained by self-gating technique were slightly inferior than the pulse-wave triggered MRI. (orig.)

  6. Murine cardiac images obtained with focusing pinhole SPECT are barely influenced by extra-cardiac activity

    Science.gov (United States)

    Branderhorst, Woutjan; van der Have, Frans; Vastenhouw, Brendan; Viergever, Max A.; Beekman, Freek J.

    2012-02-01

    Ultra-high-resolution SPECT images can be obtained with focused multipinhole collimators. Here we investigate the influence of unwanted high tracer uptake outside the scan volume on reconstructed tracer distributions inside the scan volume, for 99mTc-tetrofosmin myocardial perfusion scanning in mice. Simulated projections of a digital mouse phantom (MOBY) in a focusing multipinhole SPECT system (U-SPECT-II, MILabs, The Netherlands) were generated. With this system differently sized user-defined scan volumes can be selected, by translating the animal in 3D through the focusing collimators. Scan volume selections were set to (i) a minimal volume containing just the heart, acquired without translating the animal during scanning, (ii) a slightly larger scan volume as is typically applied for the heart, requiring only small XYZ translations during scanning, (iii) same as (ii), but extended further transaxially, and (iv) same as (ii), but extended transaxially to cover the full thorax width (gold standard). Despite an overall negative bias that is significant for the minimal scan volume, all selected volumes resulted in visually similar images. Quantitative differences in the reconstructed myocardium between gold standard and the results from the smaller scan volume selections were small; the 17 standardized myocardial segments of a bull's eye plot, normalized to the myocardial mean of the gold standard, deviated on average 6.0%, 2.5% and 1.9% for respectively the minimal, the typical and the extended scan volume, while maximum absolute deviations were respectively 18.6%, 9.0% and 5.2%. Averaged over ten low-count noisy simulations, the mean absolute deviations were respectively 7.9%, 3.2% and 1.9%. In low-count noisy simulations, the mean and maximum absolute deviations for the minimal scan volume could be reduced to respectively 4.2% and 12.5% by performing a short survey scan of the exterior activity and focusing the remaining scan time at the organ of interest. We

  7. Image artefact propagation in motion estimation and reconstruction in interventional cardiac C-arm CT.

    Science.gov (United States)

    Müller, K; Maier, A K; Schwemmer, C; Lauritsch, G; De Buck, S; Wielandts, J-Y; Hornegger, J; Fahrig, R

    2014-06-21

    The acquisition of data for cardiac imaging using a C-arm computed tomography system requires several seconds and multiple heartbeats. Hence, incorporation of motion correction in the reconstruction step may improve the resulting image quality. Cardiac motion can be estimated by deformable three-dimensional (3D)/3D registration performed on initial 3D images of different heart phases. This motion information can be used for a motion-compensated reconstruction allowing the use of all acquired data for image reconstruction. However, the result of the registration procedure and hence the estimated deformations are influenced by the quality of the initial 3D images. In this paper, the sensitivity of the 3D/3D registration step to the image quality of the initial images is studied. Different reconstruction algorithms are evaluated for a recently proposed cardiac C-arm CT acquisition protocol. The initial 3D images are all based on retrospective electrocardiogram (ECG)-gated data. ECG-gating of data from a single C-arm rotation provides only a few projections per heart phase for image reconstruction. This view sparsity leads to prominent streak artefacts and a poor signal to noise ratio. Five different initial image reconstructions are evaluated: (1) cone beam filtered-backprojection (FDK), (2) cone beam filtered-backprojection and an additional bilateral filter (FFDK), (3) removal of the shadow of dense objects (catheter, pacing electrode, etc) before reconstruction with a cone beam filtered-backprojection (cathFDK), (4) removal of the shadow of dense objects before reconstruction with a cone beam filtered-backprojection and a bilateral filter (cathFFDK). The last method (5) is an iterative few-view reconstruction (FV), the prior image constrained compressed sensing combined with the improved total variation algorithm. All reconstructions are investigated with respect to the final motion-compensated reconstruction quality. The algorithms were tested on a mathematical

  8. Kalman filter techniques for accelerated Cartesian dynamic cardiac imaging.

    Science.gov (United States)

    Feng, Xue; Salerno, Michael; Kramer, Christopher M; Meyer, Craig H

    2013-05-01

    In dynamic MRI, spatial and temporal parallel imaging can be exploited to reduce scan time. Real-time reconstruction enables immediate visualization during the scan. Commonly used view-sharing techniques suffer from limited temporal resolution, and many of the more advanced reconstruction methods are either retrospective, time-consuming, or both. A Kalman filter model capable of real-time reconstruction can be used to increase the spatial and temporal resolution in dynamic MRI reconstruction. The original study describing the use of the Kalman filter in dynamic MRI was limited to non-Cartesian trajectories because of a limitation intrinsic to the dynamic model used in that study. Here the limitation is overcome, and the model is applied to the more commonly used Cartesian trajectory with fast reconstruction. Furthermore, a combination of the Kalman filter model with Cartesian parallel imaging is presented to further increase the spatial and temporal resolution and signal-to-noise ratio. Simulations and experiments were conducted to demonstrate that the Kalman filter model can increase the temporal resolution of the image series compared with view-sharing techniques and decrease the spatial aliasing compared with TGRAPPA. The method requires relatively little computation, and thus is suitable for real-time reconstruction.

  9. Cardiac gating with a pulse oximeter for dual-energy imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shkumat, N A; Siewerdsen, J H [Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5G 2M9 (Canada); Dhanantwari, A C; Williams, D B [Ontario Cancer Institute, Princess Margaret Hospital, 610 University Ave., Toronto, Ontario, M5G 2M9 (Canada); Paul, N S [Department of Medical Imaging, University Health Network, Toronto, Ontario, M5G 2M9 (Canada); Yorkston, J; Van Metter, R [Carestream Health Inc., Rochester, NY 14650 (United States)], E-mail: jeff.siewerdsen@uhn.on.ca

    2008-11-07

    The development and evaluation of a prototype cardiac gating system for double-shot dual-energy (DE) imaging is described. By acquiring both low- and high-kVp images during the resting phase of the cardiac cycle (diastole), heart misalignment between images can be reduced, thereby decreasing the magnitude of cardiac motion artifacts. For this initial implementation, a fingertip pulse oximeter was employed to measure the peripheral pulse waveform ('plethysmogram'), offering potential logistic, cost and workflow advantages compared to an electrocardiogram. A gating method was developed that accommodates temporal delays due to physiological pulse propagation, oximeter waveform processing and the imaging system (software, filter-wheel, anti-scatter Bucky-grid and flat-panel detector). Modeling the diastolic period allowed the calculation of an implemented delay, t{sub imp}, required to trigger correctly during diastole at any patient heart rate (HR). The model suggests a triggering scheme characterized by two HR regimes, separated by a threshold, HR{sub thresh}. For rates at or below HR{sub thresh}, sufficient time exists to expose on the same heartbeat as the plethysmogram pulse [t{sub imp}(HR) = 0]. Above HR{sub thresh}, a characteristic t{sub imp}(HR) delays exposure to the subsequent heartbeat, accounting for all fixed and variable system delays. Performance was evaluated in terms of accuracy and precision of diastole-trigger coincidence and quantitative evaluation of artifact severity in gated and ungated DE images. Initial implementation indicated 85% accuracy in diastole-trigger coincidence. Through the identification of an improved HR estimation method (modified temporal smoothing of the oximeter waveform), trigger accuracy of 100% could be achieved with improved precision. To quantify the effect of the gating system on DE image quality, human observer tests were conducted to measure the magnitude of cardiac artifact under conditions of successful and

  10. Cardiac gating with a pulse oximeter for dual-energy imaging

    Science.gov (United States)

    Shkumat, N. A.; Siewerdsen, J. H.; Dhanantwari, A. C.; Williams, D. B.; Paul, N. S.; Yorkston, J.; Van Metter, R.

    2008-11-01

    The development and evaluation of a prototype cardiac gating system for double-shot dual-energy (DE) imaging is described. By acquiring both low- and high-kVp images during the resting phase of the cardiac cycle (diastole), heart misalignment between images can be reduced, thereby decreasing the magnitude of cardiac motion artifacts. For this initial implementation, a fingertip pulse oximeter was employed to measure the peripheral pulse waveform ('plethysmogram'), offering potential logistic, cost and workflow advantages compared to an electrocardiogram. A gating method was developed that accommodates temporal delays due to physiological pulse propagation, oximeter waveform processing and the imaging system (software, filter-wheel, anti-scatter Bucky-grid and flat-panel detector). Modeling the diastolic period allowed the calculation of an implemented delay, timp, required to trigger correctly during diastole at any patient heart rate (HR). The model suggests a triggering scheme characterized by two HR regimes, separated by a threshold, HRthresh. For rates at or below HRthresh, sufficient time exists to expose on the same heartbeat as the plethysmogram pulse [timp(HR) = 0]. Above HRthresh, a characteristic timp(HR) delays exposure to the subsequent heartbeat, accounting for all fixed and variable system delays. Performance was evaluated in terms of accuracy and precision of diastole-trigger coincidence and quantitative evaluation of artifact severity in gated and ungated DE images. Initial implementation indicated 85% accuracy in diastole-trigger coincidence. Through the identification of an improved HR estimation method (modified temporal smoothing of the oximeter waveform), trigger accuracy of 100% could be achieved with improved precision. To quantify the effect of the gating system on DE image quality, human observer tests were conducted to measure the magnitude of cardiac artifact under conditions of successful and unsuccessful diastolic gating. Six observers

  11. Preparation and evaluation of technetium-99m labeled cardiac glycoside derivatives as potential myocardial imaging agent

    Energy Technology Data Exchange (ETDEWEB)

    Misra, Mridula; Sarkar, H.S.; Chatterjee, Mita; Banerjee, Somenath

    1988-01-01

    Three cardiac glycosides, two natural, cymarin and convallotoxin and one synthetic, strophanthidin-..beta..-D-glucoside were converted to their thiosemicarbazone and subsequently radiolabeled with sup(99m)Tc by chelation. The resulting radioactive chelate complexes were evaluated in animals to determine the suitability of this class of compounds for myocardial imaging. It was observed from the animal biodistribution data of the three radioactive compounds that there was a considerable variation in the heart to non-target organ uptake ratio. A possible explanation of this variation was offered in the light of their lipophilic character, protein binding ability and affinity towards non-target receptors. It is anticipated that this study may help to develop a sup(99m)Tc-cardiac glycoside complex with better distribution characteristics, and such a compound may offer a suitable alternative to /sup 201/Tl, which is at present used for myocardial imaging.

  12. Interventional guidance for cardiac resynchronization therapies: merging anatomic X-ray imaging with functional ultrasound imaging based on mutually-shared landmarks

    Energy Technology Data Exchange (ETDEWEB)

    Manzke, R.; Shechter, G.; Gutierrez, L.; Chan, R.C. [Philips Research North America, Briarcliff Manor, NY (United States); Tournoux, F.; Singh, J.; Picard, M. [Dept. of Cardiology, Massachusetts General Hospital, Harvard Medical School (United States); Brink, B. v.d.; Boomen, R. v.d. [Philips Medical System, Best (Netherlands); Gerard, O. [Philips Medical Systems, Paris (France)

    2007-06-15

    Detailed knowledge of cardiac anatomy and function is required for complex cardiac electrophysiology interventions. Cardiac resynchronization therapies (CRT), for example, requires information about coronary venous anatomy for left ventricular lead placement. In CRT, heart failure patients are equipped with dual-chamber pacemakers in order to improve cardiac output and heart failure symptoms. Cardiac function is mainly assessed with Ultrasound imaging. Fusion of complementary information from X-ray and ultrasound is an essential step towards fully utilizing all available information for CRT guidance. We present an approach for fusion of anatomical information (coronary vein structure) from X-ray with functional information (left ventricular deformation and dynamics) from ultrasound. We propose an image-based fusion approach based on mutually-shared landmarks which enable registration of both imaging spaces without the need for external tracking. (orig.)

  13. 1093 Automatic delineation of endo- and epicardial contours in late-enhancement cardiac MR images

    OpenAIRE

    Hautvast Gilion; Mory Benoit; Fradkin Maxim; Ciofolo Cybele; Breeuwer Marcel

    2008-01-01

    The authors would like to acknowledge BioMed Central for allowing open access to this paper. Please download the publisher version by using http://jcmr-online.com/content/10/S1/A218 International audience We propose a novel method to automatically delineate the endo- and epicardial contours in late-enhancement short-axis cardiac MR images in order to provide an automatic, accurate quantitative viability assessment.

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

    International Nuclear Information System (INIS)

    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/m2; range, 48-116 ml/m2) and normalized LV end-systolic volume in 20 % (31.5 ± 13.3 ml/m2; range, 15-74 ml/m2). EF was reduced in 33 % (58.4 ± 7.6 %; range, 37-69 %) and normalized LV myocardial mass in 80 % (40.5 ± 6.8 g/m2; range, 31-55 g/m2). 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.)

  15. 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.)

  16. Myocardial Infarct Segmentation From Magnetic Resonance Images for Personalized Modeling of Cardiac Electrophysiology.

    Science.gov (United States)

    Ukwatta, Eranga; Arevalo, Hermenegild; Li, Kristina; Yuan, Jing; Qiu, Wu; Malamas, Peter; Wu, Katherine C; Trayanova, Natalia A; Vadakkumpadan, Fijoy

    2016-06-01

    Accurate representation of myocardial infarct geometry is crucial to patient-specific computational modeling of the heart in ischemic cardiomyopathy. We have developed a methodology for segmentation of left ventricular (LV) infarct from clinically acquired, two-dimensional (2D), late-gadolinium enhanced cardiac magnetic resonance (LGE-CMR) images, for personalized modeling of ventricular electrophysiology. The infarct segmentation was expressed as a continuous min-cut optimization problem, which was solved using its dual formulation, the continuous max-flow (CMF). The optimization objective comprised of a smoothness term, and a data term that quantified the similarity between image intensity histograms of segmented regions and those of a set of training images. A manual segmentation of the LV myocardium was used to initialize and constrain the developed method. The three-dimensional geometry of infarct was reconstructed from its segmentation using an implicit, shape-based interpolation method. The proposed methodology was extensively evaluated using metrics based on geometry, and outcomes of individualized electrophysiological simulations of cardiac dys(function). Several existing LV infarct segmentation approaches were implemented, and compared with the proposed method. Our results demonstrated that the CMF method was more accurate than the existing approaches in reproducing expert manual LV infarct segmentations, and in electrophysiological simulations. The infarct segmentation method we have developed and comprehensively evaluated in this study constitutes an important step in advancing clinical applications of personalized simulations of cardiac electrophysiology. PMID:26731693

  17. Cardiac diffusion tensor imaging based on compressed sensing using joint sparsity and low-rank approximation.

    Science.gov (United States)

    Huang, Jianping; Wang, Lihui; Chu, Chunyu; Zhang, Yanli; Liu, Wanyu; Zhu, Yuemin

    2016-04-29

    Diffusion tensor magnetic resonance (DTMR) imaging and diffusion tensor imaging (DTI) have been widely used to probe noninvasively biological tissue structures. However, DTI suffers from long acquisition times, which limit its practical and clinical applications. This paper proposes a new Compressed Sensing (CS) reconstruction method that employs joint sparsity and rank deficiency to reconstruct cardiac DTMR images from undersampled k-space data. Diffusion-weighted images acquired in different diffusion directions were firstly stacked as columns to form the matrix. The matrix was row sparse in the transform domain and had a low rank. These two properties were then incorporated into the CS reconstruction framework. The underlying constrained optimization problem was finally solved by the first-order fast method. Experiments were carried out on both simulation and real human cardiac DTMR images. The results demonstrated that the proposed approach had lower reconstruction errors for DTI indices, including fractional anisotropy (FA) and mean diffusivities (MD), compared to the existing CS-DTMR image reconstruction techniques. PMID:27163322

  18. First pass cable artefact correction for cardiac C-arm CT imaging.

    Science.gov (United States)

    Haase, C; Schäfer, D; Kim, M; Chen, S J; Carroll, J D; Eshuis, P; Dössel, O; Grass, M

    2014-07-21

    Cardiac C-arm CT imaging delivers a tomographic region-of-interest reconstruction of the patient's heart during image guided catheter interventions. Due to the limited size of the flat detector a volume image is reconstructed, which is truncated in the cone-beam (along the patient axis) and the fan-beam (in the transaxial plane) direction. To practically address this local tomography problem correction methods, like projection extension, are available for first pass image reconstruction. For second pass correction methods, like metal artefact reduction, alternative correction schemes are required when the field of view is limited to a region-of-interest of the patient. In classical CT imaging metal artefacts are corrected by metal identification in a first volume reconstruction and generation of a corrected projection data set followed by a second reconstruction. This approach fails when the metal structures are located outside the reconstruction field of view. When a C-arm CT is performed during a cardiac intervention pacing leads and other cables are frequently positioned on the patients skin, which results in propagating streak artefacts in the reconstruction volume. A first pass approach to reduce this type of artefact is introduced and evaluated here. It makes use of the fact that the projected position of objects outside the reconstruction volume changes with the projection perspective. It is shown that projection based identification, tracking and removal of high contrast structures like cables, only detected in a subset of the projections, delivers a more consistent reconstruction volume with reduced artefact level. The method is quantitatively evaluated based on 50 simulations using cardiac CT data sets with variable cable positioning. These data sets are forward projected using a C-arm CT system geometry and generate artefacts comparable to those observed in clinical cardiac C-arm CT acquisitions. A C-arm CT simulation of every cardiac CT data set without

  19. First pass cable artefact correction for cardiac C-arm CT imaging

    International Nuclear Information System (INIS)

    Cardiac C-arm CT imaging delivers a tomographic region-of-interest reconstruction of the patient's heart during image guided catheter interventions. Due to the limited size of the flat detector a volume image is reconstructed, which is truncated in the cone-beam (along the patient axis) and the fan-beam (in the transaxial plane) direction. To practically address this local tomography problem correction methods, like projection extension, are available for first pass image reconstruction. For second pass correction methods, like metal artefact reduction, alternative correction schemes are required when the field of view is limited to a region-of-interest of the patient. In classical CT imaging metal artefacts are corrected by metal identification in a first volume reconstruction and generation of a corrected projection data set followed by a second reconstruction. This approach fails when the metal structures are located outside the reconstruction field of view. When a C-arm CT is performed during a cardiac intervention pacing leads and other cables are frequently positioned on the patients skin, which results in propagating streak artefacts in the reconstruction volume. A first pass approach to reduce this type of artefact is introduced and evaluated here. It makes use of the fact that the projected position of objects outside the reconstruction volume changes with the projection perspective. It is shown that projection based identification, tracking and removal of high contrast structures like cables, only detected in a subset of the projections, delivers a more consistent reconstruction volume with reduced artefact level. The method is quantitatively evaluated based on 50 simulations using cardiac CT data sets with variable cable positioning. These data sets are forward projected using a C-arm CT system geometry and generate artefacts comparable to those observed in clinical cardiac C-arm CT acquisitions. A C-arm CT simulation of every cardiac CT data set

  20. Cardiac imaging assessment of the left ventricular ejection fraction%心脏影像学对左室射血分数的评估

    Institute of Scientific and Technical Information of China (English)

    丁磊; 范大立

    2012-01-01

    Left ventricular ejection fraction ( LVEF) is the most important measurement of the left ventricular function and the most commonly used parameter in clinical cardiac imaging. LVEF can be measured with different cardiac imaging techniques; left ventricular contrast angiography by catheterization, echocardiography, radionuclide ventriculography, cardiac magnetic resonance imaging and cardiac computed tomography. In this article, we reviewed the specifics of each of the cardiac imaging modality, their strength and pitfalls. We also compared the consistency and variance between them. The selection of a specific cardiac imaging modality in clinical practice should depend on the indications, local expertise and the historic data of the patient. In general, these cardiac imaging modalities correlate well, but the variance and standard deviation are large so the measurement numbers should not be used interchangeably.

  1. Image analysis methods for tagged MRI cardiac studies

    Science.gov (United States)

    Guttman, Michael A.; Prince, Jerry L.

    1990-07-01

    Tracking of magnetic resonance (MR) tags in myocardial tissue promises to be an effective tool in the assessment of myocardial motion. The amount of data acquired is very large and the measurements are numerous and must be precise requiring automated tracking methods. We describe a hierarchy of image processing steps that estimate both the endocardial and epicardial boundaries of the left ventricle and also estimate the spines of radial tags that emanate outward from the left ventricular cavity. The first stage determines the position of the myocardial boundaries for each of 128 rays emanating from the origin. To counter the deleterious effects of noise and the presence of the tags when determining the boundary positions we use nonlinear filtering concepts from mathematical morphology together with a prion knowledge related to boundary smoothness to improve the estimates. The second stage estimates the tag spines by matching a template in a direction orthogonal to the expected tag direction. We show results on tagged images and discuss further research directions. 1.

  2. Fourier transform infrared spectroscopic imaging of cardiac tissue to detect collagen deposition after myocardial infarction

    Science.gov (United States)

    Cheheltani, Rabee; Rosano, Jenna M.; Wang, Bin; Sabri, Abdel Karim; Pleshko, Nancy; Kiani, Mohammad F.

    2012-05-01

    Myocardial infarction often leads to an increase in deposition of fibrillar collagen. Detection and characterization of this cardiac fibrosis is of great interest to investigators and clinicians. Motivated by the significant limitations of conventional staining techniques to visualize collagen deposition in cardiac tissue sections, we have developed a Fourier transform infrared imaging spectroscopy (FT-IRIS) methodology for collagen assessment. The infrared absorbance band centered at 1338 cm-1, which arises from collagen amino acid side chain vibrations, was used to map collagen deposition across heart tissue sections of a rat model of myocardial infarction, and was compared to conventional staining techniques. Comparison of the size of the collagen scar in heart tissue sections as measured with this methodology and that of trichrome staining showed a strong correlation (R=0.93). A Pearson correlation model between local intensity values in FT-IRIS and immuno-histochemical staining of collagen type I also showed a strong correlation (R=0.86). We demonstrate that FT-IRIS methodology can be utilized to visualize cardiac collagen deposition. In addition, given that vibrational spectroscopic data on proteins reflect molecular features, it also has the potential to provide additional information about the molecular structure of cardiac extracellular matrix proteins and their alterations.

  3. Serum lipidomics meets cardiac magnetic resonance imaging: profiling of subjects at risk of dilated cardiomyopathy.

    Science.gov (United States)

    Sysi-Aho, Marko; Koikkalainen, Juha; Seppänen-Laakso, Tuulikki; Kaartinen, Maija; Kuusisto, Johanna; Peuhkurinen, Keijo; Kärkkäinen, Satu; Antila, Margareta; Lauerma, Kirsi; Reissell, Eeva; Jurkko, Raija; Lötjönen, Jyrki; Heliö, Tiina; Orešič, Matej

    2011-01-20

    Dilated cardiomyopathy (DCM), characterized by left ventricular dilatation and systolic dysfunction, constitutes a significant cause for heart failure, sudden cardiac death or need for heart transplantation. Lamin A/C gene (LMNA) on chromosome 1p12 is the most significant disease gene causing DCM and has been reported to cause 7-9% of DCM leading to cardiac transplantation. We have previously performed cardiac magnetic resonance imaging (MRI) to LMNA carriers to describe the early phenotype. Clinically, early recognition of subjects at risk of developing DCM would be important but is often difficult. Thus we have earlier used the MRI findings of these LMNA carriers for creating a model by which LMNA carriers could be identified from the controls at an asymptomatic stage. Some LMNA mutations may cause lipodystrophy. To characterize possible effects of LMNA mutations on lipid profile, we set out to apply global serum lipidomics using Ultra Performance Liquid Chromatography coupled to mass spectrometry in the same LMNA carriers, DCM patients without LMNA mutation and controls. All DCM patients, with or without LMNA mutation, differed from controls in regard to distinct serum lipidomic profile dominated by diminished odd-chain triglycerides and lipid ratios related to desaturation. Furthermore, we introduce a novel approach to identify associations between the molecular lipids from serum and the MR images from the LMNA carriers. The association analysis using dependency network and regression approaches also helped us to obtain novel insights into how the affected lipids might relate to cardiac shape and volume changes. Our study provides a framework for linking serum derived molecular markers not only with clinical endpoints, but also with the more subtle intermediate phenotypes, as derived from medical imaging, of potential pathophysiological relevance.

  4. Serum lipidomics meets cardiac magnetic resonance imaging: profiling of subjects at risk of dilated cardiomyopathy.

    Directory of Open Access Journals (Sweden)

    Marko Sysi-Aho

    Full Text Available Dilated cardiomyopathy (DCM, characterized by left ventricular dilatation and systolic dysfunction, constitutes a significant cause for heart failure, sudden cardiac death or need for heart transplantation. Lamin A/C gene (LMNA on chromosome 1p12 is the most significant disease gene causing DCM and has been reported to cause 7-9% of DCM leading to cardiac transplantation. We have previously performed cardiac magnetic resonance imaging (MRI to LMNA carriers to describe the early phenotype. Clinically, early recognition of subjects at risk of developing DCM would be important but is often difficult. Thus we have earlier used the MRI findings of these LMNA carriers for creating a model by which LMNA carriers could be identified from the controls at an asymptomatic stage. Some LMNA mutations may cause lipodystrophy. To characterize possible effects of LMNA mutations on lipid profile, we set out to apply global serum lipidomics using Ultra Performance Liquid Chromatography coupled to mass spectrometry in the same LMNA carriers, DCM patients without LMNA mutation and controls. All DCM patients, with or without LMNA mutation, differed from controls in regard to distinct serum lipidomic profile dominated by diminished odd-chain triglycerides and lipid ratios related to desaturation. Furthermore, we introduce a novel approach to identify associations between the molecular lipids from serum and the MR images from the LMNA carriers. The association analysis using dependency network and regression approaches also helped us to obtain novel insights into how the affected lipids might relate to cardiac shape and volume changes. Our study provides a framework for linking serum derived molecular markers not only with clinical endpoints, but also with the more subtle intermediate phenotypes, as derived from medical imaging, of potential pathophysiological relevance.

  5. Assessment of cardiac function and synchronicity in subjects with isolated bundle branch block using Doppler imaging

    Institute of Scientific and Technical Information of China (English)

    NIU Hong-xia; HUA Wei; ZHANG Shu; SUN Xin; WANG Fang-zheng; CHEN Ke-ping; WANG Hao; CHEN Xin

    2006-01-01

    Background Using tissue Doppler imaging and conventional echocardiographic technique, we examined the cardiac function and synchronicity in individuals with isolated right bundle branch block (RBBB) or left bundle branch block (LBBB) and assessed the relationship between QRS duration and synchronicity.Methods Subjects with isolated RBBB (n=20), LBBB (n=10) and normal controls (n=20) were studied with conventional echocardiography and tissue Doppler imaging. The difference between aortic and pulmonary preejection intervals was defined as interventricular delay. Parameters in septum and lateral wall were measured using tissue Doppler imaging, including peak sustained systolic velocity (SM), peak early (EM) and late (AM)diastolic velocities as well as time to peak velocities (Ts, TE and TA).Results Subjects with LBBB had lower SM and longer Ts than did the RBBB and control groups (P<0.05,P<0.001 respectively). A significant difference was observed in EM, being the lowest in the LBBB and the highest in the control group (P<0.05). Moreover, TE was longer in the LBBB group compared with the other two groups (P<0.001). Both AM and TA were similar among three groups (P>0.05). In the bundle branch block groups, one ventricle lagged about 40 ms behind the other. A significant correlation was found between interventricular delay and QRS duration (r =0.713, P<0.001).Conclusions Cardiac ventricles were not well synchronized with one ventricle lagging about 40 ms behind the other in subjects with LBBB or RBBB, even though only LBBB group showed barely perceptible, impaired cardiac function. In addition, QRS duration and cardiac asynchronicity were positively correlated.

  6. Introduction to cardiac imaging in infants and children: Techniques, potential, and role in the imaging work-up of various cardiac malformations and other pediatric heart conditions

    International Nuclear Information System (INIS)

    The increasing prevalence of congenital heart disease (CHD) can be attributed to major improvements in diagnosis and treatment. Although echocardiography is the most commonly used imaging modality for diagnosis and follow-up of subjects with CHD, the evolution of cardiovascular magnetic resonance (MR) imaging and increasingly computed tomography (CT) does offer new ways to visualize the heart and the great vessels. The development of cardiovascular MR techniques allows for a comprehensive assessment of cardiac anatomy and function. This provides information about the long-term sequlae of the underlying complex anatomy, hemodynamic assessment of residual post-operative lesions and complications of surgery. As much of the functional data in CHD patients is usually acquired with invasive X-ray angiography, non-invasive alternatives such as cardiovascular MR (and CT) are desirable. This review evaluates the role of MR imaging in the management of subjects with CHD, particularly detailing recent developments in imaging techniques as they relate to the various CHD diagnoses we commonly encounter in our practice

  7. Image-Based Structural Modeling of the Cardiac Purkinje Network

    Directory of Open Access Journals (Sweden)

    Benjamin R. Liu

    2015-01-01

    Full Text Available The Purkinje network is a specialized conduction system within the heart that ensures the proper activation of the ventricles to produce effective contraction. Its role during ventricular arrhythmias is less clear, but some experimental studies have suggested that the Purkinje network may significantly affect the genesis and maintenance of ventricular arrhythmias. Despite its importance, few structural models of the Purkinje network have been developed, primarily because current physical limitations prevent examination of the intact Purkinje network. In previous modeling efforts Purkinje-like structures have been developed through either automated or hand-drawn procedures, but these networks have been created according to general principles rather than based on real networks. To allow for greater realism in Purkinje structural models, we present a method for creating three-dimensional Purkinje networks based directly on imaging data. Our approach uses Purkinje network structures extracted from photographs of dissected ventricles and projects these flat networks onto realistic endocardial surfaces. Using this method, we create models for the combined ventricle-Purkinje system that can fully activate the ventricles through a stimulus delivered to the Purkinje network and can produce simulated activation sequences that match experimental observations. The combined models have the potential to help elucidate Purkinje network contributions during ventricular arrhythmias.

  8. Cardiac motion correction based on partial angle reconstructed images in x-ray CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seungeon; Chang, Yongjin; Ra, Jong Beom, E-mail: jbra@kaist.ac.kr [Department of Electrical Engineering, KAIST, Daejeon 305-701 (Korea, Republic of)

    2015-05-15

    Purpose: Cardiac x-ray CT imaging is still challenging due to heart motion, which cannot be ignored even with the current rotation speed of the equipment. In response, many algorithms have been developed to compensate remaining motion artifacts by estimating the motion using projection data or reconstructed images. In these algorithms, accurate motion estimation is critical to the compensated image quality. In addition, since the scan range is directly related to the radiation dose, it is preferable to minimize the scan range in motion estimation. In this paper, the authors propose a novel motion estimation and compensation algorithm using a sinogram with a rotation angle of less than 360°. The algorithm estimates the motion of the whole heart area using two opposite 3D partial angle reconstructed (PAR) images and compensates the motion in the reconstruction process. Methods: A CT system scans the thoracic area including the heart over an angular range of 180° + α + β, where α and β denote the detector fan angle and an additional partial angle, respectively. The obtained cone-beam projection data are converted into cone-parallel geometry via row-wise fan-to-parallel rebinning. Two conjugate 3D PAR images, whose center projection angles are separated by 180°, are then reconstructed with an angular range of β, which is considerably smaller than a short scan range of 180° + α. Although these images include limited view angle artifacts that disturb accurate motion estimation, they have considerably better temporal resolution than a short scan image. Hence, after preprocessing these artifacts, the authors estimate a motion model during a half rotation for a whole field of view via nonrigid registration between the images. Finally, motion-compensated image reconstruction is performed at a target phase by incorporating the estimated motion model. The target phase is selected as that corresponding to a view angle that is orthogonal to the center view angles of

  9. Cardiac and vascular imaging with labeled platelets and leukocytes

    International Nuclear Information System (INIS)

    The contribution of platelets in atherosclerosis and thrombosis in animal models and in clinical studies has been quantified with 111In-platelet scintigraphy. New in vitro quantitative techniques have been developed using 111In-labeled platelets to determine the number of adherent platelets on deendothelialized surfaces of damaged vessel walls and synthetic vascular grafts. In vivo imaging techniques are semi-quantitative in nature; in these studies 111In radioactivity on thrombotic vessels or graft surfaces of iliac, femoral, or popliteal arteries is compared with contralateral vessels. Background 111In radioactivity in the circulating blood pool of venous and capillary networks and radioactivity in marrow decreases the sensitivity of these techniques. Subtraction of blood pool radioactivity with 99mTc-labeled autologous red cells and calculation of 111In radioactivity associated with platelet thrombus on vessel walls also have been performed for coronary, carotid, and femoral arteries. Although platelet concentrates are used frequently after open heart surgery (one to six per patient), consumption of platelets in the artificial lung or oxygenator, lysis of platelets during pumping, and suction of blood only recently have been quantified with the use of 111In-labeled platelets. These studies also demonstrated far less trauma to platelets with the use of a membrane rather than a bubble oxygenator. Further reduction in platelet consumption and trauma was observed with the use of prostacyclin, a short-acting drug with significant beneficial effect on platelet thrombus reduction and disaggregation of aggregated platelets. The role of polymorphonuclear leukocytes in inflammation, infection and myocardial infarction, and in vivo evaluation with 111In-leukocyte scintigraphy in animals and humans has been described

  10. Reference Values for Cardiac and Aortic Magnetic Resonance Imaging in Healthy, Young Caucasian Adults

    Science.gov (United States)

    Eikendal, Anouk L. M.; Bots, Michiel L.; Haaring, Cees; Saam, Tobias; van der Geest, Rob J.; Westenberg, Jos J. M.; den Ruijter, Hester M.; Hoefer, Imo E.; Leiner, Tim

    2016-01-01

    Background Reference values for morphological and functional parameters of the cardiovascular system in early life are relevant since they may help to identify young adults who fall outside the physiological range of arterial and cardiac ageing. This study provides age and sex specific reference values for aortic wall characteristics, cardiac function parameters and aortic pulse wave velocity (PWV) in a population-based sample of healthy, young adults using magnetic resonance (MR) imaging. Materials and Methods In 131 randomly selected healthy, young adults aged between 25 and 35 years (mean age 31.8 years, 63 men) of the general-population based Atherosclerosis-Monitoring-and-Biomarker-measurements-In-The-YOuNg (AMBITYON) study, descending thoracic aortic dimensions and wall thickness, thoracic aortic PWV and cardiac function parameters were measured using a 3.0T MR-system. Age and sex specific reference values were generated using dedicated software. Differences in reference values between two age groups (25–30 and 30–35 years) and both sexes were tested. Results Aortic diameters and areas were higher in the older age group (all p<0.007). Moreover, aortic dimensions, left ventricular mass, left and right ventricular volumes and cardiac output were lower in women than in men (all p<0.001). For mean and maximum aortic wall thickness, left and right ejection fraction and aortic PWV we did not observe a significant age or sex effect. Conclusion This study provides age and sex specific reference values for cardiovascular MR parameters in healthy, young Caucasian adults. These may aid in MR guided pre-clinical identification of young adults who fall outside the physiological range of arterial and cardiac ageing. PMID:27732640

  11. Live dynamic imaging and analysis of developmental cardiac defects in mouse models with optical coherence tomography

    Science.gov (United States)

    Lopez, Andrew L.; Wang, Shang; Garcia, Monica; Valladolid, Christian; Larin, Kirill V.; Larina, Irina V.

    2015-03-01

    Understanding mouse embryonic development is an invaluable resource for our interpretation of normal human embryology and congenital defects. Our research focuses on developing methods for live imaging and dynamic characterization of early embryonic development in mouse models of human diseases. Using multidisciplinary methods: optical coherence tomography (OCT), live mouse embryo manipulations and static embryo culture, molecular biology, advanced image processing and computational modeling we aim to understand developmental processes. We have developed an OCT based approach to image live early mouse embryos (E8.5 - E9.5) cultured on an imaging stage and visualize developmental events with a spatial resolution of a few micrometers (less than the size of an individual cell) and a frame rate of up to hundreds of frames per second and reconstruct cardiodynamics in 4D (3D+time). We are now using these methods to study how specific embryonic lethal mutations affect cardiac morphology and function during early development.

  12. Specificity of the diffuse pattern of cardiac uptake in myocardial infarction imaging with technetium-99m stannous pyrophosphate

    International Nuclear Information System (INIS)

    To analyze the specificity of the diffuse pattern of cardiac uptake with technetium-99m stannous pyrophosphate (TcPYP), we evaluated the bone scans of 1,383 noncardiac patients and the myocardial scintigrams of 120 cardiac patients. Seventy (14.4 percent) of 483 bone scans performed on a scintillation camera revealed diffuse TcPYP cardiac uptake. Among the total 603 camera bone scans and myocardial scintigrams, the incidence of diffuse cardiac uptake was 16 percent among patients with clinical coronary disease but 13 percent among those patients without clinical symptoms. Discrete myocardial uptake was seen in 25 of 26 patients with transmural infarction. Femoral vasculature was more frequently visualized (84 percent vs 3 percent, P < 0.001) and left mastectomy occurred more often (30 percent vs 1 percent, P < 0.001) among patients with diffuse cardiac uptake than among patients with negative images, indicating possible blood pool imaging. The diffuse pattern of cardiac uptake appeared nonspecific and may be due to unintentional cardiac blood pool imaging

  13. Value of cardiac 320-multidetector computed tomography and cardiac magnetic resonance imaging for assessment of myocardial perfusion defects in patients with known chronic ischemic heart disease

    DEFF Research Database (Denmark)

    Qayyum, Abbas Ali; Kühl, Jørgen T; Mathiasen, Anders B;

    2013-01-01

    The challenge for therapies targeting perfusion abnormalities is to identify and evaluate the region of interest. The aim of this study was to compare rest and stress myocardial perfusion measured by cardiac multi-detector computed tomography (MDCT) and cardiac magnetic resonance (CMR) imaging...... in patients with invasive coronary angiography demonstrated occluded vessels. Twenty-four patients with refractory angina due to occluded coronary arteries underwent perfusion imaging obtained by 320-MDCT scanner and 1.5 T MR scanner. Rest and adenosine stress images were obtained and interpreted using......) or 1 (abnormal). The summed rest and stress scores were calculated. MDCT and CMR had a high probability to identify perfusion defects. An excellent correlation between MDCT and CMR summed rest (r = 0.916) and stress scores (r = 0.915) was found. The interobserver reproducibility was high for MDCT...

  14. Improving Low-dose Cardiac CT Images based on 3D Sparse Representation

    Science.gov (United States)

    Shi, Luyao; Hu, Yining; Chen, Yang; Yin, Xindao; Shu, Huazhong; Luo, Limin; Coatrieux, Jean-Louis

    2016-03-01

    Cardiac computed tomography (CCT) is a reliable and accurate tool for diagnosis of coronary artery diseases and is also frequently used in surgery guidance. Low-dose scans should be considered in order to alleviate the harm to patients caused by X-ray radiation. However, low dose CT (LDCT) images tend to be degraded by quantum noise and streak artifacts. In order to improve the cardiac LDCT image quality, a 3D sparse representation-based processing (3D SR) is proposed by exploiting the sparsity and regularity of 3D anatomical features in CCT. The proposed method was evaluated by a clinical study of 14 patients. The performance of the proposed method was compared to the 2D spares representation-based processing (2D SR) and the state-of-the-art noise reduction algorithm BM4D. The visual assessment, quantitative assessment and qualitative assessment results show that the proposed approach can lead to effective noise/artifact suppression and detail preservation. Compared to the other two tested methods, 3D SR method can obtain results with image quality most close to the reference standard dose CT (SDCT) images.

  15. A framework of whole heart extracellular volume fraction estimation for low dose cardiac CT images

    Science.gov (United States)

    Chen, Xinjian; Summers, Ronald M.; Nacif, Marcelo Souto; Liu, Songtao; Bluemke, David A.; Yao, Jianhua

    2012-02-01

    Cardiac magnetic resonance imaging (CMRI) has been well validated and allows quantification of myocardial fibrosis in comparison to overall mass of the myocardium. Unfortunately, CMRI is relatively expensive and is contraindicated in patients with intracardiac devices. Cardiac CT (CCT) is widely available and has been validated for detection of scar and myocardial stress/rest perfusion. In this paper, we sought to evaluate the potential of low dose CCT for the measurement of myocardial whole heart extracellular volume (ECV) fraction. A novel framework was proposed for CCT whole heart ECV estimation, which consists of three main steps. First, a shape constrained graph cut (GC) method was proposed for myocardium and blood pool segmentation for post-contrast image. Second, the symmetric Demons deformable registrations method was applied to register pre-contrast to post-contrast images. Finally, the whole heart ECV value was computed. The proposed method was tested on 7 clinical low dose CCT datasets with pre-contrast and post-contrast images. The preliminary results demonstrated the feasibility and efficiency of the proposed method.

  16. Model-based imaging of cardiac electrical function in human atria

    Science.gov (United States)

    Modre, Robert; Tilg, Bernhard; Fischer, Gerald; Hanser, Friedrich; Messnarz, Bernd; Schocke, Michael F. H.; Kremser, Christian; Hintringer, Florian; Roithinger, Franz

    2003-05-01

    Noninvasive imaging of electrical function in the human atria is attained by the combination of data from electrocardiographic (ECG) mapping and magnetic resonance imaging (MRI). An anatomical computer model of the individual patient is the basis for our computer-aided diagnosis of cardiac arrhythmias. Three patients suffering from Wolff-Parkinson-White syndrome, from paroxymal atrial fibrillation, and from atrial flutter underwent an electrophysiological study. After successful treatment of the cardiac arrhythmia with invasive catheter technique, pacing protocols with stimuli at several anatomical sites (coronary sinus, left and right pulmonary vein, posterior site of the right atrium, right atrial appendage) were performed. Reconstructed activation time (AT) maps were validated with catheter-based electroanatomical data, with invasively determined pacing sites, and with pacing at anatomical markers. The individual complex anatomical model of the atria of each patient in combination with a high-quality mesh optimization enables accurate AT imaging, resulting in a localization error for the estimated pacing sites within 1 cm. Our findings may have implications for imaging of atrial activity in patients with focal arrhythmias.

  17. Three-dimensional Content-Based Cardiac Image Retrieval using global and local descriptors.

    Science.gov (United States)

    Bergamasco, Leila C C; Nunes, Fátima L S

    2015-01-01

    The increase in volume of medical images generated and stored has created difficulties in accurate image retrieval. An alternative is to generate three-dimensional (3D) models from such medical images and use them in the search. Some of the main cardiac illnesses, such as Congestive Heart Failure (CHF), have deformation in the heart's shape as one of the main symptoms, which can be identified faster in a 3D object than in slices. This article presents techniques developed to retrieve 3D cardiac models using global and local descriptors within a content-based image retrieval system. These techniques were applied in pre-classified 3D models with and without the CHF disease and they were evaluated by using Precision vs. Recall metric. We observed that local descriptors achieved better results than a global descriptor, reaching 85% of accuracy. The results confirmed the potential of using 3D models retrieval in the medical context to aid in the diagnosis. PMID:26958280

  18. Dual-source cardiac computed tomography angiography (CCTA) in the follow-up of cardiac transplant: comparison of image quality and radiation dose using three different imaging protocols

    Energy Technology Data Exchange (ETDEWEB)

    Beitzke, D.; Berger-Kulemann, V.; Unterhumer, S.; Loewe, C.; Wolf, F. [Medical University Vienna, Department of Biomedical Imaging and Image Guided Therapy, Division of Cardiovascular and Interventional Radiology, Vienna (Austria); Schoepf, V. [Medical University Vienna, Department of Biomedical Imaging and Image Guided Therapy, Division of Neuroradiology and Musculoskeletal Radiology, Vienna (Austria); Spitzer, E. [Bern University Hospital, Department of Cardiology, Bern (Switzerland); Feuchtner, G.M. [Innsbruck Medical University, Department of Radiology II, Innsbruck (Austria); Gyoengyoesi, M. [Medical University Vienna, Department of Cardiology, Vienna (Austria); Uyanik-Uenal, K.; Zuckermann, A. [Medical University Vienna, Department of Cardiac Surgery, Vienna (Austria)

    2015-08-15

    To prospectively evaluate image quality (IQ) and radiation dose of dual-source cardiac computed tomography (CCTA) using different imaging protocols. CCTA was performed in 150 patients using the retrospective ECG-gated spiral technique (rECG) the prospective ECG-gated technique (pECG), or the prospective ECG-gated technique with systolic imaging and automated tube voltage selection (pECGsys). IQ was rated using a 16-segment coronary artery model. Techniques were compared for overall IQ, IQ of the large and the small coronary artery segments. Effective dose was used for comparison of radiation dose. Overall IQ and IQ of the large segments showed no differences between the groups. IQ analysis of the small segments showed lowered IQ in pECGsys compared to rECG (p = 0.02), but not to pECG (p = 0.6). Effective dose did not differ significantly between rECG and pECG (p = 0.13), but was significantly lower for pECGsys (p < 0.001 vs. rECG and pECG). Radiation dose of dual-source CCTA in heart transplant recipients is significantly reduced by using prospective systolic scanning and automated tube voltage selection, while overall IQ and IQ of the large coronary segments are maintained. IQ appears to be lower compared to retrospective techniques with regard to small coronary segments. (orig.)

  19. Dual-source cardiac computed tomography angiography (CCTA) in the follow-up of cardiac transplant: comparison of image quality and radiation dose using three different imaging protocols

    International Nuclear Information System (INIS)

    To prospectively evaluate image quality (IQ) and radiation dose of dual-source cardiac computed tomography (CCTA) using different imaging protocols. CCTA was performed in 150 patients using the retrospective ECG-gated spiral technique (rECG) the prospective ECG-gated technique (pECG), or the prospective ECG-gated technique with systolic imaging and automated tube voltage selection (pECGsys). IQ was rated using a 16-segment coronary artery model. Techniques were compared for overall IQ, IQ of the large and the small coronary artery segments. Effective dose was used for comparison of radiation dose. Overall IQ and IQ of the large segments showed no differences between the groups. IQ analysis of the small segments showed lowered IQ in pECGsys compared to rECG (p = 0.02), but not to pECG (p = 0.6). Effective dose did not differ significantly between rECG and pECG (p = 0.13), but was significantly lower for pECGsys (p < 0.001 vs. rECG and pECG). Radiation dose of dual-source CCTA in heart transplant recipients is significantly reduced by using prospective systolic scanning and automated tube voltage selection, while overall IQ and IQ of the large coronary segments are maintained. IQ appears to be lower compared to retrospective techniques with regard to small coronary segments. (orig.)

  20. Measuring and mapping cardiac fiber and laminar architecture using diffusion tensor MR imaging.

    Science.gov (United States)

    Helm, Patrick; Beg, Mirza Faisal; Miller, Michael I; Winslow, Raimond L

    2005-06-01

    The ventricular myocardium is known to exhibit a complex spatial organization, with fiber orientation varying as a function of transmural location. It is now well established that diffusion tensor magnetic resonance imaging (DTMRI) may be used to measure this fiber orientation at high spatial resolution. Cardiac fibers are also known to be organized in sheets with surface orientation varying throughout the ventricles. This article reviews results on use of DTMRI for measuring ventricular fiber orientation, as well as presents new results providing strong evidence that the tertiary eigenvector of the diffusion tensor is aligned locally with the cardiac sheet surface normal. Considered together, these data indicate that DTMRI may be used to reconstruct both ventricular fiber and sheet organization. This article also presents the large deformation diffeomorphic metric mapping (LDDMM) algorithm and shows that this algorithm may be used to bring ensembles of imaged and reconstructed hearts into correspondence (e.g., registration) so that variability of ventricular geometry, fiber, and sheet orientation may be quantified. Ventricular geometry and fiber structure is known to be remodeled in a range of disease processes; however, descriptions of this remodeling have remained subjective and qualitative. We anticipate that use of DTMRI for reconstruction of ventricular anatomy coupled with application of the LDDMM method for image volume registration will enable the detection and quantification of changes in cardiac anatomy that are characteristic of specific disease processes in the heart. Finally, we show that epicardial electrical mapping and DTMRI imaging may be performed in the same hearts. The anatomic data may then be used to simulate electrical conduction in a computational model of the very same heart that was mapped electrically. This facilitates direct comparison and testing of model versus experimental results and opens the door to quantitative measurement

  1. Prevention of Cardiomyopathy in Transfusion-Dependent Homozygous Thalassaemia Today and the Role of Cardiac Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Athanassios Aessopos

    2009-01-01

    Full Text Available Transfusion and iron chelation therapy revolutionised survival and reduced morbidity in patients with transfusion-dependent beta thalassaemia major. Despite these improvements, cardiac disease remained the most common cause of death in those patients. Recently the ability to determine the degree of cardiac iron overload, through cardiac magnetic resonance imaging (CMR has allowed more logical approaches to iron removal, particularly from the heart. The availability of two oral chelators, deferiprone and deferasirox has reduced the need for the injectable chelator deferrioxamine and an additional benefit has been that deferiprone has been shown to be more cardioprotective than deferrioxamine. This review on the prevention of cardiac disease makes recommendations on the chelation regime that would be desirable for patients according to their cardiac iron status as determined by CMR determined by CMR. It also discusses approaches to chelation management should CMR not be available.

  2. Imaging cardiac amyloidosis: a pilot study using {sup 18}F-florbetapir positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Dorbala, Sharmila [Brigham and Women' s Hospital, Harvard Medical School, Noninvasive Cardiovascular Imaging Program, Heart and Vascular Center, Departments of Radiology and Medicine (Cardiology), Boston, MA (United States); Brigham and Women' s Hospital, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); Brigham and Women' s Hospital, Harvard Medical School, Cardiovascular Division and the Cardiac Amyloidosis Program, Department of Medicine, Boston, MA (United States); Brigham and Women' s Hospital, Boston, MA (United States); Vangala, Divya; Semer, James; Strader, Christopher; Bruyere, John R.; Moore, Stephen C. [Brigham and Women' s Hospital, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); Brigham and Women' s Hospital, Boston, MA (United States); Di Carli, Marcelo F. [Brigham and Women' s Hospital, Harvard Medical School, Noninvasive Cardiovascular Imaging Program, Heart and Vascular Center, Departments of Radiology and Medicine (Cardiology), Boston, MA (United States); Brigham and Women' s Hospital, Harvard Medical School, Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Boston, MA (United States); Brigham and Women' s Hospital, Boston, MA (United States); Falk, Rodney H. [Brigham and Women' s Hospital, Harvard Medical School, Cardiovascular Division and the Cardiac Amyloidosis Program, Department of Medicine, Boston, MA (United States); Brigham and Women' s Hospital, Boston, MA (United States)

    2014-09-15

    Cardiac amyloidosis, a restrictive heart disease with high mortality and morbidity, is underdiagnosed due to limited targeted diagnostic imaging. The primary aim of this study was to evaluate the utility of {sup 18}F-florbetapir for imaging cardiac amyloidosis. We performed a pilot study of cardiac {sup 18}F-florbetapir PET in 14 subjects: 5 control subjects without amyloidosis and 9 subjects with documented cardiac amyloidosis. Standardized uptake values (SUV) of {sup 18}F-florbetapir in the left ventricular (LV) myocardium, blood pool, liver, and vertebral bone were determined. A {sup 18}F-florbetapir retention index (RI) was computed. Mean LV myocardial SUVs, target-to-background ratio (TBR, myocardial/blood pool SUV ratio) and myocardial-to-liver SUV ratio between 0 and 30 min were calculated. Left and right ventricular myocardial uptake of {sup 18}F-florbetapir were noted in all the amyloid subjects and in none of the control subjects. The RI, TBR, LV myocardial SUV and LV myocardial to liver SUV ratio were all significantly higher in the amyloidosis subjects than in the control subjects (RI median 0.043 min{sup -1}, IQR 0.034 - 0.051 min{sup -1}, vs. 0.023 min{sup -1}, IQR 0.015 - 0.025 min{sup -1}, P = 0.002; TBR 1.84, 1.64 - 2.50, vs. 1.26, IQR 0.91 - 1.36, P = 0.001; LV myocardial SUV 3.84, IQR 1.87 - 5.65, vs. 1.35, IQR 1.17 - 2.28, P = 0.029; ratio of LV myocardial to liver SUV 0.67, IQR 0.44 - 1.64, vs. 0.18, IQR 0.15 - 0.35, P = 0.004). The myocardial RI, TBR and myocardial to liver SUV ratio also distinguished the control subjects from subjects with transthyretin and those with light chain amyloid. {sup 18}F-Florbetapir PET may be a promising technique to image light chain and transthyretin cardiac amyloidosis. Its role in diagnosing amyloid in other organ systems and in assessing response to therapy needs to be further studied. (orig.)

  3. Diminishing the impact of the partial volume effect in cardiac SPECT perfusion imaging.

    Science.gov (United States)

    Pretorius, P Hendrik; King, Michael A

    2009-01-01

    The partial volume effect (PVE) significantly restricts the absolute quantification of regional myocardial uptake and thereby limits the accuracy of absolute measurement of blood flow and coronary flow reserve by SPECT. The template-projection-reconstruction method has been previously developed for PVE compensation. This method assumes the availability of coregistered high-spatial resolution anatomical information as is now becoming available with commercial dual-modality imaging systems such as SPECT/CTs. The objective of this investigation was to determine the extent to which the impact of the PVE on cardiac perfusion SPECT imaging can be diminished if coregistered high-spatial resolution anatomical information is available. For this investigation the authors introduced an additional parameter into the template-projection-reconstruction compensation equation called the voxel filling fraction (F). This parameter specifies the extent to which structure edge voxels in the emission reconstruction are filled by the structure in question as determined by the higher spatial-resolution imaging modality and the fractional presence of the structure at different states of physiological motion as in combining phases of cardiac motion. During correction the removal of spillover to the cardiac region from the surrounding structures is performed first by using reconstructed templates of neighboring structures (liver, blood pool, lungs) to calculate spillover fractions. This is followed by determining recovery coefficients for all voxels within the heart wall from the reconstruction of the template projections of the left and right ventricles (LV and RV). The emission data are subsequently divided by these recovery coefficients taking into account the filling fraction F. The mathematical cardiac torso phantom was used for investigation correction of PVE for a normal LV distribution, a defect in the inferior wall, and a defect in the anterior wall. PVE correction resulted in a

  4. Nucleation in an ultra low ionisation environment

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker

    the measurements to ionisation levels approximately 3 order of magnitudes lower than any earlier study. Getting this close to zero ionisation allows us to distinguish between the neutral and charged contribution better than previously. The effect is explored over a range of sulphuric acid concentrations.......In this work we have studied aerosol formation at ultra-low ionisation levels, using the existing deep underground science facility at Boulby mine, UK. At 1100 m depth, with a corresponding factor 106 reduction in cosmic ray muon flux, the Boulby facility is an ideal place to study the role of ions...

  5. Cardiac MRI in Athletes

    NARCIS (Netherlands)

    Luijkx, T.

    2012-01-01

    Cardiac magnetic resonance imaging (CMR) is often used in athletes to image cardiac anatomy and function and is increasingly requested in the context of screening for pathology that can cause sudden cardiac death (SCD). In this thesis, patterns of cardiac adaptation to sports are investigated with C

  6. Multichannel receiver coils for improved coverage in cardiac metabolic imaging using prepolarized 13C substrates.

    Science.gov (United States)

    Dominguez-Viqueira, William; Lau, Angus Z; Chen, Albert P; Cunningham, Charles H

    2013-07-01

    MR imaging using hyperpolarized (13)C substrates has become a promising tool to study real-time cardiac-metabolism in vivo. For such fast imaging of nonrecoverable prepolarized magnetization it is important to optimize the RF-coils to obtain the best signal-to-noise ratio possible, given the required coverage. In this work, three different receiver-coil configurations were computed in pig and human models. The sensitivity maps were demonstrated in phantoms and in vivo experiments performed in pigs. Signal-to-noise ratio in the posterior heart was increased up to 80% with the best multichannel coil as expected. These new coil configurations will allow imaging of the different metabolite signals even in the posterior regions of the myocardium, which is not possible with a single-channel surface-coil. PMID:22907595

  7. Important advances in technology and unique applications related to cardiac magnetic resonance imaging.

    Science.gov (United States)

    Ghosn, Mohamad G; Shah, Dipan J

    2014-01-01

    Cardiac magnetic resonance has become a well-established imaging modality and is considered the gold standard for myocardial tissue viability assessment and ventricular volumes quantification. Recent technological hardware and software advancements in magnetic resonance imaging technology have allowed the development of new methods that can improve clinical cardiovascular diagnosis and prognosis. The advent of a new generation of higher magnetic field scanners can be beneficial to various clinical applications. Also, the development of faster acquisition techniques have allowed mapping of the magnetic relaxation properties T1, T2, and T2* in the myocardium that can be used to quantify myocardial diffuse fibrosis, determine the presence of edema or inflammation, and measure iron within the myocardium, respectively. Another recent major advancement in CMR has been the introduction of three-dimension (3D) phase contrast imaging, also known as 4D flow. The following review discusses key advances in cardiac magnetic resonance technology and their potential to improve clinical cardiovascular diagnosis and outcomes.

  8. Paediatric cardiac computed tomography: a review of imaging techniques and radiation dose consideration

    Energy Technology Data Exchange (ETDEWEB)

    Young, Carolyn; Taylor, Andrew M. [UCL, Institute of Child Health, Cardiorespiratory Unit, London (United Kingdom); Great Ormond Street Hospital for Children, Cardiorespiratory Unit, London (United Kingdom); Owens, Catherine M. [UCL, Institute of Child Health, Cardiorespiratory Unit, London (United Kingdom)

    2011-03-15

    The significant challenges involved in imaging the heart in small children (<15 kg) have been addressed by, and partially resolved with improvement in temporal and spatial resolution secondary to the advent of new multi-detector CT technology. This has enabled both retrospective and prospective ECG-gated imaging in children even at high heart rates (over 100 bpm) without the need for beta blockers. Recent studies have highlighted that the radiation burden associated with cardiac CT can be reduced using prospective ECG-gating. Our experience shows that the resultant dose reduction can be optimised to a level equivalent to that of a non-gated study. This article reviews the different aspects of ECG-gating and the preferred technique for cardiac imaging in the young child (<15 kg). We summarize our evidenced based recommendations for readers, referencing recent articles and using our in house data, protocols and dose measurements discussing the various methods available for dose calculations and their inherent bias. (orig.)

  9. X-ray and magnetic resonance imaging fusion for cardiac resynchronization therapy.

    Science.gov (United States)

    Choi, Jinwoo; Radau, Perry; Xu, Robert; Wright, Graham A

    2016-07-01

    Cardiac Resynchronization Therapy (CRT) can effectively treat left ventricle (LV) driven Heart Failure (HF). However, 30% of the CRT recipients do not experience symptomatic benefit. Recent studies show that the CRT response rate can reach 95% when the LV pacing lead is placed at an optimal site at a region of maximal LV dyssynchrony and away from myocardial scars. Cardiac Magnetic Resonance (CMR) can identify the optimal site in three dimensions (3D). 3D CMR data can be registered to clinical standard x-ray fluoroscopy to achieve an optimal pacing of the LV. We have developed a 3D CMR to 2D x-ray image registration method for CRT procedures. We have employed the LV pacing lead on x-ray images and coronary sinus on MR data as landmarks. The registration method makes use of a guidewire simulation algorithm, edge based image registration technique and x-ray C-arm tracking to register the coronary sinus and pacing lead landmarks. PMID:27025953

  10. Ventricular function following coronary artery bypass grafting: comparison between Gated SPECT and cardiac magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Claudio Tinoco [Hospital Pro-Cardiaco, Rio de Janeiro, RJ (Brazil). Servico de Medicina Nuclear; Instituto Nacional de Cardiologia, Rio de Janeiro, RJ (Brazil); Pessoa, Maria Carolina Pinheiro [Pro-Echo Hospital Samaritano, Rio de Janeiro, RJ (Brazil); Vasconcelos, Paulo Pontes [Centro de Diagnostico por Imagens (CDPI), Rio de Janeiro, RJ (Brazil); Oliveira Junior, Amarino Carvalho [Hospital Pro-Cardiaco, Rio de Janeiro, RJ (Brazil). Servico de Radiologia; Dohmann, Hans Fernando Rocha [Hospital Pro-Cardiaco, Rio de Janeiro, RJ (Brazil). Servico de Radiologia; Instituto Nacional de Cardiologia, Rio de Janeiro, RJ (Brazil); Reis, Adair Gomes dos [Nuclear Diagnosticos, SP (Brazil); Fonseca, Lea Mirian Barbosa da [Pro-Echo Hospital Samaritano, Rio de Janeiro, RJ (Brazil); Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

    2009-04-15

    Background: The assessment of left ventricular function may be impaired by the abnormal interventricular septal motion frequently found after coronary artery bypass grafting (CABG). Studies on the validation of gated SPECT as a tool for the assessment of left ventricular function in this patient group are scarce. Objective: We investigated the agreement and correlation between left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), and end-systolic volume (ESV) as obtained using electrocardiogram-gated myocardial perfusion scintigraphy (gated SPECT) and cardiac magnetic resonance imaging in 20 patients undergoing coronary artery bypass grafting. Methods: Correlation was measured using Spearman's correlation coefficient ({rho}). Agreement was assessed using Bland-Altman analysis. Results: A good correlation was found between gated SPECT and cardiac magnetic resonance imaging in patients after CABG with regard to left ventricular ejection fraction ({rho} = 0.85; p =0.0001), moderate correlation for end-diastolic volume ({rho} = 0.51; p = 0.02), and non-significant correlation for end-diastolic volume ({rho} = 0.13; p = 0.5). Agreement ranges for LVEF, ESV and EDV were: -20% to 12%; -38 to 54 ml and; -96 to 100 ml, respectively. Conclusion: A reliable correlation was found for left ventricular ejection fraction as obtained by gated SPECT and magnetic resonance imaging in patients undergoing CABG. For ventricular volumes, however, the correlation is not adequate. (author)

  11. Image-Based Personalization of Cardiac Anatomy for Coupled Electromechanical Modeling.

    Science.gov (United States)

    Crozier, A; Augustin, C M; Neic, A; Prassl, A J; Holler, M; Fastl, T E; Hennemuth, A; Bredies, K; Kuehne, T; Bishop, M J; Niederer, S A; Plank, G

    2016-01-01

    Computational models of cardiac electromechanics (EM) are increasingly being applied to clinical problems, with patient-specific models being generated from high fidelity imaging and used to simulate patient physiology, pathophysiology and response to treatment. Current structured meshes are limited in their ability to fully represent the detailed anatomical data available from clinical images and capture complex and varied anatomy with limited geometric accuracy. In this paper, we review the state of the art in image-based personalization of cardiac anatomy for biophysically detailed, strongly coupled EM modeling, and present our own tools for the automatic building of anatomically and structurally accurate patient-specific models. Our method relies on using high resolution unstructured meshes for discretizing both physics, electrophysiology and mechanics, in combination with efficient, strongly scalable solvers necessary to deal with the computational load imposed by the large number of degrees of freedom of these meshes. These tools permit automated anatomical model generation and strongly coupled EM simulations at an unprecedented level of anatomical and biophysical detail. PMID:26424476

  12. Cine magnetic resonance imaging for evaluation of cardiac structure and flow dynamics in congenital heart disease

    International Nuclear Information System (INIS)

    Cine magnetic resonance imaging (Cine MRI) was performed in 20 patients aged 19 days to 13 years (mean 4.0 years), who had congenital heart disease confirmed at echocardiography or angiography. Prior to cine MRI, gated MRI was performed to evaluate for cardiac structure. Cine MRI was demonstrated by fast low fip angle shot imaging technique with a 30deg flip angle, 15 msec echo time, 30-40 msec pulse repetition time, and 128 x 128 acquisition matrix. Abnormalities of cardiac structure were extremely well defined in all patients by gated MRI. Intracardiac or intravascular blood flow were visualized in 17 (85%) of 20 patients by cine MRI. Left to right shunt flow through ventricular septal defect, atrial septal defect, and endocardial cushion defect were visualized with low signal intensity area. Low intensity jets flow through the site of re-coarctation of the aorta were also visualized. However, the good recording of cine MRI was not obtained because of artifacts in 3 of 20 patients (15%) who had severe congestive heart failure or respiratory arrhythmia. Gated MRI provides excellent visualization of fine structure, and cine MRI can provide high spatial resolution imaging of flow dynamic in a variety of congenital heart disease, noninvasively. (author)

  13. Improved myocardial strain measured by strain-encoded magnetic resonance imaging in a patient with cardiac sarcoidosis.

    Science.gov (United States)

    Nakano, Shintaro; Kimura, Fumiko; Osman, Nael; Sugi, Keiki; Tanno, Jun; Uchida, Yoshitaka; Shiono, Ayako; Senbonmatsu, Takaaki; Nishimura, Shigeyuki

    2013-11-01

    A woman aged 64 years with cardiac sarcoidosis responded favourably to corticosteroid therapy in terms of recovered longitudinal myocardial strain, as evaluated by strain-encoded magnetic resonance imaging (SENC-MRI). In contrast, circumferential myocardial strain and late gadolinium enhancement demonstrated minimal improvement, suggesting relatively advanced pathology of the myocardial middle layer. We propose SENC-MRI as a marker of disease at an early stage of cardiac sarcoidosis.

  14. Induced apnea enhances image quality and visualization of cardiopulmonary anatomic during contrastenhanced cardiac computerized tomographic angiography in children

    OpenAIRE

    Murali Chakravarthy; Gubbihalli Sunilkumar; Sumant Pargaonkar; Rajathadri Hosur; Chidananda Harivelam; Deepak Kavaraganahalli; Pradeep Srinivasan

    2015-01-01

    Objective: The purpose of our study was to determine the effect of induced apnea on quality of cardiopulmonary structures during computerized tomographic (CT) angiography images in children with congenital heart diseases. Methods: Pediatric patients with congenital heart defects undergoing cardiac CT angiography at our facility in the past 3 years participated in this study. The earlier patients underwent cardiac CT angiography without induced apnea and while, later, apnea was induced in pati...

  15. Comparison of simultaneous and sequential SPECT imaging for discrimination tasks in assessment of cardiac defects

    OpenAIRE

    Trott, CM; Ouyang, J.; El Fakhri, G

    2010-01-01

    Simultaneous rest perfusion/fatty-acid metabolism studies have the potential to replace sequential rest/stress perfusion studies for the assessment of cardiac function. Simultaneous acquisition has the benefits of increased signal and lack of need for patient stress, but is complicated by cross-talk between the two radionuclide signals. We consider a simultaneous rest 99mTc-sestamibi/123I-BMIPP imaging protocol in place of the commonly-used sequential rest/stress 99mTc-sestamibi protocol. The...

  16. Automatic delineation of myocardial contours in late-enhancement long-axis cardiac MR images

    OpenAIRE

    Breeuwer Marcel; Hautvast Gilion; Fradkin Maxim; Ciofolo Cybele

    2009-01-01

    The authors would like to thank the editor, BioMed Central, for the open access to the publication International audience We propose a novel method to delineate the endo- and epicardial contours in late-enhancement long-axis cardiac MR images with a minimal user-input in order to provide an accurate quantitative viability assessment. The electronic version of this abstract is the complete one and can be found online at: http://jcmr-online.com/content/11/S1/P72

  17. Hybrid cardiac imaging: Insights in the dilemma of the appropriate clinical management of patients with suspected coronary artery disease

    International Nuclear Information System (INIS)

    Aim: To evaluate the potential of SPECT myocardial perfusion imaging (MPI)–computed tomography coronary angiography (CTCA) hybrid fusion imaging to improve the diagnostic performance of cardiac SPECT/MPI and CTCA alone in order to act as more accurate gate keeper to further investigation invasive or not. Methods and results: Twenty-five patients were subjected to SPECT/MPI and CTCA within a period of 1 month without any medical treatment modification. A fusion software package was used for cardiac SPECT–CTCA image fusion. Semiquantitative analysis was performed for cardiac SPECT, CTCA and SPECT/MPI–CTCA fusion images. Patients were classified in 2 groups according to the clinical decision for further investigation (group A), or not (group B). Statistically significant differences were observed when SPECT/MPI–CTCA fusion images were used instead of cardiac SPECT alone (p < 0.05). No statistically significant differences were observed comparing CTCA alone to SPECT/MPI–CTCA fusion images (p = 0.25). A mid-term follow-up (mean 3.58 ± 0.24 years) showed that all patients classified in group A based on the interpretation of SPECT MPI–CTCA fused images underwent conventional coronary angiography with further necessity for PTCA or CABG whereas absence of major or minor cardiac events was revealed for all patients of group B. Conclusion: In patients suspected for coronary artery disease, cardiac SPECT/MPI–CTCA fusion imaging was found to considerably alter the clinical decision for referral to further investigation derived from SPECT/MPI

  18. Cardiac MR imaging in arrhythmogenic heart diseases; Kardiale MRT in der Diagnostik arrhythmogener Herzerkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, C.K.; Dinter, D.J.; Diehl, S.J.; Neff, K.W. [Universitaetsklinikum Mannheim, Institut fuer Klinische Radiologie, Mannheim (Germany); Papavassiliu, T.; Borggrefe, M. [Universitaetsklinikum Mannheim, Medizinische Klinik, Mannheim (Germany)

    2007-04-15

    Cardiac arrhythmias are assessed with a combination of history, clinical examination, electrocardiogram, Holter monitor, if necessary supplemented by invasive cardiac electrophysiology. In ischemic heart disease (IHD) coronary angiography is performed in addition. Echocardiography is usually the primary imaging modality. MRI is increasingly recognized as an important investigation allowing more accurate cardiac morphological and functional assessment. Approximately one-fifth of deaths in Western countries are due to sudden cardiac death, 80% of which are caused by arrhythmias. Typical causes range from diseases with high prevalence (IHD in men 30%) to myocarditis (prevalence 1-9%) and rare cardiomyopathies (prevalence HCM 0.2%, ARVC 0.02%, Brugada syndrome approx. 0.5%). The characteristic MRI features of arrhythmogenic diseases and the new aspects of characteristic distribution of late enhancement allow etiologic classification and differential diagnosis. MRI represents an important tool for detection of the underlying cause and for risk stratification in many diseases associated with arrhythmias. (orig.) [German] Herzrhythmusstoerungen werden durch die Zusammenschau von Anamnese, klinischer Untersuchung, Elektrokardiogramm, Langzeit-EKG sowie ggf. einer invasiven elektrophysiologischen Untersuchung beurteilt. Bei der koronaren Herzerkrankung (KHK) erfolgt zusaetzlich eine Koronarangiographie. Die Echokardiographie stellt das primaere bildgebende Verfahren dar. Die MRT des Herzens ermoeglicht eine genauere morphologische und funktionelle Darstellung des Herzens und gewinnt damit zunehmend an Bedeutung. Etwa jeder 5. Todesfall in westlichen Industriestaaten ist auf einen ploetzlichen Herztod zurueckzufuehren, davon sind ca. 80% durch Herzrhythmusstoerungen verursacht. Typische Ursachen reichen von Krankheiten mit hoher Praevalenz (KHK bei Maennern 30%) ueber Myokarditiden (Praevalenz 1-9%) bis zu selteneren Kardiomyopathien (Praevalenz HCM 0,2%, ARVC 0,02%, Brugada

  19. Non-contact detection of cardiac rate based on visible light imaging device

    Science.gov (United States)

    Zhu, Huishi; Zhao, Yuejin; Dong, Liquan

    2012-10-01

    We have developed a non-contact method to detect human cardiac rate at a distance. This detection is based on the general lighting condition. Using the video signal of human face region captured by webcam, we acquire the cardiac rate based on the PhotoPlethysmoGraphy theory. In this paper, the cardiac rate detecting method is mainly in view of the blood's different absorptivities of the lights various wavelengths. Firstly, we discompose the video signal into RGB three color signal channels and choose the face region as region of interest to take average gray value. Then, we draw three gray-mean curves on each color channel with time as variable. When the imaging device has good fidelity of color, the green channel signal shows the PhotoPlethysmoGraphy information most clearly. But the red and blue channel signals can provide more other physiological information on the account of their light absorptive characteristics of blood. We divide red channel signal by green channel signal to acquire the pulse wave. With the passband from 0.67Hz to 3Hz as a filter of the pulse wave signal and the frequency spectrum superimposed algorithm, we design frequency extracted algorithm to achieve the cardiac rate. Finally, we experiment with 30 volunteers, containing different genders and different ages. The results of the experiments are all relatively agreeable. The difference is about 2bmp. Through the experiment, we deduce that the PhotoPlethysmoGraphy theory based on visible light can also be used to detect other physiological information.

  20. Evaluation of cardiac dyssynchrony with longitudinal strain analysis in 4-chamber cine MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kawakubo, Masateru, E-mail: masateru@med.kyushu-u.ac.jp [Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Nagao, Michinobu, E-mail: minagao@radiol.med.kyushu-u.ac.jp [Department of Molecular Imaging and Diagnosis, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Kumazawa, Seiji, E-mail: s_kmzw@hs.med.kyushu-u.ac.jp [Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Chishaki, Akiko S., E-mail: chishaki@hs.med.kyushu-u.ac.jp [Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Mukai, Yasushi, E-mail: y_mukai@cardiol.med.kyushu-u.ac.jp [Department of Cardiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Nakamura, Yasuhiko, E-mail: yas-nkmr@r-tec.med.kyushu-u.ac.jp [Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Honda, Hiroshi, E-mail: honda@radiol.med.kyushu-u.ac.jp [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan); Morishita, Junji, E-mail: junjim@med.kyushu-u.ac.jp [Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-Ku Fukuoka-city, Fukuoka 812-8582 (Japan)

    2013-12-01

    Purpose: We investigated the clinical performance of evaluation of cardiac mechanical dyssynchrony with longitudinal strain analysis using four-chamber (4CH) cine magnetic resonance imaging (MRI). Materials and methods: We retrospectively enrolled 73 chronic heart failure patients (41 men, 32 women; mean age, 57 years, NYHA 2, 3, and 4) who underwent a cardiac MRI in the present study. The left ventricular dyssynchrony (LVD) and interventricular dyssynchrony (IVD) indices were calculated by longitudinal strain analysis using 4CH cine MRI. The LVD and IVD indices were compared by the Wilcoxon rank-sum test between the patients with indication for cardiac resynchronization therapy (CRT) (n = 13) and without indication for CRT (n = 60), with LGE (n = 40) and without LGE (n = 27), the CRT responders (n = 8) and non-responders (n = 6), respectively. Results: LVD in the patients with indication for CRT were significantly longer than those without indication for CRT (LVD: 92 ± 65 vs. 28 ± 40 ms, P < .01). LVD and IVD were significantly longer in the patients with LGE than those without LGE (LVD: 54 ± 58 vs. 21 ± 30 ms, P < .01 and IVD: 51 ± 39 vs. 23 ± 34 ms, P < .01). LVD and IVD in the CRT responders were significantly longer than the CRT non-responders (LVD: 126 ± 55 vs. 62 ± 55 ms, P < .01 and IVD: 96 ± 39 vs. 52 ± 40 ms, P < .05). Conclusion: Longitudinal strain analysis with 4CH cine MRI could be useful for clinical examination in the evaluation of cardiac mechanical dyssynchrony.

  1. Comportement des pesticides ionisables dans les sols

    OpenAIRE

    Kah, Mélanie; Brown, Colin D.

    2007-01-01

    Ionisable pesticides can be partially ionised within the range of natural soil pH and this strongly influences their reactivity in soils. This group includes important, worldwide contaminants of groundwater and surface waters. It is essential that their specific behaviour is recognised within risk assessment procedures. Experiments were carried out with ten pesticides (six acids and four bases) and nine arable soils (range in pH, texture and organic matter content) to advance the understandin...

  2. Detection of Left Ventricular Regional Dysfunction and Myocardial Abnormalities Using Complementary Cardiac Magnetic Resonance Imaging in Patients with Systemic Sclerosis without Cardiac Symptoms: A Pilot Study.

    Science.gov (United States)

    Kobayashi, Yasuyuki; Kobayashi, Hitomi; T Giles, Jon; Yokoe, Isamu; Hirano, Masaharu; Nakajima, Yasuo; Takei, Masami

    2016-01-01

    Objective We sought to detect the presence of left ventricular regional dysfunction and myocardial abnormalities in systemic sclerosis (SSc) patients without cardiac symptoms using a complementary cardiac magnetic resonance (CMR) imaging approach. Methods Consecutive patients with SSc without cardiac symptoms and healthy controls underwent CMR on a 1.5 T scanner. The peak systolic regional function in the circumferential and radial strain (Ecc, % and Err, %) were calculated using a feature tracking analysis on the mid-left ventricular slices obtained with cine MRI. In addition, we investigated the myocardial characteristics by contrast MRI. Pharmacological stress and rest perfusion scans were performed to assess perfusion defect (PD) due to micro- or macrovascular impairment, and late gadolinium enhancement (LGE) images were obtained for the assessment of myocarditis and/or fibrosis. Results We compared 15 SSc patients with 10 healthy controls. No statistically significant differences were observed in the baseline characteristics between the patients and healthy controls. The mean peak Err and Ecc of all segments was significantly lower in the patients than the controls (p=0.011 and p=0.003, respectively). Four patients with LGE (28.6%) and seven patients with PD (50.0%) were observed. PD was significantly associated with digital ulcers (p=0.005). Utilizing a linear regression model, the presence of myocardial LGE was significantly associated with the peak Ecc (p=0.024). After adjusting for age, the association between myocardial LGE and the peak Ecc was strengthened. Conclusion A subclinical myocardial involvement, as detected by CMR, was prevalent in the SSc patients without cardiac symptoms. Regional dysfunction might predict the myocardial abnormalities observed in SSc patients without cardiac symptoms.

  3. Value of blood-pool subtraction in cardiac indium-111-labeled platelet imaging

    Energy Technology Data Exchange (ETDEWEB)

    Machac, J.; Vallabhajosula, S.; Goldman, M.E.; Goldsmith, S.J.; Palestro, C.; Strashun, A.; Vaquer, R.; Phillips, R.A.; Fuster, V. (Mt. Sinai Medical Center, New York, NY (USA))

    1989-09-01

    Blood-pool subtraction has been proposed to enhance {sup 111}In-labeled platelet imaging of intracardiac thrombi. We tested the accuracy of labeled platelet imaging, with and without blood-pool subtraction, in ten subjects with cardiac thrombi of varying age, eight with endocarditis being treated with antimicrobial therapy and ten normal controls. Imaging was performed early after labeled platelet injection (24 hr or less) and late (48 hr or more). Blood-pool subtraction was carried out. All images were graded subjectively by four experienced, blinded readers. Detection accuracy was measured by the sensitivity at three fixed levels of specificity estimated from receiver operator characteristic curve analysis and tested by three-way analysis of variance. Detection accuracy was generally improved on delayed images. Blood-pool subtraction did not improve accuracy. Although blood-pool subtraction increased detection sensitivity, this was offset by decreased specificity. For this population studied, blood-pool subtraction did not improve subjective detection of abnormal platelet deposition by 111In platelet imaging.

  4. Usefulness of cardiac 123I-MIBG imaging for the evaluation of diastolic heart failure

    International Nuclear Information System (INIS)

    Significance of 123I-MIBG (metaiodobenzylguanidine) scintigraphy in diagnosis of cardiac sympathetic nerve function is not yet elucidated in chronic heart failure derived from left ventricular diastolic defect despite its established importance in evaluation of severity and prognosis of chronic systolic heart failure. This study was performed to elucidate the usefulness of the imaging for chronic diastolic heart failure. Comparison was made of 47 hospitalized patients with chronic diastolic heart failure (D-group; left ejection fraction, 50% or more), 45 with chronic systolic failure (S-group; the fraction 123I-MIBG with 2-detector gamma camera (Toshiba E.CAM), of which images were analyzed by Toshiba GMS-7000. Cardiac sympathetic nerve function in D-group was found stimulated to be impaired, in a similar extent to that in S-group; severity in NYHA classification was significantly correlated with late H/M ratio and WR; WR in cases with atrial fibrillation complication showed a significant correlation with plasma BNP level; and 123I-MIBG scintigraphic evaluation of the nerve function in D-group was concluded to be useful for severity assessment. (T.I.)

  5. In vivo validation of cardiac output assessment in non-standard 3D echocardiographic images

    Science.gov (United States)

    Nillesen, M. M.; Lopata, R. G. P.; de Boode, W. P.; Gerrits, I. H.; Huisman, H. J.; Thijssen, J. M.; Kapusta, L.; de Korte, C. L.

    2009-04-01

    Automatic segmentation of the endocardial surface in three-dimensional (3D) echocardiographic images is an important tool to assess left ventricular (LV) geometry and cardiac output (CO). The presence of speckle noise as well as the nonisotropic characteristics of the myocardium impose strong demands on the segmentation algorithm. In the analysis of normal heart geometries of standardized (apical) views, it is advantageous to incorporate a priori knowledge about the shape and appearance of the heart. In contrast, when analyzing abnormal heart geometries, for example in children with congenital malformations, this a priori knowledge about the shape and anatomy of the LV might induce erroneous segmentation results. This study describes a fully automated segmentation method for the analysis of non-standard echocardiographic images, without making strong assumptions on the shape and appearance of the heart. The method was validated in vivo in a piglet model. Real-time 3D echocardiographic image sequences of five piglets were acquired in radiofrequency (rf) format. These ECG-gated full volume images were acquired intra-operatively in a non-standard view. Cardiac blood flow was measured simultaneously by an ultrasound transit time flow probe positioned around the common pulmonary artery. Three-dimensional adaptive filtering using the characteristics of speckle was performed on the demodulated rf data to reduce the influence of speckle noise and to optimize the distinction between blood and myocardium. A gradient-based 3D deformable simplex mesh was then used to segment the endocardial surface. A gradient and a speed force were included as external forces of the model. To balance data fitting and mesh regularity, one fixed set of weighting parameters of internal, gradient and speed forces was used for all data sets. End-diastolic and end-systolic volumes were computed from the segmented endocardial surface. The cardiac output derived from this automatic segmentation was

  6. In vivo validation of cardiac output assessment in non-standard 3D echocardiographic images

    Energy Technology Data Exchange (ETDEWEB)

    Nillesen, M M; Lopata, R G P; Gerrits, I H; Thijssen, J M; De Korte, C L [Clinical Physics Laboratory-833, Department of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); De Boode, W P [Neonatology, Department of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Huisman, H J [Department of Radiology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Kapusta, L [Pediatric Cardiology, Department of Pediatrics, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)], E-mail: m.m.nillesen@cukz.umcn.nl

    2009-04-07

    Automatic segmentation of the endocardial surface in three-dimensional (3D) echocardiographic images is an important tool to assess left ventricular (LV) geometry and cardiac output (CO). The presence of speckle noise as well as the nonisotropic characteristics of the myocardium impose strong demands on the segmentation algorithm. In the analysis of normal heart geometries of standardized (apical) views, it is advantageous to incorporate a priori knowledge about the shape and appearance of the heart. In contrast, when analyzing abnormal heart geometries, for example in children with congenital malformations, this a priori knowledge about the shape and anatomy of the LV might induce erroneous segmentation results. This study describes a fully automated segmentation method for the analysis of non-standard echocardiographic images, without making strong assumptions on the shape and appearance of the heart. The method was validated in vivo in a piglet model. Real-time 3D echocardiographic image sequences of five piglets were acquired in radiofrequency (rf) format. These ECG-gated full volume images were acquired intra-operatively in a non-standard view. Cardiac blood flow was measured simultaneously by an ultrasound transit time flow probe positioned around the common pulmonary artery. Three-dimensional adaptive filtering using the characteristics of speckle was performed on the demodulated rf data to reduce the influence of speckle noise and to optimize the distinction between blood and myocardium. A gradient-based 3D deformable simplex mesh was then used to segment the endocardial surface. A gradient and a speed force were included as external forces of the model. To balance data fitting and mesh regularity, one fixed set of weighting parameters of internal, gradient and speed forces was used for all data sets. End-diastolic and end-systolic volumes were computed from the segmented endocardial surface. The cardiac output derived from this automatic segmentation was

  7. Live dynamic OCT imaging of cardiac structure and function in mouse embryos with 43 Hz direct volumetric data acquisition

    Science.gov (United States)

    Wang, Shang; Singh, Manmohan; Lopez, Andrew L.; Wu, Chen; Raghunathan, Raksha; Schill, Alexander; Li, Jiasong; Larin, Kirill V.; Larina, Irina V.

    2016-03-01

    Efficient phenotyping of cardiac dynamics in live mouse embryos has significant implications on understanding of early mammalian heart development and congenital cardiac defects. Recent studies established optical coherence tomography (OCT) as a powerful tool for live embryonic heart imaging in various animal models. However, current four-dimensional (4D) OCT imaging of the beating embryonic heart largely relies on gated data acquisition or postacquisition synchronization, which brings errors when cardiac cycles lack perfect periodicity and is time consuming and computationally expensive. Here, we report direct 4D OCT imaging of the structure and function of cardiac dynamics in live mouse embryos achieved by employing a Fourier domain mode-locking swept laser source that enables ~1.5 MHz A-line rate. Through utilizing both forward and backward scans of a resonant mirror, we obtained a ~6.4 kHz frame rate, which allows for a direct volumetric data acquisition speed of ~43 Hz, around 20 times of the early-stage mouse embryonic heart rate. Our experiments were performed on mouse embryos at embryonic day 9.5. Time-resolved 3D cardiodynamics clearly shows the heart structure in motion. We present analysis of cardiac wall movement and its velocity from the primitive atrium and ventricle. Our results suggest that the combination of ultrahigh-speed OCT imaging with live embryo culture could be a useful embryonic heart phenotyping approach for mouse mutants modeling human congenital heart diseases.

  8. Trial of quantitative analysis of cardiac function by 3D reconstruction of multislice cine MR images

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Hideki (Okayama Univ. (Japan). Faculty of Education); Sei, Tetsurou; Nakagawa, Tomio; Hiraki, Yoshio

    1994-09-01

    Non-invasive techniques for measuring the dynamic behavior of the left ventricle (LV) can be invaluable tool in the diagnosis of the heart disease. In this paper we present methods for quantitative analysis of cardiac function using a compact magnetic resonance image processing system. A 256 x 256 magnetic resonance transaxial image of the left ventricle in a normal case is obtained. After gray level thresholding and region segmentation, the boundary of the left ventricular chamber is extracted. Then, the boundaries of the left ventricular chamber are displayed three-dimensionally by using the Z-buffer algorithm. Thus, LV volume and ejection fraction are calculated. Here, the value of LV ejection fraction is 60%. These results agree reasonably well with the corresponding data obtained by the echocardiography. (author).

  9. Cardiac CT for the assessment of chest pain: Imaging techniques and clinical results

    Energy Technology Data Exchange (ETDEWEB)

    Becker, Hans-Christoph, E-mail: christoph.becker@med.uni-muenchen.de [Ludwig-Maximilians-University, Grosshadern Clinic, Department of Clinical Radiology, Marchioninistr. 15, 81377 Munich (Germany); Johnson, Thorsten [Ludwig-Maximilians-University, Grosshadern Clinic, Department of Clinical Radiology, Marchioninistr. 15, 81377 Munich (Germany)

    2012-12-15

    Immediate and efficient risk stratification and management of patients with acute chest pain in the emergency department is challenging. Traditional management of these patients includes serial ECG, laboratory tests and further on radionuclide perfusion imaging or ECG treadmill testing. Due to the advances of multi-detector CT technology, dedicated coronary CT angiography provides the potential to rapidly and reliably diagnose or exclude acute coronary artery disease. Life-threatening causes of chest pain, such as aortic dissection and pulmonary embolism can simultaneously be assessed with a single scan, sometimes referred to as “triple rule out” scan. With appropriate patient selection, cardiac CT can accurately diagnose heart disease or other sources of chest pain, markedly decrease health care costs, and reliably predict clinical outcomes. This article reviews imaging techniques and clinical results for CT been used to evaluate patients with chest pain entering the emergency department.

  10. Imaging longitudinal cardiac strain on short-axis images using 3D HARP

    Science.gov (United States)

    Osman, Nael F.; Sampath, Smita; Prince, Jerry L.

    2000-04-01

    This paper presents a new method for measuring longitudinal strain of the heart using harmonic phase magnetic resonance imaging (HARP-MRI). The heart is tagged using 1-1 SPAMM at end-diastole with tagging surfaces parallel to the imaging plane. Two image sequences are acquired for a short-axis slice with two different encodings in the direction orthogonal to the imaging plane. A method to compute a sequence of longitudinal strain estimates from this data is described.

  11. Contrast-optimized composite image derived from multigradient echo cardiac magnetic resonance imaging improves reproducibility of myocardial contours and T2*measurement

    NARCIS (Netherlands)

    Triadyaksa, Pandji; Handayani, Astri; Dijkstra, Hildebrand; Aryanto, Kadek Y. E.; Pelgrim, Gert Jan; Xie, Xueqian; Willems, Tineke P.; Prakken, Niek H. J.; Oudkerk, Matthijs; Sijens, Paul E.

    2016-01-01

    Reproducibility of myocardial contour determination in cardiac magnetic resonance imaging is important, especially when determining T2* values per myocardial segment as a prognostic factor of heart failure or thalassemia. A method creating a composite image with contrasts optimized for drawing myoca

  12. Contrast-optimized composite image derived from multigradient echo cardiac magnetic resonance imaging improves reproducibility of myocardial contours and T2* measurement

    NARCIS (Netherlands)

    Triadyaksa, Pandji; Handayani, Astri; Dijkstra, Hildebrand; Aryanto, Kadek Y E; Pelgrim, Gert Jan; Xie, Xueqian; Willems, Tineke P; Prakken, Niek H J; Oudkerk, Matthijs; Sijens, Paul E

    2016-01-01

    OBJECTIVES: Reproducibility of myocardial contour determination in cardiac magnetic resonance imaging is important, especially when determining T2* values per myocardial segment as a prognostic factor of heart failure or thalassemia. A method creating a composite image with contrasts optimized for d

  13. Three-dimensional magnetic resonance imaging overlay to assist with percutaneous transhepatic access at the time of cardiac catheterization

    Directory of Open Access Journals (Sweden)

    Wendy Whiteside

    2015-01-01

    Full Text Available Multimodality image overlay is increasingly used for complex interventional procedures in the cardiac catheterization lab. We report a case in which three-dimensional magnetic resonance imaging (3D MRI overlay onto live fluoroscopic imaging was utilized to safely obtain transhepatic access in a 12-year-old patient with prune belly syndrome, complex and distorted abdominal anatomy, and a vascular mass within the liver.

  14. Three-dimensional magnetic resonance imaging overlay to assist with percutaneous transhepatic access at the time of cardiac catheterization.

    Science.gov (United States)

    Whiteside, Wendy; Christensen, Jason; Zampi, Jeffrey D

    2015-01-01

    Multimodality image overlay is increasingly used for complex interventional procedures in the cardiac catheterization lab. We report a case in which three-dimensional magnetic resonance imaging (3D MRI) overlay onto live fluoroscopic imaging was utilized to safely obtain transhepatic access in a 12-year-old patient with prune belly syndrome, complex and distorted abdominal anatomy, and a vascular mass within the liver.

  15. Three-dimensional magnetic resonance imaging overlay to assist with percutaneous transhepatic access at the time of cardiac catheterization

    International Nuclear Information System (INIS)

    Multimodality image overlay is increasingly used for complex interventional procedures in the cardiac catheterization lab. We report a case in which three-dimensional magnetic resonance imaging (3D MRI) overlay onto live fluoroscopic imaging was utilized to safely obtain transhepatic access in a 12-year-old patient with prune belly syndrome, complex and distorted abdominal anatomy, and a vascular mass within the liver

  16. 4D Cardiac Volume Reconstruction from Free-Breathing 2D Real-Time Image Acquisitions using Iterative Motion Correction

    OpenAIRE

    Jantsch, Martin; Rueckert, Daniel; Hajnal, Jo

    2012-01-01

    For diagnosis, treatment and study of various cardiac diseases directly affecting the functionality and morphology of the heart, physicians rely more and more on MR imaging techniques. MRI has good tissue contrast and can achieve high spatial and temporal resolutions. However it requires a relatively long time to obtain enough data to reconstruct useful images. Additionally, when imaging the heart, the occurring motions - breathing and heart beat - have to be taken into account. While the car...

  17. Prognostic value of cardiac time intervals measured by tissue Doppler imaging M-mode in the general population

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Mogelvang, Rasmus; Jensen, Jan Skov

    2015-01-01

    OBJECTIVE: Tissue Doppler imaging (TDI) M-mode through the mitral leaflet is an easy and precise method to estimate the cardiac time intervals. The aim was to evaluate the usability of the cardiac time intervals in predicting major cardiovascular events (MACE) in the general population. METHODS......: In a large prospective community-based study, cardiac function was evaluated in 1915 participants by both conventional echocardiography and TDI. The cardiac time intervals, including the isovolumic relaxation time (IVRT), isovolumic contraction time (IVCT) and ejection time (ET), were obtained by TDI M...... echocardiographic parameters resulted in a significant increase in the c-statistics (0.76 vs 0.75 ptime intervals that include...

  18. Application of cine cardiac MR imaging in normal subjects and patients with valvular, coronary artery, and aortic disease

    International Nuclear Information System (INIS)

    Cine MR imaging was performed on 15 normal subjects and 27 patients with cardiac disease. In normal subjects, high signal intensity of flowing blood contrasted with that of the myocardium. In 16 patients with valvular regurgitation, signal void jet due to turbulence was visualized across the diseased valves. In three IHSS patients, thickened LV myocardium, mitral regurgitant jets, and systolic LV outflow jets were noted. Five patients with myocardial infarction (MI) showed thinning and/or hypokinesis of MI regions. In three patients with Marfan syndrome, aortic dilatation, insufficiency, and flap (one pt) were identified. Cine MR imaging is potentially useful for evaluation of a variety of cardiac diseases

  19. Importance of Delayed Enhanced Cardiac MRI Imaging in Idiopathic RVOT-VT: Differentiating Mimics Including Early Stage ARVC and Cardiac Sarcoidosis

    Directory of Open Access Journals (Sweden)

    Carlos Macias, MD; Keijiro Nakamura, MD; Roderick Tung, MD; Noel G. Boyle, MD PhD; Kalyanam Shivkumar, MD, PhD and Jason S. Bradfield, MD.

    2014-12-01

    Full Text Available Abstract: A detailed understanding of cardiac anatomy and pathophysiology is necessary to optimize catheter ablation procedural success for patients with symptomatic ventricular tachycardia (VT/premature ventricular contractions (PVCs of outflow tract origin. Comprehensive imaging with cardiac magnetic resonance imaging (cMRI is now at the forefront of procedural planning for complex ventricular arrhythmia ablation for patients with structural heart disease, but is increasingly used in patients with presumed “idiopathic” outflow VT/PVCs as well. cMRI with late gadolinium enhancement (LGE can localize small regions of myocardial scar from previous myocardial infarction, fibrosis from non-ischemic cardiomyopathy, or edema/fibrosis from inflammatory disorders and help define targets for ablation. LGE, in combination with structural assessment, can help differentiate true idiopathic outflow VT/PVCs from those caused by early stage disease secondary to more significant pathology, such as arrhythmogenic right ventricular cardiomyopathy or cardiac sarcoidosis. We review the benefits of cMRI with LGE for patients with VT/PVCs of outflow origin.

  20. Hybrid cardiac imaging: SPECT/CT and PET/CT. A joint position statement by the European Association of Nuclear Medicine (EANM), the European Society of Cardiac Radiology (ESCR) and the European Council of Nuclear Cardiology (ECNC)

    DEFF Research Database (Denmark)

    Flotats, Albert; Gutberlet, Matthias; Knuuti, Juhani;

    2011-01-01

    . The European Association of Nuclear Medicine (EANM), the European Society of Cardiac Radiology (ESCR) and the European Council of Nuclear Cardiology (ECNC) in this paper want to present a position statement of the institutions on the current roles of SPECT/CT and PET/CT hybrid cardiac imaging in patients...

  1. Combined arterial and venous whole-body MR angiography with cardiac MR imaging in patients with thromboembolic disease - initial experience

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, Florian M.; Hunold, Peter; Barkhausen, Joerg [University Hospital Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Herborn, Christoph U. [University Hospital Hamburg-Eppendorf, Medical Prevention Center Hamburg (MPCH) at University Hospital Hamburg-Eppendorf, Hamburg (Germany); Ruehm, Stefan G. [David Geffen School of Medicine at UCLA, Department of Radiology, Los Angeles, CA (United States); Kroger, Knut [University Hospital Essen, Department of Angiology, Essen (Germany)

    2008-05-15

    The objective was to assess the feasibility of a combined arterial and venous whole-body three-dimensional magnetic resonance (MR) angiography, together with a cardiac MR examination, in patients with arterial thromboembolism. Ten patients with arterial thromboembolism underwent a contrast-enhanced whole-body MR examination of the arterial and venous vessels, followed by a cardiac MR examination on a separate occasion within 24 h. All examinations were performed on a 1.5-T MR scanner. For both arterial and venous MR angiography only one injection of contrast agent was necessary. The cardiac imaging protocol included dark-blood-prepared half-Fourier acquisition single-shot turbo-spin-echo sequences, fast steady-state free precession cine sequences, T2-weighted turbo-spin-echo sequences and inversion recovery gradient-echo fast low-angle-shot sequences after injection of contrast agent. MR imaging revealed additional clinically unknown arterial thromboembolisms in four patients. The thoracic aorta was depicted as embolic source in four patients, while deep vein thrombosis (DVT) was found in one patient as the underlying disease. Unsuspected infarction of parenchymal organs was detected by MRI in two patients. An unknown additional DVT was found in one patient. Four patients were considered to have arterial emboli of cardiac origin. In conclusion, acquisition of arterial and venous MR angiograms of the entire vascular system combined with cardiac MR imaging is a most comprehensive and valuable strategy in patients with arterial thromboembolism. (orig.)

  2. Cardiac risk stratification with myocardial perfusion imaging in potential renal-pancreas transplant recipients

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, M.C.; Larcos, G.; Chapman, J. [Westmead Hospital, Westmead, Sydney, NSW (Australia). Departments of Nuclear Medicine and Ultrasound

    1998-06-01

    Full text: Combined renal/pancreas transplantation is used in patients with severe type-1 diabetes and renal failure. Many patients have asymptomatic coronary artery disease (CAD). Thus, myocardial perfusion imaging (MPI) is widely used for preoperative risk assessment, however, its value has recently been challenged. The purpose of this study was to determine the predictive value of MPI compared to coronary angiography and/or thirty day perioperative cardiac events (cardiac death, myocardial infarction and unstable angina). We reviewed the MPI in 132 patients that were referred for possible renal pancreas transplantation during the period between 1987 - June 1997. Fifty five patients were excluded because of: still awaiting transplantation (n=19) ongoing medical assessment (n=21), received kidney only transplant (n=6) or other factors (n=9). Thus, 77 patients form the basis of this report. Seventy one patients were transplanted, 5 had coronary angiography and one died before transplantation but with coronary anatomy defined at autopsy. All patients (39 male, 38 female; mean age 37 years) had Tl-201 or Tc-99m MIBI SPECT at Westmead (n=54) or elsewhere (n=23). Patients underwent MPI, a mean of 12.1 months before transplantation and a mean of 6 months before coronary angiography or autopsy. MPI was normal in 64 (83%) and abnormal in 13 (17%) patients. Of the abnormal MPI, 7 patients had CAD and one had unstable angina post-operatively (PPV = 8/13; 61%). One patient had a fixed defect post CABG but proceeded to transplant with-out event; the other 4 patients had normal coronary anatomy. Of the normal MPIs there were no transplant related cardiac events, but one patient required CABG >12 months post MPI and a further patient died >12 months post transplant and was shown to have CAD at autopsy (NPV=62/64;97%). In conclusion we have found an excellent NPV and an acceptable PPV for MPI in potential renal pancreas graft recipients

  3. [11C]-Acetoacetate PET imaging: a potential early marker for cardiac heart failure

    International Nuclear Information System (INIS)

    The ketone body acetoacetate could be used as an alternate nutrient for the heart, and it also has the potential to improve cardiac function in an ischemic–reperfusion model or reduce the mitochondrial production of oxidative stress involved in cardiotoxicity. In this study, [11C]-acetoacetate was investigated as an early marker of intracellular damage in heart failure. Methods: A rat cardiotoxicity heart failure model was induced by doxorubicin, Dox(+). [14C]-Acetoacetate, a non-positron (β −) emitting radiotracer, was used to characterize the arterial blood input function and myocardial mitochondrial uptake. Afterward, [11C]-acetoacetate (β +) myocardial PET images were obtained for kinetic analysis and heart function assessment in control Dox(−) (n = 15) and treated Dox(+) (n = 6) rats. The uptake rate (K1) and myocardial clearance rate (k2or kmono) were extracted. Results: [14C]-Acetoacetate in the blood was increased in Dox(+), from 2 min post-injection until the last withdrawal point when the heart was harvested, as well as the uptake in the heart and myocardial mitochondria (unpaired t-test, p < 0.05). PET kinetic analysis of [11C]-acetoacetate showed that rate constants K1, k2 and kmono were decreased in Dox(+) (p < 0.05) combined with a reduction of 24% of the left ventricular ejection fraction (p < 0.001). Conclusion: Radioactive acetoacetate ex vivo analysis [14C], and in vivo kinetic [11C] studies provided evidence that [11C]-acetoacetate can assess heart failure Dox(+). Contrary to myocardial flow reserve (rest–stress protocol), [11C]-acetoacetate can be used to assess reduced kinetic rate constants without requirement of hyperemic stress response. The proposed [11C]-acetoacetate cardiac radiotracer in the investigation of heart disease is novel and paves the way to a potential role for [11C]-acetoacetate in cardiac pathophysiology

  4. LMI1195 PET imaging in evaluation of regional cardiac sympathetic denervation and its potential role in antiarrhythmic drug treatment

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ming; Bozek, Jody; Lamoy, Melanie; Kagan, Mikhail; Benites, Pedro; Onthank, David; Robinson, Simon P. [Lantheus Medical Imaging, Discovery Research, N. Billerica, MA (United States)

    2012-12-15

    Regional cardiac sympathetic denervation (RCSD) associated with reduced noradrenaline transporter (NAT) function has been linked to cardiac arrhythmia. This study examined the association of LMI1195, an {sup 18}F-labeled NAT substrate developed for positron emission tomography (PET) imaging, with NAT in vitro, and its imaging to detect RCSD and guide antiarrhythmic drug treatment in vivo. LMI1195 association with NAT was assessed in comparison with other substrates, noradrenaline (NA) and {sup 123}I-metaiodobenzylguanidine (MIBG), in NAT-expressing cells. LMI1195 cardiac imaging was performed for evaluation of RCSD in a rabbit model surgically developed by regional phenol application on the left ventricular (LV) wall. The normal LV areas in images were quantified as regions with radioactivity {>=}50 % maximum. Potential impact of RCSD on dofetilide, an antiarrhythmic drug, induced ECG changes was assessed. NAT blockade with desipramine reduced LMI1195 cell uptake by 90 {+-} 3 %, similar to NA and MIBG. NA, MIBG, or self inhibited LMI1195 cell uptake concentration-dependently with comparable IC{sub 50} values (1.09, 0.21, and 0.90 {mu}M). LMI1195 cardiac imaging differentiated innervated and denervated areas in RCSD rabbits. The surgery resulted in a large denervated LV area at 2 weeks which was partially recovered at 12 weeks. Myocardial perfusion imaging with flurpiridaz F 18 showed normal perfusion in RCSD areas. Dofetilide induced more prominent QTc prolongation in RCSD than control animals. However, changes in heart rate were comparable. LMI1195 exhibits high association with NAT and can be used for imaging RCSD. The detected RCSD increases cardiac risks to the antiarrhythmic drug, dofetilide, by inducing more QTc prolongation. (orig.)

  5. Churg-Strauss syndrome cardiac involvement evaluated by cardiac magnetic resonance imaging and positron-emission tomography: a prospective study on 20 patients

    International Nuclear Information System (INIS)

    Churg-Strauss syndrome (CSS) cardiac involvement is associated with a poor prognosis. Recently cardiac MRI (CMRI) has emerged as a promising technique to detect early CSS cardiac involvement. However, CMRI-detected myocardial delayed enhancement (MDE) could correspond to fibrosis or inflammation. Fluoro-2-deoxyglucose PET (FDG-PET) was previously used in other systemic diseases to distinguish between them. To determine whether the CMRI-MDE detected in CSS patients reflected fibrosis or myocardial inflammation, patients in CSS remission underwent FDG-PET. Twenty consecutive CSS patients in remission (BVAS = 0) were recruited. Fourteen patients [eight men, six women; mean (S.D.) age 49 (9) years; mean disease duration 3.5 (2.9) years] with CMRI-detected MDE, and six patients [four men, two women; mean (S.D.) age 44 (15) years; mean disease duration 3.5 (5.3) years] with normal CMRI underwent FDG-PET. Segments with MDE on CMRI were analysed on FDG-PET images, with myocardial FDG hypo-fixation defining fibrosis and hyper-fixation corresponding inflammation. Among the 14 patients with MDE on CMRI, FDG-PET showed 10 had hypo-fixation, 2 had hyper-fixation and 2 had normal scans. CSS duration at the time of CMRI was shorter for patients with myocardial inflammation than in those with fibrosis. The six patients with normal CMRI had normal FDG-PET images. For CSS patients in remission, CMRI detected subclinical active myocardial lesions and could be recommended to assess cardiac involvement. However, because CMRI-detected MDE can reflect fibrosis or inflammation, FDG-PET might help to distinguish between the two. (authors)

  6. Proposal for standardization of I-123-metaiodobenzylguanidine (MIBG) cardiac sympathetic imaging by the EANM Cardiovascular Committee and the European Council of Nuclear Cardiology

    NARCIS (Netherlands)

    A. Flotats; I. Carrio; D. Agostini; D. Le Guludec; C. Marcassa; M. Schaffers; G.A. Somsen; M. Unlu; H.J. Verberne

    2010-01-01

    This proposal for standardization of I-123-metaiodobenzylguanidine (iobenguane, MIBG) cardiac sympathetic imaging includes recommendations for patient information and preparation, radiopharmaceutical, injected activities and dosimetry, image acquisition, quality control, reconstruction methods, atte

  7. The detection of coronary stiffness in cardiac allografts using MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Kai, E-mail: kai-lin@northwestern.edu [Department of Radiology, Northwestern University, 737 N Michigan Avenue, Suite 1600, Chicago, IL 60611 (United States); Lloyd-Jones, Donald M. [Department of Preventive Medicine, Northwestern University, 680 N Lake Shore Drive, Suite 1400, Chicago, IL 60611 (United States); Taimen, Kirsi; Liu, Ying [Department of Radiology, Northwestern University, 737 N Michigan Avenue, Suite 1600, Chicago, IL 60611 (United States); Bi, Xiaoming [Cardiovascular MR R and D, Siemens Healthcare, 737 N Michigan Avenue, Suite 1600, Chicago, IL 60611 (United States); Li, Debiao; Carr, James C. [Department of Radiology, Northwestern University, 737 N Michigan Avenue, Suite 1600, Chicago, IL 60611 (United States)

    2014-08-15

    Objective: To test the hypothesis that biomechanical changes are quantitatively related to morphological features of coronary arteries in heart transplant (HTx) recipients. Materials and methods: With IRB approval, three-dimensional (3D) magnetic resonance (MR) angiography and two-dimensional (2D) black-blood stead-state free precession (SSFP) MR imaging were performed to image coronary arteries of 36 HTx patients. Contours of coronary wall were manually drawn. For each coronary segment, coronary wall thickness, wall area, lumen area (in systole and diastole) were acquired. Coronary distensibility index (CDI) and the percent of the coronary wall occupying the vessel area (PWOV) were calculated. Results: There are totally 98 coronary segments eligible for quantitative analysis from 27 HTx patients. The CDI is 4.90 ± 2.44 mmHg{sup −1}. The mean wall thickness is 1.49 ± 0.24 mm and the PWOV is 74.6% ± 7.5%. CDI has moderate correlations with wall thickness (r = −0.531, P < 0.001) and with PWOV (R = −0.435, P < 0.001). Conclusions: Detected with coronary MR imaging, CDI is quantitatively correlated with the morphological features of the coronary artery in HTx patients. Coronary stiffness has the potential to become an alternative imaging biomarker for the quantitative assessment of the status of cardiac allografts.

  8. Usefulness of breath-hold cardiac cine MR imaging with a middle field MRI system

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, Kentaro; Sato, Kiyoto; Aono, Masaki; Inoshita, Kenji; Utsumi, Naoko [Kagawa Inoshita Hospital, Ohnohara (Japan)

    1999-07-01

    To assess the accuracy of contrast-enhanced, single breath-hold cine MR imaging in calculating left ventricular volume and ejection fraction, we compared MR measurements with those obtained by using cine ventriculography in 60 patients. Fast cine MR images were acquired with a middle field MR system (0.5 T). A breath-hold single slice multi-phase fast gradient-echo (Fast Card) sequence was used to obtain fast cine MR images with the following parameters; TR of 16 ms, TE of 3 ms, flip angle of 30 degree, matrix elements of 256 x 128, view per segment of 6, field of view of 350 x 260 mm and one excitation. Left ventricular end-diastolic volume and ejection fraction obtained with contrast-enhanced Fast Card correlated well with those obtained with cine ventriculography (end-diastolic volume, y=1.00x+14.0, r=0.904, p<0.001; ejection fraction, y=0.961x+2.8, r=0.936, p<0.001). Our results show that contrast enhanced breath-hold cardiac cine MR imaging on horizontal long-axis view using a middle field MR system is an accurate method for evaluating left ventricular volume and ejection fraction. (author)

  9. Evaluation of diabetic autonomic neuropathy by 123I-metaiodobenzyl-guanidine (MIBG) cardiac imaging. Initial report

    International Nuclear Information System (INIS)

    Single-photon emission computed tomography was performed in 52 diabetics and 10 healthy volunteers using MIBG. The diabetics had no particular findings of electrocardiography, echocardiography, or exercise thallium imaging and no cardiovascular episodes. The healthy volunteers had no abnormal findings on exercise thallium imaging or glucose tolerance test. The average relative regional uptake (RRU) was decreased in the inferoposterior wall compared with the anterior or lateral wall in both the diabetics and volunteers. According to the RRU and visual images, we divided the diabetics into the following four groups: 14 who were normal (group N), 30 with segmental defects (group S), 4 with diffuse defects (group D) and 4 without accumulation (group DH). Diabetic complications (retinopathy, nephropathy, and neuropathy) and hypertension were more frequent in group S than group N. However, there were no significant differences in the physiological evidence of autonomic neuropathy (C.V. of the R-R interval on the ECG and blood pressure response to standing or deep breathing) between groups S and N. Vibration sense was significantly more impaired in group S than in group N. These results suggest that cardiac imaging with MIBG might be a useful examination for the early diagnosis of diabetic autonomic neuropathy. (author)

  10. The effects of gantry tilt on breast dose and image noise in cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Hoppe, Michael E.; Gandhi, Diksha; Schmidt, Taly Gilat [Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233 (United States); Stevens, Grant M. [GE Healthcare, Waukesha, Wisconsin 53188 (United States); Foley, W. Dennis [Department of Radiology, Medical College of Wisconsin, Froedtert Memorial Lutheran Hospital, Milwaukee, Wisconsin 53226 (United States)

    2013-12-15

    Purpose: This study investigated the effects of tilted-gantry acquisition on image noise and glandular breast dose in females during cardiac computed tomography (CT) scans. Reducing the dose to glandular breast tissue is important due to its high radiosensitivity and limited diagnostic significance in cardiac CT scans.Methods: Tilted-gantry acquisition was investigated through computer simulations and experimental measurements. Upon IRB approval, eight voxelized phantoms were constructed from previously acquired cardiac CT datasets. Monte Carlo simulations quantified the dose deposited in glandular breast tissue over a range of tilt angles. The effects of tilted-gantry acquisition on breast dose were measured on a clinical CT scanner (CT750HD, GE Healthcare) using an anthropomorphic phantom with MOSFET dosimeters in the breast regions. In both simulations and experiments, scans were performed at gantry tilt angles of 0°–30°, in 5° increments. The percent change in breast dose was calculated relative to the nontilted scan for all tilt angles. The percent change in noise standard deviation due to gantry tilt was calculated in all reconstructed simulated and experimental images.Results: Tilting the gantry reduced the breast dose in all simulated and experimental phantoms, with generally greater dose reduction at increased gantry tilts. For example, at 30° gantry tilt, the dosimeters located in the superior, middle, and inferior breast regions measured dose reductions of 74%, 61%, and 9%, respectively. The simulations estimated 0%–30% total breast dose reduction across the eight phantoms and range of tilt angles. However, tilted-gantry acquisition also increased the noise standard deviation in the simulated phantoms by 2%–50% due to increased pathlength through the iodine-filled heart. The experimental phantom, which did not contain iodine in the blood, demonstrated decreased breast dose and decreased noise at all gantry tilt angles.Conclusions: Tilting the

  11. Balancing radiation risks and benefits of cardiac imaging: challenges for developed countries

    International Nuclear Information System (INIS)

    Full text: Cardiovascular disease remains the leading cause of death in the US, EU, Canada, Australia, and New Zealand, although coronary disease mortality has decreased due to improvements in prevention, diagnosis, and treatment. In many developed countries, most cardiologists now perform procedures involving radiopharmaceuticals, CT, or fluoroscopy. Their increased utilization, while contributing to improved care for patients with known or suspected heart disease, has been accompanied by a sharp increase in collective doses from medical radiation. E.g., an estimated ∼ 10% (∼ 0.6 mSv/person/y) of the collective dose to the US population is now attributed to nuclear stress tests. Radiation risk from any modality is highly dependent on patient age and gender. Cardiologists, like most non-radiologists, have had limited training in the safe use of radiation and are generally unaware of such facts. While one encouraging sign has been the development of appropriateness criteria for various cardiac imaging modalities, much work remains to advance radiological protection for the tens of millions of patients each year who receive cardiac imaging studies. Here we address current efforts to balance benefits of cardiac imaging with radiation risks, dose-reduction strategies, and future desiderata. General themes are improvements in technology, education, clinical standards, and reimbursement policies for these examinations. The vast majority of nuclear cardiology studies are performed using SPECT, and the radiopharmaceuticals used most widely are 99mTc sestamibi and tetrofosmin, and 201Tl. Effective doses are considerably higher for standard injected activities of 201Tl than for 99mTc agents, and the highest doses, ∼ 24 mSv, are associated with dual isotope (rest 201Tl, stress 99mTc) protocols. E.g., in the US, 1/4 of nuclear stress tests are still performed using dual isotope protocols, a practice fostered by current structuring of reimbursement. Although most stress

  12. Cardiac imaging in diagnostic VCT using multi-sector data acquisition and image reconstruction: step-and-shoot scan vs. helical scan

    Science.gov (United States)

    Tang, Xiangyang; Hsieh, Jiang; Seamans, John L.; Dong, Fang; Okerlund, Darin

    2008-03-01

    Since the advent of multi-slice CT, helical scan has played an increasingly important role in cardiac imaging. With the availability of diagnostic volumetric CT, step-and-shoot scan has been becoming popular recently. Step-and-shoot scan decouples patient table motion from heart beating, and thus the temporal window for data acquisition and image reconstruction can be optimized, resulting in significantly reduced radiation dose, improved tolerance to heart beat rate variation and inter-cycle cardiac motion inconsistency. Multi-sector data acquisition and image reconstruction have been utilized in helical cardiac imaging to improve temporal resolution, but suffers from the coupling of heart beating and patient table motion. Recognizing the clinical demands, the multi-sector data acquisition scheme for step-and-shoot scan is investigated in this paper. The most outstanding feature of the multi-sector data acquisition combined with the stepand- shoot scan is the decoupling of patient table proceeding from heart beating, which offers the opportunities of employing prospective ECG-gating to improve dose efficiency and fine adjusting cardiac imaging phase to suppress artifacts caused by inter-cycle cardiac motion inconsistency. The improvement in temporal resolution and the resultant suppression of motion artifacts are evaluated via motion phantoms driven by artificial ECG signals. Both theoretical analysis and experimental evaluation show promising results for multi-sector data acquisition scheme to be employed with the step-and-shoot scan. With the ever-increasing gantry rotation speed and detector longitudinal coverage in stateof- the-art VCT scanners, it is expected that the step-and-shoot scan with multi-sector data acquisition scheme would play an increasingly important role in cardiac imaging using diagnostic VCT scanners.

  13. Post-mortem cardiac diffusion tensor imaging: detection of myocardial infarction and remodeling of myofiber architecture

    Energy Technology Data Exchange (ETDEWEB)

    Winklhofer, Sebastian; Berger, Nicole; Stolzmann, Paul [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); University of Zurich, Department of Forensic Medicine and Radiology, Institute of Forensic Medicine, Zurich (Switzerland); Stoeck, Christian T.; Kozerke, Sebastian [Institute for Biomedical Engineering University and ETH Zurich, Zurich (Switzerland); Thali, Michael [University of Zurich, Department of Forensic Medicine and Radiology, Institute of Forensic Medicine, Zurich (Switzerland); Manka, Robert [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Institute for Biomedical Engineering University and ETH Zurich, Zurich (Switzerland); University Hospital Zurich, Clinic for Cardiology, Zurich (Switzerland); Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland)

    2014-11-15

    To investigate the accuracy of post-mortem diffusion tensor imaging (DTI) for the detection of myocardial infarction (MI) and to demonstrate the feasibility of helix angle (HA) calculation to study remodelling of myofibre architecture. Cardiac DTI was performed in 26 deceased subjects prior to autopsy for medicolegal reasons. Fractional anisotropy (FA) and mean diffusivity (MD) were determined. Accuracy was calculated on per-segment (AHA classification), per-territory, and per-patient basis, with pathology as reference standard. HAs were calculated and compared between healthy segments and those with MI. Autopsy demonstrated MI in 61/440 segments (13.9 %) in 12/26 deceased subjects. Healthy myocardial segments had significantly higher FA (p < 0.01) and lower MD (p < 0.001) compared to segments with MI. Multivariate logistic regression demonstrated that FA (p < 0.10) and MD (p = 0.01) with the covariate post-mortem time (p < 0.01) predicted MI with an accuracy of 0.73. Analysis of HA distribution demonstrated remodelling of myofibre architecture, with significant differences between healthy segments and segments with chronic (p < 0.001) but not with acute MI (p > 0.05). Post-mortem cardiac DTI enablesdifferentiation between healthy and infarcted myocardial segments by means of FA and MD. HA assessment allows for the demonstration of remodelling of myofibre architecture following chronic MI. (orig.)

  14. Imaging of the autonomic nervous system: focus on cardiac sympathetic innervation.

    Science.gov (United States)

    Goldstein, David S

    2003-12-01

    Symptoms or signs of abnormal autonomic nervous system function occur commonly in several neurological disorders. Clinical evaluations have depended on physiological, pharmacological, and neurochemical approaches. Recently, imaging of sympathetic noradrenergic innervation has been introduced and applied especially in the heart. Most studies have used the radiolabeled sympathomimetic amine, (123)I-metaiodobenzylguanidine. Decreased uptake or increased "washout" of (123)I-metaiodobenzylguanidine-derived radioactivity is associated with worse prognosis or more severe disease in hypertension, congestive heart failure, arrhythmias, and diabetes mellitus. This pattern may reflect a high rate of postganglionic sympathetic nerve traffic to the heart. Many recent studies have agreed on the remarkable finding that all patients with Parkinson's disease and orthostatic hypotension have a loss of cardiac sympathetic innervation, whereas all patients with multiple system atrophy, often difficult to distinguish clinically from Parkinson's disease, have intact cardiac sympathetic innervation. Because Parkinson's disease entails a postganglionic sympathetic noradrenergic lesion, the disease appears to be not only a movement disorder, with dopamine loss in the nigrostriatal system of the brain, but also a dysautonomia, with noradrenaline loss in the sympathetic nervous system of the heart. As new ligands are developed, one may predict further discoveries of involvement of components of the autonomic nervous system in neurological diseases.

  15. Precise reconstruction of fast moving cardiac valve in high frame rate synthetic transmit aperture ultrasound imaging

    Science.gov (United States)

    Suzuki, Mayumi; Ikeda, Teiichiro; Ishihara, Chizue; Takano, Shinta; Masuzawa, Hiroshi

    2016-04-01

    To diagnose heart valve incompetence, i.e., one of the most serious cardiac dysfunctions, it is essential to obtain images of fast-moving valves at high spatial and temporal resolution. Ultrasound synthetic transmit aperture (STA) imaging has the potential to achieve high spatial resolution by synthesizing multiple pre-beamformed images obtained with corresponding multiple transmissions. However, applying STA to fast-moving targets is difficult due to serious target deformation. We propose a high-frame-rate STA (fast STA) imaging method that uses a reduced number of transmission events needed for each image. Fast STA is expected to suppress deformation of moving targets; however, it may result in deteriorated spatial resolution. In this study, we conducted a simulation study to evaluate fast STA. We quantitatively evaluated the reduction in deformation and deterioration of spatial resolution with a model involving a radially moving valve at the maximum speed of 0.5 m/s. The simulated raw channel data of the valve phantom was processed with offline beamforming programs. We compared B-mode images obtained through single received-line in a transmission (SRT) method, STA, and fast STA. The results show that fast STA with four-times-reduced events is superior in reconstructing the original shape of the moving valve to other methods. The accuracy of valve location is 97 and 100% better than those with SRT and STA, respectively. The resolution deterioration was found to be below the annoyance threshold considering the improved performance of the shape reconstruction. The obtained results are promising for providing more precise diagnostic information on cardiovascular diseases.

  16. Myocardial Extracellular Volume Fraction with Dual-Energy Equilibrium Contrast-enhanced Cardiac CT in Nonischemic Cardiomyopathy: A Prospective Comparison with Cardiac MR Imaging.

    Science.gov (United States)

    Lee, Hye-Jeong; Im, Dong Jin; Youn, Jong-Chan; Chang, Suyon; Suh, Young Joo; Hong, Yoo Jin; Kim, Young Jin; Hur, Jin; Choi, Byoung Wook

    2016-07-01

    Purpose To evaluate the feasibility of equilibrium contrast material-enhanced dual-energy cardiac computed tomography (CT) to determine extracellular volume fraction (ECV) in nonischemic cardiomyopathy (CMP) compared with magnetic resonance (MR) imaging. Materials and Methods This study was approved by the institutional review board; informed consent was obtained. Seven healthy subjects and 23 patients (six with hypertrophic CMP, nine with dilated CMP, four with amyloidosis, and four with sarcoidosis) (mean age ± standard deviation, 57.33 years ± 14.82; 19 male participants [63.3%]) were prospectively enrolled. Twelve minutes after contrast material injection (1.8 mL/kg at 3 mL/sec), dual-energy cardiac CT was performed. ECV was measured by two observers independently. Hematocrit levels were compared between healthy subjects and patients with the Mann-Whitney U test. In per-subject analysis, interobserver agreement for CT was assessed with the intraclass correlation coefficient (ICC), and intertest agreement between MR imaging and CT was assessed with Bland-Altman analysis. In per-segment analysis, Student t tests in the linear mixed model were used to compare ECV on CT images between healthy subjects and patients. Results Hematocrit level was 43.44% ± 1.80 for healthy subjects and 41.23% ± 5.61 for patients with MR imaging (P = .16) and 43.50% ± 1.92 for healthy subjects and 41.35% ± 5.92 for patients with CT (P = .15). For observer 1 in per-subject analysis, ECV was 34.18% ± 8.98 for MR imaging and 34.48% ± 8.97 for CT. For observer 2, myocardial ECV was 34.42% ± 9.03 for MR imaging and 33.98% ± 9.05 for CT. Interobserver agreement for ECV at CT was excellent (ICC = 0.987). Bland-Altman analysis between MR imaging and CT showed a small bias (-0.06%), with 95% limits of agreement of -1.19 and 1.79. Compared with healthy subjects, patients with hypertrophic CMP, dilated CMP, amyloidosis, and sarcoidosis had significantly higher myocardial ECV at dual

  17. Magnetic resonance imaging in familial hypertrophic cardiomyopathy associated with abnormal thallium perfusion and cardiac enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, Tsunehiko; Nagata, Seiki; Sakakibara, Hiroshi

    1988-05-01

    Gated magnetic resonance imaging (MRI) was performed in 6 patients with familial hypertrophic cardiomyopathy associated with abnormal thallium perfusion, and 12 patients with ordinary hypertrophic cardiomyopathy. The patients with ordinary hypertrophic cardiomyopathy and abnormal thickening of the septal wall and normal left ventricular dimensions, while the patients with familial hypertrophic cardiomyopathy had focal wall thinning (usually involving the apical-septal wall) and dilated left ventricle in addition to hypertrophied heart. The quantitative measurement for cardiac dimensions using MRI was similar to that found on echocardiography in all cases. In addition, inhomogeneous signal intensities at left ventricular wall were observed in 3 cases of familial hypertrophic cardiomyopathy, which may suggest the existence of myocardial fibrosis. Gated MRI should be performed for early detection and follow-up of hypertrophic cardiomyopathy, since some patients will progress from hypertrophic cardiomyopathy to dilated cardiomyopathy.

  18. Cardiac Time Intervals Measured by Tissue Doppler Imaging M-mode

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Mogelvang, Rasmus; Schnohr, Peter;

    2016-01-01

    function was evaluated in 1915 participants by using both conventional echocardiography and tissue Doppler imaging (TDI). The cardiac time intervals, including the isovolumic relaxation time (IVRT), isovolumic contraction time (IVCT), and ejection time (ET), were obtained by TDI M-mode through the mitral...... leaflet. IVCT/ET, IVRT/ET, and myocardial performance index [MPI=(IVRT+IVCT)/ET] were calculated. After multivariable adjustment for clinical variables the IVRT, IVRT/ET, and MPI, remained significantly impaired in persons with hypertension (n=826) compared with participants without hypertension (n=1082......). Additionally, they displayed a significant dose-response relationship, between increasing severity of elevated blood pressure and increasing left ventricular mass index (P

  19. Ex vivo 3D diffusion tensor imaging and quantification of cardiac laminar structure.

    Science.gov (United States)

    Helm, Patrick A; Tseng, Hsiang-Jer; Younes, Laurent; McVeigh, Elliot R; Winslow, Raimond L

    2005-10-01

    A three-dimensional (3D) diffusion-weighted imaging (DWI) method for measuring cardiac fiber structure at high spatial resolution is presented. The method was applied to the ex vivo reconstruction of the fiber architecture of seven canine hearts. A novel hypothesis-testing method was developed and used to show that distinct populations of secondary and tertiary eigenvalues may be distinguished at reasonable confidence levels (P < or = 0.01) within the canine ventricle. Fiber inclination and sheet angles are reported as a function of transmural depth through the anterior, lateral, and posterior left ventricle (LV) free wall. Within anisotropic regions, two consistent and dominant orientations were identified, supporting published results from histological studies and providing strong evidence that the tertiary eigenvector of the diffusion tensor (DT) defines the sheet normal.

  20. Stenosis of the branches of the neopulmonary artery after the arterial switch operation: A cardiac magnetic resonance imaging study

    Directory of Open Access Journals (Sweden)

    Boban Thomas

    2013-01-01

    Conclusions: Cardiac MR can be used as a comprehensive non-invasive imaging technique to diagnose stenosis of the branches of the neopulmonary after the ASO, allowing evaluation of anatomy and function of the neoPA, its branches, and the differential perfusion to each lung, thus facilitating clinical decision making.

  1. Indirect imaging of cardiac-specific transgene expression using a bidirectional two-step transcriptional amplification strategy

    DEFF Research Database (Denmark)

    Chen, I Y; Gheysens, O; Ray, S;

    2010-01-01

    genes, firefly luciferase (fluc) and Renilla luciferase (hrluc), driven by the cardiac troponin T (cTnT) promoter. The vector was characterized in vitro and in living mice using luminometry and bioluminescence imaging to assess its ability to mediate strong, correlated reporter gene expression...

  2. Acquiring Multiview C-Arm Images to Assist Cardiac Ablation Procedures

    Directory of Open Access Journals (Sweden)

    Pascal Fallavollita

    2010-01-01

    Full Text Available CARTO XP is an electroanatomical cardiac mapping system that provides 3D color-coded maps of the electrical activity of the heart; however it is expensive and it can only use a single costly magnetic catheter for each patient intervention. Our approach consists of integrating fluoroscopic and electrical data from the RF catheters into the same image so as to better guide RF ablation, shorten the duration of this procedure, increase its efficacy, and decrease hospital cost when compared to CARTO XP. We propose a method that relies on multi-view C-arm fluoroscopy image acquisition for (1 the 3D reconstruction of the anatomical structure of interest, (2 the robust temporal tracking of the tip-electrode of a mapping catheter between the diastolic and systolic phases and (3 the 2D/3D registration of color coded isochronal maps directly on the 2D fluoroscopy image that would help the clinician guide the ablation procedure much more effectively. The method has been tested on canine experimental data.

  3. Automatic cable artifact removal for cardiac C-arm CT imaging

    Science.gov (United States)

    Haase, C.; Schäfer, D.; Kim, M.; Chen, S. J.; Carroll, J.; Eshuis, P.; Dössel, O.; Grass, M.

    2014-03-01

    Cardiac C-arm computed tomography (CT) imaging using interventional C-arm systems can be applied in various areas of interventional cardiology ranging from structural heart disease and electrophysiology interventions to valve procedures in hybrid operating rooms. In contrast to conventional CT systems, the reconstruction field of view (FOV) of C-arm systems is limited to a region of interest in cone-beam (along the patient axis) and fan-beam (in the transaxial plane) direction. Hence, highly X-ray opaque objects (e.g. cables from the interventional setup) outside the reconstruction field of view, yield streak artifacts in the reconstruction volume. To decrease the impact of these streaks a cable tracking approach on the 2D projection sequences with subsequent interpolation is applied. The proposed approach uses the fact that the projected position of objects outside the reconstruction volume depends strongly on the projection perspective. By tracking candidate points over multiple projections only objects outside the reconstruction volume are segmented in the projections. The method is quantitatively evaluated based on 30 simulated CT data sets. The 3D root mean square deviation to a reference image could be reduced for all cases by an average of 50 % (min 16 %, max 76 %). Image quality improvement is shown for clinical whole heart data sets acquired on an interventional C-arm system.

  4. Investigation of saddle trajectories for cardiac CT imaging in cone-beam geometry

    Energy Technology Data Exchange (ETDEWEB)

    Pack, Jed D [Department of Radiology, University of Utah, Salt Lake City, UT 84112 (United States); Noo, Frederic [Department of Radiology, University of Utah, Salt Lake City, UT 84112 (United States); Kudo, H [Department of Computer Science, Graduate School of Systems and Information Engineering, University of Tsukuba (Japan)

    2004-06-07

    This paper investigates cone-beam tomography for a wide class of x-ray source trajectories called saddles. In particular, a mathematical analysis of the number of intersections between a saddle and an arbitrary plane is given. This analysis demonstrates that axially truncated cone-beam projections acquired along a saddle can be used for exact reconstruction at any point in a large volume. The reconstruction can be achieved either using a new algorithm presented herein or using a formula recently introduced by Katsevich (2003 Int. J. Math. Math. Sci. 21 1305-21). The shape of the reconstructed volume and the properties of saddles make saddles attractive for cardiac imaging. Three examples of saddles are presented with a discussion of implementation on devices similar to modern C-arm systems and multislice CT scanners. Reconstruction with one of these saddles has been tested using computer-simulated data, with and without truncation. The imaged phantom for the truncated data is a FORBILD head phantom (representing the heart) that has been modified and embedded inside the FORBILD thorax phantom. The non-truncated data were generated by excluding the thorax. The reconstructed images demonstrate the accuracy of the mathematical results.

  5. Multi-oriented windowed harmonic phase reconstruction for robust cardiac strain imaging.

    Science.gov (United States)

    Cordero-Grande, Lucilio; Royuela-del-Val, Javier; Sanz-Estébanez, Santiago; Martín-Fernández, Marcos; Alberola-López, Carlos

    2016-04-01

    The purpose of this paper is to develop a method for direct estimation of the cardiac strain tensor by extending the harmonic phase reconstruction on tagged magnetic resonance images to obtain more precise and robust measurements. The extension relies on the reconstruction of the local phase of the image by means of the windowed Fourier transform and the acquisition of an overdetermined set of stripe orientations in order to avoid the phase interferences from structures outside the myocardium and the instabilities arising from the application of a gradient operator. Results have shown that increasing the number of acquired orientations provides a significant improvement in the reproducibility of the strain measurements and that the acquisition of an extended set of orientations also improves the reproducibility when compared with acquiring repeated samples from a smaller set of orientations. Additionally, biases in local phase estimation when using the original harmonic phase formulation are greatly diminished by the one here proposed. The ideas here presented allow the design of new methods for motion sensitive magnetic resonance imaging, which could simultaneously improve the resolution, robustness and accuracy of motion estimates. PMID:26745763

  6. Heart-rate-adapted image reconstruction in multidetector-row cardiac CT: influence of physiological and technical prerequisite on image quality

    International Nuclear Information System (INIS)

    The purpose of this study was to develop strategies for optimal image reconstruction in multidetector-row cardiac CT and to discuss the results in the context of individual heart rate, cardiac physiology, and technical prerequisite. Sixty-four patients underwent multidetector-row cardiac CT. Depending on the heart rate either a single-segmental reconstruction (SSR) or an adaptive two-segmental reconstruction (ASR) was applied. Image reconstruction was done either antegrade (a) or retrograde (r) in relation to the R-peak. Reconstruction of all data sets was performed at multiple time points within the t-wave/p-wave interval, differing from each other by 50 ms. In addition, each reconstruction was assigned to one of six reconstruction intervals (A-F), each corresponding to a specific event in the cardiac cycle. While no significant time points were found for absolute values, the following interval/reconstruction technique combinations provided significant better image quality: F/r at HR 65 bpm for all segments (p≤0.002). The results show that in order to achieve optimal image quality, image reconstruction has to be adjusted to each patient's ECG curve and heart rate individually. The moment of reconstruction should be determined as absolute rather than as relative distance from the previous R-peak. (orig.)

  7. Impact assessment of ionising radiation on wildlife

    International Nuclear Information System (INIS)

    This R and D project was commissioned by the Environment Agency and English Nature in January 2001 to provide up-to-date information on the impacts of ionising radiation on wildlife, upon which a robust assessment approach may be developed. This approach will also feed into the European Commission funded project 'Framework for Assessment of Environmental Impact' (FASSET), due to complete in October 2003. This report describes the behaviour and transport of radionuclides in the environment, considers the impact of ionising radiation on wildlife, and makes recommendations on an approach for the impact assessment of ionising radiation on wildlife for England and Wales. The assessment approach focuses on three ecosystems representative of those considered potentially most at risk from the impact of authorised radioactive discharges, namely a coastal grassland (terrestrial ecosystem); estuarine and freshwater ecosystems. The likely scale of the impact on wildlife is also assessed in light of a preliminary analysis based on this assessment approach. The aims of the report are: to summarise the latest research on the behaviour, transfer and impact of ionising radiation effects on wildlife; an outline and review of the relevant European and national legislation which has impacts on the requirements for assessments of the impact of ionising radiation on wildlife in the UK; to consider the role of regulatory bodies in assessing the impact of ionising radiation on wildlife with respect to England and Wales; to make recommendations on the relative biological effectiveness of different types of radiation with respect to wildlife; and to recommend an approach to assess the impacts to wildlife from ionising radiation from authorised discharges in England and Wales, with spreadsheets to support the methodology. The report demonstrates the behaviour and transfer of radionuclides in a number of different ecosystem types. Particular emphasis is placed on exposure pathways in those

  8. Preliminary Investigation: 2D-3D Registration of MR and X-ray Cardiac Images Using Catheter Constraints

    OpenAIRE

    Truong, Michael V.N.; Aslam, Abdullah; Rinaldi, Christopher Aldo; Razavi, Reza; Penney, Graeme P.; Rhode, Kawal

    2009-01-01

    Cardiac catheterization procedures are routinely guided by X-ray fluoroscopy but suffer from poor soft-tissue contrast and a lack of depth information. These procedures often employ pre-operative magnetic resonance or computed tomography imaging for treatment planning due to their excellent soft-tissue contrast and 3D imaging capabilities. We developed a 2D-3D image registration method to consolidate the advantages of both modalities by overlaying the 3D images onto the X-ray. Our method uses...

  9. Visualization of a Small Ventricular Septal Defect at First-pass Contrast-enhanced Cardiac Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Francesco Secchi

    2013-01-01

    Full Text Available Ventricular septal defect (VSD is a congenital heart disease that accounts for up to 40% of all congenital cardiac malformations. VSD is a connection between right and left ventricle, through the ventricular septum. Echocardiography and magnetic resonance imaging (MRI help identify this entity. This case presents a 12-year-old male diagnosed with a small muscular apical VSD of 3 mm in diameter, at echocardiography. Cardiac MRI using first-pass perfusion sequence, combining the right plane of acquisition with a short bolus of contrast material, clearly confirmed the presence of VSD.

  10. Assessment of cardiac function using myocardial perfusion imaging technique on SPECT with 99mTc sestamibi

    Science.gov (United States)

    Gani, M. R. A.; Nazir, F.; Pawiro, S. A.; Soejoko, D. S.

    2016-03-01

    Suspicion on coronary heart disease can be confirmed by observing the function of left ventricle cardiac muscle with Myocardial Perfusion Imaging techniques. The function perfusion itself is indicated by the uptake of radiopharmaceutical tracer. The 31 patients were studied undergoing the MPI examination on Gatot Soebroto Hospital using 99mTc-sestamibi radiopharmaceutical with stress and rest conditions. Stress was stimulated by physical exercise or pharmacological agent. After two hours, the patient did rest condition on the same day. The difference of uptake percentage between stress and rest conditions will be used to determine the malfunction of perfusion due to ischemic or infarct. Degradation of cardiac function was determined based on the image-based assessment of five segments of left ventricle cardiac. As a result, 8 (25.8%) patients had normal myocardial perfusion and 11 (35.5%) patients suspected for having partial ischemia. Total ischemia occurred to 8 (25.8%) patients with reversible and irreversible ischemia and the remaining 4 (12.9%) patients for partial infarct with characteristic the percentage of perfusion ≤50%. It is concluded that MPI technique of image-based assessment on uptake percentage difference between stress and rest conditions can be employed to predict abnormal perfusion as complementary information to diagnose the cardiac function.

  11. Multi-slice and dual-source CT in cardiac imaging. Principles - protocols - indications - outlook. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Ohnesorge, B.M. [Siemens Medical Solutions Group China, Beijing (China); Flohr, T.G. [Siemens Medical Solutions, Forchheim (Germany). Div. CT Physics and Applications Development; Becker, C.R.; Reiser, M.F. [Muenchen Univ. Klinikum Grosshadern (Germany). Dept. of Clinical Radiology; Knez, A [Muenchen Univ. Klinikum Grosshadern (Germany). Section Head Imaging

    2007-07-01

    Cardiac diseases, and in particular coronary artery disease, are the leading cause of death and morbidity in industrialized countries. The development of non-invasive imaging techniques for the heart and the coronary arteries has been considered a key element in improving patient care. A breakthrough in cardiac imaging using CT occurred in 1998, with the introduction of multi-slice computed tomography (CT). Since then, amazing advances in performance have taken place with scanners that acquire up to 64 slices per rotation. This book discusses the state-of-the-art developments in multi-slice CT for cardiac imaging as well as those that can be anticipated in the future. It serves as a comprehensive work that covers all aspects of this technology, from the technical fundamentals and image evaluation all the way to clinical indications and protocol recommendations. This fully reworked second edition draws on the most recent clinical experience obtained with 16- and 64-slice CT scanners by world-leading experts from Europe and the United States. It also includes 'hands-on' experience in the form of 10 representative clinical case studies, which are included on the accompanying CD. As a further highlight, the latest results of the very recently introduced dual-source CT, which may soon represent the CT technology of choice for cardiac applications, are presented. This book will not only convince the reader that multi-slice cardiac CT has arrived in clinical practice, it will also make a significant contribution to the education of radiologists, cardiologists, technologists, and physicists-whether newcomers, experienced users, or researchers. (orig.)

  12. Solar Hard X-ray Source Sizes in a Beam-Heated and Ionised Chromosphere

    CERN Document Server

    O'Flannagain, A; Gallagher, P T

    2014-01-01

    Solar flare hard X-rays (HXRs) are produced as bremsstrahlung when an accelerated population of electrons interacts with the dense chromospheric plasma. HXR observations presented by using the Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) have shown that HXR source sizes are 3-6 times more extended in height than those predicted by the standard collisional thick target model (CTTM). Several possible explanations have been put forward including the multi-threaded nature of flare loops, pitch-angle scattering, and magnetic mirroring. However, the nonuniform ionisation (NUI) structure along the path of the electron beam has not been fully explored as a solution to this problem. Ionised plasma is known to be less effective at producing nonthermal bremsstrahlung HXRs when compared to neutral plasma. If the peak HXR emission was produced in a locally ionised region within the chromosphere, the intensity of emission will be preferentially reduced around this peak, resulting in a more extended source. Due to...

  13. Cardiac Event Risk in Japanese Subjects Estimated Using Gated Myocardial Perfusion Imaging, in Conjunction With Diabetes Mellitus and Chronic Kidney Disease

    OpenAIRE

    Nakajima, Kenichi; Matsuo, Shinro; Okuyama, Chio; Hatta, Tsuguru; Tsukamoto, Kazumasa; Nishimura, Shigeyuki; Yamashina, Akira; Kusuoka, Hideo; Nishimura, Tsunehiko

    2011-01-01

    Background: Cardiac event risk is estimated using quantitative gated myocardial perfusion imaging (MPI) and clinical background in patients with ischemic heart disease. The aim of the present study was to calculate major cardiac event risk and tabulate it in the Heart Risk Table for clinical use of risk stratification. Methods and Results: Multivariate logistic regression was performed based on a multicenter prognostic database (Japanese Assessment of Cardiac Events and Survival Study by Quan...

  14. CMR Imaging With Rapid Visual T1 Assessment Predicts Mortality in Patients Suspected of Cardiac Amyloidosis

    Science.gov (United States)

    White, James A.; Kim, Han W.; Shah, Dipan; Fine, Nowell; Kim, Ki-Young; Wendell, David C.; Al-Jaroudi, Wael; Parker, Michele; Patel, Manesh; Gwadry-Sridhar, Femida; Judd, Robert M.; Kim, Raymond J.

    2014-01-01

    OBJECTIVES This study tested the diagnostic and prognostic utility of a rapid, visual T1 assessment method for identification of cardiac amyloidosis (CA) in a “real-life” referral population undergoing cardiac magnetic resonance for suspected CA. BACKGROUND In patients with confirmed CA, delayed-enhancement cardiac magnetic resonance (DE-CMR) frequently shows a diffuse, global hyperenhancement (HE) pattern. However, imaging is often technically challenging, and the prognostic significance of diffuse HE is unclear. METHODS Ninety consecutive patients referred for suspected CA and 64 hypertensive patients with left ventricular hypertrophy (LVH) were prospectively enrolled and underwent a modified DE-CMR protocol. After gadolinium administration a method for rapid, visual T1 assessment was used to identify the presence of diffuse HE during the scan, allowing immediate optimization of settings for the conventional DE-CMR that followed. The primary endpoint was all-cause mortality. RESULTS Among patients with suspected CA, 66% (59 of 90) demonstrated HE, with 81% (48 of 59) of these meeting pre-specified visual T1 assessment criteria for diffuse HE. Among hypertensive LVH patients, 6% (4 of 64) had HE, with none having diffuse HE. During 29 months of follow-up (interquartile range: 12 to 44 months), there were 50 (56%) deaths in patients with suspected CA and 4 (6%) in patients with hypertensive LVH. Multivariable analysis demonstrated that the presence of diffuse HE was the most important predictor of death in the group with suspected CA (hazard ratio: 5.5, 95% confidence interval: 2.7 to 11.0; p < 0.0001) and in the population as a whole (hazard ratio: 6.0, 95% confidence interval 3.0 to 12.1; p < 0.0001). Among 25 patients with myocardial histology obtained during follow-up, the sensitivity, specificity, and accuracy of diffuse HE in the diagnosis of CA were 93%, 70%, and 84%, respectively. CONCLUSIONS Among patients suspected of CA, the presence of diffuse HE by

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

    Energy Technology Data Exchange (ETDEWEB)

    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. Cardiac and pleuropulmonary AL amyloid imaging with technetium-99m labelled aprotinin

    Energy Technology Data Exchange (ETDEWEB)

    Aprile, C. [Dept. of Nuclear Medicine, Fondazione Clinica del Lavoro-IRCCS, Pavia (Italy); Marinone, G. [Inst. of Clinical Medicine II and Research Lab. Biotechnology, Policlinico S. Matteo-IRCCS, Pavia (Italy); Saponaro, R. [Dept. of Nuclear Medicine, Fondazione Clinica del Lavoro-IRCCS, Pavia (Italy); Bonino, C. [SORIN Biomedica, Saluggia VC (Italy); Merlini, G. [Inst. of Clinical Medicine II and Research Lab. Biotechnology, Policlinico S. Matteo-IRCCS, Pavia (Italy)

    1995-12-01

    Antiproteases are known to be present in amyloid deposits. We evaluated the possibility of using an anti-serine protease (aprotinin) labelled with technetium-99m (TcA), usually employed as a cortical renal tracer, for the imaging of amyloid deposits. Because of the known high uptake of TcA by the kidneys, we limited our analysis to extra-abdominal amyloid localizations. We report the scintigraphic findings observed in 24 patients with light chain amyloidosis (AL) and one with a hereditary form who were known or suspected to have extra-abdominal involvement. Planar scans obtained 100 min after i.v. TcA administration showed myocardial accumulation in 11 patients, pleuropulmonary accumulation in nine, pericardial accumulation in two and localization in the neck region (thyroid, salivary glands and tongue) in eight. TcA scintigraphy was negative in five patients without clinical or laboratory evidence of extra-abdominal involvement, as well as in 12 control group patients with cardiac and renal diseases. These preliminary results indicate TcA to be a low-cost, readily available radiopharmaceutical for imaging of extra-abdominal involvement in AL type amyloidosis. (orig.)

  17. Quality of myocardial perfusion single-photon emission tomography imaging: multicentre evaluation with a cardiac phantom.

    Science.gov (United States)

    Heikkinen, J; Ahonen, A; Kuikka, J T; Rautio, P

    1999-10-01

    The aim of the study was to evaluate quality of myocardial perfusion single-photon emission tomography (SPET) imaging in Finnish hospitals. Nineteen nuclear medicine departments participated in the study. A myocardial phantom simulating clinical stress and rest conditions was filled with routinely used isotope solution (technetium-99m or thallium-201). The cardiac insert included three reversible defects (simulating ischaemia): 30x30x14 mm(3) septal (90% recovery at rest), 30x20x14 mm(3) posterobasal (full recovery) and 20x20x14 mm(3) lateral (full recovery). There were two fixed defects (simulating infarct): 30x20x14 mm(3) postero-apical and 10x10x6 mm(3) apical. The phantom was imaged and interpreted as a myocardial perfusion patient. Reconstruction, printout and reporting were performed according to the clinical routine of each centre. Three nuclear medicine specialists anonymously evaluated the quality of the image sets. The visual scores of the experts were ranked from 1 to 5. Additionally, points from 0 to 8 were given to research reports according to how well perfusion defects were detected. Quantitative points were calculated by comparing background-subtracted and -normalized counts from 12 regions of interest between stress and rest images. Results for technetium studies (12 departments) were better than those for thallium (7 departments). The average visual scores of the experts were 3.7+/-0. 9 for all image sets, 3.2+/-0.5 for thallium users and 3.9+/-0.6 for technetium users (P=0.003). Five laboratories received a low score which, according to the specialists, is barely sufficient for limited clinical use. Average points for the reports were 5.6+/-2.1, 4.9+/-1.5 and 6.5+/-1.7 (P=0.051), and for the quantitation 8.2+/-1. 0, 7.9+/-0.4 and 8.4+/-1.1 (P=0.185), respectively. Seven out of 22 interpreters did not detect the lateral 20x20x14 mm(3) defect; five of them used thallium. This study demonstrated the heterogeneity of myocardial perfusion SPET in

  18. Quality of myocardial perfusion single-photon emission tomography imaging: multicentre evaluation with a cardiac phantom

    Energy Technology Data Exchange (ETDEWEB)

    Heikkinen, J. [Dept. of Nuclear Medicine, Etela-Savo Hospital District, Mikkeli Central Hospital, Mikkeli (Finland); Ahonen, A. [Dept. of Nuclear Medicine, Oulu University Hospital (Finland); Kuikka, J.T. [Dept. of Clinical Physiology, Kuopio University Hospital and Niuvanniemi Hospital, Kuopio (Finland); Rautio, P. [Dept. of Clinical Physiology, North Karelia Central Hospital, Joensuu (Finland)

    1999-10-01

    The aim of the study was to evaluate quality of myocardial perfusion single-photon emission tomography (SPET) imaging in Finnish hospitals. Nineteen nuclear medicine departments participated in the study. A myocardial phantom simulating clinical stress and rest conditions was filled with routinely used isotope solution (technetium-99m or thallium-201). The cardiac insert included three reversible defects (simulating ischaemia): 30 x 30 x 14 mm{sup 3} septal (90% recovery at rest), 30 x 20 x 14 mm{sup 3} posterobasal (full recovery) and 20 x 20 x 14 mm{sup 3} lateral (full recovery). There were two fixed defects (simulating infarct): 30 x 20 x 14 mm{sup 3} postero-apical and 10 x 10 x 6 mm{sup 3} apical. The phantom was imaged and interpreted as a myocardial perfusion patient. Reconstruction, printout and reporting were performed according to the clinical routine of each centre. Three nuclear medicine specialists anonymously evaluated the quality of the image sets. The visual scores of the experts were ranked from 1 to 5. Additionally, points from 0 to 8 were given to research reports according to how well perfusion defects were detected. Quantitative points were calculated by comparing background-subtracted and -normalized counts from 12 regions of interest between stress and rest images. Results for technetium studies (12 departments) were better than those for thallium (7 departments). The average visual scores of the experts were 3.7{+-}0.9 for all image sets, 3.2{+-}0.5 for thallium users and 3.9{+-}0.6 for technetium users (P=0.003). Five laboratories received a low score which, according to the specialists, is barely sufficient for limited clinical use. Average points for the reports were 5.6{+-}2.1, 4.9{+-}1.5 and 6.5{+-}1.7 (P=0.051), and for the quantitation 8.2{+-}1.0, 7.9{+-}0.4 and 8.4{+-}1.1 (P=0.185), respectively. Seven out of 22 interpreters did not detect the lateral 20 x 20 x 14 mm{sup 3} defect; five of them used thallium. This study demonstrated

  19. Imaging of cardiac perfusion of free-breathing small animals using dynamic phase-correlated micro-CT

    Energy Technology Data Exchange (ETDEWEB)

    Sawall, Stefan; Kuntz, Jan; Socher, Michaela; Knaup, Michael; Hess, Andreas; Bartling, Soenke; Kachelriess, Marc [Institute of Medical Physics, Friedrich-Alexander-University (FAU) Erlangen-Nuernberg, 91052 Erlangen, Germany and Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Animal Laboratory Services Core Facility, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Institute of Medical Physics, Friedrich-Alexander-University (FAU) Erlangen-Nuernberg, 91052 Erlangen (Germany); Institute of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-University (FAU) Erlangen-Nuernberg, 91052 Erlangen (Germany); Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Institute of Medical Physics, Friedrich-Alexander-University (FAU) Erlangen-Nuernberg, 91052 Erlangen, Germany and Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)

    2012-12-15

    Purpose:Mouse models of cardiac diseases have proven to be a valuable tool in preclinical research. The high cardiac and respiratory rates of free breathing mice prohibit conventional in vivo cardiac perfusion studies using computed tomography even if gating methods are applied. This makes a sacrification of the animals unavoidable and only allows for the application of ex vivo methods. Methods: To overcome this issue the authors propose a low dose scan protocol and an associated reconstruction algorithm that allows for in vivo imaging of cardiac perfusion and associated processes that are retrospectively synchronized to the respiratory and cardiac motion of the animal. The scan protocol consists of repetitive injections of contrast media within several consecutive scans while the ECG, respiratory motion, and timestamp of contrast injection are recorded and synchronized to the acquired projections. The iterative reconstruction algorithm employs a six-dimensional edge-preserving filter to provide low-noise, motion artifact-free images of the animal examined using the authors' low dose scan protocol. Results: The reconstructions obtained show that the complete temporal bolus evolution can be visualized and quantified in any desired combination of cardiac and respiratory phase including reperfusion phases. The proposed reconstruction method thereby keeps the administered radiation dose at a minimum and thus reduces metabolic inference to the animal allowing for longitudinal studies. Conclusions: The authors' low dose scan protocol and phase-correlated dynamic reconstruction algorithm allow for an easy and effective way to visualize phase-correlated perfusion processes in routine laboratory studies using free-breathing mice.

  20. European Code against Cancer 4th Edition: Ionising and non-ionising radiation and cancer.

    Science.gov (United States)

    McColl, Neil; Auvinen, Anssi; Kesminiene, Ausrele; Espina, Carolina; Erdmann, Friederike; de Vries, Esther; Greinert, Rüdiger; Harrison, John; Schüz, Joachim

    2015-12-01

    Ionising radiation can transfer sufficient energy to ionise molecules, and this can lead to chemical changes, including DNA damage in cells. Key evidence for the carcinogenicity of ionising radiation comes from: follow-up studies of the survivors of the atomic bombings in Japan; other epidemiological studies of groups that have been exposed to radiation from medical, occupational or environmental sources; experimental animal studies; and studies of cellular responses to radiation. Considering exposure to environmental ionising radiation, inhalation of naturally occurring radon is the major source of radiation in the population - in doses orders of magnitude higher than those from nuclear power production or nuclear fallout. Indoor exposure to radon and its decay products is an important cause of lung cancer; radon may cause approximately one in ten lung cancers in Europe. Exposures to radon in buildings can be reduced via a three-step process of identifying those with potentially elevated radon levels, measuring radon levels, and reducing exposure by installation of remediation systems. In the 4th Edition of the European Code against Cancer it is therefore recommended to: "Find out if you are exposed to radiation from naturally high radon levels in your home. Take action to reduce high radon levels". Non-ionising types of radiation (those with insufficient energy to ionise molecules) - including extremely low-frequency electric and magnetic fields as well as radiofrequency electromagnetic fields - are not an established cause of cancer and are therefore not addressed in the recommendations to reduce cancer risk.

  1. Locally homogenized and de-noised vector fields for cardiac fiber tracking in DT-MRI images

    Science.gov (United States)

    Akhbardeh, Alireza; Vadakkumpadan, Fijoy; Bayer, Jason; Trayanova, Natalia A.

    2009-02-01

    In this study we develop a methodology to accurately extract and visualize cardiac microstructure from experimental Diffusion Tensor (DT) data. First, a test model was constructed using an image-based model generation technique on Diffusion Tensor Magnetic Resonance Imaging (DT-MRI) data. These images were derived from a dataset having 122x122x500 um3 voxel resolution. De-noising and image enhancement was applied to this high-resolution dataset to clearly define anatomical boundaries within the images. The myocardial tissue was segmented from structural images using edge detection, region growing, and level set thresholding. The primary eigenvector of the diffusion tensor for each voxel, which represents the longitudinal direction of the fiber, was calculated to generate a vector field. Then an advanced locally regularizing nonlinear anisotropic filter, termed Perona-Malik (PEM), was used to regularize this vector field to eliminate imaging artifacts inherent to DT-MRI from volume averaging of the tissue with the surrounding medium. Finally, the vector field was streamlined to visualize fibers within the segmented myocardial tissue to compare the results with unfiltered data. With this technique, we were able to recover locally regularized (homogenized) fibers with a high accuracy by applying the PEM regularization technique, particularly on anatomical surfaces where imaging artifacts were most apparent. This approach not only aides in the visualization of noisy complex 3D vector fields obtained from DT-MRI, but also eliminates volume averaging artifacts to provide a realistic cardiac microstructure for use in electrophysiological modeling studies.

  2. The limited role of myocardial fluorine-18 fluorodeoxyglucose imaging in candidates for cardiac transplantation. A planar imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Kalff, V.; Van Every, B.; Kelly, M.J. [Alfred Hospital, Prahran, VIC (Australia). Dept. of Nuclear Medicine; Barton, H.J.; Bergin, P.J.; Esmore, D.S. [Alfred Hospital, Prahran, VIC (Australia). Cardiac Transplantation Services; Berlangieri, S.U. [Austin Hospital, Heidelberg, VIC (Australia). Centre for Positron Emission Tomography

    1998-03-01

    This study compares the incidence and extent of hibernating myocardium (defined by myocardial perfusion/metabolism mismatch) in 28 cardiac transplant candidates with ischaemic cardiomyopathy and in 16 other patients with coronary artery disease (CAD) undergoing viability assessment. It then reviews the impact of myocardial perfusion metabolism imaging on management decisions in the transplant candidates at 6 months after scintigraphy. Each patient underwent a planar myocardial thallium-201 and fluorine-18 fluorodeoxyglucose scan on a modified gamma camera. Perfusion/metabolism mismatch was sized semi-quantitatively and each patient was assigned a global mismatch score. Transplant candidates had a lower left ventricular ejection fraction (LVEF) (P<0.0002) and extent of hibernating myocardium (lower global mismatch score: P=0.005) than other CAD patients but the difference in respect of mismatch frequency (8/28 vs 9/16 patients) did not reach statistical significance. Transplant candidates with LVEF <20% had a lower global mismatch score (P<0.02) than those with an LVEF {>=}20%. Interestingly, two of three other CAD patients with LVEF <20% had a moderate mismatch. Follow-up studies revealed the lack of impact of metabolic imaging as none of the three transplant candidates who eventually underwent revascularisation had hibernating myocardium and transplantation was offered to one of only two candidates with more than one minor mismatch. Thus metabolic imaging in potential transplant candidates may be of limited value because of the very low extent of hibernating myocardium, particularly if LVEF is below 20% and where clinical decisions are often based on many other factors. (orig.)

  3. 3D Multi-Object Segmentation of Cardiac MSCT Imaging by using a Multi-Agent Approach

    Science.gov (United States)

    Fleureau, Julien; Garreau, Mireille; Boulmier, Dominique; Hernandez, Alfredo

    2007-01-01

    We propose a new technique for general purpose, semi-interactive and multi-object segmentation in N-dimensional images, applied to the extraction of cardiac structures in MultiSlice Computed Tomography (MSCT) imaging. The proposed approach makes use of a multi-agent scheme combined with a supervised classification methodology allowing the introduction of a priori information and presenting fast computing times. The multi-agent system is organised around a communicating agent which manages a population of situated agents which segment the image through cooperative and competitive interactions. The proposed technique has been tested on several patient data sets. Some typical results are finally presented and discussed. PMID:18003382

  4. Contrast-free diagnosis and treatment of coronary artery disease guided by integrated cardiac imaging: concept and first clinical experience.

    Science.gov (United States)

    Siegrist, Patrick T; Sumitsuji, Satoru; Kumada, Masahiro; Kaneda, Hideaki; Tachibana, Kouichi; Nanto, Shinsuke

    2016-01-01

    The use of iodinated contrast media (ICM) remains a potential hazard for patients undergoing diagnostic cardiac imaging and percutaneous coronary intervention. In particular patients with history of prior adverse reaction to a contrast agent are at a high risk in case of re-exposure, even if designated premedication is administered. Based on a patient with recurrent angina pectoris and history of systemic anaphylactic reaction to ICM, we describe the logical stepwise approach from diagnostic imaging to safe and successful imaging guided percutaneous coronary intervention without the use of contrast agent. PMID:25612793

  5. Role of imaging in the diagnosis and management of patients with cardiac amyloidosis: state of the art review and focus on emerging nuclear techniques.

    Science.gov (United States)

    Aljaroudi, Wael A; Desai, Milind Y; Tang, W H Wilson; Phelan, Dermot; Cerqueira, Manuel D; Jaber, Wael A

    2014-04-01

    Amyloidosis is an infiltrative disease characterized by deposition of amyloid fibrils within the extracellular tissue of one or multiple organs. Involvement of the heart, cardiac amyloidosis, is recognized as a common cause of restrictive cardiomyopathy and heart failure. The two major types of cardiac amyloidosis are cardiac amyloid light-chain (AL) and transthyretin-related cardiac amyloidosis (ATTR, mutant and wild types) (Nat Rev Cardiol 2010;7:398-408). While early recognition of cardiac amyloidosis is of major clinical importance, so is the ability to differentiate between subtypes. Indeed, both prognosis and therapeutic options vary drastically depending on the subtype. While endomyocardial biopsy with immunostaining is considered the gold standard, advances in imaging provide an attractive non-invasive alternative. Currently, electrocardiography, echocardiography, and cardiac magnetic resonance imaging are all used in the evaluation of cardiac amyloidosis with varying diagnostic and prognostic accuracy. Yet, none of these modalities can effectively differentiate the cardiac amyloid subtypes. Recent data with (99m)Tc-phosphate derivatives, previously used as bone seeking radioactive tracers, have shown promising results; these radiotracers selectively bind ATTR, but not AL subtype, and can differentiate subtypes with high diagnostic accuracy. This review will initially present the non-radionuclide imaging techniques and then focus on the radionuclide imaging techniques, particularly (99m)Tc-DPD and (99m)Tc-PYP, mechanism of action, performance and interpretation of the study, diagnostic accuracy, prognostic value, future clinical perspective, and outlook. PMID:24347127

  6. Analysis of prognostic value of clinical information and myocardial perfusion imaging in diabetic patients on cardiac events occurrence

    International Nuclear Information System (INIS)

    Objective: To explore the risk factors of cardiac event (CE) occurrence and evaluate the prognostic value of myocardial perfusion imaging (MPI) in diabetic patients. Methods: We conducted a study with 172(16.4%) consecutively registered patients with diabetes (132 males, 40 females; age range 16-90 years, mean age 55.94±12.46 years) and 875(83.6%) patients without diabetes with known or suspected coronary artery disease (CAD) undergoing SPECT MPI. Follow-up information was obtained through telephone interviews. Patients were followed up for at least 18 months. End points were defined as death due to primary cardiac cause, or nonfatal acute myocardial infarction and revascularization. The mean time of follow-up was 33.25±14.95 (1∼56) months. Results: Logistic stepwise regression analysis evaluated history of smoking and drinking, hypertension, hyperlipemia and the family history of CAD as predictors. A multiple regression formula was obtained: Y=-5.593+0.958X1+0.921 X2+0.428X3, (Y=cardiac events, X1=diabetes, X2=the family history of CAD, X3=hypertension). Diabetes, the family history of CAD and hypertension were dangerous factors for cardiac events, but hyperlipemia, history of smoking and drinking were protective factors for cardiac events. Over the follow-up period, there are 42 cardiac events in diabetic group, 86 in non-diabetic group. Patients with diabetes had significantly higher rates of cardiac events (24.4% versus 9.8%; chi-square 28.5, P<0.0001), compared with rates among patients without diabetes (table 1). Kaplan-Meier survival curves analyzing the no-CE rates in the diabetic and non-diabetic groups, diabetic patients were significantly lower than non-diabetic ones (Log-rank statistic, chi-square 28.75, P <0.0001). Of 172 diabetic patients, 32.2% of the patients with abnormal MPI occurred cardiac events, but only 7.4% of the patients with normal ones did(chi-square 12.34, P <0.001) (figure 1). Abnormal SPECT MPI was associated with the higher rate

  7. Isolation and Genetic Manipulation of Adult Cardiac Myocytes for Confocal Imaging

    OpenAIRE

    Kaestner, Lars; Scholz, Anke; Hammer, Karin; Vecerdea, Anne; Ruppenthal, Sandra; Lipp, Peter

    2009-01-01

    Cardiac myocytes isolated from adult hearts are widely accepted as a model somewhere half way between embryonic and neonatal muscle cells on one side and a working heart on the other. Thus, cardiomyocytes serve as good models for cardiac cellular physiology and pathophysiology, for pharmaceutical investigations as well as for the exploration of transgenic animal models. Here we describe a method of isolating the cells from the heart. Furthermore we show how a genetic manipulation on cardiac m...

  8. Multimodality Molecular Imaging of Cardiac Cell Transplantation: Part II. In Vivo Imaging of Bone Marrow Stromal Cells in Swine with PET/CT and MR Imaging.

    Science.gov (United States)

    Parashurama, Natesh; Ahn, Byeong-Cheol; Ziv, Keren; Ito, Ken; Paulmurugan, Ramasamy; Willmann, Jürgen K; Chung, Jaehoon; Ikeno, Fumiaki; Swanson, Julia C; Merk, Denis R; Lyons, Jennifer K; Yerushalmi, David; Teramoto, Tomohiko; Kosuge, Hisanori; Dao, Catherine N; Ray, Pritha; Patel, Manishkumar; Chang, Ya-Fang; Mahmoudi, Morteza; Cohen, Jeff Eric; Goldstone, Andrew Brooks; Habte, Frezghi; Bhaumik, Srabani; Yaghoubi, Shahriar; Robbins, Robert C; Dash, Rajesh; Yang, Phillip C; Brinton, Todd J; Yock, Paul G; McConnell, Michael V; Gambhir, Sanjiv S

    2016-09-01

    Purpose To quantitatively determine the limit of detection of marrow stromal cells (MSC) after cardiac cell therapy (CCT) in swine by using clinical positron emission tomography (PET) reporter gene imaging and magnetic resonance (MR) imaging with cell prelabeling. Materials and Methods Animal studies were approved by the institutional administrative panel on laboratory animal care. Seven swine received 23 intracardiac cell injections that contained control MSC and cell mixtures of MSC expressing a multimodality triple fusion (TF) reporter gene (MSC-TF) and bearing superparamagnetic iron oxide nanoparticles (NP) (MSC-TF-NP) or NP alone. Clinical MR imaging and PET reporter gene molecular imaging were performed after intravenous injection of the radiotracer fluorine 18-radiolabeled 9-[4-fluoro-3-(hydroxyl methyl) butyl] guanine ((18)F-FHBG). Linear regression analysis of both MR imaging and PET data and nonlinear regression analysis of PET data were performed, accounting for multiple injections per animal. Results MR imaging showed a positive correlation between MSC-TF-NP cell number and dephasing (dark) signal (R(2) = 0.72, P = .0001) and a lower detection limit of at least approximately 1.5 × 10(7) cells. PET reporter gene imaging demonstrated a significant positive correlation between MSC-TF and target-to-background ratio with the linear model (R(2) = 0.88, P = .0001, root mean square error = 0.523) and the nonlinear model (R(2) = 0.99, P = .0001, root mean square error = 0.273) and a lower detection limit of 2.5 × 10(8) cells. Conclusion The authors quantitatively determined the limit of detection of MSC after CCT in swine by using clinical PET reporter gene imaging and clinical MR imaging with cell prelabeling. (©) RSNA, 2016 Online supplemental material is available for this article. PMID:27332865

  9. Feasibility study to demonstrate cardiac imaging using fast kVp switching dual-energy computed tomography: phantom study

    Science.gov (United States)

    Madhav, Priti; Imai, Yasuhiro; Narayanan, Suresh; Dutta, Sandeep; Chandra, Naveen; Hsieh, Jiang

    2012-03-01

    Dual-energy computed tomography is a novel imaging tool that has the potential to reduce beam hardening artifacts and enhance material separation over conventional imaging techniques. Dual-energy acquisitions can be performed by using a fast kVp technology to switch between acquiring adjacent projections at two distinct x-ray spectra (80 and 140 kVp). These datasets can be used to further compute material density and monochromatic images for better material separation and beam hardening reduction by virtue of the projection domain process. The purpose of this study was to evaluate the feasibility of using dual-energy in cardiac imaging for myocardial perfusion detection and coronary artery lumen visualization. Data was acquired on a heart phantom, which consisted of the chambers and aorta filled with Iodine density solution (500 HU @ 120 kVp), a defect region between the aorta and chamber (40 HU @ 120 kVp), two Iodinefilled vessels (400 HU @ 120 kVp) of different diameters with high attenuation (hydroxyapatite) plaques (HAP), and with a 30-cm water equivalent body ring around the phantom. Prospective ECG-gated single-energy and prospective ECG-gated dual-energy imaging was performed. Results showed that the generated monochromatic images had minimal beam hardening artifacts which improved the accuracy and detection of the myocardial defect region. Material density images were useful in differentiating and quantifying the actual size of the plaque and coronary artery lumen. Overall, this study shows that dual-energy cardiac imaging will be a valuable tool for cardiac applications.

  10. Flash ionisation signature in coherent cyclotron emission from Brown Dwarfs

    CERN Document Server

    Vorgul, Irena

    2016-01-01

    Brown dwarfs form mineral clouds in their atmospheres, where charged particles can produce large-scale discharges in form of lightning resulting in a substantial sudden increase of local ionisation. Brown dwarfs are observed to emit cyclotron radio emission. We show that signatures of strong transient atmospheric ionisation events (flash ionisation) can be imprinted on a pre-existing radiation. Detection of such flash ionisation events will open investigations into the ionisation state and atmospheric dynamics. Such ionisation events can also result from explosion shock waves, bursts or eruptions. We present an analytical model that describes the modulation of a pre-existing electromagnetic radiation by a time-dependent (flash) conductivity that is characteristic for flash ionisation events like lightning. Our conductivity model reproduces the conductivity function derived from observations of Terrestrial Gamma Ray Flashes, and is applicable to astrophysical objects with strong temporal variations in the loca...

  11. Cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, Marc [Charite - Universitaetsmedizin Berlin (Germany). Inst. fuer Radiologie

    2011-07-01

    Computed tomography of the heart has become a highly accurate diagnostic modality that is attracting increasing attention. This extensively illustrated book aims to assist the reader in integrating cardiac CT into daily clinical practice, while also reviewing its current technical status and applications. Clear guidance is provided on the performance and interpretation of imaging using the latest technology, which offers greater coverage, better spatial resolution, and faster imaging. The specific features of scanners from all four main vendors, including those that have only recently become available, are presented. Among the wide range of applications and issues to be discussed are coronary artery bypass grafts, stents, plaques, and anomalies, cardiac valves, congenital and acquired heart disease, and radiation exposure. Upcoming clinical uses of cardiac CT, such as plaque imaging and functional assessment, are also explored. (orig.)

  12. Application of the Karhunen-Loeve transform temporal image filter to reduce noise in real-time cardiac cine MRI

    International Nuclear Information System (INIS)

    Real-time dynamic magnetic resonance imaging (MRI) typically sacrifices the signal-to-noise ratio (SNR) to achieve higher spatial and temporal resolution. Spatial and/or temporal filtering (e.g., low-pass filtering or averaging) of dynamic images improves the SNR at the expense of edge sharpness. We describe the application of a temporal filter for dynamic MR image series based on the Karhunen-Loeve transform (KLT) to remove random noise without blurring stationary or moving edges and requiring no training data. In this paper, we present several properties of this filter and their effects on filter performance, and propose an automatic way to find the filter cutoff based on the autocorrelation of the eigenimages. Numerical simulation and in vivo real-time cardiac cine MR image series spanning multiple cardiac cycles acquired using multi-channel sensitivity-encoded MRI, i.e., parallel imaging, are used to validate and demonstrate these properties. We found that in this application, the noise standard deviation was reduced to 42% of the original with no apparent image blurring by using the proposed filter cutoff. Greater noise reduction can be achieved by increasing the length of the image series. This advantage of KLT filtering provides flexibility in the form of another scan parameter to trade for SNR.

  13. Enhancing the survival of grafted cardiac stem cells for long-term imaging

    Energy Technology Data Exchange (ETDEWEB)

    Le, Uyenchi N.; Tae, Seong Ho; Bom, Hee Seung; Min, Jung Joon [Chonnam National University Medical School, Gwangju (Korea, Republic of)

    2007-07-01

    Heat shock treatment is known to induce the protection for cells from various environmental insults. Akt (protein kinase B) - with anti-apoptotic activity - has presently been reemerged as a critical enzyme in several signal transduction pathways involved in cell proliferation and programmed cell death. We hypothesized that thermotic treatment and Akt activity in genetically modified cardiomyoblasts would improve their survival after transplantation. Embryonic rat H9c2 cardiomyoblasts were simultaneously transfected with adenovirus containing luciferase reporter gene (MOl 50) and another containing Akt gene [MOl (0 100) ]. 5x106 harvested cells were i.m. implanted into murine skeletal muscles. Bioluminescence imaging was acquired for everyday and luciferase assay was performed to validate the imaging data. For thermotic challenge, adenovirus-mediated flue expressing H9c2 cells were subjected to great heat of 42 .deg. C for 1 hr and re-cultured at 37 .deg. C for 18 hours. Expression of heat shock protein in cells was detected in vitro by Western-blotting. 5x106 normal and shocked cells were implanted into mouse thigh (n = 5) and the animals were imaged with bioluminescence imaging system. In vitro evidences showed a high level expression of Akt and HSP in transfected H9c2 cells. Animals carrying Akt expressed bioluminescence signals until day 34 of post-implantation. The Flue activity was significantly higher in the shocked H9c2 cell-implanted rats and detected over 10 days as compared with the control group. The graft cell death was reduced by 73% at day 2 (1.46+ 10-7 p/s/cm{sup 2}/sr), 51% at day 3 (1.02+10-7 p/s/cm{sup 2}/sr), and 8% at day 10 (1.62+ 10-6 p/s/cm{sup 2}/sr). We revealed here improvement of donor cell's survival induced by the anti-apoptotic means of Akt genetic therapy or heat shock. Utility of bioluminescence imaging resulted in a potential to noninvasively and repetitively monitor implanted cardiac myoblasts over time.

  14. A three-dimensional model-based partial volume correction strategy for gated cardiac mouse PET imaging

    Science.gov (United States)

    Dumouchel, Tyler; Thorn, Stephanie; Kordos, Myra; DaSilva, Jean; Beanlands, Rob S. B.; deKemp, Robert A.

    2012-07-01

    Quantification in cardiac mouse positron emission tomography (PET) imaging is limited by the imaging spatial resolution. Spillover of left ventricle (LV) myocardial activity into adjacent organs results in partial volume (PV) losses leading to underestimation of myocardial activity. A PV correction method was developed to restore accuracy of the activity distribution for FDG mouse imaging. The PV correction model was based on convolving an LV image estimate with a 3D point spread function. The LV model was described regionally by a five-parameter profile including myocardial, background and blood activities which were separated into three compartments by the endocardial radius and myocardium wall thickness. The PV correction was tested with digital simulations and a physical 3D mouse LV phantom. In vivo cardiac FDG mouse PET imaging was also performed. Following imaging, the mice were sacrificed and the tracer biodistribution in the LV and liver tissue was measured using a gamma-counter. The PV correction algorithm improved recovery from 50% to within 5% of the truth for the simulated and measured phantom data and image uniformity by 5-13%. The PV correction algorithm improved the mean myocardial LV recovery from 0.56 (0.54) to 1.13 (1.10) without (with) scatter and attenuation corrections. The mean image uniformity was improved from 26% (26%) to 17% (16%) without (with) scatter and attenuation corrections applied. Scatter and attenuation corrections were not observed to significantly impact PV-corrected myocardial recovery or image uniformity. Image-based PV correction algorithm can increase the accuracy of PET image activity and improve the uniformity of the activity distribution in normal mice. The algorithm may be applied using different tracers, in transgenic models that affect myocardial uptake, or in different species provided there is sufficient image quality and similar contrast between the myocardium and surrounding structures.

  15. Comparative imaging of cardiac structures and function for the optimization of transcatheter approaches for valvular and structural heart disease.

    Science.gov (United States)

    Bateman, Michael G; Iaizzo, Paul A

    2011-12-01

    The detailed assessment of cardiac anatomy using multiple imaging modalities is essential to understand the high degree of variations that exist in human hearts (i.e., with and without pathologies). Additionally, such information should provide one with important insights regarding which imaging modality will best provide the required visualization of device placement via a given transcatheter approach. We describe here an unique set of such studies performed on either preserved heart specimens or within reanimated large mammalian hearts, including human (using Visible Heart(®) methodologies). Such anatomical and device-tissue interface knowledge is critical for both design engineers and clinicians that seek to develop and/or employ less invasive cardiac repair approaches for patients with acquired or congenital structural heart defects. PMID:21541775

  16. Cardiac Imaging Using Clinical 1.5 T MRI Scanners in a Murine Ischemia/Reperfusion Model

    Directory of Open Access Journals (Sweden)

    Jakob G. J. Voelkl

    2011-01-01

    Full Text Available To perform cardiac imaging in mice without having to invest in expensive dedicated equipment, we adapted a clinical 1.5 Tesla (T magnetic resonance imaging (MRI scanner for use in a murine ischemia/reperfusion model. Phase-sensitive inversion recovery (PSIR sequence facilitated the determination of infarct sizes in vivo by late gadolinium enhancement. Results were compared to histological infarct areas in mice after ischemia/reperfusion procedure with a good correlation (=0.807, <.001. In addition, fractional area change (FAC was assessed with single slice cine MRI and was matched to infarct size (=−0.837 and fractional shortening (FS measured with echocardiography (=0.860; both <.001. Here, we demonstrate the use of clinical 1.5 MRI scanners as a feasible method for basic phenotyping in mice. These widely available scanners are capable of investigating in vivo infarct dimensions as well as assessment of cardiac functional parameters in mice with reasonable throughput.

  17. Quantification of Myocardial Extracellular Volume Fraction with Cardiac MR Imaging in Thalassemia Major.

    Science.gov (United States)

    Hanneman, Kate; Nguyen, Elsie T; Thavendiranathan, Paaladinesh; Ward, Richard; Greiser, Andreas; Jolly, Marie-Pierre; Butany, Jagdish; Yang, Issac Y; Sussman, Marshall S; Wintersperger, Bernd J

    2016-06-01

    Purpose To quantify myocardial extracellular volume (ECV) by using cardiac magnetic resonance (MR) imaging in thalassemia major and to investigate the relationship between ECV and myocardial iron overload. Materials and Methods With institutional review board approval and informed consent, 30 patients with thalassemia major (mean age ± standard deviation, 34.6 years ± 9.5) and 10 healthy control subjects (mean age, 31.5 years ± 4.4) were prospectively recruited (clinicaltrials.gov identification number NCT02090699). Nineteen patients (63.3%) had prior myocardial iron overload (defined as midseptal T2* tracking was assessed with same-day transthoracic echocardiography. Statistical analysis included use of the two-sample t test, Fisher exact test, and Spearman correlation. Results Unenhanced T1 values were significantly lower in patients with prior myocardial iron overload than in control subjects (850.3 ± 115.1 vs 1006.3 ± 35.4, P Online supplemental material is available for this article. PMID:26653680

  18. The Use of Cardiac Magnetic Resonance Imaging in the Diagnostic Workup and Treatment of Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Peter Haemers

    2012-01-01

    Full Text Available Atrial fibrillation (AF is the most common cardiac arrhythmia and imposes a huge clinical and economic burden. AF is correlated with an increased morbidity and mortality, mainly due to stroke and heart failure. Cardiovascular imaging modalities, including echocardiography, computed tomography (CT, and cardiovascular magnetic resonance (CMR, play a central role in the workup and treatment of AF. One of the major advantages of CMR is the high contrast to noise ratio combined with good spatial and temporal resolution, without any radiation burden. This allows a detailed assessment of the structure and function of the left atrium (LA. Of particular interest is the ability to visualize the extent of LA wall injury. We provide a focused review of the value of CMR in identifying the underlying pathophysiological mechanisms of AF, its role in stroke prevention and in the guidance of radiofrequency catheter ablation. CMR is a promising technique that could add valuable information for therapeutic decision making in specific subpopulations with AF.

  19. Estimation of post mortem interval by tomographic images of intra-cardiac hypostasis.

    Science.gov (United States)

    Zerbini, Talita; da Silva, Luiz Fernando Ferraz; Lobato Baptista, Pedro Artur; Ikari, Eduardo Seigo; Rodrigues de Araujo, Marina; de André, Carmen Diva Saldiva; da Motta Singer, Julio; da Rocha, Francisco Marcelo Monteiro; Junior, Edson Amaro; Pasqualucci, Carlos Augusto Gonçalves; Saldiva, Paulo Hilario Nascimento

    2016-02-01

    The determination of the post mortem interval (PMI) is important in many instances, especially in criminal investigations. So, we consider post mortem tomographic evaluation of intra-cardiac hypostasis as an additional method for such purpose. Tomographic images of the thoraces of the corpses of 23 patients who died in a hospital were obtained sequentially at one hour intervals to allow the analysis of changes in density due to hypostasis over time. The right and left atria, which appear in the mediastinal window, were selected for measurements of the average organ density. An exponential model was used to relate the difference between the attenuation coefficients of the anterior segment of the right atrium and the posterior segment of the left atrium to the PMI. In spite of the large variability of the data from this observational study, PMI estimates during the first 12 h after death can be estimated with a margin of error smaller than two hours. The results suggest that the difference between the attenuation coefficients stabilizes around 12 h post mortem and may be used as an additional method to estimate the PMI. PMID:26802976

  20. Cardiac Magnetic Resonance Imaging Findings in a Patient with Ebstein’s Anomaly and Left Ventricular Dysfunction

    OpenAIRE

    Nasim Naderi; Ahmad Amin; Hamidreza Pouraliakbar

    2013-01-01

    Ebstein anomaly is characterized by apical displacement of the septal and posterior tricuspid valve leaflets, leading to atrialization of the right ventricle and could be diagnosed in a routine transthoracic echocardiography exam. We reported a young man with right sided heart failure symptoms who was found to have biventricular failure with suspected apical displacement of septal leaflet of tricuspid valve. For better evaluation, cardiac magnetic resonance imaging (CMR) was performed and nic...

  1. Angiographic correlations of patients with small vessel disease diagnosed by adenosine-stress cardiac magnetic resonance imaging

    OpenAIRE

    Scheck Roland; Hoefling Berthold; Ali Eman; Klos Markus; Pilz Guenter; Bernhardt Peter

    2008-01-01

    Abstract Cardiac magnetic resonance imaging (CMR) with adenosine-stress myocardial perfusion is gaining importance for the detection and quantification of coronary artery disease (CAD). However, there is little knowledge about patients with CMR-detected ischemia, but having no relevant stenosis as seen on coronary angiography (CA). The aims of our study were to characterize these patients by CMR and CA and evaluate correlations and potential reasons for the ischemic findings. 73 patients with...

  2. Evaluation of a real-time hybrid three-dimensional echo and X-ray imaging system for guidance of cardiac catheterisation procedures.

    Science.gov (United States)

    Housden, R J; Arujuna, A; Ma, Y; Nijhof, N; Gijsbers, G; Bullens, R; O'Neill, M; Cooklin, M; Rinaldi, C A; Gill, J; Kapetanakis, S; Hancock, J; Thomas, M; Razavi, R; Rhode, K S

    2012-01-01

    Minimally invasive cardiac surgery is made possible by image guidance technology. X-ray fluoroscopy provides high contrast images of catheters and devices, whereas 3D ultrasound is better for visualising cardiac anatomy. We present a system in which the two modalities are combined, with a trans-esophageal echo volume registered to and overlaid on an X-ray projection image in real-time. We evaluate the accuracy of the system in terms of both temporal synchronisation errors and overlay registration errors. The temporal synchronisation error was found to be 10% of the typical cardiac cycle length. In 11 clinical data sets, we found an average alignment error of 2.9 mm. We conclude that the accuracy result is very encouraging and sufficient for guiding many types of cardiac interventions. The combined information is clinically useful for placing the echo image in a familiar coordinate system and for more easily identifying catheters in the echo volume.

  3. Quantification of myocardial perfusion using cardiac magnetic resonance imaging correlates significantly to rubidium-82 positron emission tomography in patients with severe coronary artery disease

    DEFF Research Database (Denmark)

    Qayyum, Abbas A; Hasbak, Philip; Larsson, Henrik B W;

    2014-01-01

    INTRODUCTION: Aim was to compare absolute myocardial perfusion using cardiac magnetic resonance imaging (CMRI) based on Tikhonov's procedure of deconvolution and rubidium-82 positron emission tomography (Rb-82 PET). MATERIALS AND METHODS: Fourteen patients with coronary artery stenosis underwent ...

  4. Image Registration and Analysis for Quantitative Myocardial Perfusion: Application to Dynamic Circular Cardiac CT

    NARCIS (Netherlands)

    Isola, A.; Schmitt, H.; Van Stevendaal, U.; Begemann, P.G.C.; Coulon, P.; Boussel, L.; Grass, M.

    2012-01-01

    Large area detector computed tomography systems with fastrotating gantries enable volumetric dynamic cardiac perfusion studies. Prospectively ECG-triggered acquisitions limit the data acquisition to a predefined cardiac phase and thereby reduce X-ray dose andlimit motion artifacts. Even in the case

  5. The Value of Conventional Echocardiographic and Tissue Doppler Imaging in the Diagnosis of Cardiac Amyloidosis

    Institute of Scientific and Technical Information of China (English)

    Li ZHANG; Mingxing XIE; Xinfang WANG; Yali YANG; Junhong HUANG; Ming CHENG; Feixiang XIANG; Qing LU

    2008-01-01

    Transthoracic echocardiographic characteristics of 17 cases of cardiac amyloidosis (CA),a rare disease in China, were analyzed in order to improve the understanding of the disease. Seventeen cases of biopsy-proven CA, admitted to Wuhan Union Hospital from June 1994 to September 2008 were retrospectively reviewed. Twenty normal volunteers served as control group. Left atrial and ventricular functions and mitral inflow velocity were measured by two-dimensional, and Doppler echocardiography, and tissue Doppler imaging (TDI)-derived peak systolic wall motion velocities (Sv), peak early diastolic wall motion velocities (Ev), and peak late diastolic wall motion (Av) were measured at the septunm. Lateral, inferior and anterior comers of mitral annulus from the apical 4- and 2 chamber views. Compared with the control group, the interventricular septal thickness (IVSd), the left ventricular posterior wall (LVPWd), right ventricular transverse diameter (RVTDd) near the end of diastole and the interauricular septum thickness (IASs), left atrial anteroposterior diameter (LAADs), right atrial transverse diameter (RATDs) near the end of systole were increased significantly (all P<0.05) and left ventricular ejection fraction (LVEF) decreased (P<0.05) in the CA group.Compared with the control group, Sv, Ev at each wall and Av at almost all walls were significantly decreased in the CA group. In the CA group, Myocardial echoes of interventricular septum and free wall of left ventricle were enhanced evidently and distributed unevenly. The echoes presented as ground glass-like images, with some spotty hyper echoes. Both atria were enlarged, and LVEF decreased, with diastolic function impaired, and mild-moderate hydropericardium found in the CA group. It was concluded that echocardiography was a relatively sensitive and highly specific non-invasive method for the diagnosis of CA.

  6. Critical ionisation velocity effects in astrophysical plasmas

    International Nuclear Information System (INIS)

    Critical ionisation velocity effects are relevant to astrophysical situations where neutral gas moves through a magnetised plasma. The experimental significance of the critical velocity is well established and the physical basis is now becoming clear. The underlying mechanism depends on the combined effects of electron impact ionisation and electron energisation by collective plasma interactions. For low density plasmas a theory based on a circular process involving electron heating through a modified two stream instability has been developed. Several applications of critical velocity effects to astrophysical plasmas have been discussed in the literature. The importance of the effect in any particular case may be determined from a detailed consideration of energy and momentum balance, using appropriate atomic rate coefficients and taking full account of collective plasma processes. (Auth.)

  7. A system for seismocardiography-based identification of quiescent heart phases: implications for cardiac imaging.

    Science.gov (United States)

    Wick, Carson A; Su, Jin-Jyh; McClellan, James H; Brand, Oliver; Bhatti, Pamela T; Buice, Ashley L; Stillman, Arthur E; Tang, Xiangyang; Tridandapani, Srini

    2012-09-01

    Seismocardiography (SCG), a representation of mechanical heart motion, may more accurately determine periods of cardiac quiescence within a cardiac cycle than the electrically derived electrocardiogram (EKG) and, thus, may have implications for gating in cardiac computed tomography. We designed and implemented a system to synchronously acquire echocardiography, EKG, and SCG data. The device was used to study the variability between EKG and SCG and characterize the relationship between the mechanical and electrical activity of the heart. For each cardiac cycle, the feature of the SCG indicating Aortic Valve Closure was identified and its time position with respect to the EKG was observed. This position was found to vary for different heart rates and between two human subjects. A color map showing the magnitude of the SCG acceleration and computed velocity was derived, allowing for direct visualization of quiescent phases of the cardiac cycle with respect to heart rate. PMID:22581141

  8. Cardiac effects of 3 months treatment of acromegaly evaluated by magnetic resonance imaging and B-type natriuretic peptides

    DEFF Research Database (Denmark)

    Andreassen, Mikkel; Faber, Jens Oscar; Kjær, Andreas;

    2010-01-01

    Long-term treatment of acromegaly prevents aggravation and reverses associated heart disease. A previous study has shown a temporary increase in serum levels of the N-terminal fraction of pro B-type natriuretic peptide (NT-proBNP) suggesting an initial decline in cardiac function when treatment...... of acromegaly is initiated. This was a three months prospective study investigating short-term cardiac effects of treatment in acromegalic patients. Cardiac function was evaluated by the gold standard method cardiac magnetic resonance imaging (CMRI) and circulating levels of B-type natriuretic peptides (BNP......) (95% CI 3-14), P = 0.007) and an increase in levels of BNP (median (ranges) 7 (0.58-286) vs. 20 (1-489) pg/mL, P = 0.033) and of NT-proBNP (63 (20-1004) vs. 80 (20-3391) pg/mL, P = 0.027). Assessed by the highly sensitive and precise CMRI method, 3 months treatment of acromegaly resulted...

  9. Fontan procedure: imaging of normal post-surgical anatomy and the spectrum of cardiac and extracardiac complications

    International Nuclear Information System (INIS)

    Univentricular congenital heart diseases include a range of entities that result in a functionally single ventricular chamber. Although the only curative therapy is cardiac transplantation, there are several palliative surgical techniques that prevent ventricular volume overload, diverting part or all the systemic venous circulation into the pulmonary arteries. The modern Fontan procedure, which consists of anastomosing both the superior (SVC) and inferior vena cava (IVC) to the right pulmonary artery (RPA), is nowadays the last step before transplantation. The importance of imaging in these entities lies not only in the understanding of the new circuit established after surgical correction, but also in the early detection of the wide spectrum of cardiac and extracardiac complications that can occur due to the new physiological condition. Due to the increased survival of these patients, long-term complications are becoming more common. The main cardiac complications are atrial enlargement, ventricular dysfunction, and stenosis or thrombosis of the conduit. Pulmonary artery stenosis, pulmonary arteriovenous fistulae (PAVF), systemic-pulmonary veno venous shunts (VVS), hepatic congestion, cardiac cirrhosis, and protein-losing enteropathy are potential extracardiac complications. - Highlights: • Fontan procedure is the main palliative surgical procedure for univentricular heart correction. • Fontan procedure entails the anastomosis of SVC and IVC to the RPA. • Complications are becoming more common due to the increased survival of patients with Fontan

  10. Early detection of cardiac dysfunction in the type 1 diabetic heart using speckle-tracking based strain imaging.

    Science.gov (United States)

    Shepherd, Danielle L; Nichols, Cody E; Croston, Tara L; McLaughlin, Sarah L; Petrone, Ashley B; Lewis, Sara E; Thapa, Dharendra; Long, Dustin M; Dick, Gregory M; Hollander, John M

    2016-01-01

    Enhanced sensitivity in echocardiographic analyses may allow for early detection of changes in cardiac function beyond the detection limits of conventional echocardiographic analyses, particularly in a small animal model. The goal of this study was to compare conventional echocardiographic measurements and speckle-tracking based strain imaging analyses in a small animal model of type 1 diabetes mellitus. Conventional analyses revealed differences in ejection fraction, fractional shortening, cardiac output, and stroke volume in diabetic animals relative to controls at 6-weeks post-diabetic onset. In contrast, when assessing short- and long-axis speckle-tracking based strain analyses, diabetic mice showed changes in average systolic radial strain, radial strain rate, radial displacement, and radial velocity, as well as decreased circumferential and longitudinal strain rate, as early as 1-week post-diabetic onset and persisting throughout the diabetic study. Further, we performed regional analyses for the LV and found that the free wall region was affected in both the short- and long-axis when assessing radial dimension parameters. These changes began 1-week post-diabetic onset and remained throughout the progression of the disease. These findings demonstrate the use of speckle-tracking based strain as an approach to elucidate cardiac dysfunction from a global perspective, identifying left ventricular cardiac regions affected during the progression of type 1 diabetes mellitus earlier than contractile changes detected by conventional echocardiographic measurements.

  11. Noninvasive diagnosis of a false left ventricular aneurysm with radioisotope gated cardiac blood pool imaging. Differentiation from true aneurysm

    International Nuclear Information System (INIS)

    Unlike the true left ventricular aneurysm, false aneurysms have recently been shown to be subject to late rupture. Rarely diagnosed before surgery or autopsy, the false aneurysm has never been identified by noninvasive techniques. We report the first such noninvasive diagnosis employing radioisotope gated cardiac blood pool imaging. Due to the unique and possibly life-threatening clinical course and potential for surgical cure of false left ventricular aneurysm, early noninvasive diagnosis by imaging techniques may be critical. The methods shown here are generally applicable, becoming widely available and may help in evaluation of false left ventricular aneurysm as a cause of sudden death

  12. Reproducibility of small animal cine and scar cardiac magnetic resonance imaging using a clinical 3.0 tesla system

    OpenAIRE

    Manka, Robert; Jahnke, Cosima; Hucko, Thomas; Dietrich, Thore; Gebker, Rolf; Schnackenburg, Bernhard; Graf, Kristof; Paetsch, Ingo

    2013-01-01

    Background To evaluate the inter-study, inter-reader and intra-reader reproducibility of cardiac cine and scar imaging in rats using a clinical 3.0 Tesla magnetic resonance (MR) system. Methods Thirty-three adult rats (Sprague–Dawley) were imaged 24 hours after surgical occlusion of the left anterior descending coronary artery using a 3.0 Tesla clinical MR scanner (Philips Healthcare, Best, The Netherlands) equipped with a dedicated 70 mm solenoid receive-only coil. Left-ventricular (LV) volu...

  13. Relationship between quantitative cardiac neuronal imaging with {sup 123}I-meta-iodobenzylguanidine and hospitalization in patients with heart failure

    Energy Technology Data Exchange (ETDEWEB)

    Parker, Matthew W.; Sood, Nitesh [University of Connecticut, School of Medicine Department of Medicine, Farmington, CT (United States); Hartford Hospital, Division of Cardiology, Hartford, CT (United States); Ahlberg, Alan W. [Hartford Hospital, Division of Cardiology, Hartford, CT (United States); Jacobson, Arnold F. [GE Healthcare, Princeton, NJ (United States); Heller, Gary V. [The Intersocietal Accreditation Commission, Ellicott City, MD (United States); Lundbye, Justin B. [University of Connecticut, School of Medicine Department of Medicine, Farmington, CT (United States); The Hospital of Central Connecticut, Division of Cardiology, New Britain, CT (United States)

    2014-09-15

    Hospitalization in patients with systolic heart failure is associated with morbidity, mortality, and cost. Myocardial sympathetic innervation, imaged by {sup 123}I-meta-iodobenzylguanidine ({sup 123}I-mIBG), has been associated with cardiac events in a recent multicenter study. The present analysis explored the relationship between {sup 123}I-mIBG imaging findings and hospitalization. Source documents from the ADMIRE-HF trial were reviewed to identify hospitalization events in patients with systolic heart failure following cardiac neuronal imaging using {sup 123}I-mIBG. Time to hospitalization was analyzed with the Kaplan-Meier method and compared to the mIBG heart-to-mediastinum (H/M) ratio using multiple-failure Cox regression. During 1.4 years of median follow-up, 362 end-point hospitalizations occurred in 207 of 961 subjects, 79 % of whom had H/M ratio <1.6. Among subjects hospitalized for any cause, 88 % had H/M ratio <1.6 and subjects with H/M ratio <1.6 experienced hospitalization earlier than subjects with higher H/M ratios (log-rank p = 0.003). After adjusting for elevated brain natriuretic peptide (BNP) and time since heart failure diagnosis, a low mIBG H/M ratio was associated with cardiac-related hospitalization (HR 1.48, 95 % CI 1.05 - 2.0; p = 0.02). The mIBG H/M ratio may risk-stratify patients with heart failure for cardiac-related hospitalization, especially when used in conjunction with BNP. Further studies are warranted to examine these relationships. (orig.)

  14. Induced apnea enhances image quality and visualization of cardiopulmonary anatomic during contrastenhanced cardiac computerized tomographic angiography in children

    Directory of Open Access Journals (Sweden)

    Murali Chakravarthy

    2015-01-01

    Full Text Available Objective: The purpose of our study was to determine the effect of induced apnea on quality of cardiopulmonary structures during computerized tomographic (CT angiography images in children with congenital heart diseases. Methods: Pediatric patients with congenital heart defects undergoing cardiac CT angiography at our facility in the past 3 years participated in this study. The earlier patients underwent cardiac CT angiography without induced apnea and while, later, apnea was induced in patients, which was followed by electrocardiogram gated cardiac CT angiography. General anesthesia was induced using sleep dose of intravenous propofol. After the initial check CT, on request by the radiologist, apnea was induced by the anesthesiologist by administering 1 mg/kg of intravenous suxamethonium. Soon after apnea ensued, the contrast was injected, and CT angiogram carried out. CT images in the "apnea group" were compared with those in "nonapnea group." After the completion of the procedure, the patients were mask ventilated with 100% oxygen till the spontaneous ventilation was restored. Results: We studied 46 patients, of whom 36 with apnea and yet another 10 without. The quality of the image, visualization of structures such as cardiac wall, outflow tracts, lung field, aortopulmonary shunts, and coronary arteries were analyzed and subjected to statistical analysis (Mann-Whitney U, Fischer′s exact test and Pearson′s Chi-square test. In the induced apnea group, overall image quality was considered excellent in 89% (n = 33 of the studies, while in the "no apnea group," only 30% of studies were excellent. Absent or minimal motion artifacts were seen in a majority of the studies in apnea group (94%. In the nonapnea group, the respiratory and body motion artifacts were severe in 50%, moderate in 30%, and minimal in 20%, but they were significantly lesser in the apnea group. All the studied parameters were statistically significant in the apnea group in

  15. An investigation of flat panel equipment variables on image quality with a dedicated cardiac phantom.

    Science.gov (United States)

    Dragusin, O; Bosmans, H; Pappas, C; Desmet, W

    2008-09-21

    Image quality (IQ) evaluation plays a key role in the process of optimization of new x-ray systems. Ideally, this process should be supported by real clinical images, but ethical issues and differences in anatomy and pathology of patients make it impossible. Phantom studies might overcome these issues. This paper presents the IQ evaluation of 30 cineangiographic films acquired with a cardiac flat panel system. The phantom used simulates the anatomy of the heart and allows the circulation of contrast agent boluses through coronary arteries. Variables investigated with influence on IQ and radiation dose are: tube potential, detector dose, added Copper filters, dynamic density optimization (DDO) and viewing angle. The IQ evaluation consisted of scoring 4 simulated calcified lesions located on different coronary artery segments in terms of degree of visualization. Eight cardiologists rated the lesions using a five-point scale ((1) lesion not visible to (5) very good visibility). Radiation doses associated to the angiograms are expressed in terms of incident air kerma (IAK) and effective dose that has been calculated with PCXMX software (STUK, Finland) from the exposure settings assuming a standard sized patient of 70 Kg. Mean IQ scores ranged from 1.68 to 4.88. The highest IQ scores were obtained for the angiograms acquired with tube potential 80 kVp, no added Cu filters, DDO 60%, RAO and LAO views and the highest entrance detector dose that has been used in the present study, namely 0.17 microGy/im. Radiation doses (IAK approximately 40 mGy and effective dose of 1 mSv) were estimated for angiograms acquired at 15 frames s(-1), detector field-of-view 20 cm, and a length of 5 s. The following parameters improved the IQ factor significantly: a change in tube potential from 96 to 80 kVp, detector dose from 0.10 microGy/im to 0.17 microGy/im, the absence of Copper filtration. DDO variable which is a post-processing parameter should be carefully evaluated because it alters

  16. An investigation of flat panel equipment variables on image quality with a dedicated cardiac phantom

    International Nuclear Information System (INIS)

    Image quality (IQ) evaluation plays a key role in the process of optimization of new x-ray systems. Ideally, this process should be supported by real clinical images, but ethical issues and differences in anatomy and pathology of patients make it impossible. Phantom studies might overcome these issues. This paper presents the IQ evaluation of 30 cineangiographic films acquired with a cardiac flat panel system. The phantom used simulates the anatomy of the heart and allows the circulation of contrast agent boluses through coronary arteries. Variables investigated with influence on IQ and radiation dose are: tube potential, detector dose, added Copper filters, dynamic density optimization (DDO) and viewing angle. The IQ evaluation consisted of scoring 4 simulated calcified lesions located on different coronary artery segments in terms of degree of visualization. Eight cardiologists rated the lesions using a five-point scale ((1) lesion not visible to (5) very good visibility). Radiation doses associated to the angiograms are expressed in terms of incident air kerma (IAK) and effective dose that has been calculated with PCXMX software (STUK, Finland) from the exposure settings assuming a standard sized patient of 70 Kg. Mean IQ scores ranged from 1.68 to 4.88. The highest IQ scores were obtained for the angiograms acquired with tube potential 80 kVp, no added Cu filters, DDO 60%, RAO and LAO views and the highest entrance detector dose that has been used in the present study, namely 0.17 μGy/im. Radiation doses (IAK ∼40 mGy and effective dose of 1 mSv) were estimated for angiograms acquired at 15 frames s-1, detector field-of-view 20 cm, and a length of 5 s. The following parameters improved the IQ factor significantly: a change in tube potential from 96 to 80 kVp, detector dose from 0.10 μGy/im to 0.17 μGy/im, the absence of Copper filtration. DDO variable which is a post-processing parameter should be carefully evaluated because it alters the quality of the

  17. Diffuse infiltrative cardiac tuberculosis

    International Nuclear Information System (INIS)

    We present the cardiac magnetic resonance images of an unusual form of cardiac tuberculosis. Nodular masses in a sheet-like distribution were seen to infiltrate the outer myocardium and pericardium along most of the cardiac chambers. The lesions showed significant resolution on antitubercular therapy

  18. Hybrid echo and x-ray image guidance for cardiac catheterization procedures by using a robotic arm: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Ma Yingliang; Penney, Graeme P; Razavi, Reza; Rhode, Kawal S [Division of Imaging Sciences, King' s College, London SE1 7EH (United Kingdom); Bos, Dennis; Frissen, Peter [Philips Applied Technologies, High Tech. Campus 7, 5656 AE Eindhoven (Netherlands); Rinaldi, C Aldo, E-mail: y.ma@kcl.ac.u [Department of Cardiology, Guy' s and St Thomas' NHS Foundation Trust, London SE1 7EH (United Kingdom)

    2010-07-07

    We present a feasibility study on hybrid echocardiography (echo) and x-ray image guidance for cardiac catheterization procedures. A self-tracked, remotely operated robotic arm with haptic feedback was developed that attached to a standard x-ray table. This was used to safely manipulate a three-dimensional (3D) trans-thoracic echo probe during simultaneous x-ray fluoroscopy and echo acquisitions. By a combination of calibration and tracking of the echo and x-ray systems, it was possible to register the 3D echo images with the 2D x-ray images. Visualization of the combined data was achieved by either overlaying triangulated surfaces extracted from segmented echo data onto the x-ray images or by overlaying volume rendered 3D echo data. Furthermore, in order to overcome the limited field of view of the echo probe, it was possible to create extended field of view (EFOV) 3D echo images by co-registering multiple tracked echo data to generate larger roadmaps for procedure guidance. The registration method was validated using a cross-wire phantom and showed a 2D target registration error of 3.5 mm. The clinical feasibility of the method was demonstrated during two clinical cases for patients undergoing cardiac pacing studies. The EFOV technique was demonstrated using two healthy volunteers. (note)

  19. Modification of the NEMA XR21-2000 cardiac phantom for testing of imaging systems used in endovascular image guided interventions

    OpenAIRE

    Ionita, C. N.; Dohatcu, A.; A Jain; Keleshis, C; Hoffmann, K. R.; Bednarek, D. R.; Rudin, S

    2009-01-01

    X-ray equipment testing using phantoms that mimic the specific human anatomy, morphology, and structure is a very important step in the research, development, and routine quality assurance for such equipment. Although the NEMA XR21 phantom exists for cardiac applications, there is no such standard phantom for neuro-, peripheral and cardio-vascular angiographic applications. We have extended the application of the NEMA XR21-2000 phantom to evaluate neurovascular x-ray imaging systems by struct...

  20. Reproducibility of small animal cine and scar cardiac magnetic resonance imaging using a clinical 3.0 tesla system

    International Nuclear Information System (INIS)

    To evaluate the inter-study, inter-reader and intra-reader reproducibility of cardiac cine and scar imaging in rats using a clinical 3.0 Tesla magnetic resonance (MR) system. Thirty-three adult rats (Sprague–Dawley) were imaged 24 hours after surgical occlusion of the left anterior descending coronary artery using a 3.0 Tesla clinical MR scanner (Philips Healthcare, Best, The Netherlands) equipped with a dedicated 70 mm solenoid receive-only coil. Left-ventricular (LV) volumes, mass, ejection fraction and amount of myocardial scar tissue were measured. Intra-and inter-observer reproducibility was assessed in all animals. In addition, repeat MR exams were performed in 6 randomly chosen rats within 24 hours to assess inter-study reproducibility. The MR imaging protocol was successfully completed in 32 (97%) animals. Bland-Altman analysis demonstrated high intra-reader reproducibility (mean bias%: LV end-diastolic volume (LVEDV), -1.7%; LV end-systolic volume (LVESV), -2.2%; LV ejection fraction (LVEF), 1.0%; LV mass, -2.7%; and scar mass, -1.2%) and high inter-reader reproducibility (mean bias%: LVEDV, 3.3%; LVESV, 6.2%; LVEF, -4.8%; LV mass, -1.9%; and scar mass, -1.8%). In addition, a high inter-study reproducibility was found (mean bias%: LVEDV, 0.1%; LVESV, -1.8%; LVEF, 1.0%; LV mass, -4.6%; and scar mass, -6.2%). Cardiac MR imaging of rats yielded highly reproducible measurements of cardiac volumes/function and myocardial infarct size on a clinical 3.0 Tesla MR scanner system. Consequently, more widely available high field clinical MR scanners can be employed for small animal imaging of the heart e.g. when aiming at serial assessments during therapeutic intervention studies

  1. Food ionisation. Realities and perspectives; L'ionisation alimentaire. Realites et perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, G

    1994-06-01

    The ionisation of food is a treatment using a certain type of energy. the radiations used in the industrial treatments are limited to three sources. The gamma radiations, the x radiations and the electrons beams emitted with accelerators. The physical treatments by ionizing radiations have for aim to cleanse and to increase the conservation time of food. Now, the applications in agriculture and food industry, are still marginal. The industrial using ionisation are these ones that did not find any alternative decontamination method. The barriers are more scientific or technical or economical than a question of regulation or behaviour. (N.C.)

  2. Stenosis of the branches of the neopulmonary artery after the arterial switch operation: A cardiac magnetic resonance imaging study

    International Nuclear Information System (INIS)

    The neonatal arterial switch operation (ASO) is now the standard of care for children born with transposition of the great arteries. Stenosis of the neopulmonary artery on long-term follow up is a known complication. We performed a retrospective analysis of eleven patients who underwent a cardiac magnetic resonance imaging (MRI) due to echocardiographic evidence suggestive of stenosis of the neopulmonary artery or its branches (mean estimated Doppler gradient 48 mmHg, min 30 mmHg, max 70 mmHg). A comprehensive evaluation of anatomy and perfusion was done by cardiac MRI. The branches of the neopulmonary artery (neo PA) showed decreased caliber in three patients unilaterally and in two patients, bilaterally. Magnetic resonance (MR) perfusion studies showed concomitant decreased flow, with discrepancy between the two lungs of 35/65% or worse, only in the three patients with unilateral obstruction, by two different MR perfusion methods. Cardiac MR can be used as a comprehensive non-invasive imaging technique to diagnose stenosis of the branches of the neopulmonary after the ASO, allowing evaluation of anatomy and function of the neoPA, its branches, and the differential perfusion to each lung, thus facilitating clinical decision making

  3. Cardiac imaging with multi-sector data acquisition in volumetric CT: variation of effective temporal resolution and its potential clinical consequences

    Science.gov (United States)

    Tang, Xiangyang; Hsieh, Jiang; Taha, Basel H.; Vass, Melissa L.; Seamans, John L.; Okerlund, Darin R.

    2009-02-01

    With increasing longitudinal detector dimension available in diagnostic volumetric CT, step-and-shoot scan is becoming popular for cardiac imaging. In comparison to helical scan, step-and-shoot scan decouples patient table movement from cardiac gating/triggering, which facilitates the cardiac imaging via multi-sector data acquisition, as well as the administration of inter-cycle heart beat variation (arrhythmia) and radiation dose efficiency. Ideally, a multi-sector data acquisition can improve temporal resolution at a factor the same as the number of sectors (best scenario). In reality, however, the effective temporal resolution is jointly determined by gantry rotation speed and patient heart beat rate, which may significantly lower than the ideal or no improvement (worst scenario). Hence, it is clinically relevant to investigate the behavior of effective temporal resolution in cardiac imaging with multi-sector data acquisition. In this study, a 5-second cine scan of a porcine heart, which cascades 6 porcine cardiac cycles, is acquired. In addition to theoretical analysis and motion phantom study, the clinical consequences due to the effective temporal resolution variation are evaluated qualitative or quantitatively. By employing a 2-sector image reconstruction strategy, a total of 15 (the permutation of P(6, 2)) cases between the best and worst scenarios are studied, providing informative guidance for the design and optimization of CT cardiac imaging in volumetric CT with multi-sector data acquisition.

  4. Unrecognized Myocardial Infarction Assessed by Cardiac Magnetic Resonance Imaging--Prognostic Implications.

    Directory of Open Access Journals (Sweden)

    Anna M Nordenskjöld

    Full Text Available Clinically unrecognized myocardial infarctions (UMI are not uncommon and may be associated with adverse outcome. The aims of this study were to determine the prognostic implication of UMI in patients with stable suspected coronary artery disease (CAD and to investigate the associations of UMI with the presence of CAD.In total 235 patients late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR imaging and coronary angiography were performed. For each patient with UMI, the stenosis grade of the coronary branch supplying the infarcted area was determined. UMIs were present in 25% of the patients and 67% of the UMIs were located in an area supplied by a coronary artery with a stenosis grade ≥70%. In an age- and gender-adjusted model, UMI independently predicted the primary endpoint (composite of death, myocardial infarction, resuscitated cardiac arrest, hospitalization for unstable angina pectoris or heart failure within 2 years of follow-up with an odds ratio of 2.9; 95% confidence interval 1.1-7.9. However, this association was abrogated after adjustment for age and presence of significant coronary disease. There was no difference in the primary endpoint rates between UMI patients with or without a significant stenosis in the corresponding coronary artery.The presence of UMI was associated with a threefold increased risk of adverse events during follow up. However, the difference was no longer statistically significant after adjustments for age and severity of CAD. Thus, the results do not support that patients with suspicion of CAD should be routinely investigated by LGE-CMR for UMI. However, coronary angiography should be considered in patients with UMI detected by LGE-CMR.ClinicalTrials.gov NTC01257282.

  5. Advanced cardiac imaging in heart failure : from subclinical myocardial dysfunction to therapy optimization

    NARCIS (Netherlands)

    Auger, Dominique

    2014-01-01

    Advanced echocardiographic techniques permit assessment of left ventricular dyssynchrony in overt heart failure patients and provide important prognostic data. These techniques may guide patients’ selection for cardiac resynchronization therapy and device optimization. Global left ventricular longit

  6. Evaluation of cardiac functions of cirrhotic children using serum brain natriuretic peptide and tissue Doppler imaging

    OpenAIRE

    Aya M Fattouh; El-Shabrawi, Mortada H; Enas H Mahmoud; Wafaa O Ahmed

    2016-01-01

    Background: Cirrhotic cardiomyopathy (CCM) is described as the presence of cardiac dysfunction in cirrhotic patients. In children with chronic liver disease, CCM has been very rarely investigated. The Aim of the Study: Is to evaluate the cardiac function of cirrhotic children to identify those with CCM. Patients and Methods: Fifty-two cirrhotic patients and 53 age and sex matched controls were assessed using serum brain-type natriuretic peptide (BNP), conventional echocardiography, and tissue...

  7. Optical coherence tomography. A new high-resolution imaging technology to study cardiac development in chick embryos

    DEFF Research Database (Denmark)

    Yelbuz, T.M.; Choma, M.A.; Thrane, L.;

    2002-01-01

    Background-Optical coherence tomography (OCT) is a depth-resolved, noninvasive, non-destructive imaging modality, the use of which has yet to be fully realized in developmental biology. Methods and Results-We visualized embryonic chick hearts at looping stages using an OCT system with a 22 mum...... axial and 27 mum lateral resolution and an acquisition rate of 4000 A-scans per second. Normal chick embryos from stages 14 to 22 and sham-operated and cardiac neural crest-ablated embryos from stages 15 and 18 were scanned by OCT. Three-dimensional data sets were acquired and processed to create...... volumetric reconstructions and short video clips. The OCT-scanned embryos (2 in each group) were photographed after histological sectioning in comparable planes to those visualized by OCT. The optical and histological results showing cardiovascular microstructures such as myocardium, the cardiac jelly, and...

  8. Acquisition and automated 3-D segmentation of respiratory/cardiac-gated PET transmission images

    International Nuclear Information System (INIS)

    To evaluate the impact of respiratory motion on attenuation correction of cardiac PET data, we acquired and automatically segmented gated transmission data for a dog breathing on its own under gas anesthesia. Data were acquired for 20 min on a CTI/Siemens ECAT EXACT HR (47-slice) scanner configured for 12 gates in a static study, Two respiratory gates were obtained using data from a pneumatic bellows placed around the dog's chest, in conjunction with 6 cardiac gates from standard EKG gating. Both signals were directed to a LabVIEW-controlled Macintosh, which translated them into one of 12 gate addresses. The respiratory gating threshold was placed near end-expiration to acquire 6 cardiac-gated datasets at end-expiration and 6 cardiac-gated datasets during breaths. Breaths occurred about once every 10 sec and lasted about 1-1.5 sec. For each respiratory gate, data were summed over cardiac gates and torso and lung surfaces were segmented automatically using a differential 3-D edge detection algorithm. Three-dimensional visualizations showed that lung surfaces adjacent to the heart translated 9 mm inferiorly during breaths. Our results suggest that respiration-compensated attenuation correction is feasible with a modest amount of gated transmission data and is necessary for accurate quantitation of high-resolution gated cardiac PET data

  9. Validation of a raw data-based synchronization signal (kymogram) for phase-correlated cardiac image reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Ertel, Dirk; Kachelriess, Marc; Kalender, Willi A. [University of Erlangen-Nuernberg, Institute of Medical Physics (IMP), Erlangen (Germany); Pflederer, Tobias; Achenbach, Stephan [University of Erlangen-Nuernberg, Department of Internal Medicine II, Erlangen (Germany); Steffen, Peter [University of Erlangen-Nuernberg, Multimedia Communications and Signal Processing, Erlangen (Germany)

    2008-02-15

    Phase-correlated reconstruction is commonly used in computed tomography (CT)-based cardiac imaging. Alternatively to the commonly used ECG, the raw data-based kymogram function can be used as a synchronization signal. We used raw data of 100 consecutive patient exams to compare the performance of kymogram function to the ECG signal. For objective validation the correlation of the ECG and the kymogram was assessed. Additionally, we performed a double-blinded comparison of ECG-based and kymogram-based phase-correlated images. The two synchronization signals showed good correlation indicated by a mean difference in the detected heart rate of negligible 0.2 bpm. The mean image quality score was 2.0 points for kymogram-correlated images and 2.3 points for ECG-correlated images, respectively (3: best; 0: worst). The kymogram and the ECG provided images adequate for diagnosis for 93 and 97 patients, respectively. For 50% of the datasets the kymogram provided an equivalent or even higher image quality compared with the ECG signal. We conclude that an acceptable image quality can be assured in most cases by the kymogram. Improvements of image quality by the kymogram function were observed in a noticeable number of cases. The kymogram can serve as a backup solution when an ECG is not available or lacking in quality. (orig.)

  10. High resolution MR imaging of the fetal heart with cardiac triggering: a feasibility study in the sheep fetus

    Energy Technology Data Exchange (ETDEWEB)

    Yamamura, Jin; Frisch, Michael; Adam, Gerhard; Wedegaertner, Ulrike [University Hospital Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Schnackenburg, Bernhard; Kooijmann, Hendrik [Philips Medical Systems, Hamburg (Germany); Hecher, Kurt [University Hospital Hamburg-Eppendorf, Department of Obstetrics and Fetal Medicine, Hamburg (Germany)

    2009-10-15

    The aim of this study was to perform fetal cardiac magnetic resonance imaging (MRI) with triggering of the fetal heart beat in utero in a sheep model. All experimental protocols were reviewed and the usage of ewes and fetuses was approved by the local animal protection authorities. Images of the hearts of six pregnant ewes were obtained by using a 1.5-T MR system (Philips Medical Systems, Best, Netherlands). The fetuses were chronically instrumented with a carotid catheter to measure the fetal heart frequency for the cardiac triggering. Pulse wave triggered, breath-hold cine-MRI with steady-state free precession (SSFP) was achieved in short axis, two-, four- and three-chamber views. The left ventricular volume and thus the function were measured from the short axis. The fetal heart frequencies ranged between 130 and 160 bpm. The mitral, tricuspid, aortic, and pulmonary valves could be clearly observed. The foramen ovale could be visualized. Myocardial contraction was shown in cine sequences. The average blood volume at the end systole was 3.4{+-}0.2 ml ({+-} SD). The average volume at end diastole was 5.2{+-}0.2 ml; thus the stroke volumes of the left ventricle in the systole were between 1.7 and 1.9 ml with ejection fractions of 38.6% and 39%, respectively. The pulse wave triggered cardiac MRI of the fetal heart allowed evaluation of anatomical structures and functional information. This feasibility study demonstrates the applicability of MRI for future evaluation of fetuses with complex congenital heart defects, once a noninvasive method has been developed to perform fetal cardiac triggering. (orig.)

  11. High resolution MR imaging of the fetal heart with cardiac triggering: a feasibility study in the sheep fetus

    International Nuclear Information System (INIS)

    The aim of this study was to perform fetal cardiac magnetic resonance imaging (MRI) with triggering of the fetal heart beat in utero in a sheep model. All experimental protocols were reviewed and the usage of ewes and fetuses was approved by the local animal protection authorities. Images of the hearts of six pregnant ewes were obtained by using a 1.5-T MR system (Philips Medical Systems, Best, Netherlands). The fetuses were chronically instrumented with a carotid catheter to measure the fetal heart frequency for the cardiac triggering. Pulse wave triggered, breath-hold cine-MRI with steady-state free precession (SSFP) was achieved in short axis, two-, four- and three-chamber views. The left ventricular volume and thus the function were measured from the short axis. The fetal heart frequencies ranged between 130 and 160 bpm. The mitral, tricuspid, aortic, and pulmonary valves could be clearly observed. The foramen ovale could be visualized. Myocardial contraction was shown in cine sequences. The average blood volume at the end systole was 3.4±0.2 ml (± SD). The average volume at end diastole was 5.2±0.2 ml; thus the stroke volumes of the left ventricle in the systole were between 1.7 and 1.9 ml with ejection fractions of 38.6% and 39%, respectively. The pulse wave triggered cardiac MRI of the fetal heart allowed evaluation of anatomical structures and functional information. This feasibility study demonstrates the applicability of MRI for future evaluation of fetuses with complex congenital heart defects, once a noninvasive method has been developed to perform fetal cardiac triggering. (orig.)

  12. No evidence for large-scale outflows in the extended ionised halo of ULIRG Mrk273

    CERN Document Server

    Spence, R A W; Tadhunter, C N; Rose, M; Cabrera-Lavers, A; Spoon, H; Munoz-Tunon, C

    2016-01-01

    We present deep new GTC/OSIRIS narrow-band images and optical WHT/ISIS long-slit spectroscopy of the merging system Mrk273 that show a spectacular extended halo of warm ionised gas out to a radius of $\\sim45$ kpc from the system nucleus. Outside of the immediate nuclear regions (r > 6 kpc), there is no evidence for kinematic disturbance in the ionised gas: in the extended regions covered by our spectroscopic slits the emission lines are relatively narrow (FWHM $\\lesssim$ 350 km$\\rm s^{-1}$) and velocity shifts small (|$\\Delta$V| $\\lesssim{} $250 km$\\rm s^{-1}$). This is despite the presence of powerful near-nuclear outflows (FWHM > 1000 km$\\rm s^{-1}$; |$\\Delta$V| > 400 km$\\rm s^{-1}$; r < 6 kpc). Diagnostic ratio plots are fully consistent with Seyfert 2 photo-ionisation to the NE of the nuclear region, however to the SW the plots are more consistent with low-velocity radiative shock models. The kinematics of the ionised gas, combined with the fact that the main structures are aligned with low-surface-bri...

  13. Pulmonary Artery Stiffness Is Independently Associated with Right Ventricular Mass and Function: A Cardiac MR Imaging Study.

    Science.gov (United States)

    Dawes, Timothy J W; Gandhi, Ajay; de Marvao, Antonio; Buzaco, Rui; Tokarczuk, Paweł; Quinlan, Marina; Durighel, Giuliana; Diamond, Tamara; Monje Garcia, Laura; de Cesare, Alain; Cook, Stuart A; O'Regan, Declan P

    2016-08-01

    Purpose To determine the relationship between pulmonary artery (PA) stiffness and both right ventricular (RV) mass and function with cardiac magnetic resonance (MR) imaging. Materials and Methods The study was approved by the local research ethics committee, and all participants gave written informed consent. Cardiac MR imaging was performed at 1.5 T in 156 healthy volunteers (63% women; age range, 19-61 years; mean age, 36.1 years). High-temporal-resolution phase-contrast imaging was performed in the main and right PAs. Pulmonary pulse wave velocity (PWV) was determined by the interval between arterial systolic upslopes. RV function was assessed with feature tracking to derive peak systolic strain and strain rate, as well as peak early-diastolic strain rate. RV volumes, ejection fraction (RVEF), and mass were measured from the cine images. The association of pulmonary PWV with RV function and mass was quantified with univariate linear regression. Interstudy repeatability was assessed with intraclass correlation. Results The repeatability coefficient for pulmonary PWV was 0.96. Increases in pulmonary PWV and RVEF were associated with increases in age (r = 0.32, P Online supplemental material is available for this article. PMID:26909648

  14. A Voluntary Breath-Hold Treatment Technique for the Left Breast With Unfavorable Cardiac Anatomy Using Surface Imaging

    International Nuclear Information System (INIS)

    Purpose: Breath-hold (BH) treatments can be used to reduce cardiac dose for patients with left-sided breast cancer and unfavorable cardiac anatomy. A surface imaging technique was developed for accurate patient setup and reproducible real-time BH positioning. Methods and Materials: Three-dimensional surface images were obtained for 20 patients. Surface imaging was used to correct the daily setup for each patient. Initial setup data were recorded for 443 fractions and were analyzed to assess random and systematic errors. Real time monitoring was used to verify surface placement during BH. The radiation beam was not turned on if the BH position difference was greater than 5 mm. Real-time surface data were analyzed for 2398 BHs and 363 treatment fractions. The mean and maximum differences were calculated. The percentage of BHs greater than tolerance was calculated. Results: The mean shifts for initial patient setup were 2.0 mm, 1.2 mm, and 0.3 mm in the vertical, longitudinal, and lateral directions, respectively. The mean 3-dimensional vector shift was 7.8 mm. Random and systematic errors were less than 4 mm. Real-time surface monitoring data indicated that 22% of the BHs were outside the 5-mm tolerance (range, 7%-41%), and there was a correlation with breast volume. The mean difference between the treated and reference BH positions was 2 mm in each direction. For out-of-tolerance BHs, the average difference in the BH position was 6.3 mm, and the average maximum difference was 8.8 mm. Conclusions: Daily real-time surface imaging ensures accurate and reproducible positioning for BH treatment of left-sided breast cancer patients with unfavorable cardiac anatomy.

  15. A Voluntary Breath-Hold Treatment Technique for the Left Breast With Unfavorable Cardiac Anatomy Using Surface Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gierga, David P., E-mail: dgierga@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Harvard Medical School, Boston, Massachusetts (United States); Turcotte, Julie C. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Sharp, Gregory C. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Harvard Medical School, Boston, Massachusetts (United States); Sedlacek, Daniel E.; Cotter, Christopher R. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Taghian, Alphonse G. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Harvard Medical School, Boston, Massachusetts (United States)

    2012-12-01

    Purpose: Breath-hold (BH) treatments can be used to reduce cardiac dose for patients with left-sided breast cancer and unfavorable cardiac anatomy. A surface imaging technique was developed for accurate patient setup and reproducible real-time BH positioning. Methods and Materials: Three-dimensional surface images were obtained for 20 patients. Surface imaging was used to correct the daily setup for each patient. Initial setup data were recorded for 443 fractions and were analyzed to assess random and systematic errors. Real time monitoring was used to verify surface placement during BH. The radiation beam was not turned on if the BH position difference was greater than 5 mm. Real-time surface data were analyzed for 2398 BHs and 363 treatment fractions. The mean and maximum differences were calculated. The percentage of BHs greater than tolerance was calculated. Results: The mean shifts for initial patient setup were 2.0 mm, 1.2 mm, and 0.3 mm in the vertical, longitudinal, and lateral directions, respectively. The mean 3-dimensional vector shift was 7.8 mm. Random and systematic errors were less than 4 mm. Real-time surface monitoring data indicated that 22% of the BHs were outside the 5-mm tolerance (range, 7%-41%), and there was a correlation with breast volume. The mean difference between the treated and reference BH positions was 2 mm in each direction. For out-of-tolerance BHs, the average difference in the BH position was 6.3 mm, and the average maximum difference was 8.8 mm. Conclusions: Daily real-time surface imaging ensures accurate and reproducible positioning for BH treatment of left-sided breast cancer patients with unfavorable cardiac anatomy.

  16. A bi-ventricular cardiac atlas built from 1000+ high resolution MR images of healthy subjects and an analysis of shape and motion.

    Science.gov (United States)

    Bai, Wenjia; Shi, Wenzhe; de Marvao, Antonio; Dawes, Timothy J W; O'Regan, Declan P; Cook, Stuart A; Rueckert, Daniel

    2015-12-01

    Atlases encode valuable anatomical and functional information from a population. In this work, a bi-ventricular cardiac atlas was built from a unique data set, which consists of high resolution cardiac MR images of 1000+ normal subjects. Based on the atlas, statistical methods were used to study the variation of cardiac shapes and the distribution of cardiac motion across the spatio-temporal domain. We have shown how statistical parametric mapping (SPM) can be combined with a general linear model to study the impact of gender and age on regional myocardial wall thickness. Finally, we have also investigated the influence of the population size on atlas construction and atlas-based analysis. The high resolution atlas, the statistical models and the SPM method will benefit more studies on cardiac anatomy and function analysis in the future.

  17. Ionising energy treatment of fresh fruit

    International Nuclear Information System (INIS)

    The main purposes of the ionising energy treatment of fresh fruit are: the extension of shelf life of the commodity due to a direct physiological effect on the particular product; the extension of shelf life of the commodity due to a reduction in the development of moulds and rots which would normally render the product worthless; and the killing of insect pests of quarantine significance, to allow for normal marketing of fresh fruit without the risk of introducing insect pests to previously pest-free areas

  18. Noninvasive cardiac risk stratification of diabetic and nondiabetic uremic renal allograft candidates using dipyridamole-thallium-201 imaging and radionuclide ventriculography

    International Nuclear Information System (INIS)

    The ability of noninvasive risk stratification using dipyridamole-thallium-201 (Tl-201) imaging and radionuclide ventriculography to predict perioperative and long-term cardiac events (myocardial infarction or cardiac death) was evaluated in 36 uremic diabetic and 29 nondiabetic candidates for renal allograft surgery. Of the 35 patients who underwent renal allograft surgery 8 +/- 7 months after the study, none had transient Tl-201 defects (although 13 had depressed left ventricular ejection fraction) and none developed perioperative cardiac events. During a mean follow-up of 23 +/- 11 months, 6 (9%) patients developed cardiac events. Logistic regression analysis was used to compare the predictive value of clinical data (including age, sex, diabetes, chest pain history, allograft recipient) and radionuclide data. Presence of transient Tl-201 defect and left ventricular ejection fraction were the only significant predictors of future cardiac events (p less than 0.01). No other patient variables, including diabetes or receiving a renal allograft, had either univariate or multivariate predictive value. All 3 patients with transient Tl-201 defects had cardiac events compared with only 3 of 62 (5%) patients without transient Tl-201 defect (p less than 0.0001). Mean left ventricular ejection fraction was lower in patients with cardiac events (44 +/- 13%) compared with patients without cardiac events (57 +/- 9%, p less than 0.005). Overall, 5 of 6 patients with cardiac events had either transient Tl-201 defects or depressed left ventricular ejection fraction. Dipyridamole-Tl-201 imaging and radionuclide ventriculography may be helpful in identifying uremic candidates for renal allograft surgery who are at low risk for perioperative and long-term cardiac events

  19. Noninvasive cardiac risk stratification of diabetic and nondiabetic uremic renal allograft candidates using dipyridamole-thallium-201 imaging and radionuclide ventriculography

    Energy Technology Data Exchange (ETDEWEB)

    Brown, K.A.; Rimmer, J.; Haisch, C. (Univ. of Vermont College of Medicine, Burlington (USA))

    1989-11-01

    The ability of noninvasive risk stratification using dipyridamole-thallium-201 (Tl-201) imaging and radionuclide ventriculography to predict perioperative and long-term cardiac events (myocardial infarction or cardiac death) was evaluated in 36 uremic diabetic and 29 nondiabetic candidates for renal allograft surgery. Of the 35 patients who underwent renal allograft surgery 8 +/- 7 months after the study, none had transient Tl-201 defects (although 13 had depressed left ventricular ejection fraction) and none developed perioperative cardiac events. During a mean follow-up of 23 +/- 11 months, 6 (9%) patients developed cardiac events. Logistic regression analysis was used to compare the predictive value of clinical data (including age, sex, diabetes, chest pain history, allograft recipient) and radionuclide data. Presence of transient Tl-201 defect and left ventricular ejection fraction were the only significant predictors of future cardiac events (p less than 0.01). No other patient variables, including diabetes or receiving a renal allograft, had either univariate or multivariate predictive value. All 3 patients with transient Tl-201 defects had cardiac events compared with only 3 of 62 (5%) patients without transient Tl-201 defect (p less than 0.0001). Mean left ventricular ejection fraction was lower in patients with cardiac events (44 +/- 13%) compared with patients without cardiac events (57 +/- 9%, p less than 0.005). Overall, 5 of 6 patients with cardiac events had either transient Tl-201 defects or depressed left ventricular ejection fraction. Dipyridamole-Tl-201 imaging and radionuclide ventriculography may be helpful in identifying uremic candidates for renal allograft surgery who are at low risk for perioperative and long-term cardiac events.

  20. Human cardiac telocytes: 3D imaging by FIB-SEM tomography.

    Science.gov (United States)

    Cretoiu, D; Hummel, E; Zimmermann, H; Gherghiceanu, M; Popescu, L M

    2014-11-01

    Telocyte (TC) is a newly identified type of cell in the cardiac interstitium (www.telocytes.com). TCs are described by classical transmission electron microscopy as cells with very thin and long telopodes (Tps; cellular prolongations) having podoms (dilations) and podomers (very thin segments). TCs' three-dimensional (3D) morphology is still unknown. Cardiac TCs seem to be particularly involved in long and short distance intercellular signalling and, therefore, their 3D architecture is important for understanding their spatial connections. Using focused ion beam scanning electron microscopy (FIB-SEM) we show, for the first time, the whole ultrastructural anatomy of cardiac TCs. 3D reconstruction of cardiac TCs by FIB-SEM tomography confirms that they have long, narrow but flattened (ribbon-like) telopodes, with humps generated by the podoms. FIB-SEM tomography also confirms the network made by TCs in the cardiac interstitium through adherens junctions. This study provides the first FIB-SEM tomography of a human cell type.

  1. Myocardial perfusion imaging for predicting cardiac events in Japanese patients with advanced chronic kidney disease: 1-year interim report of the J-ACCESS 3 investigation

    Energy Technology Data Exchange (ETDEWEB)

    Joki, Nobuhiko; Hase, Hiroki [Toho University Ohashi Medical Center, Department of Nephrology, Tokyo (Japan); Kawano, Yuhei; Nakamura, Satoko [National Cerebral and Cardiovascular Center, Division of Hypertension and Nephrology, Osaka (Japan); Nakajima, Kenichi [Kanazawa University Hospital, Department of Nuclear Medicine, Kanazawa (Japan); Hatta, Tsuguru [Hatta Medical Office of Internal Medicine, Kyoto (Japan); Nishimura, Shigeyuki [Saitama Medical University International Medical Center, Saitama (Japan); Moroi, Masao [Toho University Ohashi Medical Center, Department of Cardiology, Tokyo (Japan); Nakagawa, Susumu [Saiseikai Central Hospital, Department of Cardiology, Tokyo (Japan); Kasai, Tokuo [Tokyo Medical University Hachioji Medical Center, Tokyo (Japan); Kusuoka, Hideo [Osaka National Hospital, Osaka (Japan); Takeishi, Yasuchika [Fukushima Medical University, Department of Cardiology and Hematology, Fukushima (Japan); Momose, Mitsuru [Tokyo Women' s Medical University, Department of Diagnostic Imaging and Nuclear Medicine, Tokyo (Japan); Takehana, Kazuya [Kansai Medical University, Department of Cardiology, Osaka (Japan); Nanasato, Mamoru [Cardiovascular Center, Nagoya Daini Red Cross Hospital, Nagoya (Japan); Yoda, Shunichi [Nihon University Itabashi Hospital, Department of Cardiology, Tokyo (Japan); Nishina, Hidetaka [Tsukuba Medical Center Hospital, Department of Cardiology, Tsukuba (Japan); Matsumoto, Naoya [Suruga-dai Nihon University Hospital, Department of Cardiology, Tokyo (Japan); Nishimura, Tsunehiko [Kyoto Prefectural University of Medicine, Kamigyo-ku, Kyoto (Japan)

    2014-09-15

    Whether myocardial perfusion imaging (MPI) can predict cardiac events in patients with advanced conservative chronic kidney disease (CKD) remains unclear. The present multicenter prospective cohort study aimed to clarify the ability of MPI to predict cardiac events in 529 patients with CKD and estimated glomerular filtration rates (eGFR) < 50 ml/min per 1.73{sup 2} without a definitive diagnosis of coronary artery disease. All patients were assessed by stress-rest MPI with {sup 99m}Tc-tetrofosmin and analyzed using summed defect scores and QGS software. Cardiac events were analyzed 1 year after registration. Myocardial perfusion abnormalities defined as summed stress score (SSS) ≥4 and ≥8 were identified in 19 and 7 % of patients, respectively. At the end of the 1-year follow-up, 33 (6.2 %) cardiac events had occurred that included cardiac death, sudden death, nonfatal myocardial infarction, and hospitalization due to heart failure. The event-free rates at that time were 0.95, 0.90, and 0.81 for groups with SSS 0-3, 4-7, and ≥8, respectively (p = 0.0009). Thus, patients with abnormal SSS had a higher incidence of cardiac events. Multivariate Cox regression analysis showed that SSS significantly impacts the prediction of cardiac events independently of eGFR and left ventricular ejection fraction. MPI would be useful to stratify patients with advanced conservative CKD who are at high risk of cardiac events without adversely affecting damaged kidneys. (orig.)

  2. 自触发心脏磁共振成像%Self-gated cardiac magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    邓尚友; 方可; 王旭霞; 谭萍

    2012-01-01

    目的 探讨和实现一种自触发磁共振心脏成像(CMRI).方法 将心电图(ECG)信号和呼吸信号从监测信号中提取出来,然后将K空间数据重新排列、重建,得到心脏图像.结果 自触发CMRI克服了传统的导联法难以获得稳定ECG信号的缺点,可提高扫描效率,得到高品质的亮血和黑血小鼠心脏电影图像.结论 采用自触发CMRI可以实现小鼠心脏电影成像以及黑血成像,并用于评价其心脏结构和功能.%Objective To discuss and realize a type of self-gated cardiac magnetic resonance imaging (CMRI). Methods K space data were rearranged according to electrocardiogram (ECG) and respiration signals, and the cardiac images were reconstructed. Results ECG and respiration signals were extracted from the Navigator, which overcame the difficulty to get stable ECG signal using conventional lead. The method improved CMRI scanning efficiency. High quality bright-blood and black-blood mouse cardiac cine images were acquired. Conclusion Self-gated CMRI can realize cine CMRI and black-blood CMRI, which can be used to evaluate the structure and function of the heart in mice.

  3. Performance of simultaneous cardiac-respiratory self-gated three-dimensional MR imaging of the heart: initial experience.

    Science.gov (United States)

    Manka, Robert; Buehrer, Martin; Boesiger, Peter; Fleck, Eckart; Kozerke, Sebastian

    2010-06-01

    This study was approved by the local institutional ethics committee, and informed consent was obtained from all volunteers and patients. The objective of the present study was to assess the performance of high-spatial-resolution three-dimensional prospective cardiac-respiratory self-gated (CRSG) magnetic resonance (MR) imaging for determining left ventricular (LV) volumes and mass, as well as right ventricular (RV) volumes, in comparison with standard electrocardiography (ECG)-triggered, two-dimensional multisection, multiple-breath-hold cine imaging. The self-gated method derives cardiac triggering and respiratory gating information prospectively on the basis of additional MR imaging signals acquired in every repetition time and, thereby, eliminates the need for ECG triggering and multiple-breath-hold procedures. Data were acquired in 15 healthy volunteers (mean age, 27.2 years +/- 7.2 [standard deviation]) and 11 patients (mean age, 60.7 years +/- 11.3). The bias between the self-gating and the reference imaging techniques was minimal for all LV and RV parameters (mean values: LV end-diastolic volume, 2.0 mL; LV end-systolic volume, 0.6 mL; RV end-diastolic volume, 2.2 mL; and RV end-systolic volume, 0.8 mL). Prospective CRSG is a valuable alternative to ECG-triggered, multisection, multiple-breath-hold cine imaging of the heart and holds considerable promise for simplifying functional imaging of the heart, particularly in patients who are unable to hold their breath for a long period and patients who show ECG signal disturbances. PMID:20501728

  4. Left ventricular 12 segmental strain imaging predicts response to cardiac resynchronization therapy

    Institute of Scientific and Technical Information of China (English)

    DONG Ying-xue; Jae K.Oh; YANG Yan-zong; Yong-mei Cha

    2013-01-01

    Background The number of non-responders to cardiac resynchronization therapy (CRT) exposes the need for better patient selection criteria for CRT.This study aimed to identify echocardiographic parameters that would predict the response to CRT.Methods Forty-five consecutive patients receiving CRT-D implantation for heart failure (HF) were included in this prospective study.New York Heart Association (NYHA) class,6-minute walk distance,electrograph character,and multi echocardiographic parameters,especially in strain patterns,were measured and compared before and six months after CRT in the responder and non-responder groups.Response to CRT was defined as a decrease in left ventricular endsystolic volume (LVESV) of 15% or more at 6-month follow up.Results Twenty-two (48.9%) patients demonstrated a response to CRT at 6-month follow-up.Significant improvement in NYHA class (P <0.01),left ventricular end-diastolic volume (LVEDV) (P <0.01),and 6-minute walk distance (P <0.01) was shown in this group.Although there was an interventricular mechanical delay determined by the difference between left and right ventricular pre-ejection intervals ((42.87±19.64) ms vs.(29.43±18.19) ms,P=0.02),the standard deviation of time to peak myocardial strain among 12 basal,mid and apical segments (Tε-SD) ((119.97±43.32) ms vs.(86.62±36.86) ms,P=0.01) and the non-ischemic etiology (P=0.03) were significantly higher in responders than non-responders,only the Tε-SD (OR=1.02,95% Cl=1.01-1.04,P=0.02) proved to be a favorable predictor of CRT response after multivariate Logistic regression analysis.Conclusion The left ventricular 12 segmental strain imaging is a promising echocardiographic parameter for predicting CRT response.

  5. Infant Cardiac CT Angiography with 64-Slice and 256-Slice CT: Comparison of Radiation Dose and Image Quality Using a Pediatric Phantom

    OpenAIRE

    Lee, Yi-Wei; Yang, Ching-Ching; Mok, Greta S. P.; Wu, Tung-Hsin

    2012-01-01

    Background The aims of this study were to investigate the image quality and radiation exposure of pediatric protocols for cardiac CT angiography (CTA) in infants under one year of age. Methodology/Principal Findings Cardiac CTA examinations were performed using an anthropomorphic phantom representing a 1-year-old child scanned with non-electrocardiogram-gated (NG), retrospectively electrocardiogram-gated helical (RGH) and prospectively electrocardiogram-gated axial (PGA) techniques in 64-slic...

  6. Impaired cardiac adrenergic innervation assessed by MIBG imaging as a predictor of treatment response in childhood dilated cardiomyopathy

    OpenAIRE

    Acar, P; Merlet, P.; Iserin, L; Bonnet, D.; Sidi, D; Syrota, A; Kachaner, J

    2001-01-01

    OBJECTIVE—To evaluate the prognostic value of metaiodobenzylguanidine (MIBG) imaging in childhood cardiomyopathy.
DESIGN—Prospective cohort study.
SETTING—Tertiary referral centre.
PATIENTS—40 children (21 boys, 19 girls; mean (SD) age, 7.0 (5.6) years) with heart failure resulting from idiopathic dilated cardiomyopathy (n = 23) or various other disorders (n = 17).
METHODS—At the initial examination, cardiac 123I-MIBG uptake and release, circulating noradrenaline (norepinephrine) concentratio...

  7. Late Gadolinium Enhancement Cardiac Magnetic Resonance Imaging Post-robotic Radiosurgical Pulmonary Vein Isolation (RRPVI): First Case in the World

    Science.gov (United States)

    Azpiri, Jose; De La Peña, Cuauhtémoc; Cardona, Carlos; Hinojosa, Miguel; Zamarripa, Rafael; Assad, Jose

    2016-01-01

    Pulmonary vein isolation using robotic radiosurgery system CyberKnife is a new non-invasive treatment of atrial fibrillation, currently in clinical phase. Robotic radiosurgical pulmonary vein isolation (RRPVI) uses stereotactic, non-invasive (painless) pinpoint radiation energy delivery to a small, precise area to accomplish ablation. The purpose of this report is to describe the finding of an increase in the enhancement of the left atrium demonstrated with the use of cardiac magnetic resonance imaging using late gadolinium enhancement (LGE-CMR) as a result of RRPVI in the first case in the world in humans using CyberKnife as a treatment for paroxysmal atrial fibrillation (PAF). PMID:27660737

  8. Influence of respiratory gating, image filtering, and animal positioning on high-resolution electrocardiography-gated murine cardiac single-photon emission computed tomography

    NARCIS (Netherlands)

    Wu, Chao; Vaissier, Pieter E. B.; Vastenhouw, Brendan; de Jong, Johan R.; Slart, Riemer H. J. A.; Beekman, Freek J.

    2015-01-01

    Cardiac parameters obtained from single-photon emission computed tomographic (SPECT) images can be affected by respiratory motion, image filtering, and animal positioning. We investigated the influence of these factors on ultra-high-resolution murine myocardial perfusion SPECT. Five mice were inject

  9. Cosmic-ray ionisation in collapsing clouds

    CERN Document Server

    Padovani, Marco; Galli, Daniele

    2013-01-01

    Cosmic rays (CR) play an important role in dense molecular cores, affecting their thermal and dynamical evolution and initiating the chemistry. Several studies have shown that the formation of protostellar discs in collapsing clouds is severely hampered by the braking torque exerted by the entrained magnetic field on the infalling gas, as long as the field remains frozen to the gas. We examine the possibility that the concentration and twisting of the field lines in the inner region of collapse can produce a significant reduction of the ionisation fraction. To check whether the CR ionisation rate (CRir) can fall below the critical value required to maintain good coupling, we first study the propagation of CRs in a model of a static magnetised cloud varying the relative strength of the toroidal/poloidal components and the mass-to-flux ratio. We then follow the path of CRs using realistic magnetic field configurations generated by numerical simulations of a rotating collapsing core. We find that an increment of...

  10. Comparison of inferior myocardial defect between planar and SPECT image of {sup 123}I-metaiodobenzylguanidine cardiac scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Hideki; Momose, Mitsuru; Kashikura, Kenichi; Matsumoto, Nobusuke; Saito, Katsumi; Asano, Ryuta; Hosoda, Saichi; Kusakabe, Kiyoko [Tokyo Women`s Medical Coll. (Japan)

    1995-02-01

    Discordant findings of inferior MIBG defect between SPECT and planar images were sometimes observed in the clinical studies. In this study, we compared inferior myocardial findings between planar and SPECT image of {sup 123}I-metaiodobenzyl-guanidine (MIBG) cardiac scintigraphy in 29 patients. All patients were estimated as normal in anterior accumulation of MIBG. The patients were divided into 3 groups according to the visual finding of inferior defect in the planar and SPECT image; normal group (normal inferior accumulation of MIBG both in the planar and SPECT image, N=10), discordance group (inferior MIBG defect was only observed in the SPECT image, but was not observed in the planar image, N=7), inferior defect group (inferior MIBG defect was observed both in the planar and SPECT image, N=12). Inferior/anterior count ratio of SPECT and planar image were 0.96{+-}0.11 vs. 0.97{+-}0.05 in normal group, 0.59{+-}0.21 vs. 0.99{+-}0.13 in discordance group, 0.46{+-}0.13 vs. 0.82{+-}0.04 in inferior defect group. Liver/heart count ratio was significantly higher in the discordance group (2.07{+-}0.49) than that in the normal (1.14{+-}0.15) and inferior defect group (1.45{+-}0.39). In phantom study, it has been reported that increased liver accumulation of MIBG causes artifactual inferior defect adjacent to the liver. These data indicate that increased liver/heart count ratio may cause artifactual inferior defect on MIBG SPECT image in the clinical studies. Planar image evaluation may be helpful to distinct the artifactual inferior defect on SPECT image. (author).

  11. Noninvasive measurement of left ventricular pressure and max dP/dt using radionuclide multigated cardiac pool image

    International Nuclear Information System (INIS)

    Noninvasive measurements of left ventricular pressure and max dP/dt were performed using radionuclide multigated cardiac pool image (RMPI). The following differential equation was derived from the Bernoulli's theorum; dP/dt=ρ/S2.(dV/dt).(d2V/dt2) where dP/dt is the first derivative of the left ventricular pressure. ρ is the density of the blood, S is an area of the aortic valvular orifice, dV/dt and d2V/dt2 are the first and second derivatives of the cardiac volume measured by RMPI. The left ventricular pressure was calculated by the integrating of this equation in 6 patients. The max dP/dt was derived from Harada's equation; max dP/dt=ρ.C.max(du/dt) where ρ is the density of the blood, c is the pulse velocity of the aorta, and u is the velocity of the blood stream, therefore, du/dt is the acceleration of the blood stream. Value of du/dt was regarded as equivalent to d2V/dt2 obtained from the RMPI volume curves using the third Fourier's transform. Results were as follows; 1) The pressure curves determined from 6 subjects by the RMPI method were not exactly identical to those obtained directly by cardiac catheterization. The discrepancy is probably due to the interaction with reflexion waves. 2) Despite the above discrepancy, there was a significant correlation (r=0.57, Y=1.18X+146, p<0.05) between max dP/dt (X) measured from 16 subjects by cardiac catheterization and calculated max dP/dt (RI) (Y). It was concluded that the max dP/dt could be estimated noninvasively by RMPI method. (author)

  12. Determinants of Left Ventricular Mass and Hypertrophy in Hemodialysis Patients Assessed by Cardiac Magnetic Resonance Imaging

    OpenAIRE

    Patel, Rajan K.; Oliver, Scott; Patrick B. Mark; Powell, Joanna R.; McQuarrie, Emily P.; Traynor, James P.; Dargie, Henry J; Jardine, Alan G

    2009-01-01

    Background and objectives: Left ventricular hypertrophy (LVH) is an independent risk factor for premature cardiovascular death in hemodialysis (HD) patients and one of the three forms of uremic cardiomyopathy. Cardiovascular magnetic resonance (CMR) is a volume-independent technique to assess cardiac structure. We used CMR to assess the determinants of left ventricular mass (LVM) and LVH in HD patients.

  13. Hyperpolarized 1-13C Pyruvate Imaging of Porcine Cardiac Metabolism shift by GIK Intervention

    DEFF Research Database (Denmark)

    Søvsø Szocska Hansen, Esben; Tougaard, Rasmus Stilling; Mikkelsen, Emmeli;

    Cardiac metabolism has gained considerable attention worldwide lately, both as a diagnostic and prognostication tool, as well as a novel target for treatment. As human trials involving hyperpolarized MR in the heart are imminent, we employed a clinically relevant, large animal model, and sought to...

  14. Cardiac Neurotransmission Imaging with 123I-Meta-iodobenzylguanidine in Postural Tachycardia Syndrome.

    OpenAIRE

    Haensch, Carl-Albrecht; Lerch, Hartmut; Schlemmer, Hans; Jigalin, Anna; Isenmann, Stefan

    2010-01-01

    Abstract Background: Postural orthostatic tachycardia syndrome (POTS) is a disorder of orthostatic intolerance characterized by excessive tachycardia of unknown etiology. Whether this condition involves abnormal cardiac sympathetic innervation or function remains elusive. Metaiodobenzylguanidine (MIBG) resembles guanethidine and is a pharmacologically inactive analogue of norepinephrine, which is similarly metabolized in noradrenergic neurons. MIBG myocardial scintigraphy is clinic...

  15. Multifocal non-Hodgkin lymphoma in an infant with cardiac involvement: whole-body MR imaging

    International Nuclear Information System (INIS)

    Non-Hodgkin lymphoma (NHL) is rare in infancy, and we present a case of aggressive NHL of T-cell lineage in an infant with multifocal bone, cardiac, mediastinal nodal, paranasal sinus, calvarial, and soft-tissue deposits on presentation that were detected on whole-body MRI. (orig.)

  16. A prediction model for 5-year cardiac mortality in patients with chronic heart failure using {sup 123}I-metaiodobenzylguanidine imaging

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Kenichi; Matsuo, Shinro [Kanazawa University Hospital, Department of Nuclear Medicine, Kanazawa (Japan); Nakata, Tomoaki [Sapporo Medical University School of Medicine, Second Department of Internal Medicine (Cardiology), Sapporo (Japan); Hakodate-Goryoukaku Hospital, Department of Cardiology, Hakodate (Japan); Yamada, Takahisa [Osaka Prefectural General Medical Center, Department of Cardiology, Osaka (Japan); Yamashina, Shohei [Toho University Omori Medical Center, Department of Cardiovascular Medicine, Tokyo (Japan); Momose, Mitsuru [Tokyo Women' s Medical University, Department of Nuclear Medicine, Tokyo (Japan); Kasama, Shu [Cardiovascular Hospital of Central Japan, Department of Cardiology, Shibukawa (Japan); Matsui, Toshiki [Social Insurance Shiga General Hospital, Department of Cardiology, Otsu (Japan); Travin, Mark I. [Albert Einstein Medical College, Department of Cardiology and Nuclear Medicine, Montefiore Medical Center, Bronx, NY (United States); Jacobson, Arnold F. [GE Healthcare, Medical Diagnostics, Princeton, NJ (United States)

    2014-09-15

    Prediction of mortality risk is important in the management of chronic heart failure (CHF). The aim of this study was to create a prediction model for 5-year cardiac death including assessment of cardiac sympathetic innervation using data from a multicenter cohort study in Japan. The original pooled database consisted of cohort studies from six sites in Japan. A total of 933 CHF patients who underwent {sup 123}I-metaiodobenzylguanidine (MIBG) imaging and whose 5-year outcomes were known were selected from this database. The late MIBG heart-to-mediastinum ratio (HMR) was used for quantification of cardiac uptake. Cox proportional hazard and logistic regression analyses were used to select appropriate variables for predicting 5-year cardiac mortality. The formula for predicting 5-year mortality was created using a logistic regression model. During the 5-year follow-up, 205 patients (22 %) died of a cardiac event including heart failure death, sudden cardiac death and fatal acute myocardial infarction (64 %, 30 % and 6 %, respectively). Multivariate logistic analysis selected four parameters, including New York Heart Association (NYHA) functional class, age, gender and left ventricular ejection fraction, without HMR (model 1) and five parameters with the addition of HMR (model 2). The net reclassification improvement analysis for all subjects was 13.8 % (p < 0.0001) by including HMR and its inclusion was most effective in the downward reclassification of low-risk patients. Nomograms for predicting 5-year cardiac mortality were created from the five-parameter regression model. Cardiac MIBG imaging had a significant additive value for predicting cardiac mortality. The prediction formula and nomograms can be used for risk stratifying in patients with CHF. (orig.)

  17. Cardiac magnetic resonance imaging in patients with congenital heart disease; Kardiale MRT bei Patienten mit angeborenen Herzfehlern

    Energy Technology Data Exchange (ETDEWEB)

    Kreitner, Karl-Friedrich [Mainz Univ. Universitaetsmedizin Mainz (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie; Kaufmann, Lilly [Mainz Univ. (Germany); Sorantin, Erich [Univ.-Klinik fuer Radiologie, Graz (Austria). Klinische Abt. fuer Kinderradiologie

    2015-06-15

    The prevalence of congenital heart disease (CHD) is around 10 per 1000 live births in Germany. More than 90 % of these patients will survive into adulthood due to improvements in therapy. The classification of CHD may be based according to the anatomic structures involved, to the presence of an intracardiac shunt, the presence of a cyanosis and the intensity of therapy and complexity of the disease. Nearly half of all patients with CHD suffer from an intracardiac shunt, whereas complex cases such as patients with a tetralogy of Fallot or transposition of the great arteries are much more rare. Cardiac magnetic resonance imaging plays an important role in the work-up and follow-up of patients with CHD, especially after infancy and childhood. Depending on the abnormality in question, a multiparametric examination protocol is mandatory. Knowledge of operative procedures and findings of other imaging modalities help to optimize examination and time needed for it.

  18. Role of speckle tracking imaging in the assessment of myocardial regional ventricular function in experimental blunt cardiac injury

    Institute of Scientific and Technical Information of China (English)

    Wen-Hua Du; Xiang Wang; Xiu-Qin Xiong; Tao Li; Hua-Ping Liang

    2015-01-01

    Purpose:To evaluate the usefulness and information collecting ability of speckle tracking imaging techniques in the assessment of myocardial regional ventricular contractility in a rabbit model with blunt cardiac injury.Methods:Fifteen healthy New Zealand rabbits weighing (2.70 ± 0.28) kg were anesthetized (3% pentobarbital sodium/i.v) and impacted using the BIM-Ⅱ biological impact machine to induce myocardial contusion (MC).Hemodynamic parameters,such as heart rate,systolic pressure,mean arterial pressure,diastolic pressure and central venous pressure,were determined before and after MC.Further,parameters reflecting left ventricular functions,such as left ventricular end systolic pressure,left ventricular end diastolic pressure,isovolumic pressure (IP) and the maximal increasing/decreasing rate of left intraventricular pressure (±dp/dtmax),were also determined before and after MC.Left ventricular functions were determined either by two dimensional transthoracic echocardiography or by speckle tracking imaging for segmental abnormal ventricular wall motions.Results:Heart rate,systolic pressure,diastolic pressure and mean arterial pressure decreased significantly but transiently,while central venous pressure markedly increased after MC.In contrast to significant changes in diastolic functions,there was no significant change in cardiac systolic functions after MC.The speckle tracking imaging demonstrated that strain values of different myocardial segment significantly decreased post impact,and that of the ventricular segment decreased from segment to segment.Conclusion:Speckle tracking imaging is useful and informative to assess myocardial regional dysfunctions post MC.

  19. Effects of the electric field on ionisation in two different types of ionisation chambers

    International Nuclear Information System (INIS)

    A parallel plate cavity ionisation chamber was irradiated with 60Co γ rays from the polarising electrode. Beyond the recombinations region, the output current of the chamber increases (decreases) linearly with applied positive (negative) voltage. This effect is attributed to the change in the stopping power of air due to acceleration or deceleration of secondary electrons in the applied electric field. In a free-air ionisation chamber, secondary electrons emitted in the direction of the electric field lose energy and those emitted in the opposite direction gain energy and, hence, cause a reduction or enhancement in ionisation, respectively. Computer calculations have shown that the enhancement and reduction are in a range from 0.15 to 0.3% when exposure is measured for X rays generated at a tube voltage of 60-300 kV and at an electric field strength of 20 KV.m-1. The net increase in the output current change at this field strength is smaller than the calculation uncertainties. (author)

  20. Imaging of non-cardiac, non-traumatic causes of acute chest pain

    Energy Technology Data Exchange (ETDEWEB)

    Kienzl, Daniela, E-mail: daniela.kienzl@meduniwien.ac.at [Department of Radiology, Medical University of Vienna (Austria); Prosch, Helmut; Töpker, Michael; Herold, Christian [Department of Radiology, Medical University of Vienna (Austria)

    2012-12-15

    Non-traumatic chest pain is a common symptom in patients who present in the emergency department. From a clinical point of view, it is important to differentiate cardiac chest pain from non-cardiac chest pain (NCCP). Among the plethora of potential causes of NCCP, life-threatening diseases, such as aortic dissection, pulmonary embolism, tension pneumothorax, and esophageal rupture, must be differentiated from non-life threatening causes. The majority of NCCP, however, is reported to be benign in nature. The presentation of pain plays an important role in narrowing the differential diagnosis and initiating further diagnostic management and treatment. As the benign causes tend to recur, and may lead to patient anxiety and great costs, a meticulous evaluation of the patient is necessary to diagnose the underlying disorder or disease.

  1. Diagnostic performance of cardiac imaging methods to diagnose ischaemia-causing coronary artery disease when directly compared with fractional flow reserve as a reference standard

    DEFF Research Database (Denmark)

    Danad, Ibrahim; Szymonifka, Jackie; Twisk, Jos W R;

    2016-01-01

    -vessel specificity was highest for MRI (85%, 79-89), FFRCT (78%: 78-81), and SPECT (75%: 69-80), whereas ICA (66%: 64-68) and CCTA (58%: 55-61) yielded a lower specificity. CONCLUSIONS: In this meta-analysis comparing cardiac imaging methods directly to FFR, MRI had the highest performance for diagnosis of ischaemia-causing......), and cardiac magnetic resonance (MRI) imaging when directly compared with an FFR reference standard. METHOD AND RESULTS: PubMed and Web of Knowledge were searched for investigations published between 1 January 2002 and 28 February 2015. Studies performing FFR in at least 75% of coronary vessels...

  2. Cardiac magnetic resonance imaging parameters as surrogate endpoints in clinical trials of acute myocardial infarction

    OpenAIRE

    Gutberlet Matthias; Lurz Philipp; Fuernau Georg; de Waha Suzanne; Eitel Ingo; Desch Steffen; Schuler Gerhard; Thiele Holger

    2011-01-01

    Abstract Cardiac magnetic resonance (CMR) offers a variety of parameters potentially suited as surrogate endpoints in clinical trials of acute myocardial infarction such as infarct size, myocardial salvage, microvascular obstruction or left ventricular volumes and ejection fraction. The present article reviews each of these parameters with regard to the pathophysiological basis, practical aspects, validity, reliability and its relative value (strengths and limitations) as compared to competit...

  3. Myocardial inflammation after binge drinking assessed by cardiac magnetic resonance imaging

    OpenAIRE

    Aiche, Sascha

    2011-01-01

    Background: Chronic alcohol abuse leads to inflammatory changes in myocardium. The aim of this study was to determine acute effects of excessive consumption of alcohol – binge drinking – and hangover on the heart especially in myocardium. We assumed that binge drinking leads to detectable changes in myocardium. Methods: Cardiac-MRI (CMR) was the diagnostic method. Evaluated parameters were T2-Ratio, relative enhancement, late enhancement and left ventricular function. Additionally humoral...

  4. Delayed contrast enhancement cardiac magnetic resonance imaging in trastuzumab induced cardiomyopathy

    OpenAIRE

    Kirkpatrick Iain; Fang Tielan; Lytwyn Matthew; Fallah-Rad Nazanin; Jassal Davinder S

    2008-01-01

    Abstract Background Trastuzumab (Herceptin), an antagonist to the human epidermal growth factor 2 (HER2) receptor significantly decreases the rates of breast cancer recurrence and mortality by 50%. Despite therapeutic benefits, the risk of cardiotoxicity with trastuzumab ranges from 10–15% when administered sequentially following anthraycline chemotherapy. Little is known about the utility of cardiac magnetic resonance (CMR) in the assessment of trastuzumab mediated cardiomyopathy. Methods an...

  5. Modeling and imaging cardiac sympathetic neurodegeneration in Parkinson’s disease

    OpenAIRE

    Joers, Valerie; Emborg, Marina E.

    2014-01-01

    Parkinson’s disease (PD) is currently recognized as a multisystem disorder affecting several components of the central and peripheral nervous system. This new understanding of PD helps explain the complexity of the patients’ symptoms while challenges researchers to identify new diagnostic and therapeutic strategies. Cardiac neurodegeneration and dysautonomia affect PD patients and are associated with orthostatic hypotension, fatigue, and abnormal control of electrical heart activity. They can...

  6. Accuracy of accelerated cine MR imaging at 3 Tesla in longitudinal follow-up of cardiac function

    Energy Technology Data Exchange (ETDEWEB)

    Sandner, Torleif A.; Huber, Armin M.; Theisen, Daniel; Reiser, Maximilian F.; Wintersperger, Bernd J. [Ludwig-Maximilians-University, Department of Clinical Radiology, University Hospitals - Campus Grosshadern, Munich (Germany); Houck, Philip [Texas A and M University Health Science Center, Department of Cardiology, Scott and White Clinic and Hospital, Temple, TX (United States); Runge, Val M.; Sincleair, Spencer [Texas A and M University Health Science Center, Department of Radiology, Scott and White Clinic and Hospital, Temple, TX (United States)

    2008-10-15

    The ability of fast, parallel-imaging-based cine magnetic resonance (MR) to monitor global cardiac function in longitudinal exams at 3 Tesla was evaluated. Seventeen patients with chronic cardiac disease underwent serial cine MR imaging exams (n=3) at 3 Tesla. Data were acquired in short-axis orientation using cine steady-state free precession (SSFP) with a spatial resolution of 2.5 x 1.9 mm{sup 2} at 45 ms temporal resolution. Multislice imaging (three slices/breath-hold) was performed using TSENSE acceleration (R=3) and standard single-slice cine (non-TSENSE) was performed at identical locations in consecutive breath-holds. End-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF) and myocardial mass (MM) of both cine approaches were compared for individual time-points as well as for longitudinal comparison. TSENSE-cine did not show significant differences for EDV (2.6 ml; P=.79), ESV (2.2 ml; P=0.81), EF (-0.3%; P=0.95) and MM (2.4 g; P=0.72) in comparison with non-TSENSE. Longitudinal ANOVA analysis did not reveal significant differences for any parameter, neither for non-TSENSE data (all P>0.7) nor for TSENSE data (all P>0.9). Multifactorial ANOVA showed non-significant differences (all P>0.7) at comparable data variances. Data acquisition was significantly shortened using TSENSE. Threefold accelerated multislice cine at 3 Tesla allows accurate assessment of volumetric LV data and accurate longitudinal monitoring of global LV function at a substantially shorter overall examination time. (orig.)

  7. Innershell ionisation at small impactparameters in proton-atom collisions

    International Nuclear Information System (INIS)

    This thesis concentrates on innershell ionisation in proton-atom collisions. An experiment on K-shell ionisation of argon is described, performed in a gasfilled collision chamber under single collision conditions. Further experiments with carbon and aluminium were performed, the K-shell vacancy production in the collision of protons with these atoms being detected through the measurement of Auger-electrons. A spectrometer with a large solid angle was specially constructed for this and its performance is described. K-shell ionisation accompanying nuclear (p,γ) reactions has also been measured using 26Mg and 27Al. (Auth./C.F.)

  8. Evaluation of diabetic autonomic neuropathy by [sup 123]I-metaiodobenzyl-guanidine (MIBG) cardiac imaging. Initial report

    Energy Technology Data Exchange (ETDEWEB)

    Osonoi, Takeshi; Fukumoto, Yoshihiro; Saitou, Miyoko; Kuroda, Yasuhisa; Uchimi, Nobuo; Ishioka, Kuniharu (Mitokyoudou General Hospital, Ibaraki (Japan)); Onuma, Tomio; Suga, Shigeki; Takebe, Kazuo

    1994-11-01

    Single-photon emission computed tomography was performed in 52 diabetics and 10 healthy volunteers using MIBG. The diabetics had no particular findings of electrocardiography, echocardiography, or exercise thallium imaging and no cardiovascular episodes. The healthy volunteers had no abnormal findings on exercise thallium imaging or glucose tolerance test. The average relative regional uptake (RRU) was decreased in the inferoposterior wall compared with the anterior or lateral wall in both the diabetics and volunteers. According to the RRU and visual images, we divided the diabetics into the following four groups: 14 who were normal (group N), 30 with segmental defects (group S), 4 with diffuse defects (group D) and 4 without accumulation (group DH). Diabetic complications (retinopathy, nephropathy, and neuropathy) and hypertension were more frequent in group S than group N. However, there were no significant differences in the physiological evidence of autonomic neuropathy (C.V. of the R-R interval on the ECG and blood pressure response to standing or deep breathing) between groups S and N. Vibration sense was significantly more impaired in group S than in group N. These results suggest that cardiac imaging with MIBG might be a useful examination for the early diagnosis of diabetic autonomic neuropathy. (author).

  9. Clinical relevance and indications for cardiac magnetic resonance imaging 2013. An interdisciplinary expert statement; Klinischer Stellenwert und Indikationen zur Magnetresonanztomografie des Herzens 2013. Ein interdisziplinaeres Expertenstatement

    Energy Technology Data Exchange (ETDEWEB)

    Hergan, Klaus [Universitaetsklinikum Salzburg (Austria). Universitaetsinst. fuer Radiologie; Globits, S. [Herz-Kreislauf-Zentrum Gross Gerungs (Austria); Schuchlenz, H. [Landeskrankenhaus Graz-West (Austria). Dept. fuer Kardiologie/Intensivmedizin] [and others

    2013-03-15

    During the last years the indications of Cardiac Magnetic Resonance Imaging (CMRI) have been continuously expanded. However, the acceptance of the method by cardiologists and radiologists does not correlate with respect to the diagnostic potential. Several factors, such as expensive equipment, relatively long examination times, high technical know how and lack of remuneration, limit the application of CMRI in everyday clinical practice. Furthermore, doctors tend to apply more conventional, well established diagnostic procedures, the access to the method is still limited and there exist difficulties in the interdisciplinary collaboration. The interdisciplinary Austrian approach to Cardiac Imaging is aimed to improve the aforementioned problems and to support the implementation of CMRI in the diagnostic tree of cardiac diseases thus enabling a cost efficient management of patients in cardiology. (orig.)

  10. Assessment of sub-clinical acute cellular rejection after heart transplantation: comparison of cardiac magnetic resonance imaging and endomyocardial biopsy

    Energy Technology Data Exchange (ETDEWEB)

    Krieghoff, Christian; Hildebrand, Lysann; Grothoff, Matthias; Lehmkuhl, Lukas; Luecke, Christian; Andres, Claudia; Nitzsche, Stefan; Riese, Franziska; Gutberlet, Matthias [University Leipzig - Heart Centre, Department of Diagnostic and Interventional Radiology, Leipzig (Germany); Barten, Markus J.; Strueber, Martin; Mohr, Friedrich Wilhelm [University Leipzig - Heart Centre, Department of Cardiac Surgery, Leipzig (Germany)

    2014-10-15

    Comparing the diagnostic value of multi-sequential cardiac magnetic resonance imaging (CMR) with endomyocardial biopsy (EMB) for sub-clinical cardiac allograft rejection. One hundred and forty-six examinations in 73 patients (mean age 53 ± 12 years, 58 men) were performed using a 1.5 Tesla system and compared to EMB. Examinations included a STIR (short tau inversion recovery) sequence for calculation of edema ratio (ER), a T1-weighted spin-echo sequence for assessment of global relative enhancement (gRE), and inversion-recovery sequences to visualize late gadolinium enhancement (LGE). Histological grade ≥1B was considered relevant rejection. One hundred and twenty-seven (127/146 = 87 %) EMBs demonstrated no or mild signs of rejection (grades ≤1A) and 19/146 (13 %) a relevant rejection (grade ≥1B). Sensitivity, specificity, positive predictive, and negative predictive values were as follows: ER: 63 %, 78 %, 30 %, and 93 %; gRE: 63 %, 70 %, 24 %, and 93 %; LGE: 68 %, 36 %, 13 %, and 87 %; with the combination of ER and gRE with at least one out of two positive: 84 %, 57 %, 23 %, and 96 %. ROC analysis revealed an area under the curve of 0.724 for ER and 0.659 for gRE. CMR parameters for myocarditis are useful to detect sub-clinical acute cellular rejection after heart transplantation. Comparable results to myocarditis can be achieved with a combination of parameters. (orig.)

  11. Cardiac cine MRI: Comparison of 1.5 T, non-enhanced 3.0 T and blood pool enhanced 3.0 T imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gerretsen, S.C.; Versluis, B.; Bekkers, S.C.A.M. [Maastricht University Hospital, Department of Radiology, Maastricht (Netherlands); Leiner, T. [Maastricht University Hospital, Department of Radiology, Maastricht (Netherlands)], E-mail: leiner@rad.unimaas.nl

    2008-01-15

    Introduction: Cardiac cine imaging using balanced steady state free precession sequences (bSSFP) suffers from artefacts at 3.0 T. We compared bSSFP cardiac cine imaging at 1.5 T with gradient echo imaging at 3.0 T with and without a blood pool contrast agent. Materials and methods: Eleven patients referred for cardiac cine imaging underwent imaging at 1.5 T and 3.0 T. At 3.0 T images were acquired before and after administration of 0.03 mmol/kg gadofosveset. Blood pool signal-to-noise ratio (SNR), temporal variations in SNR, ejection fraction and myocardial mass were compared. Subjective image quality was scored on a four-point scale. Results: Blood pool SNR increased with more than 75% at 3.0 T compared to 1.5 T (p < 0.001); after contrast administration at 3.0 T SNR increased with 139% (p < 0.001). However, variations in blood pool SNR at 3.0 T were nearly three times as high versus those at 1.5 T in the absence of contrast medium (p < 0.001); after contrast administration this was reduced to approximately a factor 1.4 (p = 0.21). Saturation artefacts led to significant overestimation of ejection fraction in the absence of contrast administration (1.5 T: 44.7 {+-} 3.1 vs. 3.0 T: 50.7 {+-} 4.2 [p = 0.04] vs. 3.0 T post contrast: 43.4 {+-} 2.9 [p = 0.55]). Subjective image quality was highest for 1.5 T (2.8 {+-} 0.3), and lowest for non-enhanced 3.0 T (1.7 {+-} 0.6; p = 0.006). Conclusions: GRE cardiac cine imaging at 3.0 T after injection of the blood pool agent gadofosveset leads to improved objective and subjective cardiac cine image quality at 3.0 T and to the same conclusions regarding cardiac ejection fraction compared to bSSFP imaging at 1.5 T.

  12. Medical image of the week: extensive small cell lung cancer with cardiac invasion

    Directory of Open Access Journals (Sweden)

    Nahapetian R

    2013-03-01

    Full Text Available A 73 year old woman was seen with a lung mass and acute onset of ataxia. MRI of the brain was notable for multifocal infarcts (Figure 1. Echocardiography (ECHO was obtained to identify cardiac source of emboli and was notable for freely mobile mass tethered to the lateral left atrial wall, crossing the mitral valve into the left atrium (Figure 2. A contrast enhanced CT scan of the chest was obtained which confirmed the presence of a large right upper lobe mass with extension to the right pulmonary vein, left atrium and into the left ventricle (Figures 3 and 4. The biopsy confirmed small cell lung cancer.

  13. Non-equilibrium calcium ionisation in the solar atmosphere

    CERN Document Server

    Wedemeyer-Böhm, Sven

    2011-01-01

    Our aim is to determine the dominant processes and timescales for the ionisation equilibrium of calcium under solar chromospheric conditions. The study is based on numerical simulations with the RADYN code, which includes hydrodynamics, radiative transfer, and a detailed non-equilibrium treatment of hydrogen, calcium, and helium. The simulations are characterised by upwards propagating shock waves, which cause strong temperature fluctuations and variations of the ionisation degree of calcium. The passage of a hot shock front leads to a strong net ionisation of Ca II, rapidly followed by net recombination. The relaxation timescale of the Ca ionisation state is found to be of the order of a few seconds at the top of the photosphere and 10 to 30 s in the upper chromosphere. Generally, the timescales are significantly reduced in the wakes of hot shock fronts. The timescales can be reliably determined from a simple analysis of the eigenvalues of the transition rate matrix. The timescales are dominated by the radia...

  14. Cardiac dysfunction assessed by echocardiographic tissue Doppler imaging is an independent predictor of mortality in the general population

    DEFF Research Database (Denmark)

    Mogelvang, Rasmus; Sogaard, Peter; Pedersen, Sune A;

    2009-01-01

    parameters, left ventricular dysfunction by TDI is a powerful and independent predictor of death, especially when systolic performance and diastolic performance are considered together, recognizing their interdependency and their complex relation to deteriorating cardiac function.......BACKGROUND: Tissue Doppler imaging (TDI) detects left ventricular dysfunction in patients with heart failure and normal ejection fraction, but the prognostic significance of left ventricular dysfunction by TDI in the general population is unknown. METHODS AND RESULTS: Within the Copenhagen City...... quantified by a combined index (eas index) of diastolic and systolic performance: e'/(a' x s'). During follow-up (median, 5.3 years), 90 participants died. Left ventricular dysfunction by TDI, in terms of low s' (hazard ratio, 1.23 per 1-cm/s decrease; P

  15. Circumferential 2D-strain imaging for the prediction of long term response to cardiac resynchronization therapy

    Directory of Open Access Journals (Sweden)

    Baumann Gert

    2008-06-01

    Full Text Available Abstract Background Cardiac Resynchronization Therapy (CRT leads to hemodynamic and clinical improvement in heart failure patients. The established methods to evaluate myocardial asynchrony analyze longitudinal and radial myocardial function. This study evaluates the new method of circumferential 2D-strain imaging in the prediction of the long-term response to CRT. Methods and results 38 heart failure patients (NYHA II-III, QRS > 120 ms, LVEF Conclusion There is a significant decrease in the circumferential 2D-strain derived delays after CRT, indicating that resynchronization induces improvement in all three dimensions of myocardial contraction. However, the resulting predictive values of 2D strain delays are not superior to longitudinal and radial 2D-strain or TDI delays.

  16. Serial changes of the myocardium in patients with Duchenne's muscular dystrophy followed by cardiac nuclear imaging

    International Nuclear Information System (INIS)

    In order to evaluate the natural course of Duchenne's cardiomyopathy (DMD), 201Tl-SPECT and RI cardioangiography with 99mTc-albumin were performed in 14 patients. They were examined once a year for five years except for 6 patients. Hypo-perfusion was observed in both posterior-inferior and anterior wall at 12 years of age and extended to the lateral wall and septum with aging. The degree of cardiac involvement was different in each case. Systolic parameters (LVEF, 1/3EF, 1/3ER-mean) tended to decrease with aging from 15 years of age. Diastolic parameters (%EFV, 1/3FF, 1/3FR mean) decreased gradually after 16 years of age. Hypokinetic changes of regional wall motion were observed at 15 years of age and they became severely with aging. Although phase delay appeared visually at 16 years of age, standard deviation of phase angle increased from 15 years of age. Follow up studies by 201Tl myocardial SPECT and gated pool scintigraphy revealed well the progression of cardiac involvement in patients with DMD. (author) 84 refs

  17. Spectral pulsed-wave tissue Doppler imaging lateral-to-septal delay fails to predict clinical or echocardiographic outcome after cardiac resynchronization therapy

    NARCIS (Netherlands)

    O.I.I. Soliman (Osama Ibrahim Ibrahim); D.A.M.J. Theuns (Dominic); M.L. Geleijnse (Marcel); A. Nemes (Attila); K. Caliskan (Kadir); W.B. Vletter (Wim); L.J.L.M. Jordaens (Luc); F.J. ten Cate (Folkert)

    2007-01-01

    textabstractAims: The current study sought to assess if pre-implantation lateral-to-septal delay (LSD) ≥60 ms assessed by spectral pulsed-wave myocardial tissue Doppler imaging (PW-TDI) could predict successful long-term outcome after cardiac resynchronization therapy (CRT). Methods and results Sixt

  18. Inter- and intra-rater reproducibility of semiautomatic determination of volume parameters in cardiac magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Trieb, Thomas [Department of Radiology, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck (Austria)], E-mail: thomas.trieb@i-med.ac.at; Glodny, Bernhard; Scheiblhofer, Martin; Wolf, Christian [Department of Radiology, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck (Austria); Metzler, Bernhard; Pachinger, Otmar [Division of Cardiology, Department of Internal Medicine, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck (Austria); Jaschke, Werner R.; Schocke, Michael F.H. [Department of Radiology, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck (Austria)

    2008-12-15

    Purpose: The purpose of this study was to evaluate inter- and intra-rater reproducibility in volume assessment using cardiac magnetic resonance imaging (CMRI). Methods: Twenty-five healthy volunteers and 106 patients were included into this retrospective study and received CMRI. The patients were divided in three groups (group I, 80 patients with arrhythmia; group II, 20 patients with cardiomyopathy; group III, 6 patients after correction of septum defects). Therefore, the images were semiautomatically segmented by an experienced and an unexperienced radiologists. The analysis of end-diastolic volume (EDV), end-systolic volume (ESV) and stroke volume (SV) as well as ejection fraction (EF) and myocardial mass (MM) were performed twice by an experienced and an unexperienced radiologists. The intra-class correlation coefficients (ICC) were determined for the evaluation of inter- and intra-rater variance. Results: The intra-rater reproducibility for determination of EF, ESV, EDV and MM was excellent with ICCs ranging from 0.88 to 0.99 (all p < 0.001). The inter-observer reproducibility for these parameters was also excellent with ICCs ranging from 0.91 to 0.98 (all p < 0.001). The assessment of the SV showed an excellent intra-rater agreement with ICCs of 0.96 and 0.92 (both p < 0.001), but only a moderate ICC for the inter-rater reproducibility (0.54, p < 0.001). Conclusions: Our study shows that assessment of cardiac volumes can be performed on CMRIs with an excellent reproducibility by both experienced and unexperienced investigators.

  19. QUANTIFICATIONS OF THE DETRIMENTAL HEALTHEFFECTS OF IONISING RADIATION

    OpenAIRE

    Walsh, Linda

    2013-01-01

    This thesis, presented to The University of Manchester in 2012 by Dr. Linda Walsh, is in fulfilment of the requirements for the degree of Doctor of Science (DSc) and is entitled “Quantifications of the detrimental health effects of ionising radiation.” A body of work and ensuing publications covering 2000–2012 are presented, predominantly concerning studies of various cohorts of people exposed to ionising radiation. The major areas cover epidemiological and statistical studies on the Life spa...

  20. Iterative 4D cardiac micro-CT image reconstruction using an adaptive spatio-temporal sparsity prior

    Science.gov (United States)

    Ritschl, Ludwig; Sawall, Stefan; Knaup, Michael; Hess, Andreas; Kachelrieß, Marc

    2012-03-01

    Temporal-correlated image reconstruction, also known as 4D CT image reconstruction, is a big challenge in computed tomography. The reasons for incorporating the temporal domain into the reconstruction are motions of the scanned object, which would otherwise lead to motion artifacts. The standard method for 4D CT image reconstruction is extracting single motion phases and reconstructing them separately. These reconstructions can suffer from undersampling artifacts due to the low number of used projections in each phase. There are different iterative methods which try to incorporate some a priori knowledge to compensate for these artifacts. In this paper we want to follow this strategy. The cost function we use is a higher dimensional cost function which accounts for the sparseness of the measured signal in the spatial and temporal directions. This leads to the definition of a higher dimensional total variation. The method is validated using in vivo cardiac micro-CT mouse data. Additionally, we compare the results to phase-correlated reconstructions using the FDK algorithm and a total variation constrained reconstruction, where the total variation term is only defined in the spatial domain. The reconstructed datasets show strong improvements in terms of artifact reduction and low-contrast resolution compared to other methods. Thereby the temporal resolution of the reconstructed signal is not affected.

  1. The large-scale ionised outflow of CH Cygni

    CERN Document Server

    Corradi, R L M; Livio, M; Mampaso, A; Gonçalves, D R; Schwarz, H E; Corradi, Romano L.M.; Munari, Ulisse; Livio, Mario; Mampaso, Antonio; Goncalves, Denise R.

    2001-01-01

    HST and ground-based [OII} and [NII] images obtained from 1996 to 1999 reveal the existence of a ionised optical nebula around the symbiotic binary CH Cyg extending out to 5000 A.U. from the central stars. The observed velocity range of the nebula, derived from long-slit echelle spectra, is of 130 km/s. In spite of its complex appearence, the velocity data show that the basic morphology of the inner regions of the optical nebula is that of a bipolar (or conical) outflow extending nearly along the plane of the sky out to some 2000 A.U. from the centre. Even if the extension of this bipolar outflow and its position angle are consistent with those of the radio jet produced in 1984 (extrapolated to the time of our optical imagery), no obvious counterpart is visible of the original, dense radio bullets ejected by the system. We speculate that the optical bipolar outflow might be the remannt of the interaction of the bullets with a relatively dense circumstellar medium.

  2. Exposure of the French paediatric population to ionising radiation from diagnostic medical procedures in 2010

    Energy Technology Data Exchange (ETDEWEB)

    Etard, Cecile; Aubert, Bernard [Institut de Radioprotection et de Surete Nucleaire, Medical Expertise Unit, Fontenay-aux-Roses (France); Mezzarobba, Myriam [Institut de Radioprotection et de Surete Nucleaire, Laboratory of Epidemiology, Fontenay-aux-Roses (France); Bernier, Marie-Odile [Institut de Radioprotection et de Surete Nucleaire, Laboratory of Epidemiology, Fontenay-aux-Roses (France); Institut de Radioprotection et de Surete Nucleaire, IRSN/PRP-HOM/SRBE/LEPID, Laboratoire d' Epidemiologie, Fontenay-aux-Roses (France)

    2014-12-15

    Medical examination is the main source of artificial radiation exposure. Because children present an increased sensitivity to ionising radiation, radiology practices at a national level in paediatrics should be monitored. This study describes the ionising radiation exposure from diagnostic medical examinations of the French paediatric population in 2010. Data on frequency of examinations were provided by the French National Health Insurance through a representative sample including 107,627 children ages 0-15 years. Effective doses for each type of procedure were obtained from the published French literature. Median and mean effective doses were calculated for the studied population. About a third of the children were exposed to at least one examination using ionising radiation in 2010. Conventional radiology, dental exams, CT scans and nuclear medicine and interventional radiology represent respectively 55.3%, 42.3%, 2.1% and 0.3% of the procedures. Children 10-15 years old and babies from birth to 1 year are the most exposed populations, with respectively 1,098 and 734 examinations per 1,000 children per year. Before 1 year of age, chest and pelvis radiographs are the most common imaging tests, 54% and 32%, respectively. Only 1% of the studied population is exposed to CT scan, with 62% of these children exposed to a head-and-neck procedure. The annual median and mean effective doses were respectively 0.03 mSv and 0.7 mSv for the exposed children. This study gives updated reference data on French paediatric exposure to medical ionising radiation that can be used for public health or epidemiological purposes. Paediatric diagnostic use appears much lower than that of the whole French population as estimated in a previous study. (orig.)

  3. Using ionising radiation against terrorism and contrabandism - dosimetric problems

    International Nuclear Information System (INIS)

    As will be explained in more detail in a talk at this conference, the personnel X-ray scanners can be divided into two groups, one using the transmitted X rays for image creation, the other one using the Compton back scatters X-rays. In the case of a backscatter scanner, a narrow, pencil -like X-ray beam is produced by a rotating chopper-wheel. The person/object is scanned in a raster scan pattern. The backscattered X-rays of all points are measured and recorded. The transmission X-ray scanner can use both fan-like and pencil like X-ray beams. The transmission detectors are installed behind the object and detect the absorption of the scanned person. Due to the very low dose values of the X-ray scanner systems in combination with a high dose rate in the direct beam for a short irradiation time, special dosemeters have to be used. In the literature and in manufacturers' specifications, the dose values given for some systems are in the range from 0.05 μSv to 5 μSv per scan with a typical irradiation time of a few milliseconds. Due to this pulse-like character of the radiation fields, the dose rate is several sieverts per hour. For the measurements of the investigated scanner, dosemeters were therefore needed having the capability to measure low doses at high dose rates and to measure in pulsed radiation fields. For the optimization of the measurements, the use of measuring devices with a direct indication is necessary. Ionisation chambers are the most suitable measuring instruments to fulfill these requirements. The difficulty for the measurements with an ionisation chamber is that the leakage charge integrated over time can reach values at the level of the expected radiation-produced charge. Additionally unpredictable variations of the leakage charge can be in the same order of magnitude as the expected signal. This challenge led to the development of a special electronics which allow the execution of time-resolved measurements. With this time resolution, it is

  4. Multimodality Molecular Imaging of Cardiac Cell Transplantation: Part I. Reporter Gene Design, Characterization, and Optical in Vivo Imaging of Bone Marrow Stromal Cells after Myocardial Infarction.

    Science.gov (United States)

    Parashurama, Natesh; Ahn, Byeong-Cheol; Ziv, Keren; Ito, Ken; Paulmurugan, Ramasamy; Willmann, Jürgen K; Chung, Jaehoon; Ikeno, Fumiaki; Swanson, Julia C; Merk, Denis R; Lyons, Jennifer K; Yerushalmi, David; Teramoto, Tomohiko; Kosuge, Hisanori; Dao, Catherine N; Ray, Pritha; Patel, Manishkumar; Chang, Ya-Fang; Mahmoudi, Morteza; Cohen, Jeff Eric; Goldstone, Andrew Brooks; Habte, Frezghi; Bhaumik, Srabani; Yaghoubi, Shahriar; Robbins, Robert C; Dash, Rajesh; Yang, Phillip C; Brinton, Todd J; Yock, Paul G; McConnell, Michael V; Gambhir, Sanjiv S

    2016-09-01

    Purpose To use multimodality reporter-gene imaging to assess the serial survival of marrow stromal cells (MSC) after therapy for myocardial infarction (MI) and to determine if the requisite preclinical imaging end point was met prior to a follow-up large-animal MSC imaging study. Materials and Methods Animal studies were approved by the Institutional Administrative Panel on Laboratory Animal Care. Mice (n = 19) that had experienced MI were injected with bone marrow-derived MSC that expressed a multimodality triple fusion (TF) reporter gene. The TF reporter gene (fluc2-egfp-sr39ttk) consisted of a human promoter, ubiquitin, driving firefly luciferase 2 (fluc2), enhanced green fluorescent protein (egfp), and the sr39tk positron emission tomography reporter gene. Serial bioluminescence imaging of MSC-TF and ex vivo luciferase assays were performed. Correlations were analyzed with the Pearson product-moment correlation, and serial imaging results were analyzed with a mixed-effects regression model. Results Analysis of the MSC-TF after cardiac cell therapy showed significantly lower signal on days 8 and 14 than on day 2 (P = .011 and P = .001, respectively). MSC-TF with MI demonstrated significantly higher signal than MSC-TF without MI at days 4, 8, and 14 (P = .016). Ex vivo luciferase activity assay confirmed the presence of MSC-TF on days 8 and 14 after MI. Conclusion Multimodality reporter-gene imaging was successfully used to assess serial MSC survival after therapy for MI, and it was determined that the requisite preclinical imaging end point, 14 days of MSC survival, was met prior to a follow-up large-animal MSC study. (©) RSNA, 2016 Online supplemental material is available for this article. PMID:27308957

  5. Impact of increasing levels of advanced iterative reconstruction on image quality in low-dose cardiac CT angiography

    International Nuclear Information System (INIS)

    Purpose: To investigate the effects of an advanced iterative reconstruction (IR) technique on subjective and objective image quality (IQ) in low-dose cardiac CT angiography (CCTA). Materials and Methods: 30 datasets of prospectively triggered 'step-and-shoot' CCTA scans acquired on a 256-slice CT scanner with optimized exposure settings were processed on a prototype IR system using filtered back-projection (FBP) and 4 levels of advanced IR (iDose4, Philips) providing incremental rates of IR (level 2, 4, 6, 7). In addition, the effects of different reconstruction kernels (semi-smooth [CB], standard with edge-enhancement [XCB]) and a 'multi-resolution' feature [MR] to preserve the noise power spectrum were evaluated resulting in a total of n = 480 image sets. Contrast-to-noise ratios (CNR) were computed from regions of interest at 9 coronary locations. The subjective IQ was rated on a 4-point-scale with 'classic' image appearance and noise-related artifacts as main criteria. Results: At an effective dose of 1.7 ± 0.7 mSv, the CNR significantly improved with every increasing level of IR (range: 14.2-27.8; p < 0.001) with the best objective IQ at the highest level of IR (level 7). The subjective IQ, however, was rated best at the medium level of IR (level 4) with minimal artifacts and a more 'classic' image appearance when compared to higher IR levels. The XCB kernel provided better subjective ratings than CB (p < 0.05) and the MR feature further increased the IQ at a high level of IR. Conclusion: The objective IQ of low-dose CCTA progressively improves with an increasing level of IR. The best subjective IQ, however, is reached at medium levels of IR combined with an edge-enhancing kernel allowing for preservation of a 'classic' image appearance suggesting application in the clinical routine. (orig.)

  6. Cardiac tumours in children

    Directory of Open Access Journals (Sweden)

    Parsons Jonathan M

    2007-03-01

    Full Text Available Abstract Cardiac tumours are benign or malignant neoplasms arising primarily in the inner lining, muscle layer, or the surrounding pericardium of the heart. They can be primary or metastatic. Primary cardiac tumours are rare in paediatric practice with a prevalence of 0.0017 to 0.28 in autopsy series. In contrast, the incidence of cardiac tumours during foetal life has been reported to be approximately 0.14%. The vast majority of primary cardiac tumours in children are benign, whilst approximately 10% are malignant. Secondary malignant tumours are 10–20 times more prevalent than primary malignant tumours. Rhabdomyoma is the most common cardiac tumour during foetal life and childhood. It accounts for more than 60% of all primary cardiac tumours. The frequency and type of cardiac tumours in adults differ from those in children with 75% being benign and 25% being malignant. Myxomas are the most common primary tumours in adults constituting 40% of benign tumours. Sarcomas make up 75% of malignant cardiac masses. Echocardiography, Computing Tomography (CT and Magnetic Resonance Imaging (MRI of the heart are the main non-invasive diagnostic tools. Cardiac catheterisation is seldom necessary. Tumour biopsy with histological assessment remains the gold standard for confirmation of the diagnosis. Surgical resection of primary cardiac tumours should be considered to relieve symptoms and mechanical obstruction to blood flow. The outcome of surgical resection in symptomatic, non-myxomatous benign cardiac tumours is favourable. Patients with primary cardiac malignancies may benefit from palliative surgery but this approach should not be recommended for patients with metastatic cardiac tumours. Surgery, chemotherapy and radiotherapy may prolong survival. The prognosis for malignant primary cardiac tumours is generally extremely poor.

  7. Marketing cardiac CT programs.

    Science.gov (United States)

    Scott, Jason

    2010-01-01

    There are two components of cardiac CT discussed in this article: coronary artery calcium scoring (CACS) and coronary computed tomography angiography (CCTA).The distinctive advantages of each CT examination are outlined. In order to ensure a successful cardiac CT program, it is imperative that imaging facilities market their cardiac CT practices effectively in order to gain a competitive advantage in this valuable market share. If patients receive quality care by competent individuals, they are more likely to recommend the facility's cardiac CT program. Satisfied patients will also be more willing to come back for any further testing.

  8. Prognostic Value of Cardiac Time Intervals by Tissue Doppler Imaging M-Mode in Patients With Acute ST-Segment-Elevation Myocardial Infarction Treated With Primary Percutaneous Coronary Intervention

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Mogelvang, Rasmus; Søgaard, Peter;

    2013-01-01

    Background- Color tissue Doppler imaging M-mode through the mitral leaflet is an easy and precise method to estimate all cardiac time intervals from 1 cardiac cycle and thereby obtain the myocardial performance index (MPI). However, the prognostic value of the cardiac time intervals and the MPI a...... of new MI, being admitted with congestive heart failure or death, increased with increasing tertile of MPI, being ≈3 times as high for the third tertile compared with the first tertile (hazard ratio, 2.8; 95% confidence interval, 1.7-4.7; P......Background- Color tissue Doppler imaging M-mode through the mitral leaflet is an easy and precise method to estimate all cardiac time intervals from 1 cardiac cycle and thereby obtain the myocardial performance index (MPI). However, the prognostic value of the cardiac time intervals and the MPI...

  9. Disappearance of myocardial perfusion defects on prone SPECT imaging: Comparison with cardiac magnetic resonance imaging in patients without established coronary artery disease

    Directory of Open Access Journals (Sweden)

    Hedén Bo

    2009-08-01

    Full Text Available Abstract Background It is of great clinical importance to exclude myocardial infarction in patients with suspected coronary artery disease who do not have stress-induced ischemia. The diagnostic use of myocardial perfusion single-photon emission computed tomography (SPECT in this situation is sometimes complicated by attenuation artifacts that mimic myocardial infarction. Imaging in the prone position has been suggested as a method to overcome this problem. Methods In this study, 52 patients without known prior infarction and no stress-induced ischemia on SPECT imaging were examined in both supine and prone position. The results were compared with cardiac magnetic resonance imaging (CMR with delayed-enhancement technique to confirm or exclude myocardial infarction. Results There were 63 defects in supine-position images, 37 of which disappeared in the prone position. None of the 37 defects were associated with myocardial infarction by CMR, indicating that all of them represented attenuation artifacts. Of the remaining 26 defects that did not disappear on prone imaging, myocardial infarction was confirmed by CMR in 2; the remaining 24 had no sign of ischemic infarction but 2 had other kinds of myocardial injuries. In 3 patients, SPECT failed to detect small scars identified by CMR. Conclusion Perfusion defects in the supine position that disappeared in the prone position were caused by attenuation, not myocardial infarction. Hence, imaging in the prone position can help to rule out ischemic heart disease for some patients admitted for SPECT with suspected but not documented ischemic heart disease. This would indicate a better prognosis and prevent unnecessary further investigations and treatment.

  10. Label-free cardiac contractility monitoring for drug screening applications based on compact high-speed lens-free imaging

    Science.gov (United States)

    Pauwelyn, Thomas; Reumers, Veerle; Vanmeerbeeck, Geert; Stahl, Richard; Janssens, Stefan; Lagae, Liesbet; Braeken, Dries; Lambrechts, Andy

    2015-03-01

    Cardiotoxicity is the major cause of drug withdrawal from the market, despite rigorous toxicity testing during the drug development process. Existing safety screening techniques, some of which are based on simplified cellular assays, others on electrical (impedance) or optical (fluorescent microscopy) measurements, are either too limited in throughput or offer too poor predictability of toxicity to be applied on large numbers of compounds in the early stage of drug development. We present a compact optical system for direct (label-free) monitoring of fast cellular movements that enable low cost and high throughput drug screening. Our system is based on a high-speed lens-free in-line holographic microscope. When compared to a conventional microscope, the system can combine adequate imaging resolution (5.5 μm pixel pitch) with a large field-of-view (63.4 mm2) and high speed (170 fps) to capture physical cell motion in real-time. This combination enables registration of cardiac contractility parameters such as cell contraction frequency, total duration, and rate and duration of both contraction and relaxation. The system also quantifies conduction velocity, which is challenging in existing techniques. Additionally, to complement the imaging hardware we have developed image processing software that extracts all the contractility parameters directly from the raw interference images. The system was tested with varying concentration of the drug verapamil and at 100 nM, showed a decrease in: contraction frequency (-23.3% +/- 13%), total duration (-21% +/- 5%), contraction duration (-19% +/- 6%) and relaxation duration (-21% +/- 8%). Moreover, contraction displacement ceased at higher concentrations.

  11. Downstream resource utilization following hybrid cardiac imaging with an integrated cadmium-zinc-telluride/64-slice CT device

    International Nuclear Information System (INIS)

    Low yield of invasive coronary angiography and unnecessary coronary interventions have been identified as key cost drivers in cardiology for evaluation of coronary artery disease (CAD). This has fuelled the search for noninvasive techniques providing comprehensive functional and anatomical information on coronary lesions. We have evaluated the impact of implementation of a novel hybrid cadmium-zinc-telluride (CZT)/64-slice CT camera into the daily clinical routine on downstream resource utilization. Sixty-two patients with known or suspected CAD were referred for same-day single-session hybrid evaluation with CZT myocardial perfusion imaging (MPI) and coronary CT angiography (CCTA). Hybrid MPI/CCTA images from the integrated CZT/CT camera served for decision-making towards conservative versus invasive management. Based on the hybrid images patients were classified into those with and those without matched findings. Matched findings were defined as the combination of MPI defect with a stenosis by CCTA in the coronary artery subtending the respective territory. All patients with normal MPI and CCTA as well as those with isolated MPI or CCTA finding or combined but unmatched findings were categorized as ''no match''. All 23 patients with a matched finding underwent invasive coronary angiography and 21 (91%) were revascularized. Of the 39 patients with no match, 5 (13%, p < 0.001 vs matched) underwent catheterization and 3 (8%, p < 0.001 vs matched) were revascularized. Cardiac hybrid imaging in CAD evaluation has a profound impact on patient management and may contribute to optimal downstream resource utilization. (orig.)

  12. The effect of acquisition interval and spatial resolution on dynamic cardiac imaging with a stationary SPECT camera

    International Nuclear Information System (INIS)

    The current SPECT scanning paradigm that acquires images by slow rotation of multiple detectors in body-contoured orbits around the patient is not suited to the rapid collection of tomographically complete data. During rapid image acquisition, mechanical and patient safety constraints limit the detector orbit to circular paths at increased distances from the patient, resulting in decreased spatial resolution. We consider a novel dynamic rotating slant-hole (DyRoSH) SPECT camera that can collect full tomographic data every 2 s, employing three stationary detectors mounted with slant-hole collimators that rotate at 30 rpm. Because the detectors are stationary, they can be placed much closer to the patient than is possible with conventional SPECT systems. We propose that the decoupling of the detector position from the mechanics of rapid image acquisition offers an additional degree of freedom which can be used to improve accuracy in measured kinetic parameter estimates. With simulations and list-mode reconstructions, we consider the effects of different acquisition intervals on dynamic cardiac imaging, comparing a conventional three detector SPECT system with the proposed DyRoSH SPECT system. Kinetic parameters of a two-compartment model of myocardial perfusion for technetium-99m-teboroxime were estimated. When compared to a conventional SPECT scanner for the same acquisition periods, the proposed DyRoSH system shows equivalent or reduced bias or standard deviation values for the kinetic parameter estimates. The DyRoSH camera with a 2 s acquisition period does not show any improvement compared to a DyRoSH camera with a 10 s acquisition period

  13. Cardiac function in growth hormone deficient patients before and after 1 year with replacement therapy: a magnetic resonance imaging study

    DEFF Research Database (Denmark)

    Andreassen, Mikkel; Faber, Jens Oscar; Petersen, Claus Leth;

    2011-01-01

    gold standard method cardiac magnetic resonance imaging (CMRI) and measurements of circulating levels of B-type natriuretic peptides. Sixteen patients (8 males and 8 females, mean age 49 years (range 18-75)) with severe GHD and 16 matched control subjects were included. CMRI was performed at baseline......Assessed by conventional echocardiography the influence of growth hormone deficiency (GHD) and effects of replacement therapy on left ventricle (LV) function and mass (LVM) have shown inconsistent results. We aimed to evaluate cardiac function before and during replacement therapy employing the...... (range 63-80%), cardiac output index and levels of BNP and NT-proBNP were similar at baseline in patients compared to controls (P-values from 0.09 to 0.37). The patients had significantly smaller LV end-diastolic volume index (P = 0.032) and end-systolic volume index (P = 0.038). No significant change in...

  14. Computed tomography of cardiac pseudotumors and neoplasms.

    Science.gov (United States)

    Anavekar, Nandan S; Bonnichsen, Crystal R; Foley, Thomas A; Morris, Michael F; Martinez, Matthew W; Williamson, Eric E; Glockner, James F; Miller, Dylan V; Breen, Jerome F; Araoz, Philip A

    2010-07-01

    Important features of cardiac masses can be clearly delineated on cardiac computed tomography (CT) imaging. This modality is useful in identifying the presence of a mass, its relationship with cardiac and extracardiac structures, and the features that distinguish one type of mass from another. A multimodality approach to the evaluation of cardiac tumors is advocated, with the use of echocardiography, CT imaging and magnetic resonance imaging as appropriately indicated. In this article, various cardiac masses are described, including pseudotumors and true cardiac neoplasms, and the CT imaging findings that may be useful in distinguishing these rare entities are presented. PMID:20705174

  15. The impact of acquisition time of planar cardiac 123I-MIBG imaging on the late heart to mediastinum ratio

    International Nuclear Information System (INIS)

    The aim of this study was to investigate whether performing the late cardiac 123I-metaiodobenzylguanidine (MIBG) scan earlier than 4 h post-injection (p.i.) has relevant impact on the late heart to mediastinum ratio (H/M ratio) in patients with heart failure (HF). Forty-nine patients with HF (median left ventricular ejection fraction of 31 %, 51 % ischaemic HF) referred for cardiac 123I-MIBG scintigraphy were scanned at 15 min (early) p.i. and at 1, 2, 3 and 4 h (late) p.i. of 123I-MIBG. Late H/M ratios were calculated and evaluated using a linear mixed model with the mean late H/M ratio at 4 h p.i. as a reference. A difference in late H/M ratios of more than 0.10 between the different acquisition times in comparison with the late H/M ratio at 4 h p.i. was considered as clinically relevant. Statistically significant mean differences were observed between the late H/M ratios at 1, 2 and 3 h p.i. compared with the late H/M ratio at 4 h p.i. (0.09, 0.05 and 0.02, respectively). However, the mean differences did not exceed the cut-off value of 0.10. On an individual patient level, compared to the late H/M ratio at 4 h p.i., the late H/M ratios at 1, 2 and 3 h p.i. differed more than 0.10 in 24 (50 %), 9 (19 %) and 2 (4 %) patients, respectively. Variation in acquisition time of 123I-MIBG between 2 and 4 h p.i. does not lead to a clinically significant change in the late H/M ratio. An earlier acquisition time seems to be justified and may warrant a more time-efficient cardiac 123I-MIBG imaging protocol. (orig.)

  16. Multiple Active Contours Driven by Particle Swarm Optimization for Cardiac Medical Image Segmentation

    Directory of Open Access Journals (Sweden)

    I. Cruz-Aceves

    2013-01-01

    Full Text Available This paper presents a novel image segmentation method based on multiple active contours driven by particle swarm optimization (MACPSO. The proposed method uses particle swarm optimization over a polar coordinate system to increase the energy-minimizing capability with respect to the traditional active contour model. In the first stage, to evaluate the robustness of the proposed method, a set of synthetic images containing objects with several concavities and Gaussian noise is presented. Subsequently, MACPSO is used to segment the human heart and the human left ventricle from datasets of sequential computed tomography and magnetic resonance images, respectively. Finally, to assess the performance of the medical image segmentations with respect to regions outlined by experts and by the graph cut method objectively and quantifiably, a set of distance and similarity metrics has been adopted. The experimental results demonstrate that MACPSO outperforms the traditional active contour model in terms of segmentation accuracy and stability.

  17. Long-range non-contact imaging photoplethysmography: cardiac pulse wave sensing at a distance

    Science.gov (United States)

    Blackford, Ethan B.; Estepp, Justin R.; Piasecki, Alyssa M.; Bowers, Margaret A.; Klosterman, Samantha L.

    2016-03-01

    Non-contact, imaging photoplethysmography uses photo-optical sensors to measure variations in light absorption, caused by blood volume pulsations, to assess cardiopulmonary parameters including pulse rate, pulse rate variability, and respiration rate. Recently, researchers have studied the applications and methodology of imaging photoplethysmography. Basic research has examined some of the variables affecting data quality and accuracy of imaging photoplethysmography including signal processing, imager parameters (e.g. frame rate and resolution), lighting conditions, subject motion, and subject skin tone. This technology may be beneficial for long term or continuous monitoring where contact measurements may be harmful (e.g. skin sensitivities) or where imperceptible or unobtrusive measurements are desirable. Using previously validated signal processing methods, we examined the effects of imager-to-subject distance on one-minute, windowed estimates of pulse rate. High-resolution video of 22, stationary participants was collected using an enthusiast-grade, mirrorless, digital camera equipped with a fully-manual, super-telephoto lens at distances of 25, 50, and 100 meters with simultaneous contact measurements of electrocardiography, and fingertip photoplethysmography. By comparison, previous studies have usually been conducted with imager-to-subject distances of up to only a few meters. Mean absolute error for one-minute, windowed, pulse rate estimates (compared to those derived from gold-standard electrocardiography) were 2.0, 4.1, and 10.9 beats per minute at distances of 25, 50, and 100 meters, respectively. Long-range imaging presents several unique challenges among which include decreased, observed light reflectance and smaller regions of interest. Nevertheless, these results demonstrate that accurate pulse rate measurements can be obtained from over long imager-to-participant distances given these constraints.

  18. Analytic system matrix resolution modeling in PET: an application to Rb-82 cardiac imaging

    Science.gov (United States)

    Rahmim, A.; Tang, J.; Lodge, M. A.; Lashkari, S.; Ay, M. R.; Lautamäki, R.; Tsui, B. M. W.; Bengel, F. M.

    2008-11-01

    This work explores application of a novel resolution modeling technique based on analytic physical models which individually models the various resolution degrading effects in PET (positron range, photon non-collinearity, inter-crystal scattering and inter-crystal penetration) followed by their combination and incorporation within the image reconstruction task. In addition to phantom studies, the proposed technique was particularly applied to and studied in the task of clinical Rb-82 myocardial perfusion imaging, which presently suffers from poor statistics and resolution properties in the reconstructed images. Overall, the approach is able to produce considerable enhancements in image quality. The reconstructed FWHM for a Discovery RX PET/CT scanner was seen to improve from 5.1 mm to 7.7 mm across the field-of-view (FoV) to ~3.5 mm nearly uniformly across the FoV. Furthermore, extended-source phantom studies indicated clearly improved images in terms of contrast versus noise performance. Using Monte Carlo simulations of clinical Rb-82 imaging, the resolution modeling technique was seen to significantly outperform standard reconstructions qualitatively, and also quantitatively in terms of contrast versus noise (contrast between the myocardium and other organs, as well as between myocardial defects and the left ventricle).

  19. Assessment of central chemosensitivity and cardiac sympathetic nerve activity using I-123 MIBG imaging in central sleep apnea syndrome in patients with dilated cardiomyopathy

    International Nuclear Information System (INIS)

    Iodine-123 m-iodobenzylguanidine (MIBG) imaging has been used to study cardiac sympathetic function in various cardiac diseases. Central sleep apnea syndrome (CSAS) occurs frequently in patients with chronic heart failure (CHF) and is reported to be associated with a poor prognosis. One of the mechanisms of its poor prognosis may be related to impaired cardiac sympathetic activity. However, the relationship between chemosensitivity to carbon dioxide, which is reported to correlate with the severity of CSAS, and cardiac sympathetic activity has not been investigated. Therefore, this study was undertaken to assess cardiac sympathetic function and chemosensitivity to carbon dioxide in CHF patients. The oxygen desaturation index (ODI) was evaluated in 21 patients with dilated cardiomyopathy (male/female: 19/2, left ventricular ejection fraction (LVEF)5 times/h underwent polysomnography. Patients with an apnea hypopnea index >15/h but without evidence of obstructive apnea were defined as having CSAS. Early (15 min) and delayed (4 hr) planar MIBG images were obtained from these patients. The mean counts in the whole heart and the mediastinum were obtained. The heart-to-mediastinum count ratio of the delayed image (H/M) and the corrected myocardial washout rate (WR) were also calculated. The central chemoreflex was assessed with the rebreathing method using a hypercapnic gas mixture (7% CO2 and 93% O2). Ten of the 21 patients had CSAS. The H/M ratio was similar in patients both with and without CSAS (1.57±0.18 vs. 1.59±0.14, p=0.82). However, the WR was higher in patients with CSAS than in patients without CSAS (40±8% vs. 30±12%, p<0.05). ODI significantly correlated with central chemosensitivity to carbon dioxide. Moreover, there was a highly significant correlation between WR and central chemosensitivity (r=0.65, p<0.05). However, there was no correlation between ODI and the WR (r=0.36, p=0.11). Cardiac sympathetic nerve activity in patients with CHF and CSAS is

  20. Quantifying the effect of tissue deformation on diffusion-weighted MRI: a mathematical model and an efficient simulation framework applied to cardiac diffusion imaging

    Science.gov (United States)

    Mekkaoui, Imen; Moulin, Kevin; Croisille, Pierre; Pousin, Jerome; Viallon, Magalie

    2016-08-01

    Cardiac motion presents a major challenge in diffusion weighted MRI, often leading to large signal losses that necessitate repeated measurements. The diffusion process in the myocardium is difficult to investigate because of the unqualified sensitivity of diffusion measurements to cardiac motion. A rigorous mathematical formalism is introduced to quantify the effect of tissue motion in diffusion imaging. The presented mathematical model, based on the Bloch-Torrey equations, takes into account deformations according to the laws of continuum mechanics. Approximating this mathematical model by using finite elements method, numerical simulations can predict the sensitivity of the diffusion signal to cardiac motion. Different diffusion encoding schemes are considered and the diffusion weighted MR signals, computed numerically, are compared to available results in literature. Our numerical model can identify the existence of two time points in the cardiac cycle, at which the diffusion is unaffected by myocardial strain and cardiac motion. Of course, these time points depend on the type of diffusion encoding scheme. Our numerical results also show that the motion sensitivity of the diffusion sequence can be reduced by using either spin echo technique with acceleration motion compensation diffusion gradients or stimulated echo acquisition mode with unipolar and bipolar diffusion gradients.

  1. Quantifying the effect of tissue deformation on diffusion-weighted MRI: a mathematical model and an efficient simulation framework applied to cardiac diffusion imaging.

    Science.gov (United States)

    Mekkaoui, Imen; Moulin, Kevin; Croisille, Pierre; Pousin, Jerome; Viallon, Magalie

    2016-08-01

    Cardiac motion presents a major challenge in diffusion weighted MRI, often leading to large signal losses that necessitate repeated measurements. The diffusion process in the myocardium is difficult to investigate because of the unqualified sensitivity of diffusion measurements to cardiac motion. A rigorous mathematical formalism is introduced to quantify the effect of tissue motion in diffusion imaging. The presented mathematical model, based on the Bloch-Torrey equations, takes into account deformations according to the laws of continuum mechanics. Approximating this mathematical model by using finite elements method, numerical simulations can predict the sensitivity of the diffusion signal to cardiac motion. Different diffusion encoding schemes are considered and the diffusion weighted MR signals, computed numerically, are compared to available results in literature. Our numerical model can identify the existence of two time points in the cardiac cycle, at which the diffusion is unaffected by myocardial strain and cardiac motion. Of course, these time points depend on the type of diffusion encoding scheme. Our numerical results also show that the motion sensitivity of the diffusion sequence can be reduced by using either spin echo technique with acceleration motion compensation diffusion gradients or stimulated echo acquisition mode with unipolar and bipolar diffusion gradients. PMID:27385441

  2. Effect of thyroid hormones on cardiac function, geometry, and oxidative metabolism assessed noninvasively by positron emission tomography and magnetic resonance imaging.

    Science.gov (United States)

    Bengel, F M; Nekolla, S G; Ibrahim, T; Weniger, C; Ziegler, S I; Schwaiger, M

    2000-05-01

    Thyroid hormones influence cardiac performance directly and indirectly via changes in peripheral circulation. Little, however, is known about the effect on myocardial oxidative metabolism and its relation to cardiac function and geometry. Patients with a history of thyroidectomy for thyroid cancer present a unique model to investigate the cardiac effects of hypothyroidism. Ten patients without heart disease were investigated in the hypothyroid state and again 4-6 weeks later under euthyroid conditions. Myocardial oxidative metabolism was measured by positron emission tomography with [11C]acetate and the clearance constant k(mono). Cine magnetic resonance imaging was applied to determine left ventricular geometry. A stroke work index (SWI = stroke volume x systolic blood pressure/ventricular mass) was calculated. Then, to estimate myocardial efficiency, a work metabolic index [WMI = SWI x heart rate/k(mono)] was obtained. Compared to hormone replacement, systemic vascular resistance and left ventricular mass were significantly higher in hypothyroidism. Ejection fraction and SWI were significantly lower. Despite an additional reduction of k(mono), the WMI was significantly lower, too. In summary, cardiac oxygen consumption is reduced in hypothyroidism. This reduction is associated with increased peripheral resistance and reduced contractility. Estimates of cardiac work are more severely suppressed than those of oxidative metabolism, suggesting decreased efficiency. These findings may provide an explanation for development or worsening of heart failure in hypothyroid patients with preexisting heart disease. PMID:10843159

  3. Practicability and safety of dipyridamole cardiac imaging in patients with severe chronic obstructive pulmonary disease

    Energy Technology Data Exchange (ETDEWEB)

    Thurnheer, R.; Laube, I.; Bloch, K.E.; Russi, E.W. [Pulmonary Division, Department of Internal Medicine, University Hospital of Switzerland, Zurich (Switzerland); Kaufmann, P.A.; Stumpe, K.D.M. [Department of Radiology, Division of Nuclear Medicine, University Hospital, Zuerich (Switzerland); Stammberger, U.; Weder, W. [Department of Surgery, University Hospital, Zuerich (Switzerland)

    1999-08-01

    We tested the practicability of dipyridamole myocardial nitrogen-13 ammonia positron emission tomography (dipyridamole {sup 13}NH{sub 3}PET) for the perioperative risk assessment of coronary artery disease (CAD) in a cohort of patients with severe chronic obstructive pulmonary disease (COPD) undergoing lung volume reduction surgery (LVRS). Twenty consecutive LVRS candidates, 13 men and 7 women (mean age 57 {+-}2 years), without symptoms of CAD were prospectively studied by dipyridamole {sup 13}NH {sub 3}PET. Side-effects and overall tolerance were assessed by a questionnaire and visual analogue scale. Repeated pulmonary function tests were performed before and 4, 12, 16 and 30 minutes after dipyridamole injection. All dipyridamole {sup 13}NH {sub 3}PET studies were negative for CAD. Seventeen patients underwent LVRS without cardiac complications; three patients did not undergo LVRS for other reasons. Nine patients suffered intolerable dyspnoea requiring i.v. aminophylline. Mean FEV {sub 1} decreased significantly after dipyridamole infusion: in nine patients the reduction in FEV {sub 1}exceeded 15% from baseline. We found that dipyridamole is not well tolerated and causes significant bronchoconstriction in patients with severe COPD. Although all dipyridamole-induced side effects can be promptly reversed by aminophylline, dipyridamole cannot be recommended as a pharmacological stress in this setting. (orig.) With 1 fig., 4 tabs., 35 refs.

  4. Is metal artefact reduction mandatory in cardiac PET/CT imaging in the presence of pacemaker and implantable cardioverter defibrillator leads?

    Energy Technology Data Exchange (ETDEWEB)

    Ghafarian, Pardis [Shahid Beheshti University, Department of Radiation Medicine, Tehran (Iran, Islamic Republic of); Geneva University Hospital, Division of Nuclear Medicine, Geneva 4 (Switzerland); Tehran University of Medical Sciences, Research Center for Science and Technology in Medicine, Tehran (Iran, Islamic Republic of); Aghamiri, S.M.R. [Shahid Beheshti University, Department of Radiation Medicine, Tehran (Iran, Islamic Republic of); Ay, Mohammad R. [Tehran University of Medical Sciences, Research Center for Science and Technology in Medicine, Tehran (Iran, Islamic Republic of); Tehran University of Medical Sciences, Department of Medical Physics and Biomedical Engineering, Tehran (Iran, Islamic Republic of); Tehran University of Medical Sciences, Research Institute for Nuclear Medicine, Tehran (Iran, Islamic Republic of); Rahmim, Arman [Johns Hopkins University, Department of Radiology, Baltimore, MD (United States); Schindler, Thomas H. [Geneva University, Cardiovascular Center, Nuclear Cardiology, Geneva (Switzerland); Ratib, Osman [Geneva University Hospital, Division of Nuclear Medicine, Geneva 4 (Switzerland); Zaidi, Habib [Geneva University Hospital, Division of Nuclear Medicine, Geneva 4 (Switzerland); Geneva University, Geneva Neuroscience Center, Geneva (Switzerland)

    2011-02-15

    Cardiac PET/CT imaging is often performed in patients with pacemakers and implantable cardioverter defibrillator (ICD) leads. However, metallic implants usually produce artefacts on CT images which might propagate to CT-based attenuation-corrected (CTAC) PET images. The impact of metal artefact reduction (MAR) for CTAC of cardiac PET/CT images in the presence of pacemaker, ICD and ECG leads was investigated using both qualitative and quantitative analysis in phantom and clinical studies. The study included 14 patients with various leads undergoing perfusion and viability examinations using dedicated cardiac PET/CT protocols. The PET data were corrected for attenuation using both artefactual CT images and CT images corrected using the MAR algorithm. The severity and magnitude of metallic artefacts arising from these leads were assessed on both linear attenuation coefficient maps ({mu}-maps) and attenuation-corrected PET images. CT and PET emission data were obtained using an anthropomorphic thorax phantom and a dedicated heart phantom made in-house incorporating pacemaker and ICD leads attached at the right ventricle of the heart. Volume of interest-based analysis and regression plots were performed for regions related to the lead locations. Bull's eye view analysis was also performed on PET images corrected for attenuation with and without the MAR algorithm. In clinical studies, the visual assessment of PET images by experienced physicians and quantitative analysis did not reveal erroneous interpretation of the tracer distribution or significant differences when PET images were corrected for attenuation with and without MAR. In phantom studies, the mean differences between tracer uptake obtained without and with MAR were 10.16{+-}2.1% and 6.86{+-}2.1% in the segments of the heart in the vicinity of metallic ICD or pacemaker leads, and were 4.43{+-}0.5% and 2.98{+-}0.5% in segments far from the leads. Although the MAR algorithm was able to effectively improve

  5. Is metal artefact reduction mandatory in cardiac PET/CT imaging in the presence of pacemaker and implantable cardioverter defibrillator leads?

    International Nuclear Information System (INIS)

    Cardiac PET/CT imaging is often performed in patients with pacemakers and implantable cardioverter defibrillator (ICD) leads. However, metallic implants usually produce artefacts on CT images which might propagate to CT-based attenuation-corrected (CTAC) PET images. The impact of metal artefact reduction (MAR) for CTAC of cardiac PET/CT images in the presence of pacemaker, ICD and ECG leads was investigated using both qualitative and quantitative analysis in phantom and clinical studies. The study included 14 patients with various leads undergoing perfusion and viability examinations using dedicated cardiac PET/CT protocols. The PET data were corrected for attenuation using both artefactual CT images and CT images corrected using the MAR algorithm. The severity and magnitude of metallic artefacts arising from these leads were assessed on both linear attenuation coefficient maps (μ-maps) and attenuation-corrected PET images. CT and PET emission data were obtained using an anthropomorphic thorax phantom and a dedicated heart phantom made in-house incorporating pacemaker and ICD leads attached at the right ventricle of the heart. Volume of interest-based analysis and regression plots were performed for regions related to the lead locations. Bull's eye view analysis was also performed on PET images corrected for attenuation with and without the MAR algorithm. In clinical studies, the visual assessment of PET images by experienced physicians and quantitative analysis did not reveal erroneous interpretation of the tracer distribution or significant differences when PET images were corrected for attenuation with and without MAR. In phantom studies, the mean differences between tracer uptake obtained without and with MAR were 10.16±2.1% and 6.86±2.1% in the segments of the heart in the vicinity of metallic ICD or pacemaker leads, and were 4.43±0.5% and 2.98±0.5% in segments far from the leads. Although the MAR algorithm was able to effectively improve the quality of

  6. Acute oedema in the evaluation of microvascular reperfusion and myocardial salvage in reperfused myocardial infarction with cardiac magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Phrommintikul, Arintaya, E-mail: apromint@mail.med.cmu.ac.t [Baker Heart Research Institute, Melbourne (Australia); Department of Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai 50200 (Thailand); Abdel-Aty, Hassan, E-mail: hassan.abdel-sty@charite.d [Franz-Volhard-Klinik, Helios-Klinikum Berlin, Kardiologie, Charite Campus Berlin-Buch, Humboldt-Universitaet zu Berlin, Berlin (Germany); Department of Cardiac Sciences, Foothills Medical Centre, University of Calgary, 1403-29th Street NW, Calgary, Alberta (Canada); Schulz-Menger, Jeanette, E-mail: jeanette.schulz-menger@charite.d [Franz-Volhard-Klinik, Helios-Klinikum Berlin, Kardiologie, Charite Campus Berlin-Buch, Humboldt-Universitaet zu Berlin, Berlin (Germany); Friedrich, Matthias G., E-mail: matthias.friedrich@ucalgary.c [Franz-Volhard-Klinik, Helios-Klinikum Berlin, Kardiologie, Charite Campus Berlin-Buch, Humboldt-Universitaet zu Berlin, Berlin (Germany); Department of Cardiac Sciences, Foothills Medical Centre, University of Calgary, 1403-29th Street NW, Calgary, Alberta (Canada); Taylor, Andrew J., E-mail: andrew.taylor@baker.edu.a [Baker Heart Research Institute, Melbourne (Australia)

    2010-06-15

    The accurate measurement of myocardial salvage is critical to the ongoing refinement of reperfusion strategies in acute myocardial infarction (AMI). Cardiac magnetic resonance imaging (CMR) can define the area at risk in AMI by the presence of myocardial oedema, identified by high signal intensity on T{sub 2}-weighted imaging with a short inversion time inversion-recovery (STIR) sequence. In addition, myocardial necrosis can be identified with CMR delayed contrast enhanced imaging. In this prospective study we examined the relationship of acute oedema and necrosis with impaired microvascular reperfusion. We also evaluated acute oedema as a marker of the area at risk in AMI, for the purposes of documenting myocardial salvage. CMR was performed on 15 patients with (AMI), within 24 h of successful percutaneous coronary intervention (PCI). Left ventricular (LV) systolic dysfunction was defined by a systolic thickening <40% (severe <20%). Microvascular reperfusion was evaluated during the acute phase of contrast wash-in. CMR was repeated 3 months post-PCI to evaluate recovery of LV function and final infarct size. Myocardial salvage was defined as the percentage of the area at risk that was not infarcted on follow up CMR. There was a significant correlation between impaired microvascular reperfusion and the extent of segmental oedema (R = 0.363, P < 0.01), but not myocardial necrosis (R = 0.110, P > 0.5). The extent of myocardial salvage correlated with recovery of systolic function (R = 0.241, P < 0.05), which was strongest in LV segments with severely reduced systolic function (R = 0.422, P < 0.01). Conclusions: In acutely reperfused AMI, oedema can be used to identify the area at risk for the purpose of calculating myocardial salvage. The correlation between myocardial oedema and reperfusion status suggests a pathological role of acute oedema in the impairment of microvascular reperfusion.

  7. Evaluation of Normal Fetal Left Cardiac Function by Tissue Doppler Imaging

    Institute of Scientific and Technical Information of China (English)

    LU Yongping; DENG Youbin; LIU Ya'ni; CHANG Qing; YANG Haoyi; LI Chunlei

    2006-01-01

    To explore the feasibility of using tissue Doppler imaging technique for the evaluation of fetus's left ventricular diastolic function, and to confirm its reliability by comparing it with traditional methods, this study examined 61 pregnant women in whom satisfactory images were obtained of fetal echocardiography. The peak velocity of blood stream were measured, including E, A and E/A at mitral valve orifice on the four chamber view with pulse wave. And then tissue Doppler imaging mode was employed to measure the velocity of mitral valve annulus including Ea, Aa, Sa and Ea /Aa. Correlation analysis was conducted between the velocity of orifice and that of annulus in terms of gestation age. And then correlation analysis was performed between above data and gestation ages. A positive correlation was found between the velocity of orifice and that of annulus, and the velocity increased with the gestation age. The change was the most significant between the 28th and the 34th week of gestation age. Our study showed that it is feasible to evaluate the fetus's left ventricular diastole function by tissue Doppler imaging. Its stability can avoid the influence of fetal heart rates and preload.

  8. In-Vivo Synthetic Aperture and Plane Wave High Frame Rate Cardiac Imaging

    DEFF Research Database (Denmark)

    Stuart, Matthias Bo; Jensen, Jonas; Brandt, Andreas Hjelm;

    2014-01-01

    A comparison of synthetic aperture imaging using spherical and plane waves with low number of emission events is presented. For both wave types, a 90 degree sector is insonified using 15 emission events giving a frame rate of 200 frames per second. Field II simulations of point targets show simil...

  9. New Applications of Cardiac Computed Tomography Dual-Energy, Spectral, and Molecular CT Imaging

    NARCIS (Netherlands)

    Danad, Ibrahim; Fayad, Zahi A.; Willemink, Martin J.; Min, James K.

    2015-01-01

    Computed tomography (CT) has evolved into a powerful diagnostic tool, and it is impossible to imagine current clinical practice without CT imaging. Because of its widespread availability, ease of clinical application, superb sensitivity for the detection of coronary artery disease, and noninvasive n

  10. Comparison of three multichannel transmit/receive radiofrequency coil configurations for anatomic and functional cardiac MRI at 7.0T: implications for clinical imaging

    International Nuclear Information System (INIS)

    To implement, examine, and compare three multichannel transmit/receive coil configurations for cardiovascular MR (CMR) at 7T. Three radiofrequency transmit-receive (TX/RX) coils with 4-, 8-, and 16-coil elements were used. Ten healthy volunteers (seven males, age 28 ± 4 years) underwent CMR at 7T. For all three RX/TX coils, 2D CINE FLASH images of the heart were acquired. Cardiac chamber quantification, signal-to-noise ratio (SNR) analysis, parallel imaging performance assessment, and image quality scoring were performed. Mean total examination time was 29 ± 5 min. All images obtained with the 8- and 16-channel coils were diagnostic. No significant difference in ejection fraction (EF) (P > 0.09) or left ventricular mass (LVM) (P > 0.31) was observed between the coils. The 8- and 16-channel arrays yielded a higher mean SNR in the septum versus the 4-channel coil. The lowest geometry factors were found for the 16-channel coil (mean ± SD 2.3 ± 0.5 for R = 4). Image quality was rated significantly higher (P < 0.04) for the 16-channel coil versus the 8- and 4-channel coils. All three coil configurations are suitable for CMR at 7.0T under routine circumstances. A larger number of coil elements enhances image quality and parallel imaging performance but does not impact the accuracy of cardiac chamber quantification. (orig.)

  11. Comparison of three multichannel transmit/receive radiofrequency coil configurations for anatomic and functional cardiac MRI at 7.0T: implications for clinical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Winter, Lukas; Graessl, Andreas; Hezel, Fabian; Thalhammer, Christof [Max-Delbrueck Center for Molecular Medicine, Berlin Ultrahigh Field Facility, Berlin (Germany); Kellman, Peter [National Institutes of Health/NHLBI, Laboratory of Cardiac Energetics, Bethesda, MD (United States); Renz, Wolfgang [Max-Delbrueck Center for Molecular Medicine, Berlin Ultrahigh Field Facility, Berlin (Germany); Siemens Healthcare, Erlangen (Germany); Knobelsdorff-Brenkenhoff, Florian von; Schulz-Menger, Jeanette [Max-Delbrueck Center for Molecular Medicine, Berlin Ultrahigh Field Facility, Berlin (Germany); HELIOS Klinikum Berlin-Buch, Department of Cardiology and Nephrology, Berlin (Germany); Charite Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Experimental and Clinical Research Center, Berlin (Germany); Tkachenko, Valeriy [Charite Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Experimental and Clinical Research Center, Berlin (Germany); Niendorf, Thoralf [Max-Delbrueck Center for Molecular Medicine, Berlin Ultrahigh Field Facility, Berlin (Germany); Charite Medical Faculty and the Max-Delbrueck Center for Molecular Medicine, Experimental and Clinical Research Center, Berlin (Germany)

    2012-10-15

    To implement, examine, and compare three multichannel transmit/receive coil configurations for cardiovascular MR (CMR) at 7T. Three radiofrequency transmit-receive (TX/RX) coils with 4-, 8-, and 16-coil elements were used. Ten healthy volunteers (seven males, age 28 {+-} 4 years) underwent CMR at 7T. For all three RX/TX coils, 2D CINE FLASH images of the heart were acquired. Cardiac chamber quantification, signal-to-noise ratio (SNR) analysis, parallel imaging performance assessment, and image quality scoring were performed. Mean total examination time was 29 {+-} 5 min. All images obtained with the 8- and 16-channel coils were diagnostic. No significant difference in ejection fraction (EF) (P > 0.09) or left ventricular mass (LVM) (P > 0.31) was observed between the coils. The 8- and 16-channel arrays yielded a higher mean SNR in the septum versus the 4-channel coil. The lowest geometry factors were found for the 16-channel coil (mean {+-} SD 2.3 {+-} 0.5 for R = 4). Image quality was rated significantly higher (P < 0.04) for the 16-channel coil versus the 8- and 4-channel coils. All three coil configurations are suitable for CMR at 7.0T under routine circumstances. A larger number of coil elements enhances image quality and parallel imaging performance but does not impact the accuracy of cardiac chamber quantification. (orig.)

  12. Spectacular tails of ionised gas in the Virgo cluster galaxy NGC 4569

    CERN Document Server

    Boselli, A; Fossati, M; Boissier, S; Bomans, D; Consolandi, G; Anselmi, G; Cortese, L; Cote, P; Durrell, P; Ferrarese, L; Fumagalli, M; Gavazzi, G; Gwyn, S; Hensler, G; Sun, M; Toloba, E

    2016-01-01

    We obtained using MegaCam at the CFHT a deep narrow band Halpha+[NII] wide field image of NGC 4569, the brightest late-type galaxy in the Virgo cluster. The image reveals the presence of long tails of diffuse ionised gas without any associated stellar component extending from the disc of the galaxy up to ~ 80 kpc (projected distance) with a typical surface brightness of a few 10^-18 erg s-1 cm-2 arcsec-2. These features provide direct evidence that NGC 4569 is undergoing a ram presure stripping event. The image also shows a prominent 8 kpc spur of ionised gas associated to the nucleus that spectroscopic data identify as an outflow. With some assumptions on the 3D distribution of the gas, we use the Halpha surface brightness of these extended low surface brightness features to derive the density and the mass of the gas stripped during the interaction of the galaxy with the ICM. The comparison with ad-hoc chemo-spectrophotometric models of galaxy evolution indicates that the mass of the Halpha emitting gas in t...

  13. Modification of the NEMA XR21-2000 cardiac phantom for testing of imaging systems used in endovascular image guided interventions

    Science.gov (United States)

    Ionita, C. N.; Dohatcu, A.; Jain, A.; Keleshis, C.; Hoffmann, K. R.; Bednarek, D. R.; Rudin, S.

    2009-02-01

    X-ray equipment testing using phantoms that mimic the specific human anatomy, morphology, and structure is a very important step in the research, development, and routine quality assurance for such equipment. Although the NEMA XR21 phantom exists for cardiac applications, there is no such standard phantom for neuro-, peripheral and cardiovascular angiographic applications. We have extended the application of the NEMA XR21-2000 phantom to evaluate neurovascular x-ray imaging systems by structuring it to be head-equivalent; two aluminum plates shaped to fit into the NEMA phantom geometry were added to a 15 cm thick section. Also, to enable digital subtraction angiography (DSA) testing, two replaceable central plates with a hollow slot were made so that various angiographic sections could be inserted into the phantom. We tested the new modified phantom using a flat panel C-arm unit dedicated for endovascular image-guided interventions. All NEMA XR21-2000 standard test sections were used in evaluations with the new "headequivalent" phantom. DSA and DA are able to be tested using two standard removable blocks having simulated arteries of various thickness and iodine concentrations (AAPM Report 15). The new phantom modifications have the benefits of enabling use of the standard NEMA phantom for angiography in both neuro- and cardio-vascular applications, with the convenience of needing only one versatile phantom for multiple applications. Additional benefits compared to using multiple phantoms are increased portability and lower cost.

  14. The effectiveness of photocatalytic ionisation disinfection of filter materials.

    Science.gov (United States)

    Pietrzak, Katarzyna; Gutarowska, Beata

    2013-01-01

    The purpose of this study was to determine the effectiveness of photocatalytic ionisation as a disinfection method for filter materials contaminated by microorganisms, and to assess how air relative humidity (RH), time and microbe type influence the effectiveness of this disinfection. In the quantitative analysis of a used car air filter, bacterial contamination equalled 1.2 x 10(5) cfu/cm2, fungal contamination was 3.8 x 10(6) cfu/cm2, and the isolated microorganisms were Aspergillus niger, Bacillus megaterium, Cladosporium herbarum, Cryptococcus laurenti, Micrococcus sp., Rhodotorula glutinis and Staphylococcus cohnii. In the model experiment, three isolates (C. herbarum, R. glutinis, S. cohnii) and 3 ATCC species (A. niger, E. coli, S. aureus) were used for photocatalytic ionisation disinfection. The conditions of effective photocatalytic ionisation disinfection (R > or = 99.9%) were established as 2-3 h at RH = 77% (bacteria) and 6-24 h at RH = 53% (fungi). RH has an influence on the effectiveness of the photocatalytic disinfection process; the highest effectiveness was obtained for bacteria at RH = 77%, with results 5% higher than for RH = 49%. The studies show that the sensitivity of microorganisms to photocatalytic ionisation disinfection is ordered as follows: Gram-positive bacteria (S. cohnii, S. aureus), Gram-negative bacteria (E. coli), yeasts (R. glutinis), and moulds (C. herbarum, A. niger). Of all the mathematical models used for the description of death dynamics after photocatalytic ionisation disinfection, the Chick-Watson model is the most useful, but for more resistant microorganisms, the delayed Chick-Watson model is highly recommended. It therefore seems, that the presented disinfection method of photocatalytic ionisation can be successfully used to clean filtration materials.

  15. Imaging of cardiac innervation: when will it reach clinical value?; Bildgebung der kardialen Innervation: Wann gelingt der Sprung in die Klinik?

    Energy Technology Data Exchange (ETDEWEB)

    Schaefers, M. [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum Muenster (Germany); Inst. fuer Arterioskleroseforschung, Westfaelische Wilhelms-Univ., Muenster (Germany); Schober, O. [Klinik und Poliklinik fuer Nuklearmedizin, Universitaetsklinikum Muenster (Germany)

    2004-09-01

    The autonomic nervous system is involved in the regulation of the majority of basic cardiac and vascular functions, e.g. the control of perfusion, rhythm, metabolism and contraction. This results in an involvement of the autonomic nervous system in many pathophysiologic processes affecting the heart. Furthermore, in clinical medicine the autonomic nervous system is a target of specific pharmacological treatment such as {beta}-blockade. Imaging of the autonomic nervous system in a clinical context should therefore proof useful in clinical decision making and therapy control of cardiovascular diseases. Today, scintigraphic techniques are a unique mean to image and quantify sympathetic and parasympathetic cardiac innervation non-invasively in vivo. Although these technologies are already available, these are not yet implemented in clinical algorithms. (orig.)

  16. Correlation between myocardial fibrosis and the occurrence of atrial fibrillation in hypertrophic cardiomyopathy: A cardiac magnetic resonance imaging study

    International Nuclear Information System (INIS)

    Cardiac magnetic resonance imaging (CMR) in hypertrophic cardiomyopathy (HCM) often shows delayed contrast enhancement (DE) representing regions of focal myocardial fibrosis. Atrial fibrillation (AF) is a commonly reported complication of HCM. We determined the relationship between the presence of left ventricular myocardial fibrosis (LVMF) detected by DE-CMR and the occurrence AF in a series of patients with HCM. 67 patients with HCM (47 males; mean age 50.1 ± 18.5 years) were studied by CMR measuring mass of LVMF, left ventricular mass, volume and function, and left atrial (LA) area. AF was present in 17 (25%) patients. LVMF was observed in 57% of patients. AF was significantly more frequent in patients who also showed LVMF, compared with the group without LVMF (42.1% vs. 3.4%, respectively; p 2; respectively, p = 0.0001). AF in HCM is related with myocardial fibrosis detected by DE-CMR and dilatation of the LA. This fact adds to the proven adverse prognostic value of myocardial fibrosis in HCM, thus, reinforcing the usefulness of this technique in the assessment of these patients.

  17. Correlation between myocardial fibrosis and the occurrence of atrial fibrillation in hypertrophic cardiomyopathy: A cardiac magnetic resonance imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Pujadas, S., E-mail: sandrapujadas@gmail.co [Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Vidal-Perez, R. [Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Hidalgo, A. [Radiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Leta, R.; Carreras, F.; Barros, A. [Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Bayes-Genis, A. [Cardiomyopathy and Cardiac Transplant Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Subirana, M.T. [Congenital Heart Disease Unit, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Pons-Llado, Guillem [Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain)

    2010-08-15

    Cardiac magnetic resonance imaging (CMR) in hypertrophic cardiomyopathy (HCM) often shows delayed contrast enhancement (DE) representing regions of focal myocardial fibrosis. Atrial fibrillation (AF) is a commonly reported complication of HCM. We determined the relationship between the presence of left ventricular myocardial fibrosis (LVMF) detected by DE-CMR and the occurrence AF in a series of patients with HCM. 67 patients with HCM (47 males; mean age 50.1 {+-} 18.5 years) were studied by CMR measuring mass of LVMF, left ventricular mass, volume and function, and left atrial (LA) area. AF was present in 17 (25%) patients. LVMF was observed in 57% of patients. AF was significantly more frequent in patients who also showed LVMF, compared with the group without LVMF (42.1% vs. 3.4%, respectively; p < 0.0001). LA size was larger in patients showing DE (LA area: 37.4 {+-} 11.1 vs. 25.9 {+-} 6.8 cm{sup 2}; respectively, p = 0.0001). AF in HCM is related with myocardial fibrosis detected by DE-CMR and dilatation of the LA. This fact adds to the proven adverse prognostic value of myocardial fibrosis in HCM, thus, reinforcing the usefulness of this technique in the assessment of these patients.

  18. Prognostic value of cardiac magnetic resonance imaging for idiopathic pulmonary arterial hypertension before initiating intravenous prostacyclin therapy

    International Nuclear Information System (INIS)

    Because few have reported the prognostic significance of cardiac magnetic resonance imaging (CMR) for idiopathic pulmonary arterial hypertension (IPAH), in this study we evaluated the value of CMR measurements as a prognostic predictor of IPAH before starting intravenous prostacyclin therapy. A total of 121 consecutive CMR studies for evaluating right ventricular (RV) function were reviewed. Forty-one patients were diagnosed with IPAH and served as the study group. Factors, such as age, sex, New York Heart Association functional class (NYHAFC), 6-min walk test, plasma brain natriuretic peptide level, serum uric acid level and CMR measurements were analyzed as predictors of first hospitalization and death. The mean follow-up period was 1,350±769 days. Nine patients were hospitalized because of heart failure, and 4 patients died from cardiopulmonary causes. The univariate analyses suggested that the left ventricular (LV) mass index, the left and right ventricular end-diastolic volume indices (LVEDVI, RVEDVI), the LV and RV end-systolic volume indices (LVESVI, RVESVI) and NYHAFC predicted the risk for hospitalization and that RVEDVI, RVESVI and NYHAFC predicted mortality. The multivariate analyses suggested that RVEDVI and NYHAFC are independent predictors of both hospitalization and mortality. The effects of RVEDVI and NYHAFC on hospitalization were not substantially affected by the concomitant medication. In IPAH patients, the RVEDVI predicts both hospitalization for right heart failure and mortality before initiating intravenous prostacyclin therapy. (author)

  19. Left ventricular pacing vector selection by novel echo-particle imaging velocimetry analysis for optimization of quadripolar cardiac resynchronization device: a case report

    OpenAIRE

    Martiniello, Alfonso/A. Roberto/R.; Pedrizzetti, Gianni/G.; Bianchi, Valter/V.; Tonti, Giovanni/G.; D’Onofrio, Antonio/A.; Caso, Pio/P.

    2016-01-01

    Background The availability of pacing configurations offered by quadripolar left ventricular leads could improve patients’ response to cardiac resynchronization therapy; however, the selection of an optimal setting remains a challenge. Echo-particle imaging velocimetry has shown that regional anomalies of synchrony/synergy of the left ventricle are related to the alteration, reduction, or suppression of the physiological intracavitary pressure gradients. These observations are also supported ...

  20. 7 Tesla (T) human cardiovascular magnetic resonance imaging using FLASH and SSFP to assess cardiac function: validation against 1.5 T and 3 T

    OpenAIRE

    Suttie, J. J.; DelaBarre, L; Pitcher, A.; van de Moortele, P. F.; Dass, S; Snyder, C. J.; Francis, J M; Metzger, G. J.; Weale, P.; Ugurbil, K; Neubauer, S.; Robson, M; Vaughan, T

    2011-01-01

    We report the first comparison of cardiovascular magnetic resonance imaging (CMR) at 1.5 T, 3 T and 7 T field strengths using steady state free precession (SSFP) and fast low angle shot (FLASH) cine sequences. Cardiac volumes and mass measurements were assessed for feasibility, reproducibility and validity at each given field strength using FLASH and SSFP sequences. Ten healthy volunteers underwent retrospectively electrocardiogram (ECG) gated CMR at 1.5 T, 3 T and 7 T using FLASH and SSFP se...

  1. Angiographic correlations of patients with small vessel disease diagnosed by adenosine-stress cardiac magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Scheck Roland

    2008-01-01

    Full Text Available Abstract Cardiac magnetic resonance imaging (CMR with adenosine-stress myocardial perfusion is gaining importance for the detection and quantification of coronary artery disease (CAD. However, there is little knowledge about patients with CMR-detected ischemia, but having no relevant stenosis as seen on coronary angiography (CA. The aims of our study were to characterize these patients by CMR and CA and evaluate correlations and potential reasons for the ischemic findings. 73 patients with an indication for CA were first scanned on a 1.5T whole-body CMR-scanner including adenosine-stress first-pass perfusion. The images were analyzed by two independent investigators for myocardial perfusion which was classified as subendocardial ischemia (n = 22, no perfusion deficit (n = 27, control 1, or more than subendocardial ischemia (n = 24, control 2. All patients underwent CA, and a highly significant correlation between the classification of CMR perfusion deficit and the degree of coronary luminal narrowing was found. For quantification of coronary blood flow, corrected Thrombolysis in Myocardial Infarction (TIMI frame count (TFC was evaluated for the left anterior descending (LAD, circumflex (LCX and right coronary artery (RCA. The main result was that corrected TFC in all coronaries was significantly increased in study patients compared to both control 1 and to control 2 patients. Study patients had hypertension or diabetes more often than control 1 patients. In conclusion, patients with CMR detected subendocardial ischemia have prolonged coronary blood flow. In connection with normal resting flow values in CAD, this supports the hypothesis of underlying coronary microvascular impairment. CMR stress perfusion differentiates non-invasively between this entity and relevant CAD.

  2. Magnetic Imaging of Applied and Propagating Action Currents in Cardiac Tissue Slices: Determination of Anisotropic Electrical Conductivities in a Two-Dimensional Bidomain.

    Science.gov (United States)

    Staton, Daniel Joseph

    We describe the first, high-resolution magnetic images of applied currents and propagating action currents in slices of canine cardiac tissue. This tissue was maintained in vitro at 37^circC. Our main conclusions are summarized as follows: the action currents produce magnetic fields which are measurable; during the initial stages of the propagating action potential, small, expanding, quatrefoil loops of current develop; the magnetic fields produced by repolarization currents are larger than previously anticipated. Most of the current associated with the propagating action potential is confined within the wavefront and should be magnetically silent; however, differences in the intracellular and extracellular electrical conductivities, in both the longitudinal and transverse fiber directions, are great enough that expanding quatrefoil current densities are associated with the wavefront and produce measurable magnetic fields. Since action currents are affected by the electrical conductivities, it is of interest to determine their values, which depend not only upon the tissue characteristics, but also on the mathematical model used to interpret the measured data. In our analysis of current injection, we use the anisotropic bidomain model which incorporates a passive, linear membrane. We introduce theoretical techniques to calculate the anisotropic conductivities of a two-dimensional bidomain. To apply these techniques to magnetic fields resulting from current injection into cardiac tissue slices, we need to improve the higher spatial frequency content of our present measurements. This may be done by measuring the magnetic field closer to the cardiac slice (presently 2.5 mm), decreasing the sampling interval of the measurement, and increasing the sampling area of the field. Magnetic fields are produced by propagating action currents, which are in turn the result of the propagating action potential. From the magnetic field, we directly image isochronal transmembrane

  3. Body Image and quality of life of senior citizens included in a cardiac rehabilitation program

    Directory of Open Access Journals (Sweden)

    Fernanda Vargas Amaral

    2013-12-01

    Full Text Available Most people who have to live with some kind of disease tend to adopt healthy habits and create new ways of seeing themselves. The aim of this study is to explore the relationship between the index of quality of life and self perception of patients included in a cardiovascular rehabilitation program in Florianopolis/Brazil. The sample consists of 24 subjects of 62 ± 1.3 years of age, who have coronary artery disease. The Minnesota Living With Heart Failure Questionnaire (MLHFQ was used to assess the quality of life, and to identify the degree of body image discontentment the Stunkard and Sorensen questionnaire (1993 was applied. Statistical analysis was made through statistics programs and the software SPSS 11.0. The degree of association between variables was studied with Kendall test. It was verified that the higher the BMI and the current body shape, the greatest the degree of body image dissatisfaction. The emotional symptoms also appear to be significantly correlated with a desire for a smaller body shape and with indicators of lower quality of life (r = 0474 = 0735, p major 0.05. The physical symptoms were also considerably associated with the emotional symptoms. These results suggest that the variables concerning the quality of life are meaningful to significant body image and satisfaction, which seems to correlate with fewer emotional problems and better facing of the disease. Cardiovascular Rehabilitation Programs that implement physical activity in daily habits proves to be a suitable tool for improving these ailments in this post-acute phase

  4. Assessing Cardiac Injury in Mice With Dual Energy-MicroCT, 4D-MicroCT, and MicroSPECT Imaging After Partial Heart Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chang-Lung; Min, Hooney [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Befera, Nicholas; Clark, Darin; Qi, Yi [Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina (United States); Das, Shiva [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Johnson, G. Allan; Badea, Cristian T. [Center for In Vivo Microscopy, Department of Radiology, Duke University Medical Center, Durham, North Carolina (United States); Kirsch, David G., E-mail: david.kirsch@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina (United States)

    2014-03-01

    Purpose: To develop a mouse model of cardiac injury after partial heart irradiation (PHI) and to test whether dual energy (DE)-microCT and 4-dimensional (4D)-microCT can be used to assess cardiac injury after PHI to complement myocardial perfusion imaging using micro-single photon emission computed tomography (SPECT). Methods and Materials: To study cardiac injury from tangent field irradiation in mice, we used a small-field biological irradiator to deliver a single dose of 12 Gy x-rays to approximately one-third of the left ventricle (LV) of Tie2Cre; p53{sup FL/+} and Tie2Cre; p53{sup FL/−} mice, where 1 or both alleles of p53 are deleted in endothelial cells. Four and 8 weeks after irradiation, mice were injected with gold and iodinated nanoparticle-based contrast agents, and imaged with DE-microCT and 4D-microCT to evaluate myocardial vascular permeability and cardiac function, respectively. Additionally, the same mice were imaged with microSPECT to assess myocardial perfusion. Results: After PHI with tangent fields, DE-microCT scans showed a time-dependent increase in accumulation of gold nanoparticles (AuNp) in the myocardium of Tie2Cre; p53{sup FL/−} mice. In Tie2Cre; p53{sup FL/−} mice, extravasation of AuNp was observed within the irradiated LV, whereas in the myocardium of Tie2Cre; p53{sup FL/+} mice, AuNp were restricted to blood vessels. In addition, data from DE-microCT and microSPECT showed a linear correlation (R{sup 2} = 0.97) between the fraction of the LV that accumulated AuNp and the fraction of LV with a perfusion defect. Furthermore, 4D-microCT scans demonstrated that PHI caused a markedly decreased ejection fraction, and higher end-diastolic and end-systolic volumes, to develop in Tie2Cre; p53{sup FL/−} mice, which were associated with compensatory cardiac hypertrophy of the heart that was not irradiated. Conclusions: Our results show that DE-microCT and 4D-microCT with nanoparticle-based contrast agents are novel imaging approaches

  5. Assessing Cardiac Injury in Mice With Dual Energy-MicroCT, 4D-MicroCT, and MicroSPECT Imaging After Partial Heart Irradiation

    International Nuclear Information System (INIS)

    Purpose: To develop a mouse model of cardiac injury after partial heart irradiation (PHI) and to test whether dual energy (DE)-microCT and 4-dimensional (4D)-microCT can be used to assess cardiac injury after PHI to complement myocardial perfusion imaging using micro-single photon emission computed tomography (SPECT). Methods and Materials: To study cardiac injury from tangent field irradiation in mice, we used a small-field biological irradiator to deliver a single dose of 12 Gy x-rays to approximately one-third of the left ventricle (LV) of Tie2Cre; p53FL/+ and Tie2Cre; p53FL/− mice, where 1 or both alleles of p53 are deleted in endothelial cells. Four and 8 weeks after irradiation, mice were injected with gold and iodinated nanoparticle-based contrast agents, and imaged with DE-microCT and 4D-microCT to evaluate myocardial vascular permeability and cardiac function, respectively. Additionally, the same mice were imaged with microSPECT to assess myocardial perfusion. Results: After PHI with tangent fields, DE-microCT scans showed a time-dependent increase in accumulation of gold nanoparticles (AuNp) in the myocardium of Tie2Cre; p53FL/− mice. In Tie2Cre; p53FL/− mice, extravasation of AuNp was observed within the irradiated LV, whereas in the myocardium of Tie2Cre; p53FL/+ mice, AuNp were restricted to blood vessels. In addition, data from DE-microCT and microSPECT showed a linear correlation (R2 = 0.97) between the fraction of the LV that accumulated AuNp and the fraction of LV with a perfusion defect. Furthermore, 4D-microCT scans demonstrated that PHI caused a markedly decreased ejection fraction, and higher end-diastolic and end-systolic volumes, to develop in Tie2Cre; p53FL/− mice, which were associated with compensatory cardiac hypertrophy of the heart that was not irradiated. Conclusions: Our results show that DE-microCT and 4D-microCT with nanoparticle-based contrast agents are novel imaging approaches complementary to microSPECT for

  6. Image based cardiac acceleration map using statistical shape and 3D+t myocardial tracking models; in-vitro study on heart phantom

    Science.gov (United States)

    Pashaei, Ali; Piella, Gemma; Planes, Xavier; Duchateau, Nicolas; de Caralt, Teresa M.; Sitges, Marta; Frangi, Alejandro F.

    2013-03-01

    It has been demonstrated that the acceleration signal has potential to monitor heart function and adaptively optimize Cardiac Resynchronization Therapy (CRT) systems. In this paper, we propose a non-invasive method for computing myocardial acceleration from 3D echocardiographic sequences. Displacement of the myocardium was estimated using a two-step approach: (1) 3D automatic segmentation of the myocardium at end-diastole using 3D Active Shape Models (ASM); (2) propagation of this segmentation along the sequence using non-rigid 3D+t image registration (temporal di eomorphic free-form-deformation, TDFFD). Acceleration was obtained locally at each point of the myocardium from local displacement. The framework has been tested on images from a realistic physical heart phantom (DHP-01, Shelley Medical Imaging Technologies, London, ON, CA) in which the displacement of some control regions was known. Good correlation has been demonstrated between the estimated displacement function from the algorithms and the phantom setup. Due to the limited temporal resolution, the acceleration signals are sparse and highly noisy. The study suggests a non-invasive technique to measure the cardiac acceleration that may be used to improve the monitoring of cardiac mechanics and optimization of CRT.

  7. Biomaterials for cardiac regeneration

    CERN Document Server

    Ruel, Marc

    2015-01-01

    This book offers readers a comprehensive biomaterials-based approach to achieving clinically successful, functionally integrated vasculogenesis and myogenesis in the heart. Coverage is multidisciplinary, including the role of extracellular matrices in cardiac development, whole-heart tissue engineering, imaging the mechanisms and effects of biomaterial-based cardiac regeneration, and autologous bioengineered heart valves. Bringing current knowledge together into a single volume, this book provides a compendium to students and new researchers in the field and constitutes a platform to allow for future developments and collaborative approaches in biomaterials-based regenerative medicine, even beyond cardiac applications. This book also: Provides a valuable overview of the engineering of biomaterials for cardiac regeneration, including coverage of combined biomaterials and stem cells, as well as extracellular matrices Presents readers with multidisciplinary coverage of biomaterials for cardiac repair, including ...

  8. Turner syndrome strategies to improve care outcomes--cardiac evaluation using new imaging techniques.

    Science.gov (United States)

    Mazzanti, Laura; Lovato, Luigi; Prandstraller, Daniela; Scarano, Emanuela; Tamburrino, Federica; Montanari, Francesca; Mineo, Gian Gaspero; Perri, Annamaria; Vestrucci, Benedetta; Giardini, Andrea

    2012-05-01

    Turner syndrome (TS) is at high risk for congenital heart diseases (CHD), aortic dilatation (AoDil) and dissection. New imaging techniques such as MRI have revealed the presence of vascular anomalies (VA) undetected at echo. MR angiography has shown a high prevalence of aortic and venous anomalies. The VA often coexist and interact to increase the risk of premature death in adulthood. AoDil and VA have been found also in asymptomatic individuals with no predisposing factors, but the prevalence is still unknown. We evaluated 100 TS subjects (15-35 yrs) with no aortic CHD at echocardiography with transthoracic MRA; 42 of them showed VA and 58 did not. Aortic diameters were indexed on BSA. At the sinuses of Valsalva a higher prevalence of AoDil was found in subjects with VA than without; 57% of them showed AoDil. The presence of VA (elongation of the transverse arch, bovine arch, left superior vena cava, PAPVD etc.) increased their relative risk of AoDil by more than 2 times. Excluding BSA influence, a severe phenotype influenced positively ascending AoDil. New imaging techniques enhance our ability to provide a prognosis for their adult age and in particular before they seek to become pregnant. PMID:22946280

  9. Utility of echocardiographic tissue synchronization imaging to redirect left ventricular epicardial lead placement for cardiac resynchronization therapy

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ye; LI Zhi-an; HE Yi-hua; ZHANG Hai-bo; MENG Xu

    2013-01-01

    Background Cardiac resynchronization therapy (CRT) with biventricular pacing has demonstrated cardiac function improvement for treating congestive heart failure (HF).It has been documented that the placement of the left ventricular lead at the longest contraction delay segment has the optimal CRT benefit.This study described follow-up to surgical techniques for CRT as a viable alternative for patients with heart failure.Methods Between April 2007 and June 2012,a total of 14 consecutive heart failure patients with New York Heart Association (NYHA) Class Ⅲ-Ⅳ underwent left ventricular epicardial lead placements via surgical approach.There were eight males and six females,aged 36 to 79 years ((59.6±9.2) years).The mean left ventricular ejection fraction (LVEF)was (33.6±7.4)%.All patients were treated with left ventricular systolic dyssynchrony and underwent left ventricular epicardial lead placements via a surgical approach.Tissue Doppler imaging (TDI) and intraoperative transesophageal echocardiography were used to assess changes in left heart function and dyssynchronic parameters.Also,echo was used to select the best site for left ventricular epicardial lead placement.Results Left ventricular epicardial leads were successfully implanted in the posterior or lateral epicardial wall without serious complications in all patients.All patients had reduction in NYHA score from Ⅲ-Ⅳ preoperatively to Ⅱ-Ⅲ postoperatively.The left ventricular end-diastolic diameter (LVEDD) decreased from (67.9±12.7) mm to (61.2±7.1) mm (P<0.05),and LVEF increased from (33.6±7.4)% to (42.2±8.8)% (P<0.05).Left ventricular intraventricular dyssynchrony index decreased from (148.4±31.6) ms to (57.3±23.8) ms (P<0.05).Conclusions Minimally invasive surgical placement of the left ventricular epicardial lead is feasible,safe,and efficient.TDI can guide the epicardial lead placement to the ideal target location.

  10. Automation analysis of cardiac wall deformation from tagged magnetic resonance images; Analise automatica de deformacao do miocardio em imagens marcadas por ressonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Piva, R.M.V. [Hospital das Clinicas, Sao Paulo, SP (Brazil). Instituto do Coracao. Div. de Informatica; Kitney, R.I. [Imperial College of Science, Technology and Medicine, London (United Kingdom)

    1998-07-01

    Automation of cardiac wall deformation analysis from tagged magnetic resonance images (MRI) derives, basically, from the automatic detection of MR tags and left ventricle contours. In this work, it was adopted an approach based on image processing techniques and fuzzy logic to extract and classify image features as belonging to tags or ventricular borders. The use of fuzzy logic and IF-THEN rules, which involve image features such as length and curvature of valleys and gradients, allow the estimation of the membership of the pixels in the searched classes. The myocardial deformation is estimated in regions circumvented by contiguous tag intersections. The proposed method was applied to cine SPAMM (Spatial Modulation of Magnetization) short-axis images of the left ventricle obtained from human volunteers. (author)

  11. An application of resonant ionisation spectroscopy to accelerator based high energy physics

    International Nuclear Information System (INIS)

    The simulation of charged particle tracks by pulsed UV lasers is now used extensively in the calibration of multiwire drift chambers. The identity of the trace quantities of low ionisation potential impurities responsible for the laser induced ionisation in conventional chamber gases has caused much discussion. Using two photon resonant ionisation spectroscopy two of the major sources of ionisation in proportional counters have been identified as phenol and toluene. (author)

  12. Development and validation of a direct-comparison method for cardiac {sup 123}I-metaiodobenzylguanidine washout rates derived from late 3-hour and 4-hour imaging

    Energy Technology Data Exchange (ETDEWEB)

    Okuda, Koichi; Hashimoto, Mitsumasa [Kanazawa Medical University, Department of Physics, Kahoku, Ishikawa (Japan); Nakajima, Kenichi; Matsuo, Shinro; Taki, Junichi; Kinuya, Seigo [Kanazawa University Hospital, Department of Nuclear Medicine, Kanazawa, Ishikawa (Japan); Sugino, Shuichi [Okayama Kyokuto Hospital, Department of Radiology, Okayama, Okayama (Japan); Kirihara, Yumiko [FUJIFILM RI Pharma Co., Ltd., Chuo-Ku, Tokyo (Japan)

    2016-02-15

    The washout rate (WR) has been used in {sup 123}I-metaiodobenzylguanidine (MIBG) imaging to evaluate cardiac sympathetic innervation. However, WR varies depending on the time between the early and late MIBG scans. Late scans are performed at either 3 or 4 hours after injection of MIBG. The aim of this study was to directly compare the WR at 3 hours (WR{sub 3h}) with the WR at 4 hours (WR{sub 4h}). We hypothesized that the cardiac count would reduce linearly between the 3-hour and 4-hour scans. A linear regression model for cardiac counts at two time-points was generated. We enrolled a total of 96 patients who underwent planar {sup 123}I-MIBG scintigraphy early (15 min) and during the late phase at both 3 and 4 hours. Patients were randomly divided into two groups: a model-creation group (group 1) and a clinical validation group (group 2). Cardiac counts at 15 minutes (count{sub early}), 3 hours (count{sub 3h}) and 4 hours (count{sub 4h}) were measured. Cardiac count{sub 4h} was mathematically estimated using the linear regression model from count{sub early} and count{sub 3h}. In group 1, the actual cardiac count{sub 4h}/count{sub early} was highly significantly correlated with count{sub 3h}/count{sub early} (r = 0.979). In group 2, the average estimated count{sub 4h} was 92.8 ± 31.9, and there was no significant difference between this value and the actual count{sub 4h} (91.9 ± 31.9). Bland-Altman analysis revealed a small bias of -0.9 with 95 % limits of agreement of -6.2 and +4.3. WR{sub 4h} calculated using the estimated cardiac count{sub 4h} was comparable to the actual WR{sub 4h} (24.3 ± 9.6 % vs. 25.1 ± 9.7 %, p = ns). Bland-Altman analysis and the intraclass correlation coefficient showed that there was excellent agreement between the estimated and actual WR{sub 4h}. The linear regression model that we used accurately estimated cardiac count{sub 4h} using count{sub early} and count{sub 3h}. Moreover, WR{sub 4h} that was mathematically calculated using

  13. Selecting a CT scanner for cardiac imaging: the heart of the matter.

    Science.gov (United States)

    Lewis, Maria A; Pascoal, Ana; Keevil, Stephen F; Lewis, Cornelius A

    2016-09-01

    Coronary angiography to assess the presence and degree of arterial stenosis is an examination now routinely performed on CT scanners. Although developments in CT technology over recent years have made great strides in improving the diagnostic accuracy of this technique, patients with certain characteristics can still be "difficult to image". The various groups will benefit from different technological enhancements depending on the type of challenge they present. Good temporal and spatial resolution, wide longitudinal (z-axis) detector coverage and high X-ray output are the key requirements of a successful CT coronary angiography (CTCA) scan. The requirement for optimal patient dose is a given. The different scanner models recommended for CTCA all excel in different aspects. The specification data presented here for these scanners and the explanation of the impact of the different features should help in making a more informed decision when selecting a scanner for CTCA. PMID:27302494

  14. Assessment of cerebellar pulsation in dogs with and without Chiari-like malformation and syringomyelia using cardiac-gated cine magnetic resonance imaging.

    Science.gov (United States)

    Driver, C J; Watts, V; Bunck, A C; Van Ham, L M; Volk, H A

    2013-10-01

    Canine Chiari-like malformation (CM) is characterised by herniation of part of the cerebellum through the foramen magnum. In humans with Chiari type I malformation (CM-I), abnormal pulsation of the cerebellum during the cardiac cycle has been documented and is pivotal to theories for the pathogenesis of syringomyelia (SM). In this retrospective study, cardiac-gated cine balanced fast field echo (bFEE) magnetic resonance imaging (MRI) was used to assess pulsation of the brain in dogs and to objectively measure the degree of cerebellar pulsation with the neck in a flexed position. Overall, 17 Cavalier King Charles Spaniels (CKCS) with CM, including eight with SM and nine without SM, were compared with six small breed control dogs. Linear regions of interest were generated for the length of cerebellar herniation from each phase of the cardiac cycle and the degree of cerebellar pulsation was subsequently calculated. Age, bodyweight and angle of neck flexion were also compared. CKCS with CM and SM had significantly greater pulsation of the cerebellum than control dogs (P=0.003) and CKCS with CM only (P=0.031). There was no significant difference in age, bodyweight and angle of neck flexion between the three groups. Cardiac-gated cine bFEE MRI permitted the dynamic visualisation of cerebellar pulsation in dogs. These findings support the current theories regarding the pathogenesis of SM secondary to CM and further highlight the similarities between canine CM and human CM-I.

  15. Takotsubo cardiomyopathy, a two-stage recovery of left ventricular systolic and diastolic function as determined by cardiac magnetic resonance imaging

    DEFF Research Database (Denmark)

    Ahtarovski, Kiril Aleksov; Iversen, Kasper Karmark; Christensen, Thomas Emil;

    2014-01-01

    -12) 16 patients (mean age 66, range 39-84 years) diagnosed with TTC and 20 healthy matched controls. We performed cardiac magnetic resonance imaging (CMR) at admission, pre-discharge, and 3-month follow-up. Diastolic function was assessed by LV peak filling rate (LVPFR) and left atrial (LA) emptying...... imaging demonstrated non-coronary distributed apical oedema without contrast enhancement. CONCLUSION: Patients with TTC undergo fast systolic recovery. However, at discharge, profound diastolic dysfunction is demonstrated by CMR. At follow-up, both LV systolic and diastolic function is normalized in...

  16. An implementation of ionisation energy loss in very thin absorbers for the GEANT4 simulation package

    CERN Document Server

    Apostolakis, John; Urbàn, L; Maire, M; Bagulya, A V; Grichine, V M

    2000-01-01

    We discuss an implementation of Photo Absorption Ionisation model describing ionisation energy loss produced by a relativistic charged particle in very thin absorbers. The implementation allows us to calculate ionisation energy losses in any material consisting of elements with atomic numbers in the range 1-100. Comparisons of simulation with the experimental data from gaseous and solid state detectors are presented. (24 refs).

  17. Role of multimodality cardiac imaging in the management of patients with hypertrophic cardiomyopathy: an expert consensus of the European Association of Cardiovascular Imaging Endorsed by the Saudi Heart Association.

    Science.gov (United States)

    Cardim, Nuno; Galderisi, Maurizio; Edvardsen, Thor; Plein, Sven; Popescu, Bogdan A; D'Andrea, Antonello; Bruder, Oliver; Cosyns, Bernard; Davin, Laurent; Donal, Erwan; Freitas, Antonio; Habib, Gilbert; Kitsiou, Anastasia; Petersen, Steffen E; Schroeder, Stephen; Lancellotti, Patrizio; Camici, Paolo; Dulgheru, Raluca; Hagendorff, Andreas; Lombardi, Massimo; Muraru, Denisa; Sicari, Rosa

    2015-03-01

    Taking into account the complexity and limitations of clinical assessment in hypertrophic cardiomyopathy (HCM), imaging techniques play an essential role in the evaluation of patients with this disease. Thus, in HCM patients, imaging provides solutions for most clinical needs, from diagnosis to prognosis and risk stratification, from anatomical and functional assessment to ischaemia detection, from metabolic evaluation to monitoring of treatment modalities, from staging and clinical profiles to follow-up, and from family screening and preclinical diagnosis to differential diagnosis. Accordingly, a multimodality imaging (MMI) approach (including echocardiography, cardiac magnetic resonance, cardiac computed tomography, and cardiac nuclear imaging) is encouraged in the assessment of these patients. The choice of which technique to use should be based on a broad perspective and expert knowledge of what each technique has to offer, including its specific advantages and disadvantages. Experts in different imaging techniques should collaborate and the different methods should be seen as complementary, not as competitors. Each test must be selected in an integrated and rational way in order to provide clear answers to specific clinical questions and problems, trying to avoid redundant and duplicated information, taking into account its availability, benefits, risks, and cost. PMID:25650407

  18. Intraindividual comparison of T1 relaxation times after gadobutrol and Gd-DTPA administration for cardiac late enhancement imaging

    Energy Technology Data Exchange (ETDEWEB)

    Doeblin, Patrick, E-mail: Patrick.doeblin@charite.de [Department of Cardiology, Charité – Universitätsmedizin Berlin, Charité Campus Benjamin Franklin, Berlin (Germany); Schilling, Rene, E-mail: rene.schilling@charite.de [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); Wagner, Moritz, E-mail: moritz.wagner@charite.de [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); Luhur, Reny, E-mail: renyluhur@yahoo.com [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); Huppertz, Alexander, E-mail: alexander.huppertz@charite.de [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); Imaging Science Institute, Charité, Berlin (Germany); Hamm, Bernd, E-mail: bernd.hamm@charite.de [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); Taupitz, Matthias, E-mail: matthias.taupitz@harite.de [Department of Radiology, Charité – Universitätsmedizin Berlin, Charité Campus Mitte, Berlin (Germany); and others

    2014-04-15

    Purpose: To evaluate T1-relaxation times of chronic myocardial infarction (CMI) using gadobutrol and gadopentetate dimeglumine (Gd-DTPA) over time and to determine the optimal imaging window for late enhancement imaging with both contrast agents. Material and methods: Twelve patients with CMI were prospectively included and examined on a 1.5 T magnetic resonance (MR) system using relaxivity-adjusted doses of gadobutrol (0.15 mmol/kg) and Gd-DTPA (0.2 mmol/kg) in random order. T1-relaxation times of remote myocardium (RM), infarcted myocardium (IM), and left ventricular cavity (LVC) were assessed from short-axis TI scout imaging using the Look–Locker approach and compared intraindividually using a Wilcoxon paired signed-rank test (α < 0.05). Results: Within 3 min of contrast agent administration (CA), IM showed significantly lower T1-relaxation times than RM with both contrast agents, indicating beginning cardiac late enhancement. Differences between gadobutrol and Gd-DTPA in T1-relaxation times of IM and RM were statistically not significant through all time points. However, gadobutrol led to significantly higher T1-relaxation times of LVC than Gd-DTPA from 6 to 9 min (220 ± 15 ms vs. 195 ± 30 ms p < 0.01) onwards, resulting in a significantly greater ΔT1 of IM to LVC at 9–12 min (−20 ± 35 ms vs. 0 ± 35 ms, p < 0.05) and 12–15 min (−25 ± 45 ms vs. −10 ± 60 ms, p < 0.05). Using Gd-DTPA, comparable ΔT1 values were reached only after 25–35 min. Conclusion: This study indicates good delineation of IM to RM with both contrast agents as early as 3 min after administration. However, we found significant differences in T1 relaxation times with greater ΔT1 IM–LVC using 0.15 mmol/kg gadobutrol compared to 0.20 mmol/kg Gd-DTPA after 9–15 min post-CA suggesting earlier differentiability of IM and LVC using gadobutrol.

  19. Ca(2+ release events in cardiac myocytes up close: insights from fast confocal imaging.

    Directory of Open Access Journals (Sweden)

    Vyacheslav M Shkryl

    Full Text Available The spatio-temporal properties of Ca(2+ transients during excitation-contraction coupling and elementary Ca(2+ release events (Ca(2+ sparks were studied in atrial and ventricular myocytes with ultra-fast confocal microscopy using a Zeiss LSM 5 LIVE system that allows sampling rates of up to 60 kHz. Ca(2+ sparks which originated from subsarcolemmal junctional sarcoplasmic reticulum (j-SR release sites in atrial myocytes were anisotropic and elongated in the longitudinal direction of the cell. Ca(2+ sparks in atrial cells originating from non-junctional SR and in ventricular myocytes were symmetrical. Ca(2+ spark recording in line scan mode at 40,000 lines/s uncovered step-like increases of [Ca(2+]i. 2-D imaging of Ca(2+ transients revealed an asynchronous activation of release sites and allowed the sequential recording of Ca(2+ entry through surface membrane Ca(2+ channels and subsequent activation of Ca(2+-induced Ca(2+ release. With a latency of 2.5 ms after application of an electrical stimulus, Ca(2+ entry could be detected that was followed by SR Ca(2+ release after an additional 3 ms delay. Maximum Ca(2+ release was observed 4 ms after the beginning of release. The timing of Ca(2+ entry and release was confirmed by simultaneous [Ca(2+]i and membrane current measurements using the whole cell voltage-clamp technique. In atrial cells activation of discrete individual release sites of the j-SR led to spatially restricted Ca(2+ release events that fused into a peripheral ring of elevated [Ca(2+]i that subsequently propagated in a wave-like fashion towards the center of the cell. In ventricular myocytes asynchronous Ca(2+ release signals from discrete sites with no preferential subcellular location preceded the whole-cell Ca(2+ transient. In summary, ultra-fast confocal imaging allows investigation of Ca(2+ signals with a time resolution similar to patch clamp technique, however in a less invasive fashion.

  20. Cardiac fusion and complex congenital cardiac defects in thoracopagus twins: diagnostic value of cardiac CT

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Hyun Woo [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of); Park, Jeong-Jun [University of Ulsan College of Medicine, Asan Medical Center, Department of Pediatric Cardiac Surgery, Seoul (Korea, Republic of); Kim, Ellen Ai-Rhan [University of Ulsan College of Medicine, Asan Medical Center, Division of Neonatology, Department of Pediatrics, Seoul (Korea, Republic of); Won, Hye-Sung [University of Ulsan College of Medicine, Asan Medical Center, Department of Obstetrics and Gynecology, Seoul (Korea, Republic of)

    2014-09-15

    Most thoracopagus twins present with cardiac fusion and associated congenital cardiac defects, and assessment of this anatomy is of critical importance in determining patient care and outcome. Cardiac CT with electrocardiographic triggering provides an accurate and quick morphological assessment of both intracardiac and extracardiac structures in newborns, making it the best imaging modality to assess thoracopagus twins during the neonatal period. In this case report, we highlight the diagnostic value of cardiac CT in thoracopagus twins with an interatrial channel and complex congenital cardiac defects. (orig.)

  1. Assessment of cardiac sympathetic nerve integrity with positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Raffel, David M. E-mail: raffel@umich.edu; Wieland, Donald M

    2001-07-01

    The autonomic nervous system plays a critical role in the regulation of cardiac function. Abnormalities of cardiac innervation have been implicated in the pathophysiology of many heart diseases, including sudden cardiac death and congestive heart failure. In an effort to provide clinicians with the ability to regionally map cardiac innervation, several radiotracers for imaging cardiac sympathetic neurons have been developed. This paper reviews the development of neuronal imaging agents and discusses their emerging role in the noninvasive assessment of cardiac sympathetic innervation.

  2. Measurement of Strain in Cardiac Myocytes at Micrometer Scale Based on Rapid Scanning Confocal Microscopy and Non-Rigid Image Registration.

    Science.gov (United States)

    Lichter, J; Li, Hui; Sachse, Frank B

    2016-10-01

    Measurement of cell shortening is an important technique for assessment of physiology and pathophysiology of cardiac myocytes. Many types of heart disease are associated with decreased myocyte shortening, which is commonly caused by structural and functional remodeling. Here, we present a new approach for local measurement of 2-dimensional strain within cells at high spatial resolution. The approach applies non-rigid image registration to quantify local displacements and Cauchy strain in images of cells undergoing contraction. We extensively evaluated the approach using synthetic cell images and image sequences from rapid scanning confocal microscopy of fluorescently labeled isolated myocytes from the left ventricle of normal and diseased canine heart. Application of the approach yielded a comprehensive description of cellular strain including novel measurements of transverse strain and spatial heterogeneity of strain. Quantitative comparison with manual measurements of strain in image sequences indicated reliability of the developed approach. We suggest that the developed approach provides researchers with a novel tool to investigate contractility of cardiac myocytes at subcellular scale. In contrast to previously introduced methods for measuring cell shorting, the developed approach provides comprehensive information on the spatio-temporal distribution of 2-dimensional strain at micrometer scale.

  3. Image-based modeling and characterization of RF ablation lesions in cardiac arrhythmia therapy

    Science.gov (United States)

    Linte, Cristian A.; Camp, Jon J.; Rettmann, Maryam E.; Holmes, David R.; Robb, Richard A.

    2013-03-01

    In spite of significant efforts to enhance guidance for catheter navigation, limited research has been conducted to consider the changes that occur in the tissue during ablation as means to provide useful feedback on the progression of therapy delivery. We propose a technique to visualize lesion progression and monitor the effects of the RF energy delivery using a surrogate thermal ablation model. The model incorporates both physical and physiological tissue parameters, and uses heat transfer principles to estimate temperature distribution in the tissue and geometry of the generated lesion in near real time. The ablation model has been calibrated and evaluated using ex vivo beef muscle tissue in a clinically relevant ablation protocol. To validate the model, the predicted temperature distribution was assessed against that measured directly using fiberoptic temperature probes inserted in the tissue. Moreover, the model-predicted lesions were compared to the lesions observed in the post-ablation digital images. Results showed an agreement within 5°C between the model-predicted and experimentally measured tissue temperatures, as well as comparable predicted and observed lesion characteristics and geometry. These results suggest that the proposed technique is capable of providing reasonably accurate and sufficiently fast representations of the created RF ablation lesions, to generate lesion maps in near real time. These maps can be used to guide the placement of successive lesions to ensure continuous and enduring suppression of the arrhythmic pathway.

  4. Infected cardiac hydatid cyst

    OpenAIRE

    Ceviz, M; Becit, N; Kocak, H.

    2001-01-01

    A 24 year old woman presented with chest pain and palpitation. The presence of a semisolid mass—an echinococcal cyst or tumour—in the left ventricular apex was diagnosed by echocardiography, computed tomography, and magnetic resonance imaging. The infected cyst was seen at surgery. The cyst was removed successfully by using cardiopulmonary bypass with cross clamp.


Keywords: cardiac hydatid cyst; infected cardiac hydatid cyst

  5. Dynamic molecular imaging of cardiac innervation using a dual headpinhole SPECT system

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jicun; Boutchko, Rostyslav; Sitek, Arkadiusz; Reutter, BryanW.; Huesman, Ronald H.; Gullberg, Grant T.

    2008-03-29

    Typically 123I-MIBG is used for the study of innervation andfunction of the sympathetic nervous system in heart failure. The protocolinvolves two studies: first a planar or SPECT scan is performed tomeasure initial uptake of the tracer, followed some 3-4 hours later byanother study measuring the wash-out of the tracer from the heart. A fastwash-out is indicative of a compromised heart. In this work, a dual headpinhole SPECT system was used for imaging the distribution and kineticsof 123I-MIBG in the myocardium of spontaneous hypertensive rats (SHR) andnormotensive Wistar Kyoto (WKY) rats. The system geometry was calibratedbased on a nonlinear point projection fitting method using a three-pointsource phantom. The angle variation effect of the parameters was modeledwith a sinusoidal function. A dynamic acquisition was performed byinjecting 123I-MIBG into rats immediately after starting the dataacquisition. The detectors rotated continuously performing a 360o dataacquisition every 90 seconds. We applied the factor analysis (FA)methodand region of interest (ROI) sampling method to obtain time activitycurves (TACs)in the blood pool and myocardium and then appliedtwo-compartment modeling to estimate the kinetic parameters. Since theinitial injection bolus is too fast for obtaining a consistenttomographic data set in the first few minutes of the study, we appliedthe FA method directly to projections during the first rotation. Then thetime active curves for blood and myocardial tissue were obtained from ROIsampling. The method was applied to determine if there were differencesin the kinetics between SHR and WKY rats and requires less time byreplacing the delayed scan at 3-4 hours after injection with a dynamicacquisition over 90 to 120 minutes. The results of a faster washout and asmaller distribution volume of 123IMIBG near the end of life in the SHRmodel of hypertrophic cardiomyopthy may be indicative of a failing heartin late stages of heart failure.

  6. Adaptive anisotropic gaussian filtering to reduce acquisition time in cardiac diffusion tensor imaging.

    Science.gov (United States)

    Mazumder, Ria; Clymer, Bradley D; Mo, Xiaokui; White, Richard D; Kolipaka, Arunark

    2016-06-01

    Diffusion tensor imaging (DTI) is used to quantify myocardial fiber orientation based on helical angles (HA). Accurate HA measurements require multiple excitations (NEX) and/or several diffusion encoding directions (DED). However, increasing NEX and/or DED increases acquisition time (TA). Therefore, in this study, we propose to reduce TA by implementing a 3D adaptive anisotropic Gaussian filter (AAGF) on the DTI data acquired from ex-vivo healthy and infarcted porcine hearts. DTI was performed on ex-vivo hearts [9-healthy, 3-myocardial infarction (MI)] with several combinations of DED and NEX. AAGF, mean (AVF) and median filters (MF) were applied on the primary eigenvectors of the diffusion tensor prior to HA estimation. The performance of AAGF was compared against AVF and MF. Root mean square error (RMSE), concordance correlation-coefficients and Bland-Altman's technique was used to determine optimal combination of DED and NEX that generated the best HA maps in the least possible TA. Lastly, the effect of implementing AAGF on the infarcted porcine hearts was also investigated. RMSE in HA estimation for AAGF was lower compared to AVF or MF. Post-filtering (AAGF) fewer DED and NEX were required to achieve HA maps with similar integrity as those obtained from higher NEX and/or DED. Pathological alterations caused in HA orientation in the MI model were preserved post-filtering (AAGF). Our results demonstrate that AAGF reduces TA without affecting the integrity of the myocardial microstructure. PMID:26843150

  7. Estimation of dynamic time activity curves from dynamic cardiac SPECT imaging

    Science.gov (United States)

    Hossain, J.; Du, Y.; Links, J.; Rahmim, A.; Karakatsanis, N.; Akhbardeh, A.; Lyons, J.; Frey, E. C.

    2015-04-01

    Whole-heart coronary flow reserve (CFR) may be useful as an early predictor of cardiovascular disease or heart failure. Here we propose a simple method to extract the time-activity curve, an essential component needed for estimating the CFR, for a small number of compartments in the body, such as normal myocardium, blood pool, and ischemic myocardial regions, from SPECT data acquired with conventional cameras using slow rotation. We evaluated the method using a realistic simulation of 99mTc-teboroxime imaging. Uptake of 99mTc-teboroxime based on data from the literature were modeled. Data were simulated using the anatomically-realistic 3D NCAT phantom and an analytic projection code that realistically models attenuation, scatter, and the collimator-detector response. The proposed method was then applied to estimate time activity curves (TACs) for a set of 3D volumes of interest (VOIs) directly from the projections. We evaluated the accuracy and precision of estimated TACs and studied the effects of the presence of perfusion defects that were and were not modeled in the estimation procedure. The method produced good estimates of the myocardial and blood-pool TACS organ VOIs, with average weighted absolute biases of less than 5% for the myocardium and 10% for the blood pool when the true organ boundaries were known and the activity distributions in the organs were uniform. In the presence of unknown perfusion defects, the myocardial TAC was still estimated well (average weighted absolute bias myocardial uptake (product of defect extent and severity) was ≤5%. This indicates that the method was robust to modest model mismatch such as the presence of moderate perfusion defects and uptake nonuniformities. With larger defects where the defect VOI was included in the estimation procedure, the estimated normal myocardial and defect TACs were accurate (average weighted absolute bias ≈5% for a defect with 25% extent and 100% severity).

  8. MDCT evaluation of aortic root and aortic valve prior to TAVI. What is the optimal imaging time point in the cardiac cycle?

    Energy Technology Data Exchange (ETDEWEB)

    Jurencak, Tomas; Turek, Jakub; Nijssen, Estelle C. [Maastricht University Medical Center, Department of Radiology, P. Debyelaan 25, P.O. Box 5800, AZ, Maastricht (Netherlands); Kietselaer, Bastiaan L.J.H. [Maastricht University Medical Center, Department of Radiology, P. Debyelaan 25, P.O. Box 5800, AZ, Maastricht (Netherlands); Maastricht University Medical Center, CARIM School for Cardiovascular Diseases, Maastricht (Netherlands); Maastricht University Medical Center, Department of Cardiology, Maastricht (Netherlands); Mihl, Casper; Kok, Madeleine; Wildberger, Joachim E.; Das, Marco [Maastricht University Medical Center, Department of Radiology, P. Debyelaan 25, P.O. Box 5800, AZ, Maastricht (Netherlands); Maastricht University Medical Center, CARIM School for Cardiovascular Diseases, Maastricht (Netherlands); Ommen, Vincent G.V.A. van [Maastricht University Medical Center, Department of Cardiology, Maastricht (Netherlands); Garsse, Leen A.F.M. van [Maastricht University Medical Center, Department of Cardiothoracic Surgery, Maastricht (Netherlands)

    2015-07-15

    To determine the optimal imaging time point for transcatheter aortic valve implantation (TAVI) therapy planning by comprehensive evaluation of the aortic root. Multidetector-row CT (MDCT) examination with retrospective ECG gating was retrospectively performed in 64 consecutive patients referred for pre-TAVI assessment. Eighteen different parameters of the aortic root were evaluated at 11 different time points in the cardiac cycle. Time points at which maximal (or minimal) sizes were determined, and dimension differences to other time points were evaluated. Theoretical prosthesis sizing based on different measurements was compared. Largest dimensions were found between 10 and 20 % of the cardiac cycle for annular short diameter (10 %); mean diameter (10 %); effective diameter and circumference-derived diameter (20 %); distance from the annulus to right coronary artery ostium (10 %); aortic root at the left coronary artery level (20 %); aortic root at the widest portion of coronary sinuses (20 %); and right leaflet length (20 %). Prosthesis size selection differed depending on the chosen measurements in 25-75 % of cases. Significant changes in anatomical structures of the aortic root during the cardiac cycle are crucial for TAVI planning. Imaging in systole is mandatory to obtain maximal dimensions. (orig.)

  9. Relationship between cardiac {sup 123}I-Metaiodobenzylguanidine imaging and the transcardiac gradient of neurohumoral factors in patients with dilated cardiomyopathy

    Energy Technology Data Exchange (ETDEWEB)

    Matsui, Toshiki; Tsutamoto, Takayoshi; Kinoshita, Masahiko [Shiga Univ. of Medical Science, Otsu (Japan)

    2001-12-01

    Cardiac sympathetic nervous function is altered in congestive heart failure (CHF) and the uptake and washout rate of cardiac {sup 123}I-metaiodobenzylguanidine (MIBG) are useful markers for evaluating the severity of it. To assess what parameters predict decreased uptake or increased washout rate of MIBG, the concentrations of neurohumoral factor in both the aorta (Ao) and coronary sinus (CS) were measured, as well as hemodynamic parameters by catheterization, in patients with dilated cardiomyopathy (DCM). MIBG imaging was performed within 1 week of cardiac catheterization. Regarding MIBG parameters, the correlation with the transcardiac gradient of norepinephrine (NE), brain natriuretic peptide (BNP) and hemodynamics was investigated. Stepwise multivariate regression analysis was used to determine which variables closely correlated with cardiac MIBG parameters. There was a significant increase in the NE level between the Ao (446 pg/ml) and the CS (727 pg/ml). According to stepwise multivariate regression analysis, the heart/mediastinum (H/M) ratio independently correlated with the transcardiac gradient of BNP (r=-0.480, p<0.01), and the washout rate independently correlated with the transcardiac gradient of NE (r=0.481, p<0.01). These findings indicate that the H/M ratio may reflect the transcardiac gradient of BNP, which implies the degree of left ventricular dysfunction and/or damage and the washout rate may reflect altered cardiac sympathetic nerve terminal in DCM patients with CHF, suggesting that both the H/M ratio and washout rate provide important information about the failing ventricle. (author)

  10. Comparison of cardiac ma