WorldWideScience

Sample records for cardiac ionising imaging

  1. Cardiac Image Registration

    Directory of Open Access Journals (Sweden)

    2008-09-01

    Full Text Available Long procedure time and somewhat suboptimal results hinder the widespread use of catheter ablation of complex arrhythmias such as atrial fibrillation (AF. Due to lack of contrast differentiation between the area of interest and surrounding structures in a moving organ like heart, there is a lack of proper intraprocedural guidance using current imaging techniques for ablation. Cardiac image registration is currently under investigation and is in clinical use for AF ablation. Cardiac image registration, which involves integration of two images in the context of left atrium (LA, is intermodal, with the acquired image and the real-time reference image residing in different image spaces, and involves optimization, where one image space is transformed into the other. Unlike rigid body registration, cardiac image registration is unique and challenging due to cardiac motion during the cardiac cycle and due to respiration. This review addresses the basic principles of the emerging technique of registration and the inherent limitations as they relate to cardiac imaging and registration.

  2. Cardiac Image Registration

    Directory of Open Access Journals (Sweden)

    Jasbir Sra

    2008-09-01

    Full Text Available Long procedure time and somewhat suboptimal results hinder the widespread use of catheter ablation of complex arrhythmias such as atrial fibrillation (AF. Due to lack of contrast differentiation between the area of interest and surrounding structures in a moving organ like heart, there is a lack of proper intraprocedural guidance using current imaging techniques for ablation. Cardiac image registration is currently under investigation and is in clinical use for AF ablation. Cardiac image registration, which involves integration of two images in the context of the left atrium (LA, is intermodal, with the acquired image and the real-time reference image residing in different image spaces, and involves optimization, where one image space is transformed into the other. Unlike rigid body registration, cardiac image registration is unique and challenging due to cardiac motion during the cardiac cycle and due to respiration. This review addresses the basic principles of the emerging technique of registration and the inherent limitations as they relate to cardiac imaging and registration.

  3. Radiographic imaging method by gas ionisation

    International Nuclear Information System (INIS)

    The search for a substitute of the silver halide film has been intensified worldwide due to the shortage and price increase of silver metal. Gasionography could be an alternative to the wellknown silver film imaging techniques in roentgenology. Therefore the practical basis of the imaging process and the electrophoretic development was investigated. The technical realisation of this method was demonstrated for two different types of X-ray examen by developing a fully automatic chest changer and a mammography system that can be adapted to commercially available imaging stands. The image quality achieved with these apparatus was evaluated in comparison with conventional film techniques in the laboratory as well as in a clinical trial. (orig.)

  4. Diagnostic imaging of cardiac hypertrophy

    International Nuclear Information System (INIS)

    As imaging techniques for cardiac hypertrophy, the ultrasonic dimension gauze technique, echocardiography, ventriculography and the RI technique including emission RI tomography were outlined. (Chiba, N.)

  5. Cardiac imaging. A multimodality approach

    International Nuclear Information System (INIS)

    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.)

  6. Technique for producing cardiac radionuclide motion images

    International Nuclear Information System (INIS)

    Sequential frames of different portions of the cardiac cycle are gated into a minicomputer by using an EKG signal recorded onto digital tape simultaneously with imaging information. Serial display of these frames on the computer oscilloscope or projection of 35-mm half frames of these images provides a cardiac motion image with information content adequate for qualitatively assessing cardiac motion. (U.S.)

  7. Student and intern awareness of ionising radiation exposure from common diagnostic imaging procedures

    International Nuclear Information System (INIS)

    Full text: This study aims to evaluate medical student and intern awareness of ionising radiation exposure from common diagnostic imaging procedures and to suggest how education could be improved. Fourth to sixth year medical students enrolled at a Western Australian university and interns from three teaching hospitals in Perth were recruited. Participants were asked to complete a questionnaire consisting of 26 questions on their background, knowledge of ionising radiation doses and learning preferences for future teaching on this subject. A total of 331 completed questionnaires were received (95.9%). Of the 17 questions assessing knowledge of ionising radiation, a mean score of 6.0 was obtained by respondents (95% CI 5.8-6.2). Up to 54.8% of respondents underestimated the radiation dose from commonly requested radiological procedures. Respondents (11.3 and 25.5%) incorrectly believed that ultrasound and MRI emit ionising radiation, respectively. Of the four subgroups of respondents, the intern doctor subgroup performed significantly better (mean score 6.9, P< 0.0001, 95% CI 6.5-7.3) than each of the three medical student subgroups. When asked for the preferred method of teaching for future radiation awareness, a combination of lectures, tutorials and workshops was preferred. This study has clearly shown that awareness of ionising radiation from diagnostic imaging is lacking among senior medical students and interns. The results highlight the need for improved education to minimise unnecessary exposure of patients and the community to radiation. Further studies are required to determine the most effective form of education.

  8. 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

  9. 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)

  10. 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...

  11. Imaging features of cardiac myxoma

    International Nuclear Information System (INIS)

    Objective: To study the imaging features of cardiac myxoma and their diagnostic values. Methods: Twenty-two patrents with cardiac myxoma were reviewed retrospectively for the clinical, pathologic, and radiologic findings. Posteroanterior and lateral chest radiographs, American Imatron C-150 XP Electron Beam CT examination, and Germany Siemens 1.5T Magnetom Vision MR scan were performed on every patient. Results: (1) Radiographs of 17 patients with left atrial myxoma showed evidence of mitral valve obstruction in 14(82.3%), radiographs of 5 patients with right atrial myxoma demonstrated right atrium enlargement in 3(60%) respectively. (2) CT scans of 22 myxomas demonstrated 18 (81.8%) lesions were hypoattenuated and 4 (19.1%) were isoattenuated relative to the myocardium. Calcification or ossification was seen in 3 patients. All myxomas apart from massive one were found attaching to the atrial septum. Movie mode could dis- play the movement of myxoma across the atrioventicular valves. (3) MRI studies of 22 myxomas showed 19 (86.3%) heterogeneous signal intensity and 3 (13.7%) homogeneous. They exhibited slight high or homogeneous signal intensity with both T1- and T2-weighted sequences, and low signal intensity with cine gradient recalled echo sequences. Point of attachment was visible in 21 (95.4%) cases. Conclusion: The typical radiograph sign of cardiac myxomas is mitral valve obstruction, CT and MR can demonstrate intracavitary lobular masses attacthing to artrial spetum. The latter two kinds of examinations not only provide accurate assessment of the size, location, and attachment point of these lesions, but also have important qualitative diagnostic advantage. (authors)

  12. 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

  13. Cardiac imaging: Current and emerging applications

    OpenAIRE

    Jankharia B; Raut A

    2010-01-01

    Cardiac magnetic resonance imaging (MRI) and computed tomography (CT) scan have made big inroads as modalities used for evaluation of various pathologies of the heart. Cardiac MRI is typically used for perfusion and viability studies as well as to study various cardiomyopathies, valvular diseases and the pericardium. It has been used in the evaluation of congenital heart diseases over the last two decades. Cardiac CT is used mainly for the evaluation of the coronary arteries, typically in the...

  14. 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

  15. 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.)

  16. 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.)

  17. Cardiac imaging: Current and emerging applications

    Directory of Open Access Journals (Sweden)

    Jankharia B

    2010-01-01

    Full Text Available Cardiac magnetic resonance imaging (MRI and computed tomography (CT scan have made big inroads as modalities used for evaluation of various pathologies of the heart. Cardiac MRI is typically used for perfusion and viability studies as well as to study various cardiomyopathies, valvular diseases and the pericardium. It has been used in the evaluation of congenital heart diseases over the last two decades. Cardiac CT is used mainly for the evaluation of the coronary arteries, typically in the setting of "to rule out coronary artery disease".

  18. 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.

  19. 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.

  20. 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.

  1. 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.)

  2. Postmortem cardiac imaging in fetuses and children

    International Nuclear Information System (INIS)

    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.)

  3. 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...... structural changes and abnormalities in the heart, but it does not uncover the underlying pathophysiological processes at the cellular or molecular level. This problem is addressed with introduction of new molecular imaging methods as (18)F-fluorodesoxyglucose ((18)F-FDG) PET-CT and single photon emission...... the search for extra cardial infectious foci. A flowchart for the use of imaging in both left-sided and right-sided endocarditis is suggested....

  4. 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 in...... involved in the development of hepatic nephropathy and is associated with an impaired survival. In the field of cardiac imaging, CCM is not yet a well-characterized entity, hence various modalities of cardiac imaging have been applied. Stress testing with either physiologically or pharmacologically induced...

  5. Cardiac pathology and morphology relevant to cardiovascular imaging

    International Nuclear Information System (INIS)

    In this overview of coronary, valvular, and myocardial heart disease the structural abnormalities associated with these disorders have been described. Cardiac imaging attempts to portray the structural and functional abnormalities of the heart that cause symptomatic cardiac disease

  6. Localised manifold learning for cardiac image analysis

    Science.gov (United States)

    Bhatia, Kanwal K.; Price, Anthony N.; Hajnal, Jo V.; Rueckert, Daniel

    2012-02-01

    Manifold learning is increasingly being used to discover the underlying structure of medical image data. Traditional approaches operate on whole images with a single measure of similarity used to compare entire images. In this way, information on the locality of differences is lost and smaller trends may be masked by dominant global differences. In this paper, we propose the use of multiple local manifolds to analyse regions of images without any prior knowledge of which regions are important. Localised manifolds are created by partitioning images into regular subsections with a manifold constructed for each patch. We propose a framework for incorporating information from the neighbours of each patch to calculate a coherent embedding. This generates a simultaneous dimensionality reduction of all patches and results in the creation of embeddings which are spatially-varying. Additionally, a hierarchical method is presented to enable a multi-scale embedding solution. We use this to extract spatially-varying respiratory and cardiac motions from cardiac MRI. Although there is a complex interplay between these motions, we show how they can be separated on a regional basis. We demonstrate the utility of the localised joint embedding over a global embedding of whole images and over embedding individual patches independently.

  7. 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

  8. Antimyosin imaging in cardiac transplant rejection

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, L.L.; Cannon, P.J. (Department of Medicine, College of Physicians and Surgeons, Columbia University, New York (United States))

    1991-09-01

    Fab fragments of antibodies specific for cardiac myosin have been labeled with indium-111 and injected intravenously into animals and into patients with heart transplants. The antibodies, developed by Khaw, Haber, and co-workers, localize in cardiac myocytes that have been damaged irreversibly by ischemia, myocarditis, or the rejection process. After clearance of the labeled antibody from the cardiac blood pool, planar imaging or single photon emission computed tomography is performed. Scintigrams reveal the uptake of the labeled antimyosin in areas of myocardium undergoing transplant rejection. In animal studies, the degree of antimyosin uptake appears to correlate significantly with the degree of rejection assessed at necropsy. In patients, the correlation between scans and pathologic findings from endomyocardial biopsy is not as good, possibly because of sampling error in the endomyocardial biopsy technique. The scan results at 1 year correlate with either late complications (positive) or benign course (negative). Current limitations of the method include slow blood clearance, long half-life of indium-111, and hepatic uptake. Overcoming these limitations represents a direction for current research. It is possible that from these efforts a noninvasive approach to the diagnosis and evaluation of cardiac transplantation may evolve that will decrease the number of endomyocardial biopsies required to evaluate rejection. This would be particularly useful in infants and children. 31 references.

  9. Antimyosin imaging in cardiac transplant rejection

    International Nuclear Information System (INIS)

    Fab fragments of antibodies specific for cardiac myosin have been labeled with indium-111 and injected intravenously into animals and into patients with heart transplants. The antibodies, developed by Khaw, Haber, and co-workers, localize in cardiac myocytes that have been damaged irreversibly by ischemia, myocarditis, or the rejection process. After clearance of the labeled antibody from the cardiac blood pool, planar imaging or single photon emission computed tomography is performed. Scintigrams reveal the uptake of the labeled antimyosin in areas of myocardium undergoing transplant rejection. In animal studies, the degree of antimyosin uptake appears to correlate significantly with the degree of rejection assessed at necropsy. In patients, the correlation between scans and pathologic findings from endomyocardial biopsy is not as good, possibly because of sampling error in the endomyocardial biopsy technique. The scan results at 1 year correlate with either late complications (positive) or benign course (negative). Current limitations of the method include slow blood clearance, long half-life of indium-111, and hepatic uptake. Overcoming these limitations represents a direction for current research. It is possible that from these efforts a noninvasive approach to the diagnosis and evaluation of cardiac transplantation may evolve that will decrease the number of endomyocardial biopsies required to evaluate rejection. This would be particularly useful in infants and children. 31 references

  10. 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.

  11. Benign cardiac tumours: cardiac CT and MRI imaging appearances

    International Nuclear Information System (INIS)

    Full text: Primary benign cardiac tumours are rarely found in clinical practice and are generally evaluated with echocardiography. However, with the increasing usage of helical multislice CT, the initial detection and evaluation of these masses may be made by the radiologist during routine daily practice for other indications. The echocardiographic, CT and cardiac MRI appearances of various benign cardiac tumours and masses are described and illustrated in this review

  12. 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

  13. Patient doses in digital cardiac imaging

    International Nuclear Information System (INIS)

    In this pilot study, we obtained estimates of entrance skin doses and the corresponding effective doses to patients undergoing digital cardiac imaging procedures on a GE Advantx LC/LP Plus system. Data were obtained for six patients undergoing diagnostic examinations and six patients who had interventional procedures. For each patient examination, radiographic techniques for fluoroscopic and digital cine imaging were recorded, together with the irradiation geometry. The projection with the highest exposure resulted in an average skin dose of 0.64 ± 0.41 Gy (maximum of 1.6 Gy). The average patient skin doses taking into account overlapping projections was 1.1 ± 0.8 Gy (maximum of 3.0 Gy). The exposure area product (EAP) incident on the patient was converted into the energy imparted to the patient and the corresponding effective dose. The average patient effective dose was 28 ± 14 mSv (maximum 62 mSv), with the resultant average fatal cancer risk estimated to be of the order of 8x10-3 . Average doses for interventional procedures in cardiac imaging are higher than those associated with diagnostic examinations by approximately 50%. (author)

  14. Extracting cardiac myofiber orientations from high frequency ultrasound images

    Science.gov (United States)

    Qin, Xulei; Cong, Zhibin; Jiang, Rong; Shen, Ming; Wagner, Mary B.; Kirshbom, Paul; Fei, Baowei

    2013-03-01

    Cardiac myofiber plays an important role in stress mechanism during heart beating periods. The orientation of myofibers decides the effects of the stress distribution and the whole heart deformation. It is important to image and quantitatively extract these orientations for understanding the cardiac physiological and pathological mechanism and for diagnosis of chronic diseases. Ultrasound has been wildly used in cardiac diagnosis because of its ability of performing dynamic and noninvasive imaging and because of its low cost. An extraction method is proposed to automatically detect the cardiac myofiber orientations from high frequency ultrasound images. First, heart walls containing myofibers are imaged by B-mode high frequency (hearts.

  15. 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.

  16. 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

  17. Imaging spectrum of sudden athlete cardiac death

    International Nuclear Information System (INIS)

    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.

  18. 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.

  19. 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

  20. Ultrasound image guidance of cardiac interventions

    Science.gov (United States)

    Peters, Terry M.; Pace, Danielle F.; Lang, Pencilla; Guiraudon, Gérard M.; Jones, Douglas L.; Linte, Cristian A.

    2011-03-01

    Surgical procedures often have the unfortunate side-effect of causing the patient significant trauma while accessing the target site. Indeed, in some cases the trauma inflicted on the patient during access to the target greatly exceeds that caused by performing the therapy. Heart disease has traditionally been treated surgically using open chest techniques with the patient being placed "on pump" - i.e. their circulation being maintained by a cardio-pulmonary bypass or "heart-lung" machine. Recently, techniques have been developed for performing minimally invasive interventions on the heart, obviating the formerly invasive procedures. These new approaches rely on pre-operative images, combined with real-time images acquired during the procedure. Our approach is to register intra-operative images to the patient, and use a navigation system that combines intra-operative ultrasound with virtual models of instrumentation that has been introduced into the chamber through the heart wall. This paper illustrates the problems associated with traditional ultrasound guidance, and reviews the state of the art in real-time 3D cardiac ultrasound technology. In addition, it discusses the implementation of an image-guided intervention platform that integrates real-time ultrasound with a virtual reality environment, bringing together the pre-operative anatomy derived from MRI or CT, representations of tracked instrumentation inside the heart chamber, and the intra-operatively acquired ultrasound images.

  1. Postmortem imaging of sudden cardiac death.

    Science.gov (United States)

    Michaud, Katarzyna; Grabherr, Silke; Jackowski, Christian; Bollmann, Marc Daniel; Doenz, Franceso; Mangin, Patrice

    2014-01-01

    Postmortem imaging is increasingly used in forensic practice in cases of natural deaths related to cardiovascular diseases, which represent the most common causes of death in developed countries. While radiological examination is generally considered to be a good complement for conventional autopsy, it was thought to have limited application in cardiovascular pathology. At present, multidetector computed tomography (MDCT), CT angiography, and cardiac magnetic resonance imaging (MRI) are used in postmortem radiological investigation of cardiovascular pathologies. This review presents the actual state of postmortem imaging for cardiovascular pathologies in cases of sudden cardiac death (SCD), taking into consideration both the advantages and limitations. The radiological evaluation of ischemic heart disease (IHD), the most frequent cause of SCD in the general population of industrialized countries, includes the examination of the coronary arteries and myocardium. Postmortem CT angiography (PMCTA) is very useful for the detection of stenoses and occlusions of coronary arteries but less so for the identification of ischemic myocardium. MRI is the method of choice for the radiological investigation of the myocardium in clinical practice, but its accessibility and application are still limited in postmortem practice. There are very few reports implicating postmortem radiology in the investigation of other causes of SCD, such as cardiomyopathies, coronary artery abnormalities, and valvular pathologies. Cardiomyopathies representing the most frequent cause of SCD in young athletes cannot be diagnosed by echocardiography, the most widely available technique in clinical practice for the functional evaluation of the heart and the detection of cardiomyopathies. PMCTA and MRI have the potential to detect advanced stages of diseases when morphological substrate is present, but these methods have yet to be sufficiently validated for postmortem cases. Genetically determined

  2. 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.

  3. Cardiac imaging systems and methods employing computerized tomographic scanning

    International Nuclear Information System (INIS)

    A novel method for obtaining cardiac images with X-rays is described. The problem of blurring of the image due to motion of the heart and its associated blood vessels is overcome by monitoring the cardiac cycle to produce a repeating pulse signal indicative of the same selectable phase; a pacemaker may be used to stabilize the cardiac period. Conventional CT scanning may then be performed and only the information recorded in coincidence with certain phases of the cardiac cycle is compounded to produce cardiac images which are free from blurring. Alternatively, the X-ray tube may be gated on and off by the pulse derived from the cardiac cycle in order to reduce X-ray dosage. (U.K.)

  4. 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.

  5. Differentiation of cardiac thrombus from cardiac tumor combining cardiac MRI and 18F-FDG-PET/CT Imaging.

    Science.gov (United States)

    Rinuncini, Massimo; Zuin, Marco; Scaranello, Fiorenzo; Fejzo, Majlinda; Rampin, Lucia; Rubello, Domenico; Faggian, Giuseppe; Roncon, Loris

    2016-06-01

    Radiological differentiation of an unknown cardiac masse is often a challenging issue. 18F-FDG-PET/CT imaging was performed to evaluate a left ventricle mass visualized on transthoracic echocardiogram (TTE) and cardiac magnetic resonance (CMR) in a patient with an history of ischemic heart disease. The metabolically inert area on the PET/CT, corresponding to the relatively homogenous hypodensity in the LV, was thought to represent an old organized LV thrombus. Histopathological examination confirmed the imaging diagnosis. PMID:27038712

  6. Magnetic resonance imaging in the evaluation of congestive cardiac failure

    OpenAIRE

    Rajiah, Prabhakar

    2012-01-01

    Congestive cardiac failure is the end-result of various cardiac disorders, and is a major contributor to morbidity, mortality, and financial burden throughout the world. Due to advances in the knowledge of the disease and scanner technology, magnetic resonance imaging (MRI) is playing an increasingly important role in the evaluation of cardiac failure, including in establishing diagnosis, problem solving, risk stratification, and monitoring of therapy. This review discusses and illustrates th...

  7. 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.)

  8. Automated detection of cardiac phase from intracoronary ultrasound image sequences.

    Science.gov (United States)

    Sun, Zheng; Dong, Yi; Li, Mengchan

    2015-01-01

    Intracoronary ultrasound (ICUS) is a widely used interventional imaging modality in clinical diagnosis and treatment of cardiac vessel diseases. Due to cyclic cardiac motion and pulsatile blood flow within the lumen, there exist changes of coronary arterial dimensions and relative motion between the imaging catheter and the lumen during continuous pullback of the catheter. The action subsequently causes cyclic changes to the image intensity of the acquired image sequence. Information on cardiac phases is implied in a non-gated ICUS image sequence. A 1-D phase signal reflecting cardiac cycles was extracted according to cyclical changes in local gray-levels in ICUS images. The local extrema of the signal were then detected to retrieve cardiac phases and to retrospectively gate the image sequence. Results of clinically acquired in vivo image data showed that the average inter-frame dissimilarity of lower than 0.1 was achievable with our technique. In terms of computational efficiency and complexity, the proposed method was shown to be competitive when compared with the current methods. The average frame processing time was lower than 30 ms. We effectively reduced the effect of image noises, useless textures, and non-vessel region on the phase signal detection by discarding signal components caused by non-cardiac factors. PMID:26406038

  9. 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

  10. Clinical advantages of three dimensional cine cardiac images

    International Nuclear Information System (INIS)

    We evaluated clinical advantages and the quantitativeness of computerized three-dimensional (3D) cinematic images of a human heart, which were produced with a set of magnetic resonance (MR) images by using the computer graphic technique. Many contiguous, multi-location and multi-phase short axis images were obtained with the ECG gated conventional and fast cardiac imaging sequences in normal volunteers and selected patients with myocardial infarction, hypertrophic cardiomyopathy, dilated cardiomyopathy and left ventricular dysfunction. Judging by visual impressions of the computerized 3D cinematic cardiac images, we could easily understand and evaluate the myocardial motions or the anatomic and volumetric changes of a heart according to the cardiac phases. These images were especially useful to compare the wall motion, the left ventricular ejection-fraction (LVEF), or other cardiac functions and conditions between before and after therapeutic procedures such as percutaneous transluminal coronary angioplasty for patients with myocardial infarction. A good correlation between the LVEF calculated from a set of computerized 3D cinematic images and the ultra sound examinations were found. The results of our study showed that computerized 3D cinematic cardiac images were clinically useful to understand the myocardial motions qualitatively and to evaluate cardiac functions such as the LVEF quantitatively. (author)

  11. 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.

  12. 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.)

  13. 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.

  14. 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

  15. 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.

  16. 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

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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.

  19. An Annotated Dataset of 14 Cardiac MR Images

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille

    2002-01-01

    This note describes a dataset consisting of 14 annotated cardiac MR images. Points of correspondence are placed on each image at the left ventricle (LV). As such, the dataset can be readily used for building statistical models of shape. Further, format specifications and terms of use are given....

  20. 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.

  1. Cardiac magnetic resonance imaging of a patient with an magnetic resonance imaging conditional permanent pacemaker

    OpenAIRE

    Chris B. Pepper; Mohan Sivananthan; Artis, Nigel J.; Hogarth, Andrew J.

    2011-01-01

    Cardiac Magnetic Resonance Imaging (MRI) is increasingly used as the optimum modality for cardiac imaging. An aging population and rising numbers of patients with permanent pacemakers means many such individuals may require cardiac MRI scanning in the future. Whilst the presence of a permanent pacemaker is historically regarded as a contra-indication to MRI scanning, pacemaker systems have been developed to limit any associated risks. No reports have been published regarding the use of such d...

  2. 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.

  3. Cardiac imaging systems and methods employing computerized tomographic scanning

    International Nuclear Information System (INIS)

    The invention relates to cardiac imaging systems and methods employing computerised tomographic scanning. Apparatus is described which allows an image of the radiation attenuation of the heart at a desired phase of the cardiac cycle. The patients ECG signal can be used in a transverse-and-rotate type CT scanner as a time base, so that the beam reaches the heart at a desired phase of the cardiac cycle, or, in a purely rotational-type CT scanner continuously generated scan data is only stored for corresponding phases of successive cardiac cycles. Alternatively, gating of the beams themselves by shuttering or switching the power supply can be controlled by the ECG signal. A pacemaker is used to stabilize the cardiac period. Also used is a system for recognising unacceptable variations in the cardiac period and discarding corresponding scan data. In a transverse-and-rotate type fan-beam CT scanner, the effective beam width is narrowed to reduce the duration of the traverse of the heart. (U.K.)

  4. Antimyosin imaging in acute myocardial infarction and cardiac transplant rejection

    International Nuclear Information System (INIS)

    Antimyosin imaging both diagnosed and quantitated heterotopic cardiac transplant rejection in a small number of dogs with either recent or remote transplantation. The authors describe study in humans which showed 80% diagnostic accuracy of planar antimyosin imaging in patients with a wide range of times posttransplantation. A larger multicenter study including SPECT imaging will either confirm or extend these preliminary findings. Multiple injections of antimyosin will probably be safe if HAMA levels are followed

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

    International Nuclear Information System (INIS)

    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.)

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

    Science.gov (United States)

    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 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. PMID:25552386

  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. EANM/ESC guidelines for radionuclide imaging of cardiac function

    DEFF Research Database (Denmark)

    Hesse, B.; Lindhardt, T.B.; Acampa, W.; Anagnostopoulos, C.; Ballinger, J.; Bax, J.J.; Edenbrandt, L.; Flotats, A.; Germano, G.; Stopar, T.G.; Franken, P.; Kelion, A.; Kjaer, A.; Guludec, D. Le; Ljungberg, M.; Maenhout, A.F.; Marcassa, C.; Marving, J.; McKiddie, F.; Schaefer, W.M.; Stegger, L.; Underwood, R.

    2008-01-01

    Radionuclide imaging of cardiac function represents a number of well-validated techniques for accurate determination of right (RV) and left ventricular (LV) ejection fraction (EF) and LV volumes. These first European guidelines give recommendations for how and when to use first-pass and equilibri...

  10. 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

  11. The diagnostic value of cardiac blood pool imaging in cardiomyopathy

    International Nuclear Information System (INIS)

    Twenty-two normal controls and thirty-three patients with dilated and hypertrophic cardiomyopathy were examined by multigated cardiac imaging and phase analysis. The imaging traits of hypertrophic ones displayed thicken septal wall. The differences of synchronization of ventricular systolic function between hypertrophic ones and normal were statistically significant (P < 0.01). The imaging features of dilated cardiomyopathy showed that ventricular wall motion was seriously hypokinitic or akinitic and left ventricule enlarged abnormally. The function and synchronization of ventricular systole in dilated ones were worse than these in the hypertrophic (P < 0.01). These data suggest that the cardiac blood pool images can diagnose and differentiate the hypertrophic from dilated cardiomyopathy

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

    International Nuclear Information System (INIS)

    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.)

  13. 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.)

  14. 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.

  15. Three-dimensional display and measurement of cardiac dynamic indexes from MR images

    International Nuclear Information System (INIS)

    The cardiac dynamic index, to which such variables as cardiac output, ejection fraction, and wall motion contribute, is routinely determined using various modalities such as angiography, radionuclide imaging, US, and x-ray CT. Each of these modalities, however, has some disadvantages in regard to evaluating the cardiac dynamic index. The authors have obtained precise multidirectional projection images of the heart by means of computer graphics and reformatted data of cardiac MR images obtained with cardiac gating. The contiguous coronal MR images of the heart are made at an interimage distance of 5 mm. In each section, five or six cardiac images can be obtained, depending on the systolic or diastolic phase. These images are stored in a computer, and a three-dimensional display of the heart with biocular observation and with multiplex holograms is made possible with computer graphics. Three-dimensional measurement of the cardiac index is now being attempted, including cardiac output, ejection fraction, and wall motion

  16. 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...

  17. Automated Functional Morphology Measurement Using Cardiac SPECT Images

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Seok Yoon; Ko, Seong Jin; Kang, Se Sik; Kim, Chang Soo; Kim, Jung Hoon [Dept. of Radiological Science, College of Health Sciences, Catholic University of Pusan, Pusan (Korea, Republic of)

    2012-06-15

    For the examination of nuclear medicine, myocardial scan is a good method to evaluate a hemodynamic importance of coronary heart disease. but, the automatized qualitative measurement is additionally necessary to improve the decoding efficiency. we suggests the creation of cardiac three-dimensional model and model of three-dimensional cardiac thickness as a new measurement. For the experiment, cardiac reduced cross section was obtained from SPECT. Next, the pre-process was performed and image segmentation was fulfilled by level set. for the modeling of left cardiac thickness, it was realized by applying difference equation of two-dimensional laplace equation. As the result of experiment, it was successful to measure internal wall and external wall and three-dimensional modeling was realized by coordinate. and, with laplace formula, it was successful to develop the thickness of cardiac wall. through the three-dimensional model, defects were observed easily and position of lesion was grasped rapidly by the revolution of model. The model which was developed as the support index of decoding will provide decoding information to doctor additionally and reduce the rate of false diagnosis as well as play a great role for diagnosing IHD early.

  18. 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.)

  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. 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.

  2. 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

  3. 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.)

  4. 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

  5. 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

  6. Subtraction imaging of the ECG gated cardiac CT

    International Nuclear Information System (INIS)

    The subtracting manipulation of contrast-enhanced gated cardiac CT (GCCT) images was experimentally studied with TCT 60A - 30 type (Toshiba) for clinical use, thereby reducing the amount of contrast medium (CM). Initiallythe optimum relationship between the concentration of CM and its injected velocity was determined using the model of resected canine hearts and in actual dogs. The emphasized good-subtracted images were obtained when the difference of CT values was approximately 40 H.U. between cardiac cavity and myocardium. Such condition was feasible in the use of 25 % Diatrizoic acid and its injected veloclty of 0.02 ml/kg/sec. Finally the reduction of the amount of CM by 1/3 became possible in clinical settings. The method is applicable to multi-slice GCCT in various heart diseases. (author)

  7. Cardiac magnetic resonance imaging in children

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-01-01

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

  8. Cardiac sarcoidosis &hypen; the value of magnetic resonance imaging.

    Science.gov (United States)

    Smedema, J. P.; Doubell, A. F.

    2000-08-01

    This report describes the management of a 40-year-old woman presenting with recurrent monomorphic ventricular tachycardias secondary to cardiac sarcoidosis. She was managed with a combination of steroids, azathioprine and mexiletine. Magnetic resonance imaging proved to be of great help in diagnosing this condition as well as in following up the response to therapy. A brief review on the management of this condition is presented. PMID:11447482

  9. 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.

  10. The clinical value of cardiac sympathetic imaging in heart failure

    DEFF Research Database (Denmark)

    Christensen, Thomas Emil; Kjaer, Andreas; Hasbak, Philip

    2014-01-01

    The autonomic nervous system plays an important role in the pathology of heart failure. The single-photon emission computed tomography tracer iodine-123-metaiodobenzylguanidine ((123) I-MIBG) can be used to investigate the activity of the predominant neurotransmitter of the sympathetic nervous...... system, norepinephrine. Also, positron emission tomography tracers are being developed for the same purpose. With (123) I-MIBG as a starting point, this brief review introduces the modalities used for cardiac sympathetic imaging....

  11. Noninvasive imaging markers associated with sudden cardiac death.

    Science.gov (United States)

    van der Bijl, Pieter; Delgado, Victoria; Bax, Jeroen J

    2016-05-01

    Sudden cardiac death (SCD) accounts for approximately 15-20% of all deaths worldwide. While the majority of SCDs occur in adults, children, and adults strategy for both primary and secondary prevention of SCD is the implantable cardioverter-defibrillator (ICD). However, identification of patients who will benefit from ICD implantation remains challenging. Left ventricular ejection fraction (LVEF) is the most frequent imaging parameter used to select patients for ICD implantation for primary prevention. However, LVEF has shown to be suboptimal for prediction of benefit. Non-invasive cardiac imaging permits characterization of the arrhythmogenic substrate, including dispersion of electromechanical activation, presence of myocardial scar, and cardiac innervation status. The arrhythmogenic substrate may change across the different underlying diseases. While in ischemic cardiomyopathy, differentiation and characterization of infarct core and peri-infarct zone have been shown to refine the risk stratification of patients, in non-ischemic cardiomyopathies, the substrate may be more heterogeneous and tissue characterization assessing focal and diffuse fibrosis and inflammation processes may be more relevant. Furthermore, in channelopathies, assessment of mechanical dispersion between myocardial layers may identify the patients with increased risk of ventricular arrhythmias. Finally, potential triggers of ventricular arrhythmias such as myocardial ischemia can be evaluated. The role of noninvasive imaging in the risk stratification of SCD and the selection of candidates for ICD will be discussed in this article. PMID:26632012

  12. 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.

  13. Human torso phantom for imaging of heart with realistic modes of cardiac and respiratory motion

    Science.gov (United States)

    Boutchko, Rostyslav; Balakrishnan, Karthikayan; Gullberg, Grant T; O'Neil, James P

    2013-09-17

    A human torso phantom and its construction, wherein the phantom mimics respiratory and cardiac cycles in a human allowing acquisition of medical imaging data under conditions simulating patient cardiac and respiratory motion.

  14. Subject-specific models for image-guided cardiac surgery

    International Nuclear Information System (INIS)

    Three-dimensional visualization for planning and guidance is still not routinely available for minimally invasive cardiac surgery (MICS). This can be addressed by providing the surgeon with subject-specific geometric models derived from 3D preoperative images for planning of port locations or to rehearse the procedure. For guidance purposes, these models can also be registered to the subject using intraoperative images. In this paper, we present a method for extracting subject-specific heart geometry from preoperative MR images. The main obstacle we face is the low quality of clinical data in terms of resolution, signal-to-noise ratio, and presence of artefacts. Instead of using these images directly, we approach the problem in three steps: (1) generate a high quality template model, (2) register the template with the preoperative data, and (3) animate the result over the cardiac cycle. Validation of this approach showed that dynamic subject-specific models can be generated with a mean error of 3.6 ± 1.1 mm from low resolution target images (6 mm slices). Thus, the models are sufficiently accurate for MICS training and procedure planning. In terms of guidance, we also demonstrate how the resulting models may be adapted to the operating room using intraoperative ultrasound imaging

  15. 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

  16. Cellular and Functional Imaging of Cardiac Transplant Rejection

    Science.gov (United States)

    Wu, Yijen L.; Ye, Qing

    2011-01-01

    Heart transplantation is now an established treatment for patients suffering from end-stage heart diseases. With the advances in immunosuppressive treatment, the survival rate for transplant patients has improved greatly. However, allograft rejection, both acute and chronic, after heart transplantation is still a limitation leading to morbidity and mortality. The current clinical gold standard for screening rejection is endomyocardial biopsy (EMB), which is not only invasive, but also error-prone, due to the limited sample size and the site location of sampling. It would be highly desirable to have reliable and noninvasive alternatives for EMB in monitoring cardiac allograft rejection. The objective of this review is to highlight how cardiovascular imaging can contribute to noninvasively detecting and to evaluating both acute and chronic allograft rejection after heart transplantation, in particular, cardiovascular MRI (CMRI); and how CMRI can assess both immune cell infiltration at the rejecting organ, and the cardiac dysfunctions resulting from allograft rejection. PMID:21359095

  17. 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...... relaxation time (IVRT), isovolumic contraction time (IVCT), and ejection time (ET) were obtained by TDI M-mode through the MV. IVCT/ET, IVRT/ET and the MPI ((IVRT+IVCT)/ET) were calculated. We also included a validation population (n = 44) of patients who underwent left heart catheterization and had the...

  18. The Cardiac MR Images and Causes of Paradoxical Septal Motion

    International Nuclear Information System (INIS)

    Real-time cine MRI studies using the steady-state free precession (SSFP) technique are very useful for evaluating cardiac and septal motion. During diastole, the septum acts as a compliant membrane between the two ventricles, and its position and geometry respond to even small alterations in the trans-septal pressure gradients. Abnormal septal motion can be caused by an overload of the right ventricle, delayed ventricular filling and abnormal conduction. In this study, we illustrate, based on our experiences, the causes of abnormal septal motion such as corrective surgery for tetralogy of Fallot, an atrial septal defect, pulmonary thromboembolism, mitral stenosis, constrictive pericarditis and left bundle branch block. In addition, we discuss the significance of paradoxical septal motion in the context of cardiac MR imaging

  19. The Cardiac MR Images and Causes of Paradoxical Septal Motion

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Hun [Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Choi, Sang Il; Chun, Eun Ju [Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Choi, Sung Hun [Ulsan University Hospital, Ulsan (Korea, Republic of); Park, Jae Hyung [Seoul National University Hospital, Seoul (Korea, Republic of)

    2010-10-15

    Real-time cine MRI studies using the steady-state free precession (SSFP) technique are very useful for evaluating cardiac and septal motion. During diastole, the septum acts as a compliant membrane between the two ventricles, and its position and geometry respond to even small alterations in the trans-septal pressure gradients. Abnormal septal motion can be caused by an overload of the right ventricle, delayed ventricular filling and abnormal conduction. In this study, we illustrate, based on our experiences, the causes of abnormal septal motion such as corrective surgery for tetralogy of Fallot, an atrial septal defect, pulmonary thromboembolism, mitral stenosis, constrictive pericarditis and left bundle branch block. In addition, we discuss the significance of paradoxical septal motion in the context of cardiac MR imaging.

  20. The usefulness of magnetic resonance imaging (MRI) in cardiac myxoma

    International Nuclear Information System (INIS)

    The characteristics of cardiac myxoma on magnetic resonance imaging (MRI) were evaluated in 20 patients operated on from 1985 to 1991. MRI studies were performed with an 0.5-T system in 5 patients and an 0.15-T system in 15 patients using ECG gating. T1-weighted images (T1WI) were obtained in all 20 patients, T2-weighted images (T2WI) were obtained in 16, and Gd-DTPA-enhanced images were obtained in 9. MRI was able to correctly locate the myxoma and determine the site of attachment. MRI also correctly determined the shape of 19/20 tumors. The exception was an oval myxoma with a smooth but fibrotic and calcified margin, in which MRI visualized the signal void due to calcification as a villous surface. Myxomas showed an inhomogeneous intermediate intensity on T1WI and an inhomogeneous high intensity on T2WI. These findings were thought to be related to variations in the amount of cellular components, capillaries, and calcification within the myxoid matrix. A relatively high intensity on T1WI and enhancement was observed at the base of the myxomas, where less myxoid matrix and abundant vessels were seen histologically. A low intensity band was noted on T1WI just next to the base of 3 myxomas, and bundles of collagen fibers were observed at the same site histologically. MRI provided information about the internal architecture of these tumors, but the cause of the relatively high intensity area at the tumor based on T1WI remains unproven. In conclusion, MRI was reliable for the diagnosis of cardiac myxoma, and should be performed after cardiac ultrasonography. (author)

  1. Radionuclide reporter gene imaging for cardiac gene therapy

    International Nuclear Information System (INIS)

    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.)

  2. 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.)

  3. 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

  4. 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

  5. OsiriX plugin for integrated cardiac imaging research

    Science.gov (United States)

    Hüllebrand, Markus; Hennemuth, Anja; Messroghli, Daniel; Kühne, Titus

    2014-03-01

    Strongly evolving imaging technologies such as magnetic resonance imaging (MRI) nowadays provide a multitude of new complementary techniques for the analysis of cardiovascular tissue properties, function, and hemodynamics. The purpose of the presented work is to provide a research tool, which enables a quick validation of newly developed imaging techniques and supports the co-development of clinically usable analysis tools, which allow an integration with existing complementary examination methods. The concepts combined to this end consist of an integration with the open source research PACS OsiriX, an advanced heuristic DICOM classification and preprocessing as well as an integrative data model, which accumulates patient-specific image data, results and the data relations. Specific processing and analysis plugins can easily be integrated in such a way that they use the data integration and visualization infrastructure as well as results from other existing plugins. The presented example applications, such as the evaluation of slice orientations for cardiac function quantification or the integrated analysis of different types of image data for diagnosis of myocarditis show that the provided tool can be successfully used for a multitude of research applications in cardiovascular imaging.

  6. Dual-source CT cardiac imaging: initial experience

    International Nuclear Information System (INIS)

    The relation of heart rate and image quality in the depiction of coronary arteries, heart valves and myocardium was assessed on a dual-source computed tomography system (DSCT). Coronary CT angiography was performed on a DSCT (Somatom Definition, Siemens) with high concentration contrast media (Iopromide, Ultravist 370, Schering) in 24 patients with heart rates between 44 and 92 beats per minute. Images were reconstructed over the whole cardiac cycle in 10% steps. Two readers independently assessed the image quality with regard to the diagnostic evaluation of right and left coronary artery, heart valves and left ventricular myocardium for the assessment of vessel wall changes, coronary stenoses, valve morphology and function and ventricular function on a three point grading scale. The image quality ratings at the optimal reconstruction interval were 1.24±0.42 for the right and 1.09±0.27 for the left coronary artery. A reconstruction of diagnostic systolic and diastolic images is possible for a wide range of heart rates, allowing also a functional evaluation of valves and myocardium. Dual-source CT offers very robust diagnostic image quality in a wide range of heart rates. The high temporal resolution now also makes a functional evaluation of the heart valves and myocardium possible. (orig.)

  7. 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.

  8. Cardiac magnetic resonance imaging in patients with congenital heart disease

    International Nuclear Information System (INIS)

    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.

  9. 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.

  10. 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 ...

  11. Radiation dose in cardiac CT angiography: Protocols and image quality

    International Nuclear Information System (INIS)

    This paper aims to evaluate the radiation dose exposure of patients submitted to cardiac computed tomography angiography. The effective dose was obtained from the product of dose-length product values and the conversion factor established in the European Working Group for Guidelines on Quality Criteria in CT. The image noise and contrast-and signal-to-noise ratios were obtained for all images. Sixty-four- and 256-slice CT angiographies were used in 211 (68.5 %) and 97 (31.5 %) patients, respectively. The calculated mean effective dose with prospective CT angiography was 6.0±1.0 mSv and the retrospective mode was 8.4±1.2 mSv. The mean image noise values were 38.5±9.5 and 21.4±5.3 for prospective and retrospective modes, respectively. It was observed that the image noise increased by 44.4 % using a prospective mode. Prospective CT angiography reduces radiation dose by ∼29 % compared with the retrospective mode, while maintaining diagnostic image quality and the ability to assess obstructions in patients. (authors)

  12. 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

  13. 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.

  14. Ionising radiations regulations 1985

    International Nuclear Information System (INIS)

    The (UK) Ionising Radiations Regulations 1985 come into force on 1.1.86 with supporting Approved Code of Practice. They are discussed under the headings: introduction; notifications to start work with ionising radiations; dose limitation (ALARP -as low as reasonably practicable); designation of controlled and supervised areas; Radiation Protection Advisers to be appointed by employers; Local Rules; Radiation Protection Supervisors to be appointed by employers from among employees; instruction and training; dosimetry and medical surveillance; control of radioactive substances; radiation monitoring; assessment of hazards; articles and equipment. (U.K.)

  15. 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......-contrast cardiac multidetector computered tomography (MDCT) images. The aim of this study was to validate contrast MDCT derived measures of total PAT volume by a comparison to CMRI. In 52 patients, aged 60 years (34-81 years), Body Mass Index 28 kg/m(2) (18-39), and with stable ischemic heart disease, paired MDCT...

  16. 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

  17. Evaluation of an adaptive filtering algorithm for CT cardiac imaging with EKG modulated tube current

    Science.gov (United States)

    Li, Jianying; Hsieh, Jiang; Mohr, Kelly; Okerlund, Darin

    2005-04-01

    We have developed an adaptive filtering algorithm for cardiac CT scans with EKG-modulated tube current to optimize resolution and noise for different cardiac phases and to provide safety net for cases where end-systole phase is used for coronary imaging. This algorithm has been evaluated using patient cardiac CT scans where lower tube currents are used for the systolic phases. In this paper, we present the evaluation results. The results demonstrated that with the use of the proposed algorithm, we could improve image quality for all cardiac phases, while providing greater noise and streak artifact reduction for systole phases where lower CT dose were used.

  18. 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.)

  19. Multidetector CT and MR Imaging of Cardiac Tumors

    OpenAIRE

    Kim, Eun Young; Choe, Yeon Hyeon; Sung, Kiick; Park, Seung Woo; Kim, Ji Hye; Ko, Young-Hyeh

    2009-01-01

    The purpose of this article is to provide a current review of the spectrum of multidetector CT (MDCT) and MRI findings for a variety of cardiac neoplasms. In the diagnosis of cardiac tumors, the use of MDCT and MRI can help differentiate benign from malignant masses. Especially, the use of MDCT is advantageous in providing anatomical information and MRI is useful for tissue characterization of cardiac masses. Knowledge of the characteristic MRI findings of benign cardiac tumors or thrombi can...

  20. 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

  1. Computational Chemical Imaging for Cardiovascular Pathology: Chemical Microscopic Imaging Accurately Determines Cardiac Transplant Rejection

    Science.gov (United States)

    Tiwari, Saumya; Reddy, Vijaya B.; Bhargava, Rohit; Raman, Jaishankar

    2015-01-01

    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. PMID:25932912

  2. 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.

  3. 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

  4. Walking with Gianluca Di Bella during the development of clinical cardiac imaging

    OpenAIRE

    2010-01-01

    Cardiac magnetic resonance imaging (MRI) for the diagnosis and management of many cardiac diseases has been established in clinical practice. It provides anatomic and functional information and is the most precise technique for quantification of ventricular volume, function and mass. Among cardiac MRI sequences used in clinical practice, delayed contrast enhancement is an accurate and reliable method used in the diagnosis of ischemic and nonischemic cardiomyopathies. In addition, new technolo...

  5. 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

  6. A new web-based educational tool for training in multimodal cardiac imaging

    OpenAIRE

    Todiere, Giancarlo; L Abbate, Giuseppe Andrea; Positano, Vincenzo; Zingoni, Gloria; Esposito, Natalia; Puzzuoli, Stefano; Neglia, Danilo; Marcheschi, Paolo; Marinelli, Martina

    2012-01-01

    Purpose: The dynamic evolution of cardiac multimodal imaging is based on the increasing clinical interest on the use of different and complementary data to evaluate cardiac diseases. This is supported by the development of technologies related to single or hybrid imaging devices. The increasing use of combined imaging for diagnosis and clinical decision requires to choose an appropriate diagnostic path combining, step by step, invasive and/or noninvasive tests. The cost- risk- benefits balanc...

  7. A Novel Approach of Cardiac Segmentation In CT Image Based On Spline Interpolation

    International Nuclear Information System (INIS)

    Organ segmentation in CT images is the basis of organ model reconstruction, thus precisely detecting and extracting the organ boundary are keys for reconstruction. In CT image the cardiac are often adjacent to the surrounding tissues and gray gradient between them is too slight, which cause the difficulty of applying classical segmentation method. We proposed a novel algorithm for cardiac segmentation in CT images in this paper, which combines the gray gradient methods and the B-spline interpolation. This algorithm can perfectly detect the boundaries of cardiac, at the same time it could well keep the timeliness because of the automatic processing.

  8. Understanding the physiology of complex congenital heart disease using cardiac magnetic resonance imaging

    International Nuclear Information System (INIS)

    Complex congenital heart diseases are often associated with complex alterations in hemodynamics. Understanding these key hemodynamic changes is critical to making management decisions including surgery and postoperative management. Existing tools for imaging and hemodynamic assessment like echocardiography, computed tomography and cardiac catheterization have inherent limitations. Cardiac magnetic resonance imaging (MRI) is emerging as a powerful bouquet of tools that allow not only excellent imaging, but also a unique insight into hemodynamics. This article introduces the reader to cardiac MRI and its utility through the clinical example of a child with a complex congenital cyanotic heart disease

  9. Pulmonary embolism due to cardiac hydatid disease: imaging findings of unusual complication of hydatid cyst

    International Nuclear Information System (INIS)

    We report two cases of primary cardiac hydatid cyst in which hydatid materials caused recurrent embolizations in pulmonary arteries and pulmonary parenchyma. Cardiac hydatid cysts may stay asymptomatic for a long time, until they reveal themselves being perforated into cardiac chambers and/or pulmonary artery or systemic circulation. The role of imaging techniques in diagnosis is discussed and the importance of dynamic enhanced CT, MR imaging, and enhanced MR angiography (MRA) is reported. Imaging findings were confirmed by surgery and pathology. Early diagnosis is essential because delayed treatment increases the morbidity and mortality rates. (orig.)

  10. Denoising human cardiac diffusion tensor magnetic resonance images using sparse representation combined with segmentation

    Science.gov (United States)

    Bao, L. J.; Zhu, Y. M.; Liu, W. Y.; Croisille, P.; Pu, Z. B.; Robini, M.; Magnin, I. E.

    2009-03-01

    Cardiac diffusion tensor magnetic resonance imaging (DT-MRI) is noise sensitive, and the noise can induce numerous systematic errors in subsequent parameter calculations. This paper proposes a sparse representation-based method for denoising cardiac DT-MRI images. The method first generates a dictionary of multiple bases according to the features of the observed image. A segmentation algorithm based on nonstationary degree detector is then introduced to make the selection of atoms in the dictionary adapted to the image's features. The denoising is achieved by gradually approximating the underlying image using the atoms selected from the generated dictionary. The results on both simulated image and real cardiac DT-MRI images from ex vivo human hearts show that the proposed denoising method performs better than conventional denoising techniques by preserving image contrast and fine structures.

  11. A multimodal (MRI/ultrasound) cardiac phantom for imaging experiments

    Science.gov (United States)

    Tavakoli, Vahid; Kendrick, Michael; Shakeri, Mostafa; Alshaher, Motaz; Stoddard, Marcus F.; Amini, Amir

    2013-03-01

    A dynamic cardiac phantom can play a significant role in the evaluation and development of ultrasound and cardiac magnetic resonance (MR) motion tracking and registration methods. A four chamber multimodal cardiac phantom has been designed and built to simulate normal and pathologic hearts with different degrees of "infarction" and "scar tissues". In this set up, cardiac valves have been designed and modeled as well. The four-chamber structure can simulate the asymmetric ventricular, atrial and valve motions. Poly Vinyl Alcohol (PVA) is used as the principal material since it can simulate the shape, elasticity, and MR and ultrasound properties of the heart. The cardiac shape is simulated using a four-chamber mold made of polymer clay. An additional pathologic heart phantom containing stiff inclusions has been manufactured in order to simulate an infracted heart. The stiff inclusions are of different shapes and different degrees of elasticity and are able to simulate abnormal cardiac segments. The cardiac elasticity is adjusted based on freeze-thaw cycles of the PVA cryogel for normal and scarred regions. Ultrasound and MRI markers were inserted in the cardiac phantom as landmarks for validations. To the best of our knowledge, this is the first multimodal phantom that models a dynamic four-chamber human heart including the cardiac valve.

  12. 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.

  13. How much image noise can be added in cardiac x-ray imaging without loss in perceived image quality?

    Science.gov (United States)

    Gislason-Lee, Amber J.; Kumcu, Asli; Kengyelics, Stephen M.; Brettle, David S.; Treadgold, Laura A.; Sivananthan, Mohan; Davies, Andrew G.

    2015-09-01

    Cardiologists use x-ray image sequences of the moving heart acquired in real-time to diagnose and treat cardiac patients. The amount of radiation used is proportional to image quality; however, exposure to radiation is damaging to patients and personnel. The amount by which radiation dose can be reduced without compromising patient care was determined. For five patient image sequences, increments of computer-generated quantum noise (white + colored) were added to the images, frame by frame using pixel-to-pixel addition, to simulate corresponding increments of dose reduction. The noise adding software was calibrated for settings used in cardiac procedures, and validated using standard objective and subjective image quality measurements. The degraded images were viewed next to corresponding original (not degraded) images in a two-alternative-forced-choice staircase psychophysics experiment. Seven cardiologists and five radiographers selected their preferred image based on visualization of the coronary arteries. The point of subjective equality, i.e., level of degradation where the observer could not perceive a difference between the original and degraded images, was calculated; for all patients the median was 33%±15% dose reduction. This demonstrates that a 33%±15% increase in image noise is feasible without being perceived, indicating potential for 33%±15% dose reduction without compromising patient care.

  14. 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.

  15. Computerized method for evaluating diagnostic image quality of calcified plaque images in cardiac CT: Validation on a physical dynamic cardiac phantom

    Energy Technology Data Exchange (ETDEWEB)

    King, Martin; Rodgers, Zachary; Giger, Maryellen L.; Bardo, Dianna M. E.; Patel, Amit R. [Department of Radiology, Committee on Medical Physics, University of Chicago, 5841 South Maryland Avenue, MC 2026, Chicago, Illinois 60637 (United States); Department of Diagnostic Radiology, Oregon Health and Science University, 3181 Southwest Sam Jackson Park Road, Portland, Oregon 97239 (United States); Department of Medicine, University of Chicago, 5841 South Maryland Avenue, MC 5084, Chicago, Illinois 60637 (United States)

    2010-11-15

    Purpose: In cardiac computed tomography (CT), important clinical indices, such as the coronary calcium score and the percentage of coronary artery stenosis, are often adversely affected by motion artifacts. As a result, the expert observer must decide whether or not to use these indices during image interpretation. Computerized methods potentially can be used to assist in these decisions. In a previous study, an artificial neural network (ANN) regression model provided assessability (image quality) indices of calcified plaque images from the software NCAT phantom that were highly agreeable with those provided by expert observers. The method predicted assessability indices based on computer-extracted features of the plaque. In the current study, the ANN-predicted assessability indices were used to identify calcified plaque images with diagnostic calcium scores (based on mass) from a physical dynamic cardiac phantom. The basic assumption was that better quality images were associated with more accurate calcium scores. Methods: A 64-channel CT scanner was used to obtain 500 calcified plaque images from a physical dynamic cardiac phantom at different heart rates, cardiac phases, and plaque locations. Two expert observers independently provided separate sets of assessability indices for each of these images. Separate sets of ANN-predicted assessability indices tailored to each observer were then generated within the framework of a bootstrap resampling scheme. For each resampling iteration, the absolute calcium score error between the calcium scores of the motion-contaminated plaque image and its corresponding stationary image served as the ground truth in terms of indicating images with diagnostic calcium scores. The performances of the ANN-predicted and observer-assigned indices in identifying images with diagnostic calcium scores were then evaluated using ROC analysis. Results: Assessability indices provided by the first observer and the corresponding ANN performed

  16. 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...

  17. Automatic detection of cardiac contours on MR images using fuzzy logic and dynamic programming.

    OpenAIRE

    Lalande, A; Legrand, L; Walker, P M; Jaulent, M. C.; Guy, F.; Cottin, Y; Brunotte, F

    1997-01-01

    This paper deals with the use of fuzzy logic and dynamic programming in the detection of cardiac contours in MR Images. The definition of two parameters for each pixel allows the construction of the fuzzy set of the cardiac contour points. The first parameter takes into account the grey level, and the second the presence of an edge. A corresponding fuzzy matrix is derived from the initial image. Finally, a dynamic programming with graph searching is performed on this fuzzy matrix. The method ...

  18. Monitoring radiation use in cardiac fluoroscopy imaging procedures

    International Nuclear Information System (INIS)

    Purpose: Timely identification of systematic changes in radiation delivery of an imaging system can lead to a reduction in risk for the patients involved. However, existing quality assurance programs involving the routine testing of equipment performance using phantoms are limited in their ability to effectively carry out this task. To address this issue, the authors propose the implementation of an ongoing monitoring process that utilizes procedural data to identify unexpected large or small radiation exposures for individual patients, as well as to detect persistent changes in the radiation output of imaging platforms. Methods: Data used in this study were obtained from records routinely collected during procedures performed in the cardiac catheterization imaging facility at St. Andrew's War Memorial Hospital, Brisbane, Australia, over the period January 2008-March 2010. A two stage monitoring process employing individual and exponentially weighted moving average (EWMA) control charts was developed and used to identify unexpectedly high or low radiation exposure levels for individual patients, as well as detect persistent changes in the radiation output delivered by the imaging systems. To increase sensitivity of the charts, we account for variation in dose area product (DAP) values due to other measured factors (patient weight, fluoroscopy time, and digital acquisition frame count) using multiple linear regression. Control charts are then constructed using the residual values from this linear regression. The proposed monitoring process was evaluated using simulation to model the performance of the process under known conditions. Results: Retrospective application of this technique to actual clinical data identified a number of cases in which the DAP result could be considered unexpected. Most of these, upon review, were attributed to data entry errors. The charts monitoring the overall system radiation output trends demonstrated changes in equipment performance

  19. Monitoring radiation use in cardiac fluoroscopy imaging procedures

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, Nathaniel T.; Steiner, Stefan H.; Smith, Ian R.; MacKay, R. Jock [Department of Statistics and Actuarial Sciences, Business and Industrial Statistics Research Group, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); St. Andrew' s Medical Institute, St. Andrew' s War Memorial Hospital, Brisbane, Queensland 4000 (Australia); Department of Statistics and Actuarial Sciences, Business and Industrial Statistics Research Group, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2011-01-15

    Purpose: Timely identification of systematic changes in radiation delivery of an imaging system can lead to a reduction in risk for the patients involved. However, existing quality assurance programs involving the routine testing of equipment performance using phantoms are limited in their ability to effectively carry out this task. To address this issue, the authors propose the implementation of an ongoing monitoring process that utilizes procedural data to identify unexpected large or small radiation exposures for individual patients, as well as to detect persistent changes in the radiation output of imaging platforms. Methods: Data used in this study were obtained from records routinely collected during procedures performed in the cardiac catheterization imaging facility at St. Andrew's War Memorial Hospital, Brisbane, Australia, over the period January 2008-March 2010. A two stage monitoring process employing individual and exponentially weighted moving average (EWMA) control charts was developed and used to identify unexpectedly high or low radiation exposure levels for individual patients, as well as detect persistent changes in the radiation output delivered by the imaging systems. To increase sensitivity of the charts, we account for variation in dose area product (DAP) values due to other measured factors (patient weight, fluoroscopy time, and digital acquisition frame count) using multiple linear regression. Control charts are then constructed using the residual values from this linear regression. The proposed monitoring process was evaluated using simulation to model the performance of the process under known conditions. Results: Retrospective application of this technique to actual clinical data identified a number of cases in which the DAP result could be considered unexpected. Most of these, upon review, were attributed to data entry errors. The charts monitoring the overall system radiation output trends demonstrated changes in equipment

  20. Extra-cardiac findings in cardiovascular magnetic resonance: what the imaging cardiologist needs to know.

    Science.gov (United States)

    Rodrigues, Jonathan C L; Lyen, Stephen M; Loughborough, William; Amadu, Antonio Matteo; Baritussio, Anna; Dastidar, Amardeep Ghosh; Manghat, Nathan E; Bucciarelli-Ducci, Chiara

    2016-01-01

    Cardiovascular magnetic resonance (CMR) is an established non-invasive technique to comprehensively assess cardiovascular structure and function in a variety of acquired and inherited cardiac conditions. A significant amount of the neck, thorax and upper abdomen are imaged at the time of routine clinical CMR, particularly in the initial multi-slice axial and coronal images. The discovery of unsuspected disease at the time of imaging has ethical, financial and medico-legal implications. Extra-cardiac findings at the time of CMR are common, can be important and can change clinical management. Certain patient groups undergoing CMR are at particular risk of important extra-cardiac findings as several of the cardiovascular risk factors for atherosclerosis are also risk factors for malignancy. Furthermore, the presence of certain extra-cardiac findings may contribute to the interpretation of the primary cardiac pathology as some cardiac conditions have multi-systemic extra-cardiac involvement. The aim of this review is to give an overview of the type of extra-cardiac findings that may become apparent on CMR, subdivided by anatomical location. We focus on normal variant anatomy that may mimic disease, common incidental extra-cardiac findings and important imaging signs that help distinguish sinister pathology from benign disease. We also aim to provide a framework to the approach and potential further diagnostic work-up of incidental extra-cardiac findings discovered at the time of CMR. However, it is beyond the scope of this review to discuss and determine the clinical significance of extracardiac findings at CMR. PMID:27156861

  1. 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...

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

    International Nuclear Information System (INIS)

    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.

  3. 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...

  4. 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...

  5. 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.)

  6. 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.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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/m2 or higher were assigned to the high dose group and those given doses under 300 mg/m2 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/m2. 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/m2 appeared to be the borderline dose beyond which there were significant

  9. 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

  10. Multimodality cardiac imaging of a double chambered right ventricle with intrapulmonary shunting: a case report

    Directory of Open Access Journals (Sweden)

    Kha Lan-Chau

    2012-09-01

    Full Text Available Abstract Background Double chambered right ventricle (DCRV is a relatively rare congenital heart disease, characterized by the abnormal division of the right ventricle into a high-pressure inlet and low-pressure outlet by anomalous muscle bundles. Extra-cardiac right-to-left shunts may present with clinical symptoms in adulthood and should be sought in patients with previous cavo-pulmonary shunt procedures. Case presentation We report a case of DCRV in a 29 year old Caucasian male presenting in adulthood with a right-to-left shunt secondary to venous collaterals, following cavopulmonary anastomosis for congenital pulmonary atresia and hypoplastic right ventricle. Conclusion Multimodality cardiac imaging using echocardiography, cardiac CT, cardiac MRI and cardiac catheterization is often required for complete characterization of complex congenital heart anomalies in adulthood.

  11. 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...

  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. 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.

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

    International Nuclear Information System (INIS)

    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. Cardiac remodelling and function with primary mitral valve insufficiency studied by magnetic resonance imaging

    DEFF Research Database (Denmark)

    Aplin, Mark; Kyhl, Kasper; Bjerre, Jenny;

    2016-01-01

    AIMS: Evaluation of patients with primary mitral valve insufficiency (MI) is best supported by quantitative measures. Cardiovascular magnetic resonance imaging (CMR) offers flow and cardiac chamber volume quantification. We studied cardiac remodelling with CMR to determine MI regurgitation volumes...... (P < 0.05). In surgical patients, the MIVol correlated to the decrease in LV dimension after valve surgery (P < 0.02). CONCLUSION: CMR provides a reproducible quantitative technique for evaluation of MI, as MIVol and cardiac chamber volumes can be held against diagnostic cut-off values. The Aoflow...

  17. Evaluation of cardiac tumors with magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Luna, Antonio [Clinica Las Nieves, MR Unit, Jaen (Spain); Ribes, Ramon [Reina Sofia Hospital, MR Unit, Radiology Department, Cordoba (Spain); Caro, Pilar [MR Unit, Dadisa, Cadiz (Spain); Vida, Jose [San Juan De Dios Hospital, MR Unit, Resalta, Cordoba (Spain); Erasmus, Jeremy J. [University of Texas, Department of Radiology, Houston, TX (United States)

    2005-07-01

    Primary cardiac neoplasms are rare, and are more commonly benign than malignant. However, metastases are by far the most common cardiac neoplasms. MRI allows evaluation of myocardial infiltration, pericardial involvement and/or extracardiac extension. MRI overcomes the usual limitations of echocardiography and assesses more accurately changes in cardiac function. Specific tumoral characterization is only possible in cases of myxoma, lipoma, fibroma and hemangioma. Suggestive features of malignancy are right side location, extracardiac extension, inhomogeneity in signal intensity of the tumor and pericardial effusion. The use of intravenous contrast material improves tumor characterization and depiction of tumor borders. MRI also allows differentiation of tumor from other nontumoral masses such as intracavitary tumors or fibromuscular elements of the posterior wall of the right atrium. (orig.)

  18. 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

  19. 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.)

  20. 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.

  1. Evaluation of the left cardiac function obtained by cardiac pool imaging

    International Nuclear Information System (INIS)

    In 13 patients with angina pectoris (AP) (mean age : 68.1 +- 11.3), 13 patients with myocardial infarction (MI) (mean age : 62.0 +- 15.7), 9 patients with hypertension (HT) (mean age: 72.6 +- 7.5) and other patients with cardiac diseases (Mis) (mean age: 60.9 +- 15.4), totalling 61, who had all been treated in the First Department of the Internal Medicine of the Nissei Hospital between April, 1982 and February, 1983, the left venticle ejection frequency was determined by cardiac pool method by the use of Simis 3, data processing system of Informatek Co. Of those patients, CAG and LVG were carried on in 14, and through the comparison with LVEF obtained by cardiac pool method, the results described below were obtained: 1) In 14 patients in whom LVG was carried on, comparison between contrast EF and EF by RI produced the correlation index r = 0.87, showing favorable agreement (P < 0.01). 2) EF by diseases show 46.1 +- 18.5 % in MI, 64.5 +- 14.0 % in AP, 70.6 +- 11.3 % in HT and 66.8 +- 18.4 % in Mis. MI group showed statistically significant (P < 0.01) low value in comparison with other 3 groups. 3) The patients were divided into a group in which ST depression was recognized and another group in which the same was not recognized, and LVEF of the two groups were compared. The former represented 57.6 +- 20.0 % while the latter 70.7 +- 12.6 %, showing statistically significant (P < 0.01) difference recognized between them. 4) As calculation of LVEF by the present method allows the evaluation of cardiac function non invasively (in combination), it is useful test method if carried on simultaneously with the observation of the wall motion. (author)

  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. Intraoperative Cardiac Ultrasound Examination Using Vector Flow Imaging

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Lindskov; Pedersen, Mads Møller; Møller-Sørensen, Hasse; Kjaergaard, Jesper; Nilsson, Jens Christian; Lund, Jens Teglgaard; Jensen, Jørgen Arendt; Bachmann, Michael Bachmann

    2013-01-01

    proposed. The vector flow method implemented on a Commercial scanner provided real-time, angle-independent estimates of cardiac blood flow. Epicardiac and epiaortic, intraoperative US examinations were performed on three patients with stenosed coronary arteries scheduled for bypass surgery. Repeating...

  4. 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.

  5. Dipyridamole thallium imaging for detecting cardiac involvement in patients with systemic sclerosis (scleroderma)

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Yoshio; Matsubara, Noboru; Tani, Akihiro; Morozumi, Takakazu; Hori, Masatsugu; Kitabatake, Akira; Kamada, Takenobu; Kimura, Kazufumi; Kozuka, Takahiro (Osaka Univ. (Japan). Faculty of Medicine)

    1990-02-01

    Dipyridamole thallium-201 imaging was carried out in 21 patients with progressive systemic sclerosis (PSS) to assess its value in detecting impaired myocardium and coronary microcirculation associated with PSS. Depending upon the degree of cardiac function, the patients were classified as having either ejection fraction of 50% or more (Group I, n=17) or less than 50% (Group II, n=4). In Group I, four patients had transient defect in which perfusion defects were seen on early images but not seen on delayed images; three had reverse redistribution in which defects were not seen on early images but seen on delayed images; and three had persistent defects which were seen on both early and delayed images. A decreased washout of thallium-201 was seen in 9 patients. In an analysis of both perfusion defects and washout rate, 13 patients (76%) in Group I were found to have abnormal findings. This suggests that disturbed coronary microcirculation or impaired myocardium may frequently develop even when EF is normal. All of the patients categorized as having a decreased cardiac function (Group II) had perfusion defect, suggesting the presence of myocardial fibrosis. In PSS, deterioration of cardiac function seemed to be associated with progression of myocardial fibrosis. Dipyridamole thallium imaging may be a sensitive method for detecting cardiac lesions in PSS. It also has the potential for detecting decreased coronary flow reserve or slightly impaired myocardium even without decreased EF. (N.K.).

  6. Tetralogy of Fallot Cardiac Function Evaluation and Intelligent Diagnosis Based on Dual-Source Computed Tomography Cardiac Images.

    Science.gov (United States)

    Cai, Ken; Rongqian, Yang; Li, Lihua; Xie, Zi; Ou, Shanxing; Chen, Yuke; Dou, Jianhong

    2016-05-01

    Tetralogy of Fallot (TOF) is the most common complex congenital heart disease (CHD) of the cyanotic type. Studies on ventricular functions have received an increasing amount of attention as the development of diagnosis and treatment technology for CHD continues to advance. Reasonable options for imaging examination and accurate assessment of preoperative and postoperative left ventricular functions of TOF patients are important in improving the cure rate of TOF radical operation, therapeutic evaluation, and judgment prognosis. Therefore, with the aid of dual-source computed tomography (DSCT), cardiac images with high temporal resolution and high definition, we measured the left ventricular time-volume curve using image data and calculating the left ventricular function parameters to conduct the preliminary evaluation on TOF patients. To comprehensively evaluate the cardiac function, the segmental ventricular wall function parameters were measured, and the measurement results were mapped to a bull's eye diagram to realize the standardization of segmental ventricular wall function evaluation. Finally, we introduced a new clustering method based on auto-regression model parameters and combined this method with Euclidean distance measurements to establish an intelligent diagnosis of TOF. The results of this experiment show that the TOF evaluation and the intelligent diagnostic methods proposed in this article are feasible. PMID:26496001

  7. Noninvasive detection of human cardiac transplant rejection with indium-111 antimyosin (Fab) imaging

    International Nuclear Information System (INIS)

    Diagnosis of rejection after cardiac transplantation is currently made by right ventricular endomyocardial biopsy. To evaluate antimyosin imaging as a noninvasive means of detecting human cardiac rejection, the Fab fragment of murine monoclonal antimyosin antibodies was labeled with indium-111 and given intravenously to 18 patients (age 45 +/- 12 years) in 20 studies 7 days to 9 years after transplantation. Endomyocardial biopsy specimens were obtained at the time of each imaging study. Eight patients had positive scans confirmed by biopsy as rejection, and eight patients had negative scans and no evidence of rejection on biopsy. Discordance was observed in four studies, two with positive scans and no rejection on biopsy and two with negative scans and positive biopsy. The sensitivity, specificity, and overall accuracy of the technique were each 80%. Imaging with radiolabeled antimyosin antibody Fab fragments may be of value in the noninvasive identification of rejection in the cardiac transplant recipient

  8. Noninvasive detection of human cardiac transplant rejection with indium-111 antimyosin (Fab) imaging

    Energy Technology Data Exchange (ETDEWEB)

    Frist, W.; Yasuda, T.; Segall, G.; Khaw, B.A.; Strauss, H.W.; Gold, H.; Stinson, E.; Oyer, P.; Baldwin, J.; Billingham, M.

    1987-11-01

    Diagnosis of rejection after cardiac transplantation is currently made by right ventricular endomyocardial biopsy. To evaluate antimyosin imaging as a noninvasive means of detecting human cardiac rejection, the Fab fragment of murine monoclonal antimyosin antibodies was labeled with indium-111 and given intravenously to 18 patients (age 45 +/- 12 years) in 20 studies 7 days to 9 years after transplantation. Endomyocardial biopsy specimens were obtained at the time of each imaging study. Eight patients had positive scans confirmed by biopsy as rejection, and eight patients had negative scans and no evidence of rejection on biopsy. Discordance was observed in four studies, two with positive scans and no rejection on biopsy and two with negative scans and positive biopsy. The sensitivity, specificity, and overall accuracy of the technique were each 80%. Imaging with radiolabeled antimyosin antibody Fab fragments may be of value in the noninvasive identification of rejection in the cardiac transplant recipient.

  9. 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

  10. Strong ionisation in carbon nanowires

    Science.gov (United States)

    Kaymak, V.; Pukhov, A.; Shlyaptsev, V. N.; Rocca, J. J.

    2016-04-01

    Surfaces covered with nanostructures, such as nanowire arrays, are shown to facilitate a significantly higher absorption of laser energy as compared to flat surfaces. Due to the efficient coupling of the laser energy, highly energetic electrons are produced, which in turn can emit intense ultrafast X-ray pulses. Full three dimensional PIC simulations are used to analyse the behaviour of arrays of carbon nanowires 400 nm in diameter, irradiated by a 400-nm laser pulse of 60-fs duration at FWHM and a vector potential of α0 = 18. We analyse the ionisation dynamics of the nanowires. The difference of the ionisation strength and structure between linearly and circularly polarised laser beam is investigated. The nanowires are found to be fully ionised after about 30 laser cycles. Circularly polarised light reveals a slightly stronger ionisation effect.

  11. 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

  12. Optimal Magnetic Sensor Vests for Cardiac Source Imaging

    OpenAIRE

    Stephan Lau; Bojana Petković; Jens Haueisen

    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 t...

  13. 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

  14. 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

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

    International Nuclear Information System (INIS)

    Iodine-123 metaiodobenzylguanidine ([123I]MIBG) is a norepinephrine analog which can be used to image the sympathetic innervation of the heart. In this study, cardiac imaging with [123I]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

  16. 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

  17. 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.

  18. 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)

  19. 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...

  20. 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

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

    International Nuclear Information System (INIS)

    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

  2. Analysis of cardiac images of radionuclide ventriculography in AT-Type personal computer

    International Nuclear Information System (INIS)

    The goal of this research was to produce software for the processing of Cardiac Phase images in personal computers. The results of standard radionuclide Ventriculography and Fourier analysis, got on gamma camera Ohio Nuclear 410 Sygma and Digital PDP 11/34 computer were coded into ASCII file and then transfered via Smarterm 220/Kermit to an Accel 900 AT PC. After decoding the images they were processed with a program develope in C Lenguaje obtaining the values of Phase Angles in the whole phase images and in regions of interest drawn around the cardiac chambers. The images and values were the same as those obtained by conventional processing in the PDP 11/34 computer. This is considered a first stage for the use of PC to Nuclear Medicine imaging studies. (author)

  3. 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)

  4. Effect of high image compression on the reproducibility of cardiac Sestamibi reporting

    International Nuclear Information System (INIS)

    Full text: Compression algorithms have been mooted to minimize storage space and transmission times of digital images. We assessed the impact of high-level lousy compression using JPEG and wavelet algorithms on image quality and reporting accuracy of cardiac Sestamibi studies. Twenty stress/rest Sestamibi cardiac perfusion studies were reconstructed into horizontal short, vertical long and horizontal long axis slices using conventional methods. Each of these six sets of slices were aligned for reporting and saved (uncompressed) as a bitmap. This bitmap was then compressed using JPEG compression, then decompressed and saved as a bitmap for later viewing. This process was repeated using the original bitmap and wavelet compression. Finally, a second copy of the original bitmap was made. All 80 bitmaps were randomly coded to ensure blind reporting. The bitmaps were read blinded and by consensus of 2 experienced nuclear medicine physicians using a 5-point scale and 25 cardiac segments. Subjective image quality was also reported using a 3-point scale. Samples of the compressed images were also subtracted from the original bitmap for visual comparison of differences. Results showed an average compression ratio of 23:1 for wavelet and 13:1 for JPEG. Image subtraction showed only very minor discordance between the original and compressed images. There was no significant difference in subjective quality between the compressed and uncompressed images. There was no significant difference in reporting reproducibility of the identical bitmap copy, the JPEG image and the wavelet image compared with the original bitmap. Use of the high compression algorithms described had no significant impact on reporting reproducibility and subjective image quality of cardiac Sestamibi perfusion studies

  5. 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.)

  6. Automatic localization of the left ventricle in cardiac MRI images using deep learning.

    Science.gov (United States)

    Emad, Omar; Yassine, Inas A; Fahmy, Ahmed S

    2015-08-01

    Automatic localization of the left ventricle (LV) in cardiac MRI images is an essential step for automatic segmentation, functional analysis, and content based retrieval of cardiac images. In this paper, we introduce a new approach based on deep Convolutional Neural Network (CNN) to localize the LV in cardiac MRI in short axis views. A six-layer CNN with different kernel sizes was employed for feature extraction, followed by Softmax fully connected layer for classification. The pyramids of scales analysis was introduced in order to take account of the different sizes of the heart. A publically-available database of 33 patients was used for learning and testing. The proposed method was able it localize the LV with 98.66%, 83.91% and 99.07% for accuracy, sensitivity and specificity respectively. PMID:26736354

  7. Clinical relevance and indications for cardiac magnetic resonance imaging 2013. An interdisciplinary expert statement

    International Nuclear Information System (INIS)

    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.)

  8. 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.

  9. 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.

  10. Liquid-xenon γ-camera with ionisation readout

    International Nuclear Information System (INIS)

    The successful operation of a liquid-xenon ionisation chamber with imaging capability is reported. A bi-dimensional readout based on a mini-strip plate--a glass slab with metal strips deposited along two perpendicular directions--was developed and studied both experimentally and by computation. An image of a 122 keV γ-source of 5 mm diameter was obtained with a liquid-xenon ionisation chamber equipped with such readout. A position resolution better than 2 mm was achieved

  11. 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

  12. 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

  13. [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

  14. 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

  15. 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.

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

    International Nuclear Information System (INIS)

    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.

  17. 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.

  18. 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)

  19. 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)

  20. 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...

  1. 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

  2. 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.

  3. Internet-based transfer of cardiac ultrasound images

    Science.gov (United States)

    Firstenberg, M. S.; Greenberg, N. L.; Garcia, M. J.; Morehead, A. J.; Cardon, L. A.; Klein, A. L.; Thomas, J. D.

    2000-01-01

    A drawback to large-scale multicentre studies is the time required for the centralized evaluation of diagnostic images. We evaluated the feasibility of digital transfer of echocardiographic images to a central laboratory for rapid and accurate interpretation. Ten patients undergoing trans-oesophageal echocardiographic scanning at three sites had representative single images and multiframe loops stored digitally. The images were analysed in the ordinary way. All images were then transferred via the Internet to a central laboratory and reanalysed by a different observer. The file sizes were 1.5-72 MByte and the transfer rates achieved were 0.6-4.8 Mbit/min. Quantitative measurements were similar between most on-site and central laboratory measurements (all P > 0.25), although measurements differed for left atrial width and pulmonary venous systolic velocities (both P < 0.05). Digital transfer of echocardiographic images and data to a central laboratory may be useful for multicentre trials.

  4. 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)

  5. 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

  6. 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

  7. MRI as an adjunct to echocardiography for the diagnostic imaging of cardiac masses

    International Nuclear Information System (INIS)

    Nine patients underwent magnetic resonance imaging (MRI) as part of the diagnostic evaluation for cardiac masses; eight of them had been preliminary studied by 2D-echocardiography (US). MRI did not add to the US diagnostic information in patients affected by intracavitary masses. It represented the definitive diagnostic modality in two patients with intramural pathology: one with ventricular rhabdomyoma, the second with an echinococcyal cyst located within the left atrial wall. The complementary role of MRI to US in cardiac masses is discussed. (orig.)

  8. 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

  9. Non-rigid dual respiratory and cardiac motion correction methods after, during, and before image reconstruction for 4D cardiac PET

    Science.gov (United States)

    Feng, Tao; Wang, Jizhe; Fung, George; Tsui, Benjamin

    2016-01-01

    Respiratory motion (RM) and cardiac motion (CM) degrade the quality and resolution in cardiac PET scans. We have developed non-rigid motion estimation methods to estimate both RM and CM based on 4D cardiac gated PET data alone, and compensate the dual respiratory and cardiac (R&C) motions after (MCAR), during (MCDR), and before (MCBR) image reconstruction. In all three R&C motion correction methods, attenuation-activity mismatch effect was modeled by using transformed attenuation maps using the estimated RM. The difference of using activity preserving and non-activity preserving models in R&C correction was also studied. Realistic Monte Carlo simulated 4D cardiac PET data using the 4D XCAT phantom and accurate models of the scanner design parameters and performance characteristics at different noise levels were employed as the known truth and for method development and evaluation. Results from the simulation study suggested that all three dual R&C motion correction methods provide substantial improvement in the quality of 4D cardiac gated PET images as compared with no motion correction. Specifically, the MCDR method yields the best performance for all different noise levels compared with the MCAR and MCBR methods. While MCBR reduces computational time dramatically but the resultant 4D cardiac gated PET images has overall inferior image quality when compared to that from the MCAR and MCDR approaches in the ‘almost’ noise free case. Also, the MCBR method has better noise handling properties when compared with MCAR and provides better quantitative results in high noise cases. When the goal is to reduce scan time or patient radiation dose, MCDR and MCBR provide a good compromise between image quality and computational times.

  10. 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.)

  11. Influence of x-ray pulse parameters on the image quality for moving objects in digital cardiac imaging

    International Nuclear Information System (INIS)

    The image quality of a single frame in a modern cardiac imaging x-ray facility can be improved by adjusting the automatic pulse exposure parameters. The effects of acquisition rate on patient dose and the detectability of moving objects have been fully described in scientific literature. However, the influence of automatic pulse exposure parameters is still to be determined. Images of a moving wheel (with lead wires) were acquired using an H5000 Philips Integris cardiac x-ray system. Poly(methylmethacrylate) plastic samples 20 and 30 cm thick were employed as the build-up phantom to simulate a patient. The images were obtained using preset clinical parameters for cardiac imaging procedures. The signal detectability and motion blur of a contrast bar at a transversal speed in the range of 100-150 mm/s were evaluated with a cine pulse width of 3, 5, 7, and 10 ms under automatic mA kV regulation. Two levels of exposure at the image intensifier entrance were included in this study. Signal detectability was analyzed in terms of the signal-to-noise ratio (SNR) and the value of SNR2/entrance surface dose. The blurring was modeled as a Gaussian-shaped blurring function, and the motion blur was expressed in terms of the peak full width at half maximum and amplitude (apparent contrast) of the resolution functions. A contrast bar simulating a vessel in motion at the maximum velocities of typical cardiac structures was exposed. Severe loss of image quality occurred at pulse widths ≥7 ms. It is also shown that below 5 ms static nonlinearities, likely caused by the need to use a large focus for cine acquisition, dominate the blurring process

  12. 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.

  13. Pseudoaneurysm of the femoral artery after cardiac catheterisation: diagnosis and treatment by manual compression guided by Doppler colour flow imaging.

    OpenAIRE

    Currie, P; Turnbull, C M; Shaw, T R

    1994-01-01

    OBJECTIVE--To assess the value of Doppler colour flow imaging for diagnosing and guiding non-surgical treatment of pseudoaneurysm of the femoral artery complicating cardiac catheterisation. DESIGN--A prospective study. SETTING--Cardiac department in a teaching hospital. PATIENTS--9 patients (8 female, 1 male) who presented with pseudoaneurysm 1-15 days after cardiac catheterisation. INTERVENTIONS--The femoral arterial communication to the false aneurysm was localised by Doppler colour flow im...

  14. 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.

  15. Efficacy of the phase images in fourier analysis using gated cardiac POOL-SPECT for determining the indication for cardiac resynchronization therapy

    International Nuclear Information System (INIS)

    Although cardiac resynchronization therapy (CRT) improves quality of life and survival for patients with heart failure, exact methods to estimate the effect of cardiac asynchrony have not yet been defined. Initially, to examine whether the phase analysis images in the Fourier analysis using gated cardiac pool single photon emission computed tomography (POOL-SPECT) could be used to evaluate cardiac asynchrony, 19 consecutive patients with dilated cardiomyopathy were studied. Interventricular asynchrony was defined by whether the peak of the picture elements of the right ventricle in the phase histogram fitted that of the left ventricle and intraventricular asynchrony by whether the phase image was described homogenously or not. The patients with both inter- and intraventricular asynchrony had significant deterioration in both left ventricular ejection fraction (p<0.01) and New York Heart Association functional class (p<0.01). To evaluate the efficacy of these phase images for CRT setting, 7 patients were tested before and after CRT. During a 3.9±3.6 month follow-up period, all patients had an improvement in their condition, and the inter- and intraventricular asynchrony significantly improved after CRT. The degrees of the inter- and intraventricular asynchrony were related to the degree of cardiac depression pre CRT. These results have shown that the phase images from POOL-SPECT are useful for assessing the effect of CRT in patients with heart failure, which suggests that it may provide information about the indication for CRT. (author)

  16. Imaging technique and current status of valvular heart disease using cardiac MRI

    International Nuclear Information System (INIS)

    The main indications for cardiac magnetic resonance imaging (MRI) in the evaluation of valvular heart disease are pathologies of the aortic and pulmonary valve. For mitral and tricuspid valve pathologies MRI is not the first line modality as these are usually well visualized by echocardiography. The advantages of MRI in valvular heart disease are a high reliability in the evaluation of ventricular volumes and function as well as the assessment of the perivalvular arterial or atrial structures. This reliability and the limitless access to any imaging plane partially compensates for the lower temporal and spatial resolution in comparison to echocardiography. In patients with congenital heart disease, cardiac MRI is established as a valuable diagnostic tool in daily clinical management, especially for the evaluation of pulmonary valve defects. Nevertheless, echocardiography remains the first-line diagnostic imaging tool for the foreseeable future. (orig.)

  17. A partial defect in technetium-99m pyrophosphate image suggesting cardiac rupture following acute myocardial infarction

    International Nuclear Information System (INIS)

    We present the case of a 70-year-old woman with acute myocardial infarction who died of cardiac rupture on the 2nd hospital day. Dual isotope single photon emission tomography (SPET) using thallium-201 chloride and technetium-99m pyrophosphate (PYP) perforemd on the 2nd hospital day showed a large perfusion defect in the anteroseptal wall on 201Tl image and a increased accumulation on 99mTc-PYP image in the anterior area consistent with a partial defect. Autopsy performed 1 h after death revealed a tear in the left ventricular anterior wall consistent with the defect on the 99mTc-PYP image. We propose that the finding of a partial defect in 99mTc-PYP is an interesting finding which may be associated with cardiac rupture following acute myocardial infarction. (orig.)

  18. Sub-micrometer anatomical models of the sarcolemma of cardiac myocytes based on confocal imaging.

    Science.gov (United States)

    Sachse, Frank B; Savio-Galimberti, Eleonora; Goldhaber, Joshua I; Bridge, John H B

    2008-01-01

    We describe an approach to develop anatomical models of cardiac cells. The approach is based on confocal imaging of living ventricular myocytes with submicrometer resolution, digital image processing of three-dimensional stacks with high data volume, and generation of dense triangular surface meshes representing the sarcolemma including the transverse tubular system. The image processing includes methods for deconvolution, filtering and segmentation. We introduce and visualize models of the sarcolemma of whole ventricular myocytes and single transversal tubules. These models can be applied for computational studies of cell and sub-cellular physical behavior and physiology, in particular cell signaling. Furthermore, the approach is applicable for studying effects of cardiac development, aging and diseases, which are associated with changes of cell anatomy and protein distributions. PMID:18229702

  19. 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.)

  20. 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

  1. 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.

  2. Current artefacts in cardiac and chest magnetic resonance imaging: tips and tricks.

    Science.gov (United States)

    Alfudhili, Khalid; Masci, Pier G; Delacoste, Jean; Ledoux, Jean-B; Berchier, Grégoire; Dunet, Vincent; Qanadli, Salah D; Schwitter, Juerg; Beigelman-Aubry, Catherine

    2016-06-01

    Currently MRI is extensively used for the evaluation of cardiovascular and thoracic disorders because of the well-established advantages that include use of non-ionizing radiation, good contrast and high spatial resolution. Despite the advantages of this technique, numerous categories of artefacts are frequently encountered. They may be related to the scanner hardware or software functionalities, environmental factors or the human body itself. In particular, some artefacts may be exacerbated with high-field-strength MR machines (e.g. 3 T). Cardiac imaging poses specific challenges with respect to breath-holding and cardiac motion. In addition, new cardiac MR-conditional devices may also be responsible for peculiar artefacts. The image quality may thus be impaired and give rise to a misdiagnosis. Knowledge of acquisition and reconstruction techniques is required to understand and recognize the nature of these artefacts. This article will focus on the origin and appearance of the most common artefacts encountered in cardiac and chest MRI along with possible correcting methods to avoid or reduce them. PMID:26986460

  3. 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

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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

  12. Effect of dose-reduced scan protocols on cardiac coronary image quality with 64-row MDCT: A cardiac phantom study

    International Nuclear Information System (INIS)

    Objective: To evaluate the feasibility of using relative low-dose scan protocols in coronary imaging with 64-row MDCT. Materials and methods: A pulsating cardiac phantom was used to simulate coronary arteries of two sizes (3 and 5 mm in diameter) with three stenosis degrees (25, 50 and 75%) at 55 bpm heart rate. Cardiac scans were performed on a 64-row MDCT scanner (GE LightSpeed VCT) with rotation time of 350 ms and pitch of 0.2 under six different scan protocols: 120 kV/650 mA, 1137.5 mAs (effective) (CTDIvol 121.69 mGy), 120 kV/550 mA, 962.5 mAs (CTDIvol 102.96 mGy), 120 kV/450 mA, 787.5 mAs (CTDIvol 84.24 mGy), 120 kV/350 mA, 612.5 mAs (CTDIvol 65.52 mGy), 100 kV/590 mA, 1032.5 mAs (CTDIvol 65.17 mGy) and 140 kV/390 mA, 682.5 mAs (CTDIvol 102.22 mGy). The simulative coronary arteries were filled with contrast media to reach 300 HU in the lumen. Background noise was measured to describe the basic image quality accordingly. CNR, SNR and contour sharpness represented in slope of CT density curve was calculated as well. Measured stenosis area and rates, described by the percentage area of stenosis on the cross-section images were also calculated. Results: The corresponding image noise levels described in standard deviation of background signals varied with radiation dose, CNR and SNR mainly varied with tube current. The contour sharpness, which can reflect actual spatial resolution, is affected mainly by tube voltage. The first five protocols depicted obviously steeper curves than the sixth one (P 0.05). As for evaluation on 50 and 75% stenosis, there was no significant difference between the first two protocols, and between the second two protocols as well. However, significant difference presented between these two groups (P > 0.05). When comparing the groups with similar radiation dose, protocols with lower tube voltage gain more accuracy in representing stenosis area and rate. Conclusion: Dose level and corresponding image quality is relevant to the accuracy of

  13. 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.)

  14. 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.)

  15. 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

  16. 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.

  17. Gated cardiac scanning using limited-angle image reconstruction technique and information in the neighboring phases

    International Nuclear Information System (INIS)

    It is known that there are gaps in scan angle in gated cardiac scanning due to lack of synchronization between heart beat and CT machine rotation. The missing projections in these gaps result in artifacts in the reconstructed images. In a previous paper an iterative limited-angle reconstruction technique was employed to fill in the missing projections to remove the artifacts. It was found there that the root-mean-square errors of the limited-angle images were reduced to a level comparable to those of reconstructions using complete-angle information. In the present paper the results are further improved by using the scans of a neighboring portion of the cardiac cycle as a first estimate of the missing scans in the phase of interest when initializing the iterations. Such a modification provides a better starting point for the iterations

  18. Evaluation of cardiac morphing to improve the quality of myocardial perfusion imaging

    International Nuclear Information System (INIS)

    Objective: To explore the value of cardiac morphing in reducing cardiac motion artifacts and improving the quality of MPI. Methods: In this retrospective study, 20 healthy volunteers underwent MPI with cardiac morphing at initial consultation during March 2011 to August 2011. Coronary artery disease (CAD) was excluded in 8 patients according to their age, clinical features, ECG and CTCA. CAD was excluded by CAG in 12 patients. The number of sparse segments and the percentage of average count at the myocardial wall were obtained by 99Tcm-MIBI MPI. Cardiac morphing was performed with the workstation of GE Discovery D670 SPECT. Two experienced nuclear medicine physicians, who were blinded to each other, measured the percentage of average count in the polar bulls-eye map. The difference was compared by paired t-test. Results: A total of 10 sparse segments were identified without a morphing mode, while 4 sparse segments were identified using a morphing mode. The artifacts were reduced in apex and anterior walls using the morphing mode. The percentages of average count in the apex and anterior walls were (78.05 ± 0.83)% and (74.50 ± 2.35)%, respectively, without a morphing mode and (84.05 ± 1.32)% and (81.10 ± 1.45)%, respectively, with a morphing mode. Their differences were statistically significant (apex: t=11.854; anterior wall: t=9.413, both P<0.05). There was no significant difference between these modes in the anterolateral, posterolateral, anterior and posterior walls, as well as inferior and posterior septa (t=1.876, 1.330, 1.690, 2.014, 0.167, 1.868, all P>0.05). Conclusion: Cardiac morphing can effectively reduce cardiac motion artifacts and improve the image quality of MPI. (authors)

  19. 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.

  20. 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.)

  1. 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.)

  2. Evaluation of long-term prognosis in patients with heart failure. Is cardiac imaging with iodine-123 metaiodobenzylguanidine useful?

    International Nuclear Information System (INIS)

    The effect of cardiac sympathetic activity on long-term prognosis in patients with heart failure was evaluated by cardiac imaging with 123I-MIBG in 46 patients admitted for the first episode of heart failure. Cardiac imaging was performed with 123I-MIBG and 201Tl at rest on separate days before discharge. Using whole body imaging, the ratio of cardiac uptake of the isotope to total injected dose was calculated (percentage uptake). The cardiac uptake ratio of 123I-MIBG (percentage uptake of 123I-MIBG divided by percentage uptake of 201Tl) and percentage washout of 123I-MIBG from the heart over 3 hours were calculated as scintigraphic parameters. Cardiac events were defined as cardiac death or deterioration of heart failure requiring readmission. Scintigraphic parameters, clinical parameters, left ventricular function obtained by echocardiography and neurohumoral parameters were compared between the event group and event-free group. During the follow-up period, cardiac events developed in 14 patients (30%). Univariate analysis showed uptake ratio and washout rate of 123I-MIBG, percentage uptake of 201Tl, New York Heart Association class at discharge, fractional shortening of the left ventricle, serum norepinephrine and atrial natriuretic peptide levels differed significantly between the two groups. Cox proportional-hazard analysis showed that the uptake ratio was an independent predictor of cardiac events. When a cut-off point in the uptake ratio equal to or less than 0.50 and age equal to or more than 65 years old were included in the Cox proportional-hazard analysis instead of actual numbers, relative risks of cardiac events by each index were 31.2 and 4.2, respectively. These data suggest that cardiac uptake of 123I-MIBG is a strong and independent predictor of long-term prognosis in patients with heart failure. (K.H.)

  3. 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.

  4. 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

  5. Computational Chemical Imaging for Cardiovascular Pathology: Chemical Microscopic Imaging Accurately Determines Cardiac Transplant Rejection

    OpenAIRE

    Tiwari, Saumya; Reddy, Vijaya B.; Bhargava, Rohit; Raman, Jaishankar

    2015-01-01

    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 st...

  6. 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

  7. 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

  8. Image analysis methods for tagged MRI cardiac studies

    International Nuclear Information System (INIS)

    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. This paper describes 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 of each of 128 rays emanating from the origin. To counter the deleterious effects of nose and the presence of the tags when determining the boundary positions, we use nonlinear filtering concepts from mathematical morphology together with a priori 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. The authors show results on tagged images and discuss further research directions

  9. 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.

  10. Cardiac chamber quantification using magnetic resonance imaging at 7 Tesla - a pilot study

    International Nuclear Information System (INIS)

    Interest in cardiovascular magnetic resonance (CMR) at 7 T is motivated by the expected increase in spatial and temporal resolution, but the method is technically challenging. We examined the feasibility of cardiac chamber quantification at 7 T. A stack of short axes covering the left ventricle was obtained in nine healthy male volunteers. At 1.5 T, steady-state free precession (SSFP) and fast gradient echo (FGRE) cine imaging with 7 mm slice thickness (STH) were used. At 7 T, FGRE with 7 mm and 4 mm STH were applied. End-diastolic volume, end-systolic volume, ejection fraction and mass were calculated. All 7 T examinations provided excellent blood/myocardium contrast for all slice directions. No significant difference was found regarding ejection fraction and cardiac volumes between SSFP at 1.5 T and FGRE at 7 T, while volumes obtained from FGRE at 1.5 T were underestimated. Cardiac mass derived from FGRE at 1.5 and 7 T was larger than obtained from SSFP at 1.5 T. Agreement of volumes and mass between SSFP at 1.5 T and FGRE improved for FGRE at 7 T when combined with an STH reduction to 4 mm. This pilot study demonstrates that cardiac chamber quantification at 7 T using FGRE is feasible and agrees closely with SSFP at 1.5 T. (orig.)

  11. Cardiac chamber quantification using magnetic resonance imaging at 7 Tesla - a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Knobelsdorff-Brenkenhoff, Florian von; Schulz-Menger, Jeanette [HELIOS Klinikum Berlin-Buch, Department of Cardiology and Nephrology, Berlin (Germany); Medical University Berlin, Charite Campus Buch, Experimental and Clinical Research Center (ECRC), Working Group on Cardiovascular Magnetic Resonance, Berlin (Germany); Max Delbrueck Center for Molecular Medicine, Berlin Ultrahigh Field Facility, Berlin (Germany); Frauenrath, Tobias; Hezel, Fabian [Max Delbrueck Center for Molecular Medicine, Berlin Ultrahigh Field Facility, Berlin (Germany); Prothmann, Marcel [Medical University Berlin, Charite Campus Buch, Experimental and Clinical Research Center (ECRC), Working Group on Cardiovascular Magnetic Resonance, Berlin (Germany); Dieringer, Matthias A.; Niendorf, Thoralf [Medical University Berlin, Charite Campus Buch, Experimental and Clinical Research Center (ECRC), Working Group on Cardiovascular Magnetic Resonance, Berlin (Germany); Max Delbrueck Center for Molecular Medicine, Berlin Ultrahigh Field Facility, Berlin (Germany); Renz, Wolfgang [Max Delbrueck Center for Molecular Medicine, Berlin Ultrahigh Field Facility, Berlin (Germany); Siemens Healthcare, Erlangen (Germany); Kretschel, Kerstin [HELIOS Klinikum Berlin-Buch, Department of Cardiology and Nephrology, Berlin (Germany); Medical University Berlin, Charite Campus Buch, Experimental and Clinical Research Center (ECRC), Working Group on Cardiovascular Magnetic Resonance, Berlin (Germany)

    2010-12-15

    Interest in cardiovascular magnetic resonance (CMR) at 7 T is motivated by the expected increase in spatial and temporal resolution, but the method is technically challenging. We examined the feasibility of cardiac chamber quantification at 7 T. A stack of short axes covering the left ventricle was obtained in nine healthy male volunteers. At 1.5 T, steady-state free precession (SSFP) and fast gradient echo (FGRE) cine imaging with 7 mm slice thickness (STH) were used. At 7 T, FGRE with 7 mm and 4 mm STH were applied. End-diastolic volume, end-systolic volume, ejection fraction and mass were calculated. All 7 T examinations provided excellent blood/myocardium contrast for all slice directions. No significant difference was found regarding ejection fraction and cardiac volumes between SSFP at 1.5 T and FGRE at 7 T, while volumes obtained from FGRE at 1.5 T were underestimated. Cardiac mass derived from FGRE at 1.5 and 7 T was larger than obtained from SSFP at 1.5 T. Agreement of volumes and mass between SSFP at 1.5 T and FGRE improved for FGRE at 7 T when combined with an STH reduction to 4 mm. This pilot study demonstrates that cardiac chamber quantification at 7 T using FGRE is feasible and agrees closely with SSFP at 1.5 T. (orig.)

  12. Cardiac dysfunction in the diabetic rat: quantitative evaluation using high resolution magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Alenezy Mohammed D

    2006-04-01

    Full Text Available Abstract Background Diabetes is a major risk factor for cardiovascular disease. In particular, type 1 diabetes compromises the cardiac function of individuals at a relatively early age due to the protracted course of abnormal glucose homeostasis. The functional abnormalities of diabetic myocardium have been attributed to the pathological changes of diabetic cardiomyopathy. Methods In this study, we used high field magnetic resonance imaging (MRI to evaluate the left ventricular functional characteristics of streptozotocin treated diabetic Sprague-Dawley rats (8 weeks disease duration in comparison with age/sex matched controls. Results Our analyses of EKG gated cardiac MRI scans of the left ventricle showed a 28% decrease in the end-diastolic volume and 10% increase in the end-systolic volume of diabetic hearts compared to controls. Mean stroke volume and ejection fraction in diabetic rats were decreased (48% and 28%, respectively compared to controls. Further, dV/dt changes were suggestive of phase sensitive differences in left ventricular kinetics across the cardiac cycle between diabetic and control rats. Conclusion Thus, the MRI analyses of diabetic left ventricle suggest impairment of diastolic and systolic hemodynamics in this rat model of diabetic cardiomyopathy. Our studies also show that in vivo MRI could be used in the evaluation of cardiac dysfunction in this rat model of type 1 diabetes.

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

    International Nuclear Information System (INIS)

    To evaluate a quantitative method for individually adjusting the tube current to obtain images with consistent noise in electrocardiogram (ECG)-gated CT cardiac scans. 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. This formula was used to predict the required tube current to obtain the desired cardiac CT image noise based on the timing bolus noise measurement. Subsequently, 80 additional cardiac patients (Group B) were scanned with individually adjusted tube currents using an established formula to evaluate its ability to obtain accurate and consistent image noise across the patient population. Image quality was evaluated using score scale of 1 to 5 with a score of 3 or higher being clinically acceptable. Using the formula, we obtained an average CT image noise of 28.55 Hounsfield unit (HU), with a standard deviation of only 1.7 HU, as opposed to a target value of 28 HU. Image quality scores were 4.03 and 4.27 for images in Groups A and B, respectively, and there was no statistical difference between the image quality scores between the two groups. However, the average CT dose index (CTDIvol) was 30% lower for Group B. Adjusting the tube current based on timing bolus scans may provide a consistent image quality and dose optimization for cardiac patients of various body mass index values

  14. 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.

  15. 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

  16. Molecular cardiac PET besides FDG viability imaging; Molekulare Kardiale PET jenseits der FDG-Vitalitaetsdiagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Lindner, O.; Burchert, W. [Universitaetsklinik der Ruhr-Univ. Bochum (Germany). Inst. fuer Radiologie, Nuklearmedizin und Molekulare Bildgebung, Herz- und Diabetszentrum NRW

    2009-06-15

    Molecular cardiac non F-18-FDG PET is currently based on perfusion imaging. It is of excellent diagnostic accuracy to detect coronary artery disease (CAD) and superior to perfusion SPECT. There is also evidence for its incremental prognostic value. The unique feature of PET to measure myocardial perfusion in absolute terms and in short time periods define its impact on cardiac imaging enabling both the evaluation of early changes in CAD and the accurate characterization of multivessel disease. Currently, all available PET perfusion tracers in Europe are cyclotron products. Rb-82, a generator product, is the most frequently employed perfusion tracer in the United States and cyclotron independent. This tracer has the potential to become an alternative in Europe soon. Nowadays, PET systems are manufactured as hybrid PET-CT scanners. In oncology, hybrid imaging revealed, that the combination of functional and morphological imaging is superior to the single components. In cardiology, the integration of perfusion PET imaging with CT calcium scoring and CT anatomy of the coronary arteries represents a similar constellation. Atherosclerotic plaque evaluation by combined PET-CT technique will be one of the most promising future applications with a potential immense impact on prophylaxis, diagnosis and therapy of CAD in the future. (orig.)

  17. 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

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

    International Nuclear Information System (INIS)

    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

  19. 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.

  20. 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

  1. 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

  2. Cardiac anatomy and function determined by MR imaging: Review of 350 subjects

    International Nuclear Information System (INIS)

    MR imaging yields excellent anatomic and functional information on the cardiovascular system. The authors reviewed the MR imaging findings in 150 patients and 200 healthy subjects. Normal values for ventricular volumes and wall thickness were established. Wall thinning and motion were sensitive and specific indicators of infarction. Coronary arteries and bypass grafts were imaged, and velocity mapping led to flow measurements within them. Valvular regurgitation and intracardiac shunting were measured from ventricular stroke volumes and were found to be accurate. Anatomy in congenital heart disease was well shown, and angiographic and flow measurements were particularly valuable. Abnormalities were defined in patients with cardiomyopathy, aortic aneurysms, intracavitary clot, and cardiac tumors. MR imaging makes available a wide range of information in patients with cardiovascular disease and is an important addition to existing techniques

  3. 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.

  4. Multimodality cardiac imaging of a ventricular septal rupture post myocardial infarction: a case report

    Directory of Open Access Journals (Sweden)

    Dhaliwal Surinder

    2012-10-01

    Full Text Available Abstract Background Ventricular septal rupture (VSR, a mechanical complication following an acute myocardial infarction (MI, is thought to result from coagulation necrosis due to lack of collateral reperfusion. Although the gold standard test to confirm left-to-right shunting between ventricular cavities remains invasive ventriculography, two-dimensional transthoracic echocardiography (TTE with color flow Doppler and cardiac MRI (CMR are reliable tests for the non-invasive diagnosis of VSR. Case presentation A 62-year-old Caucasian female presented with a late case of a VSR post inferior MI diagnosed by multimodality cardiac imaging including TTE, CMR and ventriculography. Conclusion We review the presentation, diagnosis and management of VSR post MI.

  5. 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.

  6. 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.

  7. 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

  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

    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 and......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...... increase in EDVI, and increased levels of BNP and NT-proBNP suggesting an initial decrease in cardiac function....

  9. 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.

  10. 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.)

  11. 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.)

  12. 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

  13. 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)

  14. Imaging cardiac amyloidosis: a pilot study using 18F-florbetapir positron emission tomography

    International Nuclear Information System (INIS)

    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 18F-florbetapir for imaging cardiac amyloidosis. We performed a pilot study of cardiac 18F-florbetapir PET in 14 subjects: 5 control subjects without amyloidosis and 9 subjects with documented cardiac amyloidosis. Standardized uptake values (SUV) of 18F-florbetapir in the left ventricular (LV) myocardium, blood pool, liver, and vertebral bone were determined. A 18F-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 18F-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-1, IQR 0.034 - 0.051 min-1, vs. 0.023 min-1, IQR 0.015 - 0.025 min-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. 18F-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.)

  15. German Roentgen Society statement on MR imaging of patients with cardiac pacemakers

    International Nuclear Information System (INIS)

    The aim of this paper is to inform physicians, especially radiologists and cardiologists, about the technical and electrophysiological background of MR imaging of patients with implanted cardiac pacemakers (PM) and to provide dedicated clinical practice guidelines how to perform MR exams in this patient group. The presence of a conventional PM system is not any more considered an absolute contraindication for MR imaging. The prerequisites for MR imaging on pacemaker patients include the assessment of the individual risk/benefit ratio as well as to obtain full informed consent about the off label character of the procedure and all associated risks. Furthermore the use of special PM-related (e.g. re-programming of the PM) and MRI-related (e.g. limitation of whole body SAR to 2 W/kg) precautions is required and needs to be combined with adequate monitoring during MR imaging using continuous pulsoximetry. MR conditional PM devices are tested and approved for the use in the MR environment under certain conditions, including the field strength and gradient slew rate of the MR system, the maximum whole body SAR value and the presence of MR imaging exclusion zones. Safe MR imaging of patients with MR conditional PM requires the knowledge of the specific conditions of each PM system. If MR imaging within these specific conditions cannot be guaranteed in a given patient, the procedure guidelines for conventional PM should be used. The complexity of MR imaging of PM patients requires close cooperation of radiologists and cardiologists.

  16. In-Vivo Synthetic Aperture and Plane Wave High Frame Rate Cardiac Imaging

    DEFF Research Database (Denmark)

    Stuart, Matthias Bo; Jensen, Jonas; Brandt, Andreas Hjelm; Nikolov, Svetoslav; Nielsen, Michael Bachman; Jensen, Jørgen Arendt

    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 similar...... resolution of approximately one wavelength radially and one degree angularly for both wave types. The use of spherical waves is found to have higher signal strength and better cystic resolution than plane waves. Measurements on wires in water yield similar results to simulations with similar resolution.......43 for spherical and 0.70 for plane waves. All measures are well within FDA limits for cardiac imaging. In-vivo images of the heart of a healthy 28-year old volunteer are shown....

  17. 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

  18. Prognostic impact of T2-weighted CMR imaging for cardiac amyloidosis

    International Nuclear Information System (INIS)

    Using cardiac magnetic resonance imaging (MRI) we tested the diagnostic value of various markers for amyloid infiltration. We performed MRI at 1.5 T in 36 consecutive patients with cardiac amyloidosis and 48 healthy volunteers. The protocol included cine imaging, T2-weighted spin echo, T1-weighted spin echo before and early after contrast and late gadolinium enhancement. We compared the frequency of abnormalities and their relation to mortality. Median follow-up was 31 months. Twenty-three patients died. Mean left ventricular (LV) mass was 205 ± 70 g. LV ejection fraction (EF) was 55 ± 12%. T2 ratio was 1.5 ± 0.4. 33/36 patients had pericardial and 22/36 had pleural effusions. All but two had heterogeneous late enhancement. Surviving patients did not differ from those who had died with regard to gender, LV mass or volume. Surviving patients had a significantly higher LVEF (60.4 ± 9.9% vs. 51.6 ± 11.5%; p = 0.03). The deceased patients had a lower T2 ratio than those who survived (1.38 ± 0.42 vs. 1.76 ± 0.17; p = 0.005). Low T2 was associated with shorter survival (Chi-squared 11.3; p < 0.001). Cox regression analysis confirmed T2 ratio < 1.5 as the only independent predictors for survival. Cardiac amyloidosis is associated with hypointense signal on T2-weighted images. A lower T2 ratio was independently associated with shortened survival. (orig.)

  19. Prognostic impact of T2-weighted CMR imaging for cardiac amyloidosis

    Energy Technology Data Exchange (ETDEWEB)

    Wassmuth, Ralf; Schulz-Menger, Jeanette [HELIOS Klinikum Berlin Buch, Charite Campus Buch, Berlin (Germany); Abdel-Aty, Hassan [HELIOS Klinikum Berlin Buch, Charite Campus Buch, Berlin (Germany); Cardio Imaging Center Berlin, Berlin (Germany); Bohl, Steffen [HELIOS Klinikum Berlin Buch, Charite Campus Buch, Berlin (Germany); Unfallkrankenhaus Berlin, Berlin (Germany)

    2011-08-15

    Using cardiac magnetic resonance imaging (MRI) we tested the diagnostic value of various markers for amyloid infiltration. We performed MRI at 1.5 T in 36 consecutive patients with cardiac amyloidosis and 48 healthy volunteers. The protocol included cine imaging, T2-weighted spin echo, T1-weighted spin echo before and early after contrast and late gadolinium enhancement. We compared the frequency of abnormalities and their relation to mortality. Median follow-up was 31 months. Twenty-three patients died. Mean left ventricular (LV) mass was 205 {+-} 70 g. LV ejection fraction (EF) was 55 {+-} 12%. T2 ratio was 1.5 {+-} 0.4. 33/36 patients had pericardial and 22/36 had pleural effusions. All but two had heterogeneous late enhancement. Surviving patients did not differ from those who had died with regard to gender, LV mass or volume. Surviving patients had a significantly higher LVEF (60.4 {+-} 9.9% vs. 51.6 {+-} 11.5%; p = 0.03). The deceased patients had a lower T2 ratio than those who survived (1.38 {+-} 0.42 vs. 1.76 {+-} 0.17; p = 0.005). Low T2 was associated with shorter survival (Chi-squared 11.3; p < 0.001). Cox regression analysis confirmed T2 ratio < 1.5 as the only independent predictors for survival. Cardiac amyloidosis is associated with hypointense signal on T2-weighted images. A lower T2 ratio was independently associated with shortened survival. (orig.)

  20. 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...

  1. 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.)

  2. 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

  3. 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)

  4. 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

  5. The role of multidetector computed tomography coronary angiography in imaging complications post-cardiac surgery

    International Nuclear Information System (INIS)

    There have been numerous advances in the field of cardiac imaging. The advent of multidetector computed tomography coronary angiography (MDCT-CA) and in particular electrocardiographic (ECG)-gated acquisition has revolutionized the investigation of the complete spectrum of complications of common cardiothoracic surgical procedures. Generic complications, such as mediastinitis, pericardial effusion, sternal osteomyelitis, and mediastinal fibrosis, are discussed with illustrative examples of multiplanar and volume-rendered three-dimensional reconstructions. Graft-related complications of both coronary artery bypass grafts and aortic root grafts are reviewed. The role of MDCT-CA in the investigation of prosthetic valve endocarditis and root abscesses is outlined. We present a complete illustration of the detailed images that are obtained when investigating a full range of graft-related complications from both aortic and coronary surgery using ECG-gated MDCT-CA. MDCT-CA has the potential to become established as the optimal technique with which to image a multitude of complications post-cardiac surgery

  6. 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)

  7. 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...

  8. 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

  9. 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

  10. 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.

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

    International Nuclear Information System (INIS)

    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

  12. 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

  13. A prediction model for 5-year cardiac mortality in patients with chronic heart failure using 123I-metaiodobenzylguanidine imaging

    International Nuclear Information System (INIS)

    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 123I-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.)

  14. Improving low-dose cardiac CT images using 3D sparse representation based processing

    Science.gov (United States)

    Shi, Luyao; Chen, Yang; Luo, Limin

    2015-03-01

    Cardiac computed tomography (CCT) has been widely used in diagnoses of coronary artery diseases due to the continuously improving temporal and spatial resolution. When helical CT with a lower pitch scanning mode is used, the effective radiation dose can be significant when compared to other radiological exams. Many methods have been developed to reduce radiation dose in coronary CT exams including high pitch scans using dual source CT scanners and step-and-shot scanning mode for both single source and dual source CT scanners. Additionally, software methods have also been proposed to reduce noise in the reconstructed CT images and thus offering the opportunity to reduce radiation dose while maintaining the desired diagnostic performance of a certain imaging task. In this paper, we propose that low-dose scans should be considered in order to avoid the harm from accumulating unnecessary X-ray radiation. However, low dose CT (LDCT) images tend to be degraded by quantum noise and streak artifacts. Accordingly, in this paper, a 3D dictionary representation based image processing method is proposed to reduce CT image noise. Information on both spatial and temporal structure continuity is utilized in sparse representation to improve the performance of the image processing method. Clinical cases were used to validate the proposed method.

  15. 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.

  16. Cardiac remodeling following percutaneous mitral valve repair - initial results assessed by cardiovascular magnetic resonance imaging

    DEFF Research Database (Denmark)

    Radunski, U K; Franzen, O; Barmeyer, A;

    2014-01-01

    PURPOSE: 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...... mitral valve repair results in reverse LV but not in RV or LA remodeling. KEY POINTS: • Volume measurements by cardiovascular magnetic resonance imaging are feasible following percutaneous mitral valve repair despite device-related artifacts.• A significant reduction of left ventricular volume was found...... end-systolic (48 [42 - 80] vs. 51 [40 - 81] ml/m(2); p = 0.48), and LA (87 [55 - 124] vs. 92 [48 - 137] ml/m(2); p = 0.20) volume indices between BL and FU. CONCLUSION: CMR enables the assessment of cardiac volumes in patients after MitraClip implantation. Our CMR findings indicate that percutaneous...

  17. 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.)

  18. 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

  19. 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

  20. 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.

  1. 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).

  2. Investigations into possible causes of hot inferior wall artifacts in attenuation corrected cardiac perfusion images

    International Nuclear Information System (INIS)

    Through our investigations with simulated images, we have identified several causes of hot inferior wall artifacts in attenuation corrected SPECT cardiac perfusion images. With an insufficient number of iterations, the non-uniform resolution recovered in three dimensions and slow convergence rate of ML-EM reconstruction can cause this artifact when the heart is at a shallow angle (the axis of the heart is close to being horizontal) or when there exists significant background activity. Increasing the number of iterations does not help in correcting this artifact when the attenuation map used has poor resolution or its attenuation coefficients used are not accurate. We also notice that the hot inferior wall artifact is more pronounced when body contouring acquisition or when 180 degrees angular sampling is used

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

    International Nuclear Information System (INIS)

    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.

  4. The utility of magnetic resonance imaging in cardiac tissue regeneration trials.

    Science.gov (United States)

    Fuster, Valentin; Sanz, Javier; Viles-Gonzalez, Juan F; Rajagopalan, Sanjay

    2006-03-01

    The past decade has seen the emergence of paradigm shifts in concepts involving cardiovascular tissue regeneration, including the idea that adult stem cells originate in hematopoietic or bone marrow cells, the belief that even adult organs, such as the heart and nervous system, are capable of post-mitotic regeneration, and the concept of inherent plasticity in cells that have undergone limited lineage differentiation. There has consequently been a flurry of proposed regenerative strategies, and safety and limited efficacy data from both animal and limited human trials have been presented. The drive to push these advances from the bench to the bedside has created a unique environment where the therapeutic agents, delivery approaches, and methods of measuring efficacy (often imaging technology) are evolving practically in parallel. The encouraging results of recent cell-therapy trials should therefore be assessed cautiously and in consonance with an understanding of the advantages and limitations of delivery strategies and end points. Arguably, the use of imaging technologies to evaluate surrogate end points might help overcome the difficulty posed by large sample sizes required for hard end point trials in cardiovascular therapeutics. Cardiac magnetic resonance imaging is one of the most sensitive techniques available to assess spatial and temporal changes following local or systemic therapies, and the availability of a bevy of complementary techniques enables interrogation of physiology, morphology, and metabolism in one setting. We contend that cardiac magnetic resonance imaging is ideally suited to assess response to myocardial regeneration therapy and can be exploited to yield valuable insights into the mechanism of action of myocardial regeneration therapies. PMID:16501625

  5. 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

  6. 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...

  7. 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.

  8. 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

  9. Image fusion of coronary CT angiography and cardiac perfusion MRI: a pilot study

    International Nuclear Information System (INIS)

    To develop a tool for the image fusion of computed tomography coronary angiography (CTCA) and cardiac magnetic resonance imaging (CMR). Surface representations and volume-rendered images from fused CTCA/CMR data of five patients with significant coronary artery disease (CAD) on CTCA and perfusion deficits on CMR were generated using a newly developed software prototype. The spatial relationship of significant coronary artery stenosis at CTCA and myocardial defects at CMR was evaluated. Registration of CTCA and CMR images was possible in all patients. The comprehensive three-dimensional visualisation of fused CTCA and CMR data accurately demonstrated the relationship between coronary artery stenoses and myocardial defects in all patients. The introduced tool enables image fusion of CTCA and CMR data sets and allows for correct superposition of the coronary arteries derived from CTCA onto the corresponding myocardial segments derived from CMR. The method facilitates the comprehensive assessment of the functionally relevant CAD by the exact allocation of culprit coronary stenoses to corresponding myocardial defects at a low radiation dose. (orig.)

  10. Correlation of an abnormal rest 201Tl myocardial image: Pathological findings in cardiac transplant recipients

    International Nuclear Information System (INIS)

    Rest myocardial 201Tl scintigraphy was undertaken in 15 males mean age 39 years (22-54) who had been accepted for cardiac transplantation. Complete pathological correlation was obtained in 14 after transplantation and in 1 who died before a suitable donor heart became available. The average time from scintigraphy to pathological evaluation was 42 days (9-103). All the 201Tl images were grossly abnormal and on the basis of these studies it was not possible to differentiate ischemic from idiopathic cardiomyopathy. Each of the three views of the 201Tl study was divided into three segments, therefore 135 areas were available for comparison (3 x 3 x 15). Eighty-eight of these were abnormal on scan and 78 of these were abnormal pathologically. The right ventricle was seen on all rest images but the degree of uptake bore no relationship to the measured thickness of the right ventricular wall. Structures such as the atrial wall and the enlarged papillary muscle were visualized in some patients. In two patients there was an improvement of the rest 201Tl image in delayed views and histologically these areas showed a mixture of muscle and fibrous tissue. The sensitivity of 201Tl imaging in this study was 89% and there was close correlation of the images with gross and microscopic pathological findings. (orig.)

  11. 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

    . However, hybrid cardiac imaging has also generated controversy with regard to which patients should undergo such integrated examination for clinical effectiveness and minimization of costs and radiation dose, and if software-based fusion of images obtained separately would be a useful alternative....... 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...

  12. Enhanced temporal resolution at cardiac CT with a novel CT image reconstruction algorithm: Initial patient experience

    Energy Technology Data Exchange (ETDEWEB)

    Apfaltrer, Paul, E-mail: paul.apfaltrer@medma.uni-heidelberg.de [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, PO Box 250322, 169 Ashley Avenue, Charleston, SC 29425 (United States); Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Schoendube, Harald, E-mail: harald.schoendube@siemens.com [Siemens Healthcare, CT Division, Forchheim Siemens, Siemensstr. 1, 91301 Forchheim (Germany); Schoepf, U. Joseph, E-mail: schoepf@musc.edu [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, PO Box 250322, 169 Ashley Avenue, Charleston, SC 29425 (United States); Allmendinger, Thomas, E-mail: thomas.allmendinger@siemens.com [Siemens Healthcare, CT Division, Forchheim Siemens, Siemensstr. 1, 91301 Forchheim (Germany); Tricarico, Francesco, E-mail: francescotricarico82@gmail.com [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, PO Box 250322, 169 Ashley Avenue, Charleston, SC 29425 (United States); Department of Bioimaging and Radiological Sciences, Catholic University of the Sacred Heart, “A. Gemelli” Hospital, Largo A. Gemelli 8, Rome (Italy); Schindler, Andreas, E-mail: andreas.schindler@campus.lmu.de [Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, PO Box 250322, 169 Ashley Avenue, Charleston, SC 29425 (United States); Vogt, Sebastian, E-mail: sebastian.vogt@siemens.com [Siemens Healthcare, CT Division, Forchheim Siemens, Siemensstr. 1, 91301 Forchheim (Germany); Sunnegårdh, Johan, E-mail: johan.sunnegardh@siemens.com [Siemens Healthcare, CT Division, Forchheim Siemens, Siemensstr. 1, 91301 Forchheim (Germany); and others

    2013-02-15

    Objective: To evaluate the effect of a temporal resolution improvement method (TRIM) for cardiac CT on diagnostic image quality for coronary artery assessment. Materials and methods: The TRIM-algorithm employs an iterative approach to reconstruct images from less than 180° of projections and uses a histogram constraint to prevent the occurrence of limited-angle artifacts. This algorithm was applied in 11 obese patients (7 men, 67.2 ± 9.8 years) who had undergone second generation dual-source cardiac CT with 120 kV, 175–426 mAs, and 500 ms gantry rotation. All data were reconstructed with a temporal resolution of 250 ms using traditional filtered-back projection (FBP) and of 200 ms using the TRIM-algorithm. Contrast attenuation and contrast-to-noise-ratio (CNR) were measured in the ascending aorta. The presence and severity of coronary motion artifacts was rated on a 4-point Likert scale. Results: All scans were considered of diagnostic quality. Mean BMI was 36 ± 3.6 kg/m{sup 2}. Average heart rate was 60 ± 9 bpm. Mean effective dose was 13.5 ± 4.6 mSv. When comparing FBP- and TRIM reconstructed series, the attenuation within the ascending aorta (392 ± 70.7 vs. 396.8 ± 70.1 HU, p > 0.05) and CNR (13.2 ± 3.2 vs. 11.7 ± 3.1, p > 0.05) were not significantly different. A total of 110 coronary segments were evaluated. All studies were deemed diagnostic; however, there was a significant (p < 0.05) difference in the severity score distribution of coronary motion artifacts between FBP (median = 2.5) and TRIM (median = 2.0) reconstructions. Conclusion: The algorithm evaluated here delivers diagnostic imaging quality of the coronary arteries despite 500 ms gantry rotation. Possible applications include improvement of cardiac imaging on slower gantry rotation systems or mitigation of the trade-off between temporal resolution and CNR in obese patients.

  13. Enhanced temporal resolution at cardiac CT with a novel CT image reconstruction algorithm: Initial patient experience

    International Nuclear Information System (INIS)

    Objective: To evaluate the effect of a temporal resolution improvement method (TRIM) for cardiac CT on diagnostic image quality for coronary artery assessment. Materials and methods: The TRIM-algorithm employs an iterative approach to reconstruct images from less than 180° of projections and uses a histogram constraint to prevent the occurrence of limited-angle artifacts. This algorithm was applied in 11 obese patients (7 men, 67.2 ± 9.8 years) who had undergone second generation dual-source cardiac CT with 120 kV, 175–426 mAs, and 500 ms gantry rotation. All data were reconstructed with a temporal resolution of 250 ms using traditional filtered-back projection (FBP) and of 200 ms using the TRIM-algorithm. Contrast attenuation and contrast-to-noise-ratio (CNR) were measured in the ascending aorta. The presence and severity of coronary motion artifacts was rated on a 4-point Likert scale. Results: All scans were considered of diagnostic quality. Mean BMI was 36 ± 3.6 kg/m2. Average heart rate was 60 ± 9 bpm. Mean effective dose was 13.5 ± 4.6 mSv. When comparing FBP- and TRIM reconstructed series, the attenuation within the ascending aorta (392 ± 70.7 vs. 396.8 ± 70.1 HU, p > 0.05) and CNR (13.2 ± 3.2 vs. 11.7 ± 3.1, p > 0.05) were not significantly different. A total of 110 coronary segments were evaluated. All studies were deemed diagnostic; however, there was a significant (p < 0.05) difference in the severity score distribution of coronary motion artifacts between FBP (median = 2.5) and TRIM (median = 2.0) reconstructions. Conclusion: The algorithm evaluated here delivers diagnostic imaging quality of the coronary arteries despite 500 ms gantry rotation. Possible applications include improvement of cardiac imaging on slower gantry rotation systems or mitigation of the trade-off between temporal resolution and CNR in obese patients

  14. 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.

  15. Effect of hybrid iterative reconstruction technique on quantitative and qualitative image analysis at 256-slice prospective gating cardiac CT

    International Nuclear Information System (INIS)

    To evaluate the effect of hybrid iterative reconstruction on qualitative and quantitative parameters at 256-slice cardiac CT. Prospective cardiac CT images from 20 patients were analysed. Paired image sets were created using 3 reconstructions, i.e. filtered back projection (FBP) and moderate- and high-level iterative reconstructions. Quantitative parameters including CT-attenuation, noise, and contrast-to-noise ratio (CNR) were determined in both proximal- and distal coronary segments. Image quality was graded on a 4-point scale. Coronary CT attenuation values were similar for FBP, moderate- and high-level iterative reconstruction at 293 ± 74-, 290 ± 75-, and 283 ± 78 Hounsfield units (HU), respectively. CNR was significantly higher with moderate- and high-level iterative reconstructions (10.9 ± 3.5 and 18.4 ± 6.2, respectively) than FBP (8.2 ± 2.5) as was the visual grading of proximal vessels. Visualisation of distal vessels was better with high-level iterative reconstruction than FBP. The mean number of assessable segments among 289 segments was 245, 260, and 267 for FBP, moderate- and high-level iterative reconstruction, respectively; the difference between FBP and high-level iterative reconstruction was significant. Interobserver agreement was significantly higher for moderate- and high-level iterative reconstruction than FBP. Cardiac CT using hybrid iterative reconstruction yields higher CNR and better image quality than FBP. circle Cardiac CT helps clinicians to assess patients with coronary artery disease circle Hybrid iterative reconstruction provides improved cardiac CT image quality circle Hybrid iterative reconstruction improves the number of assessable coronary segments circle Hybrid iterative reconstruction improves interobserver agreement on cardiac CT. (orig.)

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

    International Nuclear Information System (INIS)

    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.)

  17. 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.)

  18. 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

  19. [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

  20. Recommendations for 18F-fluorodeoxyglucose positron emission tomography imaging for cardiac sarcoidosis. Japanese society of nuclear cardiology recommendations

    International Nuclear Information System (INIS)

    Sarcoidosis is a systemic granulomatous disease and generally the prognosis is good. However the prognosis of cardiac sarcoidosis (CS) is extremely poor and careful management is required. Guidelines for the diagnosis of CS were published in 1992 and modified in 2006 in Japan. Because the capability to diagnose CS has been improved through the use of 18F-FDG PET, The Japan Society of Sarcoidosis and other Granulomatous Diseases is currently updating its guidelines for the diagnosis of CS and positive 18F-FDG PET findings would be added for one of the criteria for the diagnosis. FDG PET Guidelines about preparation, scan protocol, image processing and image interpretation are described dealing with recommendations about dietary modification and fasting time before imaging, heparin preadministration, 18F-FDG administration dose, cardiac spot imaging, attenuation collection, use of bull's-eye map display, use of systemic MIP imaging and use of standardized uptake value. (K.S.)

  1. 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)

  2. Sodium nuclear magnetic resonance imaging of acute cardiac rejection in heterotopic heart transplantation

    International Nuclear Information System (INIS)

    Nuclear magnetic resonance (NMR) imagings have been applied to the observation of tissue sodium-23 in myocardium undergoing cardiac rejection. Six canine donor hearts were heterotopically transplanted in the recipient's chest cavity. The dogs were then killed and sodium-23 image of the excised donor hearts were obtained using a high field NMR imaging system (1.5 Tesla, Magnetom). Proton NMR imaging was also performed and T1, T2 relaxation times were calculated. Subsequently, these data were correlated with pathologic findings such as mild, moderate and severe rejection. The correlation coefficients between rejection score, and T1, T2 times and sodium NMR signal intensity were 0.79, 0.70 and 0.80, respectively. The moderate or severe rejected myocardium were clearly visible as areas of increased sodium NMR signal. These data suggested that increase of sodium may be mainly caused by the myocardial cellular necrosis. Sodium NMR will allow us to evaluate the location and extent of rejected myocardium undergoing heart transplantation. (author)

  3. Quantitative assessment of small animal cardiac 18F-FDG PET and MRI image

    International Nuclear Information System (INIS)

    Cardiac disease research relies increasingly on small animal models and non-invasive imaging methods such as positron emission tomography (PET) and magnetic resonance imaging (MRI). Delayed enhancement magnetic resonance imaging (DE-MRI) using gadolinium-based contrast agents appear to be a visualizing infracted myocardium with high spatial resolution. Polar map (or bull's-eye image) was used to determination of the myocardial infarction area. Polar map is a comprehensive interpretation of the left ventricle. The infarct size was computed as the fraction of the total polar map areas. The threshold was computed as the percentage of mean intensity of the normal region. In other study, 50% predefined threshold value in varying range (30∼70%) was most commonly use. However, predefined threshold value isn't acceptance in all case. The purpose of this study was to investigate methodological approach for automatic measurement of rat myocardial infarct size using PET and MRI polar map with adaptive threshold value driven from Multi gaussian mixture model (MGMM)

  4. 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.

  5. 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)

  6. 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)

  7. 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

  8. 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.)

  9. Assessment of cardiac sympathetic nerve activity in children with chronic heart failure using quantitative iodine-123 metaiodobenzylguanidine imaging

    International Nuclear Information System (INIS)

    Cardiac sympathetic nerve activity in children with chronic heart failure was examined by quantitative iodine-123 metaiodobenzylguanidine (MIBG) myocardial imaging in 33 patients aged 7.5±6.1 years (range 0-18 years), including 8 with cardiomyopathy, 15 with congenital heart disease, 3 with anthracycrine cardiotoxicity, 3 with myocarditis, 3 with primary pulmonary hypertension and 1 with Pompe's disease. Anterior planar images were obtained 15 min and 3 hr after the injection of iodine-123 MIBG. The cardiac iodine-123 MIBG uptake was assessed as the heart to upper mediastinum uptake activity ratio of the delayed image (H/M) and the cardiac percentage washout rate (%WR). The severity of chronic heart failure was class I (no medication) in 8 patients, class II (no symptom with medication) in 9, class III (symptom even with medication) in 10 and class IV (late cardiac death) in 6. H/M was 2.33±0.22 in chronic heart failure class I, 2.50±0.34 in class II, 1.95±0.61 in class III, and 1.39±0.29 in class IV (p<0.05). %WR was 24.8±12.8% in chronic heart failure class I, 23.3±10.2% in class II, 49.2±24.5% in class III, and 66.3±26.5% in class IV (p<0.05). The low H/M and high %WR were proportionate to the severity of chronic heart failure. Cardiac iodine-123 MIBG showed cardiac adrenergic neuronal dysfunction in children with severe chronic heart failure. Quantitative iodine-123 MIBG myocardial imaging is clinically useful as a predictor of therapeutic outcome and mortality in children with chronic heart failure. (author)

  10. Two-photon ionisation of metastable helium

    International Nuclear Information System (INIS)

    An experimental and theoretical study of two-photon ionisation of He(21S) and He(23S) by a pulsed laser strong enough to saturate the ionisation process through the 3P intermediate and to display the quadrupole transition through the 3D intermediate is presented. A pronounced dip sensitive to the laser pulse shape in the profile of the 21S-31P resonance is shown to stem from a competition between relaxation and ionisation. Further complex but reproducible unexpected structure, which is not yet understood, is seen in both the singlet and triplet 2S-3P resonances. (author)

  11. 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.

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

    International Nuclear Information System (INIS)

    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. (author)

  13. 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.

  14. 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.

  15. 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...

  16. Simultaneous dual-radionuclide myocardial perfusion imaging with a solid-state dedicated cardiac camera

    International Nuclear Information System (INIS)

    We compared simultaneous dual-radionuclide (DR) stress and rest myocardial perfusion imaging (MPI) with a novel solid-state cardiac camera and a conventional SPECT camera with separate stress and rest acquisitions. Of 27 consecutive patients recruited, 24 (64.5±11.8 years of age, 16 men) were injected with 74 MBq of 201Tl (rest) and 250 MBq 99mTc-MIBI (stress). Conventional MPI acquisition times for stress and rest are 21 min and 16 min, respectively. Rest 201Tl for 6 min and simultaneous DR 15-min list mode gated scans were performed on a D-SPECT cardiac scanner. In 11 patients DR D-SPECT was performed first and in 13 patients conventional stress 99mTc-MIBI SPECT imaging was performed followed by DR D-SPECT. The DR D-SPECT data were processed using a spill-over and scatter correction method. DR D-SPECT images were compared with rest 201Tl D-SPECT and with conventional SPECT images by visual analysis employing the 17-segment model and a five-point scale (0 normal, 4 absent) to calculate the summed stress and rest scores. Image quality was assessed on a four-point scale (1 poor, 4 very good) and gut activity was assessed on a four-point scale (0 none, 3 high). Conventional MPI studies were abnormal at stress in 17 patients and at rest in 9 patients. In the 17 abnormal stress studies DR D-SPECT MPI showed 113 abnormal segments and conventional MPI showed 93 abnormal segments. In the nine abnormal rest studies DR D-SPECT showed 45 abnormal segments and conventional MPI showed 48 abnormal segments. The summed stress and rest scores on conventional SPECT and DR D-SPECT were highly correlated (r=0.9790 and 0.9694, respectively). The summed scores of rest 201Tl D-SPECT and DR-DSPECT were also highly correlated (r=0.9968, p201Tl D-SPECT acquisition. (orig.)

  17. Role of magnetic resonance imaging for evaluation of tumors in the cardiac region

    Energy Technology Data Exchange (ETDEWEB)

    Kaminaga, T.; Takeshita, T.; Kimura, I. [Dept. of Radiology/Pathology, Teikyo Univ. Medical School, Tokyo (Japan)

    2003-12-01

    The aim of this study was to review the role of MRI in the assessment of heart neoplasm, 25 cases with heart neoplasm (10 myxoma, 6 rhabdomyoma, 5 angiosarcoma, 2 mesothelioma, 1 lymphoma, and 1 fibroma) were examined with MRI and echocardiography. Multislice T1- and T2-weighted spin-echo images and static gradient-echo images were taken in appropriate directions with electrocardiogram gating. Gadolinium enhancement was performed in 21 cases. Transthoracic echocardiography was performed in all cases. Except for the 5 patients with rhabdomyoma, the pathological diagnosis was obtained. MRI proved to be useful for tissue characterization of myxoma, angiosarcoma, mesothelioma, and fibroma in cases with tuberous sclerosis. MRI also proved to be useful for detection of the tumor, depiction of contour, relation with other cardiac structures, in cases with myxoma, angiosarcoma, mesothelioma, lymphoma, and fibroma. In the differential diagnosis, MRI provided important information in cases with myxoma, rhabdomyoma, angiosarcoma, and fibroma. In cases with tumors expanding into the mediastinum, such as mesothelioma and fibroma in this report, MRI was useful in determining the location and border. In cases with tumors adjacent to pericardium, MRI was useful in detecting pericardial invasion. Gadolinium enhancement added useful information in cases with myxoma, rhabdomyoma, angiosarcoma, and mesothelioma. The role of MRI with and without Gd enhancement differs somewhat in individual types of heart neoplasm, and adaptation must be considered in each kind of neoplasm. On the other hand, MRI is an essential examination in all cases with a cardiac mass, which has not been diagnosed, since it may provide useful information for the differential diagnosis. (orig.)

  18. Taking the perfect nuclear image: quality control, acquisition, and processing techniques for cardiac SPECT, PET, and hybrid imaging.

    Science.gov (United States)

    Case, James A; Bateman, Timothy M

    2013-10-01

    Nuclear Cardiology for the past 40 years has distinguished itself in its ability to non-invasively assess regional myocardial blood flow and identify obstructive coronary disease. This has led to advances in managing the diagnosis, risk stratification, and prognostic assessment of cardiac patients. These advances have all been predicated on the collection of high quality nuclear image data. National and international professional societies have established guidelines for nuclear laboratories to maintain high quality nuclear cardiology services. In addition, laboratory accreditation has further advanced the goal of the establishing high quality standards for the provision of nuclear cardiology services. This article summarizes the principles of nuclear cardiology single photon emission computed tomography (SPECT) and positron emission tomography (PET) imaging and techniques for maintaining quality: from the calibration of imaging equipment to post processing techniques. It also will explore the quality considerations of newer technologies such as cadmium zinc telleride (CZT)-based SPECT systems and absolute blood flow measurement techniques using PET. PMID:23868070

  19. Accuracy and Robustness Improvements of Echocardiographic Particle Image Velocimetry for Routine Clinical Cardiac Evaluation

    Science.gov (United States)

    Meyers, Brett; Vlachos, Pavlos; Charonko, John; Giarra, Matthew; Goergen, Craig

    2015-11-01

    Echo Particle Image Velocimetry (echoPIV) is a recent development in flow visualization that provides improved spatial resolution with high temporal resolution in cardiac flow measurement. Despite increased interest a limited number of published echoPIV studies are clinical, demonstrating that the method is not broadly accepted within the medical community. This is due to the fact that use of contrast agents are typically reserved for subjects whose initial evaluation produced very low quality recordings. Thus high background noise and low contrast levels characterize most scans, which hinders echoPIV from producing accurate measurements. To achieve clinical acceptance it is necessary to develop processing strategies that improve accuracy and robustness. We hypothesize that using a short-time moving window ensemble (MWE) correlation can improve echoPIV flow measurements on low image quality clinical scans. To explore the potential of the short-time MWE correlation, evaluation of artificial ultrasound images was performed. Subsequently, a clinical cohort of patients with diastolic dysfunction was evaluated. Qualitative and quantitative comparisons between echoPIV measurements and Color M-mode scans were carried out to assess the improvements delivered by the proposed methodology.

  20. Joint image reconstruction and motion parameter estimation for free-breathing navigator-gated cardiac MRI

    Science.gov (United States)

    Akçakaya, Mehmet; Basha, Tamer A.; Weingärtner, Sebastian; Nezafat, Reza

    2013-09-01

    We propose an acquisition and reconstruction technique for accelerated free-breathing cardiac MRI acquisitions. For the acquisition, a random undersampling pattern, including a fully-sampled center of k-space, is generated prospectively. The k-space lines specified by this undersampling pattern is acquired with respiratory navigating (NAV), where only the central k-space lines are acquired within the prespecified gating window. For the outer k-space lines, if the NAV signal corresponding to a k-space segment is outside the gating window, the segment is rejected, but not re-acquired. The reconstruction approach jointly estimates the underlying image using a compressed-sensing based approach, and the translational motion parameters for each segment for the outer k-space segments acquired outside the gating window. The feasibility of the approach is demonstrated in healthy adult subjects using whole-heart coronary MRI with a 3-fold accelerated random undersampling pattern. The proposed acquisition and reconstruction technique is compared to parallel imaging with uniform undersampling with 3-fold undersampling. The two techniques exhibit similar image quality with a shorter acquisition time for the proposed approach (4:25+/-0:31 minutes versus 6:52+/-0:19).

  1. 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.

  2. 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

  3. 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.)

  4. Automated classification of LV regional wall motion based on spatio-temporal profiles from cardiac cine magnetic resonance imaging

    Science.gov (United States)

    Mantilla, Juan; Garreau, Mireille; Bellanger, Jean-Jacques; Paredes, José Luis

    2013-11-01

    Assessment of the cardiac Left Ventricle (LV) wall motion is generally based on visual inspection or quantitative analysis of 2D+t sequences acquired in short-axis cardiac cine-Magnetic Resonance Imaging (MRI). Most often, cardiac dynamic is globally analized from two particular phases of the cardiac cycle. In this paper, we propose an automated method to classify regional wall motion in LV function based on spatio-temporal pro les and Support Vector Machines (SVM). This approach allows to obtain a binary classi cation between normal and abnormal motion, without the need of pre-processing and by exploiting all the images of the cardiac cycle. In each short- axis MRI slice level (basal, median, and apical), the spatio-temporal pro les are extracted from the selection of a subset of diametrical lines crossing opposites LV segments. Initialized at end-diastole phase, the pro les are concatenated with their corresponding projections into the succesive temporal phases of the cardiac cycle. These pro les are associated to di erent types of information that derive from the image (gray levels), Fourier, Wavelet or Curvelet domains. The approach has been tested on a set of 14 abnormal and 6 healthy patients by using a leave-one-out cross validation and two kernel functions for SVM classi er. The best classi cation performance is yielded by using four-level db4 wavelet transform and SVM with a linear kernel. At each slice level the results provided a classi cation rate of 87.14% in apical level, 95.48% in median level and 93.65% in basal level.

  5. 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...

  6. 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.

  7. 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...

  8. 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.

  9. 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...

  10. 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.)

  11. 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.

  12. Diagnosis of cardiac metastasis from cervical cancer in a 33-year-old patient using multimodal imaging studies: a case report and literature review

    International Nuclear Information System (INIS)

    We report a case of a 33-year-old woman with emergency admission due to dyspnoea and fever. History included squamous cell carcinoma of the cervix in complete remission. Contrast-enhanced computed tomography (CT) scanning of the chest, which was indicated to rule out pneumonia, revealed an infiltrative cardiac mass. Further assessment of the tumour by echocardiography and cardiac magnetic resonance imaging (MRI) showed transmural infiltration of the apical interventricular septum with a mass extending into the left and right ventricle cavities. The mass was highly suspicious for a cardiac metastasis. Cardiac metastases from cervical cancer are extremely rare. Recurrence of cervical carcinoma involving the heart should be considered even after a curative therapy approach. Non-invasive imaging plays a paramount role in investigating cardiac masses. Echocardiography, CT and MRI are complementary imaging modalities for complete work-up of intracardiac lesions

  13. A trial to reduce cardiac motion artifact on HR-CT images of the lung with the use of subsecond scan and special cine reconstruction algorithm

    International Nuclear Information System (INIS)

    We describe our trial to reduce cardiac motion artifacts on HR-CT images caused by cardiac pulsation by combining use of subsecond CT (scan time 0.8 s) and a special cine reconstruction algorithm (cine reconstruction algorithm with 180-degree helical interpolation). Eleven to 51 HR-CT images were reconstructed with the special cine reconstruction algorithm at the pitch of 0.1 (0.08 s) from the data obtained by two to six contigious rotation scans at the same level. Images with the fewest cardiac motion artifacts were selected for evaluation. These images were compared with those reconstructed with a conventional cine reconstruction algorithm and step-by-step scan. In spite of its increased radiation exposure, technical complexity and slight degradation of spatial resolution, our method was useful in reducing cardiac motion artifacts on HR-CT images in regions adjacent to the heart. (author)

  14. 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

  15. 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

  16. Estimation of cardiac output by first-pass data with technetium-99m-labeled myocardial perfusion imaging agent

    International Nuclear Information System (INIS)

    Technetium-99m-tetrofosmin, a myocardial perfusion imaging agent was used for estimation of cardiac output by means of first-pass radionuclide angiography performed in the anterior projection. Region of interests (ROIs) were assigned over right ventricle, left ventricle and whole chest, and time activity curves (TACs) were obtained. Cardiac output indices (COIs) were calculated by the following equation; COI=p3/2·Qc/∫0tA(s)ds, where p=number of pixels of the ventricular ROI, Qc=the peak count rate of the TAC obtained from the whole chest's ROI and ∫0tA(s)ds=the area under ventricular TAC. The COI(y) determined by ROI over the left ventricle yield the best correlation with the cardiac output by conventional radionuclide method (x) (y=0.0381x+6.22, r=0.828, n=48, p<0.001). In conclusion, cardiac output can be easily measured with first pass data using myocardial perfusion imaging agent. (author)

  17. 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.)

  18. 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

  19. The effects of noise in cardiac diffusion tensor imaging and the benefits of averaging complex data.

    Science.gov (United States)

    Scott, Andrew D; Nielles-Vallespin, Sonia; Ferreira, Pedro F; McGill, Laura-Ann; Pennell, Dudley J; Firmin, David N

    2016-05-01

    There is growing interest in cardiac diffusion tensor imaging (cDTI), but, unlike other diffusion MRI applications, there has been little investigation of the effects of noise on the parameters typically derived. One method of mitigating noise floor effects when there are multiple image averages, as in cDTI, is to average the complex rather than the magnitude data, but the phase contains contributions from bulk motion, which must be removed first. The effects of noise on the mean diffusivity (MD), fractional anisotropy (FA), helical angle (HA) and absolute secondary eigenvector angle (E2A) were simulated with various diffusion weightings (b values). The effect of averaging complex versus magnitude images was investigated. In vivo cDTI was performed in 10 healthy subjects with b = 500, 1000, 1500 and 2000 s/mm(2) . A technique for removing the motion-induced component of the image phase present in vivo was implemented by subtracting a low-resolution copy of the phase from the original images before averaging the complex images. MD, FA, E2A and the transmural gradient in HA were compared for un-averaged, magnitude- and complex-averaged reconstructions. Simulations demonstrated an over-estimation of FA and MD at low b values and an under-estimation at high b values. The transition is relatively signal-to-noise ratio (SNR) independent and occurs at a higher b value for FA (b = 1000-1250 s/mm(2) ) than MD (b ≈ 250 s/mm(2) ). E2A is under-estimated at low and high b values with a transition at b ≈ 1000 s/mm(2) , whereas the bias in HA is comparatively small. The under-estimation of FA and MD at high b values is caused by noise floor effects, which can be mitigated by averaging the complex data. Understanding the parameters of interest and the effects of noise informs the selection of the optimal b values. When complex data are available, they should be used to maximise the benefit from the acquisition of multiple averages. The combination of

  20. 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...

  1. 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.)

  2. Calculation of entrance exposed area from recorded images in cardiac diagnostic and interventional procedures

    International Nuclear Information System (INIS)

    With increasing number of interventional radiological procedures performed on patients of all ages, it is important to determine the skin entrance dose of patients to limit the side effects of radiation. In most cases the skin dose is measured using thermoluminescent detectors (TLD). However, these detectors need to be placed in the radiation field on the skin of the patient, which may interfere with the procedure. Also, not all radiological practices are equipped with TLD readers which are expensive or have staff with the appropriate knowledge and expertise to be able to make use of TLD. The alternative to TLD is to use the dose area product (DAP) measured with a diamentor fitted to the angiography x-ray equipment. The difficulties in using DAP to calculate skin dose is that the irradiated area of the skin is not known. The area could change in size and location during the procedure as the radiologist/medical specialist varies the collimation and region of interest. For angiography equipment the distance between the anode and image intensifier is variable, as is the height of the examination table. The only point of reference is the isocentre. With recorded images it is possible to determine the irradiated area of the patient at the isocentre plane using the stenosis algorithm. The recorded image is calibrated such that it corresponds to the physical size in the plane of the isocentre. For non-recorded images, it may be necessary to assume that collimation has not changed and that the irradiated area is the same as that shown on the recorded images. The Women's and Children's Hospital has a Toshiba DFP2000 Biplane Digital Imaging system used for all cardiac and general angiography and interventional procedures. With this system the exposure factors (kVp, mA, field sizes) are recorded with the images. The source to image distance (SID), magnification factor (calibration factor of the recorded images) and angle of rotation are displayed on the Display Panel of the

  3. 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.

  4. Cardiac sarcoidosis

    Science.gov (United States)

    Smedema, J.P.; Zondervan, P.E.; van Hagen, P.; ten Cate, F.J.; Bresser, P.; Doubell, A.F.; Pattynama, P.; Hoogsteden, H.C.; Balk, A.H.M.M.

    2002-01-01

    Sarcoidosis is a multi-system granulomatous disorder of unknown aetiology. Symptomatic cardiac involvement occurs in approximately 5% of patients. The prevalence of sarcoidosis in the Netherlands is unknown, but estimated to be approximately 20 per 100,000 population (3200 patients). We report on five patients who presented with different manifestations of cardiac sarcoidosis, and give a brief review on the current management of this condition. Magnetic Resonance Imaging (MRI) can be of great help in diagnosing this condition as well as in the follow-up of the response to therapy. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5Figure 6 PMID:25696121

  5. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Ding Yu; Raman, Subha V; Simonetti, Orlando P [Davis Heart and Lung Research Institute, Ohio Sate University, Columbus, OH, 43210 (United States); Chung, Y-C [Siemens Medical Solutions, Inc., Columbus, OH, 43210 (United States)], E-mail: yu.ding@osumc.edu

    2009-06-21

    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.

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

    Science.gov (United States)

    Ding, Yu; Chung, Yiu-Cho; Raman, Subha V; Simonetti, Orlando P

    2009-06-21

    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. PMID:19491455

  8. 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.

  9. 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.

  10. Evaluation of a 4-channel phased-array coil for MR cardiac imaging. Quantitative assessment of signal to noise ratio improvement

    International Nuclear Information System (INIS)

    Recently, the utility of cardiac MR imaging has been increasing for morphological and functional analysis of the heart. However, since the image acquisition time is substantially shortened with recent fast cardiac MR sequences, it is often difficult to obtain a good signal to noise ratio (SNR) in fast cardiac MR imaging. The purpose of the current study was to optimize the design of a 4-channel multi-coil array for cardiac MR imaging, and to compare the performance of this new coil array with that of other product coils by evaluation of the SNR in a phantom and in healthy volunteers. In the phantom study using SE and FGR sequences, the cardiac coils provided significantly better SNR values than those for the other coils, not only in the peripheral part but also in the center of the phantom (p<0.01). When the SNR values were calculated for the anterior, septal, posteroinferior and lateral walls of the volunteer hearts, the SNR values obtained using the cardiac coil were significantly better than those with any of the other coils evaluated in all 4 myocardial segments (p<0.01). These results suggest that the new 4-channel cardiac multi-coil array is useful for MR imaging of the heart. (author)

  11. 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

  12. 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.

  13. Four-dimensional superquadric-based cardiac phantom for Monte Carlo simulation of radiological imaging systems

    International Nuclear Information System (INIS)

    A four-dimensional (x, y, z, t) composite superquadric-based object model of the human heart for Monte Carlo simulation of radiological imaging systems has been developed. The phantom models the real temporal geometric conditions of a beating heart for frame rates up to 32 per cardiac cycle. Phantom objects are described by boolean combinations of superquadric ellipsoid sections.Moving spherical coordinate systems are chosen to model wall movement whereby points of the ventricle and atria walls are assumed to move towards a moving center-of-gravity point. Due to the non-static coordinate systems, the atrial/ventricular valve plane of the mathematical heart phantom moves up and down along the left ventricular long axis resulting in reciprocal emptying and filling of atria and ventricles. Compared to the base movement, the epicardial apex as well as the superior atria area are almost fixed in space. Since geometric parameters of the objects are directly applied on intersection calculations of the photon ray with object boundaries during Monte Carlo simulation, no phantom discretization artifacts are involved

  14. Evaluation of myocardiotoxicity with SPECT cardiac blood pool imaging for patients treated with adriamycin

    International Nuclear Information System (INIS)

    Evaluation of myocardiotoxicity on adriamycin (ADM) with SPECT cardiac blood pool imaging was presented. SPECT was done to monitor left ventricular function in 49 patients with Non-Hodgkin's Lymphoma and small cell carcinoma, they were treated with ADM of which the accumulation dose were over 300 mg/m2. The results showed that parameters of EF, PER and PFR before and after treatment with ADM were 57 +- 6%, 3.08 +- 0.63 EDV·s-1, 2.99 +- 0.23 EDV·s-1 and 50 +- 11%, 2.25 +- 0.66 EDV·s-1, 2.53 +- 0.35 EDV·s-1 respectively. The difference of these data are significant (P<0.05). The larger the accumulative dose of ADM, the more the parameters decrease, among them PFR is the most sensitive one. It was concluded that SPECT measurement of left ventricular function is a sensitive and useful method in monitoring ADM myocardiotoxicity

  15. 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

  16. 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.

  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. A novel Bayesian respiratory motion model to estimate and resolve uncertainty in image-guided cardiac interventions

    OpenAIRE

    Peressutti, Devis; Penney, Graeme P.; Housden, R. James; Kolbitsch, Christoph; Gomez Herrero, Alberto; Rijkhorst, Erik-Jan; Barratt, Dean C; Rhode, Kawal S.; King, Andrew P.

    2013-01-01

    In image-guided cardiac interventions, respiratory motion causes misalignments between the pre-procedure roadmap of the heart used for guidance and the intra-procedure position of the heart, reducing the accuracy of the guidance information and leading to potentially dangerous consequences. We propose a novel technique for motion-correcting the pre-procedural information that combines a probabilistic MRI-derived affine motion model with intra-procedure real-time 3D echocardiography (echo) ima...

  19. 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...

  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. 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

  2. Cardiac magnetic resonance imaging for myocardial perfusion and diastolic function-reference control values for women.

    Science.gov (United States)

    Bakir, May; Wei, Janet; Nelson, Michael D; Mehta, Puja K; Haftbaradaran, Afsaneh; Jones, Erika; Gill, Edward; Sharif, Behzad; Slomka, Piotr J; Li, Debiao; Shufelt, Chrisandra L; Minissian, Margo; Berman, Daniel S; Bairey Merz, C Noel; Thomson, Louise E J

    2016-02-01

    Angina, heart failure with preserved ejection fraction (HFpEF) and coronary microvascular dysfunction (CMD) in the absence of obstructive coronary artery disease (CAD) are more common in women and are associated with adverse cardiovascular prognosis. Cardiac magnetic resonance imaging (CMRI) is established for assessment of left ventricular (LV) morphology and systolic function and is increasingly used to assess myocardial perfusion and diastolic function. Indeed, stress CMRI allows measurement of myocardial perfusion reserve index (MPRI) using semi-quantitative techniques, and quantification of LV volumetric filling patterns provides valuable insight into LV diastolic function. The utility of these two techniques remains limited, because reference control values for MPRI and LV diastolic function in asymptomatic middle-aged, women have not previously been established. To address this limitation, we recruited twenty women, without clinical cardiovascular disease or cardiovascular risk factors, with normal maximal Bruce protocol exercise treadmill testing. Subjects underwent CMRI (1.5 tesla) using a standardized protocol of adenosine stress and rest perfusion and LV cinematic imaging. Commercially available with automated CMRI segmentation was used for calculation of MPRI, LV filling profiles, and ejection fraction. Mean age was 54±9 years and mean body mass index was 25±4 kg/m(3). The exercise treadmill testing results demonstrated a normotensive group with normal functional capacity and hemodynamic response. We report reference control values for semi-quantitative MPRI as well as measures of LV systolic and diastolic function including ejection fraction, stroke volume, peak filling rate (PFR), PFR adjusted for end-diastolic volume (EDV) and stroke volume, time to PFR, and EDV index. The data herein provide reference values for MPRI and diastolic function in a cohort of healthy, middle-aged of women. These reference values may be used for comparison with a

  3. Cardiac magnetic resonance imaging for myocardial perfusion and diastolic function—reference control values for women

    Science.gov (United States)

    Bakir, May; Wei, Janet; Nelson, Michael D.; Mehta, Puja K.; Haftbaradaran, Afsaneh; Jones, Erika; Gill, Edward; Sharif, Behzad; Slomka, Piotr J.; Li, Debiao; Shufelt, Chrisandra L.; Minissian, Margo; Berman, Daniel S.; Bairey Merz, C. Noel

    2016-01-01

    Angina, heart failure with preserved ejection fraction (HFpEF) and coronary microvascular dysfunction (CMD) in the absence of obstructive coronary artery disease (CAD) are more common in women and are associated with adverse cardiovascular prognosis. Cardiac magnetic resonance imaging (CMRI) is established for assessment of left ventricular (LV) morphology and systolic function and is increasingly used to assess myocardial perfusion and diastolic function. Indeed, stress CMRI allows measurement of myocardial perfusion reserve index (MPRI) using semi-quantitative techniques, and quantification of LV volumetric filling patterns provides valuable insight into LV diastolic function. The utility of these two techniques remains limited, because reference control values for MPRI and LV diastolic function in asymptomatic middle-aged, women have not previously been established. To address this limitation, we recruited twenty women, without clinical cardiovascular disease or cardiovascular risk factors, with normal maximal Bruce protocol exercise treadmill testing. Subjects underwent CMRI (1.5 tesla) using a standardized protocol of adenosine stress and rest perfusion and LV cinematic imaging. Commercially available with automated CMRI segmentation was used for calculation of MPRI, LV filling profiles, and ejection fraction. Mean age was 54±9 years and mean body mass index was 25±4 kg/m3. The exercise treadmill testing results demonstrated a normotensive group with normal functional capacity and hemodynamic response. We report reference control values for semi-quantitative MPRI as well as measures of LV systolic and diastolic function including ejection fraction, stroke volume, peak filling rate (PFR), PFR adjusted for end-diastolic volume (EDV) and stroke volume, time to PFR, and EDV index. The data herein provide reference values for MPRI and diastolic function in a cohort of healthy, middle-aged of women. These reference values may be used for comparison with a variety

  4. Cardiac Light-Sheet Fluorescent Microscopy for Multi-Scale and Rapid Imaging of Architecture and Function

    Science.gov (United States)

    Fei, Peng; Lee, Juhyun; Packard, René R. Sevag; Sereti, Konstantina-Ioanna; Xu, Hao; Ma, Jianguo; Ding, Yichen; Kang, Hanul; Chen, Harrison; Sung, Kevin; Kulkarni, Rajan; Ardehali, Reza; Kuo, C.-C. Jay; Xu, Xiaolei; Ho, Chih-Ming; Hsiai, Tzung K.

    2016-03-01

    Light Sheet Fluorescence Microscopy (LSFM) enables multi-dimensional and multi-scale imaging via illuminating specimens with a separate thin sheet of laser. It allows rapid plane illumination for reduced photo-damage and superior axial resolution and contrast. We hereby demonstrate cardiac LSFM (c-LSFM) imaging to assess the functional architecture of zebrafish embryos with a retrospective cardiac synchronization algorithm for four-dimensional reconstruction (3-D space + time). By combining our approach with tissue clearing techniques, we reveal the entire cardiac structures and hypertrabeculation of adult zebrafish hearts in response to doxorubicin treatment. By integrating the resolution enhancement technique with c-LSFM to increase the resolving power under a large field-of-view, we demonstrate the use of low power objective to resolve the entire architecture of large-scale neonatal mouse hearts, revealing the helical orientation of individual myocardial fibers. Therefore, our c-LSFM imaging approach provides multi-scale visualization of architecture and function to drive cardiovascular research with translational implication in congenital heart diseases.

  5. 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

  6. 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

  7. Ionisation as indicator for cosmic ray acceleration

    Science.gov (United States)

    Schuppan, F.; Röken, C.; Fedrau, N.; Becker Tjus, J.

    2014-06-01

    Astrospheres and wind bubbles of massive stars are believed to be sources of cosmic rays with energies E ≲ 1 TeV. These particles are not directly detectable, but their impact on surrounding matter, in particular ionisation of atomic and molecular hydrogen, can lead to observable signatures. A correlation study of both gamma ray emission, induced by proton-proton interactions of cosmic ray protons with kinetic energies Ep ≥ 280 MeV with ambient hydrogen, and ionisation induced by cosmic ray protons of kinetic energies Ep sub)TeV cosmic rays.

  8. Protection of outside workers against ionising radiation

    International Nuclear Information System (INIS)

    This HSE information sheet is aimed at employers of outside workers, managers of contractors, health physics staff, appointed safety representatives, radiation protection advisers (RPA) and radiation protection supervisors (RIPS), employers in control of controlled areas which outside workers may enter, and outside workers themselves. This guidance supplements that in the Approved Code of Practice (ACOP) supporting the Ionising Radiations Regulations 1999 (IRR99) available from HSE Books, ISBN 0 7176 1746 7. IRR99 include provisions for outside workers that were previously required under the Ionising Radiations (Outside Workers) Regulations 1993 (OWR), which were revoked when IRR99 came into effect

  9. 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

  10. 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...

  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. 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.)

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

    International Nuclear Information System (INIS)

    Hospitalization in patients with systolic heart failure is associated with morbidity, mortality, and cost. Myocardial sympathetic innervation, imaged by 123I-meta-iodobenzylguanidine (123I-mIBG), has been associated with cardiac events in a recent multicenter study. The present analysis explored the relationship between 123I-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 123I-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.

    2008-09-01

    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

  16. 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

  17. 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

  18. Postoperative myocardial infarction and cardiac death. Predictive value of dipyridamole-thallium imaging and five clinical scoring systems based on multifactorial analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lette, J.; Waters, D.; Lassonde, J.; Dube, S.; Heyen, F.; Picard, M.; Morin, M. (Maisonneuve-Rosemont Hospital, Montreal (Canada))

    1990-01-01

    Sixty-six patients unable to complete a standard preoperative exercise test because of physical limitations were studied to determine the predictive value of individual clinical parameters, of clinical scoring systems based on multifactorial analysis, and of dipyridamole-thallium imaging before major general and vascular surgery. Study endpoints were limited to postoperative myocardial infarction or cardiac death before hospital discharge. There were nine postoperative cardiac events (seven deaths and two nonfatal infarctions). There was no statistical correlation between cardiac events and preoperative clinical descriptors, including individual clinical parameters, the Dripps-American Surgical Association score, the Goldman Cardiac Risk Index score, the Detsky Modified Cardiac Risk Index score, Eagle's clinical markers of low surgical risk, and the probability of postoperative events as determined by Cooperman's equation. There were no cardiac events in 30 patients with normal dipyridamole-thallium scans or in nine patients with fixed myocardial perfusion defects. Of 21 patients with reversible perfusion defects who underwent surgery, nine had a postoperative cardiac event (sensitivity, 100%; specificity, 43%). In the six other patients with reversible defects, preoperative angiography showed severe coronary disease or cardiomyopathy. Thus in patients unable to complete a standard exercise stress test, postoperative outcome cannot be predicted clinically before major general and vascular surgery, whereas dipyridamole-thallium imaging successfully identified all patients who sustained a postoperative cardiac event.

  19. Postoperative myocardial infarction and cardiac death. Predictive value of dipyridamole-thallium imaging and five clinical scoring systems based on multifactorial analysis

    International Nuclear Information System (INIS)

    Sixty-six patients unable to complete a standard preoperative exercise test because of physical limitations were studied to determine the predictive value of individual clinical parameters, of clinical scoring systems based on multifactorial analysis, and of dipyridamole-thallium imaging before major general and vascular surgery. Study endpoints were limited to postoperative myocardial infarction or cardiac death before hospital discharge. There were nine postoperative cardiac events (seven deaths and two nonfatal infarctions). There was no statistical correlation between cardiac events and preoperative clinical descriptors, including individual clinical parameters, the Dripps-American Surgical Association score, the Goldman Cardiac Risk Index score, the Detsky Modified Cardiac Risk Index score, Eagle's clinical markers of low surgical risk, and the probability of postoperative events as determined by Cooperman's equation. There were no cardiac events in 30 patients with normal dipyridamole-thallium scans or in nine patients with fixed myocardial perfusion defects. Of 21 patients with reversible perfusion defects who underwent surgery, nine had a postoperative cardiac event (sensitivity, 100%; specificity, 43%). In the six other patients with reversible defects, preoperative angiography showed severe coronary disease or cardiomyopathy. Thus in patients unable to complete a standard exercise stress test, postoperative outcome cannot be predicted clinically before major general and vascular surgery, whereas dipyridamole-thallium imaging successfully identified all patients who sustained a postoperative cardiac event

  20. 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)

  1. A trial to reduce cardiac motion artifacts on HR-CT images of lung with combined use of subsecond scan and a high temporal resolution reconstruction algorithm

    International Nuclear Information System (INIS)

    To reduce cardiac motion artifacts with combined use of subsecond CT scanning and a high temporal resolution algorithm. Scan data were obtained with step-by-step scanning (scan time, 0.8 seconds). Two sets of images were reconstructed, with and without high temporal resolution reconstruction algorithm (HTRR), from the same set of scan data. HTRR, derived from modification of 180-degree linear helical interpolation, reduces full width at half maximum (FWHM) to half of the scan time. Motion artifacts of two sets of images were compared. The use of HTRR seemed to be useful in reducing cardiac motion artifacts owing to the improvement of effective time resolution. However, there were some images without significant reduction of cardiac motion artifacts. Our technique is useful in reducing cardiac motion artifacts without an increase in radiation exposure. (author)

  2. 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

  3. 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...

  4. 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

  5. Automated quantification of cardiac short-axis multi-slice CT images for assessment of left ventricular global function

    Science.gov (United States)

    Danilouchkine, Mikhail G.; Admiraal-Behloul, Faiza; van der Geest, Rob J.; Lelieveldt, Boudewijn P. F.; Reiber, Johan H. C.

    2005-04-01

    This paper describes a method for automatic contour detection in reformatted short-axis (SA) cardiac computed tomography (CT) using a virtual exploring robot. The robot is a tricycle with a steering front wheel. Its motion obeys a set of kinematic equations and is subject to the non-holonomic constraints. The robot is designed to navigate in the binary representation of a cardiac image, consisting of the allowed navigational and obstacle spaces. It is initially positioned inside the allowed navigational space. Avoiding obstacles, the robot autonomously cruises through the navigational space and collects information about the location of the left ventricular (LV) boundaries. Consequently, the obtained information is used to reconstruct the endocardial and epicardial contours. Validation of the method was performed on in-vivo multislice multiphase short-axis cardiac CT images of ten subjects. Results showed good correlation between the quantitative parameters, computed from manual and automatic segmentation: for end-diastolic volume (EDV) r=0.99, for end-systolic volume (ESV) r=0.98, ejection fraction (EF) r=0.83, and LV mass (LVM) r=0.95.

  6. The relationship between cardiac and liver iron evaluated by MR imaging in haematological malignancies and chronic liver disease

    International Nuclear Information System (INIS)

    Although iron overload is clinically significant, only limited data have been published on iron overload in haematological diseases. We investigated cardiac and liver iron accumulation by magnetic resonance imaging (MRI) in a cohort of 87 subjects who did not receive chelation, including 59 haematological patients. M-HIC (MRI-based hepatic iron concentration, normal values <36 μmol/g) is a non-invasive, liver biopsy-calibrated method to analyse iron concentration. This method, calibrated to R2 (transverse relaxation rate), was used as a reference standard (M-HIC(R2)). Transfusions and ferritin were evaluated. Mean M-HIC(R2) and cardiac R* of all patients were 142 μmol/g (95% CI, 114–170) and 36.4 1/s (95% CI, 34.2–38.5), respectively. M-HIC(R2) was higher in haematological patients than in patients with chronic liver disease or normal controls (P<0.001). Clearly elevated cardiac R2* was found in two myelodysplastic syndrome (MDS) patients with severe liver iron overload. A poor correlation was found between liver and cardiac iron (n=82, r=0.322, P=0.003), in contrast to a stronger correlation in MDS (n=7, r=0.905, P=0.005). In addition to transfusions, MDS seemed to be an independent factor in iron accumulation. In conclusion, the risk for cardiac iron overload in haematological diseases other than MDS is very low, despite the frequently found liver iron overload

  7. Sci—Thur PM: Imaging — 01: Position-sensitive noise characteristics in multi-pinhole cardiac SPECT imaging

    International Nuclear Information System (INIS)

    Myocardial perfusion imaging (MPI) with Single Photon Emission Computed Tomography (SPECT) is invaluable in the diagnosis and management of heart disease. It provides essential information on myocardial blood flow and ischemia. Multi-pinhole dedicated cardiac-SPECT cameras offer improved count sensitivity, and spatial and energy resolutions over parallel-hole camera designs however variable sensitivity across the field-of-view (FOV) can lead to position-dependent noise variations. Since MPI evaluates differences in the signal-to-noise ratio, noise variations in the camera could significantly impact the sensitivity of the test for ischemia. We evaluated the noise characteristics of GE Healthcare's Discovery NM530c camera with a goal of optimizing the accuracy of our patient assessment and thereby improving outcomes. Theoretical sensitivity maps of the camera FOV, including attenuation effects, were estimated analytically based on the distance and angle between the spatial position of a given voxel and each pinhole. The standard deviation in counts, σ was inferred for each voxel position from the square root of the sensitivity mapped at that position. Noise was measured experimentally from repeated (N=16) acquisitions of a uniform spherical Tc-99m-water phantom. The mean (μ) and standard deviation (σ) were calculated for each voxel position in the reconstructed FOV. Noise increased ∼2.1× across a 12 cm sphere. A correlation of 0.53 is seen when experimental noise is compared with theory suggesting that ∼53% of the noise is attributed to the combined effects of attenuation and the multi-pinhole geometry. Further investigations are warranted to determine the clinical impact of the position-dependent noise variation

  8. 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.

  9. Thyroid cancer following exposure to ionising radiation

    International Nuclear Information System (INIS)

    Exposure to ionising radiations during childhood increases the risk of thyroid cancer. Similar risk factors have been found after external radiation exposure or internal contamination with radioactive iodine isotopes. In case of contamination with radio-iodines, administration of potassium iodide can prevent thyroid irradiation. (authors)

  10. Nucleation in an ultra low ionisation environment

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker

    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...

  11. 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...

  12. Motion estimation using a multi-scale active mesh able to cope with discontinuities: application to MR cardiac images

    International Nuclear Information System (INIS)

    This work deals with the development of a novel method related to a distorted object movement estimation, able to cope with discontinuities, in a multi-scale approach. A field of displacement vectors primitives is built for each scale level from the initial primitives distribution. This distribution support is a spatial partition of the observation, given by an active mesh in correlation with the image. Its gets out of shape according to image criteria under geometrical constraints. Each mesh must show an uniform and coherent movement. The mesh deformation is obtained by minimization of a non convex energy. The mesh deformation and the associated displacement vectors field contributes alternatively to the iterative high-down relaxation process. The performances of the method are presented on syntheses images and then on real cardiac sequences with the magnetic resonance imaging. (A.L.B.)

  13. 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...

  14. 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

  15. 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.)

  16. High resolution MR imaging of the fetal heart with cardiac triggering: a feasibility study in the sheep fetus.

    Science.gov (United States)

    Yamamura, Jin; Schnackenburg, Bernhard; Kooijmann, Hendrik; Frisch, Michael; Hecher, Kurt; Adam, Gerhard; Wedegärtner, Ulrike

    2009-10-01

    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 + or - 0.2 ml (+ or - SD). The average volume at end diastole was 5.2 + or - 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. PMID:19430796

  17. 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.)

  18. 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

  19. 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. PMID:26387054

  20. 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.

  1. Luminescent detectors of ionising radiation

    International Nuclear Information System (INIS)

    At present in slow neutron imaging an active layer of an imaging plate IP contains a mixture of storage phosphors, usually BaFBr:Eu2+ used for imaging of X-rays, and a neutron converter material, usually Gd2O3, LiF. A novel Li-containing luminescent material perspective for a direct neutron conversion and storage is discussed. Irradiation of LiBaF3 crystals results in generation of Frenkel defect pairs and creation of F-type centres responsible for three absorption bands in UV-and visible spectral region. Because photo-stimulation in each of these absorption bands leads to bleaching of induced absorption, the F-type colour centres are convenient for storage of radiation dose. Photo-stimulated decay of F-centres causes recombination luminescence of impurity centres. Thermoactivated decay of F-type centres is governed by ionic process. The thermal stability of F-centres at RT and consequent material storage characteristics can be improved by doping of the LiBaF3 with heterovalent oxygen impurities. The obtained radiation energy storage, photo- and thermostimulated read-out characteristics justify that LiBaF3 is a suitable active media for imaging of slow neutrons

  2. 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

  3. 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...

  4. 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

    International Nuclear Information System (INIS)

    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) 2 without a definitive diagnosis of coronary artery disease. All patients were assessed by stress-rest MPI with 99mTc-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.)

  5. 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.)

  6. 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.

  7. Physiological changes in human cardiac sympathetic innervation and activity assessed by 123I-metaiodobenzylguanidine (MIBG) imaging

    International Nuclear Information System (INIS)

    Physiologic changes in the human sympathetic nervous system (SNS) may be associated with cardiovascular diseases, so the present study assessed the age and gender differences in global cardiac SNS in normal subjects. The 163 subjects (74 men, 89 women; age range 40-89 years) whose coronary arteriogram was normal, and who had no other cardiac or neurohormonal diseases, and no medication affecting the autonomic nervous system were included. All study subjects underwent metaiodobenzylguanidine imaging. Both initial and delayed heart-to-mediastinum (H/M) ratios had a significant gender difference and showed a progressive decrease with aging. In addition, the initial H/M ratio had a significant positive correlation with the delayed H/M ratio (r=0.89, P<0.0001). Females (50-59 years) demonstrated significantly higher delayed H/M ratio than males of the same age. After the age of 60, the delayed H/M ratio in females progressively decreased with aging, similar to males. As for the washout rate, both genders had a significantly progressive increase with aging. In addition, there was a significant decrease in the delayed H/M ratio in 10 females with surgical menopause compared with 15 age-matched females without surgical menopause. Cardiac SNS appears to be regulated by various physiological factors. (author)

  8. Identification of cardiac malformations in mice lacking Ptdsr using a novel high-throughput magnetic resonance imaging technique

    Directory of Open Access Journals (Sweden)

    Clarke Kieran

    2004-12-01

    Full Text Available Abstract Background Congenital heart defects are the leading non-infectious cause of death in children. Genetic studies in the mouse have been crucial to uncover new genes and signaling pathways associated with heart development and congenital heart disease. The identification of murine models of congenital cardiac malformations in high-throughput mutagenesis screens and in gene-targeted models is hindered by the opacity of the mouse embryo. Results We developed and optimized a novel method for high-throughput multi-embryo magnetic resonance imaging (MRI. Using this approach we identified cardiac malformations in phosphatidylserine receptor (Ptdsr deficient embryos. These included ventricular septal defects, double-outlet right ventricle, and hypoplasia of the pulmonary artery and thymus. These results indicate that Ptdsr plays a key role in cardiac development. Conclusions Our novel multi-embryo MRI technique enables high-throughput identification of murine models for human congenital cardiopulmonary malformations at high spatial resolution. The technique can be easily adapted for mouse mutagenesis screens and, thus provides an important new tool for identifying new mouse models for human congenital heart diseases.

  9. 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...

  10. 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

  11. 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...

  12. 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

  13. 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)

  14. Ionisation as indicator for cosmic ray acceleration

    CERN Document Server

    Schuppan, Florian; Fedrau, Natalie; Tjus, Julia Becker

    2014-01-01

    Astrospheres and wind bubbles of massive stars are believed to be sources of cosmic rays with energies $E\\lesssim 1\\,$TeV. These particles are not directly detectable, but their impact on surrounding matter, in particular ionisation of atomic and molecular hydrogen, can lead to observable signatures. A correlation study of both gamma ray emission, induced by proton-proton interactions of cosmic ray protons with kinetic energies $E_\\mathrm{p}\\ge 280\\,$MeV with ambient hydrogen, and ionisation induced by cosmic ray protons of kinetic energies $E_\\mathrm{p}< 280\\,$MeV can be performed in order to study potential sources of (sub)TeV cosmic rays.

  15. 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.)

  16. Risk from deterministic effects of ionising radiation

    International Nuclear Information System (INIS)

    This publication provides a review of information for assessing deterministic effects on human health likely to arise from serious overexposure to ionising radiation. It updates information in previous Board publications NRPB-R226 and NRPB-M246. It constitutes a parallel document to Documents of the NRPB, 4, No. 4 (1993), which deals with stochastic effects. These two documents, together with Documents of the NRPB, 6, No. 1 (1995), which deals specifically with stochastic risk at low dose rates, give the current Board view on all health consequences of exposure to ionising radiation. Little new primary information on deterministic effects has become available in recent years. However, advances in techniques for data analysis have been made and are incorporated in the present report. These are presented in a form suitable for use in modelling the consequences to populations of serious radiological incidents. (author)

  17. 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.)

  18. 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.

  19. 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...

  20. 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...

  1. 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.)

  2. Quantitative assessment of left ventricular function with dual-source CT in comparison to cardiac magnetic resonance imaging: initial findings

    International Nuclear Information System (INIS)

    Cardiac magnetic resonance imaging and echocardiography are currently regarded as standard modalities for the quantification of left ventricular volumes and ejection fraction. With the recent introduction of dual-source computedtomography (DSCT), the increased temporal resolution of 83 ms should also improve the assessment of cardiac function in CT. The aim of this study was to evaluate the accuracy of DSCT in the assessment of left ventricular functional parameters with cardiac magnetic resonance imaging (MRI) as standard of reference. Fifteen patients (two female, 13 male; mean age 50.8 ± 19.2 years) underwent CT and MRI examinations on a DSCT (Somatom Definition; Siemens Medical Solutions, Forchheim, Germany) and a 3.0-Tesla MR scanner (Magnetom Trio; Siemens Medical Solutions), respectively. Multiphase axial CT images were analysed with a semiautomatic region growing algorithms (Syngo Circulation; Siemens Medical Solutions) by two independent blinded observers. In MRI, dynamic cine loops of short axis slices were evaluated with semiautomatic contour detection software (ARGUS; Siemens Medical Solutions) independently by two readers. End-systolic volume (ESV), end-diastolic volume (EDV), ejection fraction (EF) and stroke volume (SV) were determined for both modalities, and correlation coefficient, systematic error, limits of agreement and inter-observer variability were assessed. In DSCT, EDV and ESV were 135.8 ± 41.9 ml and 54.9 ± 29.6 ml, respectively, compared with 132.1 ± 40.8 ml EDV and 57.6 ± 27.3 ml ESV in MRI. Thus, EDV was overestimated by 3.7 ml (limits of agreement -46.1/+53.6), while ESV was underestimated by 2.6 ml (-36.6/+31.4). Mean EF was 61.6 ± 12.4% in DSCT and 57.9 ± 9.0% in MRI, resulting in an overestimation of EF by 3.8% with limits of agreement at -14.7 and +22.2%. Rank correlation rho values were 0.81 for EDV (P = 0.0024), 0.79 for ESV (P 0.0031) and 0.64 for EF (P = 0.0168). The kappa value of inter-observer variability were

  3. Validation of an evaluation routine for left ventricular volumes, ejection fraction and wall motion from gated cardiac FDG PET: a comparison with cardiac magnetic resonance imaging

    International Nuclear Information System (INIS)

    The aim of this study was to validate the estimation of left ventricular end-diastolic and end-systolic volumes (EDV, ESV) and ejection fraction (LVEF) as well as wall motion analysis from gated fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) in patients with severe coronary artery disease (CAD) using software originally designed for gated single-photon emission tomography (SPET). Thirty patients with severe CAD referred for myocardial viability diagnostics were investigated using a standard FDG PET protocol enhanced with gated acquisition (8 gates per cardiac cycle). EDV, ESV and LVEF were calculated using standard software designed for gated SPET (QGS). Wall motion was analysed using a visual four-point wall motion score on a 17-segment model. As a reference, all patients were also examined within a median of 3 days with cardiovascular cine magnetic resonance imaging (cMRI) (20 gates per cardiac cycle). Furthermore, all gated FDG PET data sets were reoriented in a second run with deliberately misaligned axes to test the quantification procedure for robustness. Correlation between the results of gated FDG PET and cMRI was very high for EDV and ESV (R=0.96 and R=0.97) and for LVEF (R=0.95). With gated FDG PET, there was a non-significant tendency to underestimate EDV (174±61 ml vs 179±59 ml, P=0.21) and to overestimate ESV (124±58 ml vs 122±60 ml, P=0.65), resulting in underestimated LVEF values (31.5%±9.4% vs 34.2%±12.4%, P<0.003). The results of reorientations 1 and 2 showed very high correlations (for all R≥0.99). Segmental wall motion analysis revealed good agreement between gated FDG PET data and cMRI (kappa =0.62±0.03). In conclusion, despite small systematic differences which contributed mainly to the lower temporal resolution of gated FDG PET, agreement between gated FDG PET and cMRI was good across a wide range of volumes and LVEF values as well as for wall motion analysis. Therefore, gated FDG PET provides clinically

  4. The pulsatility volume index: an indicator of cerebrovascular compliance based on fast magnetic resonance imaging of cardiac and respiratory pulsatility.

    Science.gov (United States)

    Bianciardi, Marta; Toschi, Nicola; Polimeni, Jonathan R; Evans, Karleyton C; Bhat, Himanshu; Keil, Boris; Rosen, Bruce R; Boas, David A; Wald, Lawrence L

    2016-05-13

    The influence of cardiac activity on the viscoelastic properties of intracranial tissue is one of the mechanisms through which brain-heart interactions take place, and is implicated in cerebrovascular disease. Cerebrovascular disease risk is not fully explained by current risk factors, including arterial compliance. Cerebrovascular compliance is currently estimated indirectly through Doppler sonography and magnetic resonance imaging (MRI) measures of blood velocity changes. In order to meet the need for novel cerebrovascular disease risk factors, we aimed to design and validate an MRI indicator of cerebrovascular compliance based on direct endogenous measures of blood volume changes. We implemented a fast non-gated two-dimensional MRI pulse sequence based on echo-planar imaging (EPI) with ultra-short repetition time (approx. 30-50 ms), which stepped through slices every approximately 20 s. We constrained the solution of the Bloch equations for spins moving faster than a critical speed to produce an endogenous contrast primarily dependent on spin volume changes, and an approximately sixfold signal gain compared with Ernst angle acquisitions achieved by the use of a 90° flip angle. Using cardiac and respiratory peaks detected on physiological recordings, average cardiac and respiratory MRI pulse waveforms in several brain compartments were obtained at 7 Tesla, and used to derive a compliance indicator, the pulsatility volume index (pVI). The pVI, evaluated in larger cerebral arteries, displayed significant variation within and across vessels. Multi-echo EPI showed the presence of significant pulsatility effects in both S0 and [Formula: see text] signals, compatible with blood volume changes. Lastly, the pVI dynamically varied during breath-holding compared with normal breathing, as expected for a compliance indicator. In summary, we characterized and performed an initial validation of a novel MRI indicator of cerebrovascular compliance, which might prove useful

  5. Motion artifacts in cardiac CT. The Novacor left ventricular assist device and its implications for clinical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Knollman, F.D. [Strahlenklinik, Charite, Campus Virchow-Klinikum, Medizinische Fakultaet der Humboldt-Univ. zu Berlin (Germany); Klinik fuer Herz-, Thorax- und Gefaesschirurgie, Deutsches Herzzentrum Berlin (Germany); Halfmann, R. [Baxter Deutschland GmbH, Unterschleissheim (Germany); Regn, J. [Siemens AG Bereich Medizin, Erlangen (Germany); Loebe, M.; Ewert, R.; Hetzer, R. [Klinik fuer Herz-, Thorax- und Gefaesschirurgie, Deutsches Herzzentrum Berlin (Germany); Felix, R. [Strahlenklinik, Charite, Campus Virchow-Klinikum, Medizinische Fakultaet der Humboldt-Univ. zu Berlin (Germany)

    1999-11-01

    Purpose: Cardiovascular applications of CT are primarily limited by temporal resolution of the scanner. Recent development in scanner technology has greatly increased temporal resolution. We here describe a standardized method of assessing temporal properties of various CT techniques. Material and Methods: The Novacor left ventricular assist device was mounted in a water-filled circulation phantom and scanned at different pump rates with a spiral CT unit and an electron beam unit. We also evaluated the use of ECG-triggered subsecond scanning on a spiral CT unit. Results: Using the fastest conventional scanning protocol, severe motion artifacts occurred. These artifacts could not be reproduced from image to image, even if the pump rate was adjusted to scan rate (1/s). Electron beam tomography (EBT) reproducibly yielded few artifacts at 100 ms and practically no artifacts at 50 ms scanning time. Even without ECG-triggering, pump motion could be reproduced as a cine-cycle. With the ECG-triggered partial scanning CT technique, limited motion artifacts could be reproduced during diastole at a heart rate of 70-80 beats/min. Conclusion: The Novacor ventricular assist device may serve as a benchmark test in the evaluation of new scanning techniques for cardiovascular CT. While EBT presently remains the only CT technique to freeze cardiac motion throughout its cycle, ECG-triggered subsecond scans may, under certain conditions, capture cardiac anatomy in diastole. (orig.)

  6. 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.

  7. High-precision γ -ray spectroscopy of the cardiac PET imaging isotope 82Rb and its impact on dosimetry

    Science.gov (United States)

    Nino, M. N.; McCutchan, E. A.; Smith, S. V.; Lister, C. J.; Greene, J. P.; Carpenter, M. P.; Muench, L.; Sonzogni, A. A.; Zhu, S.

    2016-02-01

    82Rb is a positron-emitting isotope used in cardiac positron emission tomography (PET) imaging which has been reported to deliver a significantly lower effective radiation dose than analogous imaging isotopes like 201Tl and 99 mTc sestamibi. High-quality β -decay data are essential to accurately appraise the total dose received by the patients. A source of 82Sr was produced at the Brookhaven Linac Isotope Producer (BLIP), transported to Argonne National Laboratory, and studied with the Gammasphere facility. Significant revisions have been made to the level scheme of 82Kr including 12 new levels, 50 new γ -ray transitions, and the determination of many new spin assignments through angular correlations. These new high-quality data allow a precise reappraisal of the β -decay strength function and thus the consequent dose received by patients.

  8. 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.)

  9. 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.

  10. 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...

  11. Imaging of the atria and cardiac conduction system – from experiment to computer modelling

    OpenAIRE

    Hao, Guoliang

    2013-01-01

    Background: Experimental mapping and computer modelling provide important platforms to study the fundamental mechanisms underlying normal and abnormal activation of the heart. However, accurate computer modelling requires detailed anatomical models and needs support and validation from experimental data. Aims: 1) Construction of detailed anatomical heart models with the cardiac conduction system (CCS). 2) Mapping of the electrical activation sequence in rabbit atria to support and validate co...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. Model-based analysis of ecg-gated cardiac pet images to assess left ventricular volume and contractile function

    International Nuclear Information System (INIS)

    The goal of this thesis was to study the feasibility of automated tool support for a model-based approach. In the course of this study, PET image analysis tools were developed and validated that permit the generation of endocardial and epicardial borders on ECG-gated PET images and the calculation of diastolic and systolic cardiac volumes, LV ejection fraction and regional myocardial wall thickness. Image analysis of gated PET images was applied to a set of short axis images covering the left ventricle. On each image, 60 radial profiles were generated from the center of the LV through the ventricular wall into the extracardiac background. Nonlinear regression analysis was applied to fit a model of the expected radial tracer distribution to generated radial profiles. The expected tracer distribution was obtained by convolving a model of an assumed ideal radial tracer distribution with the known blurring function of the PET camera. For each radial profile, LV diameter and wall thickness were obtained as estimated parameters from model fitting and were combined to generate endocardial and epicardial contours. Endocardial areas were then determined for all short axis images and LV volume was calculated. The accuracy of these PET estimates of LV-volume and ejection fraction was evaluated using measurements obtained in gated MR images and echocardiography. In an experimental study, 16 patients (15M, 1F age: 61±11 yrs) underwent gated cardiac PET and MR imaging. LV-volumes (ml) by PET and MRI were 96 ± 63 and 97 ± 93 at endsystole (ESV), and 168 ± 68 and 174 ± 99 at enddiastole (EDV). Global ejection fraction (EF) was 47 ± 15 % and 49 ± 19 % by PET and MRI. A significant correlation was observed between PET and MRI for calculation of ESV (r = 0.96, SEE = 18.7, p < 0.0001), EDV (r = 0.97, SEE 17.7, p < 0.0001) and EF (r = 0.89, SEE = 7.4, p < 0.0001). For 7 patients (6M, 1F age: 59 ± 13 yrs), LV-volumes by PET and echocardiography were 142 ± 68 and 105 ± 64 for

  17. Molecular Basis of Cardiac Myxomas

    Directory of Open Access Journals (Sweden)

    Pooja Singhal

    2014-01-01

    Full Text Available Cardiac tumors are rare, and of these, primary cardiac tumors are even rarer. Metastatic cardiac tumors are about 100 times more common than the primary tumors. About 90% of primary cardiac tumors are benign, and of these the most common are cardiac myxomas. Approximately 12% of primary cardiac tumors are completely asymptomatic while others present with one or more signs and symptoms of the classical triad of hemodynamic changes due to intracardiac obstruction, embolism and nonspecific constitutional symptoms. Echocardiography is highly sensitive and specific in detecting cardiac tumors. Other helpful investigations are chest X-rays, magnetic resonance imaging and computerized tomography scan. Surgical excision is the treatment of choice for primary cardiac tumors and is usually associated with a good prognosis. This review article will focus on the general features of benign cardiac tumors with an emphasis on cardiac myxomas and their molecular basis.

  18. Thyroid cancer following exposure to ionising radiation; Cancer de la thyroide apres exposition aux rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Schlumberger, M. [Institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France); Universite Paris Sud 11, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France); Chevillard, S.; Ory, K. [Commissariat a l' energie atomique et aux energies alternatives, route du Panorama, 92265 Fontenay-aux-Roses cedex (France); Dupuy, C. [Institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France); Universite Paris Sud 11, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France); UMR 8200 CNRS, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France); Le Guen, B. [Division production nucleaire, direction production ingenierie, EDF, Tete-Pleyel, 1, place Pleyel, 93282 Saint-Denis cedex (France); De Vathaire, F. [Institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France); Universite Paris Sud 11, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France); equipe d' epidemiologie des radiations, centre d' etudes en sante des populations, UMR 1018 Inserm, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France)

    2011-08-15

    Exposure to ionising radiations during childhood increases the risk of thyroid cancer. Similar risk factors have been found after external radiation exposure or internal contamination with radioactive iodine isotopes. In case of contamination with radio-iodines, administration of potassium iodide can prevent thyroid irradiation. (authors)

  19. 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

  20. Context sensitive cardiac x-ray imaging: a machine vision approach to x-ray dose control

    Science.gov (United States)

    Kengyelics, Stephen M.; Gislason-Lee, Amber J.; Keeble, Claire; Magee, Derek R.; Davies, Andrew G.

    2015-09-01

    Modern cardiac x-ray imaging systems regulate their radiation output based on the thickness of the patient to maintain an acceptable signal at the input of the x-ray detector. This approach does not account for the context of the examination or the content of the image displayed. We have developed a machine vision algorithm that detects iodine-filled blood vessels and fits an idealized vessel model with the key parameters of contrast, diameter, and linear attenuation coefficient. The spatio-temporal distribution of the linear attenuation coefficient samples, when appropriately arranged, can be described by a simple linear relationship, despite the complexity of scene information. The algorithm was tested on static anthropomorphic chest phantom images under different radiographic factors and 60 dynamic clinical image sequences. It was found to be robust and sensitive to changes in vessel contrast resulting from variations in system parameters. The machine vision algorithm has the potential of extracting real-time context sensitive information that may be used for augmenting existing dose control strategies.

  1. Evaluating the normal individual cardiac function in different imaging phases post exercise and rest by gated SPECT myocardial perfusion

    International Nuclear Information System (INIS)

    Full text: Objectives: To evaluate the normal individual cardiac function in the different imaging phases post-exercise and rest by GSPECT. Methods: 46 normal individuals underwent exercise/rest GSPECT using 99mTc-MIBI by 2- day program. Sequential imaging was started 15, 35 and 120 minutes after exercise and rest imaging was performed the following day. The left ventricular EF and EDV, ESV values were calculated with the Cedars-Sinai program. Results: The EF values of post- exercise at 15, 35, and 120m was 64.48±7.43%, 65.02±7.66%, and 60.98±7.28% respectively, and the rest EF value was 61.46±7.23%. The post exercise EF at 15m and 35m was higher than EF at post- exercise 120m and rest, but there is a significant difference only between post exercise 35m and rest (P< 0.05), and all post exercise EF did not increase at least 5% from EF at-rest. The EDV and ESV values did not have statistically significant differences at 15, 35,120m post-exercise and rest. The heart rate at 15,35m post- exercise was higher significantly than at rest. Conclusions: The different imaging phases after exercise with 99mTc-MIBI GSPECT affects LVEF in normal individuals, the 35m post- exercise EF is highest. (author)

  2. 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.)

  3. Assessment of sub-clinical acute cellular rejection after heart transplantation: comparison of cardiac magnetic resonance imaging and endomyocardial biopsy

    International Nuclear Information System (INIS)

    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.)

  4. The use of 111In-labelled lymphocyte imaging to evaluate graft rejection following cardiac transplantation in dogs

    International Nuclear Information System (INIS)

    Lymphocytes separated from venous blood from six dogs who had heterotopic cardiac transplants have been labeled using 111In-oxine. Labeled lymphocytes were reinjected into the dogs and imaging for the heart carried out over the successive 3 or 4 days. For comparison serial ECGs and punch biopsies of the heart was clearly visible in three of the six dogs, faintly visible in two and not seen in one. 630 μCi111In was used in the dog where no uptake was seen and subsequent studies showed this amount of the radiopharmaceutical was toxic to lymphocytes. In the remaining five dogs the mean ratio of uptake of 111In in donor to recipient heart was 14:1 (range 6.5:1-21:1). The lack of substantial uptake in the transplanted heart of two dogs is attributed to a delay in rejection relative to the time the labled lymphocytes were injected. The results suggest that 111In-labeled lymphocytes have potential as a noninvasive test for detecting rejection of cardiac transplants. (orig.)

  5. 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.)

  6. Advanced cardiac chemical exchange saturation transfer (cardioCEST) MRI for in vivo cell tracking and metabolic imaging

    Science.gov (United States)

    Pumphrey, Ashley; Yang, Zhengshi; Ye, Shaojing; Powell, David K.; Thalman, Scott; Watt, David S.; Abdel-Latif, Ahmed; Unrine, Jason; Thompson, Katherine; Fornwalt, Brandon; Ferrauto, Giuseppe; Vandsburger, Moriel

    2016-01-01

    An improved pre-clinical cardiac chemical exchange saturation transfer (CEST) pulse sequence (cardioCEST) was used to selectively visualize paramagnetic CEST (paraCEST)-labeled cells following intramyocardial implantation. In addition, cardioCEST was used to examine the effect of diet-induced obesity upon myocardial creatine CEST contrast. CEST pulse sequences were designed from standard turbo-spin-echo and gradient-echo sequences, and a cardiorespiratory-gated steady-state cine gradient-echo sequence. In vitro validation studies performed in phantoms composed of 20mM Eu-HPDO3A, 20mM Yb-HPDO3A, or saline demonstrated similar CEST contrast by spin-echo and gradient-echo pulse sequences. Skeletal myoblast cells (C2C12) were labeled with either Eu-HPDO3A or saline using a hypotonic swelling procedure and implanted into the myocardium of C57B6/J mice. Inductively coupled plasma mass spectrometry confirmed cellular levels of Eu of 2.1 × 10−3 ng/cell in Eu-HPDO3A-labeled cells and 2.3 × 10−5 ng/cell in saline-labeled cells. In vivo cardioCEST imaging of labeled cells at ±15ppm was performed 24 h after implantation and revealed significantly elevated asymmetric magnetization transfer ratio values in regions of Eu-HPDO3A-labeled cells when compared with surrounding myocardium or saline-labeled cells. We further utilized the cardioCEST pulse sequence to examine changes in myocardial creatine in response to diet-induced obesity by acquiring pairs of cardioCEST images at ±1.8 ppm. While ventricular geometry and function were unchanged between mice fed either a high-fat diet or a corresponding control low-fat diet for 14 weeks, myocardial creatine CEST contrast was significantly reduced in mice fed the high-fat diet. The selective visualization of paraCEST-labeled cells using cardioCEST imaging can enable investigation of cell fate processes in cardioregenerative medicine, or multiplex imaging of cell survival with imaging of cardiac structure and function and

  7. Cardiac cine MRI: Comparison of 1.5 T, non-enhanced 3.0 T and blood pool enhanced 3.0 T imaging

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    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.

  8. Cardiac cine MRI: Comparison of 1.5 T, non-enhanced 3.0 T and blood pool enhanced 3.0 T imaging

    International Nuclear Information System (INIS)

    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

  9. Cardiac magnetic resonance imaging parameters as surrogate endpoints in clinical trials of acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Gutberlet Matthias

    2011-09-01

    Full Text Available 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 competitive modalities. Randomized controlled trials of acute myocardial infarction which have used CMR parameters as a primary endpoint are presented.

  10. 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.

  11. Does the use of additional X-ray beam filtration during cine acquisition reduce clinical image quality and effective dose in cardiac interventional imaging?

    International Nuclear Information System (INIS)

    The impact of spectral filtration in digital ('cine') acquisition was investigated using a flat panel cardiac interventional X-ray imaging system. A 0.1-mm copper (Cu) and 1.0-mm aluminium (Al) filter added to the standard acquisition mode created the filtered mode for comparison. Image sequences of 35 patients were acquired, a double-blind subjective image quality assessment was completed and dose-area product (DAP) rates were calculated. Entrance surface dose (ESD) and effective dose (E) rates were determined for 20- and 30-cm phantoms. Phantom ESD fell by 28 and 41 % and E by 1 and 0.7 %, for the 20- and 30-cm phantoms, respectively, when using the filtration. Patient DAP rates fell by 43 % with no statistically significant difference in clinical image quality. Adding 0.1-mm Cu and 1.0-mm Al filtration in acquisition substantially reduces patient ESD and DAP, with no significant change in E or clinical image quality. (authors)

  12. Cardiac Calcification

    Directory of Open Access Journals (Sweden)

    Morteza Joorabian

    2011-05-01

    Full Text Available There is a spectrum of different types of cardiac"ncalcifications with the importance and significance"nof each type of cardiac calcification, especially"ncoronary artery calcification. Radiologic detection of"ncalcifications within the heart is quite common. The"namount of coronary artery calcification correlates"nwith the severity of coronary artery disease (CAD."nCalcification of the aortic or mitral valve may indicate"nhemodynamically significant valvular stenosis."nMyocardial calcification is a sign of prior infarction,"nwhile pericardial calcification is strongly associated"nwith constrictive pericarditis. A spectrum of different"ntypes of cardiac calcifications (linear, annular,"ncurvilinear,... could be seen in chest radiography and"nother imaging modalities. So a carful inspection for"ndetection and reorganization of these calcifications"nshould be necessary. Numerous modalities exist for"nidentifying coronary calcification, including plain"nradiography, fluoroscopy, intravascular ultrasound,"nMRI, echocardiography, and conventional, helical and"nelectron-beam CT (EBCT. Coronary calcifications"ndetected on EBCT or helical CT can be quantifie,"nand a total calcification score (Cardiac Calcification"nScoring may be calculated. In an asymptomatic"npopulation and/or patients with concomitant risk"nfactors like diabetes mellitus, determination of the"npresence of coronary calcifications identifies the"npatients at risk for future myocardial infarction and"ncoronary artery disease. In patients without coronary"ncalcifications, future cardiovascular events could"nbe excluded. Therefore, detecting and recognizing"ncalcification related to the heart on chest radiography"nand other imaging modalities such as fluoroscopy, CT"nand echocardiography may have important clinical"nimplications.

  13. Cardiac event risk in Japanese subjects estimated using gated myocardial perfusion imaging, in conjunction with diabetes mellitus and chronic kidney disease

    International Nuclear Information System (INIS)

    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. Multivariate logistic regression was performed based on a multicenter prognostic database (Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated Single-photon emission computed tomography [J-ACCESS investigation]) using MPI (n=2,395). The risk of major cardiac events (cardiac death, non-fatal myocardial infarction and heart failure requiring hospitalization) was estimated using age, ejection fraction (EF), estimated glomerular filtration rate (eGFR) and presence of diabetes mellitus (DM). Age-matched standard eGFR was determined in 77 subjects. Major cardiac event risk was calculated using the equation: risk (%/3 years) =1/ (1+ Exp (- (-4.699-0.0151 x eGFR +0.7998 x DM +0.0582 x age +0.697 x summed stress score (SSS) -0.0359 x EF)) x 100, where SSS refers to summed stress scores. Risk was determined without eGFR (the initial version) and using the present formula with eGFR (revised version), with consistent results. DM and chronic kidney disease were major determinants of cardiac events. Cardiac event risk was estimated using MPI defect score and left ventricular EF in conjunction with eGFR and the presence of DM. The risk table might be used for risk evaluation in Japanese patients undergoing MPI. (author)

  14. Multimodality evaluation of ventricular function: comparison of cardiac magnetic resonance imaging, echocardiography, and planar and SPECT blood pool imaging

    Science.gov (United States)

    Feiglin, David H.; Krol, Andrzej; Tillapaugh-Fay, Gwen M.; Szeverenyi, Nikolaus M.; Thomas, Frank D.

    2001-05-01

    Fifteen patients underwent resting echocardiography (EC), ECG gated cardiac MR ventriculography (MRV) and blood pool planar and SPECT ventriculography (SPV) sequentially on the same day. In addition, 36 patients had sequential ECG gated blood pool and SPV and 20 normal volunteers, age > 18 years, had sequential ECG gated cardiac MRI performed on both Siemens closed, 1.5T, and open, 0.2T, magnets. Echocardiography was performed using a HP 5500 system equipped with an S4 transducer in 2D mode. MRV at 0.2T and 1.5T used a circular polarized body coil. Nuclear Medicine studies used 25 mCi Tc- 99m labeled red blood cells. Gated planar and SPV were acquired on a dual head Siemens E-Cam system. We have found that MRV affords the most accurate measurement of ventricular function. SPV and MRV provide similar estimations of left ventricular function (LVEF). Further, SPV consistently provides higher LVEF, as compared to the planar data simultaneously acquired. Observed significant differences in intermodality measurements indicate that follow up studies in patients, especially in patients whose management is critically dependent on functional measurement changes, should be monitored by one modality only.

  15. 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

  16. 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...

  17. 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.

  18. Inter- and intra-rater reproducibility of semiautomatic determination of volume parameters in cardiac magnetic resonance imaging

    International Nuclear Information System (INIS)

    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. Automatic registration and alignment on a template of cardiac stress and rest reoriented SPECT images.

    Science.gov (United States)

    Declerck, J; Feldmar, J; Goris, M L; Betting, F

    1997-12-01

    Single photon emission computed tomography (SPECT) imaging with 201Tl or 99mTc agent is used to assess the location or the extent of myocardial infarction or ischemia. A method is proposed to decrease the effect of operator variability in the visual or quantitative interpretation of scintigraphic myocardial perfusion studies. To effect this, the patient's myocardial images (target cases) are registered automatically over a template image, utilizing a nonrigid transformation. The intermediate steps are: 1) Extraction of feature points in both stress and rest three-dimensional (3-D) images. The images are resampled in a polar geometry to detect edge points, which in turn are filtered by the use of a priori constraints. The remaining feature points are assumed to be points on the edges of the left ventricular myocardium. 2) Registration of stress and rest images with a global affine transformation. The matching method is an adaptation of the iterative closest point algorithm. 3) Registration and morphological matching of both stress and rest images on a template using a nonrigid local spline transformation following a global affine transformation. 4) Resampling of both stress and rest images in the geometry of the template. Optimization of the method was performed on a database of 40 pairs of stress and rest images selected to obtain a wide variation of images and abnormalities. Further testing was performed on 250 cases selected from the same database on the basis of the availability of angiographic results and patient stratification. PMID:9533574

  20. Acute oedema in the evaluation of microvascular reperfusion and myocardial salvage in reperfused myocardial infarction with cardiac magnetic resonance imaging

    International Nuclear Information System (INIS)

    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 T2-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 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.

  1. Cardiac magnetic resonance imaging in patients with chest pain, high troponin levels and absence of coronary artery obstruction

    International Nuclear Information System (INIS)

    The prevalence of myocardial infarction with angiographically normal coronary arteries is approximately 7-10%. The etiological diagnosis is sometimes difficult and is important in terms of clinical practice and prognosis. The goal of our study was to show a series of consecutive patients with an initial diagnosis of acute coronary syndrome with high troponin levels and absence of coronary artery obstruction in which cardiac magnetic resonance imaging (CMRI) gave a description of the myocardial lesion, orientating towards the etiological diagnosis. From January 2005 to December 2009, 720 consecutive patients with an initial diagnosis of acute coronary syndrome and elevated troponins were included; 64 of these patients did not present angiographically significant coronary artery stenosis. Within 72 ± 24 h after coronary angiography, these patients underwent CMRI using b-SSFP sequences for cine imaging in short-axis, 2-, 3- and 4- chamber views for the evaluation of segmental wall motion, with T2-weighted and delayed enhancement (DE) images of the myocardium with an 'inversion-recovery' sequence. The following diagnoses were made: myocarditis (39 patients); myocardial infarction (12 patients); Tako-Tsubo syndrome (8 patients); apical hypertrophic cardiomyopathy (2 patients); 3 patients remained without diagnosis. These findings demonstrate the usefulness of CMRI in the clinical scenario of patients with chest pain, inconclusive ECG findings and high troponin levels with angiographically normal coronary arteries. The presence and distribution pattern of DE make it possible to define the etiological diagnosis and interpret the physiopathological process. (authors)

  2. 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.

  3. 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.)

  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. Nuclear medicine. What can we know about cardiac functions using SPECT images

    International Nuclear Information System (INIS)

    Recent development of medical treatments of contagious diseases and rapid westernization of our lives, have made cardiovascular and cerebrovascular diseases the second and third leading causes of death in Japan. These are called the diseases associated with adult lifestyle, or diseases of adult people. The cardiovascular diseases are apprehended to be prevailing in 2030' not only in our country but also in the now developing countries. Thus it is urgently expected to develop a method to diagnose the disease. We developed a method (Quantification of segmental function by solving Poisson equation, QSFP) to calculate shortening in distances between two points on the cardiac wall. This method enables us to compute synchronicity of contraction and regional works. A brief explanation of the method was presented and theoretical and technical problems of QSFP were discussed. (author)

  6. Cardiac Metastasis from Invasive Thymoma Via the Superior Vena Cava: Cardiac MRI Findings

    International Nuclear Information System (INIS)

    Cardiac tumors are rare, and metastatic deposits are more common than primary cardiac tumors. We present cardiac magnetic resonance imaging (MRI) findings of a 50-year-old woman with invasive thymoma. Cardiac MRI revealed a heterogeneous, lobulated anterior mediastinal mass invading the superior vena cava and extending to the right atrium. In cine images there was no invasion to the right atrial wall.

  7. Sudden Cardiac Arrest

    Science.gov (United States)

    ... scan, or MUGA, which shows how well your heart is pumping blood. Magnetic resonance imaging (MRI) which gives doctors detailed pictures of your heart. How is SCA treated? Sudden cardiac arrest should ...

  8. A comparison of Fourier phase/amplitude and factorial imaging in first-pass cardiac studies

    International Nuclear Information System (INIS)

    Factorial phase/amplitude imaging is shown to be a useful alternative to Fourier phase/amplitude imaging in the analysis of representative left ventricular cycles. It has the advantage of removing anomalies among normal patients due to asymmetric left ventricular curves while retaining and possibly enhancing abnormalities. (WU)

  9. Prognostic value of iodine-123-metaiodobenzylguanidine imaging and cardiac natriuretic peptide levels in patients with left ventricular dysfunction resulting from cardiomyopathy

    International Nuclear Information System (INIS)

    This study assessed the prognostic value of Iodine-123-metaiodobenzylguanidine (MIBG) imaging and of the plasma level of cardiac natriuretic peptides in patients with left ventricular dysfunction resulting from cardiomyopathy. Predictors of cardiac death or hospitalization related to progressive heart failure were examined in 171 patients with chronic heart failure (96 patients with idiopathic cardiomyopathy and 75 patients with ischemic cardiomyopathy). All patients underwent MIBG imaging at rest and other hemodynamic studies. During a mean (±SD) follow-up period of 27±11 months, 11 patients died from heat failure and 16 required hospitalization. High MIBG washout was an independent predictor of cardiac death (relative risk [RR]=1.158, p0.0001) and high MIBG washout (relative risk [RR]=1.094, p<0.0001) were predictors of progressive heart failure (ie, combined cardiac death and hospitalization). Accelerated myocardial adrenergic nerve activity as assessed by MIBG imaging and the plasma levels of BNP are powerful predictors of the patient's prognosis. (author)

  10. Creation of an ensemble of simulated cardiac cases and a human observer study: tools for the development of numerical observers for SPECT myocardial perfusion imaging

    Science.gov (United States)

    O'Connor, J. Michael; Pretorius, P. Hendrik; Gifford, Howard C.; Licho, Robert; Joffe, Samuel; McGuiness, Matthew; Mehurg, Shannon; Zacharias, Michael; Brankov, Jovan G.

    2012-02-01

    Our previous Single Photon Emission Computed Tomography (SPECT) myocardial perfusion imaging (MPI) research explored the utility of numerical observers. We recently created two hundred and eighty simulated SPECT cardiac cases using Dynamic MCAT (DMCAT) and SIMIND Monte Carlo tools. All simulated cases were then processed with two reconstruction methods: iterative ordered subset expectation maximization (OSEM) and filtered back-projection (FBP). Observer study sets were assembled for both OSEM and FBP methods. Five physicians performed an observer study on one hundred and seventy-nine images from the simulated cases. The observer task was to indicate detection of any myocardial perfusion defect using the American Society of Nuclear Cardiology (ASNC) 17-segment cardiac model and the ASNC five-scale rating guidelines. Human observer Receiver Operating Characteristic (ROC) studies established the guidelines for the subsequent evaluation of numerical model observer (NO) performance. Several NOs were formulated and their performance was compared with the human observer performance. One type of NO was based on evaluation of a cardiac polar map that had been pre-processed using a gradient-magnitude watershed segmentation algorithm. The second type of NO was also based on analysis of a cardiac polar map but with use of a priori calculated average image derived from an ensemble of normal cases.

  11. 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

  12. Immunosuppression by non-ionising and ionising radiation - are there similarities?

    International Nuclear Information System (INIS)

    Solar UV radiation, the ubiqitous environmental non-ionising radiation, initiates its immunomodulating effects almost entirely in the skin. In direct contrast, ionising radiation penetrates much more efficiently, and has a multitude of internal targets throughout the body. As a consequence, the mechanisms underlying UV-induced immunosuppression have been more readily characterised, whereas surprisingly little is known about immunosuppression resulting fro