Gated magnetic resonance imaging of congenital cardiac malformations

International Nuclear Information System (INIS)

Fletcher, B.D.; Jocobstein, M.D.; Nelson, A.D.; Riemenschneider, T.A.; Alfidi, R.J.

1984-01-01

Magnetic resonance (MR) images of a variety of cardiac malformations in 19 patients aged 1 week to 33 years were obtained using pulse plethysmographic- or ECG-gated spin echo pulse sequences. Coronal, axial, and sagittal images displaying intracardiac structures with excellent spatial and contrast resolution were acquired during systole or diastole. It is concluded that MR will be a valuable noninvasive method of diagnosing congenital heart disease

Right ventricular involvement in cardiac sarcoidosis demonstrated with cardiac magnetic resonance.

Science.gov (United States)

Smedema, Jan-Peter; van Geuns, Robert-Jan; Ainslie, Gillian; Ector, Joris; Heidbuchel, Hein; Crijns, Harry J G M

2017-11-01

Cardiac involvement in sarcoidosis is reported in up to 30% of patients. Left ventricular involvement demonstrated by contrast-enhanced cardiac magnetic resonance has been well validated. We sought to determine the prevalence and distribution of right ventricular late gadolinium enhancement in patients diagnosed with pulmonary sarcoidosis. We prospectively evaluated 87 patients diagnosed with pulmonary sarcoidosis with contrast-enhanced cardiac magnetic resonance for right ventricular involvement. Pulmonary artery pressures were non-invasively evaluated with Doppler echocardiography. Patient characteristics were compared between the groups with and without right ventricular involvement, and right ventricular enhancement was correlated with pulmonary hypertension, ventricular mass, volume, and systolic function. Left ventricular late gadolinium enhancement was demonstrated in 30 patients (34%). Fourteen patients (16%) had right ventricular late gadolinium enhancement, with sole right ventricular enhancement in only two patients. The pattern of right ventricular enhancement consisted of right ventricular outflow tract enhancement in 1 patient, free wall enhancement in 8 patients, ventricular insertion point enhancement in 10 patients, and enhancement of the right side of the interventricular septum in 11 patients. Pulmonary arterial hypertension correlated with the presence of right ventricular enhancement (P Right ventricular enhancement correlated with systolic ventricular dysfunction (P Right ventricular enhancement was present in 16% of patients diagnosed with pulmonary sarcoidosis and in 48% of patients with left ventricular enhancement. The presence of right ventricular enhancement correlated with pulmonary arterial hypertension, right ventricular systolic dysfunction, hypertrophy, and dilation. © 2017 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

Cardiac Magnetic Resonance Imaging Predictors of Short-Term Outcomes after High Risk Coronary Surgery.

Science.gov (United States)

Sheriff, Mohammed J; Mouline, Omar; Hsu, Chijen; Grieve, Stuart M; Wilson, Michael K; Bannon, Paul G; Vallely, Michael P; Puranik, Rajesh

2016-06-01

The euroSCORE II is a widely used pre-coronary artery bypass graft surgery (CAGS) risk score, but its predictive power lacks the specificity to predict outcomes in high-risk patients (surgery case mix, revascularisation techniques and related outcomes in recent years. We investigated the utility of Cardiac Magnetic Resonance Imaging (CMRI) in predicting immediate and six-week outcomes after CAGS. Fifty-two consecutive patients with high euroSCORE II (>16) and left ventricular (LV) dysfunction (magnetic resonance imaging parameters were assessed in patients who either had complications immediately post-surgery (n=35), six weeks post-surgery (n=20) or were uncomplicated. The average age of patients recruited was 69±5 years with high euroSCORE II (22±4) and low 2D-echocardiography LV ejection fraction (38%±2%). Cardiac magnetic resonance imaging results demonstrated that those with immediate complications had higher LV scar/infarct burden as a proportion of LV mass (17±3% vs 10±3%; p=0.04) with lower circumferential relaxation index (2.5±0.46 vs 2.8±0.56; p=0.05) compared to those with no complications. Early mortality from surgery was 17% (n=9) and was associated with lower RV stroke volume (55±12 vs 68±18; p=0.03) and higher LV infarct scar/burden (18±2% vs 10±2%, p=0.04). Cardiac magnetic resonance imaging showed patients with complications at six weeks post-surgery had higher LV scar/infarct burden (14.5±2% vs 6.8±2%, p=0.03) compared to those without complications. Cardiac magnetic resonance imaging preoperative LV and RV parameters are valuable in assessing the likelihood of successful outcomes from CAGS in high-risk patients with LV dysfunction. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

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.

Novel axolotl cardiac function analysis method using magnetic resonance imaging.

Directory of Open Access Journals (Sweden)

Pedro Gomes Sanches

Full Text Available The salamander axolotl is capable of complete regeneration of amputated heart tissue. However, non-invasive imaging tools for assessing its cardiac function were so far not employed. In this study, cardiac magnetic resonance imaging is introduced as a non-invasive technique to image heart function of axolotls. Three axolotls were imaged with magnetic resonance imaging using a retrospectively gated Fast Low Angle Shot cine sequence. Within one scanning session the axolotl heart was imaged three times in all planes, consecutively. Heart rate, ejection fraction, stroke volume and cardiac output were calculated using three techniques: (1 combined long-axis, (2 short-axis series, and (3 ultrasound (control for heart rate only. All values are presented as mean ± standard deviation. Heart rate (beats per minute among different animals was 32.2±6.0 (long axis, 30.4±5.5 (short axis and 32.7±4.9 (ultrasound and statistically similar regardless of the imaging method (p > 0.05. Ejection fraction (% was 59.6±10.8 (long axis and 48.1±11.3 (short axis and it differed significantly (p = 0.019. Stroke volume (μl/beat was 133.7±33.7 (long axis and 93.2±31.2 (short axis, also differed significantly (p = 0.015. Calculations were consistent among the animals and over three repeated measurements. The heart rate varied depending on depth of anaesthesia. We described a new method for defining and imaging the anatomical planes of the axolotl heart and propose one of our techniques (long axis analysis may prove useful in defining cardiac function in regenerating axolotl hearts.

Cardiac Magnetic Resonance Imaging in Myocarditis Reveals Persistent Disease Activity Despite Normalization of Cardiac Enzymes and Inflammatory Parameters at 3-Month Follow-Up.

Science.gov (United States)

Berg, Jan; Kottwitz, Jan; Baltensperger, Nora; Kissel, Christine K; Lovrinovic, Marina; Mehra, Tarun; Scherff, Frank; Schmied, Christian; Templin, Christian; Lüscher, Thomas F; Heidecker, Bettina; Manka, Robert

2017-11-01

There is a major unmet need to identify high-risk patients in myocarditis. Although decreasing cardiac and inflammatory markers are commonly interpreted as resolving myocarditis, this assumption has not been confirmed as of today. We sought to evaluate whether routine laboratory parameters at diagnosis predict dynamic of late gadolinium enhancement (LGE) as persistent LGE has been shown to be a risk marker in myocarditis. Myocarditis was diagnosed based on clinical presentation, high-sensitivity troponin T, and cardiac magnetic resonance imaging, after exclusion of obstructive coronary artery disease by angiography. Cardiac magnetic resonance imaging was repeated at 3 months. LGE extent was analyzed with the software GT Volume. Change in LGE >20% was considered significant. Investigated cardiac and inflammatory markers included high-sensitivity troponin T, creatine kinase, myoglobin, N-terminal B-type natriuretic peptide, C-reactive protein, and leukocyte count. Twenty-four patients were enrolled. Absolute levels of cardiac enzymes and inflammatory markers at baseline did not predict change in LGE at 3 months. Cardiac and inflammatory markers had normalized in 21 patients (88%). LGE significantly improved in 16 patients (67%); however, it persisted to a lesser degree in 17 of them (71%) and increased in a small percentage (21%) despite normalization of cardiac enzymes. This is the first study reporting that cardiac enzymes and inflammatory parameters do not sufficiently reflect LGE in myocarditis. Although a majority of patients with normalizing laboratory markers experienced improved LGE, in a small percentage LGE worsened. These data suggest that cardiac magnetic resonance imaging might add value to currently existing diagnostic tools for risk assessment in myocarditis. © 2017 American Heart Association, Inc.

Myocardial strain assessment by cine cardiac magnetic resonance imaging using non-rigid registration.

Science.gov (United States)

Tsadok, Yossi; Friedman, Zvi; Haluska, Brian A; Hoffmann, Rainer; Adam, Dan

2016-05-01

To evaluate a novel post-processing method for assessment of longitudinal mid-myocardial strain in standard cine cardiac magnetic resonance (CMR) imaging sequences. Cine CMR imaging and tagged cardiac magnetic resonance imaging (TMRI) were performed in 15 patients with acute myocardial infarction (AMI) and 15 healthy volunteers served as control group. A second group of 37 post-AMI patients underwent both cine CMR and late gadolinium enhancement (LGE) CMR exams. Speckle tracking echocardiography (STE) was performed in 36 of these patients. Cine CMR, TMRI and STE were analyzed to obtain longitudinal strain. LGE-CMR datasets were analyzed to evaluate scar extent. Comparison of peak systolic strain (PSS) measured from CMR and TMRI yielded a strong correlation (r=0.86, pcine CMR data. The method was found to be highly correlated with strain measurements obtained by TMRI and STE. This tool allows accurate discrimination between different transmurality states of myocardial infarction. Copyright © 2015 Elsevier Inc. All rights reserved.

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

International Nuclear Information System (INIS)

Kappanayil, Mahesh; Kannan, Rajesh; Kumar, Raman Krishna

2011-01-01

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

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.

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

International Nuclear Information System (INIS)

Dewey, Marc; Schnapauff, Dirk; Teige, Florian; Hamm, Bernd

2007-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-08-15

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

Cardiac magnetic resonance and computed tomography in hypertrophic cardiomyopathy: an update

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Diogo Costa Leandro de; Assunção, Fernanda Boldrini; Santos, Alair Agusto Sarmet Moreira Damas dos; Nacif, Marcelo Souto, E-mail: diogocloliveira@hotmail.com, E-mail: diogocloliveira@gmail.com [Universidade Federal Fluminense (UFF), Niterói, Rio de Janeiro, RJ (Brazil)

2016-08-15

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiovascular disease and represents the main cause of sudden death in young patients. Cardiac magnetic resonance (CMR) and cardiac computed tomography (CCT) are noninvasive imaging methods with high sensitivity and specificity, useful for the establishment of diagnosis and prognosis of HCM, and for the screening of patients with subclinical phenotypes. The improvement of image analysis by CMR and CCT offers the potential to promote interventions aiming at stopping the natural course of the disease. This study aims to describe the role of RCM and CCT in the diagnosis and prognosis of HCM, and how these methods can be used in the management of these patients. (author)

Myocardial blood flow quantification for evaluation of coronary artery disease by positron emission tomography, cardiac magnetic resonance imaging, and computed tomography.

Science.gov (United States)

Waller, Alfonso H; Blankstein, Ron; Kwong, Raymond Y; Di Carli, Marcelo F

2014-05-01

The noninvasive detection of the presence and functional significance of coronary artery stenosis is important in the diagnosis, risk assessment, and management of patients with known or suspected coronary artery disease. Quantitative assessment of myocardial perfusion can provide an objective and reproducible estimate of myocardial ischemia and risk prediction. Positron emission tomography, cardiac magnetic resonance, and cardiac computed tomography perfusion are modalities capable of measuring myocardial blood flow and coronary flow reserve. In this review, we will discuss the technical aspects of quantitative myocardial perfusion imaging with positron emission tomography, cardiac magnetic resonance imaging, and computed tomography, and its emerging clinical applications.

Italian registry of cardiac magnetic resonance

Energy Technology Data Exchange (ETDEWEB)

Francone, Marco [Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome (Italy); Di Cesare, Ernesto, E-mail: ernesto.dicesare@cc.univaq.it [Dipartimento di Scienze Cliniche Applicate e Biotecnologie, Università di L’Aquila (Italy); Cademartiri, Filippo [Cardio-Vascular Imaging Unit, Giovanni XXIII Hospital, Monastier di Treviso, TV (Italy); Erasmus Medical Center University, Rotterdam (Netherlands); Pontone, Gianluca [IRCCS Centro Cardiologico Monzino (Italy); Lovato, Luigi [Policlinico S. Orsola Bologna (Italy); Matta, Gildo [Azienda ospedaliera G Brotzu Cagliari (Italy); Secchi, Francesco [IRCCS Policlinico San Donato, Radiology Unit, Milan (Italy); Maffei, Erica [Cardio-Vascular Imaging Unit, Giovanni XXIII Hospital, Monastier di Treviso, TV (Italy); Erasmus Medical Center University, Rotterdam (Netherlands); Pradella, Silvia [Azienda Ospedaliera Universitaria Careggi (Italy); Carbone, Iacopo [Department of Radiological, Oncological and Pathological Sciences, Sapienza University of Rome (Italy); Marano, Riccardo [Policlinico Gemelli, Università Cattolica Roma (Italy); Bacigalupo, Lorenzo [Ospedale Galliera, Genova (Italy); Chiodi, Elisabetta [Ospedale S. Anna Ferrara (Italy); Donato, Rocco [Azienda Ospedaliera Universitaria G. Martino, Me (Italy); Sbarbati, Stefano [Ospedale Madre Giuseppina Vannini, Roma (Italy); De Cobelli, Francesco [IRCCS S. Raffaele, Università Vita Salute, Milano (Italy); Di Renzi, Paolo [Fate Bene Fratelli Isola tiberina, Roma (Italy); Ligabue, Guido; Mancini, Andrea [Azienda Ospedaliera-Universitaria Policlinico di Modena (Italy); Palmieri, Francesco [Diparimento di Diagnostica per immagini e radiologia interventistica, Ospedale S. Maria delle Grazie, Pozzuoli, Napoli (Italy); and others

2014-01-15

Objectives: Forty sites were involved in this multicenter and multivendor registry, which sought to evaluate indications, spectrum of protocols, impact on clinical decision making and safety profile of cardiac magnetic resonance (CMR). Materials and methods: Data were prospectively collected on a 6-month period and included 3376 patients (47.2 ± 19 years; range 1–92 years). Recruited centers were asked to complete a preliminary general report followed by a single form/patient. Referral physicians were not required to exhibit any specific certificate of competency in CMR imaging. Results: Exams were performed with 1.5 T scanners in 96% of cases followed by 3 T (3%) and 1 T (1%) magnets and contrast was administered in 84% of cases. The majority of cases were performed for the workup of inflammatory heart disease/cardiomyopathies representing overall 55.7% of exams followed by the assessment of myocardial viability and acute infarction (respectively 6.9% and 5.9% of patients). In 49% of cases the final diagnosis provided was considered relevant and with impact on patient's clinical/therapeutic management. Safety evaluation revealed 30 (0.88%) clinical events, most of which due to patient's preexisting conditions. Radiological reporting was recorded in 73% of exams. Conclusions: CMR is performed in a large number of centers in Italy with relevant impact on clinical decision making and high safety profile.

Cardiac magnetic resonance markers of progressive RV dilation and dysfunction after tetralogy of Fallot repair

NARCIS (Netherlands)

Wald, Rachel M.; Valente, Anne Marie; Gauvreau, Kimberlee; Babu-Narayan, Sonya V.; Assenza, Gabriele Egidy; Schreier, Jenna; Gatzoulis, Michael A.; Kilner, Philip J.; Koyak, Zeliha; Mulder, Barbara; Powell, Andrew J.; Geva, Tal

2015-01-01

Patients with repaired tetralogy of Fallot (TOF) are followed serially by cardiac magnetic resonance (CMR) for surveillance of RV dilation and dysfunction. We sought to define the prevalence of progressive RV disease and the optimal time interval between CMR evaluations. Candidates were selected

Do we need invasive confirmation of cardiac magnetic resonance results?

Directory of Open Access Journals (Sweden)

Paweł Siastała

2017-03-01

Full Text Available Introduction : Coronary artery revascularization is indicated in patients with documented significant obstruction of coronary blood flow associated with a large area of myocardial ischemia and/or untreatable symptoms. There are a few invasive or noninvasive methods that can provide information about the functional results of coronary artery narrowing. The application of more than one method of ischemia detection in one patient to reevaluate the indications for revascularization is used in case of atypical or no symptoms and/or borderline stenosis. Aim : To evaluate whether the results of cardiac magnetic resonance need to be reconfirmed by the invasive functional method. Material and methods : The hospital database revealed 25 consecutive patients with 29 stenoses who underwent cardiac magnetic resonance (CMR and fractional flow reserve (FFR between the end of 2010 and the end of 2014. The maximal time interval between CMR and FFR was 6 months. None of the patients experienced any clinical events or underwent procedures on coronary arteries between the studies. Results: According to the analysis, the agreement of CMR perfusion with the FFR method was at the level of 89.7%. Assuming that FFR is the gold standard in assessing the severity of stenoses, the sensitivity of CMR perfusion was 90.9%. The percentage of non-severe lesions which were correctly identified in CMR was 88.9%. Conclusions : The study shows that CMR perfusion is a highly sensitive method to detect hemodynamically significant CAD and exclude nonsevere lesions. With FFR as the reference standard, the diagnostic accuracy of MR perfusion to detect ischemic CAD is high.

Do we need invasive confirmation of cardiac magnetic resonance results?

Science.gov (United States)

Siastała, Paweł; Kądziela, Jacek; Małek, Łukasz A; Śpiewak, Mateusz; Lech, Katarzyna; Witkowski, Adam

2017-01-01

Coronary artery revascularization is indicated in patients with documented significant obstruction of coronary blood flow associated with a large area of myocardial ischemia and/or untreatable symptoms. There are a few invasive or noninvasive methods that can provide information about the functional results of coronary artery narrowing. The application of more than one method of ischemia detection in one patient to reevaluate the indications for revascularization is used in case of atypical or no symptoms and/or borderline stenosis. To evaluate whether the results of cardiac magnetic resonance need to be reconfirmed by the invasive functional method. The hospital database revealed 25 consecutive patients with 29 stenoses who underwent cardiac magnetic resonance (CMR) and fractional flow reserve (FFR) between the end of 2010 and the end of 2014. The maximal time interval between CMR and FFR was 6 months. None of the patients experienced any clinical events or underwent procedures on coronary arteries between the studies. According to the analysis, the agreement of CMR perfusion with the FFR method was at the level of 89.7%. Assuming that FFR is the gold standard in assessing the severity of stenoses, the sensitivity of CMR perfusion was 90.9%. The percentage of non-severe lesions which were correctly identified in CMR was 88.9%. The study shows that CMR perfusion is a highly sensitive method to detect hemodynamically significant CAD and exclude nonsevere lesions. With FFR as the reference standard, the diagnostic accuracy of MR perfusion to detect ischemic CAD is high.

Scoring of late gadolinium enhancement in cardiac magnetic resonance imaging can predict cardiac events in patients with hypertrophic cardiomyopathy

International Nuclear Information System (INIS)

Nojiri, Ayumi; Hongo, Kenichi; Kawai, Makoto; Komukai, Kimiaki; Sakuma, Toru; Taniguchi, Ikuo; Yoshimura, Michihiro

2011-01-01

Late gadolinium enhancement (LGE) of cardiac magnetic resonance imaging (MRI) represents myocardial fibrosis and may be related to the clinical outcome of various heart diseases. This study evaluated the relationship between LGE and cardiac events in hypertrophic cardiomyopathy (HCM) using a new scoring method. This study retrospectively followed 46 HCM patients without heart failure symptoms for 3.8±1.8 years. Gadolinium-enhanced cardiac MRI was performed in all patients. Cardiac events including newly developed heart failure or ventricular tachyarrhythmia were evaluated during the follow-up period. We evaluated the predictive factors to identify the patients with cardiac events. None of the risk factors reported to be related to poor outcome or the existence of LGE alone could predict cardiac events, which might be due to the small number of subjects investigated in this study. A new scoring method for LGE-positive areas (LGE score) was applied and higher LGE score can predict cardiac events in this study population. The proposed LGE score for cardiac MRI is considered to be a potentially valid method for assessing cardiac events in HCM patients. (author)

Cardiovascular magnetic resonance in congenital heart disease

International Nuclear Information System (INIS)

Cazacu, A.; Ciubotaru, A.

2010-01-01

The increasing prevalence of congenital heart disease can be attributed to major improvements in diagnosis and treatment. Cardiovascular magnetic resonance imaging plays an important role in the clinical management strategy of patients with congenital heart disease. The development of new cardiovascular magnetic resonance (CMR) techniques allows comprehensive assessment of complex cardiac anatomy and function and provides information about the long-term residual post-operative lesions and complications of surgery. It overcomes many of the limitations of echocardiography and cardiac catheterization. This review evaluates the role of cardiovascular magnetic resonance imaging modality in the management of subject with congenital heart disease (CHD). (authors)

Accurate computer-aided quantification of left ventricular parameters : experience in 1555 cardiac magnetic resonance studies from the Framingham Heart Study

NARCIS (Netherlands)

Hautvast, G.L.T.F.; Salton, C.J.; Chuang, M.L.; Breeuwer, M.; O'Donnel, C.J.; Manning, W.J.

2011-01-01

Quantitative analysis of short-axis functional cardiac magnetic resonance images can be performed using automatic contour detection methods. The resulting myocardial contours must be reviewed and possibly corrected, which can be time-consuming, particularly when performed across all cardiac phases.

Evaluation of cardiac motion and function by cine magnetic resonance imaging

International Nuclear Information System (INIS)

Kondo, Takeshi; Kurokawa, Hiroshi; Anno, Hirofumi

1992-01-01

Cardiac cine magnetic resonance imaging (MRI) was studied to evaluate the cardiac motion and function, and a water-stream phantom study was performed to clarify whether it was possible to quantitatively assess the valvular regurgitation flow by the size of the flow void. In normal subjects, the left ventricular (LV) epicardial apex swung up to the base only a few millimeters, and the mitral annulus ring moved about 14 mm as mean value toward the apex during systole. Those motions of mitral annulus ring may contribute to the left atrial filling. The LV longitudinal shortening and torsions were shown by the tagging method. This tagging method was the best method for estimating cardiac motions. Cardiac cine MRI using software including a modified Simpson's method program and a wall motion analysis program was useful for routine LV volumetry and wall motion analysis because it was a simple and reliable method. Our water-stream phantom studies demonstrated that it might be difficult to perform quantitative evaluation of valvular regurgitation flow by using only the size of the flow void without acquiring information relating to the orifice area. (author)

Utility of fetal cardiac magnetic resonance imaging to assess fetuses with right aortic arch and right ductus arteriosus.

Science.gov (United States)

Dong, Su-Zhen; Zhu, Ming

2018-06-01

To evaluate the utility of fetal cardiac magnetic resonance imaging (MRI) to diagnose right aortic arch (RAA) with right ductus arteriosus. This retrospective study included six fetuses with right aortic arch and right ductus arteriosus. The six fetal cases were examined using a 1.5-T magnetic resonance unit. The steady-state free precession (SSFP) and single-shot turbo spin echo (SSTSE) sequences were used to evaluate the fetal heart and airway. The gestational age of the six fetuses ranged from 22 to 35 weeks (mean, 26.5 weeks). The age of the pregnant women ranged from 23 to 40 years (mean 31 years). Fetal cardiac MRI diagnosed the six fetal cases with RAA with right ductus arteriosus correctly. Among the six fetuses, four were associated with other congenital heart defects. In three of six cases, the diagnoses established using prenatal echocardiography (echo) was correct when compared with postnatal diagnosis. Fetal cardiac MRI is a useful complementary tool to assess fetuses with RAA and right ductus arteriosus.

Atypical Distribution of Late Gadolinium Enhancement of the Left Ventricle on Cardiac Magnetic Resonance in Classical Anderson-Fabry Disease

OpenAIRE

Kasuya, Shusuke; Suzuki, Masayo; Inaoka, Tsutomu; Odashima, Masayuki; Nakatsuka, Tomoya; Ishikawa, Rumiko; Tokuyama, Wataru; Terada, Hitoshi

2016-01-01

Anderson-Fabry disease (AFD) is an X-linked lysosomal storage disorder caused by a deficiency of alpha-galactosidase A. Approximately 50% of patients with AFD may have cardiac involvement. Gadolinium-enhanced cardiac magnetic resonance (CMR) is useful for the diagnosis of cardiac involvement of AFD by recognizing typical late gadolinium enhancement (LGE) patterns. We report a 48-year-old man with cardiac involvement in classical AFD, showing atypical distribution of the LGE at the mid-lateral...

Phenotypic expression in hypertrophic cardiomyopathy and late gadolinium enhancement on cardiac magnetic resonance.

Science.gov (United States)

Caetano, Francisca; Botelho, Ana; Trigo, Joana; Silva, Joana; Almeida, Inês; Venâncio, Margarida; Pais, João; Sanches, Conceição; Leitão Marques, António

2014-05-01

The prognostic value of late gadolinium enhancement (LGE) for risk stratification of hypertrophic cardiomyopathy (HCM) patients is the subject of disagreement. We set out to examine the association between clinical and morphological variables, risk factors for sudden cardiac death and LGE in HCM patients. From a population of 78 patients with HCM, we studied 53 who underwent cardiac magnetic resonance. They were divided into two groups according to the presence or absence of LGE. Ventricular arrhythmias and morbidity and mortality during follow-up were analyzed. Patients with LGE were younger at the time of diagnosis (p=0.046) and more often had a family history of sudden death (p=0.008) and known coronary artery disease (p=0.086). On echocardiography they had greater maximum wall thickness (p=0.007) and left atrial area (p=0.037) and volume (p=0.035), and more often presented a restrictive pattern of diastolic dysfunction (p=0.011) with a higher E/É ratio (p=0.003) and left ventricular systolic dysfunction (p=0.038). Cardiac magnetic resonance supported the association between LGE and previous echocardiographic findings: greater left atrial area (p=0.029) and maximum wall thickness (p<0.001) and lower left ventricular ejection fraction (p=0.056). Patients with LGE more often had an implantable cardioverter-defibrillator (ICD) (p=0.015). At follow-up, no differences were found in the frequency of ventricular arrhythmias, appropriate ICD therapies or mortality. The presence of LGE emerges as a risk marker, associated with the classical predictors of sudden cardiac death in this population. However, larger studies are required to confirm its independent association with clinical events. Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

Cardiac magnetic resonance imaging in heart failure: where the alphabet begins!

Science.gov (United States)

Aljizeeri, Ahmed; Sulaiman, Abdulbaset; Alhulaimi, Naji; Alsaileek, Ahmed; Al-Mallah, Mouaz H

2017-07-01

Cardiac Magnetic Resonance Imaging has become a cornerstone in the evaluation of heart failure. It provides a comprehensive evaluation by answering all the pertinent clinical questions across the full pathological spectrum of heart failure. Nowadays, CMR is considered the gold standard in evaluation of ventricular volumes, wall motion and systolic function. Through its unique ability of tissue characterization, it provides incremental diagnostic and prognostic information and thus has emerged as a comprehensive imaging modality in heart failure. This review outlines the role of main conventional CMR sequences in the evaluation of heart failure and their impact in the management and prognosis.

Stress cardiac magnetic resonance imaging provides effective cardiac risk reclassification in patients with known or suspected stable coronary artery disease.

Science.gov (United States)

Shah, Ravi; Heydari, Bobak; Coelho-Filho, Otavio; Murthy, Venkatesh L; Abbasi, Siddique; Feng, Jiazhuo H; Pencina, Michael; Neilan, Tomas G; Meadows, Judith L; Francis, Sanjeev; Blankstein, Ron; Steigner, Michael; di Carli, Marcelo; Jerosch-Herold, Michael; Kwong, Raymond Y

2013-08-06

A recent large-scale clinical trial found that an initial invasive strategy does not improve cardiac outcomes beyond optimized medical therapy in patients with stable coronary artery disease. Novel methods to stratify at-risk patients may refine therapeutic decisions to improve outcomes. In a cohort of 815 consecutive patients referred for evaluation of myocardial ischemia, we determined the net reclassification improvement of the risk of cardiac death or nonfatal myocardial infarction (major adverse cardiac events) incremental to clinical risk models, using guideline-based low (3%) annual risk categories. In the whole cohort, inducible ischemia demonstrated a strong association with major adverse cardiac events (hazard ratio=14.66; Pstatistic, 0.81-0.86; P=0.04; adjusted hazard ratio=7.37; PStress cardiac magnetic resonance imaging effectively reclassifies patient risk beyond standard clinical variables, specifically in patients at moderate to high pretest clinical risk and in patients with previous coronary artery disease. http://www.clinicaltrials.gov. Unique identifier: NCT01821924.

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

International Nuclear Information System (INIS)

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

2009-01-01

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.

Cardiac magnetic resonance imaging after ventricular tachyarrhythmias increases diagnostic precision and reduces the need for family screening for inherited cardiac disease

DEFF Research Database (Denmark)

Marstrand, Peter; Axelsson, Anna; Thune, Jens Jakob

2016-01-01

-CAG) (81%), exercise stress test (47%), late potentials (54%), electrophysiological study (44%), pharmacological provocation (44%), and/or myocardial biopsy (16%). Family screening was indicated for 53 probands (67%) prior to CMR. After full workup, only 43 cases (54%) warranted evaluation of relatives (19......AIMS: Guidelines recommend evaluation of family members of sudden cardiac death victims. However, initiation of cascade screening in families with uncertain diagnoses is not cost-effective and may cause unnecessary concern. For these reasons, we set out to assess to what extent cardiac magnetic...... resonance imaging (CMR) would increase the diagnostic precision and thereby possibly change the indication for family screening in patients with ventricular tachyarrhythmias. METHODS AND RESULTS: We retrospectively collected data from 79 patients hospitalized with aborted cardiac arrest (resuscitated from...

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

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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.

Vibration-synchronized magnetic resonance imaging for the detection of myocardial elasticity changes.

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Elgeti, Thomas; Tzschätzsch, Heiko; Hirsch, Sebastian; Krefting, Dagmar; Klatt, Dieter; Niendorf, Thoralf; Braun, Jürgen; Sack, Ingolf

2012-04-01

Vibration synchronized magnetic resonance imaging of harmonically oscillating tissue interfaces is proposed for cardiac magnetic resonance elastography. The new approach exploits cardiac triggered cine imaging synchronized with extrinsic harmonic stimulation (f = 22.83 Hz) to display oscillatory tissue deformations in magnitude images. Oscillations are analyzed by intensity threshold-based image processing to track wave amplitude variations over the cardiac cycle. In agreement to literature data, results in 10 volunteers showed that endocardial wave amplitudes during systole (0.13 ± 0.07 mm) were significantly lower than during diastole (0.34 ± 0.14 mm, P magnetic resonance imaging improves the temporal resolution of magnetic resonance elastography as it overcomes the use of extra motion encoding gradients, is less sensitive to susceptibility artifacts, and does not suffer from dynamic range constraints frequently encountered in phase-based magnetic resonance elastography. Copyright © 2012 Wiley Periodicals, Inc.

The Role of Clinical Cardiac Magnetic Resonance Imaging in China: Current Status and the Future

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Shi Chen, MD

2016-12-01

Full Text Available Cardiac magnetic resonance (CMR imaging plays an important role in the diagnosis and management of cardiovascular diseases. The state-of-the-art CMR imaging has many advantages in cardiac imaging, including excellent spatial and temporal resolution, unrestricted imaging field, no exposure to ionizing radiation, excellent tissue contrast, and unique myocardial tissue characterization. Clinical CMR imaging is used during the cardiovascular diagnostic workup in the United States and some European countries. Use of CMR imaging is emerging in hospitals in China and has a promising future. This review briefly describes the real-world clinical application of CMR imaging in China and discuss obstacles for its future development.

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 signal loss on MRI associated with implanted metallic devices is known, we report a case where an implanted coronary stent in the left circumflex artery led to an intracardiac signal loss mimicking intracardiac thrombus/tumor....

[Anomalous pulmonary venous return in a pregnant woman identified by cardiac magnetic resonance].

Science.gov (United States)

Souto, Fernanda Maria; Andrade, Stephanie Macedo; Barreto, Ana Terra Fonseca; Souto, Maria Júlia Silveira; Russo, Maria Amélia; de Mendonça, José Teles; Oliveira, Joselina Luzia Menezes; Gonçalves, Luiz Flávio Galvão

2014-06-01

Anomalous pulmonary venous return (APVR) is a rare cardiac anomaly defined as one or more pulmonary veins draining into a structure other than the left atrium, with venous return directly or indirectly to the right atrium. The most common form is partial APVR, in which one to three pulmonary veins drain into systemic veins or into the right atrium. We report the case of a woman diagnosed with partial APVR by magnetic resonance imaging during pregnancy. Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

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

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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.

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)

Cardiac Involvement in Myotonic Dystrophy Type 2 Patients With Preserved Ejection Fraction: Detection by Cardiovascular Magnetic Resonance.

Science.gov (United States)

Schmacht, Luisa; Traber, Julius; Grieben, Ulrike; Utz, Wolfgang; Dieringer, Matthias A; Kellman, Peter; Blaszczyk, Edyta; von Knobelsdorff-Brenkenhoff, Florian; Spuler, Simone; Schulz-Menger, Jeanette

2016-07-01

Myotonic dystrophy type 2 (DM2) is a genetic disorder characterized by skeletal muscle symptoms, metabolic changes, and cardiac involvement. Histopathologic alterations of the skeletal muscle include fibrosis and fatty infiltration. The aim of this study was to investigate whether subclinical cardiac involvement in DM2 is already detectable in preserved left ventricular function by cardiovascular magnetic resonance. Twenty-seven patients (mean age, 54±10 years; 20 females) with a genetically confirmed diagnosis of DM2 were compared with 17 healthy age- and sex-matched controls using a 1.5 T magnetic resonance imaging. For myocardial tissue differentiation, T1 and T2 mapping, fat/water-separated imaging, focal fibrosis imaging (late gadolinium enhancement [LGE]), and (1)H magnetic resonance spectroscopy were performed. Extracellular volume fraction was calculated. Conduction abnormalities were diagnosed based on Groh criteria. LGE located subepicardial basal inferolateral was detectable in 22% of the patients. Extracellular volume was increased in this region and in the adjacent medial inferolateral segment (P=0.03 compared with healthy controls). In 21% of patients with DM2, fat deposits were detectable (all women). The control group showed no abnormalities. Myocardial triglycerides were not different in LGE-positive and LGE-negative subjects (P=0.47). Six patients had indicators for conduction disease (60% of LGE-positive patients and 12.5% of LGE-negative patients). In DM2, subclinical myocardial injury was already detectable in preserved left ventricular ejection fraction. Extracellular volume was also increased in regions with no focal fibrosis. Myocardial fibrosis was related to conduction abnormalities. © 2016 American Heart Association, Inc.

[Assessment of Tricuspid Insufficiency and the Function of Right Ventricle Using Cardiac Magnetic Resonance Imaging Combined with Echocardiography].

Science.gov (United States)

Chen, Hui; Zhao, Yanling; Yu, Jianqun

2015-08-01

Right-sided cardiac valvular diseases have traditionally been considered less important than disease of mitral or aortic valve. However, severe tricuspid regurgitation could lead to right ventricle dysfunction and reduce patients' survival rate. In clinic setting, tricuspid valve disease should be paid more attention for patients with secondary tricuspid regurgitation caused by left-sided valvular surgery combined with irreversible annular dilatation increasing the risk of reoperation. In this review, we summarize the epidemiology, anatomy, pathology, diagnosis, ultrasound and cardiac magnetic resonance imaging findings in patients with tricuspid regurgitation.

Evaluation of Tricuspid Annular Plane Systolic Excursion Measured with Cardiac Magnetic Resonance Imaging in Pediatric Patients with Tetralogy of Fallot

Science.gov (United States)

Soslow, Jonathan H.; Usoro, Emem; Wang, Li; Parra, David A.

2015-01-01

Background Aneurysmal dilation of the right ventricular outflow tract complicates assessment of right ventricular function in patients with repaired tetralogy of Fallot. Tricuspid annular plane systolic excursion is commonly used to estimate ejection fraction. We hypothesized that tricuspid annular plane systolic excursion measured by cardiac magnetic resonance imaging approximates global and segmental right ventricular function, specifically right ventricular sinus ejection fraction, in pediatric patients with repaired tetralogy of Fallot. Methods Tricuspid annular plane systolic excursion was measured retrospectively on cardiac magnetic resonance images in 54 patients with repaired tetralogy of Fallot. Values were compared with right ventricular global, sinus, and infundibular ejection fractions. Tricuspid annular plane systolic excursion was: 1) indexed to body surface area, 2) converted into a fractional value, and 3) converted into published pediatric Z-scores. Results Tricuspid annular plane systolic excursion measurements had good agreement between observers. Right ventricular ejection fraction did not correlate with the absolute or indexed tricuspid annular plane systolic excursion and correlated weakly with fractional tricuspid annular plane systolic excursion (r=0.41 and p=0.002). Segmental right ventricular function did not appreciably improve correlation with any of the tricuspid annular plane systolic excursion measures. Pediatric Z-scores were unable to differentiate patients with normal and abnormal right ventricular function. Conclusions Tricuspid annular plane systolic excursion measured on cardiac magnetic resonance imaging correlates poorly with global and segmental right ventricular ejection fraction in pediatric patients with repaired tetralogy of Fallot. Tricuspid annular plane systolic excursion is an unreliable approximation of right ventricular function in this patient population. PMID:26279488

The role of cardiac magnetic resonance in valvular heart disease.

Science.gov (United States)

Lopez-Mattei, Juan C; Shah, Dipan J

2013-01-01

The prevalence of valvular heart disease is increasing as the population ages. In diagnosing individuals with valve disease, echocardiography is the primary imaging modality used by clinicians both for initial assessment and for longitudinal evaluation. However, in some cases cardiovascular magnetic resonance has become a viable alternative in that it can obtain imaging data in any plane prescribed by the scan operator, which makes it ideal for accurate investigation of all cardiac valves: aortic, mitral, pulmonic, and tricuspid. In addition, CMR for valve assessment is noninvasive, free of ionizing radiation, and in most instances does not require contrast administration. The objectives of a comprehensive CMR study for evaluating valvular heart disease are threefold: (1) to provide insight into the mechanism of the valvular lesion (via anatomic assessment), (2) to quantify the severity of the valvular lesion, and (3) to discern the consequences of the valvular lesion.

Gated in vivo examination of cardiac metabolites with 31P nuclear magnetic resonance

International Nuclear Information System (INIS)

Kantor, H.L.; Briggs, R.W.; Metz, K.R.; Balaban, R.S.

1986-01-01

Phosphorus-31 nuclear magnetic resonance ( 31 P NMR) spectroscopy was used to study the temporal aspects of metabolism of canine heart in vivo. An NMR catheter coil was passed through the jugular vein of a dog into the apex of the right ventricle and spectra were recorded at four points in the cardiac cycle by triggering from the blood pressure trace of the animal. The 31 P spin-lattice relaxation times of phosphocreatine (PC) and the γ - ,α - , and β-phosphates of ATP at 1.89 Tesla are 4.4, 1.8, 1.7, and 1.6 s, respectively. The ratio of PC to ATP is 2.0. No changes in PC/ATP were noted in any of the four portions of the cardiac cycle examined, and difference spectra exhibited no observable signals, in contrast to previously reported results for glucose-perfused rat hearts. On the assumption that intracellular pH and the total creatine pool were constant, the expression for the creatine kinase reaction was used to deduce that free ADP concentrations were invariant throughout the cardiac cycle. This is in apparent disagreement with the proposed regulatory role for ADP in heart oxidative phosphorylation

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

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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.

A Magnetic Resonance Imaging-Conditional External Cardiac Defibrillator for Resuscitation Within the Magnetic Resonance Imaging Scanner Bore.

Science.gov (United States)

Schmidt, Ehud J; Watkins, Ronald D; Zviman, Menekhem M; Guttman, Michael A; Wang, Wei; Halperin, Henry A

2016-10-01

Subjects undergoing cardiac arrest within a magnetic resonance imaging (MRI) scanner are currently removed from the bore and then from the MRI suite, before the delivery of cardiopulmonary resuscitation and defibrillation, potentially increasing the risk of mortality. This precludes many higher-risk (acute ischemic and acute stroke) patients from undergoing MRI and MRI-guided intervention. An MRI-conditional cardiac defibrillator should enable scanning with defibrillation pads attached and the generator ON, enabling application of defibrillation within the seconds of MRI after a cardiac event. An MRI-conditional external defibrillator may improve patient acceptance for MRI procedures. A commercial external defibrillator was rendered 1.5 Tesla MRI-conditional by the addition of novel radiofrequency filters between the generator and commercial disposable surface pads. The radiofrequency filters reduced emission into the MRI scanner and prevented cable/surface pad heating during imaging, while preserving all the defibrillator monitoring and delivery functions. Human volunteers were imaged using high specific absorption rate sequences to validate MRI image quality and lack of heating. Swine were electrically fibrillated (n=4) and thereafter defibrillated both outside and inside the MRI bore. MRI image quality was reduced by 0.8 or 1.6 dB, with the generator in monitoring mode and operating on battery or AC power, respectively. Commercial surface pads did not create artifacts deeper than 6 mm below the skin surface. Radiofrequency heating was within US Food and Drug Administration guidelines. Defibrillation was completely successful inside and outside the MRI bore. A prototype MRI-conditional defibrillation system successfully defibrillated in the MRI without degrading the image quality or increasing the time needed for defibrillation. It can increase patient acceptance for MRI procedures. © 2016 American Heart Association, Inc.

Incremental value of normal adenosine perfusion cardiac magnetic resonance: Long-term outcome.

Science.gov (United States)

Sozzi, Fabiola B; Iacuzio, Laura; Civaia, Filippo; Canetta, Ciro; Berthier, Frederic; Rusek, Stephane; Rossi, Philippe; Lombardi, Federico; Dreyfus, Gilles; Dor, Vincent

2015-06-01

The purpose of the study was to determine the long-term prognostic value of normal adenosine stress cardiac magnetic resonance imaging (CMR) in patients referred for evaluation of myocardial ischemia. We reviewed 300 consecutive patients (age 65 ± 11 years, 74% male) with suspected or known coronary disease and normal wall motion who had undergone adenosine stress CMR negative for ischemia and scar. Most patients were at intermediate risk of coronary artery disease. The end points studied were all causes of mortality and major adverse cardiac events, including cardiac death, myocardial infarction, revascularization, and hospitalization for unstable angina. During a mean follow-up of 5.5 years (mean = 5.4 ± 1.1), 16 patients died because of various causes (cardiac death in 5 patients). Three patients had a nonfatal myocardial infarction, 7 patients were hospitalized for revascularization, and 11 were medically treated for unstable angina. The annual cardiac event rate was 1.3% (0.78% in the first 3 years and 1.9% between the fourth and sixth years). The predictors of major adverse cardiac events in a multivariate analysis model were as follows: advanced age (hazard ratio [HR] 1.15, 95% confidence interval [95% CI] 1.02-1.30), diabetes (HR 17.5, 95% CI 2.2-140), and the habit of smoking (HR 5.9, 95% CI 1.0-35.5). For all causes of mortality, the only predictor was diabetes (HR 11.4, 95% CI 1.76-74.2). Patients with normal stress CMR had an excellent outcome during the 3 years after the study. The cardiac event rate was higher between the fourth and sixth years. Over a 5.5-year period, a low event rate and excellent prognosis occurred in patients with normal adenosine stress CMR. Low- to intermediate-risk patients with a normal CMR are at low risk for subsequent cardiac events. Copyright © 2015 Elsevier Inc. All rights reserved.

Cardiac and pericardial tumors: A potential application of positron emission tomography-magnetic resonance imaging.

Science.gov (United States)

Fathala, Ahmed; Abouzied, Mohei; AlSugair, Abdul-Aziz

2017-07-26

Cardiac and pericardial masses may be neoplastic, benign and malignant, non-neoplastic such as thrombus or simple pericardial cysts, or normal variants cardiac structure can also be a diagnostic challenge. Currently, there are several imaging modalities for diagnosis of cardiac masses; each technique has its inherent advantages and disadvantages. Echocardiography, is typically the initial test utilizes in such cases, Echocardiography is considered the test of choice for evaluation and detection of cardiac mass, it is widely available, portable, with no ionizing radiation and provides comprehensive evaluation of cardiac function and valves, however, echocardiography is not very helpful in many cases such as evaluation of extracardiac extension of mass, poor tissue characterization, and it is non diagnostic in some cases. Cross sectional imaging with cardiac computed tomography provides a three dimensional data set with excellent spatial resolution but utilizes ionizing radiation, intravenous iodinated contrast and relatively limited functional evaluation of the heart. Cardiac magnetic resonance imaging (CMR) has excellent contrast resolution that allows superior soft tissue characterization. CMR offers comprehensive evaluation of morphology, function, tissue characterization. The great benefits of CMR make CMR a highly useful tool in the assessment of cardiac masses. (Fluorine 18) fluorodeoxygluocse (FDG) positron emission tomography (PET) has become a corner stone in several oncological application such as tumor staging, restaging, treatment efficiency, FDG is a very useful imaging modality in evaluation of cardiac masses. A recent advance in the imaging technology has been the development of integrated PET-MRI system that utilizes the advantages of PET and MRI in a single examination. FDG PET-MRI provides complementary information on evaluation of cardiac masses. The purpose of this review is to provide several clinical scenarios on the incremental value of PET

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

International Nuclear Information System (INIS)

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

2005-01-01

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

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

International Nuclear Information System (INIS)

Knobelsdorff-Brenkenhoff, Florian von; Schulz-Menger, Jeanette; Frauenrath, Tobias; Hezel, Fabian; Prothmann, Marcel; Dieringer, Matthias A.; Niendorf, Thoralf; Renz, Wolfgang; Kretschel, Kerstin

2010-01-01

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.)

Cardiac magnetic resonance imaging in patients with congenital heart disease

International Nuclear Information System (INIS)

Kreitner, Karl-Friedrich; Sorantin, Erich

2015-01-01

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.

Right Ventricular Volumes and Systolic Function by Cardiac Magnetic Resonance and the Impact of Sex, Age, and Obesity in a Longitudinally Followed Cohort Free of Pulmonary and Cardiovascular Disease: The Framingham Heart Study.

Science.gov (United States)

Foppa, Murilo; Arora, Garima; Gona, Philimon; Ashrafi, Arman; Salton, Carol J; Yeon, Susan B; Blease, Susan J; Levy, Daniel; O'Donnell, Christopher J; Manning, Warren J; Chuang, Michael L

2016-03-01

Cardiac magnetic resonance is uniquely well suited for noninvasive imaging of the right ventricle. We sought to define normal cardiac magnetic resonance reference values and to identify the main determinants of right ventricular (RV) volumes and systolic function using a modern imaging sequence in a community-dwelling, longitudinally followed cohort free of clinical cardiovascular and pulmonary disease. The Framingham Heart Study Offspring cohort has been followed since 1971. We scanned 1794 Offspring cohort members using steady-state free precession cardiac magnetic resonance and identified a reference group of 1336 adults (64±9 years, 576 men) free of prevalent cardiovascular and pulmonary disease. RV trabeculations and papillary muscles were considered cavity volume. Men had greater RV volumes and cardiac output before and after indexation to body size (all Pheart rate account for most of the variability in RV volumes and function in this community-dwelling population. We report sex-specific normative values for RV measurements among principally middle-aged and older adults. RV ejection fraction is greater in women. RV volumes increase with body size, are greater in men, and are smaller in older people. Body surface area seems to be appropriate for indexation of cardiac magnetic resonance-derived RV volumes. © 2016 American Heart Association, Inc.

Progress and promises of human cardiac magnetic resonance at ultrahigh fields: a physics perspective.

Science.gov (United States)

Niendorf, Thoralf; Graessl, Andreas; Thalhammer, Christof; Dieringer, Matthias A; Kraus, Oliver; Santoro, Davide; Fuchs, Katharina; Hezel, Fabian; Waiczies, Sonia; Ittermann, Bernd; Winter, Lukas

2013-04-01

A growing number of reports eloquently speak about explorations into cardiac magnetic resonance (CMR) at ultrahigh magnetic fields (B0≥7.0 T). Realizing the progress, promises and challenges of ultrahigh field (UHF) CMR this perspective outlines current trends in enabling MR technology tailored for cardiac MR in the short wavelength regime. For this purpose many channel radiofrequency (RF) technology concepts are outlined. Basic principles of mapping and shimming of transmission fields including RF power deposition considerations are presented. Explorations motivated by the safe operation of UHF-CMR even in the presence of conductive implants are described together with the physics, numerical simulations and experiments, all of which detailing antenna effects and RF heating induced by intracoronary stents at 7.0 T. Early applications of CMR at 7.0 T and their clinical implications for explorations into cardiovascular diseases are explored including assessment of cardiac function, myocardial tissue characterization, MR angiography of large and small vessels as well as heteronuclear MR of the heart and the skin. A concluding section ventures a glance beyond the horizon and explores future directions. The goal here is not to be comprehensive but to inspire the biomedical and diagnostic imaging communities to throw further weight behind the solution of the many remaining unsolved problems and technical obstacles of UHF-CMR with the goal to transfer MR physics driven methodological advancements into extra clinical value. Copyright © 2012 Elsevier Inc. All rights reserved.

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.

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.

The Use of Cardiac Magnetic Resonance in Patients with Suspected Coronary Artery Disease: A Clinical Practice Perspective

OpenAIRE

Chang, Sung-A; Kim, Raymond J.

2016-01-01

Cardiac magnetic resonance imaging (CMR) is a useful diagnostic imaging modality in patients with known or suspected coronary artery disease (CAD). It provides unique information not available from other modalities, however, it is complex. CMR is not a single technique. Instead, it consists of multiple distinct techniques and a lack of understanding of which techniques to perform and how to interpret the findings in combination limits its efficacy and widespread use. Conversely, its multipara...

Cine magnetic resonance

International Nuclear Information System (INIS)

Higgins, C.B.; Sechtem, U.P.; Pflugfelder, P.

1987-01-01

Cine magnetic resonance (MR) is a fast MR imaging process with referencing of the imaging data to the electrocardiogram (ECG) so that images corresponding to 21-msec segments of the cardiac cycle are acquired. A series of such images, each corresponding to a 21-msec segment of the cardiac cycle, can be laced together for viewing in the cine format at a framing rate of 20 to 40 frames per second. Since cine angiograms of the heart are usually done at 30 frames per second, this technique achieves a temporal resolution adequate for the evluation of central cardiovascular function. The major application of this technique is to depict central cardiovascular function and blood flow

Cardiac magnetic resonance imaging in evaluation of anatomical structure and function of the ventricles

International Nuclear Information System (INIS)

Suzuki, Jun-ichi; Usui, Masahiro; Takenaka, Katsu

1990-01-01

Cardiac magnetic resonance imaging (MRI) is being widely employed for evaluation of cardiovascular anatomies and functions. However, the indications for cardiac MRI to obtain information which cannot be obtained using other conventional methods have not yet been determined. To demonstrate the usefulness of MRI in delineating the apex of the left ventricle and free wall of the right ventricle, end-diastolic short axis MRI images were obtained in 20 patients with apical hypertrophy and in 9 normal volunteers. To compare the accuracy of estimations of left ventricular volumes obtained using the modified Simpson's method of MRI with that using the MRI area length method, 19 patients, in whom left ventriculography had been performed, were studied. The apex of the left ventricle was evaluated circumferentially and distribution of hypertrophied muscles was defined. Sixty-five percent of the length of the right ventricular free wall was clearly delineated. Correlation coefficients of the ejection fraction between MRI and angiography were 0.85 with the modified Simpson's method of MRI, and 0.62 with the area length method of MRI. Three themes were chosen to demonstrate good clinical indications for cardiac MRI. (author)

Cardiac magnetic resonance imaging for evaluation of non-compaction cardiomyopathy in patients with or without left ventricular systolic dysfunction

International Nuclear Information System (INIS)

Deviggiano, A.; Deschle, H.; Lewkowicz, J.M.; Tajer, C.D.; Carrascosa, P.; Capunay, C.; Vallejos, J.; Stewart Harris, A.

2011-01-01

Background: Non-compaction cardiomyopathy (NCC) is a genetic disorder characterized by deep trabeculations in the ventricular wall, which define recesses communicating with the main ventricular chamber. The prevalence of NCC is greater in symptomatic populations with left ventricular dysfunction; yet, it may also be detected in asymptomatic patients with normal left ventricular function using novel diagnostic tools. However, this condition is under-diagnosed due to a low index of clinical suspicion and to the use of echocardiography classifications based on different diagnostic criteria. The use of cardiac magnetic resonance imaging (CMRI) has established two diagnostic criteria that clearly recognize this disease. Objective: To evaluate the clinical and morphological characteristics of patients with NCC with and without systolic dysfunction undergoing cardiac magnetic resonance imaging (CMRI). Material and Methods: A total of 20 patients with NCC were retrospectively included. The following parameters were determined: left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV); left ventricular end-diastolic diameter (LVEDD); left ventricular end-systolic diameter (LVESD); cardiac mass and left ventricular trabeculations. The distribution of NC myocardium was evaluated according to the model of 17 myocardial segments. Results: Mean myocardial thickness was 13.1 ± 3.3 mm and 3.6 ± 0.6 mm in NC versus normal myocardium, respectively. Patients with left ventricular dysfunction presented increased LVEDD, LVEDV, total cardiac mass, and LV non-compaction and trabeculations. We found a positive correlation and a linear relationship between LVEDD and TLVM (g/m 2 ): r=0.76; r 2 =0.59; p [es

Relationship between myocardial T2* values and cardiac volumetric and functional parameters in β-thalassemia patients evaluated by cardiac magnetic resonance in association with serum ferritin levels

Energy Technology Data Exchange (ETDEWEB)

Liguori, Carlo, E-mail: c.liguori@unicampus.it [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Pitocco, Francesca, E-mail: f.pitocco@unicampus.it [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Di Giampietro, Ilenia, E-mail: i.digiampietro@unicampus.it [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Vivo, Aldo Eros de, E-mail: devivoeros@gmail.com [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Schena, Emiliano, E-mail: e.schena@unicampus.it [Unit of Measurements and Biomedical Instrumentation, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy); Cianciulli, Paolo, E-mail: CIANCIULLI.PAOLO@aslrmc.it [Thalassemia Unit, Ospedale Sant Eugenio, Piazzale dell’Umanesimo 10, 00143 Rome (Italy); Zobel, Bruno Beomonte, E-mail: b.zobel@unicampus.it [Department of Diagnostic Imaging, Campus Bio Medico University, via Alvaro del Portillo 200, 00128 Rome (Italy)

2013-09-15

Purpose: Myocardial T2* cardiovascular magnetic resonance provides a rapid and reproducible assessment of cardiac iron load in thalassemia patients. Although cardiac involvement is mainly characterized by left ventricular dysfunction caused by iron overload, little is known about right ventricular function. The aim of this study was to assess the relationship between T2* value in myocardium and left–right ventricular volumetric and functional parameters and to evaluate the existing associations between left–right ventricles volumetric and functional parameter, myocardial T2* values and blood ferritin levels. Materials and methods: A retrospective analysis of 208 patients with β-thalassemia major and thalassemia intermedia was performed (109 males and 99 females; mean age 37.7 ± 13 years; 143 thalassemia major, 65 thalassemia intermedia). Myocardial iron load was assessed by T2* measurements, and volumetric functions were analyzed using the steady state free precession sequence. Results: A significant correlation was observed between EFLV and T2* (p = 0.0001), EFRV and T2* (p = 0.0279). An inverse correlation was present between DVLV and T2* (p = 0.0468), SVLV and T2* (p = 0.0003), SVRV and T2* (p = 0.0001). There was no significant correlation between cardiac T2* and LV–RV mass indices. A significant correlation was observed between T2* and serum ferritin levels (p < 0.001) and between EFLV and serum ferritin (p < 0.05). Conclusion: Myocardial iron load assessed by T2* cardiac magnetic resonance is associated with deterioration in left–right ventricular function; this is more evident when T2* values fall below 14 ms. CMR appears to be a promising approach for cardiac risk evaluation in TM patients.

Relationship between myocardial T2* values and cardiac volumetric and functional parameters in β-thalassemia patients evaluated by cardiac magnetic resonance in association with serum ferritin levels

International Nuclear Information System (INIS)

Liguori, Carlo; Pitocco, Francesca; Di Giampietro, Ilenia; Vivo, Aldo Eros de; Schena, Emiliano; Cianciulli, Paolo; Zobel, Bruno Beomonte

2013-01-01

Purpose: Myocardial T2* cardiovascular magnetic resonance provides a rapid and reproducible assessment of cardiac iron load in thalassemia patients. Although cardiac involvement is mainly characterized by left ventricular dysfunction caused by iron overload, little is known about right ventricular function. The aim of this study was to assess the relationship between T2* value in myocardium and left–right ventricular volumetric and functional parameters and to evaluate the existing associations between left–right ventricles volumetric and functional parameter, myocardial T2* values and blood ferritin levels. Materials and methods: A retrospective analysis of 208 patients with β-thalassemia major and thalassemia intermedia was performed (109 males and 99 females; mean age 37.7 ± 13 years; 143 thalassemia major, 65 thalassemia intermedia). Myocardial iron load was assessed by T2* measurements, and volumetric functions were analyzed using the steady state free precession sequence. Results: A significant correlation was observed between EFLV and T2* (p = 0.0001), EFRV and T2* (p = 0.0279). An inverse correlation was present between DVLV and T2* (p = 0.0468), SVLV and T2* (p = 0.0003), SVRV and T2* (p = 0.0001). There was no significant correlation between cardiac T2* and LV–RV mass indices. A significant correlation was observed between T2* and serum ferritin levels (p < 0.001) and between EFLV and serum ferritin (p < 0.05). Conclusion: Myocardial iron load assessed by T2* cardiac magnetic resonance is associated with deterioration in left–right ventricular function; this is more evident when T2* values fall below 14 ms. CMR appears to be a promising approach for cardiac risk evaluation in TM patients

Pre-clinical functional magnetic resonance imaging. Pt. II. The heart

Energy Technology Data Exchange (ETDEWEB)

Messner, Nadja M.; Zoellner, Frank G.; Kalayciyan, Raffi; Schad, Lothar R. [Heidelberg Univ., Mannheim (Germany). Computer Assisted Clinical Medicine

2014-07-01

One third of all deaths worldwide in 2008 were caused by cardiovascular diseases (CVD), and the incidence of CVD related deaths rises ever more. Thus, improved imaging techniques and modalities are needed for the evaluation of cardiac morphology and function. Cardiac magnetic resonance imaging (CMRI) is a minimally invasive technique that is increasingly important due to its high spatial and temporal resolution, its high soft tissue contrast and its ability of functional and quantitative imaging. It is widely accepted as the gold standard of cardiac functional analysis. In the short period of small animal MRI, remarkable progress has been achieved concerning new, fast imaging schemes as well as purpose-built equipment. Dedicated small animal scanners allow for tapping the full potential of recently developed animal models of cardiac disease. In this paper, we review state-of-the-art cardiac magnetic resonance imaging techniques and applications in small animals at ultra-high fields (UHF).

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

Science.gov (United States)

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

2016-01-01

Reference values for morphological and functional parameters of the cardiovascular system in early life are relevant since they may help to identify young adults who fall outside the physiological range of arterial and cardiac ageing. This study provides age and sex specific reference values for aortic wall characteristics, cardiac function parameters and aortic pulse wave velocity (PWV) in a population-based sample of healthy, young adults using magnetic resonance (MR) imaging. In 131 randomly selected healthy, young adults aged between 25 and 35 years (mean age 31.8 years, 63 men) of the general-population based Atherosclerosis-Monitoring-and-Biomarker-measurements-In-The-YOuNg (AMBITYON) study, descending thoracic aortic dimensions and wall thickness, thoracic aortic PWV and cardiac function parameters were measured using a 3.0T MR-system. Age and sex specific reference values were generated using dedicated software. Differences in reference values between two age groups (25-30 and 30-35 years) and both sexes were tested. Aortic diameters and areas were higher in the older age group (all page or sex effect. This study provides age and sex specific reference values for cardiovascular MR parameters in healthy, young Caucasian adults. These may aid in MR guided pre-clinical identification of young adults who fall outside the physiological range of arterial and cardiac ageing.

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; Kjær, Andreas

2010-01-01

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

Phosphorus nuclear magnetic resonance studies on normoxic and ischemic cardiac tissue.

Science.gov (United States)

Gadian, D G; Hoult, D I; Radda, G K; Seeley, P J; Chance, B; Barlow, C

1976-12-01

The intact heart of a young rat was excised rapidly and cooled to 0 degree C; its energy-rich compounds were examined by 31P Fourier Transform nuclear magnetic resonance. The heart showed the characteristic spectrum of sugar phosphates, inorganic phosphate, phosphocreatine, and magniesium phates, inorganic phosphate, phosphocreatine, and magnesium ATP, characteristics of the energizing state of the nonbeating tissue. Warming to 30 degrees C imposes an energy load upon the heart consistent with short-term resumption of beating, concomitant intracellular acidosis, and decomposition of all detectable energy-rich compounds. The intracellular acidity causes a shift from pH 7.0 to 6.0. The effects of possible interferences with this pH measurement are considered. The method appears to have wide usefulness in cardiac infarct models for detecting the fraction of the total volume occupied by the infarct and for studying the effect of various proposed therapies upon this infarcted volume.

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

Energy Technology Data Exchange (ETDEWEB)

Sakakura, Kazuyoshi; Anno, Hirofumi; Kondo, Takeshi [Fujita Health Univ., Toyoake, Aichi (Japan); and others

1993-05-01

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[approx]0.95, p<0.05[approx]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).

Cardiac Magnetic Resonance Feature Tracking Biventricular Two-Dimensional and Three-Dimensional Strains to Evaluate Ventricular Function in Children After Repaired Tetralogy of Fallot as Compared with Healthy Children.

Science.gov (United States)

Berganza, Fernando M; de Alba, Cesar Gonzalez; Özcelik, Nazire; Adebo, Dilachew

2017-03-01

Cardiac magnetic resonance imaging is an important tool to evaluate cardiac anatomy and ventricular size and function after repaired tetralogy of Fallot. Magnetic resonance tissue tagging is the gold standard for evaluation of myocardial strain. However, myocardial tagging strain requires tagged images to be obtained prospectively, during the scan and with limited temporal resolution. Cardiac magnetic resonance feature tracking is a new tool that allows the retrospective analysis of cine images. There is limited experience with cardiac magnetic resonance feature tracking strain analysis in children. The medical records of patients with repaired tetralogy of Fallot that had a cardiac magnetic resonance (CMR) study from December 2013 to June 2015 were reviewed. The control group included patients who underwent a CMR with normal cardiac anatomy and ventricular function. Global longitudinal, circumferential and radial strain parameters (2D and 3D) were obtained by retrospectively contouring cine images from ventricular short axis, two chamber and four chamber views using post-processing software (Circle CVi 42 , Calgary, Canada). The correlation between conventional ventricular function parameters and ventricular strain was performed using Pearson's correlation. The mean age of tetralogy of Fallot and control subjects was 12.4 and 14.1 years, respectively. In patients after repaired tetralogy of Fallot, the mean left ventricular global 2D and 3D circumferential strains were -17.4 ± 2.9 and -10.1 ± 3, respectively. The mean indexed right ventricular end-diastolic volume was 135.4 cc m 2  ± 46 compared to 75.7 cc m 2  ± 17 in control subjects (P = 0.0001, CI 95%). Left ventricular global circumferential 3D strain showed a statistically significant difference in patients after TOF repair compared to normal subjects (-10.1 ± 3 vs. -14.71 ± 1.9, P = 0.00001). A strong correlation between left ventricular global circumferential 3D strain and right

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...... (CMR) to assess reverse myocardial remodeling in patients after MitraClip implantation. MATERIALS AND METHODS: 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...... 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...

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

International Nuclear Information System (INIS)

Schelhorn, Juliane; Schemuth, Haemi; Nensa, Felix; Nassenstein, Kai; Forsting, Michael; Schlosser, Thomas; Schoenecker, Anne; Neudorf, Ulrich; Schara, Ulrike

2015-01-01

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 2 ; range, 48-116 ml/m 2 ) and normalized LV end-systolic volume in 20 % (31.5 ± 13.3 ml/m 2 ; range, 15-74 ml/m 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 2 ; range, 31-55 g/m 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.)

Functional Relevance of Coronary Artery Disease by Cardiac Magnetic Resonance and Cardiac Computed Tomography: Myocardial Perfusion and Fractional Flow Reserve

Directory of Open Access Journals (Sweden)

Gianluca Pontone

2015-01-01

Full Text Available Coronary artery disease (CAD is one of the leading causes of morbidity and mortality and it is responsible for an increasing resource burden. The identification of patients at high risk for adverse events is crucial to select those who will receive the greatest benefit from revascularization. To this aim, several non-invasive functional imaging modalities are usually used as gatekeeper to invasive coronary angiography, but the diagnostic yield of elective invasive coronary angiography remains unfortunately low. Stress myocardial perfusion imaging by cardiac magnetic resonance (stress-CMR has emerged as an accurate technique for diagnosis and prognostic stratification of the patients with known or suspected CAD thanks to high spatial and temporal resolution, absence of ionizing radiation, and the multiparametric value including the assessment of cardiac anatomy, function, and viability. On the other side, cardiac computed tomography (CCT has emerged as unique technique providing coronary arteries anatomy and more recently, due to the introduction of stress-CCT and noninvasive fractional flow reserve (FFR-CT, functional relevance of CAD in a single shot scan. The current review evaluates the technical aspects and clinical experience of stress-CMR and CCT in the evaluation of functional relevance of CAD discussing the strength and weakness of each approach.

Clinical recommendations of cardiac magnetic resonance, Part II: inflammatory and congenital heart disease, cardiomyopathies and cardiac tumors: a position paper of the working group 'Applicazioni della Risonanza Magnetica' of the Italian Society of Cardiology.

Science.gov (United States)

Pontone, Gianluca; Di Bella, Gianluca; Silvia, Castelletti; Maestrini, Viviana; Festa, Pierluigi; Ait-Ali, Lamia; Masci, Pier Giorgio; Monti, Lorenzo; di Giovine, Gabriella; De Lazzari, Manuel; Cipriani, Alberto; Guaricci, Andrea I; Dellegrottaglie, Santo; Pepe, Alessia; Marra, Martina Perazzolo; Aquaro, Giovanni D

2017-04-01

The current document was developed by the working group on the 'application of cardiac magnetic resonance' of the Italian Society of Cardiology to provide a perspective on the current state of technical advances and clinical cardiac magnetic resonance applications and to inform cardiologists how to implement their clinical and diagnostic pathway with the introduction of this technique in the clinical practice. Appropriateness criteria were defined using a score system: score 1-3 = inappropriate (test is not generally acceptable and is not a reasonable approach for the indication), score 4-6 = uncertain (test may be generally acceptable and may be a reasonable approach for the indication but more research and/or patient information is needed to classify the indication definitively) and score 7-9 = appropriate (test is generally acceptable and is a reasonable approach for the indication).

Evaluation of left ventricular volumes measured by magnetic resonance imaging

DEFF Research Database (Denmark)

Møgelvang, J; Thomsen, C; Mehlsen, J

1986-01-01

Left ventricular end-diastolic and end-systolic volumes were determined in 17 patients with different levels of left ventricular function by magnetic resonance imaging (MRI). A 1.5 Tesla Magnet was used obtaining ECG triggered single and multiple slices. Calculated cardiac outputs were compared...

Role of cardiac magnetic resonance imaging focusing on QOL and preventive medicine

International Nuclear Information System (INIS)

Nishimura, Tsunehiko; Ito, Hirotoshi; Kubota, Takao

2003-01-01

Cardiac magnetic resonance imaging (MRI) using fast imaging techniques has been developing quickly recently. Left ventricular function with pharmacological intervention can be evaluated using True fast imaging with steady-state precession (FISP) method. In addition, left ventricular diastolic function can be evaluated by retrospective gating with a high frame rate. Myocardial perfusion and viability can also be evaluated by first-pass imaging and delayed enhancement with Gd-DTPA. Data concerning myocardial ischemia, viability, and left ventricular function is now almost equivalent to that of myocardial SPECT and contrast echo. Additionally, coronary arterial narrowing and coronary vessel wall can be visualized with both the bright-blood and black-blood method. These methods are still currently in the research stage. The prognostic value of myocardial perfusion and ventricular function in ischemic heart disease should be established using large numbers of patients. Multi-center trials using cardiac MRI should be recommended for this purpose. Furthermore, detecting acute coronary syndrome in the emergency department can be performed with safety and accuracy. MR coronary angiography should be used not only for flow-limiting coronary stenosis but also the atherosclerotic wall region. This provides information that may predict cardiovascular risk, and facilitate further study of artherothrombosis, progression and response to therapy. It may also provide for the assessment of subclinical disease. (author)

Organ perfusion during voluntary pulmonary hyperinflation; a magnetic resonance imaging study

DEFF Research Database (Denmark)

Kristensen, Kasper Kyhl; Drvis, Ivan; Barak, Otto

2016-01-01

. Myocardial, pulmonary, skeletal muscle, kidney, and liver perfusion were evaluated by magnetic resonance imaging in 10 elite breath-hold divers at rest and during moderate GPI. Cardiac chamber volumes, stroke volume, and thus CO were determined from cardiac short-axis cine images. Organ volumes were assessed...

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.)

Aortic valve bypass surgery in severe aortic valve stenosis: Insights from cardiac and brain magnetic resonance imaging.

Science.gov (United States)

Mantini, Cesare; Caulo, Massimo; Marinelli, Daniele; Chiacchiaretta, Piero; Tartaro, Armando; Cotroneo, Antonio Raffaele; Di Giammarco, Gabriele

2018-04-13

To investigate and describe the distribution of aortic and cerebral blood flow (CBF) in patients with severe valvular aortic stenosis (AS) before and after aortic valve bypass (AVB) surgery. We enrolled 10 consecutive patients who underwent AVB surgery for severe AS. Cardiovascular magnetic resonance imaging (CMR) and brain magnetic resonance imaging were performed as baseline before surgery and twice after surgery. Quantitative flow measurements were obtained using 1.5-T magnetic resonance imaging (MRI) scanner phase-contrast images of the ascending aorta, descending thoracic aorta (3 cm proximally and distally from the conduit-to-aorta anastomosis), and ventricular outflow portion of the conduit. The evaluation of CBF was performed using 3.0-T MRI scanner arterial spin labeling (ASL) through sequences acquired at the gray matter, dorsal default-mode network, and sensorimotor levels. Conduit flow, expressed as the percentage of total antegrade flow through the conduit, was 63.5 ± 8% and 67.8 ± 7% on early and mid-term postoperative CMR, respectively (P surgery in patients with severe AS, cardiac output is split between the native left ventricular outflow tract and the apico-aortic bypass, with two-thirds of the total antegrade flow passing through the latter and one-third passing through the former. In our experience, CBF assessment confirms that the flow redistribution does not jeopardize cerebral blood supply. Copyright © 2018 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Detection of pericardial inflammation with late-enhancement cardiac magnetic resonance imaging: initial results

International Nuclear Information System (INIS)

Taylor, Andrew M.; Dymarkowski, Steven; Bogaert, Jan; Verbeken, Eric K.

2006-01-01

To examine the value of late-enhancement cardiac magnetic resonance imaging (MRI) for detection of pericardial inflammation. Late-enhancement cardiac MRI was performed in 16 patients with clinical suspicion of pericardial disease. Pericardial effusion, pericardial thickening and pericardial enhancement were assessed. MRI findings were compared with those of definitive pericardial histology (n=14) or microbiology (n=2). A control group of 12 patients with no clinical evidence of pericardial disease were also imaged with the same MRI protocol. Sensitivity and specificity for late-enhancement MRI detection of pericardial inflammation was of 100%. There was MRI late enhancement of the pericardial layers in all five patients with histological/microbiological evidence of inflammatory pericarditis. MRI demonstrated no pericardial thickening and no MRI late enhancement with or without a pericardial effusion in any of the five patients with histological evidence of a normal pericardium. MRI detected pericardial thickening in the absence of both pericardial effusion and late enhancement in all six patients with histological evidence of chronic fibrosing pericarditis. The 12 control subjects showed no evidence of pericardial MRI late enhancement. These findings demonstrate that MRI late enhancement can be used to visualize pericardial inflammation in patients with clinical suspicion of pericardial disease. (orig.)

Cardiovascular magnetic resonance in hypertrophic cardiomyopathy and infiltrative cardiomyopathy

OpenAIRE

Schofield, Rebecca; Manacho, Katia; Castelletti, Silvia; Moon, James C.

2016-01-01

Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiac disease. Cardiac imaging plays a key role in the diagnosis and management, with cardiovascular magnetic resonance (CMR) an important modality. CMR provides a number of different techniques in one examination: structure and function, flow imaging and tissue characterisation particularly with the late gadolinium enhancement (LGE) technique. Other techniques include vasodilator perfusion, mapping (especially T1 mapping and ex...

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

Science.gov (United States)

Olivieri, Laura J; Cross, Russell R; O'Brien, Kendall E; Ratnayaka, Kanishka; Hansen, Michael S

2015-09-01

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 metal artifact reduction for the optimized TSE images was 1.6+/-1.7 mm (P 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 black-blood imaging, a TSE sequence should be used with fat saturation turned off and high receiver bandwidth.

Cardiac involvement in ANCA (+) and ANCA (-) Churg-Strauss syndrome evaluated by cardiovascular magnetic resonance.

Science.gov (United States)

Mavrogeni, Sophie; Karabela, Georgia; Gialafos, Elias; Stavropoulos, Efthymios; Spiliotis, George; Katsifis, Gikas; Kolovou, Genovefa

2013-10-01

The cardiovascular magnetic resonance (CMR) pattern of Churg-Strauss syndrome (CSS) includes myopericarditis, diffuse subendocardial vasculitis or myocardial infarction with or without cardiac symptoms and is usually associated with lack of antineutrophil cytoplasmic antibodies (ANCA). To correlate the CMR pattern with ANCA in CSS, compare it with healthy controls and systemic lupus erythematosus (SLE) patients and re-evaluate 2 yrs after the first CMR. 28 consecutive CSS, aged 42±7 yrs, were referred for CMR and 2 yrs re-evaluation. The CMR included left ventricular ejection fraction (LVEF), T2-weighted (T2-W), early (EGE) and late gadolinium enhanced (LGE) imaging. Their results were compared with 28 systemic lupus erythematosus (SLE) under remission and 28 controls with normal myocardial perfusion, assessed by scintigraphy. CMR revealed acute cardiac lesions in all ANCA (-) CSS with active disease and acute cardiac symptoms and only in one asymptomatic ANCA (+) CSS, with active disease. Diffuse subendocardial fibrosis (DSF) or past myocarditis was identified in both ANCA(+) and ANCA (-) CSS, but with higher incidence and fibrosis amount in ANCA (-) CSS (p<0.05). In comparison to SLE, both ANCA (+) and ANCA (-) CSS had higher incidence of DSF, lower incidence of myocarditis and no evidence of myocardial infarction, due to coronary artery disease (p<0.05). In 2 yrs CMR follow up, 1/3 of CSS with DSF presented LV function deterioration and one died, although immunosuppressive treatment was given early after CSS diagnosis. Cardiac involvement either as DSF or myocarditis, can be detected in both ANCA (+) and ANCA (-) CSS, although more clinically overt in ANCA (-). DSF carries an ominous prognosis for LV function. CMR, due to its capability to detect disease severity, before cardiac dysfunction takes place, is an excellent tool for CSS risk stratification and treatment individualization.

Sinus of Valsalva aneurysm and bicuspid aortic valve: detection and mechanism by cardiac magnetic resonance imaging

Directory of Open Access Journals (Sweden)

Jen Li Looi

2011-09-01

Full Text Available Cardiac magnetic resonance imaging (CMR demonstrated a sinus of Valsalva aneurysm (SVA with severe dilatation of the right coronary sinus in association with a congenital bicuspid aortic valve (BAV and subaortic membrane. The SVA had not been apparent on echocardiography as the dilatation was outside standard echo image planes. On both CMR and echo, blood flow was eccentrically directed into the right coronary sinus by the domed posterior leaflet of the BAV. The impact of the aortic jet on the wall of the right coronary sinus is probably important in the aetiology of the sinus dilatation. CMR proved valuable in demonstrating the SVA and understanding its aetiology.

Sinus of Valsalva aneurysm and bicuspid aortic valve: detection and mechanism by cardiac magnetic resonance imaging

Directory of Open Access Journals (Sweden)

Jen Li Looi

2011-10-01

Full Text Available Cardiac magnetic resonance imaging (CMR demonstrated a sinus of Valsalva aneurysm (SVA with severe dilatation of the right coronary sinus in association with a congenital bicuspid aortic valve (BAV and subaortic membrane. The SVA had not been apparent on echocardiography as the dilatation was outside standard echo image planes. On both CMR and echo, blood flow was eccentrically directed into the right coronary sinus by the domed posterior leaflet of the BAV. The impact of the aortic jet on the wall of the right coronary sinus is probably important in the aetiology of the sinus dilatation. CMR proved valuable in demonstrating the SVA and understanding its aetiology.

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

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

2011-08-15

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

Iron overload in a teenager with xerocytosis: the importance of nuclear magnetic resonance imaging

International Nuclear Information System (INIS)

Assis, Reijâne Alves de; Kassab, Carolina; Seguro, Fernanda Salles; Costa, Fernando Ferreira; Silveira, Paulo Augusto Achucarro; Wood, John; Hamerschlak, Nelson

2013-01-01

To report a case of iron overload secondary to xerocytosis, a rare disease in a teenager, diagnosed, by T2* magnetic resonance imaging. We report the case of a symptomatic patient with xerocytosis, a ferritin level of 350ng/mL and a significant cardiac iron overload. She was diagnosed by T2* magnetic resonance imaging and received chelation therapy Ektacytometric analysis confirmed the diagnosis of hereditary xerocytosis. Subsequent T2* magnetic resonance imaging demonstrated complete resolution of the iron overload in various organs, as a new echocardiography revealed a complete resolution of previous cardiac alterations. The patient remains in chelation therapy. Xerocytosis is a rare autosomal dominant genetic disorder characterized by dehydrated stomatocytosis. The patient may present with intense fatigue and iron overload. We suggest the regular use of T2* magnetic resonance imaging for the diagnosis and control of the response to iron chelation in xerocytosis, and we believe it can be used also in other hemolytic anemia requiring transfusions

Iron overload in a teenager with xerocytosis: the importance of nuclear magnetic resonance imaging

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Assis, Reijâne Alves de; Kassab, Carolina; Seguro, Fernanda Salles [Hospital Israelita Albert Einstein, São Paulo, SP (Brazil); Costa, Fernando Ferreira [Universidade Estadual de Campinas, Campinas, SP (Brazil); Silveira, Paulo Augusto Achucarro [Hospital Israelita Albert Einstein, São Paulo, SP (Brazil); Wood, John [University of Southern California, California (United States); Hamerschlak, Nelson [Hospital Israelita Albert Einstein, São Paulo, SP (Brazil)

2013-07-01

To report a case of iron overload secondary to xerocytosis, a rare disease in a teenager, diagnosed, by T2* magnetic resonance imaging. We report the case of a symptomatic patient with xerocytosis, a ferritin level of 350ng/mL and a significant cardiac iron overload. She was diagnosed by T2* magnetic resonance imaging and received chelation therapy Ektacytometric analysis confirmed the diagnosis of hereditary xerocytosis. Subsequent T2* magnetic resonance imaging demonstrated complete resolution of the iron overload in various organs, as a new echocardiography revealed a complete resolution of previous cardiac alterations. The patient remains in chelation therapy. Xerocytosis is a rare autosomal dominant genetic disorder characterized by dehydrated stomatocytosis. The patient may present with intense fatigue and iron overload. We suggest the regular use of T2* magnetic resonance imaging for the diagnosis and control of the response to iron chelation in xerocytosis, and we believe it can be used also in other hemolytic anemia requiring transfusions.

Iron overload in a teenager with xerocytosis: the importance of nuclear magnetic resonance imaging.

Science.gov (United States)

Assis, Reijâne Alves de; Kassab, Carolina; Seguro, Fernanda Salles; Costa, Fernando Ferreira; Silveira, Paulo Augusto Achucarro; Wood, John; Hamerschlak, Nelson

2013-12-01

To report a case of iron overload secondary to xerocytosis, a rare disease in a teenager, diagnosed, by T2* magnetic resonance imaging. We report the case of a symptomatic patient with xerocytosis, a ferritin level of 350ng/mL and a significant cardiac iron overload. She was diagnosed by T2* magnetic resonance imaging and received chelation therapy Ektacytometric analysis confirmed the diagnosis of hereditary xerocytosis. Subsequent T2* magnetic resonance imaging demonstrated complete resolution of the iron overload in various organs, as a new echocardiography revealed a complete resolution of previous cardiac alterations. The patient remains in chelation therapy. Xerocytosis is a rare autosomal dominant genetic disorder characterized by dehydrated stomatocytosis. The patient may present with intense fatigue and iron overload. We suggest the regular use of T2* magnetic resonance imaging for the diagnosis and control of the response to iron chelation in xerocytosis, and we believe it can be used also in other hemolytic anemia requiring transfusions.

Age- and gender-specific differences in left and right ventricular cardiac function and mass determined by cine magnetic resonance imaging

International Nuclear Information System (INIS)

Sandstede, J.; Lipke, C.; Beer, M.; Hofmann, S.; Pabst, T.; Kenn, W.; Hahn, D.; Neubauer, S.

2000-01-01

We examined possible age- and gender-specific differences in the function and mass of left (LV) and right (RV) ventricles in 36 healthy volunteers using cine gradient-recalled echo magnetic resonance imaging. Subjects were divided into four groups (nine men and nine women in each): men aged under 45 years (32 ± 7), women aged under 45 (27 ± 6), men aged over 45 (59 ± 8), and women aged over 45 (57 ± 9). Functional analysis of cardiac volume and mass and of LV wall motion was performed by manual segmentation of the endocardial and epicardial borders of the end-diastolic and end-systolic frame; both absolute and normalized (per square meter body surface area) values were evaluated. With age there was a significant decrease in both absolute and normalized LV and RV chamber volumes (EDV, ESV), while LV and RV masses remained unchanged. Gender-specific differences were found in cardiac mass and volume (for men and women, respectively: LV mass, 155 ± 18 and 110 ± 16 g; LV EDV, 118 ± 27 and 96 ± 21 ml; LV ESV, 40 ± 13 and 29 ± 9 ml; RV mass, 52 ± 10 and 39 ± 5 g; RV EDV, 131 ± 28 and 100 ± 23 ml; RV ESV, 53 ± 17 and 33 ± 15 ml). Normalization to body surface area eliminated differences in LV volumes but not those in LV mass, RV mass, or RV function. Functional parameters such as cardiac output and LV ejection fraction showed nonsignificant or only slight differences and were thus largely independent of age and gender. Intra- and interobserver variability ranged between 1.4 % and 5.9 % for all parameters. Cine magnetic resonance imaging thus shows age- and gender-specific differences in cardiac function, and therefore the evaluation of cardiac function in patients should consider age- and gender-matched normative values. (orig.)

Predictors of missed appointments in patients referred for congenital or pediatric cardiac magnetic resonance

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Lu, Jimmy C.; Dorfman, Adam L. [C.S. Mott Children' s Hospital, Department of Pediatrics and Communicable Diseases, Division of Pediatric Cardiology, University of Michigan Health System, University of Michigan Congenital Heart Center, Ann Arbor, MI (United States); C.S. Mott Children' s Hospital, Department of Radiology, University of Michigan Health System, Section of Pediatric Radiology, Ann Arbor, MI (United States); Lowery, Ray; Yu, Sunkyung [C.S. Mott Children' s Hospital, Department of Pediatrics and Communicable Diseases, Division of Pediatric Cardiology, University of Michigan Health System, University of Michigan Congenital Heart Center, Ann Arbor, MI (United States); Ghadimi Mahani, Maryam [C.S. Mott Children' s Hospital, Department of Radiology, University of Michigan Health System, Section of Pediatric Radiology, Ann Arbor, MI (United States); Agarwal, Prachi P. [University of Michigan Health System, Department of Radiology, Division of Cardiothoracic Radiology, Ann Arbor, MI (United States)

2017-07-15

Congenital cardiac magnetic resonance is a limited resource because of scanner and physician availability. Missed appointments decrease scheduling efficiency, have financial implications and represent missed care opportunities. To characterize the rate of missed appointments and identify modifiable predictors. This single-center retrospective study included all patients with outpatient congenital or pediatric cardiac MR appointments from Jan. 1, 2014, through Dec. 31, 2015. We identified missed appointments (no-shows or same-day cancellations) from the electronic medical record. We obtained demographic and clinical factors from the medical record and assessed socioeconomic factors by U.S. Census block data by patient ZIP code. Statistically significant variables (P<0.05) were included into a multivariable analysis. Of 795 outpatients (median age 18.5 years, interquartile range 13.4-27.1 years) referred for congenital cardiac MR, a total of 91 patients (11.4%) missed appointments; 28 (3.5%) missed multiple appointments. Reason for missed appointment could be identified in only 38 patients (42%), but of these, 28 (74%) were preventable or could have been identified prior to the appointment. In multivariable analysis, independent predictors of missed appointments were referral by a non-cardiologist (adjusted odds ratio [AOR] 5.8, P=0.0002), referral for research (AOR 3.6, P=0.01), having public insurance (AOR 2.1, P=0.004), and having scheduled cardiac MR from November to April (AOR 1.8, P=0.01). Demographic factors can identify patients at higher risk for missing appointments. These data may inform initiatives to limit missed appointments, such as targeted education of referring providers and patients. Further data are needed to evaluate the efficacy of potential interventions. (orig.)

Ultra-fast magnetic resonance encephalography of physiological brain activity - Glymphatic pulsation mechanisms?

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Kiviniemi, Vesa; Wang, Xindi; Korhonen, Vesa; Keinänen, Tuija; Tuovinen, Timo; Autio, Joonas; LeVan, Pierre; Keilholz, Shella; Zang, Yu-Feng; Hennig, Jürgen; Nedergaard, Maiken

2016-06-01

The theory on the glymphatic convection mechanism of cerebrospinal fluid holds that cardiac pulsations in part pump cerebrospinal fluid from the peri-arterial spaces through the extracellular tissue into the peri-venous spaces facilitated by aquaporin water channels. Since cardiac pulses cannot be the sole mechanism of glymphatic propulsion, we searched for additional cerebrospinal fluid pulsations in the human brain with ultra-fast magnetic resonance encephalography. We detected three types of physiological mechanisms affecting cerebral cerebrospinal fluid pulsations: cardiac, respiratory, and very low frequency pulsations. The cardiac pulsations induce a negative magnetic resonance encephalography signal change in peri-arterial regions that extends centrifugally and covers the brain in ≈1 Hz cycles. The respiratory ≈0.3 Hz pulsations are centripetal periodical pulses that occur dominantly in peri-venous areas. The third type of pulsation was very low frequency (VLF 0.001-0.023 Hz) and low frequency (LF 0.023-0.73 Hz) waves that both propagate with unique spatiotemporal patterns. Our findings using critically sampled magnetic resonance encephalography open a new view into cerebral fluid dynamics. Since glymphatic system failure may precede protein accumulations in diseases such as Alzheimer's dementia, this methodological advance offers a novel approach to image brain fluid dynamics that potentially can enable early detection and intervention in neurodegenerative diseases. © The Author(s) 2015.

Volume and planar gated cardiac magnetic resonance imaging: a correlative study of normal anatomy with Thallium-201 SPECT and cadaver sections

International Nuclear Information System (INIS)

Go, R.T.; MacIntyre, W.J.; Yeung, H.N.

1984-01-01

Magnetic resonance (MR) gated cardiac imaging was performed in ten subjects using a prototype 0.15-T resistive magnet imaging system. Volume and planar imaging techniques utilizing saturation recovery, proton TI-weighted relaxation time pulse sequences produced images of the heart and great vessels with exquisite anatomic detail that showed excellent correlation with cadaver sections of the heart. The left ventricular myocardial segments also showed excellent correlation with cadaver sections of the heart. The left ventricular myocardial segments also showed excellent correlation with the thallium-201 cardiac single photon emission computed tomography images. Volume acquisition allowed postprocessing selection of tomographic sections in various orientations to optimize visualization of a particular structure of interest. The excellent spatial and contrast resolution afforded by MR volume imaging, which does not involve the use of ionizing radiation and iodinated contrast material, should assure it a significant role in the diagnostic assessment of the cardiovascular system

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

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Hermans Mieke CE

2012-07-01

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

Age-related normal structural and functional ventricular values in cardiac function assessed by magnetic resonance

International Nuclear Information System (INIS)

Fiechter, Michael; Gaemperli, Oliver; Kaufmann, Philipp A; Fuchs, Tobias A; Gebhard, Catherine; Stehli, Julia; Klaeser, Bernd; Stähli, Barbara E; Manka, Robert; Manes, Costantina; Tanner, Felix C

2013-01-01

The heart is subject to structural and functional changes with advancing age. However, the magnitude of cardiac age-dependent transformation has not been conclusively elucidated. This retrospective cardiac magnetic resonance (CMR) study included 183 subjects with normal structural and functional ventricular values. End systolic volume (ESV), end diastolic volume (EDV), and ejection fraction (EF) were obtained from the left and the right ventricle in breath-hold cine CMR. Patients were classified into four age groups (20–29, 30–49, 50–69, and ≥70 years) and cardiac measurements were compared using Pearson’s rank correlation over the four different groups. With advanced age a slight but significant decrease in ESV (r=−0.41 for both ventricles, P<0.001) and EDV (r=−0.39 for left ventricle, r=−0.35 for right ventricle, P<0.001) were observed associated with a significant increase in left (r=0.28, P<0.001) and right (r=0.27, P<0.01) ventricular EF reaching a maximal increase in EF of +8.4% (P<0.001) for the left and +6.1% (P<0.01) for the right ventricle in the oldest compared to the youngest patient group. Left ventricular myocardial mass significantly decreased over the four different age groups (P<0.05). The aging process is associated with significant changes in left and right ventricular EF, ESV and EDV in subjects with no cardiac functional and structural abnormalities. These findings underline the importance of using age adapted values as standard of reference when evaluating CMR studies

Fusion of 4D echocardiography and cine cardiac magnetic resonance volumes using a salient spatio-temporal analysis

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Atehortúa, Angélica; Garreau, Mireille; Romero, Eduardo

2017-11-01

An accurate left (LV) and right ventricular (RV) function quantification is important to support evaluation, diagnosis and prognosis of cardiac pathologies such as the cardiomyopathies. Currently, diagnosis by ultrasound is the most cost-effective examination. However, this modality is highly noisy and operator dependent, hence prone to errors. Therefore, fusion with other cardiac modalities may provide complementary information and improve the analysis of the specific pathologies like cardiomyopathies. This paper proposes an automatic registration between two complementary modalities, 4D echocardiography and Magnetic resonance images, by mapping both modalities to a common space of salience where an optimal registration between them is estimated. The obtained matrix transformation is then applied to the MRI volume which is superimposed to the 4D echocardiography. Manually selected marks in both modalities are used to evaluate the precision of the superimposition. Preliminary results, in three evaluation cases, show the distance between these marked points and the estimated with the transformation is about 2 mm.

Magnetic resonance annual 1986

International Nuclear Information System (INIS)

Kressel, H.Y.

1986-01-01

This book contains papers written on magnetic resonance during 1986. Topics include: musculosketetal magnetic resonance imaging; imaging of the spine; magnetic resonance chemical shift imaging; magnetic resonance imaging in the central nervous system; comparison to computed tomography; high resolution magnetic resonance imaging using surface coils; magnetic resonance imaging of the chest; magnetic resonance imaging of the breast; magnetic resonance imaging of the liver; magnetic resonance spectroscopy of neoplasms; blood flow effects in magnetic resonance imaging; and current and potential applications of clinical sodium magnetic resonance imaging

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

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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

[Myocardial regional thickness in patients with and without cardiomyopathy assessed by cardiac magnetic resonance].

Science.gov (United States)

de Zan, Macarena; Carrascosa, Patricia; Deviggiano, Alejandro; Capuñay, Carlos; Rodríguez-Granillo, Gastón A

To explore regional differences in myocardial wall thickness (WT) among the most prevalent cardiomyopathies and in individuals without structural heart disease using cardiac magnetic resonance. Patients older than 18 years referred to cardiac magnetic resonance during the period between January 2014 and September 2014, with a diagnosis of hypertrophic cardiomyopathy, idiopathic dilated cardiomyopathy, ischemic cardiomyopathy, and myocarditis were retrospectively selected from our database. One hundred twenty patients patients were included. The control group had an average WT of 5.9±1.1mm, with a WT index of 2.9±0.8. Significantly lower mean WT in the apical segments were identified in both the control group (basal 6.7±1.3 vs. mid 6.0±1.3 vs. apical 4.6±1.0mm, P<.0001) and in all evaluated cardiomyopathies (hypertrophic cardiomyopathy: basal 10.5±2.4 vs. mid 10.8±2.7 vs. apical 7.3±3.3mm, P<.0001; idiopathic dilated cardiomyopathy: basal 7.7±1.7 vs. mid 7.6±1.3 vs. apical 5.4±1.3mm, P<.0001; ischemic cardiomyopathy: basal 7.4±1.7 vs. mid 7.5±1.9 vs. apical 5.5±1.8mm, P<.0001; myocarditis: basal 7.1±1.5 vs. mid 6.4±1.1 vs. apical 5.1±0.8, P<.0001). Significant gender differences were also evident regarding the mean WT both in the control group (male 6.5±2.1 vs. female 5.2±1.7mm, P<.0001), as in hypertrophic cardiomyopathy (10.5±5.3 vs. 8.5±5.7mm, P<.0001) and myocarditis (6.6±2.0 vs. 5.2±1.6mm, P<.0001). We found a relatively high prevalence of segments commonly deemed thinned among patients without structural heart disease. We also observed a marked asymmetry and longitudinal gradient in wall thickness both in controls and in the various cardiomyopathies evaluated. Copyright © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

Magnetic resonance imaging of implantable cardiac rhythm devices at 3.0 tesla.

Science.gov (United States)

Gimbel, J Rod

2008-07-01

A relaxation of the prohibition of scanning cardiac rhythm device patients is underway, largely because of the growing experience of safe scanning events at 1.5T. Magnetic resonance imaging (MRI) at 3T is becoming more common and may pose a different risk profile and outcome of MRI of cardiac device patients. No restrictions were placed on pacemaker dependency, region scanned, device type, or manufacturer. Sixteen scans at 3T were performed with an electrophysiologist present on 14 patients with a variety of devices from various manufacturers. An "MRI-S" strategy was used. Multimodal monitoring was required. Device interrogation was performed prior to, immediately after, and 1-3 months after the MRI. For nonpacemaker-dependent device patients, attempts were made to turn all device features off (with OOO programming the goal) conceptually rendering the device "invisible." In pacemaker-dependent patients, the device was programmed to asynchronous mode at highest output for the duration of the scan with the goal of rendering the device conceptually "invulnerable" to MRI effects. The specific absorption rate (SAR) was limited to 2W/kg. All patients were successfully scanned. No arrhythmias were noted. No significant change in the programmed parameters, pacing thresholds, sensing, impedance, or battery parameters was noted. The insertable loop recorder (ILR) recorded prolonged artifactual asystole during MRI. One patient noted chest burning during the scan. Device patients may undergo carefully tailored 3T MRI scans when pre-MRI reprogramming of the device occurs in conjunction with extensive monitoring, supervision, and follow-up.

Magnetic resonance tomography of the heart

Energy Technology Data Exchange (ETDEWEB)

Tscholakoff, D.

1987-01-01

In this experimental study (canine heart) a variety of pathologic conditions of the myocardium were studied using ECG-triggered magnetic resonance imaging (MRI). The purpose of this study was to examine the MR appearance and the T/sub 2/ relaxation times of occlusive and reperfused myocardial infarcts, of hypertrophic cardiomyopathy and of cardiac transplants with and without acute cardiac allograft rejection. MR images were correlated with the results of histology and tissue water content. MRI identified normal myocardium with T/sub 2/ values of 38 (+-4.3) msec. Myocardial infarcts and acute allograft rejection had significant (p<0.05) longer T/sub 2/ values compared to normal myocardium. On the basis of T/sub 2/ relaxation times no further differentiation among different pathologic entities was possible. Therefore, it is necessary to include morphologic criteria such as myocardial wall thickness, cardiac chamber size and intracavitary blood flow signal in the interpretation of cardiac MR tomograms.

Role of pyruvate dehydrogenase inhibition in the development of hypertrophy in the hyperthyroid rat heart: a combined magnetic resonance imaging and hyperpolarized magnetic resonance spectroscopy study.

Science.gov (United States)

Atherton, Helen J; Dodd, Michael S; Heather, Lisa C; Schroeder, Marie A; Griffin, Julian L; Radda, George K; Clarke, Kieran; Tyler, Damian J

2011-06-07

Hyperthyroidism increases heart rate, contractility, cardiac output, and metabolic rate. It is also accompanied by alterations in the regulation of cardiac substrate use. Specifically, hyperthyroidism increases the ex vivo activity of pyruvate dehydrogenase kinase, thereby inhibiting glucose oxidation via pyruvate dehydrogenase. Cardiac hypertrophy is another effect of hyperthyroidism, with an increase in the abundance of mitochondria. Although the hypertrophy is initially beneficial, it can eventually lead to heart failure. The aim of this study was to use hyperpolarized magnetic resonance spectroscopy to investigate the rate and regulation of in vivo pyruvate dehydrogenase flux in the hyperthyroid heart and to establish whether modulation of flux through pyruvate dehydrogenase would alter cardiac hypertrophy. Hyperthyroidism was induced in 18 male Wistar rats with 7 daily intraperitoneal injections of freshly prepared triiodothyronine (0.2 mg x kg(-1) x d(-1)). In vivo pyruvate dehydrogenase flux, assessed with hyperpolarized magnetic resonance spectroscopy, was reduced by 59% in hyperthyroid animals (0.0022 ± 0.0002 versus 0.0055 ± 0.0005 second(-1); P=0.0003), and this reduction was completely reversed by both short- and long-term delivery of dichloroacetic acid, a pyruvate dehydrogenase kinase inhibitor. Hyperpolarized [2-(13)C]pyruvate was also used to evaluate Krebs cycle metabolism and demonstrated a unique marker of anaplerosis, the level of which was significantly increased in the hyperthyroid heart. Cine magnetic resonance imaging showed that long-term dichloroacetic acid treatment significantly reduced the hypertrophy observed in hyperthyroid animals (100 ± 20 versus 200 ± 30 mg; P=0.04) despite no change in the increase observed in cardiac output. This work has demonstrated that inhibition of glucose oxidation in the hyperthyroid heart in vivo is mediated by pyruvate dehydrogenase kinase. Relieving this inhibition can increase the metabolic

Myocardial Viability on Cardiac Magnetic Resonance.

Science.gov (United States)

Souto, Ana Luiza Mansur; Souto, Rafael Mansur; Teixeira, Isabella Cristina Resende; Nacif, Marcelo Souto

2017-05-01

The study of myocardial viability is of great importance in the orientation and management of patients requiring myocardial revascularization or angioplasty. The technique of delayed enhancement (DE) is accurate and has transformed the study of viability into an easy test, not only for the detection of fibrosis but also as a binary test detecting what is viable or not. On DE, fibrosis equal to or greater than 50% of the segmental area is considered as non-viable, whereas that below 50% is considered viable. During the same evaluation, cardiac magnetic resonance (CMR) may also use other techniques for functional and perfusion studies to obtain a global evaluation of ischemic heart disease. This study aims to highlight the current concepts and broadly emphasize the use of CMR as a method that over the last 20 years has become a reference in the detection of infarction and assessment of myocardial viability. Resumo O estudo de viabilidade miocárdica é de grande importância para a orientação e manejo de pacientes que necessitam de cirurgia de revascularização miocárdica ou angioplastia. A técnica de realce tardio (RT) é precisa e transformou o estudo de viabilidade em um teste fácil, não só para a detecção de fibrose, mas também como um modelo binário para a detecção do que é ou não é viável. Uma fibrose identificada pelo RT é considerada como não viável quando igual ou maior do que 50% da área segmentar e como viável quando menor que 50%. A ressonância magnética cardíaca (RMC) também pode lançar mão de outras técnicas para estudo funcional e de perfusão para uma avaliação global da doença isquêmica do coração no mesmo exame. Este estudo tem como objetivo destacar os conceitos atuais e enfatizar amplamente o uso da RMC como um método que nos últimos 20 anos se tornou referência na detecção de infarto e avaliação de viabilidade miocárdica.

Association between the resolution of the ST with microvascular obstruction and the size of the infarction assessed by cardiac magnetic resonance imaging

International Nuclear Information System (INIS)

Lluveras, N.; Parma, G.; Florio, L; Zamoro, J

2012-01-01

The absence of ST-segment resolution (STR) in patients with an ST-elevation myocardial infarction (STEMI) after reperfusion strategy has been related to impaired myocardial perfusion. This is likely due to extensive microvascular obstruction (MVO) and reperfusion tissue injury. The aim of the study was to analyze the value of STR in the prediction of infarct size, perfusion impairment and left ventricular function assessed with cardiac magnetic resonance (CMR) in acute STEMI

Evaluation of cardiac and hepatic iron overload in thalassemia major patients with T2* magnetic resonance imaging.

Science.gov (United States)

Wahidiyat, Pustika Amalia; Liauw, Felix; Sekarsari, Damayanti; Putriasih, Siti Ayu; Berdoukas, Vasili; Pennell, Dudley J

2017-09-01

Recent advancements have promoted the use of T2* magnetic resonance imaging (MRI) in the non-invasive detection of iron overload in various organs for thalassemia major patients. This study aims to determine the iron load in the heart and liver of patients with thalassemia major using T2* MRI and to evaluate its correlation with serum ferritin level and iron chelation therapy. This cross-sectional study included 162 subjects diagnosed with thalassemia major, who were classified into acceptable, mild, moderate, or severe cardiac and hepatic iron overload following their T2* MRI results, respectively, and these were correlated to their serum ferritin levels and iron chelation therapy. The study found that 85.2% of the subjects had normal cardiac iron stores. In contrast, 70.4% of the subjects had severe liver iron overload. A significant but weak correlation (r = -0.28) was found between cardiac T2* MRI and serum ferritin, and a slightly more significant correlation (r = 0.37) was found between liver iron concentration (LIC) and serum ferritin. The findings of this study are consistent with several other studies, which show that patients generally manifest with liver iron overload prior to cardiac iron overload. Moreover, iron accumulation demonstrated by T2* MRI results also show a significant correlation to serum ferritin levels. This is the first study of its kind conducted in Indonesia, which supports the fact that T2* MRI is undoubtedly valuable in the early detection of cardiac and hepatic iron overload in thalassemia major patients.

Dynamic and quantitative evaluation of degenerative mitral valve disease: a dedicated framework based on cardiac magnetic resonance imaging.

Science.gov (United States)

Sturla, Francesco; Onorati, Francesco; Puppini, Giovanni; Pappalardo, Omar A; Selmi, Matteo; Votta, Emiliano; Faggian, Giuseppe; Redaelli, Alberto

2017-04-01

Accurate quantification of mitral valve (MV) morphology and dynamic behavior over the cardiac cycle is crucial to understand the mechanisms of degenerative MV dysfunction and to guide the surgical intervention. Cardiac magnetic resonance (CMR) imaging has progressively been adopted to evaluate MV pathophysiology, although a dedicated framework is required to perform a quantitative assessment of the functional MV anatomy. We investigated MV dynamic behavior in subjects with normal MV anatomy (n=10) and patients referred to surgery due to degenerative MV prolapse, classified as fibro-elastic deficiency (FED, n=9) and Barlow's disease (BD, n=10). A CMR-dedicated framework was adopted to evaluate prolapse height and volume and quantitatively assess valvular morphology and papillary muscles (PAPs) function over the cardiac cycle. Multiple comparison was used to investigate the hallmarks associated to MV degenerative prolapse and evaluate the feasibility of anatomical and functional distinction between FED and BD phenotypes. On average, annular dimensions were significantly (Pframework allows for the quantitative and dynamic evaluation of MV apparatus, with quantifiable annular alterations representing the primary hallmark of severe MV degeneration. This may aid surgeons in the evaluation of the severity of MV dysfunction and the selection of the appropriate MV treatment.

Association of Right Ventricular Pressure and Volume Overload with Non-Ischemic Septal Fibrosis on Cardiac Magnetic Resonance.

Directory of Open Access Journals (Sweden)

Jiwon Kim

Full Text Available Non-ischemic fibrosis (NIF on cardiac magnetic resonance (CMR has been linked to poor prognosis, but its association with adverse right ventricular (RV remodeling is unknown. This study examined a broad cohort of patients with RV dysfunction, so as to identify relationships between NIF and RV remodeling indices, including RV pressure load, volume and wall stress.The population comprised patients with RV dysfunction (EF 6-fold more common in the highest, vs. the lowest, common tertile of PASP and RV size (p<0.001.Among wall stress components, NIF was independently associated with RV chamber dilation and afterload, supporting the concept that NIF is linked to adverse RV chamber remodeling.

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

Directory of Open Access Journals (Sweden)

Castro Ana Valéria Barros de

2002-01-01

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

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

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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.

Magnetic resonance angiography vs. angiography in tetralogy of Fallot.

Science.gov (United States)

Rao, Uppalapati Venkateswara; Vanajakshamma, Velam; Rajasekhar, Durgaprasad; Lakshmi, Amancharla Yadagiri; Reddy, Reddivari Niranjan

2013-08-01

: To determine whether gadolinium-enhanced three-dimensional magnetic resonance angiography can provide a noninvasive alternative to diagnostic catheterization for evaluation of pulmonary artery anatomy in tetralogy of Fallot. Thirty-five consecutive patients with tetralogy of Fallot, who attended the cardiology outpatient department between January 2008 and December 2009, were included in the study. There were 21 males and 14 females, with a mean age of 9 ± 4.15 years (range, 3-21 years). Thirty-two patients had tetralogy of Fallot with varying severities of valvular and infundibular stenosis. Three patients had tetralogy of Fallot with pulmonary atresia. All patients underwent both cardiac catheterization with X-ray angiography and 3-dimensional magnetic resonance angiography within one month. Measurements of right and left pulmonary arteries and aortopulmonary collaterals were equal by both methods. There was a good correlation between magnetic resonance angiography and catheterization measurements of branch pulmonary arteries. Gadolinium-enhanced three-dimensional magnetic resonance angiography can be used as a reliable noninvasive alternative to X-ray cineangiography for delineation of pulmonary arterial anatomy in sick infants and young children, obviating the need for catheterization.

Stress Perfusion Coronary Flow Reserve Versus Cardiac Magnetic Resonance for Known or Suspected CAD.

Science.gov (United States)

Kato, Shingo; Saito, Naka; Nakachi, Tatsuya; Fukui, Kazuki; Iwasawa, Tae; Taguri, Masataka; Kosuge, Masami; Kimura, Kazuo

2017-08-15

Phase-contrast (PC) cine magnetic resonance imaging (MRI) of the coronary sinus is a noninvasive method to quantify coronary flow reserve (CFR). This study sought to compare the prognostic value of CFR by cardiac magnetic resonance (CMR) and stress perfusion CMR to predict major adverse cardiac events (MACE). Participants included 276 patients with known coronary artery disease (CAD) and 400 with suspected CAD. CFR was calculated as myocardial blood flow during adenosine triphosphate infusion divided by myocardial blood flow at rest using PC cine MRI of the coronary sinus. During a median follow-up of 2.3 years, 47 patients (7%) experienced MACE. Impaired CFR (10% ischemia on stress perfusion CMR were significantly associated with MACE in patients with known CAD (hazard ratio [HR]: 5.17 and HR: 5.10, respectively) and suspected CAD (HR: 14.16 and HR: 6.50, respectively). The area under the curve for predicting MACE was 0.773 for CFR and 0.731 for stress perfusion CMR (p = 0.58) for patients with known CAD, and 0.885 for CFR and 0.776 for stress perfusion CMR (p = 0.059) in the group with suspected CAD. In patients with known CAD, sensitivity, specificity, and positive and negative predictive values to predict MACE were 64%, 91%, 38%, and 97%, respectively, for CFR, and 82%, 59%, 15%, and 97%, respectively, for stress perfusion CMR. In the suspected CAD group, these values were 65%, 99%, 80%, and 97%, respectively, for CFR, and 72%, 83%, 22%, and 98%, respectively, for stress perfusion CMR. The predictive values of CFR and stress perfusion CMR for MACE were comparable in patients with known CAD. In patients with suspected CAD, CFR showed higher HRs and areas under the curve than stress perfusion CMR, suggesting that CFR assessment by PC cine MRI might provide better risk stratification for patients with suspected CAD. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Nuclear magnetic resonance imaging in patients with hypertrophic and dilated cardiomyopathy

International Nuclear Information System (INIS)

Boisvieux, A.

1987-01-01

Patients with hypertrophic and dilated cardiomyopathy and normal subjects were investigated with nuclear magnetic resonance imaging. To evaluate the NMR scanner possibilities, the results were compared with the echocardiographic investigation of the same patients. The capabilities of NMR imaging to provide information about intracardiac anatomy are emphasized. This study is preceded by a description of the physical principles underlying the phenomenon of nuclear magnetic resonance and of the techniques used to obtain NMR images and a review of the clinical use of NMR imaging for cardiac diagnosis [fr

Late gadolinium enhancement by magnetic resonance explains adverse cardiac events in individuals with ventricular arrhythmia

International Nuclear Information System (INIS)

Courtis, J.; Vasallo, J.; Arabia, L.; Dimitroff, M.; Gonzalez, A.; Tibaldi, M.

2012-01-01

Objective: To determine whether the presence of late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR) predict adverse cardiac events in patients with ventricular arrhythmia. Methods: We selected 74 consecutive patients with symptomatic ventricular arrhythmia (premature ventricular contractions and ventricular tachycardia) and left ventricular ejection fraction (LVEF) >55% sent to CMR for evaluation of structural heart disease previously undetected by other complementary methods. LGE, systolic function and volumes of both ventricles were analyzed. At follow-up was assessed a combined end point: hospitalization for ventricular arrhythmia, appropriate implantable cardioverter-defibrillator therapy and cardiac death. Results: During a median follow up of 575 days (interquartile range 24-1120 days) and by analyzing the population according to the presence (n=9, 12%) or not (n=65, 88%) LGE was observed that the group with positive Gd had lower LVEF (58% vs. 66% respectively, p=0.01) and larger volumes (EDV: 185 ml vs. 123 ml respectively, p=0.01 and ESV: 81 ml vs. 42 ml respectively, p=0.01) than the other group. Two (22%) patients in the LGE + group vs. one (4%) of those without LGE showed the combined endpoint (p=0.01) and when performing a logistic regression analysis it was found that the LGE is a predictor of adverse cardiac events analyzed (p=0.029). Conclusions: In this consecutive series of patients with ventricular arrhythmia we demonstrate a strong association between myocardial LGE and adverse cardiac events; this supports the hypothesis that myocardial fibrosis is an important arrhythmogenic substrate. In addition, almost all individuals without LGE were free of events during follow-up suggesting that it is possible to identify through the CMR low-risk individuals who can be treated conservatively. (authors) [es

Measurement of myocardial perfusion using magnetic resonance

DEFF Research Database (Denmark)

Fritz-Hansen, T.; Jensen, L.T.; Larsson, H.B.

2008-01-01

Cardiac magnetic resonance imaging (MRI) has evolved rapidly. Recent developments have made non-invasive quantitative myocardial perfusion measurements possible. MRI is particularly attractive due to its high spatial resolution and because it does not involve ionising radiation. This paper reviews...... myocardial perfusion imaging with MR contrast agents: methods, validation and experiences from clinical studies. Unresolved issues still restrict the use of these techniques to research although clinical applications are within reach Udgivelsesdato: 2008/12/8...

Magnetic resonance imaging in hypertrophic cardiomyopathy

International Nuclear Information System (INIS)

Ichida, Fukiko; Hamamichi, Yuuji; Hashimoto, Ikuo; Tsubata, Shinichi; Miyazaki, Ayumi; Okada, Toshio; Futatsuya, Ryuusuke; Okada, Eikichi

1994-01-01

To evaluate the capability of magnetic resonance imaging (MRI) in the anatomical diagnosis and tissue characterization, 8 children with hypertrophic cardiomyopathy were studied comparing with echocardiography and 201 Tl myocardial imaging. The severity and distribution of hypertrophy were comparable on echocardiography and MRI. MRI was superior to echocardiography to demonstrate the apical hypertrophy. In 4 patients with severe hypertrophy, heterogenous high signal intensity was demonstrated in the site of hypertrophy, which was enhanced by T 2 weighted imaging. In the patient with decreased cardiac performance and progressed cardiac failure, the heterogeneity and high signal intensity progressed in one year interval. Simultaneously performed 201 Tl myocardial imaging showed patchy perfusion defect. Histological findings of the left ventricle demonstrated hypertrophy, degeneration and marked dysarray of the myocytes and fibrosis. MRI has the potential ability for the evaluation and sequential monitoring of myocardial tissue characterization as well as cardiac anatomy in childhood hypertrophic cardiomyopathy. (author)

Magnetic resonance imaging in hypertrophic cardiomyopathy

Energy Technology Data Exchange (ETDEWEB)

Ichida, Fukiko; Hamamichi, Yuuji; Hashimoto, Ikuo; Tsubata, Shinichi; Miyazaki, Ayumi; Okada, Toshio; Futatsuya, Ryuusuke; Okada, Eikichi [Toyama Medical and Pharmaceutical Univ. (Japan)

1994-02-01

To evaluate the capability of magnetic resonance imaging (MRI) in the anatomical diagnosis and tissue characterization, 8 children with hypertrophic cardiomyopathy were studied comparing with echocardiography and [sup 201]Tl myocardial imaging. The severity and distribution of hypertrophy were comparable on echocardiography and MRI. MRI was superior to echocardiography to demonstrate the apical hypertrophy. In 4 patients with severe hypertrophy, heterogenous high signal intensity was demonstrated in the site of hypertrophy, which was enhanced by T[sub 2] weighted imaging. In the patient with decreased cardiac performance and progressed cardiac failure, the heterogeneity and high signal intensity progressed in one year interval. Simultaneously performed [sup 201]Tl myocardial imaging showed patchy perfusion defect. Histological findings of the left ventricle demonstrated hypertrophy, degeneration and marked dysarray of the myocytes and fibrosis. MRI has the potential ability for the evaluation and sequential monitoring of myocardial tissue characterization as well as cardiac anatomy in childhood hypertrophic cardiomyopathy. (author).

Pharmacologic Effects of Cannabidiol on Acute Reperfused Myocardial Infarction in Rabbits: Evaluated With 3.0T Cardiac Magnetic Resonance Imaging and Histopathology.

Science.gov (United States)

Feng, Yuanbo; Chen, Feng; Yin, Ting; Xia, Qian; Liu, Yewei; Huang, Gang; Zhang, Jian; Oyen, Raymond; Ni, Yicheng

2015-10-01

Cannabidiol (CBD) has anti-inflammatory effects. We explored its therapeutic effects on cardiac ischemia-reperfusion injury with an experimental imaging platform. Reperfused acute myocardial infarction (AMI) was induced in rabbits with a 90-minute coronary artery occlusion followed by 24-hour reperfusion. Before reperfusion, rabbits received 2 intravenous doses of 100 μg/kg CBD (n = 10) or vehicle (control, n = 10). Evans blue was intravenously injected for later detection of the AMI core. Cardiac magnetic resonance imaging was performed to evaluate cardiac morphology and function. After euthanasia, blood troponin I (cTnI) was assessed, and the heart was excised and infused with multifunctional red iodized oil dye. The heart was sliced for digital radiography to quantify the perfusion density rate, area at risk (AAR), and myocardial salvage index, followed by histomorphologic staining. Compared with controls, CBD treatment improved systolic wall thickening (P CBD therapy reduced AMI size and facilitated restoration of left ventricular function. We demonstrated that this experimental platform has potential theragnostic utility.

Early Cardiac Involvement Affects Left Ventricular Longitudinal Function in Females Carrying α-Galactosidase A Mutation: Role of Hybrid Positron Emission Tomography and Magnetic Resonance Imaging and Speckle-Tracking Echocardiography.

Science.gov (United States)

Spinelli, Letizia; Imbriaco, Massimo; Nappi, Carmela; Nicolai, Emanuele; Giugliano, Giuseppe; Ponsiglione, Andrea; Diomiaiuti, Tommaso Claudio; Riccio, Eleonora; Duro, Giovanni; Pisani, Antonio; Trimarco, Bruno; Cuocolo, Alberto

2018-04-01

Hybrid 18 F-fluorodeoxyglucose (FDG) positron emission tomography and magnetic resonance imaging may differentiate mature fibrosis or scar from fibrosis associated to active inflammation in patients with Anderson-Fabry disease, even in nonhypertrophic stage. This study was designed to compare the results of positron emission tomography and magnetic resonance cardiac imaging with those of speckle-tracking echocardiography in heterozygous Anderson-Fabry disease females. Twenty-four heterozygous females carrying α-galactosidase A mutation and without left ventricular hypertrophy underwent cardiac positron emission tomography and magnetic resonance using 18 F-FDG for glucose uptake and 2-dimensional strain echocardiography. 18 F-FDG myocardial uptake was quantified by measuring the coefficient of variation (COV) of the standardized uptake value using a 17-segment model. Focal 18 F-FDG uptake with COV >0.17 was detected in 13 patients, including 2 patients with late gadolinium enhancement at magnetic resonance. COV was 0.30±0.14 in patients with focal 18 F-FDG uptake and 0.12±0.03 in those without ( P 0.17 compared with those with COV ≤0.17 (-18.5±2.7% versus -22.2±1.8%; P =0.024). For predicting COV >0.17, a global longitudinal strain >-19.8% had 77% sensitivity and 91% specificity and a value >2 dysfunctional segments 92% sensitivity and 100% specificity. In females carrying α-galactosidase A mutation, focal 18 F-FDG uptake represents an early sign of disease-related myocardial damage and is associated with impaired left ventricular longitudinal function. These findings support the hypothesis that inflammation plays an important role in glycosphingolipids storage disorders. © 2018 American Heart Association, Inc.

Evaluation of Hydatid Disease of the Heart with Magnetic Resonance Imaging

International Nuclear Information System (INIS)

Kotoulas, Grigoris K.; Magoufis, George L.; Gouliamos, Athanasios D.; Athanassopoulou, Alexandra K.; Roussakis, Arcadios C.; Koulocheri, Dimitra P.; Kalovidouris, Angelos; Vlahos, Labros

1996-01-01

Two patients with cardiac involvement of hydatid disease are presented: one with hydatid cyst of the interventricular septum and pulmonary arteries and the other with multiple pulmonary cysts associated with intracardiac and pericardial cysts. The ability of magnetic resonance imaging (MRI) to provide a global view of cardiac anatomy in any plane with high contrast between flowing blood and soft tissue ensures it an important role in the diagnosis and preoperative assessment of hydatid disease of the heart

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

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Busch, S.; Johnson, T.R.C.; Wintersperger, B.J.; Minaifar, N.; Bhargava, A.; Rist, C.; Reiser, M.F.; Becker, C.; Nikolaou, K. [University of Munich, Department of Clinical Radiology, Munich (Germany)

2008-03-15

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

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

International Nuclear Information System (INIS)

Busch, S.; Johnson, T.R.C.; Wintersperger, B.J.; Minaifar, N.; Bhargava, A.; Rist, C.; Reiser, M.F.; Becker, C.; Nikolaou, K.

2008-01-01

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

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

International Nuclear Information System (INIS)

Akagi, Teiji; Kiyomatsu, Yumi; Ohara, Nobutoshi; Takagi, Junichi; Sato, Noboru; Kato, Hirohisa; Eto, Takaharu.

1989-01-01

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)

Quantification of right and left ventricular function by cardiovascular magnetic resonance

International Nuclear Information System (INIS)

Bellenger, N.G.; Smith, G.C.; Pennell, D.J.; Grothues, F.

2000-01-01

Cardiac dysfunction is a major cause of cardiovascular morbidity and mortality. Accurate and reproducible assessment of cardiac function is essential for the diagnosis, the assessment of prognosis and evaluation of a patient's response to therapy. Cardiovascular magnetic resonance (CMR) provides a measure of global and regional function that is not only accurate and reproducible but is noninvasive, free of ionising radiation, and independent of the geometric assumptions and acoustic windows that limit echocardiography. With the advent of faster scanners, automated analysis, increasing availability and reducing costs, CMR is fast becoming a clinically tenable reference standard for the measurement of cardiac function. (orig.) [de

Harmonic Auto-Regularization for Non Rigid Groupwise Registration in Cardiac Magnetic Resonance Imaging

Energy Technology Data Exchange (ETDEWEB)

Sanz-Estebanez, S.; Royuela-del-Val, J.; Sevilla, T.; Revilla-Orodea, A.; Aja-Fernandez, S.; Alberola-Lopez, C.

2016-07-01

In this paper we present a new approach for non rigid groupwise registration of cardiac magnetic resonance images by means of free-form deformations, imposing a prior harmonic deformation assumption. The procedure proposes a primal-dual framework for solving an equality constrained minimization problem, which allows an automatic estimate of the trade-off between image fidelity and the Laplacian smoothness terms for each iteration. The method has been applied to both a 4D extended cardio-torso phantom and to a set of voluntary patients. The accuracy of the method has been measured for the synthetic experiment as the difference in modulus between the estimated displacement field and the ground truth; as for the real data, we have calculated the Dice coefficient between the contour manual delineations provided by two cardiologists at end systolic phase and those provided by them at end diastolic phase and, consequently propagated by the registration algorithm to the systolic instant. The automatic procedure turns out to be competitive in motion compensation with other methods even though their parameters have been previously set for optimal performance in different scenarios. (Author)

Measurement of renal blood flow by phase-contrast magnetic resonance imaging during septic acute kidney injury: a pilot investigation.

Science.gov (United States)

Prowle, John R; Molan, Maurice P; Hornsey, Emma; Bellomo, Rinaldo

2012-06-01

In septic patients, decreased renal perfusion is considered to play a major role in the pathogenesis of acute kidney injury. However, the accurate measurement of renal blood flow in such patients is problematic and invasive. We sought to overcome such obstacles by measuring renal blood flow in septic patients with acute kidney injury using cine phase-contrast magnetic resonance imaging. Pilot observational study. University-affiliated general adult intensive care unit. Ten adult patients with established septic acute kidney injury and 11 normal volunteers. Cine phase-contrast magnetic resonance imaging measurement of renal blood flow and cardiac output. The median age of the study patients was 62.5 yrs and eight were male. At the time of magnetic resonance imaging, eight patients were mechanically ventilated, nine were on continuous hemofiltration, and five required vasopressors. Cine phase-contrast magnetic resonance imaging examinations were carried out without complication. Median renal blood flow was 482 mL/min (range 335-1137) in septic acute kidney injury and 1260 mL/min (range 791-1750) in healthy controls (p = .003). Renal blood flow indexed to body surface area was 244 mL/min/m2 (range 165-662) in septic acute kidney injury and 525 mL/min/m2 (range 438-869) in controls (p = .004). In patients with septic acute kidney injury, median cardiac index was 3.5 L/min/m2 (range 1.6-8.7), and median renal fraction of cardiac output was only 7.1% (range 4.4-10.8). There was no rank correlation between renal blood flow index and creatinine clearance in patients with septic acute kidney injury (r = .26, p = .45). Cine phase-contrast magnetic resonance imaging can be used to noninvasively and safely assess renal perfusion during critical illness in man. Near-simultaneous accurate measurement of cardiac output enables organ blood flow to be assessed in the context of the global circulation. Renal blood flow seems consistently reduced as a fraction of cardiac output in

Fast magnetic resonance imaging based on high degree total variation

Science.gov (United States)

Wang, Sujie; Lu, Liangliang; Zheng, Junbao; Jiang, Mingfeng

2018-04-01

In order to eliminating the artifacts and "staircase effect" of total variation in Compressive Sensing MRI, high degree total variation model is proposed for dynamic MRI reconstruction. the high degree total variation regularization term is used as a constraint to reconstruct the magnetic resonance image, and the iterative weighted MM algorithm is proposed to solve the convex optimization problem of the reconstructed MR image model, In addtion, one set of cardiac magnetic resonance data is used to verify the proposed algorithm for MRI. The results show that the high degree total variation method has a better reconstruction effect than the total variation and the total generalized variation, which can obtain higher reconstruction SNR and better structural similarity.

Impact on adenosine stress cardiac magnetic resonance for recanalisation and follow up of chronic total coronary occlusions

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Heyne, J.P. [Institute of Diagnostic and Interventional Radiology, Friedrich Schiller University Jena, Erlanger Allee 101, D-07740 Jena (Germany)], E-mail: Jens-Peter.Heyne@med.uni-jena.de; Goernig, M. [Clinic for Internal Medicine I, Friedrich Schiller University Jena, Erlanger Allee 101, D-07740 Jena (Germany)], E-mail: Matthias.Goernig@med.uni-jena.de; Feger, J. [Institute of Diagnostic and Interventional Radiology, Friedrich Schiller University Jena, Erlanger Allee 101, D-07740 Jena (Germany)], E-mail: Joachim.Feger@email.de; Kurrat, C. [Institute of Diagnostic and Interventional Radiology, Friedrich Schiller University Jena, Erlanger Allee 101, D-07740 Jena (Germany)], E-mail: Claudia.Kurrat@med.uni-jena.de; Werner, G.S. [Clinic for Internal Medicine I, Friedrich Schiller University Jena, Erlanger Allee 101, D-07740 Jena (Germany)], E-mail: Gerald.Werner@Klinikum-Darmstadt.de; Figulla, H.R. [Clinic for Internal Medicine I, Friedrich Schiller University Jena, Erlanger Allee 101, D-07740 Jena (Germany)], E-mail: Hans.Figulla@med.uni-jena.de; Kaiser, W.A. [Institute of Diagnostic and Interventional Radiology, Friedrich Schiller University Jena, Erlanger Allee 101, D-07740 Jena (Germany)], E-mail: Werner.Kaiser@med.uni-jena.de

2007-09-15

Objective: To evaluate the impact on cardiac magnetic resonance imaging (CMRI) with adenosine stress and delayed enhancement for indication and follow up after interventional recanalisation of chronic total coronary occlusions (CTOs). Material and methods: Twenty consecutive patients (15 males; 5 females; mean age 65 years) with CTO verified by cardiac catheterisation referred to CMRI. Sixteen of them got CMRI before and after coronary recanalisation. Wall motion abnormalities (WMAs), first pass perfusion with adenosine and viability were assessed using a 1.5 T MR scanner (Sonata; Siemens). CMRI results were compared with clinical classifications, the results of cardiac catheterisation and follow up angiography. Results: Sixteen patients had a successful recanalisation, 15 of the occluded coronary artery and one of collateral donor artery stenosis. After recanalisation all stress-induced progressive or new wall motion abnormalities (WMAs) of the corresponding segments and in the collateral donor territory (5 patients) and all adenosine induced perfusion defects (PD) or delay (12 patients) were regredient. 13/16 patients showed no transmural and one patient transmural delayed enhancement (DE) indicating myocardial scar. In 10/16 patients CSS grading of angina improved after recanalisation. Conclusion: After successful recanalisation of CTOs, patients with preinterventional stress-induced PDs and WMAs in viable myocardium did not display any signs of stress-induced ischemia postinterventionally. A comprehensive CMRI approach, including assessment of rest and stress WMAs, first pass perfusion and myocardial viability represents an important tool for the pre-interventional decision to recanalise CTOs and follow up.

Measurement of left atrial volume by 2D and 3D non-contrast computed tomography compared with cardiac magnetic resonance imaging

DEFF Research Database (Denmark)

Fredgart, Maise Høigaard; Carter-Storch, Rasmus; Møller, Jacob Eifer

2018-01-01

Background: Cardiac magnetic resonance imaging (MRI) is considered the gold standard for assessment of left atrial (LA) volume. We assessed the feasibility of evaluating LA volume using 3D non-contrast computed tomography (NCCT). Furthermore, since manual tracing of LA volume is time consuming, we...... evaluated the accuracy of the LA area using 2D NCCT imaging for LA volume assessment. Methods: MRI and NCCT imaging were performed in 69 patients before and one year after aortic valve replacement. In 3D MRI and 3D NCCT, each slice was manually traced, excluding the pulmonary veins and atrial appendage...

Infarct-like acute myocarditis: relation between electrocardiographic findings and myocardial damage as assessed by cardiac magnetic resonance imaging.

Science.gov (United States)

Nucifora, Gaetano; Miani, Daniela; Di Chiara, Antonio; Piccoli, Gianluca; Artico, Jessica; Puppato, Michela; Slavich, Gianaugusto; De Biasio, Marzia; Gasparini, Daniele; Proclemer, Alessandro

2013-03-01

Acute myocarditis (AM) may occasionally have an infarct-like presentation. The aim of the present study was to investigate the relation between electrocardiographic (ECG) findings in this group of patients and myocardial damage assessed by cardiac magnetic resonance imaging (MRI) with the late gadolinium enhancement (LGE) technique. Myocardial damage may be associated with ECG changes in infarct-like AM. Forty-one consecutive patients (36 males; mean age, 36 ± 12 years) with diagnosis of AM according to cardiac MRI Lake Louise criteria and infarct-like presentation were included. The relation between site of ST-segment elevation (STE), sum of STE (sumSTE), time to normalization of STE, and development of negative T wave with the extent of LGE (expressed as % of left ventricular mass [%LV LGE]), was evaluated. Most (80%) patients presented with inferolateral STE; mean sumSTE was 5 ± 3 mm. Normalization of STE occurred within 24 hours in 20 (49%) patients. Development of negative T wave occurred in 28 (68%) patients. Cardiac MRI showed LGE in all patients; mean %LV LGE was 9.6 ± 7.2%. Topographic agreement between site of STE and LGE was 68%. At multivariate analysis, sumSTE (β = 0.42, P 24 hours (β = 0.39, P 24 hours, and development of negative T wave) may help to identify patients with larger areas of myocardial damage. © 2012 Wiley Periodicals, Inc.

PET measurements of myocardial blood flow post myocardial infarction: Relationship to invasive and cardiac magnetic resonance studies and potential clinical applications.

Science.gov (United States)

Gewirtz, Henry

2017-12-01

This review focuses on clinical studies concerning assessment of coronary microvascular and conduit vessel function primarily in the context of acute and sub acute myocardial infarction (MI). The ability of quantitative PET measurements of myocardial blood flow (MBF) to delineate underlying pathophysiology and assist in clinical decision making in this setting is discussed. Likewise, considered are physiological metrics fractional flow reserve, coronary flow reserve, index of microvascular resistance (FFR, CFR, IMR) obtained from invasive studies performed in the cardiac catheterization laboratory, typically at the time of PCI for MI. The role both of invasive studies and cardiac magnetic resonance (CMR) imaging in assessing microvascular function, a key determinant of prognosis, is reviewed. The interface between quantitative PET MBF measurements and underlying pathophysiology, as demonstrated both by invasive and CMR methodology, is discussed in the context of optimal interpretation of the quantitative PET MBF exam and its potential clinical applications.

Cardiovascular magnetic resonance frontiers: Tissue characterisation with mapping

OpenAIRE

Schofield, R.; Bhuva, A.; Manacho, K.; Moon, J. C.

2016-01-01

The clinical use of cardiovascular magnetic resonance (CMR) imaging has expanded rapidly over the last decade. Its role in cardiac morphological and functional assessment is established, with perfusion and late gadolinium enhancement (LGE) imaging for scar increasingly used in day-to-day clinical decision making. LGE allows a virtual histological assessment of the myocardium, with the pattern of scar suggesting disease aetiology, and the extent of predicting risk. However, even combined, the ...

The impact of dual-source parallel radiofrequency transmission with patient-adaptive shimming on the cardiac magnetic resonance in children at 3.0 T.

Science.gov (United States)

Wang, Haipeng; Qiu, Liyun; Wang, Guangbin; Gao, Fei; Jia, Haipeng; Zhao, Junyu; Chen, Weibo; Wang, Cuiyan; Zhao, Bin

2017-06-01

The cardiac magnetic resonance (CMR) of children at 3.0 T presents a unique set of technical challenges because of their small cardiac anatomical structures, fast heart rates, and the limited ability to keep motionless and hold breathe, which could cause problems associated with field inhomogeneity and degrade the image quality. The aim of our study was to evaluate the effect of dual-source parallel radiofrequency (RF) transmission on the B1 homogeneity and image quality in children with CMR at 3.0 T. The study was approved by the institutional ethics committee and written informed consent was obtained. A total of 30 free-breathing children and 30 breath-hold children performed CMR examinations with dual-source and single-source RF transmission. The B1 homogeneity, contrast ratio (CR) of cine images, and off-resonance artifacts in cine images between dual-source and single-source RF transmission were assessed in free-breathing and breath-hold groups, respectively. In both free-breathing and breath-hold groups, higher mean percentage of flip angle (free-breathing group: 104.2 ± 4.6 vs 95.5 ± 6.3, P 3.0 T. This technology could be taken into account in CMR for children with cardiac diseases.

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.)

Cardiovascular magnetic resonance in pericardial diseases

Directory of Open Access Journals (Sweden)

Francone Marco

2009-05-01

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

MRI (Magnetic Resonance Imaging)

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... Procedures Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Magnetic Resonance Imaging (MRI) is a medical imaging procedure for ...

Bifurcation magnetic resonance in films magnetized along hard magnetization axis

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Vasilevskaya, Tatiana M., E-mail: t_vasilevs@mail.ru [Ulyanovsk State University, Leo Tolstoy 42, 432017 Ulyanovsk (Russian Federation); Sementsov, Dmitriy I.; Shutyi, Anatoliy M. [Ulyanovsk State University, Leo Tolstoy 42, 432017 Ulyanovsk (Russian Federation)

2012-09-15

We study low-frequency ferromagnetic resonance in a thin film magnetized along the hard magnetization axis performing an analysis of magnetization precession dynamics equations and numerical simulation. Two types of films are considered: polycrystalline uniaxial films and single-crystal films with cubic magnetic anisotropy. An additional (bifurcation) resonance initiated by the bistability, i.e. appearance of two closely spaced equilibrium magnetization states is registered. The modification of dynamic modes provoked by variation of the frequency, amplitude, and magnetic bias value of the ac field is studied. Both steady and chaotic magnetization precession modes are registered in the bifurcation resonance range. - Highlights: Black-Right-Pointing-Pointer An additional bifurcation resonance arises in a case of a thin film magnetized along HMA. Black-Right-Pointing-Pointer Bifurcation resonance occurs due to the presence of two closely spaced equilibrium magnetization states. Black-Right-Pointing-Pointer Both regular and chaotic precession modes are realized within bifurcation resonance range. Black-Right-Pointing-Pointer Appearance of dynamic bistability is typical for bifurcation resonance.

Bifurcation magnetic resonance in films magnetized along hard magnetization axis

International Nuclear Information System (INIS)

Vasilevskaya, Tatiana M.; Sementsov, Dmitriy I.; Shutyi, Anatoliy M.

2012-01-01

We study low-frequency ferromagnetic resonance in a thin film magnetized along the hard magnetization axis performing an analysis of magnetization precession dynamics equations and numerical simulation. Two types of films are considered: polycrystalline uniaxial films and single-crystal films with cubic magnetic anisotropy. An additional (bifurcation) resonance initiated by the bistability, i.e. appearance of two closely spaced equilibrium magnetization states is registered. The modification of dynamic modes provoked by variation of the frequency, amplitude, and magnetic bias value of the ac field is studied. Both steady and chaotic magnetization precession modes are registered in the bifurcation resonance range. - Highlights: ► An additional bifurcation resonance arises in a case of a thin film magnetized along HMA. ► Bifurcation resonance occurs due to the presence of two closely spaced equilibrium magnetization states. ► Both regular and chaotic precession modes are realized within bifurcation resonance range. ► Appearance of dynamic bistability is typical for bifurcation resonance.

Diagnostic value and prognostic implications of early cardiac magnetic resonance in survivors of out-of-hospital cardiac arrest.

Science.gov (United States)

Zorzi, Alessandro; Susana, Angela; De Lazzari, Manuel; Migliore, Federico; Vescovo, Giovanni; Scarpa, Daniele; Baritussio, Anna; Tarantini, Giuseppe; Cacciavillani, Luisa; Giorgi, Benedetta; Basso, Cristina; Iliceto, Sabino; Bucciarelli Ducci, Chiara; Corrado, Domenico; Marra, Martina Perazzolo

2018-03-15

In patients who survived out-of-hospital cardiac arrest (OHCA), it is crucial to establish the underlying cause and its potential reversibility. The purpose of this study was to assess the incremental diagnostic and prognostic role of early cardiac magnetic resonance (CMR) in survivors of OHCA. Among 139 consecutive OHCA patients, the study enrolled 44 patients (median age 43 years; 84% male) who underwent coronary angiography and CMR ≤7 days after admission. The CMR protocol included T2-weighted sequences for myocardial edema and late gadolinium enhancement (LGE) sequences for myocardial fibrosis. Coronary angiography identified obstructive coronary artery disease in 18 of 44 patients in whom CMR confirmed the diagnosis of ischemic heart disease by demonstrating subendocardial or transmural LGE. The presence of myocardial edema allowed differentiation between acute myocardial ischemia (n = 12) and postinfarction myocardial scar (n = 6). Among the remaining 26 patients without obstructive coronary artery disease, CMR in 19 (73%) showed dilated cardiomyopathy in 5, myocarditis in 4, mitral valve prolapse associated with LGE in 3, ischemic scar in 2, idiopathic nonischemic scar in 2, arrhythmogenic cardiomyopathy in 1, hypertrophic cardiomyopathy in 1, and takotsubo cardiomyopathy in 1. In this subgroup of 26 patients, 6 (23%) had myocardial edema. During mean follow-up of 36 ± 17 months, all 18 patients with myocardial edema had an uneventful outcome, whereas 9 of 26 (35%) without myocardial edema experienced sudden arrhythmic death (n = 1), appropriate defibrillator interventions (n = 5), and nonarrhythmic death (n = 3; P = .006). In survivors of OHCA, early CMR with a comprehensive tissue characterization protocol provided additional diagnostic and prognostic value. The identification of myocardial edema was associated with a favorable long-term outcome. Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

ECG gated magnetic resonance imaging in cardiovascular disease

International Nuclear Information System (INIS)

Park, Jae Hyung; Im, Chung Kie; Han, Man Chung; Kim, Chu Wan

1985-01-01

Using KAIS 0.15 Tesla resistive magnetic imaging system, ECG gated magnetic resonance (MR) image of various cardiovascular disease was obtained in 10 patients. The findings of MR image of the cardiovascular disease were analysed and the results were as follows: 1. In 6 cases of acquired and congenital cardiac diseases, there were 2 cases of myocardial infarction, 1 case of mitral stenosis and 3 cases of corrected transportation of great vessels. The others were 3 cases of aortic disease and 1 case of pericardial effusion with lymphoma. 2. Myocardial thinning and left ventricular aneurysm were detected in MR images of myocardial infarction. The left atrium was well delineated and enlarged in the case of mitral stenosis. And segmental analysis was possible in the cases of corrected transposition since all cardiac structures were well delineated anatomically. 3. In aortic diseases, the findings of MR image were enlarged lumen, compressed cardiac chambers in ascending aortic aneurysm, intimal flap, enhanced false lumen in dissecting aneurysm and irregular narrowing of aorta with arterial obstruction in Takayasu's arteritis. 4. Pericardial effusion revealed a conspicuous contrast with neighboring mediastinal fat and cardiac wall due to it low signal encircling cardiac wall. 5. ECG gated MR image is an accurate non-invasive imaging modality for the diagnosis of cardiovascular disease and better results of its clinical application are expected in the future with further development in the imaging system and more clinical experiences

Nuclear magnetic resonance

International Nuclear Information System (INIS)

Ethier, R.; Melanson, D.; Peters, T.M.

1983-01-01

Ten years following computerized tomography, a new technique called nuclear magnetic resonance revolutionizes the field of diagnostic imaging. A major advantage of nuclear magnetic resonance is that the danger of radiation is non-existent as compared to computerized tomography. When parts of the human body are subject to radio-frequencies while in a fixed magnetic field, its most detailed structures are revealed. The quality of images, the applications, as well as the indications are forever increasing. Images obtained at the level of the brain and spinal cord through nuclear magnetic resonance supercede those obtained through computerized tomography. Hence, it is most likely that myelography, along with pneumoencephalography will be eliminated as a diagnostic means. It is without a doubt that nuclear magnetic resonance is tomorrow's computerized tomography [fr

Cardiac effects of MDMA on the metabolic profile determined with 1H-magnetic resonance spectroscopy in the rat†

Science.gov (United States)

Perrine, Shane A.; Michaels, Mark S.; Ghoddoussi, Farhad; Hyde, Elisabeth M.; Tancer, Manuel E.; Galloway, Matthew P.

2010-01-01

Despite the potential for deleterious (even fatal) effects on cardiac physiology, 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) abuse abounds driven mainly by its euphoric effects. Acute exposure to MDMA has profound cardiovascular effects on blood pressure and heart rate in humans and animals. To determine the effects of MDMA on cardiac metabolites in rats, MDMA (0, 5, or 10 mg/kg) was injected every 2 h for a total of four injections; animals were sacrificed 2 h after the last injection (8 h drug exposure), and their hearts removed and tissue samples from left ventricular wall dissected. High resolution magic angle spinning proton magnetic resonance spectroscopy (1H-MRS) at 11.7 T, a specialized version of MRS aptly suited for analysis of semi-solid materials such as intact tissue samples, was used to measure the cardiac metabolomic profile, including alanine, lactate, succinate, creatine, and carnitine, in heart tissue from rats treated with MDMA. MDMA effects on MR-visible choline, glutamate, glutamine, and taurine were also determined. Body temperature was measured following each MDMA administration and serotonin and norepinephrine (NE) levels were measured by high pressure liquid chromatography (HPLC) in heart tissue from treated animals. MDMA significantly and dose-dependently increased body temperature, a hallmark of amphetamines. Serotonin, but not NE, levels were significantly and dose-dependently decreased by MDMA in the heart wall. MDMA significantly altered the MR-visible profile with an increase in carnitine and no change in other key compounds involved in cardiomyocyte energy metabolomics. Finally, choline levels were significantly decreased by MDMA in heart. The results are consistent with the notion that MDMA has significant effects on cardiovascular serotonergic tone and disrupts the metabolic homeostasis of energy regulation in cardiac tissue, potentially increasing utilization of fatty acid metabolism. The contributions of serotonergic

Cardiac effects of MDMA on the metabolic profile determined with 1H-magnetic resonance spectroscopy in the rat.

Science.gov (United States)

Perrine, Shane A; Michaels, Mark S; Ghoddoussi, Farhad; Hyde, Elisabeth M; Tancer, Manuel E; Galloway, Matthew P

2009-05-01

Despite the potential for deleterious (even fatal) effects on cardiac physiology, 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) abuse abounds driven mainly by its euphoric effects. Acute exposure to MDMA has profound cardiovascular effects on blood pressure and heart rate in humans and animals. To determine the effects of MDMA on cardiac metabolites in rats, MDMA (0, 5, or 10 mg/kg) was injected every 2 h for a total of four injections; animals were sacrificed 2 h after the last injection (8 h drug exposure), and their hearts removed and tissue samples from left ventricular wall dissected. High resolution magic angle spinning proton magnetic resonance spectroscopy ((1)H-MRS) at 11.7 T, a specialized version of MRS aptly suited for analysis of semi-solid materials such as intact tissue samples, was used to measure the cardiac metabolomic profile, including alanine, lactate, succinate, creatine, and carnitine, in heart tissue from rats treated with MDMA. MDMA effects on MR-visible choline, glutamate, glutamine, and taurine were also determined. Body temperature was measured following each MDMA administration and serotonin and norepinephrine (NE) levels were measured by high pressure liquid chromatography (HPLC) in heart tissue from treated animals. MDMA significantly and dose-dependently increased body temperature, a hallmark of amphetamines. Serotonin, but not NE, levels were significantly and dose-dependently decreased by MDMA in the heart wall. MDMA significantly altered the MR-visible profile with an increase in carnitine and no change in other key compounds involved in cardiomyocyte energy metabolomics. Finally, choline levels were significantly decreased by MDMA in heart. The results are consistent with the notion that MDMA has significant effects on cardiovascular serotonergic tone and disrupts the metabolic homeostasis of energy regulation in cardiac tissue, potentially increasing utilization of fatty acid metabolism. The contributions of serotonergic

Magnetic resonance imaging of the cardiovascular system

International Nuclear Information System (INIS)

Masuda, Yoshiaki; Imai, Hiroshi; Watanabe, Sigeru; Inagaki, Yoshiaki; Tateno, Yukio; Ikehira, Hiroo.

1990-01-01

Magnetic resonance imaging (MRI) is a new noninvasive technique for visualization of the cardiovascular system, and is used to evaluate tissue characteristics, cardiac function and blood flow abnormalities, as well as to obtain morphological information. In this paper we presented results of clinical and laboratory research obtained using conventional spin echo MRI with regard to cardiovascular anatomy, tissue characterization and physiology. Furthermore, experience with two new techniques, cine-MRI and volume-selected MR spectroscopy, and their potential clinical usefulness in detecting cardiovascular diseases are documented. (author)

Assessment of acute myocarditis by cardiac magnetic resonance imaging: Comparison of qualitative and quantitative analysis methods.

Science.gov (United States)

Imbriaco, Massimo; Nappi, Carmela; Puglia, Marta; De Giorgi, Marco; Dell'Aversana, Serena; Cuocolo, Renato; Ponsiglione, Andrea; De Giorgi, Igino; Polito, Maria Vincenza; Klain, Michele; Piscione, Federico; Pace, Leonardo; Cuocolo, Alberto

2017-10-26

To compare cardiac magnetic resonance (CMR) qualitative and quantitative analysis methods for the noninvasive assessment of myocardial inflammation in patients with suspected acute myocarditis (AM). A total of 61 patients with suspected AM underwent coronary angiography and CMR. Qualitative analysis was performed applying Lake-Louise Criteria (LLC), followed by quantitative analysis based on the evaluation of edema ratio (ER) and global relative enhancement (RE). Diagnostic performance was assessed for each method by measuring the area under the curves (AUC) of the receiver operating characteristic analyses. The final diagnosis of AM was based on symptoms and signs suggestive of cardiac disease, evidence of myocardial injury as defined by electrocardiogram changes, elevated troponin I, exclusion of coronary artery disease by coronary angiography, and clinical and echocardiographic follow-up at 3 months after admission to the chest pain unit. In all patients, coronary angiography did not show significant coronary artery stenosis. Troponin I levels and creatine kinase were higher in patients with AM compared to those without (both P quantitative (ER 0.89 and global RE 0.80) analyses were also similar. Qualitative and quantitative CMR analysis methods show similar diagnostic accuracy for the diagnosis of AM. These findings suggest that a simplified approach using a shortened CMR protocol including only T2-weighted STIR sequences might be useful to rule out AM in patients with acute coronary syndrome and normal coronary angiography.

Diffuse infiltrative cardiac tuberculosis

International Nuclear Information System (INIS)

Gulati, Gurpreet S; Kothari, Shyam S

2011-01-01

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

Magnetic resonance imaging apparatus

International Nuclear Information System (INIS)

Ehnholm, G.J.

1991-01-01

This patent describes an electron spin resonance enhanced magnetic resonance (MR) imaging (ESREMRI) apparatus able to generate a primary magnetic field during periods of nuclear spin transition excitation and magnetic resonance signal detection. This allows the generation of ESREMRI images of a subject. A primary magnetic field of a second and higher value generated during periods of nuclear spin transition excitation and magnetic resonance signal detection can be used to generate conventional MR images of a subject. The ESREMRI and native MR images so generated may be combined, (or superimposed). (author)

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.

Nuclear magnetic resonance imaging with cardiac synchronization in chronic thrombosis of main pulmonary arteries. A case review with CT scan imaging correlation

International Nuclear Information System (INIS)

Coulomb, M.; Wolf, J.E.; Rose-Pittet, L.; Le Bas, J.F.; Dalsoglio, S.; Paramelle, B.

1986-01-01

Results of nuclear magnetic resonance exploration in a patient with chronic thrombosis of main pulmonary arteries are used to outline an elementary semiology in agreement with current documented data. Signs observed relate to the thrombosis and showing of flow due to associated pulmonary artery hypertension. Cardiac synchronization is essential: obtaining 2 echos by the spin-echo technique allows differentiation of circulatory slowing phenomena, which provoke increased strength of 2nd echo, from the thrombus itself. Correlations established with V/Q scintigraphy, angiography and CT scan findings in this case provided preliminary evaluation of use of this imaging technique in this affection [fr

Cardiac Magnetic Resonance-Verified Myocardial Fibrosis in Chagas Disease: Clinical Correlates and Risk Stratification

Directory of Open Access Journals (Sweden)

Marly Uellendahl

Full Text Available Abstract Background: Chagas disease (CD is an important cause of heart failure and mortality, mainly in Latin America. This study evaluated the morphological and functional characteristics of the heart as well the extent of myocardial fibrosis (MF in patients with CD by cardiac magnetic resonance (CMR. The prognostic value of MF evaluated by myocardial-delayed enhancement (MDE was compared with that via Rassi score. Methods: This study assessed 39 patients divided into 2 groups: 28 asymptomatic patients as indeterminate form group (IND; and symptomatic patients as Chagas Heart Disease (CHD group. All patients underwent CMR using the techniques of cine-MRI and MDE, and the amount of MF was compared with the Rassi score. Results: Regarding the morphological and functional analysis, significant differences were observed between both groups (p < 0.001. Furthermore, there was a strong correlation between the extent of MF and the Rassi score (r = 0.76. Conclusions: CMR is an important technique for evaluating patients with CD, stressing morphological and functional differences in all clinical presentations. The strong correlation with the Rassi score and the extent of MF detected by CMR emphasizes its role in the prognostic stratification of patients with CD.

Magnetic resonance of phase transitions

CERN Document Server

Owens, Frank J; Farach, Horacio A

1979-01-01

Magnetic Resonance of Phase Transitions shows how the effects of phase transitions are manifested in the magnetic resonance data. The book discusses the basic concepts of structural phase and magnetic resonance; various types of magnetic resonances and their underlying principles; and the radiofrequency methods of nuclear magnetic resonance. The text also describes quadrupole methods; the microwave technique of electron spin resonance; and the Mössbauer effect. Phase transitions in various systems such as fluids, liquid crystals, and crystals, including paramagnets and ferroelectrics, are also

Prognostic Value of Quantitative Stress Perfusion Cardiac Magnetic Resonance.

Science.gov (United States)

Sammut, Eva C; Villa, Adriana D M; Di Giovine, Gabriella; Dancy, Luke; Bosio, Filippo; Gibbs, Thomas; Jeyabraba, Swarna; Schwenke, Susanne; Williams, Steven E; Marber, Michael; Alfakih, Khaled; Ismail, Tevfik F; Razavi, Reza; Chiribiri, Amedeo

2018-05-01

This study sought to evaluate the prognostic usefulness of visual and quantitative perfusion cardiac magnetic resonance (CMR) ischemic burden in an unselected group of patients and to assess the validity of consensus-based ischemic burden thresholds extrapolated from nuclear studies. There are limited data on the prognostic value of assessing myocardial ischemic burden by CMR, and there are none using quantitative perfusion analysis. Patients with suspected coronary artery disease referred for adenosine-stress perfusion CMR were included (n = 395; 70% male; age 58 ± 13 years). The primary endpoint was a composite of cardiovascular death, nonfatal myocardial infarction, aborted sudden death, and revascularization after 90 days. Perfusion scans were assessed visually and with quantitative analysis. Cross-validated Cox regression analysis and net reclassification improvement were used to assess the incremental prognostic value of visual or quantitative perfusion analysis over a baseline clinical model, initially as continuous covariates, then using accepted thresholds of ≥2 segments or ≥10% myocardium. After a median 460 days (interquartile range: 190 to 869 days) follow-up, 52 patients reached the primary endpoint. At 2 years, the addition of ischemic burden was found to increase prognostic value over a baseline model of age, sex, and late gadolinium enhancement (baseline model area under the curve [AUC]: 0.75; visual AUC: 0.84; quantitative AUC: 0.85). Dichotomized quantitative ischemic burden performed better than visual assessment (net reclassification improvement 0.043 vs. 0.003 against baseline model). This study was the first to address the prognostic benefit of quantitative analysis of perfusion CMR and to support the use of consensus-based ischemic burden thresholds by perfusion CMR for prognostic evaluation of patients with suspected coronary artery disease. Quantitative analysis provided incremental prognostic value to visual assessment and

Magnetic resonance imaging at Rikshospitalet

International Nuclear Information System (INIS)

Smith, H.J.

1990-01-01

During the first 18 months of operations of the nuclear magnetic resonance (NMR) unit at Rikshospitalet, 1453 NMR examinations have been performed on 1431 patients. 64% of the time has been devoted to examinations of the central nervous system and spine in children and adults, 9% of the time has been used on non-neuroradiology pediatric patients, while the rest of the time has been spent equally on ear, nose and throat, thoracic (including cardiac) and abdominal examinations in adult patients. The indications for doing NMR at Rikshospitalet are listed and discussed, and it is concluded that NMR has proved to be useful at several conditions in most organ systems. 15 refs

Diagnosis of pericardial cysts using diffusion weighted magnetic resonance imaging: A case series

Directory of Open Access Journals (Sweden)

Mousavi Negareh

2011-09-01

Full Text Available Abstract Introduction Congenital pericardial cysts are benign lesions that arise from the pericardium during embryonic development. The diagnosis is based on typical imaging features, but atypical locations and signal magnetic resonance imaging sequences make it difficult to exclude other lesions. Diffusion-weighted magnetic resonance imaging is a novel method that can be used to differentiate tissues based on their restriction to proton diffusion. Its use in differentiating pericardial cysts from other pericardial lesions has not yet been described. Case presentation We present three cases (a 51-year-old Caucasian woman, a 66-year-old Caucasian woman and a 77-year-old Caucasian woman with pericardial cysts evaluated with diffusion-weighted imaging using cardiac magnetic resonance imaging. Each lesion demonstrated a high apparent diffusion coefficient similar to that of free water. Conclusion This case series is the first attempt to investigate the utility of diffusion-weighted magnetic resonance imaging in the assessment of pericardial cysts. Diffusion-weighted imaging may be a useful noninvasive diagnostic tool for pericardial cysts when conventional imaging findings are inconclusive.

Value of nuclear magnetic resonance imaging in cardiology

International Nuclear Information System (INIS)

Cabon-Martin, C.

1987-01-01

The present study summarizes an experience with Magnetic Resonance Imaging (MRI) in the evaluation of twelve patients with a variety of cardiac abnormalities (myocardial infarction, mural thrombi, obstructive cardiomyopathy, pericarditis). The results are compared with clinical data, with measurements from other techniques such as two-dimensional echocardiography and with the images in normal subjects. An anticipated advantage of MRI is the ability to provide better tissue characterization, than has been attained with other imaging techniques, by relaxation time measurement [fr

Exploratory use of cardiovascular magnetic resonance imaging in liver transplantation: a one-stop shop for preoperative cardiohepatic evaluation.

Science.gov (United States)

Reddy, Sahadev T; Thai, Ngoc L; Fakhri, Asghar A; Oliva, Jose; Tom, Kusum B; Dishart, Michael K; Doyle, Mark; Yamrozik, June A; Williams, Ronald B; Grant, Saundra B; Poydence, Jacqueline; Shah, Moneal; Singh, Anil; Nathan, Swami; Biederman, Robert W W

2013-11-15

Preoperative cardiovascular risk stratification in orthotopic liver transplantation candidates has proven challenging due to limitations of current noninvasive modalities. Additionally, the preoperative workup is logistically cumbersome and expensive given the need for separate cardiac, vascular, and abdominal imaging. We evaluated the feasibility of a "one-stop shop" in a magnetic resonance suite, performing assessment of cardiac structure, function, and viability, along with simultaneous evaluation of thoracoabdominal vasculature and liver anatomy. In this pilot study, patients underwent steady-state free precession sequences and stress cardiac magnetic resonance (CMR), thoracoabdominal magnetic resonance angiography, and abdominal magnetic resonance imaging (MRI) on a standard MRI scanner. Pharmacologic stress was performed using regadenoson, adenosine, or dobutamine. Viability was assessed using late gadolinium enhancement. Over 2 years, 51 of 77 liver transplant candidates (mean age, 56 years; 35% female; mean Model for End-stage Liver Disease score, 10.8; range, 6-40) underwent MRI. All referred patients completed standard dynamic CMR, 98% completed stress CMR, 82% completed late gadolinium enhancement for viability, 94% completed liver MRI, and 88% completed magnetic resonance angiography. The mean duration of the entire study was 72 min, and 45 patients were able to complete the entire examination. Among all 51 patients, 4 required follow-up coronary angiography (3 for evidence of ischemia on perfusion CMR and 1 for postoperative ischemia), and none had flow-limiting coronary disease. Nine proceeded to orthotopic liver transplantation (mean 74 days to transplantation after MRI). There were six ascertained mortalities in the nontransplant group and one death in the transplanted group. Explant pathology confirmed 100% detection/exclusion of hepatocellular carcinoma. No complications during CMR examination were encountered. In this proof-of-concept study, it

Magnetic resonance butterfly coils: Design and application for hyperpolarized 13C studies

DEFF Research Database (Denmark)

Giovannetti, Giulio; Frijia, Francesca; Attanasio, Simona

2013-01-01

Hyperpolarized 13C magnetic resonance spectroscopy in pig models enables cardiac metabolism assessment and provides a powerful tool for heart physiology studies, although the low molar concentration of derivate metabolites gives rise to technological limitations in terms of data quality. The desi...... throughout the volume of interest for cardiac imaging in pig. Experimental SNR-vs-depth profiles, extracted from the [1-13C]acetate phantom chemical shift image (CSI), permitted to highlight the performance of the proposed coils configuration. © 2013 Elsevier Ltd. All rights reserved....

Gadolinium-enhanced magnetic resonance imaging in acute myocardial infarction

International Nuclear Information System (INIS)

Dijkman, P.R.M. van; Wall, E.E. van der; Roos, A. de; Doornbos, J.; Laarse, A. van der; Voorthuisen, A.E. van; Bruschke, A.V.G.; Rossum, A.C. van

1990-01-01

To evaluate he usefulness of the paramagnetic contrast agent Gadolinium-DTPA (diethylenetriaminepentaacetic acid) in Magnetic Resonance. Imaging of acute myocardial infarction, we studied a total of 45 patients with a first acute myocardial infarction by ECG-gated magnetic resonance imaging before and after intravenous administration of 0.1 mmol/kg Gadolinium-DTPA. All patients received thrombolytic treatment by intravenous streptokinase. The magnetic resonance imaging studies were preformed after a meam of 88 h (range 15-241) after the acute onset of acute myocardial infarction. Five patients without evidence of cardiac disease served as controls. Spin-echo measurements (TE 30 ms) were made using a Philips Gyroscan (0.5 Tesla) or a Teslacon II (0.6 Tesla). The 45 patients were divided into four groups of patients. In Group I( patients) Gadolinium-DTPA improved the detection of myocardial infarction by Gadolinium-DTPA. In Group II (20 patients) the magnetic resonance imaging procedure was repeated every 10 min for up to 40 min following administration of Gadolinium-DTPA. Optimal contrast enhancement was obtained 20-25 min after Gadolinium-DTPA. In Group III (27 patients) signal intensities were significantly higher in the patients who underwent the magnetic resonance imaging study more than 72 h (mean 120) after the acute event, suggesting increased acculumation of Gadolinium-DTPA in a more advanced stage of the infarction process. In Group IV (45 patients) Gadolinium-DTPA was administered in an attempt to distinguish between reperfused and nonreperfused myocardial areas after thrombolytic treatment for acute myocardial infarction. The signal intensities did not differ, but reperfused areas showed a more homogeneous aspect whereas nonreperfused areas were visualized as a more heterogeneous contrast enhancement. It is concluded that magnetic resonance imaging using the contrast agent Gadolinium-DTPA significantly improves the detection of infarcted myocardial areas

Magnetic resonance imaging

International Nuclear Information System (INIS)

Anon.

1988-01-01

Magnetic resonance imaging (MRI) is a new and innovative technique that affords anatomic images in multiple planes and that may provide information about tissue characterization. The magnetic resonance images are obtained by placing the patient or the area of interest within a powerful, highly uniform, static magnetic field. Magnetized protons (hydrogen nuclei) within the patient align like small magnets in this field. Radiofrequency pulses are then used to create an oscillating magnetic field perpendicular to the main field. Magnetic resonance images differ from those produced by x-rays: the latter are associated with absorption of x-ray energy while magnetic resonance images are based on proton density and proton relaxation dynamics. Proton characteristics vary according to the tissue under examination and reflect its physical and chemical properties. To resolve issues regarding safety and efficacy, the Warren Grant Magnuson Clinical Center and the Office of Medical Applications of Research of the National Institutes of Health (NIH) convened a consensus conference about MRI Oct 26 through 28, 1987. At the NIH, the Consensus Development Conference brings together investigators in the biomedical sciences, clinical investigators, practicing physicians, and consumer and special interest groups to make a scientific assessment of technologies, including drugs, devices, and procedures, and to seek agreement on their safety and effectiveness

Morphological and Functional Measurements of the Heart Obtained by Magnetic Resonance Imaging in Brazilians

Energy Technology Data Exchange (ETDEWEB)

Macedo, Robson, E-mail: robmacedo@yahoo.com [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil); Fernandes, Juliano Lara [Universidade Estadual de Campinas, Campinas, SP (Brazil); Andrade, Solange Souza; Rochitte, Carlos Eduardo [Instituto do Coração, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Lima, Kênio Costa; Maciel, Álvaro Campos Cavalcanti [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil); Maciel, Fernanda Cunha; Alves, Geraldo Souza Pinho [Universidade Potiguar, Natal, RN (Brazil); Coelho, Otávio Rizzi [Universidade Estadual de Campinas, Campinas, SP (Brazil); Diniz, Rosiane Viana Zuza [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil)

2013-07-15

Still today, measurements used as a reference in the cardiac magnetic resonance imaging have been obtained mainly from studies carried out in North-American and European populations. To obtain measurements of the diastolic diameter, systolic diameter, end diastolic volume, end systolic volume, ejection fraction, and myocardial mass of the left and right ventricles in Brazilians. 54 men and 53 women, with mean age of 43.4 ± 13.1 years, asymptomatic, with no cardiomyopathies, have been subjected to the cardiac magnetic resonance imaging, using a balanced steady state free precession technique. The averages and the standard deviations of the parameters for the left ventricle have been: diastolic diameter =4.8 ± 0.5 cm; systolic diameter = 3.0 ± 0.6 cm; end diastolic volume = 128.4 ± 29.6 mL; end systolic volume = 45.2 ± 16.6 mL; ejection fraction = 65.5 ± 6.3%; mass = 95.2 ± 30.8 g. For the right ventricle, they have been: diastolic diameter = 3.9 ± 1.3 cm; systolic diameter = 2.5 ± 0.5 cm; end diastolic volume = 126.5 ± 30.7 mL; end systolic volume = 53.6 ± 18.4 mL; ejection fraction = 58.3 ± 8.0%, and mass = 26.1 ± 6.1 g. The masses and the volumes were significantly greater in the men, except for the end systolic volume of the left ventricle. The ejection fraction of the right ventricle has been significantly greater in the women. There has been a significant and inverted correlation of the systolic volume of the right volume with the progression of the age. This study has described, for the first time, cardiac measurements obtained through the cardiac magnetic resonance imaging in Brazilians, asymptomatic, with no cardiomyopathies, showing differences in accordance with gender and age.

Morphological and Functional Measurements of the Heart Obtained by Magnetic Resonance Imaging in Brazilians

International Nuclear Information System (INIS)

Macedo, Robson; Fernandes, Juliano Lara; Andrade, Solange Souza; Rochitte, Carlos Eduardo; Lima, Kênio Costa; Maciel, Álvaro Campos Cavalcanti; Maciel, Fernanda Cunha; Alves, Geraldo Souza Pinho; Coelho, Otávio Rizzi; Diniz, Rosiane Viana Zuza

2013-01-01

Still today, measurements used as a reference in the cardiac magnetic resonance imaging have been obtained mainly from studies carried out in North-American and European populations. To obtain measurements of the diastolic diameter, systolic diameter, end diastolic volume, end systolic volume, ejection fraction, and myocardial mass of the left and right ventricles in Brazilians. 54 men and 53 women, with mean age of 43.4 ± 13.1 years, asymptomatic, with no cardiomyopathies, have been subjected to the cardiac magnetic resonance imaging, using a balanced steady state free precession technique. The averages and the standard deviations of the parameters for the left ventricle have been: diastolic diameter =4.8 ± 0.5 cm; systolic diameter = 3.0 ± 0.6 cm; end diastolic volume = 128.4 ± 29.6 mL; end systolic volume = 45.2 ± 16.6 mL; ejection fraction = 65.5 ± 6.3%; mass = 95.2 ± 30.8 g. For the right ventricle, they have been: diastolic diameter = 3.9 ± 1.3 cm; systolic diameter = 2.5 ± 0.5 cm; end diastolic volume = 126.5 ± 30.7 mL; end systolic volume = 53.6 ± 18.4 mL; ejection fraction = 58.3 ± 8.0%, and mass = 26.1 ± 6.1 g. The masses and the volumes were significantly greater in the men, except for the end systolic volume of the left ventricle. The ejection fraction of the right ventricle has been significantly greater in the women. There has been a significant and inverted correlation of the systolic volume of the right volume with the progression of the age. This study has described, for the first time, cardiac measurements obtained through the cardiac magnetic resonance imaging in Brazilians, asymptomatic, with no cardiomyopathies, showing differences in accordance with gender and age

Left atrial volume assessment in atrial fibrillation using multimodality imaging: a comparison of echocardiography, invasive three-dimensional CARTO and cardiac magnetic resonance imaging.

Science.gov (United States)

Rabbat, Mark G; Wilber, David; Thomas, Kevin; Malick, Owais; Bashir, Atif; Agrawal, Anoop; Biswas, Santanu; Sanagala, Thriveni; Syed, Mushabbar A

2015-06-01

Left atrial size in atrial fibrillation is a strong predictor of successful ablation and cardiovascular events. Cardiac magnetic resonance multislice method (CMR-MSM) is the current gold standard for left atrial volume (LAV) assessment but is time consuming. We investigated whether LAV with more rapid area-length method by echocardiography (Echo-AL) or cardiac magnetic resonance (CMR-AL) and invasive measurement by 3D-CARTO mapping during ablation correlate with the CMR-MSM. We studied 250 consecutive patients prior to atrial fibrillation ablation. CMR images were acquired on 3T scanner to measure LAV by MSM and biplane area-length method. Standard echocardiography views were used to calculate LAV by biplane area-length method. LAV during ablation was measured by 3D-CARTO mapping. LAV was compared using intra-class correlation (ICC), Pearson's correlation and Bland-Altman plots. CMR-MSM was used as the reference standard. Mean LAV using CMR-MSM was 112.7 ± 36.7 ml. CMR-AL method overestimated LAV by 13.3 ± 21.8 ml (11.2%, p atrial fibrillation. CMR-AL and 3D-CARTO correlated and agreed well with CMR-MSM (r = 0.87 and 0.74, ICC = 0.80 and 0.77 respectively). However, Echo-AL had poor correlation and agreement with CMR-MSM (r = 0.66 and ICC = 0.48). Bland-Altman plots confirmed these findings. CMR-AL method may be used as an alternative to CMR-MSM, as it is non-invasive, rapid, and correlates well with CMR-MSM. LAV by different modalities should not be used interchangeably.

Feasibility of real-time magnetic resonance imaging-guided endomyocardial biopsies: An in-vitro study.

Science.gov (United States)

Lossnitzer, Dirk; Seitz, Sebastian A; Krautz, Birgit; Schnackenburg, Bernhard; André, Florian; Korosoglou, Grigorios; Katus, Hugo A; Steen, Henning

2015-07-26

To investigate if magnetic resonance (MR)-guided biopsy can improve the performance and safety of such procedures. A novel MR-compatible bioptome was evaluated in a series of in-vitro experiments in a 1.5T magnetic resonance imaging (MRI) system. The bioptome was inserted into explanted porcine and bovine hearts under real-time MR-guidance employing a steady state free precession sequence. The artifact produced by the metal element at the tip and the signal voids caused by the bioptome were visually tracked for navigation and allowed its constant and precise localization. Cardiac structural elements and the target regions for the biopsy were clearly visible. Our method allowed a significantly better spatial visualization of the bioptoms tip compared to conventional X-ray guidance. The specific device design of the bioptome avoided inducible currents and therefore subsequent heating. The novel MR-compatible bioptome provided a superior cardiovascular magnetic resonance (imaging) soft-tissue visualization for MR-guided myocardial biopsies. Not at least the use of MRI guidance for endomyocardial biopsies completely avoided radiation exposure for both patients and interventionalists. MRI-guided endomyocardial biopsies provide a better than conventional X-ray guided navigation and could therefore improve the specificity and reproducibility of cardiac biopsies in future studies.

Magnetic resonance imaging in cardiovascular disease

International Nuclear Information System (INIS)

Eckel, C.G.; Mettler, F.A. Jr.; Wicks, J.D.; Stevens, G.F.

1986-01-01

How does magnetic resonance imaging (MRI) currently contribute in the evaluation of patients with suspected heart disease? What role will MRI play in the future in evaluation of cardiovascular disease? To understand better where MRI fits into the diagnostic algorithm of cardiovascular disease the authors first consider the characteristics that they would like to see in the ideal diagnostic test and then survey the available cardiac diagnostic tests to note the characteristics that limit or recommend a test. In the final analysis, the justification for expensive diagnostic tests such as MRI must be an overall improvement in survival or quality of life in those patients treated after diagnosis

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

International Nuclear Information System (INIS)

Trieb, Thomas; Glodny, Bernhard; Scheiblhofer, Martin; Wolf, Christian; Metzler, Bernhard; Pachinger, Otmar; Jaschke, Werner R.; Schocke, Michael F.H.

2008-01-01

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

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

International Nuclear Information System (INIS)

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

2013-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-10-15

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

Research cardiac magnetic resonance imaging in end stage renal disease - incidence, significance and implications of unexpected incidental findings

Energy Technology Data Exchange (ETDEWEB)

Rutherford, Elaine; Weir-McCall, Jonathan R.; Houston, J.G.; Struthers, Allan D. [Ninewells Hospital, Division of Cardiovascular and Diabetes Medicine, Dundee (United Kingdom); Patel, Rajan K.; Jardine, Alan G.; Mark, Patrick B. [Institute of Cardiovascular and Medical Sciences, Glasgow (United Kingdom); Roditi, Giles [NHS Greater Glasgow and Clyde, Department of Radiology, Glasgow Royal Infirmary, Glasgow (United Kingdom)

2017-01-15

Left ventricular mass (LVM) at cardiac magnetic resonance imaging (CMR) is a frequent end point in clinical trials in nephrology. Trial participants with end stage renal disease (ESRD) may have a greater frequency of incidental findings (IF). We retrospectively investigated prevalence of IF in previous research CMR and reviewed their subsequent impact on participants. Between 2002 and 2006, 161 ESRD patients underwent CMR in a transplant assessment study. Images were used to assess LV mass and function. In the current study a radiologist reviewed the scans for IF. Review of patient records determined the subsequent clinical significance of IF. There were 150 IF in 95 study participants. Eighty-four (56 %) were new diagnoses. One hundred and two were non-cardiac. Fifteen were suspicious of malignancy. There was a clinically significant IF for 14.9 % of the participants. In six cases earlier identification of an IF may have improved quality of life or survival. Without radiology support clinically important IF may be missed on CMR. Patients undergoing CMR in trials should be counselled about the frequency and implications of IF. Patients with ESRD have a higher prevalence of IF than reported in other populations. Nephrology studies require mechanisms for radiologist reporting and strategies for dealing with IF. (orig.)

Pediatric magnetic resonance imaging

International Nuclear Information System (INIS)

Cohen, M.D.

1986-01-01

This book defines the current clinical potential of magnetic resonance imaging and focuses on direct clinical work with pediatric patients. A section dealing with the physics of magnetic resonance imaging provides an introduction to enable clinicians to utilize the machine and interpret the images. Magnetic resonance imaging is presented as an appropriate imaging modality for pediatric patients utilizing no radiation

Advances in magnetic resonance 10

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 10, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains three chapters that examine superoperators in magnetic resonance; ultrasonically modulated paramagnetic resonance; and the utility of electron paramagnetic resonance (EPR) and electron-nuclear double-resonance (ENDOR) techniques for studying low-frequency modes of atomic fluctuations and their significance for understanding the mechanism of structural phase transitions in solids.

Cardiovascular magnetic resonance myocardial T1 mapping to detect and quantify cardiac involvement in familial amyloid polyneuropathy

Energy Technology Data Exchange (ETDEWEB)

Oda, Seitaro [Kumamoto University, Faculty of Life Sciences, Department of Diagnostic Radiology, Chuo-ku, Kumamoto (Japan); Utsunomiya, Daisuke; Nakaura, Takeshi; Yuki, Hideaki; Kidoh, Masafumi; Hirata, Kenichiro; Taguchi, Narumi; Tsuda, Noriko; Shiraishi, Shinya; Namimoto, Tomohiro; Yamashita, Yasuyuki [Kumamoto University, Faculty of Life Sciences, Department of Diagnostic Radiology, Chuo-ku, Kumamoto (Japan); Morita, Kosuke [Kumamoto University Hospital, Department of Central Radiology, Kumamoto (Japan); Hirakawa, Kyoko; Takashio, Seiji; Izumiya, Yasuhiro; Yamamuro, Megumi; Hokimoto, Seiji; Tsujita, Kenichi [Kumamoto University, Faculty of Life Sciences, Department of Cardiology, Kumamoto (Japan); Ueda, Mitsuharu; Yamashita, Taro; Ando, Yukio [Kumamoto University, Faculty of Life Sciences, Department of Neurology, Kumamoto (Japan)

2017-11-15

This study sought to explore the potential role of non-contrast T1 mapping for the detection and quantification of cardiac involvement in familial amyloid polyneuropathy (FAP). Japanese patients with FAP [n = 41, age 53.2 ± 13.9 years, genotype Val30Met (n = 25), non-Val30Met (n = 16)] underwent cardiac magnetic resonance imaging that included T1 mapping (saturation-recovery method) and late gadolinium-enhanced (LGE) imaging on a 3.0-T MR scanner. Their native T1 was measured on mid-ventricular short-axis images and compared with 30 controls. Of the 41 FAP patients 29 were LGE positive. The native T1 was significantly higher in FAP patients than in the controls (1,634.1 ± 126.3 ms vs. 1,432.4 ± 69.0 ms, p < 0.01), significantly higher in LGE-positive- than LGE-negative FAP patients (1,687.1 ± 104.4 ms vs. 1,505.4 ± 68.5 ms, p < 0.01), and significantly higher in LGE-negative FAP patients than the controls (p < 0.01). A native T1 cutoff value of 1,610 ms yielded 85.4% accuracy for identifying LGE-positive FAP. The native T1 significantly correlated with the interventricular septum wall thickness, the left ventricular mass, the LGE volume, the plasma B-type natriuretic peptide level, and the E/e{sup '} ratio (all p < 0.01). T1 mapping is of high diagnostic accuracy for the detection of LGE-positive FAP. The native myocardial T1 may be correlated with the severity of cardiac amyloid deposition. (orig.)

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.

Aerobic Training after Myocardial Infarction: Remodeling Evaluated by Cardiac Magnetic Resonance

Energy Technology Data Exchange (ETDEWEB)

Izeli, Nataly Lino; Santos, Aurélia Juliana dos; Crescêncio, Júlio César; Gonçalves, Ana Clara Campagnolo Real; Papa, Valéria; Marques, Fabiana [Divisão de Cardiologia do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto - USP, Ribeirão Preto, SP (Brazil); Pazin-Filho, Antônio [Divisão de Emergência da Faculdade de Medicina de Ribeirão Preto - USP, Ribeirão Preto, SP (Brazil); Gallo-Júnior, Lourenço; Schmidt, André, E-mail: aschmidt@fmrp.usp.br [Divisão de Cardiologia do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto - USP, Ribeirão Preto, SP (Brazil)

2016-04-15

Numerous studies show the benefits of exercise training after myocardial infarction (MI). Nevertheless, the effects on function and remodeling are still controversial. To evaluate, in patients after (MI), the effects of aerobic exercise of moderate intensity on ventricular remodeling by cardiac magnetic resonance imaging (CMR). 26 male patients, 52.9 ± 7.9 years, after a first MI, were assigned to groups: trained group (TG), 18; and control group (CG), 8. The TG performed supervised aerobic exercise on treadmill twice a week, and unsupervised sessions on 2 additional days per week, for at least 3 months. Laboratory tests, anthropometric measurements, resting heart rate (HR), exercise test, and CMR were conducted at baseline and follow-up. The TG showed a 10.8% reduction in fasting blood glucose (p = 0.01), and a 7.3-bpm reduction in resting HR in both sitting and supine positions (p < 0.0001). There was an increase in oxygen uptake only in the TG (35.4 ± 8.1 to 49.1 ± 9.6 mL/kg/min, p < 0.0001). There was a statistically significant decrease in the TG left ventricular mass (LVmass) (128.7 ± 38.9 to 117.2 ± 27.2 g, p = 0.0032). There were no statistically significant changes in the values of left ventricular end-diastolic volume (LVEDV) and ejection fraction in the groups. The LVmass/EDV ratio demonstrated a statistically significant positive remodeling in the TG (p = 0.015). Aerobic exercise of moderate intensity improved physical capacity and other cardiovascular variables. A positive remodeling was identified in the TG, where a left ventricular diastolic dimension increase was associated with LVmass reduction.

Aerobic Training after Myocardial Infarction: Remodeling Evaluated by Cardiac Magnetic Resonance

International Nuclear Information System (INIS)

Izeli, Nataly Lino; Santos, Aurélia Juliana dos; Crescêncio, Júlio César; Gonçalves, Ana Clara Campagnolo Real; Papa, Valéria; Marques, Fabiana; Pazin-Filho, Antônio; Gallo-Júnior, Lourenço; Schmidt, André

2016-01-01

Numerous studies show the benefits of exercise training after myocardial infarction (MI). Nevertheless, the effects on function and remodeling are still controversial. To evaluate, in patients after (MI), the effects of aerobic exercise of moderate intensity on ventricular remodeling by cardiac magnetic resonance imaging (CMR). 26 male patients, 52.9 ± 7.9 years, after a first MI, were assigned to groups: trained group (TG), 18; and control group (CG), 8. The TG performed supervised aerobic exercise on treadmill twice a week, and unsupervised sessions on 2 additional days per week, for at least 3 months. Laboratory tests, anthropometric measurements, resting heart rate (HR), exercise test, and CMR were conducted at baseline and follow-up. The TG showed a 10.8% reduction in fasting blood glucose (p = 0.01), and a 7.3-bpm reduction in resting HR in both sitting and supine positions (p < 0.0001). There was an increase in oxygen uptake only in the TG (35.4 ± 8.1 to 49.1 ± 9.6 mL/kg/min, p < 0.0001). There was a statistically significant decrease in the TG left ventricular mass (LVmass) (128.7 ± 38.9 to 117.2 ± 27.2 g, p = 0.0032). There were no statistically significant changes in the values of left ventricular end-diastolic volume (LVEDV) and ejection fraction in the groups. The LVmass/EDV ratio demonstrated a statistically significant positive remodeling in the TG (p = 0.015). Aerobic exercise of moderate intensity improved physical capacity and other cardiovascular variables. A positive remodeling was identified in the TG, where a left ventricular diastolic dimension increase was associated with LVmass reduction

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.

Interference with cardiac pacemakers by magnetic resonance imaging: are there irreversible changes at 0.5 Tesla?

Science.gov (United States)

Vahlhaus, C; Sommer, T; Lewalter, T; Schimpf, R; Schumacher, B; Jung, W; Lüderitz, B

2001-04-01

The safety and feasibility of magnetic resonance imaging (MRI) in patients with cardiac pacemakers is an issue of gaining significance. The effect of MRI on patients' pacemaker systems has only been analyzed retrospectively in some case reports. Therefore, this study prospectively investigated if MRI causes irreversible changes in patients' pacemaker systems. The effect of MRI at 0.5 Tesla on sensing and stimulation thresholds, lead impedance and battery voltage, current, and impedance was estimated during 34 MRI examinations in 32 patients with implanted pacemakers. After measurements at baseline and with documentation of intrinsic rhythm and modification of the pacing mode, patients underwent MRI. The rest of the function time of the pacemaker was calculated. Measurements were again performed after 99.5 +/- 29.6 minutes (mean +/- SD), immediately after MRI examination, and 3 months later. Lead impedance and sensing and stimulation thresholds did not change after MRI. Battery voltage decreased immediately after MRI and recovered 3 months later. Battery current and impedance tended to increase. The calculated rest of function time did not change immediately after MRI. MRI affected neither pacemaker programmed data, nor the ability to interrogate, program, or use telemetry. Surprisingly, in the gantry of the scanner, temporary deactivation of the reed switch occurred in 12 of 32 patients when positioned in the center of the magnetic field. Missing activation of the reed switch through the static magnetic field at 0.5 Tesla is not unusual. MRI at 0.5 Tesla does not cause irreversible changes in patients' pacemaker systems.

Fractionated magnetic-resonance elastography on the human heart

International Nuclear Information System (INIS)

Rump, Jens

2008-01-01

Imaging techniques, including magnetic resonance imaging, belong to the most important tools in modern medical diagnostics. Another diagnostic aid is palpation, which is suitable for the qualitative characterization of pathological changes in organs near the surface. Magnetic resonance elastography (MRE) is a combination of these techniques. In principle, MRE uses motionsensitive MR-imaging to depict tissue deformation caused by externally induced shear waves. The type of deformation supply useful information about the elasticity of the tissue. Cardiac disorders are among the most common diseases. The goal of this study was to develop a method of applying in-vivo MRE to the human heart. The development of the mechanical stimulus, ultimately resulting in the introduction of an audio speaker as the source of vibration, provided the necessary means to introduce vibrations into inner organs. A crucial factor in applying MRE to the heart is the speed of the recording, which led to the development of ''fractional MRE''. The currently conventional fast heart imaging techniques were used as a starting point. The use of an unbalanced phase preparation gradient in the balanced steady-state imaging technique resulted in an improved phase-to-noise ratio. Along with the spoiled steady-state MRE imaging technique, initial MRE-studies on the human heart were performed. For the first time, externally induced mechanical vibrations were successfully introduced into the heart and were detected using fractional MRE with a high temporal resolution. The modulation of the shear wave amplitudes observed in the myocard of 6 healthy subjects correlated with the phases of the cardiac cycle. The techniques and methods developed here are a step toward routine clinical application of MRE of the heart and indicate high potential in the area of early diagnosis of cardiac disease. (orig.)

Children's (Pediatric) Magnetic Resonance Imaging

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... Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) ... limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a noninvasive ...

Magnetic Resonance Sensors

Directory of Open Access Journals (Sweden)

Robert H. Morris

2014-11-01

Full Text Available Magnetic Resonance finds countless applications, from spectroscopy to imaging, routinely in almost all research and medical institutions across the globe. It is also becoming more frequently used for specific applications in which the whole instrument and system is designed for a dedicated application. With beginnings in borehole logging for the petro-chemical industry Magnetic Resonance sensors have been applied to fields as varied as online process monitoring for food manufacture and medical point of care diagnostics. This great diversity is seeing exciting developments in magnetic resonance sensing technology published in application specific journals where they are often not seen by the wider sensor community. It is clear that there is enormous interest in magnetic resonance sensors which represents a significant growth area. The aim of this special edition of Sensors was to address the wide distribution of relevant articles by providing a forum to disseminate cutting edge research in this field in a single open source publication.[...

Study of optimal flip angle for inversion-recovery gradient echo method in delayed contrast-enhanced cardiac magnetic resonance imaging

International Nuclear Information System (INIS)

Ogawa, Masashi; Matsumura, Yoshio; Tsuchihashi, Toshio

2013-01-01

Delayed contrast-enhanced cardiac magnetic resonance imaging (MRI) is a valuable tool for detecting myocardial infarction and assessing myocardial viability. The standard viability MRI technique is the inversion-recovery gradient echo (IR-GRE) method. Several previous studies have demonstrated that this imaging technique provides superior image quality at high magnetic field strengths, e.g., 3.0 T. However, there are numerous possible flip angles. We investigated the optimal flip angle of IR-GRE in delayed contrast-enhanced cardiac MRI. Phantoms were made that modeled infarcted myocardium and normal myocardium after administration of contrast agent. To determine optimal flip angle, we compared the contrast-to-noise ratio (CNR) among these phantoms and evaluated the degree of artifacts induced by increased flip angle. The flip angle that showed the highest CNR for 2D IR-GRE and 3D IR-GRE was 30deg/15deg at 1.5 T and 25deg/15deg at 3.0 T. The flip angle that showed the highest CNR was independent of R-R interval. Streak artifacts induced by increased flip angle tended to occur more readily at 3.0 T than 1.5 T. The optimal flip angle for 2D IR-GRE and 3D IR-GRE at 1.5 T was 30deg and 15deg, respectively. At 3.0 T, taking into account the results for both CNR and streak artifacts, we concluded the optimal flip angle of 2D IR-GRE to be 15-20deg. (author)

Magnetic Resonance Imaging (MRI) -- Head

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

Children's (Pediatric) Magnetic Resonance Imaging

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Full Text Available ... Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) ... limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a noninvasive ...

Children's (Pediatric) Magnetic Resonance Imaging

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Full Text Available ... News Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging ( ... the limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a ...

Magnetic resonance angiography (MRA)

International Nuclear Information System (INIS)

Arlart, I.P.; Guhl, L.

1992-01-01

An account is given in this paper of the physical and technical principles underlying the 'time-of-flight' technique for imaging of vessels by magnetic resonance tomography. Major indications for the new procedure of magnetic resonance angiography at present are intracerebral and extracerebral vessels, with digital subtraction angiography quite often being required to cope with minor alterations (small aneurysms, small occlusions). Magnetic resonance angiography and digital subtraction angiography are compared to each other for advantages and disadvantages. Basically, replacement of radiological angiography by magnetic resonance angiography appears to be possible only within limits, since X-ray diagnostics primarily provides morphological information about vessels, whereas flow dynamics is visualized by the 'time-of-flight' technique. (orig.) [de

Acute Cardiac Impairment Associated With Concurrent Chemoradiotherapy for Esophageal Cancer: Magnetic Resonance Evaluation

International Nuclear Information System (INIS)

Hatakenaka, Masamitsu; Yonezawa, Masato; Nonoshita, Takeshi; Nakamura, Katsumasa; Yabuuchi, Hidetake; Shioyama, Yoshiyuki; Nagao, Michinobu; Matsuo, Yoshio; Kamitani, Takeshi; Higo, Taiki; Nishikawa, Kei; Setoguchi, Taro; Honda, Hiroshi

2012-01-01

Purpose: To evaluate acute cardiac effects of concurrent chemoradiotherapy (CCRT) for esophageal cancer. Methods and Materials: This prospective study was approved by the institutional review board, and written informed consent was obtained from all participants. The left ventricular function (LVF) of 31 patients with esophageal cancer who received cisplatin and 5-fluorouracil–based CCRT was evaluated using cardiac cine magnetic resonance imaging. The patients were classified into two groups according to mean LV dose. The parameters related to LVF were compared between before and during (40 Gy) or between before and after CCRT using a Wilcoxon matched-pairs single rank test, and parameter ratios (during/before CCRT, after/before CCRT) were also compared between the groups with a t test. Data were expressed as mean ± SE. Results: In the low LV-dose group (n = 10; mean LV dose 2 ), LV stroke volume index (38.6 ± 1.56 vs. 29.9 ± 1.60 mL/m 2 ), and LV ejection fraction (56.9% ± 1.79% vs. 52.8% ± 1.15%) decreased significantly (p < 0.05) after CCRT. Heart rate increased significantly (before vs. during vs. after CCRT; 66.8 ± 3.05 vs. 72.4 ± 4.04 vs. 85.4 ± 3.75 beats per minute, p < 0.01). Left ventricle wall motion decreased significantly (p < 0.05) in segments 8 (before vs. during vs. after CCRT; 6.64 ± 0.54 vs. 4.78 ± 0.43 vs. 4.79 ± 0.50 mm), 9 (6.88 ± 0.45 vs. 5.04 ± 0.38 vs. 5.27 ± 0.47 mm), and 10 (9.22 ± 0.48 vs. 8.08 ± 0.34 vs. 8.19 ± 0.56 mm). The parameter ratios of LV end-diastolic volume index, stroke volume index, wall motion in segment 9, and heart rate showed significant difference (p < 0.05) after CCRT between the groups. Conclusions: Concurrent chemoradiotherapy for esophageal cancer impairs LVF from an early treatment stage. This impairment is prominent in patients with high LV dose.

Magnetic Resonance Imaging (MRI) -- Head

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

Evaluation of congenital heart disease by magnetic resonance imaging

International Nuclear Information System (INIS)

Roos, A. de; Roest, A.A.W.

2000-01-01

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

Magnetic nanoparticles in magnetic resonance imaging and diagnostics.

Science.gov (United States)

Rümenapp, Christine; Gleich, Bernhard; Haase, Axel

2012-05-01

Magnetic nanoparticles are useful as contrast agents for magnetic resonance imaging (MRI). Paramagnetic contrast agents have been used for a long time, but more recently superparamagnetic iron oxide nanoparticles (SPIOs) have been discovered to influence MRI contrast as well. In contrast to paramagnetic contrast agents, SPIOs can be functionalized and size-tailored in order to adapt to various kinds of soft tissues. Although both types of contrast agents have a inducible magnetization, their mechanisms of influence on spin-spin and spin-lattice relaxation of protons are different. A special emphasis on the basic magnetism of nanoparticles and their structures as well as on the principle of nuclear magnetic resonance is made. Examples of different contrast-enhanced magnetic resonance images are given. The potential use of magnetic nanoparticles as diagnostic tracers is explored. Additionally, SPIOs can be used in diagnostic magnetic resonance, since the spin relaxation time of water protons differs, whether magnetic nanoparticles are bound to a target or not.

Left Ventricle Non compaction: Physiopathology and Findings by Magnetic Resonance

International Nuclear Information System (INIS)

Parra R, Rodrigo; Cadavid Lina

2009-01-01

A Left ventricular non compaction (LVNC) has recently been classified as a primary cardiomyopathy with a genetic origin. It is morphologically characterized by numerous prominent trabeculations and deep inter trabecular recesses. LVNC is probably secondary to an arrest in the normal process of myocardial compaction during fetal life. LVNC may be an isolated finding in the absence of any coexisting cardiac anomaly or may be associated with other congenital heart anomalies or neuromuscular disorders. LVNC includes both asymptomatic and symptomatic patients with severe heart failure, systemic embolism, arrhythmia or sudden death. Diagnosis has moved from autopsy to recognition during life by non-invasive means: echocardiography and more recently cardiac magnetic resonance imaging.

Magnetic resonance fingerprinting.

Science.gov (United States)

Ma, Dan; Gulani, Vikas; Seiberlich, Nicole; Liu, Kecheng; Sunshine, Jeffrey L; Duerk, Jeffrey L; Griswold, Mark A

2013-03-14

Magnetic resonance is an exceptionally powerful and versatile measurement technique. The basic structure of a magnetic resonance experiment has remained largely unchanged for almost 50 years, being mainly restricted to the qualitative probing of only a limited set of the properties that can in principle be accessed by this technique. Here we introduce an approach to data acquisition, post-processing and visualization--which we term 'magnetic resonance fingerprinting' (MRF)--that permits the simultaneous non-invasive quantification of multiple important properties of a material or tissue. MRF thus provides an alternative way to quantitatively detect and analyse complex changes that can represent physical alterations of a substance or early indicators of disease. MRF can also be used to identify the presence of a specific target material or tissue, which will increase the sensitivity, specificity and speed of a magnetic resonance study, and potentially lead to new diagnostic testing methodologies. When paired with an appropriate pattern-recognition algorithm, MRF inherently suppresses measurement errors and can thus improve measurement accuracy.

Advances in magnetic resonance 6

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 6 focuses on the theoretical and practical aspects of applying magnetic resonance methods to various problems in physical chemistry, emphasizing the different aspects of the exegesis of these problems. This book discusses the gas phase magnetic resonance of electronically excited molecules; techniques for observing excited electronic states; NMR studies in liquids at high pressure; and effect of pressure on self-diffusion in liquids. The nuclear magnetic resonance investigations of organic free radicals; measurement of proton coupling constants by NMR; an

Clinical applications of cardiovascular magnetic resonance imaging

International Nuclear Information System (INIS)

Marcu, C.B.; Beek, A.M.; Van Rossum, A.C.

2006-01-01

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

Postmortem magnetic resonance imaging: Reproducing typical autopsy heart measurements.

Science.gov (United States)

Ampanozi, Garyfalia; Hatch, Gary M; Flach, Patricia M; Thali, Michael J; Ruder, Thomas D

2015-11-01

The aim of this study was to evaluate the utility of cardiac postmortem magnetic resonance (PMMR) to perform routine measurements of the ventricular wall thicknesses and the heart valves and to assess if imaging measurements are consistent with traditional autopsy measurements. In this retrospective study, 25 cases with cardiac PMMR and subsequent autopsy were included. The thicknesses of the myocardial walls as well as the circumferences of all heart valves were measured on cardiac PMMR and compared to autopsy measurements. Paired samples T-test and the Wilcoxon-Signed rank test, were used to compare autopsy and cardiac PMMR measurements. For exploring correlations, the Pearson's Correlation coefficient and the Spearman's Rho test were used. Cardiac PMMR measurements of the aortic and pulmonary valve circumferences showed no significant differences from autopsy measurements. The mitral and tricuspid valves circumferences differed significantly from autopsy measurements. Left myocardial and right myocardial wall thickness also differed significantly from autopsy measurements. Left and right myocardial wall thickness, and tricuspid valve circumference measurements on cardiac PMMR and autopsy, correlated strongly and significantly. Several PMMR measurements of cardiac parameters differ significantly from corresponding autopsy measurements. However, there is a strong correlation between cardiac PMMR measurements and autopsy measurements in the majority of these parameters. It is important to note that myocardial walls are thicker when measured in situ on cardiac PMMR than when measured at autopsy. Investigators using post-mortem MR should be aware of these differences in order to avoid false diagnoses of cardiac pathology based on cardiac PMMR. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

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

International Nuclear Information System (INIS)

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

2013-01-01

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

The Role of Coronary Computed Tomography Angiography and Cardiac Magnetic Resonance in STEMI Patients with Normal Coronary Angiography

Directory of Open Access Journals (Sweden)

Beganu Elena

2017-09-01

Full Text Available Usually, the diagnosis of myocardial infarction based on patient symptoms, electrocardiogram (ECG changes, and cardiac enzymes, is not a challenge for cardiologists. The correlation between coronary anatomy and the ECG territories that present ischemic changes can help the clinician to estimate which coronary artery presents lesions upon performing a coronary angiogram. In certain situations, the diagnosis of myocardial infarction can be difficult due to the lack of correlations between the clinical and paraclinical examinations and the coronary angiogram. In some cases, patients with chest pain and ST-segment elevation on the ECG tracing present with a normal coronary angiography. In other cases, patients without important changes on the ECG can present critical lesions or even occlusions upon angiographic examination. The aim of this article is to highlight the role of noninvasive coronary magnetic resonance and multi-slice computed tomography in patients with ST-segment elevation myocardial infarction and normal coronary angiography.

Cardiac CT and cardiac MRI - competitive or complementary for nuclear cardiology

International Nuclear Information System (INIS)

Moshage, W.

2004-01-01

In summary, cardiac computed tomography (CT) and cardiac magnetic resonance (MR) are two different technologies with distinct imaging properties that gain increasing importance in clinical cardiology. Even though images may look similar, the areas of application of CT and MR are quite different. Clinical applications of cardiac CT focus on on-invasive imaging of the coronary arteries. In this respect, the higher spatial resolution of cardiac CT constitutes a significant advantage as compared to MR and clinical results are superior. Clinical applications of cardiac MR, next to morphologic imaging of the heart, are most frequently found in the context of intra-and pericardial masses, complex congenital anomalies, and the assessment of left ventricular function (dobutamine) and perfusion (adenosine) under stress. The evaluation of the size and localization of myocardial necrosis, scars, and fibrosis gains increasing importance, for example in the workup of myocardial infarction, but also myocarditis and cardiomyopathies. In this respect, magnetic resonance imaging partly constitutes an alternative to nuclear medicine methods. Due to the lack of ionizing radiation and a relatively high spatial resolution, an increase of MR diagnostic procedures at the expense of nuclear medicine can be expected. (orig.)

Proton magnetic resonance spectroscopy and perfusion magnetic resonance imaging in the evaluation of musculoskeletal tumors

International Nuclear Information System (INIS)

Costa, Flavia Martins; Setti, Marcela; Vianna, Evandro Miguelote; Domingues, Romulo Cortes; Meohas, Walter; Rezende, Jose Francisco; Gasparetto, Emerson Leandro

2009-01-01

Objective: To assess the role of proton magnetic resonance spectroscopy and dynamic contrast-enhanced magnetic resonance imaging in the differentiation between malignant and benign musculoskeletal tumors. Materials And Methods: Fifty-five patients with musculoskeletal tumors (27 malignant and 28 benign) were studied. The examinations were performed in a 1.5 T magnetic resonance scanner with standard protocol, and single voxel proton magnetic resonance spectroscopy with 135 msec echo time. The dynamic contrast study was performed using T1-weighted gradient-echo sequence after intravenous gadolinium injection. Time signal intensity curves and slope values were calculated. The statistical analysis was performed with the Levene's test, followed by a Student's t-test, besides the Pearson's chi-squared and Fischer's exact tests. Results: Proton magnetic resonance spectroscopy sensitivity, specificity and accuracy were, respectively, 87.5%, 92.3% and 90.9% (p < 0.0001). Statistically significant difference was observed in the slope (%/min) between benign (mean, 27.5%/min) and malignant (mean, 110.9%/min) lesions (p < 0.0001). Conclusion: The time-intensity curve and slope values using dynamic-enhanced perfusion magnetic resonance imaging in association with the presence of choline peak demonstrated by single voxel magnetic resonance spectroscopy study are useful in the differentiation between malignant and benign musculoskeletal tumors. (author)

Postmortem cardiovascular magnetic resonance imaging in fetuses and children: a masked comparison study with conventional autopsy.

Science.gov (United States)

Taylor, Andrew M; Sebire, Neil J; Ashworth, Michael T; Schievano, Silvia; Scott, Rosemary J; Wade, Angie; Chitty, Lyn S; Robertson, Nikki; Thayyil, Sudhin

2014-05-13

Perinatal and pediatric autopsies have declined worldwide in the past decade. We compared the diagnostic accuracy of postmortem, cardiovascular magnetic resonance (CMR) imaging with conventional autopsy and histopathology assessment in fetuses and children. We performed postmortem magnetic resonance imaging in 400 fetuses and children, using a 1.5-T Siemens Avanto magnetic resonance scanner before conventional autopsy. A pediatric CMR imager reported the CMR images, masked to autopsy information. The pathologists were masked to the information from CMR images. The institutional research ethics committee approved the study, and parental consent was obtained. Assuming a diagnostic accuracy of 50%, 400 cases were required for a 5% precision of estimate. Three cases were excluded from analysis, 2 with no conventional autopsy performed and 1 with insufficient CMR sequences performed. Thirty-eight CMR data sets were nondiagnostic (37 in fetuses ≤24 weeks; 1 in a fetus >24 weeks). In the remaining 359 cases, 44 cardiac abnormalities were noted at autopsy. Overall sensitivity and specificity (95% confidence interval) of CMR was 72.7% (58.2-83.7%) and 96.2% (93.5-97.8%) for detecting any cardiac pathology, with positive and negative predictive values of 72.7% (58.2-83.7%) and 96.2% (93.5-97.8%), respectively. Higher sensitivity of 92.6% (76.6-97.9%), specificity of 99.1% (97.4-99.7%), positive predictive value of 89.3% (72.8-96.3%), and negative predictive value of 99.4% (97.8-99.8%) were seen for major structural heart disease. Postmortem CMR imaging may be a useful alternative to conventional cardiac autopsy in fetuses and children for detecting cardiac abnormalities. http://www.clinicaltrials.gov. Unique identifier: NCT01417962.

Three-Dimensional Volumetric Assessment of Diastolic Function by Cardiac Magnetic Resonance Imaging: The Multi-Ethnic Study of Atherosclerosis (MESA).

Science.gov (United States)

Nacif, Marcelo S; Almeida, Andre L C; Young, Alistair A; Cowan, Brett R; Armstrong, Anderson C; Yang, Eunice; Sibley, Christopher T; Hundley, W Gregory; Liu, Songtao; Lima, Joao Ac; Bluemke, David A

2017-01-01

Cardiac Magnetic Resonance is in need of a simple and robust method for diastolic function assessment that can be done with routine protocol sequences. To develop and validate a three-dimensional (3D) model-based volumetric assessment of diastolic function using cardiac magnetic resonance (CMR) imaging and compare the results obtained with the model with those obtained by echocardiography. The study participants provided written informed consent and were included if having undergone both echocardiography and cine steady-state free precession (SSFP) CMR on the same day. Guide points at the septal and lateral mitral annulus were used to define the early longitudinal relaxation rate (E'), while a time-volume curve from the 3D model was used to assess diastolic filling parameters. We determined the correlation between 3D CMR and echocardiography and the accuracy of CMR in classifying the diastolic function grade. The study included 102 subjects. The E/A ratio by CMR was positively associated with the E/A ratio by echocardiography (r = 0.71, p deslocamento do anel mitral lateral (p = 0,007), bem como a razão entre E/e' por Doppler e E/E' pela RMC (p = 0,01). A velocidade normalizada de pico de enchimento (EM) determinada pela RMC e o tempo de desaceleração (TD) foram capazes de predizer a disfunção diastólica (áreas sob a curva [AUCs] = 0,70 e 0,72, respectivamente). Além disso, a razão E/E' lateral mostrou boa utilidade para a identificação da disfunção diastólica (AUC = 0,80). No geral, a ecocardiografia e a RMC apresentaram excelente concordância interobservador e intraobservador (coeficiente de correlação intraclasse 0,72 - 0,97). Uma modelagem 3D de imagens padrões de cine RMC foi capaz de identificar os indivíduos do estudo com função diastólica reduzida e mostrou uma boa reprodutibilidade, sugerindo ter potencial na avaliação rotineira da função diastólica por RMC.

Prognostic value of left atrial function in systemic light-chain amyloidosis: a cardiac magnetic resonance study.

Science.gov (United States)

Mohty, Dania; Boulogne, Cyrille; Magne, Julien; Varroud-Vial, Nicolas; Martin, Sylvain; Ettaif, Hind; Fadel, Bahaa M; Bridoux, Frank; Aboyans, Victor; Damy, Thibaud; Jaccard, Arnaud

2016-09-01

Cardiac involvement in systemic light-chain amyloidosis (AL) imparts an adverse impact on outcome. The left atrium (LA), by virtue of its anatomical location and muscular wall, is commonly affected by the amyloid process. Although LA infiltration by amyloid fibrils leads to a reduction in its pump function, the infiltration of the left ventricular (LV) myocardium results in diastolic dysfunction with subsequent increase in filling pressures and LA enlargement. Even though left atrial volume (LAV) is an independent prognostic marker in many cardiomyopathies, its value in amyloid heart disease remains to be determined. In addition, few data are available as to the prognostic value of LA function in systemic AL. Using cardiac magnetic resonance (CMR), the current study aims to assess the prognostic significance of the maximal LAV and total LA emptying fraction (LAEF) in patients with AL. Fifty-four consecutive patients (age 66 ± 10 years, 59% males) with confirmed systemic AL and mean LV ejection fraction of 60 ± 12% underwent CMR. As compared with patients with no or minimal cardiac involvement (Mayo Clinic [MC] stage I), those at moderate and high risk (MC stages II and III) had significantly larger indexed maximal LAV (36 ± 15 vs. 46 ± 13 vs. 52 ± 19 mL/m(2), P = 0.03) and indexed minimal LAV (20 ± 6 vs. 34 ± 11 vs. 44 ± 17 mL/m(2), P 16% (37 ± 11 vs. 94 ± 4%, P = 0.001). In multivariate analysis, lower LAEF remained independently associated with a higher risk of 2-year mortality (HR = 1.08 per 1% decrease, 95% CI: 1.02-1.15, P = 0.003). In patients with systemic AL, LAEF as assessed by CMR is associated with NYHA functional class, MC stage, myocardial LGE and 2-year mortality. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Safety of cardiac magnetic resonance and contrast angiography for neonates and small infants: a 10-year single-institution experience

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Rangamani, Sheela; Li, Ling; Harvey, Lisa; Fletcher, Scott E.; Danford, David A.; Kutty, Shelby [University of Nebraska College of Medicine/Creighton University School of Medicine, Joint Division of Pediatric Cardiology, Omaha, NE (United States); Varghese, Joby [Children' s Hospital and Medical Center, Division of Pediatric Cardiac Anesthesia, Omaha, NE (United States); Hammel, James M.; Duncan, Kim F. [Children' s Hospital and Medical Center, Division of Cardiothoracic Surgery, Omaha, NE (United States)

2012-11-15

With increasing applications of cardiac magnetic resonance (CMR) and magnetic resonance angiography (MRA) for evaluation of congenital heart disease (CHD), safety of this technology in the very young is of particular interest. We report our 10-year experience with CMR in neonates and small infants with particular focus on the safety profile and incidence of adverse events (AEs). We reviewed clinical, anesthesia and nursing records of all children {<=}120 days of age who underwent CMR. We recorded variables including cardiac diagnosis, study duration, anesthesia type and agents, prostaglandin E1 (PGE1) dependence and gadolinium (Gd) use. Serially recorded temperature, systemic saturation (SpO{sub 2}) and cardiac rhythm were analyzed. Primary outcome measure was any AE during or <24 h after the procedure, including minor AEs such as hypothermia (axillary temperature {<=}95 F), desaturation (SpO{sub 2} drop {>=}10% below baseline) and bradycardia (heart rate {<=}100 bpm). Secondary outcome measure was unplanned overnight hospitalization of outpatients. Children (n = 143; 74 boys, 69 girls) had a median age of 6 days (1-117), and 98 were {<=}30 days at the time of CMR. The median weight was 3.4 kg (1.4-6 kg) and body surface area 0.22 m{sup 2} (0.13-0.32 m{sup 2}). There were 118 (83%) inpatients (108 receiving intensive care) and 25 (17%) outpatients. Indications for CMR were assessment of aortic arch (n = 57), complex CHD (n = 41), pulmonary veins (n = 15), vascular ring (n = 8), intracardiac mass (n = 8), pulmonary artery (n = 7), ventricular volume (n = 4), and systemic veins (n = 3). CMR was performed using a 1.5-T scanner and a commercially available coil. CMR utilized general anesthesia (GA) in 86 children, deep sedation (DS) in 50 and comforting methods in seven. MRA was performed in 136 children. Fifty-nine children were PGE1-dependent and 39 had single-ventricle circulation. Among children on PGE1, 43 (73%) had GA and 10 (17%) had DS. Twelve children (9%) had

Safety of cardiac magnetic resonance and contrast angiography for neonates and small infants: a 10-year single-institution experience

International Nuclear Information System (INIS)

Rangamani, Sheela; Li, Ling; Harvey, Lisa; Fletcher, Scott E.; Danford, David A.; Kutty, Shelby; Varghese, Joby; Hammel, James M.; Duncan, Kim F.

2012-01-01

With increasing applications of cardiac magnetic resonance (CMR) and magnetic resonance angiography (MRA) for evaluation of congenital heart disease (CHD), safety of this technology in the very young is of particular interest. We report our 10-year experience with CMR in neonates and small infants with particular focus on the safety profile and incidence of adverse events (AEs). We reviewed clinical, anesthesia and nursing records of all children ≤120 days of age who underwent CMR. We recorded variables including cardiac diagnosis, study duration, anesthesia type and agents, prostaglandin E1 (PGE1) dependence and gadolinium (Gd) use. Serially recorded temperature, systemic saturation (SpO 2 ) and cardiac rhythm were analyzed. Primary outcome measure was any AE during or 2 drop ≥10% below baseline) and bradycardia (heart rate ≤100 bpm). Secondary outcome measure was unplanned overnight hospitalization of outpatients. Children (n = 143; 74 boys, 69 girls) had a median age of 6 days (1-117), and 98 were ≤30 days at the time of CMR. The median weight was 3.4 kg (1.4-6 kg) and body surface area 0.22 m 2 (0.13-0.32 m 2 ). There were 118 (83%) inpatients (108 receiving intensive care) and 25 (17%) outpatients. Indications for CMR were assessment of aortic arch (n = 57), complex CHD (n = 41), pulmonary veins (n = 15), vascular ring (n = 8), intracardiac mass (n = 8), pulmonary artery (n = 7), ventricular volume (n = 4), and systemic veins (n = 3). CMR was performed using a 1.5-T scanner and a commercially available coil. CMR utilized general anesthesia (GA) in 86 children, deep sedation (DS) in 50 and comforting methods in seven. MRA was performed in 136 children. Fifty-nine children were PGE1-dependent and 39 had single-ventricle circulation. Among children on PGE1, 43 (73%) had GA and 10 (17%) had DS. Twelve children (9%) had adverse events (AEs) - one major and 11 minor. Of those 12, nine children had GA (10%) and three had DS (6%). The single major AE was

Evaluation of valvular regurgitation by cine magnetic resonance imaging in patients with various cardiac diseases

International Nuclear Information System (INIS)

Kubota, Shuuhei; Nishimura, Tsunehiko

1990-01-01

In order to evaluate the clinical value and limitation of magnetic resonance imaging (MRI) for detection and quantification of valvular regurgitation, 98 patients with various cardiac diseases were studied by cine MRI and the results were compared with contrast angiography and doppler color-flow imaging. Cine MRI was carried out using FLASH (fast low angle shot) which employs TE of 10∼20 msec and TR of 30∼40 msec. 22 transverse tomograms per cardiac cycle with a slice thickness of 10 mm were obtained at the level of atrium and ventricle. The jet of valvular regurgitation was easily seen as a discrete are of low signal with cine MRI. Identification of the regurgitation and its severity were visually evaluated based on the relative size of the regurgitant jet from the incompetent valve orifice. Using contrast angiography as a gold standard, the sensitivity of cine MRI for detecting mitral regurgitation was 83% and was 94% for aortic regurgitation, with the specificity of 82% and 100%, respectively. For mitral requrgitation and aortic regurgitation, evaluation by cine MRI and severity agreed well with contrast angiography. By the comparative study with doppler color-flow imaging, relatively good agreement was found between the two methods in detection and quantitative evaluation of valvular regurgitation in any of four valves. Cine MRI was suggested to be useful for both the detection and semiquantification of valvular regurgitation in generally, but its clinical limitation at this point was also found because, 1)its images are not acquired in real times, as in contrast angiography or doppler color-flow imaging, but are compiled from the cumulative information from 128 heart beats, 2)the evaluation of regurgitation is made from only two-dimensional transverse tomograms. (author)

Magnetic resonance imaging of the coronary arteries: clinical results from three dimensional evaluation of a respiratory gated technique

NARCIS (Netherlands)

R.J.M. van Geuns (Robert Jan); H.G. de Bruin (Hein); B.J.W.M. Rensing (Benno); P.A. Wielopolski (Piotr); M.D. Hulshoff; P.M.A. van Ooijen (Peter); M. Oudkerk (Matthijs); P.J. de Feyter (Pim)

1999-01-01

textabstractBACKGROUND: Magnetic resonance coronary angiography is challenging because of the motion of the vessels during cardiac contraction and respiration. Additional challenges are the small calibre of the arteries and their complex three dimensional course. Respiratory

[Electromagnetic interference in the current era of cardiac implantable electronic devices designed for magnetic resonance environment].

Science.gov (United States)

Ribatti, Valentina; Santini, Luca; Forleo, Giovanni B; Della Rocca, Domenico; Panattoni, Germana; Scali, Marta; Schirripa, Valentina; Danisi, Nicola; Ammirati, Fabrizio; Santini, Massimo

2017-04-01

In the last decades we are observing a continuous increase in the number of patients wearing cardiac implantable electronic devices (CIEDs). At the same time, we face daily with a domestic and public environment featured more and more by the presence and the utilization of new emitters and finally, more medical procedures are based on electromagnetic fields as well. Therefore, the topic of the interaction of devices with electromagnetic interference (EMI) is increasingly a real and actual problem.In the medical environment most attention is paid to magnetic resonance, nevertheless the risk of interaction is present also with ionizing radiation, electrical nerve stimulation and electrosurgery. In the non-medical environment, most studies reported in the literature focused on mobile phones, metal detectors, as well as on headphones or digital players as potential EMI sources, but many other instruments and tools may be intentional or non-intentional sources of electromagnetic fields.CIED manufacturers are more and more focusing on new technological features in order to make implantable devices less susceptible to EMI. However, patients and emitter manufacturers should be aware that limitations exist and that there is not complete immunity to EMI.

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

Science.gov (United States)

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

2016-02-01

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

Magnetic resonance imaging of the heart and great vessels

International Nuclear Information System (INIS)

Aviram, G.; Fishman, J.E.

2004-01-01

In recent years, there has been increasing interest in the potential of cardiac magnetic resonance imaging (MRI) to perform a 'one-stop' global cardiac MRI examination in as little as 1 hour. This possibility is enhanced by advances in MR hardware, particularly gradient field strength and specialized coils, as well as software advances, including the availability of a wide array of new fast cardiac-triggered MR pulse sequences and improvements in MR signal use, electrocardiogram (ECG) triggering and post-processing software. MRI is an evolving technology. Currently, cardiac MRI examination provides more than just high-quality information on cardiac chamber morphological anatomy. Cardiac function including ejection fraction can also be determined by fast cine MRI studies. Velocity-encoded techniques permit measurements of blood flow, which are useful for quantifying the function of both ventricles and the severity of valvular lesions. Contrast-enhanced myocardial perfusion and functional studies with pharmaceutical stress may help determine myocardial tissue viability and offer an alternative to nuclear cardiology and stress echocardiography. Coronary MR angiography is also in progress. Nevertheless, some of these new applications have not yet achieved full maturity. Cardiac MRI already has many proven clinical indications in the study of acquired heart disease, congenital heart disease, the quantification of cardiac function, and vascular disease of the thoracic aorta and pulmonary arteries. The aim of this review is to present the main applications of currently available cardiac MR technology with a brief look into recent developments that are still not widely available for daily clinical use. (author)

Magnetic resonance for wireless power transfer

OpenAIRE

Hui, SYR

2016-01-01

Magnetic resonance has been a cornerstone of nonradiative wireless power transfer (WPT) since the late 19th century. However, some researchers have the misconception that magnetic resonance for WPT was developed recently. This article traces some early work of Tesla and other researchers related to the use of magnetic resonance in WPT. Included are some examples of magnetic resonance-based WPT projects conducted by researchers in the biomedical and power electronics communities over the last ...

Prognostic Value of Pulmonary Vascular Resistance by Magnetic Resonance in Systolic Heart Failure

Energy Technology Data Exchange (ETDEWEB)

Fabregat-Andrés, Óscar, E-mail: osfabregat@gmail.com [Departamento de Cardiologia - Hospital General Universitario de Valencia, Valencia (Spain); Fundación para la Investigación - Hospital General Universitario de Valencia, Valencia (Spain); Estornell-Erill, Jordi [Unidad de Imagen Cardiaca - ERESA - Hospital General Universitario de Valencia, Valencia (Spain); Ridocci-Soriano, Francisco [Departamento de Cardiologia - Hospital General Universitario de Valencia, Valencia (Spain); Departamento de Medicina. Universitat de Valencia, Valencia (Spain); Pérez-Boscá, José Leandro [Departamento de Cardiologia - Hospital General Universitario de Valencia, Valencia (Spain); García-González, Pilar [Unidad de Imagen Cardiaca - ERESA - Hospital General Universitario de Valencia, Valencia (Spain); Payá-Serrano, Rafael [Departamento de Cardiologia - Hospital General Universitario de Valencia, Valencia (Spain); Departamento de Medicina. Universitat de Valencia, Valencia (Spain); Morell, Salvador [Departamento de Cardiologia - Hospital General Universitario de Valencia, Valencia (Spain); Cortijo, Julio [Fundación para la Investigación - Hospital General Universitario de Valencia, Valencia (Spain); Departamento de Farmacologia. Universitat de Valencia, Valencia (Spain)

2016-03-15

Pulmonary hypertension is associated with poor prognosis in heart failure. However, non-invasive diagnosis is still challenging in clinical practice. We sought to assess the prognostic utility of non-invasive estimation of pulmonary vascular resistances (PVR) by cardiovascular magnetic resonance to predict adverse cardiovascular outcomes in heart failure with reduced ejection fraction (HFrEF). Prospective registry of patients with left ventricular ejection fraction (LVEF) < 40% and recently admitted for decompensated heart failure during three years. PVRwere calculated based on right ventricular ejection fraction and average velocity of the pulmonary artery estimated during cardiac magnetic resonance. Readmission for heart failure and all-cause mortality were considered as adverse events at follow-up. 105 patients (average LVEF 26.0 ±7.7%, ischemic etiology 43%) were included. Patients with adverse events at long-term follow-up had higher values of PVR (6.93 ± 1.9 vs. 4.6 ± 1.7estimated Wood Units (eWu), p < 0.001). In multivariate Cox regression analysis, PVR ≥ 5 eWu(cutoff value according to ROC curve) was independently associated with increased risk of adverse events at 9 months follow-up (HR2.98; 95% CI 1.12-7.88; p < 0.03). In patients with HFrEF, the presence of PVR ≥ 5.0 Wu is associated with significantly worse clinical outcome at follow-up. Non-invasive estimation of PVR by cardiac magnetic resonance might be useful for risk stratification in HFrEF, irrespective of etiology, presence of late gadolinium enhancement or LVEF.

Prognostic Value of Pulmonary Vascular Resistance by Magnetic Resonance in Systolic Heart Failure

International Nuclear Information System (INIS)

Fabregat-Andrés, Óscar; Estornell-Erill, Jordi; Ridocci-Soriano, Francisco; Pérez-Boscá, José Leandro; García-González, Pilar; Payá-Serrano, Rafael; Morell, Salvador; Cortijo, Julio

2016-01-01

Pulmonary hypertension is associated with poor prognosis in heart failure. However, non-invasive diagnosis is still challenging in clinical practice. We sought to assess the prognostic utility of non-invasive estimation of pulmonary vascular resistances (PVR) by cardiovascular magnetic resonance to predict adverse cardiovascular outcomes in heart failure with reduced ejection fraction (HFrEF). Prospective registry of patients with left ventricular ejection fraction (LVEF) < 40% and recently admitted for decompensated heart failure during three years. PVRwere calculated based on right ventricular ejection fraction and average velocity of the pulmonary artery estimated during cardiac magnetic resonance. Readmission for heart failure and all-cause mortality were considered as adverse events at follow-up. 105 patients (average LVEF 26.0 ±7.7%, ischemic etiology 43%) were included. Patients with adverse events at long-term follow-up had higher values of PVR (6.93 ± 1.9 vs. 4.6 ± 1.7estimated Wood Units (eWu), p < 0.001). In multivariate Cox regression analysis, PVR ≥ 5 eWu(cutoff value according to ROC curve) was independently associated with increased risk of adverse events at 9 months follow-up (HR2.98; 95% CI 1.12-7.88; p < 0.03). In patients with HFrEF, the presence of PVR ≥ 5.0 Wu is associated with significantly worse clinical outcome at follow-up. Non-invasive estimation of PVR by cardiac magnetic resonance might be useful for risk stratification in HFrEF, irrespective of etiology, presence of late gadolinium enhancement or LVEF

Advances in magnetic resonance 12

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 12, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains six chapters and begins with a discussion of diffusion and self-diffusion measurements by nuclear magnetic resonance. This is followed by separate chapters on spin-lattice relaxation time in hydrogen isotope mixtures; the principles of optical detection of nuclear spin alignment and nuclear quadropole resonance; and the spin-1 behavior, including the relaxation of the quasi-invariants of the motion of a system of pairs of dipolar coupled spin-1/2 nu

Magnetic Resonance Force Microscopy System

Data.gov (United States)

Federal Laboratory Consortium — The Magnetic Resonance Force Microscopy (MRFM) system, developed by ARL, is the world's most sensitive nuclear magnetic resonance (NMR) spectroscopic analysis tool,...

Magnetic resonance imaging

International Nuclear Information System (INIS)

Robertson, Angus

1990-01-01

An assessment is made of the clinical benefits of expensive diagnostic technology, such as the magnetic resonance imaging. It is concluded that to most radiologists, magnetic resonance imaging has a definite place in the diagnostic scenario, especially for demonstrating central nervous system lesions in multiple sclerosis. While it is recognized that medical and financial resources are limited, it is emphasised that the cost to society must be balanced against the patient benefit. 17 refs

Magnetic resonance imaging of the coronary arteries : clinical results from three dimensional evaluation of a respiratory gated technique

NARCIS (Netherlands)

van Geuns, R J; de Bruin, H G; Rensing, B J; Wielopolski, P A; Hulshoff, M D; van Ooijen, P M; Oudkerk, M; de Feyter, P J

1999-01-01

BACKGROUND: Magnetic resonance coronary angiography is challenging because of the motion of the vessels during cardiac contraction and respiration. Additional challenges are the small calibre of the arteries and their complex three dimensional course. Respiratory gating, turboflash acquisition, and

Advances in magnetic resonance 11

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 11, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains three chapters and begins with a discussion of the principles and applications of dynamic nuclear polarization, with emphasis on molecular motions and collisions, intermolecular couplings, and chemical interactions. Subsequent chapters focus on the assessment of a proposed broadband decoupling method and studies of time-domain (or Fourier transform) multiple-quantum nuclear magnetic resonance.

Idiopathic Dilated Cardiomyopathy-proton magnetic resonance spectroscopy ( 1 H MRS ) in evaluation of myocardial metabolism. Preliminary study

International Nuclear Information System (INIS)

Michalak, M.; Walecki, J.; Michalak, E.; Bilinska, Z.; Ruzyllo, W.

2002-01-01

Primary dilated cardiomyopathy is a disease of unknown etiology and it leads to serious cardiac insufficiency. Abnormalities in cardiac metabolism can play an important role in clinical manifestation and prognosis in this group. The aim of this study was an attempt to assess cardiac metabolism using proton spectroscopy magnetic resonance method (1H MRS) and to find a relationship between cardiac metabolites and functional class NYHA and left ventricular function parameters obtained by echocardiography. Proton spectroscopy magnetic resonance was performed in 15 patients with angiographically documented idiopathic dilated cardiomyopathy and 12 healthy volunteers with voxel localized at interventricular septum area. The contents of total creatine (CR) e.g. creatine+phosphocreatine, lipids (LIP) lactates (LAC) and their ratios (CR1A, CR2A, CR1/H20, CR2/H20, CR2/CR1, LIPA, LIP/H20, LIP/CR1, LACA, LAC/H20, LAC/CR1) were examined. Patents with dilated cardiomyopathy had significantly lower level of creatine CR1A (5.04I0.88 vs. 5.94I1.15, p<0.02) and ratios LIP/H20 (4.34I2.3 vs. 15.46I20.39, p<0.04) and LIP/CR1 (24.49I21.26 vs. 34.08I13.36, p<0.05) compared to healthy volunteers. Significant correlations between NYHA functional class and ratios CR2/CR1, CR2/H20 (r=0.59 p<0.038, r=0.59 p<0.02) and between %EFLV and LIP/CR1 (r=0.64, p<0.036), as well as between the duration of the disease (CTCH) and LIP/CR1 (r=0.67, p<0.046) were found. Preliminary study with proton spectroscopy magnetic resonance (1H MRS) showed impairment cardiac metabolism in patients with idiopathic dilated cardiomyopathy. A tendency to lowered values of creatine, lipids and some ratios of these metabolites were observed in dilated cardiomyopathy group compared to healthy subjects. Our results needs further study. (author)

Prognostic value of high-dose dobutamine stress magnetic resonance imaging in 1,493 consecutive patients: assessment of myocardial wall motion and perfusion.

Science.gov (United States)

Korosoglou, Grigorios; Elhmidi, Yacine; Steen, Henning; Schellberg, Dieter; Riedle, Nina; Ahrens, Johannes; Lehrke, Stephanie; Merten, Constanze; Lossnitzer, Dirk; Radeleff, Jannis; Zugck, Christian; Giannitsis, Evangelos; Katus, Hugo A

2010-10-05

This study sought to determine the prognostic value of wall motion and perfusion assessment during high-dose dobutamine stress (DS) cardiac magnetic resonance imaging (MRI) in a large patient cohort. DS-MRI offers the possibility to integrate myocardial perfusion and wall motion analysis in a single examination for the detection of coronary artery disease (CAD). A total of 1,493 consecutive patients with suspected or known CAD underwent DS-MRI, using a standard protocol in a 1.5-T magnetic resonance scanner. Wall motion and perfusion were assessed at baseline and during stress, and outcome data including cardiac death, nonfatal myocardial infarction ("hard events"), and "late" revascularization performed >90 days after the MR scans were collected during a 2 ± 1 year follow-up period. Fifty-three hard events, including 14 cardiac deaths and 39 nonfatal infarctions, occurred during the follow-up period, whereas 85 patients underwent "late" revascularization. Using multivariable regression analysis, an abnormal result for wall motion or perfusion during stress yielded the strongest independent prognostic value for both hard events and late revascularization, clearly surpassing that of clinical and baseline magnetic resonance parameters (for wall motion: adjusted hazard ratio [HR] of 5.9 [95% confidence interval (CI): 2.5 to 13.6] for hard events and of 3.1 [95% CI: 1.7 to 5.6] for late revascularization, and for perfusion: adjusted HR of 5.4 [95% CI: 2.3 to 12.9] for hard events and of 6.2 [95% CI: 3.3 to 11.3] for late revascularization, p < 0.001 for all). DS-MRI can accurately identify patients who are at increased risk for cardiac death and myocardial infarction, separating them from those with normal findings, who have very low risk for future cardiac events. (Prognostic Value of High Dose Dobutamine Stress Magnetic Resonance Imaging; NCT00837005). Copyright © 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Value of black blood T2* cardiovascular magnetic resonance

Directory of Open Access Journals (Sweden)

Carpenter John Paul

2011-03-01

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

Magnetic resonance imaging: effects of magnetic field strength

International Nuclear Information System (INIS)

Crooks, L.E.; Arakawa, M.; Hoenninger, J.; McCarten, B.; Watts, J.; Kaufman, L.

1984-01-01

Magnetic resonance images of the head, abdomen, and pelvis of normal adult men were obtained using varying magnetic field strength, and measurements of T1 and T2 relaxations and of signal-to-noise (SN) ratios were determined. For any one spin echo sequence, gray/white matter contrast decreases and muscle/fat contrast increases with field. SN levels rise rapidly up to 3.0 kgauss and then change more slowly, actually dropping for muscle. The optimum field for magnetic resonance imaging depends on tissue type, body part, and imaging sequence, so that it does not have a unique value. Magnetic resonance systems that operate in the 3.0-5.0 kgauss range achieve most or all of the gains that can be achieved by higher magnetic fields

Evaluation of atrial, ventricular and atrioventricular septal defects by cine magnetic resonance imaging

International Nuclear Information System (INIS)

Akagi, Teiji; Kato, Hirohisa; Kiyomatsu, Yumi; Saiki, Kuninobu; Suzuki, Kazushige; Eto, Takaharu

1992-01-01

Cine magnetic resonance imaging (MRI) was performed on 20 patients (mean age: 5.3±4.4 years) with atrial, ventricular, or atrioventricular septal defects for evaluation of cardiac structure and blood flow. Prior to cine MRI, electrocardiographycally gated MRI using multislice scquisition was performed on all patients to localize optimal slice location. Cine-MRI was obtained with a 30 deg flip angle, 15 msec echo time, and 30 msec pulse repetition time, on a 256 x 256 or 128 x 128 acquisition matrix. Abnormalities of cardiac structure were well defined in all patients by gated cardiac imaging. In 18 of the 20 patients, cine-MRI was able to detect shunt flow, visualized as a low intensity signal in comparison with the surrounding blood flow. Cine-MRI can provide not only accurate anatomy of cardiac structures but functional assessment of the cardiac chamber, wall topology and flow relations. Cine-MRI will become an important noninvasive technique for assessment of anatomy and physiology in congenital heart disease. (author)

Introduction lecture to magnetic resonance

International Nuclear Information System (INIS)

Conard, J.

1980-01-01

This lecture deals with all that is common either to electron paramagnetic resonance (E.P.R.) or to nuclear magnetic resonance (N.M.R.). It will present, in an as elementary form as possible, the main concepts used in magnetic resonance emphasizing some aspects, specific for interface science. (orig./BHO)

Artifacts in Magnetic Resonance Imaging

International Nuclear Information System (INIS)

Krupa, Katarzyna; Bekiesińska-Figatowska, Monika

2015-01-01

Artifacts in magnetic resonance imaging and foreign bodies within the patient’s body may be confused with a pathology or may reduce the quality of examinations. Radiologists are frequently not informed about the medical history of patients and face postoperative/other images they are not familiar with. A gallery of such images was presented in this manuscript. A truncation artifact in the spinal cord could be misinterpreted as a syrinx. Motion artifacts caused by breathing, cardiac movement, CSF pulsation/blood flow create a ghost artifact which can be reduced by patient immobilization, or cardiac/respiratory gating. Aliasing artifacts can be eliminated by increasing the field of view. An artificially hyperintense signal on FLAIR images can result from magnetic susceptibility artifacts, CSF/vascular pulsation, motion, but can also be found in patients undergoing MRI examinations while receiving supplemental oxygen. Metallic and other foreign bodies which may be found on and in patients’ bodies are the main group of artifacts and these are the focus of this study: e.g. make-up, tattoos, hairbands, clothes, endovascular embolization, prostheses, surgical clips, intraorbital and other medical implants, etc. Knowledge of different types of artifacts and their origin, and of possible foreign bodies is necessary to eliminate them or to reduce their negative influence on MR images by adjusting acquisition parameters. It is also necessary to take them into consideration when interpreting the images. Some proposals of reducing artifacts have been mentioned. Describing in detail the procedures to avoid or limit the artifacts would go beyond the scope of this paper but technical ways to reduce them can be found in the cited literature

Accuracy and effectiveness of self-gating signals in free-breathing three-dimensional cardiac cine magnetic resonance imaging

International Nuclear Information System (INIS)

Li Shuo; Gao Song; Wang Lei; Zhu Yan-Chun; Yang Jie; Xie Yao-Qin; Fu Nan; Wang Yi

2016-01-01

Conventional multiple breath-hold two-dimensional (2D) balanced steady-state free precession (SSFP) presents many difficulties in cardiac cine magnetic resonance imaging (MRI). Recently, a self-gated free-breathing three-dimensional (3D) SSFP technique has been proposed as an alternative in many studies. However, the accuracy and effectiveness of self-gating signals have been barely studied before. Since self-gating signals are crucially important in image reconstruction, a systematic study of self-gating signals and comparison with external monitored signals are needed.Previously developed self-gated free-breathing 3D SSFP techniques are used on twenty-eight healthy volunteers. Both electrocardiographic (ECG) and respiratory bellow signals are also acquired during the scan as external signals. Self-gating signal and external signal are compared by trigger and gating window. Gating window is proposed to evaluate the accuracy and effectiveness of respiratory self-gating signal. Relative deviation of the trigger and root-mean-square-deviation of the cycle duration are calculated. A two-tailed paired t-test is used to identify the difference between self-gating and external signals. A Wilcoxon signed rank test is used to identify the difference between peak and valley self-gating triggers.The results demonstrate an excellent correlation ( P = 0, R > 0.99) between self-gating and external triggers. Wilcoxon signed rank test shows that there is no significant difference between peak and valley self-gating triggers for both cardiac ( H = 0, P > 0.10) and respiratory ( H = 0, P > 0.44) motions. The difference between self-gating and externally monitored signals is not significant (two-tailed paired-sample t-test: H = 0, P > 0.90).The self-gating signals could demonstrate cardiac and respiratory motion accurately and effectively as ECG and respiratory bellow. The difference between the two methods is not significant and can be explained. Furthermore, few ECG trigger errors

Characteristic cardiac phenotypes are detected by cardiovascular magnetic resonance in patients with different clinical phenotypes and genotypes of mitochondrial myopathy.

Science.gov (United States)

Florian, Anca; Ludwig, Anna; Stubbe-Dräger, Bianca; Boentert, Matthias; Young, Peter; Waltenberger, Johannes; Rösch, Sabine; Sechtem, Udo; Yilmaz, Ali

2015-05-22

Mitochondrial myopathies (MM) are a heterogeneous group of inherited conditions resulting from a primary defect in the mitochondrial respiratory chain with consecutively impaired cellular energy metabolism. Small sized studies using mainly electrocardiography (ECG) and echocardiography have revealed cardiac abnormalities ranging from conduction abnormalities and arrhythmias to hypertrophic or dilated cardiomyopathy in these patients. Recently, characteristic patterns of cardiac involvement were documented by cardiovascular magnetic resonance (CMR) in patients with chronic progressive external ophthalmoplegia (CPEO)/Kearns-Sayre syndrome (KSS) and with mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS). The present study aimed to characterize the prevalence and pattern of cardiac abnormalities and to test the additional diagnostic value of CMR in this patient population. The hypothesis that different neuromuscular MM syndromes present with different cardiac disease phenotypes was evaluated. Sixty-four MM patients (50 ± 15 years, 44% male) and 25 matched controls (52 ± 14 years, 36% male) prospectively underwent cardiac evaluations including CMR (comprising cine- and late-gadolinium-enhancement (LGE) imaging). Based on the neuromuscular phenotype and genotype, the patients were grouped: (a) CPEO/KSS (N = 33); (b) MELAS/-like (N = 11); c) myoclonic epilepsy with ragged-red fibers (MERRF) (N = 3) and d) other non-specific MM forms (N = 17). Among the 64 MM patients, 34 (53%) had at least one abnormal CMR finding: 18 (28%) demonstrated an impaired left ventricular ejection-fraction (LV-EF patients showed significantly higher maximal wall thickness (10 ± 3 vs. 8 ± 2 mm, p = 0.005) and concentricity (LV mass to end-diastolic volume: 0.84 ± 0.27 vs. 0.67 ± 0.11, p patients showed the highest frequency of cardiac disease (in 10/11 (91%)), a mostly concentric LV hypertrophy (6/9; 67%) with or

Advances in magnetic resonance 9

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 9 describes the magnetic resonance in split constants and dipolar relaxation. This book discusses the temperature-dependent splitting constants in the ESR spectra of organic free radicals; temperature-dependent splittings in ion pairs; and magnetic resonance induced by electrons. The electron impact excitation of atoms and molecules; intramolecular dipolar relaxation in multi-spin systems; and dipolar cross-correlation problem are also elaborated. This text likewise covers the NMR studies of molecules oriented in thermotropic liquid crystals and diffusion

Magnetic resonance imaging of the heart and great vessels

International Nuclear Information System (INIS)

Naitoh, Hiroaki; Nishimura, Tsunehiko; Takamiya, Makoto; Kozuka, Takahiro.

1985-01-01

About sixty subjects with normal heart or various cardiovascular diseases were examined with 0.35 or 1.5 T superconductive magnetic resonance imaging (MRI) system, and ECG-gated spin-echo multislice technique was used to evaluate cardiovascular anatomy. MRI accurately demonstrated ventricular wall thinning caused by myocardial infarction and asymmetric ventricular hypertrophy owing to cardiomyopathy. Rheumatic valvular thickening, congenital cardiac malformations, aortic aneurysm and dissection were also clearly demonstrated by gated MRI without the use of any contrast media. MRI was shown to be an excellent non-invasive imaging modality for evaluation of pathoanatomy of the heart and great vessels. (author)

Clinical recommendations of cardiac magnetic resonance, Part I: ischemic and valvular heart disease: a position paper of the working group 'Applicazioni della Risonanza Magnetica' of the Italian Society of Cardiology.

Science.gov (United States)

Aquaro, Giovanni Donato; Di Bella, Gianluca; Castelletti, Silvia; Maestrini, Viviana; Festa, Pierluigi; Ait-Ali, Lamia; Masci, Pier Giorgio; Monti, Lorenzo; di Giovine, Gabriella; De Lazzari, Manuel; Cipriani, Alberto; Guaricci, Andrea I; Dellegrottaglie, Santo; Pepe, Alessia; Marra, Martina Perazzolo; Pontone, Gianluca

2017-04-01

Cardiac magnetic resonance (CMR) has emerged as a reliable and accurate diagnostic tool for the evaluation of patients with cardiac disease in several clinical settings and with proven additional diagnostic and prognostic value compared with other imaging modalities. This document has been developed by the working group on the 'application of CMR' of the Italian Society of Cardiology to provide a perspective on the current state of technical advances and clinical applications of CMR and to inform cardiologists on how to implement their clinical and diagnostic pathways with the inclusion of this technique in clinical practice. The writing committee consisted of members of the working group of the Italian Society of Cardiology and two external peer reviewers with acknowledged experience in the field of CMR.

Magnetic Resonance Imaging (MRI) Safety

Science.gov (United States)

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

Magnetic resonance study of maghemite-based magnetic fluid

International Nuclear Information System (INIS)

Figueiredo, L.C.; Lacava, B.M.; Skeff Neto, K.; Pelegrini, F.; Morais, P.C.

2008-01-01

This study reports on the magnetic resonance (MR) data (X-band experiment) of 10.2 nm average diameter maghemite nanoparticle in the temperature range of 100-230 K. Maghemite nanoparticles were suspended as low-pH ionic magnetic fluid containing 2.3x10 17 particles/cm 3 . The temperature dependence of both resonance linewidth and resonance field of the zero-field-cooled sample as well as the resonance field of the field-cooled sample (angular variation experiment) was analyzed using well-established methodology. Information regarding particle size, particle clusterization and surface magnetic anisotropy were obtained from the analysis of the MR data. The number of magnetic sites per particle from the MR data is in excellent agreement with the number provided by the transmission electron microscopy (TEM) data. The demagnetizing field value obtained from the MR data indicates cluster of particles containing on average 1.42 particles. The MR angular variation data suggest that magnetoelastic effect accounts for the non-linearity observed for the surface component of the magnetic anisotropy

Advances in magnetic resonance 1

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 1, discusses developments in various areas of magnetic resonance. The subject matter ranges from original theoretical contributions through syntheses of points of view toward series of phenomena to critical and painstaking tabulations of experimental data. The book contains six chapters and begins with a discussion of the theory of relaxation processes. This is followed by separate chapters on the development of magnetic resonance techniques for studying rate processes in chemistry and the application of these techniques to various problems; the geometri

Resonant and nonresonant magnetic scattering (invited)

International Nuclear Information System (INIS)

McWhan, D.B.; Hastings, J.B.; Kao, C.; Siddons, D.P.

1992-01-01

The tunability and the polarization of synchrotron radiation open up new possibilities for the study of magnetism. Studies on magnetic materials performed at the National Synchrotron Light Source are reviewed, and they fall into four areas: structure, evolution of magnetic order, separation of L and S, and resonance effects. In the vicinity of atomic absorption edges, the Faraday effect, magnetic circular dichroism, and resonant magnetic scattering are all related resonance effects which measure the spin-polarized density of states. The production and analysis of polarized beams are discussed in the context of the study of magnetism with synchrotron radiation

A superconducting magnet for whole-body magnetic-resonance imaging

International Nuclear Information System (INIS)

Kan, Hisao; Watanabe, Tsugio; Takechi, Moriaki; Ogino, Osamu; Yamada, Tadatoshi

1986-01-01

Magnetic-resonance imaging is a promising new clinical diagnosis system that employs magnetic resonance to generate cross-sectional images of the object under examination. A large magnet plays a critical role in this system-it must supply a high-strength magnetic field that meets rigid standards of space and time uniformity. Mitsubishi Electric has developed a superconducting magnet that not only offers excellent magnetic characteristics but also features reduced helium consumption and a horizontal service port, and permits direct mounting of a magnetic shield. (author)

Magnetic Resonance Imaging (MRI) -- Head

Medline Plus

Full Text Available ... for Brain Tumors Radiation Therapy for Head and Neck Cancer Others : American Stroke Association National Stroke Association ... MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging ( ...

Magnetic Resonance Imaging of Stroke

NARCIS (Netherlands)

Bouts, Mark. J. R. J.; Wu, O.; Dijkhuizen, R. M.

2017-01-01

Magnetic resonance imaging (MRI) provides a powerful (neuro)imaging modality for the diagnosis and outcome prediction after (acute) stroke. Since MRI allows noninvasive, longitudinal, and three-dimensional assessment of vessel occlusion (with magnetic resonance angiography (MRA)), tissue injury

Cardiac Catheterization (For Parents)

Science.gov (United States)

... cases, the doctor might call for a cardiac magnetic resonance imaging (MRI) scan or a CAT scan . ... first couple of days. This means no heavy lifting (more than 10 pounds) and no sports. After ...

Cardiac Catheterization (For Teens)

Science.gov (United States)

... doctor may also call for a cardiac MRI (magnetic resonance imaging) scan or a CT (computerized tomography) ... first couple of days. This means no heavy lifting (nothing over 10 pounds) and no sports. After ...

Magnetic resonance elastometry using a single-sided permanent magnet

International Nuclear Information System (INIS)

Tan, Carl S; Marble, Andrew E; Ono, Yuu

2012-01-01

In this paper, we describe a magnetic resonance method of measuring material elasticity using a single-sided magnet with a permanent static field gradient. This method encodes sample velocity in a reciprocal space using Hahn spin-echoes with variable timing. The experimental results show a strong correlation between magnetic resonance signal attenuation and elasticity when an oscillating force is applied on the sample. This relationship in turn provides us with information about the displacement velocity experienced by the sample, which is inversely proportional to Young's modulus. The proposed method shows promise in offering a portable and cost-effective magnetic resonance elastography system. (paper)

Children's (Pediatric) Magnetic Resonance Imaging

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Full Text Available ... Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) uses ... identify and accurately characterize diseases than other imaging methods. This detail makes MRI an invaluable tool in ...

Tunable Magnetic Resonance in Microwave Spintronics Devices

Science.gov (United States)

Chen, Yunpeng; Fan, Xin; Xie, Yunsong; Zhou, Yang; Wang, Tao; Wilson, Jeffrey D.; Simons, Rainee N.; Chui, Sui-Tat; Xiao, John Q.

2015-01-01

Magnetic resonance is one of the key properties of magnetic materials for the application of microwave spintronics devices. The conventional method for tuning magnetic resonance is to use an electromagnet, which provides very limited tuning range. Hence, the quest for enhancing the magnetic resonance tuning range without using an electromagnet has attracted tremendous attention. In this paper, we exploit the huge exchange coupling field between magnetic interlayers, which is on the order of 4000 Oe and also the high frequency modes of coupled oscillators to enhance the tuning range. Furthermore, we demonstrate a new scheme to control the magnetic resonance frequency. Moreover, we report a shift in the magnetic resonance frequency as high as 20 GHz in CoFe based tunable microwave spintronics devices, which is 10X higher than conventional methods.

Magnetic resonance cardiac perfusion imaging-a clinical perspective

International Nuclear Information System (INIS)

Hunold, Peter; Schlosser, Thomas; Barkhausen, Joerg

2006-01-01

Coronary artery disease (CAD) with its clinical appearance of stable or unstable angina and acute myocardial infarction is the leading cause of death in developed countries. In view of increasing costs and the rising number of CAD patients, there has been a major interest in reliable non-invasive imaging techniques to identify CAD in an early (i.e. asymptomatic) stage. Since myocardial perfusion deficits appear very early in the ''ischemic cascade'', a major breakthrough would be the non-invasive quantification of myocardial perfusion before functional impairment might be detected. Therefore, there is growing interest in other, target-organ-specific parameters, such as relative and absolute myocardial perfusion imaging. Magnetic resonance (MR) imaging has been proven to offer attractive concepts in this respect. However, some important difficulties have not been resolved so far, which still causes uncertainty and prevents the broad application of MR perfusion imaging in a clinical setting. This review explores recent technical developments in MR hardware, software and contrast agents, as well as their impact on the current and future clinical status of MR imaging of first-pass myocardial perfusion imaging. (orig.)

Magnetic resonance cardiac perfusion imaging-a clinical perspective

Energy Technology Data Exchange (ETDEWEB)

Hunold, Peter; Schlosser, Thomas; Barkhausen, Joerg [University Hospital, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany)

2006-08-15

Coronary artery disease (CAD) with its clinical appearance of stable or unstable angina and acute myocardial infarction is the leading cause of death in developed countries. In view of increasing costs and the rising number of CAD patients, there has been a major interest in reliable non-invasive imaging techniques to identify CAD in an early (i.e. asymptomatic) stage. Since myocardial perfusion deficits appear very early in the ''ischemic cascade'', a major breakthrough would be the non-invasive quantification of myocardial perfusion before functional impairment might be detected. Therefore, there is growing interest in other, target-organ-specific parameters, such as relative and absolute myocardial perfusion imaging. Magnetic resonance (MR) imaging has been proven to offer attractive concepts in this respect. However, some important difficulties have not been resolved so far, which still causes uncertainty and prevents the broad application of MR perfusion imaging in a clinical setting. This review explores recent technical developments in MR hardware, software and contrast agents, as well as their impact on the current and future clinical status of MR imaging of first-pass myocardial perfusion imaging. (orig.)

Children's (Pediatric) Magnetic Resonance Imaging

Medline Plus

Full Text Available ... Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) uses a powerful ... for an MRI exam contains a metal called gadolinium . Gadolinium can be used in patients with iodine ...

Children's (Pediatric) Magnetic Resonance Imaging

Medline Plus

Full Text Available ... work? Unlike conventional x-ray examinations and computed tomography (CT) scans, MRI does not utilize ionizing radiation. Instead, ... Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging (MRI) Safety Contrast Materials Children ...

Fourier transform nuclear magnetic resonance

International Nuclear Information System (INIS)

Geick, R.

1981-01-01

This review starts with the basic principles of resonance phenomena in physical systems. Especially, the connection is shown between the properties of these systems and Fourier transforms. Next, we discuss the principles of nuclear magnetic resonance. Starting from the general properties of physical systems showing resonance phenomena and from the special properties of nuclear spin systems, the main part of this paper reviews pulse and Fourier methods in nuclear magnetic resonance. Among pulse methods, an introduction will be given to spin echoes, and, apart from the principle of Fourier transform nuclear magnetic resonance, an introduction to the technical problems of this method, e.g. resolution in the frequency domain, aliasing, phase and intensity errors, stationary state of the spin systems for repetitive measurements, proton decoupling, and application of Fourier methods to systems in a nonequilibrium state. The last section is devoted to special applications of Fourier methods and recent developments, e.g. measurement of relaxation times, solvent peak suppression, 'rapid scan'-method, methods for suppressing the effects of dipolar coupling in solids, two-dimensional Fourier transform nuclear magnetic resonance, and spin mapping or zeugmatography. (author)

Accurate estimation of global and regional cardiac function by retrospectively gated multidetector row computed tomography. Comparison with cine magnetic resonance imaging

International Nuclear Information System (INIS)

Belge, Benedicte; Pasquet, Agnes; Vanoverschelde, Jean-Louis J.; Coche, Emmanuel; Gerber, Bernhard L.

2006-01-01

Retrospective reconstruction of ECG-gated images at different parts of the cardiac cycle allows the assessment of cardiac function by multi-detector row CT (MDCT) at the time of non-invasive coronary imaging. We compared the accuracy of such measurements by MDCT to cine magnetic resonance (MR). Forty patients underwent the assessment of global and regional cardiac function by 16-slice MDCT and cine MR. Left ventricular (LV) end-diastolic and end-systolic volumes estimated by MDCT (134±51 and 67±56 ml) were similar to those by MR (137±57 and 70±60 ml, respectively; both P=NS) and strongly correlated (r=0.92 and r=0.95, respectively; both P<0.001). Consequently, LV ejection fractions by MDCT and MR were also similar (55±21 vs. 56±21%; P=NS) and highly correlated (r=0.95; P<0.001). Regional end-diastolic and end-systolic wall thicknesses by MDCT were highly correlated (r=0.84 and r=0.92, respectively; both P<0.001), but significantly lower than by MR (8.3±1.8 vs. 8.8±1.9 mm and 12.7±3.4 vs. 13.3±3.5 mm, respectively; both P<0.001). Values of regional wall thickening by MDCT and MR were similar (54±30 vs. 51±31%; P=NS) and also correlated well (r=0.91; P<0.001). Retrospectively gated MDCT can accurately estimate LV volumes, EF and regional LV wall thickening compared to cine MR. (orig.)

ST-Segment resolution and clinical outcome with ischemic postconditioning and comparison to magnetic resonance

DEFF Research Database (Denmark)

Lønborg, Jacob; Holmvang, Lene; Kelbæk, Henning

2010-01-01

Ischemic postconditioning (IPost) during primary percutaneous coronary intervention (PPCI) is suggested to reduce myocardial damage. However, the association with ST-segment resolution (STR) and clinical outcome is not determined. The primary aim of this study was to evaluate the association of I...... of IPost with STR and clinical outcome. Secondly, we sought to determine the relationship between STR and cardiac magnetic resonance (CMR) parameters in these patients....

Nuclear magnetic resonance gyroscope

International Nuclear Information System (INIS)

Grover, B.C.

1984-01-01

A nuclear magnetic resonance gyro using two nuclear magnetic resonance gases, preferably xenon 129 and xenon 131, together with two alkaline metal vapors, preferably rubidium, potassium or cesium, one of the two alkaline metal vapors being pumped by light which has the wavelength of that alkaline metal vapor, and the other alkaline vapor being illuminated by light which has the wavelength of that other alkaline vapor

Cardiovascular magnetic resonance in hypertrophic cardiomyopathy

International Nuclear Information System (INIS)

Shiozaki, Afonso Akio; Parga, Jose Rodrigues; Arteaga, Edmundo; Rochitte, Carlos Eduardo; Tassi, Eduardo Marinho

2007-01-01

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

Magnetically coupled Fano resonance of dielectric pentamer oligomer

International Nuclear Information System (INIS)

Zhang, Fuli; Li, Chang; He, Xuan; Chen, Lei; Fan, Yuancheng; Zhao, Qian; Zhang, Weihong; Zhou, Ji

2017-01-01

We present magnetically induced Fano resonance inside a dielectric metamaterial pentamer composed of ceramic bricks. Unlike previous reports where different sizes of dielectric resonators were essential to produce Fano resonance, under external magnetic field excitation, central and outer dielectric bricks with identical sizes exhibit in-phase and out-of-phase magnetic Mie oscillations. An asymmetric line shape of Fano resonance along with enhanced group delay is observed due to the interference between the magnetic resonance of the central brick and the symmetric magnetic resonance of outer bricks. Besides, Fano resonance blueshifts with the increasing resonance of the smaller central brick. The thermal-dependent permittivity of ceramics allows Fano resonance to be reversibly tuned by 300 MHz when temperature varies by 60 °C. (paper)

Advances in mechanical detection of magnetic resonance

International Nuclear Information System (INIS)

Kuehn, Seppe; Hickman, Steven A.; Marohn, John A.

2008-01-01

The invention and initial demonstration of magnetic resonance force microscopy (MRFM) in the early 1990s launched a renaissance of mechanical approaches to detecting magnetic resonance. This article reviews progress made in MRFM in the last decade, including the demonstration of scanned probe detection of magnetic resonance (electron spin resonance, ferromagnetic resonance, and nuclear magnetic resonance) and the mechanical detection of electron spin resonance from a single spin. Force and force-gradient approaches to mechanical detection are reviewed and recent related work using attonewton sensitivity cantilevers to probe minute fluctuating electric fields near surfaces is discussed. Given recent progress, pushing MRFM to single proton sensitivity remains an exciting possibility. We will survey some practical and fundamental issues that must be resolved to meet this challenge.

Investigation of magnetic interactions in sulfides by means of magnetic resonance

International Nuclear Information System (INIS)

Veen, G. van.

1978-01-01

Investigations have been designed to gather more information about magnetic pair interactions in sulfides by isomorphic substitution of the magnetic ions in suitable chosen diamagnetic host lattices and measurement of electron spin resonance of coupled pairs and of electron spin resonance or electron nuclear double resonance of the hyperfine interaction due to the nuclei of diamagnetic cations. The greater part of this thesis is devoted to preliminaries of magnetic resonance interpretation and sample selection and preparation. The measurements on the magnetically diluted compounds, which are described, only have an exploratory nature. (Auth.)

Evaluation of Accordance of Magnetic Resonance Volumetric and Flow Measurements in Determining Ventricular Stroke Volume in Cardiac Patients

International Nuclear Information System (INIS)

Jeltsch, M.; Ranft, S.; Klass, O.; Aschoff, A.J.; Hoffmann, M.H.K.

2008-01-01

Background: Cardiovascular magnetic resonance imaging (CMR) has become an established noninvasive method for evaluating ventricular function utilizing three-dimensional volumetry. Postprocessing of volumetric measurements is still tedious and time consuming. Stroke volumes obtained by flow quantification across the aortic root or pulmonary trunk could be utilized to increase both speed of workflow and accuracy. Purpose: To assess accuracy of stroke volume quantification using MR volumetric imaging compared to flow quantification in patients with various cardiac diseases. Strategies for the augmentation of accuracy in clinical routine were deduced. Material and Methods: 78 patients with various cardiac diseases -excluding intra- or extracardiac shunts, regurgitant valvular defects, or heart rhythm disturbance -underwent cardiac function analysis with flow measurements across the aortic root and cine imaging of the left ventricle. Forty-six patients additionally underwent flow measurements in the pulmonary trunk and cine imaging of the right ventricle. Results: Left ventricular stroke volume (LVSV) and stroke volume of the aortic root (SVAo) correlated with r=0.97, and Bland-Altman analysis showed a mean difference of 0.11 ml and a standard error of estimation (SEE) of 4.31 ml. Ninety-two percent of the data were within the 95% limits of agreement. Right ventricular stroke volume (RVSV) and stroke volume of the pulmonary trunk (SVP) correlated with a factor of r=0.86, and mean difference in the Bland-Altman analysis was fixed at -2.62 ml (SEE 8.47 ml). For RVSV and SVP, we calculated r=0.82, and Bland-Altman analysis revealed a mean difference of 1.27 ml (SEE 9.89 ml). LVSV and RVSV correlated closely, with r=0.91 and a mean difference of 2.79 ml (SEE 7.17 ml). SVAo and SVP correlated with r=0.95 and a mean difference of 0.50 ml (SEE 5.56 ml). Conclusion: Flow quantification can be used as a guidance tool, providing accurate and reproducible stroke volumes of both

Magnetic resonance imaging the basics

CERN Document Server

Constantinides, Christakis

2014-01-01

Magnetic resonance imaging (MRI) is a rapidly developing field in basic applied science and clinical practice. Research efforts in this area have already been recognized with five Nobel prizes awarded to seven Nobel laureates in the past 70 years. Based on courses taught at The Johns Hopkins University, Magnetic Resonance Imaging: The Basics provides a solid introduction to this powerful technology. The book begins with a general description of the phenomenon of magnetic resonance and a brief summary of Fourier transformations in two dimensions. It examines the fundamental principles of physics for nuclear magnetic resonance (NMR) signal formation and image construction and provides a detailed explanation of the mathematical formulation of MRI. Numerous image quantitative indices are discussed, including (among others) signal, noise, signal-to-noise, contrast, and resolution. The second part of the book examines the hardware and electronics of an MRI scanner and the typical measurements and simulations of m...

Correlation between myocardial fibrosis and the occurrence of atrial fibrillation in hypertrophic cardiomyopathy: A cardiac magnetic resonance imaging study

International Nuclear Information System (INIS)

Pujadas, S.; Vidal-Perez, R.; Hidalgo, A.; Leta, R.; Carreras, F.; Barros, A.; Bayes-Genis, A.; Subirana, M.T.; Pons-Llado, Guillem

2010-01-01

Cardiac magnetic resonance imaging (CMR) in hypertrophic cardiomyopathy (HCM) often shows delayed contrast enhancement (DE) representing regions of focal myocardial fibrosis. Atrial fibrillation (AF) is a commonly reported complication of HCM. We determined the relationship between the presence of left ventricular myocardial fibrosis (LVMF) detected by DE-CMR and the occurrence AF in a series of patients with HCM. 67 patients with HCM (47 males; mean age 50.1 ± 18.5 years) were studied by CMR measuring mass of LVMF, left ventricular mass, volume and function, and left atrial (LA) area. AF was present in 17 (25%) patients. LVMF was observed in 57% of patients. AF was significantly more frequent in patients who also showed LVMF, compared with the group without LVMF (42.1% vs. 3.4%, respectively; p 2 ; respectively, p = 0.0001). AF in HCM is related with myocardial fibrosis detected by DE-CMR and dilatation of the LA. This fact adds to the proven adverse prognostic value of myocardial fibrosis in HCM, thus, reinforcing the usefulness of this technique in the assessment of these patients.

[Magnetic resonance compatibility research for coronary mental stents].

Science.gov (United States)

Wang, Ying; Liu, Li; Wang, Shuo; Shang, Ruyao; Wang, Chunren

2015-01-01

The objective of this article is to research magnetic resonance compatibility for coronary mental stents, and to evaluate the magnetic resonance compatibility based on laboratory testing results. Coronary stents magnetic resonance compatibility test includes magnetically induced displacement force test, magnetically induced torque test, radio frequency induced heating and evaluation of MR image. By magnetic displacement force and torque values, temperature, and image distortion values to determine metal coronary stent demagnetization effect. The methods can be applied to test magnetic resonance compatibility for coronary mental stents and evaluate its demagnetization effect.

A Magnetic Resonance Measurement Technique for Rapidly Switched Gradient Magnetic Fields in a Magnetic Resonance Tomograph

Directory of Open Access Journals (Sweden)

K. Bartušek

2003-01-01

Full Text Available This paper describes a method for measuring of the gradient magnetic field in Nuclear Magnetic Resonance (NMR tomography, which is one of the modern medical diagnostic methods. A very important prerequisite for high quality imaging is a gradient magnetic field in the instrument with exactly defined properties. Nuclear magnetic resonance enables us to measure the pulse gradient magnetic field characteristics with high accuracy. These interesting precise methods were designed, realised, and tested at the Institute of Scientific Instruments (ISI of the Academy of Sciences of the Czech Republic. The first of them was the Instantaneous Frequency (IF method, which was developed into the Instantaneous Frequency of Spin Echo (IFSE and the Instantaneous Frequency of Spin Echo Series (IFSES methods. The above named methods are described in this paper and their a comparison is also presented.

The nuclear magnetic resonance well logging

International Nuclear Information System (INIS)

Zhang Yumin; Shen Huitang

2003-01-01

In this paper, the characteristic of the nuclear magnetic resonance logging is described at first. Then its development and its principle is presented. Compared with the nuclear magnetic resonance spectrometer, the magnet techniques is the first question that we must solve in the manufacture of the NMR well logging

Advances in magnetic and optical resonance

CERN Document Server

Warren, Warren S

1997-01-01

Since 1965, Advances in Magnetic and Optical Resonance has provided researchers with timely expositions of fundamental new developments in the theory of, experimentation with, and application of magnetic and optical resonance.

Comparison of {sup 18}F-fluorodeoxyglucose positron emission tomography (FDG PET) and cardiac magnetic resonance (CMR) in corticosteroid-naive patients with conduction system disease due to cardiac sarcoidosis

Energy Technology Data Exchange (ETDEWEB)

Ohira, Hiroshi; Birnie, David H.; Mc Ardle, Brian; Dick, Alexander; Klein, Ran; Renaud, Jennifer; DeKemp, Robert A.; Davies, Ross; Hessian, Renee; Liu, Peter; Nery, Pablo B. [University of Ottawa Heart Institute, Molecular Function and Imaging Program, National Cardiac PET Centre, Ottawa, ON (Canada); University of Ottawa Heart Institute, Arrhythmia Service, Division of Cardiology, Department of Medicine, Ottawa, ON (Canada); Pena, Elena; Dennie, Carole [The Ottawa Hospital, Medical Imaging Department, Ottawa, ON (Canada); University of Ottawa, Department of Radiology, Ottawa, ON (Canada); Bernick, Jordan; Wells, George A. [University of Ottawa Heart Institute, Cardiovascular Research Methods Center, Ottawa, ON (Canada); Leung, Eugene [The Ottawa Hospital, Division of Nuclear Medicine, Department of Medicine, Ottawa, Ontario (Canada); Yoshinaga, Keiichiro [Hokkaido University School of Medicine, Department of Molecular Imaging, Hokkaido (Japan); Tsujino, Ichizo; Sato, Takahiro; Nishimura, Masaharu [Hokkaido University School of Medicine, First Department of Medicine, Hokkaido (Japan); Manabe, Osamu; Tamaki, Nagara [Hokkaido University School of Medicine, Department of Nuclear Medicine, Hokkaido (Japan); Oyama-Manabe, Noriko [Hokkaido University Hospital, Diagnostic and Interventional Radiology, Hokkaido (Japan); Ruddy, Terrence D.; Beanlands, Rob S.B. [University of Ottawa Heart Institute, Molecular Function and Imaging Program, National Cardiac PET Centre, Ottawa, ON (Canada); University of Ottawa Heart Institute, Arrhythmia Service, Division of Cardiology, Department of Medicine, Ottawa, ON (Canada); The Ottawa Hospital, Medical Imaging Department, Ottawa, ON (Canada); University of Ottawa, Department of Radiology, Ottawa, ON (Canada); The Ottawa Hospital, Division of Nuclear Medicine, Department of Medicine, Ottawa, Ontario (Canada); Chow, Benjamin J.W. [University of Ottawa Heart Institute, Molecular Function and Imaging Program, National Cardiac PET Centre, Ottawa, ON (Canada); University of Ottawa Heart Institute, Arrhythmia Service, Division of Cardiology, Department of Medicine, Ottawa, ON (Canada); The Ottawa Hospital, Medical Imaging Department, Ottawa, ON (Canada); University of Ottawa, Department of Radiology, Ottawa, ON (Canada)

2016-02-15

Cardiac sarcoidosis (CS) is a cause of conduction system disease (CSD). {sup 18}F-Fluorodeoxyglucose-positron emission tomography (FDG PET) and cardiac magnetic resonance (CMR) are used for detection of CS. The relative diagnostic value of these has not been well studied. The aim was to compare these imaging modalities in this population. We recruited steroid-naive patients with newly diagnosed CSD due to CS. All CS patients underwent both imaging studies within 12 weeks of each other. Patients were classified into two groups: group A with chronic mild CSD (right bundle branch block and/or axis deviation), and group B with new-onset atrioventricular block (AVB, Mobitz type II or third-degree AVB). Thirty patients were included. Positive findings on both imaging studies were seen in 72 % of patients (13/18) in group A and in 58 % of patients (7/12) in group B. The remainder (28 %) of the patients in group A were positive only on CMR. Of the patients in group B, 8 % were positive only on CMR and 33 % were positive only on FDG PET. Patients in group A were more likely to be positive only on CMR, and patients in group B were more likely to be positive only on FDG PET (p = 0.02). Patients in group B positive only on FDG PET underwent CMR earlier relative to their symptomatology than patients positive only on CMR (median 7.0, IQR 1.5 - 34.3, vs. 72.0, IQR 25.0 - 79.5 days; p = 0.03). The number of positive FDG PET and CMR studies was different in patients with CSD depending on their clinical presentation. This study demonstrated that CMR can adequately detect cardiac involvement associated with chronic mild CSD. In patients presenting with new-onset AVB and a negative CMR study, FDG PET may be useful for detecting cardiac involvement due to CS. (orig.)

Doppler ultrasound and magnetic resonance for evaluation of patients treated surgically for aortic coarctation

International Nuclear Information System (INIS)

Canteli, B.; Saez, F.; Garcia, F.; Cabrera, A.; Galdeano, J.M.; Rodriguez, O.

1994-01-01

Doppler ultrasound and magnetic resonance were performed in a series of 39 patients who had been treated surgically for aortic coarctation. The purpose was to assess the different Doppler gradients, comparing the findings with morphological data disclosed by magnetic resonance. The aortic caliber in the operative field was pathological in 7 patients (ratio between the caliber at the level of the lesion and that of descending aorta of less than 0.7). When the patients were considered as a group. Doppler ultrasound did not show satisfactory sensitivity (29%-43%), specificity (74%) or positive predictive value (17%-23%). Only the negative predictive value (85%-88%) presented more favorable results. When the Subgroup of patients without associated cardiac abnormalities or collateral circulation was studied alone, the following results were found: sensitivity, 100%; specificity, 81%-90%, positive predictive value, 33%-50%, negative predictive value, 100%, similar to those reported in the literature. Thus, we consider that Doppler ultrasound is a harmless and low cost diagnostic method that is highly suitable for follow-up of these patients, within certain limits. Magnetic resonance is the method of choice for the noninvasive assessment of aortic morphology. (Author)

Embroidered Coils for Magnetic Resonance Sensors

Directory of Open Access Journals (Sweden)

Michael I. Newton

2013-04-01

Full Text Available Magnetic resonance imaging is a widely used technique for medical and materials imaging. Even though the objects being imaged are often irregularly shaped, suitable coils permitting the measurement of the radio-frequency signal in these systems are usually made of solid copper. One problem often encountered is how to ensure the coils are both in close proximity and conformal to the object being imaged. Whilst embroidered conductive threads have previously been used as antennae in mobile telecommunications applications, they have not previously been reported for use within magnetic resonance. In this paper we show that an embroidered single loop coil can be used in a commercial unilateral nuclear magnetic resonance system as an alternative to a solid copper. Data is presented showing the determination of both longitudinal (T1 and effective transverse (T2eff relaxation times for a flat fabric coil and the same coil conformed to an 8 cm diameter cylinder. We thereby demonstrate the principles required for the wider use of fabric based conformal coils within nuclear magnetic resonance and magnetic resonance imaging.

Comparison of Image Processing Techniques for Nonviable Tissue Quantification in Late Gadolinium Enhancement Cardiac Magnetic Resonance Images.

Science.gov (United States)

Carminati, M Chiara; Boniotti, Cinzia; Fusini, Laura; Andreini, Daniele; Pontone, Gianluca; Pepi, Mauro; Caiani, Enrico G

2016-05-01

The aim of this study was to compare the performance of quantitative methods, either semiautomated or automated, for left ventricular (LV) nonviable tissue analysis from cardiac magnetic resonance late gadolinium enhancement (CMR-LGE) images. The investigated segmentation techniques were: (i) n-standard deviations thresholding; (ii) full width at half maximum thresholding; (iii) Gaussian mixture model classification; and (iv) fuzzy c-means clustering. These algorithms were applied either in each short axis slice (single-slice approach) or globally considering the entire short-axis stack covering the LV (global approach). CMR-LGE images from 20 patients with ischemic cardiomyopathy were retrospectively selected, and results from each technique were assessed against manual tracing. All methods provided comparable performance in terms of accuracy in scar detection, computation of local transmurality, and high correlation in scar mass compared with the manual technique. In general, no significant difference between single-slice and global approach was noted. The reproducibility of manual and investigated techniques was confirmed in all cases with slightly lower results for the nSD approach. Automated techniques resulted in accurate and reproducible evaluation of LV scars from CMR-LGE in ischemic patients with performance similar to the manual technique. Their application could minimize user interaction and computational time, even when compared with semiautomated approaches.

Nuclear magnetic resonance imaging

International Nuclear Information System (INIS)

Young, I.R.

1984-01-01

In a method of imaging a body in which nuclear magnetic resonance is excited in a region including part of the body, and the free induction decay signal is measured, a known quantity of a material of known nuclear magnetic resonance properties, for example a bag of water, is included in the region so as to enhance the measured free induction decay signal. This then reduces the generation of noise during subsequent processing of the signal. (author)

Nuclear magnetic resonance diagnostic apparatus

International Nuclear Information System (INIS)

Sugimoto, H.

1985-01-01

Nuclear magnetic resonance diagnostic apparatus including a coil for generating a gradient field in a plane perpendicular to a static magnetic field, means for controlling the operation of the coil to rotationally shift in angular steps the gradient direction of the gradient field at an angle pitch of some multiple of the unit index angle through a plurality of rotations to assume all the shift positions of the gradient direction, a rough image reconstructor for reconstructing a rough tomographic image on the basis of nuclear magnetic resonance signals acquired during a rotation of the second gradient magnetic field, a rough image display for depicting the rough tomographic image, a final image reconstructor for reconstructing a final tomographic image on the basis of all nuclear magnetic resonance signals corresponding to all of the expected rotation shift positions acquired during a plurality of rotations and a final image display for depicting the final tomographic image

Nuclear magnetic resonance apparatus

International Nuclear Information System (INIS)

Lambert, R.

1991-01-01

In order to include the effect of a magnetic object in a subject under investigation, Nuclear Magnetic Resonance (NMR) apparatus is operable at more than one radio frequency (RF) frequency. The apparatus allows normal practice as far as obtaining an NMR response or image from a given nuclear species is concerned, but, in addition, interrogates the nuclear spin system at a frequency which is different from the resonance frequency normally used for the given nuclear species, as determined from the applied magnetic field. The magnetic field close to a magnetised or magnetisable object is modified and the given nuclear species gives a response at the different frequency. Thus detection of a signal at the frequency indicates the presence of the chosen nuclei close to the magnetised or magnetisable object. Applications include validation of an object detection or automatic shape inspection system in the presence of magnetic impurities, and the detection of magnetic particles which affect measurement of liquid flow in a pipe. (author)

[Safety of cardiac pacemakers and implantable cardioverter-defibrillators in magnetic resonance imaging. Assessment of the aggregate function at 1.5 tesla].

Science.gov (United States)

Nordbeck, P; Bauer, W R

2008-03-01

Magnetic resonance imaging (MRI) is increasingly used in patients, but it is contraindicated in those with cardiac pacemakers (CP) or implantable cardioverter defibrillators (ICD). This study examined circumstances in which potentially life-threatening arrhythmias may be triggered in patients with CP undergoing MRI and whether these problems can be avoided by reprogramming of these devices. Eight CP and seven ICDs were investigated in a phantom at 1.5 tesla (experimental and imaging sequences). A decrease in battery voltage was found in four CP after MRI (indication for elective replacement). Additionally, three showed changes in programming (resets). Analogous changes did not appear in the tested ICDs, but periods of tachycardia were recorded in all types of devices during MRI depending on the pulse sequence employed. MRI-related electromagnetic fields as used in routine MRI can induce severe pacemaker device malfunctions. Device programming approaches are unreliable for prevention of patient hazards, as programming changes or resets are one of the primary malfunctions during MRI.

Influence of high magnetic field strengths and parallel acquisition strategies on image quality in cardiac 2D CINE magnetic resonance imaging: comparison of 1.5 T vs. 3.0 T

International Nuclear Information System (INIS)

Gutberlet, Matthias; Schwinge, Kerstin; Freyhardt, Patrick; Spors, Birgit; Grothoff, Matthias; Denecke, Timm; Luedemann, Lutz; Felix, Roland; Noeske, Ralph; Niendorf, Thoralf

2005-01-01

The aim of this paper is to examine signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image quality of cardiac CINE imaging at 1.5 T and 3.0 T. Twenty volunteers underwent cardiac magnetic resonance imaging (MRI) examinations using a 1.5-T and a 3.0-T scanner. Three different sets of breath-held, electrocardiogram-gated (ECG) CINE imaging techniques were employed, including: (1) unaccelerated SSFP (steady state free precession), (2) accelerated SSFP imaging and (3) gradient-echo-based myocardial tagging. Two-dimensional CINE SSFP at 3.0 T revealed an SNR improvement of 103% and a CNR increase of 19% as compared to the results obtained at 1.5 T. The SNR reduction in accelerated 2D CINE SSFP imaging was larger at 1.5 T (37%) compared to 3.0 T (26%). The mean SNR and CNR increase at 3.0 T obtained for the tagging sequence was 88% and 187%, respectively. At 3.0 T, the duration of the saturation bands persisted throughout the entire cardiac cycle. For comparison, the saturation bands were significantly diminished at 1.5 T during end-diastole. For 2D CINE SSFP imaging, no significant difference in the left ventricular volumetry and in the overall image quality was obtained. For myocardial tagging, image quality was significantly improved at 3.0 T. The SNR reduction in accelerated SSFP imaging was overcompensated by the increase in the baseline SNR at 3.0 T and did not result in any image quality degradation. For cardiac tagging techniques, 3.0 T was highly beneficial, which holds the promise to improve its diagnostic value. (orig.)

Parametric methods for characterizing myocardial tissue by magnetic resonance imaging (part 2): T2 mapping.

Science.gov (United States)

Perea Palazón, R J; Solé Arqués, M; Prat González, S; de Caralt Robira, T M; Cibeira López, M T; Ortiz Pérez, J T

2015-01-01

Cardiac magnetic resonance imaging is considered the reference technique for characterizing myocardial tissue; for example, T2-weighted sequences make it possible to evaluate areas of edema or myocardial inflammation. However, traditional sequences have many limitations and provide only qualitative information. Moreover, traditional sequences depend on the reference to remote myocardium or skeletal muscle, which limits their ability to detect and quantify diffuse myocardial damage. Recently developed magnetic resonance myocardial mapping techniques enable quantitative assessment of parameters indicative of edema. These techniques have proven better than traditional sequences both in acute cardiomyopathy and in acute ischemic heart disease. This article synthesizes current developments in T2 mapping as well as their clinical applications and limitations. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

The Adolescent and Adult with congenital heart disease: When is the Magnetic Resonance Useful?

International Nuclear Information System (INIS)

Delgado, Jorge Andres; Abad, Pedro; Llano, Juan Fernando; Pulgarin, Luis German

2008-01-01

Cardiac magnetic resonance imaging (CMR) plays an important and growing role in the morphologic and functional assessment of the adolescent and adult patient with congenital heart disease and their post surgical sequelae. CMR allows a comprehensive noninvasive evaluation of the heart and chest without the limited acoustic window and field of view of trans thoracic echocardiography. This paper reviews the CMR technique and its clinical indications, followed by several representative teaching cases.

Magnetic resonance and porous materials

International Nuclear Information System (INIS)

McDonald, P.; Strange, J.

1998-01-01

Mention the words magnetic resonance to your medical advisor and he or she will immediately think of a multi-million pound scanner that peers deep into the brain. A chemist, on the other hand, will imagine a machine that costs several hundred thousand pounds and produces high-resolution spectra for chemical analysis. Food technologists will probably think of a bench-top instrument for determining moisture content, while an oil prospector will envisage a device that can be operated several kilometres down an oil well. To a physicist the term is more likely to conjure up a mental picture of nuclear spins precessing in a magnetic field. These examples illustrate the diverse aspects of a phenomenon discovered by physicists over 50 years ago. Electron spin resonance was first discovered by Russian scientists, and nuclear magnetic resonance was discovered in the US shortly afterwards by Ed Purcell at Harvard University and Felix Bloch at Stanford University. Today, nuclear magnetic resonance (NMR) is the most widely used technique. Modern NMR machines are making it possible to probe microstructure and molecular movement in materials as diverse as polymers, cements, rocks, soil and foods. NMR allows the distribution of different components in a material to be determined with a resolution approaching 1μm, although the signal can be sensitive to even smaller lengthscales. In this article the authors describe how physicists are still developing magnetic resonance to exploit a range of new applications. (UK)

Magnetic resonance imaging by using nano-magnetic particles

Energy Technology Data Exchange (ETDEWEB)

Shokrollahi, H., E-mail: Shokrollahi@sutech.ac.ir [Electroceramics Group, Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of); Khorramdin, A. [Electroceramics Group, Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of); Isapour, Gh. [Department of Materials and Engineering, Hakim Sabzevari University (Iran, Islamic Republic of)

2014-11-15

Magnetism and magnetic materials play a major role in various biological applications, such as magnetic bioseparation, magnetic resonance imaging (MRI), hyperthermia treatment of cancer and drug delivery. Among these techniques, MRI is a powerful method not only for diagnostic radiology but also for therapeutic medicine that utilizes a magnetic field and radio waves. Recently, this technique has contributed greatly to the promotion of the human quality life. Thus, this paper presents a short review of the physical principles and recent advances of MRI, as well as providing a summary of the synthesis methods and properties of contrast agents, like different core materials and surfactants. - Highlights: • This paper studies the physics of MRI as a powerful diagnostic technique. • MRI uses the differentiation between healthy and pathological tissues. • The relaxation times can be shortened by the use of a magnetic contrast agent. • The magnetic nanoparticles act as contrast agents, helping to increase the resolution. • Different synthesis methods can influence the magnetic resonance behavior.

Parallel magnetic resonance imaging

International Nuclear Information System (INIS)

Larkman, David J; Nunes, Rita G

2007-01-01

Parallel imaging has been the single biggest innovation in magnetic resonance imaging in the last decade. The use of multiple receiver coils to augment the time consuming Fourier encoding has reduced acquisition times significantly. This increase in speed comes at a time when other approaches to acquisition time reduction were reaching engineering and human limits. A brief summary of spatial encoding in MRI is followed by an introduction to the problem parallel imaging is designed to solve. There are a large number of parallel reconstruction algorithms; this article reviews a cross-section, SENSE, SMASH, g-SMASH and GRAPPA, selected to demonstrate the different approaches. Theoretical (the g-factor) and practical (coil design) limits to acquisition speed are reviewed. The practical implementation of parallel imaging is also discussed, in particular coil calibration. How to recognize potential failure modes and their associated artefacts are shown. Well-established applications including angiography, cardiac imaging and applications using echo planar imaging are reviewed and we discuss what makes a good application for parallel imaging. Finally, active research areas where parallel imaging is being used to improve data quality by repairing artefacted images are also reviewed. (invited topical review)

Magnetic resonance imaging of the prostate

DEFF Research Database (Denmark)

Iversen, P; Kjaer, L; Thomsen, C

1988-01-01

Magnetic resonance imaging offers new possibilities in investigation of the prostate gland. Current results of imaging and tissue discrimination in the evaluation of prostatic disease are reviewed. Magnetic resonance imaging may be useful in the staging of carcinoma of the prostate....

Cardiovascular magnetic resonance frontiers: Tissue characterisation with mapping

Directory of Open Access Journals (Sweden)

Rebecca Schofield

2016-11-01

Full Text Available The clinical use of cardiovascular magnetic resonance (CMR imaging has expanded rapidly over the last decade. Its role in cardiac morphological and functional assessment is established, with perfusion and late gadolinium enhancement (LGE imaging for scar increasingly used in day-to-day clinical decision making. LGE allows a virtual histological assessment of the myocardium, with the pattern of scar suggesting disease aetiology, and the extent of predicting risk. However, even combined, the full range of pathological processes occurring in the myocardium are not interrogated. Mapping is a new frontier where the intrinsic magnetic properties of heart muscle are measured to probe further. T1, T2 and T2* mapping measures the three fundamental tissue relaxation rate constants before contrast, and the extracellular volume (ECV after contrast. These are displayed in colour, often providing an immediate appreciation of pathology. These parameters are differently sensitive to pathologies. Iron (cardiac siderosis, intramyocardial haemorrhage makes T1, T2 and T2* fall. T2 also falls with fat infiltration (Fabry disease. T2 increases with oedema (acute infarction, takotsubo cardiomyopathy, myocarditis, rheumatological disease. Native T1 increases with fibrosis, oedema and amyloid. Some of these changes are large (e.g. iron, oedema, amyloid, others more modest (diffuse fibrosis. They can be used to detect early disease, distinguish aetiology and, in some circumstances, guide therapy. In this review, we discuss these processes, illustrating clinical application and future advances.

Magnetic resonance imaging of the prostate

DEFF Research Database (Denmark)

Iversen, P; Kjaer, L; Thomsen, C

1987-01-01

Magnetic resonance imaging offers new possibilities in the investigation of the prostate. The current results of imaging and tissue discrimination in the evaluation of prostatic disease are reviewed. Magnetic resonance imaging may be of value in the staging of carcinoma of the prostate....

Magnetic resonance of low dimensional magnetic solids

Energy Technology Data Exchange (ETDEWEB)

Gatteschi, D.; Ferraro, F.; Sessoli, R. (Florence Univ. (Italy))

1994-06-01

The utility of EPR and NMR in the study of low-dimensional magnetic solids is shown. A short summary of the basis of magnetic resonance in these systems is reported, and the importance of spin-diffusion and magnetic anisotropy evidenced. Some results from experiments on metal-radical chains and clusters are presented. (authors). 37 refs., 7 figs.

Magnetic resonance of low dimensional magnetic solids

International Nuclear Information System (INIS)

Gatteschi, D.; Ferraro, F.; Sessoli, R.

1994-01-01

The utility of EPR and NMR in the study of low-dimensional magnetic solids is shown. A short summary of the basis of magnetic resonance in these systems is reported, and the importance of spin-diffusion and magnetic anisotropy evidenced. Some results from experiments on metal-radical chains and clusters are presented. (authors). 37 refs., 7 figs

Identification and assessment of Anderson-Fabry disease by cardiovascular magnetic resonance noncontrast myocardial T1 mapping.

Science.gov (United States)

Sado, Daniel M; White, Steven K; Piechnik, Stefan K; Banypersad, Sanjay M; Treibel, Thomas; Captur, Gabriella; Fontana, Marianna; Maestrini, Viviana; Flett, Andrew S; Robson, Matthew D; Lachmann, Robin H; Murphy, Elaine; Mehta, Atul; Hughes, Derralynn; Neubauer, Stefan; Elliott, Perry M; Moon, James C

2013-05-01

Anderson-Fabry disease (AFD) is a rare but underdiagnosed intracellular lipid disorder that can cause left ventricular hypertrophy (LVH). Lipid is known to shorten the magnetic resonance imaging parameter T1. We hypothesized that noncontrast T1 mapping by cardiovascular magnetic resonance would provide a novel and useful measure in this disease with potential to detect early cardiac involvement and distinguish AFD LVH from other causes. Two hundred twenty-seven subjects were studied: patients with AFD (n=44; 55% with LVH), healthy volunteers (n=67; 0% with LVH), patients with hypertension (n=41; 24% with LVH), patients with hypertrophic cardiomyopathy (n=34; 100% with LVH), those with severe aortic stenosis (n=21; 81% with LVH), and patients with definite amyloid light-chain (AL) cardiac amyloidosis (n=20; 100% with LVH). T1 mapping was performed using the shortened modified Look-Locker inversion sequence on a 1.5-T magnet before gadolinium administration with primary results derived from the basal and midseptum. Compared with health volunteers, septal T1 was lower in AFD and higher in other diseases (AFD versus healthy volunteers versus other patients, 882±47, 968±32, 1018±74 milliseconds; Pgadolinium enhancement (1001±82 versus 891±38 milliseconds; P<0.0001). Noncontrast T1 mapping shows potential as a unique and powerful measurement in the imaging assessment of LVH and AFD.

Detection of eosinophilic myocarditis using contrast-enhanced magnetic resonance imaging: case report

International Nuclear Information System (INIS)

Takahashi, N.; Murakami, Y.; Shimada, T.; Kashima, Y.; Nakamura, K.; Inoue, S.-I.; Sugamori, T.; Katoh, H.; Ishibashi, Y.; Maruyama, R.

2001-01-01

Hypereosinophilic syndrome is characterized by idiopathic eosinophilia in the peripheral blood and multiorgan dysfunction secondary to mature eosinophil infiltration. It is essential to diagnose myocardial involvement in the early stage of the disease when active myocarditis due to cardiotoxic substances from eosinophils is still taking place, but clinical tools for the diagnosis of myocardial lesions in patients without overt cardiac dysfunction are not yet available. We present a case of successful detection of myocarditis due to hypereosinophilic syndrome by gadolinium-diethylenetriaminepentaascetic acid (Gd-DTPA) enhanced magnetic resonance imaging (MRI). (author)

Detection of eosinophilic myocarditis using contrast-enhanced magnetic resonance imaging: case report

Energy Technology Data Exchange (ETDEWEB)

Takahashi, N.; Murakami, Y.; Shimada, T.; Kashima, Y.; Nakamura, K.; Inoue, S.-I.; Sugamori, T.; Katoh, H.; Ishibashi, Y. [Shimane Medical Univ., The Fourth Dept. of Internal Medicine, Izumo City, Shimane (Japan); Maruyama, R. [Shimane Medical Univ., Dept. of Laboratory Medicine, Izumo City, Shimane (Japan)

2001-02-01

Hypereosinophilic syndrome is characterized by idiopathic eosinophilia in the peripheral blood and multiorgan dysfunction secondary to mature eosinophil infiltration. It is essential to diagnose myocardial involvement in the early stage of the disease when active myocarditis due to cardiotoxic substances from eosinophils is still taking place, but clinical tools for the diagnosis of myocardial lesions in patients without overt cardiac dysfunction are not yet available. We present a case of successful detection of myocarditis due to hypereosinophilic syndrome by gadolinium-diethylenetriaminepentaascetic acid (Gd-DTPA) enhanced magnetic resonance imaging (MRI). (author)

Cardiac magnetic source imaging based on current multipole model

International Nuclear Information System (INIS)

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. (general)

The nuclear magnetic resonance spectroscopy

International Nuclear Information System (INIS)

Goyer, Ph.

1997-01-01

The spectroscopy of nuclear magnetic resonance constitutes a major analytical technique in biological and organic analysis. This technique appears now in the programme of preparatory classes and its teaching is developed in the second year of DEUG. The following article reviews on the nuclear magnetic resonance and on the possibilities it offers to bring to the fore the physico-chemical properties of molecules. (N.C.)

Advances in magnetic resonance 2

CERN Document Server

Waugh, John S

2013-01-01

Advances in Magnetic Resonance, Volume 2, features a mixture of experimental and theoretical contributions. The book contains four chapters and begins with an ambitious and general treatment of the problem of signal-to-noise ratio in magnetic resonance. This is followed by separate chapters on the interpretation of nuclear relaxation in fluids, with special reference to hydrogen; and various aspects of molecular theory of importance in NMR.

Magnetic resonance annual, 1988

International Nuclear Information System (INIS)

Kressel, H.Y.

1987-01-01

This book features reviews of high-resolution MRI of the knee, MRI of the normal and ischmeic hip, MRI of the heart, and temporomandibular joint imaging, as well as thorough discussion on artifacts in magnetic resonance imaging. Contributors consider the clinical applications of gadolinium-DTPA in magnetic resonance imaging and the clinical use of partial saturation and saturation recovery sequences. Timely reports assess the current status of rapid MRI and describe a new rapid gated cine MRI technique. Also included is an analysis of cerebrospinal fluid flow effects during MRI of the central nervous system

Magnetic resonance angiography

Science.gov (United States)

... Saunders; 2015:chap 17. Litt H, Carpenter JP. Magnetic resonance imaging. In: Cronenwett JL, Johnston KW, eds. Rutherford's Vascular Surgery . 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap ...

Children's (Pediatric) Magnetic Resonance Imaging

Medline Plus

Full Text Available ... magnetic resonance imaging (MRI) uses a powerful magnetic field, radio waves and a computer to produce detailed ... problems, medications, recent surgeries and allergies. The magnetic field is not harmful, but it may cause some ...

Cine magnetic resonance imaging in congenital heart disease

International Nuclear Information System (INIS)

Akagi, Teiji; Kiyomatsu, Yumi; Kato, Hirohisa; Abe, Toushi; Nishimura, Hiroshi; Ohtake, Hisashi; Eto, Takaharu.

1989-01-01

Cine magnetic resonance imaging (MRI) was performed in 33 patients aged 19 days to 18 years (mean 5.1 years), who had congenital heart disease comfirmed at echocardiography or angiography. Prior to cine MRI, gated MRI with spin echo (SE) sequence was perfomed to evaluate cardiac structure. Cine MRI was demonstrated by fast low fip angle shot imaging technique with a 30 deg flip angle, 15 msec echo time, 30∼40 msec pulse repetition time, and 128X128 acquisition matrix. Abnormalities of cardiac structure were extremely well defined in all patients. Intracardiac and intravasucular blood flow were visualized with high signal intensity area, whereas ventricular filling flow and left to right shunt flow through ventricular septal defect and atrial septal defect were visualized with low signal intensity area. However, in the patients who had severe congestive heart failure or respiratory arrhythmia, the good recording of cine MRI was not obtained because of artifacts. Gated MRI with SE sequence provides excellent visualization of fine structures, and cine MRI can provide high spatial resolution imaging of flow dynamic in a variety of congenital heart disease, noninvasively. (author)

Magnetic resonance imaging: hazard, risk and safety

International Nuclear Information System (INIS)

Narayan, Pradeep; Suri, S.; Singh, P.

2001-01-01

The hazard and risk associated with magnetic resonance imaging is a matter of concern. In 1982, the Food and Drug Administration (FDA), USA issued guidelines to Hospital's Investigational Review Board (IRBs) in 'Guidelines for Evaluating Electromagnetic Exposure Risks for Trials of Clinical Nuclear Magnetic Resonance (NMR)'. In 1997, the Berufsgenossenschaft (BG), professional association for precision engineering and electronics of Germany, in their preliminary proposal for safety limits extended their concerns on static magnetic field. Owing to both time varying and static magnetic fields applied in Magnetic Resonance Imaging (MRI) this became of immediate concern to user community to assess the potential hazard and risk associated with the NMR system

Magnetic resonance phenomena in dynamics of relativistic particles

International Nuclear Information System (INIS)

Ternov, I.M.; Bordovitsyn, V.A.

1987-01-01

A relativistic generalization of Rabi's formula for magnetic resonance is given. On this basis, we consider fast and slow passage through resonance. We define a magnetic resonance exterior field as usual, using unit vectors of a Cartesian coordinate system, a homogeneous magnetic field, and the amplitude of a rotating magnetic field. For the description of spin dynamics we use the Bargmann-Michel-Telegdi equation

Follow-up of regional myocardial T2 relaxation times in patients with myocardial infarction evaluated with magnetic resonance imaging

International Nuclear Information System (INIS)

Krauss, X.H.; Wall, E. van der; Laarse, A. van der; Dijkman, P.R.M. van; Bruschke, A.V.G.; Doornbos, J.; Roos, A. de; Voorthuisen, A.E. van

1990-01-01

Multi-echo spin-echo cardiac magnetic resonance imaging studies (echo times 30, 60, 90 and 120 ms) were performed in 19 patients with a 7-14-day (mean 10) old myocardial infarction and were repeated in 13 patients 4-7 months (mean 6) later. Also, 10 normal subjects were studied with magnetic resonance imaging. T2 relaxation times of certain left ventricular segments were calculated from the signal intensities at echo times of 30 and 90 ms. Compared to normal individuals, the mean T2 values on the early magnetic resonance images of the patients with inferior infarction showed significantly prolonged T2 times in the inferiorly localized segments, while on the follow-up magnetic resonance images the T2 times had almost returned to the normal range. Also the patients with anterior infarction showed significantly prolonged T2 times in the anteriorly localized segments on the early nuclear magnetic resonance images, but the T2 times remained prolonged at the follow-up magnetic resonance images. For every patient a myocardial damage score was determined, which was defined as the sum of the segmental T2 values in the patients minus the upper limit of normal T2 values obtained from the normal volunteers (= mean normal+2SD). The damage score on both the early and late magnetic resonance imaging study correlated well with the infarction size determined by myocardial enzyme release. Only the patients with an inferior infarction showed a significant decrease in damage score at follow-up magnetic resonance imaging. It is concluded that the regional T2 relaxation times are increased in infarcted myocardial regions and may remain prolonged for at least up to 7 months after the acute event, particularly in patients with an anterior infarction. These findings demonstrate the clinical potential of T2-weighted magnetic resonance imaging studies for detecting myocardial infarction, and estimating infarct size for an extended period after acute myocardial infarction. (author). 29 refs

Magnetic resonance imaging in sudden deafness

International Nuclear Information System (INIS)

Ramos, Hugo Valter Lisboa; Barros, Flavia Alencar; Penido, Norma de Oliveira; Souza, Ana Claudia Valerio de; Yamaoka, Wellington Yugo; Yamashita, Helio

2005-01-01

The etiology of sudden deafness can remain undetermined despite extensive investigation. This study addresses the value of magnetic resonance imaging in the analysis of sudden deafness patients.Study Design: transversal cohort.Material And Method: In a prospective study, 49 patients attended at otolaryngology emergency room of Federal University of Sao Paulo - Escola Paulista de Medicina, from April 2001 to May 2003, were submitted to magnetic resonance imaging.Results: Magnetic Resonance abnormalities were seen in 23 (46.9%) patients and revealed two tumors suggestive of meningioma, three vestibular schwannomas, thirteen microangiopathic changes of the brain and five (21.7%) pathological conditions of the labyrinth.Conclusion: Sudden deafness should be approached as a symptom common to different diseases. The presence of cerebellopontine angle tumors in 10.2% of our cases, among other treatable causes, justifies the recommendation of gadolinium-enhanced magnetic resonance use, not only to study the auditory peripheral pathway, but to study the whole auditory pathway including the brain. (author)

Magnetic Resonance Imaging (MRI): Brain (For Parents)

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Magnetic Resonance Imaging (MRI): Brain KidsHealth / For Parents / Magnetic Resonance Imaging (MRI): Brain What's in this article? What ...

Magnetic resonance signal moment determination using the Earth's magnetic field

KAUST Repository

Fridjonsson, Einar Orn; Creber, Sarah A.; Vrouwenvelder, Johannes S.; Johns, Michael L.

2015-01-01

We demonstrate a method to manipulate magnetic resonance data such that the moments of the signal spatial distribution are readily accessible. Usually, magnetic resonance imaging relies on data acquired in so-called k-space which is subsequently Fourier transformed to render an image. Here, via analysis of the complex signal in the vicinity of the centre of k-space we are able to access the first three moments of the signal spatial distribution, ultimately in multiple directions. This is demonstrated for biofouling of a reverse osmosis (RO) membrane module, rendering unique information and an early warning of the onset of fouling. The analysis is particularly applicable for the use of mobile magnetic resonance spectrometers; here we demonstrate it using an Earth's magnetic field system.

Magnetic resonance signal moment determination using the Earth's magnetic field

KAUST Repository

Fridjonsson, Einar Orn

2015-03-01

We demonstrate a method to manipulate magnetic resonance data such that the moments of the signal spatial distribution are readily accessible. Usually, magnetic resonance imaging relies on data acquired in so-called k-space which is subsequently Fourier transformed to render an image. Here, via analysis of the complex signal in the vicinity of the centre of k-space we are able to access the first three moments of the signal spatial distribution, ultimately in multiple directions. This is demonstrated for biofouling of a reverse osmosis (RO) membrane module, rendering unique information and an early warning of the onset of fouling. The analysis is particularly applicable for the use of mobile magnetic resonance spectrometers; here we demonstrate it using an Earth\\'s magnetic field system.

Magnetic Resonance Imaging. Chapter 15

Energy Technology Data Exchange (ETDEWEB)

Leach, M. O. [The Institute of Cancer Research and The Royal Marsden Hospital, London (United Kingdom)

2014-09-15

In Chapter 14, the principles of nuclear magnetic resonance were presented, along with an introduction to image forming processes. In this chapter, magnetic resonance imaging (MRI) will be reviewed, beginning with the hardware needed and its impact on image quality. The acquisition processes and image reconstruction will be discussed, as well as the artefacts that are possible, with discussion of the important area of safety and bioeffects completing the chapter.

Adaptive reconstructions for magnetic resonance imaging of moving organs

International Nuclear Information System (INIS)

Lohezic, Maelene

2011-01-01

Magnetic resonance imaging (MRI) is a valuable tool for the clinical diagnosis for brain imaging as well as cardiac and abdominal imaging. For instance, MRI is the only modality that enables the visualization and characterization myocardial edema. However, motion remains a challenging problem for cardiac MRI. Breathing as well as cardiac beating have to be carefully handled during patient examination. Moreover they limit the achievable temporal and spatial resolution of the images. In this work an approach that takes these physiological motions into account during image reconstruction process has been proposed. It allows performing cardiac examination while breathing freely. First, an iterative reconstruction algorithm, that compensates motion estimated from a motion model constrained by physiological signals, is applied to morphological cardiac imaging. A semi-automatic method for edema detection has been tested on reconstructed images. It has also been associated with an adaptive acquisition strategy which enables free-breathing end-systolic imaging. This reconstruction has then been extended to the assessment of transverse relaxation times T2, which is used for myocardial edema characterization. The proposed method, ARTEMIS, enables free-breathing T2 mapping without additional acquisition time. The proposed free breathing approaches take advantage of physiological signals to estimate the motion that occurs during MR acquisitions. Several solutions have been tested to measure this information. Among them, accelerometer-based external sensors allow local measurements at several locations. Another approach consists in the use of k-space based measurements, which are 'embedded' inside the MRI pulse sequence (navigator) and prevent from the requirement of additional recording hardware. Hence, several adaptive reconstruction algorithms were developed to obtain diagnostic information from free breathing acquisitions. These works allow performing efficient and accurate

Force detection of nuclear magnetic resonance

International Nuclear Information System (INIS)

Rugar, D.; Zueger, O.; Hoen, S.; Yannoni, C.S.; Vieth, H.M.; Kendrick, R.D.

1994-01-01

Micromechanical sensing of magnetic force was used to detect nuclear magnetic resonance with exceptional sensitivity and spatial resolution. With a 900 angstrom thick silicon nitride cantilever capable of detecting subfemtonewton forces, a single shot sensitivity of 1.6 x 10 13 protons was achieved for an ammonium nitrate sample mounted on the cantilever. A nearby millimeter-size iron particle produced a 600 tesla per meter magnetic field gradient, resulting in a spatial resolution of 2.6 micrometers in one dimension. These results suggest that magnetic force sensing is a viable approach for enhancing the sensitivity and spatial resolution of nuclear magnetic resonance microimaging

Magnetic resonance imaging correlates of bee sting induced multiple organ dysfunction syndrome: A case report.

Science.gov (United States)

Das, Sushant K; Zeng, Li-Chuan; Li, Bing; Niu, Xiang-Ke; Wang, Jing-Liang; Bhetuwal, Anup; Yang, Han-Feng

2014-09-28

Occasionally systemic complications with high risk of death, such as multiple organ dysfunction syndrome (MODS), can occur following multiple bee stings. This case study reports a patient who presented with MODS, i.e., acute kidney injury, hepatic and cardiac dysfunction, after multiple bee stings. The standard clinical findings were then correlated with magnetic resonance imaging (MRI) findings, which demonstrates that MRI may be utilized as a simpler tool to use than other multiple diagnostics.

Principles of magnetic resonance imaging

International Nuclear Information System (INIS)

Mlynarik, V.; Tkac, I.; Srbecky, M.

1995-01-01

The aim of this review is to describe and explain the basic principles of magnetic resonance imaging. The first part of the text is devoted to the phenomenon of magnetic resonance (the interaction of RF magnetic field with the set of magnetic moments in the homogeneous magnetic field) and to relaxation processes. Then, the creation of MR image is described (slice selection, phase and frequency encoding of spatial information). The basic and the most frequently used techniques are explained (spin echo, gradient echo). The way the repetition and echo times influence the image quality and contrast (T1 or T2 weighing) is described. The part with the technical description of the MR equipment is included in the review. The MR imagination examination are compared with X-ray computer tomography technique

Magnetic resonance imaging in clinically-definite multiple sclerosis

International Nuclear Information System (INIS)

Noakes, J.B.; Herkes, G.K.; Frith, J.A.

1990-01-01

Forty-two patients with clinically-definite multiple sclerosis were examined by magnetic resonance imaging using a 1.5-T instrument. Magnetic resonance imaging detected an abnormality in 90% of patients. In four patients, no lesions were demonstrated. The number, size and site of the lesions by magnetic resonance imaging were compared with the patients' clinical status and other variables. The Kurtzke disability status scale score increased in patients with corpus callosum atrophy, brainstem and basal ganglia lesions, and correlated with the total number of lesions. No correlation was shown between the findings of magnetic resonance imaging and disease duration, age, sex or pattern-reversal visual-evoked potentials. The variety of magnetic resonance images that could be obtained in patients with clinically-definite multiple sclerosis is highlighted. 24 refs., 8 figs., 1 tab

Nuclear magnetic resonance method and apparatus

International Nuclear Information System (INIS)

Burl, M.; Young, I.R.

1984-01-01

A method and apparatus for determining the rate of flow of a liquid in a selected region of a body by nuclear magnetic resonance techniques are described. The method includes a sequence of applying a first magnetic pulse effective to excite nuclear magnetic resonance of a chosen nucleus within the liquid preferentially in a slice of the body which includes the selected region. A period of time (tsub(D)) is waited and then a second magnetic pulse is applied which is effective to excite nuclear magnetic resonance of the nuclei preferentially in the slice, and the free induction decay signal is measured. The whole sequence is repeated for different values of the period of time (tsub(D)). The variation in the value of the measured signal with tsub(D) is then related to the rate of flow of the liquid through the slice. (author)

Interaction of magnetic resonators studied by the magnetic field enhancement

Directory of Open Access Journals (Sweden)

Yumin Hou

2013-12-01

Full Text Available It is the first time that the magnetic field enhancement (MFE is used to study the interaction of magnetic resonators (MRs, which is more sensitive than previous parameters–shift and damping of resonance frequency. To avoid the coherence of lattice and the effect of Bloch wave, the interaction is simulated between two MRs with same primary phase when the distance is changed in the range of several resonance wavelengths, which is also compared with periodic structure. The calculated MFE oscillating and decaying with distance with the period equal to resonance wavelength directly shows the retardation effect. Simulation also shows that the interaction at normal incidence is sensitive to the phase correlation which is related with retardation effect and is ultra-long-distance interaction when the two MRs are strongly localized. When the distance is very short, the amplitude of magnetic resonance is oppressed by the strong interaction and thus the MFE can be much lower than that of single MR. This study provides the design rules of metamaterials for engineering resonant properties of MRs.

Nuclear Magnetic Resonance Spectroscopy

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 1. Nuclear Magnetic Resonance Spectroscopy. Susanta Das. General Article Volume 9 Issue 1 January 2004 pp 34-49. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/009/01/0034-0049. Keywords.

Magnetic resonance imaging of the fetal brain.

Science.gov (United States)

Tee, L Mf; Kan, E Yl; Cheung, J Cy; Leung, W C

2016-06-01

This review covers the recent literature on fetal brain magnetic resonance imaging, with emphasis on techniques, advances, common indications, and safety. We conducted a search of MEDLINE for articles published after 2010. The search terms used were "(fetal OR foetal OR fetus OR foetus) AND (MR OR MRI OR [magnetic resonance]) AND (brain OR cerebral)". Consensus statements from major authorities were also included. As a result, 44 relevant articles were included and formed the basis of this review. One major challenge is fetal motion that is largely overcome by ultra-fast sequences. Currently, single-shot fast spin-echo T2-weighted imaging remains the mainstay for motion resistance and anatomical delineation. Recently, a snap-shot inversion recovery sequence has enabled robust T1-weighted images to be obtained, which is previously a challenge for standard gradient-echo acquisitions. Fetal diffusion-weighted imaging, diffusion tensor imaging, and magnetic resonance spectroscopy are also being developed. With multiplanar capabilities, superior contrast resolution and field of view, magnetic resonance imaging does not have the limitations of sonography, and can provide additional important information. Common indications include ventriculomegaly, callosum and posterior fossa abnormalities, and twin complications. There are safety concerns about magnetic resonance-induced heating and acoustic damage but current literature showed no conclusive evidence of deleterious fetal effects. The American College of Radiology guideline states that pregnant patients can be accepted to undergo magnetic resonance imaging at any stage of pregnancy if risk-benefit ratio to patients warrants that the study be performed. Magnetic resonance imaging of the fetal brain is a safe and powerful adjunct to sonography in prenatal diagnosis. It can provide additional information that aids clinical management, prognostication, and counselling.

Fractionated magnetic-resonance elastography on the human heart; Fraktionierte Magnetresonanzelastographie am menschlichen Herzen

Energy Technology Data Exchange (ETDEWEB)

Rump, Jens

2008-07-28

Imaging techniques, including magnetic resonance imaging, belong to the most important tools in modern medical diagnostics. Another diagnostic aid is palpation, which is suitable for the qualitative characterization of pathological changes in organs near the surface. Magnetic resonance elastography (MRE) is a combination of these techniques. In principle, MRE uses motionsensitive MR-imaging to depict tissue deformation caused by externally induced shear waves. The type of deformation supply useful information about the elasticity of the tissue. Cardiac disorders are among the most common diseases. The goal of this study was to develop a method of applying in-vivo MRE to the human heart. The development of the mechanical stimulus, ultimately resulting in the introduction of an audio speaker as the source of vibration, provided the necessary means to introduce vibrations into inner organs. A crucial factor in applying MRE to the heart is the speed of the recording, which led to the development of 'fractional MRE'. The currently conventional fast heart imaging techniques were used as a starting point. The use of an unbalanced phase preparation gradient in the balanced steady-state imaging technique resulted in an improved phase-to-noise ratio. Along with the spoiled steady-state MRE imaging technique, initial MRE-studies on the human heart were performed. For the first time, externally induced mechanical vibrations were successfully introduced into the heart and were detected using fractional MRE with a high temporal resolution. The modulation of the shear wave amplitudes observed in the myocard of 6 healthy subjects correlated with the phases of the cardiac cycle. The techniques and methods developed here are a step toward routine clinical application of MRE of the heart and indicate high potential in the area of early diagnosis of cardiac disease. (orig.)

Primary cardiac and pericardial tumors, imaging approach

Energy Technology Data Exchange (ETDEWEB)

Yu-Qing Liu, M D [Chinese Academy of Medical Sciences, Beijing, BJ (China). Dept. of Radiology, Fu Wai Hospital and Cardiovascular Inst.

1996-12-31

The incidence of cardiac tumor and its classification was discussed. Imaging study i.e. conventional radiology, echocardiagoaphy (echo), magnetic resonance imaging (MRI), angiography and computed tomography (CT) used also discussed briefly. (8 refs.).

Primary cardiac and pericardial tumors, imaging approach

International Nuclear Information System (INIS)

Yu-Qing Liu, M.D.

1995-01-01

The incidence of cardiac tumor and its classification was discussed. Imaging study i.e. conventional radiology, echocardiagoaphy (echo), magnetic resonance imaging (MRI), angiography and computed tomography (CT) used also discussed briefly. (8 refs.)

Cardiac magnetic resonance imaging-derived pulmonary artery distensibility index correlates with pulmonary artery stiffness and predicts functional capacity in patients with pulmonary arterial hypertension

International Nuclear Information System (INIS)

Kang, Ki-Woon; Chang, Hyuk-Jae; Kim, Young-Jin; Choi, Byoung-Wook; Yang, Woo-In; Shim, Chi-Young; Ha, Jongwon; Chung, Namsik; Lee, Hye-Sun

2011-01-01

Increased stiffness of the pulmonary vascular bed is known to increase mortality in patients with pulmonary arterial hypertension (PAH); and pulmonary artery (PA) stiffness is also thought to be associated with exercise capacity. The purpose of the present study was to investigate whether cardiac magnetic resonance imaging (CMRI)-derived PA distensibility index correlates with PA stiffness estimated on right heart catheterization (RHC) and predicts functional capacity (FC) in patients with PAH. Thirty-five consecutive PAH patients (23% male, mean age, 44±13 years; 69% idiopathic) underwent CMRI, RHC, and 6-min walk test (6MWT). PA distensibility indices were derived from cross-sectional area change (%) in the transverse view, perpendicular to the axis of the main PA, on CMRI [(maximum area-minimum area)/minimum area during cardiac cycle]. Among the PA stiffness indices, pulmonary vascular resistance (PVR) and PA capacitance were calculated using hemodynamic dataset from RHC. CMRI-derived PA distensibility was inversely correlated with PVR (R 2 =0.34, P 2 =0.35, P 2 =0.61, P<0.001). Furthermore, PA distensibility <20% predicted poor FC (<400 m in 6MWT) with a sensitivity of 82% and a specificity of 94%. Non-invasive CMRI-derived PA distensibility index correlates with PA stiffness and can predict FC in patients with PAH. (author)

NMR magnetic field controller for pulsed nuclear magnetic resonance experiments

International Nuclear Information System (INIS)

Scheler, G.; Anacker, M.

1975-01-01

A nuclear magnetic resonance controller for magnetic fields, which can also be used for pulsed NMR investigations, is described. A longtime stability of 10 -7 is achieved. The control signal is generated by a modified time sharing circuit with resonance at the first side band of the 2 H signal. An exact calibration of the magnetic field is achieved by the variation of the H 1 - or of the time-sharing frequency. (author)

Real-time MRI guidance of cardiac interventions.

Science.gov (United States)

Campbell-Washburn, Adrienne E; Tavallaei, Mohammad A; Pop, Mihaela; Grant, Elena K; Chubb, Henry; Rhode, Kawal; Wright, Graham A

2017-10-01

Cardiac magnetic resonance imaging (MRI) is appealing to guide complex cardiac procedures because it is ionizing radiation-free and offers flexible soft-tissue contrast. Interventional cardiac MR promises to improve existing procedures and enable new ones for complex arrhythmias, as well as congenital and structural heart disease. Guiding invasive procedures demands faster image acquisition, reconstruction and analysis, as well as intuitive intraprocedural display of imaging data. Standard cardiac MR techniques such as 3D anatomical imaging, cardiac function and flow, parameter mapping, and late-gadolinium enhancement can be used to gather valuable clinical data at various procedural stages. Rapid intraprocedural image analysis can extract and highlight critical information about interventional targets and outcomes. In some cases, real-time interactive imaging is used to provide a continuous stream of images displayed to interventionalists for dynamic device navigation. Alternatively, devices are navigated relative to a roadmap of major cardiac structures generated through fast segmentation and registration. Interventional devices can be visualized and tracked throughout a procedure with specialized imaging methods. In a clinical setting, advanced imaging must be integrated with other clinical tools and patient data. In order to perform these complex procedures, interventional cardiac MR relies on customized equipment, such as interactive imaging environments, in-room image display, audio communication, hemodynamic monitoring and recording systems, and electroanatomical mapping and ablation systems. Operating in this sophisticated environment requires coordination and planning. This review provides an overview of the imaging technology used in MRI-guided cardiac interventions. Specifically, this review outlines clinical targets, standard image acquisition and analysis tools, and the integration of these tools into clinical workflow. 1 Technical Efficacy: Stage 5 J

Biatrial Cardiac Metastases in a Patient with Uterine Cervix Malignant Melanoma

Directory of Open Access Journals (Sweden)

Caglayan Geredeli

2015-01-01

Full Text Available Primary malignant melanomas of uterine cervix are quite rarely seen neoplasms, and long-life prognosis of patients with this disease is poor. Immunohistochemical methods and exclusion of other primary melanoma sites are used to confirm the diagnosis. As with other melanomas, cervix malignant melanomas may also cause cardiac metastases. Cardiac metastases are among rarely seen but more commonly encountered cases, compared to primary cardiac tumors. Here, we present a case of biatrial cardiac metastases in a 73-year-old patient with uterine cervix malignant melanomas. The patient underwent echocardiography, cardiac magnetic resonance imaging, and computed tomography. Our report shows the importance of advanced diagnostic techniques, such as cardiac magnetic resonance, not only for the detection of cardiac masses, but for a better anatomic definition and tissue characterization. Although the cases of malignant melanomas leading to multiple cardiac metastasis were reported in literature, the metastatic concurrence of malignant melanomas in both right and left atriums is quite rarely encountered as metastatic malignant melanomas. Also, another intriguing point in our case is that the primary lesion of our case was stemmed from uterine cervix, but not skin.

Resonance of magnetization excited by voltage in magnetoelectric heterostructures

Science.gov (United States)

Yu, Guoliang; Zhang, Huaiwu; Li, Yuanxun; Li, Jie; Zhang, Dainan; Sun, Nian

2018-04-01

Manipulation of magnetization dynamics is critical for spin-based devices. Voltage driven magnetization resonance is promising for realizing low-power information processing systems. Here, we show through Finite Element Method (FEM) simulations that magnetization resonance in nanoscale magnetic elements can be generated by a radio frequency (rf) voltage via the converse magnetoelectric (ME) effect. The magnetization dynamics induced by voltage in a ME heterostructures is simulated by taking into account the magnetoelastic and piezoelectric coupling mechanisms among magnetization, strain and voltage. The frequency of the excited magnetization resonance is equal to the driving rf voltage frequency. The proposed voltage driven magnetization resonance excitation mechanism opens a way toward energy-efficient spin based device applications.

Laser magnetic resonance spectroscopy

International Nuclear Information System (INIS)

Ferrari, C.A.

1985-01-01

The technique of laser resonance magnetic resonance allows one to study the high-resolution spectroscopy of transient paramagnetic species, viz, atoms, radicals, and molecular ions. This article is a brief exposition of the method, describing the principles, instrumentation and applicability of the IR and FIR-LMR and shows results of HF + . (Author) [pt

Assmentment of myocardial perfusion by magnetic resonance imaging: on the way to clinical application

International Nuclear Information System (INIS)

Fischer, S.E.; Lorenz, C.H.

1997-01-01

Magnetic resonance imaging detects the flow of contrast - enhanced blood and even allows the quantitative assessment of myocardial perfusion. The clinical application of this method is being held back by the difficulties in image evaluation and the limitation of standard techniques to the acquisition of a single slice per heart beat cycle. Recent developments in scanner hardware as well as in image acquisition techniques open up the possibility of assessing myocardial perfusion over the entire heart with a spatial resolution in the range of 2 mm. As an example of such a new scanning strategy, a segmented gradient-echo recalled echo planar imaging sequence with preceding saturation is discussed and results in a patient with an infarction are presented. The clinical use of perfusion assessment covering the entire heart for the diagnosis of coronary artery disease is enhanced by the flexibility of magnetic resonance imaging for the assessment of functional cardiac parameters. (orig.) [de

Waveguide volume probe for magnetic resonance imaging and spectroscopy

DEFF Research Database (Denmark)

2015-01-01

The present disclosure relates to a probe for use within the field of nuclear magnetic resonance, such as magnetic resonance imaging (MRI), and magnetic resonance spectroscopy (MRS)). One embodiment relates to an RF probe for magnetic resonance imaging and/or spectroscopy comprising a conductive...... non-magnetic hollow waveguide having an internal volume and at least one open end, one or more capacitors and at least a first conductive non-magnetic wire, wherein said first conductive wire connects at least one of said one or more capacitors to opposite walls of one open end of the waveguide...

Magnetic Resonance Imaging in Myocardial Fibrosis Related to Ischemic Events

Directory of Open Access Journals (Sweden)

Himcinschi Elisabeta

2017-09-01

Full Text Available Given the higher amount of detail it offers, the use of magnetic resonance (MR in the field of cardiology has increased, thus leading to a decrease in the use of invasive and irradiating methods for diagnosing various cardiovascular disorders. The only precautions for MR imaging are metallic implants and advanced-stage chronic kidney disease. For the acquisition of clear and dynamic myocardial images, methods such as spin echo imaging for anatomical description, steady-state free precession imaging for the assessment of ventricular cavity size and function, flow velocity encoding for blood flow measurements, radiofrequency tagging for dynamics, and even spectroscopy for metabolism evaluation are used. Cardiac magnetic resonance (CMR is considered the gold standard imaging method for the anatomical characterization of the heart and obtaining information related to myocardial dynamics. In case of ischemic events, CMR is used for a detailed description of the necrotic area and the complications, and for tracking the ventricular remodeling. By administrating a contrast agent (gadolinium, the difference between sub-endothelial and transmural infarctions can be distinguished, highlighting even microvascular lesions responsible for the extension of the necrosis. The assessment of the dynamics of ventricular remodeling and viability through late gadolinium enhancement (LGE technology highlights the area of fibrosis and the occurrence of late complications.

Observation of ferromagnetic resonance in a microscopic sample using magnetic resonance force microscopy

International Nuclear Information System (INIS)

Zhang, Z.; Hammel, P.C.; Wigen, P.E.

1996-01-01

We report the observation of a ferromagnetic resonance signal arising from a microscopic (∼20μmx40μm) particle of thin (3μm) yttrium iron garnet film using magnetic resonance force microscopy (MRFM). The large signal intensity in the resonance spectra suggests that MRFM could become a powerful microscopic ferromagnetic resonance technique with a micron or sub-micron resolution. We also observe a very strong nonresonance signal which occurs in the field regime where the sample magnetization readily reorients in response to the modulation of the magnetic field. This signal will be the main noise source in applications where a magnet is mounted on the cantilever. copyright 1996 American Institute of Physics

Magnetic resonance imaging pre- and postoperative evaluation of tetralogy of Fallot

International Nuclear Information System (INIS)

Bernardes, Renata Junqueira Moll; Simoes, Luiz Carlos

2004-01-01

The purpose of this study was to assess the usefulness of magnetic resonance imaging (MRI) in the pre- and postoperative evaluation of patients with tetralogy of Fallot. Twenty patients aged 1 to 29 years were prospectively evaluated with black-blood and contrast-enhanced angiographic techniques, 11 with the classic form of tetralogy of Fallot and 9 with tetralogy of Fallot and pulmonary atresia. MRI studies provided adequate visualization of the aorta that was classified as dilated or not dilated, and definition of its position in all cases. The use of contrast-enhanced MR angiographic techniques provided excellent imaging of the main right and left pulmonary arteries. The results suggest that MRI, including contrast-enhanced angiography techniques, is a useful tool in the evaluation of patients with tetralogy of Fallot before and after cardiac surgery since it provides important anatomical information that is not always obtained with echocardiography. MRI can be considered an alternative to cardiac catheterization, particularly in the evaluation of the pulmonary vascular anatomy. (author)

The Role of Cardiovascular Magnetic Resonance Imaging in Heart Failure.

Science.gov (United States)

Peterzan, Mark A; Rider, Oliver J; Anderson, Lisa J

2016-11-01

Cardiovascular imaging is key for the assessment of patients with heart failure. Today, cardiovascular magnetic resonance imaging plays an established role in the assessment of patients with suspected and confirmed heart failure syndromes, in particular identifying aetiology. Its role in informing prognosis and guiding decisions around therapy are evolving. Key strengths include its accuracy; reproducibility; unrestricted field of view; lack of radiation; multiple abilities to characterise myocardial tissue, thrombus and scar; as well as unparalleled assessment of left and right ventricular volumes. T2* has an established role in the assessment and follow-up of iron overload cardiomyopathy and a role for T1 in specific therapies for cardiac amyloid and Anderson-Fabry disease is emerging.

The particle concentration effect on magnetic resonance linewidth for magnetic liquids with chain aggregates

International Nuclear Information System (INIS)

Marin, C.N.

2002-01-01

Based on the assumption of particle chains formation within a magnetic liquid, computer simulation of the magnetic resonance line is presented. The dependence on particle concentration within a magnetic liquid of magnetic resonance linewidth is analyzed. The computer simulation demonstrates that the particles chaining has an important effect on the enlargement of the magnetic resonance line. Increasing the particle concentration within magnetic liquid leads to an increase in the linewidth. The agreement with some experimental findings is discussed

Free-breathing whole-heart 3D cine magnetic resonance imaging with prospective respiratory motion compensation.

Science.gov (United States)

Moghari, Mehdi H; Barthur, Ashita; Amaral, Maria E; Geva, Tal; Powell, Andrew J

2018-07-01

To develop and validate a new prospective respiratory motion compensation algorithm for free-breathing whole-heart 3D cine steady-state free precession (SSFP) imaging. In a 3D cine SSFP sequence, 4 excitations per cardiac cycle are re-purposed to prospectively track heart position. Specifically, their 1D image is reconstructed and routed into the scanner's standard diaphragmatic navigator processing system. If all 4 signals are in end-expiration, cine image data from the entire cardiac cycle is accepted for image reconstruction. Prospective validation was carried out in patients (N = 17) by comparing in each a conventional breath-hold 2D cine ventricular short-axis stack and a free-breathing whole-heart 3D cine data set. All 3D cine SSFP acquisitions were successful and the mean scan time was 5.9 ± 2.7 min. Left and right ventricular end-diastolic, end-systolic, and stroke volumes by 3D cine SSFP were all larger than those from 2D cine SSFP. This bias was 3D cine images had a lower ventricular blood-to-myocardium contrast ratio, contrast-to-noise ratio, mass, and subjective quality score. The novel prospective respiratory motion compensation method for 3D cine SSFP imaging was robust and efficient and yielded slightly larger ventricular volumes and lower mass compared to breath-hold 2D cine imaging. Magn Reson Med 80:181-189, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

76 FR 58281 - Magnetic Resonance Imaging Safety; Public Workshop

Science.gov (United States)

2011-09-20

...] Magnetic Resonance Imaging Safety; Public Workshop AGENCY: Food and Drug Administration, HHS. ACTION... announcing a public workshop entitled: ``Magnetic Resonance Imaging (MRI) Safety Public Workshop.'' The purpose of the public workshop is to discuss factors affecting the safe use of magnetic resonance imaging...

Functional magnetic resonance imaging of the primary motor cortex ...

Indian Academy of Sciences (India)

Unknown

Abbreviations used: BOLD, Blood oxygenation level dependent; CBF, cerebral blood flow; fMRI, functional magnetic resonance imaging; EPI, eco-planar imaging; FOV, field of view; MRI, Magnetic resonance imaging; MRS, magnetic resonance spectroscopy;. PET, position emission tomography; rCBF, regional cerebral ...

Free-breathing steady-state free precession cine cardiac magnetic resonance with respiratory navigator gating.

Science.gov (United States)

Moghari, Mehdi H; Komarlu, Rukmini; Annese, David; Geva, Tal; Powell, Andrew J

2015-04-01

To develop and validate a respiratory motion compensation method for free-breathing cardiac cine imaging. A free-breathing navigator-gated cine steady-state free precession acquisition (Cine-Nav) was developed which preserves the equilibrium state of the net magnetization vector, maintains the high spatial and temporal resolutions of standard breath-hold (BH) acquisition, and images entire cardiac cycle. Cine image data is accepted only from cardiac cycles occurring entirely during end-expiration. Prospective validation was performed in 10 patients by obtaining in each three complete ventricular image stacks with different respiratory motion compensation approaches: (1) BH, (2) free-breathing with 3 signal averages (3AVG), and (3) free-breathing with Cine-Nav. The subjective image quality score (1 = worst, 4 = best) for Cine-Nav (3.8 ± 0.4) was significantly better than for 3AVG (2.2 ± 0.5, P = 0.002), and similar to BH (4.0 ± 0.0, P = 0.13). The blood-to-myocardium contrast ratio for Cine-Nav (6.3 ± 1.5) was similar to BH (5.9 ± 1.6, P = 0.52) and to 3AVG (5.6 ± 2.5, P = 0.43). There were no significant differences between Cine-Nav and BH for the ventricular volumes and mass. In contrast, there were significant differences between 3AVG and BH in all of these measurements but right ventricular mass. Free-breathing cine imaging with Cine-Nav yielded comparable image quality and ventricular measurements to BH, and was superior to 3AVG. © 2014 Wiley Periodicals, Inc.

Magnetic resonance angiography for the head and neck region

International Nuclear Information System (INIS)

Aschenbach, R.; Esser, D.

2004-01-01

Magnetic resonance angiography is a noninvasive method in vascular imaging using noncontrast- enhanced and contrast-enhanced techniques. The contrast media used in contrast- enhanced magnetic resonance angiography are different from the X-ray contrast media and do not affect the thyroid gland or renal function. In detecting hypervascularized lesions in the head and neck, contrast-enhanced magnetic resonance angiography is the method of choice, which provides an acceptable quality in comparison to digital subtraction angiography. Future developments in magnetic resonance imaging techniques will cause a wider use of magnetic resonance angiography, especially in head and neck imaging. Digital subtraction angiography should therefore only be used in problem cases and for preoperative embolization [de

Single voxel magnetic resonance spectroscopy in distinguishing ...

African Journals Online (AJOL)

Objective: Assess diagnostic utility of combined magnetic resonance imaging and magnetic resonance spectroscopy (MRI, MRS) in differentiating focal neoplastic lesions from focal non- neoplastic (infective or degenerative) brain lesions. Design: Descriptive, analytical - prospective study. Setting: The Aga Khan University ...

Your Radiologist Explains Magnetic Resonance Angiography (MRA)

Medline Plus

Full Text Available ... Sponsored by Image/Video Gallery Your Radiologist Explains Magnetic Resonance Angiography (MRA) Transcript Welcome to Radiology Info dot ... I’d like to talk with you about magnetic resonance angiography, or as it’s commonly known, MRA. MRA ...

Differentiation between acute and chronic myocardial infarction by means of texture analysis of late gadolinium enhancement and cine cardiac magnetic resonance imaging.

Science.gov (United States)

Larroza, Andrés; Materka, Andrzej; López-Lereu, María P; Monmeneu, José V; Bodí, Vicente; Moratal, David

2017-07-01

The purpose of this study was to differentiate acute from chronic myocardial infarction using machine learning techniques and texture features extracted from cardiac magnetic resonance imaging (MRI). The study group comprised 22 cases with acute myocardial infarction (AMI) and 22 cases with chronic myocardial infarction (CMI). Cine and late gadolinium enhancement (LGE) MRI were analyzed independently to differentiate AMI from CMI. A total of 279 texture features were extracted from predefined regions of interest (ROIs): the infarcted area on LGE MRI, and the entire myocardium on cine MRI. Classification performance was evaluated by a nested cross-validation approach combining a feature selection technique with three predictive models: random forest, support vector machine (SVM) with Gaussian Kernel, and SVM with polynomial kernel. The polynomial SVM yielded the best classification performance. Receiver operating characteristic curves provided area-under-the-curve (AUC) (mean±standard deviation) of 0.86±0.06 on LGE MRI using 72 features; AMI sensitivity=0.81±0.08 and specificity=0.84±0.09. On cine MRI, AUC=0.82±0.06 using 75 features; AMI sensitivity=0.79±0.10 and specificity=0.80±0.10. We concluded that texture analysis can be used for differentiation of AMI from CMI on cardiac LGE MRI, and also on standard cine sequences in which the infarction is visually imperceptible in most cases. Copyright © 2017 Elsevier B.V. All rights reserved.

Contrast agents in magnetic resonance imaging

International Nuclear Information System (INIS)

Karadjian, V.

1987-01-01

The origine of nuclear magnetic resonance signal is reminded and different ways for contrast enhancement in magnetic resonance imaging are presented, especially, modifications of tissus relaxation times. Investigations have focused on development of agents incorporating either paramagnetic ions or stable free radicals. Pharmacological and toxicological aspects are developed. The diagnostic potential of these substances is illustrated by the example of gadolinium complexes [fr

Magnetic resonance: discovery, investigations, and applications

International Nuclear Information System (INIS)

Kessenikh, Aleksandr V

2009-01-01

The history of the development of the theoretical ideas and experimental methods of magnetic resonance, as well as the applications of these methods in modern natural science, technology, and medicine, are outlined, with allowance for the contribution of Russian researchers. An assessment of some promising trends of studies and applications of magnetic resonance is given. (from the history of physics)

Reducing Field Distortion in Magnetic Resonance Imaging

Science.gov (United States)

Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob

2010-01-01

A concept for a magnetic resonance imaging (MRI) system that would utilize a relatively weak magnetic field provides for several design features that differ significantly from the corresponding features of conventional MRI systems. Notable among these features are a magnetic-field configuration that reduces (relative to the conventional configuration) distortion and blurring of the image, the use of a superconducting quantum interference device (SQUID) magnetometer as the detector, and an imaging procedure suited for the unconventional field configuration and sensor. In a typical application of MRI, a radio-frequency pulse is used to excite precession of the magnetic moments of protons in an applied magnetic field, and the decaying precession is detected for a short time following the pulse. The precession occurs at a resonance frequency proportional to the strengths of the magnetic field and the proton magnetic moment. The magnetic field is configured to vary with position in a known way; hence, by virtue of the aforesaid proportionality, the resonance frequency varies with position in a known way. In other words, position is encoded as resonance frequency. MRI using magnetic fields weaker than those of conventional MRI offers several advantages, including cheaper and smaller equipment, greater compatibility with metallic objects, and higher image quality because of low susceptibility distortion and enhanced spin-lattice-relaxation- time contrast. SQUID MRI is being developed into a practical MRI method for applied magnetic flux densities of the order of only 100 T

Diagnostic contribution of cardiac magnetic resonance in patients with acute coronary syndrome and culprit-free angiograms.

Science.gov (United States)

Kawecki, Damian; Morawiec, Beata; Monney, Pierre; Pellaton, Cyril; Wojciechowska, Celina; Jojko, Joanna; Basiak, Marcin; Przywara-Chowaniec, Brygida; Fournier, Stephane; Nowalany-Kozielska, Ewa; Schwitter, Juerg; Muller, Olivier

2015-01-14

In spite of robust knowledge about underlying ischemic myocardial damage, acute coronary syndromes (ACS) with culprit-free angiograms raise diagnostic concerns. The present study aimed to evaluate the additional value of cardiac magnetic resonance (CMR) over commonly available non-CMR standard tests, for the differentiation of myocardial injury in patients with ACS and non-obstructed coronary arteries. Patients with ACS, elevated hs-TnT, and a culprit-free angiogram were prospectively enrolled into the study between January 2009 and July 2013. After initial evaluation with standard tests (ECG, echocardiography, hs-TnT) and provisional exclusion of acute myocardial infarction (AMI) in coronary angiogram, patients were referred for CMR with the suspicion of myocarditis or Takotsubo cardiomyopathy (TTC). According to the result of CMR, patients were reclassified as having myocarditis, AMI, TTC, or non-injured myocardium as assessed by late gadolinium enhancement. Out of 5110 patients admitted with ACS, 75 had normal coronary angiograms and entered the study; 69 of them (92%) were suspected for myocarditis and 6 (8%) for TTC. After CMR, 49 patients were finally diagnosed with myocarditis (65%), 3 with TTC (4%), 7 with AMI (9%), and 16 (21%) with non-injured myocardium. The provisional diagnosis was changed or excluded in 23 patients (31%), with a 9% rate of unrecognized AMI. The study results suggest that the evaluation of patients with ACS and culprit-free angiogram should be complemented by a CMR examination, if available, because the initial work-up with non-CMR tests leads to a significant proportion of misdiagnosed AMI.

Pulse sequences for contrast-enhanced magnetic resonance imaging

International Nuclear Information System (INIS)

Graves, Martin J.

2007-01-01

The theory and application of magnetic resonance imaging (MRI) pulse sequences following the administration of an exogenous contrast agent are discussed. Pulse sequences are categorised according to the contrast agent mechanism: changes in proton density, relaxivity, magnetic susceptibility and resonant frequency shift. Applications in morphological imaging, magnetic resonance angiography, dynamic imaging and cell labelling are described. The importance of optimising the pulse sequence for each application is emphasised

Magnetic field induced incommensurate resonance in cuprate superconductors

International Nuclear Information System (INIS)

Zhang Jingge; Cheng Li; Guo Huaiming; Feng Shiping

2009-01-01

The influence of a uniform external magnetic field on the dynamical spin response of cuprate superconductors in the superconducting state is studied based on the kinetic energy driven superconducting mechanism. It is shown that the magnetic scattering around low and intermediate energies is dramatically changed with a modest external magnetic field. With increasing the external magnetic field, although the incommensurate magnetic scattering from both low and high energies is rather robust, the commensurate magnetic resonance scattering peak is broadened. The part of the spin excitation dispersion seems to be an hourglass-like dispersion, which breaks down at the heavily low energy regime. The theory also predicts that the commensurate resonance scattering at zero external magnetic field is induced into the incommensurate resonance scattering by applying an external magnetic field large enough

Magnetic resonance imaging- physical principles and clinical application

International Nuclear Information System (INIS)

Tavri, Omprakash J.

1996-01-01

The advances in equipment and knowledge related to radiology are occurring at an astonishingly rapid rate. On November 8, 1895, William Conrad Roentgen discovered x-rays. In 1972, Godfrey Hounsfield and George Ambrose introduced computec tomography at a meeting of the British Institute of Radiology. In the same year, Paul Lauterbur published the idea of spatially resolving nuclear magnetic resonance samples, naming it zeugmatography. In 1977, Waldo Hinshaw and co-workers published a magnetic resonance image of a human hand and wrist, and by 1981 several centres were obtaining clinical magnetic resonance (MR) images. In a very short time, magnetic resonance imaging (MRI) has gained acceptance as a clinically useful imaging tool. (author)

Cardiac MRI in ischemic heart disease

International Nuclear Information System (INIS)

Ishida, Masaki; Kato, Shingo; Sakuma, Hajime

2009-01-01

Considerable progress has been made in cardiac magnetic resonance imaging (MRI). Cine MRI is recognized as the most accurate method for evaluating ventricular function. Late gadolinium-enhanced MRI can clearly delineate subendocardial infarction, and the assessment of transmural extent of infarction on MRI is widely useful for predicting myocardial viability. Stress myocardial perfusion MRI allows for detection of subendocardial myocardial ischemia, and the diagnostic accuracy of stress perfusion MRI is superior to stress perfusion single-photon emission computed tomography in patients with multivessel coronary artery disease (CAD). In recent years, image quality, volume coverage, acquisition speed and arterial contrast of 3-dimensional coronary magnetic resonance angiography (MRA) have been substantially improved with use of steady-state free precession sequences and parallel imaging techniques, permitting the acquisition of high-quality, whole-heart coronary MRA within a reasonably short imaging time. It is now widely recognized that cardiac MRI has tremendous potential for the evaluation of ischemic heart disease. However, cardiac MRI is technically complicated and its use in clinical practice is relatively limited. With further improvements in education and training, as well as standardization of appropriate study protocols, cardiac MRI will play a central role in managing patients with CAD. (author)

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

Science.gov (United States)

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

2016-06-07

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

Correlation between myocardial fibrosis and the occurrence of atrial fibrillation in hypertrophic cardiomyopathy: A cardiac magnetic resonance imaging study

Energy Technology Data Exchange (ETDEWEB)

Pujadas, S., E-mail: sandrapujadas@gmail.co [Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Vidal-Perez, R. [Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Hidalgo, A. [Radiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Leta, R.; Carreras, F.; Barros, A. [Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Bayes-Genis, A. [Cardiomyopathy and Cardiac Transplant Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Subirana, M.T. [Congenital Heart Disease Unit, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain); Pons-Llado, Guillem [Cardiac Imaging Unit, Cardiology Department, Hospital de la Santa Creu i Sant Pau, Av. Pare M Claret 167, 08025 Barcelona (Spain)

2010-08-15

Cardiac magnetic resonance imaging (CMR) in hypertrophic cardiomyopathy (HCM) often shows delayed contrast enhancement (DE) representing regions of focal myocardial fibrosis. Atrial fibrillation (AF) is a commonly reported complication of HCM. We determined the relationship between the presence of left ventricular myocardial fibrosis (LVMF) detected by DE-CMR and the occurrence AF in a series of patients with HCM. 67 patients with HCM (47 males; mean age 50.1 {+-} 18.5 years) were studied by CMR measuring mass of LVMF, left ventricular mass, volume and function, and left atrial (LA) area. AF was present in 17 (25%) patients. LVMF was observed in 57% of patients. AF was significantly more frequent in patients who also showed LVMF, compared with the group without LVMF (42.1% vs. 3.4%, respectively; p < 0.0001). LA size was larger in patients showing DE (LA area: 37.4 {+-} 11.1 vs. 25.9 {+-} 6.8 cm{sup 2}; respectively, p = 0.0001). AF in HCM is related with myocardial fibrosis detected by DE-CMR and dilatation of the LA. This fact adds to the proven adverse prognostic value of myocardial fibrosis in HCM, thus, reinforcing the usefulness of this technique in the assessment of these patients.

Low field magnetic resonance imaging

Science.gov (United States)

Pines, Alexander; Sakellariou, Dimitrios; Meriles, Carlos A.; Trabesinger, Andreas H.

2010-07-13

A method and system of magnetic resonance imaging does not need a large homogenous field to truncate a gradient field. Spatial information is encoded into the spin magnetization by allowing the magnetization to evolve in a non-truncated gradient field and inducing a set of 180 degree rotations prior to signal acquisition.

Magnetic Resonance Imaging (MRI) -- Head

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Full Text Available ... by the interpreting radiologist. Frequently, the differentiation of abnormal (diseased) tissue from normal tissues is better with ... Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...

Tuning Coler Magnetic Current Apparatus with Magneto-Acoustic Resonance

Science.gov (United States)

Ludwig, Thorsten

An attempt was made to tune the Coler magnetic current apparatus with the magneto acoustic resonance of the magnetic rods. Measurements with a replica of the famous Coler "Magnetstromapparat" were conducted. In order to tune the acoustic, magnetic and electric resonance circuits of the Coler device the magneto-acoustic resonance was measured with a frequency scan through a function generator and a lock-in amplifier. The frequency generator was powering a driving coil, while the lock-in was connected to a pickup coil. Both coils were placed on a magnetic rod. Resonances were observed up to the 17th harmonic. The quality Q of the observed resonances was 270. To study the magneto-acoustic resonance in the time domain a pair of Permendur rods were employed. The magneto-acoustic resonances of the Permendur rods were observed with an oscilloscope. Spectra of the magneto acoustic resonance were measured for the Permendur rods and for a Coler replica magnet in the frequency range from 25 kHz to 380 kHz. The next step was to bring the resonances of the Permendur rods close together so that they overlap. The 10thharmonic was chosen because it was close to the 180 kHz that Hans Coler related to ferromagnetism. Further more magneto-acoustic coupling between the Permendur rods was studied. Finally the question was explored if Hans Coler converted vacuum fluctuations via magnetic and acoustic resonance into electricity. There is a strong connection between magnetism and quantum field zero point energy (ZPE). An outlook is given on next steps in the experiments to unveil the working mechanism of the Coler magnetic current apparatus.

Migraine and magnetic resonance spectroscopy

DEFF Research Database (Denmark)

Younis, Samaira; Hougaard, Anders; Vestergaard, Mark B.

2017-01-01

Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation in the meth......Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation...

Radiographic Evaluation of Valvular Heart Disease With Computed Tomography and Magnetic Resonance Correlation.

Science.gov (United States)

Lempel, Jason K; Bolen, Michael A; Renapurkar, Rahul D; Azok, Joseph T; White, Charles S

2016-09-01

Valvular heart disease is a group of complex entities with varying etiologies and clinical presentations. There are a number of imaging tools available to supplement clinical evaluation of suspected valvular heart disease, with echocardiography being the most common and clinically established, and more recent emergence of computed tomography and magnetic resonance imaging as additional supportive techniques. Yet even with these newer and more sophisticated modalities, chest radiography remains one of the earliest and most common diagnostic examinations performed during the triage of patients with suspected cardiac dysfunction. Recognizing the anatomic and pathologic features of cardiac radiography including the heart's adaptation to varying hemodynamic changes can provide clues to the radiologist regarding the underlying etiology. In this article, we will elucidate several principles relating to chamber modifications in response to pressure and volume overload as well as radiographic appearances associated with pulmonary fluid status and cardiac dysfunction. We will also present a pattern approach to optimize analysis of the chest radiograph for valvular heart disease, which will help guide the radiologist down a differential diagnostic pathway and create a more meaningful clinical report.

Rotational characteristics in the resonance state of the HTSC-permanent magnet hybrid magnetic bearing

Energy Technology Data Exchange (ETDEWEB)

Morii, Y.; Sukedai, M. [Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan); Ohashi, S., E-mail: ohashi@kansai-u.ac.jp [Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680 (Japan)

2011-11-15

The hybrid magnetic bearing has been developed. In the hybrid system, effect of the pinning force becomes smaller. Influence of the vibration and the gradient angle in the resonance state is large. The resonance frequency becomes small in the hybrid bearing system. The hybrid magnetic bearing using permanent magnets and the high-Tc bulk superconductor (HTSC) has been developed. Repulsive force of the permanent magnet is introduced to increase the load weight of the magnetic bearing. Effect of the hybrid system has been shown. In this paper, influence of the hybrid system on the dynamic characteristics of the rotor is studied. The rotational characteristics in the mechanical resonance state are studied, and the equivalent magnetic spring coefficient is estimated from the experimental results of the load weight. The resonance frequency is measured by the rotation experiments. The rotor achieves stable levitation even in the resonance state. In the hybrid system, effect of the pinning force becomes smaller than that of the lateral force generated by the repulsive force between the two permanent magnets at the smaller air gap. Thus influence of the lateral vibration and the gradient angle in the resonance state becomes larger at a smaller air gap. The equivalent magnetic spring coefficient becomes also small, and the resonance frequency becomes small in the hybrid bearing system.

Characterization of human breast disease using phosphorus magnetic resonance spectroscopy and proton magnetic resonance imaging

International Nuclear Information System (INIS)

Merchant, T.E.

1992-01-01

This thesis provides the fundamental characterization and differentiation of breast tissues using in vivo and ex vivo MR techniques in the hope that these techniques and experimental findings will be used on a larger scale and in a predictive manner in order to improve the specificity of diagnosis and treatment of breast cancer. In this dissertation, clinical studies were performed using proton magnetic resonance imaging and phosphorus magnetic resonance spectro-scopy ( 31 P MRS) to characterize and differentiate malignant breast tumors, benign breast tumors and normal breast tissues in vivo. These studies were carried out following the methodical characterization of chemical extracts of malignant breast tumor, benign breast tumor and normal breast parenchymal surgical tissue specimens using high resolution 31 P MRS. Alterations in breast tissue metabolism, as a result of pathological processes, were postulated to be responsible for measurable differences between malignant breast tumors, benign breast tumors and normal breast tissues using magnetic resonance techniques. (author). 365 refs.; 37 figs.; 25 tabs

Texture analysis of cardiac cine magnetic resonance imaging to detect nonviable segments in patients with chronic myocardial infarction.

Science.gov (United States)

Larroza, Andrés; López-Lereu, María P; Monmeneu, José V; Gavara, Jose; Chorro, Francisco J; Bodí, Vicente; Moratal, David

2018-04-01

To investigate the ability of texture analysis to differentiate between infarcted nonviable, viable, and remote segments on cardiac cine magnetic resonance imaging (MRI). This retrospective study included 50 patients suffering chronic myocardial infarction. The data were randomly split into training (30 patients) and testing (20 patients) sets. The left ventricular myocardium was segmented according to the 17-segment model in both cine and late gadolinium enhancement (LGE) MRI. Infarcted myocardium regions were identified on LGE in short-axis views. Nonviable segments were identified as those showing LGE ≥ 50%, and viable segments those showing 0 cine images. A support vector machine (SVM) classifier was trained with different combination of texture features to obtain a model that provided optimal classification performance. The best classification on testing set was achieved with local binary patterns features using a 2D + t approach, in which the features are computed by including information of the time dimension available in cine sequences. The best overall area under the receiver operating characteristic curve (AUC) were: 0.849, sensitivity of 92% to detect nonviable segments, 72% to detect viable segments, and 85% to detect remote segments. Nonviable segments can be detected on cine MRI using texture analysis and this may be used as hypothesis for future research aiming to detect the infarcted myocardium by means of a gadolinium-free approach. © 2018 American Association of Physicists in Medicine.

Cardiac magnetic resonance findings predicting mortality in patients with pulmonary arterial hypertension: a systematic review and meta-analysis

International Nuclear Information System (INIS)

Baggen, Vivan J.M.; Leiner, Tim; Habets, Jesse; Post, Marco C.; Dijk, Arie P. van; Sieswerda, Gertjan T.; Roos-Hesselink, Jolien W.; Boersma, Eric

2016-01-01

To provide a comprehensive overview of all reported cardiac magnetic resonance (CMR) findings that predict clinical deterioration in pulmonary arterial hypertension (PAH). MEDLINE and EMBASE electronic databases were systematically searched for longitudinal studies published by April 2015 that reported associations between CMR findings and adverse clinical outcome in PAH. Studies were appraised using previously developed criteria for prognostic studies. Meta-analysis using random effect models was performed for CMR findings investigated by three or more studies. Eight papers (539 patients) investigating 21 different CMR findings were included. Meta-analysis showed that right ventricular (RV) ejection fraction was the strongest predictor of mortality in PAH (pooled HR 1.23 [95 % CI 1.07-1.41], p = 0.003) per 5 % decrease. In addition, RV end-diastolic volume index (pooled HR 1.06 [95 % CI 1.00-1.12], p = 0.049), RV end-systolic volume index (pooled HR 1.05 [95 % CI 1.01-1.09], p = 0.013) and left ventricular end-diastolic volume index (pooled HR 1.16 [95 % CI 1.00-1.34], p = 0.045) were of prognostic importance. RV and LV mass did not provide prognostic information (p = 0.852 and p = 0.983, respectively). This meta-analysis substantiates the clinical yield of specific CMR findings in the prognostication of PAH patients. Decreased RV ejection is the strongest and most well established predictor of mortality. (orig.)

Cardiac magnetic resonance findings predicting mortality in patients with pulmonary arterial hypertension: a systematic review and meta-analysis

Energy Technology Data Exchange (ETDEWEB)

Baggen, Vivan J.M. [AHMaZON Centre for Adult Congenital Heart Disease, University Medical Centre Utrecht, Radboud University Medical Centre Nijmegen and St. Antonius Hospital Nieuwegein, Department of Cardiology, Utrecht (Netherlands); Erasmus Medical Centre, Department of Cardiology, Rotterdam (Netherlands); Leiner, Tim; Habets, Jesse [University Medical Centre Utrecht, Department of Radiology, Utrecht (Netherlands); Post, Marco C.; Dijk, Arie P. van; Sieswerda, Gertjan T. [AHMaZON Centre for Adult Congenital Heart Disease, University Medical Centre Utrecht, Radboud University Medical Centre Nijmegen and St. Antonius Hospital Nieuwegein, Department of Cardiology, Utrecht (Netherlands); Roos-Hesselink, Jolien W. [Erasmus Medical Centre, Department of Cardiology, Rotterdam (Netherlands); Boersma, Eric [Erasmus Medical Centre, Department of Cardiology, Rotterdam (Netherlands); Erasmus Medical Centre, Department of Clinical Epidemiology, Rotterdam (Netherlands)

2016-11-15

To provide a comprehensive overview of all reported cardiac magnetic resonance (CMR) findings that predict clinical deterioration in pulmonary arterial hypertension (PAH). MEDLINE and EMBASE electronic databases were systematically searched for longitudinal studies published by April 2015 that reported associations between CMR findings and adverse clinical outcome in PAH. Studies were appraised using previously developed criteria for prognostic studies. Meta-analysis using random effect models was performed for CMR findings investigated by three or more studies. Eight papers (539 patients) investigating 21 different CMR findings were included. Meta-analysis showed that right ventricular (RV) ejection fraction was the strongest predictor of mortality in PAH (pooled HR 1.23 [95 % CI 1.07-1.41], p = 0.003) per 5 % decrease. In addition, RV end-diastolic volume index (pooled HR 1.06 [95 % CI 1.00-1.12], p = 0.049), RV end-systolic volume index (pooled HR 1.05 [95 % CI 1.01-1.09], p = 0.013) and left ventricular end-diastolic volume index (pooled HR 1.16 [95 % CI 1.00-1.34], p = 0.045) were of prognostic importance. RV and LV mass did not provide prognostic information (p = 0.852 and p = 0.983, respectively). This meta-analysis substantiates the clinical yield of specific CMR findings in the prognostication of PAH patients. Decreased RV ejection is the strongest and most well established predictor of mortality. (orig.)

Children's (Pediatric) Magnetic Resonance Imaging

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Full Text Available ... Related Articles and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic ... the possible charges you will incur. Web page review process: This Web page is reviewed regularly by ...

Magnetic resonance imaging of the central nervous system

International Nuclear Information System (INIS)

Brant-Zawadzki, M.; Norman, D.

1987-01-01

This book presents the papers on technological advancement and diagnostic uses g magnetic resonance imaging. A comparative evaluation with computerized tomography is presented. Topics covered are imaging principles g magnetic resonance;instrumentation of magnetic resonance (MR);pathophysiology;quality and limitations g images;NMR imaging of brain and spinal cord;MR spectroscopy and its applications;neuroanatomy;Congenital malformations of brain and MR imaging;planning g MR imaging of spine and head and neck imaging

Comparative cardiac imaging

International Nuclear Information System (INIS)

Brundage, B.H.

1990-01-01

This book is designed to compare all major cardiac imaging techniques. All major imaging techniques - including conventional angiography, digital angiography, echocardiography and Doppler imaging, conventional radioisotope techniques, computed tomography, and magnetic resonance imaging - are covered in this text as they apply to the major cardiovascular disorders. There is brief coverage of positron emission tomography and an extensive presentation of ultrafast computed tomography

Nuclear magnetic resonance spectroscopy and imaging

International Nuclear Information System (INIS)

Jiang Weiping; Wang Qi; Zhou Xin

2013-01-01

This paper briefly introduces the basic principle of nuclear magnetic resonance (NMR). Protein's structures and functions and dynamics studied by liquid NMR are elaborated; methods for enhancing the resolution of solid state NMR and its applications are discussed; the principle of magnetic resonance imaging (MRI) is interpreted, and applications in different aspects are reviewed. Finally, the progress of NMR is commented. (authors)

Diagnostic apparatus employing nuclear magnetic resonance

International Nuclear Information System (INIS)

Hoshino, K.; Yamada, N.; Yoshitome, E.; Matsuura, H.

1987-01-01

An NMR diagnostic apparatus is described comprising means for applying a primary magnetic field to a subject; means for applying RF pulses to the subject to give nuclear magnetic resonance to the nuclei of atoms in the subject; means for applying gradient magnetic fields to project an NMR signal of the nuclei at least in one direction; means for observing the NMR signal projected by the gradient magnetic fields applying means; and arithmetic means for constructing a distribution of information on resonance energy as an image from an output signal from the observing means; wherein the gradient magnetic fields applying means comprises means for applying the gradient magnetic fields at a predetermined time and for not applying the gradient magnetic fields at another predetermined time, during the time period of one view; and wherein the gradient magnetic fields applying means further comprises means for measuring the NMR signal during the predetermined time when the gradient magnetic fields are applied, and means for measuring the intensity of the primary magnetic field during the other predetermined time when no gradient magnetic fields are applied

Children's (Pediatric) Magnetic Resonance Imaging

Medline Plus

Full Text Available ... immediately after the exam. A few patients experience side effects from the contrast material, including nausea and local ... Related Articles and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic ...

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

Energy Technology Data Exchange (ETDEWEB)

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

2008-11-15

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

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

International Nuclear Information System (INIS)

Fonte, Mariana Vieira de Melo da; Otaduy, Maria Concepcion Garcia; Lucato, Leandro Tavares; Reed, Umbertina Conti; Leite, Claudia da Costa; Costa, Maria Olivia Rodrigues; Amaral, Raquel Portugal Guimaraes; Reed, Umbertina Conti; Rosemberg, Sergio

2008-01-01

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

Evaluation of nuclear magnetic resonance spectroscopy variability

Energy Technology Data Exchange (ETDEWEB)

Barreto, Felipe Rodrigues; Salmon, Carlos Ernesto Garrido, E-mail: garrido@ffclrp.usp.br [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Filisofia, Ciencias e Letras; Otaduy, Maria Concepcion Garcia [Universidade de Sao Paulo (FAMUS/USP), Sao Paulo, SP (Brazil). Fac. de Medicina. Departamento de Radiologia

2014-11-01

Introduction: the intrinsically high sensitivity of Magnetic Resonance Spectroscopy (MRS) causes considerable variability in metabolite quantification. In this study, we evaluated the variability of MRS in two research centers using the same model of magnetic resonance image scanner. Methods: two metabolic phantoms were created to simulate magnetic resonance spectra from in vivo hippocampus. The phantoms were filled with the same basic solution containing the following metabolites: N-acetyl-aspartate, creatine, choline, glutamate, glutamine and inositol. Spectra were acquired over 15 months on 26 acquisition dates, resulting in a total of 130 spectra per center. Results: the phantoms did not undergo any physical changes during the 15-month period. Temporal analysis from both centers showed mean metabolic variations of 3.7% in acquisitions on the same day and of 8.7% over the 15-month period. Conclusion: The low deviations demonstrated here, combined with the high specificity of Magnetic Resonance Spectroscopy, confirm that it is feasible to use this technique in multicenter studies in neuroscience research. (author)

Magnetic Resonance Imaging (MRI): Lumbar Spine (For Parents)

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español Magnetic Resonance Imaging (MRI): Lumbar Spine KidsHealth / For Parents / Magnetic Resonance Imaging (MRI): Lumbar Spine What's in this article? ...

Nuclear magnetic resonance and earth magnetic field

International Nuclear Information System (INIS)

Anon.

1998-01-01

Nuclear magnetic resonance concerns nuclei whose spin is different from 0. These nuclei exposed to a magnetic field is comparable to a peg top spinning around its axis while being moved by a precession movement called Larmor precession. This article presents an experiment whose aim is to reveal nuclear magnetism of nuclei by observing Larmor precession phenomena due to the earth magnetic field. The earth magnetic field being too weak, it is necessary to increase the magnetization of the sample during a polarization phase. First the sample is submitted to a magnetic field B perpendicular to the earth magnetic field B 0 , then B is cut off and the nuclei move back to their equilibrium position by executing a precession movement due to B 0 field. (A.C.)

Usefulness of 3-Tesla cardiac magnetic resonance imaging in the assessment of aortic stenosis severity in routine clinical practice.

Science.gov (United States)

Levy, Franck; Iacuzio, Laura; Civaia, Filippo; Rusek, Stephane; Dommerc, Carine; Hugues, Nicolas; Alexandrescu, Clara; Dor, Vincent; Tribouilloy, Christophe; Dreyfus, Gilles

2016-11-01

Recently, 1.5-Tesla cardiac magnetic resonance imaging (CMR) was reported to provide a reliable alternative to transthoracic echocardiography (TTE) for the quantification of aortic stenosis (AS) severity. Few data are available using higher magnetic field strength MRI systems in this context. To evaluate the feasibility and reproducibility of the assessment of aortic valve area (AVA) using 3-Tesla CMR in routine clinical practice, and to assess concordance between TTE and CMR for the estimation of AS severity. Ninety-one consecutive patients (60 men; mean age 74±10years) with known AS documented by TTE were included prospectively in the study. All patients underwent comprehensive TTE and CMR examination, including AVA estimation using the TTE continuity equation (0.81±0.18cm 2 ), direct CMR planimetry (CMRp) (0.90±0.22cm 2 ) and CMR using Hakki's formula (CMRhk), a simplified Gorlin formula (0.70±0.19cm 2 ). Although significant agreement with TTE was found for CMRp (r=0.72) and CMRhk (r=0.66), CMRp slightly overestimated (bias=0.11±0.18cm 2 ) and CMRhk slightly underestimated (bias=-0.11±0.17cm 2 ) AVA compared with TTE. Inter- and intraobserver reproducibilities of CMR measurements were excellent (r=0.72 and r=0.74 for CMRp and r=0.88 and r=0.92 for peak aortic velocity, respectively). 3-Tesla CMR is a feasible, radiation-free, reproducible imaging modality for the estimation of severity of AS in routine practice, knowing that CMRp tends to overestimate AVA and CMRhk to underestimate AVA compared with TTE. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Resonance double magnetic bremsstrahlung in a strong magnetic field

International Nuclear Information System (INIS)

Fomin, P.I.; Kholodov, R.I.

2003-01-01

The possibility of resonance double magnetic bremsstrahlung in the approximation of weakly excited electron states in a strong external magnetic field is analyzed. The differential probability of this process in the Breit-Wigner form is obtained. The probability of double magnetic bremsstrahlung (second-order process of perturbation theory) is compared with the probability of magnetic bremsstrahlung (first-order process of perturbation theory)

Evaluation of urogenital fistulas by magnetic resonance urography

International Nuclear Information System (INIS)

Mamere, Augusto Elias; Coelho, Rafael Darahem Souza; Cecin, Alexandre Oliveira; Feltrin, Leonir Terezinha; Lucchesi, Fabiano Rubiao; Seabra, Daniel

2008-01-01

Objective: Vesicovaginal and ureterovaginal fistulas are unusual complications secondary to pelvic surgery or pelvic diseases. The therapeutic success in these cases depends on an appropriate preoperative evaluation for diagnosis and visualization of the fistulous tract. The present study is aimed at demonstrating the potential of magnetic resonance urography for the diagnosis of vesicovaginal and ureterovaginal fistulas as well as for defining the fistulous tracts. Materials And Methods: Seven female patients clinically diagnosed with vesicovaginal or ureterovaginal fistulas had their medical records, radiological and magnetic resonance images retrospectively reviewed. Magnetic resonance urography included 3D-HASTE sequences with fat saturation. Results: Six patients presented vesicovaginal fistulas and, in one patient, a right-sided ureterovaginal fistula was diagnosed. Magnetic resonance urography allowed the demonstration of the fistulous tract in six (85.7%) of the seven patients evaluated in the present study, without the need of bladder catheterization or contrast injection. Conclusion: This study demonstrates both the potential and applicability of magnetic resonance urography in the evaluation of these types of fistulas. (author)

Accuracy and effectiveness of self-gating signals in free-breathing three-dimensional cardiac cine magnetic resonance imaging

Science.gov (United States)

Li, Shuo; Wang, Lei; Zhu, Yan-Chun; Yang, Jie; Xie, Yao-Qin; Fu, Nan; Wang, Yi; Gao, Song

2016-12-01

Conventional multiple breath-hold two-dimensional (2D) balanced steady-state free precession (SSFP) presents many difficulties in cardiac cine magnetic resonance imaging (MRI). Recently, a self-gated free-breathing three-dimensional (3D) SSFP technique has been proposed as an alternative in many studies. However, the accuracy and effectiveness of self-gating signals have been barely studied before. Since self-gating signals are crucially important in image reconstruction, a systematic study of self-gating signals and comparison with external monitored signals are needed. Previously developed self-gated free-breathing 3D SSFP techniques are used on twenty-eight healthy volunteers. Both electrocardiographic (ECG) and respiratory bellow signals are also acquired during the scan as external signals. Self-gating signal and external signal are compared by trigger and gating window. Gating window is proposed to evaluate the accuracy and effectiveness of respiratory self-gating signal. Relative deviation of the trigger and root-mean-square-deviation of the cycle duration are calculated. A two-tailed paired t-test is used to identify the difference between self-gating and external signals. A Wilcoxon signed rank test is used to identify the difference between peak and valley self-gating triggers. The results demonstrate an excellent correlation (P = 0, R > 0.99) between self-gating and external triggers. Wilcoxon signed rank test shows that there is no significant difference between peak and valley self-gating triggers for both cardiac (H = 0, P > 0.10) and respiratory (H = 0, P > 0.44) motions. The difference between self-gating and externally monitored signals is not significant (two-tailed paired-sample t-test: H = 0, P > 0.90). The self-gating signals could demonstrate cardiac and respiratory motion accurately and effectively as ECG and respiratory bellow. The difference between the two methods is not significant and can be explained. Furthermore, few ECG trigger errors

Potential interference of small neodymium magnets with cardiac pacemakers and implantable cardioverter-defibrillators.

Science.gov (United States)

Wolber, Thomas; Ryf, Salome; Binggeli, Christian; Holzmeister, Johannes; Brunckhorst, Corinna; Luechinger, Roger; Duru, Firat

2007-01-01

Magnetic fields may interfere with the function of cardiac pacemakers and implantable cardioverter-defibrillators (ICDs). Neodymium-iron-boron (NdFeB) magnets, which are small in size but produce strong magnetic fields, have become widely available in recent years. Therefore, NdFeB magnets may be associated with an emerging risk of device interference. We conducted a clinical study to evaluate the potential of small NdFeB magnets to interfere with cardiac pacemakers and ICDs. The effect of four NdFeB magnets (two spherical magnets 8 and 10 mm in diameter, a necklace made of 45 spherical magnets, and a magnetic name tag) was tested in forty-one ambulatory patients with a pacemaker and 29 patients with an ICD. The maximum distance at which the magnetic switch of a device was influenced was observed. Magnetic interference was observed in all patients. The maximum distance resulting in device interference was 3 cm. No significant differences were found with respect to device manufacturer and device types. Small NdFeB magnets may cause interference with cardiac pacemakers and ICDs. Patients should be cautioned about the interference risk associated with NdFeB magnets during daily life.

Object-oriented magnetic resonance classes and objects, calculations and computations

CERN Document Server

Mehring, Michael

2001-01-01

This book presents, for the first time, a unified treatment of the quantum mechanisms of magnetic resonance, including both nuclear magnetic resonance (NMR) and electron spin resonance (ESR). Magnetic resonance is perhaps the most advanced type of spectroscopy and it is applied in biology, chemistry, physics, material science, and medicine. If applied in conjunction with spectroscopy, the imaging version of magnetic resonance has no counterpart in any type of experimental technique. The authors present explanations and applications from fundamental to advanced levels. Additionally, the

Magnetic resonance enterography in pediatric celiac disease.

Science.gov (United States)

Koc, Gonca; Doganay, Selim; Sevinc, Eylem; Deniz, Kemal; Chavhan, Govind; Gorkem, Sureyya B; Karacabey, Neslihan; Dogan, Mehmet S; Coskun, Abdulhakim; Aslan, Duran

To assess if magnetic resonance enterography is capable of showing evidence/extent of disease in pediatric patients with biopsy-proven celiac disease by comparing with a control group, and to correlate the magnetic resonance enterography findings with anti-endomysial antibody level, which is an indicator of gluten-free dietary compliance. Thirty-one pediatric patients (mean age 11.7±3.1 years) with biopsy-proven celiac disease and 40 pediatric patients as a control group were recruited in the study. The magnetic resonance enterography images of both patients with celiac disease and those of the control group were evaluated by two pediatric radiologists in a blinded manner for the mucosal pattern, presence of wall thickening, luminal distention of the small bowel, and extra-intestinal findings. Patient charts were reviewed to note clinical features and laboratory findings. The histopathologic review of the duodenal biopsies was re-conducted. The mean duration of the disease was 5.6±1.8 years (range: 3-7.2 years). In 24 (77%) of the patients, anti-endomysial antibody levels were elevated (mean 119.2±66.6RU/mL). Magnetic resonance enterography revealed normal fold pattern in all the patients. Ten (32%) patients had enlarged mesenteric lymph nodes. Although a majority of the patients had elevated anti-endomysial antibody levels indicating poor dietary compliance, magnetic resonance enterography did not show any mucosal abnormality associated with the inability of magnetic resonance enterography to detect mild/early changes of celiac disease in children. Therefore, it may not be useful for the follow-up of pediatric celiac disease. Copyright © 2017 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Theoretical study of ferromagnetic resonance in exchange - coupled magnetic / nonmagnetic / magnetic multilayer structure

International Nuclear Information System (INIS)

Oezdogan, K.; Oezdemir, M.; Yalcin, O.; Aktas, B.

2002-01-01

The dispersion relation on ferromagnetic films was calculation by using torque equation of motion with a damping term. The total energy including zeeman, demagnetizing and anisotropy energy terms was used to get ferromagnetic resonance frequency for both uniform and higher order spin wave modes. In antiferromagnetic films, the torque equation of motion for each sub-lattice were written to derive an expression for the dispersion relation. The magnetic trilayer system under investigation consist of two ferromagnetic layers separated by a nonmagnetic layer. The dispersion relation of magnetic/nonmagnetic/magnetic three layers is calculated by using Landau-Lifshitz dynamic equation of motion for the magnetization with interlayer exchange energy. As for the exchange-coupled resonance of ferromagnetic resonance (FMR), the theoretical study has been calculated for both symmetrical and asymmetrical structures. In this systems, the exchange-coupling parameter A 12 between neighboring layers was used to get resonance fields as a function of the angle between the magnetization vectors of each magnetic layers

Magnetic elliptical polarization of Schumann resonances

International Nuclear Information System (INIS)

Sentman, D.D.

1987-01-01

Measurements of orthogonal, horizontal components of the magnetic field in the ELF range obtained during September 1985 show that the Schumann resonance eigenfrequencies determined separately for the north-south and east-west magnetic components differ by as much as 0.5 Hz, suggesting that the underlying magnetic signal is not linearly polarized at such times. The high degree of magnetic ellipticity found suggests that the side multiplets of the Schumann resonances corresponding to azimuthally inhomogeneous normal modes are strongly excited in the highly asymmetric earth-ionosphere cavity. The dominant sense of polarization over the measurement passband is found to be right-handed during local daylight hours, and to be left-handed during local nighttime hours. 16 references

Functional magnetic resonance imaging by visual stimulation

International Nuclear Information System (INIS)

Nishimura, Yukiko; Negoro, Kiyoshi; Morimatsu, Mitsunori; Hashida, Masahiro

1996-01-01

We evaluated functional magnetic resonance images obtained in 8 healthy subjects in response to visual stimulation using a conventional clinical magnetic resonance imaging system with multi-slice spin-echo echo planar imaging. Activation in the visual cortex was clearly demonstrated by the multi-slice experiment with a task-related change in signal intensity. In addition to the primary visual cortex, other areas were also activated by a complicated visual task. Multi-slice spin-echo echo planar imaging offers high temporal resolution and allows the three-dimensional analysis of brain function. Functional magnetic resonance imaging provides a useful noninvasive method of mapping brain function. (author)

Visualization of coronary venous anatomy by cardiovascular magnetic resonance

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Crean Andrew

2009-08-01

Full Text Available Abstract Background Coronary venous imaging with whole-heart cardiovascular magnetic resonance (CMR angiography has recently been described using developmental pulse sequences and intravascular contrast agents. However, the practical utility of coronary venous imaging will be for patients with heart failure in whom cardiac resynchronisation therapy (CRT is being considered. As such complementary information on ventricular function and myocardial viability will be required. The aim of this study was to determine if the coronary venous anatomy could be depicted as part of a comprehensive CMR protocol and using a standard extracellular contrast agent. Methods and Results Thirty-one 3D whole heart CMR studies, performed after intravenous administration of 0.05 mmol/kg gadolinium DTPA, were reviewed. The cardiac venous system was visualized in all patients. The lateral vein of the left ventricle was present in 74%, the anterior interventricular vein in 65%, and the posterior interventricular vein in 74% of patients. The mean maximum distance of demonstrable cardiac vein on the 3D images was 81.5 mm and was dependent on the quality of the 3D data set. Five patients showed evidence of myocardial infarction on late gadolinium enhancement (LGE images. Conclusion Coronary venous anatomy can be reliably demonstrated using a comprehensive CMR protocol and a standard extracellular contrast agent. The combination of coronary venous imaging, assessment of ventricular function and LGE may be useful in the management of patients with LV dysfunction being considered for CRT.

Electromyography tests in patients with implanted cardiac devices are safe regardless of magnet placement.

Science.gov (United States)

Ohira, Masayuki; Silcox, Jade; Haygood, Deavin; Harper-King, Valerie; Alsharabati, Mohammad; Lu, Liang; Morgan, Marla B; Young, Angela M; Claussen, Gwen C; King, Peter H; Oh, Shin J

2013-01-01

We compared the problems or complications associated with electrodiagnostic testing in 77 patients with implanted cardiac devices. Thirty tests were performed after magnet placement, and 47 were performed without magnet application. All electrodiagnostic tests were performed safely in all patients without any serious effect on the implanted cardiac devices with or without magnet placement. A significantly higher number of patient symptoms and procedure changes were reported in the magnet group (P magnet group patients had an approximately 11-fold greater risk of symptoms than those in the control group. Our data do not support a recommendation that magnet placement is necessary for routine electrodiagnostic testing in patients with implanted cardiac devices, as long as our general and specific guidelines are followed. Copyright © 2012 Wiley Periodicals, Inc.

Morphological evaluation of complex congenital heart disease by magnetic resonance imaging

International Nuclear Information System (INIS)

Takahashi, Osahiro

1993-01-01

Ninety infants and children with complex congenital heart disease were examined with magnetic resonance imaging and the accuracy of morphological diagnoses by MRI was tested by comparison to the final diagnoses primarily based on angiocardiography. The sensitivity and specificity of MRI diagnoses were generally excellent in evaluating vena caval and atrial morphology, type of AV connection, ventricular morphology, type of VA connection and great vessel morphology. Although some difficulty with evaluating the detailed anatomy of the AV valve and its suspension system and fine vascular structures, MRI could demonstrate the entire cardiac structures clearly and provide the 3-dimensional information regarding the intracardiac structures, and it was extremely valuable in morphological assessment of complex congenital heart disease. (author)

Relation between N-terminal pro-brain natriuretic peptide and cardiac remodeling and function assessed by cardiovascular magnetic resonance imaging in patients with arrhythmogenic right ventricular cardiomyopathy.

Science.gov (United States)

Cheng, Huaibing; Lu, Minjie; Hou, Cuihong; Chen, Xuhua; Wang, Jing; Yin, Gang; Chu, Jianmin; Zhang, Shu; Prasad, Sanjay K; Pu, Jielin; Zhao, Shihua

2015-02-01

Although N-terminal pro-brain natriuretic peptide (NT-proBNP) is a useful screening test of impaired right ventricular (RV) function in conditions affecting the right-sided cardiac muscle, the role of NT-proBNP remains unclear in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). This study was designed to clarify the relation between the plasma NT-proBNP level and the RV function evaluated by cardiovascular magnetic resonance (CMR) imaging. We selected 56 patients with confirmed ARVC only when their blood specimens for NT-proBNP measurements were collected within 48 hours of a CMR scan. The NT-proBNP level was significantly higher in patients with RV dysfunction than in patients without RV dysfunction (median of 655.3 [interquartile range 556.4 to 870.0] vs 347.0 [interquartile range 308.0 to 456.2] pmol/L, p rights reserved.

Musculoskeletal applications of magnetic resonance imaging: Council on Scientific Affairs

International Nuclear Information System (INIS)

Harms, S.E.; Fisher, C.F.; Fulmer, J.M.

1989-01-01

Magnetic resonance imaging provides superior contrast, resolution, and multiplanar imaging capability, allowing excellent definition of soft-tissue and bone marrow abnormalities. For these reasons, magnetic resonance imaging has become a major diagnostic imaging method for the evaluation of many musculoskeletal disorders. The applications of magnetic resonance imaging for musculoskeletal diagnosis are summarized and examples of common clinical situations are given. General guidelines are suggested for the musculoskeletal applications of magnetic resonance imaging

Magnetic resonance of native defects of spin-Peierls magnetics CuGeO3

International Nuclear Information System (INIS)

Smirnov, A.I.; Glazkov, V.N.; Leonyuk, L.I.; Vetkin, A.G.; Eremina, R.M.

1998-01-01

Magnetic resonance within 9-75 GHz frequency range and 1.2-25 K temperature range was studied in pure monocrystalline spin-Peierls CuGwO 3 . Splitting of the magnetic resonance line is observed within temperature range below 5 K. Analysis of magnetic resonance spectra at various directions of magnetic field and under various temperatures enables to set off EPR-signals of spin-Peierls phase defects with S=1/2 and defects with S=1 from these components; g-factor corresponding to these EPR signals is similar one and close to values typical for Cu 2+ ion [ru

Cerebral metabolic abnormalities in congestive heart failure detected by proton magnetic resonance spectroscopy.

Science.gov (United States)

Lee, C W; Lee, J H; Kim, J J; Park, S W; Hong, M K; Kim, S T; Lim, T H; Park, S J

1999-04-01

Using proton magnetic resonance spectroscopy, we investigated cerebral metabolism and its determinants in congestive heart failure (CHF), and the effects of cardiac transplantation on these measurements. Few data are available about cerebral metabolism in CHF. Fifty patients with CHF (ejection fraction OGM) and parietal white matter (PWM). Absolute levels of the metabolites (N-acetylaspartate, creatine, choline, myo-inositol) were calculated. In PWM only creatine level was significantly lower in CHF than in control subjects, but in OGM all four metabolite levels were decreased in CHF. The creatine level was independently correlated with half-recovery time and duration of heart failure symptoms in PWM (r = -0.56, p OGM (r = 0.58, p < 0.05). Cerebral metabolic abnormalities were improved after successful cardiac transplantation. This study shows that cerebral metabolism is abnormally deranged in advanced CHF and it may serve as a potential marker of the disease severity.

Green’s function theory of ferromagnetic resonance in magnetic superlattices with damping

International Nuclear Information System (INIS)

Qiu, R.K.; Guo, F.F.; Zhang, Z.D.

2016-01-01

We explore a quantum Green’s-function method to study the resonance absorption of magnetic materials. The relationship between the resonance magnon (spin wave) density and the resonance frequency of a superlattice consisting of two magnetic layers with damping and antiferromagnetic interlayer exchange coupling is studied. The effects of temperature, interlayer coupling, anisotropy, external magnetic field and damping on the the resonance frequency and resonance magnon density are investigated. The resonance excitation probability for a magnon is proportional to the resonance magnon density. In the classic methods, the imaginary part of magnetic permeability represents the resonance absorption in magnetic materials. In the quantum approach, the resonance magnon density can be used to estimate the strength of the resonance absorption. In the present work, a quantum approach is developed to study resonance absorption of magnetic materials and the results show the method to obtain a magnetic multilayered materials with both high resonance frequency and high resonance absorption.

Green’s function theory of ferromagnetic resonance in magnetic superlattices with damping

Energy Technology Data Exchange (ETDEWEB)

Qiu, R.K., E-mail: rkqiu@163.com [Shenyang University of Technology, Shenyang 110870 (China); Guo, F.F. [Shenyang University of Technology, Shenyang 110870 (China); Zhang, Z.D. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

2016-02-01

We explore a quantum Green’s-function method to study the resonance absorption of magnetic materials. The relationship between the resonance magnon (spin wave) density and the resonance frequency of a superlattice consisting of two magnetic layers with damping and antiferromagnetic interlayer exchange coupling is studied. The effects of temperature, interlayer coupling, anisotropy, external magnetic field and damping on the the resonance frequency and resonance magnon density are investigated. The resonance excitation probability for a magnon is proportional to the resonance magnon density. In the classic methods, the imaginary part of magnetic permeability represents the resonance absorption in magnetic materials. In the quantum approach, the resonance magnon density can be used to estimate the strength of the resonance absorption. In the present work, a quantum approach is developed to study resonance absorption of magnetic materials and the results show the method to obtain a magnetic multilayered materials with both high resonance frequency and high resonance absorption.

Least Squares Magnetic-Field Optimization for Portable Nuclear Magnetic Resonance Magnet Design

International Nuclear Information System (INIS)

Paulsen, Jeffrey L; Franck, John; Demas, Vasiliki; Bouchard, Louis-S.

2008-01-01

Single-sided and mobile nuclear magnetic resonance (NMR) sensors have the advantages of portability, low cost, and low power consumption compared to conventional high-field NMR and magnetic resonance imaging (MRI) systems. We present fast, flexible, and easy-to-implement target field algorithms for mobile NMR and MRI magnet design. The optimization finds a global optimum in a cost function that minimizes the error in the target magnetic field in the sense of least squares. When the technique is tested on a ring array of permanent-magnet elements, the solution matches the classical dipole Halbach solution. For a single-sided handheld NMR sensor, the algorithm yields a 640 G field homogeneous to 16,100 ppm across a 1.9 cc volume located 1.5 cm above the top of the magnets and homogeneous to 32,200 ppm over a 7.6 cc volume. This regime is adequate for MRI applications. We demonstrate that the homogeneous region can be continuously moved away from the sensor by rotating magnet rod elements, opening the way for NMR sensors with adjustable 'sensitive volumes'

Clinical magnetic resonance: imaging and spectroscopy

International Nuclear Information System (INIS)

Andrew, E.R.; Bydder, Graeme; Griffiths, John; Iles, Richard; Styles, Peter

1990-01-01

This book begins with a readable, comprehensive but non-mathematical introduction to the basic underlying principles of magnetic resonance. Further chapters include information on the theory and principles of MRI and MRS, the interpretation of MR images, the clinical applications and scope of MRI and MRS, practical aspects of spectroscopy and magnetic resonance, and also the practical problems associated with the siting, safety and operation of large MRI and MRS equipment. (author)

Magnetic resonance in prenatal diagnosis of thoracic anomalies

International Nuclear Information System (INIS)

Pietrani, M.; Elias, D.; Wojakowski, A.; Fataljaef, V.; Carcano, M.; Otano, L.

2007-01-01

The objective of this article is to communicate the experience in the evaluation of fetal anomalies thoracic by means of magnetic resonance. Between January, 2001 - March, 2007 16 fetus were evaluated by means of magnetic resonance with echographic diagnosis of thoracic anomalies. An equipment of 1.5 TESLA was used. The thoracic anatomy was valued in general. At the presence of discovering pulmonary mass, their size, volume and intensity of sign were determined. The echographic and magnetic resonance findings were checked against the perinatal results [es

Role of chelates in magnetic resonance imaging studies

Directory of Open Access Journals (Sweden)

Tripathi Laxmi

2009-01-01

Full Text Available Imaging studies are tests performed with a variety of techniques that produce pictures of the inside of a patient′s body. Magnetic resonance imaging (MRI is an imaging technique based on the principles of nuclear magnetic resonance. MRI uses a powerful magnetic field, radio waves, and a computer to produce detailed pictures of organs, soft tissues, bone, and virtually all other internal body structures. Chelates have a wide application in such imaging techniques. Chelates in imaging studies are used alone as radioactive agents or conjugated to monoclonal antibodies or to DNA as radioactive agents. Technetium chelates and gadolinium chelates are being widely used as magnetic resonance contrast media.

Recommendations concerning magnetic resonance spectroscopy

International Nuclear Information System (INIS)

1986-01-01

In medicine the technique of nuclear magnetic resonance (NMR) is applied in the form of in vivo nuclear magnetic resonance spectroscopy (MRS). In vivo MRS can be carried out non-invasively. The committee of the Dutch Health Council briefly discusses the qualities and potentialities of the nuclei that will probably be used in future clinical spectroscopy: 31 P, 13 C, 1 H (and possibly 19 F and 23 Na). The committee discusses several possibilities of combining imaging and spectroscopy. The imaging of nuclei other than protons is also possible with MRS. Potential applications are considered in oncology, cardiology, neurology and hepatology. (Auth.)

Cardiac Magnetic Resonance-Verified Myocardial Fibrosis in Chagas Disease: Clinical Correlates and Risk Stratification.

Science.gov (United States)

Uellendahl, Marly; Siqueira, Maria Eduarda Menezes de; Calado, Eveline Barros; Kalil-Filho, Roberto; Sobral, Dário; Ribeiro, Clébia; Oliveira, Wilson; Martins, Silvia; Narula, Jagat; Rochitte, Carlos Eduardo

2016-11-01

Chagas disease (CD) is an important cause of heart failure and mortality, mainly in Latin America. This study evaluated the morphological and functional characteristics of the heart as well the extent of myocardial fibrosis (MF) in patients with CD by cardiac magnetic resonance (CMR). The prognostic value of MF evaluated by myocardial-delayed enhancement (MDE) was compared with that via Rassi score. This study assessed 39 patients divided into 2 groups: 28 asymptomatic patients as indeterminate form group (IND); and symptomatic patients as Chagas Heart Disease (CHD) group. All patients underwent CMR using the techniques of cine-MRI and MDE, and the amount of MF was compared with the Rassi score. Regarding the morphological and functional analysis, significant differences were observed between both groups (p realce tardio miocárdico (RTM) foi comparado àquele do escore de Rassi. Avaliação de 39 pacientes divididos em 2 grupos: grupo 'forma indeterminada' (IND), 28 pacientes assintomáticos; e grupo 'cardiopatia chagásica' (CC), pacientes sintomáticos. Todos os pacientes foram submetidos a RMC com as técnicas de cine-RM e RTM, sendo a quantidade de FM evidenciada ao exame comparada ao escore de Rassi. As análises morfológica e funcional mostraram significativas diferenças entre os 2 grupos (p < 0,001). Houve ainda uma forte correlação entre a extensão da FM e o escore de Rassi (r = 0,76). A RMC é uma importante técnica para avaliar pacientes com DC, ressaltando as diferenças morfológicas e funcionais em todas as apresentações clínicas. A forte correlação entre o escore de Rassi e a extensão da FM detectada por RMC enfatiza seu papel na estratificação prognóstica de pacientes com DC.

Major prognostic impact of persistent microvascular obstruction as assessed by contrast-enhanced cardiac magnetic resonance in reperfused acute myocardial infarction

International Nuclear Information System (INIS)

Cochet, Alexandre A.; Lalande, Alain; Walker, Paul M.; Touzery, Claude; Brunotte, Francois; Lorgis, Luc; Beer, Jean-Claude; Cottin, Yves; Zeller, Marianne; Wolf, Jean-Eric

2009-01-01

The aim of this study was to compare the prognostic significance of microvascular obstruction (MO) and persistent microvascular obstruction (PMO) as assessed by cardiac magnetic resonance (CMR) in patients with acute myocardial infarction (AMI). CMR was performed in 184 patients within the week following successfully reperfused first AMI. First-pass images were performed to evaluate extent of MO and late gadolinium-enhanced images to assess PMO and infarct size (IS). Major adverse cardiac events (MACE) were collected at 1-year follow-up. MO and PMO were found in 127 (69%) and 87 (47%) patients, respectively. By using univariate logistic regression analysis, high Global Registry of Acute Coronary Events (GRACE) risk score (odds ratio [OR] 95% confidence interval [CI]: 3.6 [1.8-7.4], p < 0.001), IS greater than 10% (OR [95% CI]: 2.7 [1.1-6.9], p = 0.036), left ventricular ejection fraction less than 40% (OR [95% CI]: 2.4 [1.1-5.2], p = 0.027), presence of MO (OR [95% CI]: 3.1 [1.3-7.3], p = 0.004) and presence of PMO (OR [95% CI]:10 [4.1-23.9], p < 0.001) were shown to be significantly associated with the outcome. By using multivariate analysis, presence of MO (OR [95% CI]: 2.5 [1.0-6.2], p = 0.045) or of PMO (OR [95% CI]: 8.7 [3.6-21.1], p < 0.001), associated with GRACE score, were predictors of MACE. Presence of microvascular obstruction and persistent microvascular obstruction is very common in AMI patients even after successful reperfusion and is associated with a dramatically higher risk of subsequent cardiovascular events, beyond established prognostic markers. Moreover, our data suggest that the prognostic impact of PMO might be superior to MO. (orig.)

Prebiopsy magnetic resonance spectroscopy and imaging in the diagnosis of prostate cancer

International Nuclear Information System (INIS)

Kumar, V.; Jagannathan, N.R.; Thulkar, S.; Kumar, R.

2012-01-01

Existing screening investigations for the diagnosis of early prostate cancer lack specificity, resulting in a high negative biopsy rate. There is increasing interest in the use of various magnetic resonance methods for improving the yield of transrectal ultrasound-guided biopsies of the prostate in men suspected to have prostate cancer. We review the existing status of such investigations. A literature search was carried out using the Pubmed database to identify articles related to magnetic resonance methods for diagnosing prostate cancer. References from these articles were also extracted and reviewed. Recent studies have focused on prebiopsy magnetic resonance investigations using conventional magnetic resonance imaging, dynamic contrast enhanced magnetic resonance imaging, diffusion weighted magnetic resonance imaging, magnetization transfer imaging and magnetic resonance spectroscopy of the prostate. This marks a shift from the earlier strategy of carrying out postbiopsy magnetic resonance investigations. Prebiopsy magnetic resonance investigations has been useful in identifying patients who are more likely to have a biopsy positive for malignancy. Prebiopsy magnetic resonance investigations has a potential role in increasing specificity of screening for early prostate cancer. It has a role in the targeting of biopsy sites, avoiding unnecessary biopsies and predicting the outcome of biopsies. (author)

Magnetic Resonance Imaging of Surgical Implants Made from Weak Magnetic Materials

Science.gov (United States)

Gogola, D.; Krafčík, A.; Štrbák, O.; Frollo, I.

2013-08-01

Materials with high magnetic susceptibility cause local inhomogeneities in the main field of the magnetic resonance (MR) tomograph. These inhomogeneities lead to loss of phase coherence, and thus to a rapid loss of signal in the image. In our research we investigated inhomogeneous field of magnetic implants such as magnetic fibers, designed for inner suture during surgery. The magnetic field inhomogeneities were studied at low magnetic planar phantom, which was made from four thin strips of magnetic tape, arranged grid-wise. We optimized the properties of imaging sequences with the aim to find the best setup for magnetic fiber visualization. These fibers can be potentially exploited in surgery for internal stitches. Stitches can be visualized by the magnetic resonance imaging (MRI) method after surgery. This study shows that the imaging of magnetic implants is possible by using the low field MRI systems, without the use of complicated post processing techniques (e.g., IDEAL).

Magnetic resonance instrumentation

International Nuclear Information System (INIS)

Bell, R.A.

1987-01-01

Magnetic resonance (MR), while opening new vistas to diagnostic medicine, utilizes equipment that is unfamiliar to most clinicians. Beyond learning to cope with new terms, such as spin-echo, T1, T2, and spin density, health care professionals are faced with the inclusion of magnetic and radiofrequency effects in their facilities produced by a complex array of devices. It is the purpose of this chapter to outline the components of an MR imaging system, to discuss their functions, and to note the variations in equipment commercially available