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Sample records for contrast cardiovascular magnetic

  1. 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

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

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    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.

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

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

    2016-12-15

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

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

    International Nuclear Information System (INIS)

    Johnson, Joyce T.; Robinson, Joshua D.; Deng, Jie; Rigsby, Cynthia K.

    2016-01-01

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

  5. Fluorine cardiovascular magnetic resonance angiography in vivo at 1.5 T with perfluorocarbon nanoparticle contrast agents.

    Science.gov (United States)

    Neubauer, Anne M; Caruthers, Shelton D; Hockett, Franklin D; Cyrus, Tillman; Robertson, J David; Allen, J Stacy; Williams, Todd D; Fuhrhop, Ralph W; Lanza, Gregory M; Wickline, Samuel A

    2007-01-01

    While the current gold standard for coronary imaging is X-ray angiography, evidence is accumulating that it may not be the most sensitive technique for detecting unstable plaque. Other imaging modalities, such as cardiovascular magnetic resonance (CMR), can be used for plaque characterization, but suffer from long scan and reconstruction times for determining regions of stenosis. We have developed an intravascular fluorinated contrast agent that can be used for angiography with cardiovascular magnetic resosnace at clinical field strengths (1.5 T). This liquid perfluorocarbon nanoparticle contains a high concentration of fluorine atoms that can be used to generate contrast on 19F MR images without any competing background signal from surrounding tissues. By using a perfluorocarbon with 20 equivalent fluorine molecules, custom-built RF coils, a modified clinical scanner, and an efficient steady-state free procession sequence, we demonstrate the use of this agent for angiography of small vessels in vitro, ex vivo, and in vivo. The surprisingly high signal generated with very short scan times and low doses of perfluorocarbon indicates that this technique may be useful in clinical settings when coupled with advanced imaging strategies.

  6. Baseline correction of phase-contrast images in congenital cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Lai Wyman W

    2010-03-01

    Full Text Available Abstract Background One potential source of error in phase contrast (PC congenital CMR flow measurements is caused by phase offsets due to local non-compensated eddy currents. Phantom correction of these phase offset errors has been shown to result in more accurate measurements of blood flow in adults with structurally normal hearts. We report the effect of phantom correction on PC flow measurements at a clinical congenital CMR program. Results Flow was measured in the ascending aorta, main pulmonary artery, and right and left pulmonary arteries as clinically indicated, and additional values such as Qp/Qs were derived from these measurements. Phantom correction in our study population of 149 patients resulted in clinically significant changes in 13% to 48% of these phase-contrast measurements in patients with known or suspected heart disease. Overall, 640 measurements or calculated values were analyzed, and clinically significant changes were found in 31%. Larger vessels were associated with greater phase offset errors, with 22% of the changes in PC flow measurements attributed to the size of the vessel measured. In patients with structurally normal hearts, the pulmonary-to-systemic flow ratio after phantom correction was closer to 1.0 than before phantom correction. There was no significant difference in the effect of phantom correction for patients with tetralogy of Fallot as compared to the group as a whole. Conclusions Phantom correction often resulted in clinically significant changes in PC blood flow measurements in patients with known or suspected congenital heart disease. In laboratories performing clinical CMR with suspected phase offset errors of significance, the routine use of phantom correction for PC flow measurements should be considered.

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

    Science.gov (United States)

    2013-01-01

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

  8. Detection and characteristics of microvascular obstruction in reperfused acute myocardial infarction using an optimized protocol for contrast-enhanced cardiovascular magnetic resonance imaging

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    Bekkers, Sebastiaan C.A.M.; Gorgels, Anton P.M.; Passos, Valeria Lima; Waltenberger, Johannes; Crijns, Harry J.G.M.; Schalla, Simon [Maastricht University Medical Center, Department of Cardiology, P. Debyelaan 25, PO Box 5800, Maastricht (Netherlands); Backes, Walter H.; Snoep, Gabriel [Maastricht University Medical Center, Department of Radiology, P. Debyelaan 25, PO Box 5800, Maastricht (Netherlands); Kim, Raymond J. [Duke University Medical Center, Duke Cardiovascular Magnetic Resonance Center, PO Box 3934, Durham, NC (United States)

    2009-12-15

    Several cardiovascular magnetic resonance imaging (CMR) techniques are used to detect microvascular obstruction (MVO) after acute myocardial infarction (AMI). To determine the prevalence of MVO and gain more insight into the dynamic changes in appearance of MVO, we studied 84 consecutive patients with a reperfused AMI on average 5 and 104 days after admission, using an optimised single breath-hold 3D inversion recovery gradient echo pulse sequence (IR-GRE) protocol. Early MVO (2 min post-contrast) was detected in 53 patients (63%) and late MVO (10 min post-contrast) in 45 patients (54%; p = 0.008). The extent of MVO decreased from early to late imaging (4.3 {+-} 3.2% vs. 1.8 {+-} 1.8%, p < 0.001) and showed a heterogeneous pattern. At baseline, patients without MVO (early and late) had a higher left ventricular ejection fraction (LVEF) than patients with persistent late MVO (56 {+-} 7% vs. 48 {+-} 7%, p < 0.001) and LVEF was intermediate in patients with early MVO but late MVO disappearance (54 {+-} 6%). During follow-up, LVEF improved in all three subgroups but remained intermediate in patients with late MVO disappearance. This optimised single breath-hold 3D IR-GRE technique for imaging MVO early and late after contrast administration is fast, accurate and allows detection of patients with intermediate remodelling at follow-up. (orig.)

  9. Right and Left Ventricular Function and Mass in Male Elite Master Athletes: A Controlled Contrast-Enhanced Cardiovascular Magnetic Resonance Study.

    Science.gov (United States)

    Bohm, Philipp; Schneider, Günther; Linneweber, Lutz; Rentzsch, Axel; Krämer, Nadine; Abdul-Khaliq, Hashim; Kindermann, Wilfried; Meyer, Tim; Scharhag, Jürgen

    2016-05-17

    It is under debate whether the cumulative effects of intensive endurance exercise induce chronic cardiac damage, mainly involving the right heart. The aim of this study was to examine the cardiac structure and function in long-term elite master endurance athletes with special focus on the right ventricle by contrast-enhanced cardiovascular magnetic resonance. Thirty-three healthy white competitive elite male master endurance athletes (age range, 30-60 years) with a training history of 29±8 years, and 33 white control subjects pair-matched for age, height, and weight underwent cardiopulmonary exercise testing, echocardiography including tissue-Doppler imaging and speckle tracking, and cardiovascular magnetic resonance. Indexed left ventricular mass and right ventricular mass (left ventricular mass/body surface area, 96±13 and 62±10 g/m(2); Pright ventricular mass/body surface area, 36±7 and 24±5 g/m(2); Pleft ventricular end-diastolic volume and right ventricular end-diastolic volume (left ventricular end-diastolic volume/body surface area, 104±13 and 69±18 mL/m(2); Pright ventricular end-diastolic volume/body surface area, 110±22 and 66±16 mL/m(2); PRight ventricular ejection fraction did not differ between athletes and control subjects (52±8 and 54±6%; P=0.26). Pathological late enhancement was detected in 1 athlete. No correlations were found for left ventricular and right ventricular volumes and ejection fraction with N-terminal pro-brain natriuretic peptide, and high-sensitive troponin was negative in all subjects. Based on our results, chronic right ventricular damage in elite endurance master athletes with lifelong high training volumes seems to be unlikely. Thus, the hypothesis of an exercise-induced arrhythmogenic right ventricular cardiomyopathy has to be questioned. © 2016 American Heart Association, Inc.

  10. ASCI 2010 contrast media guideline for cardiac imaging: a report of the Asian Society of Cardiovascular Imaging cardiac computed tomography and cardiac magnetic resonance imaging guideline working group

    Science.gov (United States)

    Kitagawa, Kakuya; Tsai, I-Chen; Chan, Carmen; Yu, Wei; Yong, Hwan Seok; Choi, Byoung Wook

    2010-01-01

    The use of contrast media for cardiac imaging becomes increasing as the widespread of cardiac CT and cardiac MR. A radiologist needs to carefully consider the indication and the injection protocol of contrast media to be used as well as the possibility of adverse effect. There are several guidelines for contrast media in western countries. However, these are focusing the adverse effect of contrast media. The Asian Society of Cardiovascular Imaging, the only society dedicated to cardiovascular imaging in Asia, formed a Working Group and created a guideline, which summarizes the integrated knowledge of contrast media for cardiac imaging. In cardiac imaging, coronary artery evaluation is feasible by non-contrast MR angiography, which can be an alternative examination in high risk patients for the use of iodine contrast media. Furthermore, the body habitus of Asian patients is usually smaller than that of their western counterparts. This necessitates modifications in the injection protocol and in the formula for calculation of estimated glomerular filtration rate. This guideline provided fundamental information for the use of contrast media for Asian patients in cardiac imaging. PMID:20931289

  11. Black-blood thrombus imaging (BTI): a contrast-free cardiovascular magnetic resonance approach for the diagnosis of non-acute deep vein thrombosis.

    Science.gov (United States)

    Xie, Guoxi; Chen, Hanwei; He, Xueping; Liang, Jianke; Deng, Wei; He, Zhuonan; Ye, Yufeng; Yang, Qi; Bi, Xiaoming; Liu, Xin; Li, Debiao; Fan, Zhaoyang

    2017-01-18

    Deep vein thrombosis (DVT) is a common but elusive illness that can result in long-term disability or death. Accurate detection of thrombosis and assessment of its size and distribution are critical for treatment decision-making. In the present study, we sought to develop and evaluate a cardiovascular magnetic resonance (CMR) black-blood thrombus imaging (BTI) technique, based on delay alternating with nutation for tailored excitation black-blood preparation and variable flip angle turbo-spin-echo readout, for the diagnosis of non-acute DVT. METHODS: This prospective study was approved by institutional review board and informed consent obtained from all subjects. BTI was first conducted in 11 healthy subjects for parameter optimization and then conducted in 18 non-acute DVT patients to evaluate its diagnostic performance. Two clinically used CMR techniques, contrast-enhanced CMR venography (CE-MRV) and three dimensional magnetization prepared rapid acquisition gradient echo (MPRAGE), were also conducted in all patients for comparison. All images obtained from patients were analyzed on a per-segment basis. Using the consensus diagnosis of CE-MRV as the reference, the sensitivity (SE), specificity (SP), positive and negative predictive values (PPV and NPV), and accuracy (ACC) of BTI and MPRAGE as well as their diagnostic agreement with CE-MRV were calculated. Besides, diagnostic confidence and interreader diagnostic agreement were evaluated for all three techniques. BTI with optimized parameters effectively nulled the venous blood flow signal and allowed directly visualizing the thrombus within the black-blood lumen. Higher SE (90.4% vs 67.6%), SP (99.0% vs. 97.4%), PPV (95.4% vs. 85.6%), NPV (97.8% vs 92.9%) and ACC (97.4% vs. 91.8%) were obtained by BTI in comparison with MPRAGE. Good diagnostic confidence and excellent diagnostic and interreader agreements were achieved by BTI, which were superior to MPRAGE on detecting the chronic thrombus. BTI allows

  12. 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)

  13. Tracers and contrast agents in cardiovascular imaging: present and future

    International Nuclear Information System (INIS)

    Marmion, M.; Deutsch, E.

    1996-01-01

    This brief article addresses the current status and future potential of nuclear medicine, X-ray computed tomography (CT), ultrasound (US), and magnetic resonance (MR) imaging in the diagnosis of cardiovascular diseases. The currently perceived advantages and disadvantages, as well as the possible future roles, of each of the modalities with regard to the evaluation of coronary artery disease are delineated. The certain advent of Mr and US myocardial contrast agents, combined with the inexorable pressures of health care reform, will alter the future usage patterns of all four modalities. Future debates about which modality should be used in which clinical situation will be based not on 'anatomy vs function', nor on the issues of cost effectiveness and patient outcomes

  14. Cardiovascular magnetic resonance in adults with previous cardiovascular surgery.

    Science.gov (United States)

    von Knobelsdorff-Brenkenhoff, Florian; Trauzeddel, Ralf Felix; Schulz-Menger, Jeanette

    2014-03-01

    Cardiovascular magnetic resonance (CMR) is a versatile non-invasive imaging modality that serves a broad spectrum of indications in clinical cardiology and has proven evidence. Most of the numerous applications are appropriate in patients with previous cardiovascular surgery in the same manner as in non-surgical subjects. However, some specifics have to be considered. This review article is intended to provide information about the application of CMR in adults with previous cardiovascular surgery. In particular, the two main scenarios, i.e. following coronary artery bypass surgery and following heart valve surgery, are highlighted. Furthermore, several pictorial descriptions of other potential indications for CMR after cardiovascular surgery are given.

  15. 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)

  16. 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

  17. 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)

  18. Contrast Agent in Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Vu-Quang, Hieu

    2015-01-01

    Nanoparticles have been employed as contrast agent in magnetic resonance imaging (MRI) in order to improve sensitivity and accuracy in diagnosis. In addition, these contrast agents are potentially combined with other therapeutic compounds or near infrared bio-imaging (NIR) fluorophores to obtain...... theranostic or dual imaging purposes, respectively. There were two main types of MRI contrast agent that were synthesized during this PhD project including fluorine containing nanoparticles and magnetic nanoparticles. In regard of fluorine containing nanoparticles, there were two types contrast agent...... cancer cells for cancer diagnosis in MRI. F127-Folate coated SPION were stable in various types of suspension medium for over six months. They could specifically target folate receptor of cancer cells in vitro and in vivo thus enhancing the contrast in MRI T2/T2* weighted images. These are preliminary...

  19. 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.

  20. 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

  1. Quantification of myocardium at risk in ST- elevation myocardial infarction: a comparison of contrast-enhanced steady-state free precession cine cardiovascular magnetic resonance with coronary angiographic jeopardy scores.

    Science.gov (United States)

    De Palma, Rodney; Sörensson, Peder; Verouhis, Dinos; Pernow, John; Saleh, Nawzad

    2017-07-27

    Clinical outcome following acute myocardial infarction is predicted by final infarct size evaluated in relation to left ventricular myocardium at risk (MaR). Contrast-enhanced steady-state free precession (CE-SSFP) cardiovascular magnetic resonance imaging (CMR) is not widely used for assessing MaR. Evidence of its utility compared to traditional assessment methods and as a surrogate for clinical outcome is needed. Retrospective analysis within a study evaluating post-conditioning during ST elevation myocardial infarction (STEMI) treated with coronary intervention (n = 78). CE-SSFP post-infarction was compared with angiographic jeopardy methods. Differences and variability between CMR and angiographic methods using Bland-Altman analyses were evaluated. Clinical outcomes were compared to MaR and extent of infarction. MaR showed correlation between CE-SSFP, and both BARI and APPROACH scores of 0.83 (p < 0.0001) and 0.84 (p < 0.0001) respectively. Bias between CE-SSFP and BARI was 1.1% (agreement limits -11.4 to +9.1). Bias between CE-SSFP and APPROACH was 1.2% (agreement limits -13 to +10.5). Inter-observer variability for the BARI score was 0.56 ± 2.9; 0.42 ± 2.1 for the APPROACH score; -1.4 ± 3.1% for CE-SSFP. Intra-observer variability was 0.15 ± 1.85 for the BARI score; for the APPROACH score 0.19 ± 1.6; and for CE-SSFP -0.58 ± 2.9%. Quantification of MaR with CE-SSFP imaging following STEMI shows high correlation and low bias compared with angiographic scoring and supports its use as a reliable and practical method to determine myocardial salvage in this patient population. Clinical trial registration information for the parent clinical trial: Karolinska Clinical Trial Registration (2008) Unique identifier: CT20080014. Registered 04 th January 2008.

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

    Directory of Open Access Journals (Sweden)

    Pauly John M

    2008-04-01

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

  3. MRI contrast enhancement using Magnetic Carbon Nanoparticles

    Science.gov (United States)

    Chaudhary, Rakesh P.; Kangasniemi, Kim; Takahashi, Masaya; Mohanty, Samarendra K.; Koymen, Ali R.; Department of Physics, University of Texas at Arlington Team; University of Texas Southwestern Medical Center Team

    2014-03-01

    In recent years, nanotechnology has become one of the most exciting forefront fields in cancer diagnosis and therapeutics such as drug delivery, thermal therapy and detection of cancer. Here, we report development of core (Fe)-shell (carbon) nanoparticles with enhanced magnetic properties for contrast enhancement in MRI imaging. These new classes of magnetic carbon nanoparticles (MCNPs) are synthesized using a bottom-up approach in various organic solvents, using the electric plasma discharge generated in the cavitation field of an ultrasonic horn. Gradient echo MRI images of well-dispersed MCNP-solutions (in tube) were acquired. For T2 measurements, a multi echo spin echo sequence was performed. From the slope of the 1/T2 versus concentration plot, the R2 value for different CMCNP-samples was measured. Since MCNPs were found to be extremely non-reactive, and highly absorbing in NIR regime, development of carbon-based MRI contrast enhancement will allow its simultaneous use in biomedical applications. We aim to localize the MCNPs in targeted tissue regions by external DC magnetic field, followed by MRI imaging and subsequent photothermal therapy.

  4. Cardiovascular magnetic resonance in carotid atherosclerotic disease

    Directory of Open Access Journals (Sweden)

    Chen Huijun

    2009-12-01

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

  5. 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

  6. Smart Contrast Agents for Magnetic Resonance Imaging.

    Science.gov (United States)

    Bonnet, Célia S; Tóth, Éva

    2016-01-01

    By visualizing bioactive molecules or biological parameters in vivo, molecular imaging is searching for information at the molecular level in living organisms. In addition to contributing to earlier and more personalized diagnosis in medicine, it also helps understand and rationalize the molecular factors underlying physiological and pathological processes. In magnetic resonance imaging (MRI), complexes of paramagnetic metal ions, mostly lanthanides, are commonly used to enhance the intrinsic image contrast. They rely either on the relaxation effect of these metal chelates (T(1) agents), or on the phenomenon of paramagnetic chemical exchange saturation transfer (PARACEST agents). In both cases, responsive molecular magnetic resonance imaging probes can be designed to report on various biomarkers of biological interest. In this context, we review recent work in the literature and from our group on responsive T(1) and PARACEST MRI agents for the detection of biogenic metal ions (such as calcium or zinc), enzymatic activities, or neurotransmitter release. These examples illustrate the general strategies that can be applied to create molecular imaging agents with an MRI detectable response to biologically relevant parameters.

  7. Magnetic resonance perfusion imaging without contrast media

    International Nuclear Information System (INIS)

    Martirosian, Petros; Graf, Hansjoerg; Schick, Fritz; Boss, Andreas; Schraml, Christina; Schwenzer, Nina F.; Claussen, Claus D.

    2010-01-01

    Principles of magnetic resonance imaging techniques providing perfusion-related contrast weighting without administration of contrast media are reported and analysed systematically. Especially common approaches to arterial spin labelling (ASL) perfusion imaging allowing quantitative assessment of specific perfusion rates are described in detail. The potential of ASL for perfusion imaging was tested in several types of tissue. After a systematic comparison of technical aspects of continuous and pulsed ASL techniques the standard kinetic model and tissue properties of influence to quantitative measurements of perfusion are reported. For the applications demonstrated in this paper a flow-sensitive alternating inversion recovery (FAIR) ASL perfusion preparation approach followed by true fast imaging with steady precession (true FISP) data recording was developed and implemented on whole-body scanners operating at 0.2, 1.5 and 3 T for quantitative perfusion measurement in various types of tissue. ASL imaging provides a non-invasive tool for assessment of tissue perfusion rates in vivo. Images recorded from kidney, lung, brain, salivary gland and thyroid gland provide a spatial resolution of a few millimetres and sufficient signal to noise ratio in perfusion maps after 2-5 min of examination time. Newly developed ASL techniques provide especially high image quality and quantitative perfusion maps in tissues with relatively high perfusion rates (as also present in many tumours). Averaging of acquisitions and image subtraction procedures are mandatory, leading to the necessity of synchronization of data recording to breathing in abdominal and thoracic organs. (orig.)

  8. 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)

  9. Cardiovascular magnetic resonance in pulmonary hypertension

    Science.gov (United States)

    2012-01-01

    Pulmonary hypertension represents a group of conditions characterized by higher than normal pulmonary artery pressures. Despite improved treatments, outcomes in many instances remain poor. In recent years, there has been growing interest in the use of Cardiovascular Magnetic Resonance (CMR) in patients with pulmonary hypertension. This technique offers certain advantages over other imaging modalities since it is well suited to the assessment of the right ventricle and the proximal pulmonary arteries. Reflecting the relatively sparse evidence supporting its use, CMR is not routinely recommended for patients with pulmonary hypertension. However, it is particularly useful in patient with pulmonary arterial hypertension associated with congenital heart disease. Furthermore, it has proven informative in a number of ways; illustrating how right ventricular remodeling is favorably reversed by drug therapies and providing explicit confirmation of the importance of the right ventricle to clinical outcome. This review will discuss these aspects and practical considerations before speculating on future applications. PMID:22257586

  10. Topical contrast-enhanced magnetic resonance dacryocystography

    International Nuclear Information System (INIS)

    Yoshikawa, Takeshi; Sugimura, Kazuro; Hirota, Shozo

    2000-01-01

    The purpose of this study was to evaluate the usefulness of magnetic resonance dacryocystography (MRD) with topical administration of normal saline solution and diluted Gd-DTPA solution for the assessment of lacrimal outflow disorders. Two T2-weighted sequences and two T1-weighted sequences were evaluated in this study. The 1:100 diluted Gd solution was prepared by diluting Gd-DTPA (Magnevist) with normal saline solution. A phantom study using tube phantoms of various diameters filled with normal saline solution and 1:100 diluted Gd solution was performed. A preliminary study was performed in ten normal volunteers Eighteen patients with lacrimal outflow disorders underwent clinical MRD, and 14 also underwent conventional dacryocystography (CDG). MRD images were evaluated and compared with clinical symptoms and CDG images. In all sequences, MRD could visualize the full length of 0.7 to 1.7 mm diameter tube phantoms and could show all of the normal lacrimal sacs and nasolacrimal ducts. In the clinical study, MRD findings were compatible with the symptoms in 14 patients but were not compatible with CDG findings in half of the cases. Topical contrast-enhanced MRD provided a simple, non-invasive means of obtaining detailed morphological and functional information on the lacrimal drainage apparatus. (author)

  11. Enhancing contrast of magnetic resonance imaging in patients with ...

    African Journals Online (AJOL)

    DTPA), a recent magnetic resonance imaging (MRI) contrast agent, in hepatobiliary system of patients with liver cirrhosis. Methods: Liver cirrhosis patients that underwent contrast MRI examination at Renai Hospital, Taipei City, Taiwan were ...

  12. NON-CONTRAST MAGNETIC RESONANCE UROGRAPHY

    Directory of Open Access Journals (Sweden)

    Arpita C

    2016-07-01

    Full Text Available BACKGROUND AND PURPOSE Magnetic Resonance (MR urography with its optimal contrast resolution and lack of ionizing radiation provides a comprehensive examination of the entire urinary tract noninvasively. MR urography is clinically useful in the evaluation of suspected urinary tract obstruction, haematuria, congenital anomalies, and surgically altered anatomy. It is particularly useful in cases of where there is contraindication of ionizing radiation and in paediatric and pregnant patients. The common MR urographic techniques are: Static-fluid MR urography and excretory MR urography. Static-fluid MR urography uses of heavily T2-weighted sequences to image the urinary tract as a static collection of fluid, can be repeated sequentially (Cine MR urography to better demonstrate the ureters in their entirety and to confirm the presence of fixed stenoses. Excretory MR urography is performed during the excretory phase of enhancement after the intravenous administration of gadolinium-based contrast material; thus, the patient must have sufficient renal function to allow the excretion. Static-fluid and excretory MR urography can be combined with conventional MR imaging for comprehensive evaluation of the urinary tract. The limitations are limited availability, high cost, relatively long examination time, low spatial resolution compared to IVU (Intravenous Urogram and CT Urography; sensitivity to motion (breathing and ureteral peristalsis inherent contraindications like patients with pacemakers, claustrophobia, and relative insensitivity for calcification and ureteric calculi. In this article, an attempt has been made to demonstrate the potential of static-fluid MRU to demonstrate a spectrum of urologic pathology involving the kidneys, ureters, and bladder while discussing the limitations. METHODS Thirty patients with urinary tract abnormalities were evaluated with MR urography performed between May 2014 to April 2016 using routine MR sequences and

  13. 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.

  14. Clinical advances in cardiovascular magnetic resonace imaging and angiography

    NARCIS (Netherlands)

    Bosch, van den H.C.M.

    2018-01-01

    Cardiovascular magnetic resonance imaging is an important noninvasive imaging modality for the diagnosis, clinical work‐up and treatment planning in patients suspected for a wide range of cardiovascular pathology. CMR imaging is accurate and reliable, and provides invaluable information to evaluate

  15. Visualization of coronary venous anatomy by cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    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.

  16. Contrasts agents in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Bonnet, P.A.; Fernandez, J.P.; Milhavet, J.C.; Chapat, J.P.; Almes, C.; Bruel, J.M.; Rouanet, J.P.; Lamarque, J.L.

    1984-01-01

    Changing different parameters involved in imaging procedures, paramagnetic substances provide contrast enhancement in MRI. Contrast agents presently studied in animals and clinical trials, are either salts or complexes of mineral ions either nitroxide stable free radicals. Their development should extend the possibilities of tissular characterization and fonctional or metabolic evaluation of the MRI [fr

  17. 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

  18. A method to implement the reservoir-wave hypothesis using phase-contrast magnetic resonance imaging

    OpenAIRE

    Gray, Robert D.M.; Parker, Kim H.; Quail, Michael A.; Taylor, Andrew M.; Biglino, Giovanni

    2016-01-01

    The reservoir-wave hypothesis states that the blood pressure waveform can be usefully divided into a “reservoir pressure” related to the global compliance and resistance of the arterial system, and an “excess pressure” that depends on local conditions. The formulation of the reservoir-wave hypothesis applied to the area waveform is shown, and the analysis is applied to area and velocity data from high-resolution phase-contrast cardiovascular magnetic resonance (CMR) imaging. A validation stud...

  19. Dynamic Contrast-Enhanced Magnetic Resonance Enterography and Dynamic Contrast-Enhanced Ultrasonography in Crohn's Disease

    DEFF Research Database (Denmark)

    Wilkens, Rune; Peters, David A; Nielsen, Agnete Hedemann

    2017-01-01

    Purpose e Cross-sectional imaging methods are important for objective evaluationof small intestinal inflammationinCrohn'sdisease(CD).The primary aim was to compare relative parameters of intestinal perfusion between contrast-enhanced ultrasonography (CEUS) and dynamic contrast-enhanced magnetic...

  20. Magnetic resonance imaging contrast agents: Overview and perspectives

    International Nuclear Information System (INIS)

    Yan Guoping; Robinson, Leslie; Hogg, Peter

    2007-01-01

    Magnetic resonance imaging (MRI) is a non-invasive clinical imaging modality, which has become widely used in the diagnosis and/or staging of human diseases around the world. Some MRI examinations include the use of contrast agents. The categorizations of currently available contrast agents have been described according to their effect on the image, magnetic behavior and biodistribution in the body, respectively. In this field, superparamagnetic iron oxide particles and soluble paramagnetic metal chelates are two main classes of contrast agents for MRI. This review outlines the research and development of MRI contrast agents. In future, the ideal MRI contrast agent will be focused on the neutral tissue- or organ-targeting materials with high relaxivity and specificity, low toxicity and side effects, suitable long intravascular duration and excretion time, high contrast enhancement with low dose in vivo, and with minimal cost

  1. Magnetic iron oxide for contrast-enhanced MR imaging

    International Nuclear Information System (INIS)

    Fahlvik, A.K.

    1991-05-01

    The main objective of this experimental work has been to study the biological fate and the contrast enhancing potential of a model preparation of magnetic iron oxide (MSM) after intravenous injection to rodents. This was achieved by: Studying in vitro contrast efficacy of various magnetic iron oxide preparations by relaxation analysis. Studying in vivo contrast efficacy of MSM by relaxation analysis and NMR imaging. Studying the biodistribution and bioelimination of MSM in independent experiments using relaxation analysis, radioactivity studies and histological techniques. Studying interactions of MSM with target cells and target organelles using ex vivo techniques. Based on the presented experimental study, the MSM model preparation of magnetic iron oxide seems to fulfill basic requirements of NMR contrast agents: efficient proton relaxation, specific in vivo distribution, and biological tolerance. 177 refs., 5 figs., 2 tabs

  2. Brain magnetic resonance imaging with contrast dependent on blood oxygenation

    International Nuclear Information System (INIS)

    Ogawa, S.; Lee, T.M.; Kay, A.R.; Tank, D.W.

    1990-01-01

    Paramagnetic deoxyhemoglobin in venous blood is a naturally occurring contrast agent for magnetic resonance imaging (MRI). By accentuating the effects of this agent through the use of gradient-echo techniques in high yields, the authors demonstrate in vivo images of brain microvasculature with image contrast reflecting the blood oxygen level. This blood oxygenation level-dependent (BOLD) contrast follows blood oxygen changes induced by anesthetics, by insulin-induced hypoglycemia, and by inhaled gas mixtures that alter metabolic demand or blood flow. The results suggest that BOLD contrast can be used to provide in vivo real-time maps of blood oxygenation in the brain under normal physiological conditions. BOLD contrast adds an additional feature to magnetic resonance imaging and complement other techniques that are attempting to provide position emission tomography-like measurements related to regional neural activity

  3. Cardiovascular magnetic resonance physics for clinicians: part I.

    Science.gov (United States)

    Ridgway, John P

    2010-11-30

    There are many excellent specialised texts and articles that describe the physical principles of cardiovascular magnetic resonance (CMR) techniques. There are also many texts written with the clinician in mind that provide an understandable, more general introduction to the basic physical principles of magnetic resonance (MR) techniques and applications. There are however very few texts or articles that attempt to provide a basic MR physics introduction that is tailored for clinicians using CMR in their daily practice. This is the first of two reviews that are intended to cover the essential aspects of CMR physics in a way that is understandable and relevant to this group. It begins by explaining the basic physical principles of MR, including a description of the main components of an MR imaging system and the three types of magnetic field that they generate. The origin and method of production of the MR signal in biological systems are explained, focusing in particular on the two tissue magnetisation relaxation properties (T1 and T2) that give rise to signal differences from tissues, showing how they can be exploited to generate image contrast for tissue characterisation. The method most commonly used to localise and encode MR signal echoes to form a cross sectional image is described, introducing the concept of k-space and showing how the MR signal data stored within it relates to properties within the reconstructed image. Before describing the CMR acquisition methods in detail, the basic spin echo and gradient pulse sequences are introduced, identifying the key parameters that influence image contrast, including appearances in the presence of flowing blood, resolution and image acquisition time. The main derivatives of these two pulse sequences used for cardiac imaging are then described in more detail. Two of the key requirements for CMR are the need for data acquisition first to be to be synchronised with the subject's ECG and to be fast enough for the subject

  4. The study of cardiovascular changes by intravascular injection of contrast media

    International Nuclear Information System (INIS)

    Kim, Yang Sook; Park, Chang Yoon

    1986-01-01

    This investigation was aimed to study the effect of contrast media on the cardiovascular system. So in this study, pithed rats were used whether alteration in cardiovascular system by contrast media were controlled centrally. Furthermore, several hypertonic solutions were also used to clarify the effect of contrast media. The results are as follows: 1. Intravenous injection of contrast media in rats (2.5 ml/kg) caused hypotension and bradycardia. The effects were neither blocked by pretreatment of atropine nor pyribenzamine+atropine. 2. NaCI 4.7%, dextrose 24.8%, urea 9.0% and glycerol 10.1% (v/v) which were equiosmolar with contrast media, caused hypotension, but did not affect the heart rate. 3. In pithed rats, intravenous injection of Angiografin increased blood pressure in a dose-dependant manner, and caused decrease in heart rate compared with those of control rats. 4. In pithed rats, bradycardia by intravascular injection with Angiografin was partially blocked by atropine. 5. Metrizamide of which iodine content was adjusted to 280 mg/ml caused increased in blood pressure when was injected intravenously in pithed rats with little effect on heart rate. 6. When perfused with contrast media in rat hindlimb at 15 ml/min./kg speed both perfusion pressure and flow effluent increased, simultaneously. These results suggest that hypotension might be caused by the central effect due to hyperosmolarity of contrast media and bradycardia caused by both parasympathetic stimulation and direct inhibitory action on the cardiac conductive system.

  5. Recent advances in contrast-enhanced magnetic resonance angiography

    International Nuclear Information System (INIS)

    Meaney, J.F.M.; Goyen, M.

    2007-01-01

    Magnetic resonance angiography (MRA) provides a means of visualizing vascular structures noninvasively and is increasingly replacing conventional X-ray angiography in routine use. Contrast-enhanced MRA (CE-MRA), in which gadolinium contrast agents are used to shorten the T1 relaxation, offers increased resolution and higher signal-to-noise ratio compared with earlier flow-dependent [time-of-flight (TOF) or phase-contrast (PC)] techniques. Currently available contrast agents differ in their ability to lower T1 values, and hence the choice of contrast agent is an important consideration in the successful use of CE-MRA. Gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany) is the first of a new class of intravascular contrast agents. This agent is extensively (approximately 85%) and reversibly bound to human serum albumin and is retained within the vasculature thus allowing steady-state imaging to be perform-ed. An additional benefit is that gado0fosveset offers higher relaxivity compared with other contrast agents, thus giving a lower blood T1 values which also makes it ideal for first-pass imaging. Clinical trials have consistently shown that gadofosveset enhanced MRA is more sensitive, specific and accurate than time-of-flight MRA, gives fewer uninterpretable scans and affords greater diagnostic confidence. Intravascular contrast agents such as gadofosveset, therefore, offer the potential for improved vascular imaging. (orig.)

  6. Technical competence in cardiovascular magnetic resonance and computed tomography

    International Nuclear Information System (INIS)

    Fernandes, Juliano Lara; Shiozaki, Afonso Akio; Azevedo Filho, Clerio Francisco de; Rochitte, Carlos Eduardo; Pinto, Ibraim Marciarelli Francisco; Lopes, Marly Maria Uellendahl; Schvartzman, Paulo Roberto

    2009-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-15

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

  8. 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...

  9. 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 ...

  10. Functional valve assessment: the emerging role of cardiovascular magnetic resonance.

    Science.gov (United States)

    Shah, Dipan J

    2010-01-01

    The prevalence of valvular heart disease is increasing along with the life span of the population. In assessing individuals with valve disease, echocardiography is the primary imaging modality used by clinicians both for initial assessment and for longitudinal evaluation. Information regarding valve morphology and function, cardiac chamber size, wall thickness, ventricular function, and estimates of pulmonary artery pressures can be readily obtained and integrated to formulate an assessment of valve disease severity. In some instances, body habitus or the presence of coexisting lung disease may result in suboptimal acoustic windows on echocardiography, which may lead to technically difficult studies. Additionally, in some patients, information from clinical history and physical examination or other diagnostic tests may be discordant with echocardiographic findings. In these instances, there is a significant clinical role for cardiovascular magnetic resonance (CMR). The diagnostic capabilities of CMR have increased substantially over the past 20 years due to hardware and software advances. Today, CMR has a number of unique advantages over other imaging modalities - primarily, it provides a view of the entire heart without limitations from inadequate imaging windows or body habitus. Furthermore, CMR can obtain imaging data in any imaging 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. Since a comprehensive review of the role of CMR in all valve lesions is beyond the scope of this article, we will focus on the most common valvular indication for performance of clinical CMR techniques and an overview of selected validation and reproducibility studies. The objectives of a comprehensive CMR study for evaluating mitral

  11. The clinical use of contrast agents in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Bydder, G.M.

    1987-01-01

    Interest in the use of external agents to increase tissue contrasts has come from many sources dating back to the earliest work in NMR, to animal studies and to the widespread use of contrast agents in conventional radiological practice. The first clinical magnetic resonance images were published in 1980 and in the following year a brief account of the use of the paramagnetic agents in human volunteers was established. It was apparent relatively early in the development of magnetic resonance imaging (MRI) that a high level of soft tissue contrast was available de novo and the need for externally administered agents might therefore be small. This observation was tempered by the fact that separation of tumour from oedema was frequently better with contrast enhanced CT X-ray than with unenhanced MRI and that of a contrast agent might therefore be needed for MRI. At the end of 1983 the first parenteral agent gadoliminum diethylene triamine pentaacetic acid (Gd-DTPA) was used in volunteers and clinical studies began in 1984. At the present time only molecular O/sub 2/, oral iron compounds and Gd-DTPA are in clinical use although there are a number of other agents which have been used in animals and some of these may become available for clinical use in the foreseeable future

  12. Synthesis Of Gd-dtpa-folat For Magnetic Resonance Imaging Contrast Agent And Characterization By Using 153gd-dtpa-folate Radioactive

    OpenAIRE

    G., Adang H; S., Yono; Maskur

    2012-01-01

    Contrast agent was used to clarify the image of the organ that is difficult to distinguish by MRI (Magnetic Resonance Imaging) techniques, particularly in soft tissues of the central nervous system, liver, digestive system, lymphatic system, breast, cardiovascular and pulmonary systems. One of the commonly used contrast agents in hospitals is Gadolinium-DieThylenetriamine Pentaacetic Acid (Gd-DTPA). Gd-DTPA is non specific contrast agent, therefore it has led to develop a contrast agent that ...

  13. Microcomputer simulation of nuclear magnetic resonance imaging contrasts

    International Nuclear Information System (INIS)

    Le Bihan, D.

    1985-01-01

    The high information content of magnetic resonance images is due to the multiplicity of its parameters. However, this advantage introduces a difficulty in the interpretation of the contrast: an image is strongly modified according to the visualised parameters. The author proposes a micro-computer simulation program. After recalling the main intrinsic and extrinsic parameters, he shows how the program works and its interest as a pedagogic tool and as an aid for contrast optimisation of images as a function of the suspected pathology [fr

  14. Perfusion imaging with magnetic-susceptibility contrast media

    International Nuclear Information System (INIS)

    Rosen, B.R.; Belliveau, J.W.; Betteridge, D.; Cohen, M.S.; Weisskoff, R.M.; Vevea, J.M.; Rzedzian, R.P.; Brady, T.J.

    1989-01-01

    In animal models, transient signal los on T2-weighted images has been well documented following intravenous injection of high-magnetic-susceptibility contrast agents that are compartmentalized within the brain intravascular space. These signal changes have been correlated with physiologic parameters, such as blood flow and volume. The advent of whole-body single-shot imaging capability, coupled with the approval of paramagnetic contrasts agents for human use, has enabled the authors to demonstrate susceptibility contrast in the human brain, allowing for generation of functional images. With use of a 1.5-T imaging system gradient-echo images (TE = 60 msec) were acquired in 75 msec. Sequential single-sections images were sampled every 1 second following bolus administration of 0.1 mmol/kg of Gd-DTPA

  15. 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.

  16. Contrasting patterns of hot spell effects on morbidity and mortality for cardiovascular diseases in the Czech Republic, 1994-2009

    Czech Academy of Sciences Publication Activity Database

    Hanzlíková, Hana; Plavcová, E.; Kynčl, J.; Kříž, B.; Kyselý, J.

    2015-01-01

    Roč. 59, č. 11 (2015), s. 1673-1684 ISSN 0020-7128 Institutional support: RVO:67985530 Keywords : hot spells * cardiovascular disease * cerebrovascular disease Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 2.309, year: 2015

  17. The use of contrast-enhanced post Mortem CT in the detection of cardiovascular deaths.

    Directory of Open Access Journals (Sweden)

    Jonas Christoph Apitzsch

    Full Text Available OBJECTIVES: To evaluate the diagnostic value of contrast enhanced post mortem computed tomography (PMCT in comparison to non-enhanced post mortem CT in the detection of cardiovascular causes of death (COD. BACKGROUND: As autopsy rates decline, new methods to determine CODs are necessary. So contrast enhanced PMCT shall be evaluated in comparison to established non-enhanced PMCT in order to further improve the method. METHODS: In a prospective study, 20 corpses were examined using a 64-row multisclice CT (MSCT before and after intraarterial perfusion with a newly developed, barium-bearing contrast agent and ventilation of the lungs. The cause of death was determined in enhanced and unenhanced scans and a level of confidence (LOC was given by three experienced radiologists on a scale between 0 and 4. Results were compared to autopsy results as gold standard. Autopsy was performed blinded to PMCT-findings. RESULTS: The method allowed visualization of different types of cause of death. There was a significant improvement in LOC in enhanced scans compared to unenhanced scans as well as an improvement in the detection of COD. The cause of death could be determined in 19 out of 20 patients. CONCLUSIONS: PMCT is feasible and appears to be robust for diagnosing cardiovascular causes of death. When compared with unenhanced post-mortem CT intraarterial perfusion and pulmonary ventilation significantly improve visualization and diagnostic accuracy. These promising results warrant further studies.

  18. Magnetic susceptibility imaging with a nonionic contrast agent

    International Nuclear Information System (INIS)

    Cacheris, W.; Rocklage, S.M.; Quay, S.; Dow, W.; Love, D.; Worah, D.; Lim, K.

    1988-01-01

    The magnetic susceptibility mechanism for MR imaging contrast enhancement has the advantage of providing useful information, such as cerebral blood flow, without crossing the blood-brain barrier. In this paper the authors report the use of a highly effective, relatively nontoxic chelate as a magnetic susceptibility agent. Dy-DTPA-bis(methylamide) (Dy-DTPA-BMA) has an extremely low acute toxicity (LD-50, intravenous, mice ∼ 40 mmol/kg). Doses of 1 mmol/kg and 2 mmol/kg Dy-DTPA-BMA lowered the initial signal intensity 63% to 57%, respectively. The utility of this technique in detecting areas of reduced blood flow within the brain was demonstrated by imaging a rabbit with a cerebral perfusion deficit

  19. Macromolecular and dendrimer-based magnetic resonance contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Bumb, Ambika; Brechbiel, Martin W. (Radiation Oncology Branch, National Cancer Inst., National Inst. of Health, Bethesda, MD (United States)), e-mail: pchoyke@mail.nih.gov; Choyke, Peter (Molecular Imaging Program, National Cancer Inst., National Inst. of Health, Bethesda, MD (United States))

    2010-09-15

    Magnetic resonance imaging (MRI) is a powerful imaging modality that can provide an assessment of function or molecular expression in tandem with anatomic detail. Over the last 20-25 years, a number of gadolinium-based MR contrast agents have been developed to enhance signal by altering proton relaxation properties. This review explores a range of these agents from small molecule chelates, such as Gd-DTPA and Gd-DOTA, to macromolecular structures composed of albumin, polylysine, polysaccharides (dextran, inulin, starch), poly(ethylene glycol), copolymers of cystamine and cystine with GD-DTPA, and various dendritic structures based on polyamidoamine and polylysine (Gadomers). The synthesis, structure, biodistribution, and targeting of dendrimer-based MR contrast agents are also discussed

  20. A smart magnetic resonance contrast agent for selective copper sensing.

    Science.gov (United States)

    Que, Emily L; Chang, Christopher J

    2006-12-20

    We describe the synthesis and properties of Copper-Gad-1 (CG1), a new type of smart magnetic resonance (MR) sensor for selective detection of copper. CG1 is composed of a gadolinium contrast agent core tethered to copper-selective recognition motif. Cu2+-induced modulation of inner-sphere water access to the Gd3+ center provides a sensing mechanism for reporting Cu2+ levels by reading out changes in longitudinal proton relaxivity values. CG1 features good selectivity for Cu2+ over abundant biological cations and a 41% increase in relaxivity upon Cu2+ binding and is capable of detecting micromolar changes in Cu2+ concentrations in aqueous media.

  1. Magnetic Resonance Imaging Contrast Agents: A Review of Literature

    Directory of Open Access Journals (Sweden)

    Zahra Sahraei

    2015-10-01

    Full Text Available  Magnetic Resonance Imaging (MRI contrast agents most commonly agents used in diagnosing different diseases. Several agents have been ever introduced with different peculiar characteristics. They vary in potency, adverse reaction and other specification, so it is important to select the proper agent in different situations. We conducted a systematic literature search in MEDLINE/PUBMED, Web of Science (ISI, Scopus,Google Scholar by using keywords "gadolinium" and "MRI contrast Medias", "Gadofosvest", "Gadobenate" and "Gadoxetate". The most frequent contrast media agents made based on gadolinium (Gd. These are divided into two categories based on the structure of their chelating parts, linear agents and macrocyclic agents. All characteristics of contrast media factors, including efficiency, kinetic properties, stability, side effects and the rate of resolution are directly related to the structure of chelating part of that formulation.In vitro data has shown that the macrocyclic compounds are the most stable Gd-CA as they do not bind to serum proteins, they all possess similar and relatively low relaxivity and the prevalence of Nephrogenic Systemic Fibrosis (NSF has decreased by increasing the use of macrocyclic agents in recent years. No cases of NSF have been recorded after the administration of any of the high-relaxivity protein interacting agents, the vascular imaging agent gadofosveset trisodium (Ablavar, the hepatic imaging agent gadoxetate meglumine (Eovist, and the multipurpose agent gadobenate dimeglumine (MultiHance. In pregnancy and lactating women, stable macrocyclic agent is recommended.

  2. Magnetic resonance imaging of the cardiovascular system: present state of the art and future potential

    International Nuclear Information System (INIS)

    Jacobson, H.G.

    1988-01-01

    State-of-the-art magnetic resonance imaging (MRI) generates high-resolution images of the cardiovascular system. Conventional MRI techniques provide images in six to ten minutes per tomographic slice. New strategies have substantially improved the speed of imaging. The technology is relatively expensive, and its cost-effectiveness remains to be defined in relation to other effective, less expensive, and noninvasive technologies, such as echocardiography and nuclear medicine. The ultimate role of MRI will depend on several factors, including the development of specific applications such as (1) noninvasive angiography, especially of the coronary arteries;(2) noninvasive, high-resolution assessment of regional myocardial blood flow distribution (e.g., using paramagnetic contrast agents); (3) characterization of myocardial diseases using proton-relaxation property changes; and (4) evaluation of in vivo myocardial biochemistry. The three-dimensional imaging capability and the ability to image cardiovascular structures without contrast material give MRI a potential advantage over existing noninvasive diagnostic imaging techniques. This report analyzes current applications of MRI to the cardiovascular system and speculates on their future

  3. Review of Journal of Cardiovascular Magnetic Resonance 2009

    Directory of Open Access Journals (Sweden)

    Neubauer S

    2010-03-01

    Full Text Available Abstract There were 56 articles published in the Journal of Cardiovascular Magnetic Resonance in 2009. The editors were impressed with the high quality of the submissions, of which our acceptance rate was about 40%. In accordance with open-access publishing, the articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. We have therefore chosen to briefly summarise the papers in this article for quick reference for our readers in broad areas of interest, which we feel will be useful to practitioners of cardiovascular magnetic resonance (CMR. In some cases where it is considered useful, the articles are also put into the wider context with a short narrative and recent CMR references. It has been a privilege to serve as the Editor of the JCMR this past year. I hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality manuscripts to JCMR for publication.

  4. Flow imaging of the cardiovascular system using magnetic resonance imaging

    International Nuclear Information System (INIS)

    Imai, Hitoshi; Sakakibara, Makoto; Sunami, Yuko

    1988-01-01

    Blood flow images by magnetic resonance imaging (MRI) using a 0.25 T unit were evaluated for nine normal volunteers and 108 subjects with a variety of cardiovascular abnormalities. Using the non-gated short-spin echo (SE) technique, blood flow in the cardiovascular systems was not imaged in the normal volunteers. Using end-systolic and end-diastolic SE techniques for the normal subjects, blood flow in the cardiac chambers was not clearly imaged. Blood flow in the ascending aorta and aortic arch often did not appear in the gated SE images of the normal subjects. However, blood flow in the descending aorta was often observed in the gated SE images. Blood flow imaging was demonstrated by both non-gated and gated SE techniques in regions where blood flow was relatively slow; for example, in the left atrium of mitral stenosis, in an aortic aneurysm, in a false lumen of an aortic dissection, and in the left ventricle having old myocardial infarction. Using the non-gated inversion recovery (IR) technique, no blood flow was imaged in the cardiovascular system except in the left atrium of one case with mitral stenosis. Using the non-gated short SE technique, there was good correlation between the thrombus formation and the presence of blood flow images in the left atria of 17 patients with mitral stenosis, and in the aneurysmal portions of the aorta or in the false lumens of aortic dissection of 18 patients. It was suggested that mural thrombi in such diseases were related to the relatively slow blood flow. Blood flow imaging easily distinguished stagnant blood flow from mural thrombi using non-gated short SE, end-systolic SE, and IR techniques. Thus, blood flow imaging using MRI should become an important means of evaluating the cardiovascular system. (author)

  5. Contrast agents for tumor diagnosis in magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Rensuke; Doi, Hisayoshi; Okada, Shoji [University of Shizuoka (Japan). School of Pharmaceutical Science; Yano, Masayuki; Katano, Susumu; Nakajima, Nobuaki

    1992-01-01

    In order to develop contrast agents for tumor diagnosis in magnetic resonance imaging (MRI), we investigated the effects of several gadolinium complexes on T{sub 1} relaxation time of proton in some tissues of Ehrlich solid tumor-bearing mice. L-Aspartic acid, L-glutamic acid, DL-homocysteine, L-glutamyl-glutamic acid, glutathione, sperimidine and ethylenediaminetetrakis (methylenephosphate) (EDTMP) were used as ligands for Gd{sup 3+}. Since each Gd-complex could not be purified except Gd-EDTMP, the mixture of GdCl{sub 3} and a ligand was administered intravenously. Among the compounds tested, the mixture of aspartic acid, glutathione or spermidine with GdCl{sub 3} showed almost the same or above reduction of T{sub 1} relaxation times in the tumor tissue compared with Gd-diethylenetriamine pentaacetic acid (Gd-DTPA) which is used clinically. Furthermore, the contrast-enhancing effect of the three mixtures in the tumor was observed by in vivo T{sub 1}-weighted magnetic resonance imaging. The in vivo tissue distribution using radioactive {sup 153}Gd{sup 3+} showed that these mixtures mentioned above were also taken up more highly in the tumor than {sup 153}GdCl{sub 3} itself and {sup 153}Gd-DTPA, suggesting the formation of Gd-complexes. However, the overall tissue distribution of the mixtures was similar to that of {sup 153}GdCl{sub 3} because the Gd-complexes were not purified. Gd-EDTMP exhibited the almost same effects with Gd-DTPA as a contrast agent. (author).

  6. Image fusion for dynamic contrast enhanced magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Leach Martin O

    2004-10-01

    Full Text Available Abstract Background Multivariate imaging techniques such as dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI have been shown to provide valuable information for medical diagnosis. Even though these techniques provide new information, integrating and evaluating the much wider range of information is a challenging task for the human observer. This task may be assisted with the use of image fusion algorithms. Methods In this paper, image fusion based on Kernel Principal Component Analysis (KPCA is proposed for the first time. It is demonstrated that a priori knowledge about the data domain can be easily incorporated into the parametrisation of the KPCA, leading to task-oriented visualisations of the multivariate data. The results of the fusion process are compared with those of the well-known and established standard linear Principal Component Analysis (PCA by means of temporal sequences of 3D MRI volumes from six patients who took part in a breast cancer screening study. Results The PCA and KPCA algorithms are able to integrate information from a sequence of MRI volumes into informative gray value or colour images. By incorporating a priori knowledge, the fusion process can be automated and optimised in order to visualise suspicious lesions with high contrast to normal tissue. Conclusion Our machine learning based image fusion approach maps the full signal space of a temporal DCE-MRI sequence to a single meaningful visualisation with good tissue/lesion contrast and thus supports the radiologist during manual image evaluation.

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

    Directory of Open Access Journals (Sweden)

    Dargie Henry J

    2011-10-01

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

  8. Ultra-small superparamagnetic particles of iron oxide in magnetic resonance imaging of cardiovascular disease

    Directory of Open Access Journals (Sweden)

    Stirrat CG

    2014-10-01

    Full Text Available Colin G Stirrat,1 Alex T Vesey,1 Olivia MB McBride,1 Jennifer MJ Robson,1 Shirjel R Alam,1 William A Wallace,2 Scott I Semple,1,3 Peter A Henriksen,1 David E Newby1 1British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK; 2Department of Pathology, University of Edinburgh, Edinburgh, UK; 3Clinical Research Imaging Centre, University of Edinburgh, Edinburgh, UK Abstract: Ultra-small superparamagnetic particles of iron oxide (USPIO are iron-oxide based contrast agents that enhance and complement in vivo magnetic resonance imaging (MRI by shortening T1, T2, and T2* relaxation times. USPIO can be employed to provide immediate blood pool contrast, or to act as subsequent markers of cellular inflammation through uptake by inflammatory cells. They can also be targeted to specific cell-surface markers using antibody or ligand labeling. This review will discuss the application of USPIO contrast in MRI studies of cardiovascular disease. Keywords: cardiac, aortic, MRI, USPIO, carotid, vascular, molecular imaging

  9. Dual Contrast - Magnetic Resonance Fingerprinting (DC-MRF): A Platform for Simultaneous Quantification of Multiple MRI Contrast Agents.

    Science.gov (United States)

    Anderson, Christian E; Donnola, Shannon B; Jiang, Yun; Batesole, Joshua; Darrah, Rebecca; Drumm, Mitchell L; Brady-Kalnay, Susann M; Steinmetz, Nicole F; Yu, Xin; Griswold, Mark A; Flask, Chris A

    2017-08-16

    Injectable Magnetic Resonance Imaging (MRI) contrast agents have been widely used to provide critical assessments of disease for both clinical and basic science imaging research studies. The scope of available MRI contrast agents has expanded over the years with the emergence of molecular imaging contrast agents specifically targeted to biological markers. Unfortunately, synergistic application of more than a single molecular contrast agent has been limited by MRI's ability to only dynamically measure a single agent at a time. In this study, a new Dual Contrast - Magnetic Resonance Fingerprinting (DC - MRF) methodology is described that can detect and independently quantify the local concentration of multiple MRI contrast agents following simultaneous administration. This "multi-color" MRI methodology provides the opportunity to monitor multiple molecular species simultaneously and provides a practical, quantitative imaging framework for the eventual clinical translation of molecular imaging contrast agents.

  10. Photo-magnetic imaging: resolving optical contrast at MRI resolution

    International Nuclear Information System (INIS)

    Lin Yuting; Thayer, David; Luk, Alex L; Gulsen, Gultekin; Gao Hao

    2013-01-01

    In this paper, we establish the mathematical framework of a novel imaging technique, namely photo-magnetic imaging (PMI). PMI uses a laser to illuminate biological tissues and measure the induced temperature variations using magnetic resonance imaging (MRI). PMI overcomes the limitation of conventional optical imaging and allows imaging of the optical contrast at MRI spatial resolution. The image reconstruction for PMI, using a finite-element-based algorithm with an iterative approach, is presented in this paper. The quantitative accuracy of PMI is investigated for various inclusion sizes, depths and absorption values. Then, a comparison between conventional diffuse optical tomography (DOT) and PMI is carried out to illustrate the superior performance of PMI. An example is presented showing that two 2 mm diameter inclusions embedded 4.5 mm deep and located side by side in a 25 mm diameter circular geometry medium are recovered as a single 6 mm diameter object with DOT. However, these two objects are not only effectively resolved with PMI, but their true concentrations are also recovered successfully. (paper)

  11. Clinical cardiovascular experiences with iopamidol: a new non-ionic contrast medium

    International Nuclear Information System (INIS)

    Partridge, J.B.; Robinson, P.J.; Turnbull, C.M.; Stoker, J.B.; Morrison, G.W.; Boyle, R.M.

    1981-01-01

    Iopamidol, a new non-ionic water-soluble contrast medium, has been compared with standard ionic media in a number of cardiovascular applications. It is stable in aqueous solution, is much less viscous and only slightly more osmolar than metrizamide. Compared to sodium meglumine diatrizoate in a series of 40 coronary arteriograms, it produced a consistent and highly significant decrease in the incidence and severity of hypotension and bradycardia following intracoronary injection. In the same group and in 62 children undergoing ventricular or great vessel angiocardiography, a subjective assessment of patient reaction showed that iopamidol was better tolerated than the ionic medium. There was a very strong patient preference for iopamidol in a group of 10 of the adult patients who had also consented to femoral artery injections of both media. Throughout these series there was no detectable difference in arterial image quality between the media. Venous phase opacification during arterioportography was assessed in 11 cases comparing iopamidol with sodium meglumine iothalamate. No significant difference was found. We conclude that iopamidol is clearly preferable to ionic media for routine cardiovascular applications. (author)

  12. Cardiovascular fluid dynamics. Methods for flow and pressure field analysis from magnetic resonance imaging

    International Nuclear Information System (INIS)

    Ebbers, T.

    2001-01-01

    Cardiovascular blood flow is highly complex and incompletely understood. Blood flow patterns are expected to influence the opening and closing of normal and prosthetic heart valves, the efficiency of cardiac filling and ejection, and the resistance to thrombus formation within the heart. Conventional diagnostic techniques are poorly suited to the study of the three-dimensional (3D) blood flow patterns in the heart chambers and large vessels. Noninvasive methods have also been inadequate in studying intracardiac pressure differences, which are the driving force of flow and are critical in the evaluation of many cardiovascular abnormalities. This thesis focuses on the development of non-invasive methods for analysis of 3D cardiovascular blood flow. Simultaneous study of cardiovascular fluid dynamics allowed knowledge exchange across the two disciplines, facilitating the development process and broadening the applicability of the methods. A time-resolved 3D phase-contrast Magnetic Resonance Imaging (MRI) technique was used to acquire the velocity vector field in a 3D volume encompassing the entire heart or a large vessel. Cardiovascular blood flow patterns were visualized by use of particle traces, which revealed, for instance, vortical flow patterns in the left atrium. By applying the Navier-Stokes equation along a user-defined line in the 3D velocity vector field, the relative pressure could be obtained as an excellent supplement to the flow pattern visualization. Using a delineation of the blood pool, the time-varying 3D relative pressure field in the human left ventricle was obtained from the velocity field by use of the pressure Poisson equation. A delineation of the heart muscle, a task that is almost impossible to perform on 3D MRI either automatically or manually, was also achieved by usage of particle traces. This segmentation allows automatic calculation of the 3D relative pressure field, as well as calculation of well-established parameters such as

  13. Cardiovascular fluid dynamics. Methods for flow and pressure field analysis from magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ebbers, T

    2001-05-01

    Cardiovascular blood flow is highly complex and incompletely understood. Blood flow patterns are expected to influence the opening and closing of normal and prosthetic heart valves, the efficiency of cardiac filling and ejection, and the resistance to thrombus formation within the heart. Conventional diagnostic techniques are poorly suited to the study of the three-dimensional (3D) blood flow patterns in the heart chambers and large vessels. Noninvasive methods have also been inadequate in studying intracardiac pressure differences, which are the driving force of flow and are critical in the evaluation of many cardiovascular abnormalities. This thesis focuses on the development of non-invasive methods for analysis of 3D cardiovascular blood flow. Simultaneous study of cardiovascular fluid dynamics allowed knowledge exchange across the two disciplines, facilitating the development process and broadening the applicability of the methods. A time-resolved 3D phase-contrast Magnetic Resonance Imaging (MRI) technique was used to acquire the velocity vector field in a 3D volume encompassing the entire heart or a large vessel. Cardiovascular blood flow patterns were visualized by use of particle traces, which revealed, for instance, vortical flow patterns in the left atrium. By applying the Navier-Stokes equation along a user-defined line in the 3D velocity vector field, the relative pressure could be obtained as an excellent supplement to the flow pattern visualization. Using a delineation of the blood pool, the time-varying 3D relative pressure field in the human left ventricle was obtained from the velocity field by use of the pressure Poisson equation. A delineation of the heart muscle, a task that is almost impossible to perform on 3D MRI either automatically or manually, was also achieved by usage of particle traces. This segmentation allows automatic calculation of the 3D relative pressure field, as well as calculation of well-established parameters such as

  14. Contrasting cardiovascular properties of the µ-opioid agonists morphine and methadone in the rat.

    Science.gov (United States)

    Tung, Kenneth H; Angus, James A; Wright, Christine E

    2015-09-05

    Morphine and methadone share the property of μ-opioid receptor agonism yet have markedly different cardiovascular actions suggesting additional properties are at play. We investigated the i.v. dose-response relationships of the opioids on cardiovascular metameters in anaesthetised rats in the absence or presence of H1- and H2-receptor antagonism and the μ-opioid antagonist naloxone. In vitro tissue assays were employed to define more clearly cardiac and vascular mechanisms of action. Morphine (9, 30, 90mg/kg i.v.) decreased heart rate (HR) and mean arterial pressure (MAP) - responses that were blocked by naloxone pretreatment (10mg/kg i.v.). In contrast, methadone (3, 10, 30mg/kg i.v.) caused dramatic short-lived (1-3min) bradycardia, hypotension and lengthening of the QT interval before stabilising 5min after i.v. dosing. Only the steady-state responses of HR and MAP were blocked by naloxone. Mepyramine (10mg/kg i.v.) and cimetidine (100mg/kg i.v.) also blocked the naloxone-sensitive components. In isolated small mesenteric arteries precontracted by K(+) 62mM or endothelin-1, methadone (1-30μM) relaxed vessels while morphine (1-100μM) had no effect. Pretreatment with naloxone (10μM), indomethacin (30μM) or nitro-l-arginine (100μM) did not affect the relaxation to methadone. In rat isolated left atria, morphine and methadone inhibited inotropic responses at high concentrations (100μM). In rat papillary muscle and right atria, methadone was more than 30 times more potent at lengthening the refractory period and slowing the atrial rate than morphine. We conclude that methadone is a potent vasodilator agent, possibly through blocking L-type calcium channels. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. 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.

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

    International Nuclear Information System (INIS)

    Ghadimi Mahani, Maryam; Morani, Ajaykumar C.; Lu, Jimmy C.; Dorfman, Adam L.; Fazeli Dehkordy, Soudabeh; Jeph, Sunil; Agarwal, Prachi P.

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-04-15

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

  18. Cardiovascular responses to the intracarotid injections of ionic contrast media and iohexol in the dog

    International Nuclear Information System (INIS)

    Hayakawa, K.; Morris, T.W.; Katzberg, R.W.; Fischer, H.W.

    1986-01-01

    Hypotension and bradycardia are the most significant cardiovascular responses resulting from intracarotid injections of hypertonic contrast media (CM). We have assessed both local and systemic vascular responses to the selective intracarotid injections of ionic and non-ionic CM in twelve pentobarbital anesthetized dogs. Alterations in blood pressure, heart rate, and femoral, renal and carotid blood flows were monitored following right common carotid artery injections of ionic contrast media (282-288 mg I/ml), isotonic saline, and iohexol (300 mg I/ml). Ionic CM led to early (0 to 10 s) decreases in blood pressure, heart rate and femoral vascular resistance. Isotonic saline induced no significant early changes in these same parameters while iohexol caused a decrease in heart rate. Our observations suggest that the early (0 to 10 s) decreases in femoral vascular resistance, heart rate and pressure that occur with the intracarotid injection of hypertonic CM are mediated via the autonomic nervous system and initiated from a site in the carotid circulation. During the 15 to 40 s period when the CM has reached the systemic circulation, iohexol produced smaller effects on systemic blood pressure and peripheral vascular resistances than did the ionic CM. During this 15 to 40 s period there were decreased vascular resistances in the carotid and renal vascular beds that probably result from local effects of the CM, however, the femoral resistance was actually increased. This later increase in femoral resistance probably represents the results of increased symphathetic nervous system activity working to offset the decrease in renal and carotid resistances and thus maintain pressure at baseline values. The vascular resistance changes observed demonstrate a complexity of responses to CM not previously appreciated. (orig.)

  19. Gadolinium-based contrast agents in pediatric magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gale, Eric M.; Caravan, Peter [Massachusetts General Hospital, Harvard Medical School, Department of Radiology, The Martinos Center for Biomedical Imaging, Boston, MA (United States); Rao, Anil G. [Medical University of South Carolina, Department of Radiology and Radiological Science, Charleston, SC (United States); McDonald, Robert J. [College of Medicine, Mayo Clinic, Department of Radiology, Rochester, MN (United States); Winfeld, Matthew [University of Pennsylvania Perelman School of Medicine, Philadelphia, PA (United States); Fleck, Robert J. [Cincinnati Children' s Hospital Medical Center, Department of Pediatric Radiology, Cincinnati, OH (United States); Gee, Michael S. [MassGeneral Hospital for Children, Harvard Medical School, Division of Pediatric Imaging, Department of Radiology, Boston, MA (United States)

    2017-05-15

    Gadolinium-based contrast agents can increase the accuracy and expediency of an MRI examination. However the benefits of a contrast-enhanced scan must be carefully weighed against the well-documented risks associated with administration of exogenous contrast media. The purpose of this review is to discuss commercially available gadolinium-based contrast agents (GBCAs) in the context of pediatric radiology. We discuss the chemistry, regulatory status, safety and clinical applications, with particular emphasis on imaging of the blood vessels, heart, hepatobiliary tree and central nervous system. We also discuss non-GBCA MRI contrast agents that are less frequently used or not commercially available. (orig.)

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

    Science.gov (United States)

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

    2013-07-19

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

  1. Arrhythmogenic right ventricular cardiomyopathy mimics: role of cardiovascular magnetic resonance

    Science.gov (United States)

    2013-01-01

    Background Cardiovascular magnetic resonance (CMR) is commonly used in patients with suspected arrhythmogenic right ventricular cardiomyopathy (ARVC) based on ECG, echocardiogram and Holter. However, various diseases may present with clinical characteristics resembling ARVC causing diagnostic dilemmas. The aim of this study was to explore the role of CMR in the differential diagnosis of patients with suspected ARVC. Methods 657 CMR referrals suspicious for ARVC in a single tertiary referral centre were analysed. Standardized CMR imaging protocols for ARVC were performed. Potential ARVC mimics were grouped into: 1) displacement of the heart, 2) right ventricular overload, and 3) non ARVC-like cardiac scarring. For each, a judgment of clinical impact was made. Results Twenty patients (3.0%) fulfilled imaging ARVC criteria. Thirty (4.6%) had a potential ARVC mimic, of which 25 (3.8%) were considered clinically important: cardiac displacement (n=17), RV overload (n=7) and non-ARVC like myocardial scarring (n=4). One patient had two mimics; one patient had dual pathology with important mimic and ARVC. RV overload and scarring conditions were always thought clinically important whilst the importance of cardiac displacement depended on the degree of displacement from severe (partial absence of pericardium) to epiphenomenon (minor kyphoscoliosis). Conclusions Some patients referred for CMR with suspected ARVC fulfil ARVC imaging criteria (3%) but more have otherwise unrecognised diseases (4.6%) mimicking potentially ARVC. Clinical assessment should reflect this, emphasising the assessment and/or exclusion of potential mimics in parallel with the detection of ARVC major and minor criteria. PMID:23398958

  2. Cardiovascular magnetic resonance in hypertrophic cardiomyopathy and infiltrative cardiomyopathy

    Directory of Open Access Journals (Sweden)

    Rebecca Schofield

    2016-11-01

    Full Text Available 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 extracellular volume quantification [ECV] and diffusion-weighted imaging with its potential to detect disarray. Clinically, the uses of CMR are diverse. The imaging must be considered within the context of work-up, particularly the personal and family history, Electrocardiogram (ECG and echocardiogram findings. Subtle markers of possible HCM can be identified in genotype positive left ventricular hypertrophy (LVH-negative subjects. CMR has particular advantages for assessment of the left ventricle (LV apex and is able to detect both missed LVH (apical and basal antero-septum, when the echocardiography is normal but the ECG abnormal. CMR is important in distinguishing HCM from both common phenocopies (hypertensive heart disease, athletic adaptation, ageing related changes and rarer pheno and/or genocopies such as Fabry disease and amyloidosis. For these, in particular the LGE technique and T1 mapping are very useful with a low T1 in Fabry’s, and high T1 and very high ECV in amyloidosis. Moreover, the tissue characterisation that is possible using CMR offers a potential role in patient risk stratification, as scar is a very strong predictor of future heart failure. Scar may also play a role in the prediction of sudden death. CMR is helpful in follow-up assessment, especially after septal alcohol ablation and myomectomy.

  3. Review of Journal of Cardiovascular Magnetic Resonance 2012

    Science.gov (United States)

    2013-01-01

    There were 90 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2012, which is an 8% increase in the number of articles since 2011. The quality of the submissions continues to increase. The editors are delighted to report that the 2011 JCMR Impact Factor (which is published in June 2012) has risen to 4.44, up from 3.72 for 2010 (as published in June 2011), a 20% increase. The 2011 impact factor means that the JCMR papers that were published in 2009 and 2010 were cited on average 4.44 times in 2011. The impact factor undergoes natural variation according to citation rates of papers in the 2 years following publication, and is significantly influenced by highly cited papers such as official reports. However, the progress of the journal's impact over the last 5 years has been impressive. Our acceptance rate is approximately 25%, and has been falling as the number of articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. For this reason, the Editors have felt that it is useful once per calendar year to summarize the papers for the readership into broad areas of interest or theme, so that areas of interest can be reviewed in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality manuscripts to JCMR for publication. PMID:24006874

  4. Clusters of magnetic nanoparticles as contrast agents for MRI: effect of aggregation on transverse relaxivity

    Czech Academy of Sciences Publication Activity Database

    Dědourková, T.; Kaman, Ondřej; Veverka, Pavel; Koktan, Jakub; Veverka, Miroslav; Kuličková, Jarmila; Jirák, Zdeněk; Herynek, V.

    2015-01-01

    Roč. 51, č. 11 (2015), s. 5300804 ISSN 0018-9464 R&D Projects: GA ČR GA15-10088S; GA MPO FR-TI3/521 Institutional support: RVO:68378271 Keywords : contrast agents * magnetic resonance imaging * magnetic nanoparticles * manganites * transverse relaxivity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.277, year: 2015

  5. Indication-related dosing for magnetic resonance contrast media

    International Nuclear Information System (INIS)

    Yuh, W.T.C.; Parker, J.R.; Carvlin, M.J.

    1997-01-01

    This presentation reviews the issue of contrast media dosing and imaging protocols for the optimal MR imaging detection and characterization of pathology. The cumulative clinical experience gained in performing contrast-enhanced MR examinations with gadolinium chelates indicates that a dose of 0.1 mmol/kg body weight provides safe and effective enhancement of most CNS pathology. Doses lower than 0.1 mmol/kg have been shown to be inadequate for delineating all but selected types of CNS pathology, such as masses with a high lesion to background ratio on post-contrast images (acoustic neuromas) or lesions located in areas in which the normal tissue very rapidly takes up contrast agent (e. g. microadenomas in the pituitary gland). Recent clinical studies have suggested a role for high dose gadolinium administration (up to 0.3 mmol/kg) for the optimal detection and delineation of cerebral metastases or other small or poorly enhancing lesions. Differences in the histopathologic characteristics (capillary permeability, vascularity, location, size) of specific diseased tissues may require varying doses or even a different contrast agent to be used for optimal imaging results. As new MR contrast agents and new scanning techniques are introduced, the specific diagnostic question posed will likely determine the choice of pulse sequence, contrast agent and dose used. (orig.)

  6. Gadolinium chloride as a contrast agent for imaging wood composite components by magnetic resonance

    Science.gov (United States)

    Thomas L. Eberhardt; Chi-Leung So; Andrea Protti; Po-Wah So

    2009-01-01

    Although paramagnetic contrast agents have an established track record in medical uses of magnetic resonance imaging (MRI), only recently has a contrast agent been used for enhancing MRI images of solid wood specimens. Expanding on this concept, wood veneers were treated with a gadolinium-based contrast agent and used in a model system comprising three-ply plywood...

  7. Analysis on the entrance surface dose and contrast medium dose at computed tomography and angiography in cardiovascular examination

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Young Hyun [Dept. of Cardiovascular Center, Yeocheon Jeonnam Hospital, Yeosu (Korea, Republic of); Han, Jae Bok; Choi, Nam Gil; Song, Jong Nam [Dept. of Radiological Science, Dongshin University, Naju (Korea, Republic of)

    2016-12-15

    This study aimed to identify dose reduction measures by retrospectively analyzing the entrance surface dose at computed tomography and angiography in cardiovascular examination and to contribute the patients with renal impairmend and a high probability of side effects to determine the inspection's direction by measuring the contrast usages actually to active actions for the dose by actually measuring the contrast medium dose. The CTDIvol value and air kerma value, which are the entrance surface doses of the two examinations, and the contrast medium dose depending on the number of slides were compared and analyzed. This study was conducted in 21 subjects (11 males; 10 females) who underwent Cardiac Computed Tomographic Angiography (CCTA) and Coronary Angiography (CAG) in this hospital during the period from May 2014 to May 2016. The subject's age was 48-85 years old (mean 65±10 years old), and the weight was 37.6~83.3 kg (mean 63±6 kg). Dose reduction could be expected in the cardiovascular examination using CCTA rather than in the examination using CAG. In terms of contrast medium dose, CAG used a smaller dose than CCTA. In particular, as the number of slides increases at CAG, the contrast medium dose increases. Therefore, in order to reduce the contrast medium dose, the number of slides suitable for the scan range must be selected.

  8. Enhancing contrast of magnetic resonance imaging in patients with ...

    African Journals Online (AJOL)

    11031, Taiwan, 2Institute of Biological Chemistry, Academia Sinica, 128 Academia Road, Section 2 ... Purpose: To determine transit times for excretion of gadoxetic acid (Gd-EOB-DTPA), a recent magnetic .... evaluated by the same radiologist.

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

    Directory of Open Access Journals (Sweden)

    Stalder Aurelien F

    2008-06-01

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

  10. Magnetic nanoparticles as contrast agents for molecular imaging in medicine

    Science.gov (United States)

    O'Donnell, Matthew

    2018-05-01

    For over twenty years, superparamagnetic nanoparticles have been developed for a number of medical applications ranging from bioseparations, magnetic drug targeting, hyperthermia and imaging. Recent studies have shown that they can be functionalized for in vivo biological targeting, potentially enabling nanoagents for molecular imaging and site-localized drug delivery. Here we review several imaging technologies developed using functionalized superparamagnetic iron oxide nanoparticles (SPIONs) as targeted molecular agents. Several imaging modalities have exploited the large induced magnetic moment of SPIONs to create local mechanical force. Magnetic force microscopy can probe nanoparticle uptake in single cells. For in vivo applications, magnetomotive modulation of primary images in ultrasound (US), photoacoustics (PA), and optical coherence tomography (OCT) can help identify very small concentrations of nanoagents while simultaneously suppressing intrinsic background signals from tissue.

  11. Non-contrast enhanced magnetic resonance angiography techniques in candidates for kidney transplantation: A comparative study

    International Nuclear Information System (INIS)

    Blankholm, Anne Dorte; Ginnerup-Pedersen, Bodil; Stausbøl-Grøn, Brian; Haislund, Margit; Laustsen, Sussie; Ringgaard, Steffen

    2013-01-01

    Aim: Detailed knowledge of vessel status in potential candidates for kidney transplantation is essential for the surgeon. Contrast enhanced magnetic resonance angiography has previously been used intensively for assessing this, but the discovery that use of gadolinium based contrast agents in magnetic resonance imaging can cause Nephrogenic Systemic Fibrosis in patients suffering from severe kidney disease has lead to renewed interest in non-contrast enhanced magnetic resonance angiography. The aim of this study was to find a non-contrast enhanced magnetic resonance angiography method for preoperative evaluation of the pelvic vessels prior to kidney transplantation, providing a sufficient image quality. Method: In a prospective study we consecutively included 54 patients undergoing examinations prior to kidney transplantation. The patients were examined with the following magnetic resonance angiography sequences: A 2D Time of flight (n = 54), 3D Time of flight (n = 52) patients, 3D Phase Contrast (n = 54), 3D Balanced Steady State Free Precession (n = 52) and a 2D TRiggered Angiography Non-Contrast Enhanced (TRANCE) (a Spin Echo sequence with subtraction) (n = 48). The sequences were evaluated with respect to contrast, diagnostic performance and artefact burden. Results: Evaluating contrast, 3D Phase Contrast was significantly better than 2D Time of flight (p 0.2). The 2D Time of flight was significantly better than the other sequences (p < 0.001) in all cases. The artefact score was lowest for the Phase Contrast images and significantly superior to the 2D Time of flight (p < 0.005). The 2D Time of flight was significantly better than the three other sequences (p < 0.001) in all cases. Conclusion: Non-contrast enhanced magnetic resonance angiography offers a safe preoperative examination for assessment of vessel status before kidney transplantation. A combination of 2D Time of flight and 3D Phase Contrast acquisitions is recommended and can be performed within a

  12. Magnetic resonance imaging (MRI) of congenital cardiovascular malformations

    International Nuclear Information System (INIS)

    Sakakibara, Makoto; Kobayashi, Shirou; Imai, Hitoshi; Watanabe, Shigeru; Masuda, Yoshiaki; Inagaki, Yoshiaki; Morita, Huminori; Uematsu, Sadao; Arimizu, Noboru

    1986-01-01

    In order to determine the value of MRI in diagnosing congenital cardiovascular malformations, MR Images were obtained in 25 adult patients with congenital cardiovascular malformations. Gated MRI detected all of 13 atrial septal defects, and all of 4 ventricular septal defects, but ungated MRI detected none of 3 atrial septal defects. Other congenital cardiovascular malformations (2 with Ebstein's disease, 1 with Fallot's pentalogy, and 1 with Pulmonary stenosis) were well visualized. Vascular malformations (1 with Patent ducts arteriosus, 1 with Supravalvelar aortic stenosis, 1 with Coarctation of Aorta, 1 with Right Aortic Arch) were well visualized in all of 7 patients by ungated MRI. MRI was a valuable noninvasive method of diagnosing congenital heart disease. (author)

  13. Cardiovascular magnetic resonance imaging of hypoplastic left heart syndrome in children

    International Nuclear Information System (INIS)

    Dillman, Jonathan R.; Hernandez, Ramiro J.; Dorfman, Adam L.; Attili, Anil K.; Agarwal, Prachi P.; Mueller, Gisela C.; Bell, Aaron

    2010-01-01

    Cardiovascular magnetic resonance imaging (CMR) plays an important complementary role to echocardiography and conventional angiography in the evaluation of hypoplastic left heart syndrome. This imaging modality is particularly useful for assessing cardiovascular postsurgical changes, extracardiac vascular anatomy, ventricular and valvular function, and a variety of complications. The purpose of this article is to provide a contemporary review of the role of CMR in the management of untreated and surgically palliated hypoplastic left heart syndrome in children. (orig.)

  14. Dobutamine stress cardiovascular magnetic resonance at 3 Tesla

    Directory of Open Access Journals (Sweden)

    Klein C

    2008-10-01

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

  15. 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.

  16. Cardiovascular effects of contrast materials on left ventricular angiography in rabbits

    International Nuclear Information System (INIS)

    Yeon, Kyung Mo; Han, Man Chung; Kim, Chu Wan

    1985-01-01

    The precise pathologic anatomy in complex congenital heart disease requires multiple injections of iodinated contrast materials into the cardiac chambers and/or great vessels. In the presence of intracardial shunts, more large volumes of contrast material is often required. In neonates and infants the total volume of contrast material during single angiographic procedure is limited up to 3-4ml/kg. This limitation results from the deleterious effects of systemic hyperosmolarity caused by the contrast materials and may be intensified in the neonate because of the relative immaturity of infants kidneys and delayed excretion of contrast materials. We therefore tried to compare the EKG and left ventricular pressure change with those of high osmolar and low osmolar contrast agent in experimental model. The purpose of the study is to determine and compare the effects of contrast materials on left ventricular hemodynamics

  17. Contrasting the magnetic response between magnetic-glass and reentrant spin-glass

    OpenAIRE

    Roy, S. B.; Chattopadhyay, M. K.

    2008-01-01

    Magnetic-glass is a recently identified phenomenon in various classes of magnetic systems undergoing a first order magnetic phase transition. We shall highlight here a few experimentally determined characteristics of magnetic-glass and the relevant set of experiments, which will enable to distinguish a magnetic-glass unequivocally from the well known phenomena of spin-glass and reentrant spin-glass.

  18. Utility decay rates of T1-weighted magnetic resonance imaging contrast based on redox-sensitive paramagnetic nitroxyl contrast agents

    International Nuclear Information System (INIS)

    Matsumoto, Ken-ichiro

    2009-01-01

    The availability and applicability of the combination of paramagnetic nitroxyl contrast agent and T 1 -weighted gradient echo (GE)-based dynamic magnetic resonance imaging (MRI) measurement for redox imaging are described. The time courses of T 1 -weighted GE MRI signal intensities according to first-order paramagnetic loss of a nitroxyl contrast agent were simulated for several experimental conditions. The apparent decay rate calculated based on decreasing T 1 -weighted MRI contrast (k MRI ) can show an approximate value of the original decay rate (k true ) discretionarily given for simulation with suitable experimental parameters. The difference between k MRI and k true can be sufficiently small under T 1 -weighted spoiled gradient echo (SPGR) scan conditions (repetition time=75 ms, echo time=3 ms, and flip angle=45deg), with a conventional redox-sensitive nitroxyl contrast agent, such as 4-hydroxy-2,2,6,6,-tetramethylpiperidine-N-oxyl (TEMPOL) and/or 3-carbamoyl-2,2,5,5-tetramethylpyrrolidine-N-oxyl (carbamoyl-PROXYL), and with intravenous (i.v.) doses of below 1.5 γmol/g body weight (b.w.) for mice. The results of this simulation suggest that the k MRI of nitroxyl contrast agents can be the primary index of redox status under biological conditions. (author)

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

    Science.gov (United States)

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

    2018-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Pedersen Erik M

    2011-04-01

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

  1. Perfusion magnetic resonance imaging and magnetic resonance spectroscopy of cerebral gliomas showing imperceptible contrast enhancement on conventional magnetic resonance imaging

    International Nuclear Information System (INIS)

    Batra, A.; Tripathi, R.P.; Singh, A.K.

    2004-01-01

    The purpose of the present paper was to evaluate the utility of perfusion MRI in cerebral gliomas showing imperceptible contrast enhancement on conventional MRI, and to evaluate the relationships of perfusion MRI and magnetic resonance (MR) spectroscopic results in these tumours. Twenty-two patients with histopathologically proven cerebral gliomas and showing insignificant contrast enhancement on conventional MR were included in the present study. All patients underwent perfusion MRI and MR spectroscopy on a 1.5-T MR system. Significant differences of the relative cerebral blood volume (rCBV) values and the choline : creatine ratios were noted between low-grade and anaplastic gliomas (P < 0.01). Good correlation was found between the rCBV values and the choline : creatine values (y = 0. 532x + 1.5643; r = 0.67). Perfusion MRI can be a useful tool in assessing the histopathological grade of non-contrast-enhancing cerebral gliomas. Along with MR spectroscopic imaging it can serve as an important technique for preoperative characterization of such gliomas, so that accurate targeting by stereotactic biopsies is possible. Copyright (2004) Blackwell Science Pty Ltd

  2. Factors influencing fast low angle positive contrast steady-state free precession (FLAPS) magnetic resonance imaging

    International Nuclear Information System (INIS)

    Dharmakumar, Rohan; Koktzoglou, Ioannis; Li Debiao

    2007-01-01

    The presence of susceptibility-shifting media can lead to signal voids in magnetic resonance images. While signal voids have been traditionally used to detect such magnetic perturbers, selective magnetic resonance imaging of off-resonant spins surrounding susceptibility-shifted media allows for them to be visualized as hyper-intense (positive contrast) regions. These positive contrast methods can potentially improve the detection conspicuity of magnetic perturbers against regions that appear dark due to the absence of protons, such as air. Recently, a fast low angle positive contrast steady-state free precession (FLAPS) technique has been proposed as a positive contrast imaging method. This work systematically evaluates the contrast characteristics and acquisition strategies of FLAPS-based imaging from the standpoint of imaging parameters and physical properties of the magnetic perturbers. Results show that scan parameters (T R , flip angle, B 0 ), physical properties of the perturber (size and concentration of shift reagent) and the ratio of the relaxation constants (T 1 /T 2 ) of the medium are significant factors influencing the FLAPS-based positive contrast

  3. Studies on polyaspartamide gadolinium complexes as potential magnetic resonance imaging contrast agents

    International Nuclear Information System (INIS)

    Yan Guoping; Liu Maili; Li Liyun

    2005-01-01

    Purpose: A series of polyaspartamide gadolinium complexes containing pyridoxamine groups were studied as the potential magnetic resonance imaging (MRI) contrast agents for liver enhancement. Methods: These polyaspartamide gadolinium complexes were prepared and evaluated by relaxivity, acute toxicity studies and magnetic resonance imaging of the liver in rats. Results: These polyaspartamide gadolinium complexes have higher relaxation effectiveness than that of the clinically used gadolinium diethylenetriaminepentaacetic acid and possess the low intravenous acute toxicities to Institute for Cancer Research (ICR) mice. Magnetic resonance imaging of the liver in rats indicated that they greatly enhance the contrast of magnetic resonance images and provide prolonged intravascular duration in the liver. Conclusion: These results indicated that the polyaspartamide gadolinium complexes containing pyridoxamine groups could be considered as the appropriate MRI contrast agents for liver enhancement

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-04-15

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

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

    International Nuclear Information System (INIS)

    Mortensen, Kristian H.; Jones, Alexander; Steeden, Jennifer A.; Taylor, Andrew M.; Muthurangu, Vivek

    2016-01-01

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

  6. Carboxylated magnetic nanoparticles as MRI contrast agents: Relaxation measurements at different field strengths

    Energy Technology Data Exchange (ETDEWEB)

    Jedlovszky-Hajdu, Angela, E-mail: angela.hajdu@net.sote.hu [Laboratory of Nanochemistry, Department of Biophysics and Radiation Biology, Semmelweis University, Nagyvarad Sq 4, H-1089 Budapest (Hungary); Tombacz, Etelka, E-mail: tombacz@chem.u-szeged.hu [Department of Physical Chemistry and Material Science, University of Szeged, Aradi Vt. Sq 1, Szeged 6720 (Hungary); Banyai, Istvan, E-mail: banyai.istvan@science.unideb.hu [Department of Colloid and Environmental Chemistry, University of Debrecen (Hungary); Babos, Magor, E-mail: babosmagor@yahoo.com [Euromedic Diagnostics Szeged Ltd., Semmelweis St 6, Szeged 6720 (Hungary); Palko, Andras, E-mail: palko@radio.szote.u-szeged.hu [Faculty of Medicine, Department of Radiology, University of Szeged (Hungary)

    2012-09-15

    At the moment the biomedical applications of magnetic fluids are the subject of intensive scientific interest. In the present work, magnetite nanoparticles (MNPs) were synthesized and stabilized in aqueous medium with different carboxylic compounds (citric acid (CA), polyacrylic acid (PAA), and sodium oleate (NaOA)), in order to prepare well stabilized magnetic fluids (MFs). The magnetic nanoparticles can be used in the magnetic resonance imaging (MRI) as contrast agents. Magnetic resonance relaxation measurements of the above MFs were performed at different field strengths (i.e., 0.47, 1.5 and 9.4 T) to reveal the field strength dependence of their magnetic responses, and to compare them with that of ferucarbotran, a well-known superparamagnetic contrast agent. The measurements showed characteristic differences between the tested magnetic fluids stabilized by carboxylic compounds and ferucarbotran. It is worthy of note that our magnetic fluids have the highest r2 relaxivities at the field strength of 1.5 T, where the most of the MRI works in worldwide. - Highlights: Black-Right-Pointing-Pointer Magnetic resonance relaxation measurements were done at different field strengths. Black-Right-Pointing-Pointer Results show characteristic differences between the tested carboxylated MFs. Black-Right-Pointing-Pointer r1 and r2 relaxivities depend on the thickness of the protecting layer. Black-Right-Pointing-Pointer MFs have high r2/r1 ratios at each magnetic field.

  7. Value of Cardiovascular Magnetic Resonance Imaging in Noninvasive Risk Stratification in Tetralogy of Fallot

    NARCIS (Netherlands)

    Bokma, Jouke P.; de Wilde, Koen C.; Vliegen, Hubert W.; van Dijk, Arie P.; van Melle, Joost P.; Meijboom, Folkert J.; Zwinderman, Aeilko H.; Groenink, Maarten; Mulder, Barbara J. M.; Bouma, Berto J.

    IMPORTANCE Adults late after total correction of tetralogy of Fallot (TOF) are at risk for majorcomplications. Cardiovascular magnetic resonance (CMR) imaging is recommended toquantify right ventricular (RV) and left ventricular (LV) function. However, a commonly usedrisk model by Khairy et al

  8. Synthesis and evaluation of nanoglobule-cystamine-(Gd-DO3A, a biodegradable nanosized magnetic resonance contrast agent for dynamic contrast-enhanced magnetic resonance urography

    Directory of Open Access Journals (Sweden)

    Rongzuo Xu

    2010-09-01

    Full Text Available Rongzuo Xu1, Todd Lyle Kaneshiro1, Eun-Kee Jeong2, Dennis L Parker2, Zheng-Rong Lu31Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT, USA; 2Department of Radiology, University of Utah, Salt Lake City, UT, USA; 3Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USAAbstract: Dynamic contrast-enhanced magnetic resonance imaging has been recently shown to be effective for diagnostic urography. High-resolution urographic images can be acquired with T1 contrast agents for the kidney and urinary tract with minimal noise in the abdomen. Currently, clinical contrast agents are low molecular weight agents and can rapidly extravasate from blood circulation, leading to slow contrast agent elimination through kidney and consequently providing limited contrast enhancement in urinary tract. In this study, a new biodegradable macromolecular contrast agent, nanoglobule-G4-cystamine-(Gd-DO3A, was prepared by conjugating Gd-DO3A chelates on the surface of a generation 4 nanoglobule, poly-l-lysine octa(3-aminopropylsilsesquioxane dendrimer, via a disulfide spacer, where the carrier had a precisely defined nanosize that is far smaller than the renal filtration threshold. The in vivo contrast enhancement and dynamic imaging of the urinary tract of the agent was evaluated in nude mice using a low molecular weight agent Gd(DTPA-BMA as a control. The agent eliminated rapidly from blood circulation and accumulated more abundantly in urinary tract than Gd(DTPA-BMA. The fast elimination kinetics is ideal for functional evaluation of the kidneys. The morphology of the kidneys and urinary tract was better visualized by the biodegradable nanoglobular contrast agent than Gd(DTPA-BMA. The agent also resulted in low liver contrast enhancement, indicating low nonspecific tissue deposition. These features render the G4 nanoglobule-cystamine-(Gd-DO3A conjugate a promising contrast agent for magnetic

  9. Confident Diagnosis of Bronchobiliary Fistula Using Contrast-Enhanced Magnetic Resonance Cholangiography

    Energy Technology Data Exchange (ETDEWEB)

    Karabulut, Nevzat; Cakmak, Vefa; Kiter, Go ksel [Pamukkale University Medical Center, Denizli (Turkmenistan)

    2010-08-15

    We report the utility of contrast-enhanced magnetic resonance cholangiography (MRC) using gadoxetic acid (Gd-EOB-DTPA) in the diagnosis of bronchobiliary fistula associated with liver hydatid cyst. Contrast-enhanced MRC clearly delineated the leakage of contrast agent from the biliary duct and its communication with the bronchial tree. Providing functional information about physiologic or pathologic biliary flow in addition to the display of biliary anatomy, contrast enhanced MRC stands as a robust technique in confidently detecting bronchobiliary fistula and bile leaks

  10. Magnetic resonance tomography for focal lesions in the liver using the para-magnetic contrast medium gadolinium DTPA

    International Nuclear Information System (INIS)

    Hamm, B.; Roemer, T.; Felix, R.; Wolf, K.J.; Klinikum Charlottenburg, Berlin

    1986-01-01

    The use of the para-magnetic contrast medium gadolinium DTPA for magnetic resonance tomography of focal lesions in the liver was investigated in 31 patients. Two dosage schedules of the contrast medium (0.1 and 0.2 mmol/kg body weight) were used with field strengths of 0.35 and 0.5 Tesla. Using T 1 sequences, gadolinium DTPA showed increased signal intensity in the liver and in tumours, but this was significantly more marked in the tumour. On T 1 spin-echo sequences, previously iso-intense lesions became visible after administration of contrast. On the other hand, contrast-enhanced lesions were less well seen on inversion recovery sequences because of a reduction in the contrast between tumour and liver tissue. The contrast between tumour and liver tissue was not improved by gadolinium DTPA in comparison with precontrast inversion recovery sequences and T 2 spin-echo sequences. The perfusion of intra-hepatic tumours could be elucidated by magnetic resonance tomography after the administration of gadolinium DTPA. (orig.) [de

  11. Clinical role of non-contrast magnetic resonance angiography for evaluation of renal artery stenosis

    International Nuclear Information System (INIS)

    Utsunomiya, Daisuke; Nomitsu, Yohei; Komeda, Yosuke; Okigawa, Takashi; Urata, Joji; Miyazaki, Mitsue; Yamashita, Yasuyuki

    2008-01-01

    The association between a gadolinium-based contrast material and nephrogenic systemic fibrosis has been discussed. The purpose of our study was to evaluate whether non-contrast enhanced magnetic resonance angiography (MRA) might provide sufficient information of renal artery stenosis. The non-contrast MRA of 26 patients with hypertension was retrospectively reviewed in the present study. The significant renal artery stenosis was visually evaluated by comparing non-contrast MRA with computed tomography or conventional angiographic finding. Difference of the intensities between the proximal and distal aorta was quantitatively evaluated. The sensitivity, specificity, positive predictive value and negative predictive value of non-contrast MRA in the evaluation of the renal artery stenosis was 78%, 91%, 64% and 96%, respectively. The distal abdominal aorta showed less signal intensity than the proximal aorta by 16.9±12.2%. Non-contrast MRA is a non-invasive and effective method that allows evaluation of the renal artery stenosis. (author)

  12. 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

  13. Technological Innovations in Magnetic Resonance for Early Detection of Cardiovascular Diseases.

    Science.gov (United States)

    Santarelli, Maria F; Positano, Vincenzo; Martini, Nicola; Valvano, Giuseppe; Landini, Luigi

    2016-01-01

    Most recent technical innovations in cardiovascular MR imaging (CMRI) are presented in this review. They include hardware and software developments, and novelties in parametric mapping. All these recent improvements lead to high spatial and temporal resolution and quantitative information on the heart structure and function. They make it achievable ambitious goals in the field of magnetic resonance, such as the early detection of cardiovascular pathologies. In this review article, we present recent innovations in CMRI, emphasizing the progresses performed and the solutions proposed to some yet opened technical problems.

  14. Whole body cardiovascular magnetic resonance imaging to stratify symptomatic and asymptomatic atherosclerotic burden in patients with isolated cardiovascular disease

    International Nuclear Information System (INIS)

    Weir-McCall, Jonathan R.; Duce, Suzanne L.; Gandy, Stephen J.; Matthew, Shona Z.; Martin, Patricia; Cassidy, Deirdre B.; McCormick, Lynne; Belch, Jill J. F.; Struthers, Allan D.; Colhoun, Helen M.; Houston, J. Graeme

    2016-01-01

    The aim of this study was to use whole body cardiovascular magnetic resonance imaging (WB CVMR) to assess the heart and arterial network in a single examination, so as to describe the burden of atherosclerosis and subclinical disease in participants with symptomatic single site vascular disease. 64 patients with a history of symptomatic single site vascular disease (38 coronary artery disease (CAD), 9 cerebrovascular disease, 17 peripheral arterial disease (PAD)) underwent whole body angiogram and cardiac MR in a 3 T scanner. The arterial tree was subdivided into 31 segments and each scored according to the degree of stenosis. From this a standardised atheroma score (SAS) was calculated. Cine and late gadolinium enhancement images of the left ventricle were obtained. Asymptomatic atherosclerotic disease with greater than 50 % stenosis in arteries other than that responsible for their presenting complain was detected in 37 % of CAD, 33 % of cerebrovascular and 47 % of PAD patients. Unrecognised myocardial infarcts were observed in 29 % of PAD patients. SAS was significantly higher in PAD patients 24 (17.5-30.5) compared to CAD 4 (2–11.25) or cerebrovascular disease patients 6 (2-10) (ANCOVA p < 0.001). Standardised atheroma score positively correlated with age (β 0.36 p = 0.002), smoking status (β 0.34 p = 0.002), and LV mass (β -0.61 p = 0.001) on multiple linear regression. WB CVMR is an effective method for the stratification of cardiovascular disease. The high prevalence of asymptomatic arterial disease, and silent myocardial infarctions, particularly in the peripheral arterial disease group, demonstrates the importance of a systematic approach to the assessment of cardiovascular disease

  15. Can cardiovascular magnetic resonance prompt early cardiovascular/rheumatic treatment in autoimmune rheumatic diseases? Current practice and future perspectives.

    Science.gov (United States)

    Mavrogeni, Sophie I; Sfikakis, Petros P; Dimitroulas, Theodoros; Koutsogeorgopoulou, Loukia; Katsifis, Gikas; Markousis-Mavrogenis, George; Kolovou, Genovefa; Kitas, George D

    2018-06-01

    Life expectancy in autoimmune rheumatic diseases (ARDs) remains lower compared to the general population, due to various comoborbidities. Cardiovascular disease (CVD) represents the main contributor to premature mortality. Conventional and biologic disease-modifying antirheumatic drugs (DMARDs) have considerably improved long-term outcomes in ARDs not only by suppressing systemic inflammation but also by lowering CVD burden. Regarding atherosclerotic disease prevention, EULAR has recommended tight disease control accompanied by regular assessment of traditional CVD risk factors and lifestyle changes. However, this approach, although rational and evidence-based, does not account for important issues such as myocardial inflammation and the long asymptomatic period that usually proceeds clinical manifestations of CVD disease in ARDs before or after the diagnosis of systemic disease. Cardiovascular magnetic resonance (CMR) can offer reliable, reproducible and operator independent information regarding myocardial inflammation, ischemia and fibrosis. Some studies suggest a role for CMR in the risk stratification of ARDs and demonstrate that oedema/fibrosis visualisation with CMR may have the potential to inform cardiac and rheumatic treatment modification in ARDs with or without abnormal routine cardiac evaluation. In this review, we discuss how CMR findings could influence anti-rheumatic treatment decisions targeting optimal control of both systemic and myocardial inflammation irrespective of clinical manifestations of cardiac disease. CMR can provide a different approach that is very promising for risk stratification and treatment modification; however, further studies are needed before the inclusion of CMR in the routine evaluation and treatment of patients with ARDs.

  16. Magnetic iodixanol - a novel contrast agent and its early characterization.

    Science.gov (United States)

    Arokiaraj, M C; Menesson, E; Feltin, N

    2018-02-01

    Contrast-induced nephropathy is a commonly encountered problem in clinical practice. The purpose of the study was to design and develop a novel contrast agent, which could be used to prevent contrast-induced nephropathy in the future. In total, 20-220nm magnetic nanoparticles were conjugated with iodixanol, and their radio-opacity and magnetic properties were assessed thereafter. Scanning electron microscopy pictures were acquired. Thereafter, the nanoparticles conjugate was tested in cell culture (HUVEC cells), and Quantibody ® assay was studied after cell treatment in 1:5 dilutions for 48h, compared with control. The conjugate preparation had an adequate radio-opacity. A 4mm magnetic bubble was attached to a bar magnet and the properties were studied. The magnetic bubble maintained its structural integrity in all angles including antigravity position. Scanning electron microscopy showed magnetic nanoparticles in all pictures and the particles are of 100-400nm agglomerates with primary particle sizes of roughly 20nm. 1:5 diluted particles had no effect on secretion of IL-1a, IL-1b, IL-4, IL-10, IL-13 and TNFa. Particles increased secretion of IL-8 from 24h and 48h. Secretion of IFNg was also increased when particles were added to the cells as early as 1h. Likewise, IL-6 was strongly secreted by HUVEC treated with particles from 24h incubation time. In contrast, the secretion of MCP-1 was slightly reduced on HUVEC treated with particles. There is potential for a novel iodixanol-magnetic nanoparticle conjugate to be used in cineradiography. Further investigations need to be performed to study its performance in vitro and in vivo. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  17. The effects of breath-holding on pulmonary regurgitation measured by cardiovascular magnetic resonance velocity mapping

    Directory of Open Access Journals (Sweden)

    Babu-Narayan Sonya V

    2009-01-01

    Full Text Available Abstract Background Pulmonary regurgitation is a common and clinically important residual lesion after repair of tetralogy of Fallot. Cardiovascular magnetic resonance (CMR phase contrast velocity mapping is widely used for measurement of pulmonary regurgitant fraction. Breath-hold acquisitions, usually acquired during held expiration, are more convenient than the non-breath-hold approach, but we hypothesized that breath-holding might affect the amount of pulmonary regurgitation. Methods Forty-three adult patients with a previous repair of tetralogy of Fallot and residual pulmonary regurgitation were investigated with CMR. In each, pulmonary regurgitant fraction was measured from velocity maps transecting the pulmonary trunk, acquired during held expiration, held inspiration, by non-breath-hold acquisition, and also from the difference of right and left ventricular stroke volume measurements. Results Pulmonary regurgitant fraction was lower when measured by velocity mapping in held expiration compared with held inspiration, non-breath-hold or stroke volume difference (30.8 vs. 37.0, 35.6, 35.4%, p = 0.00017, 0.0035, 0.026. The regurgitant volume was lower in held expiration than in held inspiration (41.9 vs. 48.3, p = 0.0018. Pulmonary forward flow volume was larger during held expiration than during non-breath-hold (132 vs. 124 ml, p = 0.0024. Conclusion Pulmonary regurgitant fraction was significantly lower in held expiration compared with held inspiration, free breathing and stroke volume difference. Altered airway pressure could be a contributory factor. This information is relevant if breath-hold acquisition is to be substituted for non-breath-hold in the investigation of patients with a view to re-intervention.

  18. Uncomplicated obesity is associated with abnormal aortic function assessed by cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Channon Keith M

    2008-02-01

    Full Text Available Abstract Aims Obese subjects with insulin resistance and hypertension have abnormal aortic elastic function, which may predispose them to the development of left ventricular dysfunction. We hypothesised that obesity, uncomplicated by other cardiovascular risk factors, is independently associated with aortic function. Methods and results We used magnetic resonance imaging to measure aortic compliance, distensibility and stiffness index in 27 obese subjects (BMI 33 kg/m2 without insulin resistance and with normal cholesterol and blood pressure, and 12 controls (BMI 23 kg/m2. Obesity was associated with reduced aortic compliance (0.9 ± 0.1 vs. 1.5 ± 0.2 mm2/mmHg in controls, p -1 × 10-3, p Conclusion Aortic elastic function is abnormal in obese subjects without other cardiovascular risk factors. These findings highlight the independent importance of obesity in the development of cardiovascular disease.

  19. Technical aspects of contrast-enhanced magnetic resonance imaging of the breast: literature review

    International Nuclear Information System (INIS)

    Leopoldino, Denise de Deus; Gracio, Tatiana Schiller; D'Ippolito, Giuseppe; Bezerra, Alexandre Sergio de Araujo; Gracio, Tatiana Schiller

    2005-01-01

    With the advances in surface coil technology and the development of new imaging protocols in addition to the increase of the use of contrast agents, contrast enhanced magnetic resonance imaging (MRI) has emerged as a promising modality for detection, diagnosis and staging of breast cancer. Despite these advances, there are some unresolved issues, including no defined standard technique for contrast-enhanced breast MRI and no standard criteria of interpretation for the evaluation of such studies. In this article, we review the literature and discuss the general requirements and recommendations for contrast agent-enhanced breast MRI, including image interpretation criteria, MR equipment, dedicated radiofrequency coils, use of paramagnetic contrast agents, fat-suppression techniques, planes of acquisition, pulse sequence specifications and artifact sources. (author)

  20. Measuring SPIO and Gd contrast agent magnetization using 3 T MRI

    Science.gov (United States)

    Cantillon-Murphy, Pádraig; Wald, Lawrence L.; Zahn, Markus; Adalsteinsson, Elfar

    2011-01-01

    Traditional methods of measuring magnetization in magnetic fluid samples, such as vibrating sample magnetometry (VSM), are typically limited to maximum field strengths of about 1 T. This work demonstrates the ability of MRI to measure the magnetization associated with two commercial MRI contrast agents at 3 T by comparing analytical solutions to experimental imaging results for the field pattern associated with agents in cylindrical vials. The results of the VSM and fitted MRI data match closely. The method represents an improvement over VSM measurements since results are attainable at imaging field strengths. The agents investigated are Feridex, a superparamagnetic iron oxide suspension used primarily for liver imaging, and Magnevist, a paramagnetic, gadolinium-based compound used for tumors, inflammation and vascular lesions. MR imaging of the agents took place in sealed cylindrical vials in the presence of a surrounding volume of deionized water where the effects of the contrast agents had a measurable effect on the water's magnetization in the vicinity of the compartment of contrast agent. A pair of phase images were used to reconstruct a B0 fieldmap. The resultant B0 maps in the water region, corrected for shimming and container edge effects, were used to predict the agent's magnetization at 3 T. The results were compared with the results from VSM measurements up to 1.2 T and close correlation was observed. The technique should be of interest to those seeking quantification of the magnetization associated with magnetic suspensions beyond the traditional scope of VSM. The magnetization needs to be sufficiently strong (Ms≳50 Am2/kg Fe for Feridex and χm≳5 × 10−5 m3/kg Gd for Magnevist) for a measurable dipole field in the surrounding water. For this reason, the technique is mostly suitable for undiluted agents. PMID:19588450

  1. Simultaneous topographic and elemental chemical and magnetic contrast in scanning tunneling microscopy

    Science.gov (United States)

    Rose, Volker; Preissner, Curt A; Hla, Saw-Wai; Wang, Kangkang; Rosenmann, Daniel

    2014-09-30

    A method and system for performing simultaneous topographic and elemental chemical and magnetic contrast analysis in a scanning, tunneling microscope. The method and system also includes nanofabricated coaxial multilayer tips with a nanoscale conducting apex and a programmable in-situ nanomanipulator to fabricate these tips and also to rotate tips controllably.

  2. Tumor microvascular changes in antiangiogenic treatment : Assessment by magnetic resonance contrast media of different molecular weights

    NARCIS (Netherlands)

    Turetschek, K; Preda, A; Novikov, [No Value; Brasch, RC; Weinmann, HJ; Wunderbaldinger, P; Roberts, TPL

    Purpose: To test magnetic resonance (MR) contrast media of different molecular weights (MWs) for their potential to characterize noninvasively microvascular changes in an experimental tumor treatment model. Materials and Methods: MD-MBA-435, a poorly differentiated human breast cancer cell line, was

  3. Three-dimensional magnetic resonance coronary angiography using a new blood pool contrast agent : Initial experience

    NARCIS (Netherlands)

    Bedaux, WLF; Hofman, MBM; Wielopolski, PA; de Cock, CC; Hoffmann, [No Value; Oudkerk, M; de Feyter, PJ; van Rossum, AC

    2002-01-01

    Objective: The aim of this feasibility study was to assess the effect of a new blood pool contrast agent on magnetic resonance coronary angiography (MRCA) in patients suspected of having coronary artery disease. Methods: Nine patients referred for diagnostic x-ray coronary, angiography in the

  4. Data driven analysis of dynamic contrast-enhanced magnetic resonance imaging data in breast cancer diagnosis

    NARCIS (Netherlands)

    Twellmann, T.

    2005-01-01

    In the European Union, breast cancer is the most common type of cancer affecting women. If diagnosed in an early stage, breast cancer has an encouraging cure rate. Thus, early detection of breast cancer continues to be the key for an effective treatment. Recently, Dynamic Contrast-Enhanced Magnetic

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

    Directory of Open Access Journals (Sweden)

    Schwitter Juerg

    2009-11-01

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

  6. Diagnosis of Popliteal Venous Entrapment Syndrome by Magnetic Resonance Imaging Using Blood-Pool Contrast Agents

    International Nuclear Information System (INIS)

    Beitzke, Dietrich; Wolf, Florian; Juelg, Gregor; Lammer, Johannes; Loewe, Christian

    2011-01-01

    Popliteal vascular entrapment syndrome is caused by aberrations or hypertrophy of the gastrocnemius muscles, which compress the neurovascular structures of the popliteal fossa, leading to symptoms of vascular and degeneration as well as aneurysm formation. Imaging of popliteal vascular entrapment may be performed with ultrasound, magnetic resonance imaging (MRI), computed tomography angiography, and conventional angiography. The use of blood-pool contrast agents in MRI when popliteal vascular entrapment is suspected offers the possibility to perform vascular imaging with first-pass magnetic resonance angiographic, high-resolution, steady-state imaging and allows functional tests all within one examination with a single dose of contrast agent. We present imaging findings in a case of symptomatic popliteal vein entrapment diagnosed by the use of blood pool contrast-enhanced MRI.

  7. Diethylenetriaminepentaacetic acid-gadolinium (DTPA-Gd)-conjugated polysuccinimide derivatives as magnetic resonance imaging contrast agents.

    Science.gov (United States)

    Lee, Ha Young; Jee, Hye Won; Seo, Sung Mi; Kwak, Byung Kook; Khang, Gilson; Cho, Sun Hang

    2006-01-01

    Biocompatible polysuccinimide (PSI) derivatives conjugated with diethylenetriaminepentaacetic acid gadolinium (DTPA-Gd) were prepared as magnetic resonance imaging (MRI) contrast agents. In this study, we synthesized PSI derivatives incorporating methoxy-poly(ethylene glycol) (mPEG) as hydrophilic ligand, hexadecylamine as hydrophobic ligand, and DTPA-Gd as contrast agent. PSI was synthesized by the polycondensation polymerization of aspartic acid. All the synthesized materials were characterized by proton nuclear magnetic resonance (1H NMR). Critical micellization concentrations were determined using fluorescent probes (pyrene). Micelle size and shape were measured by electro-photometer light scattering (ELS) and atomic force microscopy (AFM). The formed micelle size ranged from 100 to 300 nm. The T1-weighted MR images of the phantom prepared with PSI-mPEG-C16-(DTPA-Gd) were obtained in a 3.0 T clinical MR imager, and the conjugates showed a great potential as MRI contrast agents.

  8. BOLD cardiovascular magnetic resonance at 3.0 tesla in myocardial ischemia.

    OpenAIRE

    Manka, R; Paetsch, I; Schnackenburg, B; Gebker, R; Fleck, E; Jahnke, C

    2010-01-01

    Abstract Background The purpose of this study was to determine the ability of Blood Oxygen Level Dependent (BOLD) cardiovascular magnetic resonance (CMR) to detect stress-inducible myocardial ischemic reactions in the presence of angiographically significant coronary artery disease (CAD). Methods Forty-six patients (34 men; age 65 ± 9 years,) with suspected or known coronary artery disease underwent CMR at 3Tesla prior to clinically indicated invasive coronary angiography. BOLD CMR was perfor...

  9. RGD-conjugated iron oxide magnetic nanoparticles for magnetic resonance imaging contrast enhancement and hyperthermia.

    Science.gov (United States)

    Zheng, S W; Huang, M; Hong, R Y; Deng, S M; Cheng, L F; Gao, B; Badami, D

    2014-03-01

    The purpose of this study was to develop a specific targeting magnetic nanoparticle probe for magnetic resonance imaging and therapy in the form of local hyperthermia. Carboxymethyl dextran-coated ultrasmall superparamagnetic iron oxide nanoparticles with carboxyl groups were coupled to cyclic arginine-glycine-aspartic peptides for integrin α(v)β₃ targeting. The particle size, magnetic properties, heating effect, and stability of the arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide were measured. The arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide demonstrates excellent stability and fast magneto-temperature response. Magnetic resonance imaging signal intensity of Bcap37 cells incubated with arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide was significantly decreased compared with that incubated with plain ultrasmall superparamagnetic iron oxide. The preferential uptake of arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide by target cells was further confirmed by Prussian blue staining and confocal laser scanning microscopy.

  10. 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.

  11. [Utilization of polymeric micelle magnetic resonance imaging (MRI) contrast agent for theranostic system].

    Science.gov (United States)

    Shiraishi, Kouichi

    2013-01-01

    We applied a polymeric micelle carrier system for the targeting of a magnetic resonance imaging (MRI) contrast agent. Prepared polymeric micelle MRI contrast agent exhibited a long circulation characteristic in blood, and considerable amount of the contrast agent was found to accumulate in colon 26 solid tumor by the EPR effect. The signal intensities of tumor area showed 2-folds increase in T1-weighted images at 24 h after i.v. injection. To observe enhancement of the EPR effect by Cderiv pretreatment on tumor targeting, we used the contrast agent for the evaluation by means of MRI. Cderiv pretreatment significantly enhanced tumor accumulation of the contrast agent. Interestingly, very high signal intensity in tumor region was found at 24 h after the contrast agent injection in Cderiv pretreated mice. The contrast agent visualized a microenvironmental change in tumor. These results indicate that the contrast agent exhibits potential use for tumor diagnostic agent. To combine with a polymeric micelle carrier system for therapeutic agent, the usage of the combination makes a new concept of "theranostic" for a better cancer treatment.

  12. Magnetic resonance imaging (MRI) of the cardiovascular system

    International Nuclear Information System (INIS)

    Yoshida, Shigeru

    1991-01-01

    Qualitative assessments of the hypertrophied myocardium were performed using spin-lattice relaxation time (T1) and spin-spin relaxation time (T2) obtained by magnetic resonance imaging (MRI) in 15 normotensive patients with asymmetric septal hypertrophy (ASH), 10 hypertensive patients with concentric hypertrophy (CH) and 5 normal subjects (N). The changes of these values were evaluated related to cardiac cycle, and their usefulness in differentiating diseases. The wall thickness and internal dimension of the left ventricle (LV) in 10 cases were obtained using echocardiography and MRI, and there was a good correlation coefficient in wall thickness (r=0.987) and in internal dimension (r=0.991). Left ventricular short-axis images were obtained using ECG-gated spin-echo sequence (Te=30, 80 msec) and using inversion recovery sequence. T1 and T2 images were calculated at endsystolic and diastolic cardiac phases. The regional wall thickness (WT) and T1 and T2 values were measured in the anterior septum, anterior wall, lateral wall, posterior wall and posterior septum. Myocardial T1 and T2 values were significantly decreased in systole (T1: 185.6±37.9 msec, T2: 24.4±6.3 msec) compared to those in diastole (T1: 249.2±56.7 msec, T2: 31.7±9.4 msec). In both ASH and CH groups, significant correlations were observed between diastolic T1 values and WT (ASH: r=0.80, CH: r=0.45), and between diastolic T2 values and WT (ASH: r=0.58, CH: r=0.60). In the regions where diastolic WT were more than 17 mm, T1 values in the ASH group (343.4±40.5 msec) were significantly higher than those of the CH group (247.3±21.4 msec), although the mean wall thickness values were similar in both groups. These results indicate that myocardial relaxation times are related to cardiac cycle, wall thickness and types of hypertrophy. The T1 and T2 values at diastolic cardiac phase might be useful for distinguishing hypertrophic cardiomyopathy from hypertrophy due to hypertension. (author)

  13. Contrast-enhanced magnetic resonance imaging of tumours of the central nervous systems: a clinical review

    International Nuclear Information System (INIS)

    Graif, M.; Steiner, R.E.

    1986-01-01

    The clinical application of the intravascular paramagnetic contrast agent gadolinium-DTPA for magnetic resonance imaging (MRI) imaging of tumours of the central nervous system (CNS) has been assessed over the past 3 years. Various patterns of contrast enhancement were observed, and situations in MRI where the administration of contrast medium may be useful have been defined. These include lesions which are isointense with normal brain matter, the separation of tumour from surrounding oedema, evaluation of the degree of blood-brain barrier breakdown, delineation of tumours obscured by overlying calcification on computed tomography (CT) and in the investigation of lesions in anatomical areas where CT has known limitations (brain, stem, cervical spine). Changes in relaxation times in normal and abnormal tissues following contrast medium, toxicity and dosage of gadolinium-DTPA, and MRI pulse sequence techniques are reviewed. (author)

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

    Directory of Open Access Journals (Sweden)

    Kim Raymond J

    2008-07-01

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

  15. Serial contrast-enhanced magnetic resonance and magnetization transfer in the study of patients with multiple sclerosis

    International Nuclear Information System (INIS)

    Rovira, A.; Alonso, J.; Cucurella, G.; Nos, C.; Tintore, M.; Pedraza, S.; Rio, J.; Montalban, X.

    1997-01-01

    To demonstrate the changes in the magnetization transfer ratio (MTR) of different demyelinating plaques, correlating them with the baseline values in T1-weighted contrast-enhanced magnetic resonance (MR) sequences in order to relate them more closely to the underlying disease. The study was based on 33 demyelinating plaques obtained from six patients clinically diagnosed as having remitting-recurring multiple sclerosis (MS). All the patients underwent two MR studies at a 3 to 5-month interval, including contrast-enhanced T1 and T2- weighted sequences and magnetization transfer images. The latter were used to calculate the MTR for each of the demyelinating plaques included in the study. The statistical analysis of the results obtained revealed statistically significant between initial MTR values and those of subsequent T1-weighted sequences. The MTR demonstrate significant differences between plaques according to contrast-enhanced T1-weigh tes sequences, probably indicating variable degrees of edema, demyelination and tissue destruction. These differences should be taken into account to enable the use of T1-weighted sequences to quantify the lesion load in MS patients. (Author) 35 refs

  16. Cine Magnetic Resonance Imaging of the Small Bowel: Comparison of Different Oral Contrast Media

    International Nuclear Information System (INIS)

    Asbach, P.; Breitwieser, C.; Diederichs, G.; Eisele, S.; Kivelitz, D.; Taupitz, M.; Zeitz, M.; Hamm, B.; Klessen, C.

    2006-01-01

    Purpose: To evaluate several substances regarding small bowel distension and contrast on balanced steady-state free precession (bSSFP) cine magnetic resonance (MR) images. Material and Methods: Luminal contrast was evaluated in 24 volunteers after oral application of two different contrast agent groups leading to either bright lumen (pineapple, blueberry juice) or dark lumen (tap water, orange juice) on T1-weighted images. Bowel distension was evaluated in 30 patients ingesting either methylcellulose or mannitol solution for limiting intestinal absorption. Fifteen patients with duodeno-jejunal intubation served as the control. Quantitative evaluation included measurement of luminal signal intensities and diameters of four bowel segments, qualitative evaluation assessed luminal contrast and distension on a five-point scale. Results: Quantitative and qualitative evaluation of the four contrast agents revealed no significant differences regarding luminal contrast on bSSFP images. Quantitative evaluation revealed significantly lower (P<0.05) small bowel distension for three out of four segments (qualitative evaluation: two out of four segments) for methylcellulose in comparison to the control. Mannitol was found to be equal to the control. Conclusion: Oral ingestion of tap water or orange juice in combination with mannitol is recommended for cine MR imaging of the small bowel regarding luminal contrast and small bowel distension on bSSFP sequences

  17. Cine Magnetic Resonance Imaging of the Small Bowel: Comparison of Different Oral Contrast Media

    Energy Technology Data Exchange (ETDEWEB)

    Asbach, P.; Breitwieser, C.; Diederichs, G.; Eisele, S.; Kivelitz, D.; Taupitz, M.; Zeitz, M.; Hamm, B.; Klessen, C. [Charite - Universitatsmedizin Berlin, Charite Campus Mitte, Berlin (Germany). Dept. of Radiology

    2006-11-15

    Purpose: To evaluate several substances regarding small bowel distension and contrast on balanced steady-state free precession (bSSFP) cine magnetic resonance (MR) images. Material and Methods: Luminal contrast was evaluated in 24 volunteers after oral application of two different contrast agent groups leading to either bright lumen (pineapple, blueberry juice) or dark lumen (tap water, orange juice) on T1-weighted images. Bowel distension was evaluated in 30 patients ingesting either methylcellulose or mannitol solution for limiting intestinal absorption. Fifteen patients with duodeno-jejunal intubation served as the control. Quantitative evaluation included measurement of luminal signal intensities and diameters of four bowel segments, qualitative evaluation assessed luminal contrast and distension on a five-point scale. Results: Quantitative and qualitative evaluation of the four contrast agents revealed no significant differences regarding luminal contrast on bSSFP images. Quantitative evaluation revealed significantly lower (P<0.05) small bowel distension for three out of four segments (qualitative evaluation: two out of four segments) for methylcellulose in comparison to the control. Mannitol was found to be equal to the control. Conclusion: Oral ingestion of tap water or orange juice in combination with mannitol is recommended for cine MR imaging of the small bowel regarding luminal contrast and small bowel distension on bSSFP sequences.

  18. Magnetic resonance imaging with liver-specific contrast agent in primary amyloidosis and intrahepatic cholestasis

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, J.M.; Santoni-Rugiu, E.; Chabanova, E.; Logager, V.; Hansen, A.B.; Thomsen, H.S. [Depts. of Radiology and Pathology, Copenhagen Univ. Hospital, Herlev (Denmark)

    2007-02-15

    Magnetic resonance imaging (MRI) findings in hepatic amyloidosis are not well defined. Here, we report on a patient with renal failure caused by primary amyloidosis (AL type) who developed jaundice. Ultrasound and computed tomography were normal except for some ascites. MRI with oral manganese-containing contrast agent revealed several focal areas without contrast uptake in the hepatocytes and no bile secretion after 8 hours. No extrahepatic bile obstructions were found. Liver biopsy showed severe intraportal, vascular, and parenchymal amyloidosis causing severe cholestasis and atrophy of hepatocytes.

  19. Application of phase-contrast cine magnetic resonance imaging in endoscopic aqueductoplasty.

    Science.gov (United States)

    Chen, Guoqiang; Zheng, Jiaping; Xiao, Qing; Liu, Yunsheng

    2013-06-01

    The aim of this study was to evaluate the application of phase-contrast cine magnetic resonance imaging (MRI) in endoscopic aqueductoplasty (EA) for patients with obstructive hydrocephalus. The clinical diagnosis of hydrocephalus caused by aqueduct obstruction in 23 patients was confirmed by phase-contrast cine MRI examination. The patients were treated with EA and MRI was repeated during the follow-up. The cerebrospinal fluid (CSF) flow velocity in the aqueduct was measured to determine whether the aqueduct was obstructed. The results of phase-contrast cine MRI examinations indicated that there was no CSF flow in the aqueduct for all patients prior to surgery. Aqueductoplasty was successfully performed in all patients. The results of phase-contrast cine MRI examinations performed a week after surgery demonstrated an average CSF flow velocity of 4.74±1.77 cm/sec. During the follow-up, intracranial hypertension recurred in two patients in whom CSF flow was not observed in the aqueduct by the phase-contrast cine MRI scan. Aqueduct re-occlusion was revealed by an endoscopic exploration. By measuring the CSF flow velocity, phase-contrast cine MRI accurately identifies aqueduct obstruction. Cine MRI is a nontraumatic, simple and reliable method for determining whether the aqueduct is successfully opened following aqueductoplasty.

  20. Characterization of nanoparticle-based contrast agents for molecular magnetic resonance imaging

    International Nuclear Information System (INIS)

    Shan, Liang; Chopra, Arvind; Leung, Kam; Eckelman, William C.; Menkens, Anne E.

    2012-01-01

    The development of molecular imaging agents is currently undergoing a dramatic expansion. As of October 2011, ∼4,800 newly developed agents have been synthesized and characterized in vitro and in animal models of human disease. Despite this rapid progress, the transfer of these agents to clinical practice is rather slow. To address this issue, the National Institutes of Health launched the Molecular Imaging and Contrast Agents Database (MICAD) in 2005 to provide freely accessible online information regarding molecular imaging probes and contrast agents for the imaging community. While compiling information regarding imaging agents published in peer-reviewed journals, the MICAD editors have observed that some important information regarding the characterization of a contrast agent is not consistently reported. This makes it difficult for investigators to evaluate and meta-analyze data generated from different studies of imaging agents, especially for the agents based on nanoparticles. This article is intended to serve as a guideline for new investigators for the characterization of preclinical studies performed with nanoparticle-based MRI contrast agents. The common characterization parameters are summarized into seven categories: contrast agent designation, physicochemical properties, magnetic properties, in vitro studies, animal studies, MRI studies, and toxicity. Although no single set of parameters is suitable to define the properties of the various types of contrast agents, it is essential to ensure that these agents meet certain quality control parameters at the preclinical stage, so that they can be used without delay for clinical studies.

  1. Nitroxide radicals as contrast substances for magnetic resonance imaging diagnostics. Part 1

    International Nuclear Information System (INIS)

    Zhelev, Z.

    2016-01-01

    In last ten years, there is a significant progress in the selective and localized detection of redox-active compounds in the cells, tissues, and intact organisms. This progress is due to the development of new synthetic and genetically encoded redox-sensitive contrast substances, as well as due to the improvement of the techniques for their imaging: fluorescent, chemiluminescent, magnetic resonance, nuclear, ultrasonic. One of the most attractive redox-sensitive contrast substances are cyclic (stable) nitroxide radicals. They can be visualized and analyzed in vitro and in vivo by a variety of magnetic resonance techniques - electron-paramagnetic resonance imaging (EPRI), magnetic resonance imaging (MRI), Overhauser-enhanced MRI (OMRI). This review describes the merits and demerits of the nitroxide-enhanced EPR and MRI and the perspectives for their application in biomedical studies and clinical practice. The article is intended for a wide range of readers - from students to specialists in the field. Key words: Magnetic Resonance Imaging (MRI). Electron-Paramagnetic Resonance (EPR). Overhauser-Enhanced MRI (O MRI). Nitroxide

  2. Complications from the use of intravenous gadolinium-based contrast agents for magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Elias Junior, Jorge; Santos, Antonio Carlos dos; Nogueira-Barbosa, Marcello Henrique; Muglia, Valdair Francisco; Koenigkam-Santos, Marcel [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Hospital das Clinicas. Centro de Ciencias das Imagens e Fisica Medica]. E-mail: jejunior@fmrp.usp.br

    2008-07-15

    Gadolinium-based contrast agents are much safer than the iodinated ones; however complications may occur and should be recognized for appropriate orientation and management. The total incidence of adverse reactions to contrast agents in magnetic resonance imaging ranges between 2% and 4%. Cases of severe acute reactions to gadolinium, such as laryngospasm and anaphylactic shock, are rare. Chronic complications secondary to the use of gadolinium also can occur and, recently an association between its use and a rare dermatologic disease occurring in patients with renal failure has been reported. Nephrogenic systemic fibrosis was the subject of an official health notification issued by the American Food and Drug Administration. This progressive disease is characterized by hardened skin with fibrotic nodules and plaques which may involve other parts of the body. Patients who have been affected by this disorder presented chronic renal failure, with metabolic acidosis and had been submitted to magnetic resonance angiography, probably involving exposure to large amounts of intravenous paramagnetic contrast. This review is aimed at presenting a succinct description of the gadolinium-based contrast agent types, possible secondary complications, their preventive measures and management. (author)

  3. MRI contrast agent for molecular imaging of the HER2/neu receptor using targeted magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Rasaneh, Samira; Rajabi, Hossein, E-mail: hrajabi@modares.ac.ir [Tarbiat Modares University, Department of Medical Physics (Iran, Islamic Republic of); Babaei, Mohammad Hossein [Nuclear Science and Technology Research Institute, Department of Radioisotope (Iran, Islamic Republic of); Akhlaghpoor, Shahram [Sina Hospital, Tehran Medical University, Noor Medical Imaging Center (Iran, Islamic Republic of)

    2011-06-15

    In this study, Trastuzumab modified Magnetic Nanoparticles (TMNs) were prepared as a new contrast agent for detecting HER2 (Human epidermal growth factor receptor-2) expression tumors by magnetic resonance imaging (MRI). TMNs were prepared based on iron oxide nanoparticles core and Trastuzumab modified dextran coating. The TMNs core and hydrodynamic size were determined by transmission electron microscopy and dynamic light scattering. TMNs stability and cytotoxicity were investigated. The ability of TMNs for HER2 detection were evaluated in breast carcinoma cell lines (SKBr3 and MCF7 cells) and tumor-bearing mice by MRI and iron uptake determination. The particles core and hydrodynamic size were 9 {+-} 2.5 and 41 {+-} 15 nm (size range: 15-87 nm), respectively. The molar antibody/nanoparticle ratio was 3.1-3.5. TMNs were non-toxic to the cells below the 30 {mu}g (Fe)/mL concentration and good stable up to 8 weeks in PBS buffer. TMNs could detect HER2 oncogenes in the cells surface with imagable contrast by MRI. The invivo study in mice bearing tumors indicated that TMNs possessed a good diagnostic ability as HER2 specific contrast agent by MRI. TMNs were demonstrated to be able to selectively accumulate in the tumor cells, with a proper signal enhancement in MRI T2 images. So, the complex may be considered for further investigations as an MRI contrast agent for detection of HER2 expression tumors in human.

  4. Design and Optimization of Gadolinium Based Contrast Agents for Magnetic Resonance Imaging

    International Nuclear Information System (INIS)

    Pereira, G.A.; Geraldes, C.F.G.C.; University of Coimbra

    2007-01-01

    The role of Gd 3+ chelates as contrast agents in Magnetic Resonance Imaging is discussed. The theory describing the different contributions to paramagnetic relaxation relevant to the understanding of the molecular parameters determining the relativity of those Gd 3+ chelates, is presented. The experimental techniques used to obtain those parameters are also described. Then, the various approaches taken to optimize those parameters, leading to maximum relativity (efficiency) of the contrast agents, are also illustrated with relevant examples taken from the literature. The various types of Gd 3+ -based agents, besides non-specific and hepatobiliary agents, are also discussed, namely blood pool, targeting, responsive and paramagnetic chemical shift saturation transfer (PARACEST) agents. Finally, a perspective is presented of some of the challenges lying ahead in the optimization of MRI contrast agents to be useful in Molecular Imaging. (author)

  5. Magnetic resonance tomography (MR) of intracranial tumours: Contrast versus T2-weighted tomograms

    International Nuclear Information System (INIS)

    Schoerner, W.; Laniado, M.; Claussen, C.; Kazner, E.; Niendorf, H.P.; Felix, R.

    1986-01-01

    Nuclear magnetic resonance tomography was performed on 38 patients with intracranial tumours, before and after the administration of contrast, using a 0.35 T Magnetom. The MR examinations included various plain spin-echo sequences (SE 400/35, 800/35, 1600/35, 1600/70, 1600/105, 1600/120) as well as examinations after the iv-administration of gadolinium-DTPA (SE 800/35). On all occasions, the abnormalities were visible without contrast. Differentiation of tumour and its surroundings was possible in 19 out of 38 cases without contrast. Delineation of expansively growing tumours (eg. meningiomas) was possible in twelve out of 14 cases, but in only seven out of 24 cases with infiltrating tumours (eg. glioblastomas). On the other hand, clear differentiation between tumour and adjacent edema and normal brain, respectively, was possible in 35 out of 38 cases after Gadolinium-DTPA. (orig.) [de

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

    Directory of Open Access Journals (Sweden)

    Merboldt Klaus-Dietmar

    2010-07-01

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

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

    Science.gov (United States)

    Zhang, Shuo; Uecker, Martin; Voit, Dirk; Merboldt, Klaus-Dietmar; Frahm, Jens

    2010-07-08

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

  8. Gadolinium-porphyrins: new potential magnetic resonance imaging contrast agents for melanoma detection

    Directory of Open Access Journals (Sweden)

    Daryoush Shahbazi-Gahrouei

    2006-11-01

    Full Text Available BACKGROUND: Two new porphyrin-based magnetic resonance imaging (MRI contrast agents, Gd-hematoporphyrin (Gd-H and Gd-tetra-carboranylmethoxyphenyl-porphyrin (Gd-TCP were synthesized and tested in nude mice with human melanoma (MM-138 xenografts as new melanoma contrast agents. METHODS: Subcutaneous xenografts of human melanoma cells (MM-138 were studied in 30 (five groups of six nude mice. The effect of different contrast agents (Gd-TCP, Gd-H, GdCl3 and Gd-DTPA on proton relaxation times was measured in tumors and other organs. T1 values, signal enhancement and the Gd concentration for different contrast agent solutions were also investigated. RESULTS: The porphyrin agents showed higher relaxivity compared to the clincal agent, Gd-DTPA. A significant 16% and 21% modification in T1 relaxation time of the water in human melanoma tumors grafted in the nude mice was revealed 24 hours after injection of Gd-TCP and Gd-H, respectively. The percentage of injected Gd localized to the tumor measured by inductively coupled plasma atomic emission spectrometry (ICP-AES was approximately 21% for Gd-TCP and 28% for Gd-H which were higher than that of Gd-DTPA (10%. CONCLUSIONS: The high concentration of Gd in the tumor is indicative of a selective retention of the compounds and indicates that Gd-TCP and Gd-H are promising MR imaging contrast agents for melanoma detection. Gd-porphyrins have considerable promise for further diagnostic applications in magnetic resonance imaging. KEY WORDS: MRI, porphyrin-based contrast agent, hematoporphyrin, melanoma.

  9. Carbon Nano-Allotrope/Magnetic Nanoparticle Hybrid Nanomaterials as T2 Contrast Agents for Magnetic Resonance Imaging Applications

    Directory of Open Access Journals (Sweden)

    Yunxiang Gao

    2018-02-01

    Full Text Available Magnetic resonance imaging (MRI is the most powerful tool for deep penetration and high-quality 3D imaging of tissues with anatomical details. However, the sensitivity of the MRI technique is not as good as that of the radioactive or optical imaging methods. Carbon-based nanomaterials have attracted significant attention in biomaterial research in recent decades due to their unique physical properties, versatile functionalization chemistry, as well as excellent biological compatibility. Researchers have employed various carbon nano-allotropes to develop hybrid MRI contrast agents for improved sensitivity. This review summarizes the new research progresses in carbon-based hybrid MRI contrast agents, especially those reported in the past five years. The review will only focus on T2-weighted MRI agents and will be categorized by the different carbon allotrope types and magnetic components. Considering the strong trend in recent bio-nanotechnology research towards multifunctional diagnosis and therapy, carbon-based MRI contrast agents integrated with other imaging modalities or therapeutic functions are also covered.

  10. Metal-oxo containing polymer nanobeads as potential contrast agents for magnetic resonance imaging

    Science.gov (United States)

    Pablico, Michele Huelar

    Magnetic resonance imaging (MRI) has greatly revolutionized the way diseases are detected and treated, as it is a non-invasive imaging modality solely based on the interaction of radiowaves and hydrogen nuclei in the presence of an external magnetic field. It is widely used today for the diagnosis of diseases as it offers an efficient method of mapping structure and function of soft tissues in the body. Most MRI examinations utilize paramagnetic materials known as contrast agents, which enhance the MR signal by decreasing the longitudinal (T1) and transverse (T2) relaxation times of the surrounding water protons in biological systems. This results into increased signal intensity differences thereby allowing better interpretation and analysis of pathological tissues. Contrast agents function by lowering the T1 or lowering the T2, resulting into bright and dark contrasts, respectively. The most common MRI contrast agents that are in clinical use today are gadolinium chelates and superparamagnetic iron oxide nanoparticles, both of which have their own advantages in terms of contrast enhancement properties. In the past few years, however, there has been interest in utilizing metal-containing clusters for MRI contrast enhancement as these materials bridge the gap between the constrained structure and magnetic properties of the gadolinium chelates with the superparamagnetic behavior of the iron oxide nanoparticles. Recently, metallic clusters containing Mn and Fe metal centers have received increased attention mainly because of their potential for high spin states and benign nature. In the quest to further develop novel imaging agents, this research has focused on investigating the use of metal-oxo clusters as potential contrast agents for MRI. The primary goal of this project is to identify clusters that meet the following criteria: high paramagnetic susceptibility, water-soluble, stable, cheap, contain environmentally benign metals, and easily derivatized. This work is

  11. Myocardial blood flow estimates from dynamic contrast-enhanced magnetic resonance imaging: three quantitative methods

    Science.gov (United States)

    Borrazzo, Cristian; Galea, Nicola; Pacilio, Massimiliano; Altabella, Luisa; Preziosi, Enrico; Carnì, Marco; Ciolina, Federica; Vullo, Francesco; Francone, Marco; Catalano, Carlo; Carbone, Iacopo

    2018-02-01

    Dynamic contrast-enhanced cardiovascular magnetic resonance imaging can be used to quantitatively assess the myocardial blood flow (MBF), recovering the tissue impulse response function for the transit of a gadolinium bolus through the myocardium. Several deconvolution techniques are available, using various models for the impulse response. The method of choice may influence the results, producing differences that have not been deeply investigated yet. Three methods for quantifying myocardial perfusion have been compared: Fermi function modelling (FFM), the Tofts model (TM) and the gamma function model (GF), with the latter traditionally used in brain perfusion MRI. Thirty human subjects were studied at rest as well as under cold pressor test stress (submerging hands in ice-cold water), and a single bolus of gadolinium weighing 0.1  ±  0.05 mmol kg-1 was injected. Perfusion estimate differences between the methods were analysed by paired comparisons with Student’s t-test, linear regression analysis, and Bland-Altman plots, as well as also using the two-way ANOVA, considering the MBF values of all patients grouped according to two categories: calculation method and rest/stress conditions. Perfusion estimates obtained by various methods in both rest and stress conditions were not significantly different, and were in good agreement with the literature. The results obtained during the first-pass transit time (20 s) yielded p-values in the range 0.20-0.28 for Student’s t-test, linear regression analysis slopes between 0.98-1.03, and R values between 0.92-1.01. From the Bland-Altman plots, the paired comparisons yielded a bias (and a 95% CI)—expressed as ml/min/g—for FFM versus TM, -0.01 (-0.20, 0.17) or 0.02 (-0.49, 0.52) at rest or under stress respectively, for FFM versus GF, -0.05 (-0.29, 0.20) or  -0.07 (-0.55, 0.41) at rest or under stress, and for TM versus GF, -0.03 (-0.30, 0.24) or  -0.09 (-0.43, 0.26) at rest or under stress. With the

  12. Non Hodgkin lymphoma metastasis to the heart detected by cardiovascular magnetic resonance

    International Nuclear Information System (INIS)

    Martinez, Florange; Morales, Marisela; Pedreanez, Norma; Pabon, Luz; Carrillo, Milton

    2009-01-01

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

  13. Contrast-enhanced magnetic resonance angiography of persistent fifth aortic arch in children

    International Nuclear Information System (INIS)

    Zhong, Yumin; Zhu, Ming; Sun, Aimin; Li, Yuhua; Jaffe, Richard B.; Gao, Wei

    2007-01-01

    Cine angiography and echocardiography have been utilized to diagnose congenital aortic arch anomalies. However, the visualization of great vessels by echocardiography is limited, while cine angiography requires cardiac catheterization with ionizing radiation. Contrast-enhanced magnetic resonance angiography (MRA) is a noninvasive modality suitable for visualization of congenital aortic arch anomalies. To evaluate the utility of contrast-enhanced MRA in the diagnosis of persistent fifth aortic arch, a rare congenital aortic arch anomaly, and to compare the diagnostic accuracy of MRA with that of echocardiography and cine angiography. In four pediatric patients, contrast-enhanced MRA studies were performed for diagnosing persistent fifth aortic arch. The findings of MRA were compared with echocardiographic findings and confirmed by cine angiography and operation. Transthoracic surface echocardiography noted an aberrant vessel arising from the ascending aorta in two of four patients; the etiology of this vessel was uncertain. In the other two patients a diagnosis of coarctation was made. Of the four patients, only one was diagnosed with interruption of the aortic arch. Contrast-enhanced MRA clarified uncertain echocardiographic findings, enabling the correct diagnosis of persistent fifth aortic arch with fourth aortic arch interruption in all four patients. Contrast-enhanced MRA is a safe, accurate, and fast imaging technique for the evaluation of persistent fifth aortic arch and may obviate the need for conventional cine angiography. Cardiac catheterization may be reserved for some types of complicated congenital heart disease and for obtaining hemodynamic information. (orig.)

  14. Magnetization transfer contrast MR imaging of the knee at 0.3 T

    International Nuclear Information System (INIS)

    Yoshioka, Hiroshi; Onaya, Hiroaki; Niitsu, Mamoru; Anno, Izumi; Itai, Yuji; Nishimura, Hiroshi; Kajiyama, Koji; Masuda, Tomonori; Nakajima, Kotaro.

    1994-01-01

    It has been reported that magnetization transfer contrast (MTC) images were effective in evaluating the articular cartilage. However, only one in vivo study of the articular cartilage in the knee has been demonstrated at 1.5T. The purpose of this study was to evaluate the optimal off-resonance MTC pulse at 0.3T MR imager and assess its clinical usefulness. Five normal volunteers and eleven patients with suspected knee injuries were investigated using off-resonance sinc, gaussian, constant shaped irradiation pulses. All MTC images revealed higher contrast and contrast-to-noise (C/N) ratio between articular cartilage and external reference (saline) in the normal volunteers' knee than conventional gradient recalled echo images. MTC images with the gaussian or sinc shaped pulse were judged superior to those with constant wave pulse because the former images showed a fewer artifact with lower specific absorption rate than the latter images. The sinc MTC images were performed with the lowest SAR. The gaussian MTC images revealed better contrast and C/N between articular cartilage and joint fluid than the sinc MTC images in patients. 3D MTC images using Guassian pulse were also performed within a clinically tolerable imaging time (13 min 39 sec). Thus, MTC images in the knee at 0.3T using off-resonance pulse may be effective to assess knee injury due to better contrast between articular cartilage and joint fluid. (author)

  15. Pineapple juice labeled with gadolinium: a convenient oral contrast for magnetic resonance cholangiopancreatography

    International Nuclear Information System (INIS)

    Coppens, Emmanuel; Metens, Thierry; Winant, Catherine; Matos, Celso

    2005-01-01

    The aim of our study was to prepare in vitro a pineapple juice (PJ) solution labeled with a minimal gadolinium concentration working as a negative contrast agent in heavily T2-weighted imaging and to assess that solution in vivo as a negative oral contrast agent for magnetic resonance cholangiopancreatography (MRCP). Three PJs were compared in vitro according to their T2. Increasing concentrations of gadolinium (Gd)-DOTA in PJ were assessed in vitro for T2 reduction. Single-shot turbo spin echo T2-weighted MR cholangiopancreatograms were obtained for 35 patients with suspected biliopancreatic duct disease, before and after ingestion of the PJ/Gd-DOTA solution. Signal intensity (SI) measurements of gastroduodenal lumens, pancreatobiliary ducts, and image quality scores were obtained systematically before and after contrast ingestion. The in vitro selected Gd-DOTA concentration in the PJ was 2.76 mmol/l. Ingestion of 180 ml of PJ labeled with 1 ml of Gd-DOTA eliminated efficiently the gastroduodenal SI in MRCP, improving significantly the rates of complete visualization of the pancreatobiliary ducts (P<0.01) and the MRCP image quality scores (P<0.05). All patients easily ingested the contrast solution and found the solution palatable. PJ labeled with gadolinium constituted an efficient and convenient negative oral contrast agent for MRCP. (orig.)

  16. Pineapple juice labeled with gadolinium: a convenient oral contrast for magnetic resonance cholangiopancreatography

    Energy Technology Data Exchange (ETDEWEB)

    Coppens, Emmanuel; Metens, Thierry; Winant, Catherine; Matos, Celso [Hopital Erasme, Universite Libre de Bruxelles, Department of Radiology, Division of Magnetic Resonance, Brussels (Belgium)

    2005-10-01

    The aim of our study was to prepare in vitro a pineapple juice (PJ) solution labeled with a minimal gadolinium concentration working as a negative contrast agent in heavily T2-weighted imaging and to assess that solution in vivo as a negative oral contrast agent for magnetic resonance cholangiopancreatography (MRCP). Three PJs were compared in vitro according to their T2. Increasing concentrations of gadolinium (Gd)-DOTA in PJ were assessed in vitro for T2 reduction. Single-shot turbo spin echo T2-weighted MR cholangiopancreatograms were obtained for 35 patients with suspected biliopancreatic duct disease, before and after ingestion of the PJ/Gd-DOTA solution. Signal intensity (SI) measurements of gastroduodenal lumens, pancreatobiliary ducts, and image quality scores were obtained systematically before and after contrast ingestion. The in vitro selected Gd-DOTA concentration in the PJ was 2.76 mmol/l. Ingestion of 180 ml of PJ labeled with 1 ml of Gd-DOTA eliminated efficiently the gastroduodenal SI in MRCP, improving significantly the rates of complete visualization of the pancreatobiliary ducts (P<0.01) and the MRCP image quality scores (P<0.05). All patients easily ingested the contrast solution and found the solution palatable. PJ labeled with gadolinium constituted an efficient and convenient negative oral contrast agent for MRCP. (orig.)

  17. Nanoparticles in magnetic resonance imaging: from simple to dual contrast agents

    Directory of Open Access Journals (Sweden)

    Estelrich J

    2015-03-01

    Full Text Available Joan Estelrich,1,2 María Jesús Sánchez-Martín,1 Maria Antònia Busquets1,2 1Departament de Fisicoquímica, Facultat de Farmàcia, Universitat de Barcelona, Barcelona, Catalonia, Spain; 2Institut de Nanociència I Nanotecnologia (IN2UB, Barcelona, Catalonia, SpainAbstract: Magnetic resonance imaging (MRI has become one of the most widely used and powerful tools for noninvasive clinical diagnosis owing to its high degree of soft tissue contrast, spatial resolution, and depth of penetration. MRI signal intensity is related to the relaxation times (T1, spin–lattice relaxation and T2, spin–spin relaxation of in vivo water protons. To increase contrast, various inorganic nanoparticles and complexes (the so-called contrast agents are administered prior to the scanning. Shortening T1 and T2 increases the corresponding relaxation rates, 1/T1 and 1/T2, producing hyperintense and hypointense signals respectively in shorter times. Moreover, the signal-to-noise ratio can be improved with the acquisition of a large number of measurements. The contrast agents used are generally based on either iron oxide nanoparticles or ferrites, providing negative contrast in T2-weighted images; or complexes of lanthanide metals (mostly containing gadolinium ions, providing positive contrast in T1-weighted images. Recently, lanthanide complexes have been immobilized in nanostructured materials in order to develop a new class of contrast agents with functions including blood-pool and organ (or tumor targeting. Meanwhile, to overcome the limitations of individual imaging modalities, multimodal imaging techniques have been developed. An important challenge is to design all-in-one contrast agents that can be detected by multimodal techniques. Magnetoliposomes are efficient multimodal contrast agents. They can simultaneously bear both kinds of contrast and can, furthermore, incorporate targeting ligands and chains of polyethylene glycol to enhance the accumulation of

  18. Chemistry of paramagnetic and diamagnetic contrast agents for Magnetic Resonance Imaging and Spectroscopy

    International Nuclear Information System (INIS)

    Perez-Mayoral, Elena; Negri, Viviana; Soler-Padros, Jordi; Cerdan, Sebastian; Ballesteros, Paloma

    2008-01-01

    We provide a brief overview of the chemistry and most relevant properties of paramagnetic and diamagnetic contrast agents (CAs) for Magnetic Resonance Imaging and Magnetic Resonance Spectroscopic Imaging. Paramagnetic CAs for MRI consist mainly of Gd(III) complexes from linear or macrocyclic polyaminopolycarboxylates. These agents reduce, the relaxation times T 1 and T 2 of the water protons in a concentration dependent manner, increasing selectively MRI contrast in those regions in which they accumulate. In most instances they provide anatomical information on the localization of lesions and in some specific cases they may allow to estimate some physiological properties of tissues including mainly vascular performance. Because of its ability to discriminate easily between normal and diseased tissue, extracellular pH (pH e ) has been added recently, to the battery of variables amenable to MRI investigation. A variety of Gd(III) containing macrocycles sensitive to pH, endogenous or exogenous polypeptides or even liposomes have been investigated for this purpose, using the pH dependence of their relaxivity or magnetization transfer rate constant (chemical exchange saturation transfer, CEST). Many environmental circumstances in addition to pH affect, however, relaxivity or magnetization transfer rate constants of these agents, making the results of pH measurements by MRI difficult to interpret. To overcome these limitations, our laboratory synthesized and developed a novel series of diamagnetic CAs for Magnetic Resonance Spectroscopic Imaging, a new family of monomeric and dimeric imidazolic derivatives able to provide unambiguous measurements of pH e , independent of water relaxivity, diffusion or exchange

  19. Chemistry of paramagnetic and diamagnetic contrast agents for Magnetic Resonance Imaging and Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Mayoral, Elena [Laboratorio de Sintesis Organica e Imagen Molecular por Resonancia Magnetica, Facultad de Ciencias, UNED, Paseo Senda del Rey 9, E-28040 Madrid (Spain); Departamento de Quimica Inorganica y Quimica Tecnica, Facultad de Ciencias, UNED, Paseo Senda del Rey 9, E-28040 Madrid (Spain); Negri, Viviana; Soler-Padros, Jordi [Laboratorio de Sintesis Organica e Imagen Molecular por Resonancia Magnetica, Facultad de Ciencias, UNED, Paseo Senda del Rey 9, E-28040 Madrid (Spain); Cerdan, Sebastian [Laboratorio de Imagen Espectroscopica por Resonancia Magnetica (LIERM), Instituto de Investigaciones Biomedicas ' Alberto Sols' , CSIC/UAM, c/Arturo Duperier 4, E-28029 Madrid (Spain); Ballesteros, Paloma [Laboratorio de Sintesis Organica e Imagen Molecular por Resonancia Magnetica, Facultad de Ciencias, UNED, Paseo Senda del Rey 9, E-28040 Madrid (Spain)], E-mail: pballesteros@ccia.uned.es

    2008-09-15

    We provide a brief overview of the chemistry and most relevant properties of paramagnetic and diamagnetic contrast agents (CAs) for Magnetic Resonance Imaging and Magnetic Resonance Spectroscopic Imaging. Paramagnetic CAs for MRI consist mainly of Gd(III) complexes from linear or macrocyclic polyaminopolycarboxylates. These agents reduce, the relaxation times T{sub 1} and T{sub 2} of the water protons in a concentration dependent manner, increasing selectively MRI contrast in those regions in which they accumulate. In most instances they provide anatomical information on the localization of lesions and in some specific cases they may allow to estimate some physiological properties of tissues including mainly vascular performance. Because of its ability to discriminate easily between normal and diseased tissue, extracellular pH (pH{sub e}) has been added recently, to the battery of variables amenable to MRI investigation. A variety of Gd(III) containing macrocycles sensitive to pH, endogenous or exogenous polypeptides or even liposomes have been investigated for this purpose, using the pH dependence of their relaxivity or magnetization transfer rate constant (chemical exchange saturation transfer, CEST). Many environmental circumstances in addition to pH affect, however, relaxivity or magnetization transfer rate constants of these agents, making the results of pH measurements by MRI difficult to interpret. To overcome these limitations, our laboratory synthesized and developed a novel series of diamagnetic CAs for Magnetic Resonance Spectroscopic Imaging, a new family of monomeric and dimeric imidazolic derivatives able to provide unambiguous measurements of pH{sub e}, independent of water relaxivity, diffusion or exchange.

  20. Contrast Induced by a Static Magnetic Field for Improved Detection in Nanodiamond Fluorescence Microscopy

    Science.gov (United States)

    Singam, Shashi K. R.; Motylewski, Jaroslaw; Monaco, Antonina; Gjorgievska, Elena; Bourgeois, Emilie; Nesládek, Milos; Giugliano, Michele; Goovaerts, Etienne

    2016-12-01

    Diamond nanoparticles with negatively charged nitrogen-vacancy (NV) centers are highly efficient nonblinking emitters that exhibit spin-dependent intensity. An attractive application of these emitters is background-free fluorescence microscopy exploiting the fluorescence quenching induced either by resonant microwaves (RMWs) or by an applied static magnetic field (SMF). Here, we compare RMW- and SMF-induced contrast measurements over a wide range of optical excitation rates for fluorescent nanodiamonds (FNDs) and for NV centers shallowly buried under the (100)-oriented surface of a diamond single crystal (SC). Contrast levels are found to be systematically lower in the FNDs than in the SC. At low excitation rates, the RMW contrast initially rises to a maximum (up to 7% in FNDs and 13% in the SC) but then decreases steadily at higher intensities. Conversely, the SMF contrast increases from approximately 12% at low excitation rates to high values of 20% and 38% for the FNDs and SC, respectively. These observations are well described in a rate-equations model for the charged NV defect using parameters in good agreement with the literature. The SMF approach yields higher induced contrast in image collection under commonly applied optical excitation. Unlike the RMW method, there is no thermal load exerted on the aqueous media in biological samples in the SMF approach. We demonstrate imaging by SMF-induced contrast in neuronal cultures incorporating FNDs (i) in a setup for patch-clamp experiments in parallel with differential-interference-contrast microscopy, (ii) after a commonly used staining procedure as an illustration of the high selectivity against background fluorescence, and (iii) in a confocal fluorescence microscope in combination with bright-field microscopy.

  1. Paramagnetic contrast media for magnetic resonance imaging of the central nervous system

    International Nuclear Information System (INIS)

    McNamara, M.T.

    1987-01-01

    Presently, a variety of radiofrequency (RF) and magnetic field gradient pulse sequences is used to manipulate magnetic resonance (MR) image contrast. Such manipulation may be performed by altering the RF pulse sequence repetition time (TR), the spin-echo delay time (TE), the inversion-delay time (TI), and the flip angle. The detection and characterization of a lesion or structure may thus be optimized. Although such contrast manipulation is noninvasive, magnetic resonance imaging (MRI) still suffers somewhat from lack of specificity. Also, the use of multiple imaging sequences to locate and characterize a lesion may prolong the imaging time and, thus, might place an economic burden on the system. Paramagnetic pharmaceuticals offer promise in this regard. They shorten tissue relaxation times, thus permitting the use of shorter imaging parameters, and in some circumstances, may obviate additional and more time-consuming pulse sequences. Paramagnetics could expand the sensitivity and specificity of MRI and provide functional information with regard to tissue perfusion, tissue viability, and blood-brain barrier integrity

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

    OpenAIRE

    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

    FUNDAMENTO: A hipertensão arterial pulmonar é uma doença grave e progressiva. O maior desafio clínico é seu diagnóstico precoce. OBJETIVO: Avaliar a presença e a extensão do realce tardio miocárdico pela ressonância magnética cardíaca bem como verificar se o percentual da massa de fibrose miocárdica é indicador de gravidade. MÉTODOS: Estudo transversal com 30 pacientes com hipertensão arterial pulmonar dos grupos I e IV, submetidos às avaliações clínica, funcional e hemodinâmica, e à ressonân...

  3. Hyperpolarized krypton-83 as a contrast agent for magnetic resonance imaging.

    Science.gov (United States)

    Pavlovskaya, Galina E; Cleveland, Zackary I; Stupic, Karl F; Basaraba, Randall J; Meersmann, Thomas

    2005-12-20

    For the first time, magnetic resonance imaging (MRI) with hyperpolarized (hp) krypton-83 (83Kr) has become available. The relaxation of the nuclear spin of 83Kr atoms (I = 9/2) is driven by quadrupolar interactions during brief adsorption periods on surrounding material interfaces. Experiments in model systems reveal that the longitudinal relaxation of hp 83Kr gas strongly depends on the chemical composition of the materials. The relaxation-weighted contrast in hp 83Kr MRI allows for the distinction between hydrophobic and hydrophilic surfaces. The feasibility of hp 83Kr MRI of airways is tested in canine lung tissue by using krypton gas with natural abundance isotopic distribution. Additionally, the influence of magnetic field strength and the presence of a breathable concentration of molecular oxygen on longitudinal relaxation are investigated.

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

    Science.gov (United States)

    2012-01-01

    Background Real-time cardiovascular magnetic resonance (rtCMR) is considered attractive for guiding TAVI. Owing to an unlimited scan plane orientation and an unsurpassed soft-tissue contrast with simultaneous device visualization, rtCMR is presumed to allow safe device navigation and to offer optimal orientation for precise axial positioning. We sought to evaluate the preclinical feasibility of rtCMR-guided transarterial aortic valve implatation (TAVI) using the nitinol-based Medtronic CoreValve bioprosthesis. Methods rtCMR-guided transfemoral (n = 2) and transsubclavian (n = 6) TAVI was performed in 8 swine using the original CoreValve prosthesis and a modified, CMR-compatible delivery catheter without ferromagnetic components. Results rtCMR using TrueFISP sequences provided reliable imaging guidance during TAVI, which was successful in 6 swine. One transfemoral attempt failed due to unsuccessful aortic arch passage and one pericardial tamponade with subsequent death occurred as a result of ventricular perforation by the device tip due to an operating error, this complication being detected without delay by rtCMR. rtCMR allowed for a detailed, simultaneous visualization of the delivery system with the mounted stent-valve and the surrounding anatomy, resulting in improved visualization during navigation through the vasculature, passage of the aortic valve, and during placement and deployment of the stent-valve. Post-interventional success could be confirmed using ECG-triggered time-resolved cine-TrueFISP and flow-sensitive phase-contrast sequences. Intended valve position was confirmed by ex-vivo histology. Conclusions Our study shows that rtCMR-guided TAVI using the commercial CoreValve prosthesis in conjunction with a modified delivery system is feasible in swine, allowing improved procedural guidance including immediate detection of complications and direct functional assessment with reduction of radiation and omission of contrast media. PMID:22453050

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

    Science.gov (United States)

    Kahlert, Philipp; Parohl, Nina; Albert, Juliane; Schäfer, Lena; Reinhardt, Renate; Kaiser, Gernot M; McDougall, Ian; Decker, Brad; Plicht, Björn; Erbel, Raimund; Eggebrecht, Holger; Ladd, Mark E; Quick, Harald H

    2012-03-27

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

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

    Directory of Open Access Journals (Sweden)

    Kahlert Philipp

    2012-03-01

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

  7. Development of a universal dual-bolus injection scheme for the quantitative assessment of myocardial perfusion cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Alfakih Khaled

    2011-05-01

    Full Text Available Abstract Background The dual-bolus protocol enables accurate quantification of myocardial blood flow (MBF by first-pass perfusion cardiovascular magnetic resonance (CMR. However, despite the advantages and increasing demand for the dual-bolus method for accurate quantification of MBF, thus far, it has not been widely used in the field of quantitative perfusion CMR. The main reasons for this are that the setup for the dual-bolus method is complex and requires a state-of-the-art injector and there is also a lack of post processing software. As a solution to one of these problems, we have devised a universal dual-bolus injection scheme for use in a clinical setting. The purpose of this study is to show the setup and feasibility of the universal dual-bolus injection scheme. Methods The universal dual-bolus injection scheme was tested using multiple combinations of different contrast agents, contrast agent dose, power injectors, perfusion sequences, and CMR scanners. This included 3 different contrast agents (Gd-DO3A-butrol, Gd-DTPA and Gd-DOTA, 4 different doses (0.025 mmol/kg, 0.05 mmol/kg, 0.075 mmol/kg and 0.1 mmol/kg, 2 different types of injectors (with and without "pause" function, 5 different sequences (turbo field echo (TFE, balanced TFE, k-space and time (k-t accelerated TFE, k-t accelerated balanced TFE, turbo fast low-angle shot and 3 different CMR scanners from 2 different manufacturers. The relation between the time width of dilute contrast agent bolus curve and cardiac output was obtained to determine the optimal predefined pause duration between dilute and neat contrast agent injection. Results 161 dual-bolus perfusion scans were performed. Three non-injector-related technical errors were observed (1.9%. No injector-related errors were observed. The dual-bolus scheme worked well in all the combinations of parameters if the optimal predefined pause was used. Linear regression analysis showed that the optimal duration for the predefined

  8. Contrast-enhanced magnetic resonance angiography: evaluation of renal arteries in living renal transplant donors

    International Nuclear Information System (INIS)

    Firat, Ali; Akin, Oguz; Muhtesem Agildere, Ahmet; Aytekin, Cuneyt; Haberal, Mehmet

    2004-01-01

    One of the most important steps before living-donor nephrectomy is assessment of renal vascular anatomy. The number, origins and lengths of the renal arteries and variations of renal veins must be determined in order to identify the kidney that is most suitable for transplantation. Digital subtraction angiography was long considered the standard procedure for this purpose, but this method has been replaced by non-invasive techniques. Contrast-enhanced magnetic resonance angiography is an accurate, safe and reliable method for imaging vasculature. This article reviews the technique and the clinical features of this method in the evaluation of living renal transplant donors

  9. Effect of collagen on magnetization transfer contrast assessed in cultured cartilage

    International Nuclear Information System (INIS)

    Aoki, Jun; Seo, Gwy-Suk; Karakida, Osamu; Ueda, Hitoshi; Sone, Shusuke; Hiraki, Yuji; Shukunami, Chisa; Moriya, Hiroto.

    1996-01-01

    We investigated the effect of collagen on magnetization transfer contrast (MTC) in cultured cartilage. In our culture system, only collagen synthesis was increased by the addition of vitamin C, while proteoglycan synthesis and the number of chondrocytes were unaffected. The MTC effect was assessed by using an off-resonance RF pulse (0.3 KHz off-resonance, sinc wave of 18 msec, maximum amplitude 4.61 x 10 -4 T) on a GRASS sequence. The cartilage cultured with vitamin C showed a higher MTC effect than that cultured without vitamin C. The major role of collagen on MTC was confirmed in living cartilage tissue. (author)

  10. Contrast-enhanced magnetic resonance angiography: evaluation of renal arteries in living renal transplant donors

    Energy Technology Data Exchange (ETDEWEB)

    Firat, Ali; Akin, Oguz; Muhtesem Agildere, Ahmet; Aytekin, Cuneyt; Haberal, Mehmet

    2004-10-01

    One of the most important steps before living-donor nephrectomy is assessment of renal vascular anatomy. The number, origins and lengths of the renal arteries and variations of renal veins must be determined in order to identify the kidney that is most suitable for transplantation. Digital subtraction angiography was long considered the standard procedure for this purpose, but this method has been replaced by non-invasive techniques. Contrast-enhanced magnetic resonance angiography is an accurate, safe and reliable method for imaging vasculature. This article reviews the technique and the clinical features of this method in the evaluation of living renal transplant donors.

  11. Rapid non-contrast magnetic resonance imaging for post appendectomy intra-abdominal abscess in children

    International Nuclear Information System (INIS)

    Lee, Megan H.; Eutsler, Eric P.; Khanna, Geetika; Sheybani, Elizabeth F.

    2017-01-01

    Acute appendicitis, especially if perforated at presentation, is often complicated by postoperative abscess formation. The detection of a postoperative abscess relies primarily on imaging. This has traditionally been done with contrast-enhanced computed tomography. Non-contrast magnetic resonance imaging (MRI) has the potential to accurately detect intra-abdominal abscesses, especially with the use of diffusion-weighted imaging (DWI). To evaluate our single-center experience with a rapid non-contrast MRI protocol evaluating post-appendectomy abscesses in children with persistent postsurgical symptoms. In this retrospective, institutional review board-approved study, all patients underwent a clinically indicated non-contrast 1.5- or 3-Tesla abdomen/pelvis MRI consisting of single-shot fast spin echo, inversion recovery and DWI sequences. All MRI studies were reviewed by two blinded pediatric radiologists to identify the presence of a drainable fluid collection. Each fluid collection was further characterized as accessible or not accessible for percutaneous or transrectal drainage. Imaging findings were compared to clinical outcome. Seven of the 15 patients had a clinically significant fluid collection, and 5 of these patients were treated with percutaneous drain placement or exploratory laparotomy. The other patients had a phlegmon or a clinically insignificant fluid collection and were discharged home within 48 h. Rapid non-contrast MRI utilizing fluid-sensitive and DWI sequences can be used to identify drainable fluid collections in post-appendectomy patients. This protocol can be used to triage patients between conservative management vs. abscess drainage without oral/intravenous contrast or exposure to ionizing radiation. (orig.)

  12. Rapid non-contrast magnetic resonance imaging for post appendectomy intra-abdominal abscess in children

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Megan H. [Washington University School of Medicine in St. Louis, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Eutsler, Eric P.; Khanna, Geetika [Washington University School of Medicine in St. Louis, Pediatric Radiology, Mallinckrodt Institute of Radiology, St. Louis, MO (United States); Sheybani, Elizabeth F. [Mercy Hospital St. Louis, Department of Radiology, St. Louis, MO (United States)

    2017-07-15

    Acute appendicitis, especially if perforated at presentation, is often complicated by postoperative abscess formation. The detection of a postoperative abscess relies primarily on imaging. This has traditionally been done with contrast-enhanced computed tomography. Non-contrast magnetic resonance imaging (MRI) has the potential to accurately detect intra-abdominal abscesses, especially with the use of diffusion-weighted imaging (DWI). To evaluate our single-center experience with a rapid non-contrast MRI protocol evaluating post-appendectomy abscesses in children with persistent postsurgical symptoms. In this retrospective, institutional review board-approved study, all patients underwent a clinically indicated non-contrast 1.5- or 3-Tesla abdomen/pelvis MRI consisting of single-shot fast spin echo, inversion recovery and DWI sequences. All MRI studies were reviewed by two blinded pediatric radiologists to identify the presence of a drainable fluid collection. Each fluid collection was further characterized as accessible or not accessible for percutaneous or transrectal drainage. Imaging findings were compared to clinical outcome. Seven of the 15 patients had a clinically significant fluid collection, and 5 of these patients were treated with percutaneous drain placement or exploratory laparotomy. The other patients had a phlegmon or a clinically insignificant fluid collection and were discharged home within 48 h. Rapid non-contrast MRI utilizing fluid-sensitive and DWI sequences can be used to identify drainable fluid collections in post-appendectomy patients. This protocol can be used to triage patients between conservative management vs. abscess drainage without oral/intravenous contrast or exposure to ionizing radiation. (orig.)

  13. Non-invasive assessment of pulsatile intracranial pressure with phase-contrast magnetic resonance imaging.

    Directory of Open Access Journals (Sweden)

    Geir Ringstad

    Full Text Available Invasive monitoring of pulsatile intracranial pressure can accurately predict shunt response in patients with idiopathic normal pressure hydrocephalus, but may potentially cause complications such as bleeding and infection. We tested how a proposed surrogate parameter for pulsatile intracranial pressure, the phase-contrast magnetic resonance imaging derived pulse pressure gradient, compared with its invasive counterpart. In 22 patients with suspected idiopathic normal pressure hydrocephalus, preceding invasive intracranial pressure monitoring, and any surgical shunt procedure, we calculated the pulse pressure gradient from phase-contrast magnetic resonance imaging derived cerebrospinal fluid flow velocities obtained at the upper cervical spinal canal using a simplified Navier-Stokes equation. Repeated measurements of the pulse pressure gradient were also undertaken in four healthy controls. Of 17 shunted patients, 16 responded, indicating high proportion of "true" normal pressure hydrocephalus in the patient cohort. However, there was no correlation between the magnetic resonance imaging derived pulse pressure gradient and pulsatile intracranial pressure (R = -.18, P = .43. Pulse pressure gradients were also similar in patients and healthy controls (P = .26, and did not differ between individuals with pulsatile intracranial pressure above or below established thresholds for shunt treatment (P = .97. Assessment of pulse pressure gradient at level C2 was therefore not found feasible to replace invasive monitoring of pulsatile intracranial pressure in selection of patients with idiopathic normal pressure hydrocephalus for surgical shunting. Unlike invasive, overnight monitoring, the pulse pressure gradient from magnetic resonance imaging comprises short-term pressure fluctuations only. Moreover, complexity of cervical cerebrospinal fluid flow and -pulsatility at the upper cervical spinal canal may render the pulse pressure gradient a poor surrogate

  14. Magnetic resonance imaging of urinary bladder carcinoma: tumor staging and gadolinium contrast-enhanced imaging

    International Nuclear Information System (INIS)

    Doringer, E.; Joos, H.; Forstner, R.; Schmoller, H.

    1992-01-01

    Forty-nine patients with urinary bladder carcinomas underwent pre-operative examinations using magnetic resonance (MR) imaging. The results of the MR examinations were correlated with the clinical-pathological findings following transurethral resection (TUR) and bimanual palpation (n = 47) or radical cystectomy (n = 2). The results of pre-contrast MR tumor staging (T1, T2), viewing stages Tis-T2 collectively, and subsequent to separate assessments of stages T3b-T4b, were correct 76.6% of the time. Gadolinium-DTPA (Gd-DTPA) contrast-enhanced examinations (pre-contrast T1 and after Gd-DTPA) showed a staging accuracy rate of 85.7%. T2-weighted images did not indicate any advantage when compared to T1-weighted images following Gd-DTPA. The signal intensity ratios of tumor/fat and tumor/muscle tissue were measured on T1-weighted pre-contrast images and following Gd-DTPA and then evaluated statistically, whereby the increased tumor signal intensity was statistically significant (Wilcoxon test, P < 0.01). Due to the relatively short examination time needed for T1-weighted images and the specific tumor enhancement, the administration of Gd-DTPA proves valuable in the diagnosis of bladder carcinomas. T2-weighted images are not necessary. (orig.)

  15. Differentiation between early rheumatoid arthritis patients and healthy persons by conventional and dynamic contrast-enhanced magnetic resonance imaging

    DEFF Research Database (Denmark)

    Axelsen, Mette Bjørndal; Ejbjerg, B J; Hetland, M L

    2014-01-01

    OBJECTIVES: To identify the magnetic resonance imaging (MRI) parameter that best differentiates healthy persons and patients with early rheumatoid arthritis (RA), and to investigated responsiveness to treatment of various MRI parameters. METHOD: Conventional MRI and dynamic contrast-enhanced (DCE...

  16. Prospective study of ultrasound with perflutrene contrast compared to magnetic resonance imaging in the diagnosis of hepatic hemangiomas

    Directory of Open Access Journals (Sweden)

    Joel Schmillevitch

    2011-06-01

    Full Text Available CONTEXT:The incidence of hepatic hemangiomas ranges from 0.4% to 20% in the general population. Conventional ultrasound is usually the first diagnostic method to identify these hemangiomas, typically as an incidental finding. Ultrasonography with second generation contrast materials is being used in various areas of hepatology, yielding similar results to those obtained with computerized tomography and magnetic resonance imaging in the diagnosis of hepatic hemangiomas. OBJECTIVE: To evaluate the agreement between ultrasound with perflutrene contrast and magnetic resonance imaging in the diagnosis of hepatic hemangiomas. METHODS: A total of 37 patients were prospectively examined between January 2006 and August 2008. A total of 57 hepatic nodules were documented in this group as incidental findings on routine ultrasound exams. The 37 patients were administered perflutrene contrast without adverse reactions, and were all submitted to magnetic resonance exams. RESULTS: Conventional ultrasound identified 15 patients with nodules typical of hemangiomas and 22 patients with other nodules. In 35 patients, the contrast characteristics were consistent with hepatic hemangiomas. CONCLUSION: Agreement between the data obtained from ultrasound with contrast and magnetic resonance was 94.5%. In discordant cases, the magnetic resonance diagnosis prevailed. In the case which presented indeterminate findings on contrast ultrasonography, magnetic resonance was repeated after 3 months, confirming the diagnosis of a hepatic hemangioma. A biopsy was performed on the suspected malignant nodule which also confirmed the presence of a hepatic hemangioma. Ultrasonography with contrast has the advantages of being more accessible to the public at large and lower cost than magnetic resonance. The results of our study highlight the need for a new protocol in hepatic nodules incidentally identified on conventional ultrasonography. In the case of typical hemangiomas

  17. Novel Gd nanoparticles enhance vascular contrast for high-resolution magnetic resonance imaging.

    Directory of Open Access Journals (Sweden)

    Tot Bui

    2010-09-01

    Full Text Available Gadolinium (Gd, with its 7 unpaired electrons in 4f orbitals that provide a very large magnetic moment, is proven to be among the best agents for contrast enhanced MRI. Unfortunately, the most potent MR contrast agent based on Gd requires relatively high doses of Gd. The Gd-chelated to diethylene-triamine-penta-acetic acid (DTPA, or other derivatives (at 0.1 mmole/kg recommended dose, distribute broadly into tissues and clear through the kidney. These contrast agents carry the risk of Nephrogenic Systemic Fibrosis (NSF, particularly in kidney impaired subjects. Thus, Gd contrast agents that produce higher resolution images using a much lower Gd dose could address both imaging sensitivity and Gd safety.To determine whether a biocompatible lipid nanoparticle with surface bound Gd can improve MRI contrast sensitivity, we constructed Gd-lipid nanoparticles (Gd-LNP containing lipid bound DTPA and Gd. The Gd-LNP were intravenously administered to rats and MR images collected. We found that Gd in Gd-LNP produced a greater than 33-fold higher longitudinal (T(1 relaxivity, r(1, constant than the current FDA approved Gd-chelated contrast agents. Intravenous administration of these Gd-LNP at only 3% of the recommended clinical Gd dose produced MRI signal-to-noise ratios of greater than 300 in all vasculatures. Unlike current Gd contrast agents, these Gd-LNP stably retained Gd in normal vasculature, and are eliminated predominately through the biliary, instead of the renal system. Gd-LNP did not appear to accumulate in the liver or kidney, and was eliminated completely within 24 hrs.The novel Gd-nanoparticles provide high quality contrast enhanced vascular MRI at 97% reduced dose of Gd and do not rely on renal clearance. This new agent is likely to be suitable for patients exhibiting varying degrees of renal impairment. The simple and adaptive nanoparticle design could accommodate ligand or receptor coating for drug delivery optimization and in vivo drug

  18. The optimization of scan timing for contrast-enhanced magnetic resonance angiography

    International Nuclear Information System (INIS)

    Lee, Jong Min; Chang, Yong Min; Ryeom, Hun Kyu; Lee, Sang Kwon; Kim, Yong Sun; Kang, Duk Sik; Tirman, Philip J.

    2000-01-01

    To determine the optimal scan timing for contrast-enhanced magnetic resonance angiography and to evaluate a new timing method based on the arteriovenous circulation time. Eighty-nine contrast-enhanced magnetic resonance angiographic examinations were performed mainly in the extremities. A 1.5T scanner with a 3-D turbo-FLASH sequence was used, and during each study, two consecutive arterial phases and one venous phase were acquired. Scan delay time was calculated from the time-intensity curve by the traditional (n = 48) and/or the new (n = 41) method. This latter was based on arteriovenous circulation time rather than peak arterial enhancement time, as used in the traditional method. The numbers of first-phase images showing a properly enhanced arterial phase were compared between the two methods. Mean scan delay time was 5.4 sec longer with the new method than with the traditional. Properly enhanced first-phase images were found in 65% of cases (31/48) using the traditional timing method, and 95% (39/41) using the new method. When cases in which there was mismatch between the target vessel and the Time-intensity curve acquisition site are excluded, erroneous acquisition occurred in seven cases with the traditional method, but in none with the new method. The calculation of scan delay time on the basis of arteriovenous circulation time provides better timing for arterial phase acquisition than the traditional method

  19. Dynamic contrast-enhanced magnetic resonance imaging of the sarcopenic muscle

    Energy Technology Data Exchange (ETDEWEB)

    Nicolato, Elena; Farace, Paolo; Asperio, Roberto M; Marzola, Pasquina; Lunati, Ernesto; Sbarbati, Andrea; Osculati, Francesco [Dipartimento di Scienze Morfologico-Biomediche, Sezione di Anatomia ed Istologia, Università di Verona, Verona, I-37194 (Italy)

    2002-06-05

    Studies about capillarity of the aged muscle provided conflicting results and no data are currently available about the magnetic resonance imaging (MRI) in vivo characteristics of the microvascular bed in aged rats. We have studied age-related modifications of the skeletal muscle by in vivo T2-relaxometry and dynamic contrast-enhanced magnetic resonance imaging (CE-MRI) at high field intensity (4.7 T). The aim of the work was to test the hypothesis that the ageing process involves microvessels in skeletal muscle. The study was performed in 4-month-old (n = 6) and 20-month-old (n = 6) rats. At MRI examination, the relaxation time T2 of the gastrocnemius muscle showed no significant difference between these two groups. The kinetic of contrast penetration in the tissue showed that in 4-month-old rats the enhancement values of the signal intensity at different time-points were significantly higher than those found in senescent rats. The reported finding suggests that there is a modification of the microcirculatory function in skeletal muscle of aged rats. This work also demonstrates that CE-MRI allows for an in vivo quantification of the multiple biological processes involving the skeletal muscle during aging. Therefore, CE-MRI could represent a further tool for the follow up of tissue modification and therapeutic intervention both in patients with sarcopenia and in experimental models of this pathology.

  20. Dynamic contrast-enhanced magnetic resonance imaging of the sarcopenic muscle

    International Nuclear Information System (INIS)

    Nicolato, Elena; Farace, Paolo; Asperio, Roberto M; Marzola, Pasquina; Lunati, Ernesto; Sbarbati, Andrea; Osculati, Francesco

    2002-01-01

    Studies about capillarity of the aged muscle provided conflicting results and no data are currently available about the magnetic resonance imaging (MRI) in vivo characteristics of the microvascular bed in aged rats. We have studied age-related modifications of the skeletal muscle by in vivo T2-relaxometry and dynamic contrast-enhanced magnetic resonance imaging (CE-MRI) at high field intensity (4.7 T). The aim of the work was to test the hypothesis that the ageing process involves microvessels in skeletal muscle. The study was performed in 4-month-old (n = 6) and 20-month-old (n = 6) rats. At MRI examination, the relaxation time T2 of the gastrocnemius muscle showed no significant difference between these two groups. The kinetic of contrast penetration in the tissue showed that in 4-month-old rats the enhancement values of the signal intensity at different time-points were significantly higher than those found in senescent rats. The reported finding suggests that there is a modification of the microcirculatory function in skeletal muscle of aged rats. This work also demonstrates that CE-MRI allows for an in vivo quantification of the multiple biological processes involving the skeletal muscle during aging. Therefore, CE-MRI could represent a further tool for the follow up of tissue modification and therapeutic intervention both in patients with sarcopenia and in experimental models of this pathology

  1. Fast magnetic resonance fingerprinting for dynamic contrast-enhanced studies in mice.

    Science.gov (United States)

    Gu, Yuning; Wang, Charlie Y; Anderson, Christian E; Liu, Yuchi; Hu, He; Johansen, Mette L; Ma, Dan; Jiang, Yun; Ramos-Estebanez, Ciro; Brady-Kalnay, Susann; Griswold, Mark A; Flask, Chris A; Yu, Xin

    2018-05-09

    The goal of this study was to develop a fast MR fingerprinting (MRF) method for simultaneous T 1 and T 2 mapping in DCE-MRI studies in mice. The MRF sequences based on balanced SSFP and fast imaging with steady-state precession were implemented and evaluated on a 7T preclinical scanner. The readout used a zeroth-moment-compensated variable-density spiral trajectory that fully sampled the entire k-space and the inner 10 × 10 k-space with 48 and 4 interleaves, respectively. In vitro and in vivo studies of mouse brain were performed to evaluate the accuracy of MRF measurements with both fully sampled and undersampled data. The application of MRF to dynamic T 1 and T 2 mapping in DCE-MRI studies were demonstrated in a mouse model of heterotopic glioblastoma using gadolinium-based and dysprosium-based contrast agents. The T 1 and T 2 measurements in phantom showed strong agreement between the MRF and the conventional methods. The MRF with spiral encoding allowed up to 8-fold undersampling without loss of measurement accuracy. This enabled simultaneous T 1 and T 2 mapping with 2-minute temporal resolution in DCE-MRI studies. Magnetic resonance fingerprinting provides the opportunity for dynamic quantification of contrast agent distribution in preclinical tumor models on high-field MRI scanners. © 2018 International Society for Magnetic Resonance in Medicine.

  2. Dynamic contrast-enhanced magnetic resonance imaging of the sarcopenic muscle

    Directory of Open Access Journals (Sweden)

    Sbarbati Andrea

    2002-06-01

    Full Text Available Abstract Background Studies about capillarity of the aged muscle provided conflicting results and no data are currently available about the magnetic resonance imaging (MRI in vivo characteristics of the microvascular bed in aged rats. We have studied age-related modifications of the skeletal muscle by in vivo T2-relaxometry and dynamic contrast-enhanced magnetic resonance imaging (CE-MRI at high field intensity (4.7 T. The aim of the work was to test the hypothesis that the ageing process involves microvessels in skeletal muscle. Methods The study was performed in 4-month-old (n = 6 and 20-month-old (n = 6 rats. Results At MRI examination, the relaxation time T2 of the gastrocnemius muscle showed no significant difference between these two groups. The kinetic of contrast penetration in the tissue showed that in 4-month-old rats the enhancement values of the signal intensity at different time-points were significantly higher than those found in senescent rats. Conclusion The reported finding suggests that there is a modification of the microcirculatory function in skeletal muscle of aged rats. This work also demonstrates that CE-MRI allows for an in vivo quantification of the multiple biological processes involving the skeletal muscle during aging. Therefore, CE-MRI could represent a further tool for the follow up of tissue modification and therapeutic intervention both in patients with sarcopenia and in experimental models of this pathology.

  3. Magnetic resonance imaging of osteosarcoma using a bis(alendronate)-based bone-targeted contrast agent.

    Science.gov (United States)

    Ge, Pingju; Sheng, Fugeng; Jin, Yiguang; Tong, Li; Du, Lina; Zhang, Lei; Tian, Ning; Li, Gongjie

    2016-12-01

    Magnetic resonance (MR) is currently used for diagnosis of osteosarcoma but not well even though contrast agents are administered. Here, we report a novel bone-targeted MR imaging contrast agent, Gd 2 -diethylenetriaminepentaacetate-bis(alendronate) (Gd 2 -DTPA-BA) for the diagnosis of osteosarcoma. It is the conjugate of a bone cell-seeking molecule (i.e., alendronate) and an MR imaging contrast agent (i.e., Gd-DTPA). Its physicochemical parameters were measured, including pK a , complex constant, and T 1 relaxivity. Its bone cell-seeking ability was evaluated by measuring its adsorption on hydroxyapatite. Hemolysis was investigated. MR imaging and biodistribution of Gd 2 -DTPA-BA and Gd-DTPA were studied on healthy and osteosarcoma-bearing nude mice. Gd 2 -DTPA-BA showed high adsorption on hydroxyapatite, the high MR relaxivity (r 1 ) of 7.613mM -1 s -1 (2.6 folds of Gd-DTPA), and no hemolysis. The MR contrast effect of Gd 2 -DTPA-BA was much higher than that of Gd-DTPA after intravenous injection to the mice. More importantly, the MR imaging of osteosarcoma was significantly improved by Gd 2 -DTPA-BA. The signal intensity of Gd 2 -DTPA-BA reached 120.3% at 50min, equal to three folds of Gd-DTPA. The bone targeting index (bone/blood) of Gd 2 -DTPA-BA in the osteosarcoma-bearing mice was very high to 130 at 180min. Furthermore, the contrast enhancement could also be found in the lung due to metastasis of osteosarcoma. Gd 2 -DTPA-BA plays a promising role in the diagnoses of osteosacomas, including the primary bone tumors and metastases. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  4. Analysis of an automated background correction method for cardiovascular MR phase contrast imaging in children and young adults

    Energy Technology Data Exchange (ETDEWEB)

    Rigsby, Cynthia K.; Hilpipre, Nicholas; Boylan, Emma E.; Popescu, Andrada R.; Deng, Jie [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States); McNeal, Gary R. [Siemens Medical Solutions USA Inc., Customer Solutions Group, Cardiovascular MR R and D, Chicago, IL (United States); Zhang, Gang [Ann and Robert H. Lurie Children' s Hospital of Chicago Research Center, Biostatistics Research Core, Chicago, IL (United States); Choi, Grace [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Greiser, Andreas [Siemens AG Healthcare Sector, Erlangen (Germany)

    2014-03-15

    Phase contrast magnetic resonance imaging (MRI) is a powerful tool for evaluating vessel blood flow. Inherent errors in acquisition, such as phase offset, eddy currents and gradient field effects, can cause significant inaccuracies in flow parameters. These errors can be rectified with the use of background correction software. To evaluate the performance of an automated phase contrast MRI background phase correction method in children and young adults undergoing cardiac MR imaging. We conducted a retrospective review of patients undergoing routine clinical cardiac MRI including phase contrast MRI for flow quantification in the aorta (Ao) and main pulmonary artery (MPA). When phase contrast MRI of the right and left pulmonary arteries was also performed, these data were included. We excluded patients with known shunts and metallic implants causing visible MRI artifact and those with more than mild to moderate aortic or pulmonary stenosis. Phase contrast MRI of the Ao, mid MPA, proximal right pulmonary artery (RPA) and left pulmonary artery (LPA) using 2-D gradient echo Fast Low Angle SHot (FLASH) imaging was acquired during normal respiration with retrospective cardiac gating. Standard phase image reconstruction and the automatic spatially dependent background-phase-corrected reconstruction were performed on each phase contrast MRI dataset. Non-background-corrected and background-phase-corrected net flow, forward flow, regurgitant volume, regurgitant fraction, and vessel cardiac output were recorded for each vessel. We compared standard non-background-corrected and background-phase-corrected mean flow values for the Ao and MPA. The ratio of pulmonary to systemic blood flow (Qp:Qs) was calculated for the standard non-background and background-phase-corrected data and these values were compared to each other and for proximity to 1. In a subset of patients who also underwent phase contrast MRI of the MPA, RPA, and LPA a comparison was made between standard non

  5. Magnetic and relaxometric properties of polyethylenimine-coated superparamagnetic MRI contrast agents

    International Nuclear Information System (INIS)

    Corti, M.; Lascialfari, A.; Marinone, M.; Masotti, A.; Micotti, E.; Orsini, F.; Ortaggi, G.; Poletti, G.; Innocenti, C.; Sangregorio, C.

    2008-01-01

    Novel systems to be employed as superparamagnetic contrast agents (CA) for magnetic resonance imaging (MRI) have been synthesized. These compounds are composed of an iron oxide magnetic core coated by polyethylenimine (PEI) or carboxylated polyethylenimine (PEI-COOH). The aim of the present work was to prepare and study new nanostructured systems (with better or at least comparable relaxivities, R 1 and R 2 , with respect to the commercial ones) with controlled, almost monodisperse average dimensions and shape, as candidates for molecular targeting. By means of atomic force microscopy (AFM) measurements we determined the average diameter, of the order of 200 nm, and the shape of the particles. The superparamagnetic behavior was assessed by SQUID measurements. From X-ray data the estimated average diameters of the magnetic cores were found to be ∼5.8 nm for PEI-COOH60 and ∼20 nm for the compound named PEI25. By NMR-dispersion (NMRD), we found that PEI-COOH60 presents R 1 and R 2 relaxivities slightly lower than Endorem. The experimental results suggest that these novel compounds can be used as MRI CA

  6. A study on utility of magnetic resonance imaging for female pelvic cavity using enteral MRI contrast media

    International Nuclear Information System (INIS)

    Kim, Ham Gyum

    1997-01-01

    For radiological test in soft tissue or neighboring part with same signal intensity, proper test method and equipment shall be selected as needed. In case of female pelvic cavity, ultrasonography or computed tomography alternatively used, but MRI can be more usefully applied to design treatment method or operation plan by improving the diagnostic accuracy and careful observation of lesion characteristics. Magnetic Resonance Imaging using recently developed Enteral MRI contrast media can acquire more diagnostic information than using only intravenous contrast media. Thus this study attempted to examine the utility of anatomic structure and diagnostic acquisition by imaging the female pelvic cavity using Enteral MRI contrast media. As a result of analyzing magnetic resonance imaging after administering Enteral MRI contrast media to pelvic cavity suspect patients, more diagnostic information media could be acquired than only using intravenous contrast. Especially, in the diagnosis of lesion position, shape, distinction from neighboring tissues it is thought that external Enteral MRI contrast media should be used

  7. Longitudinal and transverse right ventricular function in pulmonary hypertension: cardiovascular magnetic resonance imaging study from the ASPIRE registry.

    Science.gov (United States)

    Swift, Andrew J; Rajaram, Smitha; Capener, Dave; Elliot, Charlie; Condliffe, Robin; Wild, Jim M; Kiely, David G

    2015-09-01

    Right ventricular (RV) function is a strong predictor of outcome in cardiovascular diseases. Two components of RV function, longitudinal and transverse motion, have been investigated in pulmonary hypertension (PH). However, their individual clinical significance remains uncertain. The aim of this study was to determine the factors associated with transverse and longitudinal RV motion in patients with PH. In 149 treatment-naive patients with PH and 16 patients with suspected PH found to have mean pulmonary arterial pressure of transverse motion (fractional septum to free wall distance [f-SFD]; P = 0.002). In patients without PH, no significant difference between f-SFD and f-TAAD was identified (P = 0.442). Longitudinal RV motion was singularly associated with RV ejection fraction independent of age, invasive hemodynamics, and cardiac magnetic resonance measurements (P = 0.024). In contrast, transverse RV motion was independently associated with left ventricular eccentricity (P = 0.036) in addition to RV ejection fraction (P = 0.014). In conclusion, RV motion is significantly greater in the longitudinal direction in patients with PH, whereas patients without PH have equal contributions of transverse and longitudinal motion. Longitudinal RV motion is primarily associated with global RV pump function in PH. Transverse RV motion not only reflects global pump function but is independently influenced by ventricular interaction in patients with PH.

  8. Contrast enhanced magnetic resonance imaging of the brain using gadolinium-DTPA

    International Nuclear Information System (INIS)

    Valk, J.; Slegte, R.G.M. de; Crezee, F.C.; Hazenberg, G.J.; Thjaha, S.I.; Nauta, J.J.P.; Vrije Univ., Amsterdam; Vrije Univ., Amsterdam; Vrije Univ., Amsterdam

    1987-01-01

    This report concerns a clinical trial with gadolinium-DTPA (Gd-DTPA) as an intravenous contrast medium for magnetic resonance imaging (MRI) in patients with disorders of the central nervous system. Fifty patients, 30 females and 20 males, were examined without and with Gd-GTPA. The contrast medium was well tolerated by all patients. The results of MRI scanning without and with Gd-DTPA and those obtained with computed tomography (CT) using intravenous contrast enhancement were compared. This investigation comprised mainly patients with intracranial tumors, multiple sclerosis, and nasopharyngeal tumors. The results may be summarized as follows: 1) MRI with Gd-DTPA (MRI+) gave better results than MRI without Gd as regards delineation of the lesion, blood vessels and edema in cerebral tumors, pituitary adenomas and acute forms of multiple sclerosis (MS). MRI+ was better than CT in 32 of the 50 cases examined; with intracerebral tumors it was better in 15 out of 18 cases. 3) MRI+ was always better than CT in patients with MS. In 3 out of 7 cases MRI demonstrated the acute MS lesions. 4) MRI+ seemed to have advantages also in nasopharyngeal tumors as ascertained from this limited experience. (orig.)

  9. PEGylated chitosan grafted with polyamidoaminedendron as tumor-targeted magnetic resonance imaging contrast agent

    International Nuclear Information System (INIS)

    Guangyue Zu; Xiaoyan Tong; Yi Cao; Ye Kuang; Yajie Zhang; Min Liu; Renjun Pei

    2017-01-01

    Macromolecular contrast agents labeled with targeting ligands are now receiving growing interest in tumor-targeted magnetic resonance imaging. In this study, a macromolecular contrast agent based on PEGylated chitosan was synthesized and characterized, and its application as an MRI contrast agent was then demonstrated both in vitro and in vivo. First, the chitosan backbone was partially grafted with poly(ethylene glycol), which was used to improve the in vivo stability, followed by modifying with azide groups. Second, alkynyl-terminated PAMAM dendron modified with gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) was synthesized and conjugated onto the chitosan backbone through click chemistry. Finally, the obtained mCA was further functionalized with folic acid to improve the target specificity. The obtained FA labeled mCA exhibited higher relaxivity (9.53 mM"-"1.s"-"1) relative to Gd-DTPA (4.25 mM"-"1.s"-"1) and showed negligible toxicity as determined by the WST assay. In vivo MRI results suggested that a relatively high signal enhancement was observed in the tumor region, which made it a promising candidate for tumor-targeted MRI CA. (authors)

  10. Interactive neonatal gastrointestinal magnetic resonance imaging using fruit juice as an oral contrast media

    International Nuclear Information System (INIS)

    Arthurs, Owen J; Graves, Martin J; Edwards, Andrea D; Joubert, Ilse; Set, Pat AK; Lomas, David J

    2014-01-01

    The objective was to evaluate the use of fruit juice with an interactive inversion recovery (IR) MR pulse sequence to visualise the gastrointestinal tract. We investigated the relaxation properties of 12 different natural fruit juices in vitro, to identify which could be used as oral contrast. We then describe our initial experience using an interactive MR pulse sequence to allow optimal visualisation after administering pineapple juice orally, and suppressing pre-existing bowel fluid contents, with variable TI in three adult and one child volunteer. Pineapple juice (PJ) had both the shortest T 1 (243 ms) and shortest T 2 (48 ms) of the fruit juices tested. Optimal signal differentiation between pre-existing bowel contents and oral PJ administration was obtained with TIs of between 900 and 1100 ms. The use of an inversion recovery preparation allowed long T 1 pre-existing bowel contents to be suppressed whilst the short T 1 of fruit juice acts as a positive contrast medium. Pineapple juice could be used as oral contrast agent for neonatal gastrointestinal magnetic resonance imaging

  11. Highly stabilized gadolinium chelates functionalized on metal nanoparticles as magnetic resonance imaging contrast agent

    Science.gov (United States)

    Siddiqui, Talha S.

    Magnetic resonance imaging (MRI) is a non-invasive method for imaging and diagnosing tissue damage, organ function and the vascular system. Magnevist(TM) a complex of diethylenetriaminepentaacetic acid (DTPA) and Gd3+ is a clinically approved contrast agent for MRI. A derivative of DTPA was formed by the addition of two cysteine groups (DTPA-L-Cys) through amide linkage. The Gd complex of this ligand bonds with the silver surfaces through the cysteine thiols. GdDTPA-L-Cys was bound to ˜10nm diameter Ag nanoparticles for use as a multifunctional MRI contrast agent. The ligand and complex were characterized by 1H and 13C NMR, ESI-MS and IR spectroscopy. The silver construct was characterized by TEM, TGA and UV-Vis absorption spectra. The per metal complex r1 relaxivity of GdDTPA-L-Cys{Ag} greater than that of Magnavist(TM) with the same molarity for both compounds. The synthesis of a DTPA derivative is described that allows it to bind to silver or gold nanoparticles through a single thiol linkage (DTPASH). The resulting Gd complex, GdDTPASH, was bound to Ag nanoparticles to create a single monolayer on the surface. The construct was further stabilized in buffered solution with the addition of a thiolated PEG chain. The highly stabilized nanoparticle construct delivers a high payload of Gd compelex and is an effective T1 brightening agent. The production of this type of construct opens the way for engineered multimodal MRI contrast agents.

  12. Clinical use of gadobutrol for contrast-enhanced magnetic resonance imaging of neurological diseases

    Directory of Open Access Journals (Sweden)

    Cheng KT

    2012-02-01

    Full Text Available Kenneth T Cheng1, Hannah Y Cheng2, Kam Leung31Department of Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD, USA; 2Freelance Technical Writer, New Orleans, LA, USA; 3National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USAAbstract: Contrast-enhanced magnetic resonance imaging (CE-MRI is an important clinical tool for diagnosing neurological diseases. The appropriate use of a suitable MRI contrast agent or contrast pharmaceutical is essential for CE-MRI to produce desirable diagnostic images. Currently, there are seven contrast agents (CAs or pharmaceuticals approved for clinical imaging of the central nervous system (CNS in the US, Europe, or Japan. All of the clinically approved CAs are water-soluble gadolinium-based contrast agents (GBCAs which do not penetrate the CNS blood–brain barrier (BBB. These agents are used for imaging CNS areas without a BBB, or various pathologies, such as tumors and infection that break down the BBB and allow CAs to enter into the surrounding parenchyma. Clinically, GBCAs are most useful for detecting primary and secondary cerebral neoplastic lesions. Among these CNS GBCAs, gadobutrol (Gd-BT-DO3A, Gadovist™ is a neutral, nonionic, macrocyclic compound that showed promising results from clinical trials of CNS imaging. In comparison with other GBCAs, Gd-BT-DO3A has relatively high in vitro kinetic stability and r1 relaxivity. Gd-BT-DO3A has been recently approved by the US Food and Drug Administration (FDA in 2011 for CNS imaging. A review of available literature shows that Gd-BT-DO3A exhibits similar safety and clinical efficacy profiles to other GBCAs. Gd-BT-DO3A has the distinguishing feature that it is the only clinical agent commercially available in a formulation of 1.0 M concentration with a relatively higher in vitro T1 shortening per unit volume than other clinical GBCAs which are only

  13. The progress in diagnostic imaging for staging of bladder and prostate cancer. Endorectal magnetic resonance imaging and magnetization transfer contrast

    International Nuclear Information System (INIS)

    Arima, Kiminobu; Hayashi, Norio; Yanagawa, Makoto; Kawamura, Juichi; Kobayashi, Shigeki; Takeda, Kan; Sugimura, Yoshiki

    1999-01-01

    We retrospectively studied the staging accuracy of endorectal magnetic resonance imaging (MRI) in comparison with transrectal ultrasound examination (TRUS) for 71 localized bladder cancers and 19 localized prostate cancers (PC) radically resected. The accuracy of clinical staging for bladder cancer in endorectal MRI and TRUS was 85.9% and 69.2%, respectively. The presence or absence of the continuity of submucosal enhancement on T2-weighted MRI images could be useful for the staging of bladder cancer. The accuracy of the seminal vesicular invasion for prostate cancer in endorectal MRI and TRUS was 95% and 63%, respectively. To determine whether magnetization transfer contrast (MTC) provides additional information in the diagnosis of prostate cancer, the magnetization transfer ratios (MTRs) were calculated in 22 patients with PC, 5 with benign prostatic hyperplasia (BPH) and 4 controls. The mean MTR in the peripheral zone of the normal prostate (8.0%±3.4 [standard deviation]) showed a statistically significant decrease relative to that in the inner zone of the normal prostate (27.4%±3.4, p<0.01), BPH (25.5%±3.7, p<0.01), pre-treatment PC (30.6%±5.9, p<0.01), and PC after hormonal therapy (20.3%±6.3, p<0.01). The mean MTR in pre-treatment PC was significantly higher than that in BPH, or in PC after hormonal therapy (p<0.01). MTC was considered to be useful for conspicuity of prostate cancer lesion. (author)

  14. Dobutamine cardiovascular magnetic resonance for the detection of myocardial ischemia with the use of myocardial tagging.

    Science.gov (United States)

    Kuijpers, Dirkjan; Ho, Kai Yiu J A M; van Dijkman, Paul R M; Vliegenthart, Rozemarijn; Oudkerk, Matthijs

    2003-04-01

    The purpose of this study was to assess the value of high-dose dobutamine cardiovascular magnetic resonance (CMR) with myocardial tagging for the detection of wall motion abnormalities as a measure of myocardial ischemia in patients with known or suspected coronary artery disease. Two hundred eleven consecutive patients with chest pain underwent dobutamine-CMR 4 days after antianginal medication was stopped. Dobutamine-CMR was performed at rest and during increasing doses of dobutamine. Cine-images were acquired during breath-hold with and without myocardial tagging at 3 short-axis levels. Regional wall motion was assessed in a 16-segment short-axis model. Patients with new wall motion abnormalities (NWMA) were examined by coronary angiography. Dobutamine-CMR was successfully performed in 194 patients. Dobutamine-CMR without tagging detected NWMA in 58 patients, whereas NWMA were detected in 68 patients with tagging (P=0.002, McNemar). Coronary angiography showed coronary artery disease in 65 (96%) of these 68 patients. All but 3 of the 65 patients needed revascularization. In the 112 patients with a negative dobutamine-CMR study, without baseline wall motion abnormalities, the cardiovascular occurrence-free survival rate was 98.2% during the mean follow-up period of 17.3 months (range, 7 to 31). Dobutamine-CMR with myocardial tagging detected more NWMA compared with dobutamine-CMR without tagging and reliably separated patients with a normal life expectancy from those at increased risk of major adverse cardiac events.

  15. Performance characteristics of magnetic resonance imaging without contrast agents or sedation in pediatric appendicitis

    Energy Technology Data Exchange (ETDEWEB)

    Didier, Ryne A.; Hopkins, Katharine L.; Coakley, Fergus V.; Foster, Bryan R. [Oregon Health and Science University, Department of Diagnostic Radiology, Portland, OR (United States); Krishnaswami, Sanjay [Oregon Health and Science University, Department of Surgery, Portland, OR (United States); Oregon Health and Science University, Department of Pediatrics, Portland, OR (United States); Spiro, David M. [Oregon Health and Science University, Department of Pediatrics, Portland, OR (United States)

    2017-09-15

    Magnetic resonance imaging (MRI) has emerged as a promising modality for evaluating pediatric appendicitis. However optimal imaging protocols, including roles of contrast agents and sedation, have not been established and diagnostic criteria have not been fully evaluated. To investigate performance characteristics of rapid MRI without contrast agents or sedation in the diagnosis of pediatric appendicitis. We included patients ages 4-18 years with suspicion of appendicitis who underwent rapid MRI between October 2013 and March 2015 without contrast agent or sedation. After two-radiologist review, we determined performance characteristics of individual diagnostic criteria and aggregate diagnostic criteria by comparing MRI results to clinical outcomes. We used receiver operating characteristic (ROC) curves to determine cut-points for appendiceal diameter and wall thickness for optimization of predictive power, and we calculated area under the curve (AUC) as a measure of test accuracy. Ninety-eight MRI examinations were performed in 97 subjects. Overall, MRI had a 94% sensitivity, 95% specificity, 91% positive predictive value and 97% negative predictive value. Optimal cut-points for appendiceal diameter and wall thickness were ≥7 mm and ≥2 mm, respectively. Independently, those cut-points produced sensitivities of 91% and 84% and specificities of 84% and 43%. Presence of intraluminal fluid (30/33) or localized periappendiceal fluid (32/33) showed a significant association with acute appendicitis (P<0.01), with sensitivities of 91% and 97% and specificities of 60% and 50%. For examinations in which the appendix was not identified by one or both reviewers (23/98), the clinical outcome was negative. Rapid MRI without contrast agents or sedation is accurate for diagnosis of pediatric appendicitis when multiple diagnostic criteria are considered in aggregate. Individual diagnostic criteria including optimized cut-points of ≥7 mm for diameter and ≥2 mm for wall

  16. Performance characteristics of magnetic resonance imaging without contrast agents or sedation in pediatric appendicitis

    International Nuclear Information System (INIS)

    Didier, Ryne A.; Hopkins, Katharine L.; Coakley, Fergus V.; Foster, Bryan R.; Krishnaswami, Sanjay; Spiro, David M.

    2017-01-01

    Magnetic resonance imaging (MRI) has emerged as a promising modality for evaluating pediatric appendicitis. However optimal imaging protocols, including roles of contrast agents and sedation, have not been established and diagnostic criteria have not been fully evaluated. To investigate performance characteristics of rapid MRI without contrast agents or sedation in the diagnosis of pediatric appendicitis. We included patients ages 4-18 years with suspicion of appendicitis who underwent rapid MRI between October 2013 and March 2015 without contrast agent or sedation. After two-radiologist review, we determined performance characteristics of individual diagnostic criteria and aggregate diagnostic criteria by comparing MRI results to clinical outcomes. We used receiver operating characteristic (ROC) curves to determine cut-points for appendiceal diameter and wall thickness for optimization of predictive power, and we calculated area under the curve (AUC) as a measure of test accuracy. Ninety-eight MRI examinations were performed in 97 subjects. Overall, MRI had a 94% sensitivity, 95% specificity, 91% positive predictive value and 97% negative predictive value. Optimal cut-points for appendiceal diameter and wall thickness were ≥7 mm and ≥2 mm, respectively. Independently, those cut-points produced sensitivities of 91% and 84% and specificities of 84% and 43%. Presence of intraluminal fluid (30/33) or localized periappendiceal fluid (32/33) showed a significant association with acute appendicitis (P<0.01), with sensitivities of 91% and 97% and specificities of 60% and 50%. For examinations in which the appendix was not identified by one or both reviewers (23/98), the clinical outcome was negative. Rapid MRI without contrast agents or sedation is accurate for diagnosis of pediatric appendicitis when multiple diagnostic criteria are considered in aggregate. Individual diagnostic criteria including optimized cut-points of ≥7 mm for diameter and ≥2 mm for wall

  17. Chitosan-coated nickel-ferrite nanoparticles as contrast agents in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Ahmad, Tanveer; Bae, Hongsub; Iqbal, Yousaf; Rhee, Ilsu; Hong, Sungwook; Chang, Yongmin; Lee, Jaejun; Sohn, Derac

    2015-01-01

    We report evidence for the possible application of chitosan-coated nickel-ferrite (NiFe 2 O 4 ) nanoparticles as both T 1 and T 2 contrast agents in magnetic resonance imaging (MRI). The coating of nickel-ferrite nanoparticles with chitosan was performed simultaneously with the synthesis of the nickel-ferrite nanoparticles by a chemical co-precipitation method. The coated nanoparticles were cylindrical in shape with an average length of 17 nm and an average width of 4.4 nm. The bonding of chitosan onto the ferrite nanoparticles was confirmed by Fourier transform infrared spectroscopy. The T 1 and T 2 relaxivities were 0.858±0.04 and 1.71±0.03 mM −1 s −1 , respectively. In animal experimentation, both a 25% signal enhancement in the T 1 -weighted mage and a 71% signal loss in the T 2 -weighted image were observed. This demonstrated that chitosan-coated nickel-ferrite nanoparticles are suitable as both T 1 and T 2 contrast agents in MRI. We note that the applicability of our nanoparticles as both T 1 and T 2 contrast agents is due to their cylindrical shape, which gives rise to both inner and outer sphere processes of nanoparticles. - Highlights: • Chitosan-coated nickel-ferrite (Ni-Fe 2 O 4 ) nanoparticles were synthesized in an aqueous system by chemical co-precipitation. • The characterization of bare and chitosan-coated nanoparticles were performed using various analytical tools, such as TEM, FTIR, XRD, and VMS. • We evaluated the coated particles as potential T 1 and T 2 contrast agents for MRI by measuring T 1 and T 2 relaxation times as a function of iron concentration. • Both T 1 and T 2 effects were also observed in animal experimentation

  18. Cardiovascular magnetic resonance imaging in the assessment of carcinoid heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Sandmann, H.; Pakkal, M. [Queen Elizabeth Hospital, Birmingham (United Kingdom); Steeds, R. [Queen Elizabeth Hospital, Birmingham (United Kingdom)], E-mail: rick.steeds@uhb.nhs.uk

    2009-08-15

    Carcinoid disease arises from a low-grade neuroendocrine tumour derived from serotonin-producing enterochromaffin cells. It is the most common tumour affecting the small bowel. The majority of patients who progress to carcinoid syndrome develop cardiac disease selectively involving the right side of the heart, whereas left heart disease is unusual. The most common cause of death is dilatation and dysfunction of the right ventricle. Right ventricular dysfunction is largely secondary to pathological endocardial fibrosis of the tricuspid and pulmonary valves, presenting with regurgitation and stenosis. Average survival falls to only 11 months with the onset of symptoms, but recent evidence suggests that survival can be improved by early surgery in selected individuals. This article reviews the particular role that cardiovascular magnetic resonance imaging has in the management of carcinoid heart disease.

  19. Cardiovascular magnetic resonance in the follow-up of patients with corrected tetralogy of Fallot: a review

    NARCIS (Netherlands)

    Oosterhof, Thomas; Mulder, Barbara J. M.; Vliegen, Hubert W.; de Roos, Albert

    2006-01-01

    Cardiovascular magnetic resonance (CMR) is becoming an important tool in the clinical management of patients with congenital heart disease. Because of the diverse problems patients may face after initial correction for tetralogy of Fallot and the large amount of CMR techniques that can be applied,

  20. Cardiovascular Magnetic Resonance T2-STIR Imaging is Unable to Discriminate Between Intramyocardial Haemorrhage and Microvascular Obstruction

    DEFF Research Database (Denmark)

    Søvsø Szocska Hansen, Esben; Pedersen, Steen Fjord; Pedersen, Steen Bønløkke

    2015-01-01

    Recent studies have used cardiovascular magnetic resonance (CMR) and T2-weighted short tau inversion recovery (T2-STIR) imaging to detect intramyocardial haemorrhage (IMH) as a measure of ischemic/reperfusion injury. We investigated the ability of T2-STIR to differentiate between microvascular...

  1. Imaging vascular function for early stage clinical trials using dynamic contrast-enhanced magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Leach, M.O.; Orton, M. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Cancer Research UK and EPSRC Cancer Imaging Centre, Sutton, Surrey (United Kingdom); Morgan, B. [Univ. of Leicester, College of Medicine, Biological Sciences and Psychology, Leicester (United Kingdom); Tofts, P.S. [Brighton and Sussex Medical School, Univ. of Sussex, Clinical Imaging Sciences Centre, Sussex (United Kingdom); Buckley, D.L. [University of Leeds, Division of Medical Physics, Leeds (United Kingdom); Huang, W. [Oregon Health and Science Univ., Advanced Imaging Research Centre, Portland, OR (United States); Horsfield, M.A. [Medical Physics Section, Leicester Royal Infirmary, Dept. of Cardiovascular Sciences, Leicester (United Kingdom); Chenevert, T.L. [Univ. of Michigan Health System, Ann Arbor, MI (United States); Collins, D.J. [Royal Marsden Hospital NHS Foundation Trust, Cancer Research UK and EPSRC Cancer Imaging Centre, Sutton, Surrey (United Kingdom); Jackson, A. [Univ. of Manchester, Wolfson Molecular Imaging Centre, Withington, Manchester, M20 3LJ (United Kingdom); Lomas, D. [Univ. of Cambridge, Dept. of Radiology, Cambridge (United Kingdom); Whitcher, B. [Unit 2 Greenways Business Park, Mango Solutions, Chippenham (United Kingdom); Clarke, L. [Cancer Imaging Program, Imaging Technology Development Branch, Rockville, MD (United States); Plummer, R. [Univ. of Newcastle Upon Tyne, The Medical School, Medical Oncology, Northern Inst. for Cancer Research, Newcastle Upon Tyne (United Kingdom); Judson, I. [Royal Marsden Hospital, Sutton, Surrey (United Kingdom); Jones, R. [Beatson West of Scotland Cancer Centre, Glasgow (United Kingdom); Alonzi, R. [Mount Vernon Cancer Centre, Northwood (United Kingdom); Brunner, T. [Gray Inst. for Radiation, Oncology and Biology, Oxford (United Kingdom); Koh, D.M. [Royal Marsden NHS Foundation Trust, Diagnostic Radiology, Sutton, Surrey (United Kingdom)] [and others

    2012-07-15

    Many therapeutic approaches to cancer affect the tumour vasculature, either indirectly or as a direct target. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has become an important means of investigating this action, both pre-clinically and in early stage clinical trials. For such trials, it is essential that the measurement process (i.e. image acquisition and analysis) can be performed effectively and with consistency among contributing centres. As the technique continues to develop in order to provide potential improvements in sensitivity and physiological relevance, there is considerable scope for between-centre variation in techniques. A workshop was convened by the Imaging Committee of the Experimental Cancer Medicine Centres (ECMC) to review the current status of DCE-MRI and to provide recommendations on how the technique can best be used for early stage trials. This review and the consequent recommendations are summarised here. (orig.)

  2. Turbulent stress measurements with phase-contrast magnetic resonance through tilted slices

    Energy Technology Data Exchange (ETDEWEB)

    MacKenzie, Jordan; Soederberg, Daniel; Lundell, Fredrik [Linne FLOW Centre, KTH Mechanics, Stockholm (Sweden); Swerin, Agne [SP Technical Research Institute of Sweden-Chemistry, Materials and Surfaces, Stockholm (Sweden); KTH Royal Institute of Technology, Surface and Corrosion Science, Stockholm (Sweden)

    2017-05-15

    Aiming at turbulent measurements in opaque suspensions, a simplistic methodology for measuring the turbulent stresses with phase-contrast magnetic resonance velocimetry is described. The method relies on flow-compensated and flow-encoding protocols with the flow encoding gradient normal to the slice. The experimental data is compared with direct numerical simulations (DNS), both directly but also, more importantly, after spatial averaging of the DNS data that resembles the measurement and data treatment of the experimental data. The results show that the most important MRI data (streamwise velocity, streamwise variance and Reynolds shear stress) is reliable up to at least anti r = 0.75 without any correction, paving the way for dearly needed turbulence and stress measurements in opaque suspensions. (orig.)

  3. Evaluation of potential practical oral contrast agents for pediatric magnetic resonance imaging

    International Nuclear Information System (INIS)

    Bisset, G.S. III; Cincinnati Univ., OH; Children's Hospital Medical Center, Cincinnati, OH

    1989-01-01

    Development of a practical oral contrast agent for magnetic resonance imaging is necessary to improve differentiation of bowel from adjacent structures. In order to find a readily available, inexpensive, non-toxic, palatable solution for use in the pediatric population, several formulas, milk products and a common oral sedative were evaluated in vitro. T1, T2 and signal intensity measurements were performed on a 1.5 T system. Similac with standard iron proved to be a useful high signal intensity agent on multiple pulse sequences. Early in vivo experience in four normal volunteers indicates that this agent provides excellent delineation of the stomach and duodenum from contiguous viscera. Distal small bowel visualization is less predictabel. Further clinical trials should confirm the utility of this solution, which contains a combination of iron salts and paramagnetic metallic ions. (orig.)

  4. Reliability and responsiveness of dynamic contrast-enhanced magnetic resonance imaging in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Axelsen, M.B.; Poggenborg, R.P.; Stoltenberg, M.

    2013-01-01

    intraarticular injection with 80 mg methylprednisolone. Using semi-automated image processing software, DCE-MRI parameters, including the initial rate of enhancement (IRE) and maximal enhancement (ME), were generated for three regions of interest (ROIs): ‘Whole slice’, ‘Quick ROI’, and ‘Precise ROI......Objectives: To investigate the responsiveness to treatment and the reliability of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in rheumatoid arthritis (RA) knee joints. Methods: DCE-MRI was performed in 12 clinically active RA knee joints before and 1, 7, 30, and 180 days after......’. The smallest detectable difference (SDD), the smallest detectable change (SDC), and intra- and inter-reader intraclass correlation coefficients (ICCs) were used to assess the reliability of DCE-MRI. Responsiveness to treatment was assessed by the standardized response mean (SRM). Results: In all patients...

  5. Magnetization transfer contrast on gradient echo MR imaging of the temporomandibular joint

    International Nuclear Information System (INIS)

    Niitsu, M.; Hirohata, H.; Yoshioka, H.; Anno, I.; Campeau, N.G.; Itai, Y.

    1995-01-01

    Thirty-nine temporomandibular joints (TMJ) from 20 patients with suspected internal derangements were imaged by a 1.5 T MR imager. The on-resonance binomial magnetization transfer contrast (MTC) pulse was applied to gradient echo images with a dual receiver coil (9 s/section). With the use of an opening device, a series of sequential images were obtained at increments of mouth opening and closing. The tissue signal intensities with (Ms) and without (Mo) MTC were measured and subjective image analysis was performed. Compared with the standard images, MTC technique provided selective signal suppression of disks. The average of Ms/Mo ratio of the disks (0.56) was lower than that of the retrodiskal pad (0.79) and of the effusion (0.89). With MTC technique, fluid conspicuity was superior to standard image. However, no significant superiority was found in disk definition subjectively. (orig.)

  6. 3D Modeling of Vascular Pathologies from contrast enhanced magnetic resonance images (MRI)

    International Nuclear Information System (INIS)

    Cantor Rivera, Diego; Orkisz, Maciej; Arias, Julian; Uriza, Luis Felipe

    2007-01-01

    This paper presents a method for generating 3D vascular models from contrast enhanced magnetic resonance images (MRI) using a fast marching algorithm. The main contributions of this work are: the use of the original image for defining a speed function (which determines the movement of the interface) and the calculation of the time in which the interface identifies the artery. The proposed method was validated on pathologic carotid artery images of patients and vascular phantoms. A visual appraisal of vascular models obtained with the method shows a satisfactory extraction of the vascular wall. A quantitative assessment proved that the generated models depend on the values of algorithm parameters. The maximum induced error was equal to 1.34 voxels in the diameter of the measured stenoses.

  7. Current status of superparamagnetic iron oxide contrast agents for liver magnetic resonance imaging.

    Science.gov (United States)

    Wang, Yi-Xiang J

    2015-12-21

    Five types of superparamagnetic iron oxide (SPIO), i.e. Ferumoxides (Feridex(®) IV, Berlex Laboratories), Ferucarbotran (Resovist(®), Bayer Healthcare), Ferumoxtran-10 (AMI-227 or Code-7227, Combidex(®), AMAG Pharma; Sinerem(®), Guerbet), NC100150 (Clariscan(®), Nycomed,) and (VSOP C184, Ferropharm) have been designed and clinically tested as magnetic resonance contrast agents. However, until now Resovist(®) is current available in only a few countries. The other four agents have been stopped for further development or withdrawn from the market. Another SPIO agent Ferumoxytol (Feraheme(®)) is approved for the treatment of iron deficiency in adult chronic kidney disease patients. Ferumoxytol is comprised of iron oxide particles surrounded by a carbohydrate coat, and it is being explored as a potential imaging approach for evaluating lymph nodes and certain liver tumors.

  8. Dynamic susceptibility contrast magnetic resonance imaging in neuropsychiatry: present utility and future promise

    International Nuclear Information System (INIS)

    Renshaw, P.F.; Levin, J.M.; Kaufman, M.J.; Ross, M.H.; Lewis, R.F.; Harris, G.J.

    1997-01-01

    Dynamic susceptibility contrast magnetic resonance imaging (DSC MRI) provides a noninvasive means to create high resolution maps of the regional distribution of cerebral blood volume (CBV). Most DSC MRI studies conducted to date have focused on the evaluation of patients with cerebral neoplasms, ischemia or infarction, and epilepsy. However, preliminary work suggests that DSC MRI may also provide clinically important information for the evaluation of patients with neuropsychiatric disorders, especially dementia and schizophrenia. Additionally, with appropriate modification, DSC MRI may be used to reliably evaluate the effects of pharmacological challenges on cerebral hemodynamics. As pharmacotherapy is an important component in the treatment of a range of psychiatric disorders, the dynamic assessment of changes in cerebral perfusion associated with drug administration may ultimately lead to the development of ''brain function tests'' for a wide range of disorders. (orig.)

  9. Biocompatible KMnF3 nanoparticular contrast agent with proper plasma retention time for in vivo magnetic resonance imaging.

    Science.gov (United States)

    Liu, Zhi-jun; Song, Xiao-xia; Xu, Xian-zhu; Tang, Qun

    2014-04-18

    Nanoparticular MRI contrast agents are rapidly becoming suitable for use in clinical diagnosis. An ideal nanoparticular contrast agent should be endowed with high relaxivity, biocompatibility, proper plasma retention time, and tissue-specific or tumor-targeting imaging. Herein we introduce PEGylated KMnF3 nanoparticles as a new type of T1 contrast agent. Studies showed that the nanoparticular contrast agent revealed high bio-stability with bovine serum albumin in PBS buffer solution, and presented excellent biocompatibility (low cytotoxicity, undetectable hemolysis and hemagglutination). Meanwhile the new contrast agent possessed proper plasma retention time (circulation half-life t1/2 is approximately 2 h) in the body of the administrated mice. It can be delivered into brain vessels and maintained there for hours, and is mostly cleared from the body within 48 h, as demonstrated by time-resolved MRI and Mn-biodistribution analysis. Those distinguishing features make it suitable to obtain contrast-enhanced brain magnetic resonance angiography. Moreover, through the process of passive targeting delivery, the T1 contrast agent clearly illuminates a brain tumor (glioma) with high contrast image and defined shape. This study demonstrates that PEGylated KMnF3 nanoparticles represent a promising biocompatible vascular contrast agent for magnetic resonance angiography and can potentially be further developed into an active targeted tumor MRI contrast agent.

  10. Use of contrast media in computed tomography and magnetic resonance imaging in horses: Techniques, adverse events and opportunities.

    Science.gov (United States)

    Nelson, B B; Goodrich, L R; Barrett, M F; Grinstaff, M W; Kawcak, C E

    2017-07-01

    The use of contrast media in computed tomography (CT) and magnetic resonance imaging (MRI) is increasing in horses. These contrast-enhanced imaging techniques provide improved tissue delineation and evaluation, thereby expanding diagnostic capabilities. While generally considered safe, not all contrast media exhibit the same safety profiles. The safety of contrast media use and descriptions of adverse events occurring in horses are sparsely reported. This review summarises the reported evidence of contrast media use and adverse events that occur in horses, with added contribution from other veterinary species and studies in man for comparison. This comprehensive data set empowers equine clinicians to develop use and monitoring strategies when working with contrast media. Finally, it summarises the current state-of-the-art and highlights the potential applications of contrast-enhanced CT and MRI for assessment of diseased or injured equine tissues, as well as (patho)physiological processes. © 2017 EVJ Ltd.

  11. Extent of myocardium at risk for left anterior descending artery, right coronary artery, and left circumflex artery occlusion depicted by contrast-enhanced steady state free precession and T2-weighted short tau inversion recovery magnetic resonance imaging

    DEFF Research Database (Denmark)

    Nordlund, David; Heiberg, Einar; Carlsson, Marcus

    2016-01-01

    Background - Contrast-enhanced steady state free precession (CE-SSFP) and T2-weighted short tau inversion recovery (T2-STIR) have been clinically validated to estimate myocardium at risk (MaR) by cardiovascular magnetic resonance while using myocardial perfusion single-photon emission computed...... tomography as reference standard. Myocardial perfusion single-photon emission computed tomography has been used to describe the coronary perfusion territories during myocardial ischemia. Compared with myocardial perfusion single-photon emission computed tomography, cardiovascular magnetic resonance offers...... to show the main coronary perfusion territories using CE-SSFP and T2-STIR. The good agreement between CE-SSFP and T2-STIR from this study and myocardial perfusion single-photon emission computed tomography from previous studies indicates that these 3 methods depict MaR accurately in individual patients...

  12. Acute myocardial ischemia: magnetic resonance contrast enhancement with gadolinium-DTPA

    International Nuclear Information System (INIS)

    McNamara, M.T.; Higgins, C.B.; Ehman, R.L.; Revel, D.; Sievers, R.; Brasch, R.C.

    1984-01-01

    Gadolinium-DTPA (Gd-DTPA) was used to improve the diagnostic utility of magnetic resonance (MR) in detecting early ischemia, before the onset of infarction. Following one minute of left anterior descending coronary artery occlusion, 9 dogs were intraveneously injected with either 0.5 mM/kg of Gd-DTPA (6 dogs) or normal saline (3 dogs). There was no visible difference in intensity or alterations in magnetic relaxation times between normal and ischemic myocardium in the control (saline-injected) animals. The Gd-DTPA-injected dogs had a well-defined segment of high intensity representing the ischemic myocardium in the anterior wall of the left ventricle. Both T1 and T2 were significantly shortened in the normal myocardium of the Gd-DTPA animals, but relatively greater T2 relaxation rate enhancement resulted in reduced intensity of normal myocardium, thus increasing contrast with ischemic myocardium. It is concluded that Gd-DTPA has the potential to expand the sensitivity and diagnostic utility of MR in the study of occlusive coronary artery disease

  13. Magnetic resonance angiography with blood-pool contrast agents: future applications

    Energy Technology Data Exchange (ETDEWEB)

    Fink, C. [Univ. Hospitals, Grosshadern, Munich (Germany); Goyen, M. [Univ. Medical Center, Hamburg-Eppendorf, Hamburg (Germany); Lotz, J. [Hannover Medical School, Hannover (Germany)

    2007-03-15

    Blood pool agents remain in the intravascular space for a longer time period. Therefore the optimal imaging window for vascular structures is widened to about 30 minutes. Gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany) is the first blood-pool contrast agent approved in Europe for contrast-enhanced magnetic resonance angiography (MRA) of vessels in the abdomen, pelvis and lower extremity in adults. Other possible applications of blood-pool agents are now being considered, such as assessment of venous thromboembolism, coronary artery disease or sinus venous thrombosis. Perfusion MR imaging holds promise for detecting lung perfusion defects with higher spatial resolution and reduced scan time compared with radionuclide scintigraphy. In coronary artery disease, blood-pool agents enable a substantial increase in the quality of coronary artery imaging. Quantitative myocardial perfusion and myocardial viability seem to be possible, although modifications in protocols and sequence design are necessary for optimal results. Other novel applications of blood-pool agents include monitoring of inflammatory changes in systemic lupus erythematosus and evaluation of tumour invasion into lymph nodes and more reliable assessment of cerebral venous and sinus thrombosis. (orig.)

  14. Magnetic resonance angiography with blood-pool contrast agents: future applications

    International Nuclear Information System (INIS)

    Fink, C.; Goyen, M.; Lotz, J.

    2007-01-01

    Blood pool agents remain in the intravascular space for a longer time period. Therefore the optimal imaging window for vascular structures is widened to about 30 minutes. Gadofosveset trisodium (Vasovist, Bayer Schering Pharma AG, Berlin, Germany) is the first blood-pool contrast agent approved in Europe for contrast-enhanced magnetic resonance angiography (MRA) of vessels in the abdomen, pelvis and lower extremity in adults. Other possible applications of blood-pool agents are now being considered, such as assessment of venous thromboembolism, coronary artery disease or sinus venous thrombosis. Perfusion MR imaging holds promise for detecting lung perfusion defects with higher spatial resolution and reduced scan time compared with radionuclide scintigraphy. In coronary artery disease, blood-pool agents enable a substantial increase in the quality of coronary artery imaging. Quantitative myocardial perfusion and myocardial viability seem to be possible, although modifications in protocols and sequence design are necessary for optimal results. Other novel applications of blood-pool agents include monitoring of inflammatory changes in systemic lupus erythematosus and evaluation of tumour invasion into lymph nodes and more reliable assessment of cerebral venous and sinus thrombosis. (orig.)

  15. Initial study of magnetization transfer contrast MR imaging of the knee at 3 Tesla

    Energy Technology Data Exchange (ETDEWEB)

    Yoshioka, Hiroshi; Echigo, Junko; Niitsu, Mamoru; Anno, Izumi; Itai, Yuji [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine; Nakai, Toshiharu; Sato, Hiroshi; Tsukamoto, Tetsuji

    1998-10-01

    It has been reported that various image sequences, including magnetization transfer contrast (MTC) were effective in evaluating articular cartilage. It is difficult to identify cartilaginous structures, however, using conventional MR imaging because of low spatial resolution and low signal-to-noise (S/N) ratio. The purpose of the present study was to evaluate the optimal imaging sequences with MTC pulse at 3 T and to assess the feasibility of the clinical application thereof. Five porcine knees were studied using varying imaging parameters (frequency offset, flip angle (FA) and echo time (TE)) combined with off-resonance sinc radiation pulses. The effect of MTC was analyzed by dividing the signal intensity of MTC GRE images by that of conventional GRE images (Ms/Mo). MTC images were obtained with a low specific absorption rate (SAR). With an offset frequency of 1.5 kHz (repetition time/TE/FA=60 ms/8 ms/30 degrees), the mean Ms/Mo of articular cartilage and meniscus was 0.70 and 0.65, respectively. An FA of 20 to 30 degrees and a TE of 11 to 12 ms appear to be optimal parameters at 3 T with MTC pulse because of the higher S/N ratio of cartilage and higher contrast-to-noise ratio of cartilage relative to that of distilled water. These findings suggest that MTC at 3 T may be feasible and effective for assessment of cartilage and meniscus in clinical applications. (author)

  16. Characterization of colloidal manganese hydroxylapatite: A potential magnetic resonance contrast agent

    Science.gov (United States)

    Dorshow, Richard B.; Kofi Adzamli, I.; Nosco, Dennis L.; Joslin, Frederick L.

    1996-03-01

    Particulate contrast agents for blood pool imaging need to be constructed with the appropriate particle size distribution (PSD), and need to be resistant to opsonization. Hence, the PSD of an aqueous colloidal suspension of polyethylene glycol (PEG)-stabilized manganese hydroxylapatite (potentially useful as a magnetic resonance contrast agent for blood pool imaging) has been investigated as a function of PEG concentration and molecular weight. At low PEG concentrations, dynamic light scattering (DLS) and sedimentation field flow fractionation measurements yield a broad PSD, with the largest particle diameters near 100nm. Flow field flow fractionation (FlFFF) measurements, however, yield a distinct population near 10nm, which is not readily detectable by the other two techniques. As the PEG concentration is increased, the PSD shifts toward the lower size population. At the highest PEG concentration employed, only particles of diameter 10nm remain, verified by both FlFFF and DLS. Thus, the search for an optimum PSD for blood pool imaging is facilitated by choice of PEG molecular weight and concentration, and by employing complementary use of light scattering and field flow fractionation techniques.

  17. A Novel Polyacrylamide Magnetic Nanoparticle Contrast Agent for Molecular Imaging using MRI

    Directory of Open Access Journals (Sweden)

    Bradford A. Moffat

    2003-10-01

    Full Text Available A novel Polyacrylamide superparamagnetic iron oxide nanoparticle platform is described which has been synthetically prepared such that multiple crystals of iron oxide are encapsulated within a single Polyacrylamide matrix (PolyAcrylamide Magnetic [PAM] nanoparticles. This formulation provides for an extremely large T2 and T2* relaxivity of between 620 and 1140 sec−1 mM−1. Administration of PAM nanoparticles into rats bearing orthotopic 9L gliomas allowed quantitative pharmacokinetic analysis of the uptake of nanoparticles in the vasculature, brain, and glioma. Addition of polyethylene glycol of varying sizes (0.6, 2, and 10 kDa to the surface of the PAM nanoparticles resulted in an increase in plasma half-life and affected tumor uptake and retention of the nanoparticles as quantified by changes in tissue contrast using MRI. The flexible formulation of these nanoparticles suggests that future modifications could be accomplished allowing for their use as a targeted molecular imaging contrast agent and/or therapeutic platform for multiple indications.

  18. Cross-linkable liposomes stabilize a magnetic resonance contrast-enhancing polymeric fastener.

    Science.gov (United States)

    Smith, Cartney E; Kong, Hyunjoon

    2014-04-08

    Liposomes are commonly used to deliver drugs and contrast agents to their target site in a controlled manner. One of the greatest obstacles in the performance of such delivery vehicles is their stability in the presence of serum. Here, we demonstrate a method to stabilize a class of liposomes that load gadolinium, a magnetic resonance (MR) contrast agent, as a model cargo on their surfaces. We hypothesized that the sequential adsorption of a gadolinium-binding chitosan fastener on the liposome surface followed by covalent cross-linking of the lipid bilayer would provide enhanced stability and improved MR signal in the presence of human serum. To investigate this hypothesis, liposomes composed of diyne-containing lipids were assembled and functionalized via chitosan conjugated with a hydrophobic anchor and diethylenetriaminepentaacetic acid (DTPA). This postadsorption cross-linking strategy served to stabilize the thermodynamically favorable association between liposome and polymeric fastener. Furthermore, the chitosan-coated, cross-linked liposomes proved more effective as delivery vehicles of gadolinium than uncross-linked liposomes due to the reduced liposome degradation and chitosan desorption. Overall, this study demonstrates a useful method to stabilize a broad class of particles used for systemic delivery of various molecular payloads.

  19. Diagnostic Accuracy of Dynamic Contrast Enhanced Magnetic Resonance Imaging in Characterizing Lung Masses

    Science.gov (United States)

    Inan, Nagihan; Arslan, Arzu; Donmez, Muhammed; Sarisoy, Hasan Tahsin

    2016-01-01

    Background Imaging plays a critical role not only in the detection, but also in the characterization of lung masses as benign or malignant. Objectives To determine the diagnostic accuracy of dynamic magnetic resonance imaging (MRI) in the differential diagnosis of benign and malignant lung masses. Patients and Methods Ninety-four masses were included in this prospective study. Five dynamic series of T1-weighted spoiled gradient echo (FFE) images were obtained, followed by a T1-weighted FFE sequence in the late phase (5th minutes). Contrast enhancement patterns in the early (25th second) and late (5th minute) phase images were evaluated. For the quantitative evaluation, signal intensity (SI)-time curves were obtained and the maximum relative enhancement, wash-in rate, and time-to-peak enhancement of masses in both groups were calculated. Results The early phase contrast enhancement patterns were homogeneous in 78.2% of the benign masses, while heterogeneous in 74.4% of the malignant tumors. On the late phase images, 70.8% of the benign masses showed homogeneous enhancement, while most of the malignant masses showed heterogeneous enhancement (82.4%). During the first pass, the maximum relative enhancement and wash-in rate values of malignant masses were significantly higher than those of the benign masses (P = 0.03 and 0.04, respectively). The cutoff value at 15% yielded a sensitivity of 85.4%, specificity of 61.2%, and positive predictive value of 68.7% for the maximum relative enhancement. Conclusion Contrast enhancement patterns and SI-time curve analysis of MRI are helpful in the differential diagnosis of benign and malignant lung masses. PMID:27703654

  20. Magnetic Resonance angiography with bolus contrast agent in abdominal aortic aneurysms

    International Nuclear Information System (INIS)

    Di Cesare, E.; Cerone, G.; Giordano, A.V.; Marsili, L.; Barile, A.; Michelini, O.; Masciocchi, C.; Spartera, C.

    2000-01-01

    Purpose of this paper is to investigate the potentials of 3D breath-hold contrast-enhanced Magnetic Resonance Angiography (MRA) in the diagnosis, follow-up and treatment planning of abdominal aortic aneurysms. Twenty-four patients with infrarenal aortic aneurysm underwent MRA. It was used a 1.5 T unit (GE Horizon, Echospeed 8.2), a phased array surface coil and 3D Fast SPGR T1-weighted sequences acquired on the coronal plane during patient breath-hold and after contrast agent i.v. administration. A bolus-test was done before angiography to optimize imaging delay time. After 3D MRA a Fast-SPGR T1-weighted sequence was acquired on the axial plane. The 3D MRA source images were processed with the MIP algorithm. Qualitative and quantitative analyses were carried out. Helical CT was performed in 6 cases and DSA in 7 cases. Surgery was the reference standard in 15 patients. MRA depicted aneurysm thrombosis in 22 cases, carrefour involvement in 18 cases and iliac arteries involvement in 3 cases. Accessory renal arteries were shown in 4 cases; iliac artery stenosis was associated in 5 cases. There was agreement between MR and Helical CT and DSA findings: surgery confirmed MRA results in 15/15 cases. 3D contrast-enhanced MRA can be considered the method of choice in the follow-up and treatment planning of abdominal aortic aneurysms, because it provides both angiographic and tomographic images: this allows to obtain more information, noninvasively and without the use of ionizing radiations [it

  1. Performance characteristics of magnetic resonance imaging without contrast agents or sedation in pediatric appendicitis.

    Science.gov (United States)

    Didier, Ryne A; Hopkins, Katharine L; Coakley, Fergus V; Krishnaswami, Sanjay; Spiro, David M; Foster, Bryan R

    2017-09-01

    Magnetic resonance imaging (MRI) has emerged as a promising modality for evaluating pediatric appendicitis. However optimal imaging protocols, including roles of contrast agents and sedation, have not been established and diagnostic criteria have not been fully evaluated. To investigate performance characteristics of rapid MRI without contrast agents or sedation in the diagnosis of pediatric appendicitis. We included patients ages 4-18 years with suspicion of appendicitis who underwent rapid MRI between October 2013 and March 2015 without contrast agent or sedation. After two-radiologist review, we determined performance characteristics of individual diagnostic criteria and aggregate diagnostic criteria by comparing MRI results to clinical outcomes. We used receiver operating characteristic (ROC) curves to determine cut-points for appendiceal diameter and wall thickness for optimization of predictive power, and we calculated area under the curve (AUC) as a measure of test accuracy. Ninety-eight MRI examinations were performed in 97 subjects. Overall, MRI had a 94% sensitivity, 95% specificity, 91% positive predictive value and 97% negative predictive value. Optimal cut-points for appendiceal diameter and wall thickness were ≥7 mm and ≥2 mm, respectively. Independently, those cut-points produced sensitivities of 91% and 84% and specificities of 84% and 43%. Presence of intraluminal fluid (30/33) or localized periappendiceal fluid (32/33) showed a significant association with acute appendicitis (Pappendicitis when multiple diagnostic criteria are considered in aggregate. Individual diagnostic criteria including optimized cut-points of ≥7 mm for diameter and ≥2 mm for wall thickness demonstrate high sensitivities but relatively low specificities. Nonvisualization of the appendix favors a negative diagnosis.

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

    International Nuclear Information System (INIS)

    Boraschi, P.; Donati, F.; Gigoni, R.; Salemi, S.; Urbani, L.; Filipponi, F.; Falaschi, F.; Bartolozzi, C.

    2008-01-01

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

  3. 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.

  4. Non-immunogenic dextran-coated superparamagnetic iron oxide nanoparticles: a biocompatible, size-tunable contrast agent for magnetic resonance imaging.

    Science.gov (United States)

    Unterweger, Harald; Janko, Christina; Schwarz, Marc; Dézsi, László; Urbanics, Rudolf; Matuszak, Jasmin; Őrfi, Erik; Fülöp, Tamás; Bäuerle, Tobias; Szebeni, János; Journé, Clément; Boccaccini, Aldo R; Alexiou, Christoph; Lyer, Stefan; Cicha, Iwona

    2017-01-01

    Iron oxide-based contrast agents have been in clinical use for magnetic resonance imaging (MRI) of lymph nodes, liver, intestines, and the cardiovascular system. Superparamagnetic iron oxide nanoparticles (SPIONs) have high potential as a contrast agent for MRI, but no intravenous iron oxide-containing agents are currently approved for clinical imaging. The aim of our work was to analyze the hemocompatibility and immuno-safety of a new type of dextran-coated SPIONs (SPIONdex) and to characterize these nanoparticles with ultra-high-field MRI. Key parameters related to nanoparticle hemocompatibility and immuno-safety were investigated in vitro and ex vivo. To address concerns associated with hypersensitivity reactions to injectable nanoparticulate agents, we analyzed complement activation-related pseudoallergy (CARPA) upon intravenous administration of SPIONdex in a pig model. Furthermore, the size-tunability of SPIONdex and the effects of size reduction on their biocompatibility were investigated. In vitro, SPIONdex did not induce hemolysis, complement or platelet activation, plasma coagulation, or leukocyte procoagulant activity, and had no relevant effect on endothelial cell viability or endothelial-monocytic cell interactions. Furthermore, SPIONdex did not induce CARPA even upon intravenous administration of 5 mg Fe/kg in pigs. Upon SPIONdex administration in mice, decreased liver signal intensity was observed after 15 minutes and was still detectable 24 h later. In addition, by changing synthesis parameters, a reduction in particle size contrast agent.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-15

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

  6. Chitosan-coated nickel-ferrite nanoparticles as contrast agents in magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Tanveer [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Department of Physics, Abdul Wali Khan University, Mardan (Pakistan); Bae, Hongsub; Iqbal, Yousaf [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Rhee, Ilsu, E-mail: ilrhee@knu.ac.kr [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Hong, Sungwook [Division of Science Education, Daegu University, Gyeongsan 712-714 (Korea, Republic of); Chang, Yongmin; Lee, Jaejun [Department of Diagnostic Radiology, College of Medicine, Kyungpook National University and Hospital, Daegu 700-721 (Korea, Republic of); Sohn, Derac [Department of Physics, Hannam University, Daejon (Korea, Republic of)

    2015-05-01

    We report evidence for the possible application of chitosan-coated nickel-ferrite (NiFe{sub 2}O{sub 4}) nanoparticles as both T{sub 1} and T{sub 2} contrast agents in magnetic resonance imaging (MRI). The coating of nickel-ferrite nanoparticles with chitosan was performed simultaneously with the synthesis of the nickel-ferrite nanoparticles by a chemical co-precipitation method. The coated nanoparticles were cylindrical in shape with an average length of 17 nm and an average width of 4.4 nm. The bonding of chitosan onto the ferrite nanoparticles was confirmed by Fourier transform infrared spectroscopy. The T{sub 1} and T{sub 2} relaxivities were 0.858±0.04 and 1.71±0.03 mM{sup −1} s{sup −1}, respectively. In animal experimentation, both a 25% signal enhancement in the T{sub 1}-weighted mage and a 71% signal loss in the T{sub 2}-weighted image were observed. This demonstrated that chitosan-coated nickel-ferrite nanoparticles are suitable as both T{sub 1} and T{sub 2} contrast agents in MRI. We note that the applicability of our nanoparticles as both T{sub 1} and T{sub 2} contrast agents is due to their cylindrical shape, which gives rise to both inner and outer sphere processes of nanoparticles. - Highlights: • Chitosan-coated nickel-ferrite (Ni-Fe{sub 2}O{sub 4}) nanoparticles were synthesized in an aqueous system by chemical co-precipitation. • The characterization of bare and chitosan-coated nanoparticles were performed using various analytical tools, such as TEM, FTIR, XRD, and VMS. • We evaluated the coated particles as potential T{sub 1} and T{sub 2} contrast agents for MRI by measuring T{sub 1} and T{sub 2} relaxation times as a function of iron concentration. • Both T{sub 1} and T{sub 2} effects were also observed in animal experimentation.

  7. Simple method for quantification of gadolinium magnetic resonance imaging contrast agents using ESR spectroscopy.

    Science.gov (United States)

    Takeshita, Keizo; Kinoshita, Shota; Okazaki, Shoko

    2012-01-01

    To develop an estimation method of gadolinium magnetic resonance imaging (MRI) contrast agents, the effect of concentration of Gd compounds on the ESR spectrum of nitroxyl radical was examined. A solution of either 4-oxo-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPONE) or 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPOL) was mixed with a solution of Gd compound and the ESR spectrum was recorded. Increased concentration of gadolinium-diethylenetriamine pentaacetic acid chelate (Gd-DTPA), an MRI contrast agent, increased the peak-to-peak line widths of ESR spectra of the nitroxyl radicals, in accordance with a decrease of their signal heights. A linear relationship was observed between concentration of Gd-DTPA and line width of ESR signal, up to approximately 50 mmol/L Gd-DTPA, with a high correlation coefficient. Response of TEMPONE was 1.4-times higher than that of TEMPOL as evaluated from the slopes of the lines. The response was slightly different among Gd compounds; the slopes of calibration curves for acua[N,N-bis[2-[(carboxymethyl)[(methylcarbamoyl)methyl]amino]ethyl]glycinato(3-)]gadolinium hydrate (Gd-DTPA-BMA) (6.22 μT·L/mmol) and gadolinium-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid chelate (Gd-DOTA) (6.62 μT·L/mmol) were steeper than the slope for Gd-DTPA (5.45 μT·L/mmol), whereas the slope for gadolinium chloride (4.94 μT·L/mmol) was less steep than that for Gd-DTPA. This method is simple to apply. The results indicate that this method is useful for rough estimation of the concentration of Gd contrast agents if calibration is carried out with each standard compound. It was also found that the plot of the reciprocal square root of signal height against concentrations of contrast agents could be useful for the estimation if a constant volume of sample solution is taken and measured at the same position in the ESR cavity every time.

  8. Clinical application of nuclear magnetic resonance imaging (resistive type) on cardiovascular disease

    International Nuclear Information System (INIS)

    Imai, Hitoshi; Yoshida, Katsuya; Watanabe, Shigeru; Masuda, Yoshiaki; Inagaki, Yoshiaki; Ikehira, Hiroo; Fukuda, Nobuo; Tateno, Yukio.

    1984-01-01

    In order to evaluate the usefulness of Nuclear Magnetic Resonance (NMR) imaging in diagnosing cardiovascular disease, 27 subjects were examined using a 0.1-Tesla resistive type (ASAHI MARK-J). In 10 normal subjects, four cardiac chambers, interventricular septum, aorta, pulmonary vessels and vena cava were clearly identified in NMR imaging. In two patients with old anteroseptal myocardial infarction, anteroseptal wall thinning and left ventricular aneurysm with mural thrombi were demonstrated. In two cases of antrolateral and posterolateral myocardial infarction, however, infarcted areas were not identified in NMR imaging. In one patient with congestive cardiomyopathy, enlarged left ventricle without hypertrophy was recognized. In two patients with hypertrophic obstructive cardiomyopathy, NMR imaging disclosed thickened left ventricular wall associated with its narrowed cavity. A mural thrombus in the right ventricle was distinctly visualized in one patient with cardio-vascular Behcet's disease. In two patients with mitral valve stenosis, enlarged left atrium with a mural thrombus was clearly demonstrated in both cross and longitudinal sections. In three patients with thoratic aortic aneurysm, local dilatation of aorta and mural thrombi were recognized. In four patients with dissecting aortic aneurysm, double channels with an intimal flap in the aorta were visualized in NMR imaging. Mean T 1 values and standard deviations of left ventricle, left ventricular wall, and thrombi were 593+-89, 341+-20, 316+-84 msec, respectively. Mean T 1 values of thrombi were ordinally shorter than those of left ventricule. But some thrombi which might be expected fresh had longer T 1 values. (J.P.N.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-12-15

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

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

    International Nuclear Information System (INIS)

    Quail, Michael A.; Nordmeyer, Johannes; Schievano, Silvia; Reinthaler, Markus; Mullen, Michael J.; Taylor, Andrew M.

    2012-01-01

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

  11. Role of late gadolinium enhancement cardiovascular magnetic resonance in the risk stratification of hypertrophic cardiomyopathy.

    Science.gov (United States)

    Ismail, Tevfik F; Jabbour, Andrew; Gulati, Ankur; Mallorie, Amy; Raza, Sadaf; Cowling, Thomas E; Das, Bibek; Khwaja, Jahanzaib; Alpendurada, Francisco D; Wage, Ricardo; Roughton, Michael; McKenna, William J; Moon, James C; Varnava, Amanda; Shakespeare, Carl; Cowie, Martin R; Cook, Stuart A; Elliott, Perry; O'Hanlon, Rory; Pennell, Dudley J; Prasad, Sanjay K

    2014-12-01

    Myocardial fibrosis identified by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) in patients with hypertrophic cardiomyopathy (HCM) is associated with adverse cardiovascular events, but its value as an independent risk factor for sudden cardiac death (SCD) is unknown. We investigated the role of LGE-CMR in the risk stratification of HCM. We conducted a prospective cohort study in a tertiary referral centre. Consecutive patients with HCM (n=711, median age 56.3 years, IQR 46.7-66.6; 70.0% male) underwent LGE-CMR and were followed for a median 3.5 years. The primary end point was SCD or aborted SCD. Overall, 471 patients (66.2%) had myocardial fibrosis (median 5.9% of left ventricular mass, IQR: 2.2-13.3). Twenty-two (3.1%) reached the primary end point. The extent but not the presence of fibrosis was a significant univariable predictor of the primary end point (HR per 5% LGE: 1.24, 95% CI 1.06 to 1.45; p=0.007 and HR for LGE: 2.69, 95% CI 0.91 to 7.97; p=0.073, respectively). However, on multivariable analysis, only LV-EF remained statistically significant (HR: 0.92, 95% CI 0.89 to 0.95; p<0.001). For the secondary outcome of cardiovascular mortality/aborted SCD, the presence and the amount of fibrosis were significant predictors on univariable but not multivariable analysis after adjusting for LV-EF and non-sustained ventricular tachycardia. The amount of myocardial fibrosis was a strong univariable predictor of SCD risk. However, this effect was not maintained after adjusting for LV-EF. Further work is required to elucidate the interrelationship between fibrosis and traditional predictors of outcome in HCM. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  12. Comparison of Accuracy of Contrast Enhanced Computed Tomography with Accuracy of Non-Contrast Magnetic Resonance Imaging in Evaluation of Local Extension of Base of Tongue Malignancies

    Directory of Open Access Journals (Sweden)

    Ketan Rathod

    2018-01-01

    Full Text Available Diagnosis of base of tongue malignancy can be obtained through clinical examination and biopsy. Magnetic Resonance Imaging (MRI and Computed Tomography (CT are used to detect its local extension, nodal spread and distant metastases. The main aim of study was to compare the accuracy of MRI and contrast enhanced CT in determining the local extent of base of tongue malignancy. Twenty five patients, biopsy proven cases of squamous cell carcinoma of base of tongue were taken. 1.5 Tesla Magnetic Resonance Unit with T2 weighted axial, coronal image; T1 weighted axial, coronal image; and STIR (Short tau inversion recovery axial and coronal images were used. 16 slice Computed Tomography unit with non-contrast and contrast enhanced images were used. Accuracy of CT to detect midline crossing: 50%; accuracy of MRI to detect midline crossing: 100%; accuracy of CT to detect anterior extension: 92%; accuracy of MRI to detect anterior extension: 100%; accuracy of CT to detect tonsillar fossa invasion: 83%; accuracy of MRI to detect tonsillar fossa invasion: 100%; accuracy of CT to detect oro pharyngeal spread: 83%; accuracy of MRI to detect oro pharyngeal spread: 100%; accuracy of CT to detect bone involvement: 20%; accuracy of MRI to detect bone involvement: 100%. MRI proved to be a better investigation than CT, in terms of evaluation of depth of invasion, presence of bony involvement, extension to opposite side, anterior half of tongue, tonsillar fossa, floor of mouth or oropharynx.

  13. Contrasting patterns of hot spell effects on morbidity and mortality for cardiovascular diseases in the Czech Republic, 1994–2009

    Czech Academy of Sciences Publication Activity Database

    Hanzlíková, Hana; Plavcová, Eva; Kynčl, J.; Kříž, B.; Kyselý, Jan

    2015-01-01

    Roč. 59, č. 11 (2015), s. 1673-1684 ISSN 0020-7128 R&D Projects: GA ČR(CZ) GAP209/11/1985 Institutional support: RVO:68378289 Keywords : hot spells * cardiovascular disease * cerebrovascular disease * ischaemic heart disease * mortality * morbidity * Central Europe Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 2.309, year: 2015 http://link.springer.com/article/10.1007%2Fs00484-015-0974-1

  14. Comparison by magnetic resonance phase contrast imaging of pulse-wave velocity in patients with single ventricle who have reconstructed aortas versus those without.

    Science.gov (United States)

    Fogel, Mark A; Li, Christine; Nicolson, Susan C; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Keller, Marc S; Harris, Matthew A; Yoganathan, Ajit P; Whitehead, Kevin K

    2014-12-15

    Pulse-wave velocity (PWV), a measure of arterial stiffness, is a known independent risk factor for cardiovascular events. Patients with single ventricle who undergo aortic to pulmonary anastomosis (recon) have noncompliant patch material inserted into the neoaorta, possibly increasing vessel stiffness and afterload. The purpose of this study is to determine if PWV in patients with single ventricle differed between those who did and those who did not undergo aortic reconstruction (nonrecon). We retrospectively reviewed cardiac magnetic resonance anatomic, cine, and phase contrast evaluations in the ascending aorta and descending aorta (DAo) at the level of the diaphragm data from 126 patients with single ventricle (8.6 ± 8.0 years) from January 2012 to May 2013. Significance = p 13 years old had a higher PWV than those 13 years old, PWV of those with recon was higher than nonrecon DAo distensibility was similar between both groups. There was no difference in age, body surface area, or cardiac index between recon and nonrecon. No correlations between various hemodynamic and ventricular function parameters with PWV were noted. In conclusion, PWV in recon is higher than in nonrecon with similar DAo distensibility implicating the aortic reconstruction as a possible cause of increased afterload; older recon patients have stiffer aortas than younger ones, possibly imposing an additional cardiovascular risk in the future. Other biomaterials may potentially moderate PWV if clinical outcome is adversely affected. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Comparison by Magnetic Resonance Phase Contrast of Pulse Wave Velocity in Patients with Single Ventricle and Reconstructed Aortas versus Those Without

    Science.gov (United States)

    Fogel, Mark A.; Li, Christine; Nicolson, Susan C; Spray, Thomas L; Gaynor, J William; Fuller, Stephanie; Keller, Marc S.; Harris, Matthew A.; Yoganathan, Ajit P; Whitehead, Kevin K.

    2015-01-01

    Pulse wave velocity (PWV), a measure of arterial stiffness, is a known independent risk factor for cardiovascular events. Single ventricle patients who undergo aortic to pulmonary anastomosis (recon) have non-compliant patch material inserted into the neo-aorta, possibly increasing vessel stiffness and afterload. The purpose of this study is to determine if PWV differed in single ventricle patients who did and did not undergo aortic reconstruction (no-recon). We retrospectively reviewed cardiac magnetic resonance anatomic, cine and phase contrast evaluations in the ascending (AAo) and descending aorta (DAo) at the level of the diaphragm data from 126 single ventricle patients (8.6±8.0 years) from January 2012 to May, 2013. Significance = P 13 years had a higher PWV than those < 7 years (4.5±0.6 vs 3.5±0.7 m/s, P=0.004). DAo distensibility was similar between both groups. There was no difference in age, body surface area or cardiac index between recon and no-recon. No correlations between various hemodynamic and ventricular function parameters with PWV were noted. In conclusion, PWV in recon is higher than in no-recon with similar DAo distensibility implicating the aortic reconstruction as a possible cause of increased afterload; older recon have stiffer aortas than younger ones possibly imposing an additional cardiovascular risk in the future. Other biomaterials may potentially moderate PWV if clinical outcome is adversely affected. PMID:25432153

  16. Effects of iodinated contrast agent, xylocaine and gadolinium concentration on the signal emitted in magnetic resonance arthrography: a samples study

    Directory of Open Access Journals (Sweden)

    Yvana Lopes Pinheiro da Silva

    2015-04-01

    Full Text Available Objective: To investigate the effects of dilution of paramagnetic contrast agent with iodinated contrast and xylocaine on the signal intensity during magnetic resonance arthrography, and to improve the paramagnetic contrast agent concentration utilized in this imaging modality. Materials and Methods: Samples specially prepared for the study with three different concentrations of paramagnetic contrast agent diluted in saline, iodinated contrast agent and xylocaine were imaged with fast spin echo T1-weighted sequences with fat saturation. The samples were placed into flasks and graphical analysis of the signal intensity was performed as a function of the paramagnetic contrast concentration. Results: As compared with samples of equal concentrations diluted only with saline, the authors have observed an average signal intensity decrease of 20.67% for iodinated contrast agent, and of 28.34% for xylocaine. However, the increased gadolinium concentration in the samples caused decrease in signal intensity with all the dilutions. Conclusion: Minimizing the use of iodinated contrast media and xylocaine and/or the use of a gadolinium concentration of 2.5 mmol/L diluted in saline will improve the sensitivity of magnetic resonance arthrography.

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

    Directory of Open Access Journals (Sweden)

    Frank Seifert

    2010-12-01

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

  18. Ultra-wideband sensors for improved magnetic resonance imaging, cardiovascular monitoring and tumour diagnostics.

    Science.gov (United States)

    Thiel, Florian; Kosch, Olaf; Seifert, Frank

    2010-01-01

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

  19. Malignancy assessment of brain tumours with magnetic resonance spectroscopy and dynamic susceptibility contrast MRI

    Energy Technology Data Exchange (ETDEWEB)

    Fayed, Nicolas; Davila, Jorge; Medrano, Jaime [Diagnostic Radiology Department, Clinica Quiron, Zaragoza (Spain); Olmos, Salvador [Instituto de Investigacion en Ingenieria de Aragon, Zaragoza (Spain)], E-mail: olmos@unizar.es

    2008-09-15

    Magnetic resonance imaging (MRI) is the most common and well-established imaging modality for evaluation of intracerebral neoplasms, but there are still some incompletely solved challenges, such as reliable distinction between high- and low-grade tumours, exact delineation of tumour extension, and discrimination between recurrent tumour and radiation necrosis. The aim of this study was to evaluate the contribution of two MRI techniques to non-invasively estimate brain tumour grade. Twenty-four patients referred to MRI examination were analyzed and diagnosed with single intra-axial brain tumour. Lastly, histopathological analysis was performed to verify tumour type. Ten patients presented low-grade gliomas, while the remaining patients showed high-grade tumours, including glioblastomas in eight cases, isolated metastases in four patients and two cases with anaplastic gliomas. MRI examinations were performed on a 1.5-T scanner (Signa, General Electric). The acquisition protocol included the following sequences: saggital T1-weighted localizer, axial T1- and T2-weighted MRI, single-voxel magnetic resonance spectroscopy (MRS), dynamic susceptibility contrast (DSC) MRI and contrast-enhanced T1-weighted MRI. MRS data was analyzed with standard software provided by the scanner manufacturer. The metabolite ratio with the largest significant difference between tumour grades was the choline/creatine (Ch/Cr) ratio with elevated values in high-grade gliomas and metastases. A Ch/Cr ratio equal or larger than 1.55 predicted malignancy grade with 92% sensitivity and 80% specificity. The area under the ROC curve was 0.92 (CI: 95%; 0.81-1). Regarding to perfusion parameters, relative cerebral blood volume (rCBV) maps were estimated from the MR signal intensity time series during bolus passage with two commercial software packages. Two different regions of interest (ROI) were used to evaluate rCBV: lesion centre and perilesional region. All rCBV values were normalized to CBV in a

  20. Malignancy assessment of brain tumours with magnetic resonance spectroscopy and dynamic susceptibility contrast MRI

    International Nuclear Information System (INIS)

    Fayed, Nicolas; Davila, Jorge; Medrano, Jaime; Olmos, Salvador

    2008-01-01

    Magnetic resonance imaging (MRI) is the most common and well-established imaging modality for evaluation of intracerebral neoplasms, but there are still some incompletely solved challenges, such as reliable distinction between high- and low-grade tumours, exact delineation of tumour extension, and discrimination between recurrent tumour and radiation necrosis. The aim of this study was to evaluate the contribution of two MRI techniques to non-invasively estimate brain tumour grade. Twenty-four patients referred to MRI examination were analyzed and diagnosed with single intra-axial brain tumour. Lastly, histopathological analysis was performed to verify tumour type. Ten patients presented low-grade gliomas, while the remaining patients showed high-grade tumours, including glioblastomas in eight cases, isolated metastases in four patients and two cases with anaplastic gliomas. MRI examinations were performed on a 1.5-T scanner (Signa, General Electric). The acquisition protocol included the following sequences: saggital T1-weighted localizer, axial T1- and T2-weighted MRI, single-voxel magnetic resonance spectroscopy (MRS), dynamic susceptibility contrast (DSC) MRI and contrast-enhanced T1-weighted MRI. MRS data was analyzed with standard software provided by the scanner manufacturer. The metabolite ratio with the largest significant difference between tumour grades was the choline/creatine (Ch/Cr) ratio with elevated values in high-grade gliomas and metastases. A Ch/Cr ratio equal or larger than 1.55 predicted malignancy grade with 92% sensitivity and 80% specificity. The area under the ROC curve was 0.92 (CI: 95%; 0.81-1). Regarding to perfusion parameters, relative cerebral blood volume (rCBV) maps were estimated from the MR signal intensity time series during bolus passage with two commercial software packages. Two different regions of interest (ROI) were used to evaluate rCBV: lesion centre and perilesional region. All rCBV values were normalized to CBV in a

  1. Gd_2O_3 nanoparticles stabilized by hydrothermally modified dextrose for positive contrast magnetic resonance imaging

    International Nuclear Information System (INIS)

    Babić-Stojić, Branka; Jokanović, Vukoman; Milivojević, Dušan; Požek, Miroslav; Jagličić, Zvonko; Makovec, Darko; Arsikin, Katarina; Paunović, Verica

    2016-01-01

    Gd_2O_3 nanoparticles of a few nm in size and their agglomerates dispersed in dextrose derived polymer template were synthesized by hydrothermal treatment. The produced nanosized material was investigated by TEM, FTIR spectroscopy, SQUID measurements and NMR relaxometry. Biological evaluation of this material was done by crystal violet and MTT assays to determine the cell viability. Longitudinal and transverse NMR relaxivities of water diluted Gd_2O_3 nanoparticle dispersions measured at the magnetic field of 1.5 T, estimated to be r_1(Gd_2O_3)=9.6 s"−"1 mM"−"1 in the Gd concentration range 0.1–30 mM and r_2(Gd_2O_3)=17.7 s"−"1 mM"−"1 in the lower concentration range 0.1–0.8 mM, are significantly higher than the corresponding relaxivities measured for the standard contrast agent r_1(Gd-DTPA)=4.1 s"−"1 mM"−"1 and r_2(Gd-DTPA)=5.1 s"−"1 mM"−"1. The ratio of the two relaxivities for Gd_2O_3 nanoparticles r_2/r_1=1.8 is suitable for T_1-weighted imaging. Good MRI signal intensities of the water diluted Gd_2O_3 nanoparticle dispersions were recorded at lower Gd concentrations 0.2–0.8 mM. The Gd_2O_3 samples did not exert any significant cytotoxic effects at Gd concentrations of 0.2 mM and below. These properties of the produced Gd_2O_3 nanoparticles in hydrothermally modified dextrose make them promising for potential application in MRI for the design of a positive MRI contrast agent. - Highlights: • Gd_2O_3 nanoparticles (NPs) were stabilized by hydrothermally modified dextrose. • Magnetic moment per Gd"3"+ ion in the Gd_2O_3 NPs is much lower than that in the bulk. • The ratio r_2/r_1=1.8 for Gd_2O_3 NPs dispersions is favorable for T_1-weighted MRI. • Gd_2O_3 NPs dispersions had good MRI signal intensity just at lower Gd concentrations. • Gd concentrations of 0.2 mM and below in the Gd_2O_3 NPs dispersions were not toxic.

  2. Cardiac magnetic resonance: is phonocardiogram gating reliable in velocity-encoded phase contrast imaging?

    International Nuclear Information System (INIS)

    Nassenstein, Kai; Schlosser, Thomas; Orzada, Stephan; Ladd, Mark E.; Maderwald, Stefan; Haering, Lars; Czylwik, Andreas; Jensen, Christoph; Bruder, Oliver

    2012-01-01

    To assess the diagnostic accuracy of phonocardiogram (PCG) gated velocity-encoded phase contrast magnetic resonance imaging (MRI). Flow quantification above the aortic valve was performed in 68 patients by acquiring a retrospectively PCG- and a retrospectively ECG-gated velocity-encoded GE-sequence at 1.5 T. Peak velocity (PV), average velocity (AV), forward volume (FV), reverse volume (RV), net forward volume (NFV), as well as the regurgitant fraction (RF) were assessed for both datasets, as well as for the PCG-gated datasets after compensation for the PCG trigger delay. PCG-gated image acquisition was feasible in 64 patients, ECG-gated in all patients. PCG-gated flow quantification overestimated PV (Δ 3.8 ± 14.1 cm/s; P = 0.037) and underestimated FV (Δ -4.9 ± 15.7 ml; P = 0.015) and NFV (Δ -4.5 ± 16.5 ml; P = 0.033) compared with ECG-gated imaging. After compensation for the PCG trigger delay, differences were only observed for PV (Δ 3.8 ± 14.1 cm/s; P = 0.037). Wide limits of agreement between PCG- and ECG-gated flow quantification were observed for all variables (PV: -23.9 to 31.4 cm/s; AV: -4.5 to 3.9 cm/s; FV: -35.6 to 25.9 ml; RV: -8.0 to 7.2 ml; NFV: -36.8 to 27.8 ml; RF: -10.4 to 10.2 %). The present study demonstrates that PCG gating in its current form is not reliable enough for flow quantification based on velocity-encoded phase contrast gradient echo (GE) sequences. (orig.)

  3. Gd2O3 nanoparticles stabilized by hydrothermally modified dextrose for positive contrast magnetic resonance imaging

    Science.gov (United States)

    Babić-Stojić, Branka; Jokanović, Vukoman; Milivojević, Dušan; Požek, Miroslav; Jagličić, Zvonko; Makovec, Darko; Arsikin, Katarina; Paunović, Verica

    2016-04-01

    Gd2O3 nanoparticles of a few nm in size and their agglomerates dispersed in dextrose derived polymer template were synthesized by hydrothermal treatment. The produced nanosized material was investigated by TEM, FTIR spectroscopy, SQUID measurements and NMR relaxometry. Biological evaluation of this material was done by crystal violet and MTT assays to determine the cell viability. Longitudinal and transverse NMR relaxivities of water diluted Gd2O3 nanoparticle dispersions measured at the magnetic field of 1.5 T, estimated to be r1(Gd2O3)=9.6 s-1 mM-1 in the Gd concentration range 0.1-30 mM and r2(Gd2O3)=17.7 s-1 mM-1 in the lower concentration range 0.1-0.8 mM, are significantly higher than the corresponding relaxivities measured for the standard contrast agent r1(Gd-DTPA)=4.1 s-1 mM-1 and r2(Gd-DTPA)=5.1 s-1 mM-1. The ratio of the two relaxivities for Gd2O3 nanoparticles r2/r1=1.8 is suitable for T1-weighted imaging. Good MRI signal intensities of the water diluted Gd2O3 nanoparticle dispersions were recorded at lower Gd concentrations 0.2-0.8 mM. The Gd2O3 samples did not exert any significant cytotoxic effects at Gd concentrations of 0.2 mM and below. These properties of the produced Gd2O3 nanoparticles in hydrothermally modified dextrose make them promising for potential application in MRI for the design of a positive MRI contrast agent.

  4. The unique value of cardiovascular magnetic resonance in patients with suspected acute coronary syndrome and culprit-free coronary angiograms.

    Science.gov (United States)

    Panovský, Roman; Borová, Júlia; Pleva, Martin; Feitová, Věra; Novotný, Petr; Kincl, Vladimír; Holeček, Tomáš; Meluzín, Jaroslav; Sochor, Ondřej; Štěpánová, Radka

    2017-06-28

    Patients with chest pain, elevated troponin, and unobstructed coronary disease present a clinical dilemma. The purpose of this study was to investigate the incremental diagnostic value of cardiovascular magnetic resonance (CMR) in a cohort of patients with suspected acute coronary syndrome (ACS) and unobstructed coronary arteries. Data files of patients meeting the inclusion criteria in two cardiology centres were searched and analysed. The inclusion criteria included: 1) thoracic pain suspected with ACS; 2) a significant increase in the high-sensitive Troponin T value; 3) ECG changes; 4) coronary arteries without any significant stenosis; 5) a CMR examination included in the diagnostic process; 6) an uncertain diagnosis before the CMR exam; and 7) the absence of known CMR and contrast media contraindications. Special attention was paid to the benefits of CMR in determining the final diagnosis. In total, 136 patients who underwent coronary angiography for chest pain were analysed. The most frequent underlying causes were myocarditis (38%) and perimyocarditis (18%), followed by angiographically unrecognised acute myocardial infarction (18%) and Takotsubo cardiomyopathy (15%). The final diagnosis remained unclear in 6% of the patients. The contribution of CMR in determining the final diagnosis determination was crucial in 57% of the patients. In another 35% of the patients, CMR confirmed the suspicion and, only 8% of the CMR examinations did not help at all and had no influence on diagnosis or treatment. CMR provided a powerful incremental diagnostic value in the cohort of patients with suspected ACS and unobstructed coronary arteries. CMR is highly recommended to be incorporated as an inalienable part of the diagnostic algorithms in these patients.

  5. Maximum Entropy Approach in Dynamic Contrast-Enhanced Magnetic Resonance Imaging.

    Science.gov (United States)

    Farsani, Zahra Amini; Schmid, Volker J

    2017-01-01

    In the estimation of physiological kinetic parameters from Dynamic Contrast-Enhanced Magnetic Resonance Imaging (DCE-MRI) data, the determination of the arterial input function (AIF) plays a key role. This paper proposes a Bayesian method to estimate the physiological parameters of DCE-MRI along with the AIF in situations, where no measurement of the AIF is available. In the proposed algorithm, the maximum entropy method (MEM) is combined with the maximum a posterior approach (MAP). To this end, MEM is used to specify a prior probability distribution of the unknown AIF. The ability of this method to estimate the AIF is validated using the Kullback-Leibler divergence. Subsequently, the kinetic parameters can be estimated with MAP. The proposed algorithm is evaluated with a data set from a breast cancer MRI study. The application shows that the AIF can reliably be determined from the DCE-MRI data using MEM. Kinetic parameters can be estimated subsequently. The maximum entropy method is a powerful tool to reconstructing images from many types of data. This method is useful for generating the probability distribution based on given information. The proposed method gives an alternative way to assess the input function from the existing data. The proposed method allows a good fit of the data and therefore a better estimation of the kinetic parameters. In the end, this allows for a more reliable use of DCE-MRI. Schattauer GmbH.

  6. Venous reflux on contrast-enhanced head and neck magnetic resonance angiography: Analysis of causative factors

    International Nuclear Information System (INIS)

    Shin, Dong Jae; Lee, Eun Ja; Bae, Jong Myon

    2016-01-01

    The purpose of this study was to analyze the causative factors of venous reflux on contrast-enhanced head and neck magnetic resonance angiography. We retrospectively reviewed 150 patients with right-arm injections and 150 patients with left-arm injections. We included the age, gender, body mass index, history of hypertension, and history of diabetes mellitus in the evaluation of all patients. We measured the shortest width of the left or right brachiocephalic vein (BCV), the diameter of the aortic arch, and the distance between the sternum and vertebral body. The relationship between these factors and the venous reflux was analyzed. In patients with venous reflux, we performed qualitative image scoring for suboptimal images. In patients with venous reflux, the image quality of the left-arm injection group was significantly inferior to the image quality of the right-arm injection group. The mean age and the male-to-female ratio of patients with venous reflux were significantly higher than those of patients without venous reflux. In patients receiving the left-arm injection, the mean shortest width of the left BCV was significantly narrower in patients with venous reflux than in patients without venous reflux. A left-arm injection should be avoided, especially in elderly patients, to acquire an optimal image

  7. Venous reflux on contrast-enhanced head and neck magnetic resonance angiography: Analysis of causative factors

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Dong Jae; Lee, Eun Ja [Dept. of Radiology, Dongguk University Ilsan Hospital, Goyang (Korea, Republic of); Bae, Jong Myon [Dept. of Preventive Medicine, Jeju National University School of Medicine, Jeju (Korea, Republic of)

    2016-12-15

    The purpose of this study was to analyze the causative factors of venous reflux on contrast-enhanced head and neck magnetic resonance angiography. We retrospectively reviewed 150 patients with right-arm injections and 150 patients with left-arm injections. We included the age, gender, body mass index, history of hypertension, and history of diabetes mellitus in the evaluation of all patients. We measured the shortest width of the left or right brachiocephalic vein (BCV), the diameter of the aortic arch, and the distance between the sternum and vertebral body. The relationship between these factors and the venous reflux was analyzed. In patients with venous reflux, we performed qualitative image scoring for suboptimal images. In patients with venous reflux, the image quality of the left-arm injection group was significantly inferior to the image quality of the right-arm injection group. The mean age and the male-to-female ratio of patients with venous reflux were significantly higher than those of patients without venous reflux. In patients receiving the left-arm injection, the mean shortest width of the left BCV was significantly narrower in patients with venous reflux than in patients without venous reflux. A left-arm injection should be avoided, especially in elderly patients, to acquire an optimal image.

  8. Evaluation of colonic involvement in endometriosis: double-contrast barium enema vs. magnetic resonance imaging.

    Science.gov (United States)

    Faccioli, N; Foti, G; Manfredi, R; Mainardi, P; Spoto, E; Ruffo, G; Minelli, L; Mucelli, R Pozzi

    2010-08-01

    The purpose of the study was to compare the accuracy of double-contrast barium enema (DCBE) and magnetic resonance imaging (MRI) in the diagnosis of intestinal endometriosis using the histological examination on resected specimen as comparative standard. Eighty-three consecutive patients with suspected intestinal endometriosis, resected between 2005 and 2007, were prospectively evaluated. All of the women underwent preoperative DCBE and MRI on the same day. We evaluated number, site (rectum, sigmoid, cecum), and size of the lesions. The imaging findings were correlated with those resulting at pathology. Among the 65 women who underwent surgery, 50/65 (76.9%) were found to have bowel endometriosis, with 9/50 (18%) patients presenting two lesions; DCBE allowed to detect 50/59 (84.7%) lesions. MRI allowed to detect 42/59 (71.1%) lesions. DCBE showed sensibility, specificity, PPV, NPV, and accuracy of respectively 84.7, 93.7, 98.0, 62.5, and 86.6%, MRI of 71.1, 83.3, 93.3, 46.8, and 74.6%. DCBE is more accurate than unenhanced MRI in the diagnosis of bowel endometriosis, and should be preferred in the preoperative management of this disease, since it usually enables a proper surgical planning.

  9. Demonstration of evolution of hemispherical spondysclerosis by contrast enhanced Gd-DTPA magnetic resonance imaging

    International Nuclear Information System (INIS)

    Jevtic, V.; Majcen, N.

    2004-01-01

    Background. The purpose of the study was to estimate the value of Gd-DTPA magnetic resonance imaging (MRI) in demonstrating the evolution of hemispherical spondylosclerosis (HSS). Patients and methods. In eighteen patients with chronic low back pain and typical radiographic findings of HSS seen on plain films, Gd-DTPA MRI of the lumbar spine was performed. MRI morphological and signal intensity appearances of HSS were analysed and compared with radiographic changes. Results. On the basis of MRI features, three distinct groups of cases were identifiable. Within the first group the region of dome-shaped osteosclerosis demonstrated low signal intensity on T1-weighted precontrast spin-echo images, high signal intensity on T2-weighted images and diffuse contrast enhancement on T1-weighted postcontrast images, findings compatible with bone marrow oedema and hyperaemia. The second group showed high signal intensity vertebral body corners surrounded by low signal intensity area, which indicated the combination of fat accumulation and the sclerotic bone. In the third intermediate group anterior disco-vertebral junctions revealed a mixture of MRI appearances characteristic of the first and the second group. Conclusions. Gd-DTPA MRI is capable of demonstrating a spectrum of features which reflect the evolution of HSS. These typical appearances showed by MRI could be of eventual clinical relevance in following the progression of HSS. (author)

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

    Directory of Open Access Journals (Sweden)

    Vido Diane

    2008-07-01

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

  11. 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...

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

    Science.gov (United States)

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

    2007-12-01

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

  13. BOLD cardiovascular magnetic resonance at 3.0 tesla in myocardial ischemia.

    Science.gov (United States)

    Manka, Robert; Paetsch, Ingo; Schnackenburg, Bernhard; Gebker, Rolf; Fleck, Eckart; Jahnke, Cosima

    2010-09-22

    The purpose of this study was to determine the ability of blood oxygen level dependent (BOLD) cardiovascular magnetic resonance (CMR) to detect stress-inducible myocardial ischemic reactions in the presence of angiographically significant coronary artery disease (CAD). Forty-six patients (34 men; age 65 ± 9 years,) with suspected or known coronary artery disease underwent CMR at 3Tesla prior to clinically indicated invasive coronary angiography. BOLD CMR was performed in 3 short axis slices of the heart at rest and during adenosine stress (140 μg/kg/min) followed by late gadolinium enhancement (LGE) imaging. In all 16 standard myocardial segments, T2* values were derived at rest and under adenosine stress. Quantitative coronary angiography served as the standard of reference and defined normal myocardial segments (i.e. all 16 segments in patients without any CAD), ischemic segments (i.e. supplied by a coronary artery with ≥50% luminal narrowing) and non-ischemic segments (i.e. supplied by a non-significantly stenosed coronary artery in patients with significant CAD). Coronary angiography demonstrated significant CAD in 23 patients. BOLD CMR at rest revealed significantly lower T2* values for ischemic segments (26.7 ± 11.6 ms) compared to normal (31.9 ± 11.9 ms; p BOLD CMR at 3Tesla proved feasible and differentiated between ischemic, non-ischemic, and normal myocardial segments in a clinical patient population. BOLD CMR during vasodilator stress identified patients with significant CAD.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Multi-parametric quantification of tricuspid regurgitation using cardiovascular magnetic resonance: A comparison to echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Medvedofsky, Diego [Department of Medicine, University of Chicago Medical Center, Chicago, IL (United States); Jimenez, Javier Leon [Complejo Hospitalario Universitario de Huelva, Huelva (Spain); Addetia, Karima; Singh, Amita; Lang, Roberto M. [Department of Medicine, University of Chicago Medical Center, Chicago, IL (United States); Mor-Avi, Victor, E-mail: vmoravi@bsd.uchicago.edu [Department of Medicine, University of Chicago Medical Center, Chicago, IL (United States); Patel, Amit R. [Department of Medicine, University of Chicago Medical Center, Chicago, IL (United States)

    2017-01-15

    Background: Velocity-encoding is used to quantify tricuspid regurgitation (TR) by cardiovascular magnetic resonance (CMR), but requires additional dedicated imaging. We hypothesized that size and signal intensity (SI) of the cross-sectional TR jet area in the right atrium in short-axis steady-state free-precession images could be used to assess TR severity. Methods: We studied 61 patients with TR, who underwent CMR and echocardiography within 24 h. TR severity was determined by vena contracta: severe (N = 20), moderate or mild (N = 41). CMR TR jet area and normalized SI were measured in the plane and frame that depicted maximum area. ROC analysis was performed in 21/61 patients to determine diagnostic accuracy of differentiating degrees of TR. Optimal cutoffs were independently tested in the remaining 40 patients. Results: Measurable regions of signal loss depicting TR jets were noted in 51/61 patients, while 9/10 remaining patients had mild TR by echocardiography. With increasing TR severity, jet area significantly increased (15 ± 14 to 38 ± 20 mm{sup 2}), while normalized SI decreased (57 ± 27 to 23 ± 11). ROC analysis showed high AUC values in the derivation group and good accuracy in the test group. Conclusion: TR can be quantified from short-axis CMR images in agreement with echocardiography, while circumventing additional image acquisition.

  16. Non-invasive methods for estimating mPAP in COPD using cardiovascular magnetic resonance imaging

    International Nuclear Information System (INIS)

    Johns, C.S.; Capener, D.A.; Oram, C.; Wild, J.M.; Rajaram, S.; Elliot, C.; Condliffe, R.; Kiely, D.G.; Swift, A.J.

    2018-01-01

    Pulmonary hypertension (PH) is associated with a poor outcome in chronic obstructive pulmonary disease (COPD) and is diagnosed invasively. We aimed to assess the diagnostic accuracy and prognostic value of non-invasive cardiovascular magnetic resonance (CMR) models. Patients with COPD and suspected PH, who underwent CMR and right heart catheter (RHC) were identified. Three candidate models were assessed: 1, CMR-RV model, based on right ventricular (RV) mass and interventricular septal angle; 2, CMR PA/RV includes RV mass, septal angle and pulmonary artery (PA) measurements; 3, the Alpha index, based on RV ejection fraction and PA size. Of 102 COPD patients, 87 had PH. The CMR-PA/RV model had the strongest diagnostic accuracy (sensitivity 92%, specificity 80%, positive predictive value 96% and negative predictive value 63%, AUC 0.93, p<0.0001). Splitting RHC-mPAP, CMR-RV and CMR-PA/RV models by 35mmHg gave a significant difference in survival, with log-rank chi-squared 5.03, 5.47 and 7.10. RV mass and PA relative area change were the independent predictors of mortality at multivariate Cox regression (p=0.002 and 0.030). CMR provides diagnostic and prognostic information in PH-COPD. The CMR-PA/RV model is useful for diagnosis, the RV mass index and PA relative area change are useful to assess prognosis. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Muellerleile Kai

    2012-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Thoralf eNiendorf

    2015-11-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Importance of contrast-enhanced fluid-attenuated inversion reconvery magnetic resonance imaging in various intracranial pathologic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Kyoung; Lee, Eun Ja; Kim, Sung Won; Lee, Yong Seok [Dept. of Radiology, Dongguk University Ilsan Hospital, Goyang(Korea, Republic of)

    2016-02-15

    Intracranial lesions may show contrast enhancement through various mechanisms that are closely associated with the disease process. The preferred magnetic resonance sequence in contrast imaging is T1-weighted imaging (T1WI) at most institutions. However, lesion enhancement is occasionally inconspicuous on T1WI. Although fluid-attenuated inversion recovery (FLAIR) sequences are commonly considered as T2-weighted imaging with dark cerebrospinal fluid, they also show mild T1-weighted contrast, which is responsible for the contrast enhancement. For several years, FLAIR imaging has been successfully incorporated as a routine sequence at our institution for contrast-enhanced (CE) brain imaging in detecting various intracranial diseases. In this pictorial essay, we describe and illustrate the diagnostic importance of CE-FLAIR imaging in various intracranial pathologic conditions.

  1. The role of cardiovascular magnetic resonance in assessment of patients after radical surgical correction of tetralogy of Fallot

    International Nuclear Information System (INIS)

    Genova, K.; Dasheva, A.

    2014-01-01

    Surgical management of tetralogy of Fallot (TOF) results in residual anatomic and functional abnormalities in majority of patients. Primarily considered as a benign pulmonary regurgitation with the time results in right ventricular overload, loses the compensatory mechanisms and irreversible right ventricular dilatation and dysfunction. Cardiovascular magnetic resonance (CMR) has evolved during the last two decades as the reference standard imaging modality to assess the anatomic and functional changes in patients with repaired TOF. This article reviews the role of CMR to assess the right ventricular function and to evaluate the degree of pulmonary regurgitation and comments some technical aspects, based to our experience. Key words: Tetralogy of Fallot. Cardiovascular Magnetic Resonance. Pulmonary regurgitation. Right ventricular assessment

  2. Randomized trial of one-hour sodium bicarbonate vs standard periprocedural saline hydration in chronic kidney disease patients undergoing cardiovascular contrast procedures.

    Directory of Open Access Journals (Sweden)

    Judith Kooiman

    Full Text Available Guidelines advise periprocedural saline hydration for prevention of contrast induced-acute kidney injury (CI-AKI. We analysed whether 1-hour sodium bicarbonate hydration administered solely prior to intra-arterial contrast exposure is non-inferior to standard periprocedural saline hydration in chronic kidney disease (CKD patients undergoing elective cardiovascular diagnostic or interventional contrast procedures.We performed an open-label multicentre non-inferiority trial between 2011-2014. Patients were randomized to 1 hour pre-procedure sodium bicarbonate hydration (250 ml 1.4%, N = 168 or 4-12 hours saline hydration (1000 ml 0.9%, N = 165 prior to and following contrast administration (2000 ml of saline total. Primary outcome was the relative serum creatinine increase (% 48-96 hours post contrast exposure. Secondary outcomes were: incidence of CI-AKI (serum creatinine increase>25% or >44μmol/L, recovery of renal function, the need for dialysis, and hospital costs within two months follow-up.Mean relative creatinine increase was 3.1% (95%CI 0.9 to 5.2% in the bicarbonate and 1.1% (95%CI -1.2 to 3.5% in the saline arm, mean difference 1.9% (95%CI -1.2 to 5.1%, p-non-inferiority <0.001. CI-AKI occurred in 11 (6.7% patients randomized to sodium bicarbonate and 12 (7.5% to saline (p = 0.79. Renal function did not fully recover in 40.0% and 44.4% of CI-AKI patients, respectively (p = 0.84. No patient required dialysis. Mean costs for preventive hydration and clinical preparation for the contrast procedure were $1158 for sodium bicarbonate vs. $1561 for saline (p < 0.001.Short hydration with sodium bicarbonate prior to elective cardiovascular diagnostic or therapeutic contrast procedures is non-inferior to standard periprocedural saline hydration in CKD patients with respect to renal safety and results in considerable healthcare savings.Netherlands Trial Register (http://www.trialregister.nl/trialreg/index.asp, Nr NTR2699.

  3. Randomized trial of one-hour sodium bicarbonate vs standard periprocedural saline hydration in chronic kidney disease patients undergoing cardiovascular contrast procedures.

    Science.gov (United States)

    Kooiman, Judith; de Vries, Jean-Paul P M; Van der Heyden, Jan; Sijpkens, Yvo W J; van Dijkman, Paul R M; Wever, Jan J; van Overhagen, Hans; Vahl, Antonie C; Aarts, Nico; Verberk-Jonkers, Iris J A M; Brulez, Harald F H; Hamming, Jaap F; van der Molen, Aart J; Cannegieter, Suzanne C; Putter, Hein; van den Hout, Wilbert B; Kilicsoy, Inci; Rabelink, Ton J; Huisman, Menno V

    2018-01-01

    Guidelines advise periprocedural saline hydration for prevention of contrast induced-acute kidney injury (CI-AKI). We analysed whether 1-hour sodium bicarbonate hydration administered solely prior to intra-arterial contrast exposure is non-inferior to standard periprocedural saline hydration in chronic kidney disease (CKD) patients undergoing elective cardiovascular diagnostic or interventional contrast procedures. We performed an open-label multicentre non-inferiority trial between 2011-2014. Patients were randomized to 1 hour pre-procedure sodium bicarbonate hydration (250 ml 1.4%, N = 168) or 4-12 hours saline hydration (1000 ml 0.9%, N = 165) prior to and following contrast administration (2000 ml of saline total). Primary outcome was the relative serum creatinine increase (%) 48-96 hours post contrast exposure. Secondary outcomes were: incidence of CI-AKI (serum creatinine increase>25% or >44μmol/L), recovery of renal function, the need for dialysis, and hospital costs within two months follow-up. Mean relative creatinine increase was 3.1% (95%CI 0.9 to 5.2%) in the bicarbonate and 1.1% (95%CI -1.2 to 3.5%) in the saline arm, mean difference 1.9% (95%CI -1.2 to 5.1%, p-non-inferiority <0.001). CI-AKI occurred in 11 (6.7%) patients randomized to sodium bicarbonate and 12 (7.5%) to saline (p = 0.79). Renal function did not fully recover in 40.0% and 44.4% of CI-AKI patients, respectively (p = 0.84). No patient required dialysis. Mean costs for preventive hydration and clinical preparation for the contrast procedure were $1158 for sodium bicarbonate vs. $1561 for saline (p < 0.001). Short hydration with sodium bicarbonate prior to elective cardiovascular diagnostic or therapeutic contrast procedures is non-inferior to standard periprocedural saline hydration in CKD patients with respect to renal safety and results in considerable healthcare savings. Netherlands Trial Register (http://www.trialregister.nl/trialreg/index.asp), Nr NTR2699.

  4. Multivalent contrast agents based on Gd-DTPA-terminated poly (propylene imine) dendrimers for Magnetic Resonance Imaging

    NARCIS (Netherlands)

    Langereis, S.; Lussanet, de Q.G; Genderen, van M.H.P.; Backes, W.H.; Meijer, E.W.

    2004-01-01

    A convenient methodol. has been developed for the synthesis of gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA)-terminated poly(propylene imine) dendrimers as contrast agents for magnetic resonance imaging (MRI). In our strategy, isocyanate-activated, tert-butyl-protected DTPA analogs were

  5. Significance of left ventricular apical-basal muscle bundle identified by cardiovascular magnetic resonance imaging in patients with hypertrophic cardiomyopathy

    OpenAIRE

    Gruner, Christiane; Chan, Raymond H.; Crean, Andrew; Rakowski, Harry; Rowin, Ethan J.; Care, Melanie; Deva, Djeven; Williams, Lynne; Appelbaum, Evan; Gibson, C. Michael; Lesser, John R.; Haas, Tammy S.; Udelson, James E.; Manning, Warren J.; Siminovitch, Katherine

    2017-01-01

    Aims Cardiovascular magnetic resonance (CMR) has improved diagnostic and management strategies in hypertrophic cardiomyopathy (HCM) by expanding our appreciation for the diverse phenotypic expression. We sought to characterize the prevalence and clinical significance of a recently identified accessory left ventricular (LV) muscle bundle extending from the apex to the basal septum or anterior wall (i.e. apical-basal). Methods and results CMR was performed in 230 genotyped HCM patients (48 ± 15...

  6. The histological basis of late gadolinium enhancement cardiovascular magnetic resonance in a patient with Anderson-Fabry disease

    OpenAIRE

    Moon, J. C.; Sheppard, M.; Reed, E.; Lee, P.; Elliott, P. M.; Pennell, D. J.

    2006-01-01

    Anderson-Fabry Disease (AFD) is a storage disease that mimics hypertrophic cardiomyopathy. Late gadolinium enhancement (LGE) by cardiovascular magnetic resonance occurs in approximately 50% of patients in the basal inferolateral LV wall, but how an intracellular storage disease causes focal LGE is unknown. We present a whole-heart histological validation that LGE is caused by focal myocardial collagen scarring. This scarring may be the substrate for electrical re-entry and sudden arrhythmic d...

  7. Adenosine stress cardiovascular magnetic resonance with variable-density spiral pulse sequences accurately detects coronary artery disease: initial clinical evaluation.

    Science.gov (United States)

    Salerno, Michael; Taylor, Angela; Yang, Yang; Kuruvilla, Sujith; Ragosta, Michael; Meyer, Craig H; Kramer, Christopher M

    2014-07-01

    Adenosine stress cardiovascular magnetic resonance perfusion imaging can be limited by motion-induced dark-rim artifacts, which may be mistaken for true perfusion abnormalities. A high-resolution variable-density spiral pulse sequence with a novel density compensation strategy has been shown to reduce dark-rim artifacts in first-pass perfusion imaging. We aimed to assess the clinical performance of adenosine stress cardiovascular magnetic resonance using this new perfusion sequence to detect obstructive coronary artery disease. Cardiovascular magnetic resonance perfusion imaging was performed during adenosine stress (140 μg/kg per minute) and at rest on a Siemens 1.5-T Avanto scanner in 41 subjects with chest pain scheduled for coronary angiography. Perfusion images were acquired during injection of 0.1 mmol/kg Gadolinium-diethylenetriaminepentacetate at 3 short-axis locations using a saturation recovery interleaved variable-density spiral pulse sequence. Significant stenosis was defined as >50% by quantitative coronary angiography. Two blinded reviewers evaluated the perfusion images for the presence of adenosine-induced perfusion abnormalities and assessed image quality using a 5-point scale (1 [poor] to 5 [excellent]). The prevalence of obstructive coronary artery disease by quantitative coronary angiography was 68%. The average sensitivity, specificity, and accuracy were 89%, 85%, and 88%, respectively, with a positive predictive value and negative predictive value of 93% and 79%, respectively. The average image quality score was 4.4±0.7, with only 1 study with more than mild dark-rim artifacts. There was good inter-reader reliability with a κ statistic of 0.67. Spiral adenosine stress cardiovascular magnetic resonance results in high diagnostic accuracy for the detection of obstructive coronary artery disease with excellent image quality and minimal dark-rim artifacts. © 2014 American Heart Association, Inc.

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

    Directory of Open Access Journals (Sweden)

    Ibrahim El-Sayed H

    2011-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Karl-Heinz Hiller

    2006-04-01

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

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

    Directory of Open Access Journals (Sweden)

    Fan YANG

    2017-02-01

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

  11. New calcium-selective smart contrast agents for magnetic resonance imaging.

    Science.gov (United States)

    Verma, Kirti Dhingra; Forgács, Attila; Uh, Hyounsoo; Beyerlein, Michael; Maier, Martin E; Petoud, Stéphane; Botta, Mauro; Logothetis, Nikos K

    2013-12-23

    Calcium plays a vital role in the human body and especially in the central nervous system. Precise maintenance of Ca(2+) levels is very crucial for normal cell physiology and health. The deregulation of calcium homeostasis can lead to neuronal cell death and brain damage. To study this functional role played by Ca(2+) in the brain noninvasively by using magnetic resonance imaging, we have synthesized a new set of Ca(2+) -sensitive smart contrast agents (CAs). The agents were found to be highly selective to Ca(2+) in the presence of other competitive anions and cations in buffer and in physiological fluids. The structure of CAs comprises Gd(3+)-DO3A (DO3A=1,4,7-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecane) coupled to a Ca(2+) chelator o-amino phenol-N,N,O-triacetate (APTRA). The agents are designed to sense Ca(2+) present in extracellular fluid of the brain where its concentration is relatively high, that is, 1.2-0.8 mM. The determined dissociation constant of the CAs to Ca(2+) falls in the range required to sense and report changes in extracellular Ca(2+) levels followed by an increase in neural activity. In buffer, with the addition of Ca(2+) the increase in relaxivity ranged from 100-157%, the highest ever known for any T1-based Ca(2+)-sensitive smart CA. The CAs were analyzed extensively by the measurement of luminescence lifetime measurement on Tb(3+) analogues, nuclear magnetic relaxation dispersion (NMRD), and (17)O NMR transverse relaxation and shift experiments. The results obtained confirmed that the large relaxivity enhancement observed upon Ca(2+) addition is due to the increase of the hydration state of the complexes together with the slowing down of the molecular rotation and the retention of a significant contribution of the water molecules of the second sphere of hydration. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Differentiating perforated from non-perforated appendicitis on contrast-enhanced magnetic resonance imaging

    International Nuclear Information System (INIS)

    Rosenbaum, Daniel G.; Kovanlikaya, Arzu; Askin, Gulce; Beneck, Debra M.

    2017-01-01

    The role of magnetic resonance imaging (MRI) in pediatric appendicitis is increasing; MRI findings predictive of appendiceal perforation have not been specifically evaluated. To assess the performance of MRI in differentiating perforated from non-perforated appendicitis. A retrospective review of pediatric patients undergoing contrast-enhanced MRI and subsequent appendectomy was performed, with surgicopathological confirmation of perforation. Appendiceal diameter and the following 10 MRI findings were assessed: appendiceal restricted diffusion, wall defect, appendicolith, periappendiceal free fluid, remote free fluid, restricted diffusion within free fluid, abscess, peritoneal enhancement, ileocecal wall thickening and ileus. Two-sample t-test and chi-square tests were used to analyze continuous and discrete data, respectively. Sensitivity and specificity for individual MRI findings were calculated and optimal thresholds for measures of accuracy were selected. Seventy-seven patients (mean age: 12.2 years) with appendicitis were included, of whom 22 had perforation. The perforated group had a larger mean appendiceal diameter and mean number of MRI findings than the non-perforated group (12.3 mm vs. 8.6 mm; 5.0 vs. 2.0, respectively). Abscess, wall defect and restricted diffusion within free fluid had the greatest specificity for perforation (1.00, 1.00 and 0.96, respectively) but low sensitivity (0.36, 0.25 and 0.32, respectively). The receiver operator characteristic curve for total number of MRI findings had an area under the curve of 0.92, with an optimal threshold of 3.5. A threshold of any 4 findings had the best ability to accurately discriminate between perforated and non-perforated cases, with a sensitivity of 82% and specificity of 85%. Contrast-enhanced MRI can differentiate perforated from non-perforated appendicitis. The presence of multiple findings increases diagnostic accuracy, with a threshold of any four findings optimally discriminating between

  13. Differentiating perforated from non-perforated appendicitis on contrast-enhanced magnetic resonance imaging.

    Science.gov (United States)

    Rosenbaum, Daniel G; Askin, Gulce; Beneck, Debra M; Kovanlikaya, Arzu

    2017-10-01

    The role of magnetic resonance imaging (MRI) in pediatric appendicitis is increasing; MRI findings predictive of appendiceal perforation have not been specifically evaluated. To assess the performance of MRI in differentiating perforated from non-perforated appendicitis. A retrospective review of pediatric patients undergoing contrast-enhanced MRI and subsequent appendectomy was performed, with surgicopathological confirmation of perforation. Appendiceal diameter and the following 10 MRI findings were assessed: appendiceal restricted diffusion, wall defect, appendicolith, periappendiceal free fluid, remote free fluid, restricted diffusion within free fluid, abscess, peritoneal enhancement, ileocecal wall thickening and ileus. Two-sample t-test and chi-square tests were used to analyze continuous and discrete data, respectively. Sensitivity and specificity for individual MRI findings were calculated and optimal thresholds for measures of accuracy were selected. Seventy-seven patients (mean age: 12.2 years) with appendicitis were included, of whom 22 had perforation. The perforated group had a larger mean appendiceal diameter and mean number of MRI findings than the non-perforated group (12.3 mm vs. 8.6 mm; 5.0 vs. 2.0, respectively). Abscess, wall defect and restricted diffusion within free fluid had the greatest specificity for perforation (1.00, 1.00 and 0.96, respectively) but low sensitivity (0.36, 0.25 and 0.32, respectively). The receiver operator characteristic curve for total number of MRI findings had an area under the curve of 0.92, with an optimal threshold of 3.5. A threshold of any 4 findings had the best ability to accurately discriminate between perforated and non-perforated cases, with a sensitivity of 82% and specificity of 85%. Contrast-enhanced MRI can differentiate perforated from non-perforated appendicitis. The presence of multiple findings increases diagnostic accuracy, with a threshold of any four findings optimally discriminating between

  14. Differentiating perforated from non-perforated appendicitis on contrast-enhanced magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Rosenbaum, Daniel G.; Kovanlikaya, Arzu [New York-Presbyterian Hospital/Weill Cornell Medicine, Division of Pediatric Radiology, New York, NY (United States); Askin, Gulce [Weill Cornell Medical College, Division of Biostatistics and Epidemiology, New York, NY (United States); Beneck, Debra M. [New York-Presbyterian Hospital/Weill Cornell Medicine, Department of Pathology, New York, NY (United States)

    2017-10-15

    The role of magnetic resonance imaging (MRI) in pediatric appendicitis is increasing; MRI findings predictive of appendiceal perforation have not been specifically evaluated. To assess the performance of MRI in differentiating perforated from non-perforated appendicitis. A retrospective review of pediatric patients undergoing contrast-enhanced MRI and subsequent appendectomy was performed, with surgicopathological confirmation of perforation. Appendiceal diameter and the following 10 MRI findings were assessed: appendiceal restricted diffusion, wall defect, appendicolith, periappendiceal free fluid, remote free fluid, restricted diffusion within free fluid, abscess, peritoneal enhancement, ileocecal wall thickening and ileus. Two-sample t-test and chi-square tests were used to analyze continuous and discrete data, respectively. Sensitivity and specificity for individual MRI findings were calculated and optimal thresholds for measures of accuracy were selected. Seventy-seven patients (mean age: 12.2 years) with appendicitis were included, of whom 22 had perforation. The perforated group had a larger mean appendiceal diameter and mean number of MRI findings than the non-perforated group (12.3 mm vs. 8.6 mm; 5.0 vs. 2.0, respectively). Abscess, wall defect and restricted diffusion within free fluid had the greatest specificity for perforation (1.00, 1.00 and 0.96, respectively) but low sensitivity (0.36, 0.25 and 0.32, respectively). The receiver operator characteristic curve for total number of MRI findings had an area under the curve of 0.92, with an optimal threshold of 3.5. A threshold of any 4 findings had the best ability to accurately discriminate between perforated and non-perforated cases, with a sensitivity of 82% and specificity of 85%. Contrast-enhanced MRI can differentiate perforated from non-perforated appendicitis. The presence of multiple findings increases diagnostic accuracy, with a threshold of any four findings optimally discriminating between

  15. Assessment of Tumor Radioresponsiveness and Metastatic Potential by Dynamic Contrast-Enhanced Magnetic Resonance Imaging

    International Nuclear Information System (INIS)

    Ovrebo, Kirsti Marie; Gulliksrud, Kristine; Mathiesen, Berit; Rofstad, Einar K.

    2011-01-01

    Purpose: It has been suggested that gadolinium diethylene-triamine penta-acetic acid (Gd-DTPA)-based dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) may provide clinically useful biomarkers for personalized cancer treatment. In this preclinical study, we investigated the potential of DCE-MRI as a noninvasive method for assessing the radioresponsiveness and metastatic potential of tumors. Methods and Materials: R-18 melanoma xenografts growing in BALB/c nu/nu mice were used as experimental tumor models. Fifty tumors were subjected to DCE-MRI, and parametric images of K trans (the volume transfer constant of Gd-DTPA) and v e (the fractional distribution volume of Gd-DTPA) were produced by pharmacokinetic analysis of the DCE-MRI series. The tumors were irradiated after the DCE-MRI, either with a single dose of 10 Gy for detection of radiobiological hypoxia (30 tumors) or with five fractions of 4 Gy in 48 h for assessment of radioresponsiveness (20 tumors). The host mice were then euthanized and examined for lymph node metastases, and the primary tumors were resected for measurement of cell survival in vitro. Results: Tumors with hypoxic cells showed significantly lower K trans values than tumors without significant hypoxia (p trans decreased with increasing cell surviving fraction for tumors given fractionated radiation treatment (p trans values than tumors in metastasis-negative mice (p e and tumor hypoxia, radioresponsiveness, or metastatic potential could not be detected. Conclusions: R-18 tumors with low K trans values are likely to be resistant to radiation treatment and have a high probability of developing lymph node metastases. The general validity of these observations should be investigated further by studying preclinical tumor models with biological properties different from those of the R-18 tumors.

  16. Assessment of Hypoxia in Human Cervical Carcinoma Xenografts by Dynamic Contrast-Enhanced Magnetic Resonance Imaging

    International Nuclear Information System (INIS)

    Ellingsen, Christine; Egeland, Tormod A.M.; Gulliksrud, Kristine M.Sc.; Gaustad, Jon-Vidar; Mathiesen, Berit; Rofstad, Einar K.

    2009-01-01

    Purpose: Patients with advanced cervical cancer and highly hypoxic primary tumors show increased frequency of locoregional treatment failure and poor disease-free and overall survival rates. The potential usefulness of gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA)-based dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing tumor hypoxia noninvasively was investigated in the present preclinical study. Methods and Materials: CK-160 and TS-415 human cervical carcinoma xenografts transplanted intramuscularly (i.m.) or subcutaneously (s.c.) in BALB/c nu/nu mice were subjected to DCE-MRI and measurement of fraction of radiobiologically hypoxic cells. Tumor images of K trans (the volume transfer constant of Gd-DTPA) and v e (the extracellular volume fraction of the imaged tissue) were produced by pharmacokinetic analysis of the DCE-MRI data. Fraction of radiobiologically hypoxic cells was measured by using the paired survival curve method. Results: Fraction of radiobiologically hypoxic cells differed significantly among the four tumor groups. The mean values ± SE were determined to be 44% ± 7% (i.m. CK-160), 77% ± 10% (s.c. CK-160), 23% ± 5% (i.m. TS-415), and 52% ± 6% (s.c. TS-415). The four tumor groups differed significantly also in K trans , and there was an unambiguous inverse relationship between K trans and fraction of radiobiologically hypoxic cells. On the other hand, significant differences among the groups in v e could not be detected. Conclusions: The study supports the clinical development of DCE-MRI as a method for assessing the extent of hypoxia in carcinoma of the cervix

  17. Assessment of irradiated brain metastases using dynamic contrast-enhanced magnetic resonance imaging

    International Nuclear Information System (INIS)

    Almeida-Freitas, Daniela B.; Pinho, Marco C.; Otaduy, Maria C.G.; Costa Leite, Claudia da; Braga, Henrique F.; Meira-Freitas, Daniel

    2014-01-01

    The purpose of this study was to evaluate the effect of stereotactic radiosurgery (SRS) on cerebral metastases using the transfer constant (K trans ) assessed by dynamic contrast-enhanced (DCE) MRI. Furthermore, we aimed to evaluate the ability of K trans measurements to predict midterm tumor outcomes after SRS. The study received institutional review board approval, and informed consent was obtained from all subjects. Twenty-six adult patients with a total of 34 cerebral metastases underwent T1-weighted DCE MRI in a 1.5-T magnet at baseline (prior to SRS) and 4-8 weeks after treatment. Quantitative analysis of DCE MRI was performed by generating K trans parametric maps, and region-of-interest-based measurements were acquired for each metastasis. Conventional MRI was performed at least 16 weeks after SRS to assess midterm tumor outcome using volume variation. The mean (±SD) K trans value was 0.13 ± 0.11 min -1 at baseline and 0.08 ± 0.07 min -1 after 4-8 weeks post-treatment (p trans after SRS was predictive of tumor progression (hazard ratio = 1.50; 95 % CI = 1.16-1.70, p trans showed a sensitivity of 78 % and a specificity of 85 % for the prediction of progression at midterm follow-up. SRS was associated with a reduction of K trans values of the cerebral metastases in the early post-treatment period. Furthermore, K trans variation as assessed using DCE MRI may be helpful to predict midterm outcomes after SRS. (orig.)

  18. Variation in supratentorial cerebrospinal fluid production rate in one day. Measurement by nontriggered phase-contrast magnetic resonance imaging

    International Nuclear Information System (INIS)

    Takahashi, Hiroto; Tanaka, Hisashi; Fujita, Norihiko; Murase, Kenya; Tomiyama, Noriyuki

    2011-01-01

    Measuring the cerebrospinal fluid (CSF) production rate is important for understanding the physiology related to normal conditions and neurological disorders. Triggered phase-contrast magnetic resonance imaging (MRI) has been used to measure CSF production rate, but the use of nontriggered phase-contrast MRI has not been reported. The purposes of this study were to assess the feasibility of using nontriggered phase-contrast MRI to measure CSF flow and to determine whether CSF production exhibits circadian rhythm. The feasibility of phase-contrast MRI was assessed with a phantom simulated human cerebral aqueduct. CSF flow through the cerebral aqueduct was measured with nontriggered phase-contrast MRI four times during 1 day in 10 normal volunteers. In the phantom study, linear regression analysis gave the following measured values (ml/h): 0.80 x (value of steady flow)-10.0 for triggered phase-contrast MRI and 1.27 x (value of steady flow)-12.2 for nontriggered phase-contrast MRI. One-factor analysis of variance showed no significant effect of the time of the measurements (P=0.47). The supratentorial CSF production rate was 510±549 ml/day (mean ± SD). Nontriggered phase-contrast MRI provided good estimates of the flow rate in the phantom study. We observed no circadian rhythm in CSF production. (author)

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

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    Shaffer Jean M

    2010-05-01

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

  20. Correlative Study of Angiogenesis and Dynamic Contrast-Enhanced Magnetic Resonance Imaging Features of Hepatocellular Carcinoma

    International Nuclear Information System (INIS)

    Wang, B.; Gao, Z.Q.; Yan, X.

    2005-01-01

    Purpose: To explore the correlation between contrast-enhancement patterns on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and angiogenesis by analyzing microvessel density (MVD), vascular endothelial growth factor (VEGF), and P53 protein expression in hepatocellular carcinoma (HCC). Material and Methods: MRI was performed with a GE Signa 5T MR scanner using SE and FMPSPGR sequences in 30 patients (38 lesions) during the period October 1998 to March 2000. All had histopathologically proven HCC. MR images were reviewed/analyzed retrospectively. The 30 patients were between 35 and 65 years of age. SE T1WI, PDWI, and T2WI were acquired initially. The FMPSPGR sequence was acquired in the same position. The DCE-MRI was performed in the arterial, portal vein, and delay phase after a bolus injection of Gd-DTPA. The specimens were stained immunohistochemically for CD34, VEGF, and P53. MVD was highlighted by anti-CD34 antibody staining. The enhancement features of HCC lesions were studied correlatively with the tumor MVD, VEGF, and P53 expression at protein level. Results: In the arterial phase, the results showed that MVD of HCC in the high-enhancement group (229.76±80.96) was higher than that in the equal-enhancement (173.09±61.38) and low-enhancement groups (153.00±108.58) (P <0.01, respectively). VEGF expression of HCC in the high-enhancement group (68.42%) was higher than that in the equal-enhancement (36.36%) and low-enhancement groups (38.89%) (P <0.05, respectively). In the portal vein phase, MVD of HCC in the enhancement group (259.80±93.30) was higher than that in the non-enhancement group (178.64±92.65) (P <0.05). No significant correlation was found between VEGF expression and the enhancement feature in the portal vein phase. In the delay phase, MVD of HCC in the ring-enhancement group (269.06±57.89) was significantly higher than that in the non-ring-enhancement group (144.10±88.90) (P <0.01). There was a significant difference in VEGF

  1. Ultrasmall cationic superparamagnetic iron oxide nanoparticles as nontoxic and efficient MRI contrast agent and magnetic-targeting tool

    Science.gov (United States)

    Uchiyama, Mayara Klimuk; Toma, Sergio Hiroshi; Rodrigues, Stephen Fernandes; Shimada, Ana Lucia Borges; Loiola, Rodrigo Azevedo; Cervantes Rodríguez, Hernán Joel; Oliveira, Pedro Vitoriano; Luz, Maciel Santos; Rabbani, Said Rahnamaye; Toma, Henrique Eisi; Poliselli Farsky, Sandra Helena; Araki, Koiti

    2015-01-01

    Fully dispersible, cationic ultrasmall (7 nm diameter) superparamagnetic iron oxide nanoparticles, exhibiting high relaxivity (178 mM−1s−1 in 0.47 T) and no acute or subchronic toxicity in Wistar rats, were studied and their suitability as contrast agents for magnetic resonance imaging and material for development of new diagnostic and treatment tools demonstrated. After intravenous injection (10 mg/kg body weight), they circulated throughout the vascular system causing no microhemorrhage or thrombus, neither inflammatory processes at the mesentery vascular bed and hepatic sinusoids (leukocyte rolling, adhesion, or migration as evaluated by intravital microscopy), but having been spontaneously concentrated in the liver, spleen, and kidneys, they caused strong negative contrast. The nanoparticles are cleared from kidneys and bladder in few days, whereas the complete elimination from liver and spleen occurred only after 4 weeks. Ex vivo studies demonstrated that cationic ultrasmall superparamagnetic iron oxide nanoparticles caused no effects on hepatic and renal enzymes dosage as well as on leukocyte count. In addition, they were readily concentrated in rat thigh by a magnet showing its potential as magnetically targeted carriers of therapeutic and diagnostic agents. Summarizing, cationic ultrasmall superparamagnetic iron oxide nanoparticles are nontoxic and efficient magnetic resonance imaging contrast agents useful as platform for the development of new materials for application in theranostics. PMID:26251595

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

    International Nuclear Information System (INIS)

    Delewi, Ronak; Nijveldt, Robin; Hirsch, Alexander; Marcu, Constantin B.; Robbers, Lourens; Hassell, Marriela E.C.J.; Bruin, Rianne H.A. de; Vleugels, Jim; Laan, Anja M. van der; Bouma, Berto J.; Tio, René A.; Tijssen, Jan G.P.; Rossum, Albert C. van; Zijlstra, Felix; Piek, Jan J.

    2012-01-01

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

  3. Strain-encoding cardiovascular magnetic resonance for assessment of right-ventricular regional function

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    Abraham M Roselle

    2008-07-01

    Full Text Available Abstract Background Tissue tagging by cardiovascular magnetic resonance (CMR is a comprehensive method for the assessment of cardiac regional function. However, imaging the right ventricle (RV using this technique is problematic due to the thin wall of the RV relative to tag spacing which limits assessment of regional function using conventional in-plane tagging. Hypothesis We hypothesize that the use of through-plane tags in the strain-encoding (SENC CMR technique would result in reproducible measurements of the RV regional function due to the high image quality and spatial resolution possible with SENC. Aim To test the intra- and inter-observer variabilities of RV peak systolic strain measurements with SENC CMR for assessment of RV regional function (systolic strain in healthy volunteers. Methods Healthy volunteers (n = 21 were imaged using SENC. A four-chamber view was acquired in a single breath-hold. Circumferential strain was measured during systole at six equidistant points along the RV free wall. Peak contraction is defined as the maximum value of circumferential strain averaged from the six points, and regional function is defined as the strain value at each point at the time of peak contraction. Results Mean values for peak circumferential strain (± standard deviation of the basal, mid, and apical regions of the RV free wall were -20.4 ± 2.9%, -18.8 ± 3.9%, and -16.5 ± 5.7%, Altman plots showed good intra- and inter-observer agreements with mean difference of 0.11% and 0.32% and limits of agreement of -4.038 to 4.174 and -4.903 to 5.836, respectively. Conclusion SENC CMR allows for rapid quantification of RV regional function with low intra- and inter-observer variabilities, which could permit accurate quantification of regional strain in patients with RV dysfunction.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-12-15

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

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

    Directory of Open Access Journals (Sweden)

    Ait-Ali Lamia

    2011-11-01

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

  6. Left ventricular hypertrophy: The relationship between the electrocardiogram and cardiovascular magnetic resonance imaging.

    Science.gov (United States)

    Bacharova, Ljuba; Ugander, Martin

    2014-11-01

    Conventional assessment of left ventricular hypertrophy (LVH) using the electrocardiogram (ECG), for example, by the Sokolow-Lyon, Romhilt-Estes or Cornell criteria, have relied on assessing changes in the amplitude and/or duration of the QRS complex of the ECG to quantify LV mass. ECG measures of LV mass have typically been validated by imaging with echocardiography or cardiovascular magnetic resonance imaging (CMR). However, LVH can be the result of diverse etiologies, and LVH is also characterized by pathological changes in myocardial tissue characteristics on the genetic, molecular, cellular, and tissue level beyond a pure increase in the number of otherwise normal cardiomyocytes. For example, slowed conduction velocity through the myocardium, which can be due to diffuse myocardial fibrosis, has been shown to be an important determinant of conventional ECG LVH criteria regardless of LV mass. Myocardial tissue characterization by CMR has emerged to not only quantify LV mass, but also detect and quantify the extent and severity of focal or diffuse myocardial fibrosis, edema, inflammation, myocarditis, fatty replacement, myocardial disarray, and myocardial deposition of amyloid proteins (amyloidosis), glycolipids (Fabry disease), or iron (siderosis). This can be undertaken using CMR techniques including late gadolinium enhancement (LGE), T1 mapping, T2 mapping, T2* mapping, extracellular volume fraction (ECV) mapping, fat/water-weighted imaging, and diffusion tensor CMR. This review presents an overview of current and emerging concepts regarding the diagnostic possibilities of both ECG and CMR for LVH in an attempt to narrow gaps in our knowledge regarding the ECG diagnosis of LVH. © 2014 Wiley Periodicals, Inc.

  7. 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.

  8. BOLD cardiovascular magnetic resonance at 3.0 tesla in myocardial ischemia

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    Gebker Rolf

    2010-09-01

    Full Text Available Abstract Background The purpose of this study was to determine the ability of Blood Oxygen Level Dependent (BOLD cardiovascular magnetic resonance (CMR to detect stress-inducible myocardial ischemic reactions in the presence of angiographically significant coronary artery disease (CAD. Methods Forty-six patients (34 men; age 65 ± 9 years, with suspected or known coronary artery disease underwent CMR at 3Tesla prior to clinically indicated invasive coronary angiography. BOLD CMR was performed in 3 short axis slices of the heart at rest and during adenosine stress (140 μg/kg/min followed by late gadolinium enhancement (LGE imaging. In all 16 standard myocardial segments, T2* values were derived at rest and under adenosine stress. Quantitative coronary angiography served as the standard of reference and defined normal myocardial segments (i.e. all 16 segments in patients without any CAD, ischemic segments (i.e. supplied by a coronary artery with ≥50% luminal narrowing and non-ischemic segments (i.e. supplied by a non-significantly stenosed coronary artery in patients with significant CAD. Results Coronary angiography demonstrated significant CAD in 23 patients. BOLD CMR at rest revealed significantly lower T2* values for ischemic segments (26.7 ± 11.6 ms compared to normal (31.9 ± 11.9 ms; p Conclusions Rest and stress BOLD CMR at 3Tesla proved feasible and differentiated between ischemic, non-ischemic, and normal myocardial segments in a clinical patient population. BOLD CMR during vasodilator stress identified patients with significant CAD.

  9. Cardiovascular magnetic resonance imaging (CMR) reveals characteristic pattern of myocardial damage in patients with mitochondrial myopathy.

    Science.gov (United States)

    Yilmaz, Ali; Gdynia, Hans-Jürgen; Ponfick, Matthias; Rösch, Sabine; Lindner, Alfred; Ludolph, Albert C; Sechtem, Udo

    2012-04-01

    Mitochondrial myopathy comprises various clinical subforms of neuromuscular disorders that are characterised by impaired mitochondrial energy metabolism due to dysfunction of the mitochondrial respiratory chain. No comprehensive and targeted cardiovascular magnetic resonance (CMR) studies have been performed so far in patients with mitochondrial disorders. The present study aimed at characterising cardiac disease manifestations in patients with mitochondrial myopathy and elucidating the in vivo cardiac damage pattern of patients with different subforms of mitochondrial disease by CMR studies. In a prospective study, 37 patients with mitochondrial myopathy underwent comprehensive neurological and cardiac evaluations including physical examination, resting ECG and CMR. The CMR studies comprised cine-CMR, T2-weighted "edema" imaging and T1-weighted late-gadolinium-enhancement (LGE) imaging. Various patterns and degrees of skeletal myopathy were present in the participants of this study, whereas clinical symptoms such as chest pain symptoms (in eight (22%) patients) and various degrees of dyspnea (in 16 (43%) patients) were less frequent. Pathological ECG findings were documented in eight (22%) patients. T2-weighted "edema" imaging was positive in one (3%) patient with MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes) only. LGE imaging demonstrated the presence of non-ischemic LGE in 12 (32%) patients: 10 out of 24 (42%) patients with CPEO (chronic progressive external ophthalmoplegia) or KSS (Kearns-Sayre syndrome) and 2 of 3 (67%) patients with MELAS were LGE positive. All 10 LGE-positive patients with CPEO or KSS demonstrated a potentially typical pattern of diffuse intramural LGE in the left-ventricular (LV) inferolateral segments. Cardiac involvement is a frequent finding in patients with mitochondrial myopathy. A potentially characteristic pattern of diffuse intramural LGE in the LV inferolateral segments was identified in

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

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    Brown Michael A

    2010-07-01

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

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

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    O'Hanlon Rory

    2010-07-01

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

  12. Cardiovascular magnetic resonance findings in a pediatric population with isolated left ventricular non-compaction

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    Uribe Sergio

    2012-01-01

    Full Text Available Abstract Background Isolated Left Ventricular Non-compaction (LVNC is an uncommon disorder characterized by the presence of increased trabeculations and deep intertrabecular recesses. In adults, it has been found that Ejection Fraction (EF decreases significantly as non-compaction severity increases. In children however, there are a few data describing the relation between anatomical characteristics of LVNC and ventricular function. We aimed to find correlations between morphological features and ventricular performance in children and young adolescents with LVNC using Cardiovascular Magnetic Resonance (CMR. Methods 15 children with LVNC (10 males, mean age 9.7 y.o., range 0.6 - 17 y.o., underwent a CMR scan. Different morphological measures such as the Compacted Myocardial Mass (CMM, Non-Compaction (NC to the Compaction (C distance ratio, Compacted Myocardial Area (CMA and Non-Compacted Myocardial Area (NCMA, distribution of NC, and the assessment of ventricular wall motion abnormalities were performed to investigate correlations with ventricular performance. EF was considered normal over 53%. Results The distribution of non-compaction in children was similar to published adult data with a predilection for apical, mid-inferior and mid-lateral segments. Five patients had systolic dysfunction with decreased EF. The number of affected segments was the strongest predictor of systolic dysfunction, all five patients had greater than 9 affected segments. Basal segments were less commonly affected but they were affected only in these five severe cases. Conclusion The segmental pattern of involvement of non-compaction in children is similar to that seen in adults. Systolic dysfunction in children is closely related to the number of affected segments.

  13. Characterization of Chronic Aortic and Mitral Regurgitation Undergoing Valve Surgery Using Cardiovascular Magnetic Resonance.

    Science.gov (United States)

    Polte, Christian L; Gao, Sinsia A; Johnsson, Åse A; Lagerstrand, Kerstin M; Bech-Hanssen, Odd

    2017-06-15

    Grading of chronic aortic regurgitation (AR) and mitral regurgitation (MR) by cardiovascular magnetic resonance (CMR) is currently based on thresholds, which are neither modality nor quantification method specific. Accordingly, this study sought to identify CMR-specific and quantification method-specific thresholds for regurgitant volumes (RVols), RVol indexes, and regurgitant fractions (RFs), which denote severe chronic AR or MR with an indication for surgery. The study comprised patients with moderate and severe chronic AR (n = 38) and MR (n = 40). Echocardiography and CMR was performed at baseline and in all operated AR/MR patients (n = 23/25) 10 ± 1 months after surgery. CMR quantification of AR: direct (aortic flow) and indirect method (left ventricular stroke volume [LVSV] - pulmonary stroke volume [PuSV]); MR: 2 indirect methods (LVSV - aortic forward flow [AoFF]; mitral inflow [MiIF] - AoFF). All operated patients had severe regurgitation and benefited from surgery, indicated by a significant postsurgical reduction in end-diastolic volume index and improvement or relief of symptoms. The discriminatory ability between moderate and severe AR was strong for RVol >40 ml, RVol index >20 ml/m 2 , and RF >30% (direct method) and RVol >62 ml, RVol index >31 ml/m 2 , and RF >36% (LVSV-PuSV) with a negative likelihood ratio ≤ 0.2. In MR, the discriminatory ability was very strong for RVol >64 ml, RVol index >32 ml/m 2 , and RF >41% (LVSV-AoFF) and RVol >40 ml, RVol index >20 ml/m 2 , and RF >30% (MiIF-AoFF) with a negative likelihood ratio surgery. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. The effect of major adverse renal cardiovascular event (MARCE) incidence, procedure volume, and unit cost on the hospital savings resulting from contrast media use in inpatient angioplasty.

    Science.gov (United States)

    Keuffel, Eric; McCullough, Peter A; Todoran, Thomas M; Brilakis, Emmanouil S; Palli, Swetha R; Ryan, Michael P; Gunnarsson, Candace

    2018-04-01

    To determine the net economic impact of switching from low-osmolar contrast media (LOCM) to iso-osmolar contrast media (IOCM; iodixanol) in patients undergoing inpatient coronary or peripheral angioplasty in the United States (US). A budget impact model (BIM) was developed from a hospital perspective. Nationally representative procedural and contrast media prevalence rates, along with MARCE (major adverse renal cardiovascular event) incidence and episode-related cost data were derived from Premier Hospital Data (October 2014 to September 2015). A previously estimated relative risk reduction in MARCE associated with IOCM usage (9.3%) was applied. The higher cost of IOCM was included when calculating the net impact estimates at the aggregate, hospital type, and per hospital levels. One-way (±25%) and probabilistic sensitivity analyses identified the model's most important inputs. Based on weighted analysis, 513,882 US inpatient angioplasties and 35,610 MARCE cases were estimated annually. Switching to an "IOCM only" strategy from a "LOCM only" strategy increases contrast media cost, but prevents 2,900 MARCE events. The annual budget impact was an estimated saving of $30.71 million, aggregated across all US hospitals, $6,316 per hospital, or $60 per procedure. Net savings were maintained across all univariate sensitivity analyses. While MARCE/event-free cost differential was the most important factor driving total net savings for hospitals in the Northeast and West, procedural volume was important in the Midwest and rural locations. Switching to an "IOCM only" strategy from a "LOCM only" approach yields substantial net global savings to hospitals, both at the national level and within hospital sub-groups. Hospital administrators should maintain awareness of the factors that are likely to be more influential for their hospital and recognize that purchasing on the basis of lower contrast media cost may result in higher overall costs for patients undergoing inpatient

  15. Cardiovascular cine imaging and flow evaluation using Fast Interrupted Steady-State (FISS) magnetic resonance.

    Science.gov (United States)

    Edelman, Robert R; Serhal, Ali; Pursnani, Amit; Pang, Jianing; Koktzoglou, Ioannis

    2018-02-19

    Existing cine imaging techniques rely on balanced steady-state free precession (bSSFP) or spoiled gradient-echo readouts, each of which has limitations. For instance, with bSSFP, artifacts occur from rapid through-plane flow and off-resonance effects. We hypothesized that a prototype cine technique, radial fast interrupted steady-state (FISS), could overcome these limitations. The technique was compared with standard cine bSSFP for cardiac function, coronary artery conspicuity, and aortic valve morphology. Given its advantageous properties, we further hypothesized that the cine FISS technique, in combination with arterial spin labeling (ASL), could provide an alternative to phase contrast for visualizing in-plane flow patterns within the aorta and branch vessels. The study was IRB-approved and subjects provided consent. Breath-hold cine FISS and bSSFP were acquired using similar imaging parameters. There was no significant difference in biplane left ventricular ejection fraction or cardiac image quality between the two techniques. Compared with cine bSSFP, cine FISS demonstrated a marked decrease in fat signal which improved conspicuity of the coronary arteries, while suppression of through-plane flow artifact on thin-slice cine FISS images improved visualization of the aortic valve. Banding artifacts in the subcutaneous tissues were reduced. In healthy subjects, dynamic flow patterns were well visualized in the aorta, coronary and renal arteries using cine FISS ASL, even when the slice was substantially thicker than the vessel diameter. Cine FISS demonstrates several benefits for cardiovascular imaging compared with cine bSSFP, including better suppression of fat signal and reduced artifacts from through-plane flow and off-resonance effects. The main drawback is a slight (~ 20%) decrease in temporal resolution. In addition, preliminary results suggest that cine FISS ASL provides a potential alternative to phase contrast techniques for in-plane flow

  16. Human Aortic Endothelial Cell Labeling with Positive Contrast Gadolinium Oxide Nanoparticles for Cellular Magnetic Resonance Imaging at 7 Tesla

    Directory of Open Access Journals (Sweden)

    Yasir Loai

    2012-03-01

    Full Text Available Positive T1 contrast using gadolinium (Gd contrast agents can potentially improve detection of labeled cells on magnetic resonance imaging (MRI. Recently, gadolinium oxide (Gd2O3 nanoparticles have shown promise as a sensitive T1 agent for cell labeling at clinical field strengths compared to conventional Gd chelates. The objective of this study was to investigate Gado CELLTrack, a commercially available Gd2O3 nanoparticle, for cell labeling and MRI at 7 T. Relaxivity measurements yielded r1 = 4.7 s−1 mM−1 and r2/r1 = 6.2. Human aortic endothelial cells were labeled with Gd2O3 at various concentrations and underwent MRI from 1 to 7 days postlabeling. The magnetic resonance relaxation times T1 and T2 of labeled cell pellets were measured. Cellular contrast agent uptake was quantified by inductively coupled plasma–atomic emission spectroscopy, which showed very high uptake compared to conventional Gd compounds. MRI demonstrated significant positive T1 contrast and stable labeling on cells. Enhancement was optimal at low Gd concentrations, attained in the 0.02 to 0.1 mM incubation concentration range (corresponding cell uptake was 7.26 to 34.1 pg Gd/cell. Cell viability and proliferation were unaffected at the concentrations tested and up to at least 3 days postlabeling. Gd2O3 is a promising sensitive and stable positive contrast agent for cellular MRI at 7 T.

  17. Diagnosing upper extremity deep vein thrombosis with non-contrast-enhanced Magnetic Resonance Direct Thrombus Imaging: A pilot study.

    Science.gov (United States)

    Dronkers, C E A; Klok, F A; van Haren, G R; Gleditsch, J; Westerlund, E; Huisman, M V; Kroft, L J M

    2018-03-01

    Diagnosing upper extremity deep vein thrombosis (UEDVT) can be challenging. Compression ultrasonography is often inconclusive because of overlying anatomic structures that hamper compressing veins. Contrast venography is invasive and has a risk of contrast allergy. Magnetic Resonance Direct Thrombus Imaging (MRDTI) and Three Dimensional Turbo Spin-echo Spectral Attenuated Inversion Recovery (3D TSE-SPAIR) are both non-contrast-enhanced Magnetic Resonance Imaging (MRI) sequences that can visualize a thrombus directly by the visualization of methemoglobin, which is formed in a fresh blood clot. MRDTI has been proven to be accurate in diagnosing deep venous thrombosis (DVT) of the leg. The primary aim of this pilot study was to test the feasibility of diagnosing UEDVT with these MRI techniques. MRDTI and 3D TSE-SPAIR were performed in 3 pilot patients who were already diagnosed with UEDVT by ultrasonography or contrast venography. In all patients, UEDVT diagnosis could be confirmed by MRDTI and 3D TSE-SPAIR in all vein segments. In conclusion, this study showed that non-contrast MRDTI and 3D TSE-SPAIR sequences may be feasible tests to diagnose UEDVT. However diagnostic accuracy and management studies have to be performed before these techniques can be routinely used in clinical practice. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Assessing the efficacy of nano- and micro-sized magnetic particles as contrast agents for MRI cell tracking.

    Directory of Open Access Journals (Sweden)

    Arthur Taylor

    Full Text Available Iron-oxide based contrast agents play an important role in magnetic resonance imaging (MRI of labelled cells in vivo. Currently, a wide range of such contrast agents is available with sizes varying from several nanometers up to a few micrometers and consisting of single or multiple magnetic cores. Here, we evaluate the effectiveness of these different particles for labelling and imaging stem cells, using a mouse mesenchymal stem cell line to investigate intracellular uptake, retention and processing of nano- and microsized contrast agents. The effect of intracellular confinement on transverse relaxivity was measured by MRI at 7 T and in compliance with the principles of the '3Rs', the suitability of the contrast agents for MR-based cell tracking in vivo was tested using a chick embryo model. We show that for all particles tested, relaxivity was markedly reduced following cellular internalisation, indicating that contrast agent relaxivity in colloidal suspension does not accurately predict performance in MR-based cell tracking studies. Using a bimodal imaging approach comprising fluorescence and MRI, we demonstrate that labelled MSC remain viable following in vivo transplantation and can be tracked effectively using MRI. Importantly, our data suggest that larger particles might confer advantages for longer-term imaging.

  19. Semi-parametric arterial input functions for quantitative dynamic contrast enhanced magnetic resonance imaging in mice

    Czech Academy of Sciences Publication Activity Database

    Taxt, T.; Reed, R. K.; Pavlin, T.; Rygh, C. B.; Andersen, E.; Jiřík, Radovan

    2018-01-01

    Roč. 46, FEB (2018), s. 10-20 ISSN 0730-725X R&D Projects: GA ČR GA17-13830S; GA MŠk(CZ) LO1212 Institutional support: RVO:68081731 Keywords : DCE-MRI * blind deconvolution * arterial input function Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 2.225, year: 2016

  20. Magnetization transfer contrast (MTC) and MTC-subtraction: enhancement of cartilage lesions and intracartilaginous degeneration in vitro

    International Nuclear Information System (INIS)

    Vahlensieck, M.; Dombrowski, F.; Leutner, C.; Wagner, U.; Reiser, M.

    1994-01-01

    Human articular cartilage from 16 cadaveric or amputated knees was studied using standard magnetic resonance imaging (MRI), on-resonance magnetization transfer contrast (MTC) and MTC-subtraction MRI. Results were compared with subsequent macroscopic and histopathological findings. MTC-subtraction and T2-weighted spin-echo images visualized cartilaginous surface defects with high sensitivity and specificity. MTC and T2-weighted spin-echo images revealed intra-cartilaginous signal loss without surface defects in 80% of the cases, corresponding to an increased collagen concentration. It is concluded that MTC is sensitive to early cartilage degeneration and MTC-subtraction can be helpful in detecting cartilage defects. (orig.)

  1. Electric-field responsive contrast agent based on liquid crystals and magnetic nanoparticles

    Science.gov (United States)

    Mair, Lamar O.; Martinez-Miranda, Luz J.; Kurihara, Lynn K.; Nacev, Aleksandar; Hilaman, Ryan; Chowdhury, Sagar; Jafari, Sahar; Ijanaten, Said; da Silva, Claudian; Baker-McKee, James; Stepanov, Pavel Y.; Weinberg, Irving N.

    2018-05-01

    The properties of liquid crystal-magnetic nanoparticle composites have potential for sensing in the body. We study the response of a liquid crystal-magnetic nanoparticle (LC-MNP) composite to applied potentials of hundreds of volts per meter. Measuring samples using X-ray diffraction (XRD) and imaging composites using magnetic resonance imaging (MRI), we demonstrate that electric potentials applied across centimeter scale LC-MNP composite samples can be detected using XRD and MRI techniques.

  2. Tracer kinetic model selection for dynamic contrast-enhanced magnetic resonance imaging of locally advanced cervical cancer

    DEFF Research Database (Denmark)

    Kallehauge, Jesper Folsted; Tanderup, Kari; Duan, Chong

    2014-01-01

    , the TM was optimal in 17.0%, the ETM was optimal in 2.2%, the C-TU in 23.4% and the 2CXM was optimal in 57.3%. Throughout the tumour, a high correlation was found between Ktrans(TM) and Fp(2CXM), ρ = 0.91. Conclusion. The 2CXM was most often optimal in describing the contrast agent enhancement of pre......Background. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) offers a unique capability to probe tumour microvasculature. Different analysis of the acquired data will possibly lead to different conclusions. Therefore, the objective of this study was to investigate under which...

  3. Evaluation of heart perfusion in patients with acute myocardial infarction using dynamic contrast-enhanced magnetic resonance imaging

    DEFF Research Database (Denmark)

    Nielsen, Gitte; Fritz-Hansen, Thomas; Dirks, Christina G

    2004-01-01

    with acute transmural myocardial infarction were studied using a Turbo-fast low angle shot (FLASH) MRI sequence to monitor the first pass of an extravascular contrast agent (CA), gadolinium diethylene triamine pentaacetic acid (Gd-DTPA). Quantitation of perfusion, expressed as Ki (mL/100 g/minute), in five......PURPOSE: To investigate the diagnostic ability of quantitative magnetic resonance imaging (MRI) heart perfusion in acute heart patients, a fast, multislice dynamic contrast-enhanced MRI sequence was applied to patients with acute myocardial infarction. MATERIALS AND METHODS: Seven patients...

  4. Serial contrast-enhanced magnetic resonance and magnetization transfer in the study of patients with multiple sclerosis; Resonancia magnetica con contraste y transferencia de magnetizacion en el estudio seriado de pacientes con esclerosis multiple

    Energy Technology Data Exchange (ETDEWEB)

    Rovira, A; Alonso, J; Cucurella, G; Nos, C; Tintore, M; Pedraza, S; Rio, J; Montalban, X [Hospital General i Universitari Vall d` Hebron. Barcelona (Spain)

    1998-12-31

    To demonstrate the changes in the magnetization transfer ratio (MTR) of different demyelinating plaques, correlating them with the baseline values in T1-weighted contrast-enhanced magnetic resonance (MR) sequences in order to relate them more closely to the underlying disease. The study was based on 33 demyelinating plaques obtained from six patients clinically diagnosed as having remitting-recurring multiple sclerosis (MS). All the patients underwent two MR studies at a 3 to 5-month interval, including contrast-enhanced T1 and T2- weighted sequences and magnetization transfer images. The latter were used to calculate the MTR for each of the demyelinating plaques included in the study. The statistical analysis of the results obtained revealed statistically significant between initial MTR values and those of subsequent T1-weighted sequences. The MTR demonstrate significant differences between plaques according to contrast-enhanced T1-weigh tes sequences, probably indicating variable degrees of edema, demyelination and tissue destruction. These differences should be taken into account to enable the use of T1-weighted sequences to quantify the lesion load in MS patients. (Author) 35 refs.

  5. Contrast Media for X-ray and Magnetic Resonance Imaging: Development, Current Status and Future Perspectives.

    Science.gov (United States)

    Frenzel, Thomas; Lawaczeck, Rüdiger; Taupitz, Matthias; Jost, Gregor; Lohrke, Jessica; Sieber, Martin A; Pietsch, Hubertus

    2015-09-01

    Over the last 120 years, the extensive advances in medical imaging allowed enhanced diagnosis and therapy of many diseases and thereby improved the quality of life of many patient generations. From the beginning, all technical solutions and imaging procedures were combined with dedicated pharmaceutical developments of contrast media, to further enhance the visualization of morphology and physiology. This symbiosis of imaging hardware and contrast media development was of high importance for the development of modern clinical radiology. Today, all available clinically approved contrast media fulfill the highest requirements for clinical safety and efficacy. All new concepts to increase the efficacy of contrast media have also to consider the high clinical safety standards and cost of goods of current marketed contrast media. Nevertheless, diagnostic imaging will contribute significantly to the progresses in medicine, and new contrast media developments are mandatory to address the medical needs of the future.

  6. Magnetic resonance tomography of the orbit: First experiences with the paramagnetic contrast medium gadolinium-DTPA

    International Nuclear Information System (INIS)

    Markl, A.; Vogl, T.; Scheidhauer, K.; Riedel, K.G.; Oeckler, R.

    1986-01-01

    In 21 patients with orbital mass lesions MRI was performed before and after administration of paramagnetic contrast medium, gadolinium-DPTA. In comparison to the plain scan the differentiation of the tumorous tissue against the surrounding structures was improved after application of contrast medium despite a partially moderate increase in signal intensity. Especially highly vascular tumors and vessel diseases show a significant contrast enhancement. With increasing experience in larger number of patients a tissue differentiation seems to be possible. (orig.) [de

  7. Neuromyelitis optica with linear enhancement of corpus callosum in brain magnetic resonance imaging with contrast: a case report.

    Science.gov (United States)

    Sahraian, Mohammad Ali; Moghadasi, Abdorreza Naser; Owji, Mahsa; Naghshineh, Hoda; Minagar, Alireza

    2015-06-10

    Neuromyelitis optica is a demyelinating disease of the central nervous system with various patterns of brain lesions. Corpus callosum may be involved in both multiple sclerosis and neuromyelitis optica. Previous case reports have demonstrated that callosal lesions in neuromyelitis optica are usually large and edematous and have a heterogeneous intensity showing a "marbled pattern" in the acute phase. Their size and intensity may reduce with time or disappear in the chronic stages. In this report, we describe a case of a 25-year-old Caucasian man with neuromyelitis optica who presented clinically with optic neuritis and myelitis. His brain magnetic resonance imaging demonstrated linear enhancement of the corpus callosum. Brain images with contrast agent added also showed linear ependymal layer enhancement of the lateral ventricles, which has been reported in this disease previously. Linear enhancement of corpus callosum in magnetic resonance imaging with contrast agent could help in diagnosing neuromyelitis optica and differentiating it from other demyelinating disease, especially multiple sclerosis.

  8. Preoperative radiological characterization of hepatic angiomyolipoma using magnetic resonance imaging and contrast-enhanced ultrasonography: a case report

    Directory of Open Access Journals (Sweden)

    Schmid Roland M

    2011-09-01

    Full Text Available Abstract Introduction A hepatic angiomyolipoma is a rare benign tumor of the liver composed of a mixture of smooth muscle cells, blood vessels and a variable amount of adipose tissue. Differentiating them from malignant liver tumors can often be very difficult. Case presentation We report the case of a 43-year-old Caucasian man presenting with a large liver mass in the right lobe. The results of magnetic resonance imaging and contrast-enhanced ultrasonography were consistent with a well-demarcated adipose tissue- containing tumor, showing prolonged hyperperfusion in comparison with the surrounding liver tissue. Surgery was performed and the diagnosis of hepatic angiomyolipoma was made with histopathology. Conclusion Preoperative radiological characterization using magnetic resonance imaging and contrast-enhanced ultrasonography may improve diagnostic accuracy of hepatic angiomyolipoma. Identification of smooth muscle cells, blood vessels and adipose tissue with a positive immunohistochemical reaction for HMB-45 is the final evidence for an angiomyolipoma.

  9. 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

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

    Directory of Open Access Journals (Sweden)

    Kalaf Jose M

    2011-01-01

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

  11. Gd-DTPA: a bowel contrast agent for magnetic resonance imaging of the abdomen

    International Nuclear Information System (INIS)

    Vlahos, L.; Gouliamos, A.; Clauss, W.; Kalovidouris, A.; Hadjiioannou, A.; Athanasopoulou, A.; Trakadas, S.; Papavasiliou, C.

    1992-01-01

    Forty patients with suspected pathology in the abdomen and pelvis have been investigated with MRI before and after administration of Gd-DTPA as an oral or rectal solution. The findings are analysed with respect to: (a) filling of the GI tract; (b) contrast in the region of interest, surrounding fat and vessels; (c) diagnostic yield in comparison to non-enhanced MRI and contrast CT. At a concentration of 1 mmol/l Gd-DTPA provided consistent positive contrast in the stomach and bowel in all cases. In 57.5% of cases we achieved complete filling of the GI tract. The opacification in the region of interest was good or satisfactory in 90% of cases. The diagnostic value of contrast MRI was better in 93% of cases than the non-enhanced MRI of the abdomen. In comparison with contrast CT, the contrast MRI was better or of the same value in 92% of cases. Despite the disadvantage of poor fat-to-bowel contrast (35% of cases were classified as poor), it is concluded that Gd-DTPA-enhanced MRI provides good delineation of organs adjacent to the bowel so this contrast agent has potential for a future role in abdominal MRI. (orig.)

  12. Gd-DTPA: a bowel contrast agent for magnetic resonance imaging of the abdomen

    Energy Technology Data Exchange (ETDEWEB)

    Vlahos, L. [Dept. of Radiology, Univ. of Athens, Areteion Hospital (Greece); Gouliamos, A. [Dept. of Radiology, Univ. of Athens, Areteion Hospital (Greece); Clauss, W. [Schering A. G., Berlin (Germany); Kalovidouris, A. [Dept. of Radiology, Univ. of Athens, Areteion Hospital (Greece); Hadjiioannou, A. [Dept. of Radiology, Univ. of Athens, Areteion Hospital (Greece); Athanasopoulou, A. [Dept. of Radiology, Univ. of Athens, Areteion Hospital (Greece); Trakadas, S. [Dept. of Radiology, Univ. of Athens, Areteion Hospital (Greece); Papavasiliou, C. [Dept. of Radiology, Univ. of Athens, Areteion Hospital (Greece)

    1992-08-01

    Forty patients with suspected pathology in the abdomen and pelvis have been investigated with MRI before and after administration of Gd-DTPA as an oral or rectal solution. The findings are analysed with respect to: (a) filling of the GI tract; (b) contrast in the region of interest, surrounding fat and vessels; (c) diagnostic yield in comparison to non-enhanced MRI and contrast CT. At a concentration of 1 mmol/l Gd-DTPA provided consistent positive contrast in the stomach and bowel in all cases. In 57.5% of cases we achieved complete filling of the GI tract. The opacification in the region of interest was good or satisfactory in 90% of cases. The diagnostic value of contrast MRI was better in 93% of cases than the non-enhanced MRI of the abdomen. In comparison with contrast CT, the contrast MRI was better or of the same value in 92% of cases. Despite the disadvantage of poor fat-to-bowel contrast (35% of cases were classified as poor), it is concluded that Gd-DTPA-enhanced MRI provides good delineation of organs adjacent to the bowel so this contrast agent has potential for a future role in abdominal MRI. (orig.)

  13. Accuracy of pre-contrast imaging in abdominal magnetic resonance imaging of pediatric oncology patients

    International Nuclear Information System (INIS)

    Mohd Zaki, Faizah; Moineddin, Rahim; Grant, Ronald; Chavhan, Govind B.

    2016-01-01

    Safety concerns are increasingly raised regarding the use of gadolinium-based contrast media for MR imaging. To determine the accuracy of pre-contrast abdominal MR imaging for lesion detection and characterization in pediatric oncology patients. We included 120 children (37 boys and 83 girls; mean age 8.94 years) referred by oncology services. Twenty-five had MRI for the first time and 95 were follow-up scans. Two authors independently reviewed pre-contrast MR images to note the following information about the lesions: location, number, solid vs. cystic and likely nature. Pre- and post-contrast imaging reviewed together served as the reference standard. The overall sensitivity was 88% for the first reader and 90% for the second; specificity was 94% and 91%; positive predictive value was 96% and 94%; negative predictive value was 82% and 84%; accuracy of pre-contrast imaging for lesion detection as compared to the reference standard was 90% for both readers. The difference between mean number of lesions detected on pre-contrast imaging and reference standard was not significant for either reader (reader 1, P = 0.072; reader 2, P = 0.071). There was substantial agreement (kappa values of 0.76 and 0.72 for readers 1 and 2) between pre-contrast imaging and reference standard for determining solid vs. cystic lesion and likely nature of the lesion. The addition of post-contrast imaging increased confidence of both readers significantly (P < 0.0001), but the interobserver agreement for the change in confidence was poor (kappa 0.12). Pre-contrast abdominal MR imaging has high accuracy in lesion detection in pediatric oncology patients and shows substantial agreement with the reference standard for characterization of lesions. Gadolinium-based contrast media administration cannot be completely eliminated but can be avoided in many cases, with the decision made on a case-by-case basis, taking into consideration location and type of tumor. (orig.)

  14. Accuracy of pre-contrast imaging in abdominal magnetic resonance imaging of pediatric oncology patients

    Energy Technology Data Exchange (ETDEWEB)

    Mohd Zaki, Faizah [University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children and Medical Imaging, Toronto, ON (Canada); Universiti Kebangsaan Malaysia Medical Center, Department of Radiology, Kuala Lumpur (Malaysia); Moineddin, Rahim [University of Toronto, Department of Family and Community Medicine, Toronto, ON (Canada); Grant, Ronald [University of Toronto, Department of Hematology and Oncology, The Hospital for Sick Children and Medical Imaging, Toronto, ON (Canada); Chavhan, Govind B. [University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children and Medical Imaging, Toronto, ON (Canada)

    2016-11-15

    Safety concerns are increasingly raised regarding the use of gadolinium-based contrast media for MR imaging. To determine the accuracy of pre-contrast abdominal MR imaging for lesion detection and characterization in pediatric oncology patients. We included 120 children (37 boys and 83 girls; mean age 8.94 years) referred by oncology services. Twenty-five had MRI for the first time and 95 were follow-up scans. Two authors independently reviewed pre-contrast MR images to note the following information about the lesions: location, number, solid vs. cystic and likely nature. Pre- and post-contrast imaging reviewed together served as the reference standard. The overall sensitivity was 88% for the first reader and 90% for the second; specificity was 94% and 91%; positive predictive value was 96% and 94%; negative predictive value was 82% and 84%; accuracy of pre-contrast imaging for lesion detection as compared to the reference standard was 90% for both readers. The difference between mean number of lesions detected on pre-contrast imaging and reference standard was not significant for either reader (reader 1, P = 0.072; reader 2, P = 0.071). There was substantial agreement (kappa values of 0.76 and 0.72 for readers 1 and 2) between pre-contrast imaging and reference standard for determining solid vs. cystic lesion and likely nature of the lesion. The addition of post-contrast imaging increased confidence of both readers significantly (P < 0.0001), but the interobserver agreement for the change in confidence was poor (kappa 0.12). Pre-contrast abdominal MR imaging has high accuracy in lesion detection in pediatric oncology patients and shows substantial agreement with the reference standard for characterization of lesions. Gadolinium-based contrast media administration cannot be completely eliminated but can be avoided in many cases, with the decision made on a case-by-case basis, taking into consideration location and type of tumor. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Ladd Mark E

    2010-10-01

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

  16. Vessel Wall Inflammation of Takayasu Arteritis Detected by Contrast-Enhanced Magnetic Resonance Imaging: Association with Disease Distribution and Activity.

    Directory of Open Access Journals (Sweden)

    Yoko Kato

    Full Text Available The assessment of the distribution and activity of vessel wall inflammation is clinically important in patients with Takayasu arteritis. Magnetic resonance imaging (MRI is a useful tool, but the clinical utility of late gadolinium enhancement (LGE in Takayasu arteritis has yet to be determined. The aim of the present study was to evaluate the utility of LGE in assessing vessel wall inflammation and disease activity in Takayasu arteritis.We enrolled 49 patients with Takayasu arteritis who had undergone 1.5 T MRI. Patients were divided into Active (n = 19 and Inactive disease (n = 30 groups. The distribution of vessel wall inflammation using angiography and LGE was assessed by qualitative analysis. In 79% and 63% of patients in Active and Inactive groups, respectively, greater distribution of vessel wall inflammation was observed with LGE than with conventional angiography. MRI values of pre- and post-contrast signal-to-noise ratios (SNR, SNR increment (post-SNR minus pre-SNR, pre- and post-contrast contrast-to-noise ratios (CNR, and CNR increment (post-CNR minus pre-CNR were evaluated at arterial wall sites with the highest signal intensity using quantitative analysis of post-contrast LGE images. No statistically significant differences in MRI parameters were observed between Active and Inactive groups. Contrast-enhanced MRI was unable to accurately detect active disease.Contrast-enhanced MRI has utility in detecting the distribution of vessel wall inflammation but has less utility in assessing disease activity in Takayasu arteritis.

  17. Dynamic magnetic resonance angiography of the arteries of the hand. A comparison between an extracellular and an intravascular contrast agent

    International Nuclear Information System (INIS)

    Reisinger, Clemens; Gluecker, Thomas; Jacob, Augustinus Ludwig; Bongartz, Georg; Bilecen, Deniz

    2009-01-01

    The purpose of this study was to compare the image quality of the intravascular contrast agent gadofosveset with the extracellular contrast agent gadoterate meglumine in time-resolved three-dimensional magnetic resonance (MR) angiography of the human arteries of the hand. The value of cuff compression technique for suppression of venous enhancement for both contrast agents was also investigated. Three-dimensional MR angiograms of both hands of 11 healthy volunteers were acquired for each contrast agent at 1.5-T, while subsystolic cuff compression was applied at one side. Quantitative and qualitative evaluation were performed and analyzed with Student's t-test. Visualization of vessels was superior in the images acquired with gadofosveset, especially in the late phases. Quantitative and qualitative evaluation showed significantly higher values for gadofosveset. The cuff compression at the lower arm proved to be an effective method to enhance arterial vessels. In conclusion the blood pool agent gadofosveset is superior for the dynamic imaging of the vessels of the hand when compared with the extracellular contrast agent gadoterate meglumine. To fully utilize the advantages of intravascular contrast agents, venous overlay has to be delayed or reduced, which can be achieved effectively by subsystolic lower arm cuff compression. (orig.)

  18. Cardiovascular mortality and exposure to extremely low frequency magnetic fields: a cohort study of Swiss railway workers

    Directory of Open Access Journals (Sweden)

    Pfluger Dominik

    2008-07-01

    Full Text Available Abstract Background Exposure to intermittent magnetic fields of 16 Hz has been shown to reduce heart rate variability, and decreased heart rate variability predicts cardiovascular mortality. We examined mortality from cardiovascular causes in railway workers exposed to varying degrees to intermittent 16.7 Hz magnetic fields. Methods We studied a cohort of 20,141 Swiss railway employees between 1972 and 2002, including highly exposed train drivers (median lifetime exposure 120.5 μT-years, and less or little exposed shunting yard engineers (42.1 μT-years, train attendants (13.3 μT-years and station masters (5.7 μT-years. During 464,129 person-years of follow up, 5,413 deaths were recorded and 3,594 deaths were attributed to cardio-vascular diseases. We analyzed data using Cox proportional hazards models. Results For all cardiovascular mortality the hazard ratio compared to station masters was 0.99 (95%CI: 0.91, 1.08 in train drivers, 1.13 (95%CI: 0.98, 1.30 in shunting yard engineers, and 1.09 (95%CI: 1.00, 1.19 in train attendants.Corresponding hazard ratios for arrhythmia related deaths were 1.04 (95%CI: 0.68, 1.59, 0.58 (95%CI: 0.24, 1.37 and 1.30 (95%CI: 0.87, 1.93 and for acute myocardial infarction 1.00 (95%CI: 0.73, 1.36, 1.56 (95%CI: 1.04, 2.32, and 1.14 (95%CI: 0.85, 1.53. The hazard ratio for arrhythmia related deaths per 100 μT-years of cumulative exposure was 0.94 (95%CI: 0.71, 1.24 and 0.91 (95%CI: 0.75, 1.11 for acute myocardial infarction. Conclusion This study provides evidence against an association between long-term occupational exposure to intermittent 16.7 Hz magnetic fields and cardiovascular mortality.

  19. The Impact of Injector-Based Contrast Agent Administration on Bolus Shape and Magnetic Resonance Angiography Image Quality.

    Science.gov (United States)

    Jost, Gregor; Endrikat, Jan; Pietsch, Hubertus

    2017-01-01

    To compare injector-based contrast agent (CA) administration with hand injection in magnetic resonance angiography (MRA). Gadobutrol was administered in 6 minipigs with 3 protocols: (a) hand injection (one senior technician), (b) hand injection (6 less-experienced technicians), and (c) power injector administration. The arterial bolus shape was quantified by test bolus measurements. A head and neck MRA was performed for quantitative and qualitative comparison of signal enhancement. A significantly shorter time to peak was observed for protocol C, whereas no significant differences between protocols were found for peak height and bolus width. However, for protocol C, these parameters showed a much lower variation. The MRA revealed a significantly higher signal-to-noise ratio for injector-based administration. A superimposed strong contrast of the jugular vein was found in 50% of the hand injections. Injector-based CA administration results in a more standardized bolus shape, a higher vascular contrast, and a more robust visualization of target vessels.

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

    Directory of Open Access Journals (Sweden)

    Sjögren Jane

    2012-01-01

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

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

    Science.gov (United States)

    Sjögren, Jane; Ubachs, Joey F A; Engblom, Henrik; Carlsson, Marcus; Arheden, Håkan; Heiberg, Einar

    2012-01-31

    T2-weighted cardiovascular magnetic resonance (CMR) has been shown to be a promising technique for determination of ischemic myocardium, referred to as myocardium at risk (MaR), after an acute coronary event. Quantification of MaR in T2-weighted CMR has been proposed to be performed by manual delineation or the threshold methods of two standard deviations from remote (2SD), full width half maximum intensity (FWHM) or Otsu. However, manual delineation is subjective and threshold methods have inherent limitations related to threshold definition and lack of a priori information about cardiac anatomy and physiology. Therefore, the aim of this study was to develop an automatic segmentation algorithm for quantification of MaR using anatomical a priori information. Forty-seven patients with first-time acute ST-elevation myocardial infarction underwent T2-weighted CMR within 1 week after admission. Endocardial and epicardial borders of the left ventricle, as well as the hyper enhanced MaR regions were manually delineated by experienced observers and used as reference method. A new automatic segmentation algorithm, called Segment MaR, defines the MaR region as the continuous region most probable of being MaR, by estimating the intensities of normal myocardium and MaR with an expectation maximization algorithm and restricting the MaR region by an a priori model of the maximal extent for the user defined culprit artery. The segmentation by Segment MaR was compared against inter observer variability of manual delineation and the threshold methods of 2SD, FWHM and Otsu. MaR was 32.9 ± 10.9% of left ventricular mass (LVM) when assessed by the reference observer and 31.0 ± 8.8% of LVM assessed by Segment MaR. The bias and correlation was, -1.9 ± 6.4% of LVM, R = 0.81 (p Segment MaR, -2.3 ± 4.9%, R = 0.91 (p Segment MaR and manually assessed MaR in T2-weighted CMR. Thus, the proposed algorithm seems to be a promising, objective method for standardized MaR quantification in T2

  2. An interactive videogame designed to improve respiratory navigator efficiency in children undergoing cardiovascular magnetic resonance.

    Science.gov (United States)

    Hamlet, Sean M; Haggerty, Christopher M; Suever, Jonathan D; Wehner, Gregory J; Grabau, Jonathan D; Andres, Kristin N; Vandsburger, Moriel H; Powell, David K; Sorrell, Vincent L; Fornwalt, Brandon K

    2016-09-06

    Advanced cardiovascular magnetic resonance (CMR) acquisitions often require long scan durations that necessitate respiratory navigator gating. The tradeoff of navigator gating is reduced scan efficiency, particularly when the patient's breathing patterns are inconsistent, as is commonly seen in children. We hypothesized that engaging pediatric participants with a navigator-controlled videogame to help control breathing patterns would improve navigator efficiency and maintain image quality. We developed custom software that processed the Siemens respiratory navigator image in real-time during CMR and represented diaphragm position using a cartoon avatar, which was projected to the participant in the scanner as visual feedback. The game incentivized children to breathe such that the avatar was positioned within the navigator acceptance window (±3 mm) throughout image acquisition. Using a 3T Siemens Tim Trio, 50 children (Age: 14 ± 3 years, 48 % female) with no significant past medical history underwent a respiratory navigator-gated 2D spiral cine displacement encoding with stimulated echoes (DENSE) CMR acquisition first with no feedback (NF) and then with the feedback game (FG). Thirty of the 50 children were randomized to undergo extensive off-scanner training with the FG using a MRI simulator, or no off-scanner training. Navigator efficiency, signal-to-noise ratio (SNR), and global left-ventricular strains were determined for each participant and compared. Using the FG improved average navigator efficiency from 33 ± 15 to 58 ± 13 % (p < 0.001) and improved SNR by 5 % (p = 0.01) compared to acquisitions with NF. There was no difference in navigator efficiency (p = 0.90) or SNR (p = 0.77) between untrained and trained participants for FG acquisitions. Circumferential and radial strains derived from FG acquisitions were slightly reduced compared to NF acquisitions (-16 ± 2 % vs -17 ± 2 %, p < 0.001; 40 ± 10

  3. Predictors of ischaemic mitral regurgitation recurrence in patients undergoing combined surgery: additional value of cardiovascular magnetic resonance imaging.

    Science.gov (United States)

    Glaveckaite, Sigita; Uzdavinyte-Gateliene, Egle; Petrulioniene, Zaneta; Palionis, Darius; Valeviciene, Nomeda; Kalinauskas, Gintaras; Serpytis, Pranas; Laucevicius, Aleksandras

    2018-03-09

    We aimed to evaluate (i) the effectiveness of combined surgery (coronary artery bypass grafting with restrictive mitral valve annuloplasty) and (ii) the late gadolinium enhancement cardiovascular magnetic resonance-based predictors of ischaemic mitral regurgitation (IMR) recurrence. The prospective analysis included 40 patients with multivessel coronary artery disease, IMR >II° and left ventricular (LV) dysfunction undergoing combined surgery. The degree of IMR and LV parameters were assessed preoperatively by transthoracic echocardiography, 3D transoesophageal echocardiography and cardiovascular magnetic resonance and postoperatively by transthoracic echocardiography. The effective mitral valve repair group (n = 30) was defined as having recurrent ischaemic mitral regurgitation (RIMR) ≤II° at the end of follow-up (25 ± 11 months). The surgery was effective: freedom from RIMR >II° at 1 and 2 years after surgery was 80% and 75%, respectively. Using multivariable logistic regression, 2 independent predictors of RIMR >II° were identified: ≥3 non-viable LV segments (odds ratio 22, P = 0.027) and ≥1 non-viable segment in the LV posterior wall (odds ratio 11, P = 0.026). Using classification trees, the best combinations of cardiovascular magnetic resonance-based and 3D transoesophageal echocardiography-based predictors for RIMR >II° were (i) posterior mitral valve leaflet angle >40° and LV end-systolic volume index >45 ml/m2 (sensitivity 100%, specificity 89%) and (ii) scar transmurality >68% in the inferior LV wall and EuroSCORE II >8 (sensitivity 83%, specificity 78%). There is a clear relationship between the amount of non-viable LV segments, especially in the LV posterior and inferior walls, and the recurrence of IMR after the combined surgery.

  4. Verification of novel magnetic nanoparticles as a contrast media for MRI-CT/SPECT imaging

    Czech Academy of Sciences Publication Activity Database

    Kostiv, Uliana; Laudová, B.; Lobaz, Volodymyr; Kučka, Jan; Franová, P.; Hrubý, Martin; Horák, Daniel; Šefc, L.

    2017-01-01

    Roč. 13, č. 1 (2017), s. 156 ISSN 1336-7242. [Zjazd chemikov /69./. 11.09.2017-15.09.2017, Horný Smokovec] Institutional support: RVO:61389013 Keywords : magnetic nanoparticles * diagnostics Subject RIV: CD - Macromolecular Chemistry

  5. Ultrasmall cationic superparamagnetic iron oxide nanoparticles as nontoxic and efficient MRI contrast agent and magnetic-targeting tool

    Directory of Open Access Journals (Sweden)

    Uchiyama MK

    2015-07-01

    Full Text Available Mayara Klimuk Uchiyama,1 Sergio Hiroshi Toma,1 Stephen Fernandes de Paula Rodrigues,2 Ana Lucia Borges Shimada,2 Rodrigo Azevedo Loiola,2 Hernán Joel Cervantes Rodríguez,3 Pedro Vitoriano Oliveira,4 Maciel Santos Luz,4 Said Rahnamaye Rabbani,3 Henrique Eisi Toma,1 Sandra Helena Poliselli Farsky,2 Koiti Araki11Laboratory of Supramolecular Chemistry and Nanotechnology, Department of Fundamental Chemistry, Institute of Chemistry, 2Laboratory of Experimental Toxicology, Department of Clinical and Toxicological Analysis, Faculty of Pharmaceutical Sciences, 3Magnetic Resonance Laboratory, Department of General Physics, Institute of Physics, 4Analysis and Research Group in Spectrometry, Department of Fundamental Chemistry, Institute of Chemistry, University of Sao Paulo, Sao Paulo, SP, BrazilAbstract: Fully dispersible, cationic ultrasmall (7 nm diameter superparamagnetic iron oxide nanoparticles, exhibiting high relaxivity (178 mM-1s-1 in 0.47 T and no acute or subchronic toxicity in Wistar rats, were studied and their suitability as contrast agents for magnetic resonance imaging and material for development of new diagnostic and treatment tools demonstrated. After intravenous injection (10 mg/kg body weight, they circulated throughout the vascular system causing no microhemorrhage or thrombus, neither inflammatory processes at the mesentery vascular bed and hepatic sinusoids (leukocyte rolling, adhesion, or migration as evaluated by intravital microscopy, but having been spontaneously concentrated in the liver, spleen, and kidneys, they caused strong negative contrast. The nanoparticles are cleared from kidneys and bladder in few days, whereas the complete elimination from liver and spleen occurred only after 4 weeks. Ex vivo studies demonstrated that cationic ultrasmall superparamagnetic iron oxide nanoparticles caused no effects on hepatic and renal enzymes dosage as well as on leukocyte count. In addition, they were readily concentrated in rat

  6. The histological basis of late gadolinium enhancement cardiovascular magnetic resonance in a patient with Anderson-Fabry disease.

    Science.gov (United States)

    Moon, James C; Sheppard, Mary; Reed, Emma; Lee, Phillip; Elliott, Perry M; Pennell, Dudley J

    2006-01-01

    Anderson-Fabry Disease (AFD) is a storage disease that mimics hypertrophic cardiomyopathy. Late gadolinium enhancement (LGE) by cardiovascular magnetic resonance occurs in approximately 50% of patients in the basal inferolateral LV wall, but how an intracellular storage disease causes focal LGE is unknown. We present a whole-heart histological validation that LGE is caused by focal myocardial collagen scarring. This scarring may be the substrate for electrical re-entry and sudden arrhythmic death. The reasons for this distribution of fibrosis are unclear, but may reflect inhomogeneous left ventricular wall stress.

  7. Regional contrast agent quantification in a mouse model of myocardial infarction using 3D cardiac T1 mapping

    NARCIS (Netherlands)

    Coolen, Bram F.; Geelen, Tessa; Paulis, Leonie E. M.; Nicolay, Klaas; Strijkers, Gustav J.

    2011-01-01

    Quantitative relaxation time measurements by cardiovascular magnetic resonance (CMR) are of paramount importance in contrast-enhanced studies of experimental myocardial infarction. First, compared to qualitative measurements based on signal intensity changes, they are less sensitive to specific

  8. Dynamic contrast-enhanced magnetic resonance imaging of the wrist in children with juvenile idiopathic arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Nusman, Charlotte M. [Emma Children' s Hospital, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Academic Medical Center, Amsterdam (Netherlands); Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Lavini, Cristina; Hemke, Robert; Caan, Matthan W.A.; Maas, Mario [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Schonenberg-Meinema, Dieneke; Berg, J.M. van den; Kuijpers, Taco W. [Emma Children' s Hospital, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Academic Medical Center, Amsterdam (Netherlands); Dolman, Koert M. [Sint Lucas Andreas Hospital, Department of Pediatrics, Amsterdam (Netherlands); Reade Institute location Jan van Breemen, Department of Pediatric Rheumatology, Amsterdam (Netherlands); Rossum, Marion A.J. van [Reade Institute location Jan van Breemen, Department of Pediatric Rheumatology, Amsterdam (Netherlands); Emma Children' s Hospital, Department of Pediatrics, Academic Medical Center, Amsterdam (Netherlands)

    2017-02-15

    Dynamic contrast-enhanced MRI provides information on the heterogeneity of the synovium, the primary target of disease in children with juvenile idiopathic arthritis (JIA). To evaluate the feasibility of dynamic contrast-enhanced MRI in the wrist of children with JIA using conventional descriptive measures and time-intensity-curve shape analysis. To explore the association between enhancement characteristics and clinical disease status. Thirty-two children with JIA and wrist involvement underwent dynamic contrast-enhanced MRI with movement-registration and were classified using validated criteria as clinically active (n = 27) or inactive (n = 5). Outcome measures included descriptive parameters and the classification into time-intensity-curve shapes, which represent the patterns of signal intensity change over time. Differences in dynamic contrast-enhanced MRI outcome measures between clinically active and clinically inactive disease were analyzed and correlation with the Juvenile Arthritis Disease Activity Score was determined. Comprehensive evaluation of disease status was technically feasible and the quality of the dynamic dataset was improved by movement registration. The conventional descriptive measure maximum enhancement differed significantly between clinically active and inactive disease (P = 0.019), whereas time-intensity-curve shape analysis showed no differences. Juvenile Arthritis Disease Activity Score correlated moderately with enhancing volume (P = 0.484). Dynamic contrast-enhanced MRI is a promising biomarker for evaluating disease status in children with JIA and wrist involvement. Conventional descriptive dynamic contrast-enhanced MRI measures are better associated with clinically active disease than time-intensity-curve shape analysis. (orig.)

  9. Absolute quantification of regional renal blood flow in swine by dynamic contrast-enhanced magnetic resonance imaging using a blood pool contrast agent.

    Science.gov (United States)

    Lüdemann, Lutz; Nafz, Benno; Elsner, Franz; Grosse-Siestrup, Christian; Meissler, Michael; Kaufels, Nicola; Rehbein, Hagen; Persson, Pontus B; Michaely, Henrik J; Lengsfeld, Philipp; Voth, Matthias; Gutberlet, Matthias

    2009-03-01

    To evaluate for the first time in an animal model the possibility of absolute regional quantification of renal medullary and cortical perfusion by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using a blood pool contrast agent. A total of 18 adult female pigs (age, 16-22 weeks; body weight, 45-65 kg; no dietary restrictions) were investigated by DCE-MRI. Absolute renal blood flow (RBF) measured by an ultrasound transit time flow probe around the renal vein was used as the standard of reference. An inflatable stainless cuff placed around the renal artery near its origin from the abdominal aorta was used to reduce RBF to 60%, 40%, and 20% of the baseline flow. The last measurement was performed with the cuff fully reopened. Absolute RBF values during these 4 perfusion states were compared with the results of DCE-MRI performed on a 1.5-T scanner with an 8-channel phased-array surface coil. All scans were acquired in breath-hold technique in the coronal plane using a field of view of 460 mm.Each dynamic scan commenced with a set of five 3D T1-weighted gradient echo sequences with different flip angles (alpha = 2 degrees, 5 degrees, 10 degrees, 20 degrees, 30 degrees): TE, 0.88 milliseconds; TR, 2.65 milliseconds; slice thickness, 8.8 mm for 4 slices; acquisition matrix, 128 x 128; and acquisitions, 4. These data served to calculate 3D intrinsic longitudinal relaxation rate maps (R10) and magnetization (M0). Immediately after these images, the dynamic 3D T1-weighted gradient echo images were acquired with the same parameters and a constant alpha = 30 degrees, half Fourier, 1 acquisition, 64 frames, a time interval of 1.65 seconds between each frame, and a total duration of 105.6. Three milliliters of an albumin-binding blood pool contrast agent (0.25 mmol/mL gadofosveset trisodium, Vasovist, Bayer Schering Pharma AG, Berlin, Germany) was injected at a rate of 3 mL/s. Perfusion was calculated using the arterial input function from the aorta, which was

  10. Validation of Perfusion Quantification with 3D Gradient Echo Dynamic Contrast-Enhanced Magnetic Resonance Imaging Using a Blood Pool Contrast Agent in Skeletal Swine Muscle.

    Directory of Open Access Journals (Sweden)

    Stefan Hindel

    Full Text Available The purpose of our study was to validate perfusion quantification in a low-perfused tissue by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI with shared k-space sampling using a blood pool contrast agent. Perfusion measurements were performed in a total of seven female pigs. An ultrasonic Doppler probe was attached to the right femoral artery to determine total flow in the hind leg musculature. The femoral artery was catheterized for continuous local administration of adenosine to increase blood flow up to four times the baseline level. Three different stable perfusion levels were induced. The MR protocol included a 3D gradient-echo sequence with a temporal resolution of approximately 1.5 seconds. Before each dynamic sequence, static MR images were acquired with flip angles of 5°, 10°, 20°, and 30°. Both static and dynamic images were used to generate relaxation rate and baseline magnetization maps with a flip angle method. 0.1 mL/kg body weight of blood pool contrast medium was injected via a central venous catheter at a flow rate of 5 mL/s. The right hind leg was segmented in 3D into medial, cranial, lateral, and pelvic thigh muscles, lower leg, bones, skin, and fat. The arterial input function (AIF was measured in the aorta. Perfusion of the different anatomic regions was calculated using a one- and a two-compartment model with delay- and dispersion-corrected AIFs. The F-test for model comparison was used to decide whether to use the results of the one- or two-compartment model fit. Total flow was calculated by integrating volume-weighted perfusion values over the whole measured region. The resulting values of delay, dispersion, blood volume, mean transit time, and flow were all in physiologically and physically reasonable ranges. In 107 of 160 ROIs, the blood signal was separated, using a two-compartment model, into a capillary and an arteriolar signal contribution, decided by the F-test. Overall flow in hind leg muscles

  11. Combined dynamic contrast-enhancement and serial 3D-subtraction analysis in magnetic resonance imaging of osteoid osteomas

    Energy Technology Data Exchange (ETDEWEB)

    Kalle, T. von; Winkler, P. [Klinikum Stuttgart Olgahospital, Department of Paediatric Radiology, Stuttgart (Germany); Langendoerfer, M.; Fernandez, F.F. [Klinikum Stuttgart Olgahospital, Department of Paediatric Orthopaedics, Stuttgart (Germany)

    2009-10-15

    The purpose of this study was to retrospectively correlate the results of dynamic contrast-enhanced magnetic resonance imaging (MRI) with histological and clinical diagnoses in patients with osteoid osteomas. Fifty-four patients with the MR diagnosis of osteoid osteoma were studied. MRI (1.5 Tesla) consisted of thin-section STIR sequences, dynamic 3D T1 gradient echo sequences during application of contrast material, and high-resolution postcontrast T1 spin echo sequences with fat saturation (maximum voxel size 0.6 x 0.6 x 3.0 mm). Evaluation was focused on serial image subtraction during the early phase after contrast injection and on time-intensity curves. The surrounding edema was helpful in finding the nidus in each lesion. In 49 of 54 patients (90.7%), the diagnosis of osteoid osteoma was certain or highly probable (sensitivity 1.0, positive predictive value 0.91). A total of 38 of 54 osteoid osteomas were histologically proven. Five MRI diagnoses were regarded as false positives. A similar proportion has been reported for computed tomography. Tailored high-resolution MR examinations with dynamic contrast enhancement can reliably diagnose osteoid osteomas and exactly localize the nidus without radiation exposure. We propose a stepwise approach with STIR sequences, dynamic contrast-enhanced scanning, and high-resolution postcontrast T1 spin echo sequences with fat saturation. (orig.)

  12. Combined dynamic contrast-enhancement and serial 3D-subtraction analysis in magnetic resonance imaging of osteoid osteomas

    International Nuclear Information System (INIS)

    Kalle, T. von; Winkler, P.; Langendoerfer, M.; Fernandez, F.F.

    2009-01-01

    The purpose of this study was to retrospectively correlate the results of dynamic contrast-enhanced magnetic resonance imaging (MRI) with histological and clinical diagnoses in patients with osteoid osteomas. Fifty-four patients with the MR diagnosis of osteoid osteoma were studied. MRI (1.5 Tesla) consisted of thin-section STIR sequences, dynamic 3D T1 gradient echo sequences during application of contrast material, and high-resolution postcontrast T1 spin echo sequences with fat saturation (maximum voxel size 0.6 x 0.6 x 3.0 mm). Evaluation was focused on serial image subtraction during the early phase after contrast injection and on time-intensity curves. The surrounding edema was helpful in finding the nidus in each lesion. In 49 of 54 patients (90.7%), the diagnosis of osteoid osteoma was certain or highly probable (sensitivity 1.0, positive predictive value 0.91). A total of 38 of 54 osteoid osteomas were histologically proven. Five MRI diagnoses were regarded as false positives. A similar proportion has been reported for computed tomography. Tailored high-resolution MR examinations with dynamic contrast enhancement can reliably diagnose osteoid osteomas and exactly localize the nidus without radiation exposure. We propose a stepwise approach with STIR sequences, dynamic contrast-enhanced scanning, and high-resolution postcontrast T1 spin echo sequences with fat saturation. (orig.)

  13. Gadolinium Contrast Agent is of Limited Value for Magnetic Resonance Imaging Assessment of Synovial Hypertrophy in Hemophiliacs

    Energy Technology Data Exchange (ETDEWEB)

    Lundin, B.; Berntorp, E.; Pettersson, H.; Wirestam, R.; Jonsson, K.; Staahlberg, F.; Ljung, R. [Dept. of Radiology, Univ Hospital of Lund, Lund (Sweden)

    2007-07-15

    Purpose: To examine the influence of different doses of gadolinium contrast agent on synovial enhancement, to compare magnetic resonance imaging (MRI) findings of synovial hypertrophy and radiographic joint changes in hemophiliacs, and to investigate the value of gadolinium in MRI assessment of synovial hypertrophy in hemophiliacs using dynamic MRI and MRI scoring. Material and Methods: Twenty-one hemophiliacs on prophylactic factor treatment without recent bleeds were subjected to radiography and gadolinium contrast-enhanced dynamic and static MRI of the knee using a standard dose of 0.1 mmol/kg b.w. gadoteridol. In 17 of the patients, the MRI procedure was repeated after a triple dose of gadoteridol. Results: MRI findings of synovial hypertrophy were significantly correlated with Pettersson radiographic scores. In 19 of the 21 MRI investigated joints, administration of contrast agent did not alter the result of the evaluation of synovial hypertrophy. Conclusion: The optimal time interval for volume assessment of synovial hypertrophy after injection of gadolinium contrast agent is dose dependent. Hemophiliacs without recent bleeds have minor to abundant synovial hypertrophy in joints with pronounced radiographic changes. Dynamic MRI is not useful for evaluating hemophilic arthropathy, and gadolinium contrast agent is not routinely indicated for MRI scoring of joints in hemophiliacs.

  14. Gadolinium Contrast Agent is of Limited Value for Magnetic Resonance Imaging Assessment of Synovial Hypertrophy in Hemophiliacs

    International Nuclear Information System (INIS)

    Lundin, B.; Berntorp, E.; Pettersson, H.; Wirestam, R.; Jonsson, K.; Staahlberg, F.; Ljung, R.

    2007-01-01

    Purpose: To examine the influence of different doses of gadolinium contrast agent on synovial enhancement, to compare magnetic resonance imaging (MRI) findings of synovial hypertrophy and radiographic joint changes in hemophiliacs, and to investigate the value of gadolinium in MRI assessment of synovial hypertrophy in hemophiliacs using dynamic MRI and MRI scoring. Material and Methods: Twenty-one hemophiliacs on prophylactic factor treatment without recent bleeds were subjected to radiography and gadolinium contrast-enhanced dynamic and static MRI of the knee using a standard dose of 0.1 mmol/kg b.w. gadoteridol. In 17 of the patients, the MRI procedure was repeated after a triple dose of gadoteridol. Results: MRI findings of synovial hypertrophy were significantly correlated with Pettersson radiographic scores. In 19 of the 21 MRI investigated joints, administration of contrast agent did not alter the result of the evaluation of synovial hypertrophy. Conclusion: The optimal time interval for volume assessment of synovial hypertrophy after injection of gadolinium contrast agent is dose dependent. Hemophiliacs without recent bleeds have minor to abundant synovial hypertrophy in joints with pronounced radiographic changes. Dynamic MRI is not useful for evaluating hemophilic arthropathy, and gadolinium contrast agent is not routinely indicated for MRI scoring of joints in hemophiliacs

  15. Magnetic Resonance Spectroscopy of the Breast at 3T: Pre- and Post-Contrast Evaluation for Breast Lesion Characterization

    Directory of Open Access Journals (Sweden)

    E. Kousi

    2012-01-01

    Full Text Available Purpose. To determine whether in vivo proton magnetic resonance spectroscopy at 3T can provide accurate breast lesion characterization, and to determine the effect of gadolinium on the resonance of tCho. Methods. Twenty-four positive-mammogram patients were examined on a 3T MR scanner. 1H-MRS was performed before and after gadolinium administration. tCho peak was qualitatively evaluated before and after contrast injection. Results. Fourteen out of 27 lesions proved to be malignant after histopathological diagnosis. Using 1H-MRS, before contrast injection, 6/14 confirmed malignancies and 11/13 benign lesions were correctly classified; while, after contrast injection, 11/14 confirmed malignancies and 12/13 benign processes were correctly classified. Post gadolinium 1H-MRS proved useful in picking up tCho signal, improving the overall accuracy, sensitivity, and specificity by 35%, 83%, and 9%, respectively. Conclusion. 1H-MRS overall accuracy, sensitivity, and specificity in detecting breast lesion’s malignancy were increased after gadolinium administration. It is prudent to perform 1H-MRS before contrast injection in large breast lesions to avoid choline underestimation. In cases of small or non-mass lesions, it is recommended to perform 1H-MRS after contrast injection for better voxel prescription to enable a reliable preoperative diagnosis.

  16. Gadolinium-based magnetic resonance contrast agents at 7 Tesla: in vitro T1 relaxivities in human blood plasma.

    Science.gov (United States)

    Noebauer-Huhmann, Iris M; Szomolanyi, Pavol; Juras, Vladimír; Kraff, Oliver; Ladd, Mark E; Trattnig, Siegfried

    2010-09-01

    PURPOSE/INTRODUCTION: The aim of this study was to determine the T1 relaxivities (r1) of 8 gadolinium (Gd)-based MR contrast agents in human blood plasma at 7 Tesla, compared with 3 Tesla. Eight commercially available Gd-based MR contrast agents were diluted in human blood plasma to concentrations of 0, 0.25, 0.5, 1, and 2 mmol/L. In vitro measurements were performed at 37 degrees C, on a 7 Tesla and on a 3 Tesla whole-body magnetic resonance imaging scanner. For the determination of T1 relaxation times, Inversion Recovery Sequences with inversion times from 0 to 3500 ms were used. The relaxivities were calculated. The r1 relaxivities of all agents, diluted in human blood plasma at body temperature, were lower at 7 Tesla than at 3 Tesla. The values at 3 Tesla were comparable to those published earlier. Notably, in some agents, a minor negative correlation of r1 with a concentration of up to 2 mmol/L could be observed. This was most pronounced in the agents with the highest protein-binding capacity. At 7 Tesla, the in vitro r1 relaxivities of Gd-based contrast agents in human blood plasma are lower than those at 3 Tesla. This work may serve as a basis for the application of Gd-based MR contrast agents at 7 Tesla. Further studies are required to optimize the contrast agent dose in vivo.

  17. 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.

  18. Development of Gd(III) porphyrin-conjugated chitosan nanoparticles as contrast agents for magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Jahanbin, Tania [Université Paul Sabatier, Toulouse III, INSERM U825, CHU Purpan, 31059 Toulouse Cedex 9 (France); Sauriat-Dorizon, Hélène [Institut de Chimie Moléculaire et des Matériaux d' Orsay, UMR CNRS 8182, ECBB, Université Paris-Sud, 91405 Orsay (France); Spearman, Peter [Faculty of Science, Engineering and Computing, University of Kingston, Penrhyn Road Kingston upon Thames Surrey KT1 2EE, London (United Kingdom); Benderbous, Soraya, E-mail: soraya.benderbous@univ-tlse3.fr [Université Paul Sabatier, Toulouse III, INSERM U825, CHU Purpan, 31059 Toulouse Cedex 9 (France); Korri-Youssoufi, Hafsa, E-mail: hafsa.korri-youssoufi@u-psud.fr [Institut de Chimie Moléculaire et des Matériaux d' Orsay, UMR CNRS 8182, ECBB, Université Paris-Sud, 91405 Orsay (France)

    2015-07-01

    A novel magnetic resonance imaging (MRI) contrast agent based on gadolinium meso-tetrakis(4-pyridyl)porphyrin [Gd(TPyP)] conjugated with chitosan nanoparticles has been developed. The chitosan nanoparticles were synthesized following an ionic gelation method and the conditions optimized to generate small nanoparticles (CNs) with a narrow size distribution of 35–65 nm. The gadolinium meso-tetrakis(4-pyridyl)porphyrin [Gd(TPyP)] was loaded into chitosan nanoparticles by passive adsorption. The interaction of chitosan with Gd(TPyP) has been examined by UV–visible, Fourier transform infrared spectroscopies (FT-IR) and inductively coupled plasma mass spectrometry (ICP-MS), which indicate the successful association of Gd(TPyP) without any structural distortion throughout the chitosan nanoparticles. The potential of Gd(TPyP)-CNs as MRI contrast agent has been investigated by magnetic resonance imaging (MRI) in-vitro. Relaxivities of Gd(TPyP)-CNs obtained from T{sub 1}-weighted images, increased with Gd concentration and attained an optimum r{sub 1} of 38.35 mM{sup −1} s{sup −1}, which is 12-fold higher compared to commercial Gd-DOTA (~ 4 mM{sup −1} s{sup −1} at 3T). The combination of such strong MRI contrast with the known properties of porphyrins in photodynamic therapy and biocompatibility of chitosan, presents a new perspective in using these compounds in cancer theranostics. - Highlights: • Synthesis of chitosan nanoparticles with small size • Study of loading properties with gadolinium porphyrins • In vitro properties of the conjugated complex as contrast agent for MRI imaging • Comparison of MRI properties with commercial contrast agent Gd-DOTA.

  19. Highly stable silica-coated manganese ferrite nanoparticles as high-efficacy T2 contrast agents for magnetic resonance imaging

    Science.gov (United States)

    Ahmad, Ashfaq; Bae, Hongsub; Rhee, Ilsu

    2018-05-01

    Highly stable silica-coated manganese ferrite nanoparticles were fabricated for application as magnetic resonance imagining (MRI) contrast agents. The manganese ferrite nanoparticles were synthesized using a hydrothermal technique and coated with silica. The particle size was investigated using transmission electron microscopy and was found to be 40-60 nm. The presence of the silica coating on the particle surface was confirmed by Fourier transform infrared spectroscopy. The crystalline structure was investigated by X-ray diffraction, and the particles were revealed to have an inverse spinel structure. Superparamagnetism was confirmed by the magnetic hysteresis curves obtained using a vibrating sample magnetometer. The efficiency of the MRI contrast agents was investigated by using aqueous solutions of the particles in a 4.7 T MRI scanner. The T1 and T2 relaxivities of the particles were 1.42 and 60.65 s-1 mM-1, respectively, in water. The ratio r2/r1 was 48.91, confirming that the silica-coated manganese ferrite nanoparticles were suitable high-efficacy T2 contrast agents.

  20. Non-contrast magnetic resonance angiography in renal transplantation and renal donation

    DEFF Research Database (Denmark)

    Blankholm, Anne Dorte

    2015-01-01

    for this purpose, including US, CTA and CEMRA. CTA is based on x-ray technology, and the applied iodine-based contrast agent can cause nephropathy and, in rare cases, severe allergic reactions. Allergic reactions to Gd used in CEMRA are extremely rare. Thus, CEMRA was often used for preoperative examination before...... renal transplantation. In 2006, it was realised that the Gd used in CEMRA could cause NSF, which prompted the Danish National Board of Health to produce guidelines for the use of contrast agents in patients with severe renal disease. This thesis discusses different preoperative imaging methods without...... contrast agents before kidney transplantation and kidney donation. Study I is a review of NCMRA techniques and clinical applications. In study II, we searched for an NCMRA method with consistently good image quality for the examination of the pelvic vessels in patients with severe renal disease. Five...

  1. Gadolinium enhanced cardiovascular magnetic resonance in Anderson-Fabry disease. Evidence for a disease specific abnormality of the myocardial interstitium.

    Science.gov (United States)

    Moon, James C C; Sachdev, Bhavesh; Elkington, Andrew G; McKenna, William J; Mehta, Atul; Pennell, Dudley J; Leed, Philip J; Elliott, Perry M

    2003-12-01

    Anderson-Fabry Disease (AFD), an X-linked disorder of sphingolipid metabolism, is a cause of idiopathic left ventricular hypertrophy but the mechanism of hypertrophy is poorly understood. Gadolinium enhanced cardiovascular magnetic resonance can detect focal myocardial fibrosis. We hypothesised that hyperenhancement would be present in AFD. Eighteen males (mean 43+/-14 years) and eight female heterozygotes (mean 48+/-12 years) with AFD underwent cine and late gadolinium cardiovascular magnetic resonance. Nine male (50%) had myocardial hyperenhancement ranging from 3.4% to 20.6% (mean 7.7+/-5.7%) of total myocardium; in males, percentage hyperenhancement related to LV mass index (r=0.78, P=0.0002) but not to ejection fraction or left ventricular volumes. Lesser hyperenhancement was also found in four (50%) heterozygous females (mean 4.6%). In 12 (92%) patients with abnormal gadolinium uptake, hyperenhancement occurred in the basal infero-lateral wall where, unlike myocardial infarction, it was not sub-endocardial. In two male patients with severe LVH (left ventricular hypertrophy) and systolic impairment there was additional hyperenhancement in other myocardial segments. These observations suggests that myocardial fibrosis occurs in AFD and may contribute to the hypertrophy and the natural history of the disease.

  2. Use of gadolinium chloride as a contrast agent for imaging spruce knots by magnetic resonance

    Science.gov (United States)

    Thomas L. Eberhardt; Chi-Leung So; Amy H. Herlihy; Po-Wah So

    2006-01-01

    Treatments of knot-containing spruce wood blocks with a paramagnetic salt, gadolinium (III) chloride, in combination with solvent pretreatments, were evaluated as strategies to enhance the visualization of wood features by magnetic resonance imaging (MRI). Initial experiments with clear wood and excised knot samples showed differences in moisture uptake after...

  3. Contrast-enhanced magnetic resonance imaging for the detection of acute haemorrhagic necrotizing pancreatitis

    International Nuclear Information System (INIS)

    Piironen, A.; Kivisaari, R.; Pitkaeranta, P.; Poutanen, V.P.; Laippala, P.; Laurila, P.; Kivisaari, L.

    1997-01-01

    Eleven piglets with haemorrhagic necrotizing pancreatitis and nine piglets with oedematous pancreatitis were imaged using a multi-breath-hold TurboFLASH (TR 6.5 ms, TE 3 ms, TI 300 ms, flip angle 8 , three slices) pre-excited T1-weighted sequence with an IV bolus injection of gadopentetate dimeglumine (Gd-DTPA, 0.3 mmol/kg) as a contrast agent to show dynamic contrast enhancement of the pancreas by MRI. All piglets were imaged according to the same protocol before inducing the disease. Following the IV Gd-DTPA bolus, time-enhancement curve of the pancreas during haemorrhagic necrotizing pancreatitis was significantly lower than during oedematous pancreatitis. The enhancement curves for the healthy piglets and piglets with oedematous pancreatitis did not differ significantly. Each piglet served as its own control. Because the results of this initial study are similar to those obtained with contrast-enhanced CT, we conclude that our results may encourage further clinical trials, and contrast-enhanced dynamic MRI may be an alternative to the established method of CT for diagnosing acute haemorrhagic necrotizing pancreatitis. (orig.). With 3 figs

  4. Magnetic Resonance Imaging in degenerative disease of the lumbar spine: Fat Saturation technique and contrast medium.

    Science.gov (United States)

    D'Aprile, Paola; Nasuto, Michelangelo; Tarantino, Alfredo; Cornacchia, Samantha; Guglielmi, Giuseppe; Jinkins, J Randy

    2018-01-19

    To examine both anterior and posterior elements of the lumbar spine in patients with low back pain using MRI T2-weighted sequences with Fat Saturation (FS) and contrast enhanced T1-weighted sequences with FS. Two thousand eight hundred and twenty (2820) patients (1628 male, 1192 female, mean age 54) presenting low back pain underwent MRI standard examination (Sagittal T1w TSE and T2w TSE, axial T1 SE) with the addition of sagittal and axial T2w Fat Sat (FS) sequences. Among all the patients, 987 (35%) have been studied adding Contrast Enhanced (CE) T1w FS sequences after administration of contrast medium. Among 987 patients studied with contrast medium, we found: active-inflammatory intervertebral osteochondrosis in 646 (65%) patients; degenerative-inflammatory changes in facet joints (facet joint effusion, synovitis, synovial cysts) in 462 (47%); spondylolysis in 69 (7%); degenerative-inflammatory changes of the flava, interspinous and supraspinous ligaments in 245 (25%); inflammatory changes of posterior perispinal muscles in 84 (8%) patients. In patients with suspected no-disc-related low back pain, the implementation of T2w FS and CE T1w FS sequences to the standard MR protocol could allow a better identification of degenerative-inflammatory changes more likely associated to the pain.

  5. Three-dimensional anisotropy contrast (3DAC) magnetic resonance imaging of the human brain. Application to assess Wallerian degeneration

    Energy Technology Data Exchange (ETDEWEB)

    Igarashi, Hironaka; Katayama, Yasuo; Tsuganezawa, Toshikazu; Yamamuro, Manabu; Terashi, Akiro; Owan, Chojin [Nippon Medical School, Tokyo (Japan)

    1998-08-01

    Three-dimensional anisotropy contrast (3DAC) magnetic resonance imaging is a new algorithm for the treatment of apparent diffusion tensor using the three primary colors. To determine if 3DAC has a clinical application for human brain, six normal volunteers and twenty patients with supratentorial cerebrovascular accidents were examined using clinical magnetic resonance imaging (MRI), and the changes in the 3DAC images associated with Wallerian degeneration of the pyramidal tract were evaluated. The 3DAC images exhibited impressive anatomical resolution. In all chronic stage patients with hemiparesis, the colors in the pyramidal tract were faded. Patients examined during the acute stage who later recovered from hemiparesis had no visible changes of the 3DAC image, whereas patients who recovered poorly showed distinct color fading in the pyramidal tract within 14 days following stroke. In conclusion, very fine anatomical structures are visible on 3DAC images, and it can be used as a diagnostic tool for the human brain. (author)

  6. Three-dimensional anisotropy contrast (3DAC) magnetic resonance imaging of the human brain. Application to assess Wallerian degeneration

    International Nuclear Information System (INIS)

    Igarashi, Hironaka; Katayama, Yasuo; Tsuganezawa, Toshikazu; Yamamuro, Manabu; Terashi, Akiro; Owan, Chojin

    1998-01-01

    Three-dimensional anisotropy contrast (3DAC) magnetic resonance imaging is a new algorithm for the treatment of apparent diffusion tensor using the three primary colors. To determine if 3DAC has a clinical application for human brain, six normal volunteers and twenty patients with supratentorial cerebrovascular accidents were examined using clinical magnetic resonance imaging (MRI), and the changes in the 3DAC images associated with Wallerian degeneration of the pyramidal tract were evaluated. The 3DAC images exhibited impressive anatomical resolution. In all chronic stage patients with hemiparesis, the colors in the pyramidal tract were faded. Patients examined during the acute stage who later recovered from hemiparesis had no visible changes of the 3DAC image, whereas patients who recovered poorly showed distinct color fading in the pyramidal tract within 14 days following stroke. In conclusion, very fine anatomical structures are visible on 3DAC images, and it can be used as a diagnostic tool for the human brain. (author)

  7. Neural - levelset shape detection segmentation of brain tumors in dynamic susceptibility contrast enhanced and diffusion weighted magnetic resonance images

    International Nuclear Information System (INIS)

    Vijayakumar, C.; Bhargava, Sunil; Gharpure, Damayanti Chandrashekhar

    2008-01-01

    A novel Neuro - level set shape detection algorithm is proposed and evaluated for segmentation and grading of brain tumours. The algorithm evaluates vascular and cellular information provided by dynamic contrast susceptibility magnetic resonance images and apparent diffusion coefficient maps. The proposed neural shape detection algorithm is based on the levels at algorithm (shape detection algorithm) and utilizes a neural block to provide the speed image for the level set methods. In this study, two different architectures of level set method have been implemented and their results are compared. The results show that the proposed Neuro-shape detection performs better in differentiating the tumor, edema, necrosis in reconstructed images of perfusion and diffusion weighted magnetic resonance images. (author)

  8. Contrast-induced acute kidney injury in children with cardiovascular defects – results of a pilot study

    Directory of Open Access Journals (Sweden)

    Daria Tomczyk

    2016-12-01

    Full Text Available Introduction: Contrast-induced nephropathy – acute kidney injury is an acquired kidney injury that is an important factor in short- and long-term cardiovascular complications. Contrast-induced nephropathy – acute kidney injury continues to be diagnosed based on serum creatinine level. Serum creatinine, however, is a delayed indicator of contrast-induced nephropathy, as its levels typically peak between 1 and 3 days following contrast exposure. Currently, more sensitive biomarkers of kidney injury are sought, with human neutrophil lipocalin (also known as neutrophil gelatinase-associated lipocalin highlighted in literature as a troponin-like biomarker of early nephropathy. Aim of the study: Changes in serum and urine neutrophil gelatinase-associated lipocalin levels were assessed in children with congenital heart diseases, following a scheduled cardiac catheterization procedure. Material and methods: The group studied comprised 16 patients. The neutrophil gelatinaseassociated lipocalin and creatinine levels, along with urine and serum neutrophil gelatinase-associated lipocalin/creatinine ratio were evaluated five times at different time intervals from the procedure. The group did not vary in respect of kidney function, preprocedure management, and volume expansion (hydration therapy prior to the procedure. Results: In the assessed material, median neutrophil gelatinase-associated lipocalin rose as early as 2 hours after exposure to contrast as compared with baseline [median = 28.2 ng/mL (Quartile 1 = 22.8 – Quartile 3 = 33.77 vs. median = 25.87 ng/mL (Quartile 1 = 19.4 – Quartile 3 = 29.6]. Serum neutrophil gelatinase-associated lipocalin level peaked in hour 6 of our study: median – 30.6 ng/mL (Quartile 1 = 22.32 – Quartile 3 = 42.17, then reverting to normal. Urine neutrophil gelatinaseassociated lipocalin peaked in hour 24 of the study, subsequently dropping below baseline in hour 48

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

    Directory of Open Access Journals (Sweden)

    Francesco Secchi

    2013-01-01

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

  10. Contrast-enhanced magnetic resonance angiography in carotid artery disease: does automated image registration improve image quality?

    International Nuclear Information System (INIS)

    Menke, Jan; Larsen, Joerg

    2009-01-01

    Contrast-enhanced magnetic resonance angiography (MRA) is a noninvasive imaging alternative to digital subtraction angiography (DSA) for patients with carotid artery disease. In DSA, image quality can be improved by shifting the mask image if the patient has moved during angiography. This study investigated whether such image registration may also help to improve the image quality of carotid MRA. Data from 370 carotid MRA examinations of patients likely to have carotid artery disease were prospectively collected. The standard nonregistered MRAs were compared to automatically linear, affine and warp registered MRA by using three image quality parameters: the vessel detection probability (VDP) in maximum intensity projection (MIP) images, contrast-to-noise ratio (CNR) in MIP images, and contrast-to-noise ratio in three-dimensional image volumes. A body shift of less than 1 mm occurred in 96.2% of cases. Analysis of variance revealed no significant influence of image registration and body shift on image quality (p > 0.05). In conclusion, standard contrast-enhanced carotid MRA usually requires no image registration to improve image quality and is generally robust against any naturally occurring body shift. (orig.)

  11. Characterization of the enhancing lesions on dynamic contrast enhanced magnetic resonance imaging in patients with interstitial mammoplasty

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Yun [Department of Radiology, Seoul St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Kim, Sung Hun, E-mail: rad-ksh@catholic.ac.kr [Department of Radiology, Seoul St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Kang, Bong Joo [Department of Radiology, Seoul St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Kim, Hyeon Sook [Department of Radiology, St. Paul Hospital, The Catholic University of Korea (Korea, Republic of); Cha, Eun Suk [Department of Radiology, Ewha Womans University, School of Medicine, Mokdong Hospital (Korea, Republic of); Kim, Ji Youn [Department of Radiology, Yeouido St. Mary' s Hospital, The Catholic University of Korea (Korea, Republic of); Song, Byung Joo [Department of Surgery, Seoul St. Mary' s Hospital, The Catholic University of Korea, Seoul (Korea, Republic of)

    2013-12-01

    Purpose: The purpose of this study was to categorize the morphologic and kinetic features of enhancing lesions in breasts with interstitial mammoplasty using dynamic contrast-enhanced magnetic resonance imaging and to assess factors predictive of breast cancer. Materials and methods: We retrospectively reviewed the clinical and radiological data of 21 enhancing lesions in 19 patients with interstitial mammoplasty, who underwent breast magnetic resonance imaging and biopsy or an operation in our hospital from September 2008 to July 2012. These lesions were sorted by morphological and kinetic features and final assessment category according to the BI-RADS lexicon. Results: Nine cases were confirmed to be ductal carcinoma in situ (n = 2) and invasive ductal carcinoma (n = 7), and the remaining 12 cases were fibrocystic disease (n = 2), fibroadenoma (n = 2), fat necrosis (n = 1), foreign body granuloma (n = 3) and silicone mastitis (n = 1). Common features of malignancy included irregular shape (50.0%), spiculated margins (75.0%), heterogeneous enhancement (50.0%) and type III kinetic pattern (87.5%). The correlations of margins and kinetic curve pattern with benignity and malignancy approached statistical significance (p = 0.02, respectively). We found no correlation for shape (p = 0.33) or internal enhancement (p = 0.42) between lesion types. The malignancy rate of enhancing lesions was 42.8% (9/21). The sensitivity and specificity of dynamic contrast-enhanced magnetic resonance imaging were 100% and 16.67%, respectively. The positive predictive value, negative predictive value and accuracy of magnetic resonance imaging were 47.38%, 100% and 52.38%. Overall inter-observer agreement for the kinetic curve pattern was good (κ = 0.67). Moderate agreement was seen in describing the shape, margin, enhancement and assessing the final category (κ = 0.59, 0.46, 0.58 and 0.49, respectively). Conclusion: Dynamic contrast-enhanced magnetic resonance imaging had a high

  12. Characterization of the enhancing lesions on dynamic contrast enhanced magnetic resonance imaging in patients with interstitial mammoplasty

    International Nuclear Information System (INIS)

    Kim, Tae Yun; Kim, Sung Hun; Kang, Bong Joo; Kim, Hyeon Sook; Cha, Eun Suk; Kim, Ji Youn; Song, Byung Joo

    2013-01-01

    Purpose: The purpose of this study was to categorize the morphologic and kinetic features of enhancing lesions in breasts with interstitial mammoplasty using dynamic contrast-enhanced magnetic resonance imaging and to assess factors predictive of breast cancer. Materials and methods: We retrospectively reviewed the clinical and radiological data of 21 enhancing lesions in 19 patients with interstitial mammoplasty, who underwent breast magnetic resonance imaging and biopsy or an operation in our hospital from September 2008 to July 2012. These lesions were sorted by morphological and kinetic features and final assessment category according to the BI-RADS lexicon. Results: Nine cases were confirmed to be ductal carcinoma in situ (n = 2) and invasive ductal carcinoma (n = 7), and the remaining 12 cases were fibrocystic disease (n = 2), fibroadenoma (n = 2), fat necrosis (n = 1), foreign body granuloma (n = 3) and silicone mastitis (n = 1). Common features of malignancy included irregular shape (50.0%), spiculated margins (75.0%), heterogeneous enhancement (50.0%) and type III kinetic pattern (87.5%). The correlations of margins and kinetic curve pattern with benignity and malignancy approached statistical significance (p = 0.02, respectively). We found no correlation for shape (p = 0.33) or internal enhancement (p = 0.42) between lesion types. The malignancy rate of enhancing lesions was 42.8% (9/21). The sensitivity and specificity of dynamic contrast-enhanced magnetic resonance imaging were 100% and 16.67%, respectively. The positive predictive value, negative predictive value and accuracy of magnetic resonance imaging were 47.38%, 100% and 52.38%. Overall inter-observer agreement for the kinetic curve pattern was good (κ = 0.67). Moderate agreement was seen in describing the shape, margin, enhancement and assessing the final category (κ = 0.59, 0.46, 0.58 and 0.49, respectively). Conclusion: Dynamic contrast-enhanced magnetic resonance imaging had a high

  13. Phase contrast image simulations for electron holography of magnetic and electric fields

    DEFF Research Database (Denmark)

    Beleggia, Marco; Pozzi, Giulio

    2013-01-01

    representation of the magnetic vector potential, that enables us to simulate realistic phase images of fluxons. The aim of this paper is to review the main ideas underpinning our computational framework and the results we have obtained throughout the collaboration. Furthermore, we outline how to generalize...... the approach to model other samples and structures of interest, in particular thin ferromagnetic films, ferromagnetic nanoparticles and p–n junctions....

  14. Contrasting magnetism in dilute and supersaturated cobalt-fullerene mixture films

    Czech Academy of Sciences Publication Activity Database

    Lavrentiev, Vasyl; Stupakov, Alexandr; Pokorný, Jan; Lavrentieva, Inna; Vacík, Jiří; Dejneka, Alexandr; Barchuk, M.; Čapková, P.

    2015-01-01

    Roč. 48, č. 33 (2015), s. 335002 ISSN 0022-3727 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:68378271 ; RVO:61389005 Keywords : cobalt * fullerene * nanomagnetism * nanostructure * self-organization Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders; BM - Solid Matter Physics ; Magnetism (FZU-D) Impact factor: 2.772, year: 2015

  15. Magnesium sulfate as an oral contrast medium in magnetic resonance imaging of the small intestine.

    Science.gov (United States)

    Shi, Hao; Liu, Cun; Ding, Hong Yu; Li, Chun Wei

    2012-03-01

    To explore the use of magnesium sulfate (MgSO4) as an oral contrast medium (CM) in MRI of the small intestine. By comparing MgSO4 SNRs at different concentrations, we determined that 2.5% MgSO4 is the ideal concentration for small bowel MRI. Twenty volunteers underwent MRI after drinking 2.5% MgSO4. Thirty-one patients with clinical suspicion of small intestinal pathology underwent both MRI and the air-barium contrast examination. The patient's tolerance, side effects and complications were noted. 2.5% MgSO4 can decrease the absorption of water and fully fill the enteric cavity, thereby increasing the contrast between the intestinal wall and lumen and facilitating radiographic examination of the small bowel. The mean diameter of the small intestine was 19.8±1.21 mm in the 20 volunteers consuming 2.5% MgSO4 and 12.7±0.84 mm in the 20 volunteers given water. There was a significant difference (P0.05) in side effects between MgSO4 and water groups. Small intestinal MRI was successfully performed in all 31 patients, who were also examined by the double contrast barium, which gave almost identical diagnoses to MRI in all cases except for 1 patient with small intestinal hemorrhage. MRI with 2.5% MgSO4 can demonstrate intestinal abnormalities. Therefore, 2.5% MgSO4 solution is an ideal oral CM for small bowel MRI. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  16. Assessment of myocardial infarction by magnetic resonance imaging with the aid of contrast agents

    International Nuclear Information System (INIS)

    Roos, A. de; Doornbos, J.

    1991-01-01

    The potential of MR imaging in myocardial ischemia with low-temporal-resolution spin-echo techniques both with and without MR contrast agents has been explored. There are indications that early MR imaging after administration of Gd-DTPA is capable to differentiate reperfused from non-reperfused infarcts. Furthermore, MR infarct sizing using Gd-DTPA is feasible to demonstrate infarct size reduction in patients with successful reperfusion. (H.W.). 50 refs.; 9 figs

  17. Magnetic resonance imaging using paramagnetic contrast agents in the clinical evaluation of myocardial infarction. Chapter 15

    International Nuclear Information System (INIS)

    Dijkman, P.R.M. van; Wall, E.E. van der

    1992-01-01

    MRI is noninvasive and specific method for production of high resolution tomographic images in blocks of 3D information. Apart from scintigraphic techniques and computed tomography for evaluation of myocardial ischemia and infarcts, MRI has emerged as a new diagnostic technique to study the extent of anatomical and functional abnormalities in patients with coronary artery disease. Conventional noncontrast MRI can identify acute-infarcted myocardial areas, although the difficulty in identifying myocardial ischemia and infarct with noncontrast MRI suggests a potential role for contrast enhanced MRI. Use of the paramagnetic contrast agent gadolinium diethylene triamine pentaacetic acid (Gd-DTPA) improves depiction of infarcted myocardium on T1-weighted spin -echo MR images that are obtained soon after acute myocardial infarction. This is of particular interest for the estimation of myocardial infarct size. Furthermore, ultrafast subsecond imaging, in combination with Gd-DTPA, offers the potential to analyze cardiac first pass and myocardial perfusion. The development of nontoxic paramagnetic contrast agents which are selectively taken up by viable myocardium would be helpful in assessing the presence of ischemic/infarcted myocardium salvage by MRI following reperfusion. (author). 58 refs., 6 figs

  18. Targeted gadolinium-loaded dendrimer nanoparticles for tumor-specific magnetic resonance contrast enhancement

    Directory of Open Access Journals (Sweden)

    Scott D Swanson

    2008-06-01

    Full Text Available Scott D Swanson1, Jolanta F Kukowska-Latallo2, Anil K Patri5, Chunyan Chen6, Song Ge4, Zhengyi Cao3, Alina Kotlyar3, Andrea T East7, James R Baker31Department of Radiology, The University of Michigan Medical School, 2Department of Internal Medicine, The University of Michigan Medical School, 3Michigan Nanotechnology Institute for Medicine and Biological Sciences, The University of Michigan, 4Applied Physics, The University of Michigan, MD, USA; 5Present address: National Cancer Institute at Frederick (Contractor, MD, USA; 6Present address: Intel Corporation, Chandler, AZ, USA; 7Present address: Stritch School of Medicine, Chicago, ILL, USAAbstract: A target-specific MRI contrast agent for tumor cells expressing high affinity folate receptor was synthesized using generation five (G5 of polyamidoamine (PAMAM dendrimer. Surface modified dendrimer was functionalized for targeting with folic acid (FA and the remaining terminal primary amines of the dendrimer were conjugated with the bifunctional NCS-DOTA chelator that forms stable complexes with gadolinium (Gd III. Dendrimer-DOTA conjugates were then complexed with GdCl3, followed by ICP-OES as well as MRI measurement of their longitudinal relaxivity (T1 s−1 mM−1 of water. In xenograft tumors established in immunodeficient (SCID mice with KB human epithelial cancer cells expressing folate receptor (FAR, the 3D MRI results showed specific and statistically significant signal enhancement in tumors generated with targeted Gd(III-DOTA-G5-FA compared with signal generated by non-targeted Gd(III-DOTA-G5 contrast nanoparticle. The targeted dendrimer contrast nanoparticles infiltrated tumor and were retained in tumor cells up to 48 hours post-injection of targeted contrast nanoparticle. The presence of folic acid on the dendrimer resulted in specific delivery of the nanoparticle to tissues and xenograft tumor cells expressing folate receptor in vivo. We present the specificity of the dendrimer

  19. Temporomandibular joint (TMJ) pain revisited with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)

    International Nuclear Information System (INIS)

    Tasali, N.; Cubuk, R.; Aricak, M.; Ozarar, M.; Saydam, B.; Nur, H.; Tuncbilek, N.

    2012-01-01

    Purpose: We aimed to assess the contrast enhancement patterns of the retrodiscal tissue with dynamic contrast-enhanced MR imaging (DCE-MRI) with respect to different temporomandibular joint disc pathologies. Additionally, we questioned the relationship between the temporomandibular joint (TMJ) pain and the contrast enhancement pattern of the retrodiscal tissue regardless of the TMJ disc position. Materials and methods: 52 joints of 26 patients (4 males and 22 females) who have pain in at least at one of their TMJ were included in this study. For the qualitative analysis, the joints were divided into four groups in terms of their disc positions: normal (1), partially displaced with or without reduction (2), totally dislocated with reduction (3) and totally dislocated without reduction (4). Besides, two different joint groups were constituted, namely the painful group and painless group according to the clinical findings without taking the TMJ disc positions into account. Quantitative analyses were made by means of measuring signal intensity ratios (SI) ratio at the retrodiscal tissue (from internal side and external side of the each joint) using DCE-MRI and these measurements were analyzed with paired samples t test to define the difference between the measurements. At the second stage, the time-dependent arithmetical mean values of the SI ratios were calculated for each joint group and significant differences between the groups were questioned using analysis of variance (ANOVA) test. Besides, painful and painless groups which were classified on the basis of the clinical data were compared according to the mean SI ratios found for each joint and the significant differences between these two groups were assessed by means of Student's T test. The results were assessed in 95% confidence interval where the significance level was p < 0.05. Results: A significant difference was observed between the internal and external contrast enhancement of the joints with partial

  20. 4-D flow magnetic resonance imaging: blood flow quantification compared to 2-D phase-contrast magnetic resonance imaging and Doppler echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Gabbour, Maya [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Schnell, Susanne [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Jarvis, Kelly [Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Robinson, Joshua D. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatrics, Division of Pediatric Cardiology, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Pediatrics, Chicago, IL (United States); Markl, Michael [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Rigsby, Cynthia K. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States)

    2015-06-15

    Doppler echocardiography (echo) is the reference standard for blood flow velocity analysis, and two-dimensional (2-D) phase-contrast magnetic resonance imaging (MRI) is considered the reference standard for quantitative blood flow assessment. However, both clinical standard-of-care techniques are limited by 2-D acquisitions and single-direction velocity encoding and may make them inadequate to assess the complex three-dimensional hemodynamics seen in congenital heart disease. Four-dimensional flow MRI (4-D flow) enables qualitative and quantitative analysis of complex blood flow in the heart and great arteries. The objectives of this study are to compare 4-D flow with 2-D phase-contrast MRI for quantification of aortic and pulmonary flow and to evaluate the advantage of 4-D flow-based volumetric flow analysis compared to 2-D phase-contrast MRI and echo for peak velocity assessment in children and young adults. Two-dimensional phase-contrast MRI of the aortic root, main pulmonary artery (MPA), and right and left pulmonary arteries (RPA, LPA) and 4-D flow with volumetric coverage of the aorta and pulmonary arteries were performed in 50 patients (mean age: 13.1 ± 6.4 years). Four-dimensional flow analyses included calculation of net flow and regurgitant fraction with 4-D flow analysis planes similarly positioned to 2-D planes. In addition, 4-D flow volumetric assessment of aortic root/ascending aorta and MPA peak velocities was performed and compared to 2-D phase-contrast MRI and echo. Excellent correlation and agreement were found between 2-D phase-contrast MRI and 4-D flow for net flow (r = 0.97, P < 0.001) and excellent correlation with good agreement was found for regurgitant fraction (r = 0.88, P < 0.001) in all vessels. Two-dimensional phase-contrast MRI significantly underestimated aortic (P = 0.032) and MPA (P < 0.001) peak velocities compared to echo, while volumetric 4-D flow analysis resulted in higher (aortic: P = 0.001) or similar (MPA: P = 0.98) peak

  1. Magnetic field perturbation in proton MR imaging - A study of a contrast agent and of distortions due to metallic implants

    International Nuclear Information System (INIS)

    Olsson, M.

    1992-01-01

    Perturbations of the static magnetic field in proton MR imaging (NMR imaging, MRI, MRT) result in image distortion and/or signal loss. An investigation of a superparamagnetic contrast agent for MR imaging has been performed. Magnetite particles were embedded in biodegradable starch spheres with a diameter of one micrometer. Animal experiments showed that the agent was quickly accumulated in the reticulo-endothelial system (RES), causing a decrease in signal intensity in this region. Diffusion within the locally generated magnetic field perturbation is responsible for signal loss in spin-echo images. Furthermore, the magnetic properties of various aneurysm clips were investigated to determine which clips could be used safely in a clinical MR investigation. MR artifacts caused by the metallic clips were studied using a geometric phantom. Non-ferromagnetic clips were concluded to be safe for examinations with medium field (0.3 tesla) MR imaging systems. A comparison study between MR and CT was performed on patients harbouring intracranial, nonferromagnetic aneurysm clips. The artifacts close to the clips were equally serve for MR and CT, but at some distance, the MR images were much less affected than the CT images. Finally, a computer program capable of simulating any realistic MR imaging situation has been developed. Raw data matrices are obtained by solving the Bloch equations. Corrections for intravascular spin behaviour have been implemented together with efficient algorithms. A quantitative investigation of signal displacement and signal loss, caused by small metallic implants, has been performed by computer simulation. An exact expression for the magnetic field outside a homogeneous ellipsoid in an external magnetic field has been derived. Distortions in MR images, caused by perturbing ellipsoids of different shapes and orientations, were studied. (30 refs.) (au)

  2. 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)

  3. 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)

  4. Phase contrast image simulations for electron holography of magnetic and electric fields.

    Science.gov (United States)

    Beleggia, Marco; Pozzi, Giulio

    2013-06-01

    The research on flux line lattices and pancake vortices in superconducting materials, carried out within a long and fruitful collaboration with Akira Tonomura and his group at the Hitachi Advanced Research Laboratory, led us to develop a mathematical framework, based on the reciprocal representation of the magnetic vector potential, that enables us to simulate realistic phase images of fluxons. The aim of this paper is to review the main ideas underpinning our computational framework and the results we have obtained throughout the collaboration. Furthermore, we outline how to generalize the approach to model other samples and structures of interest, in particular thin ferromagnetic films, ferromagnetic nanoparticles and p-n junctions.

  5. 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

  6. Shoulder Magnetic Resonance Arthrography: A Prospective Randomized Study of Anterior and Posterior Ultrasonography-Guided Contrast Injections

    Energy Technology Data Exchange (ETDEWEB)

    Koivikko, M.P.; Mustonen, A.O.T. (Dept. of Radiology, Helsinki Univ. Central Hospital, Helsinki (Finland))

    2008-10-15

    Background: Magnetic resonance (MR) arthrography is an accurate imaging method for internal shoulder derangements and rotator cuff pathologies. Both anterior and posterior contrast injection techniques, under palpatory, fluoroscopic, or ultrasonographic guidance have been described in the literature. However, clinical comparisons of the injection techniques remain few. Purpose: To compare the performance of anterior and posterior ultrasonography (US)-guided arthrography injections of the shoulder regarding patient discomfort and influence on diagnostic MR reading, and to illustrate the typical artifacts resulting from contrast leakage in the respective techniques. Material and Methods: 43 MR arthrographies were prospectively randomized into anterior and posterior US-guided contrast injections and performed by two radiologists, with the study of artifacts from contrast leakage. Pain from the injections was assessed by a survey utilizing a 100-mm visual analogue scale (VAS). Results: Of the 23 anterior injections, nine caused contrast artifacts in the subscapular tendon, and in three the leakage extended further anteriorly. Of the 20 posterior injections, 12 showed injection artifacts of the rotator cuff, extending outside the cuff in seven. Two of the anterior and none of the posterior artifacts compromised diagnostic quality. In posterior injections, the leakage regularly occurred at the caudal edge of the infraspinatus muscle and was easily distinguishable from rotator cuff tears. All patients completed the pain survey. Mean VAS scores were 25.0 (median 18, SD 22) for anterior, and 25.4 (median 16, SD 25) for posterior injections. The two radiologists achieved different mean VAS scores but closely agreed as to anterior and posterior VAS scores. Conclusion: Arthrography injections were fairly simple to perform under US guidance. Patient discomfort for anterior and posterior injections was equally minor. A tailored approach utilizing anterior or posterior injections

  7. Iron oxide nanoparticles for use in contrast agents in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Oliveira, Elisa M.N. de; Rocha, Maximiliano S. da; Caimi, Priscila de A.; Basso, Nara R. de S.; Zanini, Mara L.; Papaleo, Ricardo M.

    2015-01-01

    In this work were carried out synthesis of iron oxide nanoparticles coated with dextran, comparing the results of using different concentrations of dextran, iron salts, temperature and reaction time. The compounds were analyzed by DLS, XRD, TGA, TEM, FTIR, Zeta Potential and relaxivity. Nanoparticles with dispersion around 10-15 nm and average hydrodynamic diameters of 16-50 nm, with superparamagnetic behavior were obtained. The ratio of the relaxivities (r2/r1) in aqueous solutions was 5.30, close to value of the commercially available iron oxide contrast agents. (author)

  8. T1 mapping cardiovascular magnetic resonance imaging to detect myocarditis—Impact of slice orientation on the diagnostic performance

    Energy Technology Data Exchange (ETDEWEB)

    Bohnen, Sebastian, E-mail: s.bohnen@uke.de [University Medical Center Hamburg-Eppendorf, University Heart Center, General and Interventional Cardiology, Hamburg (Germany); Radunski, Ulf K., E-mail: u.radunski@uke.de [University Medical Center Hamburg-Eppendorf, University Heart Center, General and Interventional Cardiology, Hamburg (Germany); Lund, Gunnar K., E-mail: glund@uke.de [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Tahir, Enver, E-mail: e.tahir@uke.de [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Avanesov, Maxim, E-mail: m.avanesov@uke.de [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Stehning, Christian, E-mail: christian.stehning@philips.com [Philips Research, Hamburg (Germany); Schnackenburg, Bernhard, E-mail: bernhard.schnackenburg@philips.com [Philips Healthcare Germany, Hamburg (Germany); Adam, Gerhard, E-mail: g.adam@uke.de [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Blankenberg, Stefan, E-mail: s.blankenberg@uke.de [University Medical Center Hamburg-Eppendorf, University Heart Center, General and Interventional Cardiology, Hamburg (Germany); Muellerleile, Kai, E-mail: kamuellerleile@uke.de [University Medical Center Hamburg-Eppendorf, University Heart Center, General and Interventional Cardiology, Hamburg (Germany)

    2017-01-15

    Background: T1 mapping is a promising diagnostic tool to improve the diagnostic accuracy of cardiovascular magnetic resonance (CMR) in patients with suspected myocarditis. However, there are currently no data on the potential influence of slice orientation on the diagnostic performance of CMR. Thus, we compared the diagnostic performance of global myocardial T1 and extracellular volume (ECV) values to differentiate patients with myocarditis from healthy individuals between different slice orientations. Methods: This study included 48 patients with clinically defined myocarditis and 13 healthy controls who underwent CMR at 1.5 T. A modified Look-Locker inversion-recovery (MOLLI) sequence was used for T1 mapping before and 15 min after administration of 0.075 mmol/kg Gadolinium-BOPTA. T1 mapping was performed on three short and on three long axes slices, respectively. Native T1, post-contrast T1 and extracellular volume (ECV) −BOPTA maps were calculated using a dedicated plug-in written for the OsiriX software and compared between the mean value of three short-axes slices (3SAX), the central short-axis (1SAX), the mean value of three long-axes slices (3LAX), the four-chamber view (4CH), the three-chamber view (3CH) and the two-chamber view (2CH). Results: There were significantly lower native T1 values on 3LAX (1081 ms (1037–1131 ms)) compared to 3SAX (1107 ms (1069–1143 ms), p = 0.0022) in patients with myocarditis, but not in controls (1026 ms (1009–1059 ms) vs. 1039 ms (1023–1055 ms), p = 0.2719). The areas under the curve (AUC) to discriminate between myocarditis and healthy controls by native myocardial T1 were 0.85 (p < 0.0001) on 3SAX, 0.85 (p < 0.0001) on 1SAX, 0.76 (p = 0.0002) on 3LAX, 0.70 (p = 0.0075) on 4CH, 0.72 (p = 0.0020) on 3CH and 0.75 (p = 0.0003) on 2CH. The AUCs for ECV-BOPTA were 0.83 (p < 0.0001) on 3 SAX, 0.82 (p < 0.0001) on 1SAX, 0.77 (p = 0.0005) on 3LAX, 0.71 (p = 0.0079) on 4CH, 0.69 (p = 0.0371) on 3CH and 0.75 (p = 0.0006) on

  9. T1 mapping cardiovascular magnetic resonance imaging to detect myocarditis—Impact of slice orientation on the diagnostic performance

    International Nuclear Information System (INIS)

    Bohnen, Sebastian; Radunski, Ulf K.; Lund, Gunnar K.; Tahir, Enver; Avanesov, Maxim; Stehning, Christian; Schnackenburg, Bernhard; Adam, Gerhard; Blankenberg, Stefan; Muellerleile, Kai

    2017-01-01

    Background: T1 mapping is a promising diagnostic tool to improve the diagnostic accuracy of cardiovascular magnetic resonance (CMR) in patients with suspected myocarditis. However, there are currently no data on the potential influence of slice orientation on the diagnostic performance of CMR. Thus, we compared the diagnostic performance of global myocardial T1 and extracellular volume (ECV) values to differentiate patients with myocarditis from healthy individuals between different slice orientations. Methods: This study included 48 patients with clinically defined myocarditis and 13 healthy controls who underwent CMR at 1.5 T. A modified Look-Locker inversion-recovery (MOLLI) sequence was used for T1 mapping before and 15 min after administration of 0.075 mmol/kg Gadolinium-BOPTA. T1 mapping was performed on three short and on three long axes slices, respectively. Native T1, post-contrast T1 and extracellular volume (ECV) −BOPTA maps were calculated using a dedicated plug-in written for the OsiriX software and compared between the mean value of three short-axes slices (3SAX), the central short-axis (1SAX), the mean value of three long-axes slices (3LAX), the four-chamber view (4CH), the three-chamber view (3CH) and the two-chamber view (2CH). Results: There were significantly lower native T1 values on 3LAX (1081 ms (1037–1131 ms)) compared to 3SAX (1107 ms (1069–1143 ms), p = 0.0022) in patients with myocarditis, but not in controls (1026 ms (1009–1059 ms) vs. 1039 ms (1023–1055 ms), p = 0.2719). The areas under the curve (AUC) to discriminate between myocarditis and healthy controls by native myocardial T1 were 0.85 (p < 0.0001) on 3SAX, 0.85 (p < 0.0001) on 1SAX, 0.76 (p = 0.0002) on 3LAX, 0.70 (p = 0.0075) on 4CH, 0.72 (p = 0.0020) on 3CH and 0.75 (p = 0.0003) on 2CH. The AUCs for ECV-BOPTA were 0.83 (p < 0.0001) on 3 SAX, 0.82 (p < 0.0001) on 1SAX, 0.77 (p = 0.0005) on 3LAX, 0.71 (p = 0.0079) on 4CH, 0.69 (p = 0.0371) on 3CH and 0.75 (p = 0.0006) on

  10. Effect of increased convective clearance by on-line hemodiafiltration on all cause and cardiovascular mortality in chronic hemodialysis patients – the Dutch CONvective TRAnsport STudy (CONTRAST: rationale and design of a randomised controlled trial [ISRCTN38365125

    Directory of Open Access Journals (Sweden)

    Nubé Menso J

    2005-05-01

    Full Text Available Abstract Background The high incidence of cardiovascular disease in patients with end stage renal disease (ESRD is related to the accumulation of uremic toxins in the middle and large-middle molecular weight range. As online hemodiafiltration (HDF removes these molecules more effectively than standard hemodialysis (HD, it has been suggested that online HDF improves survival and cardiovascular outcome. Thus far, no conclusive data of HDF on target organ damage and cardiovascular morbidity and mortality are available. Therefore, the CONvective TRAnsport STudy (CONTRAST has been initiated. Methods CONTRAST is a Dutch multi-center randomised controlled trial. In this trial, approximately 800 chronic hemodialysis patients will be randomised between online HDF and low-flux HD, and followed for three years. The primary endpoint is all cause mortality. The main secondary outcome variables are fatal and non-fatal cardiovascular events. Conclusion The study is designed to provide conclusive evidence whether online HDF leads to a lower mortality and less cardiovascular events as compared to standard HD.

  11. 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.

  12. Synthesis route and three different core-shell impacts on magnetic characterization of gadolinium oxide-based nanoparticles as new contrast agents for molecular magnetic resonance imaging

    Science.gov (United States)

    Azizian, Gholamreza; Riyahi-Alam, Nader; Haghgoo, Soheila; Moghimi, Hamid Reza; Zohdiaghdam, Reza; Rafiei, Behrooz; Gorji, Ensieh

    2012-10-01

    Despite its good resolution, magnetic resonance imaging intrinsically has low sensitivity. Recently, contrast agent nanoparticles have been used as sensitivity and contrast enhancer. The aim of this study was to investigate a new controlled synthesis method for gadolinium oxide-based nanoparticle preparation. For this purpose, diethyleneglycol coating of gadolinium oxide (Gd2O3-DEG) was performed using new supervised polyol route, and small particulate gadolinium oxide (SPGO) PEGylation was obtained with methoxy-polyethylene-glycol-silane (550 and 2,000 Da) coatings as SPGO-mPEG-silane550 and 2,000, respectively. Physicochemical characterization and magnetic properties of these three contrast agents in comparison with conventional Gd-DTPA were verified by dynamic light scattering transmission electron microscopy, Fourier transform infrared spectroscopy, inductively coupled plasma, X-ray diffraction, vibrating sample magnetometer, and the signal intensity and relaxivity measurements were performed using 1.5-T MRI scanner. As a result, the nanoparticle sizes of Gd2O3-DEG, SPGO-mPEG-silane550, and SPGO-mPEG-silane2000 could be reached to 5.9, 51.3, 194.2 nm, respectively. The image signal intensity and longitudinal ( r 1) and transverse relaxivity ( r 2) measurements in different concentrations (0.3 to approximately 2.5 mM), revealed the r 2/ r 1 ratios of 1.13, 0.89, 33.34, and 33.72 for Gd-DTPA, Gd2O3-DEG, SPGO-mPEG-silane550, and SPGO-mPEG-silane2000, respectively. The achievement of new synthesis route of Gd2O3-DEG resulted in lower r 2/ r 1 ratio for Gd2O3-DEG than Gd-DTPA and other previous synthesized methods by this and other groups. The smaller r 2/ r 1 ratios of two PEGylated-SPGO contrast agents in our study in comparison with r 2/ r 1 ratio of previous PEGylation ( r 2/ r 1 = 81.9 for mPEG-silane 6,000 MW) showed that these new three introduced contrast agents could potentially be proper contrast enhancers for cellular and molecular MR imaging.

  13. Contrast-enhanced magnetic resonance imaging of pulmonary lesions: Description of a technique aiming clinical practice

    International Nuclear Information System (INIS)

    Koenigkam-Santos, Marcel; Optazaite, Elzbieta; Sommer, Gregor; Safi, Seyer; Heussel, Claus Peter; Kauczor, Hans-Ulrich

    2015-01-01

    To propose a technique for evaluation of pulmonary lesions using contrast-enhanced MRI; to assess morphological patterns of enhancement and correlate quantitative analysis with histopathology. Material and methods: Thirty-six patients were prospectively studied. Volumetric-interpolated T1W images were obtained during consecutive breath holds after bolus triggered contrast injection. Volume coverage of first three acquisitions was limited (higher temporal resolution) and last acquisition obtained at 4th min. Two radiologists individually evaluated the patterns of enhancement. Region-of-interest-based signal intensity (SI)-time curves were created to assess quantitative parameters. Results: Readers agreed moderately to substantially concerning lesions’ enhancement pattern. SI-time curves could be created for all lesions. In comparison to benign, malignant lesions showed higher values of maximum enhancement, early peak, slope and 4th min enhancement. Early peak >15% showed 100% sensitivity to detect malignancy, maximum enhancement >40% showed 100% specificity. Conclusions: The proposed technique is robust, simple to perform and can be applied in clinical scenario. It allows visual evaluation of enhancement pattern/progression together with creation of SI-time curves and assessment of derived quantitative parameters. Perfusion analysis was highly sensitive to detect malignancy, in accordance to what is recommended by most recent guidelines on imaging evaluation of pulmonary lesions

  14. Contrast-enhanced magnetic resonance imaging of pulmonary lesions: Description of a technique aiming clinical practice

    Energy Technology Data Exchange (ETDEWEB)

    Koenigkam-Santos, Marcel, E-mail: marcelk46@yahoo.com.br [Department of Diagnostic and Interventional Radiology, University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Radiology Department, German Cancer Research Center (Deutsches Krebsforschungszentrum – DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Department of Radiology, University Hospital of the School of Medicine of Ribeirao Preto, University of Sao Paulo, Avenida Bandeirantes 3900, Campus Universitario Monte Alegre, 14048 900 Ribeirao Preto, Sao Paulo (Brazil); Optazaite, Elzbieta, E-mail: optazaite@andrulis.eu [Diagnostic and Interventional Radiology with Nuclear Medicine, Chest Clinic (Thoraxklinik), University of Heidelberg, Amalienstraße 5, 69126 Heidelberg (Germany); Sommer, Gregor, E-mail: gregor.sommer@usb.ch [Clinic of Radiology and Nuclear Medicine, University Hospital Basel, Petersgraben 4, CH-4031 Basel (Switzerland); Safi, Seyer, E-mail: seyer.safi@gmail.com [Surgery Department, Chest Clinic (Thoraxklinik), University of Heidelberg, Amalienstraße 5, 69126 Heidelberg (Germany); Heussel, Claus Peter, E-mail: heussel@uni-heidelberg.de [Diagnostic and Interventional Radiology with Nuclear Medicine, Chest Clinic (Thoraxklinik), University of Heidelberg, Amalienstraße 5, 69126 Heidelberg (Germany); Translational Lung Research Center (TLRC), Member of the German Center for Lung Research (DZL), Im Neuenheimer Feld 350, 69120 Heidelberg (Germany); Kauczor, Hans-Ulrich, E-mail: hans-ulrich.kauczor@med.uni-heidelberg.de [Department of Diagnostic and Interventional Radiology, University of Heidelberg, Im Neuenheimer Feld 110, 69120 Heidelberg (Germany); Translational Lung Research Center (TLRC), Member of the German Center for Lung Research (DZL), Im Neuenheimer Feld 350, 69120 Heidelberg (Germany); and others

    2015-01-15

    To propose a technique for evaluation of pulmonary lesions using contrast-enhanced MRI; to assess morphological patterns of enhancement and correlate quantitative analysis with histopathology. Material and methods: Thirty-six patients were prospectively studied. Volumetric-interpolated T1W images were obtained during consecutive breath holds after bolus triggered contrast injection. Volume coverage of first three acquisitions was limited (higher temporal resolution) and last acquisition obtained at 4th min. Two radiologists individually evaluated the patterns of enhancement. Region-of-interest-based signal intensity (SI)-time curves were created to assess quantitative parameters. Results: Readers agreed moderately to substantially concerning lesions’ enhancement pattern. SI-time curves could be created for all lesions. In comparison to benign, malignant lesions showed higher values of maximum enhancement, early peak, slope and 4th min enhancement. Early peak >15% showed 100% sensitivity to detect malignancy, maximum enhancement >40% showed 100% specificity. Conclusions: The proposed technique is robust, simple to perform and can be applied in clinical scenario. It allows visual evaluation of enhancement pattern/progression together with creation of SI-time curves and assessment of derived quantitative parameters. Perfusion analysis was highly sensitive to detect malignancy, in accordance to what is recommended by most recent guidelines on imaging evaluation of pulmonary lesions.

  15. Porphyrin-containing polyaspartamide gadolinium complexes as potential magnetic resonance imaging contrast agents.

    Science.gov (United States)

    Yan, Guo-Ping; Li, Zhen; Xu, Wei; Zhou, Cheng-Kai; Yang, Lian; Zhang, Qiao; Li, Liang; Liu, Fan; Han, Lin; Ge, Yuan-Xing; Guo, Jun-Fang

    2011-04-04

    Porphyrin-containing polyaspartamide ligands (APTSPP-PHEA-DTPA) were synthesized by the incorporation of diethylenetriaminepentaacetic acid (DTPA) and 5-(4'-aminophenyl)-10,15,20-tris(4'-sulfonatophenyl) porphyrin, trisodium salt (APTSPP) into poly-α,β-[N-(2-hydroxyethyl)-l-aspartamide] (PHEA). These ligands were further reacted with gadolinium chloride to produce macromolecule-gadolinium complexes (APTSPP-PHEA-DTPA-Gd). Experimental data of (1)H NMR, IR, UV and elemental analysis evidenced the formation of the polyaspartamide ligands and gadolinium complexes. In vitro and in vivo property tests indicated that APTSPP-PHEA-DTPA-Gd possessed noticeably higher relaxation effectiveness, less toxicity to HeLa cells, and significantly higher enhanced signal intensities (SI) of the VX2 carcinoma in rabbits with lower injection dose requirement than that of Gd-DTPA. Moreover, APTSPP-PHEA-DTPA-Gd was found to greatly enhance the contrast of MR images of the VX2 carcinoma, providing prolonged intravascular duration, and distinguished the VX2 carcinoma and normal tissues in rabbits according to MR image signal enhancements. These porphyrin-containing polyaspartamide gadolinium complexes can be used as the candidates of contrast agents for targeted MRI to tumors. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  16. Gadolinium- and manganite-based contrast agents with fluorescent probes for both magnetic resonance and fluorescence imaging of pancreatic islets: a comparative study

    Czech Academy of Sciences Publication Activity Database

    Berková, Z.; Jirák, D.; Zacharovová, K.; Lukeš, I.; Kotková, Z.; Kotek, J.; Kačenka, M.; Kaman, Ondřej; Řehoř, I.; Hájek, M.; Saudek, F.

    2013-01-01

    Roč. 8, č. 4 (2013), s. 614-621 ISSN 1860-7179 Institutional support: RVO:68378271 Keywords : contrast agents * gadolinium * magnetic resonance imaging * manganite * pancreatic islet s Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.046, year: 2013

  17. Combining scanning tunneling microscopy and synchrotron radiation for high-resolution imaging and spectroscopy with chemical, electronic, and magnetic contrast

    International Nuclear Information System (INIS)

    Cummings, M.L.; Chien, T.Y.; Preissner, C.; Madhavan, V.; Diesing, D.; Bode, M.; Freeland, J.W.; Rose, V.

    2012-01-01

    The combination of high-brilliance synchrotron radiation with scanning tunneling microscopy opens the path to high-resolution imaging with chemical, electronic, and magnetic contrast. Here, the design and experimental results of an in-situ synchrotron enhanced x-ray scanning tunneling microscope (SXSTM) system are presented. The system is designed to allow monochromatic synchrotron radiation to enter the chamber, illuminating the sample with x-ray radiation, while an insulator-coated tip (metallic tip apex open for tunneling, electron collection) is scanned over the surface. A unique feature of the SXSTM is the STM mount assembly, designed with a two free-flex pivot, providing an angular degree of freedom for the alignment of the tip and sample with respect to the incoming x-ray beam. The system designed successfully demonstrates the ability to resolve atomic-scale corrugations. In addition, experiments with synchrotron x-ray radiation validate the SXSTM system as an accurate analysis technique for the study of local magnetic and chemical properties on sample surfaces. The SXSTM system's capabilities have the potential to broaden and deepen the general understanding of surface phenomena by adding elemental contrast to the high-resolution of STM. -- Highlights: ► Synchrotron enhanced x-ray scanning tunneling microscope (SXSTM) system designed. ► Unique STM mount design allows angular DOF for tip alignment with x-ray beam. ► System demonstrates ability to resolve atomic corrugations on HOPG. ► Studies show chemical sensitivity with STM tip from photocurrent and tunneling. ► Results show system's ability to study local magnetic (XMCD) properties on Fe films.

  18. Three-dimensional imaging of the aortic vessel wall using an elastin-specific magnetic resonance contrast agent.

    Science.gov (United States)

    Makowski, Marcus R; Preissel, Anne; von Bary, Christian; Warley, Alice; Schachoff, Sylvia; Keithan, Alexandra; Cesati, Richard R; Onthank, David C; Schwaiger, Markus; Robinson, Simon P; Botnar, René M

    2012-07-01

    The aim of this study was to demonstrate the feasibility of high-resolution 3-dimensional aortic vessel wall imaging using a novel elastin-specific magnetic resonance contrast agent (ESMA) in a large animal model. The thoracic aortic vessel wall of 6 Landrace pigs was imaged using a novel ESMA and a nonspecific control agent. On day 1, imaging was performed before and after the administration of a nonspecific control agent, gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA; Bayer Schering AG, Berlin, Germany). On day 3, identical scans were repeated before and after the administration of a novel ESMA (Lantheus Medical Imaging, North Billerica, Massachusetts). Three-dimensional inversion recovery gradient echo delayed-enhancement imaging and magnetic resonance (MR) angiography of the thoracic aortic vessel wall were performed on a 1.5-T MR scanner (Achieva; Philips Medical Systems, the Netherlands). The signal-to-noise ratio and the contrast-to-noise ratio of arterial wall enhancement, including the time course of enhancement, were assessed for ESMA and Gd-DTPA. After the completion of imaging sessions, histology, electron microscopy, and inductively coupled plasma mass spectroscopy were performed to localize and quantify the gadolinium bound to the arterial vessel wall. Administration of ESMA resulted in a strong enhancement of the aortic vessel wall on delayed-enhancement imaging, whereas no significant enhancement could be measured with Gd-DTPA. Ninety to 100 minutes after the administration of ESMA, significantly higher signal-to-noise ratio and contrast-to-noise ratio could be measured compared with the administration of Gd-DTPA (45.7 ± 9.6 vs 13.2 ± 3.5, P wall imaging using a novel ESMA in a large animal model under conditions resembling a clinical setting. Such an approach could be useful for the fast 3-dimensional assessment of the arterial vessel wall in the context of atherosclerosis, aortic aneurysms, and hypertension.

  19. Imaging in Vivo Extracellular pH with a Single Paramagnetic Chemical Exchange Saturation Transfer Magnetic Resonance Imaging Contrast Agent

    Directory of Open Access Journals (Sweden)

    Guanshu Liu

    2012-01-01

    Full Text Available The measurement of extracellular pH (pHe has potential utility for cancer diagnoses and for assessing the therapeutic effects of pH-dependent therapies. A single magnetic resonance imaging (MRI contrast agent that is detected through paramagnetic chemical exchange saturation transfer (PARACEST was designed to measure tumor pHe throughout the range of physiologic pH and with magnetic resonance saturation powers that are not harmful to a mouse model of cancer. The chemical characterization and modeling of the contrast agent Yb3+-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid, 10-o-aminoanilide (Yb-DO3A-oAA suggested that the aryl amine of the agent forms an intramolecular hydrogen bond with a proximal carboxylate ligand, which was essential for generating a practical chemical exchange saturation transfer (CEST effect from an amine. A ratio of CEST effects from the aryl amine and amide was linearly correlated with pH throughout the physiologic pH range. The pH calibration was used to produce a parametric pH map of a subcutaneous flank tumor on a mouse model of MCF-7 mammary carcinoma. Although refinements in the in vivo CEST MRI methodology may improve the accuracy of pHe measurements, this study demonstrated that the PARACEST contrast agent can be used to generate parametric pH maps of in vivo tumors with saturation power levels that are not harmful to a mouse model of cancer.

  20. Advantages of frequency-domain modeling in dynamic-susceptibility contrast magnetic resonance cerebral blood flow quantification.

    Science.gov (United States)

    Chen, Jean J; Smith, Michael R; Frayne, Richard

    2005-03-01

    In dynamic-susceptibility contrast magnetic resonance perfusion imaging, the cerebral blood flow (CBF) is estimated from the tissue residue function obtained through deconvolution of the contrast concentration functions. However, the reliability of CBF estimates obtained by deconvolution is sensitive to various distortions including high-frequency noise amplification. The frequency-domain Fourier transform-based and the time-domain singular-value decomposition-based (SVD) algorithms both have biases introduced into their CBF estimates when noise stability criteria are applied or when contrast recirculation is present. The recovery of the desired signal components from amid these distortions by modeling the residue function in the frequency domain is demonstrated. The basic advantages and applicability of the frequency-domain modeling concept are explored through a simple frequency-domain Lorentzian model (FDLM); with results compared to standard SVD-based approaches. The performance of the FDLM method is model dependent, well representing residue functions in the exponential family while less accurately representing other functions. (c) 2005 Wiley-Liss, Inc.

  1. Marginal erosive discovertebral ''Romanus'' lesions in ankylosing spondylitis demonstrated by contrast enhanced Gd-DTPA magnetic resonance imaging

    International Nuclear Information System (INIS)

    Jevtic, V.; Kos-Golja, M.; Rozman, B.; McCall, I.

    2000-01-01

    Objective. To assess the value of Gd-DTPA magnetic resonance (MR) imaging in the demonstration of marginal destructive discovertebral Romanus lesions in ankylosing spondylitis.Design and patients. A prospective study of Gd-DTPA MR imaging was performed in 39 patients with a clinical diagnosis of ankylosing spondylitis and typical Romanus lesions seen on radiographs of the thoracolumbar spine. MR morphological appearances and signal intensity changes at the discovertebral junctions were analysed and compared with the radiographic findings.Results. Ninety-nine discovertebral junctions with Romanus lesions showed low signal intensity on T1-weighted and high signal on T2-weighted and T1-weighted postcontrast images at the vertebral corners consistent with oedematous hyperaemic inflammatory tissue. There were nine discovertebral junctions with similar MR findings but normal radiographs. Fifty-three discovertebral junctions showed syndesmophyte formation with increased signal intensity on both T1- and T2-weighted images with no contrast enhancement. Sixty-five discovertebral junctions showed a mixture of radiographic features and varied high and low signal changes at the vertebral rim on MR imaging with rims of enhancement in the vertebral body following contrast administration.Conclusion. Gd-DTPA MR imaging demonstrates a variable signal pattern and degree of contrast enhancement which may reflect the evolutionary stages of discovertebral enthesitis in ankylosing spondylitis. MR imaging may identify early erosive changes in radiographically normal vertebra. The role of MR imaging needs further investigation. (orig.)

  2. Estimation of pulmonary vascular resistance in patients with pulmonary fibrosis by phase-contrast magnetic resonance imaging

    International Nuclear Information System (INIS)

    Ayukawa, Yuichiro; Murayama, Sadayuki; Tsuchiya, Nanae; Yara, Satomi; Fujita, Jiro

    2011-01-01

    The aim of this study was to assess pulmonary vascular resistance (PVR) in patients with pulmonary fibrosis (PF) by phase-contrast magnetic resonance imaging (MRI). Subjects were 11 healthy volunteers and 11 patients with PF. Using phase-contrast MRI, we measured pulmonary arterial blood flow and calculated the parameters of PVR. Parameters were compared between volunteers and patients using unpaired t-tests. The diagnostic capability of the parameters was evaluated by receiver operating characteristic (ROC) curve analysis. Patients underwent respiratory function tests (RFTs) and chest computed tomography (CT), and they were correlated with MRI parameters. Most MRI parameters were significantly different between volunteers and patients (t-test P values were <0.05 in 9 of 10 parameters). Regarding the RFT and CT visual score, only the %DLco/VA and acceleration time and the CT visual score and average flow volume had significant correlation [r=-0.667 (P=0.024) and r=-0.6 (P=0.031)], respectively. Our findings suggest that PVR derived from phase-contrast MRI is significantly higher in patients with PF than in volunteers. However, all but two of these parameters may not correlate with the severity of PF. (author)

  3. The Impact of Injector-Based Contrast Agent Administration on Bolus Shape and Magnetic Resonance Angiography Image Quality

    Directory of Open Access Journals (Sweden)

    Gregor Jost

    2017-04-01

    Full Text Available Objective: To compare injector-based contrast agent (CA administration with hand injection in magnetic resonance angiography (MRA. Methods: Gadobutrol was administered in 6 minipigs with 3 protocols: (a hand injection (one senior technician, (b hand injection (6 less-experienced technicians, and (c power injector administration. The arterial bolus shape was quantified by test bolus measurements. A head and neck MRA was performed for quantitative and qualitative comparison of signal enhancement. Results: A significantly shorter time to peak was observed for protocol C, whereas no significant differences between protocols were found for peak height and bolus width. However, for protocol C, these parameters showed a much lower variation. The MRA revealed a significantly higher signal-to-noise ratio for injector-based administration. A superimposed strong contrast of the jugular vein was found in 50% of the hand injections. Conclusions: Injector-based CA administration results in a more standardized bolus shape, a higher vascular contrast, and a more robust visualization of target vessels.

  4. Magnetic Resonance Imaging Susceptibility-Weighted Imaging Lesion and Contrast Enhancement May Represent Infectious Intracranial Aneurysm in Infective Endocarditis.

    Science.gov (United States)

    Cho, Sung-Min; Rice, Cory; Marquardt, Robert J; Zhang, Lucy Q; Khoury, Jean; Thatikunta, Prateek; Buletko, Andrew B; Hardman, Julian; Uchino, Ken; Wisco, Dolora

    2017-01-01

    Infectious intracranial aneurysm (IIA) can complicate infective endocarditis (IE). We aimed to describe the magnetic resonance imaging (MRI) characteristics of IIA. We reviewed IIAs among 116 consecutive patients with active IE by conducting a neurological evaluation at a single tertiary referral center from January 2015 to July 2016. MRIs and digital cerebral angiograms (DSA) were reviewed to identify MRI characteristics of IIAs. MRI susceptibility weighted imaging (SWI) was performed to collect data on cerebral microbleeds (CMBs) and sulcal SWI lesions. Out of 116 persons, 74 (63.8%) underwent DSA. IIAs were identified in 13 (17.6% of DSA, 11.2% of entire cohort) and 10 patients with aneurysms underwent MRI with SWI sequence. Nine (90%) out of 10 persons with IIAs had CMB >5 mm or sulcal lesions in SWI (9 in sulci, 6 in parenchyma, and 5 in both). Five out of 8 persons who underwent MRI brain with contrast had enhancement within the SWI lesions. In a multivariate logistic regression analysis, both sulcal SWI lesions (p < 0.001, OR 69, 95% CI 7.8-610) and contrast enhancement (p = 0.007, OR 16.5, 95% CI 2.3-121) were found to be significant predictors of the presence of IIAs. In the individuals with IE who underwent DSA and MRI, we found that neuroimaging characteristics, such as sulcal SWI lesion with or without contrast enhancement, are associated with the presence of IIA. © 2017 S. Karger AG, Basel.

  5. Apparent Diffusion Coefficient and Dynamic Contrast-Enhanced Magnetic Resonance Imaging in Pancreatic Cancer: Characteristics and Correlation With Histopathologic Parameters.

    Science.gov (United States)

    Ma, Wanling; Li, Na; Zhao, Weiwei; Ren, Jing; Wei, Mengqi; Yang, Yong; Wang, Yingmei; Fu, Xin; Zhang, Zhuoli; Larson, Andrew C; Huan, Yi

    2016-01-01

    To clarify diffusion and perfusion abnormalities and evaluate correlation between apparent diffusion coefficient (ADC), MR perfusion and histopathologic parameters of pancreatic cancer (PC). Eighteen patients with PC underwent diffusion-weighted imaging and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Parameters of DCE-MRI and ADC of cancer and non-cancerous tissue were compared. Correlation between the rate constant that represents transfer of contrast agent from the arterial blood into the extravascular extracellular space (K, volume of the extravascular extracellular space per unit volume of tissue (Ve), and ADC of PC and histopathologic parameters were analyzed. The rate constant that represents transfer of contrast agent from the extravascular extracellular space into blood plasma, K, tissue volume fraction occupied by vascular space, and ADC of PC were significantly lower than nontumoral pancreases. Ve of PC was significantly higher than that of nontumoral pancreas. Apparent diffusion coefficient and K values of PC were negatively correlated to fibrosis content and fibroblast activation protein staining score. Fibrosis content was positively correlated to Ve. Apparent diffusion coefficient values and parameters of DCE-MRI can differentiate PC from nontumoral pancreases. There are correlations between ADC, K, Ve, and fibrosis content of PC. Fibroblast activation protein staining score of PC is negatively correlated to ADC and K. Apparent diffusion coefficient, K, and Ve may be feasible to predict prognosis of PC.

  6. Preparation and Evaluation of Multiple Nanoemulsions Containing Gadolinium (III) Chelate as a Potential Magnetic Resonance Imaging (MRI) Contrast Agent.

    Science.gov (United States)

    Sigward, Estelle; Corvis, Yohann; Doan, Bich-Thuy; Kindsiko, Kadri; Seguin, Johanne; Scherman, Daniel; Brossard, Denis; Mignet, Nathalie; Espeau, Philippe; Crauste-Manciet, Sylvie

    2015-09-01

    The objective was to develop, characterize and assess the potentiality of W1/O/W2 self-emulsifying multiple nanoemulsions to enhance signal/noise ratio for Magnetic Resonance Imaging (MRI). For this purpose, a new formulation, was designed for encapsulation efficiency and stability. Various methods were used to characterize encapsulation efficiency ,in particular calorimetric methods (Differential Scanning Calorimetry (DSC), thermogravimetry analysis) and ultrafiltration. MRI in vitro relaxivities were assessed on loaded DTPA-Gd multiple nanoemulsions. Characterization of the formulation, in particular of encapsulation efficiency was a challenge due to interactions found with ultrafiltration method. Thanks to the specifically developed DSC protocol, we were able to confirm the formation of multiple nanoemulsions, differentiate loaded from unloaded nanoemulsions and measure the encapsulation efficiency which was found to be quite high with a 68% of drug loaded. Relaxivity studies showed that the self-emulsifying W/O/W nanoemulsions were positive contrast agents, exhibiting higher relaxivities than those of the DTPA-Gd solution taken as a reference. New self-emulsifying multiple nanoemulsions that were able to load satisfactory amounts of contrasting agent were successfully developed as potential MRI contrasting agents. A specific DSC protocol was needed to be developed to characterize these complex systems as it would be useful to develop these self-formation formulations.

  7. Dobutamine stress MRI. Part II. Risk stratification with dobutamine cardiovascular magnetic resonance in patients suspected of myocardial ischemia

    International Nuclear Information System (INIS)

    Kuijpers, Dirkjan; Dijkman, Paul R.M. van; Janssen, Caroline H.C.; Vliegenthart, Rozemarijn; Zijlstra, Felix; Oudkerk, Matthijs

    2004-01-01

    The aim of this study was to determine the prognostic value of dobutamine cardiovascular magnetic resonance (CMR) in patients suspected of myocardial ischemia. Clinical data and dobutamine-CMR results were analyzed in 299 consecutive patients. Follow-up data were analyzed in categories of risk levels defined by the history of coronary artery disease and presence of rest wall motion abnormalities (RWMA). Major adverse cardiac events (MACE) as evaluated end points included cardiac death, nonfatal myocardial infarction and clinically indicated coronary revascularization. Follow-up was completed in 214 (99%) patients with a negative dobutamine-CMR study (no signs of inducible myocardial ischemia) with an average of 24 months. The patients with a negative dobutamine-CMR study and RWMA showed a significantly higher annual MACE rate (18%) than the patients without RWMA (0.56%) (P<0.001). Patients without RWMA showed an annual MACE rate of 2% when they had a history of coronary artery disease and <0.1% without a previous coronary event (P<0.001). Dobutamine-CMR showed a positive and negative predictive value of 95 and 93%, respectively. The cardiovascular occurrence-free survival rate was 96.2%. In patients suspected of myocardial ischemia, dobutamine-CMR is able to assess risk levels for coronary events with high accuracy. (orig.)

  8. Dobutamine stress MRI. Part II. Risk stratification with dobutamine cardiovascular magnetic resonance in patients suspected of myocardial ischemia

    Energy Technology Data Exchange (ETDEWEB)

    Kuijpers, Dirkjan [State University and Academic Hospital Groningen, Department of Radiology and Cardiology, Groningen (Netherlands); Bronovo Hospital, Department of Radiology and Cardiology, Bronovolaan 1, P.O. Box 96900, The Hague (Netherlands); Dijkman, Paul R.M. van [Bronovo Hospital, Department of Radiology and Cardiology, Bronovolaan 1, P.O. Box 96900, The Hague (Netherlands); Janssen, Caroline H.C.; Vliegenthart, Rozemarijn; Zijlstra, Felix; Oudkerk, Matthijs [State University and Academic Hospital Groningen, Department of Radiology and Cardiology, Groningen (Netherlands)

    2004-11-01

    The aim of this study was to determine the prognostic value of dobutamine cardiovascular magnetic resonance (CMR) in patients suspected of myocardial ischemia. Clinical data and dobutamine-CMR results were analyzed in 299 consecutive patients. Follow-up data were analyzed in categories of risk levels defined by the history of coronary artery disease and presence of rest wall motion abnormalities (RWMA). Major adverse cardiac events (MACE) as evaluated end points included cardiac death, nonfatal myocardial infarction and clinically indicated coronary revascularization. Follow-up was completed in 214 (99%) patients with a negative dobutamine-CMR study (no signs of inducible myocardial ischemia) with an average of 24 months. The patients with a negative dobutamine-CMR study and RWMA showed a significantly higher annual MACE rate (18%) than the patients without RWMA (0.56%) (P<0.001). Patients without RWMA showed an annual MACE rate of 2% when they had a history of coronary artery disease and <0.1% without a previous coronary event (P<0.001). Dobutamine-CMR showed a positive and negative predictive value of 95 and 93%, respectively. The cardiovascular occurrence-free survival rate was 96.2%. In patients suspected of myocardial ischemia, dobutamine-CMR is able to assess risk levels for coronary events with high accuracy. (orig.)

  9. Dobutamine stress MRI. Part II. Risk stratification with dobutamine cardiovascular magnetic resonance in patients suspected of myocardial ischemia.

    Science.gov (United States)

    Kuijpers, Dirkjan; van Dijkman, Paul R M; Janssen, Caroline H C; Vliegenthart, Rozemarijn; Zijlstra, Felix; Oudkerk, Matthijs

    2004-11-01

    The aim of this study was to determine the prognostic value of dobutamine cardiovascular magnetic resonance (CMR) in patients suspected of myocardial ischemia. Clinical data and dobutamine-CMR results were analyzed in 299 consecutive patients. Follow-up data were analyzed in categories of risk levels defined by the history of coronary artery disease and presence of rest wall motion abnormalities (RWMA). Major adverse cardiac events (MACE) as evaluated end points included cardiac death, nonfatal myocardial infarction and clinically indicated coronary revascularization. Follow-up was completed in 214 (99%) patients with a negative dobutamine-CMR study (no signs of inducible myocardial ischemia) with an average of 24 months. The patients with a negative dobutamine-CMR study and RWMA showed a significantly higher annual MACE rate (18%) than the patients without RWMA (0.56%) ( P<0.001). Patients without RWMA showed an annual MACE rate of 2% when they had a history of coronary artery disease and <0.1% without a previous coronary event ( P<0.001). Dobutamine-CMR showed a positive and negative predictive value of 95 and 93%, respectively. The cardiovascular occurrence-free survival rate was 96.2%. In patients suspected of myocardial ischemia, dobutamine-CMR is able to assess risk levels for coronary events with high accuracy.

  10. Dynamic-contrast-enhanced magnetic resonance imaging of cirrhotic liver parenchyma: A comparison between gadolinium–diethylenetriamine pentaacetic acid and gadolinium–ethoxybenzyl–diethylenetriamine pentaacetic acid

    OpenAIRE

    Lin, Chun-Yi; Chang, Wei-Chou; Chou, Chen-Te; Chen, Ran-Chou

    2015-01-01

    Background: The newly developed magnetic-resonance-imaging (MRI) hepatocyte-specific contrast agent, gadolinium–ethoxybenzyl–diethylenetriamine pentaacetic acid (Gd–EOB–DTPA), has different excretion pathways from the conventional MRI contrast agent, gadolinium–diethylenetriamine pentaacetic acid (Gd–DTPA). In this study, we compare the enhancement effect of the liver and renal parenchyma between these two contrast agents for patients with liver cirrhosis. Methods: We retrospectively inclu...

  11. Repaired tetralogy of Fallot: the roles of cardiovascular magnetic resonance in evaluating pathophysiology and for pulmonary valve replacement decision support

    Science.gov (United States)

    2011-01-01

    Surgical management of tetralogy of Fallot (TOF) results in anatomic and functional abnormalities in the majority of patients. Although right ventricular volume load due to severe pulmonary regurgitation can be tolerated for many years, there is now evidence that the compensatory mechanisms of the right ventricular myocardium ultimately fail and that if the volume load is not eliminated or reduced by pulmonary valve replacement the dysfunction might be irreversible. Cardiovascular magnetic resonance (CMR) has evolved during the last 2 decades as the reference standard imaging modality to assess the anatomic and functional sequelae in patients with repaired TOF. This article reviews the pathophysiology of chronic right ventricular volume load after TOF repair and the risks and benefits of pulmonary valve replacement. The CMR techniques used to comprehensively evaluate the patient with repaired TOF are reviewed and the role of CMR in supporting clinical decisions regarding pulmonary valve replacement is discussed. PMID:21251297

  12. Effectiveness of late gadolinium enhancement to improve outcomes prediction in patients referred for cardiovascular magnetic resonance after echocardiography

    Science.gov (United States)

    2013-01-01

    Background Echocardiography (echo) is a first line test to assess cardiac structure and function. It is not known if cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) ordered during routine clinical practice in selected patients can add additional prognostic information after routine echo. We assessed whether CMR improves outcomes prediction after contemporaneous echo, which may have implications for efforts to optimize processes of care, assess effectiveness, and allocate limited health care resources. Methods and results We prospectively enrolled 1044 consecutive patients referred for CMR. There were 38 deaths and 3 cardiac transplants over a median follow-up of 1.0 years (IQR 0.4-1.5). We first reproduced previous survival curve strata (presence of LGE and ejection fraction (EF) echocardiography, CMR with LGE further improves risk stratification of individuals at risk for death or death/cardiac transplant. PMID:23324403

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

    LENUS (Irish Health Repository)

    Waterhouse, Deirdre F

    2012-11-01

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

  14. Evaluation of articular cartilage degeneration with contrast-enhanced magnetic resonance imaging

    International Nuclear Information System (INIS)

    Fujioka, Mikihiro

    1994-01-01

    The evaluation of glycosaminoglycan (GAG) concentration is important in the clinical diagnosis of articular cartilage degeneration. Glycosaminoglycan provides a large number of fixed negative charges. When manganese ion (Mn 2+ ) is administered to the cartilage matrix, this cation diffuses into the matrix and accumulates in accordance with the distribution of fixed negative charges owing to the electrostatic interaction. The accumulation of Mn 2+ causes a shortening of the relaxation times, resulting in high signal intensity in the MR image, when a T 1 -weighted image is obtained. The present study applied this new method to the articular cartilage to evaluate the degree of the cartilage degeneration. Small pieces of articular cartilage were dissected from the knee joints of young chickens. Experimentally degenerated articular cartilage was obtained by treating the specimen with various concentrations of papain solution. Then specimens were soaked in manganese solution until they obtained equilibrium and served for MR microimaging. The fixed charge density (FCD), the concentration of Mn 2+ and Na + , T 1 and T 2 relaxation times were also measured. In degenerated cartilage, lower accumulation of Mn 2+ due to lower GAG density caused a lower than normal signal intensity. Thus, administration of Mn 2+ enhances the biochemical change in the cartilage matrix in terms of differences in the relaxation time. The actual signal intensity on MRI of each specimen corresponded to the theoretical signal intensity, which was calculated from the FCD. It was concluded that MR images taken with contrast enhancement by Mn 2+ give direct visual information about the GAG density in the articular cartilage. MRI with cationic contrast agent could develop into a new method for early non-invasive diagnosis of cartilage dysfunction and degeneration. (author)

  15. Three-dimensional balanced steady state free precession myocardial perfusion cardiovascular magnetic resonance at 3T using dual-source parallel RF transmission: initial experience.

    Science.gov (United States)

    Jogiya, Roy; Schuster, Andreas; Zaman, Arshad; Motwani, Manish; Kouwenhoven, Marc; Nagel, Eike; Kozerke, Sebastian; Plein, Sven

    2014-11-28

    The purpose of this study was to establish the feasibility of three-dimensional (3D) balanced steady-state-free-precession (bSSFP) myocardial perfusion cardiovascular magnetic resonance (CMR) at 3T using local RF shimming with dual-source RF transmission, and to compare it with spoiled gradient echo (TGRE) acquisition. Dynamic contrast-enhanced 3D bSSFP perfusion imaging was performed on a 3T MRI scanner equipped with dual-source RF transmission technology. Images were reconstructed using k-space and time broad-use linear acquisition speed-up technique (k-t BLAST) and compartment based principle component analysis (k-t PCA). In phantoms and volunteers, local RF shimming with dual source RF transmission significantly improved B1 field homogeneity compared with single source transmission (P=0.01). 3D bSSFP showed improved signal-to-noise, contrast-to-noise and signal homogeneity compared with 3D TGRE (29.8 vs 26.9, P=0.045; 23.2 vs 21.6, P=0.049; 14.9% vs 12.4%, p=0.002, respectively). Image quality was similar between bSSFP and TGRE but there were more dark rim artefacts with bSSFP. k-t PCA reconstruction reduced artefacts for both sequences compared with k-t BLAST. In a subset of five patients, both methods correctly identified those with coronary artery disease. Three-dimensional bSSFP myocardial perfusion CMR using local RF shimming with dual source parallel RF transmission at 3T is feasible and improves signal characteristics compared with TGRE. Image artefact remains an important limitation of bSSFP imaging at 3T but can be reduced with k-t PCA.

  16. Cardiovascular Magnetic Resonance Imaging-Incremental Value in a Series of 361 Patients Demonstrating Cost Savings and Clinical Benefits: An Outcome-Based Study.

    Science.gov (United States)

    Hegde, Vinayak A; Biederman, Robert Ww; Mikolich, J Ronald

    2017-01-01

    This study was designed to assess the clinical impact and cost-benefit of cardiovascular magnetic resonance imaging (CMR). In the face of current health care cost concerns, cardiac imaging modalities have come under focused review. Data related to CMR clinical impact and cost-benefit are lacking. Retrospective review of 361 consecutive patients (pts) who underwent CMR exams was conducted. Indications for CMR were tabulated for appropriateness criteria. Components of the CMR exam were identified along with evidence of clinical impact. The cost of each CMR exam was ascertained along with cost savings attributable to the CMR exam for calculation of an incremental cost-effectiveness ratio. A total of 354 of 361 pts (98%) had diagnostic quality studies. Of the 361 pts, 350 (97%) had at least 1 published Appropriateness Criterion for CMR. A significant clinical impact attributable to CMR exam results was observed in 256 of 361 pts (71%). The CMR exam resulted in a new diagnosis in 69 of 361 (27%) pts. Cardiovascular magnetic resonance imaging results avoided invasive procedures in 38 (11%) pts and prevented additional diagnostic testing in 26 (7%) pts. Comparison of health care savings using CMR as opposed to current standards of care showed a net cost savings of $833 037, ie, per patient cost savings of $2308. Cardiovascular magnetic resonance imaging provides diagnostic image quality in >98% of cases. Cardiovascular magnetic resonance imaging findings have documentable clinical impact on patient management in 71% of pts undergoing the exam, in a cost beneficial manner.

  17. Diagnostic accuracy of magnetic resonance, computed tomography and contrast enhanced ultrasound in radiological multimodality assessment of peribiliary liver metastases.

    Directory of Open Access Journals (Sweden)

    Vincenza Granata

    Full Text Available We compared diagnostic performance of Magnetic Resonance (MR, Computed Tomography (CT and Ultrasound (US with (CEUS and without contrast medium to identify peribiliary metastasis.We identified 35 subjects with histological proven peribiliary metastases who underwent CEUS, CT and MR study. Four radiologists evaluated the presence of peribiliary lesions, using a 4-point confidence scale. Echogenicity, density and T1-Weigthed (T1-W, T2-W and Diffusion Weighted Imaging (DWI signal intensity as well as the enhancement pattern during contrast studies on CEUS, CT and MR so as hepatobiliary-phase on MRI was assessed.All lesions were detected by MR. CT detected 8 lesions, while US/CEUS detected one lesion. According to the site of the lesion, respect to the bile duct and hepatic parenchyma: 19 (54.3% were periductal, 15 (42.8% were intra-periductal and 1 (2.8% was periductal-intrahepatic. According to the confidence scale MRI had the best diagnostic performance to assess the lesion. CT obtained lower diagnostic performance. There was no significant difference in MR signal intensity and contrast enhancement among all metastases (p>0.05. There was no significant difference in CT density and contrast enhancement among all metastases (p>0.05.MRI is the method of choice for biliary tract tumors but it does not allow a correct differential diagnosis among different histological types of metastasis. The presence of biliary tree dilatation without hepatic lesions on CT and US/CEUS study may be an indirect sign of peribiliary metastases and for this reason the patient should be evaluated by MRI.

  18. Contrast-enhanced spectral mammography in neoadjuvant chemotherapy monitoring: a comparison with breast magnetic resonance imaging.

    Science.gov (United States)

    Iotti, Valentina; Ravaioli, Sara; Vacondio, Rita; Coriani, Chiara; Caffarri, Sabrina; Sghedoni, Roberto; Nitrosi, Andrea; Ragazzi, Moira; Gasparini, Elisa; Masini, Cristina; Bisagni, Giancarlo; Falco, Giuseppe; Ferrari, Guglielmo; Braglia, Luca; Del Prato, Alberto; Malavolti, Ivana; Ginocchi, Vladimiro; Pattacini, Pierpaolo

    2017-09-11

    Neoadjuvant-chemotherapy (NAC) is considered the standard treatment for locally advanced breast carcinomas. Accurate assessment of disease response is fundamental to increase the chances of successful breast-conserving surgery and to avoid local recurrence. The purpose of this study was to compare contrast-enhanced spectral mammography (CESM) and contrast-enhanced-MRI (MRI) in the evaluation of tumor response to NAC. This prospective study was approved by the institutional review board and written informed consent was obtained. Fifty-four consenting women with breast cancer and indication of NAC were consecutively enrolled between October 2012 and December 2014. Patients underwent both CESM and MRI before, during and after NAC. MRI was performed first, followed by CESM within 3 days. Response to therapy was evaluated for each patient, comparing the size of the residual lesion measured on CESM and MRI performed after NAC to the pathological response on surgical specimens (gold standard), independently of and blinded to the results of the other test. The agreement between measurements was evaluated using Lin's coefficient. The agreement between measurements using CESM and MRI was tested at each step of the study, before, during and after NAC. And last of all, the variation in the largest dimension of the tumor on CESM and MRI was assessed according to the parameters set in RECIST 1.1 criteria, focusing on pathological complete response (pCR). A total of 46 patients (85%) completed the study. CESM predicted pCR better than MRI (Lin's coefficient 0.81 and 0.59, respectively). Both methods tend to underestimate the real extent of residual tumor (mean 4.1mm in CESM, 7.5mm in MRI). The agreement between measurements using CESM and MRI was 0.96, 0.94 and 0.76 before, during and after NAC respectively. The distinction between responders and non-responders with CESM and MRI was identical for 45/46 patients. In the assessment of CR, sensitivity and specificity were 100% and

  19. Pulsed magnetization transfer contrast MRI by a sequence with water selective excitation

    Energy Technology Data Exchange (ETDEWEB)

    Schick, F. [Univ. of Tuebingen (Germany)

    1996-01-01

    A water selective SE imaging sequence was developed providing suitable properties for the assessment of magnetization transfer (MT) effects in tissues with considerable amounts of fat. The sequence with water selective excitation and slice selective refocusing combines the following features: The RIF exposure on the macromolecular protons is relatively low for single slice imaging without MT prepulses, since no additional pulses for fat saturation are necessary. Water selection by frequency selective excitation diminishes faults in the subtraction of images recorded with and without MT prepulses (which might arise from movements). High differences in the signal amplitudes from hyaline cartilage and muscle tissue were obtained comparing images recorded with irradiation of the series of prepulses for MT and those lacking MT prepulses. Utilizations of the described water selective approach for the assessment of MT effects in lesions of cartilage and bone are demonstrated. MT saturation was also examined in muscles with fatty degeneration of patients suffering from progressive muscular dystrophy. The described technique allows determination of MT effects with good precision in a single slice, especially in regions with dominating fat signals. 22 refs., 5 figs.

  20. Value of non-contrast sequences in magnetic resonance angiography of hepatic arterial vasculature

    Energy Technology Data Exchange (ETDEWEB)

    Kalra, Vivek B., E-mail: vivek.kalra@yale.edu [Department of Diagnostic Radiology, Yale School of Medicine, Box 208042, Tompkins East 2, 333 Cedar Street, New Haven, CT 06520-8042, United States of America (United States); Gilbert, John W., E-mail: jwgilbert@partners.org [Department of Radiology, Brigham and Women' s Hospital, Harvard Medical School, Francis Street, Boston, MA 02115, United States of America (United States); Krishnamoorthy, Saravanan, E-mail: sk3552@columbia.edu [Department of Radiology, Columbia University Medical Center, Milstein 3rd Fl, New York NY 10032 United States (United States); Cornfeld, Daniel, E-mail: daniel.cornfeld@yale.edu [Department of Diagnostic Radiology, Yale School of Medicine, Box 208042, Tompkins East 2, 333 Cedar St, New Haven, CT 06520-8042, United States of America (United States)

    2014-06-15

    Objective: To evaluate value of adding non-contrast MR angiographic sequence (In-Flow Inversion Recovery [IFIR]) to standard fat-suppressed T1-weighted postcontrast sequence (3D spoiled gradient echo [3D-GRE]) for evaluating hepatic arterial anatomy. Methods: Retrospective evaluation of 30 consecutive patients undergoing multiphase liver MRI. Individual vessels for IFIR/3D-GRE sequences were evaluated by two blinded readers using a four-point scale. Statistical analysis was performed using the Wilcoxon signed-rank test for vessel conspicuity between IFIR/3D-GRE sequences. Results: IFIR alone diagnostically imaged 8.1% of vessels, 3D-GRE alone 25.8%, 55.8% by both 3D-GRE/IFIR, and 10.3% of vessels by neither. Two patients with variant vascular anatomy were visualized with both sequences. Addition of IFIR to 3D-GRE resulted in statistically significant increase in arterial visualization (p < 0.001), 10% relative increase in identified vessels, and 3–5 mi increase in acquisition time for total scan time of 30–35 min. Conclusions: IFIR may be a useful adjunct to 3D-GRE in hepatic angiography without adding considerably to scan time. 10% more hepatic arteries were seen when combining information from IFIR/3D-GRE vs. 3D-GRE alone.

  1. Dynamic contrast-enhanced magnetic resonance imaging and pharmacokinetic models in prostate cancer

    International Nuclear Information System (INIS)

    Franiel, Tobias; Hamm, Bernd; Hricak, Hedvig

    2011-01-01

    Dynamic contrast-enhanced MRI enables noninvasive analysis of prostate vascularization as well as tumour angiogenesis and capillary permeability characteristics in prostate cancers. Pharmacokinetic models summarizing the complex information provided by signal intensity-time curves for a few quantitative pharmacokinetic parameters are increasingly being used in the routine clinical setting. This review consists of two parts. The first part discusses the advantages and disadvantages of the MR pulse sequences that can be used for performing DCE-MRI and also of the most widely used pharmacokinetic parameters and models and the parameters they describe. The second part outlines the range of current and potential future clinical applications of DCE-MRI and pharmacokinetic parametric maps in patients with prostate cancer, with reference to the current scientific literature on the topic. The potential clinical applications of DCE-MRI for prostate cancer include detection, localization, and staging, differentiation of recurrent cancer and estimation of the patient's prognosis, as well as monitoring of treatment response. (orig.)

  2. Non-immunogenic dextran-coated superparamagnetic iron oxide nanoparticles: a biocompatible, size-tunable contrast agent for magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Unterweger H

    2017-07-01

    Full Text Available Harald Unterweger,1,* Christina Janko,1,* Marc Schwarz,2 László Dézsi,3 Rudolf Urbanics,4 Jasmin Matuszak,1 Erik Őrfi,3 Tamás Fülöp,3 Tobias Bäuerle,2 János Szebeni,3,4 Clément Journé,5 Aldo R Boccaccini,6 Christoph Alexiou,1 Stefan Lyer,1 Iwona Cicha1 1Cardiovascular Nanomedicine Unit, Section of Experimental Oncology und Nanomedicine (SEON, Else Kröner-Fresenius-Stiftung-Professorship, ENT Department, University Hospital Erlangen, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, 2Preclinical Imaging Platform Erlangen (PIPE, Institute of Radiology, University Hospital Erlangen, Erlangen, Germany; 3Nanomedicine Research and Education Center, Semmelweis University, 4SeroScience Ltd., Budapest, Hungary; 5Inserm U1148, Fédération de Recherche en Imagerie Multimodalités (FRIM, X Bichat Hospital, Paris Diderot University, Paris, France; 6Institute of Biomaterials, Department of Materials Science and Engineering, University Erlangen-Nuremberg, Erlangen, Germany *These authors contributed equally to this work Abstract: Iron oxide-based contrast agents have been in clinical use for magnetic resonance imaging (MRI of lymph nodes, liver, intestines, and the cardiovascular system. Superparamagnetic iron oxide nanoparticles (SPIONs have high potential as a contrast agent for MRI, but no intravenous iron oxide-containing agents are currently approved for clinical imaging. The aim of our work was to analyze the hemocompatibility and immuno-safety of a new type of dextran-coated SPIONs (SPIONdex and to characterize these nanoparticles with ultra-high-field MRI. Key parameters related to nanoparticle hemocompatibility and immuno-safety were investigated in vitro and ex vivo. To address concerns associated with hypersensitivity reactions to injectable nanoparticulate agents, we analyzed complement activation-related pseudoallergy (CARPA upon intravenous administration of SPIONdex in a pig model. Furthermore, the size-tunability of SPIONdex and

  3. Real-time phase contrast magnetic resonance imaging for assessment of haemodynamics: from phantom to patients

    Energy Technology Data Exchange (ETDEWEB)

    Traber, Julius; Wurche, Lennart; Dieringer, Matthias A.; Utz, Wolfgang; Knobelsdorff-Brenkenhoff, Florian von; Schulz-Menger, Jeanette [Max-Delbrueck-Centrum and Charite -Medical University Berlin and HELIOS Klinikum Berlin-Buch, Department of Cardiology and Nephrology, Working Group on Cardiovascular Magnetic Resonance Imaging, Experimental and Clinical Research Center, Berlin (Germany); Greiser, Andreas [Siemens AG Healthcare Sector, Erlangen (Germany); Jin, Ning [Siemens Medical Solutions USA, Inc., Columbus, OH (United States)

    2016-04-15

    Assessment of haemodynamics is crucial in many cardiac diseases. Phase contrast MRI (PC-MRI) can accurately access it. Arrhythmia is a major limitation in conventional segmented PC-MRI (SEG). A real-time PC-MRI sequence (RT) could overcome this. We validated RT by comparing to SEG. A prototype RT using shared velocity encoding was tested against SEG at 1.5 T in a flow phantom and consecutively included patients with (n = 55) or without (n = 59) aortic valve disease. In patients with atrial fibrillation (Afib, n = 15), only RT was applied. Phantom: PC images were acquired in front of and behind an interchangeable aortic-stenosis-like inlay. Mean velocity and flow were quantified. Patients: PC images were acquired in the ascending aorta, pulmonary trunk and superior caval vein. Peak velocity, stroke volume and regurgitant fraction were quantified. Phantom: Mean velocities (11 ± 1 to 207 ± 10 cm/s) and flow correlated closely between SEG and RT (r ≥ 0.99, ICC ≥ 0.98, p < 0.0005). Patients without AVD or with aortic regurgitation: Concordance of SEG and RT was excellent regarding peak velocities, stroke volumes (r ≥ 0.91, ICC ≥ 0.94, p < 0.0005) and regurgitant fractions (r = 0.95, ICC = 0.95, p < 0.0005). RT was feasible in all patients with Afib. The real-time sequence is accurate compared to conventional segmented PC-MRI. Its applicability in Afib was shown. Real-time PC-MRI might become a valuable tool in arrhythmia. (orig.)

  4. Mammography combined with breast dynamic contrast-enhanced-magnetic resonance imaging for the diagnosis of early breast cancer

    Institute of Scientific and Technical Information of China (English)

    Yakun He; Guohui Xu; Jin Ren; Bin Feng; Xiaolei Dong; Hao Lu; Changjiu He

    2016-01-01

    Objective The aim of this study was to investigate the application of mammography combined with breast dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for the diagnosis of early breast cancer. Methods Mammography and DCE-MRI were performed for 120 patients with breast cancer (malignant, 102; benign; 18). Results The sensitivity of mammography for early diagnosis of breast cancer was 66.67%, specificity was 77.78%, and accuracy was 68.33%. The sensitivity of MRI for early diagnosis of breast cancer was 94.12%, specificity was 88.89%, and accuracy was 93.33%. However, the sensitivity of mammography combined with DCE-MRI volume imaging with enhanced water signal (VIEWS) scanning for early diagnosis of breast cancer was 97.06%, specificity was 94.44%, and accuracy was 96.67%. Conclusion Mammography combined with DCE-MRI increased the sensitivity, specificity, and accuracy of diagnosing early breast cancer.

  5. Influence of Spatial Resolution in Three-dimensional Cine Phase Contrast Magnetic Resonance Imaging on the Accuracy of Hemodynamic Analysis.

    Science.gov (United States)

    Fukuyama, Atsushi; Isoda, Haruo; Morita, Kento; Mori, Marika; Watanabe, Tomoya; Ishiguro, Kenta; Komori, Yoshiaki; Kosugi, Takafumi

    2017-10-10

    We aim to elucidate the effect of spatial resolution of three-dimensional cine phase contrast magnetic resonance (3D cine PC MR) imaging on the accuracy of the blood flow analysis, and examine the optimal setting for spatial resolution using flow phantoms. The flow phantom has five types of acrylic pipes that represent human blood vessels (inner diameters: 15, 12, 9, 6, and 3 mm). The pipes were fixed with 1% agarose containing 0.025 mol/L gadolinium contrast agent. A blood-mimicking fluid with human blood property values was circulated through the pipes at a steady flow. Magnetic resonance (MR) images (three-directional phase images with speed information and magnitude images for information of shape) were acquired using the 3-Tesla MR system and receiving coil. Temporal changes in spatially-averaged velocity and maximum velocity were calculated using hemodynamic analysis software. We calculated the error rates of the flow velocities based on the volume flow rates measured with a flowmeter and examined measurement accuracy. When the acrylic pipe was the size of the thoracicoabdominal or cervical artery and the ratio of pixel size for the pipe was set at 30% or lower, spatially-averaged velocity measurements were highly accurate. When the pixel size ratio was set at 10% or lower, maximum velocity could be measured with high accuracy. It was difficult to accurately measure maximum velocity of the 3-mm pipe, which was the size of an intracranial major artery, but the error for spatially-averaged velocity was 20% or less. Flow velocity measurement accuracy of 3D cine PC MR imaging for pipes with inner sizes equivalent to vessels in the cervical and thoracicoabdominal arteries is good. The flow velocity accuracy for the pipe with a 3-mm-diameter that is equivalent to major intracranial arteries is poor for maximum velocity, but it is relatively good for spatially-averaged velocity.

  6. Cerebral misery perfusion diagnosed using hypercapnic blood-oxygenation-level-dependent contrast functional magnetic resonance imaging: a case report

    Directory of Open Access Journals (Sweden)

    D'Souza Olympio

    2010-02-01

    Full Text Available Abstract Introduction Cerebral misery perfusion represents a failure of cerebral autoregulation. It is an important differential diagnosis in post-stroke patients presenting with collapses in the presence of haemodynamically significant cerebrovascular stenosis. This is particularly the case when cortical or internal watershed infarcts are present. When this condition occurs, further investigation should be done immediately. Case presentation A 50-year-old Caucasian man presented with a stroke secondary to complete occlusion of his left internal carotid artery. He went on to suffer recurrent seizures. Neuroimaging demonstrated numerous new watershed-territory cerebral infarcts. No source of arterial thromboembolism was demonstrable. Hypercapnic blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging was used to measure his cerebrovascular reserve capacity. The findings were suggestive of cerebral misery perfusion. Conclusions Blood-oxygenation-level-dependent-contrast functional magnetic resonance imaging allows the inference of cerebral misery perfusion. This procedure is cheaper and more readily available than positron emission tomography imaging, which is the current gold standard diagnostic test. The most evaluated treatment for cerebral misery perfusion is extracranial-intracranial bypass. Although previous trials of this have been unfavourable, the results of new studies involving extracranial-intracranial bypass in high-risk patients identified during cerebral perfusion imaging are awaited. Cerebral misery perfusion is an important and under-recognized condition in which emerging imaging and treatment modalities present the possibility of practical and evidence-based management in the near future. Physicians should thus be aware of this disorder and of recent developments in diagnostic tests that allow its detection.

  7. Computed tomography and magnetic resonance imaging contrast media injectors: technical feature review – what is really needed?

    Directory of Open Access Journals (Sweden)

    Friebe M

    2016-07-01

    Full Text Available Michael Friebe Institute of Medical Engineering, Otto-von-Guericke-University, Magdeburg, Germany Abstract: There has been little technical innovation over the last few years for contrast media (CM injectors that are used for diagnostic imaging (computed tomography [CT], magnetic resonance imaging [MRI], and hybrid imaging systems, such as positron emission tomography–CT or magnetic resonance–positron emission tomography examinations. The medical need of CM for the enhancement of diagnostic images has been around for a long time, but the application of the CM into the blood stream comes with potential medical complications for the patient and requires a lot of operator experience and training. Most power injector systems that are currently used can do significantly more than what is typically required; this complexity however, adds error potential and cost. This paper focuses on the main features that CM injector systems should have and highlights the technical developments that are useful to have but which add complexity and cost, increase setup time, and require intensive training for safe use. CM injection protocols are very different between CT and MRI, with CT requiring many more variances, has a need for multiphase protocols, and requires a higher timing accuracy. A CM injector used in the MRI suite, on the other-hand, could only need a relatively time insensitive injection with a standard injection flow rate and a volume that is dependent on the patients’ weight. This would make easy and lightweight systems possible, which are able to safely and accurately perform the injection task, while allowing full MRI compatibility with relatively low cost investment and consumable costs. Keywords: power injector, contrast media injection, injection protocols, MRI compatibility

  8. Average arterial input function for quantitative dynamic contrast enhanced magnetic resonance imaging of neck nodal metastases

    International Nuclear Information System (INIS)

    Shukla-Dave, Amita; Lee, Nancy; Stambuk, Hilda; Wang, Ya; Huang, Wei; Thaler, Howard T; Patel, Snehal G; Shah, Jatin P; Koutcher, Jason A

    2009-01-01

    The present study determines the feasibility of generating an average arterial input function (Avg-AIF) from a limited population of patients with neck nodal metastases to be used for pharmacokinetic modeling of dynamic contrast-enhanced MRI (DCE-MRI) data in clinical trials of larger populations. Twenty patients (mean age 50 years [range 27–77 years]) with neck nodal metastases underwent pretreatment DCE-MRI studies with a temporal resolution of 3.75 to 7.5 sec on a 1.5T clinical MRI scanner. Eleven individual AIFs (Ind-AIFs) met the criteria of expected enhancement pattern and were used to generate Avg-AIF. Tofts model was used to calculate pharmacokinetic DCE-MRI parameters. Bland-Altman plots and paired Student t-tests were used to describe significant differences between the pharmacokinetic parameters obtained from individual and average AIFs. Ind-AIFs obtained from eleven patients were used to calculate the Avg-AIF. No overall significant difference (bias) was observed for the transfer constant (K trans ) measured with Ind-AIFs compared to Avg-AIF (p = 0.20 for region-of-interest (ROI) analysis and p = 0.18 for histogram median analysis). Similarly, no overall significant difference was observed for interstitial fluid space volume fraction (v e ) measured with Ind-AIFs compared to Avg-AIF (p = 0.48 for ROI analysis and p = 0.93 for histogram median analysis). However, the Bland-Altman plot suggests that as K trans increases, the Ind-AIF estimates tend to become proportionally higher than the Avg-AIF estimates. We found no statistically significant overall bias in K trans or v e estimates derived from Avg-AIF, generated from a limited population, as compared with Ind-AIFs. However, further study is needed to determine whether calibration is needed across the range of K trans . The Avg-AIF obtained from a limited population may be used for pharmacokinetic modeling of DCE-MRI data in larger population studies with neck nodal metastases. Further validation of

  9. Pathological mechanism for delayed hyperenhancement of chronic scarred myocardium in contrast agent enhanced magnetic resonance imaging.

    Directory of Open Access Journals (Sweden)

    Jian Wang

    Full Text Available OBJECTIVES: To evaluate possible mechanism for delayed hyperenhancement of scarred myocardium by investigating the relationship of contrast agent (CA first pass and delayed enhancement patterns with histopathological changes. MATERIALS AND METHODS: Eighteen pigs underwent 4 weeks ligation of 1 or 2 diagonal coronary arteries to induce chronic infarction. The hearts were then removed and perfused in a Langendorff apparatus. The hearts firstly experienced phosphorus 31 MR spectroscopy. The hearts in group I (n = 9 and II (n = 9 then received the bolus injection of Gadolinium diethylenetriamine pentaacetic acid (0.05 mmol/kg and gadolinium-based macromolecular agent (P792, 15 µmol/kg, respectively. First pass T2* MRI was acquired using a gradient echo sequence. Delayed enhanced T1 MRI was acquired with an inversion recovery sequence. Masson's trichrome and anti- von Willebrand Factor (vWF staining were performed for infarct characterization. RESULTS: Wash-in of both kinds of CA caused the sharp and dramatic T2* signal decrease of scarred myocardium similar to that of normal myocardium. Myocardial blood flow and microvessel density were significantly recovered in 4-week-old scar tissue. Steady state distribution volume (ΔR1 relaxation rate of Gd-DTPA was markedly higher in scarred myocardium than in normal myocardium, whereas ΔR1 relaxation rate of P792 did not differ significantly between scarred and normal myocardium. The ratio of extracellular volume to the total water volume was significantly greater in scarred myocardium than in normal myocardium. Scarred myocardium contained massive residual capillaries and dilated vessels. Histological stains indicated the extensively discrete matrix deposition and lack of cellular structure in scarred myocardium. CONCLUSIONS: Collateral circulation formation and residual vessel effectively delivered CA into scarred myocardium. However, residual vessel without abnormal hyperpermeability allowed Gd

  10. Multiphase contrast-enhanced magnetic resonance imaging features of Bacillus Calmette-Guerin-induced granulomatous prostatitis in five patients

    Energy Technology Data Exchange (ETDEWEB)

    Kawada, Hiroshi; Kanematsu, Masayuki; Goshima, Satoshi; Kondo, Hiroshi; Watanabe, Haruo; Noda, Yoshifumi; Tanahashi, Yukichi; Kawai, Nobuyuki; Hoshi, Hiroaki [Gifu University Hospital, Gifu (Japan)

    2015-04-15

    To evaluate the multiphase contrast-enhanced magnetic resonance (MR) imaging features of Bacillus Calmette-Guerin (BCG)-induced granulomatous prostatitis (GP). Magnetic resonance images obtained from five patients with histopathologically proven BCG-induced GP were retrospectively analyzed for tumor location, size, signal intensity on T2-weighted images (T2WI) and diffusion-weighted images (DWI), apparent diffusion coefficient (ADC) value, and appearance on gadolinium-enhanced multiphase images. MR imaging findings were compared with histopathological findings. Bacillus Calmette-Guerin-induced GP (size range, 9-40 mm; mean, 21.2 mm) were identified in the peripheral zone in all patients. The T2WI showed lower signal intensity compared with the normal peripheral zone. The DWIs demonstrated high signal intensity and low ADC values (range, 0.44-0.68 x 10(-3) mm2/sec; mean, 0.56 x 10(-3) mm2/sec), which corresponded to GP. Gadolinium-enhanced multiphase MR imaging performed in five patients showed early and prolonged ring enhancement in all cases of GP. Granulomatous tissues with central caseation necrosis were identified histologically, which corresponded to ring enhancement and a central low intensity area on gadolinium-enhanced MR imaging. The findings on T2WI, DWI, and gadolinium-enhanced images became gradually obscured with time. Bacillus Calmette-Guerin-induced GP demonstrates early and prolonged ring enhancement on gadolinium-enhanced MR imaging which might be a key finding to differentiate it from prostate cancer.

  11. In-vivo quantification of wall motion in cerebral aneurysms from 2D cine phase contrast magnetic resonance images

    Energy Technology Data Exchange (ETDEWEB)

    Karmonik, C. [The Methodist Hospital Research Inst., Houston (United States); Diaz, O.; Klucznik, R. [The Methodist Hospital, Houston (United States); Grossman, R. [The Methodist Hospital, Houston (United States). Neurosurgery

    2010-02-15

    Purpose: The quantification of wall motion in cerebral aneurysms is of interest for the assessment of aneurysmal rupture risk, for providing boundary conditions for computational simulations and as a validation tool for theoretical models. Materials and Methods: 2D cine phase contrast magnetic resonance imaging (2D pcMRI) in combination with quantitative magnetic resonance angiography (QMRA) was evaluated for measuring wall motion in 7 intracranial aneurysms. In each aneurysm, 2 (in one case 3) cross sections, oriented approximately perpendicular to each other, were measured. Results: The maximum aneurysmal wall distention ranged from 0.16 mm to 1.6 mm (mean 0.67 mm), the maximum aneurysmal wall contraction was -1.91 mm to -0.34 mm (mean 0.94 mm), and the average wall displacement ranged from 0.04 mm to 0.31 mm (mean 0.15 mm). Statistically significant correlations between average wall displacement and the shape of inflow curves (p-value < 0.05) were found in 7 of 15 cross sections; statistically significant correlations between the displacement of the luminal boundary center point and the shape of inflow curves (p-value < 0.05) were found in 6 of 15 cross sections. Conclusion: 2D pcMRI in combination with QMRA is capable of visualizing and quantifying wall motion in cerebral aneurysms. However, application of this technique is currently restricted by its limited spatial resolution. (orig.)

  12. Appearance of high signal intensity and gadolinium-DTPA contrast enhancement in hypertrophied myocardium by magnetic resonance imaging

    International Nuclear Information System (INIS)

    Nishimura, Tsunehiko; Yamada, Naoaki; Nagata, Seiki

    1989-01-01

    This study was undertaken to examine the potential role of magnetic resonance imaging (MRI) for evaluating myocardial tissue characterization in hypertrophic cardiomyopathy (HCM). ECG-gated MRI images were acquired in 32 HCM patients and 30 patients with hypertensive heart disease (HHD), using a 1.5 T superconducting magnet system. The thickened areas were depicted as high signal intensities in the septum of 12 HCM patients (38%) and the endocardium of 5 HHD patients (17%). Echocardiography revealed that MRI appearance of high signal intensity was associated with more thickened myocardial wall. For evaluable 16 patients receiving i.v. injection of Gd-DTPA in a dose of 0.1 mM/kg, enhancement effects were observed in 10 patients (63%). High signal intensity appearing in the hypertrophied myocardium, as well as contrast enhancement, may not be characteristic of HCM, but reflect the likelihood of myocardial degeneration associated with the hypertrophied myocardium. Although MRI may not be capable of differentiating tissue characterization in HCM from that in HHD, it may provide different information about tissue characterization in the hypertrophied myocardium from that obtained by other techniques. (N.K.)

  13. The role of dynamic contrast-enhanced and diffusion weighted magnetic resonance imaging in the female pelvis

    Energy Technology Data Exchange (ETDEWEB)

    Sala, Evis, E-mail: es220@radiol.cam.ac.uk [University Department of Radiology, Box 218, Level 5, Addenbrooke' s Hospital, Hills Road, Cambridge CB2 0QQ (United Kingdom); Rockall, Andrea, E-mail: Andrea.Rockall@bartsandthelondon.nhs.uk [Department of Radiology, St Bartholomew' s Hospital, West Smithfield, London EC1A 7ED (United Kingdom); Rangarajan, Deepa, E-mail: rdrangarajan@googlemail.com [Department of Radiology, Box 218, Addenbrooke' s Hospital, Hills Road, Cambridge CB2 0QQ (United Kingdom); Kubik-Huch, Rahel A., E-mail: rahel.kubik@ksb.ch [Institute of Radiology, Department of Medical Services, Kantonsspital Baden Im Ergel, CH-5404 Baden (Switzerland)

    2010-12-15

    Functional imaging by means of dynamic multiphase contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion weighted magnetic resonance imaging (DW-MRI) is now part of the standard imaging protocols for evaluation of the female pelvis. DCE-MRI and DW-MRI are important MR imaging techniques which enable the radiologist to move from morphological to functional assessment of diseases of the female pelvis. This is mainly due to the limitations of morphologic imaging, particularly in lesion characterization, accurate lymph node staging, assessment of tumour response and inability to differentiate post-treatment changes from tumour recurrence. DCE-MRI improves the accuracy of T2WI in staging of endometrial cancer. It also helps differentiate tumour recurrence from radiation fibrosis in patients with cervical cancer. DCE-MRI improves characterization of cystic adnexal lesions and detection of small peritoneal implants in patients with ovarian cancer. DW-MRI is valuable in preoperative staging of patients with endometrial and cervical cancer, especially in detection of extra-uterine disease. It does increase reader's confidence for detection of recurrent disease in gynaecological malignancies and improves detection of small peritoneal implants in patients with ovarian cancer. In this review article we give an overview of both DCE-MRI and DW-MRI techniques, concentrating on their main clinical application in the female pelvis, and present a practical approach of the added value of these techniques according to the main pathological conditions, highlighting the pearls and pitfalls of each technique.

  14. Aortic Volumetry at Contrast-Enhanced Magnetic Resonance Angiography: Feasibility as a Sensitive Method for Monitoring Bicuspid Aortic Valve Aortopathy.

    Science.gov (United States)

    Trinh, Brian; Dubin, Iram; Rahman, Ozair; Ferreira Botelho, Marcos P; Naro, Nicholas; Carr, James C; Collins, Jeremy D; Barker, Alex J

    2017-04-01

    Bicuspid aortic valve patients can develop thoracic aortic aneurysms and therefore require serial imaging to monitor aortic growth. This study investigates the reliability of contrast-enhanced magnetic resonance angiography (CEMRA) volumetry compared with 2-dimensional diameter measurements to identify thoracic aortic aneurysm growth. A retrospective, institutional review board-approved, and Health Insurance Portability and Accountability Act-compliant study was conducted on 20 bicuspid aortic valve patients (45 ± 8.9 years, 20% women) who underwent serial CEMRA with a minimum imaging follow-up of 11 months. Magnetic resonance imaging was performed at 1.5 T with electrocardiogram-gated, time-resolved CEMRA. Independent observers measured the diameter at the sinuses of Valsalva (SOVs) and mid ascending aorta (MAA) as well as ascending aorta volume between the aortic valve annulus and innominate branch. Intraobserver/interobserver coefficient of variation (COV) and intraclass correlation coefficient (ICC) were computed to assess reliability. Growth rates were calculated and assessed by Student t test (P volumetry. Three-dimensional CEMRA volumetry exhibited a larger effect when examining percentage growth, a better ICC, and a marginally lower COV. Volumetry may be more sensitive to growth and possibly less affected by error than diameter measurements.

  15. Role of technetium-99m sestamibi scintimammography and contrast-enhanced magnetic resonance imaging for the evaluation of indeterminate mammograms

    International Nuclear Information System (INIS)

    Tiling, R.; Moser, R.; Meyer, G.; Tatsch, K.; Hahn, K.; Khalkhali, I.; Sommer, H.; Willemsen, F.; Pfluger, T.

    1997-01-01

    This study evaluated and compared technetium-99m sestamibi scintimammography (SMM) and breast magnetic resonance imaging (MRI) results in patients with indeterminate mammograms to determine whether either technique can improve the sensitivity and specificity for the diagnosis of breast carcinoma. From 123 consecutive patients who underwent physical examination, mammography, SMM, and histopathologic confirmation, a subgroup of 82 patients presenting with indeterminate mammograms was studied. Sixty-eight patients underwent contrast-enhanced MRI. SMM results were scored on the basis of the intensity and pattern of sestamibi uptake. MRI images were scored on the basis of signal intensity increase after administration of contrast material as well as the enhancement pattern and speed of gadolinium uptake. The results obtained with the two techniques were compared and related to the final histopathologic diagnoses. Considering indeterminate findings as positive, the sensitivity of SMM was 79% and the specificity, 70%. MRI displayed a sensitivity of 84% and a specificity of 49%. When indeterminate results were considered negative, the sensitivity and specificity of SMM were 62% and 83%, respectively. MRI revealed a sensitivity and specificity of 56% and 79%, respectively. The calculated sensitivities and specificities demonstrate the diagnostic limitations of both SMM and MRI in the evaluation of patients with indeterminate mammographic findings. Due to the higher specificity, SMM may be the preferred modality in the evaluation of selected patients with breast abnormalities. (orig.)

  16. Contrast-enhanced dynamic magnetic resonance imaging findings of hepatocellular carcinoma and their correlation with histopathologic findings

    Energy Technology Data Exchange (ETDEWEB)

    Karahan, Okkes I. [Department of Radiology, Erciyes University Medical Faculty, PK: 18 Talas 38280, Kayseri (Turkey)]. E-mail: oikarahan@yahoo.com; Yikilmaz, Ali [Department of Radiology, Erciyes University Medical Faculty, PK: 18 Talas 38280, Kayseri (Turkey); Artis, Tarik [Department of General Surgery, Erciyes University Medical Faculty, PK: 18 Talas 38280, Kayseri (Turkey); Canoz, Ozlem [Department of Pathology, Erciyes University Medical Faculty, PK: 18 Talas 38280, Kayseri (Turkey); Coskun, Abdulhakim [Department of Radiology, Erciyes University Medical Faculty, PK: 18 Talas 38280, Kayseri (Turkey); Torun, Edip [Department of Internal Medicine, Division of Gastrenterology, Erciyes University Medical Faculty, PK: 18 Talas 38280, Kayseri (Turkey)

    2006-03-15

    Purpose: To investigate the correlations of contrast-enhanced magnetic resonance (MR) imaging findings of large (>5 cm) hepatocellular carcinomas with tumor size and histopathologic findings. Materials and methods: MR imaging was performed in 30 patients with a histopathologic diagnosis of hepatocellular carcinoma. The imaging protocol included non-contrast, hepatic arterial, portal venous and late phases. The signal intensities relative to the liver, enhancement patterns and the morphologic features of the lesions were evaluated in relation to size and degree of differentiation. Results: On histopathologic examination, 12 of 30 (40%) tumors were well-differentiated (grade 1), 6 of 30 (20%) were moderately differentiated (grades 2 and 3) and 12 of 30 (40%) were poorly differentiated (grade 4). Tumor size, tumor boundary, serum alpha-fetoprotein level and portal vein invasion were found to have statistically significant correlations with the degree of differentiation (p < 0.05). Portal vein invasion, capsule formation and tumor surface characteristics showed statistically significant correlations with tumor size (p < 0.05). Conclusion: MR imaging findings of hepatocellular carcinomas larger than 5 cm are partially dependent on tumor size and degree of differentiation.

  17. Dynamics and structure of self-generated magnetics fields on solids following high contrast, high intensity laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Albertazzi, B. [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); INRS-EMT, 1650 bd L. Boulet, J3X1S2, Varennes, Québec (Canada); Graduate School of Engineering, University of Osaka, Suita, Osaka 565-087 (Japan); Chen, S. N.; Fuchs, J., E-mail: julien.fuchs@polytechnique.fr [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); Institute of Applied Physics, 46 Ulyanov Street, 603950 Nizhny Novgorod (Russian Federation); Antici, P. [INRS-EMT, 1650 bd L. Boulet, J3X1S2, Varennes, Québec (Canada); Dept. SBAI, Universita di Roma “La Sapienza,” Via A. Scarpa 14, 00161 Rome (Italy); Böker, J.; Swantusch, M.; Willi, O. [Institut für Laser-und Plasmaphysik, Heinrich-Heine-Universität, Düsseldorf (Germany); Borghesi, M. [School of Mathematics and Physics, The Queen' s University, Belfast (United Kingdom); Breil, J.; Feugeas, J. L.; Nicolaï, Ph.; Tikhonchuk, V. T.; D' Humières, E. [CELIA, University of Bordeaux - CNRS - CEA, 33405 Talence (France); Dervieux, V.; Nakatsutsumi, M.; Romagnagni, L. [LULI, École Polytechnique, CNRS, CEA, UPMC, 91128 Palaiseau (France); Lancia, L. [Dept. SBAI, Universita di Roma “La Sapienza,” Via A. Scarpa 14, 00161 Rome (Italy); Shepherd, R. [LLNL, East Av., Livermore, California 94550 (United States); Sentoku, Y. [Department of Physics, University of Nevada, Reno, Nevada 89557-0058 (United States); Starodubtsev, M. [Institute of Applied Physics, 46 Ulyanov Street, 603950 Nizhny Novgorod (Russian Federation); and others

    2015-12-15

    The dynamics of self-generated magnetic B-fields produced following the interaction of a high contrast, high intensity (I > 10{sup 19 }W cm{sup −2}) laser beam with thin (3 μm thick) solid (Al or Au) targets is investigated experimentally and numerically. Two main sources drive the growth of B-fields on the target surfaces. B-fields are first driven by laser-generated hot electron currents that relax over ∼10–20 ps. Over longer timescales, the hydrodynamic expansion of the bulk of the target into vacuum also generates B-field induced by non-collinear gradients of density and temperature. The laser irradiation of the target front side strongly localizes the energy deposition at the target front, in contrast to the target rear side, which is heated by fast electrons over a much larger area. This induces an asymmetry in the hydrodynamic expansion between the front and rear target surfaces, and consequently the associated B-fields are found strongly asymmetric. The sole long-lasting (>30 ps) B-fields are the ones growing on the target front surface, where they remain of extremely high strength (∼8–10 MG). These B-fields have been recently put by us in practical use for focusing laser-accelerated protons [B. Albertazzi et al., Rev. Sci. Instrum. 86, 043502 (2015)]; here we analyze in detail their dynamics and structure.

  18. A prospective study on contrast-enhanced magnetic resonance imaging of testicular lesions: distinctive features of Leydig cell tumours

    International Nuclear Information System (INIS)

    Manganaro, Lucia; Vinci, Valeria; Saldari, Matteo; Bernardo, Silvia; Cantisani, Vito; Catalano, Carlo; Pozza, Carlotta; Gianfrilli, Daniele; Pofi, Riccardo; Lenzi, Andrea; Isidori, Andrea M.; Scialpi, Michele

    2015-01-01

    Up to 20 % of incidentally found testicular lesions are benign Leydig cell tumours (LCTs). This study evaluates the role of contrast-enhanced magnetic resonance imaging (MRI) in the identification of LCTs in a large prospective cohort study. We enrolled 44 consecutive patients with at least one solid non-palpable testicular lesion who underwent scrotal MRI. Margins of the lesions, signal intensity and pattern of wash-in and wash-out were analysed by two radiologists. The frequency distribution of malignant and benign MRI features in the different groups was compared by using the chi-squared or Fisher's exact test. Sensitivity, specificity, positive and negative predictive value, and diagnostic accuracy were calculated. The sensitivity of scrotal MRI to diagnose LCTs was 89.47 % with 95.65 % specificity; sensitivity for malignant lesions was 95.65 % with 80.95 % specificity. A markedly hypointense signal on T2-WI, rapid and marked wash-in followed by a prolonged washout were distinctive features significantly associated with LCTs. Malignant lesions were significantly associated with blurred margins, weak hypointense signal on T2-WI,and weak and progressive wash-in. The overall diagnostic accuracy was 93 %. LCTs have distinctive contrast-enhanced MRI features that allow the differential diagnosis of incidental testicular lesions. (orig.)

  19. A prospective study on contrast-enhanced magnetic resonance imaging of testicular lesions: distinctive features of Leydig cell tumours

    Energy Technology Data Exchange (ETDEWEB)

    Manganaro, Lucia; Vinci, Valeria; Saldari, Matteo; Bernardo, Silvia; Cantisani, Vito; Catalano, Carlo [Sapienza University of Rome, Department of Radiology, Rome (Italy); Pozza, Carlotta; Gianfrilli, Daniele; Pofi, Riccardo; Lenzi, Andrea; Isidori, Andrea M. [Sapienza University of Rome, Department of Experimental Medicine, Rome (Italy); Scialpi, Michele [Perugia University, S. Maria della Misericordia Hospital, Department of Surgical and Biomedical Sciences, Division of Radiology 2, Perugia (Italy)

    2015-12-15

    Up to 20 % of incidentally found testicular lesions are benign Leydig cell tumours (LCTs). This study evaluates the role of contrast-enhanced magnetic resonance imaging (MRI) in the identification of LCTs in a large prospective cohort study. We enrolled 44 consecutive patients with at least one solid non-palpable testicular lesion who underwent scrotal MRI. Margins of the lesions, signal intensity and pattern of wash-in and wash-out were analysed by two radiologists. The frequency distribution of malignant and benign MRI features in the different groups was compared by using the chi-squared or Fisher's exact test. Sensitivity, specificity, positive and negative predictive value, and diagnostic accuracy were calculated. The sensitivity of scrotal MRI to diagnose LCTs was 89.47 % with 95.65 % specificity; sensitivity for malignant lesions was 95.65 % with 80.95 % specificity. A markedly hypointense signal on T2-WI, rapid and marked wash-in followed by a prolonged washout were distinctive features significantly associated with LCTs. Malignant lesions were significantly associated with blurred margins, weak hypointense signal on T2-WI,and weak and progressive wash-in. The overall diagnostic accuracy was 93 %. LCTs have distinctive contrast-enhanced MRI features that allow the differential diagnosis of incidental testicular lesions. (orig.)

  20. Self-assembled polymeric nanoparticles as new, smart contrast agents for cancer early detection using magnetic resonance imaging.

    Science.gov (United States)

    Mouffouk, Fouzi; Simão, Teresa; Dornelles, Daniel F; Lopes, André D; Sau, Pablo; Martins, Jorge; Abu-Salah, Khalid M; Alrokayan, Salman A; Rosa da Costa, Ana M; dos Santos, Nuno R

    2015-01-01

    Early cancer detection is a major factor in the reduction of mortality and cancer management cost. Here we developed a smart and targeted micelle-based contrast agent for magnetic resonance imaging (MRI), able to turn on its imaging capability in the presence of acidic cancer tissues. This smart contrast agent consists of pH-sensitive polymeric micelles formed by self-assembly of a diblock copolymer (poly(ethyleneglycol-b-trimethylsilyl methacrylate)), loaded with a gadolinium hydrophobic complex ((t)BuBipyGd) and exploits the acidic pH in cancer tissues. In vitro MRI experiments showed that (t)BuBipyGd-loaded micelles were pH-sensitive, as they turned on their imaging capability only in an acidic microenvironment. The micelle-targeting ability toward cancer cells was enhanced by conjugation with an antibody against the MUC1 protein. The ability of our antibody-decorated micelles to be switched on in acidic microenvironments and to target cancer cells expressing specific antigens, together with its high Gd(III) content and its small size (35-40 nm) reveals their potential use for early cancer detection by MRI.

  1. Biodegradable human serum albumin nanoparticles as contrast agents for the detection of hepatocellular carcinoma by magnetic resonance imaging.

    Science.gov (United States)

    Watcharin, Waralee; Schmithals, Christian; Pleli, Thomas; Köberle, Verena; Korkusuz, Hüdayi; Huebner, Frank; Zeuzem, Stefan; Korf, Hans W; Vogl, Thomas J; Rittmeyer, Claudia; Terfort, Andreas; Piiper, Albrecht; Gelperina, Svetlana; Kreuter, Jörg

    2014-05-01

    Tumor visualization by magnetic resonance imaging (MRI) and nanoparticle-based contrast agents may improve the imaging of solid tumors such as hepatocellular carcinoma (HCC). In particular, human serum albumin (HSA) nanoparticles appear to be a suitable carrier due to their safety and feasibility of functionalization. In the present study HSA nanoparticles were conjugated with gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) using carbodiimide chemistry. The nanoparticles had a uniform spherical shape and a diameter of 235±19nm. For better optical visualization in vitro and in vivo, the HSA-Gd nanoparticles were additionally labeled with rhodamine 123. As shown by confocal microscopy and flow cytometry analysis, the fluorescent nanoparticles were readily taken up by Huh-7 hepatocellular carcinoma cells. After 24h incubation in blood serum, less than 5% of the Gd(III) was released from the particles, which suggests that this nanoparticulate system may be stable in vivo and, therefore, may serve as potentially safe T1 MRI contrast agent for MRI of hepatocellular carcinoma. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Blood Pool Contrast-enhanced Magnetic Resonance Angiography with Correlation to Digital Subtraction Angiography: A Pictorial Review

    Directory of Open Access Journals (Sweden)

    Martha-Grace Knuttinen

    2014-01-01

    Full Text Available Magnetic resonance angiography (MRA provides noninvasive visualization of the vascular supply of soft tissue masses and vascular pathology, without harmful radiation. This is important for planning an endovascular intervention, and helps to evaluate the efficiency and effectiveness of the treatment. MRA with conventional extracellular contrast agents relies on accurate contrast bolus timing, limiting the imaging window to first-pass arterial phase. The recently introduced blood pool contrast agent (BPCA, gadofosveset trisodium, reversibly binds to human serum albumin, resulting in increased T1 relaxivity and prolonged intravascular retention time, permitting both first-pass and steady-state phase high-resolution imaging. In our practice, high-quality MRA serves as a detailed "roadmap" for the needed endovascular intervention. Cases of aortoiliac occlusive disease, inferior vena cava thrombus, pelvic congestion syndrome, and lower extremity arteriovenous malformation are discussed in this article. MRA was acquired at 1.5 T with an 8-channel phased array coil after intravenous administration of gadofosveset (0.03 mmol/kg body weight, at the first-pass phase. In the steady-state, serial T1-weighted 3D spoiled gradient echo images were obtained with high resolution. All patients underwent digital subtraction angiography (DSA and endovascular treatment. MRA and DSA findings of vascular anatomy and pathology are discussed and correlated. BPCA-enhanced MRA provides high-quality first-pass and steady-state vascular imaging. This could increase the diagnostic accuracy and create a detailed map for pre-intervention planning. Understanding the pharmacokinetics of BPCA and being familiar with the indications and technique of MRA are important for diagnosis and endovascular intervention.

  3. Contrast-enhanced magnetic resonance imaging for the detection of ruptured coronary plaques in patients with acute myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Christian H P Jansen

    Full Text Available X-ray coronary angiography (XCA is the current gold standard for the assessment of lumen encroaching coronary stenosis but XCA does not allow for early detection of rupture-prone vulnerable plaques, which are thought to be the precursor lesions of most acute myocardial infarctions (AMI and sudden death. The aim of this study was to investigate the potential of delayed contrast-enhanced magnetic resonance coronary vessel wall imaging (CE-MRCVI for the detection of culprit lesions in the coronary arteries.16 patients (13 male, age 61.9±8.6 years presenting with sub-acute MI underwent CE-MRCVI within 24-72h prior to invasive XCA. CE-MRCVI was performed using a T1-weighted 3D gradient echo inversion recovery sequence (3D IR TFE 40±4 minutes following the administration of 0.2 mmol/kg gadolinium-diethylenetriamine-pentaacetic acid (DTPA on a 3T MRI scanner equipped with a 32-channel cardiac coil.14 patients were found to have culprit lesions (7x LAD, 1xLCX, 6xRCA as identified by XCA. Quantitative CE-MRCVI correctly identified the culprit lesion location with a sensitivity of 79% and excluded culprit lesion formation with a specificity of 99%. The contrast to noise ratio (CNR of culprit lesions (9.7±4.1 significantly exceeded CNR values of segments without culprit lesions (2.9±1.9, p<0.001.CE-MRCVI allows the selective visualization of culprit lesions in patients immediately after myocardial infarction (MI. The pronounced contrast uptake in ruptured plaques may represent a surrogate biomarker of plaque activity and/or vulnerability.

  4. 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.

  5. Cardiovascular MRI with ferumoxytol

    International Nuclear Information System (INIS)

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

    2016-01-01

    The practice of contrast-enhanced magnetic resonance angiography (CEMRA) has changed significantly in the span of a decade. Concerns regarding gadolinium (Gd)-associated nephrogenic systemic fibrosis in those with severely impaired renal function spurred developments in low-dose CEMRA and non-contrast MRA as well as efforts to seek alternative MR contrast agents. Originally developed for MR imaging use, ferumoxytol (an ultra-small superparamagnetic iron oxide nanoparticle), is currently approved by the US Food and Drug Administration for the treatment of iron deficiency anaemia in adults with renal disease. Since its clinical availability in 2009, there has been rising interest in the scientific and clinical use of ferumoxytol as an MR contrast agent. The unique physicochemical and pharmacokinetic properties of ferumoxytol, including its long intravascular half-life and high r 1 relaxivity, support a spectrum of MRI applications beyond the scope of Gd-based contrast agents. Moreover, whereas Gd is not found in biological systems, iron is essential for normal metabolism, and nutritional iron deficiency poses major public health challenges worldwide. Once the carbohydrate shell of ferumoxytol is degraded, the elemental iron at its core is incorporated into the reticuloendothelial system. These considerations position ferumoxytol as a potential game changer in the field of CEMRA and MRI. In this paper, we aim to summarise our experience with the cardiovascular applications of ferumoxytol and provide a brief synopsis of ongoing investigations on ferumoxytol-enhanced MR applications.

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

    Directory of Open Access Journals (Sweden)

    Dundon BK

    2014-09-01

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

  7. Quantitating aortic regurgitation by cardiovascular magnetic resonance: significant variations due to slice location and breath holding

    International Nuclear Information System (INIS)

    Chaturvedi, Abhishek; Hamilton-Craig, Christian; Cawley, Peter J.; Maki, Jeffrey H.; Mitsumori, Lee M.; Otto, Catherine M.

    2016-01-01

    Compare variability in flow measurements by phase contrast MRI, performed at different locations in the aorta and pulmonary artery (PA) using breath-held (BH) and free-breathing (FB) sequences. Fifty-seven patients with valvular heart disease, confirmed by echocardiography, were scanned using BH technique at 3 locations in the ascending aorta (SOV = sinus of Valsalva, STJ = sinotubular junction, ASC = ascending aorta at level of right pulmonary artery) and 2 locations in PA. Single FB measurement was obtained at STJ for aorta. Obtained metrics (SV = stroke volume, FV = forward volume, BV = backward volume, RF = regurgitant fraction) were evaluated separately for patients with aortic regurgitation (AR, n = 31) and mitral regurgitation (n = 26). No difference was noted between the two measurements in the PA. Significant differences were noted in measured SV at different aortic locations. SV measurements obtained at ASC correlated best with the measurements obtained in the PA. Strongest correlation of AR was measured at the STJ. Measurements of flow volumes by phase contrast MRI differ depending on slice location. When using stroke volumes to calculate pulmonary to systemic blood flow ratio (Qp/Qs), ASC should be used. For quantifying aortic regurgitation, measurement should be obtained at STJ. (orig.)

  8. Dual-mode T_1 and T_2 magnetic resonance imaging contrast agent based on ultrasmall mixed gadolinium-dysprosium oxide nanoparticles: synthesis, characterization, and in vivo application

    International Nuclear Information System (INIS)

    Tegafaw, Tirusew; Xu, Wenlong; Ahmad, Md Wasi; Lee, Gang Ho; Baeck, Jong Su; Chang, Yongmin; Bae, Ji Eun; Chae, Kwon Seok; Kim, Tae Jeong

    2015-01-01

    A new type of dual-mode T_1 and T_2 magnetic resonance imaging (MRI) contrast agent based on mixed lanthanide oxide nanoparticles was synthesized. Gd"3"+ ("8S_7_/_2) plays an important role in T_1 MRI contrast agents because of its large electron spin magnetic moment resulting from its seven unpaired 4f-electrons, and Dy"3"+ ("6H_1_5_/_2) has the potential to be used in T_2 MRI contrast agents because of its very large total electron magnetic moment: among lanthanide oxide nanoparticles, Dy_2O_3 nanoparticles have the largest magnetic moments at room temperature. Using these properties of Gd"3"+ and Dy"3"+ and their oxide nanoparticles, ultrasmall mixed gadolinium-dysprosium oxide (GDO) nanoparticles were synthesized and their potential to act as a dual-mode T_1 and T_2 MRI contrast agent was investigated in vitro and in vivo. The D-glucuronic acid coated GDO nanoparticles (d_a_v_g = 1.0 nm) showed large r_1 and r_2 values (r_2/r_1 ≈ 6.6) and as a result clear dose-dependent contrast enhancements in R_1 and R_2 map images. Finally, the dual-mode imaging capability of the nanoparticles was confirmed by obtaining in vivo T_1 and T_2 MR images. (paper)

  9. 4D cardiovascular magnetic resonance velocity mapping of alterations of right heart flow patterns and main pulmonary artery hemodynamics in tetralogy of Fallot

    Science.gov (United States)

    2012-01-01

    Background To assess changes in right heart flow and pulmonary artery hemodynamics in patients with repaired Tetralogy of Fallot (rTOF) we used whole heart, four dimensional (4D) velocity mapping (VM) cardiovascular magnetic resonance (CMR). Methods CMR studies were performed in 11 subjects with rTOF (5M/6F; 20.1 ± 12.4 years) and 10 normal volunteers (6M/4F; 34.2 ± 13.4 years) on clinical 1.5T and 3.0T MR scanners. 4D VM-CMR was performed using PC VIPR (Phase Contrast Vastly undersampled Isotropic Projection Reconstruction). Interactive streamline and particle trace visualizations of the superior and inferior vena cava (IVC and SVC, respectively), right atrium (RA), right ventricle (RV), and pulmonary artery (PA) were generated and reviewed by three experienced readers. Main PA net flow, retrograde flow, peak flow, time-to-peak flow, peak acceleration, resistance index and mean wall shear stress were quantified. Differences in flow patterns between the two groups were tested using Fisher's exact test. Differences in quantitative parameters were analyzed with the Kruskal-Wallis rank sum test. Results 4D VM-CMR was successfully performed in all volunteers and subjects with TOF. Right heart flow patterns in rTOF subjects were characterized by (a) greater SVC/IVC flow during diastole than systole, (b) increased vortical flow patterns in the RA and in the RV during diastole, and (c) increased helical or vortical flow features in the PA's. Differences in main PA retrograde flow, resistance index, peak flow, time-to-peak flow, peak acceleration and mean wall shear stress were statistically significant. Conclusions Whole heart 4D VM-CMR with PC VIPR enables detection of both normal and abnormal right heart flow patterns, which may allow for comprehensive studies to evaluate interdependencies of post-surgically altered geometries and hemodynamics. PMID:22313680

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

    Directory of Open Access Journals (Sweden)

    Swift Andrew J

    2012-06-01

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

  11. Unrecognized myocardial infarctions assessed by cardiovascular magnetic resonance are associated with the severity of the stenosis in the supplying coronary artery.

    Science.gov (United States)

    Hammar, Per; Nordenskjöld, Anna M; Lindahl, Bertil; Duvernoy, Olov; Ahlström, Håkan; Johansson, Lars; Hadziosmanovic, Nermin; Bjerner, Tomas

    2015-11-19

    A previous study has shown an increased prevalence of late gadolinium enhancement cardiovascular magnetic resonance (LGE CMR) detected unrecognized myocardial infarction (UMI) with increasing extent and severity of coronary artery disease. However, the coronary artery disease was evaluated on a patient level assuming normal coronary anatomy. Therefore, the aims of the present study were to investigate the prevalence of UMI identified by LGE CMR imaging in patients with stable angina pectoris and no known previous myocardial infarction; and to investigate whether presence of UMI is associated with stenotic lesions in the coronary artery supplying the segment of the myocardium in which the UMI is located, using coronary angiography to determine the individual coronary anatomy in each patient. In this prospective multicenter study, we included patients with stable angina pectoris and without prior myocardial infarction, scheduled for coronary angiography. A LGE CMR examination was performed prior to the coronary angiography. The study cohort consisted of 235 patients (80 women, 155 men) with a mean age of 64.8 years. UMIs were found in 25% of patients. There was a strong association between stenotic lesions (≥70% stenosis) in a coronary artery and the presence of an UMI in the myocardial segments supplied by the stenotic artery; it was significantly more likely to have an UMI downstream a stenosis ≥ 70% as compared to < 70% (OR 5.1, CI 3.1-8.3, p < 0.0001). 56% of the UMIs were located in the inferior and infero-lateral myocardial segments, despite predominance for stenotic lesions in the left anterior descending artery. UMI is common in patients with stable angina and the results indicate that the majority of the UMIs are of ischemic origin due to severe coronary atherosclerosis. In contrast to what is seen in recognized myocardial infarctions, UMIs are predominately located in the inferior and infero-lateral myocardial segments. The PUMI study is

  12. Utility of Cardiovascular Magnetic Resonance-Derived Wave Intensity Analysis As a Marker of Ventricular Function in Children with Heart Failure and Normal Ejection Fraction.

    Science.gov (United States)

    Ntsinjana, Hopewell N; Chung, Robin; Ciliberti, Paolo; Muthurangu, Vivek; Schievano, Silvia; Marek, Jan; Parker, Kim H; Taylor, Andrew M; Biglino, Giovanni

    2017-01-01

    This study sought to explore the diagnostic insight of cardiovascular magnetic resonance (CMR)-derived wave intensity analysis to better study systolic dysfunction in young patients with chronic diastolic dysfunction and preserved ejection fraction (EF), comparing it against other echocardiographic and CMR parameters. Evaluating systolic and diastolic dysfunctions in children is challenging, and a gold standard method is currently lacking. Patients with presumed diastolic dysfunction [ n  = 18; nine aortic stenosis (AS), five hypertrophic, and four restrictive cardiomyopathies] were compared with age-matched control subjects ( n  = 18). All patients had no mitral or aortic incompetence, significant AS, or reduced systolic EF. E / A ratio, E / E ' ratio, deceleration time, and isovolumetric contraction time were assessed on echocardiography, and indexed left atrial volume (LAVi), acceleration time (AT), ejection time (ET), and wave intensity analyses were calculated from CMR. The latter was performed on CMR phase-contrast flow sequences, defining a ratio of the peaks of the early systolic forward compression wave (FCW) and the end-systolic forward expansion wave (FEW). Significant differences between patients and controls were seen in the E / E ' ratio (8.7 ± 4.0 vs. 5.1 ± 1.3, p  = 0.001) and FCW/FEW ratio (2.5 ± 1.6 vs. 7.2 ± 4.2 × 10 -5 m/s, p  wave intensity-derived ratio summarizing systolic and diastolic function could provide insight into ventricular function in children, on top of CMR and echocardiography, and it was here able to identify an element of ventricular dysfunction with preserved EF in a small group of young patients.

  13. The effective use of acai juice, blueberry juice and pineapple juice as negative contrast agents for magnetic resonance cholangiopancreatography in children

    International Nuclear Information System (INIS)

    Bittman, Mark E.; Callahan, Michael J.

    2014-01-01

    Magnetic resonance cholangiopancreatography (MRCP) is commonly performed in the evaluation of known or suspected pancreaticobiliary disease in children. The administration of a negative oral contrast agent can improve the quality of the examination without significant additional cost. We describe our experience with certain brands of acai juice, blueberry juice and pineapple juice as negative oral contrast agents in children. We believe these fruit juices are safe, palatable and may improve MRCP image quality. (orig.)

  14. Dynamic contrast-enhanced magnetic resonance imaging of articular and extraarticular synovial structures of the hands in patients with psoriatic arthritis

    DEFF Research Database (Denmark)

    Cimmino, Marco Amedeo; Barbieri, Francesca; Boesen, Mikael

    2012-01-01

    Dynamic, contrast-enhanced magnetic resonance imaging (DCE-MRI), the quantification of enhancement within the synovial membrane and bone by extracting curves using fast T1-weighted sequences during intravenous administration of contrast agent, evaluates synovitis and bone marrow edema in psoriati...... arthritis (PsA). In this pilot study, we looked at possible differences between joint synovitis and tenosynovitis in PsA as compared with rheumatoid arthritis (RA)....

  15. The effective use of acai juice, blueberry juice and pineapple juice as negative contrast agents for magnetic resonance cholangiopancreatography in children

    Energy Technology Data Exchange (ETDEWEB)

    Bittman, Mark E. [Cohen Children' s Medical Center of New York, North Shore Long Island Jewish Health System, Department of Radiology, New Hyde Park, NY (United States); Callahan, Michael J. [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States)

    2014-07-15

    Magnetic resonance cholangiopancreatography (MRCP) is commonly performed in the evaluation of known or suspected pancreaticobiliary disease in children. The administration of a negative oral contrast agent can improve the quality of the examination without significant additional cost. We describe our experience with certain brands of acai juice, blueberry juice and pineapple juice as negative oral contrast agents in children. We believe these fruit juices are safe, palatable and may improve MRCP image quality. (orig.)

  16. Pretreatment Evaluation of Microcirculation by Dynamic Contrast-Enhanced Magnetic Resonance Imaging Predicts Survival in Primary Rectal Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    DeVries, Alexander Friedrich [Department of Radio-Oncology, Academic Teaching Hospital Feldkirch, Feldkirch (Austria); Piringer, Gudrun, E-mail: gudrun.piringer@hotmail.com [Department of Oncology, Wels-Grieskirchen Medical Hospital, Wels (Austria); Kremser, Christian; Judmaier, Werner [Department of Radiology, Innsbruck Medical University, Innsbruck (Austria); Saely, Christoph Hubert [Department of Medicine and Cardiology, Academic Teaching Hospital Feldkirch, Feldkirch (Austria); Lukas, Peter [Department of Radio-Oncology, Innsbruck Medical University, Innsbruck (Austria); Öfner, Dietmar [Department of Surgery, Paracelsus Medical University, Salzburg (Austria)

    2014-12-01

    Purpose: To investigate the prognostic value of the perfusion index (PI), a microcirculatory parameter estimated from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), which integrates information on both flow and permeability, to predict overall survival and disease-free survival in patients with primary rectal cancer. Methods and Materials: A total of 83 patients with stage cT3 rectal cancer requiring neoadjuvant chemoradiation were investigated with DCE-MRI before start of therapy. Contrast-enhanced dynamic T{sub 1} mapping was obtained, and a simple data analysis strategy based on the calculation of the maximum slope of the tissue concentration–time curve divided by the maximum of the arterial input function was used as a measure of tumor microcirculation (PI), which integrates information on both flow and permeability. Results: In 39 patients (47.0%), T downstaging (ypT0-2) was observed. During a mean (±SD) follow-up period of 71 ± 29 months, 58 patients (69.9%) survived, and disease-free survival was achieved in 45 patients (54.2%). The mean PI (PImean) averaged over the group of nonresponders was significantly higher than for responders. Additionally, higher PImean in age- and gender-adjusted analyses was strongly predictive of therapy nonresponse. Most importantly, PImean strongly and significantly predicted disease-free survival (unadjusted hazard ratio [HR], 1.85 [ 95% confidence interval, 1.35-2.54; P<.001)]; HR adjusted for age and sex, 1.81 [1.30-2.51]; P<.001) as well as overall survival (unadjusted HR 1.42 [1.02-1.99], P=.040; HR adjusted for age and sex, 1.43 [1.03-1.98]; P=.034). Conclusions: This analysis identifies PImean as a novel biomarker that is predictive for therapy response, disease-free survival, and overall survival in patients with primary locally advanced rectal cancer.

  17. Cost-effectiveness of magnetic resonance imaging with a new contrast agent for the early diagnosis of Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Maria Biasutti

    Full Text Available Used as contrast agents for brain magnetic resonance imaging (MRI, markers for beta-amyloid deposits might allow early diagnosis of Alzheimer's disease (AD. We evaluated the cost-effectiveness of such a diagnostic test, MRI+CLP (contrastophore-linker-pharmacophore, should it become clinically available.We compared the cost-effectiveness of MRI+CLP to that of standard diagnosis using currently available cognition tests and of standard MRI, and investigated the impact of a hypothetical treatment efficient in early AD. The primary analysis was based on the current French context for 70-year-old patients with Mild Cognitive Impairment (MCI. In alternative "screen and treat" scenarios, we analyzed the consequences of systematic screenings of over-60 individuals (either population-wide or restricted to the ApoE4 genotype population. We used a Markov model of AD progression; model parameters, as well as incurred costs and quality-of-life weights in France were taken from the literature. We performed univariate and probabilistic multivariate sensitivity analyses. The base-case preferred strategy was the standard MRI diagnosis strategy. In the primary analysis however, MRI+CLP could become the preferred strategy under a wide array of scenarios involving lower cost and/or higher sensitivity or specificity. By contrast, in the "screen and treat" analyses, the probability of MRI+CLP becoming the preferred strategy remained lower than 5%.It is thought that anti-beta-amyloid compounds might halt the development of dementia in early stage patients. This study suggests that, even should such treatments become available, systematically screening the over-60 population for AD would only become cost-effective with highly specific tests able to diagnose early stages of the disease. However, offering a new diagnostic test based on beta-amyloid markers to elderly patients with MCI might prove cost-effective.

  18. Synthesis and characterization of Gadolinium-Lectin conjugates as selective blood-vessel contrast agents for magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Pashkunova-Martic, I.

    2004-11-01

    Molecular imaging without use of ionizing radiation has recently been developed for both magnetic resonance and ultrasound imaging (MRI, US) and is expected to play a major future role in diagnosis and monitoring of tumours. In MRI, targeted nanoparticle contrast media (CM) with high relaxivities are required in order to obtain adequate signal-to-noise ratios, due to the low number of target sites. The size, charge and chemical constitution of the targeted nanoparticle CM are expected to influence nanoparticle interactions with cells and tissue elements significantly, and hence the targeting, the accumulation and dwell time at the targeted site, and the type and rate of clearance of the nanoparticles. The work reported here aims to characterise and optimise these parameters in mouse and human models, using nanoparticles targeted to a major carbohydrate determinant of the endothelial cell surface which is present in all blood vessels. Specific binding to the endothelium was demonstrated in both living and chemically fixed human vessels and in mice. Long-standing spin-echo and FLASH-3D images were obtained in the vasculature of living mice, in strong contrast to the rapid renal clearance of gadolinium-DTPA chelates which are widely used in the clinic. Nanoparticle size was found to be a major determinant of the biological response, and our data indicate that an optimal nanoparticle size lies between 50-100 nm diameter. We expect that hyperpermeable vessels present in tumours will permit targeting of optimised nanoparticles to the tumour cells, permitting MRI monitoring of the tumour. (author)

  19. Monitoring of arterial wall remodelling in atherosclerotic rabbits with a magnetic resonance imaging contrast agent binding to matrix metalloproteinases

    Science.gov (United States)

    Hyafil, Fabien; Vucic, Esad; Cornily, Jean-Christophe; Sharma, Rahul; Amirbekian, Vardan; Blackwell, Francis; Lancelot, Eric; Corot, Claire; Fuster, Valentin; Galis, Zorina S.; Feldman, Laurent J.; Fayad, Zahi A.

    2011-01-01

    Aims P947 is a gadolinium-based magnetic resonance imaging (MRI) contrast agent with high affinity for several matrix metalloproteinases (MMPs) involved in arterial wall remodelling. We tested whether the intensity of enhancement detected in vivo in the arterial wall with P947 and MRI correlates with actual tissue MMP-related enzymatic activity measured in a rabbit atherosclerotic model subjected to dietary manipulations. Methods and results Aortas of 15 rabbits in which atherosclerotic lesions were induced by balloon angioplasty and 4 months of hypercholesterolaemic diet were imaged at ‘baseline’ with P947-enhanced MRI. Atherosclerotic rabbits were divided into three groups: five rabbits were sacrificed (‘baseline’ group); five rabbits continued to be fed a lipid-supplemented diet (‘high-fat’ group); and five rabbits were switched from atherogenic to a purified chow diet (‘low-fat’ group). Four months later, a second P947-enhanced MRI was acquired in the 10 remaining rabbits. A significantly lower signal was detected in the aortic wall of rabbits from the ‘low-fat’ group as compared with rabbits from the ‘high-fat’ group (21 ± 6 vs. 46 ± 3%, respectively; P = 0.04). Such differences were not detected with the contrast agent P1135, which lacks the MMP-specific peptide sequence. In addition, the intensity of aortic wall enhancement detected with MRI after injection of P947 strongly correlated with actual MMP-2 gelatinolytic activity measured in corresponding aortic segments using zymography (r = 0.87). Conclusion P947-enhanced MRI can distinguish dietary-induced variations in MMP-related enzymatic activity within plaques in an experimental atherosclerotic model, supporting its utility as a clinical imaging tool for in vivo detection of arterial wall remodelling. PMID:21118852

  20. Magnetization transfer contrast imaging detects early white matter changes in the APP/PS1 amyloidosis mouse model