The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Martin Funovics - One of the best experts on this subject based on the ideXlab platform.
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Perceptibility and Quantification of in-Stent Stenosis With Six Peripheral Arterial Stent Types in Vitro: Comparison of 16- MDCT Angiography, 64-MDCT Angiography, and MR Angiography
AJR. American journal of roentgenology, 2010Co-Authors: Melanie Schernthaner, Rüdiger Schernthaner, Gundula Edelhauser, Johannes Lammer, Dominik Berzaczy, Florian Wolf, Martin FunovicsAbstract:OBJECTIVE. The purpose of this study was to evaluate and compare the perceptibility of 75% and 95% in-stent stenoses with CT angiography and MR angiography using six stent types in a phantom model.MATERIALS AND METHODS. Six different stent types were placed into tubes filled with contrast agent (ioversol or Gadoteric Acid), and nylon cylinders (8 mm diameter) bored in the central axis (2 and 4 mm) to mimic 75% and 95% stenoses were inserted into the stents inside the tubes. CT angiography (16- and 64-MDCT scanners using three different kernels at 120 and 140 kV) and MR angiography (1.5 T) were performed. On 2-mm coronal sections, signal intensities in the stenosed stents were compared with unstenosed segments. In addition, perceptibility of the residual lumen was assessed using a subjective score. Image analysis was performed by two experienced and blinded radiologists.RESULTS. Sixteen-slice CT angiography showed relative in-stent signal intensities of 72–87%, whereas 64-MDCT angiography showed relative i...
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Quantification and Detectability of In-Stent Stenosis with CT Angiography and MR Angiography in Arterial Stents In Vitro
AJR. American journal of roentgenology, 2007Co-Authors: Melanie Blum, Maria Theresa Schmook, Rüdiger Schernthaner, Gundula Edelhauser, Stefan Puchner, Johannes Lammer, Martin FunovicsAbstract:OBJECTIVE. The purpose of this study was to compare CT angiography (CTA) and MR angiography (MRA) for the detectability of 75% and 95% stenoses in phantoms using six different stents.MATERIALS AND METHODS. Six different stents (Expander, Hemobahn, SelfX, Smart, Symphony, and Wallstent) were inserted into tubes filled with contrast agent (ioversol or Gadoteric Acid). To mimic stenoses of 75% and 95% of the patent lumen, 8-mm-diameter nylon cylinders were bored in the central axis (2 mm and 4 mm, respectively) and placed into the stent lumen. Intensity profiles across stenoses on 2-mm coronal reformatted sections of CTA or MRA were compared, and the detectability of the residual lumen was assessed using a subjective score.RESULTS. CTA showed relative in-stent signal attenuation for the in-stent stenoses of the tested stents ranging from 75% to 100% of the signal intensity of the control. SelfX and Symphony showed further shading of the residual lumen due to beam-hardening artifacts. Overestimation of stenos...
Michael Pedersen - One of the best experts on this subject based on the ideXlab platform.
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High-resolution ex vivo magnetic resonance angiography: a feasibility study on biological and medical tissues
BMC Physiology, 2010Co-Authors: Anne S Rasmussen, Henrik Lauridsen, Christoffer Laustsen, Bjarke G Jensen, Steen F Pedersen, Lars Uhrenholt, Lene Wt Boel, Niels Uldbjerg, Tobias Wang, Michael PedersenAbstract:Background In biomedical sciences, ex vivo angiography is a practical mean to elucidate vascular structures three-dimensionally with simultaneous estimation of intravascular volume. The objectives of this study were to develop a magnetic resonance (MR) method for ex vivo angiography and to compare the findings with computed tomography (CT). To demonstrate the usefulness of this method, examples are provided from four different tissues and species: the human placenta, a rice field eel, a porcine heart and a turtle. Results The optimal solution for ex vivo MR angiography (MRA) was a compound containing gelatine (0.05 g/mL), the CT contrast agent barium sulphate (0.43 mol/L) and the MR contrast agent Gadoteric Acid (2.5 mmol/L). It was possible to perform angiography on all specimens. We found that ex vivo MRA could only be performed on fresh tissue because formalin fixation makes the blood vessels permeable to the MR contrast agent. Conclusions Ex vivo MRA provides high-resolution images of fresh tissue and delineates fine structures that we were unable to visualise by CT. We found that MRA provided detailed information similar to or better than conventional CTA in its ability to visualize vessel configuration while avoiding interfering signals from adjacent bones. Interestingly, we found that vascular tissue becomes leaky when formalin-fixed, leading to increased permeability and extravascular leakage of MR contrast agent.
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High-resolution ex vivo magnetic resonance angiography: a feasibility study on biological and medical tissues
BMC physiology, 2010Co-Authors: Anne S Rasmussen, Henrik Lauridsen, Christoffer Laustsen, Steen F Pedersen, Lars Uhrenholt, Lene Wt Boel, Niels Uldbjerg, Tobias Wang, Bjarke Jensen, Michael PedersenAbstract:In biomedical sciences, ex vivo angiography is a practical mean to elucidate vascular structures three-dimensionally with simultaneous estimation of intravascular volume. The objectives of this study were to develop a magnetic resonance (MR) method for ex vivo angiography and to compare the findings with computed tomography (CT). To demonstrate the usefulness of this method, examples are provided from four different tissues and species: the human placenta, a rice field eel, a porcine heart and a turtle. The optimal solution for ex vivo MR angiography (MRA) was a compound containing gelatine (0.05 g/mL), the CT contrast agent barium sulphate (0.43 mol/L) and the MR contrast agent Gadoteric Acid (2.5 mmol/L). It was possible to perform angiography on all specimens. We found that ex vivo MRA could only be performed on fresh tissue because formalin fixation makes the blood vessels permeable to the MR contrast agent. Ex vivo MRA provides high-resolution images of fresh tissue and delineates fine structures that we were unable to visualise by CT. We found that MRA provided detailed information similar to or better than conventional CTA in its ability to visualize vessel configuration while avoiding interfering signals from adjacent bones. Interestingly, we found that vascular tissue becomes leaky when formalin-fixed, leading to increased permeability and extravascular leakage of MR contrast agent.
Laurent Brunereau - One of the best experts on this subject based on the ideXlab platform.
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T1 mapping, ECV and ICV before and after aortic valve replacement
Journal of Cardiovascular Magnetic Resonance, 2015Co-Authors: Emmanuelle Vermes, Nicolas Cazeneuve, Olivier Genée, Anne Delhommais, Laurent Brunereau, Daniel Alison, Julien PucheuxAbstract:Methods A prospective CMR T1 mapping study of 37 patients with severe AS before and six months after aortic valve replacement (AVR) was conducted. CMR at 1.5 T, including T1 mapping using a modified Look-Locker inversion recovery sequence (before and 15 minutes after the administration of 0.2 mmol/kg of Gadoteric Acid), was carried out. Global T1 values, ECV, ICV have been measured before and six months after surgery.
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0113: Cardiac magnetic resonance T1 mapping pre and post contrast in heart transplant patients with clinical antibody-mediated rejection: a preliminary experience
Archives of Cardiovascular Diseases Supplements, 2015Co-Authors: Emmanuelle Vermes, Anne Delhommais, Julien Pucheux, Alain Mirza, Laurent BrunereauAbstract:Background Antibody-mediated rejection (AMR) is characterized by histopathological and immunophenotypic findings such as activated endothelial cells, intravascular macrophages and evidence of capillary C4d deposition. This inflammatory reaction could be followed by diffuse fibrosis. Cardiac magnetic resonance (CMR) with recently T1 mapping is a promising technique to identify diffuse myocardial fibrosis. The purpose of this study was to assess T1 mapping in patients with AMR. Method 2 patients with clinical AMR (histopathological and immunophenotypic findings, presence of donor-specific allo antibodies and allograft dysfunction) performed a CMR study one week (for the first patient) and 3 weeks (for the second patient) after the treatment of AMR (plasmapheresis, IV Immunoglobulins and Rituximab). Images were acquired on a 1.5 Tesla scanner (Siemens) including T1 mapping using a shortened modified look-locker inversion-recovery sequence and T2 mapping in a matched mid-ventricular short axis slice using a black- blood single shot fast spin echo pulse sequence. Segmental and global T1 values were measured before and 15 minutes after administration of 0.2 mmol/kg of Gadoteric Acid and compared to our cohort of 17 controls. Results Mean non contrast T1 values were significantly higher in heart transplants patients compared to controls (1100±5ms vs 947±29ms, P Conclusion Heart transplant patients with clinical antibody-mediated rejection show a significant increased global and segmental non contrast T1 values suggesting the presence of diffuse myocardial fibrosis. Further studies are required to confirm these data.
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Cardiac magnetic resonance T1 mapping pre and post contrast in heart transplant patients with clinical antibody-mediated rejection: a preliminary experience
Journal of Cardiovascular Magnetic Resonance, 2014Co-Authors: Emmanuelle Vermes, Anne Delhommais, Daniel Alison, Julien Pucheux, Laurent BrunereauAbstract:Background Antibody-mediated rejection (AMR) is characterized by histopathological and immunophenotypic findings such as activated endothelial cells, intravascular macrophages and evidence of capillary C4d deposition. This inflammatory reaction could be followed by diffuse fibrosis. Cardiac magnetic resonance (CMR) with recently T1 mapping is a promising technique to identify diffuse myocardial fibrosis. The purpose of this study was to assess T1 mapping in patients with AMR. Methods Two patients with clinical AMR (histopathological and immunophenotypic findings, presence of donor-specific allo antibodies and allograft dysfunction) performed a CMR study one week (for the first patient) and 3 weeks (for the second patient) after the treatment of AMR (plasmapheresis, IV Immunoglobulins and Rituximab). Images were acquired on a 1.5 Tesla scanner (Siemens) including T1 mapping using a shortened modified look-locker inversion-recovery sequence and T2 mapping in a matched mid-ventricular short axis slice using a black- blood single shot fast spin echo pulse sequence. Segmental and global T1 values were measured before and 15 minutes after administration of 0.2 mmol/kg of Gadoteric Acid and compared to our cohort of 17 controls. Results Mean non contrast T1 values were significantly higher in heart transplants patients compared to controls (1100 ± 5 ms vs 947 ± 29 ms, P < 0.001). Segmental T1 values were significantly higher in the 6 regions of interest compared to controls (P < 0.001 in all segments). Mean post contrast T1 values were not significantly different in patients and controls. Mean T2 value was higher in patients compared to controls (73 ± 13 vs 50 ± 4 ms), suggesting the presence of global edema. Conclusions Heart transplant patients with clinical antibodymediated rejection show a significant increased global and segmental non contrast T1 values suggesting the presence of diffuse myocardial fibrosis. Further studies are required to confirm these data. Funding
Emmanuelle Vermes - One of the best experts on this subject based on the ideXlab platform.
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T1 mapping, ECV and ICV before and after aortic valve replacement
Journal of Cardiovascular Magnetic Resonance, 2015Co-Authors: Emmanuelle Vermes, Nicolas Cazeneuve, Olivier Genée, Anne Delhommais, Laurent Brunereau, Daniel Alison, Julien PucheuxAbstract:Methods A prospective CMR T1 mapping study of 37 patients with severe AS before and six months after aortic valve replacement (AVR) was conducted. CMR at 1.5 T, including T1 mapping using a modified Look-Locker inversion recovery sequence (before and 15 minutes after the administration of 0.2 mmol/kg of Gadoteric Acid), was carried out. Global T1 values, ECV, ICV have been measured before and six months after surgery.
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0113: Cardiac magnetic resonance T1 mapping pre and post contrast in heart transplant patients with clinical antibody-mediated rejection: a preliminary experience
Archives of Cardiovascular Diseases Supplements, 2015Co-Authors: Emmanuelle Vermes, Anne Delhommais, Julien Pucheux, Alain Mirza, Laurent BrunereauAbstract:Background Antibody-mediated rejection (AMR) is characterized by histopathological and immunophenotypic findings such as activated endothelial cells, intravascular macrophages and evidence of capillary C4d deposition. This inflammatory reaction could be followed by diffuse fibrosis. Cardiac magnetic resonance (CMR) with recently T1 mapping is a promising technique to identify diffuse myocardial fibrosis. The purpose of this study was to assess T1 mapping in patients with AMR. Method 2 patients with clinical AMR (histopathological and immunophenotypic findings, presence of donor-specific allo antibodies and allograft dysfunction) performed a CMR study one week (for the first patient) and 3 weeks (for the second patient) after the treatment of AMR (plasmapheresis, IV Immunoglobulins and Rituximab). Images were acquired on a 1.5 Tesla scanner (Siemens) including T1 mapping using a shortened modified look-locker inversion-recovery sequence and T2 mapping in a matched mid-ventricular short axis slice using a black- blood single shot fast spin echo pulse sequence. Segmental and global T1 values were measured before and 15 minutes after administration of 0.2 mmol/kg of Gadoteric Acid and compared to our cohort of 17 controls. Results Mean non contrast T1 values were significantly higher in heart transplants patients compared to controls (1100±5ms vs 947±29ms, P Conclusion Heart transplant patients with clinical antibody-mediated rejection show a significant increased global and segmental non contrast T1 values suggesting the presence of diffuse myocardial fibrosis. Further studies are required to confirm these data.
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Cardiac magnetic resonance T1 mapping pre and post contrast in heart transplant patients with clinical antibody-mediated rejection: a preliminary experience
Journal of Cardiovascular Magnetic Resonance, 2014Co-Authors: Emmanuelle Vermes, Anne Delhommais, Daniel Alison, Julien Pucheux, Laurent BrunereauAbstract:Background Antibody-mediated rejection (AMR) is characterized by histopathological and immunophenotypic findings such as activated endothelial cells, intravascular macrophages and evidence of capillary C4d deposition. This inflammatory reaction could be followed by diffuse fibrosis. Cardiac magnetic resonance (CMR) with recently T1 mapping is a promising technique to identify diffuse myocardial fibrosis. The purpose of this study was to assess T1 mapping in patients with AMR. Methods Two patients with clinical AMR (histopathological and immunophenotypic findings, presence of donor-specific allo antibodies and allograft dysfunction) performed a CMR study one week (for the first patient) and 3 weeks (for the second patient) after the treatment of AMR (plasmapheresis, IV Immunoglobulins and Rituximab). Images were acquired on a 1.5 Tesla scanner (Siemens) including T1 mapping using a shortened modified look-locker inversion-recovery sequence and T2 mapping in a matched mid-ventricular short axis slice using a black- blood single shot fast spin echo pulse sequence. Segmental and global T1 values were measured before and 15 minutes after administration of 0.2 mmol/kg of Gadoteric Acid and compared to our cohort of 17 controls. Results Mean non contrast T1 values were significantly higher in heart transplants patients compared to controls (1100 ± 5 ms vs 947 ± 29 ms, P < 0.001). Segmental T1 values were significantly higher in the 6 regions of interest compared to controls (P < 0.001 in all segments). Mean post contrast T1 values were not significantly different in patients and controls. Mean T2 value was higher in patients compared to controls (73 ± 13 vs 50 ± 4 ms), suggesting the presence of global edema. Conclusions Heart transplant patients with clinical antibodymediated rejection show a significant increased global and segmental non contrast T1 values suggesting the presence of diffuse myocardial fibrosis. Further studies are required to confirm these data. Funding
Julien Pucheux - One of the best experts on this subject based on the ideXlab platform.
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T1 mapping, ECV and ICV before and after aortic valve replacement
Journal of Cardiovascular Magnetic Resonance, 2015Co-Authors: Emmanuelle Vermes, Nicolas Cazeneuve, Olivier Genée, Anne Delhommais, Laurent Brunereau, Daniel Alison, Julien PucheuxAbstract:Methods A prospective CMR T1 mapping study of 37 patients with severe AS before and six months after aortic valve replacement (AVR) was conducted. CMR at 1.5 T, including T1 mapping using a modified Look-Locker inversion recovery sequence (before and 15 minutes after the administration of 0.2 mmol/kg of Gadoteric Acid), was carried out. Global T1 values, ECV, ICV have been measured before and six months after surgery.
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0113: Cardiac magnetic resonance T1 mapping pre and post contrast in heart transplant patients with clinical antibody-mediated rejection: a preliminary experience
Archives of Cardiovascular Diseases Supplements, 2015Co-Authors: Emmanuelle Vermes, Anne Delhommais, Julien Pucheux, Alain Mirza, Laurent BrunereauAbstract:Background Antibody-mediated rejection (AMR) is characterized by histopathological and immunophenotypic findings such as activated endothelial cells, intravascular macrophages and evidence of capillary C4d deposition. This inflammatory reaction could be followed by diffuse fibrosis. Cardiac magnetic resonance (CMR) with recently T1 mapping is a promising technique to identify diffuse myocardial fibrosis. The purpose of this study was to assess T1 mapping in patients with AMR. Method 2 patients with clinical AMR (histopathological and immunophenotypic findings, presence of donor-specific allo antibodies and allograft dysfunction) performed a CMR study one week (for the first patient) and 3 weeks (for the second patient) after the treatment of AMR (plasmapheresis, IV Immunoglobulins and Rituximab). Images were acquired on a 1.5 Tesla scanner (Siemens) including T1 mapping using a shortened modified look-locker inversion-recovery sequence and T2 mapping in a matched mid-ventricular short axis slice using a black- blood single shot fast spin echo pulse sequence. Segmental and global T1 values were measured before and 15 minutes after administration of 0.2 mmol/kg of Gadoteric Acid and compared to our cohort of 17 controls. Results Mean non contrast T1 values were significantly higher in heart transplants patients compared to controls (1100±5ms vs 947±29ms, P Conclusion Heart transplant patients with clinical antibody-mediated rejection show a significant increased global and segmental non contrast T1 values suggesting the presence of diffuse myocardial fibrosis. Further studies are required to confirm these data.
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Cardiac magnetic resonance T1 mapping pre and post contrast in heart transplant patients with clinical antibody-mediated rejection: a preliminary experience
Journal of Cardiovascular Magnetic Resonance, 2014Co-Authors: Emmanuelle Vermes, Anne Delhommais, Daniel Alison, Julien Pucheux, Laurent BrunereauAbstract:Background Antibody-mediated rejection (AMR) is characterized by histopathological and immunophenotypic findings such as activated endothelial cells, intravascular macrophages and evidence of capillary C4d deposition. This inflammatory reaction could be followed by diffuse fibrosis. Cardiac magnetic resonance (CMR) with recently T1 mapping is a promising technique to identify diffuse myocardial fibrosis. The purpose of this study was to assess T1 mapping in patients with AMR. Methods Two patients with clinical AMR (histopathological and immunophenotypic findings, presence of donor-specific allo antibodies and allograft dysfunction) performed a CMR study one week (for the first patient) and 3 weeks (for the second patient) after the treatment of AMR (plasmapheresis, IV Immunoglobulins and Rituximab). Images were acquired on a 1.5 Tesla scanner (Siemens) including T1 mapping using a shortened modified look-locker inversion-recovery sequence and T2 mapping in a matched mid-ventricular short axis slice using a black- blood single shot fast spin echo pulse sequence. Segmental and global T1 values were measured before and 15 minutes after administration of 0.2 mmol/kg of Gadoteric Acid and compared to our cohort of 17 controls. Results Mean non contrast T1 values were significantly higher in heart transplants patients compared to controls (1100 ± 5 ms vs 947 ± 29 ms, P < 0.001). Segmental T1 values were significantly higher in the 6 regions of interest compared to controls (P < 0.001 in all segments). Mean post contrast T1 values were not significantly different in patients and controls. Mean T2 value was higher in patients compared to controls (73 ± 13 vs 50 ± 4 ms), suggesting the presence of global edema. Conclusions Heart transplant patients with clinical antibodymediated rejection show a significant increased global and segmental non contrast T1 values suggesting the presence of diffuse myocardial fibrosis. Further studies are required to confirm these data. Funding
