The Experts below are selected from a list of 144357 Experts worldwide ranked by ideXlab platform
Bernard De Bruyne - One of the best experts on this subject based on the ideXlab platform.
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Pressure-Derived Measurement of coronary flow reserve
Journal of the American College of Cardiology, 2005Co-Authors: Philip Maccarthy, Alexandre Berger, Emanuele Barbato, Jozef Bartunek, Guy R. Heyndrickx, Ganesh Manoharan, William Wijns, Nico H J Pijls, Bernard De BruyneAbstract:Objectives We aimed to validate the technique of measuring the coronary flow reserve (CFR) with coronary pressure Measurements against an established thermodilution technique. Background The CFR has traditionally required Measurement of coronary blood flow velocity with the Doppler wire and, more recently, using a thermodilution technique with the coronary pressure wire. However, recent work has suggested that the CFR may be Derived from pressure Measurements alone (the ratio of the square root of the pressure drop across an epicardial stenosis during hyperemia to that value at rest). This depends on the assumption that friction losses across a coronary stenosis are negligible. Methods We compared pressure-Derived CFR values with those obtained by the thermodilution technique using the intracoronary pressure wire in 38 stenoses in 34 patients with significant coronary stenoses undergoing percutaneous intervention. We also compared these two techniques of measuring CFR in 25 stenoses (6 vessels) artificially created by inflating small balloons within a stented coronary artery after percutaneous intervention. Results There is a close linear relationship between pressure-Derived and thermodilution CFR in native (r 2 = 0.52; p 2 = 0.54; p Conclusions Coronary flow reserve cannot be measured merely with pressure alone, and it cannot be safely assumed that friction losses are negligible across a native coronary stenosis. These data suggest that friction loss is an important determinant of the pressure gradient along an atherosclerotic coronary artery.
Philip Maccarthy - One of the best experts on this subject based on the ideXlab platform.
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Pressure-Derived Measurement of coronary flow reserve
Journal of the American College of Cardiology, 2005Co-Authors: Philip Maccarthy, Alexandre Berger, Emanuele Barbato, Jozef Bartunek, Guy R. Heyndrickx, Ganesh Manoharan, William Wijns, Nico H J Pijls, Bernard De BruyneAbstract:Objectives We aimed to validate the technique of measuring the coronary flow reserve (CFR) with coronary pressure Measurements against an established thermodilution technique. Background The CFR has traditionally required Measurement of coronary blood flow velocity with the Doppler wire and, more recently, using a thermodilution technique with the coronary pressure wire. However, recent work has suggested that the CFR may be Derived from pressure Measurements alone (the ratio of the square root of the pressure drop across an epicardial stenosis during hyperemia to that value at rest). This depends on the assumption that friction losses across a coronary stenosis are negligible. Methods We compared pressure-Derived CFR values with those obtained by the thermodilution technique using the intracoronary pressure wire in 38 stenoses in 34 patients with significant coronary stenoses undergoing percutaneous intervention. We also compared these two techniques of measuring CFR in 25 stenoses (6 vessels) artificially created by inflating small balloons within a stented coronary artery after percutaneous intervention. Results There is a close linear relationship between pressure-Derived and thermodilution CFR in native (r 2 = 0.52; p 2 = 0.54; p Conclusions Coronary flow reserve cannot be measured merely with pressure alone, and it cannot be safely assumed that friction losses are negligible across a native coronary stenosis. These data suggest that friction loss is an important determinant of the pressure gradient along an atherosclerotic coronary artery.
Alan Jackson - One of the best experts on this subject based on the ideXlab platform.
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candidate biomarkers of extravascular extracellular space a direct comparison of apparent diffusion coefficient and dynamic contrast enhanced mr imaging Derived Measurement of the volume of the extravascular extracellular space in glioblastoma multiforme
American Journal of Neuroradiology, 2010Co-Authors: Samantha J Mills, C Soh, C J Rose, Susan Cheung, Sha Zhao, Geoffrey J M Parker, Alan JacksonAbstract:BACKGROUND AND PURPOSE: ADC Measurements have been shown to have an inverse relationship with tumor cell density. DCE-MR imaging modeling techniques can produce a Measurement of the v e , which would also be expected to have an inverse relationship with cell density. The objective of this study was to test the hypothesis that areas of increased cellularity, and therefore low ADC, would be expected to have a small EES (low v e ). MATERIALS AND METHODS: Nineteen patients with GBM were recruited. All imaging was performed before surgery on a 3T MR imaging scanner. Imaging included diffusion tensor imaging, T1-weighted DCE-MR imaging, and anatomic sequences. Tumor VOIs were defined on the anatomic images and modified to contain only enhancing voxels. Parametric maps of ADC and v e were generated. Statistical analysis of ADC and v e was performed on both a voxel-by-voxel basis and comparison of median values. RESULTS: No correlation was demonstrated between ADC and v e in either a voxel-by-voxel analysis or comparison of median values ( P = .124). CONCLUSIONS: This study failed to demonstrate a correlation between ADC and v e . This is important because it suggests that though the mechanisms underlying these parameters are theoretically similar, they actually reflect different aspects of tumor microenvironment. Consequently ADC and v e should be considered to provide independent information about the properties of the EES.
Jozef Bartunek - One of the best experts on this subject based on the ideXlab platform.
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Pressure-Derived Measurement of coronary flow reserve
Journal of the American College of Cardiology, 2005Co-Authors: Philip Maccarthy, Alexandre Berger, Emanuele Barbato, Jozef Bartunek, Guy R. Heyndrickx, Ganesh Manoharan, William Wijns, Nico H J Pijls, Bernard De BruyneAbstract:Objectives We aimed to validate the technique of measuring the coronary flow reserve (CFR) with coronary pressure Measurements against an established thermodilution technique. Background The CFR has traditionally required Measurement of coronary blood flow velocity with the Doppler wire and, more recently, using a thermodilution technique with the coronary pressure wire. However, recent work has suggested that the CFR may be Derived from pressure Measurements alone (the ratio of the square root of the pressure drop across an epicardial stenosis during hyperemia to that value at rest). This depends on the assumption that friction losses across a coronary stenosis are negligible. Methods We compared pressure-Derived CFR values with those obtained by the thermodilution technique using the intracoronary pressure wire in 38 stenoses in 34 patients with significant coronary stenoses undergoing percutaneous intervention. We also compared these two techniques of measuring CFR in 25 stenoses (6 vessels) artificially created by inflating small balloons within a stented coronary artery after percutaneous intervention. Results There is a close linear relationship between pressure-Derived and thermodilution CFR in native (r 2 = 0.52; p 2 = 0.54; p Conclusions Coronary flow reserve cannot be measured merely with pressure alone, and it cannot be safely assumed that friction losses are negligible across a native coronary stenosis. These data suggest that friction loss is an important determinant of the pressure gradient along an atherosclerotic coronary artery.
Alexandre Berger - One of the best experts on this subject based on the ideXlab platform.
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Pressure-Derived Measurement of coronary flow reserve
Journal of the American College of Cardiology, 2005Co-Authors: Philip Maccarthy, Alexandre Berger, Emanuele Barbato, Jozef Bartunek, Guy R. Heyndrickx, Ganesh Manoharan, William Wijns, Nico H J Pijls, Bernard De BruyneAbstract:Objectives We aimed to validate the technique of measuring the coronary flow reserve (CFR) with coronary pressure Measurements against an established thermodilution technique. Background The CFR has traditionally required Measurement of coronary blood flow velocity with the Doppler wire and, more recently, using a thermodilution technique with the coronary pressure wire. However, recent work has suggested that the CFR may be Derived from pressure Measurements alone (the ratio of the square root of the pressure drop across an epicardial stenosis during hyperemia to that value at rest). This depends on the assumption that friction losses across a coronary stenosis are negligible. Methods We compared pressure-Derived CFR values with those obtained by the thermodilution technique using the intracoronary pressure wire in 38 stenoses in 34 patients with significant coronary stenoses undergoing percutaneous intervention. We also compared these two techniques of measuring CFR in 25 stenoses (6 vessels) artificially created by inflating small balloons within a stented coronary artery after percutaneous intervention. Results There is a close linear relationship between pressure-Derived and thermodilution CFR in native (r 2 = 0.52; p 2 = 0.54; p Conclusions Coronary flow reserve cannot be measured merely with pressure alone, and it cannot be safely assumed that friction losses are negligible across a native coronary stenosis. These data suggest that friction loss is an important determinant of the pressure gradient along an atherosclerotic coronary artery.