Measurement of systolic and diastolic arterial wall shear stress in the ascending aorta
| Autor: | Demosthenes G. Katritsis, Ioannis Pantos, George Patatoukas, Nikolaos Kelekis, Efstathios P. Efstathopoulos, Odysseas Benekos |
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| Rok vydání: | 2007 |
| Předmět: |
Adult
Male Systole Biophysics Diastole General Physics and Astronomy Geometry Young Adult Elastic Modulus Image Interpretation Computer-Assisted Shear stress Humans Radiology Nuclear Medicine and imaging Mean flow Computer Simulation Aorta Mathematics Aged Cardiac cycle Maximum flow problem Models Cardiovascular General Medicine Blood flow Mechanics Middle Aged Hagen–Poiseuille equation Magnetic Resonance Imaging Flow velocity cardiovascular system Female Shear Strength Blood Flow Velocity |
| Zdroj: | Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB). 24(4) |
| ISSN: | 1120-1797 |
| Popis: | Purpose Wall shear stress (WSS) appears to contribute significantly in the initiation and progression of atherosclerotic disease. The purpose of this work is to present in vivo systolic and diastolic WSS calculations in the human ascending aorta by the application of three straightforward methodologies based on Poiseuille's theory of flow. Materials and methods Blood flow measurements were performed retrospectively in the ascending aorta of 20 non-atherosclerotic patients using phase-contrast MRI. WSS calculations were performed assuming Poiseuille's theory of flow based on average flow volume, average flow velocity and maximum flow velocity. Systolic and diastolic WSS values were calculated and compared with the calculated maximum and minimum values of WSS throughout the cardiac cycle. Results Systolic WSS values calculated by average flow volume, average flow velocity and maximum flow velocity were similar (0.4 ± 0.2 N/m 2 , 0.4 ± 0.3 N/m 2 and 0.4 ± 0.2 N/m 2 , respectively). Diastolic WSS values calculated by maximum flow velocity were significantly higher (11.6 ± 7.0 × 10 −2 N/m 2 ) compared to values calculated by average flow volume (0.3 ± 0.9 × 10 −2 N/m 2 ) and average flow velocity (0.3 ± 1.0 × 10 −2 N/m 2 ). Comparison of systolic and diastolic WSS values with maximum and minimum WSS values showed that time instances of maximum and minimum blood flow velocities do not coincide with time instances of maximum and minimum blood flow volume. Conclusion In vivo calculation of WSS in the ascending aorta is feasible by phase-contrast MRI flow measurements and straightforward methodologies based on Poiseuille's theory of flow. However, measurements based on maximum flow velocity show larger deviations compared to measurements based on mean flow volume or mean flow velocity. |
| Databáze: | OpenAIRE |
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