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Subject-Specific Fully-Coupled and One-Way Fluid-Structure Interaction Models for Modeling of Carotid Atherosclerotic Plaques in Humans.

Tao X, Gao P, Jing L, Lin Y, Sui B - Med. Sci. Monit. (2015)

Bottom Line: The maximum von Mises stress and the minimum pressure and velocity were significantly increased in the stenosis group compared with controls based on one-way FSI (all P<0.05).The maximum von Mises stress and the minimum pressure were significantly higher and the velocity was significantly lower based on fully coupled FSI compared with on-way FSI (all P<0.05).The maximum von Mises stress of the group with fibrous cap defect was significantly higher than the group without fibrous cap defect (P=0.001).

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China (mainland).

ABSTRACT

Background: Hemodynamics play an important role in the development and progression of carotid atherosclerosis, and may be important in the assessment of plaque vulnerability. The aim of this study was to develop a system to assess the hemodynamics of carotid atherosclerotic plaques using subject-specific fluid-structure interaction (FSI) models based on magnetic resonance imaging (MRI).

Material and methods: Models of carotid bifurcations (n=86 with plaques from 52 patients, n=14 normal carotids from 12 participants) were obtained at the Department of Radiology, Beijing Tian Tan Hospital between 2010 and 2013. The maximum von Mises stress, minimum pressure, and flow velocity values were assessed at the most stenotic site in patients, or at the carotid bifurcations in healthy volunteers. Results of one-way FSI were compared with fully-coupled FSI for the plaques of 19 randomly selected models.

Results: The maximum von Mises stress and the minimum pressure and velocity were significantly increased in the stenosis group compared with controls based on one-way FSI (all P<0.05). The maximum von Mises stress and the minimum pressure were significantly higher and the velocity was significantly lower based on fully coupled FSI compared with on-way FSI (all P<0.05). Although there were differences in numerical values, both methods were equivalent. The maximum von Mises stress of vulnerable plaques was significantly higher than stable plaques (P<0.001). The maximum von Mises stress of the group with fibrous cap defect was significantly higher than the group without fibrous cap defect (P=0.001).

Conclusions: The hemodynamics of atherosclerotic plaques can be assessed noninvasively using subject-specific models of FSI based on MRI.

No MeSH data available.


Related in: MedlinePlus

A patient who underwent both one-way FSI and fully coupled FSI. MRI shows a plaque in the left common carotid artery. (A–D) MRI using the TOF, T2WI, PDWI and T1WI protocols, respectively. The arrows indicated the plaques. (E) Comparison of the von Mises stress of the one-way FSI (a) and fully coupled FSI (b). The map of the one-way FSI shows an increase in stress near the plaques (black arrow). The von Mises stress map of the fully coupled FSI shows that stress is elevated near the plaque (black arrow). Although there were differences in the numerical values of the von Mises stress in the two simulation types, their tendencies and distributions were identical. The color scale varies from red (high von Mises stress) to blue (low von Mises stress). (F) Comparison of cross-sectional slices of the von Mises stress of the one-way FSI (a) and fully coupled FSI (b). Both show that the maximum von Mises stress is at the shoulders of the plaque (black arrow), but the numerical values are different. The numerical values of fully coupled FSI were high. (G) Comparison of plaque pressure of the one-way FSI (a) and fully coupled FSI (b). The pressure map of the one-way FSI shows a reduction in pressure at the throat of the plaque (black arrow). The pressure map of the fully coupled FSI shows a drop in pressure at the throat of the plaque (black arrow). Although there were differences in the numerical values of pressure between the two simulation types, their tendencies and distributions were identical. The color scale varies from red (high pressure) to blue (low pressure).
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f3-medscimonit-21-3279: A patient who underwent both one-way FSI and fully coupled FSI. MRI shows a plaque in the left common carotid artery. (A–D) MRI using the TOF, T2WI, PDWI and T1WI protocols, respectively. The arrows indicated the plaques. (E) Comparison of the von Mises stress of the one-way FSI (a) and fully coupled FSI (b). The map of the one-way FSI shows an increase in stress near the plaques (black arrow). The von Mises stress map of the fully coupled FSI shows that stress is elevated near the plaque (black arrow). Although there were differences in the numerical values of the von Mises stress in the two simulation types, their tendencies and distributions were identical. The color scale varies from red (high von Mises stress) to blue (low von Mises stress). (F) Comparison of cross-sectional slices of the von Mises stress of the one-way FSI (a) and fully coupled FSI (b). Both show that the maximum von Mises stress is at the shoulders of the plaque (black arrow), but the numerical values are different. The numerical values of fully coupled FSI were high. (G) Comparison of plaque pressure of the one-way FSI (a) and fully coupled FSI (b). The pressure map of the one-way FSI shows a reduction in pressure at the throat of the plaque (black arrow). The pressure map of the fully coupled FSI shows a drop in pressure at the throat of the plaque (black arrow). Although there were differences in the numerical values of pressure between the two simulation types, their tendencies and distributions were identical. The color scale varies from red (high pressure) to blue (low pressure).

Mentions: The models of 86 carotid artery plaques (Figure 2A–2D and Figure 3A–3D) and 14 normal carotid bifurcations were assessed. The flow velocity accelerated as blood passed through the region of stenosis, leading to a decline in pressure. Areas with maximum velocity and minimum pressure were located at the throat of the plaques (Figure 2E, 2F). The maximum von Mises stress in the plaques was detected at the top of the plaque or at the shoulders of the plaques, but those at the shoulders were more frequent (Figure 2G, 2H).


Subject-Specific Fully-Coupled and One-Way Fluid-Structure Interaction Models for Modeling of Carotid Atherosclerotic Plaques in Humans.

Tao X, Gao P, Jing L, Lin Y, Sui B - Med. Sci. Monit. (2015)

A patient who underwent both one-way FSI and fully coupled FSI. MRI shows a plaque in the left common carotid artery. (A–D) MRI using the TOF, T2WI, PDWI and T1WI protocols, respectively. The arrows indicated the plaques. (E) Comparison of the von Mises stress of the one-way FSI (a) and fully coupled FSI (b). The map of the one-way FSI shows an increase in stress near the plaques (black arrow). The von Mises stress map of the fully coupled FSI shows that stress is elevated near the plaque (black arrow). Although there were differences in the numerical values of the von Mises stress in the two simulation types, their tendencies and distributions were identical. The color scale varies from red (high von Mises stress) to blue (low von Mises stress). (F) Comparison of cross-sectional slices of the von Mises stress of the one-way FSI (a) and fully coupled FSI (b). Both show that the maximum von Mises stress is at the shoulders of the plaque (black arrow), but the numerical values are different. The numerical values of fully coupled FSI were high. (G) Comparison of plaque pressure of the one-way FSI (a) and fully coupled FSI (b). The pressure map of the one-way FSI shows a reduction in pressure at the throat of the plaque (black arrow). The pressure map of the fully coupled FSI shows a drop in pressure at the throat of the plaque (black arrow). Although there were differences in the numerical values of pressure between the two simulation types, their tendencies and distributions were identical. The color scale varies from red (high pressure) to blue (low pressure).
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4630957&req=5

f3-medscimonit-21-3279: A patient who underwent both one-way FSI and fully coupled FSI. MRI shows a plaque in the left common carotid artery. (A–D) MRI using the TOF, T2WI, PDWI and T1WI protocols, respectively. The arrows indicated the plaques. (E) Comparison of the von Mises stress of the one-way FSI (a) and fully coupled FSI (b). The map of the one-way FSI shows an increase in stress near the plaques (black arrow). The von Mises stress map of the fully coupled FSI shows that stress is elevated near the plaque (black arrow). Although there were differences in the numerical values of the von Mises stress in the two simulation types, their tendencies and distributions were identical. The color scale varies from red (high von Mises stress) to blue (low von Mises stress). (F) Comparison of cross-sectional slices of the von Mises stress of the one-way FSI (a) and fully coupled FSI (b). Both show that the maximum von Mises stress is at the shoulders of the plaque (black arrow), but the numerical values are different. The numerical values of fully coupled FSI were high. (G) Comparison of plaque pressure of the one-way FSI (a) and fully coupled FSI (b). The pressure map of the one-way FSI shows a reduction in pressure at the throat of the plaque (black arrow). The pressure map of the fully coupled FSI shows a drop in pressure at the throat of the plaque (black arrow). Although there were differences in the numerical values of pressure between the two simulation types, their tendencies and distributions were identical. The color scale varies from red (high pressure) to blue (low pressure).
Mentions: The models of 86 carotid artery plaques (Figure 2A–2D and Figure 3A–3D) and 14 normal carotid bifurcations were assessed. The flow velocity accelerated as blood passed through the region of stenosis, leading to a decline in pressure. Areas with maximum velocity and minimum pressure were located at the throat of the plaques (Figure 2E, 2F). The maximum von Mises stress in the plaques was detected at the top of the plaque or at the shoulders of the plaques, but those at the shoulders were more frequent (Figure 2G, 2H).

Bottom Line: The maximum von Mises stress and the minimum pressure and velocity were significantly increased in the stenosis group compared with controls based on one-way FSI (all P<0.05).The maximum von Mises stress and the minimum pressure were significantly higher and the velocity was significantly lower based on fully coupled FSI compared with on-way FSI (all P<0.05).The maximum von Mises stress of the group with fibrous cap defect was significantly higher than the group without fibrous cap defect (P=0.001).

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China (mainland).

ABSTRACT

Background: Hemodynamics play an important role in the development and progression of carotid atherosclerosis, and may be important in the assessment of plaque vulnerability. The aim of this study was to develop a system to assess the hemodynamics of carotid atherosclerotic plaques using subject-specific fluid-structure interaction (FSI) models based on magnetic resonance imaging (MRI).

Material and methods: Models of carotid bifurcations (n=86 with plaques from 52 patients, n=14 normal carotids from 12 participants) were obtained at the Department of Radiology, Beijing Tian Tan Hospital between 2010 and 2013. The maximum von Mises stress, minimum pressure, and flow velocity values were assessed at the most stenotic site in patients, or at the carotid bifurcations in healthy volunteers. Results of one-way FSI were compared with fully-coupled FSI for the plaques of 19 randomly selected models.

Results: The maximum von Mises stress and the minimum pressure and velocity were significantly increased in the stenosis group compared with controls based on one-way FSI (all P<0.05). The maximum von Mises stress and the minimum pressure were significantly higher and the velocity was significantly lower based on fully coupled FSI compared with on-way FSI (all P<0.05). Although there were differences in numerical values, both methods were equivalent. The maximum von Mises stress of vulnerable plaques was significantly higher than stable plaques (P<0.001). The maximum von Mises stress of the group with fibrous cap defect was significantly higher than the group without fibrous cap defect (P=0.001).

Conclusions: The hemodynamics of atherosclerotic plaques can be assessed noninvasively using subject-specific models of FSI based on MRI.

No MeSH data available.


Related in: MedlinePlus