Identifying vulnerable carotid plaques in vivo using high resolution magnetic resonance imaging–based finite element analysis

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Object

Individuals with carotid atherosclerosis develop symptoms following rupture of vulnerable plaques. Biomechanical stresses within this plaque may increase vulnerability to rupture. In this report the authors describe the use of in vivo carotid plaque imaging and computational mechanics to document the magnitude and distribution of intrinsic plaque stresses.

Methods

Ten (five symptomatic and five asymptomatic) individuals underwent plaque characterization magnetic resonance (MR) imaging. Plaque geometry and composition were determined by multisequence review. Intrinsic plaque stress profiles were generated from 3D meshes by using finite element computational analysis. Differences in principal (shear) stress between normal and diseased sections of the carotid artery and between symptomatic and asymptomatic plaques were noted.

Results

There was a significant difference in peak principal stress between diseased and nondiseased segments of the artery (mean difference 537.65 kPa, p < 0.05). Symptomatic plaques had higher mean stresses than asymptomatic plaques (627.6 kPa compared with 370.2 kPa, p = 0.05), which were independent of luminal stenosis and plaque composition.

Conclusions

Significant differences in plaque stress exist between plaques from symptomatic individuals and those from asymptomatic individuals. The MR imaging–based computational analysis may therefore be a useful aid to identification of vulnerable plaques in vivo.

Abbreviations used in this paper:FEA = finite element analysis; MR = magnetic resonance; STIR = short tau inversion recovery.
Article Information

Contributor Notes

Address reprint requests to: Rikin A. Trivedi, M.R.C.P.(UK), Box 1669, Academic Neurosurgery Unit, Addenbrooke's Hospital, Hills Road, Cambridge, CB2 2QQ, United Kingdom. email: rt256@radiol.cam.ac.uk.
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