Stress distribution analysis in healthy and stenosed carotid artery models reconstructed from in vivo ultrasonography

Soleimani, Effat; Mokhtari-Dizaji, Manijhe; Fatouraee, Nasser; Saberi, Hazhir

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Original Article

Stress distribution analysis in healthy and stenosed carotid artery models reconstructed from in vivo ultrasonography

Effat Soleimani¹, Manijhe Mokhtari-Dizaji¹

, Nasser Fatouraee², Hazhir Saberi³

¹Department of Medical Physics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Ira, Tehran, Iran
²Department of Medical Engineering, AmirKabir University of Technology, Tehran, Iran
³Department of Radiology, Tehran Medical Sciences University, Imaging Center of Imam Khomeini Hospital, Tehran, Iran

Corresponding Author: Manijhe Mokhtari-Dizaji ,Tel: 00989123234205, Fax: 009882883828, Email: mokhtarm@modares.ac.ir

Received: August 18, 2020; Accepted: January 5, 2021. Published online: January 5, 2021.

ABSTRACT

Purpose:
This study was to evaluate the accuracy of the reconstructed models from ultrasound image processing by comparing the radial displacement waveforms of the subject-specific artery model and to find the stress changes in the proximal shoulder, throat, and distal shoulder of the plaques depending on the degree of carotid artery stenosis.
Methods:
Three groups of subjects including healthy, less, and more than 50% carotid stenosis were evaluated with ultrasonography. 2D transverse imaging of the common carotid artery was carried to reconstruct geometry. A longitudinal view of the same region was recorded to extract the Kelvin viscoelastic model parameters. Pulse pressure waveform and the effective pressure of perivascular tissue was loaded to the internal and external walls of the model. Effective, circumferential, and principal stresses applied to the plaque throat, proximal and distal shoulders in the transverse planes were extracted.
Results:
Our results showed a high correlation between the radial displacement waveforms of the model and those of image processing in healthy, less and more than 50% stenosed groups. The mean of the effective, circumferential, and principal stresses of the healthy arteries were 15.01±4.93, 12.97±5.07, and 12.39±2.86 kPa, respectively. With increasing stenosis from mild to significant, the mean values of the effective, circumferential, and first principal stresses increase significantly 97%, 74%, and 103% at plaque throat, respectively (p<0.05). The minimum effective stress was located at the lipid pool. The effective stress in the calcified area was higher than in other parts of the artery wall.
Conclusion:
This model can discriminate the differences of stresses applied to mildly and severely stenotic plaques.

Keywords: Carotid artery; Atherosclerotic plaque; Rupture; Finite element modeling; Viscoelastic model; Ultrasonography