Cardiac thermal pulse at the neck-skin surface as a measure of stenosis in the carotid artery

Abstract

In this study, a cardiac thermal pulse evaluation-based carotid artery stenosis detection method is proposed. It is postulated that the presence of stenosis in the carotid artery results in a thermal lag in skin temperature at the neck skin surface that can be quantified to the degree of stenosis. A finite volume method-based transient bioheat transfer study was performed on a carotid artery-jugular vein 3-Dimensional (3D) geometry model encapsulated by the neck tissue. As the transient physiological blood flow in the carotid artery thermally interacts with the blood perfusion in the neck tissue, a thermal fluctuation or cardiac thermal pulse is resulted in the top-neck skin localized surface temperature contours. Two tissue blood perfusion models, constant (temperature-independent) and varying (temperature-dependent), were used to comparatively study the cardiac thermal pulse characterized by their signal noise. For 0% stenosis case, compared to the constant perfusion model, the average instantaneous noise for the varying perfusion model was found to be significantly lower (0.02 ± 0.01 versus 0.05 ± 0.01, p < 0.01). Furthermore, varying degrees of stenosis (25%, 50%, and 75%) were introduced in the carotid artery to study their effect on the cardiac thermal pulse. It was observed that there is a successive shift in the phase of the cardiac thermal pulse with an increase in the degree of stenosis in the carotid artery. This study demonstrates the potential of a cardiac thermal pulse evaluation-based indirect screening tool for carotid artery stenosis.