Evaluation of Plaque Vulnerability via Combination of Hemodynamic Analysis and Simultaneous Non-Contrast Angiography and Intraplaque Hemorrhage (SNAP) Sequence for Carotid Intraplaque Hemorrhage.

Ui Yun Lee,Hyo Sung Kwak

doi:10.3390/jpm11090856

Abstract

The purpose of this study was to assess the vulnerability of plaque using a combination of simultaneous non-contrast angiography, intraplaque hemorrhage (SNAP) sequence, and local hemodynamic analysis in an intraplaque hemorrhage (IPH), and to evaluate the association between morphological and hemodynamic factors and IPH by comparing the IPH (presence of IPH) and non-IPH (plaque with absence of IPH) groups. In total, 27 IPH patients and 27 non-IPH patients were involved in this study, and baseline characteristics were collected. For morphological factors, diameters, and areas of the internal carotid artery (ICA), external carotid artery, and common carotid artery were measured, and bifurcation angle (α) and ICA angle (β) were also measured for comparison between the IPH group and non-IPH group. For hemodynamic factors, time-averaged wall shear stress (WSS), minimum WSS, maximum WSS, and oscillatory shear index were calculated using computational fluid dynamics (CFD) simulations. For the qualitative analysis, cross-sectional images with analyzed WSS and SNAP sequences were combined to precisely assess local hemodynamics. Bifurcation angle (α) was significantly different between the IPH and non-IPH groups (39.47 degrees vs. 47.60 degrees, p = 0.041). Significantly higher time-averaged WSS, minimum WSS, and maximum WSS were observed in the IPH group compared to the non-IPH group. In the IPH group, when using the combined analysis with SNAP sequences and WSS, the WSS of the region with IPH was significantly higher than the region without IPH (2.32 vs. 1.21 Pa, p = 0.005). A smaller bifurcation angle (α) and higher time-averaged WSS, minimum WSS, and maximum WSS were associated with IPH. The combined analysis of SNAP sequences and WSS might help to evaluate the risk of carotid IPH.

Highlights

Ischemic stroke is a major cause of disability and morbidity in adults worldwide [1].Atherosclerosis in the carotid artery progresses via various biological mechanisms leading to the formation of multiple components
The final group was selected based on the following exclusion criteria: (1) poor image quality to evaluate the plaque, (2) insufficient quality of raw data for computational fluid dynamics (CFD) simulations, and (3) more than 15% stenosis according to the North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria
A significantly smaller bifurcation angle (α) was observed in the Intraplaque hemorrhage (IPH) group compared to the non-IPH group (39.47 degrees vs. 47.60 degrees, p = 0.041)

Summary

Introduction

Atherosclerosis in the carotid artery progresses via various biological mechanisms leading to the formation of multiple components. The composition of plaque is related to plaque rupture and cerebrovascular events. Intraplaque hemorrhage (IPH), a large lipid-rich necrotic core (LRNC), and a thin fibrous cap increase the risk of rupture. The presence of calcification is associated with plaque stability [2,3,4,5]. IPH has six-fold susceptibility to the development of cerebrovascular events [6,7]. Carotid IPH is vulnerable to embolization regardless of the severity of stenosis [8]. The simultaneous non-contrast angiography and intraplaque hemorrhage (SNAP) sequence has been employed as a useful tool to detect

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