Three-dimensional ultrasonographic evaluation of carotid artery plaque surface irregularity

Intraobserver and Interobserver Consistency Evaluation of Carotid Plaque Volume Measured by Different 3-Dimensional Ultrasound Methods

ABSTRACT

This study aims to evaluate the accuracy of the semiautomatic planimetric measurement (SAPM) method and the necessity of manually adjusted boundary measurement in 3-dimensional ultrasound measurement of plaque volume. A total of 50 patients with 82 plaques in the common carotid arteries between December 2020 and March 2021 were included in this study. Two observers measured the 3-dimensional volume of plaque for each patient in 3 different methods (contour tracing method [CTM], SAPM method without manually adjusted boundary [SAPM1], and SAPM method with manually adjusted boundary [SAPM2]). The difference in measurement time between the 3 methods was evaluated by Kruskal-Wallis H test. Intraclass correlation coefficient and 95% confidence interval were used to evaluate the intraobserver and interobserver reliability of the 3 measurement modes. The Bland-Altman analysis was used to assess the agreement, which was expressed as the mean difference with the 95% limits of agreement (LOA). The difference in measurement time between the 3 methods was statistically significant ( P < 0.001). Both observers' intraobserver and interobserver reliability showed well in the 3 methods (all of the intraclass correlation coefficients were >0.75). The mean differences of the plaque volume measurement were 38.17, 26.42, and 11.75 mm 3 , respectively. The agreement between CTM and SAPM2 was the best, and LOA was -57.00 to 80.51. The agreement between SAPM1 and SAPM2 and the agreement between SAPM1 and CTM were similar, and the LOAs were -126.10 to 202.40 and -158.00 to 210.80, respectively. The SAPM method may be recommended to measure plaque volume in clinical practice.

3D-Arterial analysis software and CEUS in the assessment of severity and vulnerability of carotid atherosclerotic plaque: a comparison with CTA and histopathology

Purpose

Our purpose is to assess Multiparametric Ultrasound (MPUS) efficacy for evaluation of carotid plaque vulnerability and carotid stenosis degree in comparison with Computed Tomography angiography (CTA) and histology.

Material and methods

3D-Arterial Analysis is a 3D ultrasound software that automatically provides the degree of carotid stenosis and a colorimetric map of carotid plaque vulnerability.

We enrolled 106 patients who were candidates for carotid endarterectomy. Prior to undergoing surgery, all carotid artery plaques were evaluated with Color-Doppler-US (CDUS), Contrast-Enhanced Ultrasound (CEUS), and 3D Arterial analysis (3DAA) US along with Computerized Tomographic Angiography (CTA) to assess the carotid artery stenosis degree. Post-surgery, the carotid specimens were fixed with 10% neutral buffered formalin solution, embedded in paraffin and used for light microscopic examination to assess plaque vulnerability morphological features.

Results

The results of the CTA examinations revealed 91 patients with severe carotid stenoses with a resultant diagnostic accuracy of 82.3% for CDUS, 94.5% for CEUS, 98.4% for 3DAA, respectively. The histopathological examination showed 71 vulnerable plaques with diagnostic accuracy values of 85.8% for CDUS, 93.4% for CEUS, 90.3% for 3DAA, 92% for CTA, respectively.

Conclusions

The combination of CEUS and 3D Arterial Analysis may provide a powerful new clinical tool to identify and stratify “at-risk” patients with atherosclerotic carotid artery disease, identifying vulnerable plaques. These applications may also help in the postoperative assessment of treatment options to manage cardiovascular risks.

Long-term survival of carotid stenting patients with regard to single- or double-vessel carotid artery disease: a propensity score matching analysis

INTRODUCTION

There is lack of long-term data outside of controlled clinical trials in carotid artery stenting (CAS). In this study, we compared the short-term outcome, long-term survival, and rate of re-interventions for restenosis in patients after CAS, related to the extent of carotid atherosclerosis classified as single-vessel (unilateral) or double-vessel (bilateral) carotid artery disease.

MATERIAL AND METHODS

We retrospectively evaluated 599 patients with significant carotid artery stenosis, who underwent 763 CAS procedures, and used the propensity score to match 226 pairs (452 patients) in the single- or double-vessel carotid disease.

RESULTS

There was no significant difference in the occurrence of in-hospital major adverse events (3.5% vs. 3.1% of patients in the double-vessel carotid group vs. the single-vessel carotid group; p = 1) The mean follow-up was 6.1 ±4.0 years, and a total of 181 (40%) deaths occurred during 2759 patient-years, which translates into 7.8 and 5.3 deaths per 100 patient-years in the double-vessel carotid group and the single-vessel carotid group, respectively (p < 0.01). The survival in the double-vessel carotid group vs. the single-vessel carotid group at 10 years was 46% (95% CI: 38-54%) vs. 55% (95% CI: 47-63%) (p < 0.01). Twenty-four (11%) patients and 6 (3%) patients underwent re-interventions for restenosis in the double-vessel and the single-vessel carotid disease group, respectively (p < 0.01).

CONCLUSIONS

Patients with CAS and significant double-vessel carotid artery disease had similar peri-procedural risk, but had a worse long-term survival, and a higher rate of re-interventions for restenosis compared to the single-vessel carotid artery disease patients.

Ultrasound methods of imaging atherosclerotic plaque in carotid arteries: examinations using contrast agents

The primary technique for detecting the presence and monitoring the development of carotid atherosclerotic plaque is ultrasound. The development of ultrasound techniques has made it possible to precisely visualise not only blood flow, but also vessel walls, including atherosclerotic plaque. Contrast-enhanced ultrasound examination enables one to make an objective observation of atherosclerotic plaque neovascularisation, clearly indicating active inflammation, which is an inherent feature of vulnerable (unstable) plaque. Depending on the examination method used, it is possible to precisely visualise different components of the plaque and its behaviour during blood flow through the vessel lumen or through the neovessels of the plaque, and, consequently, determine the possible presence of inflammation, which is a defining feature of plaque stability. The full utilisation of physical phenomena that underlie contrast-enhanced ultrasound will bring further enormous progress of diagnostic and probably also therapeutic methods for carotid atherosclerosis. The selection of the right examination method significantly accelerates diagnosis and adequate classification of plaque, and makes it possible to monitor the progression of atherosclerosis. However, one needs to bear in mind that ultrasound remains a very subjective method. The success of contrast-enhanced ultrasound also depends on the skills and experience of the examiner. Current attempts at increasing the objectivity of contrast-enhanced ultrasound examination using artificial intelligence will make it possible in the future to make a definitive evaluation of atherosclerotic plaque stability. This will allow one to assess the risk of ischaemic stroke adequately.

Ultrasonography of vulnerable atherosclerotic plaque in the carotid arteries: B-mode imaging

The most common type of stroke, i.e. ischemic stroke, is a great challenge for contemporary medicine as it poses both diagnostic and therapeutic difficulties. Atherosclerosis, which is rapidly beginning to affect more and more social groups, is the main cause of cerebrovascular accidents. Atherosclerosis is currently defined as a generalized, dynamic and heterogeneous inflammatory and immune process affecting arterial walls. Atherosclerotic plaque is the emanation of this disease. As the paradigm of the diagnosis of atherosclerosis has changed, it has become crucial to properly identify plaque instability within the carotid arteries by evaluating parameters and phenomena that signify a developing cascade of complications, eventually leading to stroke. Irrespective of the ultrasound technique employed, proper morphological evaluation of atherosclerotic plaque, involving observation of its echogenicity, i.e. subjective analysis of its structure, with the classification to Gray-Weale–Nicolaides types as well as assessment of the integrity of its surface, makes it possible to roughly evaluate plaque morphology and thereby its stability. This enables treatment planning and therapy monitoring. This evaluation should be a prelude to further diagnostic work-up, which involves non-invasive examinations that enable unambiguous assessment of plaque stability. These examinations include contrast-enhanced ultrasound to assess progression or recession of inflammation, which presents as plaque neovascularization, or shear wave elastography to objectively define tissue stiffness, and thereby its mineralization.