Quantitative assessment of carotid artery atherosclerosis by three-dimensional magnetic resonance and two-dimensional ultrasound imaging: a comparison study

Engineering Nanoplatforms for Theranostics of Atherosclerotic Plaques

Atherosclerotic plaque formation is considered the primary pathological mechanism underlying atherosclerotic cardiovascular diseases, leading to severe cardiovascular events such as stroke, acute coronary syndromes, and even sudden cardiac death. Early detection and timely intervention of plaques are challenging due to the lack of typical symptoms in the initial stages. Therefore, precise early detection and intervention play a crucial role in risk stratification of atherosclerotic plaques and achieving favorable post-interventional outcomes. The continuously advancing nanoplatforms have demonstrated numerous advantages including high signal-to-noise ratio, enhanced bioavailability, and specific targeting capabilities for imaging agents and therapeutic drugs, enabling effective visualization and management of atherosclerotic plaques. Motivated by these superior properties, various noninvasive imaging modalities for early recognition of plaques in the preliminary stage of atherosclerosis are comprehensively summarized. Additionally, several therapeutic strategies are proposed to enhance the efficacy of treating atherosclerotic plaques. Finally, existing challenges and promising prospects for accelerating clinical translation of nanoplatform-based molecular imaging and therapy for atherosclerotic plaques are discussed. In conclusion, this review provides an insightful perspective on the diagnosis and therapy of atherosclerotic plaques.

Imaging diagnosis and research progress of carotid plaque vulnerability

Ischemic stroke (IS) exhibits a high disability rate, mortality, and recurrence rate, imposing a serious threat to human survival and health. Its occurrence is affected by various factors. Although the previous research has demonstrated that the occurrence of IS is mainly associated with lumen stenosis caused by carotid atherosclerotic plaque (AP), recent studies have revealed that many patients will still suffer from IS even with mild carotid artery lumen stenosis. Blood supply disturbance causes 10% of IS to the corresponding cerebral blood supply area caused by carotid vulnerable plaque. Thrombus blockage of distal branch vessels caused by rupture of vulnerable carotid plaque is the main cause of ischemic stroke. Therefore, how to accurately evaluate vulnerable plaque and intervene as soon as possible is a problem that needs to be solved in clinic. The vulnerability of plaque is determined by its internal components, including thin and incomplete fibrous cap, necrotic lipid core, intra-plaque hemorrhage, intra-plaque neovascularization, and ulcerative plaque formation. The development of imaging technology enables the routine detection of AP vulnerability. By analyzing the pathological changes, characteristics, and formation mechanism of carotid plaque vulnerability, this article aims to explore the modern imaging methods which can be used to identify plaque composition and plaque vulnerability to provide a reference basis for disease diagnosis and differential diagnosis.

Added value of femoral artery atherosclerosis for determining severity of white matter lesion by carotid atherosclerosis: a magnetic resonance imaging study

BACKGROUND

Previous studies reported that single vascular atherosclerosis was an effective indicator for white matter lesions (WMLs).

PURPOSE

To investigate the added value of femoral atherosclerosis for determining severity of WMLs by carotid atherosclerosis using three-dimensional vessel wall magnetic resonance imaging (MRI).

MATERIAL AND METHODS

Elderly individuals without cardiovascular symptoms within the previous six months were recruited. The plaque features of carotid and femoral arteries were evaluated and compared between individuals with WML score ≤ 3 and those with WML score > 3. Logistic regression and receiver operating characteristic (ROC) analyses were used to determine the value of plaque features in discriminating WMLs with score > 3.

RESULTS

In total, 112 individuals (49 men, mean age 72.0±5.6 years) were included. Participants with a WML score > 3 showed a significantly greater carotid wall area and femoral artery stenosis and higher incidence of carotid calcification and femoral artery calcification and lipid-rich necrotic cores (LRNC) compared to those with a WML score ≤ 3 (all P < 0.05). Carotid artery calcification and femoral artery calcification, LRNC, and stenosis were found to be significantly associated with severe WMLs before and after adjustment for clinical factors (odds ratio 1.51-3.79, all P < 0.05). ROC analysis showed, in discriminating severe WMLs, the area under the curve increased from 0.615 to 0.754 after combining femoral artery LRNC and stenosis with carotid calcification compared to the carotid calcification alone.

CONCLUSION

Characteristics of femoral artery atherosclerosis determined by vessel wall MRI have added value for carotid atherosclerosis in determining the severity of WMLs.

Assessment of neovascularization of carotid artery atherosclerotic plaques using superb microvascular imaging: a comparison with contrast-enhanced ultrasound imaging and histology

Background

This study aimed to investigate the usefulness of superb microvascular imaging (SMI), a novel non-contrast-enhanced ultrasound technique, in characterizing neovessels within carotid atherosclerotic plaques through comparison with contrast-enhanced ultrasound (CEUS) and histology.

Methods

Patients with carotid plaque were recruited and underwent SMI and CEUS ultrasound imaging of the carotid arteries. The maximum plaque thickness, length, and stenosis of each plaque were measured. Grade of the neovessels was determined by SMI and CEUS, respectively. Grade 0 was defined as no blood flow signal/microbubbles within plaques; grade 1 was defined as moderate blood flow signals/microbubbles confined to the shoulder and/or adventitial side of the plaque; and grade 2 was defined as extensive intraplaque signals/microbubbles. Patients with symptomatic carotid stenosis (stenosis ≥50%) or asymptomatic carotid stenosis (stenosis ≥70%) underwent endarterectomy, and plaque specimens were subjected to immunohistochemical analysis of CD31 expression. The neovessels were quantified by histology. The agreement of SMI with CEUS and histology in characterizing neovessels was analyzed using weighted Kappa statistic and Spearman's correlation analyses.

Results

Seventy-eight patients (mean age: 67.3±8.9 years old, 63 males) were recruited. Of these patients, 52 (66.7%) had a unilateral plaque and 26 (33.3%) had bilateral plaques in the carotid arteries. For the 104 carotid plaques detected, the mean plaque thickness and length were 4.3±1.1 and 18.8±6.6 mm, respectively. The prevalence of <50%, 50-69%, and ≥70% stenosis was 43.3%, 24.0%, and 32.7%, respectively. Excellent agreement was found between SMI and CEUS (κ=0.825 at the plaque level; κ=0.820 at the patient level) in evaluating the neovessel grade within the carotid plaques. Of the 25 patients who underwent carotid endarterectomy, a strong correlation (r=0.660, P<0.001) was found between SMI and histology in the evaluation of intraplaque neovessels. SMI had excellent scan-rescan (κ=0.857), intra-reader (κ=0.810), and inter-reader (κ=0.754) agreement in the assessment of intraplaque neovessels.

Conclusions

The SMI technique is capable of reliably characterizing neovessels within carotid atherosclerotic plaques and demonstrates good to excellent agreement with histology and CEUS.