MR Imaging of Carotid Artery Atherosclerosis: Updated Evidence on High-Risk Plaque Features and Emerging Trends

Radiomics based on dual-energy CT virtual monoenergetic images to identify symptomatic carotid plaques: a multicenter study

This study aims to create a radiomics nomogram using dual-energy computed tomography (DECT) virtual monoenergetic images (VMI) to accurately identify symptomatic carotid plaques. Between January 2018 and May 2023, data from 416 patients were collected from two centers for retrospective analysis. Center 1 provided data for the training (n = 213) and internal validation (n = 93) sets, and center 2 supplied the external validation set (n = 110). Plaques imaged at 40 keV, 70 keV, and 100 keV were outlined, and the selected radiomics features were used to establish the radiomics model. The classifier with the highest area under the curve (AUC) in the training set generated the radiomics score (Rad-Score). Logistic regression was used to identify risk factors and establish a clinical model. A radiomics nomogram integrating the Rad-score and clinical risk factors was constructed. The predictive performance was evaluated using receiver operating characteristic (ROC) analysis and decision curve analysis (DCA). Plaque ulceration and plaque burden are independent risk factors for symptomatic carotid plaques. The 40 + 70 keV radiomics model achieved excellent diagnostic performance, with an average AUC of 0.805 across all validation sets. Furthermore, the radiomics nomogram, integrating the Rad-score with clinical predictors, demonstrated robust diagnostic accuracy, with AUCs of 0.909, 0.850, and 0.804 in the training, internal validation, and external validation sets, respectively. DCA results suggested that the nomogram was clinically valuable. Our study developed and validated a DECT VMI-based radiomics nomogram for early identification of symptomatic carotid plaques, which can be used to assist clinical diagnosis and treatment decisions. The study introduces an innovative radiomics nomogram utilizing DECT VMI to discern symptomatic carotid plaques with high precision.

Angiotensin II: A novel biomarker in vascular diseases

The renin-angiotensin system (RAS), composed mainly of renin, angiotensin, and aldosterone, is a key endocrine pathway involved in cardiovascular activity regulation. Under physiological conditions, the RAS plays a vital role in water and salt metabolism, blood pressure regulation, and electrolyte balance. Angiotensin II (Ang II) is the most important active component of the RAS, and its receptors are concentrated in vascular, pulmonary, cardiac, and renal tissues in vivo. Moreover, Ang II is closely associated with the development of vascular lesions. Ang II expression is closely associated with atherosclerosis, aortic aneurysm/dissection, ischemic stroke, hypertension, pulmonary hypertension, and type 2 diabetes mellitus. Given the significant pathophysiological role of Ang II in vascular diseases and the availability of advanced detection methods, Ang II holds promise as a reliable biomarker and therapeutic target in clinical settings. This review summarizes the mechanisms through which Ang II contributes to different vascular diseases and discusses its potential application as a biomarker for disease diagnosis.

Visualization of Atherosclerotic Plaques Paired with Joheksol 350 (Omnipaque)

Background: Cardiovascular disease is one of the leading causes of death around the globe. Atherosclerosis, a chronic inflammatory blood vessel disease that takes years to develop, is its primary cause. Instability and further plaque buildup are caused by chronic inflammation, which creates the conditions for possible rupture. The visualization of arterial lesions in situ can enhance understanding of atherosclerosis progression and potentially improve experimental therapies. Conventional histology methods for assessing atherosclerotic lesions are robust but are destructive and may prevent further tissue analysis. Objectives: The objective of the current study was to evaluate a novel, nondestructive method for the visualization and characterization of atherosclerotic lesions. Methods and Results: Thus, we tested the hypothesis that MRI paired with an iodine-based radiopaque stain would effectively characterize atherosclerotic plaques in a manner comparable to routine histology while maintaining sample integrity and providing whole-volume data.

Ultrasound Strain Imaging for Characterizing Atherosclerotic Plaque in the Carotid Arteries of Asymptomatic Subjects

OBJECTIVE

The rupture of vulnerable plaques in the carotid artery is a leading cause of strokes. While magnetic resonance imaging (MRI) is the standard for quantifying plaque composition, its high costs and lengthy procedure times limit large-scale use. Compound ultrasound strain imaging (CUSI) ultrasound offers a non-invasively alternative by assessing tissue deformation/strain within the arterial wall. Previous studies have demonstrated the relationship between strain values and plaque composition, primarily focusing on longitudinal acquisitions, which only image the proximal and distal parts of the wall. This study examines CUSI in transverse imaging planes, which enables visualization of the entire cross-section of the vessel wall. CUSI has already been validated on a symptomatic population. Therefore, the aim is to determine whether CUSI can differentiate plaque composition in asymptomatic individuals with an increased cardiovascular risk profile, validated by MRI.

METHODS

This cross-sectional study included 42 plaques in 28 participants. Ultrasound data were acquired with a Samsung Medison Accuvix V10 with an L5-13IS transducer and RF-interface. An experienced neuroradiologist classified plaques with MRI using the Siemens 3.0T MAGNETOM Skyra MRI (Erlangen, Germany) with a dedicated coil. Strain differences were compared across four plaque categories (calcified, lipid, hemorrhagic, fibrous/aspecific) and for vulnerable versus stable plaques.

RESULTS

A difference in strain values was found between lipid and calcified plaques (Kruskal-Wallis test, p < 0.05). Additionally, vulnerable plaques exhibited higher strain values than stable plaques (independent samples test, p < 0.05).

CONCLUSION

CUSI values differ between lipid and calcified and between stable and vulnerable plaques. Minor differences were found between the other plaque types.

Correlation of intracranial and extracranial carotid atherosclerotic plaque characteristics with ischemic stroke recurrence: a high-resolution vessel wall imaging study

Objectives

To evaluate the ability of the plaque characteristics of extracranial carotid and intracranial arteries to predict large atherosclerotic ischemic stroke recurrence via head and neck combined high-resolution vessel wall imaging (HR-VWI).

Methods

This prospective cohort study included 169 patients with large atherosclerotic ischemic stroke who underwent head and neck combined HR-VWI from April 2022 to May 2023. The baseline clinical data and atherosclerotic plaque characteristics of the intracranial and extracranial carotid arteries were collected, and the patients were followed up for 1 year, with the endpoint event defined as recurrent ischemic stroke. Clinical and imaging data were compared between the recurrent and nonrecurrent groups. Independent risk factors associated with stroke recurrence were assessed via multivariate Cox regression analysis. The receiver operating characteristic (ROC) curves of the relevant variables were also plotted, and the area under the curve (AUC) was calculated to assess their ability to predict stroke recurrence. Kaplan-Meier survival curves were used to compare the probability of stroke recurrence.

Results

During the 12-month follow-up, stroke recurrence occurred in 35 of the 169 patients. Multivariate Cox regression analysis revealed that the total number of intracranial and extracranial carotid plaques (p = 0.010) and coexisting extracranial carotid plaques and intracranial significantly enhanced plaques (p = 0.047) were independent risk factors for recurrent ischemic stroke. The AUCs for predicting stroke recurrence were 0.787 and 0.710, respectively. The Kaplan-Meier survival curve revealed that the risk of stroke recurrence was significantly greater in patients whose total number of intracranial and extracranial carotid plaques was >4.5 than in patients whose total number of plaques was <4.5 (p < 0.001) and was significantly greater in patients with coexisting extracranial carotid plaques and intracranial significantly enhanced plaques than in patients without coexisting plaques (p < 0.001).

Conclusion

A greater total number of intracranial and extracranial carotid plaques and the coexistence of extracranial carotid plaques and intracranially significantly enhanced plaques are independent risk factors associated with recurrent ischemic stroke. Head and neck combined HR-VWI may provide new indicators for the prediction of stroke recurrence, thus helping clinicians identify high-risk patients and target therapy to reduce the recurrence of ischemic events.

Interleukin-6 and thyroid-stimulating hormone index predict plaque stability in carotid artery stenosis: analyses by lasso-logistic regression

Objective

To develop and validate a new prediction model based on the Lass-logistic regression with inflammatory serologic markers for the assessment of carotid plaque stability, providing clinicians with a reliable tool for risk stratification and decision-making in the management of carotid artery disease.

Methods

In this study, we retrospectively collected the data of the patients who underwent carotid endarterectomy (CEA) from 2019 to 2023 in Nanjing Drum Tower Hospital. Demographic characteristics, vascular risk factors, and the results of preoperative serum biochemistry were measured and collected. The risk factors for vulnerable carotid plaque were analyzed. A Lasso-logistic regression prediction model was developed and compared with traditional logistic regression models. The Akaike information criterion (AIC) and Bayesian information criterion (BIC) were used to evaluate the performance of three models.

Results

A total of 131 patients were collected in this study, including 66 (50.4%) in the vulnerable plaque group and 65 (49.6%) in the stable plaque group. The final Lasso-logistic regression model included 4 features:IL-6, TSH, TSHI, and TT4RI; AIC = 161.6376, BIC = 176.0136, both lower than the all-variable logistic regression model (AIC = 181.0881, BIC = 261.5936), and the BIC was smaller than the stepwise logistic regression model (AIC = 154.024, BIC = 179.9007). Finally, the prediction model was constructed based on the variables screened by the Lasso regression, and the model had favorable discrimination and calibration.

Conclusions

The noninvasive prediction model based on IL-6 and TSHI is a quantitative tool for predicting vulnerable carotid plaques. It has high diagnostic efficacy and is worth popularizing and applying.

Apolipoprotein E Gene ε4 Allele is Associated with Atherosclerosis in Multiple Vascular Beds

Background

Atherosclerosis is a systemic disease that can involve multiple vascular beds. The risk factors for atherosclerosis in multiple vascular beds remain unclear. Apolipoprotein E (APOE) is involved in inflammation and lipid deposition in the process of atherosclerosis. The objective of this study was to investigate whether APOE polymorphisms are associated with atherosclerosis in multiple vascular beds.

Methods

A total of 416 patients with atherosclerosis in single vascular bed and 658 patients with atherosclerosis in multiple vascular beds were included. APOE genotypes were detected and the differences of APOE genotypes between the groups were compared. Logistic regression analysis was performed to analyze the relationship between APOE genotypes and atherosclerosis in multiple vascular beds.

Results

APOE E3/E4 genotype frequency was lower in the patients with atherosclerosis in multiple vascular beds than that of patients with atherosclerosis in single vascular bed (11.4% vs 17.8%, P=0.004). There was no significant difference in age and gender distribution, proportion of history of smoking, alcohol consumption, hypertension, and diabetes mellitus between the two groups (all P>0.05), and among patients with different APOE alleles (all P>0.05). Logistic regression analysis indicated that APOE E3/E4 genotype (E3/E4 vs E3/E3: odds ratio (OR) 0.598, 95% confidence interval (CI): 0.419-0.854, P=0.005), and APOE ε4 allele (ε4 vs ε3: OR 0.630, 95% CI: 0.444-0.895, P=0.010) associated with atherosclerosis in multiple vascular beds.

Conclusion

APOE ε4 allele is associated with atherosclerosis in multiple vascular beds.

Novel imaging modalities for the identification of vulnerable plaques

Atherosclerosis is a slow, progressive disease that is closely associated with major adverse cardiovascular events. Early diagnosis and risk assessment of atherosclerosis can effectively improve the prognosis and reduce the occurrence of adverse cardiovascular events in the later stage. A variety of invasive and non-invasive imaging modalities are important tools for diagnosing lesions, monitoring the efficacy of treatments, and predicting associated risk events. This review mainly introduces the four commonly used non-invasive imaging modalities in clinical practice and intravascular imaging such as optical coherence tomography, intravascular ultrasound imaging, and near-infrared spectroscopy, compares the advantages and disadvantages in the diagnosis of vulnerable plaques, and briefly summarizes the new progressions of each.

Evaluation of Cone-Beam Computed Tomography Scans to Develop a Staging Method of External Carotid Artery Calcification

Background: The objective of this study was to develop a practical staging method for reporting external carotid artery calcifications (ECACs) using cone-beam computed tomography (CBCT) imaging, specifically to standardize reporting for oral and maxillofacial radiologists. Methods: This retrospective study evaluated 489 CBCT scans for the presence of ECACs. Two calibrated evaluators assessed the scans in all three orthogonal planes, using the axial plane to develop the staging system. Calcifications were graded on a scale from 0 to 5. Results: ECACs were found in 170 out of 489 scans (34.7%). There was a statistically significant increase in ECAC distribution with age progression. The prevalence of ECACs was similar between genders. Grade 1 calcifications were most common in the 51-60 age group, Grade 2 in the 61-70 and 71-80 groups, and Grades 3 and 4 in the 81-90 group. No Grade 5 calcifications were observed in any age group. The inter-rater reliability showed an excellent correlation in the identification and grading of ECACs. Conclusions: The proposed grading system enables oral and maxillofacial radiologists to quantitatively report ECACs, facilitating timely referrals to physicians for further evaluation and early intervention, thereby potentially reducing the risk of cardiovascular events.

Why selective screening for asymptomatic carotid stenosis is currently appropriate: a special report

INTRODUCTION

Two of the main reasons recent guidelines do not recommend routine population-wide screening programs for asymptomatic carotid artery stenosis (AsxCS) is that screening could lead to an increase of carotid revascularization procedures and that such mass screening programs may not be cost-effective. Nevertheless, selective screening for AsxCS could have several benefits. This article presents the rationale for such a program.

AREAS COVERED

The benefits of selective screening for AsxCS include early recognition of AsxCS allowing timely initiation of preventive measures to reduce future myocardial infarction (MI), stroke, cardiac death and cardiovascular (CV) event rates.

EXPERT OPINION

Mass screening programs for AsxCS are neither clinically effective nor cost-effective. Nevertheless, targeted screening of populations at high risk for AsxCS provides an opportunity to identify these individuals earlier rather than later and to initiate a number of lifestyle measures, risk factor modifications, and intensive medical therapy in order to prevent future strokes and CV events. For patients at 'higher risk of stroke' on best medical treatment, a prophylactic carotid intervention may be considered.