Imaging modalities to diagnose carotid artery stenosis: progress and prospect

Imaging-validated correlates and implications of the pathophysiologic mechanisms of ageing-related cerebral large artery and small vessel diseases: a systematic review and meta-analysis

BACKGROUND

Cerebral large artery and small vessel diseases are considered substrates of neurological disorders. We explored how the mechanisms of neurovascular uncoupling, dysfunctional blood-brain-barrier (BBB), compromised glymphatic pathway, and impaired cerebrovascular reactivity (CVR) and autoregulation, identified through diverse neuroimaging techniques, impact cerebral large artery and small vessel diseases.

METHODS

Studies (1990-2024) that reported on neuroradiological findings on ageing-related cerebral large artery and small vessel diseases were reviewed. Fifty-two studies involving 23,693 participants explored the disease mechanisms, 9 studies (sample size = 3,729) of which compared metrics of cerebrovascular functions (CF) between participants with cerebral large artery and small vessel diseases (target group) and controls with no vascular disease. Measures of CF included CVR, cerebral blood flow (CBF), blood pressure and arterial stiffness.

RESULTS

The findings from 9 studies (sample size = 3,729, mean age = 60.2 ± 11.5 years), revealed negative effect sizes of CVR [SMD = - 1.86 (95% CI - 2.80, - 0.92)] and CBF [SMD = - 2.26 (95% CI - 4.16, - 0.35)], respectively indicating a reduction in cerebrovascular functions in the target group compared to their controls. Conversely, there were significant increases in the measures of blood pressure [SMD = 0.32 (95% CI 0.18, 0.46)] and arterial stiffness [SMD = 0.87 (95% CI 0.77, 0.98)], which signified poor cerebrovascular functions in the target group. In the combined model the overall average effect size was negative [SMD = - 0.81 (95% CI - 1.53 to - 0.08), p < 0.001]. Comparatively, this suggests that the negative impacts of CVR and CBF reductions significantly outweighed the effects of blood pressure and arterial stiffness, thereby predominantly shaping the overall model. Against their controls, trends of reduction in CF were observed exclusively among participants with cerebral large artery disease (SMD = - 2.09 [95% CI: - 3.57, - 0.62]), as well as those with small vessel diseases (SMD = - 0.85 [95% CI - 1.34, - 0.36]). We further delineated the underlying mechanisms and discussed their interconnectedness with cognitive impairments.

CONCLUSION

In a vicious cycle, dysfunctional mechanisms in the glymphatic system, neurovascular unit, BBB, autoregulation, and reactivity play distinct roles that contribute to reduced CF and cognitive risk among individuals with cerebral large artery and/or small vessel diseases. Reduction in CVR and CBF points to reductions in CF, which is associated with increased risk of cognitive impairment among ageing populations ≥ 60 years.

Feasibility of U-Net model for cerebral arteries segmentation with low-dose computed tomography angiographic images with pre-processing methods

Subtraction computed tomography angiography (sCTA) can effectively separate enhanced cerebral arteries from similar signal intensity and proximity (i.e., vertebrae and skull). However, sCTA is not considered mainstream because of the high radiation dose generated by the two-scan protocol. We aimed to solve the overexposure problem by training a U-Net-based CA segmentation model using a low-dose computed tomographic angiography (CTA) image-based dataset with various pre-processing methods to achieve a performance similar to that of sCTA. We optimized a non-local means (NLM) algorithm using the coefficient of variation and contrast-to-noise ratio. In addition, datasets were constructed by predicting the CA mask using a semiautomatic thresholding technique based on region growing method. Then, CTA images of 35 (2052 slices), 4 (248 slices), and 5 patients (594 slices) were used, respectively, for the train, validation, and test sets. To evaluate the performance of the U-Net-based CA segmentation model quantitatively according to the constructed dataset, the average precision (AP), intersection over union (IoU), and F1-score were calculated. For the dataset to which both the optimized NLM algorithm and semiautomatic thresholding technique were applied, the segmentation model showed the most improved performance. In particular, the quantitative evaluation of the low-dose CTA image with the NLM algorithm and the semiautomatic thresholding-based U-Net model calculated AP, IoU, and F1-scores of approximately 0.880, 0.955, and 0.809, respectively, which were most similar to the CA segmentation performance of the sCTA technique. The proposed U-Net model provided CA segmentation results without additional radiation exposure. In addition, the selection and optimization of an appropriate pre-processing methods were identified as essential for achieving higher segmentation performance for the U-Net model.

National Trends in Central Retinal Artery Occlusion Presentations and Stroke Workup in United States Emergency Department

PURPOSE

To investigate trends in acute central retinal artery occlusion (CRAO) diagnostic assessments and sociodemographic characteristics of patients in the United States (US) emergency department (ED).

DESIGN

Retrospective trend study.

SUBJECTS

Adult patients with CRAO presenting to ED from 2016 through 2021.

METHODS

The National Emergency Department Sample (NEDS) was queried with International Classification of Diseases, Tenth Revision (ICD-10) codes with a primary diagnosis of CRAO. Stroke workup modalities assessed included brain imaging (CT/CTA and MRI/MRA), carotid imaging (US, CTA, MRA), cardiac diagnostics (Echocardiogram/ECG), and laboratory workup (ESR/CRP).

MAIN OUTCOME MEASURE

Proportion of studied participants receiving stroke workup modalities.

RESULTS

3,736 patients were identified with mean age of 69 [13.72] years, majority were male (53.02%), and predominantly insured by Medicare (62.77%). Comorbidities included hypertension (75.45%), hyperlipidemia (44.67%), coronary artery disease (20.26%), diabetes (27.38%), and obesity (11%). CRAO incidence significantly increased over the five-year period from 1,698 to 3,526 (p=0.024). Utilization rates of all workup modalities including brain imaging, carotid imaging, heart, and laboratory tests showed a linear increase from 2016 through 2021. The proportion of patients receiving no stroke workup decreased from 66.75% to 57.87% (p=0.259).

CONCLUSIONS

The US has increased the screening and stroke workup of CRAO in the ED over time, yet greater than 50% of patients continue to not receive any type of stroke workup imaging. Greater awareness of these trends and current guidelines could result in improved screening and patient outcomes.

Mechanical characteristics of braided composite stents for carotid artery stenosis using finite element method

Self-expandable braided stents are widely used for carotid artery stenosis due to flexibility. Finite element (FE) models of braided composite stents with different proportions of NiTi and Mg-2.1Nd-0.2Zn-0.5Zr (JDBM) alloy (24NiTi (24:0), 20NiTi (20:4), 16NiTi (16:8), 12NiTi (12:12), 8NiTi (8:16), 4NiTi (4:20)) were constructed to analyze their radial compression strength and longitudinal bending flexibility. The 4NiTi stent showed the highest radial support (16.39N) and decreased bending strength by 7.72%. These results suggest that replacing more NiTi with JDBM wires enhances the stent's radial strength and reduces bending stiffness, providing new insights into stent design.

Shear Wave Elastography for Carotid Artery Stiffness: Ready for Prime Time?

Carotid artery stiffness is associated with aging and atherosclerotic disease, leading to cerebrovascular events. Shear Wave Elastography (SWE) is a novel ultrasound technique offering a direct, quantitative assessment of the arterial wall elasticity. The aim of this study is to validate the technical feasibility of SWE in measuring carotid stiffness (CS). A literature search was performed across the PubMed and Scopus databases, with keywords including "carotid stiffness", "Shear Wave Elastography", "atherosclerosis", and "vascular elasticity". The findings reveal the potential of SWE in quantifying carotid Intima-Media Complex (IMC) stiffness, with implications for the early diagnosis of vascular disease, aiding in clinical decision making and prognostic assessment. Based on the findings of the literature search, a small pilot study was conducted involving 10 participants, using the Philips EPIQ Elite system for the SWE measurements. The technical analysis revealed optimizing the region of interest (ROI) size, probe positioning, and cine-loop analysis as crucial factors for obtaining accurate results. The results of the literature review and small pilot study demonstrate the potential of SWE as a non-invasive method for assessing carotid stiffness. Certain technical adjustments, such as smaller ROIs and careful probe placement, improved the accuracy and repeatability of carotid SWE measurements. Further studies are needed to assess and standardize carotid SWE across larger patient populations.

Non-invasive imaging modalities for diagnosing pulsatile tinnitus: a comprehensive review and recommended imaging algorithm

Pulsatile tinnitus (PT) is a challenging diagnostic condition arising from various vascular, neoplastic, and systemic disorders. Non-invasive imaging is essential for identifying underlying causes while minimizing risks of invasive diagnostic angiography. Although no consensus exists on the primary imaging modality for PT and currently CT, ultrasound, and MRI are used in the diagnostic pathway, MRI is increasingly preferred as the first-line screening test for its diagnostic efficacy and safety. MRI protocols such as time-of-flight, magnetic resonance angiography, diffusion-weighted imaging, and arterial spin labeling can identify serious causes, including vascular shunting lesions, venous sinus stenosis, and tumors. In this narrative review of the current literature we discuss the benefits and limitations of various non-invasive imaging modalities in identifying the characteristic imaging findings of the most common causes of PT and also provide an algorithm that clinicians can use to guide the imaging evaluation.

The diagnosis and treatment of asymptomatic and symptomatic patients with carotid artery stenosis

Carotid artery atherosclerotic stenosis is an important annual cause of stroke in the United States. Moreover, the incidence of carotid artery stenosis is significantly increasing due to the widespread popularity of high fat and high salt diets, sedentary lifestyles, and the increasing age of the population. Of major importance to cardiovascular specialists is the fact that individuals with atherosclerotic carotid artery stenosis can have a prevalence of atherosclerotic coronary artery disease as high as 50 to 75%. Vascular screening for carotid artery stenosis with Doppler ultrasound should be considered for all symptomatic patients with possible carotid stenosis and also considered for asymptomatic patients with (1) symptomatic peripheral arterial disease, coronary artery disease, or atherosclerotic aortic aneurysm or, (2) multiple atherosclerotic risk factors. Carotid artery atherosclerotic plaques that are at high risk for rupture and thrombosis or cerebral embolization are characterized by large lipid cores, intraplaque hemorrhage, thin fibrous caps less than 165 μms that are infiltrated by macrophages and T cells or have surface ulcer(s) or fissures. Carotid artery plaque rupture with cerebral embolism can cause a stroke, transient ischemic attacks (TIA), or ipsilateral blindness (amaurosis fugax). Medical treatment based on the recommendations of the American and European Societies for Vascular Surgery and the American Heart Association for symptomatic patients with carotid stenosis and also asymptomatic patients with high risk carotid stenosis plaques include antiplatelet drugs, antihypertensive drugs for hypertension control and lipid lowering drugs. Management strategies and decisions about carotid revascularization in asymptomatic patients with high risk carotid stenosis should involve a multidisciplinary team and shared decision-making is recommended. The 30 day and five to 10 year outcomes in asymptomatic carotid stenosis patients who have undergone carotid endarterectomy, carotid stenting and/or optimal medical therapy are summarized from the Veterans Administration Cooperative Study, the Asymptomatic Carotid Atherosclerosis Study and the Asymptomatic Carotid Surgery Trials. The current Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial (CREST-2) should help to resolve the debate regarding carotid artery revascularization versus primary medical treatment in asymptomatic patients with >70% carotid artery stenosis. Symptomatic patients who present within 4.5 hours of stroke onset require evaluation for acute intravenous pharmacologic thrombolysis and patients who present with large vessel occlusion within 24 hours of symptom onset should be considered for mechanical thrombectomy to reduce the neurologic deficit. Patients with carotid artery stenosis who present with a history of cerebral infarct in the preceding six months due to cerebral embolism require medical treatment and evaluation by a multidisciplinary team for carotid revascularization in order to prevent future strokes or TIAs. The outcomes of the North American Symptomatic Carotid Endarterectomy Trial, Carotid Revascularization Endarterectomy Versus Stent Trial, Stent-Supported Percutaneous Angioplasty of the Carotid Artery vs. Endarterectomy Trial, and the Safety and Efficacy Study for Reverse Flow Used during Carotid Artery Stenting Procedure trials for symptomatic patients with carotid stenosis are reviewed. A synopsis of treatment guidelines for symptomatic and asymptomatic carotid stenosis patients from the American and European Societies of Vascular Surgery and the American Heart Association/American Stroke Association are presented. Each patient with carotid artery stenosis must be carefully evaluated to determine the best treatment based on the clinical presentation, the imaging and laboratory diagnostic information, the treatment guidelines, and the patient needs and preferences as well as the patient's social and cultural factors.

LINC01088 Targets miR-195-5p to Promote Proliferation and Migration and Reduce Apoptosis in the Inhibition of Carotid Artery Stenosis

Carotid artery stenosis (CAS) often goes undetected until it reaches an advanced stage, which can result in serious complications. The present study evaluated the potential of long noncoding RNA (lncRNA) LINC01088 as a biomarker for CAS. 92 CAS patients and 92 healthy controls (Control group) were included. RT-qPCR was performed to assess the relative levels of LINC01088 and miR-195-5p. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic potential of LINC01088. The relationship between LINC01088 and miR-195-5p was identified by luciferase reporter assay. Proliferation, migration, and apoptosis in human aortic endothelial cells (HAECs) were assessed using CCK8, transwell, and flow cytometry assay. DAVID was employed for Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses. CAS patients showed decreased LINC01088 expression and increased miR-195-5p expression compared to Control, with a negative correlation between their expression levels in CAS. LINC01088 demonstrated high sensitivity and specificity in distinguishing CAS patients from healthy individuals. LINC01088 directly targets miR-195-5p. Upregulation of LINC01088 reversed the effects of ox-LDL treatment, restoring proliferation and migration while reducing apoptosis in HAECs. However, miR-195-5p mimic reduced the protection of LINC01088 on HAECs proliferation, migration, and apoptosis. For miR-195-5p target genes, GO revealed protein metabolism pathways and KEGG highlighted the p53 and MAPK signaling pathways. The present study revealed the diagnosis value of LINC01088. LINC01088 reversed ox-LDL-induced proliferation, apoptosis, and migration by acting as sponges of miR-195-5p in HAECs. LINC01088 may serve as a protective biomarker in CAS progression.

Symptomatic Cervical Carotid Artery Stenosis: Evolving Paradigms in Risk Stratification and Intervention

Symptomatic carotid disease, characterized by atherosclerotic or non-atherosclerotic internal carotid artery disease with ipsilateral stroke symptoms, represents a critical condition in stroke neurology. This "hot carotid" state carries a high risk of stroke recurrence, with almost one-fourth of the patients experiencing recurrent ischemic events within 2 weeks of initial presentation. The global prevalence of significant carotid stenosis (conventionally defined as ≥50% narrowing) is estimated at around 1.8% in men and 1.2% in women and increases with age. Management of symptomatic carotid disease remains challenging, requiring a balance between urgent medical and surgical interventions and their associated risks. Current treatment approaches combine medical management, focusing on optimal antithrombotic therapy, with revascularization procedures such as carotid endarterectomy or carotid artery stenting. However, decision making has evolved beyond considering stenosis degree alone, now incorporating advanced imaging data on plaque composition and intraluminal characteristics. Even though there are numerous randomized trials, uncertainties persist regarding optimal management, particularly in light of improved medical therapies and emerging concepts like symptomatic non-stenotic carotid disease. Future research directions include exploring newer antithrombotic regimens, refining patient selection criteria for revascularization, and evaluating novel techniques like transcarotid artery revascularization.

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.

Calcified carotid artery atheroma on standard dental radiographs: A public health opportunity for cardiovascular risk reduction

Objective

Calcified carotid artery atheroma (CCAA) can be identified incidentally on standard dental panoramic radiographs (DPRs). We sought to (1) determine the prevalence of CCAA on DPRs in a general dental population and (2) establish the proportion of patients in whom this would represent a new statin-indicated condition.

Methods

We identified patients aged ≥30 with DPRs from 2019 to 2021 from the University of British Columbia Dental Clinic. Patient charts were reviewed for use of lipid-lowering therapies (LLT) and existing statin-indicated conditions. DPRs for each patient were evaluated for the presence and characteristics of CCAA.

Results

Of 921 patients with a DPR and documented medical history, 548 (59.5 %) were diagnostic for evaluation of CCAA. Although 116/548 (21.2 %) of these patients had evidence of CCAA, only 25.9 % (30/116) were already on LLT; another 20.7 % (24/116) of patients with CCAA had a pre-existing statin-indicated condition but were not on LLT. Therefore, in 53.4 % (62/116) of patients with CCAA-positive DPRs, this constituted a new diagnosis of atherosclerosis not yet treated with LLT, representing 6.7 % (62/921) of the clinic population and 11.3 % of individuals with DPRs of diagnostic quality (62/548). Dyslipidemia, hypertension, coronary artery disease, diabetes, atrial fibrillation, stroke/transient ischemic attack, older age, and male sex were all found to be significant predictors of CCAA.

Conclusion

CCAA is a common finding among patients with DPRs and in over half of cases, the presence of CCAA represents a new diagnosis of atherosclerosis. The high prevalence of new, untreated atherosclerosis in this population indicates an opportunity for risk factor modification and collaboration between dentists and physicians to optimize patient care.

Identification of symptomatic carotid artery plaque: a predictive model combining angiography with optical coherence tomography

Objective

Symptomatic carotid artery disease is indicative of an elevated likelihood of experiencing a subsequent stroke, with the morphology of plaque and its specific features being closely linked to the risk of stroke occurrence. Our study based on the characteristics of carotid plaque assessed by optical coherence tomography (OCT), the plaque morphology evaluated by digital subtraction angiography (DSA) and clinical laboratory indicators were combined, develop a combined predictive model to identify symptomatic carotid plaque.

Methods

Patients diagnosed with carotid atherosclerotic stenosis who underwent whole-brain DSA and OCT examination at the Affiliated Hospital of Jining Medical University from January 2021 to November 2023 were evaluated. Clinical features, as well as DSA and OCT plaque characteristics, were analyzed for differences between symptomatic and asymptomatic cohorts. An analysis of logistic regression was carried out to identify factors associated with the presence of symptomatic carotid plaque. A multivariate binary logistic regression equation was established with the odds ratio (OR) serving as the risk assessment parameter. The receiver operating characteristic curve was utilized to assess the combined predictive model and independent influencing factors.

Results

A total of 52 patients were included in the study (symptomatic: 44.2%, asymptomatic: 55.8%). Symptomatic carotid stenosis was significantly linked to four main factors: low-density lipoprotein-cholesterol >3.36 mmol/L [OR, 6.400; 95% confidence interval (CI), 1.067-38.402; p = 0.042], irregular plaque (OR, 6.054; 95% CI, 1.016-36.083; p = 0.048), ruptured plaque (OR, 6.077; 95% CI, 1.046-35.298; p = 0.048), and thrombus (OR, 6.773; 95% CI, 1.194-38.433; p = 0.044). The combined predictive model generated using four indicators showed good discrimination (Area Under Curve, 0.924; 95% CI, 0.815-0. 979). The p value was <0.05 with 78.26% sensitivity and 93.10% specificity.

Conclusion

OCT is valuable in evaluating the plaque characteristics of carotid atherosclerotic stenosis. The combined predictive model comprising low-density lipoprotein-cholesterol >3.36 mmol/L, irregular plaque, ruptured plaque, and thrombus could help in the detection of symptomatic carotid plaque. Further research conducted on additional independent cohorts is necessary to confirm the clinical significance of the predictive model for symptomatic carotid plaque.

Differential miR-195-5p and its potential role during the development of carotid artery stenosis

OBJECTIVES

Carotid artery stenosis (CAS) is a leading cause of cerebral ischemic events (CIE). Timely detection and risk assessment can aid in managing CAS patients and improving their prognosis. The aim of the current study is to identify a new biomarker for CAS and to further investigate the impact of miR-195-5p on cellular processes in vascular smooth muscle cells (VSMCs).

METHODS

This study involved 112 CAS patients and 65 healthy individuals. Serum miR-195-5p levels were measured using RT-qPCR. The ROC curve was then plotted to evaluate the diagnostic potential of miR-195-5p for CAS. The Kaplan-Meier curve and Cox regression were employed to determine miR-195-5p's prognostic significance. In vitro, the effects of miR-195-5p mimic or inhibitor on VSMC proliferation and migration were assessed using CCK-8 and Transwell assays.

RESULTS

In CAS patients, serum miR-195-5p levels were elevated and correlated with the degree of CAS. The ROC curve had an AUC value of 0.897, with sensitivity of 71.4% and specificity of 95.4%. Higher levels of miR-195-5p indicated a higher risk of CIE occurrence and may serve as an independent predictor of CIE. The upregulation of miR-195-5p promoted VSMC proliferation and migration, while downregulation had the opposite effect.

CONCLUSIONS

miR-195-5p was demonstrated to have diagnostic and prognostic significance in CAS and may serve as a potential biomarker. It may contribute to the progression of CAS by promoting the proliferation and migration of VSMCs.

Assessments of arterial and venous phase radiodensity does not improve carotid near-occlusion diagnostics

The hypothesis of this study was that evaluation of radiodensity assessment beyond a carotid stenosis in arterial and/or venous phase can be used to separate near-occlusion and conventional ≥ 50% stenosis. We prospectively included participants with ≥ 50% carotid stenosis with inclusion preference for cases with extracranial internal carotid artery (ICA) asymmetry. All participants were examined with a research biphasic computed tomography angiography (CTA) protocol (arterial and venous phase). Reference diagnosis was set by interpretation on CTA and radiodensity difference between ipsilateral and contralateral ICA (c-corrected) or vertebral (v-corrected) was compared. We included 93 participants, 62 with near-occlusion and 31 with conventional ≥ 50% stenosis. Just beyond the stenosis, median c-corrected radiodensity was - 20 Hounsfield units (HU) among near-occlusions and - 1 HU among conventional ≥ 50% stenoses (p < 0.001) in the arterial phase. For the venous phase, these findings were + 17 HU and + 3 HU (p = 0.007). Similar group differences were seen for v-correction. No parameter had good diagnostic performance, area under the curve ≤ 0.82. With specificity set at ≥ 95%, detected near-occlusions were foremost those with large side-to-side differences in distal ICA-diameter. Carotid near-occlusions can have reduced radiodensity beyond the stenosis in arterial phases and increased radiodensity in venous phases compared to a reference artery-which was not clearly seen for conventional stenoses. However, these radiodensity findings are best seen in near-occlusion cases that are not diagnostically challenging, while they work poorly as additional diagnostic aids.

Carotid Artery Stenosis and Ischemic Stroke in Patients With Head and Neck Cancer Treated With Radiation Therapy: A Critical Review

The purpose of this review is to summarize the literature on carotid artery stenosis (CAS) and ischemic stroke (IS) in patients with head and neck cancer (HNC) treated with radiation therapy (RT) to guide assessment, screening, and management strategies. Patients treated with RT for HNC are at an elevated risk of developing CAS, with published meta-analyses demonstrating that CAS >50% occurs in approximately 25% of patients. Previous research suggests a 10-year cumulative incidence of stroke between 5.7% and 12.5%. Cardiovascular disease (CVD) risk prediction tools such as Qstroke, QRISK-2, and Framingham risk score perform poorly for predicting IS for patients with HNC who received RT. Duplex ultrasound is the most common imaging modality to assess CAS, but controversy remains as to the utility of screening asymptomatic individuals. Only 3 of the 5 major HNC survivorship guidelines acknowledge RT as a risk factor for CAS or IS, while only 1 makes a specific recommendation on screening for CAS (American Head and Neck Society). Within the general population, only 1 CVD guideline discusses RT as a risk factor for CAS (Society for Vascular Surgery). Clinicians involved in the care of patients with HNC treated with RT should be aware of the increased risk of CAS and IS and the challenges in risk prediction. Although there is a lack of evidence to make firm recommendations, HNC survivorship recommendations should ensure HNC survivors and primary care providers are informed of these risks and the importance of assessment and management of CVD risk factors. Future studies are required to refine risk prediction models in patients with HNC and to determine those most likely to benefit from targeted screening and initiation of early preventative strategies.

Evaluafion of the efficacy of wall shear stress in carotid artery stenting

Objective

To characterize the value of carotid wall shear stress (WSS) following carotid artery stenting (CAS) in patients with carotid stenosis.

Methods

Twenty-eight patients with carotid stenosis treated with CAS between March 2021 to May 2022 in the eighth medical center of the PLA General Hospital were selected for our study. Carotid ultrasound was performed before the operation, one week post-operation, and six months post-operation. Carotid artery WSS was detected by blood flow vector imaging, and the changes in WSS before and after the operation were collected. Genetic testing of drugs was detected for patients with restenosis.

Results

Pre-operative WSS of the proximal, narrowest region, and distal carotid arteries in patients with ischemic carotid artery stenosis was 7.88 ± 3.18Pa, 14.36 ± 6.66Pa, and 1.55 ± 1.15Pa, respectively. Comparatively, pre-operative WSS of the proximal, narrowest region and distal carotid arteries in patients without ischemic symptoms was 5.02 ± 1.99Pa, 9.68 ± 4.23Pa, and 1.10 ± 0.68Pa, respectively, with a significant difference between the two groups (p < 0.001). Overall WSS of the proximal, narrowest region, and distal carotid arteries in patients before CAS was 6.68 ± 3.0Pa, 12.47 ± 5.98Pa, and 1.39 ± 0. 96Pa. WSS of the proximal, narrowest region, and distal carotid was 4.15 ± 1.42Pa, 6.71 ± 2.64Pa, and1.86 ± 1.13Pa one week after CAS, compared to 4.44 ± 1.91Pa, 7.90 ± 4.38Pa, and 2. 36 ± 1.09Pa six months after CAS. WSS of the proximal and narrowest region of the carotid artery was reduced after carotid stenting, and the difference was statistically significant (p < 0.001). There was no statistically significant difference in WSS between one week and six months after stenting (P > 0.05).

Conclusion

We employed early carotid WSS as a means of evaluating the efficacy of carotid artery stenting. Changes in carotid WSS are closely associated with carotid artery stenosis, providing valuable hemodynamic information for CAS treatment. This technique holds great application value in pre-operative evaluation and long-term follow-up.

Brazilian Angiology and Vascular Surgery Society Guidelines for the treatment of extracranial cerebrovascular disease

Extracranial cerebrovascular disease has been the subject of intense research throughout the world, and is of paramount importance for vascular surgeons. This guideline, written by the Brazilian Society of Angiology and Vascular Surgery (SBACV), supersedes the 2015 guideline. Non-atherosclerotic carotid artery diseases were not included in this document. The purpose of this guideline is to bring together the most robust evidence in this area in order to help specialists in the treatment decision-making process. The AGREE II methodology and the European Society of Cardiology system were used for recommendations and levels of evidence. The recommendations were graded from I to III, and levels of evidence were classified as A, B, or C. This guideline is divided into 11 chapters dealing with the various aspects of extracranial cerebrovascular disease: diagnosis, treatments and complications, based on up-to-date knowledge and the recommendations proposed by SBACV.

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.

Cost-Effectiveness of Screening Asymptomatic Carotid Stenosis by Atherosclerotic Cardiovascular Risk

Importance

Extracranial internal carotid artery stenosis (50-99% arterial narrowing) is an important risk factor for ischemic stroke. Yet, the benefits and harms of targeted screening for asymptomatic carotid artery stenosis (ACAS) have not been assessed in population-based studies.

Objective

To estimate the cost-effectiveness of one-time, targeted ACAS screening stratified by atherosclerotic cardiovascular disease (ASCVD) risk using the American Heart Association's Pooled Cohort Equations.

Design Setting and Participants

We developed a lifetime microsimulation model of ACAS and stroke for a hypothetical cohort representative of US adults aged 50-80 years without stroke history. We used the Cardiovascular Health Study to estimate the probability and severity of ACAS based on individual characteristics (e.g., age, sex, smoking status, blood pressure, and cholesterol). Stroke risks were functions of these characteristics and ACAS severity. In the model, individuals testing positive for >70% stenosis with Duplex ultrasound and a confirmatory diagnostic test undergo revascularization, which may reduce the risk of stroke but also introduces complication risks. Diagnostic performance parameters, revascularization benefits and risks, utility weights, and costs were estimated from published sources. Cost-effectiveness was assessed from the health care sector perspective using a $100,000/quality-adjusted life year (QALY) threshold.

Main Outcomes and Measures

Estimated stroke events prevented, lifetime costs, QALYs, and incremental cost-effectiveness ratios (ICERs) associated with ACAS screening. Costs (2023 USD) and QALYs were discounted at 3% annually.

Results

We found that screening individuals with a 10-year ASCVD risk >30% was the most cost-effective strategy, with an ICER of $89,000/QALY. This strategy would make approximately 11.9% of the population eligible for screening, averting an estimated 24,084 strokes. Results were sensitive to variations in the efficacy and complication risk of revascularization. In probabilistic sensitivity analysis, screening those in lower ASCVD risk groups (0-20%) only had a 0.6% chance of being cost-effective.

Conclusion and Relevance

A one-time screening may only be cost-effective for adults at a relatively high ASCVD risk. Our findings provide a framework that can be adapted as future clinical trial data continue to improve our understanding of the role of revascularization and intensive medical therapy in contemporary stroke prevention secondary to carotid disease.

Noninvasive cardiac-specific biomarkers for the diagnosis and prevention of vascular stenosis in cardiovascular disorder

Background

The most frequent lesion in the blood vessels feeding the myocardium is vascular stenosis, a condition that develops slowly but can prove to be deadly in a long run. Non-invasive biomarkers could play a significant role in timely diagnosis, detection and management for vascular stenosis events associated with cardiovascular disorders.

Aims

The study aimed to investigate high sensitivity troponin I (hs-TnI), cardiac troponin I (c-TnI) and high sensitivity C-reactive protein (hs-CRP) that may be used solely or in combination in detecting the extent of vascular stenosis in CVD patients.

Methodology

274 patients with dyspnea/orthopnea complaints visiting the cardiologists were enrolled in this study. Angiographic study was conducted on the enrolled patients to examine the extent of stenosis in the five prominent vessels (LDA, LCX, PDA/PLV, RCA, and OM) connected to the myocardium. Samples from all the cases suspected to be having coronary artery stenosis were collected, and subjected to biochemical evaluation of certain cardiac inflammatory biomarkers (c-TnI, hsTn-I and hs-CRP) to check their sensitivity with the level of vascular stenosis. The extent of mild and culprit stenosis was detected during angiographic examination and the same was reported in the form significant (≥50% stenosis in the vessels) and non-significant (<50% stenosis in the vessels) Carotid Stenosis. Ethical Clearance for the study was provided by Dr. Ram Manohar Lohia Institute of Medical Sciences Institutional Ethical Committee. Informed consent was obtained from all the participants enrolled in the study.

Results

We observed that 85% of the total population enrolled in this study was suffering from hypertension followed by 62.40% detected with sporadic episodes of chest pain. Most of the subjects (42% of the total population) had stenosis in their LAD followed by 38% who had stenosis in their RCA. Almost 23% patients were reported to have stenosis in their LCX followed by OM (18% patients), PDA/PLV (13%) and only 10% patients had blockage problem in their diagonal. 24% of the subjects were found to have stenosis in a single vessel and hence were categorized in the Single Vessel Disease (SVD) group while 76% were having stenosis in two or more than two arteries (Multiple Vessel Disease). hs-TnI level was found to be correlated with the levels of stenosis and was higher in the MVD group as compared to the SVD group.

Conclusion

hs-TnI could be used as a novel marker as it shows prominence in detecting the level of stenosis quite earlier as compared to c-TnI which gets detected only after a long duration in the CVD patients admitted for angiography. hs- CRP gets readily detected as inflammation marker in these patients and hence could be used in combination with hs-TnI to detect the risk of developing coronary artery disease.

Foundations of the Diagnosis and Management of Idiopathic Intracranial Hypertension and Pulsatile Tinnitus

Venous sinus stenosis has garnered increasing academic attention as a potential etiology of idiopathic intracranial hypertension (IIH) and pulsatile tinnitus (PT). The complex anatomy of the cerebral venous sinuses and veins plays a crucial role in the pathophysiology of these conditions. Venous sinus stenosis, often found in the superior sagittal or transverse sinus, can lead to elevated intracranial pressure (ICP) and characteristic IIH symptoms. Stenosis, variations in dural venous anatomy, and flow dominance patterns contribute to aberrant flow and subsequent PT. Accurate imaging plays a vital role in diagnosis, and magnetic resonance (MR) venography is particularly useful for detecting stenosis. Management strategies for IIH and PT focus on treating the underlying disease, weight management, medical interventions, and, in severe cases, surgical or endovascular procedures. Recently, venous sinus stenting has gained interest as a minimally invasive treatment option for IIH and PT. Stenting addresses venous sinus stenosis, breaking the feedback loop between elevated ICP and stenosis, thus reducing ICP and promoting cerebrospinal fluid outflow. The correction and resolution of flow aberrances can also mitigate or resolve PT symptoms. While venous sinus stenting remains an emerging field, initial results are promising. Further research is needed to refine patient selection criteria and evaluate the long-term efficacy of stenting as compared to traditional treatments.

Predictive stroke risk model with vision transformer-based Doppler features

BACKGROUND

Acute stroke is the leading cause of death and disability globally, with an estimated 16 million cases each year. The progression of carotid stenosis reduces blood flow to the intracranial vasculature, causing stroke. Early recognition of ischemic stroke is crucial for disease treatment and management.

PURPOSE

A computer-aided diagnosis (CAD) system was proposed in this study to rapidly evaluate ischemic stroke in carotid color Doppler (CCD).

METHODS

Based on the ground truth from the clinical examination report, the vision transformer (ViT) features extracted from all CCD images (513 stroke and 458 normal images) were combined in machine learning classifiers to generate the likelihood of ischemic stroke for each image. The pretrained weights from ImageNet reduced the time-consuming training process. The accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve were calculated to evaluate the stroke prediction model. The chi-square test, DeLong test, and Bonferroni correction for multiple comparisons were applied to deal with the type-I error. Only p values equal to or less than 0.00125 were considered to be statistically significant.

RESULTS

The proposed CAD system achieved an accuracy of 89%, a sensitivity of 94%, a specificity of 84%, and an area under the receiver operating characteristic curve of 0.95, outperforming the convolutional neural networks AlexNet (82%, p < 0.001), Inception-v3 (78%, p < 0.001), ResNet101 (84%, p < 0.001), and DenseNet201 (85%, p < 0.01). The computational time in model training was only 30 s, which would be efficient and practical in clinical use.

CONCLUSIONS

The experiment shows the promising use of CCD images in stroke estimation. Using the pretrained ViT architecture, the image features can be automatically and efficiently generated without human intervention. The proposed CAD system provides a rapid and reliable suggestion for diagnosing ischemic stroke.

Unravelling the role of carotid atherosclerosis in predicting cardiovascular disease risk: A review

Carotid atherosclerosis disease assessment can predict the patient's risk of cardiovascular disease (CVD). The purpose of this review is to provide a comprehensive review of carotid atherosclerosis disease's pathophysiology, diagnostic evaluation, imaging applications, and treatment strategies. Carotid atherosclerosis is diagnosed using a variety of techniques, including transcranial Doppler imaging (TCD), computed tomography angiography (CTA), magnetic resonance angiography (MRA), and cerebral digital subtraction angiography (DSA), with duplex ultrasound (DUS) as the primary screening. Measurements of carotid intima-media thickness (CIMT) have drawn attention recently as a marker of early-stage carotid atherosclerosis or CVD risk prediction. The classification of cardiovascular risk may be enhanced by the expanding fields of stress testing and carotid plaque screening.

Non-invasive Diagnosis and Postoperative Evaluation of Carotid Artery Stenosis by BSA-Gd2O3 Nanoparticles-Based Magnetic Resonance Angiography

Contrast-enhanced magnetic resonance angiography is a powerful and effective method to accurately diagnose carotid artery stenosis. Small molecular gadolinium (Gd)-based agents have reliable signal enhancement, but their short circulating time may result in a loss of image resolution due to insufficient vascular filling or contrast agent emptying. Here, we report an MRA imaging approach to diagnose carotid artery stenosis using long-circulating bovine serum albumin (BSA)-Gd2O3 nanoparticles (NPs). The BSA-Gd2O3 NPs synthesized by a simple biomineralization approach exhibit admirable monodispersity, uniform size, favorable aqueous solubility, good biocompatibility, and high relaxivity (14.86 mM-1 s-1 in water, 6.41 mM-1 s-1 in plasma). In vivo MRA imaging shows that outstanding vascular enhancement of BSA-Gd2O3 NPs (0.05 mmol Gd/kg, half the dose in the clinic) can be maintained for at least 2 h, much longer than Gd-DTPA. Vessels as small as 0.3 mm can be clearly observed in MRA images with high resolution. In a rat carotid artery stenosis model, the BSA-Gd2O3 NPs-based MRA enables the precise diagnosis of the severity and location and the therapeutic effect following the surgery of carotid artery stenosis, which provides a method for the theranostics of vascular diseases.

Ultrasound Examination Without Axial Imaging is Sufficient for Preoperative Planning in Transcarotid Artery Revascularization (TCAR)

BACKGROUND

Duplex ultrasound is frequently used to determine the degree of carotid stenosis. However, axial imaging is typically obtained for operative planning for transcarotid artery revascularization (TCAR). We examined if ultrasound alone is sufficient before TCAR.

METHODS

Data from the Vascular Quality Initiative TCAR Surveillance Project registry between 2016 and 2021 was obtained. Patients were divided into 2 groups-those with preoperative ultrasound-alone (US) and those with additional axial imaging (AX). Perioperative outcomes were compared utilizing univariate Chi-square, independent t-test, multivariate logistic regression, and Kaplan-Meier analysis.

RESULTS

There were 3,418 patients identified: 682 in the US group and 2,736 in the AX group. More preoperative hypertension was reported in US (16.1% vs. 10.2%, P < 0.001) while cardiovascular disease (23% vs. 28.9%, P = 0.006) and prior ipsilateral stroke (22% vs. 32.7%, P = 0.002) were more prevalent in AX. More patients had history of contralateral carotid endarterectomy (13.6% vs. 16.7%, P = 0.035) or either ipsilateral (2.6% vs. 1.2%, P = 0.002) or contralateral (7.9% vs. 4.9%, P = 0.008) carotid artery stenting in the US group. Lower preoperative creatinine was reported in the US cohort (1.09 ± 0.01 vs. 1.18 ± 0.02, P < 0.001) while more were symptomatic in AX (28.2% vs. 36.2%, P < 0.001). There were no significant differences between lesion characteristics or operative decision making. A slightly higher total procedure time was seen in AX (73.7 ± 0.6 vs. 68.6 ± 1.3 min, P = 0.017). No differences were seen in perioperative transient ischemic attack/stroke or other immediate complications. At 2-year follow-up, both groups reported no significant differences in stroke-free survival (P = 0.750) and independent functional status remained near-identical (97.3% vs. 97.4%, P = 0.921). Kaplan-Meier analysis yielded no significant difference between mortality at 2 years (P = 0.563). Bivariate logistic regression modeling did reveal a statistically significant increase in likelihood of long-term ipsilateral stroke (odds ratio 1.77, P = 0.015) and non stroke-related complication in the postoperative period (odds ratio 4.81, P = 0.005). However, only a statistically significant relationship persisted in non-stroke complication when the model was controlled for between-group differences.

CONCLUSIONS

No significant differences in postoperative or long-term complications were noted with additional AX in preoperative TCAR planning. Thus, duplex ultrasound offers a safe and effective alternative for those with contraindication or axial imaging.

Imaging modality-dependent carotid stenosis severity variations against intravascular ultrasound as a reference: Carotid Artery intravasculaR Ultrasound Study (CARUS)

PURPOSE

Different non-invasive and invasive imaging modalities are used to determine carotid artery stenosis severity that remains a principal parameter in clinical decision-making. We compared stenosis degree obtained with different modalities against vascular imaging gold standard, intravascular ultrasound, IVUS.

METHODS

300 consecutive patients (age 47-83 years, 192 men, 64% asymptomatic) with carotid artery stenosis of " ≥ 50%" referred for potential revascularization received as per study protocol (i) duplex ultrasound (DUS), (ii) computed tomography angiography (CTA), (iii) intraarterial quantitative angiography (iQA) and (iv) and (iv) IVUS. Correlation of measurements with IVUS (r), proportion of those concordant (within 10%) and proportion of under/overestimated were calculated along with recipient-operating-characteristics (ROC).

RESULTS

For IVUS area stenosis (AS) and IVUS minimal lumen area (MLA), there was only a moderate correlation with DUS velocities (peak-systolic, PSV; end-diastolic, EDV; r values of 0.42-0.51, p < 0.001 for all). CTA systematically underestimated both reference area and MLA (80.4% and 92.3% cases) but CTA error was lesser for AS (proportion concordant-57.4%; CTA under/overestimation-12.5%/30.1%). iQA diameter stenosis (DS) was found concordant with IVUS in 41.1% measurements (iQA under/overestimation 7.9%/51.0%). By univariate model, PSV (ROC area-under-the-curve, AUC, 0.77, cutoff 2.6 m/s), EDV (AUC 0.72, cutoff 0.71 m/s) and CTA-DS (AUC 0.83, cutoff 59.6%) were predictors of ≥ 50% DS by IVUS (p < 0.001 for all). Best predictor, however, of ≥ 50% DS by IVUS was stenosis severity evaluation by automated contrast column density measurement on iQA (AUC 0.87, cutoff 68%, p < 0.001). Regarding non-invasive techniques, CTA was the only independent diagnostic modality against IVUS on multivariate model (p = 0.008).

CONCLUSION

IVUS validation shows significant imaging modality-dependent variations in carotid stenosis severity determination.

Artificial intelligence-based predictive models in vascular diseases

Cardiovascular disease represents a source of major health problems worldwide, and although medical and technical advances have been achieved, they are still associated with high morbidity and mortality rates. Personalized medicine would benefit from novel tools to better predict individual prognosis and outcomes after intervention. Artificial intelligence (AI) has brought new insights to cardiovascular medicine, especially with the use of machine learning techniques that allow the identification of hidden patterns and complex associations in health data without any a priori assumptions. This review provides an overview on the use of artificial intelligence-based prediction models in vascular diseases, specifically focusing on aortic aneurysm, lower extremity arterial disease, and carotid stenosis. Potential benefits include the development of precision medicine in patients with vascular diseases. In addition, the main challenges that remain to be overcome to integrate artificial intelligence-based predictive models in clinical practice are discussed.

Length of Carotid Plaque Impacts Retinal Microvascular Densities of Carotid Artery Stenosis Patients

Purpose

We explored the retinal microvascular changes in carotid artery stenosis (CAS) and their relationship with carotid plaque morphology.

Methods

All participants were diagnosed with carotid artery stenosis by a neurologist. Participants underwent digital subtraction angiography (DSA) and optical coherence tomography angiography (OCTA) imaging. The degree and length of carotid plaque were obtained from the DSA tool. OCTA tool measured the densities in the superficial vascular complex (SVC) and deep vascular complex (DVC).

Results

One hundred seventeen patients with CAS patients were included in our data analysis. Eyes with ipsilateral stenosis had reduced retinal microvascular densities when compared to contralateral eyes in patients with CAS (P = 0.016 for SVC, and P = 0.004 for DVC). Microvascular densities correlated with the length of carotid plaque (P = 0.015 for SVC, and P = 0.022 for DVC) in our CAS cohort, although they did not correlate with the degree of carotid plaque (P = 0.264 for SVC, and P = 0.298 for DVC). However, when stratified into moderate and severe subgroups, the degree of carotid plaque correlated with microvascular densities in patients with severe stenosis (P = 0.045 for SVC, and P = 0.038 for DVC).

Conclusions

Our study suggests that OCTA can noninvasively detect retinal microvascular changes in patients with CAS and that these changes correlated with the length of the stenosis, but future studies are required to confirm these findings.

Translational Relevance

Noninvasive and rapid acquisition of the OCTA image might have the potential to be used as a screening tool to detect microvascular changes in carotid artery stenosis.

Ultrasound-Based Image Analysis for Predicting Carotid Artery Stenosis Risk: A Comprehensive Review of the Problem, Techniques, Datasets, and Future Directions

The carotid artery is a major blood vessel that supplies blood to the brain. Plaque buildup in the arteries can lead to cardiovascular diseases such as atherosclerosis, stroke, ruptured arteries, and even death. Both invasive and non-invasive methods are used to detect plaque buildup in the arteries, with ultrasound imaging being the first line of diagnosis. This paper presents a comprehensive review of the existing literature on ultrasound image analysis methods for detecting and characterizing plaque buildup in the carotid artery. The review includes an in-depth analysis of datasets; image segmentation techniques for the carotid artery plaque area, lumen area, and intima-media thickness (IMT); and plaque measurement, characterization, classification, and stenosis grading using deep learning and machine learning. Additionally, the paper provides an overview of the performance of these methods, including challenges in analysis, and future directions for research.

Viscoelastic Characteristics in Mouse Model of Hepatic Steatosis With Inflammation by Kelvin-Voigt Fractional Derivative Modeling

OBJECTIVE

The aim of the work described here was to measure the characteristics of viscoelasticity and fluidity in a mouse model of hepatic steatosis and inflammation using a nano-indentation test and the Kelvin-Voigt fractional derivative (KVFD) model and to explore the viscoelasticity and fluidity characteristics in mice with different degrees of hepatic steatosis with inflammation.

METHODS

Twenty-five ApoE mice were randomly divided into an experimental high-fat diet group (n = 15) and an ordinary-food control group (n = 10), then subdivided into four subgroups based on pathological degree of hepatic steatosis: S0 (normal), S1 (mild), S2 (moderate) and S3 (severe). The 25 liver specimens from these mice were evaluated by a slope-keeping relaxation nano-indentation test.

RESULTS

Elasticity (E0) was significantly higher in the S3 group than in the S1 and S2 groups, while fluidity (α) and viscosity (τ) were significantly lower in S3 than in S1 and S2 (all p values < 0.05). The following cutoff values for the diagnosis of hepatic steatosis >33% with inflammation were also determined: E0 > 85.01 Pa (area under the curve [AUC]: 0.917, 95% confidence interval [CI]: 0.735-0.989), α ≤ 0.38 (AUC: 0.885, 95% CI: 0.695-0.977),\ and τ ≤ 3.92 (AUC: 0.813, 95% CI: 0.607-0.939).

CONCLUSION

Increases in the degree of hepatic steatosis with inflammation in mice paralleled gradual increases in the stiffness of the liver and gradual decreases in the fluidity and viscosity of the liver.

Focus on the Most Common Paucisymptomatic Vasculopathic Population, from Diagnosis to Secondary Prevention of Complications

Middle-aged adults can start to be affected by some arterial diseases (ADs), such as abdominal aortic or popliteal artery aneurysms, lower extremity arterial disease, internal carotid, or renal artery or subclavian artery stenosis. These vasculopathies are often asymptomatic or paucisymptomatic before manifesting themselves with dramatic complications. Therefore, early detection of ADs is fundamental to reduce the risk of major adverse cardiovascular and limb events. Furthermore, ADs carry a high correlation with silent coronary artery disease (CAD). This study focuses on the most common ADs, in the attempt to summarize some key points which should selectively drive screening. Since the human and economic possibilities to instrumentally screen wide populations is not evident, deep knowledge of semeiotics and careful anamnesis must play a central role in our daily activity as physicians. The presence of some risk factors for atherosclerosis, or an already known history of CAD, can raise the clinical suspicion of ADs after a careful clinical history and a deep physical examination. The clinical suspicion must then be confirmed by a first-level ultrasound investigation and, if so, adequate treatments can be adopted to prevent dreadful complications.

Carotid Artery Stenosis: A Look Into the Diagnostic and Management Strategies, and Related Complications

Carotid stenosis (CS) is a buildup of atherosclerotic plaque within the artery leading to a wide range of symptoms, from mild symptoms, including blurred vision and confusion, to much more life-threatening presentations, including paralysis due to stroke. The presentation is insidious, with symptoms exhibiting predominantly at severe stenosis; hence the emphasis is placed on the importance of early diagnosis, treatment, and lifestyle modifications. CS is seen undergoing almost the same pathogenesis of any atherosclerotic plaque formation, from endothelial damage of the artery lumen to the formation of a fibrous cap with a foam cell, lipid-filled core. The findings of our review article were consistent with the recent literature, depicting that comorbid hypertension, diabetes, and chronic kidney disease (CKD), and lifestyle aspects, including smoking and diet, played the most salient role in plaque development. Among several imaging modalities, duplex ultrasound (DUS) imaging is the widely preferred method in clinical practice. Carotid endarterectomy (CEA) and carotid stenting are the primarily advocated procedures for symptomatic severe stenosis, with similar long-term outcomes. Although, earlier clinical trials showed promising results in mitigating the risk of stroke among asymptomatic severe CS with surgical intervention. However, recent advancements have shifted the focus to medical management alone due to comparable results among the asymptomatic population. Both surgical and medical regimens are beneficial in treating patients, but it is still an ongoing debate as to which is predominantly superior. The currently advancing trials and research will help elucidate definitive guidelines. However, the massive impact of lifestyle modifications advocates some degree of individualized multidisciplinary management strategies.

Transcranial Doppler versus CT angiography: a comparative analysis for the diagnosis of ischaemic cerebrovascular disease

AIMS

To compare the sensitivity, specificity, accuracy, and clinical usefulness of transcranial Doppler (TCD) ultrasound against computed tomography angiography (CTA) for the diagnosis of ischaemic cerebrovascular disease.

METHODS

A total of 1,183 sites (vascular segments) of 169 patients who had been diagnosed with cerebrovascular disease using digital subtraction angiography (DSA) were evaluated by CTA and TCD for the diagnosis of the arterial lesions.

RESULTS

Lesions were identified in 509 sites and 674 sites did not have lesions according to the DSA examination. Each individual site had higher sensitivity, specificity, and accuracy for TCD than those for CTA, respectively. For all sites, TCD had higher true-positive (p=0.0029) and -negative (p=0.0151) values and fewer false-positive and -negative (p<0.0001 for both) values than those of CTA. The sensitivity, specificity, and accuracy of CTA for all sites to detect lesions were 77%, 88%, and 84%, respectively. The same parameters for TCD were 94%, 97%, and 95%, respectively. The beneficial scores for CTA and TCD to detect lesions were 0-0.795 diagnostic confidence and 0-0.91 diagnostic confidence, respectively. Beneficial scores >0.795 and >0.91 indicated a risk of underdiagnosis of lesions at CTA and TCD, respectively.

CONCLUSIONS

Compared with DSA (reference standard) and CTA, the study underscores the use of TCD in cerebrovascular pathology.

Performance of high-resolution CT for detection and discrimination tasks related to stenotic lesions - A phantom study using model observers

BACKGROUND

Accurate detection and grading of atheromatous stenotic lesions within the cardiac, renal, and intracranial vasculature is imperative for early recognition of disease and guiding treatment strategies.

PURPOSE

In this work, a stenotic lesion phantom was used to compare high resolution and normal resolution modes on the same CT scanner in terms of detection and size discrimination performance.

MATERIALS AND METHODS

The phantom is comprised of three acrylic cylinders (each 15.0 cm in diameter and 1.3 cm thick) with a matching array of holes in each module. The outer two modules contain holes that are slightly larger than the corresponding hole in the central module to simulate stenotic narrowing in vasculature. The stack of modules was submerged in an iodine solution simulating contrast-enhanced stenotic lesions with a range of lumen diameters (1.32-10.08 mm) and stenosis severity (0%, 50%, 60%, 70%, and 80%). The phantom was imaged on the Canon Aquilion Precision high-resolution CT scanner in high-resolution (HR) mode (0.25 mm × 0.50 mm detector element size) and normal-resolution (NR) mode (0.50 mm × 0.50 mm) using 120 kV and two dose levels (14 and 21 mGy SSDE) with 30 repeat scans acquired for each combination. Filtered back-projection (FBP) and a hybrid-iterative reconstruction (AIDR) were used with the FC18 kernel, as well as a deep learning algorithm (AiCE) which is only available for HR. A non-prewhitening model observer with an eye filter was implemented to quantify performance for detection and size discrimination tasks in the axial plane.

RESULTS

Detection performance improved with increasing diameter, dose, and for AIDR in comparison to FBP for a fixed resolution mode. Performance in the HR mode was generally higher than NR for the smaller lumen diameters (1-5 mm) with decreasing differences as the diameter increased. Performance in NR mode surpassed HR mode for lumen diameters greater than ∼4 mm and ∼5 mm for 14 mGy and 21 mGy, respectively. AiCE provided consistently higher detection performance compared with AIDR-FC18 (48% higher for a 6 mm lumen diameter). Discrimination performance increased with increasing nominal diameter, dose, and for larger differences in stenosis severity. When comparing discrimination performance in HR to NR modes, the largest relative differences occur at the smallest nominal diameters and smallest differences in stenosis severity. The AiCE reconstruction algorithm produced the highest overall discrimination performance values, and these were significantly higher than AIDR-FC18 for nominal diameters of 7.14 and 10.08 mm.

CONCLUSIONS

HR mode outperforms NR for detection up to a specific diameter and the results improve with AiCE and for higher dose levels. For the task of size discrimination, HR mode consistently outperforms NR if AIDR-FC18 is used for dose levels of at least 21 mGy, and the results improve with AiCE and for the smallest differences in stenosis severity investigated (50% vs. 60%). High-resolution CT appears to be beneficial for detecting smaller simulated lumen diameters (<5 mm) and is generally advantageous for discrimination tasks related to stenotic lesions, which inherently contain information at higher frequencies, given the right reconstruction algorithm and dose level.

Deep Learning for Head and Neck CT Angiography: Stenosis and Plaque Classification

Background Studies have rarely investigated stenosis detection from head and neck CT angiography scans because accurate interpretation is time consuming and labor intensive. Purpose To develop an automated convolutional neural network-based method for accurate stenosis detection and plaque classification in head and neck CT angiography images and compare its performance with that of radiologists. Materials and Methods A deep learning (DL) algorithm was constructed and trained with use of head and neck CT angiography images that were collected retrospectively from four tertiary hospitals between March 2020 and July 2021. CT scans were partitioned into training, validation, and independent test sets at a ratio of 7:2:1. An independent test set of CT angiography scans was collected prospectively between October 2021 and December 2021 in one of the four tertiary centers. Stenosis grade categories were as follows: mild stenosis (<50%), moderate stenosis (50%-69%), severe stenosis (70%-99%), and occlusion (100%). The stenosis diagnosis and plaque classification of the algorithm were compared with the ground truth of consensus by two radiologists (with more than 10 years of experience). The performance of the models was analyzed in terms of accuracy, sensitivity, specificity, and areas under the receiver operating characteristic curve. Results There were 3266 patients (mean age ± SD, 62 years ± 12; 2096 men) evaluated. The consistency between radiologists and the DL-assisted algorithm on plaque classification was 85.6% (320 of 374 cases [95% CI: 83.2, 88.6]) on a per-vessel basis. Moreover, the artificial intelligence model assisted in visual assessment, such as increasing confidence in the degree of stenosis. This reduced the time needed for diagnosis and report writing of radiologists from 28.8 minutes ± 5.6 to 12.4 minutes ± 2.0 (P < .001). Conclusion A deep learning algorithm for head and neck CT angiography interpretation accurately determined vessel stenosis and plaque classification and had equivalent diagnostic performance when compared with experienced radiologists. © RSNA, 2023 Supplemental material is available for this article.

3D Ultrasound Reconstructions of the Carotid Artery and Thyroid Gland Using Artificial-Intelligence-Based Automatic Segmentation-Qualitative and Quantitative Evaluation of the Segmentation Results via Comparison with CT Angiography

The aim of this study was to evaluate the feasibility of a noninvasive and low-operator-dependent imaging method for carotid-artery-stenosis diagnosis. A previously developed prototype for 3D ultrasound scans based on a standard ultrasound machine and a pose reading sensor was used for this study. Working in a 3D space and processing data using automatic segmentation lowers operator dependency. Additionally, ultrasound imaging is a noninvasive diagnosis method. Artificial intelligence (AI)-based automatic segmentation of the acquired data was performed for the reconstruction and visualization of the scanned area: the carotid artery wall, the carotid artery circulated lumen, soft plaque, and calcified plaque. A qualitative evaluation was conducted via comparing the US reconstruction results with the CT angiographies of healthy and carotid-artery-disease patients. The overall scores for the automated segmentation using the MultiResUNet model for all segmented classes in our study were 0.80 for the IoU and 0.94 for the Dice. The present study demonstrated the potential of the MultiResUNet-based model for 2D-ultrasound-image automated segmentation for atherosclerosis diagnosis purposes. Using 3D ultrasound reconstructions may help operators achieve better spatial orientation and evaluation of segmentation results.

Simultaneous T1, T2, and T2* Mapping of Carotid Plaque: The SIMPLE* Technique

Background Quantitative T1, T2, and T2* measurements of carotid atherosclerotic plaque are important in evaluating plaque vulnerability and monitoring its progression. Purpose To develop a sequence to simultaneously quantify T1, T2, and T2* of carotid plaque. Materials and Methods The simultaneous T1, T2, and T2* mapping of carotid plaque (SIMPLE*) sequence is composed of three modules with different T2 preparation pulses, inversion-recovery pulses, and acquisition schemas. Single-echo data were used for T1 and T2 quantification, while the multiecho (ME) data were used for T2* quantification. The quantitative accuracy of SIMPLE* was tested in a phantom study by comparing its measurements with those of reference standard sequences. In vivo feasibility of the technique was prospectively evaluated between November 2020 and February 2022 in healthy volunteers and participants with carotid atherosclerotic plaque. The Pearson or Spearman correlation test, Student t test, and Wilcoxon rank-sum test were used. Results T1, T2, and T2* estimated with SIMPLE* strongly correlated with inversion-recovery spin-echo (SE) (correlation coefficient [r] = 0.99), ME-SE (r = 0.99), and ME gradient-echo (r = 0.99) sequences in the phantom study. In five healthy volunteers (mean age, 25 years ± 3 [SD]; three women), measurements were similar between SIMPLE* and modified Look-Locker inversion recovery, or MOLLI (1151 msec ± 71 vs 1098 msec ± 64; P = .14), ME turbo SE (31 msec ± 1 vs 31 msec ± 1; P = .32), and ME turbo field echo (24 msec ± 2 vs 25 msec ± 2; P = .19). In 18 participants with carotid plaque (mean age, 65 years ± 9; 16 men), quantitative T1, T2, and T2* of plaque components were consistent with their signal characteristics on multicontrast images. Conclusion A quantitative technique for simultaneous T1, T2, and T2* mapping of carotid plaque with 100-mm³ coverage and 0.8-mm³ resolution was developed using the proposed SIMPLE* sequence and demonstrated high accuracy and in vivo feasibility. © RSNA, 2023 Supplemental material is available for this article.

Spectral analysis of ultrasound backscatter for non-invasive measurement of plaque composition

Carotid atherosclerotic plaque composition may be an important indication of patient risk for future cerebrovascular events. Ultrasound spectral analysis has the potential to provide a robust measure of plaque composition in vivo if the backscatter transfer function can be sufficiently isolated from the effects of attenuation from overlying tissue, receive and transmit transfer functions from the ultrasound system and transducer, and diffraction. This study examines the usefulness of the nonlinearly generated second harmonic portion of the backscatter signal and the effects of a variety of attenuation compensation techniques for noninvasively characterizing human carotid plaque using spectral analysis and machine learning. Post-beamformed ultrasound backscatter radiofrequency (RF) data were acquired from 6 normal subjects and 119 carotid endarterectomy patients prior to surgery. Plaque obtained following surgery was histologically processed, and regions of interest (ROI) corresponding to homogenous tissue types (fibrous/fibro-lipidic, hemorrhagic and/or necrotic core and calcified) were selected from RF data. Both the harmonic and fundamental power spectra for each ROI was obtained and normalized by data from a uniform phantom (0.5 dB/cm-MHz slope of attenuation). Additional attenuation compensation approaches were compared to simply using the reference phantom: (1) optimum power spectral shift estimation, (2) one-step adventitial, or (3) two-step adventitial. Spectral parameters extracted from both the fundamental and harmonic estimates of the backscatter transfer function of 363 ROI's from 152 plaque specimens were used to train and test random forest and support vector machine classification models. The best results came from using spectral parameters derived from both the fundamental and second harmonic bands with a predictive accuracy of 65-68%, kappa statistic of 0.49-0.54, and accuracies of 84% for fibrous, 68-74% for hemorrhagic and/or necrotic core, and 78-81% for calcified ROI's. The result indicated that the nonlinearly generated second harmonic portion of backscatter is useful for carotid plaque tissue characterization and that a reference phantom approach with a 0.5 dB/cm-MHz slope of attenuation works as well as more complicated approaches.

Use of PETRA-MRA to assess intracranial arterial stenosis: Comparison with TOF-MRA, CTA, and DSA

Background and purpose

Non-invasive and accurate assessment of intracranial arterial stenosis (ICAS) is important for the evaluation of intracranial atherosclerotic disease. This study aimed to evaluate the performance of 3D pointwise encoding time reduction magnetic resonance angiography (PETRA-MRA) and compare its performance with that of 3D time-of-flight (TOF) MRA and computed tomography angiography (CTA), using digital subtraction angiography (DSA) as the reference standard in measuring the degree of stenosis and lesion length.

Materials and methods

This single-center, prospective study included a total of 52 patients (mean age 57 ± 11 years, 27 men, 25 women) with 90 intracranial arterial stenoses who underwent PETRA-MRA, TOF-MRA, CTA, and DSA within 1 month. The degree of stenosis and lesion length were measured independently by two radiologists on these four datasets. The degree of stenosis was classified according to DSA measurement. Severe stenosis was defined as a single lesion with >70% diameter stenosis. The smaller artery stenosis referred to the stenosis, which occurred at the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery, except for the first segment of them. The continuous variables were compared using paired t-test or Wilcoxon signed rank test. The intraclass correlation coefficients (ICCs) were used to assess the agreement between MRAs/CTA and DSA as well as inter-reader variabilities. The ICC value >0.80 indicated excellent agreement. The agreement of data was assessed further by Bland-Altman analysis and Spearman's correlation coefficients. When the difference between MRAs/CTA and DSA was statistically significant in the degree of stenosis, the measurement of MRAs/CTA was larger than that of DSA, which referred to the overestimation of MRAs/CTA for the degree of stenosis.

Results

The four imaging methods exhibited excellent inter-reader agreement [intraclass correlation coefficients (ICCs) > 0.80]. PETRA-MRA was more consistent with DSA than with TOF-MRA and CTA in measuring the degree of stenosis (ICC = 0.94 vs. 0.79 and 0.89) and lesion length (ICC = 0.99 vs. 0.97 and 0.73). PETRA-MRA obtained the highest specificity and positive predictive value (PPV) than TOF-MRA and CTA for detecting stenosis of >50% and stenosis of >75%. TOF-MRA and CTA overestimated considerably the degree of stenosis compared with DSA (63.0% ± 15.8% and 61.0% ± 18.6% vs. 54.0% ± 18.6%, P < 0.01, respectively), whereas PETRA-MRA did not overestimate (P = 0.13). The degree of stenosis acquired on PETRA-MRA was also more consistent with that on DSA than with that on TOF-MRA and CTA in severe stenosis (ICC = 0.78 vs. 0.30 and 0.57) and smaller artery stenosis (ICC = 0.95 vs. 0.70 and 0.80). In anterior artery circulation stenosis, PETRA-MRA also achieved a little bigger ICC than TOF-MRA and CTA in measuring the degree of stenosis (0.93 vs. 0.78 and 0.88). In posterior artery circulation stenosis, PETRA-MRA had a bigger ICC than TOF-MRA (0.94 vs. 0.71) and a comparable ICC to CTA (0.94 vs. 0.91) in measuring the degree of stenosis.

Conclusion

PETRA-MRA is more accurate than TOF-MRA and CTA for the evaluation of intracranial stenosis and lesion length when using DSA as a reference standard. PETRA-MRA is a promising non-invasive tool for ICAS assessment.

Choice of imaging to evaluate carotid stenosis and guide management

Carotid artery disease is a cause of ischemic stroke and is associated with cognitive decline. Besides the evaluation of the degree of stenosis, it is also crucial to assess the morphology of the atherosclerotic plaque, for a prompt and accurate diagnosis, and to make the best decision for the patient. On top of noninvasive duplex ultrasound (DUS) and invasive digital subtraction angiography (DSA), compute tomography angiography (CTA) and magnetic resonance angiography (MRA) are often used effectively as noninvasive imaging tools to study carotid stenoses. This review describes the fundamental characteristics of carotid artery plaques, and how they can be best evaluated with currently available imaging methods.

Computational modelling and application of mechanical waves to detect arterial network anomalies: Diagnosis of common carotid stenosis

BACKGROUND AND OBJECTIVE

This paper proposes a novel strategy to localize anomalies in the arterial network based on its response to controlled transient waves. The idea is borrowed from system identification theories in which wave reflections can render significant information about a target system. Cardiovascular system studies often focus on the waves originating from the heart pulsations, which are of low bandwidth and, hence, can hardly carry information about the arteries with the desired resolution.

METHODS

Our strategy uses a relatively higher bandwidth transient signal to characterize healthy and unhealthy arterial networks through a frequency response function (FRF). We tested our novel approach on data simulated using a one-dimensional cardiovascular model that produced pulse waves in the larger arteries of the arterial network. Specifically, we excited the blood flow from the brachial artery with a relatively high bandwidth flow disturbance and collected the subsequent pressure waveform at peripheral positions. To better differentiate FRFs of healthy and unhealthy networks, we used a FRF that removes the effects of heart pulsations.

RESULTS

Results demonstrate the ability of the proposed FRF to detect and follow-up on the development of a common carotid artery (CCA) stenosis. We tested distinct geometrical variations of the stenosis (size, length and position) and observed differences between the FRFs of healthy and unhealthy networks in all cases; such differences were mainly due to geometrical variations determined by the stenosis.

CONCLUSIONS

We have provided a theoretical proof of concept that demonstrates the ability of our novel strategy to detect and track the development of CCA stenosis by using peripheral pressure waves that can be measured non-invasively in clinical practice.

Differential hemodynamics between arteriovenous fistulas with or without intervention before successful use

A significant number of arteriovenous fistulas (AVFs) fail to maturate for dialysis. Although interventions promote maturation, functional primary patency loss is higher for AVFs with interventions (assisted maturation) than AVFs without interventions (un-assisted maturation). Although blood flow-associated hemodynamics have long been proposed to affect AVF remodeling, the optimal hemodynamic parameters for un-assisted maturation are unclear. Additionally, AVF maturation progress is generally not investigated until 6 weeks after AVF creation, and the examination is focused on the AVF's venous limb. In this exploratory study, patients (n = 6) underwent magnetic resonance imaging (MRI) at 1 day, 6 weeks, and 6 months after AVF creation surgery. Before successful use for hemodialysis, three AVFs required intervention and three did not. MRI of the AVFs were used to calculate lumen cross-sectional area (CSA) and perform computational fluid dynamics (CFD) to analyze hemodynamics, including velocity, wall shear stress (WSS), and vorticity. For the venous limb, the no-intervention group and intervention group had similar pre-surgery vein diameter and 1-day post-surgery venous CSA. However, the no-intervention group had statistically larger 1-day venous velocity (0.97 ± 0.67 m/s; mean ± SD), WSS (333 ± 336 dyne/cm2) and vorticity (1709 ± 1290 1/s) than the intervention group (velocity = 0.23 ± 0.10 m/s; WSS = 49 ± 40 dyne/cm2; vorticity = 493.1 ± 227 1/s) (P < 0.05). At 6 months, the no-intervention group had statistically larger venous CSA (43.5 ± 27.4 mm2) than the intervention group (15.1 ± 6.2 mm2) (P < 0.05). Regarding the arterial limb, no-intervention AVF arteries also had statistically larger 1-day velocity (1.17 ± 1.0 m/s), WSS (340 ± 423 dyne/cm2), vorticity (1787 ± 1694 1/s), and 6-month CSA (22.6 ± 22.7 mm2) than the intervention group (velocity = 0.64 ± 0.36 m/s; WSS = 104 ± 116 dyne/cm2, P < 0.05; vorticity = 867 ± 4551/s; CSA = 10.7 ± 6.0 mm2, P < 0.05). Larger venous velocity, WSS, and vorticity immediately after AVF creation surgery may be important for later lumen enlargement and AVF maturation, with the potential to be used as a tool to help diagnose poor AVF maturation earlier. However, future studies using a larger cohort are needed to validate this finding and determine cut off values, if any.

Ultrasound diagnosis of carotid artery stenosis and occlusion

Carotid artery ultrasonography is capable of diagnosing or inferring the presence or absence of stenosis or occlusion of the internal carotid artery (ICA) and vertebral artery (VA), as well as the not directly observable distal ICA, middle cerebral artery (MCA), and basilar artery (BA). Stenosis at the origin of the ICA is mainly evaluated using the parameter peak systolic velocity (PSV), with values of ≥ 200-230 cm/s indicating severe stenosis. Recently, the acceleration time ratio has been reported for diagnosis of ICA origin stenosis. An indicator called the end-diastolic (ED) ratio can be used for diagnosing occlusion of the distal ICA or the M1 segment of the MCA. The PSV of stenosis can be used to diagnose stenosis at the beginning of the VA or V1, and mean flow velocity, mean ratio, and diameter ratio can be used to diagnose distal VA occlusion. Furthermore, the usefulness of the VA pulsatility index and resistance index has been suggested for diagnosing stenosis or occlusion of the BA. This review outlines diagnostic sonography criteria for stenosis and occlusion of extracranial and intracranial arteries.

Fast prediction of blood flow in stenosed arteries using machine learning and immersed boundary-lattice Boltzmann method

A fast prediction of blood flow in stenosed arteries with a hybrid framework of machine learning and immersed boundary-lattice Boltzmann method (IB–LBM) is presented. The integrated framework incorporates the immersed boundary method for its excellent capability in handling complex boundaries, the multi-relaxation-time LBM for its efficient modelling for unsteady flows and the deep neural network (DNN) for its high efficiency in artificial learning. Specifically, the stenosed artery is modelled by a channel for two-dimensional (2D) cases or a tube for three-dimensional (3D) cases with a stenosis approximated by a fifth-order polynomial. An IB–LBM is adopted to obtain the training data for the DNN which is constructed to generate an approximate model for the fast flow prediction. In the DNN, the inputs are the characteristic parameters of the stenosis and fluid node coordinates, and the outputs are the mean velocity and pressure at each node. To characterise complex stenosis, a convolutional neural network (CNN) is built to extract the stenosis properties by using the data generated by the aforementioned polynomial. Both 2D and 3D cases (including 3D asymmetrical case) are constructed and examined to demonstrate the effectiveness of the proposed method. Once the DNN model is trained, the prediction efficiency of blood flow in stenosed arteries is much higher compared with the direct computational fluid dynamics simulations. The proposed method has a potential for applications in clinical diagnosis and treatment where the real-time modelling results are desired.

Dynamic Changes of Carotid Atherosclerosis and Their Relation with Stroke Recurrence in Patients with Stroke or Transient Ischemic Attack

BACKGROUND AND PURPOSE

The purpose of this study was to show dynamic changes in carotid and vertebral artery using carotid Doppler ultrasonography (DUS) through a long-term follow- up exam, and determine their associations with stroke recurrence.

METHODS

We consecutively enrolled stroke or transient ischemic attack (TIA) patients who had undergone DUS more than twice with intervals of three months or more. Stroke recurrence during follow-up was also investigated by reviewing medical records. Progress or regress of plaque was defined as more than 0.1 mm change from the initial scan with a semi-quantitative measurement. The development of new plaque was also regarded as plaque progress. Increased intima-media thickness and plaque presence were interpreted at the initial and follow-up scans. Factors related to progression or regression were analyzed. The relationship between plaque change and stroke recurrence was investigated.

RESULTS

A total of 201 patients were enrolled (186 ischemic stroke patients and 15 TIA patients). There were 61 (30.3%) females. Their mean age was 64.2 ± 9.9 years. During a follow-up of 35.0 ± 22.6 (mean ± SD) months, plaque progress was observed in 92 (45.8%) and plaque regress in 13 (6.5%). Stroke recurred in 18 patients. Plaque progression showed no significant association with age, risk factors, statin use, or subtype. After adjustment of age, sex, diabetes, and stroke subtype, multiple logistic regression showed a significant association of plaque progression with stroke recurrence (odds ratio: 3.8, 95% confidence interval: 1.1 to 13.1, p = 0.034). Patients with plaque regress were significantly younger than those without plaque regress (57.8 years vs. 64.6 years, p = 0.041).

CONCLUSION

Plaque progression occurred in 46% of stroke or TIA patients. Plaque progression was significantly associated with clinical stroke recurrence. Plaque regressed in 6.5% of patients. Patients with regression were younger than those without.

The impact of sex on outcomes following carotid endarterectomy

BACKGROUND

Previous studies have demonstrated significant sex differences in vascular surgery outcomes. We assessed stroke or death rates following carotid endarterectomy (CEA) in women vs. men.

METHODS

The Vascular Quality Initiative (VQI) was used to identify all patients who underwent CEA between 2010-2019. Demographic, clinical, and procedural characteristics were recorded and differences between women vs. men were assessed using independent t-test and chi-square test. The primary outcomes were 30-day and 1-year stroke or death. Associations between sex and outcomes were assessed using univariate/multivariate logistic regression and Cox proportional hazards analysis.

RESULTS

52,137 women and 79,974 men underwent CEA in VQI sites during the study period. Women were younger (70.3 vs. 70.5 years, p < 0.001) and more likely to have hypertension (89.2% vs. 88.9%, p < 0.05) and diabetes (36.2% vs. 35.8%, p < 0.001), but less likely to be diagnosed with coronary artery disease (23.2% vs. 31.0%, p < 0.001). A greater proportion of men were receiving cardiovascular risk reduction medications and had symptomatic carotid stenosis (28.5% vs. 26.7%, p < 0.001). Women had shorter procedure times (113 vs. 122 minutes, p < 0.001) and were less likely to receive electroencephalography neuromonitoring (27.9% vs. 28.8%, p < 0.001), drain (35.9% vs. 37.3%, p < 0.001), and protamine (67.4% vs. 68.0%, p < 0.01). Stroke or death at 30 days (1.9% vs. 1.8%, p = 0.60) and 1 year (HR 0.98 [95% CI 0.94 - 1.01], p = 0.20) were similar between groups, which persisted in asymptomatic patients (HR 0.97 [95% CI 0.93 - 1.01], p = 0.17) and symptomatic patients (HR 0.99 [95% CI 0.93 - 1.05], p = 0.71). The similarities in 1-year stroke or death rates existed in both the US (HR 0.96 [95% CI 0.92 - 1.01], p = 0.09) and Canada (HR 1.21 [95% CI 0.47 - 3.11], p = 0.70).

CONCLUSIONS

Despite sex differences in clinical and procedural characteristics, women and men have similar 30-day and 1-year outcomes following carotid endarterectomy.

Identification of Biomarkers of Autophagy-Related Genes Between Early and Advanced Carotid Atherosclerosis

Background

Accumulating evidence demonstrates that autophagy is important in inhibiting inflammation and cholesterol efflux. It suggested the autophagy may be a treatment of atherosclerosis. Thus, we screened autophagy-related mRNA to explore their mechanism of scientific basis for early diagnosis and therapy of atherosclerosis.

Methods

The GSE28829 datasets were assessed to analyze differentially expressed genes by GEO2R. And autophagy-related hub genes were identified by HADb. The biological function of autophagy-related DEmRNAs was examined by Metascape. The construction of a protein–protein network was explored by String. Cytohubba was utilized to screen hub genes. Analysis of DEmiRNA-mRNA pairs was executed by DIANA microT-CDS database. Finally, correlation analysis was carried out to identify the relationship between DEARGs and clinical and prognostic factors.

Results

A number of 1087 DEGs and 19 autophagy-related DEmRNAs were identified in advanced carotid atherosclerotic plaque compared with the early. The biological function containing development and growth was enriched. Moreover, we screened the top hub nodes with the highest degrees. MicroRNAs (miRNAs) are confirmed to participate in genesis and progression of atherosclerosis, so we further analyzed the miRNA–mRNA regulatory network genes with four hub genes to explore their potential mechanism in atherosclerosis. Then, we revealed co-expression of four key genes CTSB, ITGB1, CXCR4, TNFSF10 and autophagy-related genes. As for the clinical factors, hypertension factor showed higher expression of ITGB1. The probability of coronary heart disease factor was significantly increased with high expression of CTSB and CXCR4, as well as low expression of ITGB1 and TNFSF10. Diabetes factor tended to express distinguished levels of CTSB and ITGB1. TNFSF10 was highly expressed in both hyperlipidemia and ischemic stroke factor.

Conclusion

CTSB, ITGB1, CXCR4 and TNFSF10 may be critical in atherosclerosis development and were thought to be potential diagnostic biomarkers for atherosclerosis.

Comparison between conventional duplex ultrasonography and the dual-gate Doppler mode for hemodynamic measurements of the carotid arteries

Purpose

This study investigated the correlations of hemodynamic parameters measured to quantify stenosis between the gold-standard duplex ultrasonography and the dual-gate Doppler mode.

Methods

Patients examined due to suspicion of carotid artery stenosis or for surveillance of known stenosis were invited to participate in this prospective single-center study. Upon acceptance, the hemodynamic characteristics of the carotid arteries were determined successively in standard duplex and dual-gate Doppler modes. The correlations between the two modes were analyzed by computing Pearson coefficients (r²) and Lin concordance coefficients (ρ_c). The degree of agreement between the two methods was visualized using Bland-Altman graphical representations.

Results

The correlation between internal carotid artery peak systolic velocity measured by standard duplex ultrasonography and dual-gate Doppler mode was good (r²=0.642). The same high level of correlation was observed for the carotid ratio (r²=0.544). However, the Bland-Altman graphical representation and the Lin concordance coefficients (ρ_c=0.75 and ρ_c=0.74 for the internal carotid artery peak systolic velocity and carotid ratio, respectively) showed that a lack of precision generated some discrepancies between the two measurement methods.

Conclusion

Although some discrepancies were observed, the hemodynamic measurements were closely correlated between the two ultrasonography modes. Therefore, the dual-gate Doppler mode may have obvious advantages over conventional ultrasonography, offering interesting development possibilities.

Numerical simulation in the abdominal aorta and the visceral arteries with or without stenosis based on 2D PCMRI

It is important to obtain accurate boundary conditions (BCs) in hemodynamic simulations. This article aimed to improve the accuracy of BCs in computational fluid dynamics (CFD) simulation and analyze the differences in hemodynamics between healthy volunteers and patients with visceral arterial stenosis (VAS). The geometric models of seven cases were reconstructed using the magnetic resonance angiogram (MRA) or computed tomography angiogram (CTA) imaging data. The physiological flow waveforms obtained from 2D Phase Contrast Magnetic Resonance Imaging (PCMRI) were imposed on the aortic inlet and the visceral arteries' outlets. The individualized RCR values of the three-element Windkessel model were imposed on the aortic outlet. CFD simulations were run in the open-source software: svSolver. Two specific time points were selected to compare the hemodynamics of healthy volunteers and patients with VAS. The results suggested that blood in the stenotic visceral arteries flowed at high speed throughout the cardiac cycle. The low pressure is distributed at stenotic lesions. The wall shear stress (WSS) reached 4 Pa near stenotic locations. The low time average wall shear stress (TAWSS), high oscillatory shear index (OSI), and high relative residence time (RRT) concentrated in the abdominal aorta. Besides, the ratios of the areas with low TAWSS, high OSI, and high RRT to the computational domain were higher in patients with VAS than which in the healthy volunteers. The individualized BCs were used for hemodynamic simulations and results suggest that patients with stenosis have a higher risk of blood retention and atherosclerosis formation in the abdominal aorta.