The reliability of ultrasound measurements of carotid stenosis compared to MRA and DSA

Association of visceral adiposity index with asymptomatic intracranial arterial stenosis: a population-based study in Shandong, China

BACKGROUND AND OBJECTIVE

The visceral adiposity index (VAI), as a composite indictor to evaluate visceral adipose function, has been demonstrated to be correlated with atherosclerosis. The study objective was to explore the association between asymptomatic intracranial arterial stenosis (aICAS) and VAI in Chinese rural dwellers.

METHODS

The cross-sectional study consisted of 1942 participants  ≥ 40 years old who were living in Pingyin County, Shandong Province and free from history of clinical stroke and transient ischemic attack. The aICAS in the study was diagnosed by transcranial doppler ultrasound combined with magnetic resonance angiography. The multivariate logistic regression models were deployed to explore the correlation of VAI with aICAS, and receiver operating characteristic (ROC) curve were plotted to compare the performance of models.

RESULTS

The participants with aICAS comparing to those without had a significantly higher VAI. After adjusting for confounding factors including age, hypertension, DM, sex, drinking habit, LDL-C, hsCRP, and smoking habit, the VAI-Tertile 3 (vs. VAI-Tertile 1) was positively associated with aICAS (OR, 2.15; 95% CI, 1.25-3.65; P = 0.005). The VAI-Tertile 3 was still markedly associated with aICAS among the underweight and normal weight (BMI ≤ 23.9 kg/m²) participants (OR, 3.17; 95% CI, 1.15-8.71; P = 0.026) with an AUC = 0.684. A similar relationship between VAI and aICAS was obtained among the participants with no abdominal obesity (WHR < 1, OR, 2.03; 95% CI, 1.14-3.62; P = 0.017).

CONCLUSIONS

The possible correlation between VAI and aICAS was found to be positive for the first time among Chinese rural residents over 40 years old. A higher VAI was found to be significantly associated with aICAS among the participants who were underweight or normal weight, and these results may provide additional risk stratification information for aICAS.

Duplex ultrasound for diagnosing symptomatic carotid stenosis in the extracranial segments

BACKGROUND

Carotid artery stenosis is an important cause of stroke and transient ischemic attack. Correctly and rapidly identifying patients with symptomatic carotid artery stenosis is essential for adequate treatment with early cerebral revascularization. Doubts about the diagnostic value regarding the accuracy of duplex ultrasound (DUS) and the possibility of using DUS as the single diagnostic test before carotid revascularization are still debated.

OBJECTIVES

To estimate the accuracy of DUS in individuals with symptomatic carotid stenosis verified by either digital subtraction angiography (DSA), computed tomography angiography (CTA), or magnetic resonance angiography (MRA).

SEARCH METHODS

We searched CRDTAS, CENTRAL, MEDLINE (Ovid), Embase (Ovid), ISI Web of Science, HTA, DARE, and LILACS up to 15 February 2021. We handsearched the reference lists of all included studies and other relevant publications and contacted experts in the field to identify additional studies or unpublished data.

SELECTION CRITERIA

We included studies assessing DUS accuracy against an acceptable reference standard (DSA, MRA, or CTA) in symptomatic patients. We considered the classification of carotid stenosis with DUS defined with validated duplex velocity criteria, and the NASCET criteria for carotid stenosis measures on DSA, MRA, and CTA. We excluded studies that included < 70% of symptomatic patients; the time between the index test and the reference standard was longer than four weeks or not described, or that presented no objective criteria to estimate carotid stenosis.

DATA COLLECTION AND ANALYSIS

The review authors independently screened articles, extracted data, and assessed the risk of bias and applicability concerns using the QUADAS-2 domain list. We extracted data with an effort to complete a 2 × 2 table (true positives, true negatives, false positives, and false negatives) for each of the different categories of carotid stenosis and reference standards. We produced forest plots and summary receiver operating characteristic (ROC) plots to summarize the data. Where meta-analysis was possible, we used a bivariate meta-analysis model.

MAIN RESULTS

We identified 25,087 unique studies, of which 22 were deemed eligible for inclusion (4957 carotid arteries). The risk of bias varied considerably across the studies, and studies were generally of moderate to low quality. We narratively described the results without meta-analysis in seven studies in which the criteria used to determine stenosis were too different from the duplex velocity criteria proposed in our protocol or studies that provided insufficient data to complete a 2 × 2 table for at least in one category of stenosis. Nine studies (2770 carotid arteries) presented DUS versus DSA results for 70% to 99% carotid artery stenosis, and two (685 carotid arteries) presented results from DUS versus CTA in this category. Seven studies presented results for occlusion with DSA as the reference standard and three with CTA as the reference standard. Five studies compared DUS versus DSA for 50% to 99% carotid artery stenosis. Only one study presented results from 50% to 69% carotid artery stenosis. For DUS versus DSA, for < 50% carotid artery stenosis, the summary sensitivity was 0.63 (95% confidence interval [CI] 0.48 to 0.76) and the summary specificity was 0.99 (95% CI 0.96 to 0.99); for the 50% to 69% range, only one study was included and meta-analysis not performed; for the 50% to 99% range, the summary sensitivity was 0.97 (95% CI 0.95 to 0.98) and the summary specificity was 0.70 (95% CI 0.67 to 0.73); for the 70% to 99% range, the summary sensitivity was 0.85 (95% CI 0.77 to 0.91) and the summary specificity was 0.98 (95% CI 0.74 to 0.90); for occlusion, the summary sensitivity was 0.91 (95% CI 0.81 to 0.97) and the summary specificity was 0.95 (95% CI 0.76 to 0.99). For sensitivity analyses, excluding studies in which participants were selected based on the presence of occlusion on DUS had an impact on specificity: 0.98 (95% CI 0.97 to 0.99). For DUS versus CTA, we found two studies in the range of 70% to 99%; the sensitivity varied from 0.57 to 0.94 and the specificity varied from 0.87 to 0.98. For occlusion, the summary sensitivity was 0.95 (95% CI 0.80 to 0.99) and the summary specificity was 0.91 (95% CI 0.09 to 0.99). For DUS versus MRA, there was one study with results for 50% to 99% carotid artery stenosis, with a sensitivity of 0.88 (95% CI 0.70 to 0.98) and specificity of 0.60 (95% CI 0.15 to 0.95); in the 70% to 99% range, two studies were included, with sensitivity that varied from 0.54 to 0.99 and specificity that varied from 0.78 to 0.89. We could perform only a few of the proposed sensitivity analyses because of the small number of studies included.

AUTHORS' CONCLUSIONS

This review provides evidence that the diagnostic accuracy of DUS is high, especially at discriminating between the presence or absence of significant carotid artery stenosis (< 50% or 50% to 99%). This evidence, plus its less invasive nature, supports the early use of DUS for the detection of carotid artery stenosis. The accuracy for 70% to 99% carotid artery stenosis and occlusion is high. Clinicians should exercise caution when using DUS as the single preoperative diagnostic method, and the limitations should be considered. There was little evidence of the accuracy of DUS when compared with CTA or MRA. The results of this review should be interpreted with caution because they are based on studies of low methodological quality, mainly due to the patient selection method. Methodological problems in participant inclusion criteria from the studies discussed above apparently influenced an overestimated estimate of prevalence values. Most of the studies included failed to precisely describe inclusion criteria and previous testing. Future diagnostic accuracy studies should include direct comparisons of the various modalities of diagnostic tests (mainly DUS, CTA, and MRA) for carotid artery stenosis since DSA is no longer considered to be the best method for diagnosing carotid stenosis and less invasive tests are now used as reference standards in clinical practice. Also, for future studies, the participant inclusion criteria require careful attention.

Correlation of orthostatic hypotension with extracranial carotid and intracranial cerebral arteries atherosclerosis in patients with acute ischemic stroke under cerebral angiography

OBJECTIVE

The clinical management of patients with acute ischemic stroke (AIS) is complicated by orthostatic hypotension, which might have close relationship with the atherosclerosis of cerebral arteries. The primary objectives were to evaluate the relationship of orthostatic hypotension with extracranial carotid arteries atherosclerosis (ECAS) and intracranial atherosclerosis (ICAS) in AIS patients.

METHODS

This study was a prospective cohort analysis of consecutive AIS patients under cerebrovascular angiography. A total of 289 patients were included. orthostatic hypotension was defined as a systolic BP decline ≥20 mmHg or a diastolic BP decline ≥10 mmHg within 3 min of standing. Univariate and multivariate analysis were performed to investigate the association of the clinical variables with orthostatic hypotension.

RESULTS

Orthostatic hypotension was identified in 80 (27.7%) of all patients. ECAS (≥70%) and ICAS (≥50%) was found in 39 (13.5%) and 71 (24.6%) respectively. In multivariate analysis, only diabetes mellitus (odds ratio = 2.00, 95% confidence interval, 1.12-3.58, P = 0.019) and ECAS (odds ratio = 1.97, 95% confidence interval, 1.54-2.51, P < 0.001) were independent risk factors for orthostatic hypotension.

CONCLUSIONS

Orthostatic hypotension is a relatively common finding among patients with AIS. AIS patients should be screened for orthostatic hypotension, especially combined with severe ECAS and diabetes mellitus.

Association Between Metabolic Syndrome and Asymptomatic Cerebral Arterial Stenosis: A Cross-Sectional Study in Shandong, China

Metabolic syndrome (MetS) can worsen cerebral arterial atherosclerosis stenosis in patients with stroke; however, its effect on patients without stroke remains ambiguous. This study explored the association of MetS and its individual components with asymptomatic intracranial arterial stenosis (aICAS) and asymptomatic extracranial arterial stenosis (aECAS) among older Chinese adults. A total of 1988 participants from the Kongcun Town study aged ≥40 years and without a history of stroke were enrolled. The baseline data were obtained via face-to-face interviews. MetS was defined according to International Diabetes Federation criteria. Detection of aICAS was conducted using transcranial Doppler ultrasound, followed by diagnosis via magnetic resonance angiography. The evaluation of aECAS was performed using bilateral carotid ultrasonography. The aICAS and aECAS groups were 1:1 matched separately to the non-stenosis group by age and sex. The association between MetS and aICAS or aECAS was analyzed using multivariate logistic regression. Among the 1988 participants, 909 were diagnosed with MetS. The prevalence of MetS was higher in the aICAS group than in the non-stenosis group (P <0.001), but did not differ significantly between the aECAS and non-stenosis groups. The prevalence of aICAS increased with the number of MetS components from 3.4% in the ≤ 1 component group to 12.7% in the ≥4 components group (P for trend <0.001). After adjusting for confounding factors, MetS components associated with aICAS included central obesity, elevated triglyceride levels, and elevated blood pressure. None of the MetS components was associated with aECAS. MetS was positively associated with aICAS, but not with aECAS. Further, different components play different roles in the pathological process leading to aICAS.

ACR Appropriateness Criteria® Cerebrovascular Disease

Diseases of the cerebral vasculature represent a heterogeneous group of ischemic and hemorrhagic etiologies, which often manifest clinically as an acute neurologic deficit also known as stroke or less commonly with symptoms such as headache or seizures. Stroke is the fourth leading cause of death and is a leading cause of serious long-term disability in the United States. Eighty-seven percent of strokes are ischemic, 10% are due to intracerebral hemorrhage, and 3% are secondary to subarachnoid hemorrhage. The past two decades have seen significant developments in the screening, diagnosis, and treatment of ischemic and hemorrhagic causes of stroke with advancements in CT and MRI technology and novel treatment devices and techniques. Multiple different imaging modalities can be used in the evaluation of cerebrovascular disease. The different imaging modalities all have their own niches and their own advantages and disadvantages in the evaluation of cerebrovascular disease. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Comparative analysis of 3D time-resolved contrast-enhanced magnetic resonance angiography, color Doppler ultrasound and digital subtraction angiography in symptomatic carotid stenosis

The present study aimed to compare the diagnostic value of contrast-enhanced magnetic resonance angiography (CE MRA) with 3D time-resolved imaging of contrast kinetics, color Doppler ultrasound (CDUS) and digital subtraction angiography (DSA) in extracranial carotid stenosis (CS). A total of 54 patients with symptomatic CS were subjected to CDUS, CE MRA and DSA examination. Results of DSA were defined as the standard, and a total of 216 vessels were examined. In each patient four vessels were examined, namely the bilateral common carotid arteries and the bilateral internal carotid arteries. The sensitivities and specificities of CE MRA and CDUS for various degrees of CS were also determined. It was observed that the sensitivities to mild-level (1-49%), moderate-level (50-69%) and severe-level (70-99%) CS were 85.45, 100 and 100% for CE MRA, and 78.18, 50 and 100% for CDUS, respectively. The corresponding specificities were 95.27, 98.58 and 99.53% for CE MRA, and 79.05, 93.36 and 98.10% for CDUS, respectively. In addition, the carotid sinus plaque detection rate for CDUS was significantly higher than that of DSA and CE MRA (both P<0.001). Detection rates for common carotid artery plaques and internal carotid artery plaques did not significantly differ among the three examination methods (all P>0.05). These data demonstrate that CE MRA has higher sensitivity and specificity than CDUS for the diagnosis of CS, and that CDUS has a higher carotid sinus plaque detection rate than DSA and CE MRA. Therefore, the combination of MRI and CDUS may be a 'gold standard' diagnostic method for the detection of moderate and severe CS.

ACR Appropriateness Criteria® on cerebrovascular disease

Stroke is the sudden onset of focal neurologic symptoms due to ischemia or hemorrhage in the brain. Current FDA-approved clinical treatment of acute ischemic stroke involves the use of the intravenous thrombolytic agent recombinant tissue plasminogen activator given <3 hours after symptom onset, following the exclusion of intracerebral hemorrhage by a noncontrast CT scan. Advanced MRI, CT, and other techniques may confirm the stroke diagnosis and subtype, demonstrate lesion location, identify vascular occlusion, and guide other management decisions but, within the first 3 hours after ictus, should not delay or be used to withhold recombinant tissue plasminogen activator therapy after the exclusion of acute hemorrhage on noncontrast CT scans. MR diffusion-weighted imaging is highly sensitive and specific for acute cerebral ischemia and, when combined with perfusion-weighted imaging, may be used to identify potentially salvageable ischemic tissue, especially in the period >3 hours after symptom onset. Advanced CT perfusion methods improve sensitivity to acute ischemia and are increasingly used with CT angiography to evaluate acute stroke as a supplement to noncontrast CT. The ACR Appropriateness Criteria(®) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Automatic segmentation of 3D micro-CT coronary vascular images

Although there are many algorithms available in the literature aimed at segmentation and model reconstruction of 3D angiographic images, many are focused on characterizing only a part of the vascular network. This study is motivated by the recent emerging prospects of whole-organ simulations in coronary hemodynamics, autoregulation and tissue oxygen delivery for which anatomically accurate vascular meshes of extended scale are highly desirable. The key requirements of a reconstruction technique for this purpose are automation of processing and sub-voxel accuracy. We have designed a vascular reconstruction algorithm which satisfies these two criteria. It combines automatic seeding and tracking of vessels with radius detection based on active contours. The method was first examined through a series of tests on synthetic data, for accuracy in reproduced topology and morphology of the network and was shown to exhibit errors of less than 0.5 voxel for centerline and radius detections, and 3 degrees for initial seed directions. The algorithm was then applied on real-world data of full rat coronary structure acquired using a micro-CT scanner at 20 microm voxel size. For this, a further validation of radius quantification was carried out against a partially rescanned portion of the network at 8 microm voxel size, which estimated less than 10% radius error in vessels larger than 2 voxels in radius.